To judge the wear degree of the lifting plates of a coal slime dryer, it is necessary to combine three dimensions: visual inspection, dimensional measurement, and operating conditions, and accurately classify the wear levels to determine the repair or replacement plan. The specific methods are as follows:
First, visual surface inspection. After shutting down the equipment and cooling it down, clean the material adhering to the plate surface and observe its surface condition:
- Mild wear: Characterized by uniform shallow scratches on the plate surface, intact and crack-free welds, and no overall deformation.
- Moderate wear: Presented as local depressions with a wear depth reaching 1/3 of the plate thickness, slight edge curling, and fine weld cracks with a length not exceeding 1/5 of the plate length.
- Severe wear: Accompanied by large-area deep pits, a wear depth exceeding 1/2 of the plate thickness, edge defects over 50 mm, weld cracks over 1/3 of the plate length, and even deformation or partial falling-off of the lifting plates.
Second, quantitative dimensional measurement. Use a caliper to measure the remaining thickness at the most severely worn part and compare it with the original thickness:
- Remaining thickness ≥ 2/3 of the original → Mild wear
- Remaining thickness ≤ 2/3 and ≥ 1/2 of the original → Moderate wear
- Remaining thickness ≤ 1/2 of the original → Severe wear
Meanwhile, measure the effective lifting height; if the height is reduced by more than 1/3, it is directly classified as moderate or above wear.
Third, auxiliary judgment based on operating conditions. If the drying efficiency decreases, the moisture content of the discharged materials fluctuates significantly, and material “sliding” occurs inside the cylinder, it indicates insufficient lifting capacity of the lifting plates. If metallic abnormal noises are detected during equipment operation and cylinder vibration intensifies, it is highly probable that the lifting plates are deformed or the welds are cracked, and the equipment must be shut down for inspection.
Based on the wear levels, the corresponding solutions are as follows: shorten the inspection cycle for mild wear; conduct weld overlaying repair for moderate wear; and replace the lifting plates immediately for severe wear.