The stresses in rotary kiln tyres -: a critical analysis

The tyre of a rotary tube kiln is stressed by its own dead weight and by a proportion of the weights of the rotary kiln cylinder kiln brickwork and loose material. It is dimensioned principally on the basis of its flextural stress and deformation. Numerous computation formulae have been put forward in the literature for determining the behaviour patterns of the moment, marginal force and deformation. One of the oldest computation formulae goes back to H. W. Nies. More recent papers have been, produced by R. S. Alwar and R Ramamurti, H. Mettle?; and L. S. Gupta and R Ramamurti. Gocer has been able to show by numerical calculations that by using a stress function for the tyre which is closer to reality when compared with the work by Nies and by Alwar and Ramamurti it is possible to obtain stress values which on the whole are more favourable, especially for the deformation. According to his calculation the flextural stress at the point of support on the supporting roller is lowest when this is set at an angle of 30 degrees to the central axis of the kiln tube. It is interesting to note that since the rotary kiln was introduced at the end of the last century the numerous manufacturers throughout the world have always supported it at this setting angle.