JPH0696137B2 - Pneumatic transportation device for powder in tank - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-tank powder pneumatic transportation device for transporting powder contained in a tank using compressed air.

[0002]

Such a device is known from EP 0 184 994 B1. This device is primarily useful for pneumatically transporting powder coatings which are sprayed onto the object to be coated by the spray coating method. With this system, powder can be directly extracted from bags, cartons, barrels, boxes, etc., and can be directly and automatically supplied to a spray device or spray coating system without using a fluidizing tank or other intermediate tanks. To Before the development of such a device, the powder manufacturer “fluidizes” the powder from the transport tank that the powder manufacturer puts in the powder and delivers it to the powder user.
I had to replace it with. Such "fluidization tank"
Has an air-permeable intermediate bed inside, through which air flows in the form of a number of trickles from bottom to top, blowing up the powder on the middle bed, so that the powder particles "float or drift" in the air stream. Move. This state is called "fluidized powder". The fluidized powder can be sucked by a pneumatic suction device and supplied to the spray device of the spray coating system. The spray coating device may be a hand gun or a mechanical gun mounted in a spray coating system. All spray painting processes can be automated, including powder feeding. Both the known system and the device according to the invention perform the two functions of fluidizing the powder and pneumatically delivering it to the application site. In the case of the conventional device, a suction pipe and a compressed air pipe which is arranged adjacent to and parallel to the suction pipe extend through the lid of the tank. At the lower end of the compressed air pipe, there is an air distribution device provided with a vertically elongated air distribution element made of a porous material, from which a thin stream of compressed air flows and fluidizes the powder at the lower end of the suction pipe. A suction device is attached to the upper end of the suction pipe above the tank lid, and this device sucks up the fluidized powder from the tank and pneumatically conveys it to a coating place, for example, a spray device. It is not over the entire cross section of the tank that the compressed air fluidizes the powder in the tank, but only in a limited, narrow area under the suction pipe. During the suction of the powder, a cavity is created under the lower end of the suction pipe, and the powder continuously flows into the cavity there. This inflow and thus the continuous filling of the cavities below the suction pipe and, in connection with it, the continuous and uniform powder suction is also improved by vibrating the tank with a vibrator. When the tank is empty, the air distributor must be kept away from the lower end of the suction pipe and the lower end of the compressed air pipe, the suction pipe and the compressed air pipe must be pulled out from the lid of the tank, and then both emptied. It is necessary to insert it into the lid of the tank which is not and fix the air distribution device to both again. If it is necessary to take out different types of coating powder from different tanks to coat an object, even if a very small amount of powder remains in the equipment, the coating quality will be deteriorated. The tank must be thoroughly cleaned after every replacement. However, even when using the same type of powder from different tanks for a long period of time, it is essential to clean the device even after long-term use so that powder residue does not accumulate inside. Such a powder residue causes clogging of the flow path that hinders uniform transport, and even if the residue is eliminated, color unevenness and coating failure may occur.

[0003] Furthermore, the powder feeding device from a tank described in EP 0 008 270 B1 consists of a suction pipe inside and a compressed air pipe and two coaxial pipes outside it. The lower ends of both pipes form a common ring-shaped slot nozzle, and compressed air in the shape of a ring jet directed obliquely downward from the annular space between the pipes is applied to the cylindrical wall of the tank. The ring-shaped compressed air jet moves the powder from the cylindrical tank wall diagonally down the center of the tank and from there to the lower end of the suction pipe. Thus, in contrast to the first-mentioned device, the powder is fluidized not only for a part of the tank cross section, but for the entire tank cross section. For that purpose, the powder tank must have a relatively small, mainly circular cross-section. According to the publication, the tank of this known device is in the form of a bottle, the neck of the bottle being threaded and hanging on a holder to screw the neck. The pipe arrangement with both pipes is hermetically and coaxially inserted into the holder toward the tank. It is said that this device can completely remove the contents of the tank without leaving powder on the tank wall.

Another device described in EP 0 103 745 B1 likewise aims at emptying the tank as completely as possible. For this reason, the pipe arrangement of this device is not axial at the center of the tank, but rather runs diagonally through the tank to a corner of the tank bottom. The tank is placed diagonally so that the powder can move to this corner. This device is 2
Unlike other types of devices, it does not work with compressed air and simply has a suction pipe. The air sucked from the tank flows into the tank again from the surrounding environment through the guide pipe coaxially surrounding the suction pipe.

The term "powder" as used herein means a fine powdery to granular material.

