Slurry volume loss runtime Slurry in operation, the pump fluid pressure throughout the body is unequal, a high pressure area, there are low-pressure area. Since the structural needs, there are many gaps in the pump body, when the gap around the pressure range, the liquid will flow from the high pressure zone to the low-pressure area, this part of the high pressure zone of the liquid back into the low pressure region, while flowing through the energy functional is obtained when the impeller, but not the effective use, but the circulation of the pump body, because the gap to overcome the resistance and consumed, this energy loss is called volume loss.
As the liquid out of a portion of the impeller in the pump back, not discharged out of the pump, the pump discharge flow rate Q of the actual ratio of the flow rate through the impeller Q ‘be small.
Volume loss classification
(1) where the entrance of the impeller, the impeller and the pump body has a small sealing gap. Pressure inside the cavity of the pump impeller inlet than the high, so there is a small gap from the stock liquid through the seal back into the impeller inlet impeller exit. This part of the liquid as the impeller of a successful bid is effectively utilized, and the loss is to overcome the resistance of the seal gap. Typically, this part of the energy loss is called seal ring leakage losses. Available water flows through the mechanics of the formula to calculate the amount of leakage at the sealing ring q1 (m ^ 3 / s): dry liquids or liquids with solids along grain pump, seal ring clearance should be greater than the value in Table 2-1 slightly . Sealing ring gap length l can be determined according to the specific structure.
(2) In general centrifugal axial force balance in both institutions, such as balancing hole (Figure 2-11) and the balance plate and so on. Although a portion of the liquid obtained from the impeller of energy, but not effectively utilized and consumed to overcome the resistance by balancing mechanism, which also belong to the volume loss in energy loss. On the adoption of multi-stage pump balancing disc calculation of the amount of fluid leak will be discussed in Chapter VII. On the amount of leakage through the balance hole can be approximated by the formula (2-13), is the presence of the balance hole pump efficiency will generally 3-6%.
In addition, the multi-stage pump, in addition to the above two categories belong to the gap leakage volume loss, there are not part of the clearance volume loss leakage. In multi-stage pumps are generally level partition plate, since the level of the liquid after the pressure partition plate varies, slurry pump manufacturer so a portion of the liquid through the level back into the plate gap between the impeller side of the pre-clearance, the leakage gap between the liquid level, through between the impeller and guide vane backlash after mixing with the liquid from the impeller, the guide vanes and ABM leaves, but also by the level gap between the impeller back into the pre-backlash, and so on. Since this part of the liquid does not pass through the impeller, does not affect the flow of the pump, so this part of the energy losses are not volume loss.
Post time: Jul-13-2021