All About Boilers,Types Of Boilers
Climax boiler
Flued boiler
Multi Tube Boilers
A significant step forward came in France in 1828 when Marc Seguin devised a two-pass boiler of which the second pass was formed by a bundle of multiple tubes. A similar design with natural induction used for marine purposes was the popular “Scotch” marine boiler.
Prior to the Rainhill trials of 1829 Henry Booth, treasurer of the Liverpool and Manchester Railway suggested to George Stephenson, a scheme for a multi-tube one-pass horizontal boiler made up of two units: a firebox surrounded by water spaces and a boiler barrel consisting of two telescopic rings inside which were mounted 25 copper tubes; the tube bundle occupied much of the water space in the barrel and vastly improved heat transfer. Old George immediately communicated the scheme to his son Robert and this was the boiler used on Stephenson's Rocket, outright winner of the trial. The design was and formed the basis for all subsequent Stephensonian-built locomotives, being immediately taken up by other constructors; this pattern of fire-tube boiler has been built ever since.
steam generator
A boiler or steam generator is used wherever a source of steam is required. The form and size depends on the application: mobile steam engines such as steam locomotives, portable engines and steam-powered road vehicles typically use a smaller boiler that forms an integral part of the vehicle; stationary steam engines, industrial installations and power stations will usually have a larger separate steam generating facility connected to the point-of-use by piping. A notable exception is the steam-powered fireless locomotive, where separately-generated steam is transferred to a receiver (tank) on the locomotive.
Solar water heaters
Increasingly, solar powered water heaters are being used. Their solar collectors are installed outside dwellings, typically on the roof or walls or nearby. Many models are the direct-gain type, consisting of flat panels in which water circulates. Heating water itself directly is inherently more efficient than heating it indirectly via antifreeze and heat exchangers. However with hard water supplies, direct solar heaters may need limescale control.
Another type of solar collector is the evacuated tube. It has a row of glass tubes containing heat conducting rods, typically copper which as heating elements in a circulating loop of antifreeze. The captured heat is transferred into the domestic hot water system via a heat exchanger. Usefully, this design is smaller and more efficient than traditional flat plate collectors, and works well in very cold climates. The evacuated description refers to air having been removed from the glass tubes to create a vacuum. This results in very low heat loss, once the inside coating has absorbed solar radiation. So the antifreeze, if pressurised, can be heated to well over 100C if required. Vacuum tubes can be deployed successfully in homes where suitable roof space is a limiting factor: where there is typically less than 1 sqm of sunny roof per person. Other types of solar collector may use solar concentrator dish or trough mirrors to concentrate sunlight on a collector tube filled with water, brine or other heat transfer fluid.
A storage vessel/container is placed indoors or out. Circulation is ideally zero carbon, caused by either natural convection thermosyphon or by a small solar electric pump. However it can also be low carbon circulation, typically, when higher power mains electric powered pumps are used, for example to cope with viscous antifreeze based circuits in cold climates. At night, or when insufficient sunlight is present, circulation through the panel can be stopped by closing a motorised valve and/or stopping the circulating pump, to keep hot water in the storage tank from cooling. Depending on local climate, freeze protection (e.g. via freeze-tolerant silicone rubber water channels, draining the system down or the use of antifreeze), as well as prevention of overheating, must be addressed in their design, installation, and operation.