Three phase decanters

The decanter centrifuge below is an example, NES would require full details of your requirements before suggesting a suitable machine


Operation: - With the bowl spinning at 3,000 rpm the feed slurry is fed through a fixed central pipe into the distributor located in the scroll. The product is accelerated smoothly to bowl speed as it passes through the feed ports in the scroll into the bowl.

Separation takes place in the conical cylindrical bowl when he slurry forms a rotating liquid tube under the centrifugal force caused by the bowl rotational speed. The solids in the slurry are deposited against the bowl wall and the remaining liquids separate into a light and heavy phase giving three concentric layers held against the bowl by centrifugal force.

The scroll is rotating at a differential speed to that of the bowl and conveys the separated solids in the direction of the conical end of the bowl. The length of time the solids remain in the bowl is an important factor in determining the dryness of the final solids discharge. The residence time can be adjusted by changing the differential speed of the scroll in relation to the bowl.

The separated solids are discharged through openings at the conical end of the bowl into a fixed discharge housing and then down the discharge chute.

While the liquid phases are being clarified they progress to the cylindrical end of the bowl where they are decanted through separate discharge systems to prevent cross-contamination.

The lighter phase is normally discharged under gravity whilst the heavier phase is removed under pressure by the variable pitch impeller. By altering the impeller during operation the clarity of the two liquid phases can be optimised.

General Description of NES  Hydraulic Driven Centrifuge Unit


Tricanter Z4D-4/441 VS2I-370A


Centrifuge for continuous separation of two liquids with different specific weight and one settleable solids phase.

The first liquid phase is ejected under pressure via an adjustable impeller disc (continuous optimization of the liquid separation line during operation of the machine).

The second liquid phase flows without pressure by gravity over an adjustable weir.

All product contact parts are made of stainless steel. The other metal parts are protected against corrosion by multilayer finish.

Sealing: Material NBR

Scroll: Surface ground

Wear protection:

Feed compartment armoured with cast iron bushings

Scroll blade protected by tungsten carbide

Bowl: Wear protection:

Discharge area outside: hard metal

Flanged wheel: hard metal

Execution inside:

Wear protection by strips and cast iron bushings

Rotor housing: stainless steel

Solids housing: integrated in rotor housing

Machine base: carbon steel

with vibration insulators

Rotor: exchangeable for easy maintenance

Belt guard: according to EEC safety rules

Central lubrication

system: manually operated

Drive bowl: Hydraulic motor with fluid coupling

Visual differential and bowl speed measuring device

for indication of the bowl and differential speed.

Initiators mounted on power packs

NESL fully hydraulic drive VS2I-370 A aggregate

for continuous adjustment of bowl- and scroll differential speed as well as for control of scroll diff. Speed (from 3 to 22 min-1 during operation and under load.

This variant of drive makes a slow start-up of the machine possible without the high electric starting current, which is required otherwise, and also almost constant dryness of the solids with heavy fluctuating solids contents in the inflow. At the same time the machine is protected against overload and clogging, including Parker double pump (variable displacement type), and air-cooled heat exchanger for hydraulic oil.

Effluent hopper (422-04)

For leading and lagging operation of the machine, revolving.

Dosing device in material 1.4301 (462-02)

Enables the addition of flocculent or other separation aids directly in front of the inlet area of the decanter.



NESL 402C Hydraulic Power Packs to drive centrifuges

Engine- Iveco 8061 6 cyl diesel water cooled


Power(continuous) 76 KW@ 2500rpm

Displacement 5.9 l - 12v electrics

Fitted with splitter box for 2 X tandem pumps 1+2 and 3+4

Pump No.1 for the bowl - Plunger type pilot operated with variable displacement 65 l/min 250 bar

Pump No.2 for the scroll Gear pump fixed displacement 54.5 l/min 250 bar

Pump No.3 for centrifuge feed pump Gear pump fixed displacement 54.5 l/min *

Pump No.4 for the bypass oil cooler 12 Kw and filtration Gear pump fixed displacement 54.5 l/m

Mounting Protection Frame with lifting point

Pressure line filtration 10 micron abs.

Fuel and Hydraulic Tanks- incorporated

Full instrumentation and controls fitted

Safety- Spark Arrestor/Chalwyn inlet valve/Engine protection

No return line filtration is allowed

Only Mineral oil with viscosity VG68 (68mm2/s, 68cst) to DIN 51524HLP to HL68 to ISO HM68 is permitted



copyright 1996-2010 by Non Entry Systems Ltd (NESL)