SU1098594A1 - Gravity air classifier - Google Patents

Abstract

GRAVITATIONAL PNEUMATIC CLASSIFIER, including a vertical housing: shafts consisting of separate sections having upper and lower rectangular bases, loading and unloading devices, an air supply system that, in order to improve the quality of separation and increase productivity by additional cleaning of the material and flow deformation in the transverse direction, the upper and lower rectangular bases of each section are rotated one relative to another, and their axes are located perpendicular to the horizontal plane. CO 00 JV x 4:

Description

The invention relates to the pneumatic classification of bulk materials in the upstream air flow and can be used in the metallurgical, mining, chemical, construction and other industries. The pneumatic classifier is known, including a working chamber with pouring shelves, air inlets, starting material and discharging the Cl3 separation products. The disadvantage of the classifier is the low quality of the separation products. The closest in technical essence and the achieved result to the proposed is the gravitational pneumatic classifier, which includes a vertical mine body consisting of. separate sections having upper and lower rectangular bases, unloading and loading devices, the C 2 air supply system. A disadvantage of the known classifier is the poor quality of separation, since the negative influence of the wall layer has not been completely eliminated. Material is diverted to the airflow core from only two opposite walls. From the other two walls, the material is not retracted. At the same time, the air flow rate in the near-wall region is zero and fine particles (below the boundary size) can be deposited in this layer into a large product, which leads to its contamination and deterioration of the quality of separation. The fine product is contaminated with large particles due to the airflow core (where the speed is higher than the average, corresponding to the boundary grain). In addition, conglomerates of particles (dense clusters of particles of different sizes) are not sufficiently broken, since the main air flow moves in both structures with a zigzag tape. Destruction of conglomerates is possible only in places of overfilling. The volume of the shaft of a classifier is not sufficiently effective. In each section of the apparatus, only one transfer is carried out, which does not allow improving the quality of separation and increasing the load (capacity). The purpose of the invention is to improve the quality of separation and increase productivity by additional cleaning of the material and deformation of the flow in the transverse direction. The goal is achieved by the fact that in the gravity pneumatic classification the mountain includes a housing in the form of a vertical shaft consisting of separate sections. having upper and lower rectangular bases, loading and unloading devices, the upper and lower rectangular bases of each section are rotated one relative to another, and their axes are located perpendicularly in the horizontal plane. In fig. 1 shows a classifier, a general view; .on FIG. 2 shows section A-A in FIG. one; in fig. 3 - classifier,. top view of fig. 4 - classifier section in axonometry; in fig. 5 movement of material in the section. The gravitational pneumatic classifier consists of a vertical charge 1 containing sections of the same type 2, estrus 3 dp of raw material supply (Large product bunker, cyclone and fan (the bunker, cyclone and fan are not listed). The classifier 3 is supplied to one of the middle sections 2, where under the influence of the air flow directed towards the movement of the material, the separation process takes place. Small particles are picked up by the upward air flow and move upwards, and The hinge plates under the action of the prevailing force of gravity are lowered, while the particles that accidentally fall into the near-wall layer are diverted to the center of the flow, which prevents the large product from becoming soiled with fine particles and improves the quality of separation. The wall of each section In the proposed classifier, all four walls have inclined surfaces that allow the material to be removed from the core layer. Since the upper rectangular base of section 2 (Fig. 2 is perpendicular to the lower, in each section the two side surfaces are inclined towards the air flow and the material is diverted into the core of the flow, which allows you to organize two cleanings of the material {in the prototype - one cleanout) . This leads to a more complete utilization of the volume of section 2, which makes it possible to increase the separation efficiency and increase the load, i.e. classifier performance. The arrangement of the rectangular bases of each section mutually perpendicular in the horizontal plane causes the deformation of the vertical air flow in the transverse direction. Moreover, due to the fact that the living section in the upper and lower parts is the same, there is no compression or expansion of the flow (i.e., an abrupt change in velocity and

pressure), and the flow changes its shape according to the shape of the channel restricting it. With such a deformation of the flow, along with Gravitational, a cross-flow separation factor appears, which consists in imparting impulses to particles in the transverse direction. The velocity impulse imparted to the particles due to the strain rate is directed to the section walls. This new separating effect of the flow removes large particles from the flow core, which prevents them from accidentally falling into the fine product and improves the quality of the separation. At the same time, small parts move due to low inertia due to the upward air flow. Due to the deformation of the flow, the destruction of conglomerates also occurs, and this destruction occurs not only in the places of reprocessing, as in the well-known classifier, but also in the whole of its classifier.

The small particles moving from section to section are affected by the gravitational and transverse separation effect and fall into the upper section of the classifier, from where they are diverted into the cyclone, and the large ones come from the lower section into the bunker of a large product.

To determine the optimum ratios of the sides of the bases of the section, laboratory studies of the separation process of various materials were carried out. The studies were carried out on classifiers with a ratio of -2-, equal to 2 1 1 1 1. 1 „

 3 2 48162b. The starting material was molding sand, copper powder and ferroselicium. The range of separation was varied from 20 µm to 5000 µm, the speed of the air flow from 0.4 m / s to 10 m / s. The separation efficiency was determined according to the Eder-Meier index) {- X75

Lt

The test results are shown in the table.

From the data in the table it follows that, regardless of the material and separation boundary, the assignment with (1 is not a cel 20

figuratively, since a further decrease in the ratio leads to a decrease in effective

separation efficiency is also reduced.

Thus, for most materials, the optimal ratio of -65 is in the range from -j to -.

Claims (1)

GRAVITY PNEUMATIC CLASSIFIER, comprising a housing in the form of a vertical shaft, consisting of separate sections having upper and lower rectangular bases, loading and unloading devices, an air supply system, characterized in that, in order to improve the quality of separation and increase productivity by additional cleaning material and flow deformations in the transverse direction, the upper and lower rectangular bases of each section are rotated one relative to the other, and their axes are located per perpendicularly in the horizontal plane. _from