The solid-wall bowl (6) has a cylindrical section for efficient separation and
clarification of the liquid and a conical section for solids dewatering. The product enters the decanter through the feed (1) and passes through the distributor (3) into the centrifugation space (14). The liquid level in the bowl can be adjusted by means of the regulating ring (15). Due to the impact of the centrifugal forces, the solid particles are flung onto the bowl wall. The hard-metal faced scroll (7) transports the solids to solids discharge (2). The clarified liquid leaves the centrifugation space via the centripetal pump at discharge (3) under pressure (CC 458-21-32). The centrate can be discharged under gravity or in multi-phase mode. 

1 Feed
2 Solids discharge
3 Centrate discharge
4 Sealing gas
5 Leakage
6 Bowl
7 Scroll
8 Housing seal, dynamic
9 Feed tube seal
10 Scroll bearing seal
11 Housing seal, static
12 Washing medium (flushing medium)
13 Distributor
14 Centrifugation space
15 Regulating ring
16 Bowl bearing
17 Secondary gear
18 Primary gear
19 Secondary motor

The gas-tight decanter housing is sealed off from the atmosphere at both housing sides and at the feed tube by means of gas-sealed gaskets. Various gasket constructions can be used, for example carbon ring sealing rings or PTFE lip seals. The maximum admissible overpressure of the decanter housing is 0.05 bar.

The following conditions must be met to ensure safe operation of the decanter
with highly inflammable product:

• Blanketing of the housing with inert gas
• 0.03 – 0.04 bar are maintained at the overpressure vent
• Continuous monitoring of the inert gas blanketing. For this purpose, GEA Westfalia Separator offers a separately installed control unit for inert gas

Inert gas blanketing has the additional advantage that grease-decaying product vapours are kept away from the main bowl bearings. Further, oxidation of the product is prevented.