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Author Topic:   output rate formula
gpedicino
Member

Posts: 2
From:Guarenas,Miranda,Venezuela
Registered: Jul 2007

posted July 25, 2007 08:41 PM     Click Here to See the Profile for gpedicino     Edit/Delete Message   Reply w/Quote
Im working in the Output rate formula, I know that it comes from: Qt = Qd +- Qp, Drag flow rate + or - Pressure flow rate.

I have some problems with the pressure flow rate:
How can I calculate the incremental pressure difference.
When can I consider that one equal to zero.

Regards.

Giacomo

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Tom C
Moderator

Posts: 872
From:Brodheadsville, PA USA
Registered: Jun 2001

posted July 25, 2007 08:55 PM     Click Here to See the Profile for Tom C     Edit/Delete Message   Reply w/Quote
If you have a vented screw, the pressure is zero at the vent using an estimated head pressure then you can make the calculation. The most difficult part is knowing the viscosity.

Are you interested in some professional software that can make these calculations?

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Best Regards,

Tom Cunningham

www.ExtrusionTechnicalServices.com

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gpedicino
Member

Posts: 2
From:Guarenas,Miranda,Venezuela
Registered: Jul 2007

posted July 25, 2007 10:10 PM     Click Here to See the Profile for gpedicino     Edit/Delete Message   Reply w/Quote
Ok.
Some sofware can help, but first of all I want to learn about how to calculate that.
If I have the viscosity from table of polymers. How can I calculate the pressure diference.

Best regards

Giacomo

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