Thermally prestressed cylindrical structure and method of making same

摘要

The invention is a method of prestressing a heat transfer cylinder by thermal means to create residual stresses which act to reduce the operating thermal stresses in the cylinder wall. The invention also includes a cylinder prestressed by the method. An example might be a cylindrical drum having a heat source adjacent its inner surface to be used for heating a material on its outer surface. The drum would be thermally prestressed to have residual compression stresses at its outer surface and residual tension stresses at its inner surface under conditions of no heat flow. These stresses are opposite in direction to those induced by heat flow through through the drum wall during operation.