WO2014109671A1 - Charging and distributing device for shaft furnaces for calcining lump material - Google Patents

Abstract

The present invention relates to charging and distributing devices for shaft furnaces for calcining lump material, predominantly limestone, and can be used in the metallurgical, building, chemical and food industries. The device contains a charge hopper having a vertical feeder-pipe passing through the furnace roof, and a discharging apparatus, positioned under said feeder-pipe with a gap therebetween and connected by means of brackets to a sleeve that coaxially encompasses the feeder-pipe. The discharging apparatus and the charge hopper are provided with individual drives, configured to enable adjustment of their relative speed and direction of rotation. Hollow, radially-oriented troughs of varying lengths are provided, facing radially, in the discharging apparatus, for uniformly discharging lump material across the cross section of the furnace. The technical result of the present invention consists in providing for the uniform distribution, according to particle size, of lumps of material to be fired across the cross section of a furnace.

Description

 Shaft furnace loading and distribution device

 for firing bulk material.

The invention relates to loading and distributing devices of shaft furnaces for firing bulk material, mainly limestone, and can find application in metallurgical, construction, chemical, food and other industries that use quicklime.

 Of great importance in the production of high-quality quicklime in shaft kilns is the uniform distribution of large and small pieces over the cross section of the shaft, as well as the continuity of their loading into the furnace, which is ensured mainly by the design of the loading and distribution devices.

 To solve this problem, a significant number of various loading and distribution devices of shaft furnaces have been created, but so far it has not been possible to completely eliminate the problem of ensuring uniform distribution of material by size and continuity of loading.

 The fact is that due to the effect of segregation of pieces of falling material for its uniform distribution by size over the mine section, it is necessary to complicate the design of the mentioned loading and distribution devices, and this, in turn, leads to the complication of the shaft furnace as a whole. In addition, the applied structures mainly provide cyclic discharge of material into the furnace using tambours. Therefore, the creation of the proposed simplified loading and distribution device that provides uniform distribution by size of bulk material over the furnace cross section and its continuous loading into the furnace is an objectively necessary technical solution.

It is well known loading and distributing device of a shaft furnace for firing lump material, designed for uniform distribution of large and small fractions of raw materials over the cross section of the shaft and its sealing during loading, which consists of a housing, a rotary receiving hopper (bowl) with a rotation drive and a two-valve shutter, equipped with rotary and lifting mechanisms. Raising and lowering the valves is carried out by ropes passed through the differential blocks. The roller clutch serves to prevent the lower valve from turning when the hopper rotates with the upper valve. The bottom valve is helical scattering cone with two baffle plates and when lifting is rotated by a predetermined angle. When the rod moves down, the protrusion on it slides in a spiral slot and rotates the rod with a scattering cone. The rotation of the rod is fixed with a ratchet mechanism. The rotation drive of the receiving hopper includes an electric motor with a gearbox, on the shaft of which a bevel gear is mounted, which in turn provides rotation of the ring gear meshed with the pinion gear rigidly mounted on the surface of the receiving hopper (see A.V. Monastyrev, R. F. Galiakhmetov "Furnaces for the production of lime", Voronezh, "Sources", 2011., S. 29-30). The main disadvantages of this device, as follows from the source of information, are its structural complexity, due to the presence of a large number of movable mechanical units and elements, as well as the uneven distribution of material over the mine cross section. In addition, its high specific metal consumption, complexity of manufacturing and operation are noted. The furnace is loaded in batches, which leads to fluctuations in the temperature of the exhaust gases and the aerodynamic drag of the furnace.

Various rotary trough loading and distribution devices that are used in shaft furnaces for more or less evenly distributing bulk material over the furnace cross-sectional surface are also known. The gutter has a channel with a concave rounded surface, along which material loaded into it is poured into the furnace. The gutter is pivotally fixed to the rotor, which rotates around the vertical axis and can rotate around the horizontal axis of the suspension with a change in the slope of its loading valve. The rotation of the rotor around the vertical axis and the simultaneous change in the inclination of the gutter using a rotating rotation mechanism make it possible to distribute bulk material onto the loading surface inside the furnace along a spiral path. Loading and distributing devices of a similar design are described, for example, in patents B 5022806, RU 2127318, RU 2208207 and other similar inventions. In these known devices having a rotating pivot chute, the pivot mechanism that is used to tilt the channel of the chute transmits significant pivotal moments to the rotating chute. A cantilevered gutter several meters long requires effective protection against wear and exposure to high temperatures and, therefore, has a very large mass, which necessitates the creation of large turning torques by the turning mechanism, during transmission of which to the rotating gutter many technical problems, the elimination of which significantly increases the cost of these loading and distribution devices.

