Important Factors When Debugging Decanter Centrifuges

1. Rotation Speed of Solids Bowl Adjustment (Namely Separation Factor)

Separation factor refers to the ratio between sedimentation rates of solids particles under the centrifugal force and gravity force in the drum of a decanter centrifuge.

If the difference of densities between solids and liquid in suspension is large or liquid viscosity is small, the sedimentation velocity will be high, and separation effect is good. 

The influence of solids particle size on the separation effect is most obvious, big size particles are easy to settle and separate, small size particles are not easy to settle and separate, that is to say the handling capacity and efficiency (solid phase moisture content and liquid phase solids content) is proportional to the size of solids and inversely proportional to the viscosity of liquid. 

According to different materials and working conditions, the separation factors to be selected are also different. If the solid particles in materials and density difference between solids and liquid  in the drum of a decanter centrifuge are all small, and the liquid viscosity is large (low temperature), the separation factor should be relatively bigger. 

If the solid particles in materials and density difference between solids and liquid  in the drum of a decanter centrifuge are large, and liquid viscosity is small (high temperature), the separation factor can be smaller. 

If the flocculating agent added coagulates and settles during the process of solid-liquid separation, separation factor can be lower. 

2. Spiral and Drum Rotation Speed Difference

To make the rotation speed difference between a spiral and a drum keep stable, a decanter centrifuge usually equipped with a large reduction ratio differential. When the drum rotation speed is fixed, change the differential input shaft speed can change the spiral and drum rotation speed difference, while changing the transmission capacity (slag discharge ability) of the spiral, thereby affecting the centrifuge separation effect.

Under the premise of other operating conditions remain unchanged, if use a small differential speed, screw conveyor speed will be reduced, residence time of solid phase in the dewatering zone will increase, and lower moisture content solids phase can be obtained. As the spiral conveyor speed is reduced, its transmission capacity decreased, liquid clarity will be reduced, and vice versa.

3. Liquid Pool Depth

The distance from drum liquid surface to drum wall is the “height” of the liquid, often referred to drum liquid pool depth. Different Liquid pool depth can be adjusted through adjusting the height of overflow plate, and the lengths of drum dewatering zone and settling zone can be changed accordingly, thus changing the sedimentation and dewatering ability of a decanter centrifuge. 

Under the premise of other operating conditions remain unchanged, if adopt large diameter overflow plate, the liquid pool depth will be reduced, shortening the length of the settlement area, and reducing the sedimentation ability of a decanter centrifuge. But on the other hand, the length of the dewatering zone and solid phase dewatering time will be increased, thus improving the dewatering ability of a centrifuge. And vice versa. But the solid content of clear liquid will be affected if the sedimentation pond is too shallow. 

These three elements of debugging decanter centrifuges are the most basic elements, all decanter centrifuges are adjusted through adjusting the aboved three elements, and then adjusting the centrifuge treatment effect, but each material has a suitable parameter, not every element should be adjusted as high as possible, otherwise it will be counterproductive. Specific requirements need to be understood according to the physical properties of materials , for example, some materials will slip if the rotation speed is too high , thus affecting the treatment effect. 

You are welcome to contact Tangshan OGEM Solids Control to get more detailed infos, we will supply our best service for you. 

Any requirements, please contact with us freely!

Tangshan Aojie Petroleum Machinery Equipment Make Co., Ltd (Short for: OGEM Solids Control)

Address: NO.2 Jingxi Road,Lunan District,Tangshan city,Hebei province,China

Tel: 86-315-8676484

Fax: 86-315-2648099

Zip Code: 063000

Email: ogem2@ogemsolidscontrol.com

Website: http://www.ogemsolidscontrol.com/

                                                     

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