The quality of concrete production is very critical, in which the equipment can be normal operation of its impact on the quality of a great impact. In order to improve the production efficiency of the equipment and reduce the probability of failure during the operation of the equipment, it is necessary to analyze and deal with the common faults in the concrete mixing building. Based on this, the article analyzes the common faults of the concrete mixing building and puts forward the countermeasures.
In the production process of concrete, the most important production system is the concrete mixing building, mixing room mainly by the feeding system, weighing system, mixing host and control system composed of four parts. The normal operation of each system in the mixing building is very important to ensure the quality of concrete production. In the actual production process, due to various factors, the concrete mixing building is often in the process of running Some failures, the occurrence of these failures will have a greater impact on the quality of concrete, making it difficult to meet the requirements of engineering construction, resulting in more serious economic losses, the concrete mixing tower in the common causes of failure and treatment measures Simple analysis has a positive effect on ensuring the continued production and quality of concrete.
Fault Analysis and Treatment of Mixer
Mixer is a very important equipment in a concrete mixing building. If there is an abnormal sound or condition during the course of its work, the cause of the mixing is likely to be the overload of the mixer, which is affected during the working process. The value of the instantaneous load exceeds its bearing range, resulting in a fixed bearing on the shaft end of the mixer or a fixed bearing of the drive motor that is damaged during the course of the work. The reason is usually overloaded by over-loading or inaccurate weighing. To perform a reset process or to replace, and to calibrate the weighing system. The blade has a large foreign body, the blade or end scraper and the tank wall gap is too large, the mixer is internal protection board, the blade or the arm appears to fall off or damage phenomenon, it is easy to lead to The phenomenon of uneven mixing occurs, then need to manually exclude foreign matter and re-adjust the gap or replacement parts. Mixer leakage slurry, mixer shaft seal ring or outlet liner liner wear caused by the shaft end of the leakage is mainly sealed ring seal oil can not be normal injection or a long time did not adjust the seal ring, the slurry caused by the loss of concrete water-cement ratio, Directly affect the quality of concrete. Concrete mixing uneven, another reason, mixer. Mixer equipment gear box temperature is too high, the oil viscosity is too high or too low, then need to release the oil, add new oil, bearing damage, then need to change the new bearings.
Fault Analysis and Treatment of Hoist for Lifting Feeding System
2.1 Analysis of common faults of roller and wire rope
The hopper in the lifting process in the process of lifting the sudden emergence of the phenomenon of derailment, the fault site to check, if it is because the hopper wheel shaft reed or broken wheel wheel caused by the detachment, in the relevant parts of the maintenance and replacement, And the track between the lubrication and maintenance work is very necessary, the failure of the above, and the roller has a direct relationship between the improper maintenance of the roller running material up and down operation, the wheel wear, bearing damage, deformation of the track will lead to derailment And run up and down poor. Wire rope in the long-term operation of the process, prone to wear and tear, resulting in its safety performance is difficult to protect, which requires the work of the hoist in the process, do a good job of wire rope inspection and lubrication work, the unit cross- Real-time concern, once found that the number of broken wire to reach the retirement standard, should immediately implement the replacement of wire rope to ensure the safety of the hoist operation.
2.2 Analysis of common faults in lifting hopper
In the initial stage of installation and commissioning of the mixing plant, if the thermal relay, the control button and the lower limit switch connector of the equipment are shown to be working normally, and the lifting hopper can only be lifted, the contact of the AC contactor should be carried out Check, usually due to the hoisting of the hoisting action has a control role of the AC contactor of the normally closed contact caused by poor contact, it should be opened for maintenance. In addition, if the fuse in the equipment there is a fuse phenomenon, which will lead to the hopper is difficult to complete the rise and fall movements.
On the other hand, it is necessary to do the maintenance work of the hopper. It is very important to do the cleaning work of the hopper in the daily maintenance work of the hopper. If the material is placed in the hopper for a long time, it will condense in the hopper, The impact of the fit between the track and the pulley, easy to cause the pulley appears to be vacant phenomenon, the normal closure of the hopper door will be affected, to do the maintenance of the wheel assembly, the roller regularly on the operation and lubrication to check , Found abnormal should be taken in a timely manner to deal with the phenomenon of wear more serious wheel should be replaced in a timely manner to prevent the occurrence of security incidents.
