Title of Invention	SEPARATING FLOOR FOR A DISTILLATION COLUMN
Abstract	Separating floor (23) for a column (1) for distillation of a polymerisable material, comprising at least one floor plate (29) with a plurality of openings (30) and at least one attachment (31), characterised in that the attachment (31) divides the plurality of openings (30) into groups (32), whereby with the at least one attachment (31) apertures (33) are formed through which a fluid can flow.

Full Text

Separating floor for a distillation column The invention relates to a separating floor for a column for distillation of a poly- merisable material, a process for production of a polymerisable material and the use of a polymerisable material obtainable by the above process, as well as chemical products which are based on the polymerisable material as starting mate- rial. As polymerisable material, in general, all monomers used in radical polymerisa- tion come into consideration. Methacrylic acid, acrylic acid, styrene or a-methyl styrene fall hereunder; in particular, methacrylic acid or acrylic acid, in the fol- lowing referred to collectively as "(meth)acrylic acid" should be mentioned, whereby acrylic acid is particularly preferred. The standards of purity of monomers used on a large scale for polymerisation are ever increasing. Ever higher purity standards are also demanded of mass plastics. This is particularly the case for polymers used in the areas of medicine or hygiene. Water or aqueous liquids-absorbing polymers, which are generally referred to as "superabsorbers", are an important component of many products in medical and hygiene areas. Preferably, superabsorbers are used in diapers, feminine hygiene products and incontinence articles. Superabsorbers, as well as other artificial ma- terials, are often obtained by radical polymerisation of monomers comprising a double bond. Such monomers comprising a double bond, such as (meth)acrylic acid are, thus, very reactive substances, which tend to radically polymerise spon- taneously under thermal stress. Distillation is a suitable processing method which has been proven on a large scale for obtaining high purities. Because of the thermal stress on the monomer to be purified which occurs during distillation, the monomer tends, however, to un- dergo undesired polymerisation. Here, despite addition of inhibitors, polymerisa- tion seeds form, initially mostly in dead zones through overheating and too long residence times of the monomer, which seeds grow in the course of time and lead to an ever increasing formation of undesired polymer, which leads to a shutting down of the distillation operation and to a time-consuming cleaning of the distilla- tion apparatus, which is very costly and linked with a significant strain for man and the environment. Distillation columns are, for example, known from WO 00/53561. In this docu- ment "Dual-Flow-Floors" are disclosed as column floors, with which the separa- tion performance should be increased, but no measures are disclosed with which the above disadvantages should be counteracted. In principle, it is the object of the present invention to overcome the disadvanta- geous linked to the state of the art. It is, in particular, an aim of the present invention to increase the temporal separa- tion of maintenance intervals of distillation columns of this type, whereby, pref- erably, the downtimes are also significantly reduced. A further object lies in achieving as high a degree of purity as possible in the course of the distillation process by means of more than one separating floor, whereby at each separation stage, exactly reproducible and/or pre-determined chemical processes take place. It is a farther object of the invention to provide a homogenous distribution of the polymerisable material in fluid or gaseous phase in a separation stage, without formation of polymer deposits. The above-mentioned object are solved by a separating floor with the features of claim 1, a process according to claim 14, a use according to claim 20 and 22 and a product according to claim 21 and 23. Further advantageous embodiments of the separating floor are described in the respective dependent claims, whereby the further advantageous embodiments mentioned therein can also be used in combi- nation with each other. The separating floor according to the invention for a column for distillation of a polymerisable material comprises at least one floor plate with a plurality of open- ings and at least one attachment which divides the plurality of openings into groups, whereby with the at least one attachment, apertures which can be flowed through by a fluid are formed. The floor plate preferably comprises metallic material, although other tempera- ture- and acid-resistant material can also be used. The outer design of the floor plate is to be selected with respect to the distillation column, so that this can com- prise, for example, round, square or similar forms. The floor plate is provided with a plurality of opening, whereby it is, in particular, intended that a fluid and/or gas exchange through the floor plate is possible. The openings are, thus, preferably so large that it is possible to retain the fluid material, and preferably a bubbling layer for heat and component exchange forms between the fluid and vapour material. The arrangement of the openings with re- spect to the floor plate can, in principal, be freely selected and should be aligned with the conditions on the inside of the column. It is thus, for example, possible to provide a uniform distribution of the openings over the whole floor plate, on the other hand, it can also be necessary to take a design of the floor plate which devi- ates herefrom. This would be, for example, the case, if edge regions of the floor plate were necessary for positioning in the column. A similar case is, for example, if the floor plate must be supported on one side because of its spatial extension and the supports would close openings of this type. It is then advantageous to pro- vide no openings in these regions of the floor plate. It is now proposed that the attachment divides the plurality of openings into groups, whereby with the at least one attachment, apertures are formed which can be flowed through by a fluid. A foreground function of this attachment is to influ- ence the movement of the fluid, which has collected on the floor plate, so that, on the one hand, a high flow speed is avoided, and on the other hand, however, that no "dead zones" are formed in which relatively long resistance times of the fluids prevail. Particularly high flow speeds can, for example, occur if the gaseous material pass- ing through the floor plate is not introduced completely uniformly over the cross- section of the floor plate, but, rather, in one region a particularly strong source is formed. A wave like stimulus to the fluid can then occur. In order to prevent a wave front of this type spreading over the whole floor plate and thus leading to different fluid levels on the floor plate, the attachment serves as a type of wave breaker, in that upper fluid or vapour bubble layers are calmed with respect waves. Indeed, the spatially strictly delimited division of the floor plates from each other into different sectors does not necessarily guarantee an improved behaviour of the fluid. Rather, by means of the division, groups of openings can be formed, which are less impinged on by the polymerisable material, so that, with respect to the sectors, different degrees of distillation can occur. For this reason, it is proposed that the fluid is indeed restricted in its freedom of movement by the attachment, but is not restricted with respect to the reachability of a plurality of openings of other sectors (in particular of all openings). This is achieved in that with the at- tachment, apertures which can be flowed through by a fluid are still formed. The apertures ensure that the fluid can preferably flow towards any opening of the floor plate. The design of the aperture should also be selected here taking into account the fluid, the polymerisable material, the column or its operation. By way of example, round apertures, square apertures, slots, etc. are mentioned here. It should also be clarified that the apertures can be fully or partially limited and/or formed by the attachment. In principal, it is advantageous in the arrangement of such apertures, to arrange these in lower regions, i.e. near to the floor plate. In this way it is en- sured that, on the one hand, the propagation of the wave movement of the upper liquid or fluid layers is interrupted, while deeper-lying layers near to different groups of openings can communicate with each other. Attention should be paid that the apertures are designed so that as few as possible, preferably no, dead zones are formed, whereby in this context, zones are meant in which the fluid has a relatively long residence time. The fluid tends to polymerise in dead zones of this type, whereby this can lead in the long term to at least partial blocking of the openings. This has the result that the gas or fluid exchange then only occurs through a smaller number of openings, whereby the increasing gas pressure results in an additional wave stimulus of the fluid. With increasing polymerisation of material, the distillation step can no longer be carried out in the desired quality, making purification and/or mainte- nance measures necessary. This in turn has the result that the distillation process must be interrupted and the column shut down. The separating floors must be fur- ther cleaned in a time-consuming process and then remounted. By means of the herein-proposed attachment on the floor plate, such complex measures can at least be deferred over a longer time period. Because of the fact that polymer deposits occur at significantly fewer positions, the purification can also be carried out more quickly. This means that the distillation column, on the one hand, is ready for op- eration over a longer time period with the desired distillation results, on the other hand, however, the purification procedure can be carried out more quickly and, thus, the down times of the distillation column are shortened. According to an advantageous further form of the separating floor, the apertures extend beyond the floor plate over a height in the range from 1 mm to 100 mm, preferably from 5 mm to 50 mm and particularly preferably from 10 mm to 30 mm. This means, in particular, that the apertures are only partially limited by the attachment. They are, in this case, at least also partially limited by the floor plate. It is here possible, that the apertures are only limited by the floor plate and the attachment, however, further components can also be used for limitation of the apertures. The height is selected such the fluid in the proximity of the floor plate can move or flow relatively unhindered, and, thus, it is ensured that the liquid and/or the fluid can flow uniformly towards the openings. At the same time, the liquid and/or fluid layers which are far from the floor plate are pulled through by the attachment. According to a preferred embodiment the at least one attachment comprises at least one straight bar. Such an embodiment of the attachment should then be se- lected if the floor plate also has straight edges, i.e. is, in particular, square or quad- ratic. In this way, it is possible in a simple way, to divide the openings in the floor plate in groups of almost equal number. It can also, however, be necessary that the attachment, in addition to linear bars and/or sections, comprises curved guide sur- faces, which effect a flow of the appearing fluid in such way that dead zones near to the attachment are avoided. The orientation of the bar with respect to the floor plate can, in principle, be freely selected. This also means that the linear bar ex- tends over the entire floor plate or, however, also only part-regions of the floor plates. In exactly this context, it is advantageous that the attachment has at least one of the following configurations: a) more than one attachment is provided with a bar; b) one attachment is provided with more than one bar, preferably joined to- gether with each other. This means, in particular, that the attachment can be constructed as component with a plurality of different or same bars, on the other hand, one-piece attachments