RU2095711C1 - Lump material classifier - Google Patents

Abstract

FIELD: ferrous metallurgy and other industries for classification of poly-fractional grainy materials. SUBSTANCE: classifier includes stationary hearth mounted in housing and assembled from sections arranged at angle relative to each other at inclination to different sides from additional partition located in fine fraction compartment which is isolated from coarse fraction compartment by means of compartment partition provided with suspended gate valve and blast nozzles mounted on side of compartment and connected with delivery air line of fan. Remaining part of hearth is solid but for sections between partitions. During operation of classifier, air blown through material loaded by nozzles and grid section of hearth between partitions which divides material into fine fraction rolling off one section of hearth and coarse fraction rolling off other section of hearth. Fractions are unloaded through discharge ports and air is evacuated through upper port. EFFECT: enhanced efficiency. 1 dwg

Description

 The invention relates to ferrous metallurgy, to the sorting of blast furnace sinter, limestone, coke and other bulk materials and can be used in various industries for the classification of polyfraction granular materials.

 Known sorting screening devices for sifting sinter and other bulk materials on sheets with holes of a given size (see, for example, "Blast furnace production." Reference book, t. 1. M. Metallurgizdat, 1963, pp. 208-213).

 The disadvantages of these devices are the complexity of separating small classes, clogging of holes with material, intensive wear of the sieves.

These shortcomings are eliminated in pneumatic classifiers, divided into the following main types (see Yu.S. Karabasov et al. "Use of fuel in agglomeration". M. Metallurgy, 1976, pp. 187-197):
a) mechanical intracirculation (centrifugal-lobed);
b) air passage with rotating jack blades;
c) air passage without the use of moving mechanical devices;
g) chamber.

 A common drawback of these classifiers is the need for increased air velocities (hence, its flow rate) for removal from the material stream and pneumatic transportation of the separated fine fractions (for example, about 0-5 mm). The disadvantage of classifiers with rotating additional mechanical devices is, in addition, structural complexity.

 A pneumatic classifier with a fluidized bed of material is known, which is a multi-cone apparatus, in one of the cones of which a fluidized bed is blown through with compressed air, from which small fractions are carried out and large ones fail (see N.I. Halperin and other "Fundamentals of Fluidization Technique". M Chemistry, 1967, pp. 488-489, Fig. IX-82).

 The disadvantages of this classifier are: multicone, the ability to classify the material in a relatively small fractional range (of the order of 0-12 mm), because fluidization of larger particles is unprofitable, the need for sufficiently high fluidization rates for the removal of fine fractions from the fluidized bed.

 Partially, these shortcomings are eliminated in another known device, which is closest to the classifier of bulk materials that is proposed in terms of technical nature and the achieved result (see auth. Certificate N 1196655), containing an inclined conveyor air distribution grill enclosed in the housing, a loading window located in the upper part of the housing, and adjoining to it a shut-off partition with a pivotally suspended gate separating the superlattice space into compartments for small and large fractions, each of which has a discharge a clean and vent window and connected to a blower fan. The classifier is equipped with blast nozzles located in the cut-off partition from the side of the coarse fraction compartment and an additional partition located in the fine fraction compartment directly above the grill so that the upper edge of this partition is located at the level of the suspension of the shut-off partition gate.

 When the classifier (prototype) is working, air is blown through the feed material both from below, from under the grate, and from the side through the blast nozzles, which contributes to a more complete blowing of the fine fraction moving on the air cushion under the slope of the grate, against its movement, while a large fraction is transported by a grill. An additional partition prevents the coarse fraction from rolling off along with small things, especially at large angles of inclination of the grating.

 The well-known classifier (prototype) allows you to combine the classification functions of the material with the functions of the feeder, regulating the supply of large fractions by changing the speed of the air distribution grill.

 However, in many technological processes, for example, when classifying a blast furnace sinter after a cooler, there is no need for a controlled (supply) supply of material from the classifier.

 A serious drawback of the known classifier is the structural complexity due to the presence of a moving (conveyor) air distribution grill, the need for its sealing, which is always difficult with moving nodes, and the installation of a special drive.

 A significant drawback of the classifier is also significant air loss through leaks, because it is known that when air is blown (or sucked) through conveyor air distribution grilles, as a result of the difficulty of compaction, about 30-45% of the air agent is unproductive (see, for example, N.M.Babushkin et al. "Cooling of sinter and pellets", Moscow, Metallurgy, 1975, p. 172, second paragraph above).

 The aim of the invention is to simplify the design of the device and reduce the energy intensity of the classification process without compromising its quality.

 This goal is solved by the fact that in the classifier of bulk materials containing an inclined hearth, small and large fraction compartments with discharge windows and blow nozzles connected to the fan and installed on the side of the coarse fraction compartment in the shut-off partition with a gate, at the level of the hinge suspension of which there is an upper the edge of the additional partition installed in the small fraction compartment, the bottom is stationary and mounted from sections that are installed at an angle to each other with a slope of nye side of the additional partition, and by discharging the fine fraction box compartment to the additional compartment walls and the coarse fraction made of whole hearth.

