Function and Features of Decanter Centrifuge

Decanter Centrifuge Function and working principle

Decanter centrifuge is one type of solid-liquid separation equipment, which can be used in many fields, such as chemical industry, coal chemical industry, steel, resin, Food(starch and protein), kitchen waste, fermentation, medicine, water treatment and other fields.

When Liquid continuously enters the centrifuge screw conveyor through an inlet SS pipe, then entering the bowl through the feed hole, the bowl rotates in high speed; under the action of gearbox, screw conveyor achieves a differential speed that lags the bowl.

Thus, the bowl and conveyor composes transmission mechanism with slight differential speed and high-speed rotation in same direction.

With the centrifugal force tens even hundreds of times as large as gravity, an annular liquid pool is formed inside of the bowl.

The density contrast between solid and liquid phases enables heavier solid-phased particles to be settled down on interior wall of bowl and form sediments, which are pushed to the small holes of the bowl with the relative movement between spiral shades and bowl, and finally discharged from the holes.

The clarified effluent of inner circle is discharged from overflow port through a spiral channel.

Consequently, the production process of continuous separation of solids phase and liquid phase is realized.

The light liquid will be discharged into the housing through radial holes in the large end hub.

The heavy liquid will be discharged through axial holes in the large end hub.

The liquid level can be controlled by one adjustable plate.

To prevent the light liquid from leaving the bowl through the heavy liquid outlet, there will a separating plate be placed on the inside of the large end hub.

The heavy liquid has to pass under the separating plate before being discharged into the housing.

The Main Parts and Technical Features of the ZK centrifuge

All contact parts are made of stainless steel.

The bowl, conveyor, inlet tube, outlets, cover and other parts in direct contact with the raw materials are all made of stainless steel, such as SS304, SS316, 2205 and etc. To prolong the service life, the welded hard facing or spray coating, the ceramic, and Tungsten carbide tiles used.

Special heavy liquid-phase discharging design

The heavy liquid phase separated by the three-phase centrifuge can adopt two different liquid discharging modes, namely gravity discharging and discharging through the built-in centripetal pump, wherein the latter includes liquid layer fixed mode and the online adjustable mode of heavy phase liquid layer, which is selected according to the process conditions.

Light phase liquid layer adjustable technology

From the current three-phase centrifuge structure for liquid transportation of centripetal pumps adopted at home and abroad, the adjustment of the light phase liquid layer requires disassembling the centrifuge, and replacement takes more than 8 hours. The centrifuge, with the patented technology of our company, just requires opening the hood to adjust the light phase liquid layer.

Fully automatic control

Bowl speed is adjustable by VFD control panel, PLC and touch screen automatic adjustable differential speed. Automatic control mode from start to separation to cleaning to stop reduces human intervention during the operation of the equipment and lowers the requirements on operator quality. ZK centrifuge is equipped with sensors for vibration and temperature measurement.

3-phase AC Double motor drive by frequency converter

The main and back motors of the centrifuge are controlled by a high-performance inverter. Two motor drive can enable the differential speed to be regulated cost-effectively under good running conditions. The back motor is always in the generator state under the differential speed. The inverter adopts common DC bus technology. The back inverter can convert the electric energy generated by the back motor into the power source to drive the main motor, thereby achieving the purpose of energy conservation. Through the double-motor and double-frequency conversion control technology, the stepless adjustment of the centrifuge differential speed can be realized. It features fast reaction speed, accurate torque detection, stable torque control, and low failure rate.

Main advantages of decanter centrifuge

  1. Decanter centrifuges is with good adaptability, can be used in many fields, and treat & separate many types of raw materials.
  2. Decanter centrifuge can be continuously operated 24 h/day, big capacity and good separation efficiency.
  3. Low labor cost. Completely active operation, reliable operation, without manual intervention. Only one person per shift is needed, which has low technical requirements for workers and reduces labor cost.
  4. Under normal operating conditions, the fault-free operation of the horizontal centrifuge should not be less than 8000 hours. And the service life is not less than 8 years.
  5. Compact structure, small floor area, easy to operate, convenient for protection and low cost of protection.
  6. Completely safety and reliable protection, the centrifuge is equipped with torque protection, power control, electrical interlock, sound-light alarm and other multiple protection, which can effectively eliminate or reduce the damage caused by sudden faults to the machine.