Orifice flow meters are throttling devices that measure the flow differential pressure sensing element. With the differential pressure transmitter and the actual, recording, integrating and regulating instruments, can be used to measure, accumulate and control the instantaneous flow, cumulative flow of liquids, steam and gases. Pro Breeze Dehumidifier,Xiaomi Dehumidifier,Cordless Dehumidifier,Pro Breeze Electric Mini Dehumidifier Yuyao Veedai Electrical Appliance Co., Ltd , https://www.kxveed.com
The throttling device has the advantages of simple structure, convenient installation, reliable use, low price, convenient maintenance, and wide selection range (standard tube diameter can be measured from 50mm to 1200mm, non-standard throttling device can also be used as small as 6mm. As large as 3000mm; measuring temperature up to 555°C; pressure resistance up to 42MPa), and the standard throttling device also has the advantage of no separate calibration, is the most widely used and most mature product in flow meters, and is therefore widely used Power, chemical, metallurgy, petroleum, textile, military and other fields.
The throttling device consists of a throttling element, a pressure-receiving device (including a pressure-reducing port, a pressure-inducing tube, a valve, etc.), and a supporting flange, and sometimes includes a straight pipe section that conforms to the standard. Standard throttling devices include standard orifice plates, standard nozzles, and standard venturi tubes. The standard orifice is divided into angles according to the pressure (circular room or borehole), pressure is taken from the flange, pressure is taken from the span; the standard nozzle is divided into nozzles and long-diameter nozzles; the standard venturi is divided into venturis according to the form Nozzles, venturis (coarse cast or machined or coiled). Non-standard throttling devices include small orifice plates, 1/4 round orifice plates, round orifice plates, round orifice plates, eccentric orifice plates, double orifice plates, built-in orifice plates, and conical inlet orifice plates. Other types of throttling devices include pitot tubes, constant velocity tubes, wedges, cones, and the like.
When using standard throttling devices, the nature and condition of the fluid must meet the following conditions:
(1) The fluid must be filled with pipes and throttling devices and continuously flow through the pipes;
(2) Fluid flow does not change with time or changes very slowly;
(3) No flow occurs when the fluid flows through the throttle;
(4) The fluid must be a Newtonian fluid, ie, physically and thermodynamically homogeneous, single-phase, or it may be considered as a single phase, including a mixture of gases, the solution and disperse particles being less than o. 1 m colloid. Solid particles with not more than 2% (mass content) uniformly dispersed in gas, or evenly dispersed bubbles with not more than 5% (volume content) in liquid, may also be considered as single-phase fluids, but the density should be taken as the average density ;
(5) Before the fluid flows through the throttle, the stream is a non-rotating flow parallel to the axis of the pipe.
Standard throttling devices are not suitable for flow measurement of flow and critical flow. The throttling device artificially causes throttling in the medium flowing through the pipeline. When the measured medium flows through the throttling device, it causes a local contraction, the flow bundle is concentrated, the flow velocity increases, and the static pressure decreases, so the upstream and downstream of the throttling device There is a static pressure difference on both sides. The static pressure difference is a function of the flow rate. The larger the flow, the greater the static pressure difference generated. Therefore, the flow rate can be measured by measuring the differential pressure.
The difference between orifice flowmeters and other flowmeters is that the orifice flowmeters are based on parametric design drawings and are finally processed. Only the orifice plate material is selected based on the measurement media.