of two-stage pusher centrifuge

Process
pusher centrifuge utilize continuous filtration for the separation of suspended, fast draining, crystalline, granular or fibrous solids from the liquid phase.
the solids can be washed as they are transported through the basket.

Application
pusher centrifuges are used in all fields for the separation of slurries with solids which filter easily.

Typical products
• chemicals : glaubers salt,salt, boric acid, ascorbic acid, adipic acid, sodium chloride, iron sulphate, sodium sulphate, copper sulphate, sodium bichromate.
• fertilisers : ammonium sulphate, potash, urea, calcium nitrate, potassium sulphate.
• food stuff animal feeds : extraction residues, meat pulp.
• benefication : rock phosphate, gypsum, ores, coal.

Mode of operation
• feeding :
slurries are fed via a feed pipe - non flowable products are conveyed via a screw - into the feed distributor which rotates at basket speed. Here the feed is accelerated and evenly distributed over the screen.
• filtration and transport :
the majority of the liquid is drained at the feed zone of the slot screen and is discharged into the filtrate housing, while the solids form a cake which is moved axially into the solids discharged housing by the oscillating pusher plate. During this axial movement, the solids are dewatered to low final moisture. While in single stage basket speed moves the cake over the screen, a combination of an oscillating inner basket and a stationary pusher plate is used for the cake movement in two stage baskets.
• filtrate removal :
as a result of ventilation from the rotating baskets the filtrate usually is mixed with air. For this reason we recommended venting at the filtrate outlet flange.

the filtrate housing can be subdivided by partitions for the separation of main filtrate and wash filtrate. An efficient separation can be expected, even for counter-current wash systems, specifically with single stage units.

the filtrate outlet can be directed downwards, or to the right or left of the centerline, with the appropriate change in the direction of basket rotation.

• cake washing :
the solids layer on the screen can be washed with nozzles or wash basket.
• discharge of solids :
the cake is discharged from the basket into the solids collecting housing or into a volute race at peripheral speed. Thus a volute race discharge can be used to conveying the solids directly to the dryer.

Design concepts
• complete separation of mechanical unit from the process area.
• long and short baskets.