and/or connecting systems made from more than one bar, preferably connected with each other by means of joining technology, are suitable for production. The bars can, in connection systems of this type, be removable or connected to each other by means of material connection. As a different criterion with these two configurations can, for example, be mentioned that the more than one attachments comprising respectively one bar are merely in contact with each other by means of the floor plate and/or other components of the column, while with a one-piece, more complex attachment and/or the bars which are connected together to form an attachment, a direct connection and/or link by means of components of the bar and/or of the attachment is formed itself. While alternative (a) enables a very flexible arrangement of the bars with respect to each other, the configuration (b) has the advantage that this can be mounted simply and with little time expendi- ture. In view of these points, it can be advantageous that in a central region, the complex attachment formed from more than one bar is used, while in the edge areas, depending on the form and/or design of the attachment or of the column, additional individual bars are positioned for completion of the first attachment. In this way, it can be ensured that, for example, groups of openings are formed with substantially the same number. According to an advantageous further development, the at least one bar has a length, whereby the plurality of apertures is limited at least partially by at least one of the following elements: (a) at least one rod, which is part of the bar; (b) at least one spacer, which is a separate part. whereby these elements comprise a width and the sum of the widths of the ele- ments is less than 80 %, preferably less than 60 %, in particular less than 40 % of the length of the bar. Besides the possibility of fixing the attachment mentioned with a certain distance with respect to the floor plate at the column and/or the con- tainer, it is here preferred to propose an easily mountable construction unit with the floor plate. This means, in particular, that the floor plate with the at least one attachment can be incorporated together into the column. This has the result that the at least one attachment should be fixed onto the floor plate itself. It is now here proposed to effect this by means of rods or spacers or both elements. The rods, which are themselves parts of the bar, can, for example, be produced by form-giving processes, such as, for example, pouring, milling or the like. It fol- lows therefrom that the rods are formed from the same material as the bar itself. It can be, however, advantageous that the rods and the bar itself are built from dif- ferent materials, whereby, for example, first the bar is produced in one piece and then the rods are connected to the bar using a joining technology manufacturing process (removable or non-removable). Alternatively or in combination thereto, separate spacers can be positioned on the floor plate, which themselves comprise means for fixing of the bar. This has the advantage that the bars can, for example, all be formed substantially square, whereby by means of respective different designs of the spacer, the desired heights of the apertures can be generated. This results, on the one hand, in a cost- effective production of the bars and a simple process-dependent adaptation of the apertures. The rods and/or spacers serve in particular to stabilise and/or position the bar in relation to the floor plate. That means that the bar is arranged, for example, in the edge regions of the floor plate by means of respectively a rod and/or a spacer, while in the central regions, depending on the length of the bar, an additional ele- ment (rod and/or spacer) is provided. These then extend preferably to the floor plate; the rods can, however, also be designed shorter, in order to generate the certain profile of the apertures, which has, for example, advantageous influences with respect to the flow behaviour of the fluid. As already mentioned, it is particularly advantageous that the sum of the widths of the rods and/or spacers is less than 8 %, preferably less than 60 % and particularly preferably less than 40 % of the length of the bar. It is, accordingly, preferred that as few as possible, and preferably relatively slim elements for stabilisation of the bar should be used. This ensures that the flow of the fluid in the proximity of the floor plate can propagate relatively unhindered. It can be advantageous hereby to equip the bars and/or spacers with a flow-technical favourable profile, in particu- lar to form suitable edges for flowing around (e.g. round cross-section forms). Corresponding to the flow speed appearing, it can be necessary to provide an in- creased number of rods and/or spacers, but to design these relatively thin, while in other applications, respectively one rod and/or one spacer in the edge region of the floor plate is sufficient, but the central region is free from rods and/or spacers. By means of clarification, it should be maintained here that the length of the bar de- scribes the longest extension in a direction and the width of the rods and/or of the spacers should be determined in the same direction, whereby the widths and the lengths can be arranged in one level or in levels which are parallel to each other. According to yet a further design, the separating floor is designed such that the at least one attachment forms sectors of the floor plate with respectively one group of openings, whereby the sectors preferably comprise an area in the range from 1.2 m2 to 0.3 m2, preferably 1.0 m2 to 0.5 m2 and in particular 0.8 m2 to 0.6 m2. In principle, separating floors of this type can be formed with a one-piece or a multi- piece floor plate and from more than one individual floor plate, whereby it is, in principle, ensured that an unevenness of the floor plate of less than 3 mm/m, in particular less than 2 mm/m and preferably less than 1 mm/m is achieved. A round floor plate preferably has, in total, a diameter in the range from 2 m to 7 m, in particular 3 m and 5 m. In this way, the openings in the floor plate preferably have a diameter of 15 mm to 40 mm, in particular from 20 mm to 30 mm. It is further proposed that the separating floor has a cover plate, whereby this is pref- erably arranged at a separation in the range from 60 mm to 200 mm, preferably from 80 mm to 150 mm and particularly preferably from 100 mm to 120 mm from the floor plate, and, in particular, likewise comprises a plurality of openings. The cover plate has a plurality of different functions. Thus, for example, one func- tion can be seen as being that in this way, it is hindered or at least substantially reduced that the rising vapour-form material pulls with it parts of the liquid mate- rial accumulated on the floor plate. In this way, the separated liquid which accu- mulates at the cover plate when the vapour-form material rises, is uniformly dis- tributed again and conducted back down to the floor plate. In order to strengthen- ing this effect, the cover plate comprises openings, which do not run parallel to the preferred flow direction of the vapour-form material, but, rather, diagonally thereto, e.g. within an angle between 10° and 50°. In this way, a more intensive contact of the material with the cover plate is enabled. These advantageous effects lead, individually and particularly in combination with each other, to an increase of the efficiency of the separating floor. Furthermore, the cover plate can favour at least the material exchange or the heat exchange, whereby a further improvement of the separation performance is created. At the same time, a uniform flowing away of the vapour-form material from the separating floor through which it has just passed to the next is enabled. Accordingly, the cover plate functions like a flow rectifier, which ensures a uniform flow to the following separating floor. Accordingly, the cover plate can be designed exactly like such a flow rectifier, with a grating structure or honeycomb structure or a hole plate similar to the floor plate. In the design of the cover plate according to a honeycomb structure of more than one structured plate layer, which form channels which can be flown through, the cover plate has a thickness of at least 50 mm, preferably at least 100 mm, in particular 150 mm, however, particular preferably not greater than 300 mm. According to an advantageous further development of the separating floor, this comprises a holder, which comprises at least one solid carrier, which is in contact with the side of the floor plate which faces away from the at least one attachment, preferably over at least a dimension in the range from 200 mm to 1000 mm, pref- erably from 350 mm to 800 mm and particularly preferably from 400 mm to 600 mm. It also possible that the carriers are at least partially directly substantially perpendicular to each other and are optionally connected to each other with con- nection elements, whereby the carriers can be provided in different directions with different dimensions to each other. The holder mentioned can take over a plurality of functions, whereby, here, in particular, at least one of the following functions stands in the foreground: The fixing of the separating floor in relation to the column and/or further separating floors, or the increase of the stiffness of the separating floor. If this holder serves for fixing, these are preferably arranged such that it extends to the edge region of the separating floor, so that it can be connected to components of adjacent con- stituents (e.g. of the column of further separating floors). The function relating to the increase of the stiffness of the separating floor then comes, in particular, into the foreground if the separating floor or all floor plates together spans an area of more than 10 m2, preferably more than 13 m2 and particularly preferably more than 15 m2. With increasing sides of the separating floor, it is ensured by use of the holders that the floor plate is, nonetheless, even, and that in central regions, a sinking of the floor plate in relation to the edge regions is avoided. Unevennesses of the floor plate of this type would have the result that in proximity to the floor plate, border layers would be formed, which have a reduced tendency to flow and thus tend to polymerise. Since these unevennesses would have relatively large areas, a very large numbers of openings could be blocked by these polymerisation deposits. These processes which restrict the functional capability of the distillation column can be avoided by the use of the here-proposed holders. In this respect, it should be mentioned that by a solid carrier should be understood in particular a carrier without hollow spaces in its interior, i.e. spaces which are completely surrounded by the material of the carrier, whereby inclusions or cavi- ties necessary for production are excepted. Preferably, the carriers are also not designed such that stiff, yet hollow space-forming profiles are provided. Although it is, in principal, possible, to produce such holders from U-profiles with relatively thin walls, here, relatively thick-walled, solid carriers are preferably proposed. The carriers are affixed to the side of the floor plate which is facing away from the fluid level. Accordingly, they do not serve for direct flow influencing, but only optionally as flowing away edges or services for fluid or liquid which has passed through the openings of the floor plates or which is condensed at the holder or at the separating plate. According to a further embodiment, the at least one carrier has, near the floor plate, at least one recess with an extension, whereby the sum of the extensions lies at least in the range from 80 % to 30 %, preferably from 70 % to 40 % and par- ticularly preferably from 60 % to 55 % of the dimension 46. The recesses have inter alia the function of enabling a flowing through with the vapour-form mate- rial, and optionally of representing tear edges for fluid flows rippling towards the carrier. The greater the surface of such a carrier, the more the fluid which has passed through the openings can collect there. Thus, the risk would also exist that border layers are formed, in which polymerisation could rapidly occur. For this