Composition system and fault handling of mixing plant

The importance of fault detection and handling in mixing plants. In the process of modern construction engineering, a large amount of concrete is required. The use of concrete can effectively improve the strength of buildings and extend their service life. In the process of concrete construction, using a concrete mixing plant to mix concrete can effectively accelerate the construction progress of the project and optimize the construction process. With the continuous development and progress of the construction industry, its requirements for concrete are also increasing, requiring professional mixing plant equipment for mixing; Once equipment failure occurs in a concrete mixing plant, it will affect the mixing of concrete. Therefore, it is very important to carry out corresponding equipment failure inspection and handling.
Operation System of Mixing Plant Equipment: A concrete mixing plant is composed of multiple different systems, each of which is responsible for a different part during operation. Any problem with one system can lead to problems with the entire concrete mixing plant. During the operation of the mixing plant, cement and aggregate need to be proportioned according to the designed mix ratio, and then subjected to centralized mixing. Concrete mixing plants have a series of characteristics such as high automation and uniform mixing during operation.
The mixing plant is mainly composed of the following different systems:
2.1 Mixing system
The mixing system of the mixing plant mainly consists of a mixing host, a support frame, and a lubrication mechanism. In general construction concrete mixing plants, there are two different forms of mixing machines, one is forced type and the other is self falling type. The mixing tank of the mixing host is welded from steel and equipped with wear-resistant lining plates inside to ensure its long-term use. Mixing machinery uses motors to drive the mixing shaft, thereby achieving internal concrete mixing. After completing the mixing of concrete, it is necessary to unload the mixed concrete in a timely manner and not leave it in the mixer for a long time.
2.2 Aggregate Supply and Storage System
The aggregate supply and storage system is mainly used for transporting and storing aggregates. The transportation system is used to transport concrete materials to the measuring area, and after completing the measurement, they are transported to the mixing silo for mixing. The storage system is mainly used to preserve the aggregates that have not yet been mixed to prevent them from deteriorating.
2.3 Cement Supply and Storage System
The cement supply and storage system mainly includes three parts: cement storage hopper, conveying equipment, and cement silo. During operation, its basic process is basically the same as that of the aggregate supply and transportation system.
2.4 Ingredient system
The batching system mainly includes control devices, weighing equipment, and batching equipment. It is mainly responsible for batching concrete according to the designed mix proportion, ensuring that the proportions of various materials used to make up the concrete match the mix composition.
2.5 Integrated Control System
The integrated control system is the core part of the concrete mixing plant, which directly controls the operation of other systems in the concrete mixing plant. Through the integrated control system, the management and control of the entire concrete mixing plant can be achieved. Generally speaking, a concrete mixing plant consists of two different parts: a pneumatic system and an electrical control system. The electrical control system is mainly controlled by computers and processes the concrete production and feeding process of the mixing plant through relevant production programs, achieving automatic operation of the concrete mixing plant.

