Solid bowl centrifuges - FLOTTWEG DECANTERS
The basic principle of the solid bowl centrifuge has been known since the end of 19th century. Over the course of time, technology improvements along with the availability of high strength and corrosion resistant raw materials have allowed solid bowl decanters to be applicable to many processes. The utilization of electronic and electromechanical measuring and control components has improved the performance and availability of the machines. The basic design of a solid bowl centrifuge is relatively simple and can be customized by Flottweg for different requirements. Of all modern industrial centrifuges, solid bowl centrifuges have the broadest range of application.
Constructive features of the FLOTTWEG-DECANTER for optimum separation
The slurry is fed through a stationary pipe into the feed zone located in the center of the scroll. The product is then accelerated circumferentially and delivered through distribution ports into the bowl.
The bowl has a cylindrical/conical shape and rotates at a pre-set speed optimal for the application. The slurry rotates with a different scroll design or by modifying an existing scroll. Scroll pitch and single or multiple flight configurations are important design variables.
The scroll rotates at a slightly different speed than the bowl and conveys the deposited solids toward the conical end of the bowl. This differential speed determines the residence time of the solids in the bowl. Residence time is an important variable for the dry solids content. It can be adjusted by changing the differential speed of the scroll thus providing optimal separation. If the physical properties of the slurry change, FLOTTWEG DECANTERS can be supplied with a different scroll design or by modifying an existing scroll. Scroll pitch and single or multiple flight configurations are important design variables.
Settled solids are ejected through ports at the conical end of the bowl into the solids housing and fall through the discharge chute.
Materials of construction
FLOTTWEG uses high-quality stainless steel for all wetted areas. Bowl and scroll castings are made from centrifugal cast high strength and corrosion resistant stainless steel.
A special selection and arrangement of bearings provides long life and exceptional reliability. A central lubrication system supplies either grease or oil to bearings.
The clarified liquids flow to the cylindrical end of the bowl where they exit over weir plates. Easily adjustable precision weir plates allow for the precise adjustment of the pond depth in the bowl. Overflow is then collected in a centrate chamber and discharged by gravity.
The clarified liquid can also be decanted with an impeller and discharged from the bowl under pressure. This eliminates the need for a separate centrate pump. The FLOTTWEG adjustable impeller is an engineering refinement that permits quick and precise adjustment of the pond depth during operation to accommodate changing conditions.