reason, it is here proposed that, already after short flow paths, edges are formed which prevent a further flow along the carrier as a result of gravity. These edges have the result that, for example, drops form, which separate from the carrier and continue to move freely in the direction of the lower floor of the distillation col- umn or separating floors lying therebetween. In order to ensure that, on the one hand, such advantageous dropping away of the fluid is ensured, but on the other hand, also, the stiffness-increasing property of the carrier is ensured, it is proposed that the sum of the dimensions lies in the above-mentioned percentage region of the dimension. It is also noted in this context that the dimension should be deter- mined in the direction of the longest extension of a carrier, whereby the extension of the recesses should be determined in the same direction, so that extension and dimension lie in the same level of the carrier or in levels of the carrier which are parallel to each other. According to a further embodiment, the carrier is designed T-shaped, whereby the at least one recess is arranged in the carrier part which is substantially perpendicu- lar to the floor plate. The T-shaped embodiment has the advantage that with the upper carrier part which lies substantially parallel to the floor plate, a contact area is formed with respect to the floor plate, which ensures an even and relatively large surface support. In this way, sufficient possibilities for connecting to the floor plate are given. In this respect, it is further advantageous that the floor plate comprises no openings in the region of the installation with the carrier. Further- more, this carrier part lying substantially parallel to the floor plate has the advan- tage that upon flowing away of the fluid, the first tear edge is formed already after a short path, namely, exactly there where the upper carrier part stops. The carrier part arranged substantially perpendicular to the floor plate is here positioned so far from this edge that an accumulation of fluid as a result of the surface tension in the region of the meeting of the upper and lower carrier part is avoided. It should be taken into account that the gaseous, polymerisable material can con- dense at the lower side of the carrier part lying substantially parallel to the floor plate, and now the possibility exists that this liquid flows away at the carrier part lying substantially perpendicular to the floor plate. For this reason, the arrange- ment of at least one recess is proposed. Furthermore, the provision of such re- cesses is advantageous because in this way, material is economised and thus the production costs, the component weight, and also the human strength for mount- ing of such separating floors can be considerably reduced. Taking these points into account, the recesses can also be designed according to the criteria of light building methods, as are already often used. The points of view of the light con- struction methods can be further strengthened by appropriate selection of material. According to an advantageous further embodiment of the separating floor, it is proposed that the at least one T-shaped carrier has a foot arranged parallel to the floor plate, with a dimension in the range from 50 mm to 100 mm, preferably from 60 mm to 90 mm and particularly preferably within 70 mm to 80 mm, whereby the at least one recess is arranged at a distance of less than 10 mm from, in particular directly at the foot, and preferably has a width in the range from 40 mm to 120 mm, preferably from 60 mm to 100 mm and particularly preferably from 75 mm to 85 mm. For the production of such a carrier, it is also possible to connect more than one individual part removably (e.g. with connecting elements) or non-removably (e.g. by means of weld-connections) with each other. The di- mensioning of the T-shaped carrier occurs substantially taking into account two interests. On the one hand, care should be taken that the carrier provides suffi- ciently the desired stiffness of the separating floor; on the other hand, it should be taken into account that the head capacity of such a carrier can play an important role with respect to the operation of the distillation column. This means that with temperature variations inside the column, overly large temperature differences between the gas flowing past and the carrier must not occur, since this results in an increased risk of condensation and/or polymerisation of the material. It is further proposed that the at least one carrier and the least one attachment are arranged perpendicular to each other. This means that the carrier and the at least one attachment form a type of framework which results in stabilisation of the floor plate in a level. This is increasingly true as the at least one attachment com- prises direct connection regions with the floor plate (also in the central region). Such a stiffening of the floor plate by means of such a framework system has the result that the above-described regions concerning the dimension and/or the width of the T-shaped carrier can be designed more slimly, preferably in regions of the lower half or the lower third of the value regions given. It is further proposed that the separating floor is provided at least partially with a coating, which has an improved glide property for fluids compared to steel. It should here be mentioned that a coating of this type extends at least partially over one of the following components: the floor plate, the holder, the attachment, the spacer. In principle, the coating can extend, starting from the surface of the com- ponents, over a few micrometers up to a few millimetres (preferably 50 µm to 1000 µm, in particular 100 µm to 800 µm, preferably 200 µm to 400 urn). As coating, in particular a polyfluorohydrocarbon, preferably Teflon®, polyaniline varnishes or coatings with a metal ion-free surface (e.g. glass) or also mixtures of at least two of these types of coatings are proposed. If glass is used as coating agent, in particular technical glass, which has been obtained from cooled melts of silicon dioxide (SiO2), calcium oxide (CaO), sodium oxide (Na2O), optionally with greater amounts of boron trioxide (B2O3), aluminium oxide (Al2O3), lead oxide (PbO), magnesium oxide (MgO), barium oxide (BaO) or potassium oxide (K2O) are preferred. Preferably this technical glass consists to at least 50 wt.%, yet more preferably to at least 65 wt.% and most preferably to at least 80 wt.% of SiO2. It is, in principle, also possible to produce the separating floor at least partially from a non-metallic material, so that a separate coating of the above-mentioned type is not required. In addition to the above-mentioned materials, plastics or a composite (e.g. from Teflon® and plastic) can be used for production of at least one component or of the entire separating floor. The provision of the floor plate from Teflon® or plastic is particularly advantageous. It should also be mentioned in addition, that it is advantageous that the container comprises a plurality of separating floors and at least one spray unit is provided, with which a lower side of at least one separating floor can be sprayed with the polymerisable material. A spray unit of this type removes effectively partial amounts of the polymerisable material adhering to the lower side of the separating floor, so that a polymerisation at these positions can be avoided. The embodiment is preferred here in which the lowest separating floor of the column is positioned within reach of such a spray unit. It is here advantageous that the spray unit is supplied with liquid polymerisable material from the collecting reservoir of the container and this is sprayed uniformly distributed on the lower side of the sepa- rating floor. The spray unit preferably comprises a plurality of nozzles, which form uniformly distributed spray regions over the cross-section of the separating floor. Particularly preferably, the spray unit is operated with high pressure, e.g. in the range from 2 to 5 bar, preferably at 3 bar. It is further preferred that the spray unit is positioned at a small distance to the lower side of the separating floor, pref- erably at most 1 meter or 50 cm, whereby this can be varied taking into account the spray region and/or the number of nozzles. The above-described spray unit should preferably be used in combination with a separating floor of the type de- scribed here according to the invention. Further details can be found in the figures description. The invention further relates to a process for purification of a polymerisable mate- rial, whereby the polymerisable material in the column according to the invention is introduced as a material fluid through the inlet and in the inner region is trans- ferred to an at least partially material gas phase. It is hereby preferred that the ma- terial gas phase flows with a isotropic density against a first separating floor ar- ranged above the inlet, whereby within a level between the inlet and the first sepa- rating floor the maximum deviation from an average volume of the isotropic den- sity is at most 50 %. It is particularly advantageous if the maximum deviation is at most 10 %, in particular only 5 %. The level here lies preferably relatively tight and parallel to the first separating floor, in order to ensure a relatively compact construction of the column. The level lies preferably at most 100 mm below the first separating floor, the distance of the level from the first separating floor can, however, also be at most 50 mm or even only at most 10 mm. A particularly even distillation with a very low tendency to polymerise in the col- umn is given if the at least one separating floor is designed such that the isotropic density is also reached in the fluid phase of the polymerisable material. This can be achieved particularly by the use of a so-called "Dual-Flow-Floor". In this way, optionally flows of the material gas phase over the separating floor can be imple- mented with the proposed isotropic density, whereby the maximum deviation oc- curring is further clearly reduced. In general, as polymerisable material, according to the invention, all chemical compounds which tend to polymerise and are known to the skilled person come into consideration. Preferred polymerisable materials are monomers used in the production of mass plastics, such as, styrene, a-methyl styrene, methylmethacry- late, butylacrylate and the like. It is, furthermore, preferred that the polymerisable material used in the process according to the invention is (meth)acrylic acid. The term "(meth)acrylic acid" here stands both for the compound with the nomencla- ture name "acrylic acid" and for the compound with the nomenclature name "methacrylic acid", whereby of the two, acrylic acid is preferred. It is additionally preferred that in the process according to the invention, in the inner region an ab- solute pressure prevails. This pressure preferably lies in the range from 50 to 400 hPa (hectopascal), preferably 100 to 300 hPa and particularly preferably 150 to 250 hPa in the inner region of the column (whereby 1 hPa = 1 mbar = 102 New- ton/meter2 [N/m2] = 102 Pa). It is additionally preferred in the process according to the invention that the mate- rial fluid is overheated. In this context, it is preferred that the temperature of the main component of the material fluid, mostly the polymerisable material, lies at least 1 °C, preferably at least 5 °C and particularly preferably at least 10 °C above the boiling temperature of the pure head component of the material fluid. The invention further relates to a process for production of a polymerisable mate- rial, whereby the polymerisable material is synthesised from at least one reagent in a reactor and then subjected to a process according to the invention for purifica- tion. The synthesis of the polymerisable material is not limited to a particular process. Rather, all processes known to the skilled person can be considered. In the synthesis of acrylic acid, a preferably at least two-step gas phase oxidation reaction, in which preferably in a first step, by catalytic oxidation of propylene, acrolein is obtained and in a further step, acrylic acid is obtained as gas phase. This gas phase is then brought into contact, in a quench unit, with a fluid, prefera- bly water or an organic