WO1997001396A1

WO1997001396A1 - Separation assembly

Info

Publication number: WO1997001396A1
Application number: PCT/GB1996/001540
Authority: WO
Inventors: Alan Williams
Original assignee: Paint & Powder Systems Limited
Priority date: 1995-06-28
Filing date: 1996-06-27
Publication date: 1997-01-16
Also published as: EP0835167A1; GB9513177D0; AU6235796A; GB2302663A

Abstract

A separator assembly (10) for use in removing airborne particles from a powder coating booth (12). The assembly (10) comprises a frame (16) with an inlet connectable to the spray booth (12) and an outlet connectable with a second separator arrangement (22) providing substantially total filtration of airborne particles. A first separator arrangement (24) in the form of a multi-cyclone (26) is removably slidably locatable within the frame (16). A separator arrangement (24) for each colour and/or material to be sprayed in the booth (12) is provided to permit ready recycling with a reduced risk of contamination.

Description

SEPARATION ASSEMBLY

This invention relates to separation assemblies, and particularly but not exclusively assemblies for separating solids from a fluid; and especially separation assemblies for use with powder coating equipment .

In powder coating an article to be coated is usually located in a booth and electrostatically sprayed. In a continuous arrangement, articles sequentially pass through the booth which is therefore required to be open at one or both ends. With an open booth it is necessary to provide negative pressure in the booth to prevent sprayed material passing out of the opening or openings in the booth. This is generally provided using a fan arrangement with a separation assembly to remove airborne sprayed material, usually when possible for subsequent re-use.

A problem with recycling sprayed material is that a build-up of fine material tends to occur which is undesirable, as fine material is difficult to charge. Eventually if the proportion of fine material becomes too high such material would have to be discarded. Increasingly, powder coating apparatus is required to be usable with more than one colour of material. Thorough cleaning of the apparatus is required before a new colour can be sprayed. Some separation apparatus is relatively difficult to clean and may include a number of areas where material can become trapped. If cleaning is not adequately carried out, due to recycling of the sprayed material, this can lead to contamination of a whole batch of material as well as wasted product which has been sprayed with contaminated material. This means the powder coating tends to be a rather inflexible system with inherent dangers in changing the colour of material to be sprayed.

According to the present invention there is provided a separation assembly, the assembly comprising a first separator arrangement for removing solids from a fluid, and a second separator arrangement located in use downstream of the first arrangement, the first arrangement being selectively removable from the assembly to permit a further such arrangement to be incorporated in the assembly.

Preferably the first separator assembly permits re-use of the separated solids, and a removable container for the separated solids may be provided in the assembly.

The second separator arrangement preferably comprises a filtration arrangement which desirably removes substantially all solids from the fluid. The first separator arrangement preferably substantially only removes solids above a predetermined size from the fluid. The first arrangement may comprise a physical separator, and may be a c clone and desirably a multi-cyclone .

The assembly preferably comprises a frame into and out of which the first separator arrangement is movable and desirably slidably movable. An inlet and outlet are preferably provided on the frame alignable with respective openings on the first separator arrangement, the outlet connecting with the second separator arrangement. Seal means engageable with the first separator arrangement are preferably provided around the inlet and outlet, and the seal means may be selectively inflatable. Means may be provided to indicate correct positioning of the first separator arrangement in the frame, and the seal means may be automatically inflatable upon sensing correct positioning of the separator arrangement.

The invention also provides a separation assembly for removing solid material in air from a powder coating assembly, the separator assembly being according to any of the preceding four paragraphs.

The inlet preferably communicates with the interior of the spray booth of the coating assembly. A fan to provide suction is desirably located downstream in use of the second separator arrangement.

A plurality of first separator arrangements are preferably provided, each desirably for use with a different material or differently coloured material to be sprayed.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:-

Fig. 1 is a perspective view of part of a first separator assembly according to the invention in a first condition ;

Fig. 2 is a perspective view of the first assembly in a second condition;

Fig. 3 is a perspective view of the first assembly part way between the first and second conditions;

Figs. 4, 5, 6 and 7 are side views from each of four sides of part of the first assembly;

Fig. 8 is a view on the line X-X in Fig. 7; and Fig. 9 is a perspective view of a further similar assembly according to the invention in an operative position .

