DE3410721A1 - Apparatus for feeding and discharging bulk material into and out of pressure chambers - Google Patents

Abstract

For discharging damp bulk materials from a pressure chamber, a chamber sluice is proposed which has a storage container which can be closed by means of two rotary plates and which is connected to the pressure chamber via a further container. The two containers have conical extensions in the direction of passage and have an inflatable elastic lining. The surfaces of the rotary plates are formed from inflatable elastic membranes. The linings and membranes permit detachment of the adhering bulk material.

Description

Device for loading and unloading bulk goods in and

clear from pressure The invention relates to a device for and discharge of bulk material into and from pressure rooms according to the preamble of the claim 1, especially when the solid particles of the bulk material mixed with a liquid are, so that it is a moist bulk material. With the device is aims at a safe and trouble-free transfer of solid particles, preferably wetted with liquid, between rooms different pressure levels with minimal respectively.

to enable lock gas loss to be prevented.

The increasing tendency to combine technical processes in one Overpressure atmosphere makes the use of reliably working airlocks mandatory necessary. Often this is only achieved through the presence of a suitable sluice device the "printing process" enables.

An example of this is the filtration at excess pressure, which is required makes the filtered, partially dehumidified and thus cohesive and adhesive Eject filter cake as partially lumpy bulk material from the pressure chamber.

In the past, a Rotary feeder used. However, this discharge device has only to be overcome proven low pressure differences between the pressure chambers. Due to the cell and gap losses, there is a large leakage gas throughput at higher differential pressures and the resulting pressure loss in the pressure process room. Continue to join the rotary valve through the discharge material, which is guided along the housing walls a strong equipment wear and tear, in addition to the actual equipment destruction leads to an increase in gas leakage losses. When discharging a moist bulk material Must be a forced discharge from the pockets of the rotary valve in general Star rotor are provided so that the adhesive product is safely out of the lock removed.

According to another system, the moist bulk material can be passed through a gas barrier be discharged from a pressure chamber. For this purpose, the solid flows through under the action of gravity vertical or inclined pipes. The sealing effect of the gas barrier is the result from the static Pressure of the solid column and the friction pressure loss of the gas as it flows through the gas barrier. As the flow of the to be discharged Solid in the blocking section, however, depends on the differential pressure between the process rooms and the bulk material properties, fluctuations and Changes lead to operational disruptions. To ensure a safe flow of the product ensure and to avoid the formation of solid bridges, it is with the Gas barrier required, depending on product property (e.g. fluctuating residual moisture take suitable measures for pressure filtration. This also means that the bridgeable pressure difference between the two spaces through the length the blocking distance and the bulk density is determined. It follows that the Gas barrier section will always require a considerably large overall height. The type of Austrages also means that gas blocking routes are not intrinsically safe are, so that shut-off devices and safety elements for starting and stopping the system required are.

The most frequently used entry / exit system at the moment is the Chamber lock. The basic unit of the chamber lock consists of a storage tank - the chamber - as well as a gas-tight shut-off unit on the inlet and outlet side.

Logical sequence controls via a control unit ensure that that only one shut-off device is open at a time and overlaps with certainty be avoided. Usually the upper shut-off unit is first in the discharge case open, while at the same time the lower, as gas-tight as possible, kept closed will. In this state, the system pressure in the chamber is the same as in the process room, from which the bulk material is initially recorded. The product arrives thus without differential pressure into the discharge area. During the filling time must therefore for this be ensured that the lower shut-off unit even after a long period of operation and worn sealing element closes as gas-tight as possible.

When the chamber is full, the upper shut-off unit is closed. After that, in many cases, the chamber volume is ventilated or ventilated, so that subsequently the lower shut-off unit can be opened without differential pressure.

In this position, the product then falls due to gravity out of the chamber.

