(1) Vertical centrifugal dewatering machine The vertical centrifugal dewatering machine is suitable for dewatering of ore dressing products with a particle size of 12~0 mm. The structure of the continuous centrifugal dewatering machine is shown in Figure 1. The main component is a conical screen made of steel plate (called a dewatering umbrella) with a hole of 15 to 3 mm. The material is fed into the batching tray 11 by the screw conveyor. The water in the material passes through the sieve hole by centrifugal force, and the material moves downward along the sieve plate. The greater the radius of the downward turn, the stronger the centrifugal force. The material circumventing the retaining ring 10 on the screen surface (about 10 to 12 mm high) can be further loosened to facilitate drainage, and the material sliding speed is reduced, and the dehydration time is increased. The dehydrated product falls into the lower bin or funnel. The water content of the dehydrated product is related to the feed amount of the centrifuge, the particle size composition of the material, and the centrifuge speed. The size of the dewatering umbrella mesh and the moisture content of the raw material have no effect on the final result of dewatering. As the feed amount increases, the water content of the product also increases; the finer the feed size, the higher the water content of the dehydrated product; the higher the rotational speed of the centrifuge, the lower the water content of the dehydrated product. As the number of revolutions increases, the feed size becomes finer and the size of the mesh increases, which increases the solids content in the centrate. Where n—the number of dehydrator units required, Taiwan; The horizontal centrifugal dewatering machine has two rotating drums: one is a tapered outer rotating drum, and the other is an inner rotating drum with a spiral scraping plate. The two ends of the conical drum are supported by two hollow journals on the bearing for high-speed rotation, and the spiral drum is driven to rotate in the same direction through the reduction gear and the shaft, but the rotation speed of the latter is slightly slower (1 to 3% difference) In addition to the conical drum, there is also a fixed cylindrical casing. Where Q—the productivity calculated by overflow, cm 3 /s; Raw Materials for Skin Repair Products,Raw Materials for Skin Anti-inflammatory Products,Eliminate Scar Product Raw Material Ruijiming (Shandong) Biotechnology Co., Ltd , https://www.mgpdrn.com
The centrifuge must be operated to keep the rotor in balance and prevent its moving parts from deforming. At the same time, the centrate should be discharged from the centrifugal dewatering machine in time to prevent the groove in the machine from being blocked by fine mud.
The number of units required for the vertical centrifugal dewatering machine is calculated as follows:
Q—the amount of material actually entering the dewatering machine, t/h;
q———The hourly production capacity of a single dehydrator is selected according to the quota indicator, t/h;
K——— imbalance factor, 1.15～1.2.[next]
(2) Horizontal centrifugal dewatering machine The horizontal centrifugal dewatering machine is specially used for dehydration of fine-grained materials. The configuration and working principle are shown in Figure 2.
The slurry is inserted into the opening of the pipe in the journal of one end of the conical drum, and falls into the space sandwiched by the spiral drum and the conical drum. The solid particles precipitate on the inner wall of the drum under the action of centrifugal force.
Since the spiral drum has a relative speed with the cone (about 15 to 30 rpm), the sediment is conveyed by the spiral scraper to the left end of the cone and through the discharge hole in the drum wall. Discharge, the liquid moves in the opposite direction and is discharged through the overflow weir on the right end cover of the conical drum.
After the liquid is exposed to the liquid surface, it passes through a section of dewatering zone where it is further dehydrated and finally discharged through the discharge orifice.
The productivity of a horizontal sedimentation centrifuge can be calculated as follows:
d p ———separation particle size, cm;
Δ—the density of ore, g/cm 3 ;
△—the density of the liquid, g/cm 3 ;
——the viscosity of the liquid, Pa · s;
D 0 ———the average diameter of the overflow layer, cm;
L—the length of the sedimentation zone, ie the horizontal distance from the inflow of the slurry to the weir, cm;
n———The rotation speed of the drum, r/min.
The above formula is suitable for separating particles with a particle size of 10 to 15 μm, and when the separation particle size is larger than 15 μm, it should be appropriately modified.
The main factors affecting the operation of the sedimentation centrifuge are the centrifugal separation factor K and the length of the settling zone. In actual operation, the size of L can be changed by changing the position of the feed port (moving the feed pipe in the axial direction) and the height of the weir to achieve the purpose of changing the separation granularity d p . When the height of the weir increases, the length of the sedimentation zone increases, and the separation particle size will become smaller. However, the length of the dewatering zone is bound to decrease, which in turn will lead to an increase in the moisture content of the precipitated product. Therefore, in the adjustment, it is necessary to consider both the separation particle size and the product moisture.
Practice of precipitation selected from the centrifuge clarified coal washing plant demonstrate good effect, solids recovery rate of 85%, while the solids content of the overflow is 2 to 6 grams / liter. When used for fine-grain (3 to 0 mm) coal dewatering, the product moisture can be reduced to less than 9.5%. The use of a sedimentation centrifuge not only has high dewatering efficiency, but also simplifies the dewatering process. Its disadvantages are: the equipment is complex, the manufacturing is difficult and the power consumption is large. However, due to its many advantages, it is still being used.
In addition to being used for concentration, the sedimentation centrifuge is also used as a device for deliming, fine particle classification, and centrifugal force beneficiation.