Examples boilers

Process or heating plant may have controls ranging from manual operation with some processes supervised by interlocks to semi-automatic and fully automatic operation. Deciding factors will include temperature of operation, frequency of ignition, degree of operator supervision, and rating of the plant. For example, boiler plant, both steam and water, will invariably have automatic control whereas tunnel kilns operated continuously at high temperature are unlikely to require it. 

Almost all boiler section scale, fouling, deposit, or corrosion problems, however, tend to be associated with additional (and often very similar) problems both upstream and downstream of the boiler itself. Therefore, the presence of, for example, boiler deposits or localized corrosion issues should never be viewed in isolation. Rather, they should be investigated in the light of a likely chain of cause and effect, and the basic causes of the problems should be eliminated wherever possible, rather than simply the noticeable effects. 

Examples Boilers Flares Fired heaters Burners Examples Continuous or batch chemical reactions Catalytic cracking Coking... 

Determine the required capacity of the pump. The required capacity is the flow rate that must be handled in gal/min, million gal/day, ft3/s, gal/h, bbl/day, lb/h, acre-ft/day, mil/h, or some similar measure. Obtain the required flow rate from the process conditions—for example, boiler feed rate,... 

Elevated temperatury properties are, however, quoted in an increasing number of European standards. In Britain, Italy and France, for example, boiler plate standards include elevated temperature properties for some or all of the more important grades. Most of these specifications give impact properties for one or more temperatures. Such properties are not necessarily achieved, of course, unless the steel is specified to be impact tested. 

Steam generation depends on heat recovery equipment installed, for example boilers, economisers, etc., and factors such as feed water temperature, boiler operating pressures, etc. 

The fu notion of refractory materials is to protect metal parts from coming into direct contact with flames or with very hot gases or solids. For example, boiler plate undergoes a marked decline in strength at temperatures above 400 C, while clinker temperatures are in the range of about 1350°—1550°C and the flames in kilns attain almost 1900°C. 

The separation of high risk areas - all rooms and areas containing high fire risks, for example boiler rooms, kitchens, tea rooms or rooms In which high risk processes are carried out, should be separated from the remainder of the building by fire resisting construction of... 

Explosion Is a multi-valued term sometimes its meaning is vague because it is used to express various ideas, for example boiler explosion, short circuit explosion, deflagration-to-detonation transition, deflagration in vessels filled with combustible mixtures. The term explosion correlates with shock waves, fire balls and debris. At the early stage of explosion investigations this phenomenon was determined as a gas rush accompanied by loud sound and mechanical effects into a space much larger than the initial source . 

Fuel switch. The choice of fuel used in furnaces and steam boilers has a major effect on the gaseous utility waste from products of combustion. For example, a switch from coal to natural gas in a steam boiler can lead to a reduction in carbon dioxide emissions of typically 40 percent for the same heat released. This results from the lower carbon content of natural gas. In addition, it is likely that a switch from coal to natural gas also will lead to a considerable reduction in both SO, and NO, emissions, as we shall discuss later. 

However, the deposition of salts from temporarily hard water in boilers, and so on (for example the fur found in kettles) makes it desirable to soften such water for domestic and industrial use. Very... 

Some beehive ovens, having various improvements and additions of waste heat boilers, thereby allowing heat recovery from the combustion products, may stiU be in operation. Generally, however, the beehive oven has been replaced by waH-heated, horizontal chamber, ie, slot, ovens in which higher temperatures can be achieved as well as a better control over the quality of the coke. Modem slot-type coke ovens are approximately 15 m long, approximately 6 m high, and the width is chosen to suit the carbonization behavior of the coal to be processed. For example, the most common widths are ca 0.5 m, but some ovens may be as narrow as 0.3 m, or as wide as 0.6 m. 

Chemically Resistant Fibers. Fibers with exceUent chemical resistance to corrosive and/or chemical warfare agents or extreme pH conditions (eg, very acidic or very alkaline) were initially used for protective clothing. However, appHcations for filtration of gases and Hquids in numerous industrial faciHties are now the more important. For example, PPS is suitable for use in filter fabrics for coal-fired boilers because of its outstanding chemical and heat resistance to acidic flue gases and its exceUent durabUity under these end use conditions. Many high tenacity fibers are also chemically inert or relatively unaffected under a variety of conditions. Aramids, gel spun polyethylene, polypropylene, fluorocarbon, and carbon fibers meet these criteria and have been used or are being considered for appHcations where chemical resistance is important. 

Phosphonic acid is an intermediate in the production of alkylphosphonates that are used as herbicides and as water treatment chemicals for sequestration, scale inhibition, deflocculation, and ion-control agents in oil weUs, cooling tower waters, and boiler feed waters. For example, aqueous phosphonic acid reacts with formaldehyde and ammonium chloride in the presence of hydrochloric acid to yield aminotri(methylenephosphonic acid) [6419-19-8]. 

Emissions control systems play an important role at most coal-fired power plants. For example, PC-fired plants sited in the United States require some type of sulfur dioxide control system to meet the regulations set forth in the Clean Air Act Amendments of 1990, unless the boiler bums low sulfur coal or benefits from offsets from other highly controlled boilers within a given utiUty system. Flue-gas desulfurization (FGD) is most commonly accomphshed by the appHcation of either dry- or wet-limestone systems. Wet FGD systems, also referred to as wet scmbbers, are the most effective solution for large faciUties. Modem scmbbers can typically produce a saleable waUboard-quaUty gypsum as a by-product of the SO2 control process (see SULFURREMOVAL AND RECOVERY). 

Moderately Volatile Ma.teria.ls, For moderately volatile materials, such as the amines commonly used in feedwater and boiler water chemical treatment, the distribution ratios vary from 0.1 to 30 for gases, the ratios are much higher. The distribution ratios of amines and organic acids are generally temperature-dependent. The distribution ratios for ammonia [7664-41-7] morpholine [110-91-8] and acetic acid [64-19-7] are shown in Figure 16 as examples. 

Analytical Methods. A classical and stiU widely employed analytical method is iodimetric titration. This is suitable for determination of sodium sulfite, for example, in boiler water. Standard potassium iodate—potassium iodide solution is commonly used as the titrant with a starch or starch-substitute indicator. Sodium bisulfite occurring as an impurity in sodium sulfite can be determined by addition of hydrogen peroxide to oxidize the bisulfite to bisulfate, followed by titration with standard sodium hydroxide (279). 

Figure 5 shows the phosphate—pH relationship recommended to control boiler corrosion. Different forms of phosphate consume or add caustic as the phosphate shifts to the proper form. For example, addition of monosodium phosphate consumes caustic as it reacts with caustic to form disodium phosphate in the boiler water according to the following reaction ... 

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