Apr 25

Important factors about choosing a Decanter Centrifuge

1.1 Differential ratio

The settling velocity of solids in different media is different, and the degree of aggregation is different, so different differential speed ratios should be used. When the other parameters remain unchanged, the differential speed is large, the solid material is pushed out faster, the amount increases, and the liquid content increases, the shaft power generally decreases, but the separation effect will decrease, that is, the solid content in the filtered liquid Will increase. As the differential speed increases, it actually acts as a stirrer in the drum. Choosing the right differential ratio is the first factor to consider when choosing a model.

1.2 Length-to-diameter ratio

The aspect ratio is the ratio of the axial length of the Decanter Centrifuge drum to its diameter. The working area of the Decanter Centrifuge is divided into several areas such as feeding, sedimentation, drying, and unloading. The length of the settlement area is the main parameter that determines the separation effect. The longer the settlement area, the greater the aspect ratio, the better the separation effect, but the greater the shaft power. Different length-to-diameter ratios should be selected according to different media properties (mainly settlement performance), and should be considered in combination with differential speed ratios.

1.3 Power

The use of larger power can improve the processing capacity, especially when the settlement performance of the medium is very good. The user has certain difficulty in choosing the model. In the face of new media or media without successful use experience, relevant tests should be conducted.

2 Determination of operating parameters

2.1 Adjustment of overflow diameter

There are four options for the overflow diameter of the general Decanter Centrifuge. The larger the diameter of the overflow, the longer the drying zone, and the lower the water content of the filter cake, but the higher the solid content of the filtered liquid, so the appropriate overflow diameter should be adjusted. For the “three mud” that is not easy to settle, it should be smaller, and for the medium that is easy to settle, such as TA residue, it should be larger.

2.2 speed

According to the working principle of the Decanter Centrifuge, the higher the speed, the better the separation effect, the dryer the filter cake, the clearer the filtered liquid, and the greater the shaft power. This is an important parameter in actual operation, but it is not that the higher the speed, the better the effect. Generally speaking, for the medium that is easy to settle, the higher the speed, the greater the shaft power, which is easy to cause the mechanical or solid material to be pushed out, causing the material to block. Therefore, the appropriate speed should be selected according to the factors such as the power of the Decanter Centrifuge, the feed, the dehydration effect and other factors. For the “three muds” that are not easy to settle, when the rotation speed is high to a certain value, there will be a phenomenon that the separation effect decreases, the sludge production decreases, and the solid content in the filtered liquid increases. When the rotation speed is reduced, the mud production fork will increase. This is because the material slips in the drum and cannot be pushed out. At the same time, as the speed increases, the absolute differential increases, and the stirring effect of the spiral drum is enhanced.

written by Decanter Centrifuge

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