Figs. 1-8 show a separator assembly 10 for use in removing airborne particles from a powder coating booth 12. Fig. 9 shows a similar separator assembly 14 but which is configured slightly differently to the assembly 10. Similar reference numerals are used for both assemblies 10 and 14.

The assemblies 10,14 comprise an upstanding rectangular frame 16 which is open on one side (see Fig. 4). The frame 16 has a rectangular inlet 18 on one side sealingly mountable against a corresponding outlet (not shown) on a spray booth 12. A circular outlet 20 is provided on another side of the frame 16 at a greater height than the inlet 18. The outlet 20 is sealingly locatable against an inlet (not shown) of a second separator arrangement 22. The separator arrangement 22 is of a conventional fixed arrangement providing a substantially total filter to remove all airborne particles. The arrangement 22 is of relatively standard construction, and its construction does not form part of the invention and will thus not be described in any detail. A fan is provided in the arrangement 22 to draw air therethrough from the booth 12 via a first separator arrangement 24 to be hereinafter described.

In the assembly 10 the inlet 18 and outlet 20 are provided on opposite sides*, of the frame 16. In the assembly 14 the inlet 18 and outlet 20 are provided on adjacent sides as is convenient for the particular arrangement shown in Fig. 9.

The separator arrangement 24 is in the form of a multi-cyclone 26 comprising four cyclone pods 28, only three pods are provided in the arrangement 14. The arrangement 24 is carried on a frame 30 mounted on wheels 32 and which is slidably locatable within the frame 16 through the open side thereof. The multi-cyclone 26 is connectable via an inlet 34 to the inlet 18. An inflatable seal 36 is provided around the inlet 18 to provide sealing engagement with the inlet 34.

The multi-cyclone 26 has an air outlet 38 locatable adjacent the outlet 20, with an inflatable seal 40 around the outlet 20 engageable with the outlet 38. The outlet 38 communicates with central vortices 42 of each of the pods 28, and is located at a greater height than the inlet 34. Each of the cyclone pods 28 also has a material outlet 44 located directly above a removable container 46. A pair of alignment holes 48 are provided through a plate 50 on the side of the frame 16 opposite the open side thereof. A pair of fingers 52 are provided respectively above and below each of the holes 48, and aligned openings 54 are provided through each respective pair of fingers 52. Two correspondingly positioned fingers 56 are provided on the appropriate side of the frame 30 so as to be locatable respectively through the holes 48 when the frame 30 is located fully within the frame 16. An opening 58 is provided through each of the fingers 56 alignable with the respective openings 54. A pneumatic cylinder 60 with a piston rod 62 is locatable beneath each respective pair of fingers 52 such that the rod 62 is locatable through the openings 54,58. A reed switch (not shown) is provided on the cylinder 60 and connected so as to detect full extension of the rod 62 through the openings 54,58 and thereby automatically inflate the seals 36,40.

In use, the arrangement 24 is located within the frame 16 as outlined above. The fan in the arrangement 22 can then be switched on to provide a negative pressure within the booth 12 and permit powder coating to take place. Air from the booth 12 carrying a certain amount of the sprayed material is drawn through the inlet 18 into the multi-cyclone 26. The air descends downwardly and around the cyclone pods 28. Much of the solid material in the air is thrown outwardly and slides down the side of the pods 28 into the container 46 for subsequent re-use.

The multi-cyclone only tends to remove particles above a particular size from the air such that very fine particles remain in the air which travels up the vortices 42 of the multi-cyclone 60 through the outlets 20,38 and into the arrangement 22 for removal of the fine particles from the air. In powder coating, typically epoxy powders or polyester powders would be used with a size range of 5 to 85 microns. The multi-cyclone 26 would only tend to remove particles down to a submicron level, thereby leaving the submicron particles to proceed to the arrangement 22 for removal and subsequent discard, thus ensuring the quality of the product in the container 46 for re-use.

