Air-Cooled Heat Exchangers – Construction & Standards
Air-cooled heat exchangers are essential components of many industrial and commercial systems. They are designed to transfer heat away from a system by cooling with air. Air-cooled heat exchangers are used in various applications, from cooling air conditioning systems to cooling industrial process fluids and lubricants. They are also used in power plants, oil and gas plants, and commercial buildings. Let’s discuss the construction and standards for air-cooled heat exchangers before you place your order.
Air-Cooled Exchanger Standards
The main standard air-cooled heat exchangers must follow is ASME Code, Sect. VIII Div1 or Div2 regulates all pressure vessels. and any Petrochemical or refinery services typically follow API 661 as an additional specification in addition to their own standards.
Constructing an Air-Cooled Heat Exchanger
Several components must be constructed for every air-cooled heat exchanger, starting with the tube bundle. The tube bundle is the main component of the heat exchanger and is typically made from carbon steel, stainless steel, duplex, copper, or aluminum.
The bundle is then mounted onto the fan deck which is designed to distribute air evenly across the tube bundle. The fan deck is usually made from metal sheets and can be configured in various ways, depending on the design of the unit.
Most air-cooled heat exchangers also require fans, which are mounted either below (forced draft) or on top (induced draft) of the bundle and move air across the tube bundle. The fans are typically made from steel, aluminum, or fibre-reinforced plastic (FRP) and are powered by electric motors.
The fans are connected to motors via belt drives, which are mounted to the structure of the air-cooler bay. Fan and belt guards encase the moving mechanical components for personnel protection. Grease lines permit easy access to lubricate bearings.
Instrumentation is often specified such as thermocouples, averaging RTDs (temperature sensors), and vibration switches or transmitters.
Louvers and actuators may be required for warm-air recirculation, aka winterization. If required, space heaters or heating coils are used to pre-heat the air-cooler bay prior to start-up.
Ladders and platforms are typically required at one or two ends of the air cooler to access header plugs and nozzle flanges.
Often the heat exchanger must have “bug screens” (air filters) to ensure that the air is free of particles and contaminants like poplar fluff before it reaches the tube bundle. The screens are typically made from fine mesh and are designed to capture any debris that may be in the air.
When ordering an air-cooled heat exchanger, make sure to specify the operating conditions and design constraints that the manufacturer needs to consider in addition to the required build standards. This way, you can be sure that your air-cooled heat exchanger will perform as expected in your system and according to local regulations.
Begin Building Your Air-Cooled Heat Exchanger With Altex
Altex is Canada’s leading provider of air-cooled heat exchangers. Our experienced engineers and technicians can help you design and build the perfect air-cooled heat exchanger for your application. Contact us today to learn more about our air-cooled heat exchangers and how we can help you build the right system for your needs and bring your project to life.