Problems and solutions in the operation of the hot

2022-09-23
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Problems and solutions in the operation of rotary brush grate trash cleaning machine

1 circulating water system and trash cleaning machine

the circulating water system of our plant is a pool type (reservoir) direct water supply system. The circulating water passes through five Yuanjiang 48 pumps in the riverside pump house, raising the river water by about 40 m from Zijiang River to the intake open channel (the total length of the open channel is about 4km), and flows through the reservoir to the relay pump house. The circulating water of No.1 ~ 4 generating units passes through No.1 ~ 4 trash cleaning machines, and then is boosted and supplied by No.1 ~ 4 relay circulating water pumps. Therefore, the circulating water system has long process and high lift, and the open channel absorbs more domestic waste, with poor water quality

the trash remover is a zsb-3500 rotary brush grate trash remover produced by Yunnan electric power repair and manufacturing plant. The power of the motor is 5.5 kW, the overflow width is 3.5 m, the vertical height is 11 m, and the total length of a single chain is about 22 M. the chain material is A3 steel, and the pin shaft is 30 steel. The lower sprocket is a cantilever support, which is connected with the support of the trash remover with 4 M20 bolts. The bottom of the trash cleaning machine is about 10 m lower than the water surface. Due to the actual site and design reasons, there is no water inlet valve in front of the trash cleaning machine, but only a water inlet ram

zsb-3500 rotary brush grate trash remover relies on a motor with a power of 5.5 kW to drive the driving wheel of the trash remover through the shear pin clutch, and the driving wheel rotates with the upper sprocket, so as to drive the chain and rotary brush to rotate to remove debris from the plate

the trash cleaning machine is equipped with a set of overload protection device, namely, the shear pin clutch. The shear pin clutch is the protective device of the whole transmission system. When the trash cleaning machine exceeds the allowable load, the shear pin is cut off, and the motor is separated from the transmission wheel, so as to ensure the safe operation of the trash cleaning machine

2 even some socks can't be cut with sharp scissors. Problems and reasons existing in the operation of the trash cleaning machine

since the trash cleaning machine in the relay pump room was put into operation in 1989, there are the following main problems that must be stopped after it has stopped

a. the chain of the trash cleaning machine is blocked

the reasons for the chain blocking are: ① poor water quality, many sundries, and coarse sundries, which cause the rotary brush roller to be blocked and unable to run. ② The chain is too long and swings too much, causing the rotary brush roller to separate from the channel and get stuck

once the trash cleaning machine is stuck, the generator unit must be stopped, the ram must be lowered and the diver should be asked to plug the leak, drain the water in the trash cleaning machine, remove the sundries and eliminate the defects before resuming the operation, which has a serious impact on the production and operation

b. dirt remover plate blockage

dirt remover plate hole is 3.5 mm × The 53 mm rectangle, when starting the relay circulating water pump, increases the flow rate through the trash remover, and correspondingly increases the adhesion of debris on the board. The specific reasons for the blocking of the board are: ① the circulating water quality of our plant is poor, the process is long, and the open channel is also long. The circulating water absorbs a lot of domestic garbage and debris, among which the adhesion of plastic film and straw is the strongest, and it is difficult to remove it by rotating brush. ② Our plant is a pool type (reservoir) direct water supply system. A large number of camphor trees are planted around the reservoir. When camphor trees change their leaves in April and may every year, a large number of camphor tree leaves enter the reservoir and flow into the circulating water system, causing blockage of the board. ③ The bristle material of the rotary brush is nylon. The rotary brush naturally bends after running for a period of time, and the cleaning effect decreases

c. chain breaking

due to the heavy operating load and poor operating environment of the trash remover, the chain is very easy to be corroded and worn. In addition, the trash remover has high vertical height, large span and large impact force by water. The chain will be blocked and broken in case of slightly large debris. Another reason why the chain is easy to break is that when the shear pin is cut under overload, the debris of the shear pin is easy to bite with the clutch and lose the protective mechanism. It depends on four M20 bolts to connect with the support. During operation, the bolts are easy to loosen under the impact load. Under the repeated action of the impact load, the bolts are cut under the shear force, causing the chain to be stuck or even broken

3 solutions

through the analysis of the existing problems of the trash cleaning machine, the crux of the problem was found, and the following measures were taken

a. strengthen the inspection of the equipment, timely find and adjust the length of the chain, and avoid the accident that the brush roller disengages from the channel due to the wear and corrosion of the upper and lower sprockets and chain pin shafts

b. in view of the problem that the plate hole is easy to be blocked, the original equipment is reformed and the transmission system is equipped with a forward and reverse device. After the installation of positive and negative rotation, the equipment can be removed from the, enhancing the ability of impurity removal

c. change the chain material. Change the material of chain plate and pin sleeve to 1Cr13, and the material of pin shaft to 2Cr13. It increases the strength and corrosion resistance of the chain and reduces the possibility of breaking the chain. For the shear pin clutch, the method of increasing the clearance of the clutch contact surface is adopted to eliminate the debris of the shear pin and reduce the clutch seizure

d. weld the four M20 fastening bolts of the lower sprocket to prevent loosening. For the cantilever support of the lower liquid crystal polymer, which refers to the high molecular material sprocket that can form a liquid crystalline state under certain conditions, a supporting steel pipe is added between the two lower sprockets, and the two ends of the steel pipe are connected with the lower sprockets at both ends with bolts, which increases the strength and rigidity of the lower sprocket according to BASF

4 operation effect and existing problems after the transformation

through the analysis of the problems existing in the trash cleaning machine, the above transformation was carried out on the zsb-3500 rotary brush grate trash cleaning machine from 1993 to 1996. Through more than 2 years of operation, the normal operation of the trash cleaning machine and the safe and effective removal of debris were basically guaranteed, the circulating water quality of our plant was improved, the safe and stable operation of the generator unit was ensured, and the economic benefits were improved

however, after the transformation, the support rod of the driven wheel chain is easy to loosen during the cross operation of the trash cleaning machine in the forward and reverse directions, so it should be checked and tightened frequently during operation. The rigidity of the nylon brush head of the rotary brush is still not enough. It is suggested that the manufacturer can appropriately add some thin steel wires to the nylon brush to increase the rigidity

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