AIR JET DEVICE FOR PREVENTING ADHESION OF POWDER

PURPOSE:To easily and reliably adjust the timing of high-pressure air jetting for preventing adhesion of powder by providing a piston air-pressure timer for operating a timing valve. CONSTITUTION:Air decompressed by a reducing valve 22 is passed through a flow adjust valve 24 and sent at a fixed flow rate to a timer cylinder 29 of an air timer 28, and the air pressure in the cylinder 29 increases so that a piston starts to move to the right at the point of time when the air pressure is balanced with the pressure of a spring 16. A pinion 19 is turned by a rack 18 of the air timer 28, and an air switch valve 21 is operated by a cam 20 engaged with the pinion, so that compressed air supplied from a discharge pipe 2 of a compressor through a valve 27 to the switch valve 21 acts upon the lower surface of a timing piston 13 to open a valve body 31 of a timing valve 31. Thus, a jet valve 5 is instantaneously opened to instantaneously jet air accumulated in a tank 4 through a conduit pipe 6 connected to the tank 4 to a powder transport pipe 7. Accordingly, powder is checked from adhering to the inner wall of the pipe 7.