Title of Invention

A MIXING DEVICE FOR PRODUCING FINELY DIVIDED DISPERSION OF FLUIDS

Abstract

57) Abstract:- This invention provides a mixing device for producing finely divided dispersion of fluids comprises a turbulence chamber having a diameter of 0.5 mm to !0 mm, at least one inlet nozzle having a bore diameter of 0.05mm to 1.0 mm and at least one outlet nozzle, having a diameter of 0.05 mm to 1.5 mm, the said at least one inlet nozzle and the said at least one outlet nozzle being pressed in sequence in a cylindrical support such that the axes of the bores of the inlet nozzle and the outlet nozzle are arranged parallel to one another.

Full Text

The present invention relates to a mixing device for producing finely divided dispersion of fluids. European Patent Publication EP 0776 997 Al describes a method for the production of a finely divided dispersion of solids in which a pre-dispersion is pumped through one or more slotted nozzles. The particle size of the dispersed phase lies in the region of 0.01 μm to 20μm. The diameter of the nozzle bore is 0.05 mm to 1 mm. The ratio of bore length to bore diameter is 1:1 to 1:10. A preferred combination comprises a device which has two nozzle bodies with the nozzles lying opposite their outlet. Also described are devices in which the crude dispersion or pre-dispersion is pumped through two or more nozzles having an equal or decreasing bore diameter. The slotted nozzle suitably consists of a ceramic material, for example, of zirconium oxide, or of metal coated with ceramic. In International Patent Publication WO 97/17946 there is described a method for the production of a liposome dispersion in which an aqueous pre-dispersion of one or more amphiphilic substances is pumped at 600 bar to 900 bar through at least one homogenizing nozzle having a diameter of 0.1 mm to 0.5 mm. The homogenizing nozzle has an inlet channel and an outlet channel and consists of a hard ceramic plate, in which the bore is situated, pressed in a steel body. The inlet channel and the outlet channel are also incorporated in the steel body. When several nozzles are used, these are arranged opposite and have a parallel inflow. The pre-dispersion is pumped in the circuit through the homogenizing nozzle until the average particle size of the liposome dispersion lies between about 35 nm and about 80 nm. The problem which forms the basis of the present invention is to provide a method for mixing or dispersing liquids which permits an improved intermixing with lower energy expenditure compared with the state of the art. The problem is solved in accordance with the invention by pumping the liquids to be mixed or to be dispersed at temperatures of about 20' C to about 250"C, preferably of about 20'C to about 200°C, and pressures of about 50 bar to about 2500 bar, preferably of about 100 bar to about 800 bar, through a mixing device which consists of one or more inlet nozzles, one or more turbulence chambers and one or more outlet nozzles, with the inlet nozzle(s), turbulence chamber{s) and outlet nozzle(s} being pressed in sequence in a cylindrical support and the axes of the bores of the inlet nozzle and the outlet nozzle being arranged axially to one another. The process is especially suitable for the production of finely divided dispersions having average particle sizes of about 10 nm to about 1000 nm, preferably of about 50 nm to about 400 nm. For the production of liquid dispersions, a pre-emulsion is pumped at temperatures of about 20°C to about 250 C, preferably of about 20°C to about 200°C, and pressures of about 50 bar to about 2500 bar, preferably of about 100 bar to about 800 bar, through the aforementioned mixing device (dispersing unit}. The residence time of the liquids to be mixed or to be dispersed in the mixing device is about 10-6 sec to about 10"' sec. The term "pre-emulsion" denotes one of the following systems; a) oil-in-water emulsion (0/W emulsion), b) water-in-oil emulsion (W/0 emulsion), c) oil in-water emulsion in which a lipophilic active substance is dissolved in the oil, d) water-immiscible solvent-in-water emulsion in which a lipophilic active substance is dissolved