Feed pump

[nwjoe]

Hello, I am looking for a feed pump controller that will allow me to feed my process vessel automatically as my culture grows and demands more feed.
I want the controller to ramp to set point and hold for 10min and then ramp to the next set piont and hold for 10min and so on and so on for 48hrs. What is the best way to do this?
Thanks,
nwjoe

 

[nbucska]

Can you give more detailed specs?

<nbucska@pcperipherals DOT com> subj: eng-tips
read FAQ240-1032

 

[stevekuech]

Is there a measureable parameter of the process that the pump output is intended to control? If so, an analyzer that is able to measure the parameter and deliver a corresponding analog output would be my preferred method. The analog signal (4-20ma) can then be used to control the speed of the pump through use of a variable frequency drive for an AC motor. If your pump has a DC motor, some signal conditioning may be required to obtain a potentiometric signal for an input to a DC controller. By using this method, the pump runs at exactly the speed required to maintain the process at the optimal levels rather than relying on where the process should be after a given period of time.

 

[Jigneshpadia2002]

I guess pH can be that output control. And I have done such experiments where pH is the control for the Feed pump or Acid pump and sometimes DO valve ! So I guess the suggestion by Steve is perfect and should solve your issue!