Shell Boilers _ International site for Spirax Sarco

Shell Boilers _ International site for Spirax Sarco - Shell...

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International site for Spirax Sarco Tel : (800) 575-0394 Fax : (803) 714-2222 [email protected] You are here: Home Resources Steam Engineering Tutorials The Boiler House Shell Boilers Overview of the different types of shell boiler with layouts, heat and steam release considerations plus pressure and output limitations. Use the quick links below to take you to the main sections of this tutorial: The printable version of this page has now been replaced by The Steam and Condensate Loop Book View the complete collection of Steam Engineering Tutorials Shell Boilers Shell boilers may be defined as those boilers in which the heat transfer surfaces are all contained within a steel shell. Shell boilers may also be referred to as 'fire tube' or 'smoke tube' boilers because the products of combustion pass through the boiler tubes, which in turn transfer heat to the surrounding boiler water. Several different combinations of tube layout are used in shell boilers, involving the number of passes the heat from the boiler furnace will usefully make before being discharged. Figures 3.2.1a and 3.2.1b show a typical two-pass boiler configuration. Figure 3.2.1a shows a dry back boiler where the hot gases are reversed by a refractory lined chamber on the outer plating of the boiler. Fig. 3.2.1 Shell boiler - Wet and dry back configurations Figure 3.2.1b shows a more efficient method of reversing the hot gases through a wet back boiler configuration. The reversal chamber is contained entirely within the boiler. This allows for a greater heat transfer area, as well as allowing the boiler water to be heated at the point where the heat from the furnace will be greatest - on the end of the chamber wall. It is important to note that the combustion gases should be cooled to at least 420°C for plain steel boilers and 470°C for alloy steel boilers before entering the reversal chamber. Temperatures in excess of this will cause overheating and cracking of the tube end plates. The boiler designer will have taken this into consideration, and it is an important point if different fuels are being considered. The Boiler House Introduction Shell Boilers Water-tube Boilers Miscellaneous Boiler Types, Economisers and Superheaters Boiler Ratings Boiler Efficiency and Combustion Boiler Fittings and Mountings Steam Headers and Off-takes Water Treatment, Storage and Blowdown for Steam Boilers Water for the Boiler The Feedtank and Feedwater Conditioning Controlling TDS in the Boiler Water Heat Recovery from Boiler Blowdown (TDS control only) Bottom Blowdown Water Levels in Steam Boilers Methods of Detecting Water Level in Steam Boilers Automatic Level Control Systems Water Level Alarms Installation of Level Controls Testing Requirements in the Boiler House Pressurised Deaerators Steam Accumulators Related Content Steam Tables A comprehensive set of steam tables is available here. Home
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This note was uploaded on 03/19/2012 for the course ECON 256 taught by Professor Lopez during the Spring '10 term at École Normale Supérieure.

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Shell Boilers _ International site for Spirax Sarco - Shell...

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