Concrete spraying machine is a kind of construction equipment widely used in engineering construction. It uses compressed air or other power to transport the mixture in a certain proportion through the pipeline and spray it to the sprayed surface at high speed to solidify and harden, thereby forming a concrete support layer. This article mainly talks about the advantages and operation safety technology of wet concrete spraying machine.
1. Advantages of wet concrete spraying machine
1. Greatly reduce the dust concentration near the machine and outside the nozzle, eliminating the harm to workers' health.
2. High productivity. Dry concrete spraying machine generally does not exceed 5m3/h. When using wet concrete spraying machine, the manual operation can reach 10m3/h; when using the manipulator operation, it can reach 20m3/h.
3. Low rebound. When dry-spraying, the resilience of concrete can reach 15%-50%. Using wet spray technology. The rebound rate can be reduced to below 10%.
4. During wet spraying, because the water-cement ratio is easy to control and the degree of concrete is not high, it can greatly improve the quality of the sprayed concrete and improve the uniformity of the concrete. When dry spraying, the water-cement ratio of the concrete is controlled by the sprayer Adjusted according to experience and visual inspection, the quality of the concrete depends to a large extent on the correctness of the operator's operation.
2. Operation safety technology of wet concrete spraying machine
1. The sprayer should use dry spraying operation, and should be proportioned according to the mix ratio specified in the factory manual. The air source should be a stable voltage source that meets the requirements. The power supply, water source, and feeding equipment should be matched.
2. The pipeline installation should be correct, and the joints should be tightly sealed. When the pipeline passes through the road, it should be installed in the trench and covered with protection.
3. The inside of the spray machine should be kept dry and clean. The added dry material mix ratio and wetting procedure should meet the performance requirements of the spray machine. No agglomerated cement and unscreened sand and stone should be used.
4. The key inspection items before operation should meet the following requirements:
(1) The safety valve is sensitive and reliable;
(2) The power cord is not broken, and the wiring is reliable;
(3) The seals of all parts are well sealed, and the obvious grooves of the rubber bonding plate and the rotating plate are repaired in time;
(4) The pointer of the pressure gauge is between the upper and lower limits, and the limit value of the upper limit pressure is adjusted according to the delivery distance;
(5) The eyelet of the spray gun water ring (including double water ring) is unblocked.
5. Before starting, connect ventilation, water, and electricity, open the intake valve to gradually reach the rated pressure, and then start the motor to run without load, and confirm that everything is normal before starting the feeding operation.
6. Mechanical operation and spraying operators should have contact signals. When supplying air, adding material, stopping material, stopping air, and blocking, they should contact in time and cooperate closely.
7. It is strictly forbidden to stand in front of the nozzle, the operator should always stand within the sprayed concrete support surface.
8. During the operation, when the pause time exceeds 1h, all the dry mixture in the silo and the conveying pipe should be sprayed out.
9. When a pipe blockage occurs, the feeding should be stopped first, and the blocked part should be knocked to force the material to loosen, and then blown through with compressed air. At this time, the operator should hold the nozzle tightly, and it is strictly forbidden to shake the pipe to hurt people. When there is pressure in the pipeline, the pipe joint must not be disassembled.
10. When transferring the working surface, the air supply and water supply system should move with it, and the feeding hose must not be dragged and bent anywhere.
11. When stopping, the feeding should be stopped before turning off the motor and stopping the compressed air.
12. After the operation, all the dry mixture in the silo and the conveying hose should be sprayed out, and the nozzle should be removed and cleaned to remove the concrete and debris adhering to the inside and outside of the fuselage. At the same time, the feed pipe should be cleaned, and the seal should be in a relaxed state.