compound which boils higher than water or a mixture thereof and indirectly or directly subjected to the process according to the inven- tion for purification. Details concerning the production and further purification processes for acrylic acid can be taken from WO 02/055469 and the reference cited therein, which are hereby referred as part of this disclosure. In addition, the invention relates to the use of an inlet according to the invention for distillation of a polymerisable material. Furthermore, the invention relates to a polymerisable material obtainable accord- ing to a process according to the invention, whereby the polymerisable material is preferably acrylic acid or methacrylic acid, particularly preferably acrylic acid. In addition, the invention relates to the use of a polymerisable material according to the invention, preferably of acrylic acid, as starting material in formed masses, fibres, sheets, absorbent polymers, in polymers for leather and textile processing, in polymers for water treatment or in polymers for soap production. The invention also relates to formed masses, fibres, sheets, absorbent polymers, polymers for leather and textile processing, polymers for water treatment or polymers for soap production, at least partially based on a polymerisable material according to the invention, preferably based on acrylic acid. The invention is now more closely illustrated by means of the figures, whereby the example embodiments depicted show particularly preferred embodiments of the invention or of the incorporation of the invention into the known field of dis- tillation columns illustrated. It should be mentioned that the invention is not re- stricted to the depicted example embodiments. In addition, independent thereof, further particulars are also described concerning the technical area of distillation columns. The figures show Fig. 1 schematically and in perspective, the construction of a column with an inlet for a polymerisable material; Fig. 2 schematically, a sectional view through a design of a separating floor; Fig. 3 a schematic view of a further embodiment of a separating floor; Fig. 4 a further schematic view of a further embodiment of the separating floor in section; Fig. 5 simplified schematic representation of different embodiments of a flow rectifier; Fig. 6 a schematic detailed view of an embodiment of a coated floor plate of a separating floor; Fig. 7 a schematic representation of an installation for production of acrylic acid; Fig. 8 schematically, the construction of a trial arrangement for determination of the density distribution; Fig. 9 schematically and in perspective, a waved floor plate of a separating floor; Fig. 10 schematically and in perspective, a further embodiment of the inlet with a flow mixer; Fig. 11 a partial section of a container with a spray unit in cross-section; and Fig. 12 the top view of the spray unit shown in fig. 11. Fig. 1 shows schematically and in a section view a column 1 for distillation of polymerisable material, whereby this comprises a container 2 with a lower floor 8 as an inlet 4 for the polymerisable material. The inlet 4 leads into an inner region 5 of the container 2. As more closely detailed in the following, column 1 com- prises various means for uniform distribution of the material in the container 2. In order to be able, in principal, to understand the flow course of the polymer- isable material, its path through column 1 is first described. Generally, the poly- merisable material is initially present as fluid and is transformed and/or over- heated into a vapour and/or gaseous state by means of a heater 27. Starting from heater 27, the material flows in flow direction 25 through an inlet 4 into the inner region 5 of the container 2. At entry, or a short time after entry into the inner re- gion 5, the partially fluid, partially vaporous material flows further in flow direc- tion 25 (here depicted vertically upwards by means of the arrows) towards a sepa- rating floor 23, in which a first distillation stage is carried out. Condensed compo- nents of the material in the form of drops fall back in the direction opposed to flow direction 25 onto the inlet 4 or onto the lower floor 8 of container 2. At the lowest position, container 2 comprises a collecting reservoir 24, in which the con- densate collects. This collecting reservoir is connected to a pump 28, which ef- fects the transport away of the condensate in the collecting reservoir 24 from col- umn 1. Upon closer observation of inlet 4, it can first be seen that this has an entry orifice 13 and an exit orifice 14, whereby, here, the exit orifice 14 is arranged closer and substantially parallel to the lower floor 8 of container 2. The inlet 4 is depicted as separate component, which extends through an attachment 3 through container 2 into the inner region 5. The inlet 4 comprises straight and bent partial regions, whereby these are here designed so that the exit orifice 14 is positioned with its central axis 19 central to the central axis 62 of container 2. On the inside of the inlet 4, a flow influencer 15 is arranged over a section 18 towards the exit orifice 14. The flow influencer 15 comprises a plurality of baffles 16, which ensure chan- nels 17 for equilibration of the flow of the polymerisable material on the inside of the inlet 4. Central to the central axis 19 or to the central axis 62, a conical flow distributor 20 is arranged such that its tip 21 is closest to the exit orifice 14. As depicted in fig. 1 by means of the arrow (flow direction 25), the arrangement of the flow distributor 20 in the inner region 5 of the container 2 results in a devia- tion of the inflowing material, whereby in support, the container 8 is additionally designed such that the guiding surfaces 61 support the uniform distribution of the material in the container 2. Furthermore, with the depicted arrangement of the flow distributor 20, the advantage is achieved that the inflowing material is not mixed directly with the condensate stored in the collecting reservoir 24, so that the flow distributor 20 also has a protective function here. With respect to inlet 4, it should be noted that this is provided with a plurality of means for thermal insulation with respect to the inner region 5, whereby these are arranged in partial area 9, which extends over the total outer area 6 of inlet 4, which is in contact with the inner area 5 of container 2. The inlet 4 is formed as a double-walled pipe, so that it comprises two jackets 10, which are arranged co- axial to each other. Between the two jackets 10 a thermally insulated layer 11 is present as vacuum, whereby the inner surfaces 12 of the jacket 10 are mirrored. In order to prevent that in particular fluid components of the polymerisable mate- rial collect and/or remain adhered to the surfaces limiting the inner space 5, the whole outer surface 6 of the inlet 4, the whole jacket surface and/or tip 21 of the flow distributor 22 and also the inner wall of the container 2 are provided with the coating 22, which has an improved glide property for fluids compared to steel. Fig. 2 shows schematically and in a partial section a separating floor 23, which comprises a cover plate 41, an attachment 31, a floor plate 29 and a carrier 44. The fluid 60 is arranged between the cover plate 41 and the floor plate 29. The gaseous, polymerisable material comes into contact in flow direction 25 with the fluid 60 through the opening 30 of the floor plate 29, whereby different border layers form between the floor plate 29 and the cover plate 41. In this way, a fluid layer 36 can be recognized, which is substantially free from bubbles 59. Above this, a vapour bubble layer 57 and/or a type of foam layer is arranged. This repre- sents practically a type of border layer between the fluid 60 and the gaseous vol- ume. Between the cover plate 41 and this vapour bubble layer 57, a droplet layer 58 is further arranged, whereby this is substantially characterised by a gase- ous state of the material to be distilled, which is pervaded by fluid drops 26 com- ing from cover plate 41. While the gaseous material moves from below to above in flow direction 25 (as depicted in the picture) the fluid 60 follows gravity 55 and falls in the opposite direction (counter current flow principal) towards the lower floor 8 (not depicted). It should further be mentioned at this point that the cover plate 41 is not necessar- ily constructed in one part but can also be in more than one part. Preferably, the cover plate 41 comprises a plurality of structured plates and/or plastic elements, which are piled into packages and between which (preferably not linear) flow pas- sages form. The plates and/or plastic elements are preferably arranged substan- tially parallel to the direction of gravity, in particular at a distance 42 from the floor plate 29 in the range from 100 to 200 mm. The plates and/or plastic elements are preferably provided in such a way that a thickness of the cover plate 41 or of the package of about 100 to 200 mm results. The floor plate 29 comprises a plurality of openings 30, which are divided with assistance from the attachment 31 into more than one group 32 (see figure 3). The attachment 31 is, however, designed such that apertures 33 through which fluid and/or liquid 60 can flow and which ensure, in the direction of arrow 54 (i.e. sub- stantially parallel to floor plate 29 and/or substantially perpendicular to flow di- rection 25 of the material), a fluid exchange from openings 30 arranged adjacent to each other. Attachment 31 is here provided with a coating 22, which has an improved glide property for fluids compared to steel. At the same time, the at- tachment 31 functions as separation limiter and/or supporting wall with respect to the two plates 29 and 41. In this way, it is ensured that the cover plate 41 is ar- ranged at a pre-determined separation 42 from the floor plate 29, preferably paral- lel to floor plate 29. Taking into account the size and/or height 34 of the apertures 33, it should be recognized that this is formed substantially somewhat smaller than the fluid layer 56, so that in upper-lying regions of the fluid layer 56 which are arranged near to the vapour bubble layer 57, the flow is hindered, while near to the floor plate 29 in the direction of the arrow 54 relatively unhindered fluid movements are enabled. The cover plate 41 can also be formed as flow rectifier 64, in particular as honeycomb structure 68 with a plurality of channels through which a fluid can flow. On the side 45 facing away from attachment 31, a carrier 44 is provided as holder. The carrier 44 is formed T-shaped and comprises a foot 49 arranged substantially parallel to floor plate 29, with an imaginary dimension 50 as well as a lower car- rier part which is substantially perpendicular hereto. Recesses 47 are provided in the carrier part of the T-shaped carrier 44 substantially perpendicular to the floor plate 29. In the embodiment example depicted, the recesses 47 are arranged at a separation 51 of less than 3 mm. In this way, a plurality of tear edges 63 is formed which have the result that draining fluid (depicted as dashed line) forms drops 26 and comes away from the surface in the direction of gravity 55. In support of this effect, both the floor plate 29 and the carrier 44 are provided with a coating 22, which comprises in particular Teflon®. Fig. 3 shows, schematically and in a top view, the further embodiment of a sepa- rating floor 23 according to the invention. As can be seen here, the depicted sepa- rating floor 23 spans the total inner area 5 of the column 1 or of the container 2. It is, however, also possible that a plurality of separating floors 23 of this type, but preferably square, are put together in a unified platform, which then spans the total inner area 5 of the column 1. The round embodiment shown here of the sepa- rating floor 23 comprises a plurality of openings 30, whereby these are divided by attachment 31 into several groups 32. The attachment 31 comprises a plurality of bars 35, which are connected in regular arrangement with each other by means of joining technology. The thus-designed attachment 31 forms sectors 40 of the floor plate 29 with respectively one group 32 of openings 30. The attachment 31 is de- signed such that, in the direction of the arrow 54, an exchange of liquid or