Common equipment malfunctions and their solutions
3.1 Electrical system faults and troubleshooting methods
For some large concrete mixing plants, PLC control systems are used as the basis for overall control. During their operation, especially in harsh environments, various electrical failures are easily caused by external factors, which can affect the operation of the concrete mixing plant. During the operation of a concrete mixing plant, some sensing devices may experience interference from the working environment, which can affect the accuracy of information collection and result in inaccurate information, leading to various information failures. To avoid this problem, it is necessary to seal the circuit boards in the system with a sealed box to prevent dust and moisture from affecting signal acquisition and ensure the accuracy of its information collection function. Different sensors should be measured in different ways. Generally speaking, for compaction sensors, if abnormal data is found in the instrument panel of the PLC control system, voltage detection and sensor resistance measurement methods can be used to detect the sensor and determine whether there is a problem. For electromagnetic directional valves, their operating mode can be manually controlled to determine whether they can perform directional changes, and then the voltage value can be checked using a multimeter to ensure that it is within the rated range of the electromagnetic directional valve. For pneumatic control valves, considering the presence of a large amount of water vapor in the circuit, icing is prone to occur under low temperature conditions. Therefore, heating the air circuit can be used to ensure the stable operation of the control valve. In the process of conducting electrical component testing, in order to ensure the accuracy and reliability of the testing results, it is often necessary to replace the original components to test the components. Therefore, it is necessary to prepare an appropriate amount of components in advance during the detection process for timely replacement.
3.2 Common faults and troubleshooting methods of horizontal inclined belt conveyor
The horizontal inclined belt of the concrete mixing plant is mainly used for material transportation, ensuring that the materials can be delivered to the corresponding positions in a timely manner, which directly affects the normal operation of the mixing plant.
In practical use, horizontal inclined belt conveyors often encounter the following faults:
3.2.1 Belt deviation. When the belt deviates, it can be solved by adjusting the corresponding position of the roller group, or by adjusting the position of the reversing drum.
3.2.2 Belt conveyor for material withdrawal. Generally, the occurrence of this problem is mostly due to the aging or damage of the rubber skirt board. To solve this problem, adjusting the degree of belt deviation can effectively solve it.
3.2.3 Belt slippage. If there is a phenomenon of belt slippage, the load can be increased appropriately, the tension of the belt can be adjusted, and the degree of rubber wear of the drum motor drum can be checked.
3.3 Common faults and troubleshooting methods of pneumatic system
The air compressor, gate valve, air source processing three components, electromagnetic directional valve, pipeline and joint together form the air circuit system. For the HZS120 concrete mixing plant, its air circuit system is divided into two parts, one for the main part and the other for the batching system.
The common faults include:
3.3.1 Air source failure.
During the operation of the mixing plant, if the internal pressure rise is too low, it will cause the pressure reducing valve to malfunction. When such a malfunction occurs, it is necessary to replace the pressure regulating spring with a new one and thoroughly clean the filter screen. During the operation of the system, if the hose joint is not tightly connected, it is easy to cause leakage of the joint, leading to the occurrence of faults. The maintenance personnel should identify the specific location of the leakage, clean the leaked area, remove condensed water from the pipeline, and promptly repair it to ensure a tight connection. In the pneumatic system, once the oil-water separator or oil mist device malfunctions, it will cause problems in the operation of the compressed air treatment components. In this case, it is necessary to conduct separate inspections for each component, first cleaning the filter element, then removing impurities from the sewage collector, and replacing the pressure regulating spring. The entire pneumatic system should be thoroughly cleaned and inspected to ensure its overall stable operation.
3.3.2 Pneumatic actuator failure.
Improper assembly or long-term use of cylinders can cause internal and external leakage of pneumatic actuators, as well as insufficient output force, unstable operation, poor buffering effect, and cylinder head damage. Exclusion method: Once there is leakage inside and outside the cylinder, the center of the piston rod should be adjusted to ensure the coaxiality between the piston rod and the cylinder barrel; Regularly check the reliability of cylinder operation, replace worn piston rings and sealing rings in a timely manner, remove impurities in the cylinder in a timely manner, and replace damaged piston rods in a timely manner. When the output force of the cylinder is insufficient or the action is unstable, adjust the center of the piston rod, check for blockages in the gas supply pipeline, and promptly remove condensed water and impurities from the cylinder. When the buffering effect of the cylinder is not good, replace the worn sealing ring in a timely manner and replace the damaged screws. When the cylinder piston rod or cylinder head is damaged, adjust the center position of the piston rod, adjust the screw, and replace the buffer seal ring in a timely manner.
3.4 Common faults and troubleshooting methods of mixing system
The mixing system is a very important part of the operation of a concrete mixing plant. During operation, it drives the overall tank body and mixing device to rotate through the mixing rotating device. In this process, the feeding device and unloading device will achieve the mixing and transportation of concrete, ensuring real-time and efficient mixing. During the operation of the mixing system in a concrete mixing plant, one of the common faults is the phenomenon of stuck trucks on site. The reasons for this phenomenon are as follows: the control unit inside the mixing system malfunctions, leading to the failure of the operating system; The transmission device has malfunctioned, causing problems in the transmission system; The operator made incorrect operations during the operation process; The voltage of the mixing system is too low during operation; The mix proportion of concrete was not well controlled during mixing, and the mix setting was unreasonable; The amount of material added during the feeding process exceeds the rated value. In the process of dealing with the phenomenon of stuffiness in concrete mixing plants, relevant operators must promptly detect the residual aggregate content in the machine to ensure that it is less than 5%. And it is necessary to check the gap between the mixing blades and the drum to ensure that the gap size between the blades and the inner wall of the drum is appropriate. If the gap is found to be too large, it can be solved by replacing the blades or lining.

Composition system and fault handling of mixing plant

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