Coal grinding pinion run of the cause of the accident and handling measures

Run coal grinding pinion set of 2020 - the cause of the accident and handling measures 11 - 07 Zhao Xiaozeng ( Dalian tianrui cement co. , LTD. ) A company MFB wind swept coal mill put into operation in May 2010, has been running normally. At the end of December 2015, after the big gear and small gear over overhaul once a fixed end bearing temperature rise is unusual, for failing to accurately determine the cause of the malfunction in time and accurate position of the failure, eventually run pinion set of accidents. Regarding the fault processing of summary, for the colleague reference. A, the cause of the problem in the end of December 2015 equipment overhaul, because of the coal mill big gear and small gear face wear heavier, need to change. Considering the spare parts cost is higher and the purchasing cycle is long, eventually take over continue to use the maintenance plan, the outsourcing unit is responsible for the construction. After the completion of the end of March 2016 overhaul, the empty load and full load trial run, the various parameters are normal. In early April 2016 but returned to normal production after a week or so, small gear fixed end bearing abnormal temperature and vibration time, therefore, the company organization maintenance personnel to the transmission parts of the equipment and the anchor bolt, bearing clearance, bearing grease lubrication condition, temperature measurement system for inspection, in addition to the pinion free end and the anchor bolt looseness slightly outside of the bearing, the rest parts are normal. After all loose anchor bolt fastening, equipment operation parameters and back to normal again. Is there a few times during the bearing temperature and vibration anomalies, but caused no downtime, did not cause the attention of the relevant management personnel. Jada until September 17, on-site inspection discovered coal grinding large gear ring cover by small teeth fixed end bearing sparks and emergency stop. After the accident, the on-site inspection, found that small bulge on either side of the gear set of locking bolt looseness has fully, free end side expansion set of outer ring fracture, fracture fixed inside the end side of the locking ring, oil baffle ring injury, on both sides of the pinion set of serious, coal mill have been unable to run normally, as shown in figure 1. Figure 1 pinion set the scene photos as, the coal grinding pinion USES is Z2 bulging tight connection sleeves, D = 380 mm diameter dX diameter & times; 475 mm, gear inner hole tolerance & Phi; 475H80+0. 097, the surface roughness Ra3. 2, both ends of the gear inner hole coaxial degree level 6. After the disintegration of measuring found that gear free end of the inner hole size of 476. 26 mm, fixed end inner hole size of 475. 18 mm, size are out-of-tolerance slants big, assortments of sets have been unable to live on both sides of the pinion. It is important to note that after the collapse of gear on both sides of the inner hole were not obvious traces of friction damage, this shows that in the end of December 2015 equipment overhaul, the pinion to turn over face, in the process of gear inner hole size out-of-tolerance, have maintenance personnel did not detect size, failed to find a major threat and direct to assemble, the bolt tightening process is not in accordance with the relevant technical requirements and screw down the steps to tighten. Equipment in the process of running, the big gear and small gear relative sliding friction causes pinion appear, finally gear and ring gear cover cut ceng, sparks, caused the accident. Second, the treatment measures after the cause of the accident to find, take the following remedies: ( 1) Will be Kong Xian on both sides of the gear processing to 478 mm, and then repair welding process, in strict accordance with the size & Phi; 475H80+0. 097, the surface roughness Ra3. 2, both ends of the gear inner hole alignment control level 6. ( 2) Purchasing a new Z2 - 380× 475 bulging tight connection sleeves. ( 3) According to the installation requirements and bolt locking screw down the steps for installation and bolts. ( 4) On both sides of the retaining ring and the sealing end cover, the original cylindrical structure into a semicircle split structure, all will be in the outer surface of the oil ring and seal end cover inner surface for processing, make sure the allow sufficient clearance. After the completion of the three, fault alarm processing, coal grinding on normal operation. This accident is a reminder that in equipment maintenance, related maintenance personnel do not cut corners, paralysis, and must be strictly in accordance with the requirements for equipment related technical files and test construction, ensure compliance with technical requirements in order to boot, or the devil. Source: 'China cement' 10, 2018