A steam generator on a ship is an auxiliary boiler which draws high-pressure

superheated steam Superheated steam is steam at a temperature higher than its vaporization point at the absolute pressure where the temperature is measured. Superheated steam can therefore cool (lose internal energy) by some amount, resulting in a lowering of ...

from the vessel's propulsion system to generate low pressure

saturated steam Steam is a substance containing water in the gas phase, and sometimes also an aerosol of liquid water droplets, or air. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization ...

. This secondary steam is then used to power auxiliary shipboard engines driving winches or pumps, or to meet any steam requirement that does not require superheating, such as

boiler feedwater Boiler feedwater is an essential part of boiler operations. The feed water is put into the steam drum from a feed pump. In the steam drum the feed water is then turned into steam from the heat. After the steam is used it is then dumped to the m ...

and freshwater

evaporator An evaporator is a device used to turn the liquid form of a chemical substance, such as water, into a vapor. Uses Air conditioning and refrigeration Some air conditioners and refrigerators use a compressed liquid with a low boiling point, s ...

Types

Low-pressure steam generators

A typical generator uses inlet steam supplied at 600 psi to produce around 10,000 lb/hour at around 120 psi. It is constructed as a cylindrical steel pressure vessel, either horizontal or vertical, containing a series of heating coils. The design bears a strong resemblance to a marine evaporator, though simpler, as it uses treated feedwater, rather than

scale Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number ...

-producing raw seawater.

References

Steam boilers Boilers Marine steam propulsion {{ship-type-stub