Concrete pump supplier shares this article for you.
1. Improper operation can easily cause pipe blockage
1. The operator is not concentrated
The operator of the transfer pump should concentrate on the pumping construction and always pay attention to the reading of the pumping pressure gauge. Once the reading of the pressure gauge is found to increase suddenly, the pump should be reversed for 2~3 strokes, and then the pump should be adjusted to eliminate the pipe blockage. . If the reverse pump (positive pump several operation cycles) has not been eliminated, the pipe should be removed and cleaned in time, otherwise the pipe blockage will be more serious.
2. Improper selection of pumping speed
When pumping, the choice of speed is very important. Operators can't blindly map fast, and sometimes speed is not achieved. When pumping for the first time, due to the large pipeline resistance, pumping at low speed should be done at this time. After the pumping is normal, the pumping speed can be appropriately increased. When there is a sign of pipe blockage or the concrete sag of a certain truck is small, pump at low speed to eliminate the pipe blockage in the bud.
3. Improper control of remaining material
When pumping, the operator must observe the remaining material in the hopper at any time, and the remaining material should not be lower than the mixing shaft. If the remaining material is too small, it is easy to inhale air and cause pipe blockage. The material in the hopper should not be piled up too much, and should be lower than the protective fence to facilitate the timely cleaning of coarse aggregates and oversized aggregates. When the slump of a certain truck concrete is small, the remaining material can be lower than the mixing shaft and controlled above the "S" pipe or suction port to reduce mixing resistance, swing resistance and suction resistance. This method only applies to "S" valve series concrete pumps.
4. Improper measures taken when the concrete collapse is too small
When it is found that the slump of a bucket of concrete is so small that it cannot be pumped, the concrete should be discharged from the bottom of the hopper in time. If it is greedy to save trouble, forced pumping will easily cause pipe blockage. Never add water and stir in the hopper.
5. The downtime is too long
During the shutdown period, the pump should be started every 5~10min (the specific time depends on the temperature of the day, the concrete slump, and the initial setting time of the concrete) to prevent pipe blockage. It is not advisable to continue pumping the concrete that has been down for too long and has initially set.
6. The pipeline is not cleaned
The pipeline was not cleaned after the last pumping was completed, which will cause the pipeline to be blocked during the next pumping. Therefore, the pipeline must be cleaned in accordance with the operating procedures after each pumping.
2. Pipe blockage caused by pipe connection
The following principles should be followed when taking over:
(1) When piping is arranged, the pipes should be arranged according to the shortest distance, the least elbow and the largest elbow, so as to minimize the transportation resistance and reduce the possibility of pipe blockage.
(2) The taper pipe at the outlet of the pump is not allowed to be directly connected to the elbow. At least the straight pipe shall be connected to the elbow after 5mm or more.
(3) When taking over during pumping, only one pipe can be added at a time, and the inner wall of the pipe should be lubricated with water and the air should be exhausted, otherwise the pipe will be easily blocked.
(4) For the vertical downward pipeline, an anti-segregation device should be installed at the outlet to prevent pipe blockage.
(5) For high-level pumping, the length of the horizontal pipeline should generally not be less than 15% of the length of the vertical pipeline, and a pipeline stop valve should be connected to the horizontal pipeline. When the shutdown time exceeds 5 minutes, the shut-off valve should be closed to prevent the concrete from flowing back and causing pipe blockage. When turning from horizontal to vertical, the bending radius of the 90-degree bend should be greater than 500mm.
3. Pipe blockage caused by segregation of concrete or mortar
1. When concrete or mortar meets water, it is easy to cause segregation. Sometimes when pumping mortar, pipe blockage occurs. It is caused by the separation of mortar after the mortar is in direct contact with the water in the pipeline. The prevention method is to wet the pipeline with water in front of the pump and connect the pipeline from the lowest point of the pipeline. Loosen and drain all the remaining water, or after pumping water and before pumping mortar, put in a sponge ball to separate the mortar from the water.
2. When cleaning the pipe after pumping, put a sponge ball in to separate the water from the concrete, otherwise it will easily cause pipe blockage.
4. Pipe blockage caused by local leakage
Because the mortar leaks, it affects the quality of the concrete on the one hand, and on the other hand, after the mortar leaks, it will cause the slump of the concrete to decrease and the loss of pumping pressure, resulting in pipe blockage. The main reasons for slurry leakage are as follows:
1. The joints of the pipeline are not tightly sealed
The pipeline joints are not tightly sealed, the pipe clamp is loose or the sealing ring is damaged and the slurry leaks. At this time, the pipe clamp should be tightened or the sealing ring should be replaced.
2. The gap between the glasses plate and the cutting ring is too large
When the spectacle plate and the cutting ring are severely worn, the gap between the two becomes larger. The gap between the spectacle plate and the cutting ring must be reduced by adjusting the special-shaped bolts. If the adjustment is no longer possible, the wearing parts should be replaced immediately. This method only applies to "S" valve series concrete pumps.
3. The concrete pump has serious piston wear
The operator should always observe whether the water in the water tank is turbid and whether there is mortar. Once the water is turbid or there is mortar in the water, it indicates that the concrete piston has worn out. At this time, the piston should be replaced in time, otherwise it will cause blockage due to slurry leakage and pressure loss. Tube, it will also increase the wear of the piston and the delivery cylinder.
4. Slurry leakage caused by severe abrasion of concrete delivery cylinder
If each time the piston is replaced, the water in the water tank quickly becomes turbid, and the piston is good, it indicates that the delivery cylinder is worn out, and the delivery cylinder needs to be replaced at this time.