Look behind the scenes
When pumps are used on ships and in ports, the technology must meet special requirements: this means the pumps should not only cope with a really wide variety of fluids, but should also be as space-saving, maintenance-free and easy to handle as possible.
The challenge is to have universally deployed pumps as transfer and booster pumps on ships and harbours, as well as on offshore platforms – from fuel or sludge transport, through loading and unloading, to stripping. They need to generate high pressures of up to 80 bar, and be able to transport lubricant oil, fuel and bitumen.
NETZSCH Pumpen & Systeme GmbH has also developed a range of NOTOS® screw pumps which can generate pressures of up to 80 bar even in tight spaces and can cope with liquid temperatures of up to 300°C. A series of design innovations, in line with the principle of High Efficiency Unique Design (HEUD) and involving the spindle profile and the pump chamber, make them particularly efficient. The sturdy materials used – depending on the requirement, these may for instance be simple cast iron, chrome-nickel steel, Duplex or Hastelloy alloys – enable the setting of very small tolerances between the dynamic and static parts. This keeps backflow to a minimum and improves the ratio of pumping capacity to energy used. The NOTOS® 2NS range involves a two screw pump. The drive spindle transfers the torque via hydrodynamic film to the second spindle, powered passively. Together with the housing, the two form conveying chambers, with the flow rate being determined by rotational speed, screw diameter and spindle pitch. The medium itself provides the lubrication, so the conveyed medium needs a light lubrication capacity for this type. This NOTOS® screw pump model, which achieves pumping capacities of up to 500 m³/h, is therefore used for the circulation of lubricant oils, for example in a ship’s engine room. The three screw NOTOS® 3NS pump is also characterised by a novel, patented media discharge – a double outlet with a conical widening at the end of the drive spindle – which significantly reduces turbulence at the outlet and the energy consumption due to flow losses associated with this. The maximum flow rate with the 3NS is 200 m³/h and it is for example used to supply ship diesel engines with fuel and lubricant oils. Flow rates of up to 1,500 m³/h are possible with the geared twin screw pump NOTOS® 4NS. Even non-lubricating media can be conveyed with this model, as its conveying spindles do not touch. Its high flow rate and good intake behaviour mean this type of pump is frequently used for loading and unloading liquid cargo.
Look behind the scenes