Supplementary explanation:
Air flowmeter is a flowmeter that measures flow according to Faraday's law of electromagnetic induction. The advantages of air flowmeter are extremely small pressure loss and large measurable flow range. Generally, the ratio of the maximum flow rate to the minimum flow rate of air flowmeter is above 20: 1, and the applicable industrial pipe diameter is relatively wide, up to 3m. The output signal has a linear relationship with the measured flow, and the accuracy is high. It can measure the flow rate of acid, alkali, salt solution, water, sewage, corrosive liquid, mud, pulp and other fluids with conductivity ≥ 1μs/cm. But the air flowmeter can't measure the flow of gas, steam and pure water.
Principle introduction:
When the air flow meter is used, the airflow pushes the turbine blades to rotate through the flow meter. The number of revolutions of the impeller is proportional to the volume of gas passing through the air flow meter. A specially designed patent guide frame is installed at the entrance of the flowmeter, which accelerates the airflow entering the flowmeter with the increase of flow velocity. The design of the guide frame can eliminate any potential fluid disturbance, such as eddy current or asymmetric flow. The driving force of the turbine blades also increases. It ensures that the flowmeter can accurately measure even in the case of small flow within the allowable error range. The airflow acting on the turbine blades is axial, and the turbine is installed on the main transmission shaft, which is equipped with high-strength ball bearings. After the gas passes through the turbine blades, the rotation of the turbine blades is slowed down by the gear set. The pressure in the inlet channel of air flowmeter is restored, and the channel design can ensure the optimization of flow pattern.