Calculation Method of Orifice Flow Meter

There are a variety of flow meters that measure flow. Different flow meters measure different media. Okawa engineers do not know what flow meters the market needs and what flow meters the factory will produce. All needs are determined by the market. This is the professional flow meter market.

Calculation Method of Orifice Flow Meter

Throttle orifice flowmeter is a high-precision flow measurement flowmeter. The names are different from place to place. There is a name called orifice flowmeter. This is the name we often say. How to calculate the flow when measuring the flow? Engineer Okawa said that the essence of the flowmeter In the header, the header device is called temperature and pressure compensation. This device can calculate different temperatures and pressures

Science Popularization Carrying Ceremony

Orifice flow meter is a high distance ratio differential pressure flow device that combines standard orifice plate with multi-parameter differential pressure transmitter (or differential pressure transmitter, temperature transmitter and pressure transmitter) to measure gas, steam, liquid and inflow flow.

Multi-stage orifice plate customization for drain pipe

Throttle orifice plate Single-stage throttle orifice plate Detailed description: The function of the throttle orifice plate is to make the hole diameter smaller at the appropriate position of the pipeline. When the liquid shrinks, the flow beam becomes thinner or the flow beam becomes thinner. When the pressure difference between the front and rear of the throttle orifice plate is large, the throttle orifice plate is often increased. This is because the local resistance of the orifice plate when the fluid flows in the pipeline causes the pressure of the fluid to decrease, and the energy loss is called throttling in thermodynamics. This method is simpler than using a regulating valve, but it should be selected appropriately. Otherwise, the liquid is easy to corrode, which will affect the safe operation of the pipeline.

The function of the orifice plate is to make the hole diameter smaller at the appropriate position of the pipeline, and the flow becomes thinner or shrinks when the liquid passes through the contraction. The small cross-section of the stream occurs downstream of the actual constriction and is called the constriction cross-section. The flow rate in the constricted section is large, and the increase in flow rate increases with a large decrease in pressure in the constricted section. When the stream expands to a larger area, the velocity will slow down and the pressure will increase, but the downstream pressure cannot fully recover to the upstream pressure due to greater internal turbulence and energy consumption. When the pressure PVC of the shrinking section drops below the saturated steam pressure PV at the corresponding temperature of the liquid, the stream steam and the gas dissolved in water will escape, forming small bubbles of steam and gas mixed together. The lower the pressure, the more bubbles.

When the pressure p2 downstream of the orifice plate is still lower than the saturated vapor pressure of the liquid, foam continues to occur in the downstream pipeline, and there is a two-phase mixture of liquid and vapor, which is a flash phenomenon. If the downstream pressure is restored to be higher than the saturated vapor pressure of the liquid, the bubble will quickly condense and burst under the action of high pressure, and the local cavity will occur at the moment of bubble rupture, and the high pressure will flow to the space occupied by the original bubble at a higher speed, forming an impact. The gas and steam in the bubble are all dissolved instantly without condensation. Under the action of the impact force, they are divided into small bubbles, compressed by high pressure, condensed, and repeated many times. We can imagine a similar phenomenon of sand and gravel passing through the pipeline noise. Republic. The surface of the runner material is fatigued and severely damaged due to water hammer pressure. We call the entire process of destruction of materials due to the formation, development and collapse of bubbles as cavitation. In practical engineering application, it is feasible to use multi-stage orifice plate for decompression system. In order to prevent cavitation of the pipeline, when selecting the orifice plate, the number of orifice plates and the diameter of the orifice should be calculated according to the actual situation of the pipeline

Throttle devices are a large category of differential pressure flow meters. An example of the early commercial use of throttle devices is that in 1900, the United States used orifice plates to measure natural gas flow. In the following 100 years, various throttle devices have appeared. After a large number of experiments and scientific data processing, five throttle devices have gradually formed all standards and continuously supplemented all recently promulgated ISO standards.