The installation position and installation method of the ultrasonic flowmeter.
Installation location
Selecting the installation pipe segment has a great influence on the test accuracy. The selected pipe segment should avoid the interference and eddy current, which have great influence on the measurement accuracy. Generally, the pipe segment should meet the following conditions:
1. Avoid installing the machine in the pump, high-power radio, frequency conversion, that is, where there is strong magnetic field and vibration interference;
2. Select the pipe section where the pipe should be uniform and dense, and it is easy to transmit ultrasonic waves;
3, to have a long straight pipe section, the upstream straight pipe section of the installation point must be greater than 10D (Note: D = diameter), downstream is greater than 5D;
4, the installation point upstream distance pump should have a distance of 30D;
5. The fluid should be filled with pipes;
6. There should be enough space around the pipeline to facilitate the operation of the on-site personnel. The underground pipeline needs to be a test well. The test well is as follows:
Installation method
Ultrasonic flowmeters generally have two types of probe installation methods, namely Z method and V method.
However, when D < 200mm and the site condition is one of the following conditions, it can also be installed by the Z method:
1. When the measured fluid has high turbidity, when the V method is used to measure the signal or the signal is weak;
2. When the inner wall of the pipe is lined;
3. When the service life of the pipeline is too long and the inner wall is fouled seriously;
For those with better pipeline conditions, even if D is slightly larger than 200mm, in order to improve the measurement accuracy, the V method can be used for installation.
Selection of measurement types for special industrial and commercial users
2. Case 2: A heavy machine tool factory
The main gas plant of the heavy-duty machine tool factory is 13 production kiln, and there is also a machine repair workshop and 63 mobile burners. The total gas load of all gas facilities is 1837m3/h. See Table 1 for details. The customer promised that all gas facilities could not be fully activated at the same time, the maximum gas consumption required was 1200m3/h, and the minimum pressure required before the furnace was 0.055MPa. The pressure regulator used in the on-site pressure regulating metering box is opened and ready, and the flow meter is in the form of a G1600 turbine table plus bypass.
When debugging the kiln, it was found that the flowmeter in the pressure regulating metering box had a stop-and-go phenomenon. If only some of the kiln was opened or only some of the kiln was used, there would be a phenomenon that the flowmeter did not measure or the measurement error was large.
Battery powered electromagnetic flowmeter features
1. Micro power consumption design, five 3.6V lithium batteries, continuous operation for 5~10 years, and easy to replace the battery.
2. The display adopts LCD large-screen liquid crystal display, which can display multiple flow parameters such as instantaneous flow rate, flow rate (pipe pressure), cumulative total amount of forward and reverse, and alarm prompt.
3. There are no movable and resistance parts in the measuring tube, no entanglement or clogging phenomenon, almost no pressure loss, and long-term reliable and continuous work.
4. Wide measurement range: The flow rate measurement range can reach 0.05m/s~10m/s.
5. High measurement accuracy: ±0.5% ~ ±1.0%.
6. Measurement stability: The measurement accuracy is not affected by changes in physical parameters such as temperature, pressure, viscosity and density of the measured medium.
7, with pulse output and GSM wireless data remote transmission.
8, with data storage function, up to 1000 groups of traffic data can be saved, and the data storage time can be arbitrarily set and data query.