vertical centrifuges / Biotechnology

GENERAL BTH CLARIFIER SPECIFICATIONS

  • Self-cleaning machine with clarifier bowl in a sanitary design.
  • Automatic and precise control of total or partial ejection of solids through the operating water line.
  • Closed solids discharge to avoid excessive noise. Ejection is done while the machine is operating, therefore product feed is not interrupted by discharge events.
  • The material coming into contact with product is built in special polished stainless steel.
  • Steam-sterilizable design with Sterilization in Place (SIP) system for sterilization with steam of 260.6°F (127 °C) under a pressure of up to 2.5 bar.
  • Closed product feed through a hydrohermetic feed system which ensures the gentle treatment of sensitive micro-organisms.
  • Cleaning In Place (CIP) module included with delivery.
  • Double acting ring packing as an interface for the drive chamber.
  • Built-in hydrohermetic seal to avoid oxidation by ambient air.
  • Both the solids collector and the hood itself have a special double wall design that allows for cooling of discharged solids.
  • It includes power control board with PLC.
  • It includes electric motor and interconnecting piping.
  • Delivery of tools for the machine assembly and dismantling.

Fields of application

For downstream processing or fermentation applications in sterile conditions, the machine is used mostly in pharmaceutical, biotechnology and food industries.

Generally, the machine is perfect for applications which require low oxygen levels and aseptic conditions, due to its high hermeticity and large sterilizing capacity. In particular, the following are well-known common applications:

  • Initial cultures of lactic acid bacteria
  • Escherichia Coli biomass recovery
  • Genetically engineered microorganisms and vaccine treatment
  • Discharge of biomass with cellular constitutions which can damage products

Equipment parts
1.Product feed 2. Product discharge 3. Disk stack 4. Hydrohermetic feed system 5. Cooling hood 6. Solids ejection ports 7. Annular valve 8. Discharge nozzle 9. Cooling solids collector 10. Feeding ring 11. Operating water channel 12. Operating water discharge 13. Sealing liquid discharge 14. Ring packing 15. Operating water feed 16. Valve 17. Valve 18. Leakage outlet 19. Sealing liquid feed 20. Sliding bottom 21. Closing chamber 22. Feed, solids collector cooling 23. Discharge, solids collector cooling 24. Feed, hood cooling 25. Control unit 26. Centripetal pump 27. Discharge, hood cooling 28. Turbidity meter


Operation

The product enters the bowl through a closed feeding tube (1) and inside the ring packing (3), it is divided into two phases -a clarified liquid phase and a solid phase. The clarified liquid is conveyed to the center of the bowl and discharged by pressure towards the outlet (2) through the centripetal pump (26) without foam.

The separated solids are collected in the sediment-collector chambers and ejected periodically via the ejection ports (6). Ejection is generated by a sliding piston (20) hydraulically operated by the operating water fed through the piston valve. Operating water is used only during the ejection process.

Solids ejection cycles are started automatically by the control unit (25), which can run different ejection options: partial discharge, a combination of short and long partial discharges or flush discharge after every total discharge.


Solids discharge control

Automatic solids ejections can be adjusted via a timer or equivalent time control gear, or via a photoelectric control which acts through a turbidity meter (28).

The first control alternative is suggested for applications with products which generally have a constant solids content.

In the second alternative, if a preset turbidity level is exceeded, a signal is sent to the control unit (25) which will automatically activate the solids ejection process. The turbidity monitoring system can be installed in any equipment and is recommended for use with translucent liquids with solids content or with variations in the feeding capacity.



Partial discharge sequence

When the product is processed, only partial solids discharges are performed. The sliding bottom (20) must be opened for as short time as possible so as to ensure that the solids ejection ports are wide open to allow unobstructed solids ejection.

The sliding bottom is in closed position (left side of diagram) when the closing chamber (21) is full. When the annular valve (7) is hydraulically opened (right side of diagram), the closing water flows out of the closing chamber. Then the bowl opens and solids are instantly discharged through the ejection ports.

During the discharge process, the closing chamber is continuously filled with operating water via the annular valve, which will then close until the next discharge, where the cycle will be repeated.

In the case of solids which are difficult to eject, a longer discharge cycle is performed after several partial discharges. In this cycle, remaining solids are flushed inside the bowl while the product feed is still open.



Total ejection sequence during CIP

Once the centrifugation process has been completed, the machine can be cleaned in place. During CIP, the cleaning solution (generally caustic soda-water solution and acid-water solution) flows around the centrifuge and the connected system.

Total discharges will then be started during the chemical cleaning process of the bowl, whether via the control unit automatically or via an external CIP control unit.

In the case of total discharge, the closing chamber is emptied through the annular valve by adding operating water. The sliding bottom remains open until the total contents have been ejected from the bowl. Once the total discharge has been performed, the sliding bottom closes by supplying more operating water.



Hydrohermetic seal and feed

This equipment is designed to allow the bowl contents to be perfectly sealed and isolated from the atmosphere at the height of the centripetal pump and by means of an additional immersion disc.

In addition, the product feed is hydrohermetic. This new feature prevents exterior forces from acting on the product when entering the bowl. As with the fully hermetic design, the product stream is then accelerated by the product itself in the full bowl.

This hydrohermeticity is perfect for processes which require extra care for the liquid to be clarified. It also provides maximum clarifying efficiency, especially in the case of microorganism and other sensitive products, and for processes of low feeding capacities.



Frame and drive

The frame is equipped with a speed measuring device and a lube oil level sight glass. The operating water system has manometers to measure water pressure.

The machine is driven by a three-phase AC motor connected to a variable-frequency drive which allows for gentle start-up and online speed control. Power is transmitted to the bowl spindle by means of a pinion and crown wheel gear. All bearings are oil-bath lubricated.

Delivery of the clarifier comes with an open motor, but it can also be delivered with an anti-explosive motor if required. The whole machine can also be rendered inert with a nitrogen buffer (not included with original scope of delivery).



Material Specifications

Bowl body

SS 1.4462 stainless steel

Hood

SS AISI 316L stainless steel

Cyclone

SS AISI 316L stainless steel

Frame

Alloy

Inlets and outlets

SS AISI 316L stainless steel

Gaskets and O-rings

PDA – Nitrile – EPDM – Viton (as needed)




Additional after-sales services

  • Technical supervision for assembly and installation of the product
  • Commissioning and calibration of devices
  • Equipment maintenance
  • Operator's training: operation and adjustment


Frame and drive

  • Photoeye or turbidity meter to control discharges
  • Vibration monitoring system to stop the machine when it exceeds a preset value
  • Temperature sensor and overcurrent detection for motor protection
  • Solids pump for enclosed discharge activated by solids tank level


Warranty

Warranty covers the equipment for a period of 12 months after start-up or 18 months after date of sale, whichever occurs earlier.

Warranty does not cover costs in replacement of consumable items during maintenance and will remain valid as long as service and repair of the equipments are carried out according to Woerh®'s recommendations.

Warranty does not cover damage caused by abuse, negligence or misuse of the equipment.