DE2611402A1 - Size classification plant for granular materials - removes very fine particles from material by air blast and suction - Google Patents

Abstract

The separation plant for granular materials consists of four sieves (1, 2, 3, 4) of decreasing mesh size and mounted in a vibrating frame. The sieves all slope downwards so that material which is too coarse to pass through the mesh falls off the end of each sieve into its associated hopper. The fan (6) blows air over the sieves (2, 3, 4) so that fine particles are blown against the separation banels (12, B). The very finest particles are blown upwards and are sucked out through the duct (17). The less fine particles slide down the separation panels into the hopper (16). The shutters (7a, 7b, 7c) adjust the strength of the air blast and the valve (18) control the degree of suction.

Description

Process for separating solid granular products

with the exception of Htitternduk and their precursors The invention relates a method of separating solid granular products on top of each other arranged linear vibrated sieves, the inclination of which increases from top to bottom, while the rows of stitches become smaller and the mesh sizes 1.5 - 15 times larger are than the respective separation size of the particles, the material to be separated is placed on the upper sieve at the top, the coarser particles in the direction Sieve tendency to be deflected, the finer particles initially fall through freely and then on sieves with a smaller mesh size also in the direction of the sieve inclination be deflected, the coarsest fraction of material as overflow rom the top sieve, finer Material fractions withdrawn as overflow from the following sieves and fine fractions can be deducted as sieve passes.

In many cases of mechanical process engineering, aggregates are required as well as intermediate products and end products in individual grain fractions of the same or different composition can be separated. This separation often requires a considerable expenditure on equipment and energy, which is kept as low as possible must become.

It is known that the separation on several superimposed, linear vibrated sieves perform, their inclination from top to bottom increases as the courses become smaller and the mesh sizes 2.0 - 15 times greater than the respective separation size of the particles, the one to be separated Material is fed onto the upper sieve at the upper end, the coarser particles are deflected in the direction of the sieve inclination, the finer particles are initially released fall through and then on sieves with smaller mesh size also in the direction due to the inclination of the sieve1 the coarsest fraction of material as overflow from uppermost sieve, finer material fractions drawn off as overflow from the following sieves and fine fractions are withdrawn as sieve passages.

(US-PS 2,572,177, 'tAufbereitungstechnik ", No. 2, 1975, pp.72-75).

This method enables a separation according to grain sizes with little equipment and energy expenditure. However, it does not allow separation according to grain sizes and composition of the material or the separation of a certain Grain size fraction that is practically free of fine grain.

It is also known to perform a particle size separation on several in parallel to each other and inclined to perform plates, the plates in have openings at certain distances that are one above the other and are of the same size have and be vibrated.

The separation takes place by blowing in a gas stream from the lower one End of the plates towards their upper end, whereby fine-grained material on the Plates and is driven between the plates towards the top of the plates. (GB-PS 899 449).

This process does not allow the separation into exact grain sizes fractions, has a relatively low throughput, the energy expenditure is a result the large air requirement high, and there is no separation into fractions with different Composition possible.

It is also known to perform a separation on seven, whereby air is passed through the sieves from below and / or from above (GB-PS 484 757; DT-OS 2 311 308). It is true that there is a separation into two grain fractions with a large Difference in grain size or a separation into two different fractions Composition possible, but no separation into several grain fractions is possible different composition or the separation of a certain grain size fraction practically possible without fine grain.

The invention is based on the disadvantages of the known Avoid procedures and in particular a separation according to grain size and composition of the material or the separation of a certain grain size fraction, which is practical is free of fine grain. In doing so, the apparatus and energetic Effort should be as low as possible.

This object is achieved according to the invention in that a gaseous medium approximately transversely to the sieve direction and at least through part of the for sieving required work space passed when passing through the work space the specifically lighter material of each grain fraction is carried along between two sieves, the gaseous medium loaded with the specifically lighter material into a separation chamber passed and there solid material is separated from the gas stream.

