Abstract: An exhaust system includes a tubular inner shell for passing therethrough exhaust gases from a combustion engine, and a tubular outer shell enclosing the tubular inner shell and cooperating therewith to define a sound silencing chamber into which the exhaust gases are introduced. The tubular inner shell forms an inner peripheral wall of the sound silencing chamber, and an upstream portion of the inner peripheral wall is formed with a perforated wall area having a plurality of communicating perforations for communicating between an interior of the tubular inner shell and the sound silencing chamber, and a downstream portion of the inner peripheral wall has a non-perforated wall area having no communicating perforation defined therein.

Abstract: An exhaust system includes a tubular inner shell for passing therethrough exhaust gases from a combustion engine, and a tubular outer shell enclosing the tubular inner shell and cooperating therewith to define a sound silencing chamber into which the exhaust gases are introduced. The tubular inner shell forms an inner peripheral wall of the sound silencing chamber, and an upstream portion of the inner peripheral wall is formed with a perforated wall area having a plurality of communicating perforations for communicating between an interior of the tubular inner shell and the sound silencing chamber, and a downstream portion of the inner peripheral wall has a non-perforated wall area having no communicating perforation defined therein.

Abstract: 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).

Abstract: 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).

Abstract: A vortex flowmeter detector is attached to or detachable from a vortex generation body for measurement of flow rate. The vortex flowmeter detector comprises a cylindrical oscillation tube having a bottom and a vortex detection part which is fixed by a fixing flange of the oscillation tube, wherein the oscillation tube is detachably inserted into a hole which is open to the vortex generation body at one end thereof, and the oscillation tube is fixed by a flange. An alternate pressure caused by a Karman vortex is introduced from both sides of the vortex generation body into the hole so as to oscillate the oscillation tube. This oscillation is received by a spring plate by way of an element cover, and it is transmitted to piezoelectric elements which are stuck to two chamfers of an elastic base material.