Plug in thermal gas mass flowmeter

Overview of Plug in Thermal Gas Mass Flow Meter

The plug-in thermal gas mass flowmeter is based on the principle that the rate of heat absorption is directly related to the mass flow rate. The sensor of this instrument consists of two reference level thermal resistors (platinum RTDs). One is the mass velocity sensor T1, and the other is the temperature sensor T2 that measures changes in gas temperature. When these two RTDs are placed in the measured gas, sensor T1 is heated to a constant temperature difference above the gas temperature, while sensor T2 is used to sense the temperature of the measured gas. As the gas mass flow rate increases, the airflow carries away more heat, causing the temperature of sensor T1 to decrease. To maintain a constant temperature difference between T1 and T2, the heating power of T1 needs to be increased. According to the King's law of thermal effects. When moving gas molecules collide with a thermistor, they absorb and carry away heat. The larger the flow rate, the more molecules come into contact with the thermistor, and the more heat is absorbed. The heat absorption is related to the number of molecules, thermal properties, and flow characteristics of a certain gas. There is a definite mathematical relationship between heating power P, temperature difference △ T (T1-T2), and mass flow rate Q.
P/△ T=K1+K2 f（Q）K3
K1, K2, and K3 are constants related to the physical properties of gases.

The plug-in thermal gas mass flowmeter is different from other gas flowmeters in that it does not require pressure and temperature correction. It directly measures the mass flow rate of gas and is a true direct mass flowmeter. One sensor can achieve a range from extremely low to high.

Plug in thermal gas mass flowmeterScope of application

Measurement of oxygen, nitrogen, hydrogen, chlorine, and multi-component gases. (excluding acetylene gas).
Measurement of blast furnace gas and coke oven gas.
● Measurement of flue gas.
Aeration and chlorine gas measurement in biogas and water treatment.
Compressed air measurement.
Measurement of gas flow rates such as natural gas, liquefied gas, and flare gas.
Measurement of primary and secondary air flow in power plant blast furnaces.
Measurement of flow rate in underground ventilation or exhaust systems.

Characteristics of plug-in thermal gas mass flowmeter

Measure gas mass flow rate without temperature or pressure compensation.
● Large range ratio, measuring flow velocity range: 0.1Nm/s to 100Nm/s.
No pressure loss, suitable for any shape of pipeline with known cross-sectional area.
Corrosion resistant sensor, suitable for measuring corrosive gases.
Expert algorithms for the full range range range are particularly suitable for large-diameter measurements, ensuring measurement accuracy and making them suitable for trade settlements.

Can perform excellent leak detection and equipment work on process pipelines.

The construction volume is extremely small, and due to the use of an insertable structure, it can be installed and maintained online.

Base type instruments can display locally and have alarm control.

Main technical indicators of plug-in thermal gas mass flowmeter

Product composition of plug-in thermal gas mass flowmeter

The plug-in thermal gas mass flowmeter consists of an integrated flow converter and a flow sensor. According to the type of flow sensor, it can be divided into plug-in and pipe segment plug-in thermal gas mass flow meters.

Plug in sensors: can be installed and maintained online. The installation process is to first weld a base with external threads on the outer wall of the pipeline, install 1/2 inch stainless steel ball valves on the base, and then use a special tool to drill a hole with a diameter of 22mm in the pipeline. After drilling, remove the special tool, and finally install the sensor on the valve and insert it into the center of the pipeline (the insertion position of the sensor is determined at the factory). If the pipeline material cannot be welded (such as cast iron, PVC, fiberglass, cement, etc.), we can use our company's specialized fixtures to fix the sensor on the pipeline. Plug in sensors are suitable for pipeline diameters ranging from DN80 to 6000mm (to be specified when ordering larger diameters).

Related information: Thermal mass flowmeter for mass flow meters