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Have you ever wondered how sailors and seamen manage to get access to fresh water when they are sailing?

Well, the answer is through the use of the freshwater generator which converts the seawater into freshwater. example is the alfa laval freshwater generator and lots more.

What is freshwater generator & What is the purpose of fresh water generator?


It is one of the sizable pieces of equipment onboard a ship, is something impossible to live without.

Freshwater introduced from the freshwater generator is applied for drinking, cooking, washing.

It is also used in running different significant hardware which makes use of clean water as a cooling medium.

What is the working principle of fresh water generator? (Mechanism of the freshwater generator)

Freshwater is commonly introduced onboard utilizing the evaporation method.

Two things are available in plenty on the ship to supply clean water, Seawater, and heat. The basic freshwater generator working principle is to ensure steady supply of quality fresh water to the seamen.

In this manner, clean water is introduced with the aid of using evaporating ocean water utilizing heat from any of the heat sources.

How much vacuum is created in fresh water generator?

The evaporated ocean water is alternatively cooled with the aid of using the seawater and the cycle repeats.

That’s performed by creating a vacuum in the chamber in which the evaporation is occurring.
In addition, due to the vacuum, the cooling of the evaporated ocean water will likewise occur at a lower temperature.
This cooled water is collected and moved to the tank.

What are the types of fresh water generator?

Plate Type Fresh Water Generator

This is a water maker designed and made as a single stage incorporated with double titanium plate packs chamber, specifically used onboard for the generation of fresh water to the seamen. This type of fresh water generator adopts the principle of converting the sea water to freshwater through the vacuum distillation approach which consists of the evaporation and condensation of the water.

Submerged Tube Type Fresh Water Generator

Just as the name goes submerged Tube fresh water generator  makes use of heat generated from the engine or steam to evaporate the  air/brine due to the available  high vacuum,  one side of  the shell and tube heat exchangers works as the evaporating  unit while the next works act the condensing unit.

Reverse osmosis plant

This is  another way of generating  freshwater to seamen through the use of the reverse osmosis method.This approach has to do with the elimination of dissolved minerals and other contaminants in the water by passing it through a membrane meant for such purpose.

It is one of the standard method of water treatment practiced in most of the modern water treatment plant. some ships have the mini-version of this plant  which helps to convert the sea water into freshwater for the seamen.


Flaws/Problems in freshwater generator

Issues in freshwater generators lower the overall performance of the system.
This results in diminishing high-satisfactory and quantity of freshwater created on ships.
These anomalies have to be identified and addressed fast to assure that the right purpose of the freshwater generator is done.

The Normal deficiencies in the freshwater generator are:

Loss of Vacuum or Over-pressure component of Shell

The shell pressure of the freshwater generator will increase and the quantity of freshwater produced decreases.
The reasons are:
1. Air leaks into the evaporator shell in large quantities and the air ejector cant adapt.
2. The cooling water route through the condenser is decreased or cooling water temperature is high.
This causes saturation temperature and henceforth saturation pressure in the condenser to rise.
3. Breaking down the air ejector.
4. The flow pace of the heating medium will increase and the abundance of water vapor created.
Since this overabundance vapor cant is condensed, shell pressure will increase or vacuum falls.

Salt Water Carryover

Saltwater might be carried in large quantities for the duration of activity of the clean water generator.
This is referred to as priming.

General reasons for priming are:

1. Level of saltwater in the shell is high.
At the point whilst the water level is high, unsettling due to bubbling takes place and saltwater may also retain along with the fumes.
2. At the point whilst the saltwater saline solution density is excessively high, agitation of saltwater takes place which brings about priming.
3. Increased evaporation rate.
Gradual Increase in Level of Brine
For the coolest operation of the freshwater generator, there’s a consistent degree of saline solution to be kept up within the shell.
Saline solution is the concentrated seawater after the evaporation of water.
This saline solution is gradually eliminated from the shell.
Generally, that is done with the aid of using the combined air-brine solution ejector.
It eliminates air in addition to brine from the shell.
Any flaw within the ejector or brine ejection pump causes the increment within the saline solution level.

Increase in Salinity of Freshwater Potential reasons are:

• Brine level inside shell excessively high.
• Leaking condenser tubes or plates.
• Operation of evaporator near shore with tainted feed water.
• Shell temperature and pressure were excessively low.
• Increased solubility of CO2 constituted of the saltwater due to decreased seawater temperature.
This disintegrated CO2 makes water acidic and the conductivity of water increases.
Consequently, a salinometer indicates increased saltiness, which’s a proportion of conductivity and not the presence of salt.

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