Analysis and repair of wear in vertical grindingDate: 2019-06-28 Views:
Vertical grinding is an ideal large grinding equipment, which is widely used in cement, power, metallurgy, chemical industry, non-metallic ore and other industries. It integrates crushing, drying, grinding and grading transportation, and has high production efficiency. It can grind bulk, granular and powdery raw materials into the required powdery materials. Especially since 1960s, with the birth of preheating pre-decomposition technology, the new dry process cement production line has been large-scale, and the manufacture and application of vertical grinding has been very mature.
Vertical grinding is the most important part of cement enterprise. once the wear problems of shaft and bearing chamber occur, it will have a serious impact on the operation of the whole equipment and bring a series of problems.
First, the equipment problems that are easy to occur in the normal production and operation of vertical mill:
(1) vertical grinding of the main bearing position and wear of the bearing chamber;
(2) the body wear of vertical grinding roller;
(3) Oil leakage of vertical mill reducer;
(4) bearing position of vertical grinding rocker arm and wear of bearing chamber;
(5)Vertical mill separator keyway roller;
(6) the position wear of high speed bearing in vertical grinding.
Second, there are several problems that should be paid attention to in the field repair of vertical mill by using cable mine technology:
The main results are as follows:1) Sand blasting treatment is carried out to ensure the effect of surface treatment.
2) welding the positioning points, and grinding the positioning points according to the template rule to ensure the concentricity and the taper after the repair;
3) The bolt must be tightened according to the specified torque: first, the bolt of the grinding roller shall be tightened three times according to the requirements. In addition, during normal shutdown, the degree of tightness of the grinding roller bolt shall be checked, and if there is any looseness, the bolt shall be tightened again, and the loose bolt shall be recorded and inspected to prevent the further deterioration;
3. The step of the on-site repair of the grinding roller of the vertical mill:
1) baking the scratched part with an oxygen-acetylene flame (master temperature, avoiding surface annealing), baking the oil which penetrates into the metal surface, and baking until there is no spark, so as to prevent the temperature from being high, and can be used for multiple baking in a plurality of times;
3) the welding positioning points are uniformly distributed along the conical surface of the hub and the cylindrical fit surface;
4) using the template ruler as the basis, grinding the positioning point;
5) the wear surface is large or deep, if the time permits, a large area surfacing can be adopted, and the welding height is slightly lower than the positioning point;
6) cooperate with surface sandblasting treatment, meet the sandblasting standard of Sa2.5, use compressed air to blow clean;
7) empty test roll sleeve to check the fit gap;
8) clean the surface with acetone or anhydrous ethanol to ensure that the surface is clean, dry and rough;
9) Sorey carbon nanopolymer materials are fully reconciled strictly and proportionately until the color is uniform and consistent, and there is no color difference.
10) removing the floating rust from the matched part of the roller sleeve, cleaning with absolute ethyl alcohol, brushing and coating the Soxious SD7000 release agent, and air-drying;
11) blend Sorey carbon nanopolymer material, scrape and coat it to the fit surface, and make it slightly higher than the original size of the fit surface, and assemble the roller sleeve vertically. And fasten the bolt according to the prescribed moment;
12) In order to ensure the normal operation of the equipment, it is necessary to ensure that the equipment is strictly and carefully installed; first, the grinding roller bolts are tightened three times according to the requirements. In addition, during normal shutdown, the degree of tightness of the grinding roller bolt shall be checked, and if there is any looseness, the loosening bolt shall be tightened again, and the loose bolts shall be recorded and checked to prevent the further deterioration.