in this solvent. An oil-in-water emulsion in which the viscosity of the dispersed phase is about 0.01 mPas to about 10,000 mPas, preferably about 0.1 mPas to about 2000 mPas, is preferred. The term "lipophilic active substance" embraces the vitamins A, D, E and K, carotenoids or food additives such as PUFAs (polyunsaturated fatty acids) and tocotrienols. Advantageously, for the production of the pre-emulsion the liquid to be dispersed is stirred into an aqueous emulsifier solution, optionally while warming. Processes for the production of finely divided liquid dispersions relate not only to processes used in the food manufacturing field and in which corresponding food emulsifiers are used, but also to general industrial dispersion processes in which corresponding industrial emulsifiers are used. Processes which are used in the food manufacturing field are preferred. Suitable emulsifiers/stabilizers for dispersions which can be added to foods are, for example, ascorbyl palmitate, lecithins, polysorbates, sugar esters, fatty acid esters, citric acid esters, sorbitol iterates; as well as colloids, for example gelatines and fish gelatins; carbohydrates, for example starches and starch derivatives such as dextrin, pectin or gum arable; milk proteins and plant proteins. Mixtures of the aforementioned substances can also be used. Ascorbyl palmitate, fish gelatines or starch derivatives are preferred, with ascorbyl palmitate being especially preferred. Suitable industrial emulsifiers are, for example, lauryl ethylene oxide (LE0)-9 and (LEO)-IO. The method in accordance with the invention is especially suitable for the production of liquid dispersions from oils, such as, for example, corn oil, palm oil, sunflower oil and the like; and liquid dispersions from lipophilic active substances, such as, for example, from vitamin A, D, E and K, from carotenoids or from food additives such as PUFAs and tocotrienols. Suitable arytenoids are, for example, beta-carotene, beta-apo-4'-carotenal, beta-apo-8'-carotenal, beta-apo-12'-carotenal, beta-apo-8'-carotenoic acid, astaxanthin, canthaxanthin, zeaxanthin, cryptoxanthin, citranaxanthin, lute in, lycopene, torularodin aldehydes, torularodin ethyl ester, neurosporaxanthin ethyl ester, zeta carotene, dehydroplectania-xanthin and the like. The aforesaid lipophilic active substances can be used directly insofar as they are oily substances. Solid active substances, for example carotenoids, are used in dissolved form in oil or in water-immiscible solvents. Suitably water-immiscible solvents are halogenated aliphatic hydrocarbons such as e.g. methylene chloride, water-immiscible esters such as carix)xylic acid dimethyl ester (dimethyl carbonate), ethyl formate, methyl, ethyl or isopropyl! acetate; or water-immiscible ethers such as e.g. methyl tert ether and the like. The process in accordance with the invention provides a very efficient mixing or dispersing process for liquids. The mixing or dispersing process in accordance with the invention is also suitable for performing chemical reactions having very short reaction times, in the region of seconds or fractions of seconds. The mixing device in accordance with the invention has, in contrast to the known devices described hereinbefore, an arrangement of the bores of the inlet and oudet nozzles which is axial to one another. Thereby and by the tarbalcnce chamber positioned between the nozzles; the short term stability of mixtures, especially of dispersions, is increased. This results in the liquid dispersion being homogenized more strongly. Accordingly the present invention provides a mixing device for producing finely divided dispersion of fluids comprising a turbulence chamber having a diameter of 0.5 mm to ] 0 mm, at least one inlet nozzle having a bore diameter of 0.05mm to 1.0 mm and at least one outlet nozzle, having a diameter of 0.05 mm to 1.5 mm. the said at least one inlet nozzle and the said at least one outlet nozzle being pressed in sequence in a cylindrical support such that the axes of the bores of the inlet nozzle and the outlet nozzle are arranged parallel to one another. The invention will be illustrated hereinafter