 The distribution and distribution devices discussed above do not coincide with the proposed not only structurally, but also differ in the principle of distribution of the loaded material into the shaft furnace.

 Also known is a loading and distributing device of a shaft furnace for burning lump material, which contains a rotating funnel, a receiving hopper having locking devices, a cone-divider, consisting of small and truncated cones. The cone-divider is connected to a movable mechanism. The truncated cone has a fixed shell in which the windows are made. The fixed shell is provided with an internal movable shell. The width of the windows is 2-3 diameters of the largest piece of carbonate raw material. The inner shell, made with similar windows, is installed with the possibility of rotation around the axis, and can be made without windows, but installed with the ability to move vertically. The constructive construction of this device also determines its principle of concentric alternating fractions of the distribution of the size of the pieces of the loaded material over the entire cross section of the shaft furnace, i.e. a large fraction of the feed falls mainly to the periphery and somewhat into the middle part, while the small fraction is distributed in the center of the furnace cross section (see USSR Copyright Certificate, Jfel 295174, F27B 1/20, published March 7, 1987, Bulletin No. 9). However, this loading and distribution device of the shaft furnace, as can be seen from the description of the invention, does not provide a complete uniform fractional distribution of the loaded material over the entire cross section of the shaft furnace, which can lead to the burning of large fractions and burning of small fractions at the same temperature of limestone treatment lower quality of finished quicklime. And although this device coincides with the claimed functional purpose, namely, loading and distribution of carbonate raw materials into the shaft furnace and partly the principle of distributing it over the cross section of the shaft, in general, for the rest, they have a fundamentally different design, so this analogue cannot be adopted as a full-fledged prototype of the claimed invention.

The problem of eliminating the disadvantages of the analogue is solved by creating a new loading and distribution device of a shaft furnace of a different design and a different operating principle, which achieves a higher technical result, that is, a more uniform distribution of the processed material by size over the entire cross section, since the material is preliminarily mixes up and over The gutters rotating with the table are continuously delivered to the destination areas.

 The technical result is a simplification of the design of the loading and distribution device, continuous loading and increasing the uniformity of the distribution of material by size over the cross section of the shaft furnace is achieved by the fact that the device contains a loading hopper with a vertical, preferably cylindrical, flow, passed through the arch of the furnace, and an unloading table located with gap under this estrus. The specified unloading table is connected by brackets with a sleeve coaxially covering the heat of the loading hopper. In this case, the unloading table and the loading hopper are equipped with individual drives for their rotation, and the unloading table has hollow radially directed grooves for unloading bulk material into the furnace. The gutters are made of different lengths, and some of them are directed towards the walls of the furnace, while others are directed to its center. Of great importance for the uniform distribution of material by size over the furnace cross section is the fact that individual drives are made with the possibility of controlling the speed and changing the direction of their rotation, and their constituent elements are rigidly fixed to the outer surfaces of the hopper and sleeve estrus and connected through transmission links to motors, for example with gear motors. To ensure consistent rotation, smoothness and ease of movement of the loading hopper relative to the unloading table, respectively, their components - estrus and sleeve are equipped with individual bearings installed with the girth of their outer walls above the furnace arch, while the bearings are connected to the furnace arch, to each other and estrus at the same time.

 The present invention is novel, since the totality of the features of its formula by the applicant in the sources of patent and general technical information has not been found, and the general layout of the device is new, since it coincides with the found analogues only functionally and significantly differs constructively.

 The loading and distribution device, as a technical solution, has an inventive step, since the composition of its structural elements and its new layout, reflected in the claims as signs, are not obvious, which is confirmed by the absence of a prototype close in design.

The industrial applicability of the invention is not in doubt, since large-sized bearings, gear motors are manufactured by industry, and the manufacture of gearing of the crown wheel with the drive shaft gear, the hopper bodies and the unloading table can be performed using widely known technological processes of metalworking, bending and welding production.

