JET MIXER WITH BY-PASS DEVICE

PURPOSE:To prevent the generation of water hammer by installing a by-pass pipe which connects the inlet hole and outlet hole for feed fluid across the shortest distance and of which cross sectional area is set in such a range that the area is larger than the area formed by subtracting the minimum cross sectional area of a venturi type flow path from the cross sectional area of a feed pipe for feed fluid but not larger than the cross sectional area of the pipe. CONSTITUTION:The cross sectional area of a by-pass pipe 4 is specified in a value ranging from the cross sectional area with the same diameter as that of a feed pipe 3 to the area formed by deducting the area of a throat part which has the minimum cross sectional area in a venturi type flow path A from the cross sectional area of the feed pipe. When the outlet pressure of a jet mixer becomes higher than the inlet pressure, mixed fluid flows into the inlet hole 7 of the by-pass pipe from the outlet hole 8 of the by-pass pipe and the action keeping the balance between the inlet and outlet pressure of the jet mixer is naturally carried out and the fluid returning back to the inlet hole of the by-pass pipe joins feed fluid and is again sucked into the jet mixer. The reduction of the feed fluid is supplemented by the fluid returning back to the hole 7 and therefore, the generation of water hammer is able to be prevented.