on the basis of the Figures in the accompanying drawings. Fig. 1 shows a flow scheme of an arrangement for perturbing the method in accordance with the invention. Fig. 2 shows a cross section through a mixing device in accordance with the invention having an inlet nozzle and an outlet nozzle, Fig. 3 shows a perspective view of the mixing device in accordance with the invention. Fig. 4 shows a possibility of a scale-up arrangement, Fig. 5 shows a further possibility of a scale-up arrangement. In Fig. 1 a supply container (1) is followed by a high pressure pump (2) which is optionally connected to a heat exchanger (3), The mixing device (4) is positioned thereafter. Fig. 2 and Fig. 3 show a mixing device (4) consisting of an inlet nozzle (6) having a bore diameter of about 0.05 mm to about 1 mm, preferably about 0.05 mm to about 0.5 mm; a turbulence chamber (7) having a diameter of about 0.5 mm to about 10 mm, preferably about 1 mm to about 10 mm, especially about 1 mm to about 5 mm; an outlet nozzle (8) having a bore diameter of about 0.05 mm to about 1.5 mm, preferably about 0.05 mm to about 0,8 mm, with the inlet nozzle (6), the turbulence chamber (7) and the outlet nozzle (8) being pressed in sequence in a cylindrical support (5). The axes of the bores of the inlet nozzle and the outlet nozzle are arranged axially to one another. The ratio of length to diameter of the nozzle bore amounts in the case of the inlet nozzle or the outlet nozzle to about 1 to 10, preferably about 1 to 5. The ratio of length to diameter of the turbulence chamber is about 0.5 to about 50, preferably about 0,5 to about 20, especially about 0.5 to about 10. The diameter of the turbulence chamber must be greater than the diameter of the outlet nozzle. The bore diameters of the inlet nozzle and the outlet nozzle can be the same or different. However, an embodiment in which the bore diameter of the inlet nozzle is smaller than the bore diameter of the outlet nozzle is preferred. For example, the bore diameter of the inlet nozzle is about 0,2 mm and the bore diameter of the outlet nozzle is about 0.25 mm. The nozzles are suitably manufactured from wear-resistant materials such as e.g. sapphire, diamond, stainless steel, ceramic, silicon carbide, tungsten carbide, zirconium or the like. The bores of the nozzles can be round or rectangular or can have the form of an ellipse, A bore which has a cone in the mouth is also suitable. The support (5) likewise consists of wear-resistant materials, suitably of stainless steel. Fig. 4 shows one possibility for the scale-up of the mixing device (4). Section 4a shows a plurality of nozzles in accordance with the invention with insert (11), which are screwed into a support plate (10). The support plate is positioned in a conduit (9). Cross section 4b shows only one nozzle insert (11'). The nozzle insert (11'), the support plate (10) as well as the conduit (9) are manufactured from wear-resistant materials, preferably stainless steel. Section 4c shows the screwable nozzle support (11") which contains the nozzie in accordance with the invention. Fig. 5 shows a further scale-up possibiHty. The mixing device consisting of a support disk (12), a turbulence chamber (13) and a support disk (14), which are positioned in sequence in a tubular conduit (15), with the first support disk (12) containing a plurality of inlet nozzles (16) having a bore diameter of about 0.05 mm to about 1 mm, preferably about 0.05 mm to about 0.5 mm, and the second support disk (14) containing a plurality ofoutlet nozzles (17) having a bote diameter of about 0.05 mm to about 1 mm, preferably about 0.05 mm to about 0.8 mm. The axes of the nozzles (16) and (17) are arranged axially to one another. Thenumber of nozzles determines the diameter of the turbulence chamber (13). The ratio of length to diameter of the turbulence chamber is designed such that the residence time of the liquid to be dispersed in the dispersing unit is about 10"^ sec to about 10' sec. For the production of a finely divided liquid dispersion, set forth in Fig. 1, a pre-emulsion is firstly produced in the supply container (1) in a known manner and pumped through