Working Principle Of Acid-resistant Pump

The reason why most acid-resistant pumps can resist acid is mainly due to the material of the pump. Generally, acid-resistant pumps use non-metallic materials as the flow-through parts of the pump, such as "polyethylene, polypropylene, polyperfluoroethylene propylene, etc." Among them, polyperfluoroethylene propylene is one of the best acid-resistant materials, which can basically resist the corrosion of any acidic medium and is called the king of plastics.
Working principle: The impeller is driven by the pump shaft to rotate and work on the fluid between the blades. The fluid is thrown from the center of the impeller to the periphery under the action of centrifugal force. When the fluid reaches the periphery of the impeller, the flow rate is very high. The pump casing collects the liquid thrown from between the blades. These liquids flow in the casing along the direction of the gradual expansion of the volute-shaped channel, so that the kinetic energy of the fluid is converted into static pressure energy, reducing energy loss. Therefore, the role of the pump casing is not only to collect liquid, but also an energy conversion device. Liquid suction principle: relying on the high-speed rotation of the impeller, the liquid in the center of the impeller is forced to be thrown away at a very high speed, thereby forming a low pressure in the center of the impeller, and the liquid in the low-level tank is continuously sucked up.
To prevent the occurrence of air binding, the space inside the pump casing must be filled with external liquid before starting the centrifugal pump. This step is called priming the pump. To prevent the liquid poured into the pump casing from flowing into the low-level tank due to gravity, a check valve (bottom valve) is installed at the inlet of the pump suction pipe; if the pump is located below the liquid level in the tank, there is no need to prime the pump when starting. A guide wheel is installed on the periphery of the impeller to achieve high efficiency in the energy conversion of the liquid in the pump. The guide wheel is a fixed ring with blades located on the periphery of the impeller. The bending direction of these blades is opposite to that of the impeller blades, and its bending angle is just in line with the direction of the liquid flowing out of the impeller, guiding the liquid to change direction smoothly in the pump casing channel, minimizing energy loss and achieving high efficiency in converting dynamic pressure energy into static pressure energy. The balancing hole on the rear cover eliminates axial thrust. The pressure of the liquid leaving the periphery of the impeller is already high, and some of it will seep to the rear side of the impeller rear cover, while the liquid inlet on the front side of the impeller is low pressure, thus generating an axial thrust that pushes the impeller to the pump inlet side. This can easily cause wear at the contact point between the impeller and the pump casing, and in severe cases, vibration will also occur. The balance hole allows part of the high-pressure liquid to leak into the low-pressure area, reducing the pressure difference before and after the impeller. However, this will also cause a decrease in pump efficiency. The shaft seal device ensures the normal and efficient operation of the centrifugal pump. When the centrifugal pump is working, the pump shaft rotates while the casing does not move. If the annular gap between them is not sealed or sealed poorly, the outside air will penetrate into the low-pressure area in the center of the impeller, causing the pump flow and efficiency to decrease. In severe cases, the flow rate is zero-air binding. Usually, mechanical seals or packing seals can be used to achieve the seal between the shaft and the casing.
The working principle of the acid-resistant pump is that before starting, the outlet valve should be closed and the pump should be filled with liquid. This process is called priming. When working, the prime mover is started to rotate the impeller. The blades in the impeller drive the liquid to rotate together, thereby generating centrifugal force, so that the liquid is thrown along the blade flow channel to the impeller outlet and sent to the discharge pipe with the outlet valve opened through the volute. The liquid obtains mechanical energy from the impeller to increase the pressure energy and kinetic energy, and relies on this energy to make the liquid reach the working place.
As the liquid is continuously thrown toward the impeller outlet, low pressure is formed at the impeller inlet. A pressure difference is generated between the liquid in the suction tank and the liquid at the center line of the impeller inlet. Under the action of this pressure difference, the liquid in the suction tank continuously enters the impeller through the suction pipe and the suction chamber of the pump, thereby allowing the acid-resistant pump to work continuously.