The working principle of the wear-resistant medium-pressure multi-stage pump for mining: The middle section of the segmented multi-stage centrifugal pump is equipped with a guide wheel on the outside of each impeller. The guide wheel is a fixed disc. Part of the kinetic energy of the thrown liquid is converted into static pressure energy by deceleration, and the liquid is collected and returned in the radial direction to lead to the next stage of the impeller. The front of the seek wheel has a forward guide vane surrounding the outer edge of the impeller, and a reverse guide vane that guides the liquid to the next stage of the impeller on the back.
After the liquid is thrown out from the impeller. Gently enter the forward guide vane that is consistent with the direction of the liquid flow rate, and continue to flow outward along the forward guide vane, the speed gradually decreases, and the static pressure energy continues to increase, when it reaches the outermost cavity of the guide wheel. The flow rate is the smallest and the static pressure energy is the highest. After the liquid flows out of the forward guide vane, it bypasses the internal partition plate of the guide wheel in the axial direction, and then flows to the inside along the reverse guide vane, while reducing the annular flow velocity. Enter the next stage impeller along the axial direction.
Compared with the volute, the guide wheel has a smaller external size, and the efficiency of converting kinetic energy into static pressure energy is also lower. Because there are multiple blades in the guide wheel, when the actual working conditions of the pump deviate from the design working conditions, the trajectory of the liquid flowing out of the impeller is inconsistent with the shape of the guide wheel blades, which causes a large impact loss and reduces efficiency. Therefore, the centrifugal pump using the guide wheel device has a narrow high-efficiency working area, and the head and efficiency curves are steeper than those of the volute pump. However, due to the central symmetry of the guide wheel, it will not generate radial pressure acting on the rotor like a volute, so multi-stage pumps generally use volutes at both ends of the head and tail, and guide wheels in several sections in the middle. Due to the complex geometry of the guide wheel, it is generally cast from cast iron.
Like the single-stage centrifugal pump, the medium-pressure multi-stage pump for mining does not have the self-priming ability, and the pump must be primed before starting. The working principle of various mining multi-stage pumps is that the impeller drives the liquid to rotate at high speed, so that the liquid generates centrifugal force to obtain energy. In this way, the liquid in the suction chamber on the front side of a section of the impeller enters the first stage impeller. After the impeller performs work on it, it is thrown into the first stage guide wheel. After the first stage guide wheel is transferred, it then enters the second stage impeller. The second-stage impeller continues to work on it, and then enters the second-stage guide wheel, and so on, until it is thrown out from the final impeller, collected by the volute, and sent to the discharge outlet for discharge.
