In view of the low efficiency and high labor intensity of replacing the traditional heavy duty apron feeder chain plate devices one by one, we adopted measures such as setting up slipway platform to improve the maintenance site, pre-assembling the chain rail and chain plate in non-maintenance time, and carried out the overall replacement, which significantly improved the replacement efficiency, reduced the labor intensity of employees, and reduced the downtime of the sintering machine by more than half. The output of sintering machine is increased.
Heavy duty apron feeder is one of the important equipment in sinter transportation, its main function is to evenly transport the sinter cooling ore (≤150℃) from the outlet of the blast ring cooler to the belt conveyor. The equipment is installed in the lower part of the discharge funnel of -1.6m ring cooler, located in the ring tunnel of the discharge car of ring cooler, the working space is narrow, surrounded by dust removal pipes and bulk hopper. When the maintenance and replacement of the chain plate device is stopped, it can only accommodate 4 to 6 people to operate, which is inconvenient for replacement, long working time, low replacement efficiency, and high labor intensity. To this end, by improving the maintenance site, using the non-maintenance time to assemble the chain rail and the chain plate in advance, the whole replacement, forming a rapid replacement scheme of the chain plate device, significantly improving the replacement efficiency.
2 Structural characteristics and traditional replacement scheme
Heavy-duty apron feeder is mainly composed of electric motor, three-ring reducer, open gear, head sprocket, tail sprocket, chain plate device, roller, tail tensioning device, etc. The chain plate device is composed of chain rail, chain plate and bolt. The chain rail is composed of a number of chain links with a pin shaft connected to each other, hung on the head and tail sprocket, and the chain plate is fixed on the two chain rails with connection bolts.
Due to the small maintenance space of heavy apron feeder, few operators, and the weight of a single apron plate is about 200kg, the method of disassembling and installing a single apron plate one by one is generally adopted. At the end of the heavy apron feeder, cut the connecting bolts between the chain plate and the chain rail, use the hand hoist to remove the old chain plate one by one and flip it, and then transfer the new chain plate to the heavy apron feeder for piece-by-piece assembly. This method requires about 6 people, according to the calculation of 8h per person per day, it takes 5~7d to replace all the chain plate devices to complete, and the replacement efficiency is low, resulting in a long downtime of the sintering machine maintenance, and the labor intensity of the staff.
3. Quick replacement plan and implementation process
3.1 Quick replacement solution Using non-maintenance time, the chain rail and chain plate are pre-assembled to form a complete chain plate device, and the slipway platform is set up between the 0m platform and the heavy apron feeder tail. During maintenance, remove the old chain plate from the tail, connect one end with the tractor, pull out the whole through the slipway platform, and also pull the whole assembled chain plate device into the reverse. 3.2 Implementation Process
3.2.1 Preparation In advance Use the non-maintenance time to prepare for the assembly of the new chain plate device, the erection of the slide platform, and the positioning of the hoist. The details are as follows:
1) New chain plate device assembly. In advance, a single new chain plate and chain rail are assembled on the 0m platform outside the ring cooler to form a complete chain plate device. At the same time, the connecting pins are lubricated with lubricating oil.
2) Slipway platform erection. Remove the obstacles such as dust removal pipes and bulk hopper that hinder the construction, and set up the slipway platform with channel steel. In order to reduce the friction of the slide, a number of rollers are installed on the slide, and the width of the slide platform is not less than 70% of the width of the feeding trough. One end of the slide platform is connected to the tail of the heavy apron feeder, and the other end is connected to the 0m platform outside the ring cooler.
3) Hoist positioning. Install and fix the hoist on the 0m platform outside the ring cold, and the hoist center is consistent with the heavy apron feeder center.
3.2.2 Removing the old apron feeder In order to facilitate the removal of the old apron feeder, adjust the lead screw of the heavy apron feeder tensioning device so that the tensioning device is in the minimum position of the travel. Cut the old chain plate device from the lower part of the center line of the tail wheel of the heavy apron feeder with gas cutting, and then connect the old chain plate device with the steel wire rope of the hoist, and start the hoist to pull the old chain plate device along the made slide platform as a whole. In order to ensure the smooth pulling out of the old chain plate device, turn on the heavy apron feeder motor during the traction process, always pay attention to whether the chain plate runs off, ensure that the chain plate device and the end sprocket are normal, if there is a deviation, timely adjustment.
3.2.3 Installing new Chain plate device Lift the assembled new chain plate device onto the slipway platform with a car crane. Connect the hoisting steel wire rope from the bottom of the heavy apron feeder around the head wheel to the new chain plate device, start the hoisting machine and pull the new chain plate device into the whole along the slipway. Until the new chain plate device is pulled to the end of the heavy apron feeder tail wheel position, and the chain plate is buttoned with a pin. In order to facilitate traction, turn on the heavy apron feeder motor during traction, check whether the new chain plate device runs out of alignment at any time, ensure that the chain plate and the head and tail sprockets fit normally, and adjust in time if there is deviation