GB2040721A

GB2040721A - Spray booth with means for reclaiming excess spray

Info

Publication number: GB2040721A
Application number: GB7902468A
Authority: GB
Original assignee: HOLDSWORTH VENTILATIONS Ltd
Current assignee: HOLDSWORTH VENTILATIONS Ltd
Priority date: 1979-01-23
Filing date: 1979-01-23
Publication date: 1980-09-03
Also published as: GB2040721B

Abstract

A spray booth for use particularly in applying glaze to ceramic ware has an open-fronted enclosure (12) in which is located means (22), eg two opposed, staggered rows of vertical channel members, defining a tortuous path for gaseous medium entraining excess glaze flowing from the booth. The glaze deposits on the members and, under gravity, runs down to a collecting channel (18). A water curtain (32) may also be provided to trap residual glaze in the gaseous medium, after the latter has passed the channel members and may be followed by zig-zag baffles (4) for removal of residual glaze. <IMAGE>

Description

SPECIFICATION Improvements in or relating to spray booths The present invention relates to a spray booth, especially but not exclusively a spray booth for use in applying glaze to ceramic ware.

A prior spray booth comprises an open-fronted enclosure in which the article (or articles) to be sprayed is placed for spraying by a hand held spray gun positioned in front of the booth. Excess spray is extracted from the booth through a duct at the rear of the booth, an extractor fan being positioned in the duct.

A considerable quantity of glaze is not deposited on the article and to prevent this excess glaze passing through the duct it has been proposed to provide a water curtain at the rear of the booth to trap and carry off some of the excess glaze. This arrangement has been found to be inefficient and wasteful as the glaze collected by the curtain is often rejected or, if not, requires considerable treatment to render it suitable for re-use.

It is an object of the present invention to obviate or mitigate these disadvantages.

According to the present invention there is provided a spray booth comprising an open-fronted enclosure for spraying of an article therein with a coating material and means for collecting excess material in the spray, the collecting means comprising channel members arranged in two rows such that together the rows define a tortuous path for a flow of a gaseous medium entraining the spray of the excess glaze.

It is preferable that the channel members are arranged with the members of one row staggered relative to the other and with their bases outermost, in a plastics-coated metal frame of substantially rectangular configuration. Collecting means for excess glaze may be provided at the base of the members.

It is further preferable that the channel members are arranged upstream of a water curtain, and that the members together with their surrounding frame are mounted for removal for cleaning purposes from the enclosure through the enclosure open front.

The channel members serve to collect a large proportion of excess glaze in an unadulterated condition so that it can be re-used. Any glaze remaining in the air passing through the collecting means then encounters the water curtain which removes a large proportion of this residual glaze.

To remove any residual glaze in the air downstream of the water curtain a series of vertically arranged plates of zig-zag or corrugated formation may be removably located in a duct adjacent the enclosure, each peak of the zig-zag or corrugation having a downwardly depending member attached thereto.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a diagrammatic section elevation of a spray booth; and Figure 2 is a section on the line II, II of Figure 1.

A spray booth comprises a framework 10 on which is mounted an enclosure or cabinet 12 having an open front 14. A base 16 of the enclosure is inclined downwardly away from the opening 14 such that any spray falling thereon may run towards a collecting channel 18. A roof 20 of the enclosure is raised in the region of the opening 14 and a turntable or whirler (not shown) is supported in the enclosure for mounting articles to be sprayed. The embodiment described has been designed for use when spraying articles of ceramic sanitary ware with a suitable glaze but it will be realised that the invention applied equally well to other spraying applications.

First collection means 22 are provided towards the rear of the enclosure 12 to collect glaze which has not been deposited on the article. With reference to Figure 2 the first collection means comprises a plurality of channel members 24 of plastics material arranged vertically in two rows with the bases 26 of the members 24 outermost. The channel members of each row are transversely spaced and each side 28 of the members of one row of channel members extend into a respective one of adjacent channel members of the other row. The channel members are preferably arranged in a plastics coated metal frame of substantially rectangular configuration.

It will be realised therefore that air containing excess glaze and passing through the first collection means 22 is constrained to follow a tortuous path which results in the glaze in the spray being collected on the members 24 and, under the action of gravity, running down the members 24 to the collection channel 18.

As the glaze in the collecting channel 18 is unadulterated it can be re-used relatively quickly depending on the spraying conditions. It has been found that the first collecting means 22 moves a large proportion of unused glaze from the air passing from the enclosure 12 to an outlet duct 30, the latter being provided with an extractor fan (not shown) to cause the flow of air through the enclosure 12.

Second spray collection means are provided downstream of the first collection means 22, said second collection means comprising a water curtain 32. The water curtain is a curved sheet of plasticscoated metal extending from adjacent the top of the enclosure to adjacent the bottom thereof. A channel 34 is arranged at the top of the sheet 32 with the top edge of one side of the channel providing a weir 36.

Water is supplied to the channel such that the water passes over the weir to form a film or curtain on the sheet 32. The curtain thus traps a large proportion of the glaze remaining in the air after passage through the first collection means 32. However as most of the unused glaze is removed by the collecting means 22, the water forming the curtain is substantially cleaner than in prior types of spray booth. The life of sealing glands in circulating pumps is therefore extended, cutting maintenance costs. The further glaze entrapped in the water is removed through a further collection channel 38.

To remove glaze still remaining in the air as it enters the duct 30, a plurality of vertically arranged plates 40 of zig-zag formation are provided in the duct 30 and supported on a framework (not shown) which is removably mounted in the duct. At each crest each plate 40 is provided with a downwardly extending flange 42 and it will be realised that air passing through the duct 30 is forced to follow a tortuous path, for example impinging on a surface of one plate 40, flowing over the surface until it meets with the respective protrusion 42, and then having its direction substantially reversed, this reversal causing the glaze particles to be deposited.

Various modifications can be made to the invention without departing from the scope thereof. For example the enclosure can take any suitable shape and it is preferable that it is all coated with a plastics material, for example polypropelene. The channel members 24 of the first collection means need not be rectangular in cross section but could, for example be semi-circular and the water curtain collection means could be dispensed with.

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 whether or not particular emphasis has been placed thereon.

Claims

1. A spray booth comprising an enclosure for spraying for an article therein with a coating material, and means for reclaiming excess material in the spray, the reclaiming means defining a tortuous path for a flow of a gaseous medium entraining the excess glaze.

2. A spray booth according to claim 1, wherein the reclaiming means comprises channel members arranged in two rows.

3. A spray booth according to claim 2, wherein the channel members are arranged with the members of one of the rows staggered relative to the members of the other of the rows, and with their bases outermost.

4. A spray booth according to any of claims 1 to 3, wherein the reclaiming means is arranged in a plastics coated metal frame.

5. A spray booth according to any of the preceding claims, wherein the reclaiming means is mounted for removal through on open front of the enclosure.

6. A spray booth according to any of the preceding claims, wherein means for collecting the excess glaze is provided below the reclaiming means.

7. A spray booth according to any of the preceding claims, wherein a water curtain is provided downstream of the reclaiming means.

8. A spray booth according to any of the preceding claims, wherein a series of vertically arranged members of zig-zag or corrugated form are removably mounted in a duct adjacent to an outlet of the enclosure.

9. A spray booth according to claim 8, wherein each peak of the zig-zag orcorrugation has a downwardly depending member thereto.

10. A spray booth substantially as hereinbefore described with reference to the accompanying drawing.

11. Any novel subject matter or combination including novel subject matter herein disclosed, whether or not within the scope of or relating to the same invention as any of the preceding claims.