Boiler types

The first use of new plant, or start-up after a shutdown, poses corrosion hazards additional to those encountered in normal operation. New plant such as boilers requires special water treatment, involving boil-out, passivation and possible chemical cleaning. Actual requirements depend on the boiler type, the proposed service, the quality of water available during commissioning and the internal condition of the boiler. The condition of the boiler depends on for how long and in what conditions it has been stored. The presence of any salts, dirt or rust is harmful. An adherent, protective layer of magnetite in normal operation... 

Each boiler type may be further classified according to design, output, pressure rating, and application, although not every type is available in all permutations. 

The first three boiler types may be variously used for commercial, institutional, or industrial applications. Fire tube boilers also may be used for steam turbine generator duty at lower electrical outputs, whereas only WT and nuclear reactor boilers are employed for utility power generation. 

Boiler Types and Applications 2.3.1.3 Water Tube Exit Gas Section... 

Combined Cycle Boiler Systems These boiler types are used to harness the waste heat from one power source to provide the heat source for a second power source, usually an electricity generator via a steam turbine. They are a form of cogeneration boiler plant. 

When silica levels increase, hydroxide alkalinity measurements become increasingly important to ensure maximum silica solubilization and the reduction of risk of silica deposition. This is especially so for coil boilers because, more than any other boiler type, the use of hydroxide is critical in keeping the waterside surface of the coiled tube clean and deposit free. 

Table 12.1 Guide to Authoritative Recommendations for Operational Control of BW Chemistry, by Boiler Type...

Table 12.1 above provides a summary guide to these additional 17 tables and is classified by boiler type. 

This title is somewhat misleading. The following article is primarily concerned with expl reactions of fuel mists (and/or vapors) with oxygen of the air. The article does not include consideration of flash vaporizations that occur when very hot substances (molten A1 for example) come into contact with a volatile liquid (eg, water), nor does it concern itself with steam-boiler type explns. Thus the subject matter of this article deals with rapid fuel oxidations with the oxidant usually provided by the oxygen of the air, though reactions of monopropellant type mists will also be considered. Most of the fuels of interest are liquids at ordinary ambient conditions... 

The following sections describe each boiler type and summarize its operation with and without TDF. 

A fluidized bed combustion system (FBC) is one that has a high temperature (1500 F to 1600 F) inert material, such as sand, ash, or limestone, occupying the bottom of the chamber.14 Figure 2-3 illustrates a typical fluidized bed boiler. Limestone, either as primary bed material, or as an addition, provides the additional advantage of S02 scrubbing.14,15 The advantage of fluidized bed combustion over the other 3 boiler types is that the fluidization of the inert bed material allows fuels with higher moisture and ash content to be burned, and still yield nearly complete combustion. Further, SOx control is easily and efficiently accomplished. The bed material is fluidized by one of two methods as described below. 

Three different types of coal fired boilers were utilized in this study. One type (A) was a dry bottom boiler with direct fired burners located on opposite walls. The second type (B), wet bottom boilers 11 and 12, was operated in parallel with the same coal stream split to feed both boilers simultaneously. The third boiler types (C D) were dry bottom, tangentially fired boilers. 

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