 The invention is illustrated by drawings, in which Fig. 1 shows a general three-dimensional view of a loading and distribution device, Fig. 2 shows a longitudinal section along AA in Fig. 1, Fig. 3 is a transverse section along BB of the discharge table in FIG.

 The loading and distributing device of a shaft furnace for firing lump material, mainly limestone, comprises a loading hopper 1 with a conical part 2 and a vertical chute 3, passed through the arch 4 of the furnace, an unloading table 5, rigidly connected by brackets 6 to a sleeve 7, coaxially rotating vertically estrus 3 of the feed hopper 1. Vertical estrus 3 and sleeve 7 are equipped with individual drives 8 and 9 of their rotation. And their elements, made in the form of gears 10, are fixed rigidly on the lateral surfaces of the vertical estrus 3 and sleeves 7, and are connected through gear links 11 in the form of gears 12 and 13 with gear motors 14 and 15. Moreover, the direction of rotation of the feed hopper 1 and unloading table 5 can be either coincident or multidirectional, depending on the material being processed and the size of the available fractions. The gap 16 between the vertical estrus 3 and the upper surface 18 of the unloading table 5 should be larger than the maximum processed pieces, the available material.

 An important factor in the uniform distribution of large and small fractions is the presence on the unloading table of 5 hollow grooves 17, which are located radially to the center along the edge of its base 18 and have different lengths, while some of them are directed towards the walls of the furnace 21, and the rest - side of the center of the furnace.

 To ensure consistent rotation, smoothness and ease of movement of the loading hopper 1 relative to the unloading table 5, respectively, their components vertical heat 3 and sleeve 7 are equipped with individual bearings 19 and 20 mounted with a girth of their outer side walls above the arch 4 of the shaft furnace, while the bearings 19 and 20 are connected to the roof of the furnace 4, to each other and to heat 3 of the hopper 1 hermetically.

 Of great importance for the uniform distribution of fractions of bulk material over the furnace section is the fact that the individual drives 8 and 9 of the loading hopper 1 and the unloading table 5 are configured to control their relative rotation speed.

The loading and distribution device of a shaft furnace for roasting bulk material, mainly limestone, works as follows. The gear motors 14 and 15 of the individual drives 8 and 9 are turned on. Through the transmission links 11 and the gears 10, the loading hopper 1 and the unloading table 5 are rotated at the same speeds. Then, carbonate feed (limestone) is supplied (for example, with a skip hoist) to the rotating loading hopper 1, which due to the rotation of the hopper is partially mixed in it and fills the hopper with vertical heat 3 with a dense mass. The table of bulk material in heat 3 and hopper 1 plays the role a shutter (constipation) from air leaking into the furnace. When the furnace is in operation, heat 3 must always be filled with material. To unload the material into the furnace, the rotation speed of one of the drives 8 and 9 is changed. Due to the friction between the pieces, the material located in the gap between the estrus and the unloading table moves to the edge of the table and then is unloaded into the furnace. Simultaneous rotation with different speeds of the material in estrus and on the unloading table provides a high uniformity of distribution by size of pieces at the edge of the unloading table. If material fell directly from the edge of table 5 into the furnace, then an annular bed of uniform size would form in the furnace. The gutters 17, attached to the edge of the table 5 and having different lengths and radial directions, allow you to direct and evenly load material falling from the edge of the table over the entire cross section of the furnace. Depending on the number, length and radial direction of the gutters, when loaded in the furnace, a plurality of concentrically arranged annular mounds of uniform material in size will be formed. The length, quantity and radial direction of the gutters is selected taking into account the dimensions of the furnace and the required uniformity of the distribution of material in the zones. To stop unloading the material into the furnace, the same rotation speeds of the hopper 1 and table 5 are set, or their drives 8 and 9 are stopped. To ensure continuous unloading of the material into the furnace, taking into account the given furnace productivity, by changing the relative rotation speeds of the hopper 1 and the unloading table 5, the discharge speed is selected . Due to the high temperatures inside the furnace, the support units and drive mechanisms of the hopper and unloading table are installed externally above the arch of the furnace. As supporting nodes of the hopper 1 and unloading table 5, sealed thrust bearings with outer crowns on their bodies attached to the estrus 3 and sleeve 7 are used. The bearings are mounted on top of the furnace roof one on top of the other, with the lower bearing attached to the sleeve 7 and the upper bearing hermetically attached to the vertical heat 3 of the hopper 1, which ensures complete sealing of the support-drive unit of the loading and distribution device from the suction b air into the oven. The crown of each bearing 19 and 20 is connected with the gear of an individual drive, for example, a gear motor 14 and 15.

