的安装其实要求并不高，比如它可以不用考虑流量计前直管道的长度，这个其他流量计是要求比较严格的。 The installation of elliptical gear flowmeters is actually not very demanding. For example, it does not need to consider the length of the straight pipe in front of the flowmeter. This other flowmeter is more stringent. The oval gear flow transmitter and the secondary instrument form an oval gear flow meter. When installing the transmitter, we need to carefully understand the impurities in the pipeline. If we consider that there may be impurities in the medium to be measured during use, a filter can be installed, which can extend the service life of the oval gear flowmeter and reduce the cost of routine maintenance. If the flowmeter is used in a relatively clean place, a stainless steel flowmeter can also be used. When installing, try to install it in a horizontal position. The transmitter should be installed at the output end of the pump to reduce measurement errors. If the measurement medium is mixed with gas, a gas separator should be installed.
As long as you pay attention to the above issues, there will generally not be any problems in use, and it can be used stably for more than five years. Jinhu Dongxiang oval gear flowmeter mainly has cast iron, cast steel and stainless steel for different occasions.
The measuring part of the elliptical gear flowmeter is mainly composed of two meshing elliptical gears and its casing (metering chamber). The volume of the measured medium per round of the elliptical gear is 4 times the volume of the half-moon shape. The volume flow Q of the meteorometer is:
Q = 4nυ0
In the formula:
n-the rotation frequency of the elliptical gear (revolutions per second);
υ0——the volume of the half-moon-shaped part (shell).
的半月形容积υ0一定的条件下，只要测出椭圆齿轮的旋转速度n，便可知道被测介质的流量。 In this way, under the condition that the half-moon volume v0 of the oval gear flowmeter is constant, as long as the rotation speed n of the oval gear is measured, the flow rate of the measured medium can be known. The display of the flow signal of the elliptical gear flowmeter (ie, the rotation speed n of the elliptical gear) has two types: local display and remote transmission display. Local display After the gear's rotation is passed through a series of speed reduction and speed ratio adjustment mechanisms, it is directly connected to the indicator pin on the instrument panel, and the total amount is displayed through a mechanical counter. The remote transmission display mainly uses the decelerated gear to drive the permanent magnet to rotate, so that the contacts of the spring relay are closed or opened synchronously with the same rotation frequency as the permanent magnet, so that one electric pulse is sent to another display instrument.
The flow measurement has nothing to do with the flow state of the fluid. This is because the elliptical gear flowmeter relies on the pressure head of the measured medium to push the ellipse gear to rotate for measurement. The larger the viscosity of the medium, the smaller the amount of leakage from the gear and the measuring gap. Therefore, the larger the sticky skin of the test medium, the smaller the leakage error, and the more favorable it is for measurement. The elliptical gear flowmeter has high measurement accuracy and is suitable for measuring the flow of high-viscosity media, but it is not suitable for fluids containing solid particles (solid particles will seize the gear and make it impossible to measure the flow). If gas is contained in the liquid medium to be measured, it will also cause measurement errors
The oval gear flowmeter should be cleaned before installation. If the liquid contains solid particles, a filter must be installed upstream of the pipeline; if it contains gas, an exhaust device should be installed. The elliptical gear flowmeter does not have certain requirements for the front and rear straight pipe sections. It can be installed horizontally or vertically. During installation, the elliptical gear rotation axis of the flow meter should be parallel to the ground.
The elliptical gear flowmeter correctly installed in accordance with the requirements can ensure sufficient accuracy when used. Generally, the accuracy of the accumulated value can reach level 0.5, which is a more accurate flowmeter. However, if the flow rate of the measured medium is too small during use, the effect of the leakage error of the instrument will be prominent, and sufficient measurement accuracy cannot be guaranteed. Therefore, the oval gear flowmeters of different models and specifications have an allowable value for the minimum used flow rate. The measurement accuracy can be guaranteed only when the actual measured flow rate is greater than the lower limit flow rate allowable value.
要注意被测介质的温度不能过高，否则不仅会增加测量误差，而且有使齿轮发生卡死的可能。 Secondly, when using an elliptical gear flowmeter, pay attention to the temperature of the measured medium must not be too high, otherwise it will not only increase the measurement error, but also may cause the gear to jam. For this reason, the oval gear flowmeter is used within the operating temperature range specified by the meter. After long-term use, the gears inside the oval gear flowmeter will be corroded and worn, which will affect the measurement accuracy. Therefore, it is necessary to pay attention to observation and take it apart regularly for inspection. If conditions permit, it is better to perform calibration regularly.