Hi everyone,
I am working on a gas-solid fluidized bed in which the fluidization gas (continuous stream) and injection gas (pulsed flow) of compressed air are sent separately at certain pressure.
The bed is maintained at atmospheric pressure sometimes and vacuum (down to 30 mbar) sometimes.
My questions are:
(1) For the continuous flow or pulsed flow, in order to achieve accuracy of flow rate measurement, should I need to use the flowmeter as a flow controller or flow measuring device?
(2) For the bed under vacuum, using the flow meter as a measuring device, it is difficult to control the flow with separate needle valves installed in the downstream. On the other hand, using the flowmeter as a flow controller, the pressure drop would be so large across it that the readings will never be accurate. So, how to ensure minimal pressure drop and accurate flow rate readings through flowmeter?
I do not understand what you mean by using the flowmeter as a flow Controller. However, I have some general advice:
* If you want to measure mass flow rate use a mass flow meter. The rotameter measures volume rate. I Guess that a thermal flow meter is sufficient, but if you require higher accuracy you need to use an orifice meter which is a bit cumbersome for Your variable conditions.
* Try to measure the flow at a constant pressure.
* If Your compressed air is at 5-6-7 bar try to use a pressure reducing valve and reduce the pressure upstream the needle valve to 1-1.5 bar. That may solve Your needle valve difficulty.
I think you should use coriolis mass flow meter as this will be least error as compared to other flowmeter like vortex or turbine flowmeter
Hi Unander, thank you for your suggestion.
- Actually I need volume flow rate only, that's the reason I am using variable area flow meter. Now the question is since they are standardized at atmospheric conditions, the downstream pressure which is the operating of the flow tube should be corresponding to the standard pressure (14 psig) for the readings to be accurate. Now in my case, since the pressure downstream is vacuum sometimes, how can we make sure the flow meter to operate at atmospheric conditions?
- Badges
- Science topic
- Similar topics
- Force