Question

In: Mechanical Engineering

A single-screw polymer extruder can be thought of as a pump and a heating device for...

A single-screw polymer extruder can be thought of as a pump and a heating device for plastic pellets. A certain extrusion setup has the following characteristics:

• Polymer: Polyethylene with density 0.95 g/cm3, specific heat 1800 J/kgK

• Flow characteristics: polymer temperature increases from 25 C to 200 C, flow rate 10 kg/hr, extruded strand is a cylinder, 2 mm in diameter

• Heating elements: multiple electric heater bands available with 110 Volt, 2 Amp rating

• You measure a back pressure of 300 MPa and a torque of 100 N m at 100 rpm.

Using the energy and mass balances, answer the following about this extruder:

a. What is the linear velocity of the strand exiting the die?

b. What is the rate of shaft work required to run the screw?

c. How many heater bands are required to heat the polymer to the required melt temperature?

Solutions

Expert Solution


Related Solutions

1. What is screw pump? 2. working principle of screw pump. 3. screw pump test rig...
1. What is screw pump? 2. working principle of screw pump. 3. screw pump test rig 4. procedure 5. general use 6. identify its accuracy, precision and time respond in getting a reading. 7. the advantage and disadvantage of screw pump.
1. screw pump test rig in detail 2. general use screw pump 3. identify its accuracy,...
1. screw pump test rig in detail 2. general use screw pump 3. identify its accuracy, precision and time respond in getting a reading. 4. the advantage and disadvantage of screw pump.
A pump is used to circulate hot water in a home heating system. Water enters the...
A pump is used to circulate hot water in a home heating system. Water enters the well-insulated pump operating at steady state at a rate of 0.42 gal/min. The inlet pressure and temperature are 14.7 lbf/in.2, and 180°F, respectively; at the exit the pressure is 90 lbf/in.2 The pump requires 1/35 hp of power input. Water can be modeled as an incompressible substance with constant density of 60.58 lb/ft3 and constant specific heat of 1 Btu/lb · °R. Neglecting kinetic...
The insulin pump is a device that delivers insulin to a diabetic patient at regular intervals....
The insulin pump is a device that delivers insulin to a diabetic patient at regular intervals. It presumably regulates insulin better that standard injections. However, data to establish this point are few, especially in children. The following study was set up to assess the effect of use of the insulin pump on HbgA1c, which is a long term marker of compliance with insulin protocol. In general, a normal range for HgbA1c is < 7%. Data were collected on 256 diabetic...
Part 1. The insulin pump is a device that delivers insulin to a diabetic patient at...
Part 1. The insulin pump is a device that delivers insulin to a diabetic patient at regular intervals. It presumably regulates insulin better than standard injections. However, data to establish this point are few, especially in children. The following study was set up to assess the effect of use of the insulin pump on HbgA1c, which is a long-term marker of compliance with insulin protocols. In general, a normal range for HgbA1c is <7%. Data were collected on 256 diabetic...
A single thread power screw is 36 mm in diameter with a pitch of 6 mm....
A single thread power screw is 36 mm in diameter with a pitch of 6 mm. A vertical load on the screw imposes a force of 9 kN. The coefficients of friction are 0.09 for the collar and 0.16 for the screw. The effective diameter of the collar is 52 mm. Find the overall efficiency and torque required to raise and lower this load.
A vapor-compression heat pump with a heating capacity of 500 kJ/min is driven by a power...
A vapor-compression heat pump with a heating capacity of 500 kJ/min is driven by a power cycle with a thermal efficiency of 20%. For the heat pump, Refrigerant 134a is compressed from saturated vapor at -10°C to the condenser pressure of 10 bar. The isentropic compressor efficiency is 80%. Liquid enters the expansion valve at 9.6 bar, 34°C. For the power cycle, 80% of the heat rejected is transferred to the heated space. (a) Determine the power input to the...
A vapor-compression heat pump with a heating capacity of 500 kJ/min is driven by a power...
A vapor-compression heat pump with a heating capacity of 500 kJ/min is driven by a power cycle with a thermal efficiency of 20%. For the heat pump, Refrigerant 134a is compressed from saturated vapor at -10°C to the condenser pressure of 10 bar. The isentropic compressor efficiency is 80%. Liquid enters the expansion valve at 9.6 bar, 34°C. For the power cycle, 80% of the heat rejected is transferred to the heated space. (a) Determine the power input to the...
A vapor-compression heat pump with a heating capacity of 500 kJ/min is driven by a power...
A vapor-compression heat pump with a heating capacity of 500 kJ/min is driven by a power cycle with a thermal efficiency of 20%. For the heat pump, Refrigerant 134a is compressed from saturated vapor at -10°C to the condenser pressure of 10 bar. The isentropic compressor efficiency is 80%. Liquid enters the expansion valve at 9.6 bar, 34°C. For the power cycle, 80% of the heat rejected is transferred to the heated space. (a) Determine the power input to the...
A vapor-compression heat pump with a heating capacity of 500 kJ/min is driven by a power...
A vapor-compression heat pump with a heating capacity of 500 kJ/min is driven by a power cycle with a thermal efficiency of 20%. For the heat pump, Refrigerant 134a is compressed from saturated vapor at -10°C to the condenser pressure of 10 bar. The isentropic compressor efficiency is 80%. Liquid enters the expansion valve at 9.6 bar, 34°C. For the power cycle, 80% of the heat rejected is transferred to the heated space. (a) Determine the power input to the...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT