The orifice plate flowmeter and the wedge flowmeter belong to the differential pressure flow meter and are not easily blocked by the dirty medium. The wedge flowmeter which is more suitable for various conditions such as viscosity, impurities and high temperature has obvious advantages in maintenance. So, what are the irreplaceable advantages of orifice flowmeters?
They have the same working principle, they are both one of the differential pressure flowmeters, but has the different Pressure fetching method and throttling parts.
Orifice Flowmeter, is to add a middle hole in the pipe inside the circular plate, and then measure the steam in the orifice before and after the pressure difference, after calculation to calculate the flow of steam.
By introducing the differential pressure signal into the differential pressure transmitter, the differential pressure transmitter will feed the differential pressure signal into the flow totalizer, the Totalizer will convert the differential pressure signal into the flow signal, and the temperature and pressure of the steam are measured by the temperature and pressure sensor, and the totalizer calculates the compensated flow according to the temperature and pressure.
Wedge-shaped flowmeter, when the fluid through a wedge-shaped flowmeter, as a result of the throttle action of the wedge, in its upper and downstream side of the flow value of a square relationship with the differential pressure, the differential pressure from both sides of the wedge to take the pressure mouth out, sent to the differential pressure transmitter into the electrical signal output, and then through the special intelligent flow totalizer calculation, you can learn the flow value.
Advantages and disadvantages of the orifice plate flowmeter and wedge-shaped flowmeters
Orifice plate flowmeters
▲ The structure of the throttling device is easy to copy, simple and firm, stable and reliable, and has a long service life.
▲ It is suitable for the measurement of larger diameter pipes (currently, the flowmeter with diameter larger than DN 600 mm can only use orifice plate);
▲ Calibration is comprehensive;
▲ The price is cheap.
▲ The installation requirements for the throttling device, the pressure guiding tube and the condensation tank are very high, and the installation is complicated.
▲ The overall calibration of the orifice flowmeter is difficult. At present, the differential pressure sensor, pressure sensor and temperature sensor can only be verified separately, and the overall accuracy is difficult to ensure.
▲ Particularly suitable for high viscosity, low Reynolds number, medium with suspended particles or bubbles;
▲The measurement accuracy is not affected or restricted by the characteristics of the dielectric constant of the fluid medium;
▲The wedge structure is specially designed to have a diversion effect and prevent clogging;
▲There are compensation functions such as fluid viscosity change, temperature change and density change;
▲ Anti-vibration, anti-shock, anti-dirt, anti-corrosion;
▲ Has two-way flow measurement function;
▲ Energy saving and emission reduction: the wedge flowmeter has simple, firm and high reliability structure, convenient installation and low operation and maintenance cost;
▲ No moving parts, no wear, no need to recalibrate for long-term use.
▲ However, compared with orifice flowmeters, wedge flowmeters are also costly and must be calibrated. Whether it is in design, manufacturing, calculation, or installation, wedge flowmeters lack corresponding data and specifications.
▲The structure of the orifice plate determines that the static pressure of the fluid is significantly reduced when the fluid flows through the orifice plate, and the flow velocity is significantly increased, causing the fluid to flush the orifice plate seriously, eroding the sharp metal edge of the center of the orifice plate, resulting in a decrease in the accuracy of the orifice plate. . In the measurement of liquid flow rate of liquefied gas, propylene, etc., the physical shape of the fluid causes the erosion of the orifice plate to be more serious.
▲The structural form of the orifice plate causes a large static pressure loss after the fluid flows through the orifice plate. As a whole, the orifice flowmeter is a meter that consumes a large amount of energy, so that the mechanical power loss of the pump is increased. Conducive to the energy efficiency of the device, is an unfavorable factor for increasingly strict energy-saving requirements.
▲Summary: For the moment, wedge flowmeters and orifice flowmeters coexist, giving play to their respective advantages, but in the long run, wedge flowmeters are the development trend of the new generation of differential pressure flowmeters.
Orifice flow meters can be widely used in petroleum, chemical, natural gas, metallurgy, electric power, pharmaceutical, food, pesticide, environmental protection and other industries, continuous measurement of volume flow or mass flow of various liquids, gases, natural gas and steam.
The wedge flowmeter is a new type of throttling differential pressure flow measuring instrument that can perform high-precision flow measurement in high viscosity, low Reynolds number, Reynolds number, and 500 ready-to-use fluids. Small, large diameter flow measurement occasions have unparalleled advantages and irreplaceable effects.
Such as in the petrochemical / coal chemical industry applications:
---Oil refining device, ethylene plant;
---High viscosity and dirty media;
---High temperature and high pressure, high wear media;
---Coal water slurry (black water, gray water), coal slurry, etc.