FR2798371A1 - Transfer device for use in manufacturing animal feed has Archimedes screw in housing with normally closed valve at outlet and has inlet at lower air pressure than outlet - Google Patents

Abstract

A device transfers material from a low pressure area to a high-pressure area of a pneumatic transporter. The device has a motor driven Archimedes screw within a housing with a valve at its outlet end. An elastic device holds the valve in its closed position. An Independent claim is included for equipment for making animal feed has silo(s) for grain, minerals, etc, a crusher, a mixer, silo(s) for the finished feed and a compressor connected to a pneumatic transporter with a high pressure part for moving the grain, minerals, etc and a low pressure part. A transfer device as above separates the two parts of the transporter. Preferred Features: The housing is cylindrical and the screw extends along it. The elastic device is a spring or a pneumatic actuator. The mixer extends upwards to a filter sleeve at its top. Air is evacuated so that material is transported from the crusher into and up through the mixer .

Description

<U> DEVICE FOR ENSURING THE TRANSFER OF </ U> MATERIALS <U> OF A PART </ U> DEPRESSION <U> TOWARDS A PART </ U> <U> BY SURPRISING A PNEUMATIC CARRIER </ The present invention relates to a device for ensuring the transfer of materials from a part in depression to a part of the plant. overpressure of a pneumatic conveyor.

A carrier having a portion in depression and an overpressure portion has for example been described in the French patent filed February 1, 1999 under N 99 <B> 01076. </ B>

This transporter is used in a livestock feed production facility in which raw materials such as cereals and minerals are taken from storage silos, conveyed to a grinder and mixer for processing into flour, then conveyed to flour storage silos.

In the installation described in patent FR 99 01076, the transfer of materials from the vacuum zone to the overpressurized area of the conveyor is provided a rotary valve called lock.

The object of the present invention is a device that is both more efficient and more economical than the rotary plug device.

To this end, the invention relates to a device for ensuring the transfer of materials from a portion under vacuum to a portion in overpressure of a pneumatic conveyor, characterized in that it comprises a motor-driven Archimedes screw and disposed in a frame whose outlet end is closed by a valve held in the closed position by an elastic means. The device according to the invention is also remarkable in that - the frame is composed of a box having an inlet and a cylinder, - the Archimedes screw is disposed in the box and in the cylinder, - the axis the Archimedes screw is coincident with the axis of the cylinder, - said Archimedes screw does not extend over the entire length of the cylinder, - the elastic means is a spring, - the elastic means is a pneumatic cylinder.

The invention also relates to a food production plant for lifting, in which raw materials such as cereals and minerals are processed to obtain a finished food, said installation comprising at least silo containing raw materials, a mill, a mixer and at least one silo for storing finished foodstuffs and a pneumatic conveyor fed by a booster for transporting the materials, consisting of two parts, one in depression and the other in overpressure, characterized in that said two parts of the conveyor are separated by a device for ensuring the transfer of materials from a depression portion to an overpressure portion of a pneumatic conveyor according to the invention.

The installation is still remarkable in that - the mixer carries a decompression filter sleeve through which the air transporting the raw materials to the grinder and the mixer is evacuated and discharged by the decompression filter sleeve carried by said mixer the air necessary for transporting the flour leaving the mixer is sucked into the upper part of the mixer so that it passes through the filtering sleeve and ensures cleaning of the accumulated dust against the wall thereof during loading of said mixer.

The invention will be better understood from the following description given by way of non-limiting example with reference to the accompanying drawings, in which - FIG. 1 is a diagrammatic view of a feed production plant comprising a transfer device according to the invention, - Figure 2 is a schematic view of the transfer device according to the invention, - Figure 3 shows the device of the invention seen from the outside, - Figure 4 is a sectional view. of the device according to the invention. The food manufacturing plant comprises at least one silo containing raw materials, grain silo 3 or mineral silo 4, a hopper 1 a mill 5, a mixer 50 and at least one silo for the storage of manufactured foodstuffs, silo 6. The transport of materials, whether raw materials or finished flour, is carried out by means of a single pneumatic conveyor fed by a booster 2 and comprising a set of valves and valves.

As visible in the drawing, the pneumatic conveyor is composed of: - a pipe connecting the booster 2 to an air intake 20 'through a valve V3, - two pipes 21, 22 each comprising a valve V2 connecting said booster 2 to the hopper 1, said pipes being respectively disposed on the upstream side and the downstream side of said booster 2, - a pipe 23 connecting the raw material silos 3, 4 to the inlet of the hopper 1, - a pipe 24 comprising a valve V4 connecting the booster 2 to the outlet of the hopper 1; - a pipe 26 connecting the outlet of the hopper 1 to the storage silo 6, the inlet of the mill 5 and the inlet of the mixer 50, - a pipe 25 connecting the outlet of the mixer 50 to the inlet of the hopper Said conveyor is in two parts, one, consisting of the pipes 21, 23 and in depression, and the other, consisting of the pipes 24 and 26, in overpressure we. The booster supplying the pneumatic conveyor draws air contained in sealed hopper 1 so as to maintain its internal volume in depression.

