Seeking help in selecting a flow meter
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This post was last edited by hwindforce on 2009-12-12 at 16:31. The name of the medium is not clear: (It is only known to be prone to crystallization and may contain particles and precipitates.) . Density: 1200 kg/m3. Flow rate: MAX 5 m3/h, NORMAL 3 m3/h, MIN 2 m3/h. Dynamic viscosity: 2.4. Operating pressure: 4 kilograms. Diameter: DN50. Temperature: room temperature. With such a low flow rate, I’m not sure what to choose; please share some suggestions. What type of flow meter is better for measuring gas flow at low velocities (less than 2 m/s)?
First: Choose a mass flow meter or an elliptical gear flow meter, but a mass flow meter should be preferred first. Second: You need to choose based on the caliber size.
Choose a rotameter or a micro elliptical gear flowmeter; a filter should be installed in front of it, and it’s advisable for the pipeline to have a changing diameter； Low-flow-rate gases can be measured using double orifice plates, 1/4 circle orifice plates, rotameters, or gear flow meters
The wedge type I chose should work fine as well. With solid particles, it’s difficult to maintain the ellipse shape; a filter is necessary, and that filter also needs to be cleaned regularly
Electromagnetic options can also be considered, as there are particles present
We have only started using wedges recently, but the results on-site are not satisfactory. The main requirement is to disassemble the entire unit for inspection; the differential pressure transmitter, along with the capillary tube, must be removed as well. It has been observed that after multiple disassemblies, the capillary tube has a high failure rate, and silicone oil tends to leak, resulting in inaccurate measurements
If it conducts electricity, electromagnets should work. Gases can be measured using thermal flow meters
Choose a rotameter or a micro elliptical gear flowmeter; a filter should be placed in front of it, and it is preferable to use a mass flowmeter
First option: If conductivity is a concern, an electromagnetic flowmeter is the best choice. Low-flow gas can use an insert-type turbine.
Each has its advantages and disadvantages; it’s impossible to ignore maintenance at all. If a mass flow meter is chosen, you might consider our flow meters.
For the first option, a mass flow meter can be chosen; if accuracy requirements are not high, a target-type meter may be considered. As for the second option, the specific parameters are unclear, but generally, for low flow rates, a thermal gas mass flow meter is a suitable choice.