Rotary reject dewatering drum OBN is designed for dewatering of washed rejects during separation of impurities from a pulper treating waste paper and periodical reject separator PSN and for thickening unpulped rejects discharged into drum OBN while cleaning the pulper tank. The rotary dewatering drum parameters are determined by an actual grade of impurities in waste paper and by the type of these impurities. The dewatering drum OBN-10 capacity ranges from 40 to 60 3 m /h and OBN-20 capacity ranges from 70 3 to 100 m /h. The capacity depends on the reject input consistency and the type of impurities.

The ingoing reject should be properly deflaked and washed so that the fibres input consistency is less than 1 %. Afterwards, the
outgoing reject dryness ranges from 10 to 20 % with an insignificant loss of fibre. The machine can be used as a special accessory for a pulper tank cleaning (horizontal or vertical type).

Design

The dewatering drum is usually anchored to a concrete base or steel structure under which there is a collecting sump. The water is pumped out of the sump into a pulper. The OBN-10 is driven by electric geared motor, which rotates the perforated drum on driving rollers. The OBN-20 drive is made through a gear train.

Main parts

• Machinery frame (1) with cover (2) and safety cover (3)
• Dewatering perforated drum (4) bedded on four rollers
• Rollers bedded on pins (5)
• Electric motor with gearbox with soft starter (6)
• Shower pipe for cleaning the perforated part of the drum (7)

Material

• All parts coming in contact with the stock are made of stainless steel
• Other machine parts are made of usual engineering materials