1-.Introduction Why we need the fresh water generator? A very good question about any machinery present in any industry. See in shipping the main thing is the time and money and its pure business out there. The owner wants to get as much profit as he or she can. So, why we need fresh water generator? One use is the simple one that we need fresh water for drinking. But why we install machinery which is bigger in size, to generate water for drinking only. So what are the major uses of this? The major use of this water comes for the Boiler which operates in the ship. The boiler needs demineralized water as it will help in reducing the corrosion and scale formation in the boiler surfaces. We can’t carry water in advance for the boiler as the consumption will be more. The boiler steam is used for Steam supply, heating oil’s, laundry, cleaning and cooking service. The fresh water generator is an efficiency increasing device also. The jacket cooling water which comes out of the engine after taking heat from the various combustion spaces like near ‘liner’, is used to heat the water. So we are using the heat of engine to generate fresh water. So here we are saving money by not installing any separate burning mechanism for it. Now it’s time to check how this machine works. 2-.Process. How the fresh water is generated The thing which I said previously that it uses the cooling engine water to heat and generate water was looking good but here is a flaw. The flaw is that the temperature of the water coming out of the engine is hardly 60 or 70 degree Celsius. So, how come we can evaporate water to generate fresh water? Because water boils only at the 100 degree Celsius. So here come the minds of the marine engineers. They reduce the pressure inside the generator in order to reduce the boiling point of water. We use vacuum to evaporate water at lower temperatures like 50 or 55 degree Celsius.
1-.IntroductionWhy we need the fresh water generator?A very good
question about any machinery present in any industry. See in
shipping the main thing is the time and money and its pure business
out there. The owner wants to get as much profit as he or she can.
So,why we need fresh water generator? One use is the simple one
that we need fresh water for drinking. But why we install machinery
which is bigger in size, to generate water for drinking only. So
what are the major uses of this? The major use of this water comes
for the Boiler which operates in the ship. The boiler needs
demineralized water as it will help in reducing the corrosion and
scale formation in the boiler surfaces. We cant carry water in
advance for the boiler as the consumption will be more. The boiler
steam is used for Steam supply, heating oils, laundry, cleaning and
cooking service.
The fresh water generator is an efficiency increasing device
also. The jacket cooling water which comes out of the engine after
taking heat from the various combustion spaces like near liner, is
used to heat the water. So we are using the heat of engine to
generate fresh water. So here we are saving money by not installing
any separate burning mechanism for it. Now its time to check how
this machine works.
2-.Process. How the fresh water is generatedThe thing which I
said previously that it uses the cooling engine water to heat and
generate water was looking good but here is a flaw. The flaw is
that the temperature of the water coming out of the engine is
hardly 60 or 70 degree Celsius. So, how come we can evaporate water
to generate fresh water? Because water boils only at the 100 degree
Celsius. So here come the minds of the marine engineers. They
reduce the pressure inside the generator in order to reduce the
boiling point of water. We use vacuum to evaporate water at lower
temperatures like 50 or 55 degree Celsius.
The feed water to be distilled is taken from the sea cooling
water outlet of the condenser. It enters the evaporator where it
evaporates at about 40-50 degrees celcius as it passes between the
plates heated by the heating medium.The evaporating temperature
corresponds to a vacuum of 90-95% maintained by the brine/air
ejector. The vapours generated pad trough a demister where any
drops of seawater entrained are removed and fall due to gravity to
the brine sump (sumidero) in the bottom of the distiller chamber.
The clean freshwater vapours continue to the condenser, where they
condense into fresh water as they pass between the cold plates
cooled by the sea cooling water.In order to check continuously the
quality of the produced fresh water, a salinometer is provided
together with an electrode unit fitted on the fresh water pump
delivery side. If the salinity of the produced fresh water exceeds
the permitted maximum value /2ppm/, the solenoid valve and alarm
are activated to dump automatically the produced fresh water to the
bilge
