Plant Service Boilers

The onsite plant service boilers provided steam for the reactor coolant pump drive turbines and for the onsite turbine generator as a backup power supply (WHC 1989a). 

The boiler fuel oil system supplied No. 6 fuel oil to the plant service boilers. The total capacity of the system is 5,500,000 L (1,445,000 gal). 

Utilities and yard services (boiler plant, refrigeration, compressed air, water supply and treatment, effluents, fire protection, yard piping, yard electrical, yard materials handling, raw and finished-product storage)... 

One boiler was housed in the 184-N plant service powerhouse and two boilers were housed in the 184-N building annex. During reactor operation, the boilers were maintained in a condition capable of being brought on line to carry the shutdown load. These boilers could supply approximately 150,000 kg (340,000 lb) of steam per hour (WHC 1989a). 

N Plant Service Power House Hydrocarbons, particulates, sulfur dioxide, sulfur trioxide, carbon monoxide, nitrogen oxide, and aldehydes. Routine and systematic releases form boiler stacks. 

Minimizing steam consumption by using fired heater reboilers will minimize steam plant and boiler feedwater preparation facilities. An alternate approach is to use a hot oil loop where one furnace fires enough heat for all reboilers on the service. 

In 1983 there were 116 flue-gas desulfurization (FGD) systems in service, representing 47 gigawatts-electric of power generation capacity (66). As of 1992, more than 150 coal-fired boilers in the United States operated with FGD systems. The total electrical generating capacity of these plants has risen to 72 gigawatts (67). FGD processes are classified into (/) wet-throwaway, (2) dry-throwaway, (J) wet-regenerative, and (4) dry-regenerative processes (68). 

These heaters are avaifable with rotors up to 6 m (20 ft) in diameter. Gas temperatures up to 1255 K (1800°F) can be accommodated. Gas face velocity is usually around 2.5 m/s (500 ft/min). The rotor height depends on service, efficiency, and operating conditions but usually is between 0.2 and 0.91 m (8 and 36 in). Rotors are driven by small motors with rotor speed up to 20 r/min. Heater effectiveness can be as high as 85 to 90 percent neat recovery. Lungstrom-type heaters are used in power-plant boilers and also in the process industries for heat recoveiy and for air-conditioning and building heating. 

In 1854, the Manchester Steam Users Association was formed to help with the prevention of explosions in steam boilers and to find efficient methods in their use. To achieve this, the Association employed the first boiler inspectors, whose services were then made available to the Association s members. Within a short space of time, the members became convinced that insurance to cover the high cost of repair or replacement of damaged boilers was desirable, and this resulted in the first boiler insurance company (The Steam Boiler Assurance Company) being formed in 1858. The scope of the services for inspection and insurance later extended to include pressure vessels, steam engines, cranes, lifts and electrical plant, the insurance protection in each case being supported by an inspection service carried out by qualified engineer surveyors. 

Internal personnel will normally undertake boiler plant operation. Maintenance work may be by either internal personnel or outside contractors. Service contracts will be available from equipment suppliers covering all items of the boiler plant. Recently, companies have started offering contract energy-management schemes. These may be designed to suit individual applications and will be tailored to customer requirements. They may take over the operation of an existing plant or, if necessary, include for a new replacement plant. They will usually operate over a 3-10-year contract period. Dependent upon the terms of contract, all fuels, electricity, repairs and replacements may be covered. 

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... 

A boiler lay-up is provided when the plant is out of service for some period. The lay-up may be a wet lay-up, wherein water remains in the boiler and is intended only for short periods or a dry lay-up, which is for extended periods. 

For larger plants some water analysis, results interpretation, and recommendations for operational changes may be carried out by a boiler operator, water treatment plant technician or a laboratory analyst (or even by an outsourced subcontractor) these recommendations complement similar work undertaken by the water treatment service company representative. 

Water treatment technical service representatives must develop relationships with boiler plant operators and managers and formally meet on a periodic basis so that all involved understand what must be achieved and work in concert toward reaching common, agreed-upon objectives. The frequency of meetings depends on the size of the boiler plant, but essentially, informal communications should take place (up and down the line) very regularly, with a formal program review taking place perhaps every three to four months. 

This development has for some time involved many aspects of the boiler water treatment market but has recently extended further into the overall utilities sector. There are perhaps three levels of extended services now available the water treatment full-service program, the provision of contract labor to run a company s boiler plant, and the outsourcing of utility components or the entire facilities. 

Utilities plant contract labor Today these chemical water treatment-based full-service programs may be further enhanced by the supply of various boiler plant mechanical and electrical maintenance and repair work, plus energy management services, all from a single supplier source. In fact, many customers are now replacing their entire utilities staff with contract labor under a utilities service contract. The utilities plant contractor usually subcontracts the water treatment full-service component to a specialist water treatment and environmental services company. 

However, for most smaller industrial and commercial or institutional facilities around the world today, the concept of outsourcing just about every aspect of the requirement for utilities is not on the agenda, but it undoubtedly will come when the time is right. In fact, the added cost of full services is often prohibitive in those countries where in-house labor rates are low thus, much of the boiler plant preventative... 

To achieve this objective at the operational level, consistently good water treatment practice is required on site. However, achieving this objective cannot and should not be the sole prerogative or responsibility of any one person. Rather, if success is to be attained and maintained, it requires a proactive approach with joint participation, support, and communication by the water treatment service company and the owners and/or operators of the boiler plant. 

Apart from the provision of various permutations of (chemical-based) boiler water programs, it is common to find water treatment companies supplying value adding chemicals and services in other boiler plant-related areas where their expertise in applied chemical technology can deliver additional economic benefit. Such areas typically include cleaning services for boiler waterside and fireside and the provision of fuel treatments and combustion additives, dust suppressants (for coal and ash handling), acids, and cleaner products. 

It is generally agreed that the causes and effects of poor water chemistry, mechanical problems, boiler section corrosion, metal failure, and poor boiler plant operation are all closely interrelated. Thus, effective control over the various corrosion processes that may occur in a boiler and its auxiliary equipment is fundamental to the realization of the full life expectancy and safe operation of the plant. Corroded and wasted metal cannot be replaced easily, and the failure of a boiler in service is both potentially dangerous and expensive. 

Despite the significant encroachment of RO and EDI technologies into the premium end of the higher purity water market, there is no doubt that IX remains the most versatile purification technology available. It has by far the longest track record, being perhaps a century old. It is also a robust technology, often the best choice for use in remote boiler plant locations or where maintenance facilities and support services are limited. 

Today, there is almost always a relatively low-cost, low-tech solution available as a viable alternative to dumping condensate. Most CR recovery or polishing solutions employ a fixed installation, but mobile retrofits increasingly are being provided by outsourced service providers. See Figure 9.4d for a schematic layout of a mobile boiler condensate conditioning plant. 

With regard to the marketing of boiler water treatment programs and services, in the preface to this book I suggested that, although boiler plant can be classified in several different ways, there are from my perspective, only two groups of boiler plant owner/operator to be addressed. 

It is a fact of life that the cost of providing water treatment services increases with the size and complexity of boiler plant. This cost may be recovered with larger boiler plants by the higher volumes of chemical treatments sold, as often the chemical selling prices will include an allowance for all the anticipated (and expensive) technical service time requirements. 

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