[0006]

[Problems to be Solved by the Invention] EP 0 184 mentioned at the beginning
The device described in 994 B1 has been improved by inserting it through the guide opening of a tank lid or other guide device that guides the device in the longitudinal direction of the pipe without disassembling the device, i.e. in the fully assembled condition. The present invention solves the problem of enabling extraction and at the same time forming the places where powder adheres as much as possible. At the same time, the device should be designed so that it is not constrained to the application of a tank style or the constant tilt or vertical state of the tank. Furthermore, the need for additional holder structures or tank configurations for the device or tank, for example EP 0 008 270 B1 mentioned above, should also be avoided. Rather, the device must sink into the tank during its suction of powder from its own weight, and thus in effect by gravity.

The present invention solves the problems of the above-mentioned respective prior arts,
It is an object of the present invention to provide a pneumatic transportation device for powder in a tank, which can be attached to and detached from a guide device in a completely assembled state of a suction device.

[0008]

In order to achieve the above-mentioned object, the present invention comprises a guide device which can be placed on a tank and which is supported by the tank, and a shaft is provided through a guide opening of the guide device. A pipe array formed to suck up powder in the tank, and a vibrator for vibrating the tank, the pipe array including a suction pipe and a compressed air pipe, and an upper end of the suction pipe is compressed. It is connected to an air source, and at its lower end compressed air flows out into the tank in the form of a number of thin compressed air streams to fluidize the powder to a locally limited area of the tank cross section at the lower end of the suction pipe. And a feed pump for sucking powder from the tank through the suction pipe is provided at the upper end of the suction pipe, and the pipe array is fully assembled and operable. Can be inserted into the tank through the guide opening of the guide device and completely pulled out from the guide opening.The compressed air pipe is a pipe that surrounds the suction pipe with an annular space. The pipes are mechanically interconnected at their lower ends by a lower spacer to maintain a spacing, the lower spacers are simultaneously compressed air transfer elements of the nozzle head, and the upper ends of the suction pipe and compressed air pipes are interconnected by an upper spacer. The upper spacer is a connecting element that simultaneously supports the feed pump and connects the feed pump with the suction pipe, and further connects the compressed air source to the annular space in the compressed air pipe. It has been formed.

Each of the spacers may have a portion inserted into an annular space formed therebetween.

The feed pump may be mechanically connected to the upper spacer by a plug connection and supported by the upper spacer.

The nozzle head has at least one air distribution element made of a porous material, and the pores allow compressed air to flow from the annular space into a thin compressed air flow into the tank. .

The pipe array is provided with stoppers that can be fixed at various heights in the axial direction, and the stoppers can define the insertion depth of the pipe array in the tank depending on the axial positioning.

A portion of the guide device that can be placed on the tank is a lid, and the lid preferably has a peephole for observing the inside of the tank.

The portion of the guide device that can be placed on the tank is a lid, and the lid is preferably made of a transparent material.

The guide device is laterally supported by the tank and is provided with side stoppers for preventing lateral displacement of the guide device. The side stoppers are attached to the guide device at various intervals from each other and from the center of the guide device. It may be configured to be detachably fixed.

[0016]

With the above construction, in the pipe array consisting of the suction pipe and the compressed air pipe, the nozzle head is attached to the lower end thereof via the lower spacer, and the feed pump is provided to the upper end thereof via the upper spacer. It is sufficient to construct the device assembly, attach the pipe arrangement of the suction device from the guide opening of the guide device, and removably insert and remove, without the need for partial removal or assembly.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The device according to the invention shown in FIG. 1 essentially comprises a guide device 1 and a suction device 2. The guide device 1 has a guide means 4 having a guide opening 7, through which the suction device 2 is guided in the axial direction of the guide opening 7.
It is further moved axially. The guide device 1 can be detachably placed on the edge of the tank 6 and is supported by the tank 6. The part of the guide device 1 which is supported on the tank 6 forms in particular a lid 3 with a guide means 4, for example a central opening 5. The tank 6 is a transportation means, and the coating powder 8 for spray application is housed inside and supplied from the powder maker to the powder user. The tank 6 is composed of, for example, a carton 10 and a bag 12 made of synthetic material disposed inside the carton 10. The upper edge 14 of the bag is placed outside the upper edge 16 of the carton to cover the upper edge 1 of the carton.
It is sandwiched between 6 and the lid 3, and the lid 3 is placed on the upper edge 14 of the bag without being additionally fixed. The lid 3 comprises a downwardly projecting lid rim 18 to prevent lateral displacement of the lid 3 above the tank 6 or at least to an acceptable extent. The tank 6 is placed on a vibrating plate 20 which is supported horizontally movable on a floor 24 via spring elements 22, for example blocks or elastic rings made of rubber. The vibrating plate 20 as well as the powder tank 6 and the suction device 2 are vibrated in a known manner by the vibrator 26, that is, swung.

