8 Heat Exchangers Additional Experience-Based Principles: Gael D. Ulrich and Palligarnai T. Vasudevan, Chemical Engineering Process Design and Economics, a Practical Guide, 2 nd ed., Process Publishing, Durham, NH, 2004 Posted on the website will be Ulrich’s guide/shortcut/rules of thumb for heat exchanger design and flowsheet preparation.
17 Air Cooled Heat Exchangers www.gearainey.com Applications.. air coolers are installed throughout the world in the following applications: Forced and induced draft air cooled heat exchangers Recirculation and shoe-box air cooled heat exchangers Hydrocarbon process and steam condensers Large engine radiators Turbine lube oil coolers Turbine intercoolers Natural gas and vapor coolers Combustion pre-heaters Flue gas re-heaters Lethal service Unique customizations Air cooled heat exchangers can be used when: Cooling water source not readily available Cooling water systems adds complexity or cost to facility Lower operating / maintenance cost could be achieved
18 Air Cooled Heat Exchangers www.gearainey.com Minimizing Air Cooler Costs GEA Rainey Corporation has developed a short list of points to help you create the most economical design and assist with an initial design; most of the time GEA can provide more economical designs. Maximize tube length while maintaining >=40% fan coverage Design aircooler with a 1 to 3 ratio. For example, if your cooler is 30’ long it should typically be around 10’ wide. This helps reduce the header size, the most expensive portion of an aircooler, while still maintaining proper fan coverage. Minimize tube rows to increase heat transfer effectiveness of area, minimize header thickness. Typically between four to six tube rows Try and maintain 1” tube diameters, depending on service. Even high viscosity services that appear to benefit from larger diameter tubes can typically be designed cheaper with more 1” diameter tubes. Use a counter-current flow where possible as it reduces surface and potentially minimize header plate thickness. Increase your allowable pressure drop. This allows more passes in the bundle reducing the cooler size.