Control of processing capacity of horizontal screw centrifuge

- Dec 22, 2020-

Any horizontal screw centrifuge has a processing capacity requirement. This requirement has two aspects of data referencing guidance: one is the dry solid load that can be processed, that is, the amount of non-evaporable solids processed per hour; the other is that it can be processed Hydraulic load, that is, the sludge flow into the equipment, the product of it and the sludge concentration is the dry solid load.

In the case of normal sludge concentration, it is better to ensure that the dry solids load is 70% to 90% of the theoretical load of the equipment calibrated by the equipment manufacturer. To prevent the equipment utilization rate from being too low, and to prevent the horizontal screw centrifuge from being high Operation under load results in accelerated equipment loss and shortened maintenance cycles.
In the case of excessive load in the horizontal screw centrifuge, no matter how much flocculant is added, the treatment effect will not be improved. It shows that the degree of mud biscuit is undesirable, the supernatant carries high solids and the recovery rate decreases. The overflow of sediment carried by the supernatant causes equipment wear, damage to dynamic balance and aggravation of sensation.

Sometimes due to the addition of sludge concentration, when the sludge is fed according to the original flow rate, the actual sludge load exceeds the acceptable load index of the equipment and the treatment effect is reduced. At this time, it is necessary to gradually reduce the mud feeding frequency in time, investigate the effect, and after the effect is stable, continue to test the flocculant flow control to the economic dosage.

Conversely, when the sludge concentration drops, the sludge flow rate should be gradually added, and the flow rate of the dosing pump should be adjusted in cooperation during the same period. If the inlet sludge concentration is too low, although the dry solid load of the equipment is not high, the hydraulic load is very large. Because of the low-concentration sludge that enters under high hydraulic load, the horizontal screw centrifuge cannot form useful and uniform mud. In the ring layer, the settled solids will be carried by a lot of supernatant overflow, and then directly affect the processing effect and processing power.

Therefore, for low-concentration sludge, it is dewatered after being concentrated, perhaps mixed with high-concentration sludge. To prevent the overload of the centrifuge caused by the excessive torque caused by the excessive mud load, the frequency of the mud pump should be appropriately reduced. This situation mainly occurs when the mud concentration is added, but the original mud flow is still operating.