Emergency treatment of cracking of spherical tile of rotary kilnDate: 2019-10-10 Views:
It was found that there was a serious oil leakage in the seal of the supporting wheel of the kiln head supporting wheel group, the oil level of the supporting wheel tile oil mark showed that the tank of the supporting wheel was full of oil-water mixture.After opening the observation hole of the upper cover and the side end cover, it was found that there was no leakage at the inlet and outlet joint of circulating water, there was only a small amount of emulsified and muddy oil inside the bracket of the bearing bush, and there was a drop of water on the joint surface of the bearing bush and the spherical bush. What is the emergency treatment plan for the cracking of the spherical bush of the rotary kiln?
1. Fault diagnosis of spherical tile cracking of rotary kiln
Although the tile temperature was not high when the fault was found, the shaft surface could not establish an effective oil film, and the tile could be burnt at any time when the operation continued, so we decided to stop production for treatment.After communication with the design institute, the spherical tile of our company is non-standard design, and there is no spare part of the same model. The processing of new tile needs more than 20 days, and the cycle is too long to meet the production requirements.In order to minimize the loss, emergency treatment must be carried out on the spherical tile to ensure that the rotary kiln can resume operation in the shortest time.
When the temperature of the cylinder is cooled to about 50 ℃, use 2 sets of 500t hydraulic roof to jacking up the 1st gear belt, use 300t hydraulic roof to jacking up the supporting wheel, remove the set of copper tile and spherical tile, and determine that the spherical tile channel is damaged.
After measuring that the plane gap on both sides of the crack on the tile surface is between 0.06~ 0.1mm, which will not have a great influence on the stress of the copper tile, we decide to adopt the following solution to repair: first, we use mechanical fixation to prevent the further development of the crack;Secondly, apply special metal repair agent for crack sealing;Finally, the surface of the spherical tile was leveled with a surface modifier.
2. Emergency treatment scheme for cracking of spherical tile of rotary kiln
(1) clean the grease inside and on the surface of the spherical tile.
(2) respectively in 2 ~ 3 mm distance at both ends of crack open Φ check in 6 mm, depth is equal to the spherical channel wall thickness of 50 mm.
(3) machining v-shaped groove with width of 20 mm and depth of 30 mm along both sides of the crack and dehasting.
(4) nine oval grooves with length, width and depth of 120 mm×30 mm×20 mm were processed in the vertical direction of the surface of the spherical tile and the crack, with an interval of about 110 mm. Two M16 threaded holes were processed on both sides of the groove.
(5) make 9 pieces of 120mm × 30mm joint plates with Q235B steel plate = 16mm, and drill the step countersunk holes at both ends to correspond to the threaded holes in the square groove.
(6) use M16× 50mm inner hexagon bolt (grade 10.9) to process the inclination and install the connecting plate in the square groove, so as to tighten the spherical tile on both sides of the crack and avoid the further development of the crack.
(7) after the cracks are cleaned with cleaning agent, apply special glue to plug the micro-cracks, then use special metal repair agent to fill and level the cracks, and use electric heating to dry and keep the heat.
(8) after the repair is completely solidified, the spherical tile shall be subjected to water course cleaning and pressure test at a pressure of 0.3 MPa (50% of the standard test pressure) and pressure retention for 15 min.
(9) grinding test was carried out after the bearing bush and spherical bush were reassembled. Due to the bearing bush's strain and certain deformation after the spherical bush's crack, the contact point between the bearing bush and the shaft in the area of 30 mm×30 mm was only 1~2 points. The contact point was less difficult to scrape and grind.
After the reloading was completed, the feeding operation was carried out, and the feeding amount was steadily increased from 260 t/h to 530 t/h. The watt temperature was normal and basically maintained at about 30 ℃, and no leakage was found.In the subsequent operation process, in order to extend the service time of the watt, keep the feeding amount at about 90% of the rated capacity, and successfully persist until the shutdown for maintenance.