Cross-section of a 2-phase DECANTER with centrate discharge by gravity

Feed

The slurry is fed through a fixed central pipe into the distributor located in the scroll. The product is then accelerated gently in circumferential direction and passes through feed ports in the scroll body into the separation section of the bowl.

Bowl

The bowl has a cylindrical/conical shape and rotates at a pre-set speed specific to the application. The slurry rotates with the bowl at the operating speed and forms a concentric layer around the bowl wall. The solids contained in the slurry are Deposited against the bowl wall under the influence of centrifugal force. The length of the cylindrical bowl section and the cone angle are selected to meet the specific requirement of your application.

Scroll

The scroll rotates at a slightly different speed to that of the bowl and conveys the deposited solids towards the conical end of the bowl. The length of time the solids remain in the bowl is an important factor in determining the dry solids content of the discharged cake. The residence time can be adjusted by changing the differential speed of the scroll to provide optimum separation for the particular slurry. If the physical properties of the slurry change , Flottweg centrifuges can be adapted by supplying a different scroll design or by modifying the existing scroll. Scroll designs are available in concurrent or countercurrent and in single flight or multiple flights configuration depending on the application and processing conditions.

Weir

While the liquid is being clarified, it flows to the cylindrical end of the bowl and overflows the adjustable weir plates which determine the depth of the pond. The clarified liquid is decanted into a stationary centrate chamber and dischargedby gravity. The easily adjustable précis ion weir plates (patented system) are used in all our gravity discharge decanters.

Weir plates with eccentric adjustment (patented)

Impeller (Skimmer)

The clarified liquid can also be de-canted with an impeller and dis-charged 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 precis adjustment of the pond depth during operation to accommodate changing operating conditions.

Materials of Construction

Materials for components in contact with the product are selected on the basis of process requirements. A variety of materials can be chosen from the standard, duplex stainless steel to various grades of nickel-based alloys

Bearings

A special selection and arrangement of bearings provides long service life and exceptional reliability. A central lubrication system supplies either grease or oil to critical bearings, depending on the centrifuge model and application.