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Old April 22nd, 2005, 12:03 PM   #8
Ron Beaufort
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Join Date: Jul 2002
Location: Charleston, SC
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finally ... in Figure 8 we’ll take just one quick look at a typical flow system ...






and by now you should have the idea that a “sealed system” would allow a Proportional-only controller to actually achieve and then maintain a desired setpoint for our flow application ... but think ... how on earth would we go about designing a “sealed system” for a flow process? ... by definition, a “flow” cannot be “sealed” ... and so when you get right down to it, the more we try to increase the flow ... then the more we increase the turbulence in the system ... and the more we increase the turbulence, then the more we increase the resistance to an increase in flow ... hint: that’s why we need the pump in the first place ... SOMETHING has to overcome the inevitable resistance to the flow ...



I hope that this material helps ... as always, corrections and comments are gratefully appreciated ... I’m just sorry that it took me so long to pull this together ... lately my boss has been becoming a lot better at lining up students for my classes ... and while that’s a good thing financially, it does leave me with a lot less free time to hang around on Phil’s excellent forum ...
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