Accident analysis of the safety pin of the hottest

Analysis of the accident that the safety pin of the trash remover is cut off many times

the rotary grille trash remover is a special water treatment equipment for the physical treatment process in the early pretreatment stage of the sewage treatment plant. The main function is to take out the solid floating matter and large particles in the sewage sent to the sewage treatment plant by intercepting, lifting, transporting and stacking through the rotation of the rotary grille. At present, most sewage treatment plants use rotary grid trash removers (hereinafter referred to as rotary grids), accounting for about 50% - 60% of the total installed capacity

1. Transmission structure

through the motor and reducer, the main shaft of the rotary grid is driven by the sprocket chain, and then the closed rotary traction chain on the rotary grid is driven to operate by a pair of large sprockets on the main shaft. There are several rake teeth on the traction chain, which fish out, lift, transport and accumulate the solid floating objects and large particles in the sewage. There is a pair of safety pins at the connection between the reducer output shaft and the sprocket of the rotary grille. When the rotary grille encounters large floating objects or large particles such as sticks, the safety pin is cut off to protect the equipment

from the preparation of aluminum alloy melt to hot rolling to the coil for cold rolling, it is shortened from 20d to 20min2 Fault phenomenon

after the machine operated normally for several days, the operator reported that the rotary grille was shut down, and a pair of safety pins were cut off after inspection. At that time, it was in the trial operation stage, and no large floating objects or large particles and sticks were found in the sewage. Almost every power supply department used sundries, and no abnormal phenomena such as jamming were found. After replacing the safety pin, the rotary grille can operate normally. Since then, the safety pin has been cut off several times in succession, and no abnormality has been found. Among the three devices of the same model, only this one fails

3. Check

carry out a detailed inspection of all transmission parts, and no problems are found. Through long-term observation on site, it is found that the traction chain on one side of a pair of traction chains vibrates slightly every time it turns to a fixed position. The traction chain on this side is obviously a little loose, and the chain plate and chain plate squeeze each other, causing jamming. According to the inspection, the welding of the connection between the straight rail and the arc rail of the chain rail is slightly defective, but it is not obvious

4. Solution

tighten and adjust the obviously loose side of the traction chain, and tighten the traction chain. The financing range of most enterprises is between 5million and 50million yuan; Repair and polish the welding defects at the connection between the straight rail and the arc rail on the chain rail. Start up and run, and eliminate the fault

the safety pin of the rotary grille has been cut off for many times, and the main reason for the failure is that the traction chain on one side is obviously loose and the chain rail is slightly defective. The direct cause of the fault is the poor machining accuracy of some sections of the traction chain, which causes the extrusion between the chain plate and the chain plate, and the jamming occurs during rotation. Cause the safety pin to cut off