The basic elements of an oven that need to be considered before purchasing include oven size, internal air flow design, operating temperature, heating capacity (design BTU), fuel type, door configuration and type, oven construction and controls.
In your case, because you are replacing an existing oven, you have probably already determined the size needed, which is dictated by the largest size part or cart (which may hold multiple pieces) with additional clearance above and along the sides. Generally, it is recommended to allow 18-24 inches from the ceiling or wall-mounted ductwork where the heated air is introduced to the parts to allow for proper airflow without disrupting the uncured powder coating. Additional space may be required, depending on the method in which the carts are moved in and out or through the oven.
Once the size of the oven is determined, you must assess the available floor space. The design and location of the duct work/airflow in the oven will have an impact on overall oven size. Ultimately, part configuration and size will dictate the airflow design in the oven. The more complex and geometric the parts, the more important the airflow will be. Options include a ceiling-mounted plenum which creates a downdraft that allows for top-down airflow, as opposed to wall-mounted input and exhaust plenums which create a cross draft. Variations to these designs and nozzles can also be incorporated to create more directional airflow, as required.
The next item to consider is the operating temperature of the oven, which is based on the coatings that are being cured. Most commonly, this will be in the range of 180-450°F. Most coating companies will specify the time at temperature by which their coatings must be properly cured. This requirement most commonly refers to the surface temperature of the part, not the air temperature of the oven. For example, a lightweight sheet metal part will quickly reach the oven set-point temperature, whereas a large cast-iron part will take much longer to reach “surface temperature.”
Read more: Cleveland Ohio Powder Coating Designing Batch Ovens for Liquid Coating Operations
