Plate-fin heat exchangers, usually composed of baffles, fins, seals, and guide fins.Place fins, guide fins and seals between adjacent two baffles to form a sandwich, called passage. The sandwich is superimposed in different ways according to the fluid, and brazed as a whole to form a plate bundle, which is the core of plate-fin heat exchanger.Plate-fin heat exchangers have been widely used in petroleum, chemical and natural gas processing industries.