Detailed Steps For Safe Operation Of Concrete Batching Plant!

(1) Mechanical Principles and Coordination in a Concrete Batching Plant

There exist mutual proportions and tolerances among machinery, guided by mechanical principles that are crucial for fully harnessing the capabilities of the equipment. The key to maximizing the production capacity of a concrete batching plant lies in its reasonable mechanical principles. A concrete batching plant is divided into four parts: aggregate feeding, powder material (cement, fly ash, expansive agent, etc.) feeding, water and admixture feeding, and transportation, mixing, and storage.

(2) Workflow Steps of the Batching Plant

1. After the mixer control system is powered on, it enters the human-machine interface for operation.
2. The system initializes, including setting the recipe number, concrete grade, slump, production volume, etc.
3. Each material bin and measuring hopper is inspected based on weight, outputting signals indicating whether they are empty or full, prompting the operator to decide whether to initiate the mixing control program.
4. The sand and stone belt motors are started to feed materials into the measuring hoppers.
5. The butterfly valves of the fly ash and cement silos are opened.
6. The screw conveyor motors are started to transport fly ash and cement to the measuring hoppers.
7. The control valves of the water tank and admixture tank are opened to allow water and admixtures to flow into the measuring hoppers.
8. Once the measurement meets the set requirements, the doors of the measuring hoppers are opened.
9. The ingredients enter the already started mixer for blending. After the set time, the mixer door opens, and the concrete is discharged into the waiting truck mixer. Each machine has a specific sequence of operation, and improper operation can lead to numerous issues.

The operation sequence of the concrete batching plant is particularly important. Improper operation can cause shutdowns, machine blockages, and other problems, leading to machine repairs and maintenance.

(3) Precautions for Operating the Concrete Batching Plant

1. Before starting up, inspect all components of the concrete batching plant, including lubricating with grease and oil. Also, check and open the water valve, start the water pump to prime it, open the air compressor, open the storage bin doors, start the discharge belt, start the mixing host, start the feeding belt, and start the ingredient feeding (including aggregates and cement), as well as open the water supply. These are the pre-startup inspections for the concrete batching plant.
2. The sequence of operations when starting the concrete batching plant: Ingredient feeding (including aggregates and cement) off, water supply off, feeding off (no material on the belt), mixing host off (no material in the mixer drum), discharge belt off (no material on the belt), storage bin doors closed, air compressor off, clean the mixing drum, close the water valve, and turn off the main power. These operation sequences are extremely important. Improper operation, such as turning off the mixing host while it is still mixing, can cause concrete to become stuck in the mixer drum.
3. Mixer operators must undergo training to understand the structural and performance characteristics of the mixing system, familiarize themselves with safety operations and technical specifications, be proficient in basic computer operations, have a basic understanding of concrete quality requirements and the main properties, specifications, and functions of raw materials, and pass practical assessments conducted by the superior company before they can operate the equipment.

(4) Preparations Before Operation

1. Ensure that there are no foreign objects stuck in the transmission and moving parts of the mixing drum and various auxiliary mechanisms, as well as in the bin doors, hopper doors, and tracks.
2. Check the oil level and quality of the gearbox, add oil if insufficient, and replace it if dirty.
3. The structural parts of the batching plant must be securely connected. The limiting devices and brakes must be sensitive and reliable.
4. The rubber sleeves connected to the weighing hoppers should not be subject to tension or pressure, as this may affect weighing accuracy.
5. The installation and winding of the steel wire ropes for the lifting bucket or dragline should be correct, and the steel wire ropes and pulleys should comply with regulations. The brakes for the lifting bucket and dragline should be sensitive and effective.
6. Each electrical device should effectively control the mechanical actions, and there should be no significant damage to the contact points and moving and stationary contacts.
7. Check the mechanical operation. Only after confirming that the mixing system is normal can automatic cyclic production commence. It is strictly prohibited to stop or start the machine under load.

(5) Precautions During Operation

1. After starting the machinery, carefully inspect its operation and check if the rotation direction of each rotating part matches the direction indicated by the arrow.
2. The mixer should not be stopped when it is fully loaded with material. In the event of a fault or power outage, immediately cut off the power supply, lock the switch box, clean the concrete out of the mixing drum, and then troubleshoot or wait for the power to be restored.
3. Stay focused during operation and observe each instrument, indicator, belt conveyor, and the feeding system of the batcher. Remove any large stones or objects promptly.
4. Do not perform maintenance, servicing, lubrication, or tightening operations while the machinery is running. Keep hands and feet away from gates, mixing drums, spiral pipes, etc.
5. Before stopping the mixer, unload it first, and then turn off the switches and pipelines in sequence. Ensure that all the cement in the spiral pipe is conveyed out, leaving no residue.
6. If the dragline becomes stuck due to an obstruction, do not force it to move. Do not use the dragline to lift heavy objects. During the dragging process, do not perform any rotating operations.

(6) Precautions After Operation

1. After operation, when the equipment operator receives a notice for cleaning or maintenance, they should cut off the power supply to the equipment, lock the mixer's key switch, remove the key, lock the doors and windows of the operation room, and then notify the cleaning or maintenance personnel to proceed.
2. The cleaning personnel should close the gates of the bulk cement silos and convey all the cement out of the spiral pipes. Clean the mixing drum, discharge door, and discharge hopper, and rinse them with water. Also, rinse the admixture and its supply system. Clean the knife seats and blades of the weighing system to ensure weighing accuracy, leaving no cement residue in the pipes.
3. In freezing seasons, drain all the water from the water pump, admixture pump, water tank, and admixture tank, and run the pumps for 1-2 minutes.
4. Perform maintenance on the machinery, lubricate all lubrication points, and apply oil to protect parts from rust.