Thermal Mass Flow Meter

 

About -

Thermal mass flow meters, also known as thermal dispersion or immersible mass flow meters, are used to measure total mass flow rate of a fluid, primarily gases, flowing through closed conduits.  It is a direct mass flow meter with no moving parts.

 


Theory of Operation-

A Thermal Mass Flow Meter contains two temperature sensors for this purpose. One sensor measures the fluid temperature as a reference. The second sensor is heated and has a constant temperature differential relative to the first sensor. When the flow of air/gas starts heat is taken away from the warmer sensor. The amount of heat taken away is having a direct relation with the mass velocity of the fluid. That is how it is a direct mass flow meter.

Being a direct mass flow meter, it does not require any pressure and temperature compensation.

 

Types-
There are two types of Thermal Mass Flow meters,

1-      Thermal Dispersion/Immersible Type-

 

In case of Thermal dispersion or immersible type, the heat is transferred to the layer of the flowing fluid coming in contact with the heater surface. The convected heat from the surface of the heating element is related to point mass velocity of the fluid.

 

2-      Capillary Tube Type-

 

In second type, i.e. capillary type thermal mass flow meter, the heat is transferred to bulk of fluid passing through the small heated capillary tube.

 

Although the principles of operation of both types depend on heat convected, both methods are quite different. Thermal dispersion flow meters are commonly used for general industrial gas flow applications in pipes and ducts and hence are more popular for such industrial applications. The capillary types are primarily used for smaller flows of clean gases or liquids in tubes.

Applications-

Thermal mass flow meter is used in variety of gas flow applications such as-

·         Compressed air/ Gas Consumption measurement

·         Gas measurement at very low-pressure flowing conditions

·         Fuel Gas like CNG consumption measurement and control

·         Automobile gas engine testing

·         Industrial oxygen flow measurement and control

·         Furnace and burner control

·         Biogas measurement in digester biogas digester systems

Comments

Post a Comment

Popular posts from this blog

Steam Flow Meter

Image
What is a Steam Flow meter?   A steam flow meter is a device that measures steam flow rate, primarily of saturated and superheated steam, as well as mass flow rates of boiler feed water in closed conduits. It can be used as a heat energy transfer meter to measure thermal energy utilising a variety of fluids as heat transfer medium (including thermic fluids / thermic oils). Steam Flow Meter gives the information you need to run a plant or a building operation efficiently, giving vital inputs like how much steam is being used and how much it is costing. Steam flow meters are helpful in evaluating the performance of the system and can provide useful data in assessing boiler performance, calculating boiler efficiency, and tracking the amount of steam required by the system. In some systems, steam flow meters offer a measurement signal for the boiler control system. Additionally, steam flow meters can be valuable in benchmarking efforts.   Why steam measurement is important? ...
Read more

Thermal Mass Flow Meter

Image
  About- Thermal mass flow meters , also known as thermal dispersion or immersible mass flow meters, are used to measure total mass flow rate of a fluid, primarily gases, flowing through closed conduits.   It is a direct mass flow meter with no moving parts. Theory of Operation- A  Thermal Mass Flow Meter  contains two temperature sensors for this purpose. Single sensor measures the fluid temperature as a reference. The second sensor is heated and has a constant temperature differential relative to the main sensor. When the flow of air/gas starts heat is taken absent from the warmer sensor. The quantity of heat taken away is having a direct relation with the mass velocity of the fluid. That is how it is a straight mass flow meter. Being a through mass flow meter, it does not require any pressure and temperature compensation. Types- There are two types of Thermal Mass Flow meters:   1-       Thermal Dispersion/Immiscible Ty...
Read more