Application of Water Ring Vacuum Pump on Ship
Water-ring vacuum pump transfers mechanical energy to rotating water-ring vacuum pump relying on the rotation of impeller, and then the rotating water-ring vacuum pump transfers energy to the medium being transported, so it is called water-ring vacuum pump. Water ring pump is one of the volumetric pumps. It is primarily used to suck gas. On ships, water ring pumps can be used as diversion pumps for centrifugal pumps, etc.
During the operation of water-ring pump, the first half-rotating water-ring obtains certain kinetic energy. After entering the second half-rotating, with the addition of rotation angle, water gradually enters the blades to improve the pressure of the transported gas. In this process, part of the kinetic energy of water will be transformed into pressure energy and consumed in the gas contraction. When the final speed of the water-ring pump is reduced to a certain extent, it will not continue to work on the gas, so the maximum contraction ratio that the water-ring pump can reach is bound to be limited. The contraction ratio of water ring pump depends on the size and speed of impeller, which is different from other volumetric pumps.
The suction vacuum of water-ring pump will be constrained by the temperature of water-ring pump. When the suction pressure is lower than the vaporization pressure of the water at this temperature, the water begins to vaporize and the suction volume decreases sharply. Together, long-term operation will heat the water, so it is necessary to add the necessary amount of water to the pump in succession.
The basic structure of water ring vacuum pump has three types: axial single effect, axial double effect and radial double effect. Generally, small and medium water ring pumps use single axial effect, and more radial double effect than large pumps. However, the radial load of single-effect water-ring pump is unbalanced. In double-effect water-ring pump, the radial force acting on the hub can be actively balanced, which greatly reduces the negative stage of bearing.