In general, many chamber locks fail because of this requirement, since cohesive and adhesive products are bad or even worse without additional facilities cannot be carried out. Previous chamber lock designs are the The requirements of a moist, cohesive and mostly also adhesive bulk material are insufficient just. In addition to the already mentioned risk of caking, the incomplete and failure of the product in or out of the chamber and the associated possibility the bridging in the discharge space must be taken into account that especially very fine-grained and moist bulk goods, such as

Filter cake, too considerable in the sealing area of the shut-off units Abrasions can lead. This has the disadvantage of the system's own lock gas losses due to the leaks in the shut-off units, which occur over longer periods of operation can, even more so.

The invention is therefore based on the object of the shortcomings of the known Devices to avoid and the To design the chamber lock in such a way that that a safe bulk material infeed and outfeed, also moist, cohesive and adhesive Products in the entire grain size range of a bulk material can be achieved and the gas leaks associated with the inlet and outlet are prevented and the lock gas losses can be minimized.

This task is achieved by the characterizing features of the claim 1 solved. Advantageous embodiments can be found in the subclaims.

Exemplary embodiments are described in more detail below with reference to the drawings explained. 1 shows a section through a chamber lock; Figs. 2A and B two embodiments of turntables that can be used; Fig. 2C shows an embodiment an alternatively usable slide; 3A and B show two embodiments of Linings of the storage tank and the buffer volume; 4 shows an embodiment the sealing lip when using turntables and FIG. 5 shows an embodiment of a pressure reducing valve used in the system.

According to the structure of a chamber lock, the device in the core on a) an upper and a lower shut-off unit 1 and 2 b) one after at the bottom conically widening storage container 3 of the chamber.

In addition, above the upper shut-off unit 2 c) is also a Buffer volume 4 widening conically downwards is provided.

Storage tank 3 and buffer volume 4 are equipped with a, possibly influenceable, elastic lining 5 and provided via a bypass line 6 for the purpose of pressure equalization connected with each other. In the bypass line 6 is a for the purpose of the retention of solid particles provided gas / solids filter 7 and a 3-way shut-off device 8 installed, over that the ventilation of the storage container 3 is accomplished.

In the storage container 3 is for the purpose of detecting the fill level of the goods to be dispensed, a level measuring device 9 is installed. Furthermore is the storage container 3 is provided with a gas pressure measuring device 10, the measuring signal of which if necessary. can be forwarded to a control unit.

In a further embodiment, the storage container is with a Provide purge gas line.

The discharge device is controlled via a control unit performed.

One pressure-tight each preferably serves as shut-off units 1, 2 Bearing rotary flap unit, consisting of housing body, sealing ring, drive and turntable.

The turntable 13, 16 is designed and with additional devices provided that a permanent adhesion of cohesive discharge material largely prevented can be.

In one embodiment, the turntable 13, as in Fig. 2, Part A, shown, on both sides with an inflatable membrane 12 made of an elastic Covered with rubber material.

The interior of the membrane can pass through the hollow shaft via a compressed air line can be pressurized with compressed air.

Should material adhering to the turntable 13 during the discharge process are removed, for example with the turntable 13 standing vertically, then of compressed air is applied to one side of the hollow pressure plate shaft, and to the other Side of the hollow shaft flows off again. Due to a specifiable flow resistance in the hollow shaft the elastic membrane inflates 14. The deflection 15 of the The membrane is pressure-dependent and can therefore be influenced. Due to the swelling the surface enlargement adjusting the membrane, the adhering solid dissolves and falls off.

In another embodiment, the inflatable membrane consists, as in FIG Fig. 2, part B, shown, made of a non-elastic material which is made up in this way is that the expansion volume is given. In the non-inflated state, this subsides Membrane in folds on the turntable 16. When the bloating process is the membrane, preferably inflated by a shock-like pulse of compressed air. By the inelastic properties of the membrane 17 and that due to the packaging predetermined inflation volume ensures that the membrane does not have a jet pulse Suffering from overstretching. The pressurized air is applied by the in this case preferably one-sided drilled hollow shaft so that the compressed air through the same opening flows in and out.

