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Reduce the pump vibration measures
作者: 发布于:2011/10/13 12:41:30 点击量:

     1 mechanical structure design problems

     1) shaft design. The increase in transmission shaft support bearing number, reduce the spacing of the support, in a proper range, reducing the axial length, increasing the diameter of the shaft, to increase the rigidity of the shaft; when the pump shaft speed increases gradually and close to or integer times to pump rotor natural frequency of vibration, the pump will violent vibration, so in the design, should be the transmission shaft of the natural frequency to avoid the motor rotor angular frequency; improving shaft manufacturing quality, prevent the eccentric mass and greater tolerance of form and position.

     2) the selection of sliding bearing. With no lubricating sliding bearing; in liquid hydrocarbon, chemical pumps, sliding bearing materials should be used with good self-lubrication properties of the material, such as Teflon; in deep well water pump selection guide bushing, filled PTFE, graphite and copper material, and the rational design of the structure, so that the sliding bearing is fixed and reliable; impeller sealing ring and the pump body seal ring with small friction coefficient of friction pair, such as M20lK graphite steel; limit the maximum speed; improve the bearing capacity and bearing stiffness.

     3) the use of stress release system. For conveying hot water pump, design, should make from the pump body deformation caused by connecting pieces between the structure to release the stress, such as in the pump body bolt above increase bolt sleeve, avoiding the pump body directly and stiffness greatly based contact.

    2 pump hydraulic design matters needing attention

     1) the reasonable design of pump impeller and flow, make the impeller within the cavitation and flow separation; reasonable selection of blade number, blade outlet angle, blade width, blade outlet crowding factor, eliminate head curve hump; pump impeller outlet and volute tongue distance, the data that the values for the impeller diameter 1/10, fluctuating pressure minimum; the blade outlet edge to dip (such as made into 20. Left and right ), to reduce the impact; ensure the clearance between the impeller and volute; improve the work efficiency of the pump. At the same time, the pump outlet passage, flow to optimize the design, reduce the hydraulic losses caused by vibration. Rational design of various pump inlet section of the suction chamber, and a compression level mechanical structure, reduce the pressure pulse, can guarantee the flow field is stable, improve the work efficiency of the pump, reduce the energy loss, but also can improve the dynamic stability of the pump vibration.

     2) pump vibration cavitation vibration is an important part of. When the pump is demographic pressure lower than the corresponding temperature and pressure, can occur with severe vibration cavitation. Reduce cavitation measures include: determine the pump mounting height, so that the device is effective NPSH is greater than the minimum device pump NPSH; proper increase of inlet pipe diameter, shortening the length of a water inlet pipe, reducing pipe accessory, flow path section change rate to minimum, improve wall roughness; reduce the number and increase the pipeline elbow the turning angle to reduce the pump; operating speed; adopting the anti cavitation material, such as stainless steel, or in the prone cavitation parts coated with epoxy resin; inlet passage design should be reasonable, to smooth, make into the impeller flow velocity and the pressure distribution is uniform, avoiding the local low pressure area; improve the manufacturing process quality, avoid because of blade type line caused by the inaccurate local flow velocity is too large, too much pressure drop; improve pump cavitation performance, including in the pump is arranged on the inlet of water can be increased, energy increasing device structure, increase the pump suction pressure head, thereby increasing the pump NPSH; add geometry intrusion height; minimize the inlet pipeline head loss; uses double suction pump.

    In order to guarantee the water pipe or pressure pipe without air stockpile, any part of the suction pipe are not higher than the imported water pump. In order to reduce the water pressure pulsation of the people, pipeline diameter should be less than the diameter of a pump population size orders of magnitude, so that the flow in the pump population there is a certain degree of contraction, so that the velocity distribution is more uniform, also should be in the pump population before a straight, straight length of not less than 10 times the diameter of the pipeline.

    Pay attention to create favorable conditions in the sump water inlet, to the stable and uniform, to eliminate Carmen accompanied by vortex vibration.

     3) based design. Basis weight should be for the pump and motor and other mechanical sum weight of more than three times; a water pool based should be of considerable strength; motor bracket and the best foundation for integrated or made into surface contact; the pump and bracket is arranged between the vibration isolating pad or isolator. In addition, in line with the damping material between the connection, reduces the pipeline arrangement, can eliminate the elastic contact and the hydraulic loss of the vibration of