Static pressure at the inlet of an ejector is converted into kinetic energy and this again back into static pressure at the outlet. As a result a low pressure section in the ejector creates a suction effect. The difference between the low pressure and the static pressure at the outlet describes the delivery head of an ejector.

Practical use

Ejectors are self-priming fluidic apparatuses used for suction, pumping, evacuating, mixing or discharge of liquids, gases, vapours or solids. They are driven by liquids, gases or vapours, so ejectors do not have any electrical or mechanical drive unit, dynamic gaskets or any moving parts. Therefore they are relatively insusceptible to soiling and absolutely safe against dry running.

On-board ships ejectors are mainly tried and tested as bilge and ballast ejectors. They can be utilised for the ballast tanks, the bilges, the engine room, the chain lockers, the bow thrusters, the cofferdams, the forepeak etc. Ejectors are also used in handling grey or black water.

All Körting ejectors are customised according to the actually required performance data. The individual design qualifies us to find solutions even for extremely special requirements; in other words our ejectors will be designed exactly for your field of application. An extensive unit assembly system enables us also to customise our ejectors for all standard connection types. By using high quality materials Körting ejectors are fully resistant to the chemical attack of any medium. Our ejectors rarely need maintenance and they are ready for use at any time.

Low investment costs, a customised design and maintenance-free operation should be essential arguments for all shipping companies and ship designers in order to reduce operating costs and to ensure 100 % availability of the system. A customised bilge ejector means that the connecting pipe system can be ideally adapted to also reduce costs in the environment of the bilge ejector which includes parts such as piping, valves, fittings and other. A project-related design free of cavitation ensures durability and finally a Körting ejector may last for the ship’s lifetime. It is
always worth paying more attention to the design of the ejectors, particularly when it comes to weight-saving and consequently to a reduction in the energy consumption of the bilge ejector itself.

Körting Hannover AG is the leading company of ejector technology in shipbuilding industry and at the same time the oldest manufacturer of ejectors at all. Our longstanding experience in manufacturing and a continuous R&D are the basics of our success.

Design, R&D and manufacturing in Hannover

Design, R&D and manufacturing of our ejectors are solely done at our plant at the headquarters in Hanover, Germany. Therefore, a close alliance between theory and practice is guaranteed. It enables us to realise even unconventional technical solutions within shortest time.

Comprehensive service on-site

Our agents abroad and our project engineers are at your disposal at any time:

• during tendering / project planning
• during design / manufacturing / inspection
• during order processing
• after-sales service

Recognised by all known shipping companies

Körting bilge ejectors have been strongly linked with the shipbuilding industry since 1871. The following ships are deemed to be our oldest references:

•  The worldwide oldest paddle steamer, the “HJELEN”. She is registered in Silkeborg and has been in constant service since 1892.
• The worldwide oldest seagoing passenger ship with a coal-fired steam boiler, the steamship “SCHAARHÖRN”. She is registered in Hamburg and has been in constant service since 1908.

Project-related design

The individual design of our ejectors results in minimised energy consumption at maximum suction performance. Consequently our ejectors will be designed for the most effective size. A customised bilge ejector means that the connecting pipe system can be ideally adapted to also reduce costs in the environment of the bilge ejector which includes parts such as piping, valves, fittings and other.

Optional flange design

In order to facilitate the assembly our standard ejectors are fitted with loose flanges. The counter flanges on the part of the pipe system do not have to be adjusted. The flange dimensions can be drilled according to EN, ASME, JIS, VG or any other flange standard.

Optional connection types

Our extensive unit assembly system enables us to adjust our ejectors in any required way. Among others our product range includes thread connections, hose couplings like Storz, Guillmin, etc. or straight pipe ends for quick couplings like Straub-Grip, Norma, etc.

Extensive documentation

Our documentation includes detailed operating instructions, technical specifications, performance curves, assembly drawings as well as work‘s specific test reports. Furthermore any special requirement by the shipyard or a certrification body can be taken into consideration.

Extensive stock

A sophisticated unit assembly system ensures longterm delivery service for all of our ejectors. To that effect our extensive supplies of spare parts enables shortest possible delivery times for all spares.

Final inspections

After completion all of our ejectors are subjected to an extensive final inspection, including general visual examination, dimensional checking as well as hydrostatic pressure testing. At the customer´s request performance tests of the actual operating conditions or recordings of special characteristic curves and various other tests can be performed before shipping takes place. If required all tests and examinations can be carried out under survey of any official authority or classification society.

Classification

Our ejectors are built in order to fulfil the specific requirements of the shipbuilding industry. This of course includes full compliance with the rules and regulations of all recognized classification societies like GL, DNV, BV, LR, ABS, RMRS, KR, and others.

Let’s have a closer look at the main area where ejectors are used in shipbuilding. Bilge ejectors are fluidic devices without mechanical drives, dynamic gaskets or any moving parts. Therefore, they are not subjected to mechanical wear, require no maintenance and dry running isn’t possible. Even an operation free of cavitation can be ensured if a design is project related. The functionality of selfpriming bilge ejectors is solely based on fluid dynamics, driven by water supplied by the mechanical pumps from the ship’s own system. In order to achieve optimum efficiency, the design of a bilge ejector should always be based on the performance data at the design point. The effective pressure data in relation to the connections must be taken into consideration.

How to avoid mistakes when designing bilge ejectors

A frequent mistake in technical specifications is to treat bilge ejectors in the same way as mechanical pumps. This ignores the fact that the behaviour of the performance curves of bilge ejectors and mechanical pumps is totally different. The design of an ejector always depends on the motive pressure related to the suction pressure and the discharge pressure. Nevertheless, you will find a number of vendors dealing with ejectors by catalogue. Therefore, you need to ensure you receive a quote for bilge ejectors with a constant total manometric head only.

Lower the operating costs

The standardisation of bilge ejectors has an adverse affect and results in a loss of efficiency. On the other hand, detailed planning at an early stage leads to lower investment and operating costs. However, when selecting a bilge ejector the necessary drive energy and consequently the right mechanical pump should be taken into consideration. The wrong choice in this context, based on the pure investment costs only, could lead to higher operating expenses during the whole life time.

The efficiency’s in the details. Ask the experts at Körting Hannover for further support.