Si cavitatio antliarum centrifugarum adsit, vibrationem et strepitum in operatione quotidiana causare potest, interdum opus intermittere necesse erit. Itaque invenire debemus quae causae ad cavitationem antliarum centrifugarum ducant, tum has quaestiones callidissime vitare possumus.
The cavitation of centrifugal pumps, or the cavitation , is a process for flow liquid bubbles and then burst. When the absolute speed of flow liquid increase, as the static pressure of flow liquid decrease, for certain particle at a certain temperature of the fluid , although there is no heat from external input, but they have reached the vapor pressure, so that particle vaporization, and the bubble generated. Along the flow path.
Si pressio statica fluidi iterum augeatur, pressione vaporis altior, bulla celerrime rumpetur. Magna pars implosionis condensationis fit. Si bulla rumpitur non in fluxu liquidi, sed in pariete partium coetus ductoris, cavitatio partes humidas erosioni obnoxias faciet.
Cum antlia centrifuga sub condicione cavitationis operatur, etiam si nulla erosio partium humidarum est, animadvertere potes hoc tempore strepitum antliae centrifugae magnum esse, vibrationem intensificari, efficientiam minui, et proinde altitudinem pressionis valde humilem fieri.
The equipment NPSHa , also called as effective NPSH. The equipment is provided by suction equipment, in the suction position of centrifugal pump, unit weight of the liquid have surplus energy more than vaporization pressure and head . Overseas call this an effective net positive suction head, That pump inlet (head position is zero) with a full head of liquid minus vaporization pressure and the net surplus value, represented by NPSHa. Its value and parameters related to liquid properties. Because inhalation device is proportional to the square of the flow and hydraulic loss. So NPSH decreases with the increase in capacity. NPSH-Q is a decreasing curve. The NPSH have relationship with the flow condition of pumps, it was balance pump inlet pressure drop decided by centrifugal pump itself. That is to say, in order to avoid the cavitation for the pump, we require that there is extra energy that could exceed vapor pressure head in the pump inlet. Overseas call this a required net positive suction head. The physical meaning of the pump NPSH indicates the degree of pump inlet pressure drop of the liquid. The so-called net positive suction head required, It is to require the inhalation device must be provided such a large net positive suction head, in order to compensate the pressure drops, to ensure that the pump cavitation does not occur.
NPSH antliae centrifugae multiscalae nullam relationem cum parametris apparatus habet. Solum ad parametros motus in introitu antliae pertinet. Parametri motus ad certam celeritatem et parametri fluxus a geometria determinantur, id est, NPSH ab ipsa antlia determinatur. Pro data antlia, cuiuscumque liquidi sint, ad certam celeritatem et fluxum per introitum antliae, ergo, propter eandem celeritatem, eadem pressionis deminutio, eadem NPSHr est. Ergo NPSHr nullam relationem cum proprietatibus fluidi habet. Quo minor NPSH, quo minor pressio.
Ti requirit ut apparatus minorem NPSHa, et deinde meliorem resistentiam cavitationi antliae praebeat.
