The thermal phenomenon of the hydraulic system will directly affect the normal operation of the fine aggregate concrete pump. The harm caused by thermal phenomena mainly includes the following points:
1. when the working fluid temperature rises, the viscosity of the working fluid decreases, the leakage of the pump increases, and the actual flow of the pump decreases.
2. under high temperature, the seals of the hydraulic system and the components of the concrete delivery pump will deteriorate, and the elastic deformability will be reduced, resulting in the decrease of the sealing performance and even the failure of the seal and the increase of leakage.
3. when the valve core and valve body material of the hydraulic valve are different, and the thermal expansion coefficient is different, the valve core and the valve body are jammed due to thermal expansion, resulting in the concrete pump being unable to work.
4. when the viscosity of the working fluid decreases, the lubrication performance of the working fluid is reduced, the wear of the hydraulic components is accelerated, the wear of components is accelerated, and the service life of components is shortened.
In order to avoid these phenomena as much as possible, some concrete pumps must be shut down after a certain period of time to cool the system, thus improving the running speed of the fine aggregate concrete pump and affecting the construction progress.
Before the operation of concrete pump, the following inspection is very important.
1. check whether the bolts of each part of the concrete pump are tightened, the pipe joints should be tightly sealed, whether the protection devices are complete and reliable, and the tyres should be wedged tightly.
2. all control switches should be placed in neutral position (or cut off position).
3. when the amount of oil in the hydraulic tank of the concrete pump is insufficient, the same type of hydraulic oil should be added. Check whether the hydraulic system is normal and there is no leakage.
4. check the power supply of the concrete pump and whether the water source and safety device are connected properly according to the requirements of the original manufacturer.
5. check the cooling surface of the piston rod for cooling and lubricating the sealing cavity. If the water is not enough, fill it up; if the water is not clean, replace the water and check whether the concrete piston is damaged.
6. add lubricating oil (grease) to each lubrication point. Each lubrication point of each shift must be lubricated once.
7. there should be no sundries in the mixing hopper, and the protective grid should be tightened up.