In another version, the shut-off unit consists of a slide 18 with drive which, when opening the slide valve 18, covers the entire passage cross-section the shut-off unit releases. Swivel locks and flat slides serve as slide elements. The shooting zone of the Schieist is for the purpose of pressure-tight connection with a @@ enmat @ ach beaufs @ h @@ gbaren membrane @@@ @ring aus - @@ s @ @ Einsat @ @ Schieberorg @@ as a barrier - @@@@@ @@ ge @ @ a back @ koh @@@@@@ m Schütt - @@@@ @@@@ @@ ren dessel @@ d @@@@@@ gs - @@@@@@@ Verhi @ @ge @@@@@ k becomes @ @ @ @ @@ @ 19, @ @ -gs - @@@@@ @@ luidir; tendes @ @ @@ compressed air @ @@@@ Luftbe - @@@ @@ lgen. The @@@ @@ @@ the storage container 3) or is added to the printing process room (buffer volume 4). Is this state reached, the slide member is moved and the discharge cross-section of the chamber lock Approved. The prevention of caking on the shut-off unit through fluidization can also be transferred to the turntable in the manner described.

The buffer volume 4 and the storage container 3 are characterized by that they widen conically from top to bottom and from top to bottom no longer show constrictions. This ensures that the preferably moist, cohesive and adhesive bulk material when the failure occurs The discharge unit cannot be supported at any point, causing adhesion and growth (Bridging) is prevented.

The conical buffer volume 4 and the conical storage container 3 can consist of standard parts according to DIN 28645, but any special designs are also possible provided in the manner described.

In the case of particularly adhesive discharge materials, which despite the after Apparatus wall which widens conically at the bottom and which is free of constriction in the passage If there is a risk of caking and bridging, it is intended To provide buffer volume and storage container with an elastic lining 5. The material of the lining is preferably designed so that an expansion of the material well in one direction and in the other, perpendicular to it, not possible. This can be achieved, for example, with a textile insert. Through this will aims that the lining material can elongate in the radial direction, in axial direction but remains dimensionally stable. The elastic lining 5 is held so that that either by the elastic properties of the lining material alone in interaction with the impulses generated by the incoming and outgoing bulk material are exerted on the lining, a caking of cohesive bulk material is prevented or already adhering material is loosened and thrown off, or by from Compressed air pulses that can be imprinted on the outside of the lining can be shaken.

In one embodiment, as shown in FIG. 3, part A, they are annular Aprons 20 of different diameters so in the conical apparatus part 3.4 used that an overlapping lining is created over the entire height of the cone. These aprons can also be designed so that the release properties be reinforced, e.g. by fringing the lower edge.

In another embodiment, as shown in Fig. 3, part B, the lining material clamped at the upper and lower ends of the cone 3.4 and if necessary, additionally supported at one or more points above the height of the cone, so that a continuous covering 21 of the inner wall of the cone with the elastic Lining material results. The space between the lining and the container wall can be divided into one or more separate annular chambers, they individually, together, at the same time or in any order with a compressed air pulse to be introduced from the outside 22 can be acted upon.

In addition, any other suitable design is elastic Lining 5 conceivable, which as a combination of the embodiments described or in another type can be provided.

In addition to ensuring trouble-free transport of the bulk material through the lock apparatus, the task connected with the lock process is to be solved Stop gas leaks. These gas leaks occur when the shut-off units 1.2 do not close tightly.

This fact is mainly caused by wear of the sealing elements evoked. The sealing ring 23 of the shut-off unit 3, 4, of the rotary valve version as shown in Fig. 4, extends over the entire height of the organ, is, preferably with the turntable 24 in a horizontal position ("CLOSED" position), pneumatically from the outside retensionable. In this state, the sealing ring 25 is pressed from elastic material under the effect of the clamping pressure firmly and tightly against the edge of the rotary flap 24 at.

This ensures that the sealing mechanism even when worn Sealing edge of the shut-off element 24 is secured and also at higher differential pressures there is no gas leakage from the overpressure chamber. To do this, the pressure must, with the sealing ring 25 is tensioned, be greater than the system overpressure to be overcome.

