NYP high viscosity pump to generate magnetic noise and vibration due to cavitation caused by
NYP high viscosity pump to generate magnetic noise and vibration due to cavitation caused by
If NYP high viscosity pump generates a magnetic noise and vibration at work , along with the flow , head and efficiency is reduced and sometimes does not work , when the overhaul this pump , the blade can often be found at the entrance side of the front cover and pitting or cellular damage near the blade inlet side . In actual operation , there are many magnetic NYP high viscosity pump is damaged due to cavitation .
Magnetic NYP high viscosity pump cavitation or cavitation during the bubble generation liquid is flowing and subsequent cracking process . When the absolute velocity of the fluid increases , the fluid static pressure drop , for a certain temperature of the fluid particle is lower , although no heat input from the outside , but they have reached the vapor pressure , so that vaporized particles and bubble generation . Along the flow path , if the static pressure of the fluid with an increasing again , greater than the vapor pressure , the bubble will quickly burst , resulting in a huge explosion introverted nature of condensation shocks. If the bubble burst did not occur in the flow of liquid , but in the wall of the deflector assembly , the cavitation will cause the wall material is subjected to erosion.
When the magnetic NYP high viscosity pump operating in cavitation conditions, even if the wall material erosion did not happen , will find that this time the magnetic noise NYP high viscosity pump increases, increased vibration , decrease efficiency, and reduce lift .
Device NPSH : also known as effective NPSH . Device NPSH is due to inhalation device provided in the magnetic NYP high viscosity pump inlet with a unit weight of liquid vaporization pressure and head over the surplus energy. This is known as an effective foreign net positive suction head , namely pump inlet ( head position zero ) minus the vaporization of the liquid head pressure with a full head net surplus value and with NPSHa said . Its size and device parameters with the nature of the liquid . Because inhaled hydraulic losses and flow proportional to the square of the device, so NPSHa with traffic increases. NPSHa-Q is a decreasing curve .
Magnetic NYP high viscosity pump NPSH (NPSHr) and the pump flow related , is part of the pump inlet pressure balance by NYP high viscosity pump itself determines the magnetic drop , that is, to ensure that the pump cavitation does not occur , requiring the pump inlet with surplus energy per unit weight than vaporizing liquid pressure head . This is necessary , said foreign net positive suction head . The physical meaning of the pump NPSH indicates the degree of pump inlet pressure drop of the liquid portion . The so-called net positive suction head required , is the requirement inhalation device must provide such a large net positive suction head in order to compensate for the pressure drop , ensure that the pump cavitation does not occur .
Magnetic unrelated multistage NYP high viscosity pump NPSH and device parameters and motion parameters are only part of the relevant pump inlet . Under certain motion parameters and flow speed is determined by the geometry . This means that the pump itself is NPSHr ( suction chamber and the inlet portion of the geometry of the impeller ) decision. For a given pump , regardless of the liquid ( except very viscous . Impact velocity distribution outside ) , and flow speed at a certain flow through the pump inlet , because the speed of the same size have the same pressure drop , the same NPSHr. Therefore, regardless of the nature of the liquid and NPSHr ( thermodynamics is not considered ) . NPSHr smaller , which means that the pressure is smaller, requires NPSHa small device must be provided , and therefore the better the anti-cavitation performance of the pump
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