GB1149335A - Spray booth - Google Patents

Abstract

1,149,335. Coating apparatus. DE VILBISS CO. 21 Feb., 1968 [20 April, 1967], No. 8433/68. Heading B2L. A spray booth comprises a coating chamber containing a support for an article to be coated, an air supply chamber, an inlet opening between said chambers for directing air from the supply chamber to the coating chamber, a spray head located near the inlet opening for directing coating spray towards the article, and means for exhausting air from the coating chamber at a location remote from the inlet opening. The arrangement is designed to effect a reduction in the volume of the air as usually circulated. As shown in Fig. 3, a coating chamber 12, for articles A suspended from an overhead conveyor, is defined by walls 38 and extends from respective inlet and outlet end openings 18, 20, the width of which is controlled by sliding doors in accordance with the width of the articles 16. Openings in walls 38 are bounded by plates 50 disposed perpendicularly thereto. On each side of chamber 12 is a closed air supply chamber 36 provided with access doors 70. At each opening in wall 38 is positioned a vertical .row of spray guns 24 vertically reciprocable by means 28 on a carriage 30 mounted on rails 34 for movement towards and away from chamber 12. Rigid with and surrounding carriage 30 is a shroud of inwardly-directed plates 54, the outer peripheral edges 56 of which extend close to the plates 50, whereby restricted openings 48 are provided between the chambers 36 and the chamber 12. Fresh air is forced by a fan through ducts communicating with the chambers 36 and passes therefrom through the openings 48 into chamber 12. The air is exhausted from the latter through a floor grating 60, and after passing through a lower chamber or water tank is drawn upwardly through ducts 64, containing water sprays and baffles, by respective exhaust fans having a capacity slightly less than than that of the supply fan for maintaining a slight positive pressure in chamber 12 to prevent the ingress of dust through the end openings 18, 20. In a modification two vertical Tows of spray guns are mounted on each carriage 30. In Fig. 5 the spray booth apparatus is located in an existing room 78 from which air passes through restricted openings 88 in walls 82 into coating chambers 84, and leaves the latter through baffles 90 before being exhausted through ducts 91. Spray guns 74 are positioned at the openings 88, and the walls 82 are provided with louvres 92 for regulating the supply of air to chambers 84.