Selection of rainwater flow meter
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For the factory’s rainwater pipeline, I want to add a flow meter now. The pipeline has a diameter of DN800mm; however, on days when it doesn’t rain, only some process cooling water flows through this pipeline into the river, at a flow rate of approximately 7 t/h. During heavy rainstorms, normally 800 t/h of rainwater is discharged into the river. I’m not sure which type of flow meter would be better to use, as the range is too wide. Seeking help and experience... Thank you all in advance
Taking everything into account, an electromagnetic flowmeter can be a good choice. Firstly, water is conductive. Secondly, the range ratio of electromagnetic flowmeters is 1:100, which makes them suitable for situations where flow rates vary greatly – something that orifice flowmeters and vortex flowmeters cannot achieve. Additionally, rainwater may contain sediment, so turbine flowmeters and gear flowmeters cannot be used. Mass flowmeters can be used, but they are expensive and not cost-effective; therefore, domestic electromagnetic flowmeters with a precision of 1% are a viable option, as they meet the requirements while being inexpensive.
We can only consider open-channel flow meters; it’s not possible to determine whether the channel is full just by looking, and other flow meters cannot measure this
. . . . It shouldn’t be too hard to handle, right?:D
Yes, it’s impossible to fill the pipe completely when it’s not raining. . . Electromagnetic methods are also not suitable; the accuracy of open-channel methods is somewhat low. . . The detection is inaccurate when it isn’t raining
The accuracy of open-channel flow meters is by no means low—unless you choose a measuring element that is of poor quality and dirty, such as an ultrasonic probe. :lol
The most suitable option is a open-channel flow meter; all other flow meters are useless. Since it’s rainwater, there are many impurities, and with electromagnetic flow meters, the electrodes tend to get clogged and contaminated
In such cases, electromagnetic flowmeters are not suitable for measurement; it is recommended to use a Bacheler tank, as these tanks are designed for high-volume discharge, and low accuracy is normal in their case. For your situation, a Bacher trough is the best choice.
In such cases, there’s no need to worry about accuracy; use open channels for stable measurements, as electromagnetic methods won’t work
Can an electromagnetic flowmeter be used when there is dissatisfaction with the measurement?