Flow control, best method?

[rmayer]

I need to balance two flow circuits on the range of 1-10LPM. I was thinking of hooking up two paddle wheel flowmeters to the plc to output to two pwm solenoid valves. So far the 'beans' look like they're going to be adding up to around:
~$300 per flowmeter (X2) =$600
~$150 per sig cond (need 4020mA)(2X) =$300
~$150 per pwm solenoid valve (X2) =$300
------------------------------------------------

As is the case with all of us, I can get more done by spending less. The application is also likely to change scale so replacing the flowmeters and pwm valves each time we size-up will also prove costly. So the two questions I have are

1: Is there a better method?

2: Can you recomend any components or manufacturers
(Been looking at GEMS, ACROMAG, and ASCO as oems

 

[roydm]

If you want to balance the flow on a continuous basis you would be much better off with regular control valves.
If you just need to batch equal amounts into a tank you could just count the pulses from the paddle wheels and use two solenoids
Regards
Roy

 

[HEC]

rmayer
what are you trying to achieve? is it a mixing/ratio control problem, are teh streams going into a tank or are they mixing in line. All these will affect the answer.
Cheers

Mark Hutton

 

[vinnygalbo]

You can use TURCK flow meters/monitors

http://www.clrwtr.com/Turck-Flow-Sensors-Monitors.htm

& Weidmuller signal conditioners.

http://www.clrwtr.com/Weidmuller-Waveanalog-20LP-Signal-Conditioners.htm

I think they are less expensive than what your budget is. I'm not sure who makes a good pwm solenoid valve for cheap.

 

[rmayer]

Have a membrane seperated electrolysis cell with different volumes of gas generating on each side and influencing flow by tumbling through the lines with the liquid. We implemented a gas separation chamber to bleed it off, compress and bottle the gas but...

The gas volume generation varies and ends up providing a bias from one side to the other. We want to control the ratio of these two outputs without going fixed orifice or needle valve because of scaling, and suspended solids. We don't want to filter the liquid.

Stripping out the gas helped a lot but the reliable ratio control across a variable flow range is still what we're trying to accomplish.

 

[180zip]

Hello, I have a need for a DCS input: "XL" RUN STATUS from an air operated diaphragm pump. This is to verify operation of the pump. The pump is air operated from a Solenoid which is a DO from the DCS. I could easily put a limit switch on the solenoid for a DI to tell the DCS air to the pump is on, but this doesn't necessarily tell me the pump is running. Does anyone have a suggestion as to how I could prove the pump is operating - some sort of run status?

 

[180zip]

PUMP RUN STATUS: DIAPHRAGM PUMP: Hello, I have a need for a DCS input: "XL" RUN STATUS from an air operated diaphragm pump. This is to verify operation of the pump. The pump is air operated from a Solenoid which is a DO from the DCS. I could easily put a limit switch on the solenoid for a DI to tell the DCS air to the pump is on, but this doesn't necessarily tell me the pump is running. Does anyone have a suggestion as to how I could prove the pump is operating - some sort of run status?

 

[itsmoked]

Sorry 180Zip but you need to start your own thread not hijack this one.

Keith Cress
kcress -

http://www.flaminsystems.com