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  specific melt pump question

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Author Topic:   specific melt pump question
goulmik
Senior Member

Posts: 17
From:poissy
Registered: May 2003

posted May 20, 2003 02:53 AM     Click Here to See the Profile for goulmik   Click Here to Email goulmik     Edit/Delete Message   Reply w/Quote
hello all,

as I use a twin screw extruder, I have a pulse flow in output.
So a solution seems to be a melt pump...
If I have correctly understanded the process of the melt pump, it can stabilize my flow by acting on the extruder rotation speed.
My problem, is that I use two products as input, a liquid and a powder.
If I increase the rotation speed, I have to increase the amount of matter... In my case, it is very difficult to control.
Is there some kind of melt pump that can regulate the flow by changing its own rotation speed to insure a constant flow ?
a kind of autonomic melt pump that doesn't have to act on the extruder...

Hope the description is clear

best regards

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mixR
Member

Posts: 3
From:
Registered: Oct 2003

posted October 21, 2003 09:27 AM     Click Here to See the Profile for mixR   Click Here to Email mixR     Edit/Delete Message   Reply w/Quote
As far as I know, melt pump suction pressure is contolled by PID algo to keep suction press. stable. Of corse, the pressure is adjusted by automatic rotor speed changing. Generally, it uses PI controller without that quick and disturbing 'D' setting.

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zabielski
Senior Member

Posts: 240
From:McHenry, IL USA
Registered: Nov 2002

posted October 23, 2003 05:52 AM     Click Here to See the Profile for zabielski   Click Here to Email zabielski     Edit/Delete Message   Reply w/Quote
Slave your extruder drive to the pump RPM. Do this my using a simple Programmable Logic Controller (PLC).

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