Boiler feed water, treatment

Humidification. For wiater operation, or for special process requirements, humidification maybe required (see Simultaneous HEAT and mass transfer). Humidification can be effected by an air washer which employs direct water sprays (see Evaporation). Regulation is maintained by cycling the water sprays or by temperature control of the air or water. Where a large humidification capacity is required, an ejector which direcdy mixes air and water in a no22le may be employed. Steam may be used to power the no22le. Live low pressure steam can also be released directly into the air stream. Capillary-type humidifiers employ wetted porous media to provide extended air and water contact. Pan-type humidifiers are employed where the required capacity is small. A water filled pan is located on one side of the air duct. The water is heated electrically or by steam. The use of steam, however, necessitates additional boiler feed water treatment and may add odors to the air stream. Direct use of steam for humidification also requires careful attention to indoor air quahty. 

Site development Boiler feed-water treatment... 

Rico B, Perez D, Lema JM, Lucas T. Organic matter removal in boiler feed water treatment of a power plant with ozone. Ozone Sci Eng 1997 19 471 180. 

Boilers, steam mains, condensate lines, boiler feed water treatment plant, supply pumps ... 

The price of HP steam can be estimated from the cost of boiler feed water treatment, the price of fuel, and the boiler efficiency ... 

Where steam is used for cleaning, to sterilise either plant or product by direct injection, then it can become an integral part of the food. The composition of steam must therefore be controlled with respect to the additives employed for treatment. Since it is possible for chemicals added to boiler feed water to be carried with the steam to the point of use. No boiler feed water treatment chemical should be employed till it has been shown to be safe in respect of food product quality. In the UK permitted chemicals include [HMSO 1983] ... 

Proper cooUng water and boiler feed water treatments are important to minimize equipment fouling and corrosion. Seawater is occasionally used for acid cooling requiring careful material selection. 

Environmental control is essential to meet EPA demands. It has been estimated that for a plant consuming 37 million Btu/ton of ammonia produced, environmental control will require 0.7 million Btu, and environmental costs will be 1.1 percent of the operating costs. Discharge streams that require processing to eliminate undesirable contaminants include (1) the regeneration acid and base for boiler feed-water treatment units, (2) the regeneration steam for natural gas desulfurization catalysts, (3) the low temperature shift condensate (ammonia, amines, and methanol), and (4) CO2 removal process regeneration effluents. 

Uses Dispersant for concrete admixtures, boiler feed water treatment, dyestuff dispersant and extender, sludge conditioner Properties Bm. powd. dens. 28-32 lb/lt 3 pH 6.8 (27%) 95% act. 

The prime purpose of boiler feed water treatment is to protect the boiler, and in particular the heating surfaces, from corrosion and deposition of solids on them -the purity of the steam is largely taken care of by the evaporation of the water, which leaves behind any residual impurities in the boiler. Therefore the treatment processes have to deal with a number of contaminants in the make-up water, and these processes may be either external ones, carried out in the treatment plant, or internal, which conditions the water or steam in the feed lines or in the boiler itself. 

The other major separation task in boiler feed water treatment is the removal of dissolved gases, especially oxygen and carbon dioxide, which will cause corrosion in the boiler. These can be removed by mechanical de-aerators, or chemicals may be added that will scavenge these gases. 

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