The tank 6 and the lid 3 conforming to the shape of the tank can also be circular in cross section or rectangular as shown in FIG.
According to FIG. 2, the lid 3 has a peep hole 28 for observing the powder inside.
To provide.

If it is desired to observe the contents of the tank, the lid may be made of a transparent material such as flexible glass as shown by reference numeral 3'in FIG. FIG. 3 shows another possible use of a flat plate for the lid without the lid rim 18. However, FIG.
Holes 34, especially screw holes, are formed in the lid 3'of the lid 3'at various intervals from the lid central shaft 32, and pins 36 in place of the lid rim 18 are inserted or screwed into the holes. By moving the pins 36 into holes at different distances from the lid central axis 32, the lid 3'can be adapted to different tanks 6 with different diameters or different cross-sectional shapes. The opening 7'formed in the lid 3'has a length sufficient to guide the suction device 2 in the axial direction of the opening 7 '. Lid 3
′ Therefore constitutes the guide device 1 ′, the opening 7 ′ being a substitute for the guide means 4 and its guide opening 7.

As shown in FIGS. 1, 4, 5 and 6, the suction device 2 according to the invention is essentially a conventional pipe arrangement 40, which is mounted and supported on its upper end and operates on the ejector or venturi principle. A pneumatic pump type feed pump 42 and a stop ring 4 surrounding the pipe array 40 so that it can be attached to the pipe array 40 at various heights by an adjusting screw 46.
4 and. This allows the depth of sinking of the pipe arrangement 40 in the tank 6 to be adjusted and therefore the suction device 2
The sinking depth of is suitable for various tank depths. The guide means 4 consists of a guide ring 50 with a hole 7 for guiding the pipe arrangement 40 in the axial direction as a guide opening and a nut 54. The nut 54 is screwed to the small diameter portion 56 of the guide ring 50 that penetrates through the opening of the lid 3 and projects upward from the lid 3,
The large diameter portion 58 of the guide ring 50 comes into close contact with the lid 3 from below. The arrangement may be reversed such that the large diameter portion 58 is above the lid 3 and the small diameter portion 56 and the nut 54 are below the lid 3.

The pipe arrangement 40 is composed of two pipes which are arranged coaxially with a radial interval therebetween.
Is a suction pipe for sucking powder from the tank 6, and the outer pipe 62 is a compressed air pipe for supplying compressed air to the tank below the lower end 64 of the suction pipe 60. The pipes 60 and 62 may be arranged eccentrically to each other. The lower end 64 of the suction pipe 60 and the lower end 66 of the compressed air pipe 62 have substantially the same height. The lower ends 64 and 66 of both pipes are mechanically interconnected by an annular lower spacer 68, which is an annular space 7 between the pipes 60 and 62.
It has a thin annular portion 72 which projects into 0 and maintains the mutual spacing of both pipe lower ends 64 and 66. The spacer 6
The part 74 of the ring 8 projecting from the annular space 70 has a greater radial thickness, in which a plurality of, for example three, longitudinal air distribution elements 76 parallel to the longitudinal axis 78 of the pipe arrangement 40 are inserted, in particular screwed. . The air distribution element 76 is in flow communication with the annular space 70 via a hole 80. The air distribution element 76 blows the thin, thin compressed air stream of the annular space 70 into the tank 6 below the lower end 64 of the suction pipe 60 so that the powder in the tank 6 is not in full cross-section of the tank 6 but in the tank 6. It serves to fluidize below the suction pipe 60 over a narrow cross sectional area of 6. The air distribution element 76 is made of a porous material that is particularly permeable to compressed air, and also functions as a filter element that blocks dust particles from reaching the annular space 70 from the annular space 70 or into the tank 6. The outer diameter of the lower spacer 68 is not larger than that of the compressed air pipe 62 even in the thick portion 74. The outer peripheral surface of the particularly thick portion 74 is aligned with the outer surface of the compressed air pipe 62. The air distribution element 76 also does not extend beyond this outer diameter of the compressed air pipe 62. Therefore, removing the lid 3 from the tank 6,
Without having to remove the air distribution element 76 or the lower spacer 68, the pipe arrangement 40 together with the spacer 68 and the air distribution element 76 is inserted into the tank 6 through the guide hole 7 of the guide means 4 or via the guide means 4 completely. It is possible to remove it from the tank 6. Lower spacer 6
8 is also a joint which simultaneously connects the air distribution element 76 to the annular space 70. The lower end 64 of the suction pipe 60 is connected to the inside of the tank 6 through the center hole 65 of the spacer 68.

