What Is an Integrating Flow Meter?
An integrating flow meter is a flowmeter that displays the cumulative value of fluid passage.
It is used for a wide variety of fluids, such as cooling water and argon. There are two types of fluid flow rates: instantaneous flow rate and totalized flow rate.
The former refers to the amount of flow per fixed time, while the latter refers to the cumulative amount of flow since the start of the measurement. Integrating flow meters measure the latter and are used to measure the cumulative flow rate of a fluid.
Uses of Integrating Flow Meters
Integrating flow meters are used in a variety of industries and applications. Instantaneous flow meters are often used for process management and control applications, while integrating flow meters is often used for trading and emission standard monitoring. The following are examples of integrating flow meter applications:
1. Fluid Supply Management
Meters are used to measure and control fluid supply accurately. Familiar examples include water meters and gas meters. Monthly usage can be calculated by checking or resetting the value at the beginning of the month and rechecking it at the end of the month.
At manufacturing sites, meters are sometimes used to measure liquid fuels such as heavy oil and light oil. Liquid fuels are often transported by tanker trucks, etc., and the volume of transactions is checked with an integrating flowmeter attached to the vehicle.
2. Energy Management
Integrating flow meters are used to measure energy supply and consumption. For example, they are used to check fuel consumption, such as diesel fuel, and water consumption for cooling, contributing to energy efficiency improvement and cost reduction. It is often also used to check the volume of liquid fuel and water transactions.
3. Environmental Monitoring
Environmental monitoring is also used in environmental monitoring. It includes water quality control, flow measurement at waste treatment plants, and measurement of atmospheric emissions. Since the amount of gas emissions and wastewater discharged from plants is often regulated by ordinances, integrating flow meters are used to confirm the amount of emissions by both the emitter and the government authorities.
The amount of sewage discharged can also be checked with integrating flow meters. After being purified in a combined septic tank, etc., sewage is discharged into the sea or a river. Sewerage fees are also set, so the integrating flow meter and other devices are used to properly check the amount of sewage discharged.
Principle of Integrating Flow Meters
The totalized flowrate is obtained by multiplying the instantaneous flowrate by time. However, since the instantaneous flowrate may be unstable during flow rate changes, the totalized value often cannot be accurately displayed. Therefore, the totalized value is measured using an integrating flow meter.
Because integrating flow meters must accurately meter the totalized value, measurement principles such as the volumetric method are used. The volumetric method measures the volume of fluid as it passes through a pipe. Gears are used for volume measurement, and the flow rate of highly viscous fluids, such as gasoline, can be accurately measured.
Types of Integrating Flow Meters
There are various types of integrating flow meters. The following are examples of integrating flow meter types.
1. Volumetric Flowmeter
The volumetric flowmeter directly measures the volume of fluid as it passes through and calculates the flow rate. Turbines or gears are used to measure the volume.
Because it directly measures the volume of fluid, it has very high measurement accuracy. Since accurate flow data can be obtained, it is used to measure the flow rate of valuable liquids such as fuel.
It also has a robust construction and is durable. When properly maintained and used under appropriate environmental conditions, it can measure reliable values over a long period.
2. Vortex Flowmeter
Vortex flowmeters measure flow rate by detecting the generation and change of vortices in fluid flow. Vortices are generated as the fluid passes through the pipe, and the flow rate is estimated by measuring the frequency and amplitude of the vortices.
Both gas and liquid can be measured. It is mainly used to measure the flow rate of steam and clean water. However, it is not suitable for fluids containing slurry or powder because the measuring port is clogged.
Generally, they are durable and reliable due to their robust construction and lack of internal moving parts. Since the flow rate is estimated based on the generation and change of vortices, it is possible to measure with a high degree of accuracy. In addition, maintenance is relatively easy due to the small number of moving parts.
3. Thermal Flowmeter
Thermal flowmeter is a flowmeter that measures flow rate using the effect of thermal conduction or thermal cooling by fluid flow. Generally, there are hot wire flowmeters and thermal scattering flowmeters. A heat source and sensor are used to detect temperature differences, and the flow rate is estimated from the changes in temperature.
4. Electromagnetic Flowmeter
Electromagnetic flowmeters use the conductivity in a fluid to measure the flow rate. The flow rate is calculated by passing the fluid through a magnetic field and measuring the potential difference generated.
The flow rate can be measured without contact, and the pressure loss is very low. However, the measurement target is limited to conductive materials. It cannot be used to measure oil, such as heavy oil.