Cruise Ship

Ventilation drying of hydraulic tanks with direct proximity to the water

GIEBEL Adsorbers® protect hydraulic tanks anywhere in the world. A very extreme condition is the use on the deck of a cruise ship. High humidity, high temperature fluctuations as well as rain and swell must not have any influence on the hydraulic oil.

Shipping and operating conditions

The equipment on a ship is exposed to high loads. For example, it is exposed to low temperatures in the upper Atlantic and high temperatures in the Mediterranean. In addition, the proximity to water and the resulting high humidity is a burden and can quickly lead to corrosion.

Figure: AIDA Nova

Necessity of an adsorber

Figure: Crane with hydraulics of a lifeboat of the AIDANova.

Hydraulically operated equipment, such as the cranes of the rescue boats, are also exposed to these
cranes of rescue boats are also exposed to these conditions and are therefore at increased risk of failure if required.

Due to high humidity and long downtimes of the hydraulic system, the risk of condensation in the tank is particularly high. Diffusion in the air will cause moisture to continuously enter the hydraulic tank, remain there, and condense the next evening when the temperature drops below the dew point. Contamination of the hydraulic oil is thus pre-programmed and ensures failure when rescue systems are needed. In addition, biodegradable hydraulic oil is increasingly being used so as not to pollute the environment in the event of a leak. However, these synthetic esters are highly hygroscopic and attract atmospheric moisture to subsequently decompose and cause premature aging due to hydrolysis.

During the voyage, the temperature on the ship’s deck fluctuates greatly. For example, ambient air during the day at 20°C and 90%RH already has a dew point of 18.2°C. Thus, the water bound in the air of 15.5g/m³ will liquefy when the temperature falls below this level. The result is water in the oil, the promotion of corrosion, hydrolysis and, in the worst case, total failure.

Function – adsorber on hydraulic tank for lifeboats

To protect the hydraulic units for lowering the lifeboats on the AIDANova from moisture, original GIEBEL Adsorbers® were mounted on each tank. While dirt particles from a size of 3μm are separated, the effect of complete air drying is added. Furthermore, all adsorbers are equipped with valves so that no moisture can unnecessarily (during the long downtimes of the plants) diffuse into the adsorber or even into the tank.

With a tank volume of less than 100ltr, the smallest adsorbers of the VENT-PA-D series protect the hydraulic oil from moisture during temperature fluctuations, rain, snow and waves.

The air drawn into the tank is thus dehumidified to an initial 2%rh (average 10%rh). Thus, condensation will not occur until the temperature falls below -12.5°C. And even when the temperature falls below this, the amount of water due to condensation is very low and is less than 2g/m³ of air.

Figure: Hydraulic System of a lifeboat on AIDA Nova

Added value for AIDANova: increased safety

The use of GIEBEL adsorbers on the AIDA cruise ship makes a significant contribution to the protection of the rescue systems.
With this measure, a guaranteed maintenance interval for the hydraulic system, including the hydraulic oil, can be maintained. In addition, sudden failures of the lifeboat systems are prevented, which upgrades the quality of the entire AIDANova cruise ship.