The single-screw pump belongs to a group of self-priming displacement pumps.
The main pump working elements are:

• the impeller made of steel /A/, being single-thread screw with large pitch and round cross-section,
• the stator /B/, made of elastomer (rubber), double-threaded, with oval bore cross-section and doubled pitch of impeller thread.

When the pump is running, the impeller rotates about a fixed point in the stator, thus pumping the medium, what is possible due to that the suction area is separated from delivery area by, so called, sealing line during each phase of rotational motion. The pump also may suck media having considerable viscosity, as well as containing round shaped solid particles (maximum solid particle dimensions depend on pump size) without auxiliary

The pumps transport the medium in a continuous way. Media pumped are not subject to pulsing and centrifugal forces. Even most sensitive products are pumped gently.
The selection of rotational speed adequate for individual medium, as well as taking the specifications and degree of abrasive properties of the medium and contents of (abrasive) solids in per cent into consideration are the condition of proper pump operation. The factors mentioned above also decide on pump application. The use of the pump for pumping media with contents of fibrous, long solids is excluded, since they may wrap around the pump rotating parts. The producer does not specify the use of the pump in explosive conditions.
In case of wear of stator or impeller due to wear of working surfaces, the sealing line disappears, and the pump either stops to deliver the medium or pump delivery is reduced considerably. The stator and impeller geometrical parameters (diameter, pitch of thread, eccentricity), pump rotational speed and, slightly, the delivery pressure required (pump head) determine the pump capacity. Generally, the pump delivery for given pump size may be modified by changing the pump rotational speed.

pump drive

The pumps in standard version may be delivered either with directly coupled electric motor or with motoreducer (transmission + electric motor).
Also, other drive types may be used with pumps, such as: motors in offshore or anti-explosion version, stepless transmissions, etc.
There also is a possibility to use the frequency converter connected directly to the electric motor to ensure stepless and smooth control of pump rotational speed. ln each of these cases the producer should be consulted to confirm the possibility of pump operation with particular drive system.
The pump and pump drive system are located on the foundation frame made of welded profiles. On the customer is wish, the pump set might be delivered in portable version.

operational parameters:

• maximum pressure at the delivery connector for:
  • single-stage pumps - 0,6 MPa
  • double-stage pumps - 1,2 MPa
• Maximum vacuum at the suction connector - 0,07 MPa