Basket Centrifuges

Principles
In basket centrifuges, the solids & liquids are separated by centrifugal force using a filter media (usually a cloth) mounted over supporting mesh, which are together supported inside the rotating basket. The slurry to be filtered is fed through the feed nozzles to the basket and due to centrifugal force the liquid is forced out through the filter media while solids are retained within the filter media inside the basket. These solids then separated or discharged by various discharging methods namely - manually, bag lifting basket, through scrapper, operated manually pneumatically / hydraulically, for which different models are available.

Suspension / Mounting :
All the bottom driven basket centrifuges can be supplied either in 3 point type suspension or the newer 4 point type mounting (on VISCO Damper / Sordino Damper) anti vibration mounts.

Material of construction :
Carbon Steel, Stainless Steel, Hastalloy, Rubber Lined,
Fluoro Polymer Coatings like Halar (ECTFE), PVDF (ETFE ), Teflon (PFA) etc.

Lining / Coating can be provided on the contact parts as well as
on the exterior body for prevention from spillage and corrosive atmosphere.

Advantages of 4 Point Mounting :

• Level of vibration is much lower & operates very smoothly.
• Can be mounted on upper floor and can be easily relocated.
• Almost negligible maintenance cost.
• Working area is free from abstracts and a clean area can be maintained.

Types / Models of Basket Centrifuges :

• Pilot Plant Centrifuge
• Bottom Driven Top Discharge Type Centrifuge
• Bag Lifting Type Centrifuge
• Bottom Discharge Type Centrifuge with/without Scrapper
• Top Driven Bottom Discharge Centrifuge

Additional Features (Optional)

1. Residual Heel (Cake Removal System)
2. Cleaning in Place (CIP)
3. Leak Test as per DIN 24 400
4. Nitrogen Blanking System
5. Speed Indication with Zero Speed Switch
6. Automation
7. Cake Sensor

Pilot Plant Centrifuge :

The pilot plant centrifuges are used for taking small trial batches in plants. The same centrifuge can be optionally mounted on movable trolley for shifting purpose and the trolley is leveled by suitable locking screw pads provided at the four ends.

Bottom Driven Top Discharge Centrifuge :

Bottom discharge centrifuge is the most versatile & basic model of basket centrifuge for solid & liquid separation. After centrifugation the solids are scrapped and removed manually from top. .

Bag Lifting Centrifuges :
In Bag Lifting Centrifuges after centrifuging the solids are unloaded by lifting the basket top along with filter bag and solids. The filter bag is fitted with removal basket top with a bag holding ring. The ring holds the filter bag firmly while filtering and lifting.

Advantages :

• Easy and fast unloading.
• Complete discharge of solids.
• Original Crystal Structure will remain intact as there is no scrapping.
• Reduced human contact..
• Reduction in batch time.

Bag Lift Arrangement
In a Bag Lifting type Centrifuge a chain pulley block and hoist is required to lift the bag out of the centrifuge and there are chances of product contamination in these devices, instead for a clean room application a specially designed hydraulic lifting device is used for lifting the basket top with filter bag along with solids after filtration. This arrangement consists of a central pillar with hydraulic ram movement inside the pillar attached to the lifting arm. These ram aides the movement of arm up and down with hydraulic power pack controlled through a control panel. After filtration the basket top cover with filter bag and solids are hooked to the arm of the bag lift arrangement to lift the bag vertically upwards and to turn around through its pillar centre pivot point, mounted on bearings and the solids are unloaded. This system eliminates the usage of any chain pulley block.

The system is also available confirming to cGMP standards.

Bottom Discharge Centrifuges :
In Bottom Discharge Centrifuges, the centrifuged solids are scrapped through a scrapper operated either manually, pneumatically or through hydraulic cylinder and discharged through basket bottom plate pockets through suitable chute.

The centrifuge is driven at 3 speeds i.e. the feed speed, centrifuging feed and scrapping speed (around 60 rpm)

The drive motor is controlled by variable AC inverter drive to vary basket speed with built in dynamic braking system. The AC drive is incorporated with microcomputer and has a facility to interface with programmable logic controller(PLC) for complete automation.

Top Driven Bottom Discharge Centrifuge :
The Top Driven Bottom Discharge Centrifuge is single point suspension, where the basket is mounted over the central spindle which is suspended at top in the bearing housing. The cake is discharged at bottom through the pockets provided in the centre of the basket.