2.3 Analysis and management of hoist operation control failure
If the hopper of the mixing plant descends to the bottom of the pit, it has not stopped, and the hopper is easily rushed to the top of the track under the operation of the hoist. Under the action of the circuit breaker, the hoist is running Can stop, this operation control the emergence of fault, easy to lead to wire rope, pulley, hoisting machine cap and other components of the damage, the cause of this failure to analyze the reasons, mainly due to the existence of a pit water A foreign body, at the bottom of the pit, will hold the hopper so that it can not make good contact with the lower stroke switch at the bottom of the track, which prevents the hoist from stopping at the specified point in time, and if the operator does not Found that the operation of the hoist abnormalities, and did not manually stop the hoist operation, it will lead to wire rope rewind, hopper recoil the phenomenon of operation. After such a failure, the lower limit switch should be replaced in time and the other parts damaged in the accident should be replaced, and the foreign matter in the pits will be cleared to allow the hoist to return to normal work.
3 Weighing system failure analysis and processing
Weighing system is very important in the concrete production process, its weighing accuracy directly affects the quality of concrete. The weighing system consists of sensors, meters and controls. The weight sensor is called the heart part of the weighing system, it is the weight into micro-power signal; instrument to send the micro-charge of the sensor to enlarge, processing and display; control in accordance with the set value and weighing the value of the material Intelligent automatic control, to achieve a fast and accurate weighing of the material. Weighing system in the actual use of the process of causing a lot of reasons for failure, and sometimes several failures may occur at the same time. There are such as power supply, external magnetic field interference, the use of electronic products such as cheating. Weighing system appears cyclical over-owe: the next door opening is too large, low pressure, fine value and super-oversized alarm set value is too large, the sensor is damaged, the amplifier is damaged, the scale by external force; After the weight of the weight down: butterfly valve closed lax, ventilated and dust pipe plug, scale bucket soft connection is too tight; weighing display weight instability: sensors, amplifiers, PLC ground is not good; sensor, amplifier damage; Or interference by the outside world; weighing the number is not accurate, check the bridge voltage is stable and normal (10 ~ 12V), the sensor is good, instrument amplifier is normal. Weighing fault for the sensor reasons, which is due to the sensor is working environment is not good, check the sensor is a simple way is: resistance measurement S1 \ S2 resistance 355¦¸, EXC1 \ EXC2-side resistance 385¦¸; voltage measurement S1 \ S2 terminal voltage 1.7 ~ 6.5mV, EXC1 \ EXC2 terminal voltage 10 ~ 12V; bridge must have a good insulation. Weighing system failure both inside the equipment itself, but also improper operation, imperfect procedures, not strictly in accordance with operating procedures, sensor maintenance and repair is not timely, the staff is not strong sense of responsibility, division of labor is not clear, the accident is not timely , Environmental factors, etc., should be based on the number of weighing system failure, as well as the extent of the impact of measurement, the cause of weighing system failure to consider the reasons for the failure.
4 control system fault analysis and processing
The control system is the performer in concrete production, and its execution determines whether the system is operating properly or not. Usually composed of computers, PLCs and actuators. Computer and PLC run less, mainly in the implementation of components. Contactor beating or buzzing: contactor magnetic circuit coupling is not good, open and then close the normal, power supply voltage instability; boot switch trip: mostly load coil short circuit; vibrator frequent trip: overload or Vibration force is too large, the circuit breaker current value is set too small, the vibrator motor is damaged; the ingredients warehouse door switch is difficult: the air supply system is insufficient pressure, adjusts the air pressure; The cylinder is moving, unloading the cylinder or replacing the sealing ring; the trachea is leaking or the trachea is clogged, and the valve is loose or the trachea is blocked. , Check the trachea and dredge to remove the trachea leakage; ingredients weighing accuracy decreased or not allowed: the valve for the slow, cylinder moving unloading, dosing mouth is too large, the sensor damage or linear decline; belt belt deviation: Roller bracket installation and the frame is not vertical, adjust the drum bracket, roller installation tilt, adjust the roller, additional baffle resistance serious imbalance, to improve the additional baffle resistance, the material parts have a greater unbalanced impact, The uneven position of the uneven, the tension is not uniform, adjust the tension device, the master and the drum from the position of improper adjustment, adjust the master and slave roller position, conveyor belt interface is not straight, re-bonding belt, bracket is not straight, Bracket coupling, the overall resistance of the belt by the imbalance, adjust the roller bracket and roller bracket to balance the resistance. This is a common operation to control the failure to solve these failures, the control system can play a normal role.
Concrete mixing building is a very important equipment system in concrete processing enterprises. Whether its normal work can have a direct effect on the quality of concrete and the economic benefits of concrete processing enterprises, this paper makes a simple analysis of common faults in concrete mixing buildings, And put forward the relevant treatment measures, for the concrete mixing tower of the normal, stable production has a positive effect.
From:mobile concrete mixing plant