Twin Screw Pumps

The Twin Screw Pumps use the principle of positive displacement to function. These kinds of pumps comprise of two rotors with timing gears at their ends, fixed inside a cylindrical compartment. The pump works with the help of a motor which makes the two rotors rotate in clockwise and anti-clockwise directions separately. The rotors are fitted inside the compartment in such a manner that a gap is maintained between the rotors and the walls of the compartment as the rotors circulate. The movement of the rotors pulls the water inside the pump through the suction end. The water moves along the axis of the rotors in the gap between the rotors and the compartment. The opposite movement of the rotors nullifies the thrust of the fluid, and helps in maintaining a perfect hydraulic balance.
The Twin Screw Pumps provided by Roto Pumps adhere to API 676 3rd Edition and are approved by ATEX and CE. They ensure higher volumetric efficiency owing to their dual profile screw spindles.

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.
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