fluid from neighbouring sectors 40 is still ensured. With dashed lines are shown in ad- dition the carriers 44 on the lower side 45 of the floor plate 29 provided with a coating 22. These are here connected directly to column 1 and serve inter alia to increase the stability of floor plate 29. Fig. 4 shows a further section view for illustration of a variant of the separating floor 23 according to the invention. As can be seen from fig. 4, the holder 43 of the separating floor 23 is provided with a carrier 44, which is connected by means of projections 53 to the container 2 of column 1, so that a substantially horizontal positioning of separating floor 23 in the inner region 5 of column 1 is ensured. The projections 53 are here shown simplified. In fact, a plurality of adjustment possibilities can be provided which enable an exact horizontal positioning of the separating floor 23 in the inner space 5. The carrier 44 shown has a dimension 46 and is T-shaped. Besides the carrier part positioned substantially perpendicular to floor plate 29, the carrier 44 comprises a foot 49 which serves as support plate for the floor plate 29. Directly at this foot 49 is attached, in the perpendicular carrier part, a plurality of recesses 47, whereby these are here formed as semi-circles. The semi-circular design 47 is not compulsory, but has advantages with respect to stiffness aspects because of its rounded contours. These recesses 47 can be de- scribed by an extension 48, which should be determined substantially parallel to floor plate 29 and/or to foot 49. Perpendicular hereto, the recesses 47 comprise respectively a width 52. Preferably, the recesses 47 are so designed that the sum of the extensions 48 lies at least in the range from 80 % to 30 %, preferably from 70 % to 40 % and particularly from 60 % to 65 % of the dimension 46. In fig. 4, above the floor plate 29 is depicted an attachment 31 in the form of bar 35. The bar 35 is fixed by means of spacer 38 in the edge area of the floor plate 29 near to the container 2. By the simple provision of such spacer 38, a gap would already be generated between the bar 35 and the floor plate 29, which could al- ready result in the here-described advantageous influencing of the fluid flow. In fig. 4, for illustration, however, a further particular embodiment of the bar 35 with individual bars 37 is depicted. The bars 37 and/or the spacer 38 have a breadth 39, whereby the sum of the breadth 39 is considerable smaller than the length 36 of the bar 35 (for example less than 50 %). With respect to the above-mentioned per- centages, it should be mentioned that preferably only the spacers 38 and/or bars 37 with their width 39 go in, which are in direct contact with floor plate 29, i.e. actually hinder the flow over the total fluid layer. With assistance from the bars 37 and/or the spacers 38, apertures 33 are accordingly formed, which preferably, starting from the flow plate 29, have a height 34 in a range from 1 mm to 100 mm, preferably from 5 mm to 50 mm and particularly preferably from 10 mm to 30 mm. Fig. 5 shows schematically different embodiments of flow rectifiers 64, which serve to improve the flow of the vaporous polymerisable material towards a sepa- rating floor 23. In principal, it should first be mentioned that such a flow rectifier 64 fulfils the function of achieving a uniform flow of the polymerisable material towards the at least one separating floor 23. Uniform in this sense means that preferably at least one of the factors flow speed and flow direction over the cross- section of the inner region of the column 1 near to separating floor 23 only has a deviation in the range of less than 20 %, in particular less than 10 % and advanta- geously less than 5 %. This means, for example, that with a given flow speed of the vapour-form material of 2 m/s to 5 m/s [meter per second] at most deviations upstream of the flow rectifier of 1 m/s [50 % of 2 m/s] to 7.5 m/s [150 % of 5 m/s] are present. With respect to flow direction 25 is meant that starting from a flow impinging perpendicularly on the at least one separating floor 23 (perpendicular flow direction towards) a tolerance about this perpendicular flow direction to- wards of at most 180 °, preferably 120 ° and particularly preferably 72 °, advanta- geously even only 45 ° and particularly preferably at most 20 ° is present. In re- spect of this, a symmetrical arrangement of the tolerances in respect of the per- pendicular flow direction towards is assumed. The flow rectifier 64 is preferably designed flat and positioned substantially paral- lel to the at least one separating floor 23 and/or fixed in the inner region 5 of col- umn 1. The flow rectifier 64 is preferably at least partially made from a corrosion- and high temperature-resistant material and can be flowed through by a fluid. For this, in particular, openings are provided which, on the one hand, influence a flow profile, preferably with respect to speed and/or direction, on the other hand, how- ever, prevent a blocking or closing of the openings. The flow rectifier 54 extends preferably over the total inner region 5 of the column 1. This flow rectifier 64 comprises accordingly at least one of the following ele- ments: At least one grating structure 67, at least one honeycomb structure 68, at least one hole plate 69 or a so-called package. These elements can be connected directly or indirectly to the separating floor 23, in particular be a part of the sepa- rating floor 23. The grating structure 67 comprises more than one longitudinal, fibre-like structure, which are connected with each other chaotically or like a web. Suitable as such longitudinal, fibre-like structures are, for example, coated metal wires. The honeycomb structures 68 can be produced in one piece or from a plu- rality of components. The embodiment shown here comprises more than one smooth and structured plate layer which are connected to form a honeycomb structure 68. The hole plate 69 can, besides the depicted round embodiment, also be designed square, oval, with plural corners or in another way. The number of holes preferably is more than 30 % of the total area of the hole plate 69. Fig. 6 shows a detail of an embodiment of a separating floor 23 comprising a floor plate 29 with the coating 22 which has a reduced adhesive property for fluids compared to steel. It can be seen from the depiction that the coating 22 can be described by means of the parameters layer thickness 71, surface roughness 72 and porosity 73. The coating 22, which preferably comprises polytetrafluoroethyl- ene is applied to contact surfaces 70, which would otherwise stand in direct con- tact with the polymerisable material. In this way, it is prevented that the material accumulates and polymerises. Fig. 7 shows schematically an installation for production of acrylic acid which comprises a first gas phase oxidation reactor 76 for oxidation of propylene to ac- rolein, which is connected to a further gas phase oxidation reactor 77, in which the acrolein is subjected to a further oxidation to acrylic acid. The acrylic acid gas mixture thus obtained in the further reactor 77 is fed to a quench device 78, to which is connected indirectly or directly a column 1 according to the invention. At the column according to the invention, one or more further purification units 79 can be connected. Among these can be, for example, crystallisation devices such as layer crystallisers, suspension crystallisers which are connected to wash col- umns, or extractors or azeotropic distillers. The purification unit 79 is preferably arranged at a part of column 1 at which the acrylic acid collects with the greatest purity, whereby it is preferably the column head 80. By means of this design of device for production of acrylic acid, this is obtained in very high purity, mostly above 99.8 %. Comparable device designs are likewise conceivable for other po- lymerisable materials other than acrylic acid. Fig. 8 shows schematically the construction of an experimental arrangement for determination of this density distribution of the material gas phase. Container 2 and first separating floor 23 are shown with dashed line. With a section 85, below the separating floor 23 an imaginary level 81 is depicted in which the determina- tion of the isotropic density distribution in the material gas phase is carried out. The level 81 is, in the example depicted, free from other components of container 2 or components arranged therein. On opposite-lying regions of the level 81 are provided a source 82 for a radioactive radiation as well as a corresponding detec- tor 83 for determination of the amount of impinging radioactive radiation. The source 82 sends a beam through the central point 87 of level 81 which substan- tially corresponds to the cross-section of container 2. Furthermore, a further posi- tion of the source and of the detector is depicted with a dashed line and identified with (II). The positions (I) and (II) are taken temporally one after the other and offset with respect to each other with a direction change 86, whereby respectively a measurement process has been carried out. In this process, the detector 83 has respectively counted the impinging impulse radiation. The measurement result is shown schematically in fig. 8 by means of two bar-type graphs. The measurement was carried out over a pre-determined time-period and with a certain beam width 88. The detector 83 has generated respectively a graph which shows the distribution of the count impulses (n) over the beam width 88. The maximum values of the first measurement (position I) and of the second measurement (position II) are indicated in the diagram with nI and n. The integral of the count impulses (n) over the beam width 88 is indicated with AI or A re- spectively. The value or the form respectively of the respective integral or of the value of the count impulse is characteristic for the density of the medium through which the beam has passed or for the material gas phase through which the beam has passed. A bar-type form of the integrals or a high value of the count impulse shows that a very large proportion of the radiation emitted from source 82 has reached detector 83. Conversely, a very low value of the count impulse or a sharp form of the graph indicates a denser medium through which at least part of the radioactive radiation did not pass. If a measurement of this type is carried out at more than one position (I, II, ...) with a previously described device, in particular with an inventive device, a maximum deviation of the isotropic density within the level 81 between inlet 4 and the first separating floor 23 is at most 15 %. For the depicted embodiment example, this means that the value of nI is at least 70 % of nn. Because the number of detected impulses is characteristic for the density of the material gas phase through which the beam has passed, the parameter can be used as a measure for the density. Accordingly, in this way, it can be established that an isotropic den- sity distribution according to the invention is present. Fig. 9 shows schematically a detail of a particular form of a wave-form floor plate 29 of a separating floor 23. Such a floor plate 29, in particular with the following properties, has a plurality of holes 30 and is particularly advantageous, in combi- nation with the here-described embodiment variants but also independent there- from. The advantage of a wave-form floor plate 29 is that at the lower side the adhering fluid drops 26 run down to the wave troughs 90 and mingle locally with each other there. This further reduces the danger of polymerisation. At the same time, this accumulation of fluid leads to this also finally detaching. With a wave form of this floor plate 29, attachment 31, as, for example, shown in fig. 2 and 3, can be dispensed with, since the wave form itself provides a sort of separation, which hinders an undesired flowing back and forth of the fluid. Preferably, more than one or even all separating floors 23 of a column 1 are equipped with such wave-form floor plates 29. Preferably, in this case, floor plates 23 positioned adja- cent to each other are arranged offset to each other with respect to the positioning and/or orientation of the wave form, in particular in the form that the wave peaks 89 or wave troughs 90 respectively of floor plates 29 form an angle of about 