The history of boilers has progressed rapidly throughout the industrial age. However, the foundation of what makes a boiler successful still stays true to a few basic components. While the boiler industry benefits from constant innovation, the basic structure and function of the historical boiler isn’t all that different from the equipment we use today.
The First Boilers
The history of boilers began with steam boilers that were used to power transportation, such as those seen in early trains and ships. Early models like the “Scotch Marine” and similar early fire tube boilers were made from a steel shell with rounded tube sheets that were welded at both ends. A door on the vessel would swing outward so that the interior of the boiler could be accessed for inspections and cleaning. These early boilers were fueled by coal or wood and the tubes had to be punched often to prevent soot accumulation. While these early boilers seem rudimentary compared to what we have today, boilers helped power the U.S. during the Industrial Revolution.
Bent Tube and Cast Iron Boilers
The next stage in the history of boilers occurred in 1916 when an engineer created a boiler that used bent tubes instead of straight tubes. The resulting bent tube boilers were more compact and could better handle the cold water feeds that were ubiquitous during that period. Cast iron boilers were the next development. While fire tube and bent tube boilers were sufficient for producing high pressure steam, there was no system that was good at creating low pressure steam that could be used for applications like heating buildings. Cast iron proved to be heavy and difficult to repair, but it was an effective change in the history of boilers because it could be made in a variety of shapes and was tough enough for low pressure steam.
World War II and Beyond
The second World War was a big turning point in the history of the boiler, and the post war industrial boom prompted big demands in terms of industry. Tube boilers were developed, including the seminal Rite water tube boiler, which marked a huge improvement in the efficiency of boilers and the speed with which they were able to convert water to steam. Copper tube boilers arose after Rite boilers, but were problematic and required frequent replacements. It wasn’t until approximately fifteen years ago in the history of boilers that the contemporary condensing boiler came into use.