Theory Analysis About Axial Force Of Centrifugal Pump With Floating Impeller And Self-poise Ability

In the Machines of Pump, axial force is the necessary and considered factor in pump's design and run. In special, the segmental type pump and the high lift submerged (oil) pump is able to bring prodigious axial force in working, because its impeller is arranged in the same direction. If Pump exist excessive axial power in working, it will make for safe accident, and influence work, and result in enormous economic expense. Come to light, Pump's lift is higher, and the axial power is greater. Excessive axial power is easy to result in pump accident and shut down. So searching on the way of balancing axial power and the accurate calculating of axial power is most essential. At the same time, it has great realism signification and science value.At first, this article introduces internal and oversea search actuality about axial power from three aspects, such as the reasons of axial power's happening, the common methods of balancing axial power, the calculating way of axial power. Our search make sure that theory search on liquid pressure distributing of pump cavity is not enough thorough, and the equation of axial power is more, and the computing values calculated according to different equation have much difference. All of this makes designer bemused. On the other hand, the reports about searching on balancing axial power is little, and more literatures present traditional methods of balancing axial power, such as adding balancing hole on impeller's hub, symmetrical collocation of impeller of segmental type pump, balance disc, balance drum, and the associated action with the balance disc and the balance drum. Some new way about balancing axial power is put forward in recent years, and these are based on improving on back vane, balance disc, balance drum or aimed at certain type of pump. These equipments also receipted good balancing effect. This article brings forward the main search contents of mine based on the above search.Secondly, this article introduces the search achievement of our problem group. In allusion to the characteristic of little clearance of balance equipment, big Renault and perplexing flow, we attempt to seek the distributing of velocity and pressure through sampling the equation of Navier-Stokes. This establishes theory basis for our later searching on axial power. The Search on axial power can be considered as the search on the distributing of velocity and pressure in pump cavity. At the same time, the Velocity and the pressure is relate to the geometry size of pump cavity, the surface's coarseness, the clearance of joint ring and the balance structure and so forth. We needthink much of these aspects above mentioned.Thirdly, we spread our theory analysis on axial force of centrifugal pump with floating impeller and self-poise ability. Balance cavity is long in radial direction and short in axial direction. Aimed at this characteristic, we build up flow model for liquid in balance cavity, and educe simple Navier-Stokes using antitheses by quantum, and obtain the relation equation of pressure in balance cavity along radial direction which it's exponential function. Our search based on 3BA-6 single stage centrifugal pump obtain that the change of P is the one of the key technology to achieve floating impeller's adjusting by itself through ration analysis on the pressure in balance cavity. Influence factor of pressure's variety is the ratio fe of the total area of balance hole of impeller and the area of back joint ring's clearance S\. If ï¿¡2>1.5, the variety of pressure P in balance cavity is smoothness. Therefore, we could think that the pressure P in balance cavity is not change and its value is lift's 5-10% in corresponding working condition. This conclusion is instructional signification for design of axial power structure of centrifugal pumps with floating impeller and self-poise ability.In the end, this article pointed out that the search on axial power of centrifugal pump is unsubstantial tache, and it expects innovation in theory by science workers. At present, the search on the theory of axial power of centrifugali pump with floating impeller and self-poise ability is not perfect, and seeking the pressure P in balancing cavity also exist some difficulty. All of the science worker must study it deeper.