Boiler Cleaning

Glycohc acid [79-14-1], HOOCCH2OH, mol wt 76.05, can be obtained by the electrolytic reduction of oxaUc acid or the catalytic reduction of oxaUc acid with hydrogen in the presence of a mthenium catalyst. Because of its acidity it is used as a cleaning agent for metal surface treatments and for boiler cleaning. It also serves as an ingredient in cosmetics (qv). 

A chelant—polymer program can produce clean waterside surfaces, contributing to much more rehable boiler operation. Out-of-service boiler cleaning schedules can be extended and, in some cases, eliminated. This depends on operational control and feed-water quaUty. Chelants with high complexing stabiUties are "forgiving" treatments they can remove deposits that form when feed-water quaUty or treatment control periodically deviates from standard. 

Caustic or acid cleaners Boiler cleaning wastes Boiler refractory bricks... 

When boiler cleaning takes place, it often is followed by the circulation of a hot alkaline phosphate solution to provide adequate passivation of metal surfaces. (A typical formulation may also include sodium gluconate, antifoam, and dispersants.)... 

HEDTA has been widely used as a boiler cleaning compound, but has proved useful for iron control at elevated temperatures. HEDTA is supplied as 98% Na HjO (MW 380) and has a chelating activity of 258 mg CaC03/g at a pH level of 11. 

The burner and associated equipment must be wrapped up or otherwise protected against dirt and soot. The front doors are opened and plastic sheeting is attached to minimize the spread of soot. The tubes are brushed, and the soot and dirt are vacuumed away while brushing takes place. Some contractors have truck-mounted vacuum systems to increase efficiency and minimize post-boiler cleaning work. 

Laronge, Thomas M. Boiler Cleaning Boilers Without Mistakes. Industrial Water Treatment, Tall Oaks Publishing, Inc., USA, March/April 1995. 

AVT Barg BD BDHR BF BOF BOOM BOP BS W BSI BTA Btu/lb BW BWR BX CA CANDUR CDI CFH CFR CHA CHF CHZ Cl CIP CMC CMC CMC COC All-Volatile treatment bar (pressure), gravity blowdown blowdown and heat recovery system blast furnace basic oxygen furnace boiler build, own, operate, maintain balance of plant basic sediment and water British Standards Institution benzotriazole British thermal unit(s) per pound boiler water boiling water reactor base-exchange water softener cellulose acetate Canadian deuterium reactor continuous deionization critical heat flux Code of Federal Regulations cyclohexylamine critical heat-flux carbohydrazide cast iron boiler clean-in-place carboxymethylcellulose (sodium) carboxy-methylcellulose critical miscelle concentration cycle of concentration... 

Traditionally, a common solution to the problem of matching relatively higher levels of technical support with lower chemical volumes for these smaller customers has been via a one- to three-year, fully inclusive product and services contract. Such a contract will specify the frequency of service visits to be made to the customer s site and the type of work to be carried out. It will also, perhaps, limit the maximum volumes of chemical treatments to be supplied during the contract lifetime, or perhaps designate the amount of chemicals required based on treating a certain annual volume of boiler FW. Contracts may include for the provision of chemical feed and control equipment and for the supply of labor for boiler cleaning, chemical addition, and drum removal services (drumless delivery). Product and services contract prices may some-... 

Alkaline cleaning (flush/boil-out) is commonly employed prior to boiler cleaning to remove oil-based compounds from tube surfaces. These solutions are composed of trisodium phosphate and a surfactant and act to clear away the materials that may interfere with reactions between the boiler cleaning chemicals and deposits. 

Sulfuric acid has found limited use in boiler cleaning operations. It is not feasible for removal of hardness scales due to the formation of highly insoluble calcium sulfate. It has found some use in cases where a high-strength, low-chloride solvent is necessary. Use of sulfuric acid requires high water usage in order to rinse the boiler sufficiently. 

Yager, J.W., Hicks, J.B. and Fabianova, E. (1997) Airborne arsenic and urinary excretion of arsenic metabolites during boiler cleaning operations in a Slovak coal-fired power plant. Environmental Health Perspectives, 105(8), 836-42. 

Emissions Reduction Equipment Waste-to-Energy Biomass Energy Systems Boiler Cleaning Equipment... 

Production of heat energy at Rohm Haas has been improved by better control of combustion in boilers, cleaning and maintenance of boilers and process heaters to maintain their efficiency, elimination of steam leakages, steam trap maintenance, and improved condensate recovery (4). 

Excessive us of high-pressure steam soot blowers is a common source of tube erosion-corrosion. Other boiler cleaning methods less threating to boiler tubes are available such as mechanical rapping, shot cleaning, and compressed air soot blowing. 

DETERGENT CLEANING - A boiler cleaning process using an alkaline solution, primarily to remove oil and grease. 

The SOa-containing gas leaving the furnace is cooled in a WHRB (waste heat recovery boiler), cleaned, and then admitted to the converter of the sulfuric acid plant. 

Waste in transportation pipeline related pits Caustic or acid cleaners Boiler cleaning wastes Boiler refractory bricks Boiler scrubber fluids, sludges, and ash Incinerator ash Laboratory wastes Sanitary wastes Pesticide wastes Radioactive tracer wastes Drums, insulation, and miscellaneous solids... 

The use of the waste iron-EDTA solution is an important idea that has also been considered in the past. EDTA-containing boiler wastes have been spread on dormant alfalfa. The farm plots treated with diluted boiler wastes produced more crop than the untreated plots. This probably is due to the ammonia and iron contained in the boiler cleaning wastes. More attempts to reuse the valuable metals and "chelated micronutrients" should be investigated. 

Features Maintains efficient heat transfer and decreases the incidence of boiler clean up, thus lowering operating costs... 

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