When fuel became scarce in Germany in the final years of World War II, people increasingly tried to save energy and use domestic sources of energy. Amongst other things, technical solutions were developed to run vehicles with fuel gas and pressurised steam, produced in situ, instead of with liquid fuel. During this time, Heinrich Vorkauf (PhD), partner of Dr. Herpen – the founder of La Mont Kessel Herpen – and a specialist in forced and natural circulation boilers, designed a steam generator to operate piston engines in lorries, which he tested in practice. The steam generator was fired by readily available fuels such as wood or coal. The steam generator operated according to the principle of 'natural circulation', so as not be dependent upon a circulating pump and to make steam generation flexible enough for driving vehicles.
Based on his experience of the La Mont boiler system, Vorkauf came up with the idea of achieving a pre-separation of the heated steam produced from the water-steam mixture outside the drum by using unheated downcomers and by better positioning the risers, resulting in improved water circulation inside the boiler. The unheated downcomers were positioned in the four corners of the boiler. This meant that they not only improved the water circulation, but also acted as a supporting frame for the boiler. As a result of this type of design, the boiler came to be known as the Eckrohrkessel, or corner tube boiler in English.
More on the history of the corner tube boiler
Since then, corner tube boilers were built under license by plant manufacturers in Europe (initially by the Dutch company Bronswerk) and, from the early 1950s, in South America and Japan as well. The exchange of experience within this global network has and still does enable ERK to continue to develop and improve its systems technology, not just technologically speaking but also in terms of economic efficiency. This also means we need to acquire ever more experience to deal with ever growing capacities. Corner tube systems for steam flows of 290Mg/h, which is roughly equivalent to 250MW, with a steam pressure of 14.1MPa and superheated steam temperatures of 540°C, are now in operation. Forced circulation boilers for power capacities of roughly 2000MW have already been designed by our affiliated company La Mont GmbH. In addition to steam generators, ERK has also specialised in the production of water heaters, thermal oil heaters as well as heaters for chemicals up to a power capacity of 175MW.
In the 1950s, the corner tube boiler's frameless construction was considered to be its main advantage. This advantage became less significant after the introduction of the welded membrane wall. Today, the main focus is on ensuring the smooth realisation of various boiler efficiency factors, reliable water circulation despite load and pressure fluctuations, and the boiler's quick-start characteristics. Apart from all the operational benefits, there are also financial advantages as a result of the reduced material consumption, particularly in the higher pressure range.