 It has been experimentally established that for different materials to be processed and fractional composition, it is necessary to establish their technological speeds and directions of rotation of the loading hopper 1 and unloading table 5, which are determined experimentally based on the conditions of a uniform or predetermined size distribution of the material.

 This device is preferably used on shaft overflow furnaces operating under pressure and with a minimum vacuum (5 ... 40 Pa) in the loading part of the furnace. The uniform distribution of the fired material and solid fuel is the main problem in the operation of these furnaces.

According to the invention, tests were conducted on models in laboratory conditions, and design documentation was developed for the manufacture of a prototype of a loading and distribution device, which is planned to be manufactured and installed on a shaft gas lime furnace in the city of Asha, Chelyabinsk Region in 2013.

Sources of information taken into account during the examination.

1. USSR author's certificate 323623 F 27B 1/20, published on November 29, 1972

2. USSR author's certificate JY ° 939906 F27B1 / 20, publ. 06/30/1982

3. USSR author's certificate JST21179061 F27B1 / 20, published on September 15, 1985.

4. USSR author's certificate L1244454 F27B1 / 20, published on 07.15.1986.

5. Pat of the Russian Federation tfs2079804 F27B1 / 20, publ. 05.20.1997.

 6. Pat RF M> 2112186 F27Bl / 20, C21B7 / 20, publ. May 27, 1998.

С21В7/20,Р27В1/20,опуб.10.03.1999г. 7. PatRF

S21V7 / 20, R27V1 / 20, publ. 10.03.1999.

 8. PatRF o2196180С21В7 / 20, published on 10.01.2003.

 9. Pat of the Russian Federation JY ° 2208207 F27B1 / 20, С21В7 / 20, publ. 10.07.2003.

Yu.PatRF, 22280828 F27B1 / 20, С21В7 / 20, publ. July 27, 2006.

11. Pat RF RF JY ^O 2224799 C21B7 / 20, F27B1 / 20, publ. 02.27.2004.

 12. PatRF JY22374325 C21V7 / 20, published on November 27, 2009.

 V.PatRF e2396358 C21B7 / 20, F27B1 / 20, F27D3 / 10 published on 10.01.2009.

14.Pat RF J4 ° 2169777 С21В7 / 20, published on June 27, 2001.

15.3 application EPO) 088253, publ. 1983.

 16. Pat RF O2015476 F27B1 / 20, published on June 30, 1994.

 17. Pat. USA 4497609, publ. 05.02.1985.

 18. US Pat. JY “4881869, publ. 21.11.1989.

Claims

Claim.  1. The loading and distributing device of a shaft furnace for burning lump material, mainly limestone, characterized by the presence of a loading hopper with a vertical estrus, passed through the arch of the kiln, and an unloading table located with a gap under this estrus and connected by brackets with a sleeve installed with the coverage coaxially relative to estrus, while the unloading table and the loading hopper 1 are equipped with individual drives for their rotation, and the unloading table has hollow radially directed grooves for unloading bulk material into the furnace.  2. The loading and distribution device according to claim 1, characterized in that the hollow gutters are made of different lengths.  3. The loading and distribution device according to claim 1 and claim 2, characterized in that the hollow troughs are directed towards the walls of the furnace, and part to its center.  4. The loading and distribution device according to claim 1, characterized in that the individual drives are configured to control the speed and change the direction of rotation.  5. The loading and distribution device according to claim 1, characterized in that the sleeve and estrus are equipped with individual bearings mounted with a girth of their walls above the arch of the furnace.  6. The loading and distribution device according to claim 5, characterized in that the bearings are connected to the furnace, to each other and in heat.  7. The loading and distributing device according to claim 1.4, characterized in that the elements of the individual rotation drives of the loading hopper and unloading table are rigidly fixed to the outer surfaces of the estrus of the hopper and the liner and are connected via transmission links to their motors, for example, to gear motors.