⎝⎛星力捕鱼⎞⎠

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Address: Xiongyi, Jinhe Road, Jinhu County, Jiangsu Province
Lunan
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Industry Information
Features of long-period, high-precision operation due to wear-resistant and maintenance-free
2012-4-13 13:47:35

在工作中不会磨损;在高速流体冲击下不会变形、扭曲、震动;对于环境中可能出现的震动、粉尘、潮湿、电磁场干扰不敏感;经过长周期运行它的稳定性、灵敏度、准确性不会发生明显变化;能在最大程度上防止传感器被粘污、结疤、堵塞等等。 The elbow flowmeter will not wear during work; it will not deform, distort, and shake under the impact of high-speed fluid; it is not sensitive to vibration, dust, humidity, and electromagnetic field interference that may occur in the environment; its stability after long-term operation, Sensitivity and accuracy will not change significantly; it can prevent the sensor from being contaminated, scarred, blocked, etc. to the greatest extent. Ensure long-term high-precision measurement of the flow meter. The orifice of the orifice flowmeter is very sensitive to trace wear. The regulations stipulate that the orifice plate of the orifice plate flow meter for measurement must be subjected to a mandatory wear inspection once or more per year to ensure the accurate measurement of the orifice plate flow meter. For those large-diameter orifice plates and steam orifice plates, it is difficult to disassemble and install, and the maintenance cost is high, which brings an extra burden to the user. Due to the characteristics of wear resistance, maintenance-free and long-period high-precision operation, the elbow sensor can meet the technical conditions of direct welding installation. The welding method solves the headaches of running, dripping, leaking, etc. on the flow measurement device. . If you use the elbow flow meter correctly, you can get unexpected results.

是测量液体、气体介质流量计,尤其对工厂管道煤气,天然气,有它独特的一面。 The elbow flowmeter is a flowmeter for measuring liquid and gas media, especially for factory pipeline gas and natural gas, which has its unique aspect. Widely used in liquid, gas, and steam flow measurement in petroleum, chemical, power, metallurgy, steel and other industries. It can accurately measure the flow of various fluids in a wide range of φ10 ~ φ2000mm pipelines. The bend pipe can withstand high temperature and high pressure. , Can work normally in a variety of harsh environments such as humidity, dust, vibration. It has no inserts, no additional resistance loss, simple structure and convenient installation.

Second, the working principle of elbow flowmeter

1.Principle

The fluid flows in the pipe. When flowing through the elbow, the fluid is similar to flowing through a rectifier. Due to the guiding effect of the curved pipe wall, the inside of the fluid is accelerated about 2D before entering the elbow, and the outside of the fluid is decelerated until it enters. The flow velocity form of the elbow is rectified into a trapezoidal velocity flow pattern similar to that described by free swirl theory, and reaches a maximum at the 45 ° section of the elbow. This process will continue throughout the elbow. At the exit of the elbow and in the 2D range downstream, the change process of the velocity model is the reverse of the change in the inlet. According to the law of mass conservation, energy conservation, and momentum conservation, the velocity distribution of the particles at the 45 ° section of the elbow is the same. At the same flow cross section, the energy of each flow point is unchanged. Due to the change of the velocity of each particle, the elbow is formed. Inside and outside pressure difference △ P. This pressure difference is maximum and most stable at a 45 ° section. Moreover, the average fluid velocity υ of the 45 ° elbow section and the pressure difference △ P accord with the square proportional relationship. The larger the flow, the larger the differential pressure. The flow coefficient of a fluid flowing through an elbow is closely related to the geometric size of the elbow (bend radius R and inner diameter D), that is, the flow coefficient α = f (RD). Therefore, once the geometric size of the elbow sensor is determined, The average flow velocity υ of the fluid can be determined by measuring the internal and external pressure difference ΔP and the density ρ of the 45 ° section of the elbow.

Mathematical expressions

among them:

α (RD): flow coefficient

△ P: 45 ° internal and external pressure difference

D: inside diameter of elbow

R: bend radius

ρ: fluid density

According to the relationship between the pipeline fluid velocity υ and the flow rate Q, the following flow calculation formula can be obtained:

Q = π / 4D2υ. 3.6ρ t / h

Third, the composition of the measurement system

Used with pressure transmitters, differential pressure transmitters, and temperature transmitters: 1. The differential pressure transmitter is used to detect the differential pressure value produced by the elbow sensor, so it is necessary for the elbow flowmeter measurement system. Fewer accessories. 2. Whether the system is equipped with pressure and temperature transmitters should be determined according to the specific measurement object. For systems measuring steam or other gaseous media, in principle, temperature and pressure transmitters must be configured so that the necessary steam or gas Real-time temperature and pressure compensation.

Fourth, the advantages of the measurement system

1. The sensor structure is simple. The elbow sensor uses the elbow of the pipe system as the detection element. There is no additional pressure loss and the special installation of throttling components is its advantage. The elbow pressure opening is opened at 45o. Same, the two pressure taps in the two planes are aligned so that they can be on the same straight line; 2. Maintenance-free flow sensor elbow flowmeter will not wear during work; it will not deform under the impact of high-speed fluid , Distortion, vibration; insensitive to vibration, dust, humidity, and electromagnetic field interference that may occur in the environment; after a long period of operation, its stability, sensitivity, and accuracy will not change significantly; it can prevent the sensor from being stuck to the greatest extent Fouling, scarring, blockages, etc. Ensure long-term high-precision measurement of the flow meter. The orifice of the orifice flowmeter is very sensitive to trace wear. The regulations stipulate that the orifice plate of the orifice plate flow meter for measurement must be subjected to a mandatory wear inspection once or more per year to ensure the accurate measurement of the orifice plate flow meter. For those large-diameter orifice plates and steam orifice plates, it is difficult to disassemble and install, and the maintenance cost is high, which brings an extra burden to the user.

因耐磨损、免维护、长周期高精度运行的特点,可满足直接焊接安装的技术条件,焊接法安装解决了流量测量装置现场跑、冒、滴、漏等令人头痛的问题。 Due to the characteristics of wear resistance, maintenance-free, and long-period high-precision operation, the elbow flowmeter can meet the technical conditions of direct welding installation. The welding method installation solves the headaches of running, dripping, leaking, etc. of the flow measurement device on site. problem.