Annular continuous kiln

The German mechanical engineer Friedrich Hoffmann began registering patents in the industrial heating field in 1858. He was awarded a prize at the 1867 Universal Exposition in Paris for his annular continuous kiln, which was soon adopted for firing brick and lime. The principle of this kiln is that it has no fixed fire. Once it has been lit, the combustion moves from chamber to chamber on wagons full of coal. Heat circulates in this type of kiln, firing the bricks then allowing them to cool gradually without damage. This extremely productive and economical type of kiln came into use just at the right moment, in an era of major urban development and infrastructure projects.