If it is required to spray a different colour material in the booth 12, spraying is finished and the fan in the arrangement 22 is kept on until all airborne particles in the booth 12 have been sucked therefrom. The seals 36,40 can then be deflated and the piston rods 62 withdrawn into the cylinder 60. The arrangement 24 can then be wheeled from the frame 16, with a bar 64 on the frame 16 helping to guide the arrangement thereout of. This enables a further separator arrangement 24 to be used such that a specific arrangement 24 can be provided for each colour thereby requiring only the spray booth 12 to be cleaned between each different colour and greatly reducing the danger of contamination occurring to the recycled sprayed material.

There is thus described a separator assembly with a number of advantageous features. The multi-cyclones provide for a very efficient separation of the solid material from the air flow whilst substantially preventing accumulation of fine unchargeable material in the recycled product. As the multi-cyclones can readily be changed when a different colour is being sprayed, this greatly reduces the amount of cleaning which is required, whilst also reducing the chances of contamination occurring. The arrangement of the fingers and aligned openings ensures that the separator arrangement is correctly aligned relative to the second separator arrangement and also the booth 12. The automatic inflatable seals again provide for efficient operation. Overall though the apparatus is of relatively simple construction and can thus be inexpensively and robustly manufactured to provide long term and essentially maintenance free operation.

Various modifications may be made without departing from the scope of the invention. For example, a different separator arrangement other than a multi-cyclone could be used for the first separator arrangement, or a multi-cyclone with a different number of pods. A different means could be used to ensure correct alignment of the separator arrangement and also sealing between the arrangement and the frame.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

Qajms:-

1. A separation assembly, the assembly comprising a first separator arrangement for removing solids from a fluid, and a second separator arrangement located in use downstream of the first arrangement, the first arrangement being selectively removable from the assembly to permit a further such arrangement to be incorporated in the assembly.

2. An assembly accordmg to claim 1, in which the first separator assembly permits re-use of the separated solids.

3. An assembly according to claim 2, in which a removable contamer for the separated solids is provided in the assembly.

4. An assembly according to any of claims 1 to 3, in which the second separator arrangement comprises a filtration arrangement.

5. An assembly according to claim 4, in which the second separator arrangement removes substantially all solids from the fluid.

6. An assembly accordmg to any of the precedmg claims, in which the first separator arrangement substantially only removes solids above a predetermmed size from the fluid.

7. An assembly accordmg to any of the preceding claims, in which the first arrangement comprises a physical separator.

8. An assembly accordmg to claim 7, in which the first arrangement comprises a cyclone.

9. An assembly accordmg to claim 8, in which the first arrangement comprises a multi-cyclone.

10. An assembly according to any of the preceding claims, in which the assembly comprises a frame into and out of which the first separator arrangement is movable.

11. An assembly according to claim 10, in which the assembly comprises a frame into and out of which the first separator arrangement is slidably movable.

12. An assembly accordmg to claims 10 or 11, in which an inlet and outlet are provided on the frame alignable with respective openings on the first separator arrangement, the outlet connectmg with the second separator arrangement.

13. An assembly accordmg to claim 12, in which seal means engageable with the first separator arrangement are provided around the inlet and outlet.

14. An assembly accordmg to claim 13, in which the seal means are selectively inflatable.

15. An assembly according to any of claims 10 to 14, in which means are provided to indicate correct positioning of the first separator arrangement in the frame.

16. An assembly according to claim 15 when dependent on claim 14, in which the seal means are automatically inflatable upon sensing correct positioning of the separator arrangement.

17. A separation assembly for removing sohd material in air from a powder coatmg assembly, the separator assembly being according to any of the preceding claims.

18. An assembly according to claim 17 when dependent on at least claim 12, in which the inlet communicates with the interior of the spray booth of the coating assembly.

19. An assembly according to claims 17 or 18, in which a fan to provide suction is located downstream in use of the second separator arrangement.

20. An assembly accordmg to any of claims 17 to 19, in which a plurahty of first separator arrangements are provided.

21. An assembly accordmg to claim 20, in which each separator arrangement is for use with a different material or differently coloured material to be sprayed.

22. A separator assembly substantially as hereinbefore described with reference to Figs. 1-8 of the accompanying drawings.

23. A separator assembly substantially as hereinbefore described with reference to Fig. 9 of the accompanying drawings.

24. Any novel subject matter or combination mcluding novel subject matter disclosed, whether or not withm the scope of or relating to the same mvention as any of the preceding claims.