In the same way it is necessary that the inflatable membrane 12 or the fluidization zone 19 of the shut-off units and possibly the elastic lining 5 of the buffer volume 4 can be actuated with a pressure greater than the system overpressure. This requirement is met through the use of a pressure reducer with System overpressure reached.

As shown in FIG. 5, this is a pressure reducer according to known technology, consisting of valve housing 26, upper part 27 with adjusting spring 28 and setpoint adjuster 29. In this embodiment, the upper part 27 is through a Replaced pressure-resistant metal sleeve, which is suitable for being loaded with the system overpressure to become. The pressure-resistant metal housing 27 is connected via a connecting line 30 pressurized with the system overpressure. This is how the system overpressure works on the operating diaphragm of the pressure reducer, causing the The excess pressure to be reduced is reduced to a maximum of the system excess pressure.

By biasing the adjusting spring 28 on the setpoint adjuster 29 is now set the level of the differential pressure with which the sealing ring 23 is re-tensioned, or the expansion membrane 12 or the fluidization zone 19 is acted upon. By this device is achieved that even with fluctuating system overpressure the corresponding Apparatus parts are always supplied with the required differential overpressure.

Most bulk material lock operations in and out of pressure rooms are involved it is normal air as lock gas. In special applications, especially in In the chemical industry, valuable gases or toxic gases are also used. In this case, the lock gas in the storage container 3 after pressure equalization, before opening the lower shut-off unit 2, by means of a purge gas, e.g. ambient air, are largely displaced and so the proportion of lock gas that is to be channeled Bulky goods are transported out, can be minimized. For this purpose it flows in the Storage container 3 via a purge gas line 11 or via the fluidization zone 19 the purge gas into the storage container 3. After a long enough time of the After rinsing, the discharge process is continued in the usual way. The executions on purging the storage container with additional gas for the purpose of displacing the Lock gas also apply in the same way to the process of introducing bulk goods in a pressure room, e.g. if a reaction gas atmosphere prevails there.

The control and temporal regulation of the partly temporal one on top of the other The following discharge steps, some of which run in parallel, are carried out via a to Control unit belonging to the discharge device. These are preferably a permanently programmed control with variably adjustable times, however also controls with timers in combination with limit switches or purely mechanical Systems such as control with camshaft are provided. All control systems have in common that the timing can also be changed afterwards and so the respective lock process can be optimally adapted.

The terms used in the description are intended to be in their most general terms Meaning to be understood. Therefore, the method described and the one used for it Apparatus can be used for every inward or outward transfer process where differential pressures are involved moderate height must be overcome.

The grain size of the bulk material is not downwards and upwards limited by the largest free passage of the apparatus. The fluid content of a damp one The bulk material to be sluiced can within wide limits vary, so that on the one hand dry products, but on the other hand also pasty, liquid-like materials can be funneled. Furthermore, the Material selection of the apparatus parts described, in particular the fluidization zone 19, the retensionable sealing ring 23, the elastic and the non-elastic Membrane 12 or 16 no restrictions are provided. The cone angle of buffer volume 4 and storage container 3 can be freely selected. The overall height of the entire lock apparatus is downwards only due to the specified dimensions of the shut-off units 1.2 limited, upwards it can be increased as required. The drive of the Shut-off units are carried out by controllable drive units. Every system is there Can be used in accordance with the state of the art, such as compressed air motors, electric motors, induction-excited motors Push rods and the like. In the general sense, the gaseous gas is used as the lock gas Phase understood that with the bulk material in the storage container under pressure conditions comes into contact, which prevail before or after the chamber lock.

For a more detailed explanation, the device is made with reference to FIG the continuous pressure filtration of processed beets is described in more detail. at Rotary filters such as drum or disc filters are used for continuous pressure filtration for solid-liquid separation of pulp in one to 4 bar (in special cases up to 6 bar) Overpressure designed pressure chamber operated. After the solid-liquid separation process falls generally a lumpy to free-flowing filter cake made of fine-grained solids at, its degree of saturation S (degree of saturation S = ratio of Liquid volume to void volume of a porous volume element) between S = 0.3 to S = 1 can vary. The filter cake must be as continuous as possible as bulk material be channeled from the printing process room into the normal atmosphere. To this Purpose it falls into a discharge shaft after the filter cake has been removed from the filter, to which the discharge unit is subsequently flanged.

