Blowing device for a rotary airlock

Abstract

Disclosed is a blowing device for a rotary air lock, comprising a flushing gas stream that is fed by a gas supply line (12) in order for adhering material to be flushed and blown out of at least one compartment (20-24) of the rotary air lock (20-24) when said compartment is located next to a product outlet of the rotary air lock. A blowing unit (30), which comprises at least one blowing tube (32) and is located in a feeding shoe (10) that is arranged at the product outlet, directs the flushing gas stream to at least one compartment (20-24) of the rotary air lock.

Claims

1. A blowing device for a rotary airlock (1) having a flushing gas stream (33, 33a), which originates from a gas supply (12), for flushing and blowing out adhering material from at least one airlock chamber (20-24) when it is located closest to a product outlet (7) of the rotary airlock (1), wherein the blowing device (30) having at least one blowing tube (32, 32a) orients the flushing gas stream (33) onto at least one airlock chamber (20-24), wherein a feeding shoe (10) is arranged at the product outlet (7), in which the blowing device (30) is arranged, and the gas supply of the blowing device (30) is supplied by a conveying gas stream applied at the inlet to the blowing device (30).

2. The blowing device according to claim 1, wherein the gas supply of the blowing device (30) is supplied by a total gas quantity (40) applied at the inlet to the blowing device (30).

3. The blowing device according to claim 1, wherein the feeding shoe (10) has a terminating plate (26) as a shutoff between the gas supply (12) and the product outlet (7), at which the inlet side of the blowing device (3) is situated in a gas-conducting manner.

4. The blowing device according to claim 1, wherein the contour of the orifice (32) of the blowing tube (31, 31a) is formed profiled and/or constricted in relation to the tube cross section of the blowing tubes (31, 31a).

5. The blowing device according to claim 1, wherein the flushing gas stream (33, 33a), after flushing the airlock chamber (20-24), leaves it opposite to the injection direction.

6. The blowing device according to claim 1, wherein if at least two blowing tubes (32, 32a) are provided, the flushing gas streams (33, 33a) of the blowing tubes (31, 31a) are oriented toward one another and produce a discharge flow oriented toward the outlet in the airlock chamber (20-24).

7. The blowing device according to claim 1, wherein the injection points of the blowing device (30) into the airlock chamber (20-24) to be flushed are arranged divergently, and the produced flushing gas stream (33, 33a) is unified again in the middle region of an airlock chamber (20-24) and flows out in the direction of a collecting chamber (37).

8. The blowing device according to claim 1, wherein a component of the injected total gas quantity (40) flows as a leaked gas quantity (42) through the housing of the rotary airlock (1) and leaves the housing via a leaked gas nozzle (17).

9. The blowing device according to claim 1, wherein a number of rotary airlocks (1) are arranged serially in succession and operate on a shared conveyor line (13), wherein a blowing device (30) is associated with each of the rotary airlocks (1) arranged therein.

10. The blowing device according to claim 9, wherein a shutoff device (44) adjustable via a motor (35) is arranged downstream of the product outlet (7) and upstream of the conveyor line (13).

Description

[0032] In the figures:

[0033] FIG. 1: shows a first exemplary embodiment of the invention having a rotary airlock and a blowing device according to the invention in a feeding shoe

[0034] FIG. 2: schematically shows the example according to FIG. 1 with illustration of further details

[0035] FIG. 3: shows a perspective illustration of the feeding shoe having a blowing device installed therein

[0036] FIG. 4: shows a section through the feeding shoe according to FIG. 3

[0037] FIG. 5: shows a vertical section through the illustration according to FIG. 1

[0038] FIG. 6: shows a top view of the feeding shoe according to FIG. 3

[0039] FIG. 7: schematically shows a second embodiment of a rotary airlock, which is installed as a series part in a number of rotary airlocks arranged in succession

[0040] FIG. 8: shows the summation formulas for the gas streams in a first case and a second case

[0041] FIG. 9: shows the general summation formula for the gas guiding in the first case

[0042] FIG. 10: shows a schematically drawn overview of rotary airlocks connected in series in succession having the illustration of the gas streams

[0043] FIG. 11: shows the summation formula of the gas streams according to the series circuit according to FIG. 10

[0044] FIG. 12: shows an arrangement of a rotary airlock without blowing device according to the prior art

[0045] Firstly, the disadvantages of the prior art will be explained on the basis of FIG. 12 according to the prior art, to be able to better explain the advantages of the invention based thereon.