 The proposed implementation of the bottom of the classifier is stationary and from sections installed at an angle to each other with a slope in different directions from the additional partition, allows classification without a moving grate, because the slope of the hearth sections in different directions from the additional partition causes the rolling of small and large fractions separated by air in different directions along the motionless hearth under the action of gravity. The hearth on the sections from the discharge window to the additional partition of the fine fraction compartment and in the coarse fraction compartment is made whole (without holes), because the material moves on slopes and air is supplied, except for nozzles, only for classification on the loading section of the hearth between the additional and shut-off partitions.

 The implementation of the stationary classifier bottom significantly simplifies the design of the device and reduces the energy consumption of the classification process, because the hermetic connection of the blast duct with the stationary hearth on the section between the partitions causes a decrease in the flow rate of air supplied to the section by eliminating its unproductive losses through leaks (in a device with a moving grate) by about 30-45% (see the link to the book of N. M. Babushkin and others in the description of the disadvantages of the prototype). The energy intensity of the process is also reduced by eliminating air supply in areas with a solid hearth.

 Since the reduction of air consumption is achieved only by eliminating unproductive losses of air through leaks and its consumption for transporting small things in comparison with a device with a moving grate, the quality of classification does not deteriorate. Moreover, it is possible to improve the quality of classification by increasing air flow through the stationary hearth and blast nozzles without unproductive air losses, i.e. without taking place in the prototype device an unjustified increase in the energy intensity of the process.

 Based on the foregoing, it is shown that the distinctive features of the inventive device "Classifier of bulk materials" are necessary and sufficient to achieve the goal.

 The drawing schematically shows the proposed device.

 The device comprises a housing 1 with a loading window 2, a small fraction compartment 3 with an unloading window 4 and an air outlet window 5, and a large fraction compartment 6 with an unloading window 7, separated by a shut-off partition 8 with a gate 10 suspended on a hinge 9, in which from the compartment 6 are placed blast nozzles 11 connected to the blower duct 12 of the fan 13. In the compartment 3 of the fine fraction there is an additional partition 14.

 The classifier also contains a hearth made according to the invention, stationary and mounted from angled sections: section 15 from the discharge window 4 to the additional partition 14 of the fine fraction compartment 3 and section 16 from the additional partition 14 to the discharge window 7 of the coarse fraction 6. Sections 15 and 16 are installed at an angle to each other with a slope in different directions from the additional partition 14, which in the described embodiment is partially lowered below the bottom (section 15) of the small fraction compartment 3. The hearth section between the shut-off partition 8 and the additional partition 14 is lattice-connected and connected to the blower duct 12 of the fan 13, the rest of the hearth is made integral according to the invention (without holes).

 The classifier works as follows.

 The classified polyfraction material (for example, agglomerate, coke, limestone) is fed through the loading window 2 of the classifier housing 1 into the fine compartment 3 between the shut-off partition 8 and the additional partition 14. In the process of loading the material through the grating section of the hearth (between partitions 8 and 14) and through the blast nozzles 11, the fan 13 is blown through the duct 12 through the action of which the fine fraction is blown onto a stationary mounted inclined section 15 of the hearth, through which under the influence of gravity Pipeline to the discharge window 4. The air is purged through vent box 5. At the discharge box 4 can be mounted seal (e.g., type of emergency lights), a discharge device (not shown). A large (heavier) fraction is not blown away by air, but enters a stationary inclined section 16 of the bottom, through which, under the action of gravity, it rolls to the discharge window 7 of the compartment 6 of the large fraction, lifting its own weight suspended on the hinge 9 to the shut-off partition 8 of the gate 10. Unloading window 7 is provided with a sealing discharge device, for example, a type of emergency lamp (not shown).

 In the proposed classifier, due to the absence of moving nodes, the design of the device is greatly simplified, air losses through leaks are eliminated, which are inevitable in the classifier with a moving air distribution grill. The reduction of unproductive air losses leads to a decrease in the energy intensity of the classification process. This creates the opportunity to improve the quality of classification by using the air lost unproductively in the classifier with a moving grate to classify the material without increasing the energy consumption of the process compared to the classifier with a moving air distribution grate.

 Simplification of the design of the device, reducing the energy intensity of the classification process and improving its quality determine the economic efficiency of the invention.

Claims (1)

 A classifier of bulk materials containing an inclined hearth enclosed in a housing having perforation, loading and unloading windows located respectively in the upper and lower parts of the housing, which is divided into small and large fractions by means of a shut-off partition made with a pivotally suspended gate and equipped with blast nozzles with sides of the coarse fraction compartment, an additional partition installed in the fine fraction compartment, the upper edge of which is located at the level of the upper edge of the hinge o gate, characterized in that the hearth is stationary in the form of sections installed at an angle to each other, located with a slope in different directions from the additional partition, and the hearth is perforated in the compartment of a large fraction in the area between the additional and cut-off partitions.