Vortex flowmeter is a kind of velocity flowmeter, which is based on the conservation of mass, using the principle of fluid natural oscillation, a vortex separation flowmeter, it is also called vortex flowmeter and Karman vortex flowmeter. The vortex generating body, that is, the bluff body, is arranged in the fluid, and regular vortices are generated alternately from both sides of the vortex generating body. This vortex is called a Karman vortex street, and the number or frequency of the vortex columns is proportional to the flow velocity. Therefore, by measuring the vortex frequency, the flow rate of the fluid can be known and the fluid flow can be calculated. Vortex flowmeter vortex body there are many, a large number of cylindrical, triangular, rectangular and so on. Cylindrical pressure loss is small but eddy strength is low, rectangular eddy strength is large, but the pressure loss is also large; triangular pressure loss is generally, but the eddy intensity is large, so the triangle body has a wide range of applications in practice. The vortex flowmeter detection method utilizes the physical effects accompanying the vortex separation, and the vortex separation frequency can be detected by using a thermosensitive, force-sensitive element or by an optical and acoustic modulation method. So far, the methods used to detect the separation frequency and the components used are various. To sum up, there are the following methods: (1) The detection method of the thermal element, the frequency of the whole surface velocity pulsation or the alternating lateral flow caused by the alternating circulation generated by the vortex separation, and the detection is performed with a heated metal wire and a thermistor; (2) Force sensor detection methods, mechanical vibration caused by alternating differential pressure, alternating lift, or alternating lift caused by vortex separation, using differential capacitance, resistance strain gauges, piezoelectric crystals, piezoelectric ceramics, etc.; (3) Electromagnetic sensor detection method The frequency of the reciprocating vibration of the diaphragm or shuttle ball caused by the separation of the vortex is detected by an electromagnetic sensor; (4) Acoustic and optical signal modulation detection method uses the modulation of the vortex when the acoustic beam passes through the vortex, and the vortex separation frequency is obtained from the pulsation frequency of the received intensity or phase. (5) There are many advantages of vortex flowmeters. It has a large measuring range, high accuracy, high reliability, low pressure loss, and can measure gases, liquids, and steam. Its reading is not affected by fluid pressure, temperature, density, viscosity, and fluid composition. Replace the original inspection without re-calibration, the range is relatively large, the liquid up to 1:15, gas up to 1:30, a large range of pipe diameter, easy installation, high precision, easy maintenance, etc., the disadvantages of the team feel sensitive to mechanical vibration, Should not be used for vibration sites, changes in velocity distribution and pulsation flow affect the measurement accuracy, straight pipe requirements (upstream 20D, downstream 5D). The contamination of the test element affects the accuracy and must be cleaned frequently. When using vortex flowmeters, the piping Reynolds number should also be within the specified range. Knitwear And Sweater Equipment Knitwear And Sweater Equipment,Garment Three-Stripe Attaching Machine,Automatic Knitwear Pocket Setter,Trousers Three Stripes Sewing Machine Ngai Shing Development Limited , https://www.ngaishing.hk