[0046] The embodiment according to the prior art according to FIG. 12 essentially shows a rotary airlock 1, which is driven in a sealed manner in a housing 2 so it is rotatable in rotational direction 5, wherein the airlock 3 forms a number of airlock chambers, which are filled with a product in succession proceeding from a product supply 6.

[0047] Due to the rotation of the airlock 3 in the arrow direction 5, the product runs out downward in the arrow direction 15 via a product outlet 7, wherein the mass flow m runs out in the arrow direction 15, and reaches a feeding shoe 10, where the product is conveyed further as the product mass stream 39 in the arrow direction 14 in the conveyor line 13.

[0048] An introduction of the total quantity of gas 40 V.sub.total takes place via the gas supply 12 in the arrow direction 16.

[0049] A specific component of the total gas quantity 40 is accordingly deflected in the arrow direction 18 in the form of a leaked gas stream upward in the direction toward the rotating airlock 3 and leaves the leaked gas nozzle 17 as the leaked gas quantity 42 V.sub.LG at the leaked gas nozzle 17.

[0050] Accordingly, the leaked gas stream in the arrow direction 18 counters the product mass stream 39 flowing downward in the arrow direction 14, so that this downwardly flowing product mass stream 39 is disturbed and held up by the opposing leaked gas stream meeting it in the arrow direction 18. This even has the result that very light particles of a particulate bulk material are prevented from leaving in the conveyor line 13 in the arrow direction 14. The performance of the rotary airlock 1 according to the prior art is thus substantially impaired.

[0051] Complete emptying of the individual chambers of the airlock 3 is also not ensured, because accumulations are not removed and complete emptying of the airlock chamber is not ensured.

[0052] These advantages were already partially remedied according to the prior art according to the documents acknowledged in the introduction to the description, but only using low-volume flushing gas streams which are under low pressure. The invention begins here.

[0053] According to FIG. 1, with use of the same reference signs as in FIG. 12, it is provided that in the gas supply 12, which at the same time represents the conveyor line 13, a total gas quantity 40 is injected in the arrow direction 16, but no longer arrives directly in the outlet-side conveyor line 13. For this purpose, the most complete possible shut-off is performed in the gas supply 12 using a terminating plate 26, by which only the inlet side of a blowing device 30 is arranged in a gas-conducting manner, which consists in the present case of two parallel blowing tubes 31, 31a arranged in adjacent to one another.

[0054] The total gas quantity 40 in the arrow direction 18 is therefore now introduced with high efficiency, i.e., large volume and high pressure, into the blowing device 30, and the orifice 32, 32a of the blowing tubes 31, 31a, is preferably oriented approximately radially on the outlet side in relation to the incoming airlock chambers 24.

[0055] Proceeding from the product supply 6, the product mass stream 39 in the arrow direction 15 will fill up in sequence the individual successive airlock chambers 20, 21, 22, 23, 24, which therefore move in the rotational direction 5 in the direction toward the outlet. A flange 34, on which the feeding shoe 10 is flanged in a gas-tight manner, is arranged on the lower side of the housing 3 of the rotary airlock 1. The blowing device 30, which is oriented with its one or more blowing tubes 31 toward the airlock chambers 23, 24 rotating past on the outlet side, protrudes through the feeding shoe 10. A flushing gas stream 33 is therefore produced in the arrow directions 27, 28, which is oriented directly into the outlet-side airlock chambers 23, 24. The product outlet 7 of the housing 2 of the rotary airlock 1 overlaps three airlock chambers here, for example, which are accordingly removed in sequence in the product outlet 7 and at the same time flushed by the blowing device 30.

