Ultrasonic Flowmeter Introduction and Features
Definition:
Ultrasonic flow meters are meters that measure the flow by detecting the effect of fluid flow on the ultrasound beam (or ultrasound pulse).
Principle:
According to the principle of signal detection, ultrasonic flowmeter can be divided into propagation velocity difference method (direct time difference method, time difference method, phase difference method and frequency difference method), beam offset method, Doppler method, cross correlation method, spatial filtering method. And noise law, etc.
Ultrasonic flowmeter is the same as electromagnetic flowmeter. It is an unobstructed flowmeter because it does not have any obstruction parts. It is a kind of flowmeter suitable for solving difficult flow measurement problems, especially in large-diameter flow measurement. The advantage is that it is one of the fastest growing types of flow meters.
Features:
Unique signal digital processing technology makes the meter measurement signal more stable, anti-interference ability and more accurate measurement.
No mechanical transmission parts are not easy to damage, maintenance-free and long life.
The circuit is more optimized and integrated; the power consumption is low and the reliability is high.
Intelligent standard signal output, friendly man-machine interface, multiple secondary signal output, for you to choose.
Pipe-type small pipe diameter measurement is economical and convenient, and the measurement accuracy is high.
First, the gas turbine flowmeter installation requirements
1. When the gas flowmeter is installed, it is strictly forbidden to directly conduct electric welding at the inlet and outlet flanges to avoid burning the internal parts of the flowmeter;
2. For the newly installed or overhauled pipeline, it must be purged to remove the debris in the pipeline before installing the flowmeter;
3. The gas turbine flowmeter should be installed in a place that is easy to maintain, has no strong electromagnetic field interference, no mechanical vibration and thermal radiation;
4. Gas turbine flowmeters should not be used in places where flow is frequently interrupted and there is strong pulsating flow or pressure pulsation;
5, the gas turbine flowmeter should ensure that the pipeline is coaxial, and prevent the gasket from protruding into the pipeline, otherwise it will disturb the flow profile;
6. The flow direction of the gas turbine flowmeter should be consistent with the direction marked on the casing. The upper and lower pipelines of the flowmeter should be guaranteed with 2DN and 1DN straight pipe sections;
7. When using external power supply, the flowmeter must have reliable grounding, but it should not share the grounding wire with the high-power system; when the pipeline is installed or repaired, the grounding wire of the welding system should not be overlapped with the flowmeter.
8. Since the flowmeter needs to be repaired and calibrated, in order to ensure normal gas supply, bypass piping should be set. The bypass pipe valve must be closed during normal use;
9. When constructing pipelines, it is advisable to install telescopic tubes or bellows to avoid serious stretching and causing breakage of the flowmeter;
10. When the gas turbine flowmeter is installed outdoors, the upper part should be covered to prevent the rainwater from immersing and the sun exposure affecting the service life of the flowmeter;
11. When installing the gas turbine flowmeter, it is advisable to add a filter to the flowmeter (filtering accuracy is recommended ≤20μm).
Second, gas turbine flowmeter requirements
1. When the gas turbine flowmeter is put into operation, the upstream valve of the flowmeter should be slowly opened (not less than 15 seconds), and then the downstream valve of the flowmeter should be slowly opened to prevent the instantaneous airflow from rushing to the turbine;
2. When the flowmeter needs to have a long-distance signal, it should be connected to the external power supply (+12~+24VDC) strictly according to the electrical performance index of the gas turbine flowmeter. It is strictly forbidden to directly connect 220VAC (or 380VAC) power supply at the signal output.
Installation of plug-in electromagnetic flowmeter
The plug-in electromagnetic flowmeter sensor installation upstream straight pipe section is not less than 5D (D means pipe diameter), the downstream straight pipe section is not less than 2D:
1. Vertical installation. When the sensor is inserted into the pipeline, it should be less than 5° from the vertical diameter of the pipeline section. It is suitable for measuring the cleaning medium with small vibration of the pipeline.
2, inclined installation, the axis of the sensor and the axis of the pipe to be tested is 45 °, suitable for large pipe diameter and measuring the flow of liquid containing other impurities in the medium, the installation method is small, not suitable for entanglement.
There are two ways to insert the insertion point of the electromagnetic flowmeter sensor: one is inserted into the central axis of the pipe to be tested (ie 1/2 times the diameter of the pipe); the other is inserted into the inner wall of the pipe at 1/4 of the pipe.
Sensor installation:
1. Clean the welding slag and burrs of the base of the pipe to be tested.
2. Turn off the upstream flow control valve or use low pressure water supply.
3. Install the DN50 ball valve on the mounting base. Pay attention to the long cavity of the ball valve. Check whether the ball valve can be fully open and fully closed. Install the screw seat, compression nut and rubber sealing ring onto the ball valve and loosen the positioning nut. Insert the sensor into the rod through the ball valve and insert it into the pipe to be tested. At the same time, it should be noted that the direction of the sensor direction indicator rod should be consistent with the flow direction of the fluid. Ordering Information Please specify the name of the tested medium, working pressure, medium temperature, flow rate (flow rate) range, pipe diameter and the pipe network to be tested.