ANALYSIS OF DESIGN OF THE ROLLERS OF THROUGH FURNACES OF ROLLING MILLS

Abstract

Furnace rollers are the most expensive part of the through-type furnaces, which determine the efficiency of the whole furnace unit. The features of design of rollers that are used at different temperatures of the working space of the furnace were considered. At temperature up to 1000 °C the rollers are used without water cooling (“dry”) or with cooling only of trunnions. With increase in temperature in the furnace up to 1250 °C the rollers with cooled shaft are used. It is shown that the operating costs of the through-type furnaces of rolling mills depend on the durability of the rollers and the costs associated with their cooling. Application of modern heat-resistant materials for manufacturing of furnace rollers enable to eliminate the necessity of their cooling in the furnaces with the temperature of working space up to 1250 °С and to reduce operating costs at the expense of saving of technological fuel for furnace heating. It is noted that the use of “dry” furnace rollers at furnace temperatures up to 1250 °C would require more expensive refractory materials, which will increase their cost. Therefore, it is important to select the correct material strength criteria for the barrel rollers in the design, taking into account the demanding operating conditions of the rollers. Based on the analysis of the process loads on the furnace rollers, the strength criterion is the conditional yield strength of the barrel material at the operating temperature and a safety margin of 3.5.