The upper end 84 of the suction pipe 60 and the upper end 86 of the compressed air pipe 62 are at substantially the same height and are mechanically interconnected by an upper spacer 88. The upper spacer 88 has a small diameter annular portion 90 which extends between the upper pipe upper ends 84 and 86 into the annular space 70 to hold the ends radially spaced. Further, the upper spacer 88 has a larger diameter portion 92 having a center hole 94 that rides on the upper ends 84 and 86 of the pipes, and the hole 94 axially penetrates the upper spacer 88 to communicate with the inside of the suction pipe 60. . The central hole 94 of the upper spacer 88 has an enlarged outer hole portion 96 into which the feed pump 42 is inserted via a pipe strut 98. Therefore, the feed pump 4
2, the spacer 88 is supported from below. Upper spacer 88
Is equipped with a compressed air fitting 100 on the side, which fitting 100 passes through the upper spacer 88 via a hole 102 and an annular space 70.
Is in contact with the flow path. The compressed air fitting 100 is connected to a compressed air source 108 via an air conduit 104 to which a check valve, pressure regulating valve or pressure regulator 106 can be attached. Therefore, the upper spacer 88 not only fixes the upper ends 84 and 86 of the pipes and maintains the space therebetween, but also simultaneously fixes the pipe arrangement
0 and the feed pump 42, and the connection and connection with the compressed air source 108.

The feed pump 42 is a conventional pneumatic delivery device that operates on the Venturi or ejector principle. The feed pump 42 has an upper end 84 of the suction pipe 60,
There is a suction connection 110 that sucks powder from the tank 6 through the suction pipe 60 as the compressed air flows from the compressed air source 108 through the air conduit 112 and the air supply fitting 114. The compressed air is used for spraying the sucked powder / air mixture through the powder conduit 116, particularly at the spray device 120.
Send to. The spraying device 120 may be any conventional coating powder spraying device that sprays powder on the object to be coated in the form of a powder stream 122 with scattered powder. Spraying can be done electrostatically under high voltage by conventional methods. Compressed air can be directed from the compressed air source 108 through the air conduit 124 and the control air fitting 126 to the low pressure section 127 of the pump 42 to control negative pressure intensity and powder feed rate as is known. The air conduits 112 and 124 can be fitted with check valves, control valves and / or pressure regulators 128, 129 that allow manual or automatic regulation of flow and pressure.

[0025]

The present invention is as described in detail above, and has the effects of the following items. (1). The suction device does not require a partial removal of the device via the guide openings of the guide device, in particular the lid, but can be inserted from above and pulled out again. (2). A suction device that is dirty with powder and a lid that is also dirty with powder do not need to be removed from the tank together after emptying the tank; you can also remove the suction device first, then remove the lid from the tank and also clean This is substantially easier than removing the lid and suction device through the lid together from the tank. (3). The lid serves as a support and axial guide for the suction device movable through the lid relative to the lid. (4). Since the lid can be used for various tanks, the transport tank containing the powder does not require a special lid. (5). The suction device can use lids of various sizes with various configurations. (6). The suction device is arranged coaxially with the tank axis, especially at the center of the tank, but may be mounted eccentrically or obliquely with respect to the tank axis. (7). The suction device does not require a drive device for feeding into the tank during suction of the powder, and the self-weight of the suction device can be adjusted by the guide device of the lid that axially guides the device according to the present invention. It sinks in the powder by its own weight, and the powder is sucked in the meantime. In particular, the powder tank vibrates due to the vibrator. (8). A suction device that penetrates a plurality of lids can be mounted on the lid. (9). The lid can be provided with a peephole for observing the contents of the tank or can be made of a transparent material.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a powder transport tank and an apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a lid of the tank in FIG.

FIG. 3 is a longitudinal sectional view of a different embodiment of the lid of the device according to the present invention.

FIG. 4 is a longitudinal sectional view of the suction device according to the present invention in the device shown in FIG.

5 is a cross-sectional view taken along the arrow VV in FIG.

FIG. 6 is a transverse sectional view taken along the line VI-VI in FIG.