According to FIG. 1, the lower one is at the beginning of the discharge cycle described Shut-off unit 2, here a rotary valve, closed in the horizontal position and additionally sealed by the pneumatically retensionable seal 25.

The upper shut-off unit 1, here also a rotary valve, is in open in the vertical position. In this state the lock prevails in the chamber lock The pressure of the process room and the filter cake falls through the discharge shaft and buffer volume 4 into the storage container 3.

Furthermore, the storage container 3 is via the bypass line 6 and the suitably switched 3-way shut-off device 8 is coupled to the process room. In this position, the storage container 3 is up to a predetermined level filled, which is determined by the level measuring device 9. Form during the filling process on the lined wall 5 of the buffer volume 4 caking of moist, cohesive filter cake, these can, due to the fluttering movement, through falling pieces of filter cake in the elastic lining 5 Impulse initiation are caused to be replaced again.

When the specified level is reached, the upper rotary flap is activated 1 closed. When the upper rotary flap has reached the horizontal position, will the pneumatically still tensionable seal 23 with an overpressure greater than the pressure Tensed in the process room and firmly applied to the edge of the rotary flap 25. the Supply of the seal 23 with a sufficiently large excess pressure takes place through the called pressure reducer, Fig. 5.

If the upper shut-off unit 1 is completely tight, the 3-way shut-off element is used 8 in the bypass line 6, the coupling of the storage container 3 with the printing process chamber interrupted and at the same time a connection of the storage container 3 with the normal environment Approved.

In this way, the storage container 3 is expanded to ambient pressure. This prevents this in the bypass line 6 between the storage tank 3 and the 3-way shut-off device 8 used gas / solids filter 7 that the outflowing compressed air stream from the storage container 3 entrained solid particles in the 3-way shut-off device 8 and lead to leaks there during the opening and closing process could. At the end of the relaxation process, determined by pressure measurement 10 in the storage tank or by the lapse of a set period of time, the pressure is released from the pneumatic retensionable seal 25 of the lower shut-off unit 2 removed and the lower Rotary flap opened without differential pressure by turning to vertical position. While or immediately after the end of the turning process, the inflatable membrane 12, 16 is actuated, whereby the bulk material adhering to the rotary flap under certain circumstances is detached. At the same time the filter cake material falls by gravity from the storage container 3 into the normal environment. During the emptying process of the storage container 3 is the elastic lining 5 of the lower cone space set in motion by compressed air to detach adhering discharge material.

If the emptying period has expired, the lower shut-off unit is 2 by turning the rotary flap to the horizontal position and then closed again the pneumatically retensionable seal 23, supplied via the pressure reducer, Fig. 5, stretched again. Following in time, the bypass line 6 and the will now be suitable switched 3-way shut-off device 8 of the storage container 3 again with the printing process room coupled and covered in this way. At the end of the pressure equalization process between Storage tank 3 and pressure process room, determined by pressure measurement 10 in the storage tank 30 by lapse of a set period of time, the preloaded seal becomes 25 of the upper shut-off unit 1 relaxed and the upper rotary flap without differential pressure brought into vertical position.

During the discharge process described so far, has occurred the upper, closed shut-off unit 1 in the buffer volume 4 of the continuous accumulated filter cake. When the upper rotary flap is opened, it falls now in the storage tank 3. As for the lower shut-off unit 2 described, the inflatable membrane 12, 16 actuated and so adhering filter cake of the rotary flap detached. The same applies analogously to the one on the buffer volume wall 4 adhesive material. The upper rotary flap then remains that long opened, until the storage container 3 has reached the desired bulk material level again. The discharge process is then repeated as described.

Instead of the rotary valve with an inflatable membrane, a flat slide valve can also be used be set with fluidization zone. The times for the individual discharge steps are freely definable.

