As the modernization of cities continues to advance, the demand for concrete is increasing day by day, and concrete mixing plants, the equipment for concrete production, are becoming more and more popular in major projects. This article, combined with the guidance given by NFLG technical engineers, summarizes several common failures and methods of handling concrete mixing plant equipment, so that practitioners can solve problems in a timely manner when they encounter unexpected situations and minimize the bad impression caused by equipment problems to enterprises.
Mixing plant equipment
Common failure phenomenon:
1. poor operation of the discharge door;
2. Mixer bogging and tripping;
3. Mixer noise, caused by the mixer host can not operate normally, directly affecting the efficiency of the mixer.
1. Replace the proximity switch of the same type. Hydraulic unit: lack of hydraulic oil in the hydraulic station, replenish the hydraulic oil and adjust the pressure; check the discharge door around the accumulation of material, should be cleaned up in time.
2. Adjust the drive belt tension in time; adjust the stirring knife gap in time, and replace the stirring knife if necessary; there should be an emergency treatment plan.
3. Timely check whether the protective cover is loose and the bearing has any problem; check whether there is lubricant to follow up; whether the protective ring A/B has friction.
Aggregate conveying equipment
Common fault phenomenon:
Belt machine no-load or load running process, the phenomenon of deflection running or slipping when the belt is running under load, caused by the leakage of materials, abnormal wear and tear of equipment, reduce the efficiency of commercial concrete mixing plant.
1. Adjust the tensioning mechanism method: It is applicable to the belt running, if the belt is running in the same direction or the belt is running left and right without fixed direction, it means the belt is loose or the tensioning degree of both sides of the belt is different, so the tensioning mechanism of the belt should be adjusted to make it run normally.
2. Adjust the roller method: It is applicable to the belt deviating at the active roller, which means that the installation of the active roller is not level or different from the vertical width of the belt, and the level and parallelism of the active roller should be adjusted.
3. Adjust the bracket support method: It is suitable for the belt to run to one side when it is unloaded. The bracket of the roller near the belt run should be adjusted forward by 1~2cm along the belt running direction, or the bracket of the roller on the other side should be raised by 0.5~1cm, and the rack at the belt run should be raised appropriately.
4. Removal of attachment method: It applies to the belt after running for a period of time, due to sand, stone and other attachments attached to the surface of the drum, making the diameter of the drum increase, resulting in the uneven force, making the belt run off, should be promptly cleaned up the attachments.
5. Adjustment of belt method: If the belt edge is seriously worn, or the seam is not parallel after bonding, it will make the tension on both sides of the belt uneven, and should be repaired or replaced in time.
6. Install centering rollers and limit rollers: Installing several groups of automatic centering rollers (flat rollers or slot rollers) can automatically correct the belt deflection phenomenon; increasing limit rollers can be installed at the rack at the belt deflection, which can make the belt forced to reset.
7. Increase the friction force.
Aggregate batching equipment
Common fault phenomenon:
The pneumatic door of batching machine is not closed tightly or cannot be opened.
Check the pneumatic door gap and adjust it to a reasonable range. If the gap is too large caused by wear and tear, it is necessary to add welding steel plate or round steel at the outlet to make the gap reach reasonable value. If it is a foreign object stuck into the discharge port, it should be cleaned up in time (pay attention to safety), and check whether the filter in the storage bin is broken and repaired in time.
Powder storage, conveying equipment
Common failure phenomenon:
1. Screw conveyor loading slowly or not loading, feeding time more than two minutes.
2. In the process of bulk cement truck pumping ash to the powder bin, there is powder coming out from the top of the powder bin.
1. Open the arch-breaking device of the powder bin and check whether there are lumps at the outlet of the powder bin to be cleared in time.
2. Check the opening angle of the powder bin discharge butterfly valve and open it to a reasonable position to ensure the smooth discharge.
3. Check whether the blade of screw conveyor is deformed, if deformed, it needs to be removed and corrected or replaced.
4. Check the condition of dust collector cartridge on the top of powder bin and clean it up.
5. If there is ash on the top of the powder bin, clean up the material around the safety valve on the top of the powder bin, and check the reliability of the upper level meter and the material full alarm device.
Water circuit, additive equipment
Common failure phenomena:
Pump can not start normally, pump does not produce water or insufficient flow, pump vibration and noise.
1. In the case of turning off the power, hand poke the motor cooling fan is flexible, if it does not turn, it may be the rotor is stuck, after removing foreign objects to add lubricating grease.
2. If the pump does not produce water, it may be that the motor’s steering is reversed, at this time should immediately stop, switch any two phases of the three-phase power supply, the pump can be made to change the direction of rotation.
3. The centrifugal pump does not produce water after rotation. If the rotation is normal but no water comes out, the possible reasons are: the inlet is blocked by debris, it should be cleared and filtering device should be installed; air leakage from the inlet pipe or instrument may be caused by air leakage from the welding seam, sand eye or crack in the pipe, poor sealing of the gasket at the joint, etc.
4. The sound is abnormal or the vibration is too large. The reasons may be: impeller balance is not calibrated, should be corrected immediately; pump shaft and motor shaft are not centered, should be corrected; pump inhalation foreign matter, blockage or damage to the impeller, should be stopped to clean.
The air circuit equipment
Common failure phenomena:
Air compressor failure, pressure reducing valve failure, pipeline failure, compressed air handling components, accessories failure and air source actuators failure, etc.
1. When the air compressor is running, the pressure rises slowly, which may be caused by the damaged inlet valve, blocked air filter or broken regulating spring or ruptured diaphragm, and should be replaced in time.
2. The air leakage phenomenon is judged from the sound of air leakage, check the pipe joint, air pipe, compressed air handling components and executive parts, and replace them in time.
3. Pneumatic triplex dripping oil is very small, may be the oil volume adjustment valve blockage, seal damage or oil viscosity is too large, should clean up the device channel, replace the seal and lower viscosity of the lubricant.
4. Pneumatic actuator (cylinder) output force is insufficient, unstable action, may be the oil supply, seal damage, timely inspection of the lubricant path and replacement of components.
The above is the summary of NFLG for you about the concrete mixing plant equipment several common failures and handling methods, I hope it can play a positive role in the future of the actual production.