Mechanical Seals & Pumps

  Balancing flow is passed through the space between its rotating and non-rotating portions when the pump is running. The balancing flow experiences significant throttling as it passes through the gap. This pressure loss produces an axial force to act on the balancing device, counteracting the axial thrust of the impeller and achieving the necessary balance. If the balancing device consists of a balance disc, the entire axial thrust of the pump rotor is usually balanced. In this case, an additional thrust bearing is not required      Balancing device with balance drum                                    Balancing device with balance drum Balancing device with double drum   Other Balancing arrangements : Mechanical: complete absorption of the axial thrust via a thrust bearing Design-based: back-to-back arrangement of the impellers  Balancing or reduction of the axial thrust on the individual impeller via Balancing holes Reduction at the individual impeller by back vanes  Balancin

  Multistage pumps are utilized in locations that demand high pressure, such as application of boiler feed water. These pumps have a series arrangement of the impellers, which creates high pressure, which leads to high axial thrust. Additional devices are employed to balance the axial thrust since thrust bearings alone cannot withstand the load. Arrangements used for balancing are – Balancing Disc Balance drum Double drum HGC high-pressure multi-stage pump

 Shaft : The pump shaft transmits the drive torque to the impellers to centrifugal pumps  The impellers, shaft sleeves, bearings, couplings, and other parts are carried by the pump shaft In centrifugal pump engineering, both rigid and flexible shaft couplings are used. Rigid couplings are mainly used to connect shafts in perfect alignment & Flexible couplings are elastic, slip-free connecting elements between drive and pump which accommodate axial, radial and angular misalignment and damp shock load                                                             Exploded View of MegaCPK Bearing: The pump bearings sustain the loads brought on by the shaft coupling or belt drive, the hydraulic loads imposed on the impeller, the mass of the impeller and shaft etc. The fluid's hydraulic and momentum forces make up the hydraulic loads. Axial load and radial load are the two components of the forces acting on the impeller. The three most used ball bearing types are the single row deep gr

  The diffuser is a part that, with the least amount of loss feasible, reduces flow velocity and raises static pressure in response. A diffuser's distinguishing characteristic is a flow path with increasing cross-sectional area in the direction of flow, in a closed duct or channel The vane angle for either volute or diffuser, if properly designed, is correct for only the capacity at the BEP. If the pump is operated at some other capacity, the diffuser may act as a hindrance rather than as an aid to efficient operation.

  The specific speed of centrifugal pump is defined as speed of geometrical Similar pump which would deliver one cubic meter of liquid per second against head of one meter It is a function of shaft speed, flow rate, and differential head at the pump Best Efficiency Point  Sp.Speed It is a key consideration in the design and selection of pumps, and particularly pump impellers , is specific speed.

  Volute of a centrifugal pump is the casing that receives the fluid being pumped by the impeller As liquid exits the impeller it has high kinetic energy and the volute directs this flow through to the discharge.  As the fluid travels along the volute it is joined by more and more fluid exiting the impeller but, as the cross sectional area of the volute increases, and velocity is gradually reduces. Volute casings come in three different types:  Single volute and Double volute The fundamental benefit of a double volute over a single volute is the equalization of the pressure distribution within the volute. Radial thrust can substantially increase the pump shaft deflection Pressure distribution comparison  for non diffuser volute casing The motional energy of one or more driven rotors, known as impellers, is transferred to power a centrifugal pump.  The fluid is directed toward the pump output by the impeller's movement, which raises its pressure and velocity. Depending on the flow l