Three Screw Pump ( Series D3S/SMT/SMT16B )
Delta group of companies are pioneered in Positive Displacement Rotary Pumps since 1968.The group introduced screw pumps in 1970 mainly for power plant applications. Since then thousands of Screw pumps are supplied and commissioned under guidance to renowned European countries from time to time.
Today Delta offers under partnership with Settima Mecanica SRL, Italy, the leaders in European market since 1978.Settima – delta are on OEM list of major plant and are in position to make modifications required to suit Indian conditions for replacement market. Three Screw Pumps D3S/D3M/D3SI.
Working Principle
- Settima-Delta Three Screw pumps employ just three screw elements - one power screw and two idler screws running in the three precision bores in the housing or liner. The screws are so profiled that they form a liquid tight seal between the thread. As the screws rotate, pockets/ cavities are formed where liquid gets trapped and conveyed from one end of the infinite stroke. This results in smooth, pulsation free flow with extremely low noise and vibration levels, almost impossible to be achieved by any other design of positive displacement or other types.
- The power rotor does not drive the idlers as commonly believed. The hydraulic forces acting on screw flanks turn the idlers torquelessly thus reducing the friction. The idlers simply roll over the root diameter of idler dia.reduce the unit pressure, centralize the power rotor and absorb the radial loads. A balance piston integrally machined on power rotor takes care of axial thrusts.
- While in operation, the screws are in hydrodynamic balance on film lubrication and do not require any additional bearings. The one ball bearing often used is only for axial positioning of rotor and safer operation of mechanical seals. Small rotor dimensions enable the pump to be operated at high speeds directly coupled 3000 or 3600 RPM motors or other prime movers. Such unique design and features has demonstrated excellent reliability with pumps in operation continuously non-stop for decades together without replacement of any components or maintenance on clean fluids.
| Types | Capacity LPM | Pressure kg/cm² | Viscosity Range | Temperature |
|---|---|---|---|---|
| D3S-SMT16B | 8 – 3200 | 40 | 2 – 3,000 | 180* |
| D3S-SMT | 8 – 1200 | 80 | 2 – 10,000 | 180* |
| D3S-SM | 8 – 1200 | 80 | 4 – 2,000 | 180* |
| D3S-SMC | 8 – 1200 | 80 | 2 – 10,000 | 180* |
| D3S-SMAPI | 8 – 3200 | 40 | 2 – 3,000 | 180* |
| D3SFP | 35 – 150 | 60 | 2 – 3,000 | 180* |
Figures given are indicative for range only considering speeds up to 2900 RPM. Three screw pumps can run to speeds up to 10000 RPM under special conditions.
+ Higher viscosities can be handled up to 50, 000 cSt or more. * Higher temperatures up to 250°C can be handled with special execution.
Salient Features
- High reliability
- Long service life
- Negligible maintenance
- High efficiency
- Self priming
- Smooth pulsation free flow
- High speed capability
- Insensitive to viscosities
- High pressure capability
- Axial flow - no churning, chewing or shearing
- Excellent suction capability
- Hydraulic balancing of forces eliminates need for any bearings
Typical Applications
Fuel Oil Service
Fuel oil burner service for Thermal Power Plant/ Industrial Package, Boilers, Furnaces, Kilns and Combustion systems. Fuel transfer and booster service for Captive Diesel/ Gas Turbine Plants and Industrial Combustion Systems, Fuel Oil Circulations and Centrifuge Feeding. Tank farm tank to tank transfers.
Hydraulic Duties
Hydraulic governing service for Water Turbines, Inlet Penstock Valves. Low and medium pressure hydraulic applications, high pressure jacking oil service for rotor lifting for Turbines/ Compressors/ Alternators.
Lubricating Duty
Pressure lubrication and cooling of bearings for Turbo Machinery, Gear Boxes, Bearing Lubrication of Coal Mills, ID/FD Fans, Diesel Engines, Steel Rolling Mills, Air pre-heater guide bearings, Compressors.
Seal Oil Service
Hydrogen cooled Generators, Gas and Refrigeration Compressors.
