Coal washing cyclone It is a kind of coal preparation equipment with simple structure, no moving parts and high separation efficiency. Because the hydrocyclone has no moving parts, the separation process depends on the combination of its own structural parameters and external operating parameters to achieve the separation accuracy. This is a prominent feature of cyclone coal preparation which is different from other coal preparation methods.
1. The principle of dense medium cyclone is similar to that of classification cyclone, both of which separate underflow and overflow by huge centrifugal force.
2. Density: in the dense medium cyclone, the closer the medium density is to the cyclone wall, the greater the density is, and the closer it is to the underflow port, the greater the density. On the contrary, the closer to the center and overflow, the lower the density.
3. The coal quality is determined by the following factors: ① feed velocity; ② underflow outlet diameter; ③ cyclone length and taper.
4. Principle: similar to a tornado, the large centrifugal force in the outer layer causes low pressure in the center. Air is inhaled from the underflow port, and the coal with low density is reversely spiraled out from the overflow, while the gangue in the outer layer is discharged from the underflow due to its high density.
5. 0 bit line: the boundary between overflow spiral and underflow spiral. Within 0 bit line, it is overflow; outside is underflow.
6. The movement inside the dense medium cyclone is extremely complex, and it is also a high-precision coal preparation equipment.
Operation and adjustment
1. The concentration and fineness of overflow meet the next process conditions. This standard is a standard, that is, the condition must be met first. Here is a brief description of how to adjust the status:
(1) the overflow concentration is small and the fineness is fine. At this time, it is necessary to reduce the pressure or adjust the feed concentration, or replace the small grit nozzle to meet the requirements.
(2) the overflow concentration is large and the fineness is coarse. At this time, the requirements can be met by increasing the pressure and adjusting the feed concentration, or by changing the large sand settling nozzle. But the above adjustment can not only rely on one way to adjust, because it may make the cyclone work not normal and stable.
2. The settling sand is discharged in umbrella shape. The judgment basis is that the angle of setting sand is between 10 ° and 20 ° and the concentration is about 75%. If the sand dispersion angle is too large, there are three reasons
(1) the grit nozzle is too large and the grit concentration is too low. At this time, it can be adjusted by replacing the small sand nozzle.
(2) if the ore feeding pressure is too small, the feed pressure of the pump should be adjusted to meet the process conditions.
(3) the feeding amount is too small and the feeding concentration is too low. At this time, the feeding amount and the number of hydrocyclones can be adjusted. In short, the size of grit concentration directly affects the efficiency of the mill, affects the size of the mill discharge, and has an impact on the whole process.
3. Judgment of ore feeding pressure:
(1) the theoretical pressure regulation range of the first stage cyclone group is 0.06-0.10mpa. If the pressure is too high, the hydrocyclone will be greatly worn.
(2) the theoretical pressure regulation range of the two-stage cyclone group is 0.08-0.16mpa. If the pressure is too low, the concentration of grit will be reduced and the overflow concentration will be coarsened, which will affect the process.
In short, the pressure adjustment should ensure that the pressure of the first stage cyclone group cannot be high, and the pressure of the second stage hydrocyclone group cannot be low.
1、 During maintenance, check each screw and fastener to ensure that they are tight and watertight;
2、 If the parts are damaged, they should be replaced in time, and attention should be paid to avoid steps during replacement, otherwise the service life will be reduced;
3、 The bottom flow port of hydrocyclone is easy to be damaged, which should be inspected and replaced during maintenance;
4、 Pay attention to maintain the stability of the feed during the inspection of the feed inlet;
5、 In case of blockage, do not use heavy objects to knock, and the connecting bolts should be disassembled for treatment.