90°. Particularly preferably, the form of the floor plate 29 is with a wave height 92 in the range from 0.5 to 5.0 cm; in particular in a range from 1.2 to 1.7 cm. With wave height 92, in this context, is meant the average vertical distance of a wave peak 89 and a wave trough 90 to each other. A wave peak 89 lies here at a hori- zontal separation from its adjacent wave trough 90 (corresponds to the wave length 91) of about 3.0 cm to 10 cm, in particular the wave length 91 lies in a range from 4.0 cm to 6.0 cm. A further improvement in respect of the reduction of the tendency to polymerise can be achieved by means of special forms of surfaces of column 1 which come into contact with the polymerisable material. This is particularly the case for at least a part of the separating floor 23, of the flow distributor 20, of the inlet 4, of the flow rectifier 64 or of the container 2. According to a variant, at least one of the above-mentioned surfaces or its coating respectively is at least partially provided with a particularly low average rough- ness value (Ra). The average roughness value is the arithmetic average (over a reference path 95) of the absolute amounts of the distances 96 of the actual profile 94 from the central position 93. Here, the average roughness value preferably lies in a range less than 2.0 urn (micrometer), in particular in a range from 0.5 urn to 1.0 urn. With such an average roughness value, the tendency of the fluid to adhere relative to the surface wetted by it is reduced, so that this fluid runs away or drops away more quickly. In fig. 9, such an average roughness value is depicted as an example and illustration with reference to the surface of the floor plate 29. In addition, the possibility also exitss (alternatively or cumulatively) to provide at least one of the above-mentioned areas at least partially with a so-called self- cleaning surface and/or coating. Preferably, this self-cleaning surface has an arti- ficial, at least partially hydrophobic surface structure of raised parts and recesses, whereby the raised parts and recesses are formed by particles fixed on the surface by means of a carrier. This is advantageously distinguished in that the particles comprise a jagged structure with raised parts and/or recesses in the nanometer range (nanostructure 97 is shown schematically in fig. 9). Preferably, the raised parts comprise on average a height of 20 to 500 nm (nanometer), particularly preferably from 50 to 200 nm. The separation of the raised parts or recesses re- spectively on the particles preferably amounts to less than 500 nm, most particu- larly preferably less than 200 nm. The jagged structure with raised parts and/or recesses in the nanometer range can be formed, e.g. by means of hollow spaces, pores, scores, peaks and/or spikes. The particles themselves have an average size of less than 50 µm (micrometer), preferably of less than 30 µm and most particu- larly preferably of less than 20 µm. Preferably, the particles comprise a BET- surface area from 50 to 600 m2/g (square meter per gram). Most particularly pref- erably, the particles comprise a BET-surface area from 50 to 200 m2/g. The so- called "BET-surface area" refers to the determination of this specific surface area by the well known process of BRUNAUER, EMMET and TELLER. As structure-forming particles, diverse compounds from many branches of chem- istry can be used. Inorganic particles are preferred here. Preferably, the particles comprise at least one material selected from silicates, doped silicates, minerals, metal oxides, silicic acids, polymers and metal powders coated with silicic acid. Most particularly preferably, the particles comprise pyrogenic silicic acid or pre- cipitation silicic acids, in particular aerosils, A12O3, SiO2, TiO2, ZrO2, zinc powder jacketed with aerosol R974, preferably with the particle size of 1 nm (micrometer) or powdery polymers, such as, for example, cryogenic, milled or spray-dried polytetrafluoroethylene (PTFE) or per-fluorinated copolymers or respectively co- polymers with tetrafluoroethylene. Particles of these types and coatings for gen- eration of self-cleaning surfaces can be obtained, for example, from DEGUSSA AG. Measurement methods The isotropic density ("direction-independent" density distribution) of the mate- rial gas phase and the deviation respectively are determined, for example, with a process of the company Ingenieurburo Bulander & Esper GmbH in Zwingenberg, Germany. By means of a radioactive source, a directed beam (with a pre- determined width, e.g. 5 cm) is sent towards a detector. Source and detector are located on opposite sides of the column so that the beam extends substantially horizontally through the column. As source are used, for example, cobalt (Co 60) and caesium (Cs 137) with an activity of 0.3 to 3.7 GBq. The beam emitted during the operation of the column is measured advantageously with a scintillation detector in the form of impulses per unit time and forwarded to an analysis or display device. In principal, a plurality of detectors and/or sources can also be provided, which are optionally arranged distributed around the cir- cumference of the column. This latter arrangement has the advantage that for comparison measurements in different directions the same experimental construc- tion can be retained and simply other sources and/or detectors come into use, so that measurement imprecisions as a result of incorrect mounting can be avoided. Concerning the construction of the experimental arrangement, reference is further made to the details concerning fig. 8. While a radioactive beam of this type is emitted for a pre-determined time period through the material gas phase, a counter of the detector recognizes the impinging radiation and counts the impulses. The number of impulses per unit time is a measure of the density of the material located between source and detector. A high value characterises a low density, since a large proportion of the emitted ra- diation has reached the detector. Accordingly, a low value of the counted impulses is characteristic for a higher density. A uniform flow of the material gas phase can be recognized, for example, in that in a cross section the fluid and gaseous components are uniformly distributed. By this it can be recognized that the separating floors are locally blocked (so that, there, only a small proportion of fluid is present in the material gas phase and thus a lower density) or, for example, regions with reduced gas flows are present (where, because of the reduced counter-pressure, an increased fluid flow and thus an increased density can be observed). To determine the isotropy, it is now proposed, first to undertake a measurement in a first direction in a level below the first operating floor and to acquire the de- tected radiation over a given time period (t; e.g. 5 min) (n). In order to reduce the influence of operational variations of the column, this measurement can also be carried out plural times, whereby a value (ni) is recorded over the time period (t). An average value (N) is then formed and used as reference for the isotropy. It should here be further mentioned that the radioactive beam is emitted with a cer- tain width (e.g. 5 cm) and the detector optionally has a resolution which enables a differentiation of the measured values over this width. Then, in turn, the average value or the area under the graphs (the integral) can be taken as reference, which represents the impulse rates over the width. After a characteristic value or characteristic integral for the detected radiation has been recorded, the above-described procedure is repeated on the same level but in a direction deviating therefrom. The two directions enclose an angle which is preferably greater than 30° and particular even greater than 40°. In this way, at least two such measurements from different directions should be carried out, in particular even at least three. In principal, a direction along the diameter of the column should be selected, in order to ensure that the free radiation length through the material gas phase is equally long and that accordingly the values for the detected radiation can be compared with each other. This is then possible because the radiation has passed through the same volume of the material gas phase. It is, naturally, also possible, to select a radiation path deviating herefrom, it should simply be ensured that this has the same length for each measurement. The level can, in principal, be arranged in any way in the column and is preferably substantially parallel to at least one separating floor. In order to check the uni- formity of the flow, such directional radiations through a separating floor, the dis- tillate or through the material gas phase can be undertaken. In order to character- ise the flowing towards behaviour of the first separating floor, the level should preferably be selected in a region less than 200 mm below the first separating floor. In particular, the level lies in a region from 100 mm to 10 mm below the first separating floor. An isotropy of the density is present in the meaning of the invention, in particular, then, if the deviation of the recorded measured values (n and/or N) is at most 15 %. For determination of the deviation, an arithmetic average (M) of the meas- ured value is determined. It is defined for a given number of direction measure- ments (X) as quotient from the sum of the measured values per direction (nx and/or Nx) and the number of measured values (X). With a maximum deviation of, for example, 5 %, it is meant that the highest measured value of the impulse rate and the lowest measured value lie in a range from 0.95 M to 1.05 M. With the deviation given here, the measurement deviation as the result of cosmic environ- mental radiation (around +/- 50 count impulses for generally 3 seconds measure- ment duration and a measurement band of about 50 mm) is preferably already taken into account. Fig. 10 shows, schematically and in perspective, a further embodiment of the inlet 4 with a flow mixer 98 as a particular form of a flow influencer. The depicted inlet 4 comprises a bend 99, in which the polymerisable material is deflected. If the polymerisable material would, without a flow influencer, flow freely through such an inlet 4, the bend 99 would cause a non-uniform speed distribution of the flow over the cross-section of the inlet 4. The reason for this is flow turbulence and backflows in the region of the bend 99. In order to prevent this, it is also possible to provide a flow mixer 98 upstream in the proximity (preferably directly before) bend 99. Such a flow mixer 98 divides the polymerisable material flowing to- wards it into more than one filament 100 and deflects these such that they follow substantially the same path through the bend 99. The polymerisable material is hereby preferably at least partially set in rotation. Thereby, a unified flow can be generated without pulsations and back-mixings, so that the cross-section of the inlet 4 is uniformly flowed across, also after bend 99, and the polymerisable mate- rial impinges, for example, on the flow distributor 20 uniformly distributed. It should further be mentioned that the provision of such a flow influencer and/or flow mixer 98 can occur at more than one bend 99 of inlet 4. Fig. 11 illustrates a partial section of a container 2 with a spray unit 101 in cross- section, whereby in fig. 12 a top view of the spray unit 101 shown in fig. 11 is shown. Container 2 has a separating floor 23, whose lower side 105 (in particular during operation of the column 1) is cleaned with a spray unit 101. Such a spray unit 101 is preferably provided at least for the lowest separating floor 23 of con- tainer 2, if this comprises a plurality of separating floors 23 arranged one above the other. Through this separating floor 23 flows a fluid of the polymerisable ma- terial with a certain composition, which is then collected, for example, in a col- lecting reservoir 24 of container 2. Advantageously, it is now proposed to make this fluid available, via a supply device 104 of the spray unit 101 and thus to clean the lower side 105 of separating floor 23. The use of this fluid has the advantages that no significant influence of the distillation in the lowest separating floor 23 takes place. With this spray unit 101, components of the polymerisable