Paint and varnish spray assembly - has electrode in water circuit to give HT electrostatic field to prevent explosion

摘要

The assembly to spray a coating fluid, such as paint or varnish and the like, has a high voltage supply to generate an electrostatic field in the water recirculating through the spraying zone. The high voltage generator (38) is within a pipe section (42) of the water circuit (29), which can be connected to a voltage supply (46) outside the water recirculation circuit (29). The high voltage generator (38) is an exchangeable unit inserted into the water circuit (29), with an electrode (36) projecting into the water (14) recirculating through the circuit (20). It has an oscillator to convert a low DC voltage from an external supply (44) into a low voltage AC outlet which is transformed into a high AC voltage to be converted by a HT cascade circuit into a high DC voltage for the electrode (36). The high voltage generator (38) is within an end section (42) of a pipe section (34) forming part of the water circuit (29), with a side inlet (22) and outlet (26) for the water flow. The electrode (38) extends at least partially in the stretch between the inlet (22) and outlet (26), in the centre of the pipe (34) and axially through it. ADVANTAGE - The system greatly reduces or prevents explosion risks in the spraying zone, which is cheaply made and requires no maintenance, with simple replacement.