The copper tubing shown above is heated in an annealing furnace to a temperature of 175°C (347°F). This tubing is stacked on racks in 100kg rolls, with 4-6 rolls of copper per rack, and then fed into the oven shown below. When the tubing exits the oven, water is used to cool the copper to a temperature of approximately 35°C (95°F) with an ambient temperature of ~20°C (68°F). While effective, the use of water to cool the copper is something the manufacturer would like to replace due to constant maintenance, safety issues and cleanup time, preferring instead to use air to provide the required cooling.
I’ve blogged before about the process of determining how much air volume is needed to remove a specific amount of heat. (You can read previous blogs here and here.) This application was no different, and I used the flow chart shown below to determine the volume of 20°C ambient air needed to cool this aluminum.
Using the process outlined above, I determined the application would need 1,133 CFM of air at 20°C to cool these copper coils in one minute. This application, however, has up to 20 minutes available to cool these coils, allowing for a reduced volume of air. Extending the time available to 2 minutes, and thus reducing the volume requirement to 566.5 CFM (566.5 CFM for 2 minutes = 1,133 CFM for 1 minute), we can definitively say that a series of our model 120022 Super Air Amplifier will be able to provide ample cooling. (See below for airflow from model 120022 at 5.5 BARG (80 PSIG) at a distance of 6” from the Air Amplifier outlet.) And, in order to evenly cool the coils, (4) of these Air Amplifiers were recommended, distributed evenly around the coils.
Using a bit of calculation, we were able to provide a specific solution for this customer, eliminating the need for water in the cooling phase of this application. If you have a similar application, or would like to discuss a compressed air solution for your application, contact an EXAIR Application Engineer.