RU2388541C1 - Centrifugal two-stage mincer - Google Patents

Abstract

FIELD: process engineering. ^ SUBSTANCE: invention relates to machine building, particularly to centrifugal vertical shafts units designed to crush, mince and classify initial stock. Proposed two-stage mincer comprises loading device, housing accommodating boost rotor, rotary load-carrying table, unloading device and rejection device. Rejection device represents combination of shafts and bumper plates. Note here that every shaft has its own drive and its own flexible element designed to press the roller against free running mincing table. ^ EFFECT: higher efficiency and stability. ^ 7 cl, 3 dwg

Description

Technical field

The invention relates to the field of engineering, namely to centrifugal plants with a vertical shaft of rotation for the implementation of technological processes associated with crushing, grinding and classification of the source material.

State of the art

Known two-stage shredder containing a housing, a rotor in the form of an impeller and a cylindrical sieve shell, which are combined in the upper module. This grinder has a lower module, consisting of a case in the form of a truncated cone and a mill, also in the form of a truncated cone (see RF patent 2313394 C1, 2006). The chopper works as follows. The crushed raw materials fall on the impeller of the rotor, are discarded on the shell and are accelerated by the air flow created by the impeller of the rotor. Grinding of raw materials occurs due to impacts and friction of particles on the shell. The crushed raw materials under the influence of inertia and air pressure pass through a sieve shell and, due to their own weight, are gravity-fed from the upper module. Under-crushed raw materials under the action of gravity fall into the lower module, where it is captured by the cutter blades. The crushed particles move under the influence of the inclined cutter blades down to the moment of their jamming in the conical gap. After jamming, their further grinding occurs. At the exit from the conical gap, the crushed raw material is discharged from the grinder.

The disadvantage of this grinder is the low grinding efficiency caused by the insufficient acceleration rate of the starting material in the upper module, since the material randomly contacts the rotor blades and can fall down without contact with these blades and the mesh. The lower module of the specified grinder also has low grinding efficiency, since there is a guaranteed gap between the rotating cutter and the body, into which the unmilled material falls.

A roll mill is known, comprising a housing, a vertical support assembly, a table with a grinding track rotating on a support assembly, and grinding rolls (see patent RU 26971U1, 2002). The mill operates as follows. The crushed raw material is fed to a rotating grinding table and, moving to the periphery of the table, gets on the grinding track, where it is crushed by the interaction of the rolls with the table. After exiting from under the rolls, the compressed layer of crushed material is loosened with a toothed comb - and part of the material, under the action of centrifugal inertia, is removed from the table and removed from the mill. Unfinished large particles of material are mixed with a new portion of the feedstock and are fed through the grinding track for grinding under the next roll.

The disadvantages of this mill are: 1) low efficiency of single-stage grinding, which occurs only by crushing rolls of crushed material; 2) limited size of the source material due to the limitation of the size of the rolls; 3) the difficulty of removing already crushed material from the grinding track, which leads to a sharp decrease in the grinding efficiency during the operation of the mill.

SUMMARY OF THE INVENTION

The objective of the invention is the creation of a centrifugal grinding device having high efficiency and stability of the grinding result.

The specified technical result is achieved in that the installation containing the loading device, the housing with the accelerating rotor located therein, the rotating grinding table, the fencing device, consisting of a combination of rolls and fenders, a vertical support unit and an unloading device, has two successive grinding stages. In this case, the accelerating rotor is installed above the grinding table below the centers of the rolls, coaxially to the grinding table. At the first stage, the grinding of material flying out of the rotating rotor occurs by a free blow to the fender. In the second stage, subsequent grinding of the material occurs by crushing and abrasion as a result of the interaction of the rotating rolls and the grinding table.

In this case, each roll has its own individual drive and its own elastic element (for example, a hydraulic clamp), which provides a roll clamp to a freely rotating grinding table. The force of pressing the roll against the table provides crushing and abrasion of the material.

The number of rolls must be at least two in order to avoid uncompensated mechanical loads, which can lead to distortion of the grinding table. It is most rational to have rolls evenly spaced around the circumference of the table. In this case, stationary baffle plates are installed between the rolls around the circumference.

In addition, there is additional grinding of the material as a result of the collision of particles on the accelerating rotor and the rotating grinding table.

The rollers rotate in a direction that ensures self-tightening of the material emitted from the rotor into the gap between the rollers and the grinding table (while the grinding table and rotor rotate in the same direction).

The air flow created by the accelerating rotor and particles of material flying out of the rotor removes the crushed finished product from the grinding track of the table, thereby improving the conditions for crushing by rolls of new portions of material and increasing the grinding efficiency.

In this device, a new roll surface is constantly exposed to the impact, due to which the high uniformity of the wear of the rolls and, as a result, the stability of the impact grinding, is maintained, since the shape of the rolls changes little in contrast to other types of reflectors, for example, stationary baffle plates.