The expression "approximately transversely to the sieve direction" is intended to mean that the gaseous Medium is introduced either transversely to the sieve direction and horizontally or something twisted against the sieving direction and horizontal. As a gaseous medium, in general Air can be used. However, if the material to be separated is protected from oxygen must be, such as e.g.

In the case of substances with a tendency to dust explosions, an inert gas can be used will. The amount of gas and gas velocity become dependent of the amount of material and its composition adjusted so that the desired Separation occurs, in this way it is possible to specifically lighter material with a large grain size from specifically heavy material with a small grain size.

A preferred embodiment is that in the separation chamber the coarser solid material contained in the gas stream is separated off and the finer material is discharged from the separation chamber with the gas flow. The discharged finer one Material can then be separated from the gas in a downstream stage. As a result, the specifically lighter material can be divided into two fractions with different Grain size and possibly

different composition can be separated.

A preferred embodiment is that the separation of the coarser solid material takes place on a plate, the front edge of which is approximately parallel runs to the seven and which runs obliquely backwards and upwards, the coarser material slides down on the plate and out of the separating chamber withdrawn and the finer material with the gas stream from the separation chamber behind the plate is discharged. This enables separation to take place in a simple manner.

A preferred embodiment is that the separating cut between coarser and finer material by adjusting the incline and / or height the plate takes place. As a result, the separating cut can be varied in a simple manner.

A preferred embodiment is that the separation by Introduction of a regulated amount of additional gaseous medium into the separation chamber he follows. This reduces the gas velocity in the separation chamber, and the separation takes place accordingly.

A preferred embodiment is that different Quantities of the gaseous medium across the grain fractions between the sieves be directed. The larger amount of gas is passed between the upper sieves. This leads to an improvement in the separation effect.

A preferred embodiment is that the regulation of the different amounts of the gaseous medium by adjusting flaps the entry into the working area of the sieves takes place. This is a simple and effective regulation possible.

A preferred embodiment is that the material task takes place on the side of the inflowing gaseous medium. This avoids that specifically heavier material gets into the separation chamber, even if the Difference is small.

The invention is explained in more detail and by way of example with reference to the figures.

Figure 1 is a cross section through a separator.

FIG. 2a is a section BB according to FIG. 1, three sieves being present and the specific heavy material is separated into two grain fractions.

FIG. 2b is a section BB according to FIG. 1, five screens being present and the specific heavy material is separated into four grain fractions.

Figure 3 is a section C -C according to Figure 1, wherein in the upper part the separation chamber the coarse, specifically light material from the gaseous substance is separated and discharged downwards.

Figure 4 is a section D - D through the separation chamber, the upper Shows the separating plate in the separating chamber.

Figure 5 is a section E - E through the separation chamber, the lower Shows the separating plate in the separating chamber.

Gcmii1 Figure 1 takes place (liO Trenllwlg of specifically heavy and specifically light material that is charged through an opening (ia), n h division into different grain fractions in a housing (1) that is at an angle to each other arranged screen linings (2,3,4) of different mesh sizes is provided and through an electrically excited motor (5, Fig. 2a) is made to vibrate. Of the Side is blown by a blower (6) a certain amount of a gaseous Medium that can be regulated by a controllable motor or throttle valve, blown through a housing (8) provided with adjustable-angle flaps (7a, b, c). This housing (8) is mounted on a base (9) in such a way that it has a swivel joint (10) can be adjusted at a horizontal angle to the sieve housing (1). The flaps (7a, b, c) are arranged essentially parallel to the screen linings (2,3,4 in Fig. 2a) and can be adjusted in such a way that those between the screen linings (2,3,4) are located Work rooms can be individually supplied with more or less air.

By the gaseous gas blown through the flaps (7) by the fan (8) The medium that is abandoned through the opening (la) together with the specifically heavy one Specifically lighter material when the between the screen linings (2,3,4) falls through The work rooms located are separated from the specifically heavier material. That specifically Lighter material is carried away by the flow of the gaseous medium and conveyed into the separating chamber (11) arranged on the side of the housing (1).