material (optionally already partially polymerised) adhering to the lower side 105 of the separating floor 23 are effectively removed. The spray unit 101 itself can comprise a plurality of nozzles 102. These are de- signed such that a substantially uniform cleaning of the separating floor 23 over its entire cross-section can occur. In this case, the arrangement and/or the type of the nozzles can be accordingly selected. Fig. 12 shows schematically a possible embodiment of the spray unit 101 with uniformly distributed nozzle 102, which comprise a substantially uniform spray area 103. Such a design of the spray unit 101 is technically and economically simple, but not absolutely necessary. The nozzles 102 are arranged here such that the spray regions 103 substantially do not overlap, this is, however, also not compulsory. As nozzles 102, both simple open- ings in the spray unit 101 as well as separate nozzle components (preferred) come into consideration. List of reference numerals 1 column 2 container 3 connection 4 inlet 5 inner region 6 outer area 7 partial section 8 lower floor 9 partial area 10 jacket 11 layer 12 inner area 13 entry orifice 14 exit orifice 15 flow influencer 16 baffle 17 channel 18 section 19 central axis 20 flow distributor 21 tip 22 coating 23 separating floor 24 collecting reservoir 25 flow direction 26 drop 27 heater 28 pump 29 floor plate 30 opening 31 attachment 32 group 33 aperture 34 height 35 bar 36 length 37 rod 38 spacer 39 breadth 40 sector 41 cover plate 42 separation Stockhausen GmbH 43 holder 44 carrier 45 side 46 dimension 47 recess 48 extension 49 foot 50 dimension 51 distance 52 width 53 projection 54 arrow 55 gravity 56 fluid layer 57 vapour bubble layer 58 droplet layer 59 bubble 60 fluid 61 baffle 62 central axis 63 tear edge 64 flow rectifier Stockhausen GmbH 65 connecting element 66 jacket area 67 grating structure 68 honeycomb structure 69 hole plate 70 contact area 71 layer density 72 surface roughness 73 porosity 74 distance 75 fluid level 76 first gas phase oxidation reactor 77 further gas phase oxidation reactor 78 quench unit 79 purification unit 80 column head 81 level 82 source 83 detector 84 path 85 section 86 direction change Stockhausen GmbH 87 central point 88 beam width 89 wave peak 90 wave trough 91 wavelength 92 wave height 93 central position 94 actual profile 95 reference path 96 distance 97 nanostructure 98 flow mixer 99 bend 100 flow filament 101 spray unit 102 nozzle 103 spray region 104 supply device 105 lower side WE CLAIM: 1. Separating floor (23) for a column (1) for distillation of a polymerisable material comprising at least one floor plate (29) with a plurality of openings (30) and at least one attachment (31), the attachment (31) divides the plurality of openings (30) into groups (32), wherein with the at least one attachment (31) apertures (33) are formed through which a fluid can flow, characterized in that the at least one attachment (31) forms sectors (40) of the floor plate (29) with respectively a group (32) of openings (30), wherein the sectors (40) comprise an area in the range from 1.2 m2 to 0.3 m2. 2. Separating floor (23) as claimed in claim 1, wherein the apertures (33) extend from the floor plate (29) over a height (34) from 1 mm to 100 mm. 3. Separating floor (23) as claimed in claim 1 or claim 2, wherein the at least one attachment (31) comprises at least one straight bar (35). 4. Separating floor (23) as claimed in claim 3, wherein it comprises at least one of the following configurations: a) more than one attachment (31) is provided with a bar (35), b) one attachment (31) is provided with more than one bar (35), preferably bar (35) joined together with each other. 5. Separating floor (23) as claimed in claim 4, wherein the at least one bar (35) has a length (36) and the more than one aperture (30) is at least partially limited by at least one of the following elements: a) at least one rod (37), which is part of the bar (35), b) at least one spacer (38), which is a separate part, wherein these elements have a width (39), and the sum of the widths (39) of the elements is smaller than 80% of the length (26) of the bar (35). 6. Separating floor (23) as claimed in any one of the preceding claims, wherein it has a cover plate (41), whereby this is preferably arranged at a separation (42) of 60 mm to 200 mm from the floor plate (29) and in particular likewise comprises a plurality of openings (30). 7. Separating floor (23) as claimed in any one of the preceding claims, wherein it comprises a holder (43), whereby the holder (43) at least comprises a solid carrier (44), which is in contact with the side (45) of the floor plate (29) facing away from the at least one attachment (31) preferably by a dimension (46) in the range from 200 mm to 1000 mm. 8. Separating floor (23) as claimed in claim 7, wherein the at least one carrier (44), near the floor plate (29), has at least one recess (47) with an extension (48), wherein the sum of the extensions (48) lies at least in the range from 80% to 30% of the dimension (46). 9. Separating floor (23) as claimed in claim 8, wherein the at least one carrier (44) is T-shaped, wherein the at least one recess (47) is arranged in the part of the carrier lying substantially perpendicular to the floor plate (29). 10. Separating floor (23) as claimed in claim 9, wherein the at least one T- shaped carrier (44) has a foot (49) arranged parallel to the floor plate (29) and with a dimension (50) of 50 mm to 100 mm, whereby the at least one recess (47) is arranged at a distance (51) less than 3 mm, in particular directly connected at the foot (49) and preferably has a width (52) of 40 mm to 120 mm. 11. Separating floor (23) as claimed in any one of claims 10, wherein the at least one carrier (44) and the at least one attachment (31) are arranged perpendicular to each other. 12. Separating floor as claimed in any one of the preceding claims, wherein it is provided at least partially with a coating (22), which has an improved glide property for fluids, compared to steel. 13. Process for purification of a polymerisable material, wherein the polymerisable material, in a column (1) with at least one separating floor (23) defined in any one of claims 1 to 12, is introduced as a material-fluid through inlet (4) and, in the inner region (5), is transferred into a material-gas phase. 14. Process as claimed in claim 13, wherein the material gas phase flows with an isotropic density against a first separating floor (23) arranged above the inlet (4), wherein within a level between the inlet (4) and the first separating floor (23) the maximum deviation about an average value of the isotropic density is at most 15%. 15. Process as claimed in claim 13 or 14, wherein the polymerisable material is (meth) acrylic acid. 16. Process as claimed in any one of claims 13 to 15, wherein there is a reduced pressure in the inner region (5). 17. Process as claimed in any one of claims 13 to 16, wherein the material- fluid is overheated. 18. Process for production of a polymerisable material, wherein the polymerisable material is synthesised from at least one reagent in a reactor and subsequently subjected to a process for purification as defined in any one of claims 13 to 17. WE CLAIM; 1. Separating floor (23) for a column (1) for distillation of a polymerisable material comprising at least one floor plate (29) with a plurality of openings (30) and at least one attachment (31), the attachment (31) divides the plurality of openings (30) into groups (32), wherein with the at least one attachment (31) apertures (33) are formed through which a fluid can flow, characterized in that the at least one attachment (31) forms sectors (40) of the floor plate (29) with respectively a group (32) of openings (30), wherein the sectors (40) comprise an area in the range from 1.2 m2 to 0.3 m2. 2. Separating floor (23) as claimed in claim 1, wherein the apertures (33) extend from the floor plate (29) over a height (34) from 1 mm to 100 mm. 3. Separating floor (23) as claimed in claim 1 or claim 2, wherein the at least one attachment (31) comprises at least one straight bar (35). 4. Separating floor (23) as claimed in claim 3, wherein it comprises at least one of the following configurations: a) more than one attachment (31) is provided with a bar (35), b) one attachment (31) is provided with more than one bar (35), preferably bar (35) joined together with each other. 5. Separating floor (23) as claimed in claim 4, wherein the at least one bar (35) has a length (36) and the more than one aperture (30) is at least partially limited by at least one of the following elements: a) at least one rod (37), which is part of the bar (35), b) at least one spacer (38), which is a separate part, wherein these elements have a width (39), and the sum of the widths (39) of the elements is smaller than 80% of the length (26) of the bar (35). 6. Separating floor (23) as claimed in any one of the preceding claims, wherein it has a cover plate (41), whereby this is preferably arranged at a separation (42) of 60 mm to 200 mm from the floor plate (29) and in particular likewise comprises a plurality of openings (30). 7. Separating floor (23) as claimed in any one of the preceding claims, wherein it comprises a holder (43), whereby the holder (43) at least comprises a solid carrier (44), which is in contact with the side (45) of the floor plate (29) facing away from the at least one attachment (31) preferably by a dimension (46) in the range from 200 mm to 1000 mm. 8. Separating floor (23) as claimed in claim 7, wherein the at least one carrier (44), near the floor plate (29), has at least one recess (47) with an extension (48), wherein the sum of the extensions (48) lies at least in the range from 80% to 30% of the dimension (46). 9. Separating floor (23) as claimed in claim 8, wherein the at least one carrier (44) is T-shaped, wherein the at least one recess (47) is arranged in the part of the carrier lying substantially perpendicular to the floor plate (29). 10. Separating floor (23) as claimed in claim 9, wherein the at least one T- shaped carrier (44) has a foot (49) arranged parallel to the floor plate (29) and with a dimension (50) of 50 mm to 100 mm, whereby the at least one recess (47) is arranged at a distance (51) less than 3 mm, in particular directly connected at the foot (49) and preferably has a width (52) of 40 mm to 120 mm. 11. Separating floor (23) as claimed in any one of claims 10, wherein the at least one carrier (44) and the at least one attachment (31) are arranged perpendicular to each other. 12. Separating floor as claimed in any one of the preceding claims, wherein it is provided at least partially with a coating (22), which has an improved glide property for fluids, compared to steel. 13. Process for purification of a polymerisable material, wherein the polymerisable material, in a column (1) with at least one separating floor (23) defined in any one of claims 1 to 12, is introduced as a material-fluid through inlet (4) and, in the inner region (5), is transferred into a material-gas phase. 14. Process as claimed in claim 13, wherein the material gas phase flows with an isotropic density against a first separating floor (23) arranged above the inlet (4), wherein within a level between the inlet (4) and the first separating floor (23) the maximum deviation about an average value of the isotropic density is at most 15%. 15. Process as claimed in claim 13 or 14, wherein the polymerisable material is (meth) acrylic acid. 16. Process as claimed in any one of claims 13 to 15, wherein there is a reduced pressure in the inner region (5). 17. Process as claimed in any one of claims 13 to 16, wherein the material- fluid is overheated. 18. Process for production of a polymerisable material, wherein the polymerisable material is synthesised from at least one reagent in a reactor and subsequently subjected to a process for purification as defined in any one of claims 13 to 17. Abstract Separating floor (23) for a column (1) for distillation of a polymerisable material, comprising at least one floor plate (29) with a plurality of openings (30) and at least one attachment (31), characterised in that the attachment (31) divides the plurality of openings (30) into groups (32), whereby with the at least one attachment (31) apertures (33) are formed through which a fluid can flow.

