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Dec 26, 2018

# Pressure loss calculation of liquid turbine flowmeter

The liquid turbine flow meter is a precision flow meter that can be used to measure the flow and total volume of liquids in conjunction with the corresponding flow meter. Liquid turbine flowmeters are widely used in measurement and control systems in petroleum, chemical, metallurgical, scientific research and other fields. Liquid turbine flow meters equipped with sanitary joints can be used in the pharmaceutical industry. The liquid turbine flow meteris measured using a turbine. It first converts the flow rate to the speed of the turbine and then converts the speed into an electrical signal proportional to the flow. This flow meter is used to detect instantaneous flow and total integrated flow, and its output signal is frequency, which is easy to digitize. In the figure, the induction coil and the permanent magnet are fixed together on the casing. When the ferromagnetic turbine blade passes the magnet, the magnetic resistance of the magnetic circuit changes to generate an induced signal. The signal is amplified and shaped by an amplifier and sent to a counter or frequency meter to display the total integrated flow. At the same time, the pulse frequency is frequency-voltage converted to indicate the instantaneous flow rate. The speed of the impeller is proportional to the flow rate, and the number of revolutions of the impeller is proportional to the total amount flowing. The output of the turbine flowmeter is a frequency modulated signal that not only improves the immunity of the detection circuit, but also simplifies the flow detection system. It has a turndown ratio of 10:1 and an accuracy of ±0.2%. Turbine flowmeters with small inertia and small size have a time constant of 0.01 seconds. ## Pressure loss calculation of liquid turbine flowmeter:

The turbine flowmeter manufacturer's turbine flowmeter is the main type of speed flowmeter. It uses a multi-blade rotor (turbine) to sense the average flow velocity of the fluid, and derives the flow or total amount of the meter. Generally, it is composed of two parts, a sensor and a display, and can also be made into a unitary type.

A liquid turbine flow meter uses a turbine to measure the flow meter. It first converts the flow rate to the speed of the turbine and then converts the speed into an electrical signal proportional to the flow. This flow meter is used to detect instantaneous flow and total integrated flow, and its output signal is frequency, which is easy to digitize.

The coil and the permanent magnet are fixed together on the housing. When the ferromagnetic turbine blade passes the magnet, the magnetic resistance of the magnetic circuit changes to generate an induced signal. The signal is amplified and shaped by an amplifier and sent to a counter or frequency meter to display the total integrated flow. At the same time, the pulse frequency is frequency-voltage converted to indicate the instantaneous flow rate. The speed of the impeller is proportional to the flow rate, and the number of revolutions of the impeller is proportional to the total amount flowing. The output of the turbine flowmeter is a frequency modulated signal that not only improves the immunity of the detection circuit, but also simplifies the flow detection system. It has a turndown ratio of 10:1 and an accuracy of ±0.2%. Turbine flowmeters with small inertia and small size have a time constant of 0.01 seconds. A gas turbine flowmeter with a high-efficiency rectifying rectifier and a turbine flow sensor coupled into a structure is integrated. In the condition that the upstream side baffle is an elbow or has a half-opening valve, only 2D straight pipe length is required, for the city. With a small installation space, it is a very prominent feature. The liquid turbine flowmeter calculates whether the pressure loss has an effect on the process pipeline and is calculated by:

DP=1.2r×V2(Pa);

Where: DP: pressure loss (Pa);

r: medium density (Kg/m3);

V: average flow rate in the tube (m/s).

When the measured medium is liquid, in order to prevent gasification and cavitation, the liquid pressure of the sensor should meet the following requirements:

P≥2.6DP+1.25P1 (Pa absolute pressure);

Where: DP: pressure loss value (Pa);

P1: vapor pressure of the fluid (Pa absolute pressure).

Understanding the pressure loss calculations for liquid turbine meters can help us make better flow measurements.