Two metal separators (12, 13) are attached in this separating chamber.

The height of the partition (12) is via adjusting screws (12a) adjustable so that it is approximately parallel to the screen linings (2,3,4) in height is adjustable. This ensures that the grain size of the specifically lighter Material that is discharged downwards through the discharge opening (16) is preselected can be. The partition plate (12) is bent over a bending edge (12b) so that the coarse, specifically lighter material is diverted to the side, thus out of the main flow taken out of the gaseous medium and discharged downward through the opening (16) will. Through the adjustable partition plate (13), the sieve passages coarse proportion of specifically lighter coarse material deflected by impact and taken from the flow of the gaseous medium.

The partition plate (13) is provided with a rubber lip (15) which the Discharge opening (16) closes off towards the separation chamber. By adjusting the dividers (12,13) the coarse, specifically lighter material can also be wholly or partly according to be discharged at the top through the suction line (17). The dividing plates (12,13) are Protected against wear by a layer of cast basalt (1Z +).

The fine, specifically lighter material is transported by the flow of the entrained gaseous medium, passed under the partition plate (12) and through the suction line (17) discharged. The sucked-off quantity can be discharged through a valve (18) of the gaseous medium can be regulated.

The main advantages of the invention are that with A separation according to grain size with relatively little equipment and energy expenditure and composition of the material or the separation of a certain grain size fraction, which is practically free of fine grain is possible. (The procedure is particular suitable for separating brewing barley. Thereby something specific becomes heavier, good orn separated from specifically lighter, deaf grain, and at the same time a pure, clean fraction of that which is to be passed directly to the further process step Barley).

Claims (8)

Claims method for separating solid granular products on several linearly vibrating sieves arranged one above the other, their inclination increases from top to bottom as the courses get smaller and the mesh sizes 1.5 - 15 times larger than the respective separation size of the particles, whereby the The material to be separated is placed on the upper sieve at the upper end, the coarser one Particles are deflected in the direction of the sieve inclination, the finer particles first fall through freely and then on sieves with smaller mesh size also in the direction the inclination of the sieve, the coarsest fraction of material as overflow from uppermost sieve, finer material fractions drawn off as overflow from the following sieves and fine fractions are withdrawn as sieve passes, which is not possible nz e i c h n e t that a gaseous medium is approximately transverse to the sieve direction and at least passed through part of the work space required for sieving, when passing through the specifically lighter material of each grain fraction between two sieves carried away, the gaseous one loaded with the specifically lighter material Medium passed into a separation chamber and there solid material is separated from the gas flow will. 2. The method according to claim 1, d a d u r c h g e k e n n -z e i c h n e t that the coarser solid material contained in the gas flow in the separation chamber separated and the finer material discharged with the gas stream from the separation chamber will. .3. Method according to Claim 2, d a d u r c h g e k e n n -z e i c h n e t that the coarser solid material is separated on a plate, the edge of which runs roughly parallel to the seven, and the one sloping backwards and upwards runs upwards, the coarser material slides down on the plate and below withdrawn from the separation chamber and the finer material with the gas stream from the Separation chamber is discharged behind the plate. 4. The method according to claim 3, d a d u r c h g e k e n nz e i c h n e t that the separation cut between coarser and finer material by adjustment the inclination and / or height of the plate takes place. 5. The method according to claim 2 to 4, d a d u r c h g e k e n n z e i c h n e t that the separation by introducing a regulated amount of additional, gaseous medium takes place in the separation chamber. 6. The method according to claim 1 to 5, d a d u r c h g e k e n 1 z e i c h n e t that different amounts of the gaseous medium across the Grain fractions located between the sieves are passed. 7. The method according to claim 6, d a d u r c h g e k e n n -z e i c h n e t that the regulation of the different amounts of the gaseous medium by Adjustment of flaps takes place before entry into the working area of the sieves. 8. The method according to claim i to 7, d a d u r c h g e -k e n n z e i c h n e t that the material feed to the side of the inflowing gaseous medium he follows.