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A LaMont boiler is a type of forced circulation water-tube boiler in which the boiler water is circulated through an external pump through long closely spaced tubes of small diameter. The mechanical pump is employed in order to have an adequate and positive circulation in steam and hot water boilers.
Contents
History
Mark Benson himself in the year worked on the idea and later Benson worked with Herreshoff on the idea of parallel flow forced circulation non-drum boilers. Later, Walter Douglas Lamont brought the idea from papers to existence.Walter Douglas La Mont introduced the concept of this forced circulation boiler in the year 1925. Lamont was a Navy Lieutenant Commander and an engineer in the US marines as well as a patriot. He died of a sudden and very early death and the headlines of the Niagara Falls Gazette mentioned NAVAL ENGINEER,NATIVE OF CITY IS HEART VICTIM.
The initial designs of Lamont for this boiler confirmed the lighter, safer and higher rates of heat transfer and evaporation per square foot as compared to that of the standard water tube boilers, also the circulation of vaporized water at a differential pressure of 2.5 bar was 8 to 10 times . The time duration needed for starting a Lamont Boiler to be able to deliver an evaporation rate of 100,000 pounds per hour was between 15 and 20 mins and simultaneously was able to deliver peak loads. During the World War II the U.S navy used and relied mainly upon the Babcock & Wilcox boilers which were used commonly in those years. On the other hand, thousands were built in Europe and many German and Japanese ships used La mont boiler, Bismark was one among them and they were able to outrun the fastest steamers from the US Navy.
Principle
The circulation of water and steam mixture takes with the help of an external pump which supplies water at a higher pressure than in a natural circulation boiler.
Working
A centrifugal pump which forms the heart of this boiler is responsible to circulate water within the boiler system. It receives water from the drum and delivers this water to a distribution header as shown in the diagram here. The number of headers may differ in numbers and depends on the size and boiler design of each boiler.
The boiler heating surfaces includes a number of tubes arranged in a parallel form and the inlet ends are welded to the distributors or the headers. A circulation pressure is to be provided during the installation of the pump as per the boiler design and it should be sufficient to over come the resistance offered by the tubes. An even circulation takes place with the helps of the inlet nozzles provided at the inlet of tubes which creates the differential pressure adequate to cover the variations occurring at fluctuating loads or uneven firing conditions. The riser tubes outlet is welded to the collector headers and also directly to the drum containing steam and water .