Chemical treatments and programs

Frayne C. Chemical treatments and programs for cooling water. In Cooling Water Treatment - Principles and Practice. New York Chemical Publishing Company Inc. 1999. p 137-176. Avadahle at www.knovel.com/web/portal/browse/display7 EXT KNOVEL DISPLAY bookid = 3074 VerticalID=0. Accessed 2012 Feb 25. 

In addition to supplying the various water-steamside conditioning equipment, chemical treatments, and periodic cleaning or other specialist services, service companies are expected to provide advice, practical expertise, and general support for their program in a proactive manner, to prevent waterside and operational problems from occurring. 

Deposition can be minimized by a combination of good operating practice and overall program management, together with the use of appropriate external conditioning equipment, internal chemical treatments, and proper chemical feed and control methods. 

Under these conditions, cooling water cycles of concentration are likely to be restricted to a maximum of only 2.5 to 4x without some innovative chemical treatment and operations programming. Sources of subsurface water with hardness and alkalinity contents much higher than those cited are likely to be unsuitable for cooling systems without some form of additional pretreatment, such as dealkalization, partial softening, use of RO, or blending with lower alkalinity/lower hardness supplies. 

A characteristic of the various codes of practice and available guidelines is that they ALL recommend comprehensive water treatment programs, and, furthermore, they place reliance on conventional chemical treatments and formalized monitoring services to achieve compliance. 

At the point of system hand-over, the chemical treatment maintenance program can be regarded to have come into effect, and periodic site visits, testing, inspections, and occasional chemical top-ups then become necessary. 

Nevertheless, it is usually expected that such nonchemical control devices will already be in place (although it is still surprising to discover how many cooling towers fail to incorporate such basic items). As a result, we are primarily concerned with the dosing of chemical treatments and the control of program variables. And today, it sometimes appears that there are almost as many permutations of ideas and procedures for dosing and control systems as there are applications for cooling water. 

SENES Consultants Ltd., Acid Mine Drainage - Status of Chemical Treatment and Sludge Management Practices , Report prepared for the Canadian Mine Environment Neutral Program (MEND) and CANMET. Canadian Center of Mineral and Energy Technology, Ottawa, Canada, 1994. 

New chemical treatment programs were proposed that would permit reduction of staining at a higher pH and markedly reduce corrosion. 

Immediately following the cleaning and passivation program, the boiler should be refilled and an initial-fill dose of suitable chemical treatment inhibitors) provided. The amount of treatment added is a function of the volume of water required to fill the boiler, whereas during boiler operation the feed-rate of chemical is proportional to the demand for MU water. 

In addition, attention must be paid to the BW internal treatment program. Such programs involve the dosing of small amounts of polishing chemical treatments to specified points in the water-steam cycle system, often continuously and proportional to water flow or steam demand, to provide a desired inhibitory or protective effect. 

Also, the particular boiler plant water-steam chemistries must be reviewed and interpreted at regular intervals. The specifics and complexity of this work depend on the type of boiler plant involved and the respective chemical treatment programs employed. The frequency of testing may range from hourly to perhaps monthly, again depending on the type of boiler operation. 

Some of the chemical treatment testing work may fall to a boiler plant operator or laboratory analyst, and such involvement generally is a good idea because it stimulates interest in the boiler-related treatment processes and the chemical programs provided to a site. However, irrespective of the level of technical qualifications held by site personnel,... 

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