Accuracy class and function According to the measurement requirements and the use occasions, the instrument accuracy level is selected to achieve economical efficiency. For example, in the case of trade settlement, product handover and energy measurement, the accuracy level should be higher, such as 1.0, 0.5, or higher; for process control, select different accuracy levels according to control requirements; It is to detect the process flow, no need to do precise control and measurement, you can choose a lower accuracy level, such as 1.5, 2.5, or even 4.0, then you can use a low-cost plug-in electromagnetic flowmeter.
Measuring medium flow rate, meter range and diameter When measuring general medium, the full flow of electromagnetic flowmeter can be selected within the range of 0.5-12m/s of measuring medium flow, and the range is wider. The meter specification (caliber) is not necessarily the same as the process pipeline. It should be determined whether the measured flow range is within the flow rate range. That is, when the pipeline flow rate is too low to meet the flow meter requirements or the measurement accuracy cannot be guaranteed at this flow rate, It is necessary to reduce the gauge diameter, thereby increasing the flow rate inside the tube and obtaining satisfactory measurement results.
Try to avoid ferromagnetic objects and equipment with strong electromagnetic fields to prevent the magnetic field from affecting the working magnetic field and flow signal of the sensor.
Should be installed in the dry and ventilated place, to avoid sun and rain, the ambient temperature should be -20 ~ +60 ° C, relative humidity is less than 85%.
There should be ample space around the flowmeter for easy testing and maintenance.
Turbine flowmeter composition
Turbine flowmeters are speed flowmeters, also known as impeller flowmeters. The impeller type flowmeter utilizes the relationship between the rotational angular velocity of the impeller placed in the fluid and the fluid flow velocity. By measuring the rotational speed of the impeller to reflect the volumetric flow rate of the fluid passing through the pipeline, it is a relatively mature high-accuracy instrument in the flowmeter. One. Turbine flowmeters generally consist of the following five typical parts:
1. Body
The material of the body is generally steel or cast iron, and the ends are flanged. The small diameter gauge also has a threaded interface.
2. Measured component
The turbine has precision machined blades that together with a set of reduction gears and bearings form the measuring assembly. The two high-precision stainless steel permanent self-lubricating bearings that support the turbine ensure a long service life of the assembly. Turbine flowmeters can also be lubricated with an external lubricant pump, but be careful not to overdo it.
3. counter
The following important information is available on the counter panel:
(1) Maximum working temperature and pressure:
(2) Metering and minimum and maximum flow levels
(3) Product model and number
(4) Explosion-proof grades and signs
(5) The equivalent of the fluid corresponding to the low frequency or high frequency pulse and the wiring method.
4. Rectifier
The rectifier is used to keep the fluid flowing through the turbine flow meter in a regular state, thereby eliminating the disturbance and having an unaffected effect on the metering. High metering accuracy.
5. Magnetic coupling transmission device
The device separates the counter portion in the atmospheric environment from the gas being measured and transmits the rotation of the measuring assembly to the counter.
Third, gas turbine flowmeter daily inspection
1. Look at the display: Observe the total amount, instantaneous, temperature, pressure, and battery power. If the abnormality is reported in time.
2. Listen to the running sound of the flowmeter. (Method) The flowmeter should have no noise when it is running normally. If there is a large abnormal noise, it can be judged as damage to the movement of the movement (for example). It needs to be reported and processed in time.
3, data comparison, the output of the first 3 to 5 days before the statistics, if there is no major change, the flowmeter runs normally, such as the successive decrement phenomenon, the gas turbine flowmeter impeller (shaft, shaft core), filtration There is a problem with the device. Need to be reported in time for processing
4, gas turbine flowmeter filling lubricant
(1) Instrument refueling is an important part of the daily maintenance work of the instrument. Lubricating oil is mainly for instrument bearing; lubricating oil can protect the instrument bearing, reduce friction, reduce wear and prolong the operation cycle of the instrument;
(2) Regularly adding lubricating oil can effectively reduce the maintenance rate of the instrument and reduce the maintenance cost;
(3) Ensure the measurement accuracy of the flowmeter. "Measuring is counting money." why would you said this? The management of production and operation accounting, energy saving, cost accounting, etc. is an important production link of enterprise management. If the measurement is not in place, it will affect the economic efficiency and reputation of the enterprise. Therefore, the daily maintenance of the instrument is very important.