Measuring the Velocity and Flow of Gas Flows in Chimneys

Gas flow rate is the volume of gas passing a given point in a given time period. The gas flow rate in the chimneys is the path that the gas passing through the chimney takes in the chimney per unit time. In principle, the average velocity of the gas flow is determined by the Pitot tube used to determine the maximum velocity at certain points of the chimney.

The main standards for determining the velocity of gas flows in chimneys are:

• ISO 10780 Fixed source emissions - Measurement of velocity and volumetric flow rate of gas flows in ducts
• EPA Method 2 Speed ​​- S-type Pitot
• ISO 3966 Measurement of fluid flow in pipes - Velocity field method using Pitot tubes
• ISO 16911 Fixed source emissions - Manual and automatic determination of velocity and volumetric flow in ducts

These standards primarily utilize S-type Pitot tubes to determine flue gas flow rate. In these studies, the pipe dimensions at the sampling location are first determined, the number and location of specific measurement points are identified, Pitot tubes are placed at these points to measure pressure differences, and the gas flow rate at each sampling point is calculated based on these pressure differences. Simultaneously, the flow rate is calculated using the average velocity and cross-sectional area.

For the purposes of the standards listed above, the Pitot tube is a device that works on the principle of differential pressure measurement and is used to measure the flow rate at a point. The volume flow rate is the volumetric flow of gas axially through the flue duct. Unless specifically stated, volume flow rate means the average volume flow through the measurement plane. Point flow rate is the local gas velocity at a point in the channel. Unless otherwise specified, this expression means the axial velocity at the measuring site. The average flow velocity, multiplied by the measuring plane area of ​​the flue duct, is the velocity giving the volumetric flow in that duct. As standard conditions, the pressure value is 101.325 kPa and the temperature value is 0 degrees.

Our organization, among the numerous test, measurement, analysis and evaluation studies it provides for businesses in various sectors, also provides services to measure the speed and flow of gas flows in chimneys with its trained and expert staff and advanced technological equipment.