Thermal gas mass flow meter principle

QE600 series hot gas mass flowmeter

  First, the principle of thermal gas flowmeter

    Thermal mass flow meter using the principle of thermal diffusion, thermal diffusion technique is a kind of good performance under severe conditions, high-reliability technology. Which typically comprises two sensor element in the thermal resistance (the RTD platinum), a speed sensor, a gas temperature variation is automatic compensation temperature sensor. When two RTD medium is placed, wherein the speed sensor is heated to above ambient temperature to a constant temperature, a further temperature sensor for sensing the medium temperature. The mass flow of gas flowing through the speed sensor is calculated by the amount of heat transfer from the sensing element. As the gas flow rate increases, the amount of heat removed by the media increases. Causes the sensor temperature to decrease. In order to keep the temperature constant, the operating current through the sensor must be increased. This increased portion of the current is proportional to the flow rate of the medium.

  Second, thermal mass flowmeter introduction:

    At present, China used gas flowmeter range than there are minor problems, flow range below the lower limit of the basic loss, but this is unacceptable in certain areas, it is intolerable thermal gas mass flow meter in gas and other trade settlement occasions Solved this problem satisfactorily.

1 thermal gas mass flowmeter features

   QE600 series of hot gas mass flow meter the gas can flow metering work, also be used for process control. It introduces advanced technology from the United States to produce, without the need for temperature and pressure compensation, directly measuring the mass flow of the fluid. Its salient features are: no moving parts; pressure loss; range than the width; high precision; high reliability; easy to install and operate. The orifice plate and differential pressure flow meter can be completely replaced in all fields .

2. Thermal Mass Flow Meter Usage :

    This product is widely used in steel mills, coking plants, petroleum, chemical, thermal power, medical, thermal power plants, environmental protection and other industries.

Can be done:

Steel plant, coke plant gas flow measurement

Boiler air flow, measurement of secondary air volume

Flue gas flow measurement from the chimney

Precipitation flow measurement in water treatment

Cement, cigarette, gas flow measurement in glass factory

Compressed air flow measurement

Natural gas, gas, liquefied gas, flare gas, hydrogen gas flow measurement

Third, the technical parameters:

Measuring range: ( 0.05 ~ 80 ) Nm/s (Standard state is 20 °C, 101.33KPa )

Measurement method: Segmental plug-in

Temperature range: Ambient temperature: -40 °C to +60 °C

           Medium temperature: -10 °C to +450 °C

Accuracy: ± 1% of reading; ± 0.5% full scale

Repeatability: ± 0.5% of full scale

lose     Out: 4-20mA DC (large load 600 Ω); RS232 ; RS485

Response speed: less than 1S                   

Supply voltage: 24VDC ± 10%

Mechanical connection: 3/4NPT stainless steel fastener (insert type); flange

Probe length: 800mm (This length is a plug-in standard length, special please specify)

Probe diameter: 18mm (insert type)         

Straight pipe length: no strict requirements

Pressure loss: can be ignored

Working pressure: 1.6MPa ; 7.3MPa  

Live display: LED display ; LCD display

Data protection : Cumulative amount stored in EEROM , (power off can save for a hundred years)

Sensor and Pipe Body Material : 316L (Optional Hastelloy C )

Protection class: IP65

Explosion-proof grade: ExdIICT4

Fourth, application examples

1. Petrochemical industry

Application: Torch gas emission monitoring

Advantages of the product: Wide range ratio, the sensor is not easy to be blocked, and can be plugged and cleaned online.

2. Power industry

Application: Air flow measurement of primary, secondary and pulverized coal in boilers

Advantages of the product: easy installation, no requirement of straight pipe section, low pressure loss, no need of temperature and pressure compensation, can be used under harsh conditions (eg air contains dust, particles, serious wear, low pressure, etc.)

3. Metallurgical industry

Application: Measurement of blast furnace gas and coke oven gas

Product advantages: According to the actual media component calibration, component changes can be corrected, the sensor can be cleaned online, the insertion length can be adjusted

4. Electronic industry

Application: High-purity gas mass flow measurement

Advantages of the product: no direct measurement of mass flow with temperature and pressure compensation, the sensor head is highly polished and can be used for trade settlement

5. Heating Ventilation and Air Conditioning System ( HVAC )

Advantages of product: Sensitive product, reliable operation, no strict requirements for installation of straight pipe sections

6. Water treatment industry

Application: Measuring air flow in aeration tanks

Product advantages: dirt, dust, no pressure drop, easy installation on site

7. Food industry

Application: Pass proper amount of gas into reactor to control process and quality

Product advantages: Sanitary grade 3A , high purity, all wetted surfaces are made of stainless steel, wide range ratio