the dispersing unit (4) at temperatures of about 20°C to about 250'C, preferably about 20'C to about 200*'C, and pressures of about 50 bar to about 2500 bar, preferably about 50 bar to about 800 bar, using a high pressure pump (2). Where required, the pre-emulsion can be heated for a brief period in the heat exchanger (3). The residence time of the liquid to be dispersed in the dispersing unit is about 10"^ sec to about 10' sec. The following Examples illustrate the invention in more detail, but are not intended to limit its scope. In the Examples there was also used, in addition to the food emulsifier ascorbyl palmitate, the industrial emulsifiers lauryl ethylene oxide (LE0)-9 and (LEO)-IO. This is a so-called "more rapid" emulsifier which very rapidly stabilizes newly formed phase boundaries. Example 1: Corn oil and laurvl ethylene oxide The emulsion had the following composition: 87 wt.% deionized water, 10 wt.% corn oil and 3 wt.% lauryl ethylene oxide-9. Deionized water was placed in a ketde and warmed to 40C. The emulsifier lauryl ethylene oxide (LE0)-9 was dissolved in the water. Subsequently, the corn oil was stirred in and comminuted with an Ultra Turrax mixer at 1000 rpm. When the content of dispersed phase was 10 wt.%, the weight ratio of corn oil to lauryl ethylene oxide was I0;3. The pre-emuision was homogenized three times at a pressure of 600 bar using the dispersing unit according to Fig. 2 in accordance with the invention. The geometric dimensions of the dispersing units used are given in Table I. The particle sizes were determined in a known manner by means of photon correlation spectroscopy. Example 2: Corn oil and ascorbyl palmitate. Here, ascorbyl palmitate was used as the emulsifier. The quantitative composition of the emulsion corresponded to that in Example 1. Deionized water was placed in a kettle and warmed to 40°C, Ascorbyl palmitate was dissolved in the water at pH values between seven and eight. The production of the pre-emulsion and the homogenization were carried out according to Example 1. Example 3: dl-alpha-TocopheroI and ascorbyl palmitate. Example 3 was carried out in accordance with Example 2. Example 4: dl-alpha-Tocopherol and ascorbyl paimitate A pre-emulsion was produced in accordance with Example 2. The content of dispersed phase was 30 wt.%. The weight ratio of dl-alpha-tocopherol to ascorbyl palmitate was 10:1. The pre-emulsion was homogenized once at pressures of 100 bar, 200 bar, 300 bar, 400 bar and 500 bar using the dispersing unit in accordance with the .nvention shown in Fig. 2. Example 5: dl-alpha-Tocopherol. corn oil with ascorbyl palmitate and fish gelatine An emulsion comprising 65 wt.% deionized water, 6 wt.% ascorbyl palmitate, 4 wt,% fish gelatine, IS wt.% dl-alpha-tocopherol and 7 wt.% corn oil was produced in the manner described hereinafter. The deionized water was placed in a kettle and warmed to 60"C. The fish gelatine was dissolved in the water. Then, the ascorbyl palmitate was dissolved in the aforementioned solution at pH values between seven and eight. Subsequently, the dispersed phase consisting of dl-alpha-tocopherol and corn oil was stirred in as described in Example 1, The pre-emu!sion was homogenized in accordance with Example 4. Examples 6-10 aie comparative Examples using a single-hole nozzle. Example 6: Corn oil and lauryl ethylene oxide The pre-emuision was produced in accordance with Example 1 and homogenized three times at a pressure of 600 bar in a single-hole nozzle, said single-hole nozzle referring to a nozzle having an acute angled inlet and outlet. The geometric dimensions of the single-hole nozzle are given in Table 1. Example 7: Corn oil and ascorbyl palmitate The pre-emulsion was produced in accordance with Example 2 and homogenized in the manner described in Example 6. Example 8: dl-alpha-Tocopherol and ascorbyl palmitate The pre-emulsion was produced in accordance with Example 3 and homogenized in the manner described in Example 6. Example 9: dl-apha-Tocopherol and ascorbyl palmitate The pre-emul.sion was produced in accordance with Example 4 and homogenized once in a single-hole nozzle as described in Example 6 at