Water cooled or water injected exhaust systems creates a challenging set of design aspects. Heat reduction in the engine room. A minimal infrared signature. All-round view from the bridge. Discom Nord has been designing, building and supplying water injected exhaust gas systems that meet all these requirements and expectations for over 20 years.
Naval vessels, merchant ships, workboats, cruise ships and ferries have the most advanced techniques and technologies on board for their designed purposes. That is precisely why these demanding vessels are being equipped with water-cooled exhaust gas systems. Such a system must effectively deal with excess heat, noise, vibrations and harmful substances.

The smallest possible infrared signature and minimal noise production are of great importance for navy vessels. Cooling exhaust gases suppresses the infrared signature and reduces the visibility of the ship to detection equipment. To meet the diverse wishes of the different Navies, we can produce our solutions in various high-quality materials such as Inconel 625 and titanium.

Aboard cruise ships, the safety and comfort of guests is of great importance. By choosing a water-cooled exhaust gas system in combination with an emission reduction system from Discom, you increase the comfort of your guests. The exhaust gases are cooled back and blown into the stern wake so they do not rise to the passenger and recreational decks.

When utilizing a fully wet system, water is injected into the exhaust system as soon as possible following the engine. The exhaust gases are cooled, and most sound attenuation is obtained by passing the mixture through a water lift or a water separator.

If a water lift/separator causes too much back pressure or the spatial layout does not allow for a completely wet system, you can opt for a combined dry/wet system. In this system, the exhaust gases are initially fed uncooled by a dry – often a combined resonance/absorption – silencer. After this, water is injected to cool the gases. It is possible to install a water separator again after the water injection.

The position of the exhaust opening affects the acoustic and pressure drop performance of the exhaust system. You can choose to place it below or above the waterline.

Above the waterline – Exhaust gases are carried out through the hull and above the waterline. If you choose to separate the exhaust gases from the cooling water with a separator, you will prevent noise from the falling cooling water and soot traces on the water’s surface.

Below the waterline – The exhaust gas is carried out underwater through the hull. The extra transition between water and air creates an excellent attenuation of the exhaust sound.