[0056] The feeding shoe 10 essentially consists of a housing 35, which stands with supporting feet on a support surface, and the housing is flanged in a gas-tight manner on the housing 2 of the rotary airlock 1 at the flange 34.

[0057] The product mass stream 39 therefore flows in the arrow direction 14 downward through the collecting chamber 37 and thus leaves the feeding shoe 10, wherein the product is conveyed further by the conveyance gas quantity 41 V.sub.FG.

[0058] The component of the injected total gas quantity 40 will flow along as leaked gas through the housing of the rotary airlock 1 and be supplied to the leaked gas nozzle 17, where a specific component of the total quantity 40 leaves the nozzle as the leaked gas quantity 42 V.sub.LG.

[0059] The upper end of the feeding shoe 10 is moreover formed by a tube nozzle 11, which is part of the collecting chamber 37 and is terminated by the upper flange 34.

[0060] It is also recognizable in FIG. 1 that airlock chambers run past and are filled at the product supply 6 with a product filling 25, where this product is then let out at the outlet side in the region of the product outlet 7.

[0061] On the basis of FIG. 2, the essential advantages of the invention in relation to the prior art according to FIG. 12 will now be explained. It is recognizable that the total quantity, i.e., the total gas quantity 40 is supplied in the arrow direction 16 to the blowing device 30, because in this region the conveyor line 13 is terminated by the terminating plate 26 and a gas-conducting connection only still exists to the blowing device 30 arranged in the terminating plate 26. The total gas quantity 40 can therefore be provided for the blowing device 30. This is novel and unique over the prior art. Thereforeaccording to the illustration in FIG. 2a flushing gas stream 33, which flushes the respective outlet-side airlock chamber 24 as the reversal stream, can penetrate particularly effectively into the airlock chamber 24 and free it of material accumulated therein without residue.

[0062] Due to this reversal effect, a targeted flow also occurs in the airlock chamber, which ensures a particularly good lifting effect of the materials accumulated therein on the airlock webs.

[0063] The invention is not restricted to a complete gas termination using a terminating plate 26. In other cases, it can be provided that a bypass is present in the terminating plate 26, Which ensures that only the larger part of the total gas quantity 40 is supplied to the blowing device 30, while a smaller part is guided further in the conveyor line 13.

[0064] The invention is accordingly not restricted to a completely gas-tight termination of the gas supply 12 of the feeding shoe 10, because the terminating plate 26 can still have bypass gas openings.

[0065] FIG. 3 shows the perspective illustration of the feeding shoe 10, in which the same parts are provided with the same reference numerals. It is recognizable that the blowing device 30 consists of two blowing tubes 31, 31a, which are arranged at a distance from one another and whose blowing orifices 32, 32a are arranged oriented in opposite directions, and therefore also produce flushing gas streams 33, 33a oriented in opposite directions.

[0066] FIG. 4 shows an enlarged illustration of the sectional illustration in FIG. 1, where it is recognizable how the feeding shoe 10 is formed in section. In the exemplary embodiment shown, the terminating plate 26 forms a complete gas termination in the direction toward the inlet-side gas supply 12 of the total gas quantity 40, and the gas is supplied exclusively to the blowing device 30.

[0067] FIG. 5 shows a refinement of the embodiment according to FIGS. 3 and 4, in which the two blowing tubes 31, 31a oriented in different directions also produce flushing gas streams 33, 33a, which extend essentially over the entire axial length of the respective airlock chamber 24 to be flushed, and which each flow oriented from the outside toward the inside, so that in the middle region of the airlock chamber 24 to be flushed, the two flushing gas streams 33, 33a are unified, and therefore entrain the product mass stream 39 in the middle and convey it in the direction toward the collecting chamber 37.

[0068] FIG. 6 shows the top view in an identical illustration as FIG. 5, where the same parts are provided with the same reference signs.

