Title of Invention | "METHOD FOR CONVERTING AN INSTALLATION FOR HEAT TREATMENT, A GRATE CARRIAGE AND AN INSTALLATION THEREOF" |
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Abstract | Method for converting an installation for the heat treatment of finegrained substances, in particular an apparatus for drying, firing and/or sintering fine-grained raw materials to be used in the iron industry, having a travelling grate, which travelling grate is formed by a plurality of grate carriages (11) , each grate carriage (11) having a grate (14), a grate carriage body (12) arranged below it with in each case two opposite, substantially vertical longitudinal and transverse walls, and side walls (16) which extend upwards from the longitudinal sides of the grate carriage bodies (12), with the longitudinal and side walls arranged substantially flush above one another, characterized in that the grate carriage bodies (12) of each grate carriage are replaced by grate carriage bodies (12) whereof longitudinal walls are inclined outwards in the upward direction at an angle, and in which outwardly projecting gastight bearing elements (15) adjoin the longitudinal sides of the grates (14). |
Full Text | The present invention relates to method for converting an installation for heat treatment, a grate carriage and an installation thereof. The invention relates to a method for converting an apparatus for the heat treatment of fine-grained substances, in particular an apparatus for drying, firing and/or sintering fine-grained raw materials to be used in the iron industry, having a grate for receiving the substances that are to be treated, in order to increase the capacity. In apparatuses of this type, the maximum quantity of material to be treated which can be placed onto the grate is limited primarily by the height of the side walls, the grate surface area and the capacity to suck treatment gas through the bed of granular material. In principle, it is desirable to increase the capacity of heat treatment installations of this type. However, to procure a new plant with a higher capacity is disadvantageous on account of the high investment costs involved. Grate carriages for sintering installations and pellet-firing installations usually comprise in particular the following parts: the single-part or multipart grate carriage body, which is equipped, inter alia, with running rollers, the grate, which is arranged at the top side of the grate carriage body and is supported by the latter, what are referred to as the side walls, which are installed at the two longitudinal sides of the grate carriage and thereby delimit the grate, i.e. the width of the reaction surface. Beneath the grate, the grate carriage body with the reinforcing ribs and longitudinal and transverse walls which adjoin the grate approximately at right angles forms spacers (which can already be regarded as part of the suction boxes), through which the off-gas or process air is passed to the suction lines when the sintering or pellet installation is operating. To protect the transverse walls and reinforcing ribs from wear and excessive thermal loads, the upper side thereof is protected by what are known as exchangeable insulating pieces. Sealing elements, which seal off the grate carriage with respect to the pipe system connected to it in this region, are arranged at the underside of the longitudinal walls of the grate carriage. The grate is formed by individual grate bars which are mounted in the region of the top side of the reinforcing ribs and transverse walls running transversely with respect to the grate carriage longitudinal direction or in the insulation pieces which are usually arranged there. The grate carriages form the majority of the travelling grate of a travelling grate sintering machine or a travelling grate pellet-firing machine. It is attempted by converting existing installations to achieve increases in capacity at lower investment cost. For example, it is known from AT 395353 B to increase the capacity of grate carriages of a sintering installation by fitting gas-impermeable bearing surfaces between the grate and the side walls. However, it has emerged that this measure cannot increase the capacity of a grate carriage to the desired extent. Therefore, the object of the present invention is to increase the capacity of an apparatus for the heat treatment of fine-grained substances to a greater extent than would be possible by means of gasimpermeable bearing surfaces alone yet without requiring completely new investment. It has been possible to achieve this object by the conversion method according to the invention which comprises the removal of at least two opposite side walls and of at least the adjoining upper parts of at least two opposite suction box walls, fitting of upper parts of the suction box walls, which are inclined outwards in the upward