The device thus offers a means to even difficult, abrasive Bulk goods with liquid components, which make them particularly cohesive and adhesive Have properties, safely and with little to very little loss of lock gas in and out of pressure rooms. The chamber lock is designed so that too With long operating times, there is a high degree of certainty that caking and thus blockages will occur of the bulk material flow can be avoided by bridging in the discharge device. the Device offers the possibility of shedding heavily abrasive Materials, such as moist filter cakes from treatment products, without leakage gas losses to work and any abrasions on the shut-off units that lead to increased Loss of gas leakage could lead to compensate.

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Claims (15)

Claims 1. Device for feeding and discharging bulk material in and out of pressure chambers with a storage container connected to the pressure chamber with two openings that can be closed by shut-off devices, one of which leads to the pressure chamber leads, in that the storage container (3) is in The flow direction is flared and this storage container (3) on its inner wall an elastic lining (5, 20, 21). 2. Apparatus according to claim 1, characterized in that g e k e n n -z e i c h n e t that seen in the direction of flow in front of the storage container (3) a buffer volume (4) forming another container is arranged, which is conical in the passage direction expanded, has an elastic lining (5, 20, 21) on its inner wall, a shut-off element (1) is arranged between the two containers and the outlet cross-section of the further container is equal to or smaller than the inlet cross-section of the Storage container (3). 3. Apparatus according to claim 1 or 2, characterized in that g e -k e n n z e i c h n e t that the turntables (13,16,24) used in the shut-off devices (1,2) respectively. Slide (18) at least on its to the passage direction pointing Side have a changeable or the bulk material fluidizing surface. 4. Device according to one of claims 1 to 3, characterized g e k e n n z e i c h n e t that when using turntables (13,16,24) the edge of the turntable in the closed state enclosing seal (23, 25) can be tightened by a fluid is and here engages over the edge of the turntable radially inward. 5. Apparatus according to claim 1 or 2, characterized in that g e -k e n n z e i c h n e t that the elastic lining consists of overlapping aprons (20) consists. 6. Apparatus according to claim 5, characterized in that g e k e n n -z e i c h n e t that the aprons (20) have fringe-shaped incisions on their free edge. 7. Apparatus according to claim 1 or 2, characterized in that g e -k e n n z e i c h n e t that the elastic lining (21) with the container wall at least forms a closed annular chamber. 8. Apparatus according to claim 7, characterized in that g e k e n n -z e i c h n e t that the annular chambers of the storage container (3) and of the buffer volume (4) forming Containers can be pressurized, the at least one annular chamber furthermore Container can be acted upon with a pressure that is greater than that in with space connected to it and wherein the at least one annular chamber of the storage container (3) with a print can be acted upon, which is at least greater than the one in the space that can be connected to it via the outlet valve 2). 9. The device according to claim 4, characterized in that g e k e n n -z e i c h n e t that the seals (23, 25) can be acted upon with a pressure which is greater is than the maximum pressure occurring in the storage tank (3). 10. Apparatus according to claim 5 or 6, characterized in that g e -k e n n z e i c h n e t that the skirts (20) are cylindrical. 11. The device according to claim 3, characterized in that g e k e n n -z e i c h n e t that the surfaces by inflatable elastic or inelastic membranes (12,17) can be formed. 12. The device according to claim 11, characterized in that g e k e n n -z e i c h n e t that the inflation pressure of the membranes (12, 17) at the inlet valve (1) is greater is than the pressure in the further container and the inflation pressure of the membranes (12,17) at the outlet valve (2) is at least greater than the pressure in this valve (2) adjoining room. 13. The apparatus of claim 8 or 12, characterized in that g e -k e n n z e i c h n e t that the pressure is applied in a pulsed manner. 14. The device according to claim 3, characterized in that g e k e n n -z e i c h n e t that the surfaces each form a fluidization zone (19). 15. The device according to claim 1 to 14, characterized in that g e -k e n n z e i c h n e t that in the storage container (3) each open an inlet and an exhaust line and when the shut-off devices (1,2) are closed, the storage container (3) via the supply line a gas is supplied that the gas in the storage container (3) via the Exhaust pipe displaced.