Letters: March 2018

Andrea Sella implies that Fritz Winkler was the discoverer of the phenomenon of fluidisation in the early 1920s (Chemistry World, November 2017, p70). In fact it was well known before then, having been the subject of a US patent taken out by C E Robinson in 1879 for the roasting of ores in an improved furnace. Robinson’s description of the fluidised solids which ‘did boil and play like the waters of a fountain’ is not dissimilar to Winkler’s ‘a lively dancing movement’ of the coal powder. Other early fluidisation processes were the Fuller-Kenyon pump for the pneumatic conveyance of solids and the 1895 use of pulverised fuel in furnaces.