Manufacturing facilities face a variety of energy management challenges while controlling their processes and environmental conditions. Chemical manufacturers require large amounts of heat to carry out reactions, distillations and crystallization. Additionally, heat must be dissipated to control reactions. Similar processing of hydrocarbon liquids takes place in the oil and gas industry. Pasteurization, concentration, freezing and other food and beverage production methods involve substantial heat transfer as well. The automotive and aerospace industries commonly employ radiators, evaporators and condensers. These mechanisms are examples of heat exchangers. Heat exchangers are devices that transfer heat from one medium to another, usually without mixing. There are several types of heat exchangers available. When choosing a heat exchanger, a thorough evaluation should be conducted to ensure optimal performance.
Shell and Tube Heat Exchangers
Shell and tube heat exchangers are constructed with two sets of tubes through which fluid flows. One set carries the fluid that will be heated or cooled while the other set conveys the fluid that will conduct the heat exchange. Shell and tube heat exchangers may include many design variations. Tube diameter, thickness, length and pitch may affect efficiency and performance. Their durability lends to their use in high-pressure applications.
Plate Heat Exchangers
Plate heat exchangers are comprised of several thin, narrowly spaced plates. Small channels allow fluid to flow between the plates to accomplish heat transfer. Plate heat exchangers may vary in plate type or configuration. In plate and frame heat exchangers, plates are typically separated by gaskets and may be disassembled for cleaning. This type of heat exchanger is often employed in open loop applications such as HVAC. Others have plates that are permanently welded or brazed and are most frequently used for closed loop systems such as refrigeration.
Adiabatic Wheel Heat Exchangers
Adiabatic wheel heat exchangers use an intermediate liquid to retain heat. This liquid is transferred to the other side of the mechanism where heat exchange takes place. These heat exchangers are comprised of a wheel with filaments that are rotated through hot and cold liquids to facilitate the transfer of heat. They can be used for heating or cooling applications and are commonly employed in petroleum refining and pasteurization in the food industry.
Spiral Heat Exchangers
Spiral heat exchangers have two flat surfaces configured to form spiral channels. The flow of liquid through the channels is in opposite directions and can be one of three types: counter current flow, spiral/cross flow or distributed vapor/cross flow. The curvature of the channels provides highly efficient heat transfer. Their unique shape and characteristics allow them to be used in a number of applications including heat recovery, effluent cooling, pulp and paper processing and sludge treatment.
Solutions for Manufacturing
Heat exchangers have numerous industrial applications. They are widely used in manufacturing processes such as condensation, pasteurization and distillation. Heat exchangers can also provide energy savings that reduce operating costs. They recover heat that is produced as a by-product of processing and convert it into a usable energy form to be used elsewhere. This significantly reduces waste and saves energy required to carry out other processes.
Heat exchangers are available in a variety of types and configurations and may be customized to meet application requirements. A thorough understanding of the process is necessary to determine the type of heat exchanger needed for optimal performance. Heat exchangers provide an effective means of improving efficiency and lowering operating costs.