Cyclone overflow and run rough
Writer： admin Time：2020-08-06 13:56 Browse：℃
The diameter of the overflow pipe is too large or the diameter of the grit pipe is too small, the feed pressure is too low, or the feed concentration is too high, the type of the cyclone does not match or the parameters are not matched, etc., resulting in an increase in the short-circuit flow and a decrease in the classification efficiency.
According to different working conditions and requirements for working results, the length of the cylindrical body of the cyclone can be adjusted at will to ensure that the cyclone reaches a good working condition. When pumping to a cyclone or a group of cyclones, the size and model of the pump must be carefully designed in detail to meet the requirements of the operation. And also have to design the pumping pipe diameter and pipeline length.
The solution to the overflow and roughness of the cyclone
The proportion of fine ore in the raw ore increases, the discharge water does not increase in an appropriate amount or the discharge pipe is blocked, causing a sharp decrease in the return or no return of sand; or the processed ore has a fine grain size and a large amount of ore; The water pipe was blocked and was not discovered in time. Once the water was boiled, a large amount of ore slurry would gush out from the mill. It can be used according to actual conditions and specific requirements; reduce the diameter of the overflow pipe or increase the diameter of the grit pipe; reduce the pressure and concentration of the ore; replace the cyclone model and optimize the matching parameters to maximize the adaptor process.
1. Increase the feed pressure within the calibration pressure range of the cyclone (0.1-0.15Mpa). Adjust the feed pump: you can increase the frequency of the feed pump until the overflow does not run thick.
2. Adjust by changing the grit nozzle of the large cyclone
When the ore pressure is within the calibration range, the grit nozzle can be replaced with a larger model to reduce the roughness.
3. Confirm whether the grit nozzle of the cyclone is blocked
The clogging of the grit nozzle of the cyclone can cause a large amount of overflow and roughness, which will have a very large impact on the subsequent process. When the pressure of the cyclone is unstable, the body vibrates violently, the overflow is too thick and the bottom flow is very small, check whether the cyclone grit nozzle and the feed body are blocked in time. If it is blocked, it should be disassembled and cleaned immediately to eliminate the fault.
The structure of the cyclone is different. All the separation cyclones that use water as the medium have a larger cone angle, reaching 90-140. For example, the sorting cyclone generally has a low feed pressure, and the liquid flow does not have much rotation speed. After reaching the cone, the rotating material flow including out-of-plane is difficult to discharge downwards, so a high-concentration rotating material layer is formed, and its comprehensive density is relatively large.
can only allow dense particles to enter the bottom layer through the gap, while particles with low density are pushed to the upper layer. Differentiating layers by density occurred. With the influx of new feedstock, the bottom heavy materials are discharged from the bottom flow port, the light materials are discharged from the overflow pipe, and the sediment is discharged from the low flow (as shown in the figure below: the structure of the hydrocyclone is selected). selected.
The main characteristics of the fluid flow pattern in the hydrocyclone, the double spiral model vividly describes the two basic flows in the cyclone-internal swirling and external swirling. In addition, short-circuit flow under the cover, circulating flow, zero-speed envelope surface and air column are also the basic characteristics of the fluid flow pattern in the hydrocyclone. When the fluid rotates in the cyclone, particles of different sizes are subjected to different centrifugal forces, so their respective final settling speeds are also different. As a result, large particles are discharged from the underflow port, while fine particles are discharged from the overflow port. , So as to achieve the purpose of particle classification according to a certain size.
Due to wear and tear, the cost of repairing the pump will be much higher than that of the cyclone. When feeding materials, flocculation and under-cover phenomena will occur due to the increase in volume, which will have a bad impact on the classification efficiency of the cyclone, and will increase the energy loss of the material in order to avoid these disadvantages. The influence of thick-walled overflow pipe can be used.
This part of the underflow of the cover is what we usually call the short-circuit flow. Because it directly enters the overflow product without separation, it directly affects the separation effect. The fluid flow pattern in the cyclone and the classification process The hydrocyclone can replace the mechanical classifier in many occasions, with simple and convenient operation and strong processing capacity.
Using this design and technology, under the same working conditions, one large-diameter cyclone can be used instead of multiple small-diameter cyclones, which can save costs. According to different working conditions, the feeding method of the cyclone can be divided into involute linear feeding, spiral feeding, and tangential feeding. Among them, the spiral feeding method is used more often, because under the same conditions, this method has the characteristics of strong processing capacity and low pressure.
The reasons for the overflow and roughness of the hydrocyclone are:
①, the cyclone feed particle size is coarse;
②, the diameter of the grit nozzle is small, and the grit nozzle is blocked by coarse particles or other debris.
So if you encounter this situation at work, how to solve it?
The solution can also be divided into two types:
①, control to reduce the feed size of the cyclone, appropriately reduce the feed concentration and increase the pressure;
②. According to the actual production situation, replace the grit nozzle with a larger diameter and use a spare cyclone to clear the clogged cyclone.
The overflow concentration and fineness should be checked regularly. The increase of the overflow concentration of the cyclone or the "overflow running thick" may be related to the increase of the feed concentration and the blockage of the underflow port. Adjust the treatment method: It is found that the "overflow running thick" can first detect whether the underflow port is blocked, and then detect the feed concentration, and adjust according to the specific situation.
