DEVICE FOR FORMING NEGATIVE PRESSURE AND METHOD FOR FORMING NEGATIVE PRESSURE BY JET FLOW

摘要

PROBLEM TO BE SOLVED: To automatically change over formation of a great quantity of negative pressure and formation of high negative pressure by one negative pressure forming device and reduce a load acting on a high pressure fluid supply source during formation of high negative pressure as compared to formation of a great quantity of negative pressure.;SOLUTION: In this negative pressure forming method, a great quantity of negative pressure is formed by injecting water pressurized by a pressurizing pump 4 to a straight pipe 18 for forming a great quantity negative pressure from a small diameter injection nozzle 10, high negative pressure is formed by injecting the same to a straight pipe for forming high negative pressure. The high negative pressure is applied on the injection nozzle 10 to give the injection nozzle a suction effect. Consequently, load of the pressurizing pump 4 is reduced as compared with load in formation of a great quantity of negative pressure.;COPYRIGHT: (C)2009,JPO&INPIT