What Are The Methods For Regulating The Flow Of Slurry Pumps?

The working principle of the slurry pump is mainly to use the rotation of the impeller to cause centrifugal movement of the water.Before starting, be sure to fill the pump casing and suction pipe with water, then start the motor so that the pump shaft can drive the impeller and water to rotate. After the water undergoes centrifugal movement, it is thrown to the edge of the impeller and flows into the centrifugal pump pressure pipeline through the volute runner.The flow rate of the slurry pump is an important data, and better determining the flow rate can improve work efficiency.At the same time, it also has a variety of specifications and models, and it must also be calculated based on the specific situation when determining the flow.So how should the flow be adjusted?The editor has sorted out and then followed CNSME to see how we often adjust the flow of slurry pumps?What are the specific methods?1. Exit throttling of flow regulation　　For slurry pumps, this is the most common and cheap flow regulation method.Usually this method is also limited to use on slurry pumps.Any form of valves on partially closed outlet pipelines will increase the system pressure head, so the system pressure head curve will intersect the slurry pump pressure head curve at a smaller flow rate.The outlet throttling moves the operating point to a lower efficiency point and there is a power loss at the throttle valve.This may be important for large pump units, and investment in a higher conditioning method may be more economically attractive.The throttling dead point may cause the fluid in the pump to overheat, and bypasses can be used to maintain the necessary minimum flow, or use different adjustment methods.This is very important for the aforementioned pumps that treat hot water or volatile liquids.2. Suction port throttling for flow regulation　　There can be some power saved by throttling in the suction pipeline.Because outlet throttling will cause liquid overheating or vaporization, jet engine fuel slurry pumps often use inlet throttling.At very small flow rates, the impellers of these pumps are only partially filled with liquid, so the input power and temperature rise are approximately 1/30 of the flow of the condensate pump at the full operation of the impeller when the outlet throttling is usually controlled by the submersion depth, which is equivalent to inlet throttling.Special designs can reduce cavitation damage from these pumps to an insignificant level, but the energy level also becomes quite low.3. Bypass adjustment of flow rate adjustment. All or part of the flow can be diverted from the discharge pipeline of the slurry pump and lead to the suction port of the pump or other appropriate points through the bypass pipe.One or more flow orifices and suitable control valves may be installed in the bypass.Metering bypass is usually used to reduce the flow of the boiler feed pump, mainly to prevent overheating.If the bypass propeller pump excess flow is used to replace outlet throttling, considerable power can be saved.4. Speed \u200b\u200badjustment of flow rate adjustment　　When adjusting the flow rate in this way, the required power can be reduced to the lowest and overheating can be eliminated during the flow rate adjustment process.Steam turbine and internal combustion engines can easily adapt to speed adjustment at a very small additional cost.Various mechanical, magnetic, hydraulic transmission devices and DC and AC variable speed motors can be used to adjust the speed.Generally, variable speed motors are too expensive and can only be adjusted using adjustable blades if they have been economically studied in special circumstances and proved to be worth it.After studying the adjustable guide vanes installed in front of the impeller, it was found that the specific rotation number \u003d 5700 (2.086), this method is effective for pump regulation.The blades can produce positive pre-rotation, thereby reducing the indentation, flow rate and efficiency.And for only relatively small regulation will be obtained by the blade.Large storage pumps for power generation in Europe have been successfully used for adjustable outlet diffusion blades.Propeller pumps with variable distance blades were also very successful.A large flow rate variation range can be obtained in the case of a constant pressure head and with relatively small efficiency losses.However, these methods are too complex and expensive, and are therefore greatly restricted in practical applications.5. Replenishing air for flow regulation　　Replenishing air into the suction port of the slurry pump is also a method to regulate flow. This method can save some power compared to outlet throttling.Generally, it is not desirable to have air in the conveyed liquid, and too much air always has the risk of causing the pump to lose its filling head, so this method is rarely used in practice except on some occasions.