[0069] FIG. 7 shows a second embodiment of a rotary airlock 1, which is intended for series operation of multiple rotary airlocks 1, which are arranged in parallel adjacent to one another and are arranged at a mutual distance from one another. Each rotary airlock 1 is connected for this purpose in the case of series operation (see FIG. 10) to a silo (not shown in greater detail), so that different product mass streams can each be fed via a rotary airlock 1 into a shared conveyor line 13.

[0070] FIG. 7 specifically shows that in the refinement of the invention, a shutoff device 44, which is controllable by a motor 45, is now arranged downstream of the feeding shoe 10 and the blowing device 30. This shutoff device 44 is arranged upstream of the tube nozzle 11 of the conveyor line 13, so that depending on the position of the shutoff device 44, the product mass stream 39 can be conveyed to the conveyor line 13 or also not.

[0071] FIG. 8 shows for this purpose the case 1 which was described in the exemplary embodiment according to FIGS. 1 to 6, from which it results that the total gas quantity 40 is composed of the conveyance gas quantity 41 and the leaked gas quantity 42. As a result, the blowing device 30 is supplied with the total gas quantity 40.

[0072] In the case of a series operation, as is indicated as the case 2 in FIG. 8 in the summation formula, only the first rotary airlock located in the series has the same summation formula applied as in case 1 of the blowing device, while in the downstream second rotary airlock, the blowing device is only still supplied with leaked gas quantity 42 of the second rotary airlock.

[0073] FIG. 9 accordingly shows the exemplary embodiment according to FIGS. 1 to 6 with the associated summation formula, which is also indicated as the case 1 in FIG. 8, while FIG. 10 shows the above-described series operation, which corresponds to the case 2 in FIG. 8. The gas streams indicated therein are also entered by arrows and corresponding indices.

[0074] The summation formula according to FIG. 11 accordingly shows that the total gas quantity of the system is composed of the delivery gas quantity V.sub.FG at the first rotary airlock plus the leaked gas quantities of the downstream further rotary airlocks, which are each in operation and the shutoff devices 44 of which are each open.

[0075] The invention therefore shows that a series operation of multiple rotary airlocks 1, 1a is also possible with high efficiency, and the blowing device 30 arranged therein in the feeding shoe 10 therein is always supplied with the maximum possible gas quantity, without requiring a bypass gas quantity for flushing the airlock chambers 24.

[0076] The respective conveyance gas quantity V.sub.FG introduced at the inlet at the first rotary airlock 1 is accordingly injected in the arrow direction 46 at the inlet of the rotary airlock 1.

LIST OF REFERENCE SIGNS

[0077] 1 rotary airlock [0078] 2 housing [0079] 3 airlock [0080] 4 axis of rotation [0081] 5 rotational direction [0082] 6 product supply [0083] 7 product outlet [0084] 8 flange [0085] 9 [0086] 10 feeding shoe [0087] 11 tube nozzle [0088] 12 gas supply [0089] 13 conveyor line [0090] 14 arrow direction [0091] 15 arrow direction [0092] 16 arrow direction [0093] 17 leaked gas nozzle [0094] 18 arrow direction [0095] 19 arrow direction [0096] 20 airlock chamber [0097] 21 airlock chamber [0098] 22 airlock chamber [0099] 23 airlock chamber [0100] 24 airlock chamber [0101] 25 product filling [0102] 26 terminating plate [0103] 27 arrow direction [0104] 28 arrow direction [0105] 30 blowing device [0106] 31 blowing tube 31a [0107] 32 orifice (of 31) [0108] 33 flushing gas stream 33a [0109] 34 flange [0110] 35 housing [0111] 36 contour (of 32) [0112] 37 collecting chamber [0113] 38 [0114] 39 m=product mass stream [0115] 40 V.sub.total=total gas quantity [0116] 41 V.sub.FG=conveyance gas quantity [0117] 42 V.sub.LG=leaked gas quantity [0118] 43 flange [0119] 44 shutoff device [0120] 45 motor [0121] 46 arrow direction