Twin Screw Pumping Principle
The working principle of Roto Gear Timed Dual – Flow Twin Screw Pumps is dependent on the rotation of two screw spindles in closed compartment. Wherein, a predefined clearance is maintained between the screw spindles as well as between the outside diameter of the screw spindles and the bore of the casing/liner in which the screw spindles are located. Each half of the screw spindles is left-handed and right-handed. Thus, when the spindles start rotating, driven by a pair of timing-gears located at the end of the screw spindles, the liquid is drawn towards the end of the screw spindles and entrapped between the bore of the pumping compartment as well as the flanks of the screws and is then propelled axially from both the ends towards the centre. Such a dual flow nullifies the axial thrust completely thereby enabling the screw spindles to remain in a state of hydraulic balance. Roto’s unique double profile of the screw spindles contributes to a higher volumetric efficiency, thus an improved overall efficiency.
- Long and trouble-free service life due to absence of metal to metal contact between the pumping elements. It can even run dry for limited period of time.
- No axial thrust Dual flow of liquid in opposite direction balances axial thrust.
- Higher volumetric efficiency due to special double profile of screw flanks.
- High cavitation free suction lift due to low NPSH (R).
- Wider conformity to API 676, 2nd edition.
- Self-priming and capable of handling entrapped air/vapour/gas due to positive displacement action and being inherently self-priming.
- Uniform metered flow Being a positive displacement pump, head developed is independent of speed and capacity is approximately proportional to speed.
- Capable of handling wide variety of fluids lubricating/non-lubricating as well as aggressive liquids can be handled due to choice of different designs and material of construction.
- Safe to operate has in-built relief valve, designed to bypass up to 100% capacity.