Thursday, November 10, 2011

SCREW PRESS

Technical Specifications for Screw Press ;

TYPE
  • Continuous double scroll screw press for oil palm fruits.

CAPACITY

  • Average machine throughput of 23 tonnes FFB per hour at worm screw speed of not exceeding 10 rpm for 500 running hours.

DRIVE

  • The squirrel cage motor is to be coupled with a compatible wedge-belt pulley type hydraulic fluid coupling driving a speed-reducer.
  • The speed reducer shall be directly connected to the screw press drive shaft via a suitably sized chain type coupling.
  • The speed-reducer for the press shall be a Brevini / SEW Eurodrive or approved equivalent unit with a rated output torque of above 48,000 Nm and a reduction ratio of no more than 80:1 and shall have a service factor of 1.6 or better at a press output speed of 10 rpm. The motor shall be 420V 0.8 power factor 50 Hz nominal 1500 rpm and shall not be less than 45 KW for 20 to 25 TPH press.

CAGE & WORM SCREWS

  • The press cage shall be of carbon steel material and shall have holes flared from 4mm to 5mm diameters, the smaller diameter being at inside surface of the cage.
  • The screw flights shall be of constant pitch.
  • The screw-press performance at its rated throughput shall be proven over 500 hours processing its required FFB tonnage.

SHAFTS

  • All shafts material used shall be of ASAB 705 high tensile steel shafts or approved equivalent.

MOTORS

  • Motor shall be TEFC motor, tropically insulated to Class F, B.S. 2960 or B.S. 3979.
  • The drive motor is expected to be not less than 30 KW for 15 TPH press and 45 KW for 20 to 25 TPH press.

POWER HYDRAULICS & PRESSURE CONTROL

  • The press shall be equipped with Position Control System, which monitors the pressing pressure (motor current load) and constantly and continuously positioning the press plate to the required pressing pressure. This hydraulic system is designed to auto start upon starting the screw press, and there shall be no pressing load in case if the motor stops as the pressing cone eases off the press cake completely automatically.
  • The hydraulic system produces consistent and stable pressing pressure with precise positioning of pressing cone, and has effectively overcome operator dependency.

TEST ON COMPLETION

  • Oil loss, less than 7.5% on Non Oily Solids average over 6 continuous hours at rated throughput over three occasions.
  • Broken nuts and kernels, less than 8% to total nuts, averaged over 6 hours at rated throughput over three occasions.


Source - Tender Specification / BEA.

1 comment:

Yong KC said...

Good day En. Zainal,
I read with interest your specification on screw press and would like to post you a question which could be of mutual interest in the near future.
Question: What do you think if an electronic device call Frequency Inverter is use to control the A.C motor giving flexibility to operator control of screw speed from 0 to 10rpm.Would it improve the life span of the screw to longer than 500 hours and impact on the yield too positively. Look forward to your reply. Thank you.
From, Yong of DMC Solution S/B.