CN1003491B

CN1003491B - Device for treating bulk material with gas, particularly for air-cooling feed blocks

Info

Publication number: CN1003491B
Application number: CN86106235.3A
Authority: CN
Inventors: 雷内·特雷尔
Original assignee: Buehler AG
Current assignee: Buehler AG
Priority date: 1985-09-02
Filing date: 1986-09-02
Publication date: 1989-03-08
Also published as: CN86106235A; CH664705A5

Abstract

There is a vibrating discharge device 29-33 below the feed device 19-24 on the container 11 of the feed block cooler, and a discharge bottom plate 32 supported on the rubber buffer 35, on which a belt facing upward is fixed. The air-permeable conical bottom plate 29 of the apex 30 ensures that the processed products can be evenly distributed in all directions. The processed product is discharged between the outer edge of the container wall 10 and the bottom plate 29, and its passage cross-section is adjusted by a height-adjustable annular metering valve 38 mounted on the wall. Cooling air is poured into the device through the annular air inlet 40 and drawn through the air-permeable floor and the processed product and storage chamber at the air outlet 26 by means of an aspirator.

Description

Device for treating bulk material with gas, particularly for air-cooling feed blocks

The invention relates to a device for treating bulk goods with gas, in particular to a cooler for feed blocks, comprising a container, which has a supply device for processed goods and a storage chamber for treatment gas in the upper part and a gas-permeable discharge device for treatment gas in the lower part.

Dutch publication NL-OS 7908335 shows such an apparatus for treating work in gas convection. The discharge of the processed product from the container is carried out over the entire surface by means of a reciprocating frame which is provided with two grids arranged at a vertical spacing from each other, each grid consisting of wide, flat, transversely arranged profiles, so that the discharge channel is relatively narrow. The channels of the two grids are arranged opposite one another, so that a discharge process takes place when the discharge frame is moved. In order to prevent the processed products from being able to settle on the profiles of the lower grate during the discharge, it is necessary to provide a third fixedly mounted grate between the two moving grates, the cross members of which serve as scraper elements of the lower grate. The discharge device is therefore of relatively complex construction and it is not self-emptying. Problems may also arise with regard to the distribution of the work product over the cross-section of the container.

The device according to the invention solves this task by providing a simple device that allows an automatic distribution of the processed products over the entire cross section of the container, while all the processed products can be emptied without forming a pile. During inspection, the discharge device can be easily disassembled, so that the inner surface can be easily accessed.

The device according to the invention is characterized in that the discharge device has a conical gas-permeable bottom plate, which is provided with an upwardly pointing apex, and that the conical gas-permeable bottom plate is moved by a vibration generator with a vibration, the main direction of movement of which is horizontal, preferably with a slight tilting movement, by a rotational vibration about the vertical axis of the conical bottom plate, and that the conical bottom plate projects outwardly from the lower part of the container wall when the work product discharge gap is open.

The processed products are automatically and uniformly distributed in all directions as long as the processed products are conveyed towards the tip direction of the air-permeable bottom plate. Due to this good distribution it is possible to feed process gas from the beginning, which increases the discharge and ensures that the process is guaranteed also when the charge is not high (when the vessel is not full).

This is particularly simple if the air-permeable bottom plate is fastened to a preferably downward conical discharge bottom plate, which is provided with a central discharge opening, so that the work product at the edge of the conical bottom plate can be transferred to the discharge bottom plate, while an annular air inlet is formed between the air-permeable bottom plate and the outer edge of the discharge bottom plate. It is advantageous to provide this air inlet, which can easily be reduced to the desired size by mounting a baffle, if necessary. In addition, it is advantageous to fasten the vibration generator to the discharge floor, which can be supported on a movable support, preferably a rubber buffer.

If an annular metering valve of adjustable height is mounted on the lower edge of the container wall, the discharge of the work pieces can be accurately adjusted, the height of which relative to the gas-permeable base plate determines the passage cross section of the work pieces to be discharged. In order to increase the dosing accuracy, the dosing valve may be moved helically by means of a tilt guide or a bracket. An apparatus can be made such that: the guide means are then formed by ramps distributed around the periphery of the metering valve, which ramps are supported on rollers mounted on the container wall and have a rotary drive, preferably a pneumatic piston.

A significant advantage is obtained if the metering valves are spaced less apart around the outer edge of the gas-permeable base plate, while their lower edge is provided with notches for passage of the work piece. It is possible to completely suppress the discharge process by means of the metering valve even if the gas-permeable bottom plate vibrates. Unlike a lower edge of a uniform metering valve, these notches can greatly reduce the discharge length, for example to a quarter of the circumference of the vessel. Thus, the quantitative accuracy is again greatly improved, and it is possible to accurately control the small discharge amount. To completely empty the container, the dosing valve can be placed higher so that the residue is emptied on the entire periphery.

