Convectional heaters are an excellent method of providing low- intensive heat to the medium. In these heaters combustion chamber temperatures are tightly controlled and tube wall temperatures are kept to a minimum to ensure safe and effective heat transfer. Heat up and cool down times are negligible. For cyclical operations, the burner control can be heater-based or process-based.
The conventional heaters process temperatures ranging from cryogenic to above 1100°F and pressure ranges from full vacuum to 2500 PSIG. Based on the requirements of the process, the heater coil configurations are finned, bare, or a combination of both. In addition, a wide variety of coil materials can be used to handle even the most challenging products.
Many of the new technology systems are designed to meet the most stringent emission requirements and include high turn down burners for superior system control. Control options are virtually limited with relay label and programmable logic system available.
Features of the latest technology convection heaters
- Custom designs for up to 95% (LHV) efficiency
- Can accommodate cyclical operations
- Strict control of temperatures of process fluid & combustion chamber
- Low tube wall temperatures
- Depending on the temperature distribution assorted coil materials are used
- Uniform heat flux
- Large capacities available
- Easy tube access
Conventional heaters are purely convective heat transfer units. The process of fluid flow inside and outside the externally finned tubes creates counter current heat transfer. As a result, the fuel gas temperature constantly decreases as it travels through the convectional section. The coil section is located above the combustion section, allowing for nearly 100% convective heat transfer into the process medium. The tubes are installed in the tube supports, leaving them free to expand without restriction.