direction, to the remaining lower parts of the suction box walls, fitting of gas-impermeable bearing elements, which extend further outwards in the lateral direction, to the upper parts, which are inclined outwards in the upward direction, of the suction box walls, fitting of side walls to the side edges of the gasimpermeable bearing elements, and fitting of a grate which covers the entire clear upper cross-sectional area of the suction box. Although the present invention likewise makes use of the step of fitting gas-impermeable bearing elements and the associated increase in capacity, a further crucial aspect is the conversion of the suction box, in particular the replacement of parts of the vertical suction box walls with suction box walls which are inclined obliquely outwards in the upward direction. The embodiment of the invention described above is aimed at converting an apparatus in which the suction box directly adjoins the grate beneath it. Apparatuses of this type do not usually have a travelling grate, but rather have a stationary grate, for example sintering pans. According to an advantageous embodiment, the method according to the invention is carried out in such a manner that the upper parts, which are inclined outwards in the upward direction, of the suction box walls include an angle of 30 - 60, preferably of 45°, with the vertical. According to a further advantageous embodiment, opposite suction box walls are completely removed and are replaced by suction box walls which in each case have a vertical lower part and an upper part which is inclined outwards in the upward direction. The height of the removed upper part of the suction box walls preferably amounts to 1/30 to 1/5 of the width of the grate that was originally present. In combination with the upper part of the suction box walls being inclined preferably at an angle of 45° with respect to the vertical, this ultimately widens the area through which gas can pass, likewise to an extent of 1/30 to 1/5 of the width of the grate that was originally present. The width of the gas-impermeable bearing elements preferably likewise amounts to 1/30 to 1/5 of the width of the grate that was originally present. Overall, the combination of the two measures widens the grate by 10 to 40%. These details apply to grate carriages with a width of, for example, 4 m, which have been widened to 5 m by the method according to the invention. In some cases, the widening that can be achieved may be even greater. A further embodiment of the method according to the invention is aimed at the conversion of an installation with a travelling grate. Installations of this type, which were described in the introduction, form the majority of the capacity of sintering or pellet-firing installations. Therefore, this further embodiment of the method according to the invention relates to a method for converting an installation for the heat treatment of fine-grained substances, in particular an apparatus for drying, firing and/or sintering fine-grained raw materials to be used in the iron industry, having a travelling grate, which travelling grate is formed by a plurality of grate carriages, each grate carriage having a grate, a grate carriage body arranged below it with in each case two opposite, substantially vertical longitudinal and transverse walls, and side walls which extend upwards from the longitudinal sides of the grate carriage bodies, with the longitudinal and side walls arranged substantially flush above one another. In this further embodiment of the method according to the invention, the object which is set in accordance with the invention is achieved by the fact that the grate carriage bodies of each grate carriage are replaced by grate carriage bodies whereof longitudinal walls are inclined outwards in the upward direction at an angle, and in which outwardly projecting gastight bearing elements adjoin the longitudinal sides of the grates. The terms "longitudinal" and "transverse" relate to the movement of the grate carriage when the installation is operating. "Longitudinal walls" or "longitudinal sides" are arranged parallel to the direction of advance of the grate carriage, while "transverse walls" are arranged at a right angle to the direction of advance of the grate carriage. The design of the novel grate carriage according to the invention differs from the grate carriage which has previously been designed as standard in particular by virtue of the following features: the longitudinal walls of the grate carriage body are inclined obliquely outwards in the upward direction at an angle of preferably approx. 