(1) Low requirements for straight pipe section of V-cone flowmeter . Although all differential pressure flowmeters measure according to Bernoulli's theorem, Bernoulli's theorem has a basic requirement that the fluid to be measured must be an ideal fluid. When using a traditional differential pressure flow meter throttling device such as an orifice plate and a nozzle , in order to meet the requirements of Bernoulli's theorem as much as possible, there must be very long straight front and rear pipe sections in order to form irregular flowing fluids as much as possible. Ideal fluid. The V-cone flowmeter uses a unique streamlined throttling structure design that is placed in the center of the pipeline. Before detecting the flow, it rectifies the irregularly flowing fluid at the same time, and solves the problem of fluid rectification without adding a fluid rectifier. . The center-suspended streamlined cone can reshape the velocity curve. In a narrow area immediately upstream and downstream of the cone (front 0 ~ 3D, rear 0 ~ 1D), the liquid with irregular flow rate can be directly rectified into the ideal liquid, which can fully Meet the requirements of Bernoulli's theorem, and obtain high measurement accuracy and repeatability. V-cone flowmeters do not require very long straight pipe rectification, which is of great significance in the installation process of flowmeters .
(2) Resistant to pollution and difficult to plug. If an orifice plate flow meter or averaging tube flow meter is used , because the gas contains various impurities such as tar, naphthalene, sulfur, ammonia, etc., the orifice plate or averaging tube must be cleaned regularly or purged with steam, otherwise the orifice plate , The downstream end face, and the right-angle inlet edge of the upstream side will be contaminated, and the meter's pressure guiding tube will be unblocked or blocked, affecting the measurement accuracy of the system; water accumulation in the straight pipe section before and after the orifice plate will reduce the pipeline flow area, increase the flow rate, and increase the differential pressure The flow display value is too high. In severe cases, the transmitter cannot operate normally due to the blocked pressure tube. In order to ensure the normal and stable operation of the meter, the maintenance work of the meter worker is very heavy. The V-cone flowmeter has a self-blowing structure design feature and no dead zone. The medium will accelerate as it flows through the cone, constantly flushing the positive pressure tapping hole, the outer wall of the cone and the pipe wall near the cone, while the negative pressure tapping hole is isolated by a small section of non-flowing medium, and dirty impurities cannot enter. Therefore, the V-cone flowmeter can be used for various contaminated media containing impurities and easy to crystallize, such as coke oven gas, generator gas and other media. The use of the V-cone flowmeter can greatly reduce the maintenance workload of the instrument and improve the accuracy and reliability of gas flow measurement.
(3) Large differential pressure value and wide measuring range, suitable for flow measurement of low pressure and low flow medium. In the process of coke oven gas flow measurement, the characteristics of the measurement object are large pipe diameter, low pressure, and slow flow rate. Orifice flowmeters are generally equipped with micro differential pressure transmitters. When the gas pressure is 3500Pa, the normal differential pressure is Change between 100 ~ 1000Pa, the differential pressure signal of the flowmeter is small. In the case of averaging tube flowmeters , due to the low gas flow rate of the pipeline, the differential pressure signal is very small, which has a great impact on the accuracy of the system. If an averaging tube flowmeter is used , the maximum differential pressure is only 120Pa and the normal value is 2 ~ 5Pa. The accuracy is poor. A small differential pressure signal will affect the accuracy of the transmitter calibration and use; contamination of the orifice plate, the imperfection of the instrument pressure pipe, and the accumulation of water in the pipeline will greatly affect the accuracy of the system. The V-cone flowmeter is a throttling member similar to an orifice plate, and the differential pressure value is much larger than that of an average velocity tube. Compared to an orifice plate, the pipe edge shrinks gradually and the resistance loss is small, so the resistance loss can be the same. In the case, a V-cone flowmeter with a large differential pressure value can be selected for design.