The marine industry is nowadays mainly cocentrated in the Asian region, namely in South Korea, China and Japan. The production is split in bulk carriers and container ships, chemical and other product carriers and tankers as well as in crude oil tankers and a constantly growing numbers of cruise ships.
Although the marine industry is dominated by these countries, decisions regarding the construction and equipment are often taken in other countries by the owners, shipyards, operators or even the investors.
As the vessels are globally cruising the construction and equipment have to meet the requirements of many different regulation organisations. That means that suppliers have to be very flexible to meet the different requirements and certifications.
After the ship has been delivered the equipment suppliers are often expected to offer global service and spare parts supply to meet the tight maintenance schedules in the harbours.
Pumps can be found in numerous applications throughout the whole vessel. The most important applications are to be found in the engine room, where the fuels have to be supplied to the engines and various lubricating and hydraulic fluids have to be handled. But also water is pumped to operate the boilers or to cool machines and other aggregates.
Next to mention are the various tasks of water supply and treatment. The quantities required are of course much higher on board of cruise vessels due to the large number of passangers, compared to freight vessels which are operated with a comparatively small crew. But also on these vessels there are pumping applications involved in seawater desalination and waste water or bilge water and ballast water treatment.
On tankers also pumps for loading and unloading are required, but also pumps for fire extiguishing and many other tasks are spread all over the vessels.
Successful application examples
Multi screw pumps are used to convey lubricants for the main engine and other aggregates.
Hydraulic fluids are used on a wide range of lifting devices, winches and other deck equipment down to steering systems and pitch propellers. To convey the liquids multi screw pumps are often used as they only reqiure limited space due to their high performance density
Fresh water is generated mainly with two methods, on the one side fresh water generation from saltwater by heating and condensation. The second method is reverse osmosis whereby salt water is pressed through a membrane with high pressure, creating a clear water permeate.
The IMO regulations strictly require that only treated bilge water may be pumped out. Bilge water contains oil, sand and other contaminations. Progressing cavity pumps are ideally suited for the solid-loaden waste water, and fit well thanks to their desigeven in restricted areas next to the oil separators.
Bilgewater is pumped into a container filled with tissue. Ffine oil droplets caught in the tissue coalesce into larger droplets, which, due to their lower density, raise to the top. There the oil is collected and released through a valve, for larger amounts of oil rotary lobe pumps or multi screw pumps are used to pump the oil away.
Ballast water is used to increase the stability of the vessel, particularly in heavy weather and high waves. When the tanks of the vessel have been emptied from their liquid freight they are filled again with sea water. When the tanks shall be filled the next time the sea water is pumped out again.
While radial pumps effectively handle the large ballast water quantities pumped in and out of the tanks, rotary lobe pumps are well suited for the cleaning of the filters, the so-called "backwash", because they need no valves and the direction of flow can be changed with the rotation direction of the lobes.