In order to achieve automatic operation, it has been shown that a highly sensitive element can be arranged in the container, which element is adjusted or controlled to act on the drive of the metering valve and also on the switching-on and switching-off device of the vibration generator, so that a continuous or discontinuous discharge of the container can be carried out selectively.

The feeder device may have superimposed inclined slides which determine the transport of the work pieces along a zigzag path and allow the press provided for this purpose to be evacuated through the reservoir.

In order to obtain a sufficient pressure bleed without short circulation down the compressor, the bleed resistance indicates that the ratio of the air flow through the work piece to the bleed air flow should be above 5: 1, preferably 8: 1. This ensures that a change in the air flow in the feeding device does not have a great influence on the air flow through the work piece and thus on the cooling effect.

The drawing shows schematically a design as an example of the invention, namely:

FIG. 1 shows a vertical section through the axis of the container and the discharge device;

FIG. 2 shows a plan view with its container removed and its gas permeable base panel removed;

FIG. 3 shows an enlarged view of detail III of FIG. 1;

FIG. 4 shows the side view of FIG. 3 in the direction of arrow IV of FIG. 3;

wall 10 of bulk cooler vessel 11 is provided with a flange 12 which assists in reinforcement and serves to support vessel 11 on a support frame 13. The supporting frame 13 consists of beams 15 arranged in a quadrilateral shape, which are supported by legs 16.

A feeding device 17 is arranged in the upper part 18 of the lump-cooler. The feeder device has a feeder opening 19, below which inclined slide plates 20-23 are arranged, and a vertical wall 24 for guiding the work piece. A process air reservoir 25 formed by the upper part 18 is connected via an air outlet 26 to a suction fan, not shown.

A gas-permeable bottom plate 29 with an upwardly pointing tip 30 is fastened by means of support elements 31 to a downwardly directed conical discharge bottom plate 32, which is provided with a central discharge opening 33. The air permeable base 29 is preferably formed by a perforated plate having an aperture smaller than the size of the feed block, for example having an aperture of 3 mm.

The discharge floor 32 is provided with an outer flange 34 which bears on a rubber buffer 35 as a movable support, which in turn is supported by a bracket 36 fixed to the leg 16. The discharge floor 32 is equipped with two vibration generators 37, for example with unbalanced weights rotating about a vertical axis. Since the vibration generators 37 are arranged symmetrically and synchronously on the discharge base 32, a rotational vibration about the vertical axis of the conical base is generated on the air-permeable conical base 29 by the support elements 31, so that a substantially horizontal movement direction with a slight tilting movement is generated for the individual points of the

discharge devices

29, 32. Such a transmission with identical support is known from the U.S. patent documents US-PS3257040 and 3261592. Instead of a rubber damping element, it is also possible to use tapered rubber sleeves, articulated supports and the like as the support element, it also being possible to arrange a separate vibration generator in the middle.

On the lower edge of the wall 10 of the container 11, an annular metering valve 38 of adjustable height is provided. As can be seen from fig. 3, the gas-permeable conical bottom plate 29 projects outwardly below the wall plate 10 with an annular discharge gap 39 of the work piece open. An annular air inlet 40 is formed between the outer edge of the air-permeable bottom plate 29 or one side of the annular metering valve 38 and the other side of the discharge bottom plate 32.

The annular metering valves 38 surround the gas-permeable conical bottom plate 29 at a slight distance. The valve is provided with bearing plates 43 at different positions around its periphery, on which guide rails 44 are fixed. The guide rail 44 is supported on bearing wheels 45 which are rotatably placed on a shaft 46 fixed to the wall plate 10. For centering the annular metering valve 38, the guide rail 44 is provided with a ridge 47, which then projects into a recess 48 of the support wheel 45. On one of the beams 15, a cylinder 50 of a cylinder-piston arrangement is articulated, the piston 51 of which acts on a lug 52 of the annular metering valve 38. Depending on the direction of movement of the piston 51, the guide track is rotated to the right or to the left (fig. 4) and the annular metering valve 38 is raised or lowered in a spiral-shaped manner by the guide track 44 in cooperation with a rotatably mounted support wheel 45 arranged at a fixed point. The lower edge 54 of the annular metering valve 38 is provided with notches 55 distributed over the periphery. The total length of the gap, which is determined by the desired discharge and by the required accuracy, is preferably 10% to 50%, preferably 15% to 40%, in particular 25%, of the circumference of the annular discharge valve 38.

A highly sensitive element, not shown, can advantageously be installed in the container 11. It controls the cylinder-piston arrangements 50, 51 and thus also the height of the annular metering valve 38 relative to the outer edge of the gas-permeable conical bottom plate 29 to determine the passage cross-section of the work piece to be discharged. With the same control, the transmission of the vibration generator 37 can be disconnected if the annular metering valve 38 is closed.

