Method for flow rate control of clustering fluid and device for flow rate control of clustering fluid employed in the method

摘要

Disclosed is a method of controlling the flow rate of clustering fluid using a pressure type flow rate control device in which the flow rate Q of gas passing through an orifice is computed as K=KP 1 (where K is a constant) with the gas being in a state where the ratio P 2 /P 1 between the gas pressure P 1 on the upstream side of the orifice and the gas pressure P 2 on the downstream side of the orifice is held at a value not higher than the critical pressure ratio of the gas wherein the association of molecules is dissociated either by heating the pressure type flow rate control device to the temperature higher than 40° C., or by applying the diluting gas to the clustering fluid to make it lower than a partial pressure so the clustering fluid is permitted to pass through the orifice in a monomolecular state.