Whether for heating, cooling, condensing or evaporating, heat exchangers are a vital component in a variety of industrial processes. Their role in applying or recovering costly thermal energy from process gases or liquids means that the efficiency of heat exchangers impacts directly on energy use and therefore on the operating costs and environmental performance of a plant or process. As energy costs rise and the environmental footprint of industrial processes is increasingly in the spotlight, heat exchanger technology is also evolving to respond to new, more demanding criteria.
For more than 100 years, the classic shell-and-tube heat exchanger has been the solution for many applications, especially those involving solids or contaminants, but its efficiency is limited. Plate-and-frame heat exchangers, first developed by Dr. Richard Seligman of APV in 1923, offer higher heat transfer efficiency and cost effectiveness combined with low downtime and relatively small size and weight, thus reducing installed space requirements. The major contributor to the higher efficiency of plate-and-frame heat exchangers is the plate corrugation pattern in combination with a relatively narrow gap between the heat transfer plates. However, the fluids being handled must be relatively clean because the plates have limitations when solids or other contaminants are involved. In addition, the gaskets, which traditionally provide the seal between plates, limit the operating pressures and temperatures to typically 300 psig (20 bar) and 400°F (200°C), respectively.