The hopper 1 is equipped with a device 11 ensuring the transfer of materials from the vacuum portion of the conveyor to the overpressurized portion thereof.

The operation of the feed production facility shown in Figure 1 is recalled below.

The valves V2 and V3 being closed, the hopper 1 is put under vacuum through the pipe 21 connected to the inlet of the booster 2 by the opening of the valve Vl. The air of the hopper is sucked through a filter 10 so that the air passing through the booster 2 does not carry any dust that could disrupt the operation of said booster 2.

The booster 2 discharges downstream in a pipe 24 connected to the device 11.

The raw materials are fed into the hopper 1 by being sucked into the pipe 23 when the valve V4 is opened and an outlet valve V30 or V40 from one of the raw material silos 4 while the ventilation valves V31. and V41 are closed.

When the loading of a cereal is complete, the valve V30 of the silo which was contained is closed and the ventilation valve V31 is opened to finish the conveyance of the cereal towards the hopper 1. The ventilation valve V31 is then closed while the valve V30 of another silo 3 is opened to suck a second cereal. This cycle is repeated for all cereals needed for the flour being manufactured.

The cereals contained in the hopper 1 are conveyed through the device 11 and the pipe 26 to the mill 5 after the closing of the valves 1 and the opening of the valves V55 and V50. Once crushed, said grains are admitted into the mixer 50, the air ensuring their transport through the mill mixer 50 and being discharged by the decompression filter sleeve 51 carried by said mixer.

Usually, the minerals are not ground, they are transferred to the mixer 50 through the device 11 and the pipe 26 after closing the valve V55 and open the valve V51. Air transporting them is evacuated through the filtering sleeve 51.

As for cereals, the V40 valves of the mineral silos 4 and the V41 aeration valve are opened in turn to allow the transport of the various minerals.

A high level detector 12 is disposed in the hopper 1. When the materials reach this level, for example in the case where the flow rate of the mill 5 is lower than that of the suction of the cereals in a silo 3, the level detector top 12 is enabled. This causes the closing of the outlet valve V30 of the silo 3 in which the material is sucked and the opening of the ventilation valve V31 so as to ensure the transport of the grains already present in the pipe 23 by stopping the suction of additional material.

The ventilation valves V31 and V41 are also opened when all the materials, grains or minerals, have been extracted from the silos 3 and 4, so as to complete the delivery of these materials in the hopper 1 then in the grinder 5 or the mixer 50.

A detector 13 placed at the bottom of the hopper 1 makes it possible to observe that all the materials have been transferred through the device 11.

The valve V4 is closed when all the raw materials have been conveyed into the mixer and it is put into operation.

The control of the quantities of raw materials admitted into the installation is carried out by weighing the assembly constituted by the hopper 1, the grinder 5 and the mixer 50, weighed to control the quantity allowed for each raw material and to automatically control the installation by opening and closing valves V4, V30, V50, V56, V51 and V55 depending on the transfers to be made.

When the mixing of the raw materials is completed, the pneumatic conveyor is returned to service and the valve V5 is opened in order to circulate the flour obtained in the mixer 50 in the pipe 25 connecting the output of said mixer 50 to the hopper 1. The valves V55, V56 and V6 are open while valves V51 and V50 are closed. The flour is thus sucked into the hopper 1 and then discharged through the device 11 and the line 26 to the flour silo 6 'it is stored.

The air necessary for transporting the flour in the pipe 25 sucked into the upper part of the mixer 50. As shown in the drawing, a bypass 53 is provided on the pipe 53. This bypass 53 is equipped with a valve by means of which it is possible to adjust the flow of flour in the pipe 25, this flow being maximum when the valve V52 is closed.

During the aspiration of the air necessary for the circulation of the flour in the upper part of the mixer 50, the air passes through the filtering sleeve 51 and ensures a cleaning of the accumulated dust against the wall thereof during the loading of said mixer. The installation according to the invention further comprises channel 22 by which the booster 2 can flow into the filter 10 of the hopper when opening the valves VZ and V3 and closes the valve Vl. This operation allows to clean the filter 10 to avoid its clogging. Such an operation can be performed automatically whenever the pneumatic conveyor is stopped at the end of a use phase.

As shown in the drawings, the transfer device 11 according to the invention comprises an Archimedean screw 211 driven by a motor 212 and disposed in a frame positioned under the sealed hopper 1. The frame is composed of a box 210, having an inlet intended to be positioned under the lower end of the hopper 1 constituted by an upper opening 218, and a cylinder 215 with an axis perpendicular to the axis of the hopper 1.