45° with respect to the vertical. The width of the grate is delimited by the uppermost part of the longitudinal walls, which are inclined obliquely outwards in the upward direction, of the grate carriage body. Outwardly projecting, gastight surfaces which each have a width of up to 350 mm adjoin the two longitudinal sides of the grate. What are known as the side walls of the grate carriage, which delimit the width of the reaction area, adjoin the outer longitudinal sides of the gastight surfaces. The position of the running rollers and of the longitudinal seals can remain unchanged at the same distance from the side walls (= grate carriage width) compared to conventional grate carriages. Therefore, the invention also relates to grate carriages having a grate carriage body, which is formed by in each case two opposite longitudinal and transverse walls, a grate arranged at the top side of the grate carriage body and having two opposite side walls which extend upwards from the longitudinal sides of the grate carriage bodies. The grate carriages according to the invention achieve the object which is set in accordance with the invention by virtue of the fact that the longitudinal walls of the grate carriage body are inclined outwards at an angle in the upward direction, and that outwardly projecting, gastight bearing elements adjoin the longitudinal sides of the grate. The invention also relates to an installation for the heat treatment of fine-grained substances, in particular an apparatus for drying, firing and/or sintering fine-grained raw materials to be used in the iron industry, having a travelling grate, in which the travelling grate is formed by a plurality of grate carriages according to the invention. The novel grate carriages according to the invention have a number of advantages for sintering and pelletfiring installations: the width of a building required for the installation of a sintering machine or pellet-firing machine can be significantly reduced than when using a grate carriage of the same grate carriage width, allowing considerable savings to be made on the investment costs. The capacity of an existing sintering or pellet installation can be increased by up to approx. 40% by the installation of the novel grate carriages according to the invention, depending on the original grate carriage width, without the building in which the sintering machine or the pellet-firing machine is installed having to be altered, without the adjoining suction or pressure system, the position of the running rails and the design of the supporting structure having to be altered, and with the capacity of the suction and pressure system only having to be increased in proportion to the increased grate surface area (without the gastight surface area which is additionally formed by the gastight plates). To convert sintering installations in order to increase the capacity by installing the novel grate carriages, these installations only have to be shut down for a short time (approximately 2 weeks). The specific off-gas quantity (m3 (s.t.p.)/t of sintered product) in the sintering installation or the specific process quantity (m3(s.t.p)/t of pellets) in the case of the pellet-firing installation is significantly reduced. In the text which follows, the invention is explained in more detail by means of the diagrammatic illustrations presented in Fig. 1 to Fig. 3 of the drawings. In the drawing, Fig. 1 shows a vertical section through an apparatus prior to conversion, without any of the parts which are not pertinent to the invention, such as for example the sealing of the blower box, etc., being illustrated. The apparatus of the prior art illustrated in Fig. 1 has a suction box 2, which is formed by suction box walls 3 that extend downwards to the sides of the grate 1 and to which a suction fan (not shown) is connected. The suction fan sucks hot treatment gas through the bed 4 of fine-grained substances and the grate 1 from the top downwards. Side walls 6 which extend upwards and, as illustrated in the drawing, vertically, or may also be inclined outwards, adjoin the grate 1 at the two side edges 5. For the conversion method according to the invention, first of all the side walls 6 and usually also the grate 1 are removed. Then, an upper part of the suction box walls 3 is removed and the suction box walls 3 (Fig. 1) are shortened to form suction box walls 3a (Fig. 2). Then, parts 3b which are inclined outwards in the upward direction are secured to the lower parts of the suction box walls 3a, for example by welding. Then, gas-impermeable bearing elements 8, which are located approximately at the height of the grate 1, are secured to the side edges 7 of the parts 3b which are inclined outwards in the upward direction. The gas-impermeable bearing elements 8 do not necessarily have to be designed as plates, but rather may also, for example, be triangular in cross section. The side walls 6 which were initially removed are then refitted to the side edges 9 of the bearing elements 8. Finally, a grate 10 is put in place, which grate has either been produced by increasing the size