Application, Features and benefits of Freshwater generator

The Freshwater generator is a major advance based on proven by expertise. Freshwater generator optimized process cuts seawater needs in half, which minimizes pipework and allows the installation of smaller seawater pumps. This in turn reduces installation costs, fuel consumption and CO2 emissions.

Freshwater generator makes use of 3 in1 plate technology, which enables desalination in a single plate pack with one type of titanium plate. Since the plate pack also contains the process vacuum, freshwater generator has no outer shell and is smaller than other freshwater generators. The plate pack slides open for easy access to the interior without an additional service area.

The use of corrosion and erosion-resistant titanium, combined with an optimized process that inhibits natural scaling, ensures that freshwater generator needs little maintenance. The system has been fully tested both on and off shore, and is designed to last the lifetime of the ship.

Application

Freshwater generator uses vacuum distillation to convert seawater into high-quality freshwater for domestic and process utilization. By providing a constant supply of low-salinity water and continuously controlling the water quality, it eliminates the need for bunker water.

Freshwater generator is designed for automatic operation in periodically unmanned engine rooms and other automated operations. Jacket water, steam injection or a Hot Water Loop can all be used as heating media.

Features and benefits

• Half the seawater flow

  Compared to other freshwater generators only half the seawater is needed, which means smaller seawater pumps can be used. Optimized distribution prevents dry spots and inhibits the natural scaling process.

• Lower costs and emissions

  The reduction in seawater pumping needs has a corresponding effect on the consumption of electrical energy. Less fuel has to be burned, which reduces both operating costs and CO2 emissions.

• 3-in-1 plate technology

  Freshwater generator incorporates the evaporation, separation and condensation processes into a single type of titanium plate. Desalination is handled within a single plate pack that also contains the process vacuum. No outer shell is necessary.

• Simple, compact installation

  With no outer shell and no additional service area, Freshwater generator has a minimal weight and footprint. Assembly can be handled on site and installation is simplified by the ability to use smaller seawater pumps and pipes. 
  
  Since Freshwater generator is not sensitive to roll and pitch motions of ships, it can also be installed in any direction on board a ship.

• Easy operation and maintenance

  Freshwater generator offers start-and-forget operation, which saves time for the crew. Maintenance intervals are long and the plate pack slides open for easy access to the interior.

• Long product lifetime

  High-grade materials that resist corrosion and erosion, including titanium for the plates and other wetted parts, ensure that Freshwater generator will last as long as a ship.

• Low-salinity water

  The fresh water supplied has a lower content of salt and other dissolved solids than that supplied by other freshwater generators. It can be used directly by the steam boilers.

• Continuous quality control

  Salinometer-equipped control system continuously monitors the quality of the outgoing fresh water.

Capacity range

The series covers a capacity range from 3.1 to 60 m3/24 h, depending on the heating medium and cooling water temperatures. An freshwater generator can be dimensioned to suit any jacket water temperature from 55-95°C at any cooling water temperature.

Basic equipment

The freshwater generator consists of a single plate pack containing a flexible number of titanium process plates. These plates are suspended within a frame, which comprises a carrying bar, frame plate and pressure plate. Evaporation, separation and condensation all occur within the same plate pack.

Among the plate pack features are gaskets with rubber flaps that indicate correct plate assembly, as well as distance pipes that ensure proper plate alignment and correct tightening.

Connected to the plate pack is a combined system for feed water, condenser cooling water and ejector water. The freshwater system consists of a freshwater pump and a freshwater control sensor that ensures a stable outgoing flow.

Additional equipment

• Combined cooling and ejector water pump with electric motor
• Control panel with motor starters and salinometer
• Anti-scale chemical dosing unit for feed water

Optional equipment

• Steam heating system with direct steam injection
• Equipment for steam boosting and hot water loop system
• Extended control panel with motor starters and salinometer
• Freshwater pH adjustment equipment
• Freshwater disinfection equipment
• Connections according to DIN, JIS and ANSI standards
• Cleaning-in-Place (CIP) unit

How it works

Freshwater generator flow of feed water is taken from the flow of seawater coolant. Feed water enters the lower (evaporator) section of the plate pack, in which the plates are warmed by the heating medium. The heating medium is either engine jacket cooling water or a closed circuit heated by steam. Here the water is evaporated at around 40-60°C in a vacuum of 85-95%, which is maintained by the brine/air ejector.

The vapour produced rises between the plates into the middle (separator) section of the plate pack, where any droplets of entrained seawater are removed. Gravity causes these droplets to fall back into the brine sump at the bottom of the freshwater generator.

Only clean freshwater vapour reaches the top (condenser) section of the plate pack, which is cooled by a flow of seawater. Here the vapour is condensed into fresh water, which is pumped out of the freshwater generator by the freshwater pump.