Vortex shedding flowmeter
First Claim
1. A vortex shedding flowmeter for measuring a flow rate of a fluid which flows through a flow passage, said vortex shedding flowmeter comprising:
- a bluff body arranged in said flow passage for generatingKarman vortices of said fluid, said bluff body being provided with a pair of differential pressure introducing holes for introducing a pressure change caused by the generation of the Karman vortices of said fluid, said differential pressure change holes opening to respective side surfaces of said bluff body and penetrating through said bluff body to open to one end of said bluff body; and
a main detecting part which is independent of said bluff body,said main detecting part comprising a mounting member which is mounted on said one end of said bluff body, a pair of detecting means provided in said mounting member and a detecting circuit, said pair of detecting means being arranged separated from each other in a longitudinal direction of said flow passage and comprising a pair of first recesses provided on said mounting member, a pair of fixed electrodes mounted in said pair of first recesses, a pair of movable electrodes provided in said pair of first recesses with a predetermined distance from the respective pair of fixed electrodes, a channel provided in said mounting member for communicating a pair of spaces formed between said pair of fixed electrodes and said pair of movable electrodes, and an incompressible fluid filled up in said pair of spaces and said channel, each of said movable electrodes comprising a diaphragm which is displaced responsive to the pressure change in said fluid introduced through a corresponding one of said pair of differential pressure introducing holes and received by a surface of said diaphragm opposite to surfaces in contact with said incompressible fluid, said pair of fixed electrodes and said pair of movable electrodes constituting a pair of variable capacitors, said detecting circuit generating an electrical output responsive to changes in capacitances of said variable capacitors of said pair of detecting parts.
1 Assignment
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Accused Products
Abstract
A vortex shedding flowmeter comprises a flow passage through which a fluid flows, a bluff body arranged in the flow passage for generating Karman vortex of the fluid and provided with a pair of holes which open to respective side surfaces of the bluff body and extend toward and penetrate through one end of the bluff body for introducing a pressure change caused by the Karman vortex, a body which is an independent member from the bluff body, a pair of detecting parts provided in the body and comprising a pair of recesses provided on the body, a pair of fixed electrodes and a pair of movable electrodes provided in the recesses with a predetermined distance therebetween, a communicating hole provided in the body for communicating a pair of spaces formed between the fixed and movable electrodes, and a sealed fluid sealed in the spaces and the communicating hole, where the movable electrodes are displaced responsive to the pressure change in the fluid introduced from the bluff body and received by surfaces of the variable electrodes opposite to surfaces in contact with the sealed fluid and the fixed and movable electrodes constitute a pair of variable capacitors, and a detecting circuit for generating an electrical output responsive to changes in capacitances of the variable capacitors.
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Citations
7 Claims
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1. A vortex shedding flowmeter for measuring a flow rate of a fluid which flows through a flow passage, said vortex shedding flowmeter comprising:
- a bluff body arranged in said flow passage for generating
Karman vortices of said fluid, said bluff body being provided with a pair of differential pressure introducing holes for introducing a pressure change caused by the generation of the Karman vortices of said fluid, said differential pressure change holes opening to respective side surfaces of said bluff body and penetrating through said bluff body to open to one end of said bluff body; and a main detecting part which is independent of said bluff body, said main detecting part comprising a mounting member which is mounted on said one end of said bluff body, a pair of detecting means provided in said mounting member and a detecting circuit, said pair of detecting means being arranged separated from each other in a longitudinal direction of said flow passage and comprising a pair of first recesses provided on said mounting member, a pair of fixed electrodes mounted in said pair of first recesses, a pair of movable electrodes provided in said pair of first recesses with a predetermined distance from the respective pair of fixed electrodes, a channel provided in said mounting member for communicating a pair of spaces formed between said pair of fixed electrodes and said pair of movable electrodes, and an incompressible fluid filled up in said pair of spaces and said channel, each of said movable electrodes comprising a diaphragm which is displaced responsive to the pressure change in said fluid introduced through a corresponding one of said pair of differential pressure introducing holes and received by a surface of said diaphragm opposite to surfaces in contact with said incompressible fluid, said pair of fixed electrodes and said pair of movable electrodes constituting a pair of variable capacitors, said detecting circuit generating an electrical output responsive to changes in capacitances of said variable capacitors of said pair of detecting parts. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- a bluff body arranged in said flow passage for generating
Specification