of the grate 1 or may have been purchased new. The conversion method according to the invention has increased the original width A of the grate 1 by in each case double the lengths, projected into the horizontal, of the parts 3b which are inclined outwards in the upward direction (width B) and by double the width C of the gas-impermeable bearing elements 8. The embodiment illustrated in Fig. 3 shows a grate carriage 11 according to the invention in the form of a cross section through a sintering installation with travelling grate. The grate carriage 11 has a grate carriage body 12 which is equipped with running wheels 13. Above this is a grate 14 with gas-impermeable bearing elements 15 fitted to its longitudinal sides. Side walls 16 are arranged to the side of the gasimpermeable bearing elements 15. Beneath the grate carriage body 12 is a fixed suction box 17. The grate carriage body 12 illustrated in the figure has longitudinal walls which are inclined outwards in the upward direction at an angle of 45° with respect to the vertical. This has increased the original suction surface width D to the new suction surface width E. The gas-impermeable bearing elements 15 have increased the overall grate carriage width further, specifically to the new grate carriage width F. We claim: 1. Method for converting an installation for the heat treatment of finegrained substances, in particular an apparatus for drying, firing and/or sintering fine-grained raw materials to be used in the iron industry, having a travelling grate, which travelling grate is formed by a plurality of grate carriages (11) , each grate carriage (11) having a grate (14), a grate carriage body (12) arranged below it with in each case two opposite, substantially vertical longitudinal and transverse walls, and side walls (16) which extend upwards from the longitudinal sides of the grate carriage bodies (12), with the longitudinal and side walls arranged substantially flush above one another, characterized in that the grate carriage bodies (12) of each grate carriage are replaced by grate carriage bodies (12) whereof longitudinal walls are inclined outwards in the upward direction at an angle, and in which outwardly projecting gastight bearing elements (15) adjoin the longitudinal sides of the grates (14). 2. Grate carriage (11) having a grate carriage body (12), which is formed by in each case two opposite longitudinal and transverse walls, a grate (14) arranged at the top side of the grate carriage body (12) and having two opposite side walls (16) which extend upwards from the longitudinal sides of the grate carriage bodies, characterized in that the longitudinal walls of the grate carriage body (12) are inclined outwards at an angle in the upward direction, and in that outwardly projecting, gastight bearing elements (15) adjoin the longitudinal sides of the grate (14). 3. Grate carriage as claimed in claim 2, wherein the longitudinal walls of the grate carriage body (12) are inclined outwards in the upward direction at an angle of substantially 45° with respect to the vertical. 4. Grate carriage as claimed in claim 2 or 3, wherein the outwardly projecting, gastight bearing elements (15) are up to 350 mm wide. 5. Installation for the heat treatment of fine-grained substances, in particular an apparatus for drying, firing and/or sintering fine-grained raw materials to be used in the iron industry, having a travelling grate, characterized in that the travelling grate is formed by a plurality of grate carriages (11) according to one of claims 2 to 4. |
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5424-delnp-2006-Abstract-(29-05-2009).pdf
5424-delnp-2006-Claims-(29-05-2009).pdf
5424-DELNP-2006-Correspondence-Others-(02-12-2009).pdf
5424-delnp-2006-Correspondence-Others-(29-05-2009).pdf
5424-delnp-2006-correspondence-others.pdf
5424-delnp-2006-Description (Complete)-(29-05-2009).pdf
5424-delnp-2006-description (complete).pdf
5424-delnp-2006-Drawings-(29-05-2009).pdf
5424-delnp-2006-Form-1-(29-05-2009).pdf
5424-delnp-2006-Form-2-(29-05-2009).pdf
5424-delnp-2006-GPA-(29-05-2009).pdf
Patent Number | 241733 | |||||||||
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Indian Patent Application Number | 5424/DELNP/2006 | |||||||||
PG Journal Number | 31/2010 | |||||||||
Publication Date | 30-Jul-2010 | |||||||||
Grant Date | 22-Jul-2010 | |||||||||
Date of Filing | 19-Sep-2006 | |||||||||
Name of Patentee | VOEST-ALPINE INDUSTRIEANLAGENBAU GMBH & CO. | |||||||||
Applicant Address | TURMSTRASSE 44, A-4031 LINZ, AUSTRIA. | |||||||||
Inventors:
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PCT International Classification Number | F27B 21/02 | |||||||||
PCT International Application Number | PCT/EP2005/002428 | |||||||||
PCT International Filing date | 2005-03-08 | |||||||||
PCT Conventions:
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