[Explanation of reference symbols] 1,1 'Guide device 2 Suction device 3,3' Lid 4 Guide means 6 Tank 7,7 'Guide opening 8 Powder 12 Bag 26 Vibrator 28 Peep hole 32 Central shaft 34 Hole 36 pin (side) 40) Pipe arrangement 42 Feed pump 44 Stop ring (stopper) 46 Adjustment screw 50 Guide ring 54 Nut 60 Suction pipe 62 Compressed air pipe 68 Lower spacer 70 Annular space 76 Compressed air distribution element 88 Upper spacer 96 External hole portion 98 Pipe strut 100 Compressed Air Joint (Connection) 108 Compressed Air Source 120 Sprayer

Claims (8)

[Claims] 1. 1-1, which can be placed on a tank (6),
And a guide device (1; supported on the tank (6).
1 '), which is axially guided through the guide openings (7; 7') of the guide device (1; 1 ') 1-2, and is configured to suck up the powder in the tank (6). Equipped with a pipe arrangement (40), and a vibrator (26) for vibrating the tank (6), 1-3, the pipe arrangement (40) is a suction pipe (60) and a compressed air pipe (62). And an upper end (86) of the compressed air pipe (62) is connected to a compressed air source (108), and a lower end (66) of the compressed air pipe (62) stores compressed air in the form of multiple thin compressed air streams (6). ) And a nozzle head (68, 76) for fluidizing the powder in a locally limited area of the tank cross section at the lower end (64) of the suction pipe (60),
1-5, a feed pump (42) for sucking powder from the tank (6) through the suction pipe (60) is arranged at the upper end (84) of the suction pipe (60), The pipe arrangement (40) is fully assembled and operable from above from above the guide opening (7;
7 ') into the tank (6) and completely withdrawable from the guide opening (7; 7'), 1-
7. The compressed air pipe (62) is a suction pipe (6
0) is a pipe that surrounds 0) with annular air (70),
1-8, the suction pipe (60) and the compressed air pipe (62) have lower spacers (6, 6) at their lower ends (64, 66).
8) mechanically interconnected by means of 8) to maintain the spacing,
9. The lower spacer (68) is at the same time a compressed air transfer element of the nozzle head (68, 76), and 1-10,
The upper ends (84, 86) of the suction pipe (60) and the compressed air pipe (62) are interconnected by an upper spacer (88) to maintain a distance between them, 1-11, and the upper spacer (88) simultaneously feeds the feed. A connecting element which supports the pump (42) and connects the feed pump (42) with the suction pipe (60), and further from the compressed air source (108) to the annular space (70) in the compressed air pipe (62). An air transportation device for powder in a tank, characterized in that the connection part (100) of (1) is formed. 2. The air for powder in a tank according to claim 1, wherein each of the spacers (68, 88) has a portion inserted into an annular space (70) formed therebetween. Transport equipment. 3. The feed pump (42) is mechanically connected to the upper spacer (88) by a plug connection (96, 98) and is supported by the upper spacer (88). Item 3. A pneumatic transportation device for powder in a tank according to Item 1 or 2. 4. The nozzle head (68, 76) has at least one air distribution element (76) made of a porous material by means of which the compressed air is compressed from the annular space (70) into a fine compression. The pneumatic powder transfer device for the powder in the tank according to claim 1, 2 or 3, wherein the powder flows as an air flow into the tank (6). 5. The pipe arrangement (40) comprises stoppers (44) which can be fixed at various axial heights, the stopper (44) being arranged axially in the tank (6). The pneumatic transportation device for powder in a tank according to claim 1, 2, 3, or 4, wherein the insertion depth of (40) is defined. 6. A portion of the guide device (1) that can be placed on the tank (6) is a lid (3), and the lid (3) is a peephole (28) for observing the inside of the tank (6). The pneumatic transportation device for powder in a tank according to claim 1, 2, 3, 4, or 5. 7. The tank (6) of the guide device (1 ′)
The part that can be placed on top is the lid (3 '), and the lid (3')
2. The material according to claim 1, which is made of a transparent material.
2. A pneumatic transportation device for powder in a tank according to 2, 3, 4 or 5. 8. The guide device (1 ') is laterally supported by a tank (6) and is provided with a side stopper (36) for preventing lateral displacement of the guide device (1'). 3. The guides (36) can be removably fixed to each other and to the guide device (1 ') at various intervals from the center (32) of the guide device (1').
Pneumatic transportation device for powder in a tank according to 3, 4, 5, 6 or 7.