The Archimedean screw 211 is disposed in the box 210 and in the cylinder 21 so that its axis coincides with the axis of the cylinder 215. Said Archimedean screw 211 does not extend over the entire length of the cylinder 215.

The end of the cylinder 215 opposite the box 210 enters a view 2 communicating with the pipe 24-26 connecting the booster 2 to the device <B> 11 </ B> according to the invention and the storage silo flour 6, the inlet of the mill 5 and the mixer inlet 50.

The outlet end of the frame, that is to say the end of the cylinder 215 disposed on the side of the sight 216 is closed by a valve 213 held in the closed position by an elastic means 214 such as a spring or a pneumatic jack.

During commissioning of the food manufacturing facility, the device 11 is empty. The booster 2 being in operation the opening of the valve VI puts the sealed hopper 1 and the frame constituted by the box 20 and the cylinder 215 in depression and the opening of the valve V11 puts the pipe 24 and the look 216 in overpressure. The overpressure and vacuum portions of the conveyor are separated in a sealed manner from one another by the valve 213 repulsed by elastic means 214.

When the materials are conveyed into the sealed hopper 1 and enter the box 210 through the opening 218, the motor 21 is turned on to cause the screw 211 to rotate.

The rotation of the screw 211 causes the movement of the materials towards the end of the cylinder <B> 215 </ B> closed by the valve 213. The materials exert a pressure on said valve 213 and pushes it into the eye 216 to the against the action of the elastic means 214. The removal of the valve 213 opens the end of the cylinder 215 and allows the materials to flow in the eye 216 and the pipe 26 towards the mill 5 of the mixer 50.

The distance separating the end of the screw 211 from the end of the cylinder provided with the valve 213 makes it possible to create a cap of materials which ensures the tight separation between the zones of overpressure and depression of the conveyor when the valve 213 is open.

When the aspiration of the materials is complete, the valve V4 is closed and the valve is opened so as to clean the filter 10 and to finish emptying the frame of the device 11.

The valve V11 is closed so as to force the circulation of the air under excess pressure through the filter 10, the hopper 1 and the device 11 to expel all the materials in the pipe 26.

When closing the valve V2, the elastic means 214 pushes the valve 213 in its closed position of the transfer device 11.

As described in FR 99 01076, the materials are returned to the hopper 1 after having been ground and mixed. The motor 212 is, as described above, started to push the materials into the cylinder 215 until they open the valve 213.

The operating speed of the motor 212 is adjusted so as to ensure the rotation of the screw 211 at the appropriate speed so that the transfer of the materials from the vacuum zone to the overpressurized zone is achieved without disturbing the operation of the other elements of the engine. 'installation.

Claims (10)

1. Device intended to ensure the transfer of materials from a portion in depression to a portion in overpressure of a pneumatic conveyor, characterized in that it comprises an Archimedean screw (211) driven by a motor (212) and disposed in a frame whose output end is closed by a valve (213) held in the closed position by an elastic means (214). 2. Device according to claim 1, characterized in that the frame is composed of a box (2l0) having an inlet (218) and a cylinder (215). 3. Device according to claim 2, characterized in that the Archimedean screw (211) is disposed in the box (210) and in the cylinder (215). 4. Device according to claim 3, characterized in that the axis of the Archimedean screw 1) coincides with the axis of the cylinder (215). 5. Device according to claim 4, characterized in that said Archimedean screw I) does not extend over the entire length of the cylinder (215). 6. Device according to any one of the preceding claims, characterized in that the elastic means (244) is a spring. 7. Device according to any one of the preceding claims, characterized in that the elastic means (2I4) is a pneumatic cylinder. 8. Livestock feed production plant, in which raw materials such as cereals and minerals are processed to obtain a finished feed, said plant comprising at least one silo (3, 4) containing raw materials, a crusher (5), a mixer (50) and at least one storage silo (6) for the finished foodstuffs and a pneumatic conveyor fed by a booster (2) for conveying the materials, consisting of two parts, one (21, 23, 25) in depression and the other (24, 26) in overpressure, characterized in that said two parts of the conveyor are separated by a device (I 1) intended to ensure the transfer of materials from a portion in depression towards an overpressure portion of a pneumatic conveyor according to one of claims I to 7. 9. Installation according to claim 8, characterized in that the mixer (50) carries a decompression filter sleeve (51) through which is discharged the air transporting raw materials to the mill (5) and the mixer (50). ). 10. Installation according to claim 9, characterized in that the air necessary for the transport of the flour leaving the mixer (50) is sucked into the upper part of the mixer (50) so that it passes through the filtering sleeve (51) and ensures a cleaning of accumulated dust against the wall thereof when loading said mixer (50).