The adjustment of hydrocyclone can be adjusted by pulp pressure
Author: Time: June 3, 2020 99 views
Hydrocyclone The upper end is cylindrical and the lower part is conical. The slurry is injected into the hydrocyclone along the tangent direction through the feeding pipe by pump or by the head pressure.
The slurry entering the cyclone rotates at a high speed, so the solid particles are subjected to centrifugal force tens to hundreds of times more than gravity. There are two kinds of slurry flow in the hydrocyclone because the slurry rotates at a high speed: one is the outflow of downward rotating flow near the cone tube wall; the other is the internal flow rotating upward in the middle of the cone seed cylinder. The coarse sand in ore feeding enters into the outflow by large centrifugal force, sinks along the cyclone wall separator and is discharged from the grit setting port. The fine particles and most of the water in the feed rise in the form of internal flow, and are discharged as overflow through the overflow pipe, thus completing the unit operation.
What is the potential of hydrocyclones?
The main factors affecting the total energy consumption of hydrocyclone are inlet loss, outlet loss and internal flow loss. The inlet loss and outlet loss account for a small proportion of the total energy consumption loss. The inlet loss is mostly caused by the jet resistance and friction caused by the sudden expansion of the cross-section when the slag slurry enters the cyclone; the outlet loss is mostly caused by the kinetic energy and pressure discharged from the slag slurry, and has little impact on energy consumption.
The internal loss is large in the total energy consumption loss of hydrocyclone, which is mainly caused by inner wall friction, fluid viscous internal friction, turbulent dissipation and various local losses. To solve these problems, we can start from the following aspects.
terms of settlement:
1. Adding some annular teeth on the outer wall of the overflow pipe can greatly reduce or even short-circuit flow. When the annular teeth are added to the outer wall of the overflow pipe, the steep drop index can be increased from 0.176 to 0.332, and the separation accuracy index of z-final cyclone is 1.8 times higher than that of ordinary Hydrocyclone.
2. An annular gap is opened between the top cover of the hydrocyclone and the overflow pipe to lead out the short-circuit flow and return the short-circuit flow back to the sealed gathering chamber. The design can reduce the mixing of coarse particles in overflow products and increase the efficiency by 8 compared with the conventional classification.
3. The problem of 10% - 20% short-circuit flow in conventional hydrocyclone can be solved by adding reverse spiral to the outer wall of overflow pipe of hydrocyclone, which not only improves the separation efficiency, but also integrates the cone vortex, back vortex and short-circuit vortex into one vortex, which saves energy consumption.
4. Increasing the thickness of overflow pipe wall of hydrocyclone can increase the path of short-circuit flow and reduce the flow rate of short-circuit flow. Therefore, the separation efficiency of hydrocyclone can be improved and its internal loss can be reduced.
5. The design idea of changing the overflow pipe from the straight pipe to the gradually expanding pipe is derived from the principle of reducing the speed and increasing the pressure of the gradually expanding pipe. The slag slurry at the inlet of the overflow pipe can be discharged to the hydrocyclone smoothly under low pressure, and the energy consumption is reduced by 27 compared with that of the straight pipe. Moreover, the overflow and underflow outlet slurry velocity can be utilized, without waste and reducing the operation cost.