Selection of sealed water flow meters for lock bucket circulation pump and P chilled water pump

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Changes in the form of sealed water flow meters for lock bucket circulating pumps and P-quench water pumps: The flow meter was changed from a pointer type to a digital metal tube float flow meter to a turbine flow meter. The reason is that metal tube flow meters are easy to break. The main function of mechanical seal water is to reduce the heat generated by the friction between the moving ring and the static ring, play a cooling role, and extend the life of the moving and static rings to prevent dry grinding. If the sealing water cannot keep up with the mechanical seal, it will be easily damaged. Our company's pump and high-pressure seal water flow monitoring systems are now turbine flowmeters. The float of the metal tube float flowmeter is in the measuring tube. As the flow rate changes, the float moves upward. At a certain position, the buoyancy force on the float and the gravity of the float reach a balance. At this time, the flow annular area between the float and the orifice plate (or tapered tube) remains constant. The annulus area is proportional to the rising height of the float, that is, the rising position of the float in the measuring tube represents the flow rate. The changing position of the float is transmitted by the internal magnet to the external indicator, so that the indicator correctly indicates the flow value at this time. This prevents the indicator housing from being in direct contact with the measuring tube. Therefore, even if a limit switch or transmitter is installed, the instrument can be used under high temperature and high pressure working conditions. A common fault of the metal tube float flowmeter is that the pointer stops at a certain position. The main reason is that the float of the float flowmeter is stuck. Generally, when the float flowmeter is used, the valve is opened too quickly, causing the float to quickly impact the stopper upwards, causing the stopper to deform and jam the float. However, it is not ruled out that the float guide rod and the stop ring are not concentric, causing the float to get stuck. In addition, when installing the float flowmeter, it must be installed vertically or horizontally, and cannot be tilted, otherwise it will easily cause the meter to jam and bring errors to the measurement. Wison's float flowmeter cannot meet vertical or horizontal requirements due to pipe deformation and other factors. Long-term use and other factors cause the float flowmeter's sensing magnets, pointers, counterweights, rotating magnets and other moving parts to loosen, resulting in large errors. Turbine flowmeter When the measured fluid flows through the turbine flowmeter sensor, the impeller is forced to rotate under the action of the fluid, and its rotational speed is proportional to the average flow rate of the pipeline. The rotation of the impeller periodically changes the magnetic resistance value of the magnetoelectric converter. The magnetic flux in the detection coil changes periodically, generating a periodic induced potential, that is, an electrical pulse signal, which is amplified by an amplifier and sent to the display instrument for display. The practical flow equation of TUF is qv=f/K (7.1) qm=qvρ (7.2) where qv, qm- are the volume flow, m3/s, and mass flow, kg/s respectively. ； f - frequency of flow meter output signal, Hz ； K - instrument coefficient of flow meter, P/m3. Characteristics of Turbine Flowmeter Turbine flowmeter is a flow meter with many advantages. To sum up, it has the following characteristics. 1. High accuracy. The accuracy of turbine flowmeter is about 0.5-0. 1%. Within the linear flow range, even if the flow rate changes, the cumulative flow accuracy will not decrease. And in a short period of time, the reproducibility of the turbine flowmeter can reach 0.05%. 2. Wide range ratio. The range ratio of turbine flowmeter can reach 8-10. Under the same diameter, the maximum flow value of the turbine flowmeter is larger than that of many other flowmeters. 3. Strong adaptability The turbine flowmeter can be made into a closed structure, and its rotational speed signal is measured non-contactly, so it is easy to implement high-pressure resistant design. The installation requirements are also high, but it is easy to fix.