Alfa Laval - JWP - Single Stage Fresh Water Generator

JWP - Single Stage Fresh Water Generator

The JWP series converts seawater to freshwater by vacuum distillation for use on ships and rigs or at remote onshore locations. This single-stage automatic series is ideal for capacities from 0.5 to 35 m3/24 h and, upon request, up to 100 m3/24 h.

jwp16c 640x360

High quality freshwater

Corrosion-resistant Alfa Laval JWP freshwater generators provide high quality freshwater with low content of dissolved solids (salinity). This ensures the supply of pure water, which can be used directly as make-up for steam boilers.

Long freshwater generator lifespan

To ensure long equipment lifetime, Alfa Laval JWP freshwater generators come with high-grade, corrosion-resistant materials, such as titanium plates.

Simple freshwater generator installation

Compact and lightweight, Alfa Laval JWP freshwater generators are easy to install and assemble onsite.

Low operation and maintenance costs

Start-and-forget operation, combined with easy access to the interior, minimizes man-hours required for operation and maintenance, making Alfa Laval JWP freshwater generators easy to operate and maintain.

JWP freshwater generator range

Designed for automatic operation with continuous control of freshwater quality, the Alfa Laval JWP freshwater generator range comprises:

  • JWP-16 freshwater generator for capacities from 0.5 to 10 m3/24 h, depending on the heating medium and cooling water temperatures
  • JWP-26 freshwater generator for capacities from 4 to 35 m3/24 h, depending on the heating medium and cooling water temperatures

Upon request, Alfa Laval can tailor JWP freshwater generators with capacities up to 100 m3/24 h.

The freshwater generator can be dimensioned to suit any jacket water temperature from 55° to 95°C and any cooling water temperature required. The quantity of freshwater produced can be altered simply by varying the number of plates in the heat exchanger assemblies.

Ako to funguje

JWP freshwater generator equipment

The Alfa Laval JWP unit consists of a fresh water generator, including titanium plate heat exchangers for evaporator and condenser, generator shell, two-stage brine/air ejector, freshwater pump, freshwater control sensor and frame.

Operating principle

The feed water to be distilled is taken from the flow of seawater coolant from the condenser outlet (1). It enters the evaporator (10) where it evaporates at approximately 40° to 60°C as it passes between plates that are heated by the heating medium.

The evaporating temperature corresponds to a vacuum of 85–95%, maintained by the brine air ejector (not shown). The vapours generated pass through a demister, where any drops of seawater entrained are removed and fall due to gravity to the brine sump in the bottom of the generator chamber. The clean freshwater vapours continue to the condenser (9), where they condense into freshwater as they pass between the cold plates cooled by the cooling water.

Additional equipment necessary for operation

  • Combined cooling and ejector water pump with electric motor.
  • Manual starter box with motor starters and salinometer (JWP-16 only)
  • Control panel with motor starters and salinometer (JWP-26 only)
  • Anti-scale chemical dosing unit for feed water for heating medium temperatures that exceed 75°C.

Optional freshwater generator equipment

  • Hot water loop module for steam boosting of jacket water
  • Freshwater pH adjustment (rehardening) filter
  • Freshwater disinfection equipment
  • Extended control panel with motor starters and salinometer (JWP-26 only)
  • Individual single motor starters and salinometer (JWP-26 only)
JWP illustration large 440x440
  1. Seawater feed
  2. Heating medium in
  3. Heating out
  4. Seawater cooling in
  5. Seawater cooling out
  6. Freshwater out
  7. Evaporated steam
  8. Demister
  9. Condenser
  10. Evaporator
  11. Brine out