The functions are as follows: in the case of the device shown, the container 11 is empty and the discharge slit 39 is closed by the ring valve 38. The vibration generator 37 is turned off. The work product to be treated is thereafter continuously fed through the feed opening 19 and flows downwards at a braked speed past the slides 20-23. The vertical wall 24 deflects the work piece in the direction of the apex 30 of the conical air-permeable base 29, from the apex 30, distributing the work piece in all directions up to the discharge gap 39. This quickly covers the air-permeable bottom plate 29 with a layer of work and switches the suction fan on. Outside air is drawn into the extractor through the annular air inlet 40, the air-permeable bottom panel 29, the work and the reservoir 25, and through the air discharge opening 26. The work-pieces flowing through the slides 20-23 produce a lockage effect that satisfies the general relationship of series connected drain pipes. Otherwise, a special gate may be installed in front of the feedwell 19. When the required degree of filling of the container 11 is reached, the highly sensitive element switches on the pneumatic cylinder and piston arrangement 50, 51, causing the annular metering valve 38 to rotate to the right (fig. 4). The guide rail 44 and thus the entire annular metering valve 38 are lifted by the support wheel 45, so that the recess 55 opens up into a passage cross section and the work piece is discharged. The annular metering valve 38 is adjustable by the control device to equalize the discharge and supply. If the discharge takes place over the entire circumference, a great accuracy can be achieved in that the discharge length is reduced by the notches 55, by means of an existing vertical movement of the annular metering valve 38, for example with a small variation. However, if the container 11 is to be emptied completely, the ring-shaped metering valve 38 can be raised so that its lower edge 54 reaches above the outer edge of the conical gas-permeable bottom 29 and opens all of the discharge gap 39. This allows the container 11 to be emptied completely.

Claims

1. A device for treating bulk goods with gas, particularly suitable for air coolers for feed blocks, comprising a container with a spacer supply device and a treatment gas storage chamber in its upper part, and a treatment gas permeable discharge device below it, the discharge device having a conical gas permeable bottom plate, the cone of which is provided with an upward-pointing peak, characterized in that the discharge device is provided with an oscillation generator (37) so as to cause the conical gas permeable bottom plate to vibrate horizontally and preferably to rotate with a slight tilting movement around the vertical axis of the conical bottom plate (29), and when the annular discharge gap (39) for the processed product is open, the conical gas permeable bottom plate protrudes outwards from the lower part of the wall (10) of the container (11).

2. The device according to claim 1, characterized in that the air-permeable bottom plate (29) is fixed to a preferably downwardly directed conical discharge bottom plate (32), the conical discharge bottom plate being provided with a central discharge opening (33) so that the processed products at the edge of the air-permeable bottom plate (29) can be transferred to the discharge bottom plate (32), and an annular air inlet (40) is formed between the outer edge of the air-permeable bottom plate (29) and the discharge bottom plate (32).

3. A device according to claim 1, characterised in that there are adjustment means (38) for adjusting the effective height of the annular discharge gap (39).

4. The device according to claim 3, characterized in that a height-adjustable annular metering valve (38) is installed on the lower edge of the wall (10) of the container (11), and its height relative to the air-permeable bottom plate (29) determines the passage cross section of the processed product to be discharged.

5. A device according to claim 4, characterised in that it comprises an inclined guide or bracket (44) for enabling the dosing valve (38) to move in a spiral manner.

6. A device according to claim 5, characterized in that the guide means (44) consists of inclined guide rails (44) distributed around the periphery of the metering valve, the guide rails being supported on support wheels (45) mounted on the wall (10) of the container (11) and having a rotation transmission device (50, 51), preferably a pneumatic piston (51).

7. A device according to any one of claims 4 to 6, characterized in that the clearance around the outer edge of the air-permeable bottom plate (29) of the metering valve (38) is small, and a number of notches (55) for passage of the processed product are provided at the lower edge (54) of the metering valve (38).

8. The device according to claim 4, characterized in that the container (11) has a height sensitive element which acts on the transmission device (50, 51) of the quantitative reverse side (38) through adjustment or control, and also acts on the connection and disconnection device of the vibration generator (37), so that a continuous or discontinuous discharge process can be selectively performed.

9. An apparatus according to claim 1, characterized in that the feed device (17) has superposed inclined slides (20-23) which determine the conveyance of the product along a zigzag path and allow the press provided therefor to be evacuated through the reservoir (25).

10. An apparatus according to claim 9, characterized in that the suction resistance of the apparatus is such that the ratio of the air flow through the workpiece (paths 40, 29, 11, 25, 26) to the air flow through the suction (paths through the pressure passages 19, 20-23, 25, 26) is at least 5:1, preferably at least 8:1.