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ORGANIC WATER TREATMENT CHEMICALS
STEAM BOILERS, COOLING TOWERS, HOT AND CHILLED CLOSED SYSTEMS
FUEL OIL TREATMENT

PRODUCT REMOVAL CHART

CLASS

NAME

FORMULA

DIFFICULTY CAUSED

LIMITS OF TOLERANCE

MEANS OF REMOVAL

SPECIAL REMARKS

 

Hydrogen sulfide

H2S

Corrosion; harmful to process

Under 5 ppm

Alteration and filtration; chlerination

Found principally in ground waters and polluted steams

 

Carbon dioxide

CO2

Decreases pH of water; causes acid corrosion if alkalinity is low

Ratio of alkalinity to CO2 must be greater than 3 to 1

Aeration; neutra­­li­zation with alakalies; deaeration

CTNC, CTB CTB

Filming or neutra­li­zing amines used to prevent conden ­ sate line corrosion

 

Oxygen

O2

Corrosion and pitting (special form of corrosion)

Under 0.005 ppm for steel-tube eco­no­mizers, high­-pressure boilers

Deaeration; che­mi­cal treat­ment with sodium sulfite.

D. M. CONCENTRATE

Can also cause pitting of steam lines, turbines, condensate lines etc.

 

Sediment Turbidity

 

Sludge, scale, carry over; harmful to process

Under 5 ppm for general purposes

Coagulation; fil­tra­tion; sedimen­tation (settling)

THERMIZE

 

 

Organic matter

 

Foaming; harmful to process

Limits depend on application

Same as above; also chemical treatment  

D. M.  or THERMIZE

 

 

Oil

 

Foaming; deposits in boiler

Under 0.5 to 1 ppm

Coagulation; filtration

H. Boilout

Mostly enters with condensate

 

Hardness

Ca(HCO3)2,    Ca and CaCO3, Mg salts) CaSO4,CaCl2 Mg(HCO3l2 MgCO3,MgSO4 MgCl2)

Scale deposits in boiler; forms insoluble curds in washing proces­ses; MgCl2is also corrosive

0-2 ppm* in high pres­­sure boilers, under 17-25 ppm* for low-pressure boilers with enough sodium alkalinity present

Softening plus internal treat­ment in boiler

Calcium salts are chief cause of scale in boilers, followed by magnesium. Mag­nesium scale is not as hard as calcium scale.

 

Sodium al­ka­-linity

NaHCO3,

Na2CO3,

NaOH

Foaming; Car­bonates form CO2 in steam to cause return line corrosion; may contribute to embrit­tlement

0-5ppm* for high pressure boilers, depends on individual conditions for low-pressure boilers

Hydrogen exchanger, deioni­zation, acid treatment with deaeration

Sodium salts are found in most waters, are very soluble and can't be removed by chemical precipitation.

 

Sulfates

SO4

Hard scale if calcium is present

100-300 ppm* for general purposes

Deionization

 

 

Chlorides

Cl

Priming, foaming if present in large amounts

Depends on indivi­dual conditions

Deionization

 

 

Iron Mananese

Fe

Mn

Deposits in boiler if present in large amounts; harms process

Under 0.3 ppm for general purposes

Aeration plus filtration; ion exchange

 

 

Silica

SiO2

Hard Scale in boilers, turbine-blade deposits

Under 10-15 ppm if concentrated salines of high-pressure boilers if alkalinity is low; to under 3-5 ppm to avoid turbine deposits

Deionization; lime­-soda process with addition of ferric sulfate (cold) or Mg reagent (cold or hot)

When combined with aluminium salts forms extremely hard scale in boilers.

 * ppm as CaCo3  

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