It is advisable that the peripheral part of the rolls and grinding table would be replaceable and made of a more wear-resistant material than other elements of the housing. This embodiment of the rolls and the grinding table improves the grinding stability (the rolls and the table of the correct geometric shape touch each other only along the line, as a result of the small contact area significant contact stresses develop, which crush the material) and also allows you to increase the work of the grinder without replacing the breaker or its components elements. Replacing the periphery of the rolls and the grinding table allows you to increase the operational life of the entire installation.

The analysis of the prior art showed that the claimed combination of essential features set forth in the claims is unknown. This allows us to conclude that it meets the criterion of "novelty."

To verify the conformity of the claimed invention with the criterion of "inventive step", an additional search was carried out for known technical solutions in order to identify features that match the distinctive features of the claimed technical solution from the prototype. It is established that the claimed technical solution does not follow explicitly from the prior art. Therefore, the claimed invention meets the criterion of "inventive step". The invention is illustrated by drawings and a description of the operation of the claimed device.

List of drawings

Figure 1 shows an axial section of a centrifugal two-stage grinder.

Figure 2 presents a section aa of a centrifugal two-stage grinder.

Figure 3 presents a section bb of a centrifugal two-stage grinder, which shows the profile and location of the baffle plates inside the grinder.

The specified version of the grinder consists of: a loading device 1, a housing 2, an accelerating rotor 3, rolls with an individual drive 4, elastic elements 5 (a variant of using a hydraulic clamp is possible), a breaker device in the form of fixed plates 6 located between the rolls (a breaker device is possible in the form of pockets for self-lining with crushed material), a vertical support unit 7, for example, in the form of a bearing unit, a freely rotating element (grinding table) 8 with a flange 15, an acceleration engine the rotor 9, the air intake 10, the nozzle 11 for unloading the (coarse) fraction of the material and for returning it for re-grinding, the nozzle 12 for the output of the fine fraction of the crushed material into the classifier, replaceable wear-resistant periphery of the grinding table 13 and replaceable wear-resistant periphery of the roll 14 (replaceable periphery table and rolls can be made of parts).

Information confirming the possibility of carrying out the invention

Centrifugal two-stage shredder operates as follows. The source material (for example, crushed granite) is loaded through the loading device 1 into the housing 2, then the material enters the center of the rapidly rotating rotor 3. The accelerating rotor 3 accelerates the material to high speed. The material flies out of the accelerating rotor and collapses due to impact on the rolls 4 and the breaker device 6. The rolls are pressed by elastic elements 5 (for example, springs) to the grinding table 8, which rotates from interaction with the rolls, each having its own individual drive. Uncrushed material after impact hits the annular groove of the grinding table 8. In this groove, the material is additionally crushed and abraded by the interaction of the rotating rolls 4 and the grinding table 8. Flanging 15 on the table periphery prevents the material from prematurely falling off from the grinding track. The crushed material, caught in the air stream created by the accelerating rotor and particles flying out of the rotor, is poured from the periphery of the grinding table 8, enters the flow of ascending air and is taken out from the grinder into the classifier. Part of the material (grains) falls out of the housing 2 through the pipe 11. Next, the under-ground material is returned to the loading device 1 by an external lifting mechanism. To protect against wear, the rolls 4 and the grinding table 8 can have replaceable wear-resistant elements on the end and conical surfaces.

Based on the foregoing, we can conclude that the inventive chopper can be implemented in practice with the achievement of the claimed technical result, i.e. It meets the criterion of “industrial applicability”.

Claims (7)

1. A centrifugal two-stage shredder containing a loading device, a housing with an accelerating rotor located therein, a rotating grinding table, a vertical supporting unit, an unloading device and a breaker device, characterized in that the breaker device is made of a combination of rolls and breaker plates, each roll It has its own individual drive and its own elastic element, which provides a roll clamp to a freely rotating grinding table. 2. The centrifugal two-stage grinder according to claim 1, characterized in that the accelerating rotor is mounted above the grinding table below the centers of the rolls, coaxially to the grinding table. 3. A centrifugal two-stage grinder according to claim 1 or 2, characterized in that the rollers rotate the grinding table in the direction of rotation of the accelerating rotor. 4. The centrifugal two-stage grinder according to claim 1 or 2, characterized in that the air flow generated by the accelerating rotor and the particles of material flying out of the rotor take the crushed finished product out of the grinding track of the table. 5. The centrifugal two-stage grinder according to claim 1 or 2, characterized in that the periphery of the rolls and the grinding table is protected by replaceable wear-resistant elements made of a more wear-resistant material than other housing elements. 6. A centrifugal two-stage shredder according to claim 1 or 2, characterized in that at least two rolls are located in the device, evenly spaced around the circumference of the grinding table. 7. The centrifugal two-stage grinder according to claim 1 or 2, characterized in that the grinding table on the periphery behind the rolls has a flange.

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