| 摘要 |
A purge type vortex flowmeter capable of accurately measuring a flow rate of fluid over a wide range by reliably detecting the number of vortexes produced. A purge type vortex flowmeter which comprises a vortex generator (2) mounted in a passage of fluid to be measured in a flow pipe (1), two conduits (4a, 4b) having pressure ports (3a, 3b) in both side surfaces of the vortex generator for communication with the outside thereof and a front conduit (4c) having a pressure port (3c) in the front surface of the vortex generator. Purge fluid from a purge supply source is fed by a purge introducing means through a tube (5), the conduits (4a, 4b) and the front conduit (4c) into a flow of fluid to be measured in the flow pipe. Purge streams alternatively fluctuating by the effect of a difference from a fluctuating vortex pressure are discharged from the conduits (4a, 4b) through their pressure ports (3a, 3b). The fluctuations of the purge streams are detected by sensors (heat-sensitive elements (7a, 7b)) mounted in the conduits (4a, 4b). The purge fluid to be discharged through the pressure port (3c) varies its flow in accordance with the flow of the fluid to be measured in the flow pipe (1), thereby achieving automatic control of the purge flow to the sensor portion.
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