Thursday, May 7, 2009

Boiler

I want to introduct something about Tire Changer. Features: 1) The air operated bead lifting and pressing device make tire mounting and demounting much easier 2) The pneumatic arm makes it much easier to change the wider wheels that are commonly found on sport and race cars 3) A perfect tool for any low profile tires, especially those with stiff beads 4) Rim range with adapters: a) For ATV: 9 - 18" b) For motorcycle: 14.5 - 26" 5) Two-position bead breaker 6) Two-stage pneumatic cylinder provides very precise power and wider rim range service 7) Rim protection: plastic jaw protections are standard for all our tire changers; also, optional plastic mounting/demounting head are very useful to avoid damaging expensive rims 8) Warranty: 1 year parts onlymor

A portable boiler(preserved, Poland)

A stationary boiler(United States)
A boiler is a closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications.
Contents
1 Overview
1.1 Application
1.2 Materials
1.3 Fuel
1.4 Configurations
1.5 Safety
2 Superheated steam boilers
3 Supercritical steam generators
3.1 History of supercritical steam generation
4 Hydronic boilers
5 Accessories
5.1 Boiler fittings and accessories
5.2 Steam accessories
5.3 Combustion accessories
5.4 Other essential items
6 Controlling draft
7 See also
8 References
9 Further reading
10 External links
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Overview

Diagram of a fire-tube boiler

Diagram of a water-tube boiler.
Application
Boilers have many applications. They can be used in stationary applications to provide heat, hot water, or steam for domestic use, or in generators and they can be used in mobile applications to provide steam for locomotion in applications such as trains, ships, and boats. Using a boiler is a way to transfer stored energy from the fuel source to the water in the boiler, and then finally to the point of end use.
Materials
The pressure vessel in a boiler is usually made of steel (or alloy steel), or historically of wrought iron. Stainless steel is virtually prohibited (by the ASME Boiler Code) for use in wetted parts of modern boilers, but is used often in superheater sections that will not be exposed to liquid boiler water. In live steam models, copper or brass is often used because it is more easily fabricated in smaller size boilers. Historically, copper was often used for fireboxes (particularly for steam locomotives), because of its better formability and higher thermal conductivity; however, in more recent times, the high price of copper often makes this an uneconomic choice and cheaper substitutes (such as steel) are used instead.
For much of the Victorian "age of steam", the only material used for boilermaking was the highest grade of wrought iron, with assembly by rivetting. This iron was often obtained from specialist ironworks, such as at Cleator Moor (UK), noted for the high quality of their rolled plate and its suitability for high-reliability use in critical applications, such as high-pressure boilers. In the 20th century, design practice instead moved towards the use of steel, which is stronger and cheaper, with welded construction, which is quicker and requires less labour.
Cast iron may be used for the heating vessel of domestic water heaters. Although such heaters are usually termed "boilers", their purpose is usually to produce hot water, not steam, and so they run at low pressure and try to avoid actual boiling. The brittleness of cast iron makes it impractical for high pressure steam boilers.
Fuel
The source of heat for a boiler is combustion of any of several fuels, such as wood, coal, oil, or natural gas. Electric steam boilers use resistance- or immersion-type heating elements. Nuclear fission is also used as a heat source for generating steam. Heat recovery steam generators (HRSGs) use the heat rejected from other processes such as gas turbines.
Configurations
Boilers can be classified into the following configurations:
"Pot boiler" or "Haycock boiler": a primitive "kettle" where a fire heats a partially-filled water container from below. 18th Century Haycock boilers generally produced and stored large volumes of very low-pressure steam, often hardly above that of the atmosphere. These could burn wood or most often, coal. Efficiency was very low.
Fire-tube boiler. Here, water partially fills a boiler barrel with a small volume left above to accommodate the steam (steam space). This is the type of boiler used in nearly all steam locomotives. The heat source is inside a furnace or firebox that has to be kept permanently surrounded by the water in order to maintain the temperature of the heating surface just below boiling point. The furnace can be situated at one end of a fire-tube which lengthens the path of the hot gases, thus augmenting the heating surface which can be further increased by making the gases reverse direction through a second parallel tube or a bundle of multiple tubes (two-pass or return flue boiler); alternatively the gases may be taken along the sides and then beneath the boiler through flues (3-pass boiler). In the case of a locomotive-type boiler, a boiler barrel extends from the firebox and the hot gases pass through a bundle of fire tubes inside the barrel which greatly increase the heating surface compared to a single tube and further improve heat transfer. Fire-tube boilers usually have a comparatively low rate of steam...(and so on) To get More information , you can visit some products about agricultural machinery parts, auto air filter, . The Tire Changer products should be show more here!

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