Documents:

2818-kolnp-2006 abstract.pdf

2818-kolnp-2006 assignment.pdf

2818-kolnp-2006 claims.pdf

2818-kolnp-2006 correspondence others.pdf

2818-kolnp-2006 description (complete).pdf

2818-kolnp-2006 drawings.pdf

2818-kolnp-2006 form-1.pdf

2818-kolnp-2006 form-2.pdf

2818-kolnp-2006 form-26.pdf

2818-kolnp-2006 form-3.pdf

2818-kolnp-2006 form-5.pdf

2818-kolnp-2006 international publication.pdf

2818-kolnp-2006 international search authority report.pdf

2818-kolnp-2006 international search report.pdf

2818-kolnp-2006 priority document.pdf

2818-KOLNP-2006-(04-07-2012)-CORRESPONDENCE.pdf

2818-KOLNP-2006-(08-09-2011)-AMANDED CLAIMS.pdf

2818-KOLNP-2006-(08-09-2011)-DESCRIPTION (COMPLETE).pdf

2818-KOLNP-2006-(08-09-2011)-DRAWINGS.pdf

2818-KOLNP-2006-(08-09-2011)-ENGLISH TRANSLATION.pdf

2818-KOLNP-2006-(08-09-2011)-EXAMINATION REPORT REPLY RECIEVED.pdf

2818-KOLNP-2006-(08-09-2011)-FORM 1.pdf

2818-KOLNP-2006-(08-09-2011)-FORM 2.pdf

2818-KOLNP-2006-(08-09-2011)-FORM 3.pdf

2818-KOLNP-2006-(08-09-2011)-FORM 5.pdf

2818-KOLNP-2006-(08-09-2011)-OTHERS.pdf

2818-KOLNP-2006-(15-12-2011)--CORRESPONDENCE.pdf

2818-KOLNP-2006-(15-12-2011)--OTHER PATENT DOCUMENT-1.pdf

2818-KOLNP-2006-(15-12-2011)--OTHER PATENT DOCUMENT.pdf

2818-KOLNP-2006-(15-12-2011)-CORRESPONDENCE.pdf

2818-KOLNP-2006-(15-12-2011)-OTHER PATENT DOCUMENT-1.pdf

2818-KOLNP-2006-(15-12-2011)-OTHER PATENT DOCUMENT.pdf

2818-KOLNP-2006-CORRESPONDENCE 1.1.pdf

2818-KOLNP-2006-CORRESPONDENCE.pdf

2818-KOLNP-2006-EXAMINATION REPORT.pdf

2818-KOLNP-2006-FORM 13.pdf

2818-KOLNP-2006-FORM 18.pdf

2818-KOLNP-2006-FORM 26 1.1.pdf

2818-KOLNP-2006-FORM 3 1.1.pdf

2818-KOLNP-2006-FORM 5 1.1.pdf

2818-KOLNP-2006-GRANTED-ABSTRACT.pdf

2818-KOLNP-2006-GRANTED-CLAIMS.pdf

2818-KOLNP-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

2818-KOLNP-2006-GRANTED-DRAWINGS.pdf

2818-KOLNP-2006-GRANTED-FORM 1.pdf

2818-KOLNP-2006-GRANTED-FORM 2.pdf

2818-KOLNP-2006-GRANTED-SPECIFICATION.pdf

2818-KOLNP-2006-INTERNATIONAL PUBLICATION 1.1.pdf

2818-KOLNP-2006-INTERNATIONAL SEARCH REPORT 1.1.pdf

2818-KOLNP-2006-OTHERS PCT FORM.pdf

2818-KOLNP-2006-OTHERS.pdf

2818-KOLNP-2006-PCT PRIORITY DOCUMENT NOTIFICATION.pdf

2818-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

2818-KOLNP-2006-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf