Continuous gas flow regulating appts. - in which pressure build-up occurs via inlet valve and preset throttle valve and inlet valve is switched to determine gas mass flow

摘要

In equipment for producing a continuous regulated gas mass flow, esp. for a hot gas soldering tool (5); (i) pressure is built up in the predetermined vol. of a container (1), connected via an inlet valve (2) to a pressure source and via a preset throttle valve (4) to the soldering tool (5), by switching the inlet valve (2) into its position connecting the pressure source to the container (1); and (ii) subsequently switching the inlet valve (2) into its container-open position for a certain time (t) so that the pressure drop (p) in the predetermined vol. determines the gas mass flow (ML) via the throttle valve (4) to the soldering tool (5) according to the equation ML = f (dp/dt) in which f is a constant determined by the predetermined vol., and the preset throttle amt. ADVANTAGE - The equipment is relatively simple since it comprises only a container of certain vol., a single pressure measuring device, a throttle and a simple microprocessor-controlled inlet valve, all these components being inexpensive and being commerically available.