Multiple-effect evaporator
Encyclopedia
A multiple-effect evaporator, as defined in chemical engineering
, is an apparatus for efficiently using the heat from steam
to evaporate water.Unit Operations in Food Processing - R. L. Earle In a multiple-effect evaporator, water is boiled in a sequence of vessels, each held at a lower pressure than the last. Because the boiling temperature of water decreases as pressure decreases, the vapor boiled off in one vessel can be used to heat the next, and only the first vessel (at the highest pressure) requires an external source of heat. While in theory, evaporators may be built with an arbitrarily large number of stages, evaporators with more than four stages are rarely practical except in systems where the liquor is the desired product such as in chemical recovery systems where up to seven effects are used.
The multiple-effect evaporator was invented by American inventor and engineer Norbert Rillieux
. Although he may have designed the apparatus during the 1820s and constructed a prototype in 1834, he did not build the first industrially practical evaporator until 1845 . Originally designed for concentrating sugar
in sugar cane juice, it has since become widely used in all industrial applications where large volumes of water must be evaporated, such as salt
production and water desalination
.
Multiple-effect evaporation plants in sugar beet factories have up to eight effects.
Chemical engineering
Chemical engineering is the branch of engineering that deals with physical science , and life sciences with mathematics and economics, to the process of converting raw materials or chemicals into more useful or valuable forms...
, is an apparatus for efficiently using the heat from steam
Steam
Steam is the technical term for water vapor, the gaseous phase of water, which is formed when water boils. In common language it is often used to refer to the visible mist of water droplets formed as this water vapor condenses in the presence of cooler air...
to evaporate water.Unit Operations in Food Processing - R. L. Earle In a multiple-effect evaporator, water is boiled in a sequence of vessels, each held at a lower pressure than the last. Because the boiling temperature of water decreases as pressure decreases, the vapor boiled off in one vessel can be used to heat the next, and only the first vessel (at the highest pressure) requires an external source of heat. While in theory, evaporators may be built with an arbitrarily large number of stages, evaporators with more than four stages are rarely practical except in systems where the liquor is the desired product such as in chemical recovery systems where up to seven effects are used.
The multiple-effect evaporator was invented by American inventor and engineer Norbert Rillieux
Norbert Rillieux
Norbert Rillieux , an American inventor and engineer, is most noted for his invention of the multiple-effect evaporator, an energy-efficient means of evaporating water. This invention was an important development in the growth of the sugar industry...
. Although he may have designed the apparatus during the 1820s and constructed a prototype in 1834, he did not build the first industrially practical evaporator until 1845 . Originally designed for concentrating sugar
Sugar
Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...
in sugar cane juice, it has since become widely used in all industrial applications where large volumes of water must be evaporated, such as salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
production and water desalination
Desalination
Desalination, desalinization, or desalinisation refers to any of several processes that remove some amount of salt and other minerals from saline water...
.
Multiple-effect evaporation plants in sugar beet factories have up to eight effects.