Fans are an important component in improving productivity and energy efficiency in many applications as the drive to reduce costs continues. Properly applied, forced convection can drastically improve heat transfer rates and furnace temperature uniformity in many applications.
Industrial Gas Engineering began manufacturing high temperature fan equipment in 1924. During the past 80 years, practical experience paired with engineering judgment has shaped our views regarding fans used in heat-treating furnaces today. Properly applied, forced convection can drastically improve heat transfer rates and furnace temperature uniformity in many applications. Examples are aluminum reheat and/or solution anneal, as well as temper and draw furnaces. In other applications, forced convection is used to circulate a controlled atmosphere to promote uniform interaction between the atmosphere and the workload. Examples are carburizing and nitriding. Improperly applied, fans can be an unending source of maintenance problems for little or no furnace performance gain and in the worst case, actually worsen furnace performance. Examples of improperly applied equipment include failure to consider the atmosphere when making alloy selections, and severe thermal shock on large and/or highly stressed (rotational) fans, especially with large sectional thickness variations. Design of the recirculation flow (path and rate of flow) must consider the desired results as well as the weight and geometry of the workload.