Low shear pump is an important equipment of cyclonic pipe resistance loss compensation provides liquid hydrocyclone separation technology in liquid. To the shear pump,the oil droplet size of the oil-water mixture shear will directly affect the separation efficiency of hydrocyclone separation system in shear pump. The separation of oil-water, general small density difference is in difficult separation. In order to realize the separation, requires a larger entrance tangential velocity for shear pump, which is usually required for the mixed liquid booster pump energy. Indeed, the shear force of large conventional pump, the oil droplet breakup, particle size decreases, the cyclone separation difficult. Therefore need to have low shear pump dedicated, to ensure that the shear pump in the process of droplet breakup is minimum, create favorable conditions for further separation of oil and water when using the shear pump. Considering the processing quantity of the centrifugal shear pump, repair convenient on the centrifugal shear pump was developed, aimed to find a set can realize the centrifugal pump design criteria for low shear pump transfer.
The domestic shear pump industry mostly uses a traditional flow theory in hydraulic design of shear pump. Great differences in describing the shear pump viscous flow and simple one-dimensional flow theory will inevitably affect the hydraulic performance of the quality of the low shear pump design. There has been based company with shear pump reformation experience in a number of experimental and theoretical works and oil field, the development and improvement of a set of three Yuan flow calculation to design the program. The calculation of flow velocity distribution, pressure distribution, flow channel wall boundary layer momentum thickness and evaluation of blade load distribution low shear pump hydraulic design of an important parameter of low shear prototype pump with the program, shows the advantages of low shear pump. According to the centrifugal, low shear pump has formed three Yuan of impeller optimization criterion of design, design of the low shear pump impeller. In the choice of shear pump, need to consider the following aspects.
(1) To use low speed (less than 1500r/min) to realize the pressurization effect when using low shear pump. This is because that the high speed may lead to strong shear and the oil droplet breakup, reduce the separation efficiency of the shear pump.
(2) To avoid or reduce the low shear pump impeller exit flow separation region. Laser speed measuring shear pump flow results show that, due to the composite effect of shear pump rotation and curvature of the blade of the impeller outlet. In general there are boundary layer flow separation zone in a low shear pump, and the formation of strong / jet wake structure of “0” streetcar. This is a blade type turbomachinery flow shear is the most severe area, which will also be hydraulic low shearing booster pump the improved design of the need to focus on the problem.