pressures of 100 bar, 200 bar, 300 bar, 400 bar and 5QQ bar. The particle size was determined in a known manner by means of laser diffraction spectrometry and photon correlation spectroscopy. From Table I it will be evident that the homogenization using nozzles 1 and 11 in accordance with the invention gives a hquid dispersion with a smaller particle size compared with the homogenization using a single-hole nozzle. When nozzles I and I! are used, particle sizes up to a third smaller are produced compared with the single-hole nozzle. The best homogenization takes place in nozzle I. Here, the particle size was reduced to 200 nm after a triple homogenization. The values from Example 1 reveal that the reproducibility of the results is also good. The average particle sizes of the finely divided liquid dispersions obtained in Examples 4,5,9 and IQ are set forth in Table 3. WE CLAIM: 1. A mixing device for producing finely divided dispersion of fluids comprising a turbulence chamber (7) having a diameter of 0.5 mm to 10 mm, at least one inlet nozzle (6) having a bore diameter of Opossum to 1.0 mm and at least one outlet nozzle (8), having a diameter of 0,05 mm to 1.5 mm, the said at least one inlet nozzle (6) and the said at least one outlet nozzle (8) being pressed in sequence in a cylindrical support (5) such that the axes of the bores of the inlet nozzle and the outlet nozzle are arranged parallel to one another. 2. The device as claimed in claim 1, wherein the bore diameter of the inlet nozzle (6) is 0.05 mm to 0,5 mm, the diameter of the turbulence chamber (7) is 1 mm to 10 mm. and the bore diameter of the outlet nozzle (8) is 0.05 mm to 0.8 mm. 3. The device as claimed in claim 2, wherein the diameter of the turbulence chamber (7) is 1 mm to 5 mm. 4. The device as claimed in any one of the claims i to 3, wherein the bore diameter of the inlet nozzle (6) is smaller than the bore diameter of the outlet nozzle (8). 5. The device as claimed in any one of the claims 1 to 4, wherein the inlet nozzle and outlet nozzle are manufactured with a material selected from sapphire, diamond, stainless steel, ceramic, silicon carbide, tungsten carbide or zirconium oxide. 6. The device as claimed in any one of the claims 1 to 5, wherein the ratio of length to diameter of the nozzle bores in the inlet nozzle and the outlet nozzle is I to 10, and preferably 1 to 5. 7. The device as claimed in any one of the claims 1 to 6, wherein the ratio of length to diameter of the turbulence chamber is 0.5 to 50, preferably 0.5 to 20 preferably 0.5 to 10. 8. The device as claimed in any one of the claims 1 to 8, wherein the diameter of the turbulence chamber is greater than the diameter of the outlet nozzle. 9. The mixing device as claimed in claim 1, wherein plurality of inlet nozzles (16) and plurality of outlet nozzles (17) are provided. 10.The mixing device as claimed in claim 9 wherein the plurality of inlet and outlet nozzles (16,17)are provided with an insert(ll) screwed into a support plate (10, 12) and the support plate (10,12) is positioned in a conduit (9,15). 11.The mixing device as claimed in claim I wherein the support disk (12), the turbulence chamber (13) and support disks (12,14) are positioned in sequence in a conduit (15), the first support disk (12) containing a plurality of inlet nozzles (16) having a bore diameter of 0.05 mm to 1 mm, preferably 0.05 mm to 0.5 mm, and the second support disk (14) containing a plurality of outlet nozzles (17) having a bore diameter of 0.05 mm to 1 mm, preferably 0.05 mm to 0.8 mm, the axes of the inlet nozzles (16) and outlet nozzles (17) being arranged parallel to one another. 12.A mixing device for producing tlnely divided dispersion of fluids substantially as herein described with reference to the accompanying drawings.

Documents:

1175-mas-1999 abstract.pdf

1175-mas-1999 claims.pdf

1175-mas-1999 correspondence-others.pdf

1175-mas-1999 correspondence-po.pdf

1175-mas-1999 description (complete).pdf

1175-mas-1999 drawings.pdf

1175-mas-1999 form-1.pdf

1175-mas-1999 form-26.pdf

1175-mas-1999 form-3.pdf

1175-mas-1999 form-4.pdf

1175-mas-1999 form-5.pdf

1175-mas-1999 petition.pdf