DriSteem Vaporstream Especificações descarregar pdf (Página 39)

P a g e 3 4 • D R I - S T E E M D e s i g n G u i d e

D R I - S T E E M D e s i g n G u i d e • P a g e 3 5

High purity water yields high purity humidification

for critical process environments

Semiconductor, pharmaceutical, and electronics manufacturers,

as well as laboratories, industrial clean rooms, and healthcare

facilities often require high purity humidification. To avoid

water contaminants that can be carried into the air with water

vapor, these types of environments use highly processed – and

very pure – water in their humidification systems. For these

environments, water is cycled through several prefilters, through

a reverse osmosis permeable membrane and, frequently, through

a chemical deionization process. This type of high purity water is

often called “DI/RO” water (deionized, reverse osmosis water) and,

depending on the quality of process, can be free of minerals and

other contaminants. The purity of this water degrades upon contact

with the atmosphere and certain materials, and should remain in a

closed system contacting only chemically stable materials.

Properly maintained DI/RO water is not corrosive

A well-maintained DI/RO system produces water that consists

solely of hydrogen and hydroxides and is free of most or all total

dissolved solids (TDS) including chlorides and other molecules that

cause metal corrosion.

Many users of high purity water have the false impression that it is

highly corrosive to metals. This may be due, in part, to the water

quality found in systems that have not been properly maintained

or operated. If, for example, DI beds are not properly maintained,

or the flow rate through them exceeds their capacity, the first of

the two DI beds (the cation bed) typically becomes saturated or

ineffective, and then the weak acid solutions generated by the

second bed (the anion bed) cannot be neutralized and flow into

the water system. If this happens, chlorides and other electrolytes

are introduced into the system in large quantities, with the ability

to cause substantial corrosion. This is important to note, for any

damage to DRI-STEEM equipment caused by chlorides will void

your DRI-STEEM warranty.

Another misconception about DI/RO water is that its ion-hungry

nature causes metal corrosion, but while properly maintained high-

purity water will take some ions from the metal it contacts, this

exchange process causes, at worst, only minimal corrosion.

Figure 35-1:

Single tank (mixed bed) DI system

Figure 35-2:

Two-tank DI system

Pure water

Raw water

Causes a series of cation

and anion exchanges

Raw water

Weak acid solution

Pure water

Replaces sodium, calcium,

magnesium and other cations

with hydrogen ions (H+)

Exchanges chloride,

sulfate, and alkaline ions

for hydroxide ions (OH-)

1 2 ... 34 35 36 37 38 39 40 41 42 43 44 ... 83 84

Comentários a estes Manuais

Sem comentários

DriSteem Vaporstream Especificações Página 39

Comentários a estes Manuais

Manuais e produtos relacionados com Desumidificadores DriSteem Vaporstream