Help: Selection of gas flow meters
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I am currently working on a plan to measure gas flow rates. There are two points:A: Medium – air; Flow rate: 16,300–20,100 m3/h; Pressure: 1,994–2,577 Pa; Pipe diameter: DN400; Temperature: 250–700°C.
B: Medium – boiler exhaust gas; Flow rate: 8,020–15,129 m3/h; Pressure: 3,364–4,252 Pa; Pipe diameter: DN500; Temperature: 100–200°C.
Accuracy is of top priority, and the solution must be implementable on-site. An analog output in the 4–20mA range is also required; cost is not a concern at this stage. I would appreciate any advice from experts
We used orifice plates, but the results we achieved were not very good! Measurement of gas flow between our drying tower used in sulfuric acid production and the sulfur incinerator!
The pipe diameter is too large and the pressure is low; neither orifice plates nor vortex flow meters work. We used a VeriFlow meter, and it gave good results~~~
The precision of Weiliba is also insufficient. Personally, I prefer thermal mass flow meters; they are relatively expensive, with an accuracy of 0.5% (for samples). The same goes for exhaust gas, but is the condition specified by the poster the operating flow rate?
For medium A: Air – Flow rate: 16300–20100 m3/h; Pressure: 1994–2577 Pa; Pipe diameter: DN400; Temperature: 250–700°C. For medium B: Boiler exhaust gas – Flow rate: 8020–15129 m3/h; Pressure: 3364–4252 Pa; Pipe diameter: DN500; Temperature: 100–200°C. Given that medium A has a high temperature and high flow rate, using a split-type vortex flow meter poses additional requirements in terms of vibration resistance for the pipeline. Moreover, surge may occur in air pipelines, and the accuracy of rotameters cannot be guaranteed at such high flow rates. With a temperature range of 250–700°C, the best option is the differential pressure method. The following are some possible solutions: 1. Orifice plate combined with a differential pressure transmitter (flange-mounted pressure sensing is preferable due to the high temperature). 2. Integrated V-cone flow meter (in my opinion, its maintenance requires more effort compared to orifice plates, but it is much easier to calibrate). 3. Other types of differential pressure flow meters. For case B, it is also advisable to use the differential pressure method for measurement. Of course, when the temperature is between 100 and 200 degrees, an vortex flow meter can also be used; this depends on the conditions in the factory. When choosing a flow meter, one must consider not only the operating conditions and costs but also the consistency of instruments throughout the factory, in order to facilitate unified maintenance and repair operations in the future.
I recommend using the integrated constant-speed tube flow meter developed by Chongqing; it should meet your requirements
It is better to use a Weiba flow meter under this parameter. If you need it, please add me on QQ: 978008394. http://www.shakic.com/cp/product13.htm
I recommend using a cone tube flow meter, as the temperature of the medium is high and its pressure is low (meaning the kinetic energy of the fluid is insufficient); flow meters such as vortex flow meters will have lower measurement accuracy in such conditions. The taper tube has a larger range ratio, making it easy to adjust and highly adaptable.
Reply to 4# backhamm1982: The flow rate refers to the rated flow rate of the exhaust fan. Thank you for your suggestion
Since your pipe diameters are relatively large and the temperatures are high, it is better to use instruments such as Anubas or orifice plates. If precision is desired, voltage stabilization compensation can be applied. For other types of flowmeters, it’s not a cost issue but rather related to the diameter and temperature.
Reply to 5# meimei_____ – Your opinion is very professional; thank you very much~~~