The current capacity of screw press is only 100 kg/hr. Motor is 22kw, shaft RPM is 16, applied torque is 13,120 Nm, theoretical volume is 0.000967 cu m.

  1. Am I correct to say the press is going = 13,120 Nm divided by 0.000967 cu m will get the pressure Nm/cu m?
  2. If it is ok how can I increase the capacity to meet the same applied pressure equal to above answer?



  • $\begingroup$ Increase either the volume delivered per turn at the same speed or increase the rpm for the same volume per turn. $\endgroup$
    – Solar Mike
    Jan 12, 2019 at 7:27
  • $\begingroup$ $Nm/m^3 = N/m^2$ which is force per unit area, the definition of pressure. $\endgroup$
    – Transistor
    Feb 6, 2020 at 20:50

2 Answers 2


If you need to calculate the pressure,

A first estimate, ignoring friction, which can be substantial is,

$ F_{screw}= T/(r*tan (\alpha)) \quad$ r is screw radius , a is pitch angle.

P= F/area of press. by increasing the motor rpm, or increasing the screw pitch you can increase the output, if your motor has enough power.


The other answer gave the equation.

Your question is about how, though, so that is different. The key things you need to improve are:

  1. Find better materials. Consider composites that withstand more load.

  2. Increase the power of the motor.

  3. Use a smaller volume per area raw material if your only goal is to increase the pressure per area.

Maybe just explain what you are making or find similar designs that worked.


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