Large Aircraft Inserts
In this booth the filter wall is located on the rear of the booth (upper right). The replacement air is introduced into the booth through very large plenum doors on the front of the booth (lower left). This design for airflow gives the most consistent laminar airflow possible in a booth of this size. The tail of the plane is located at the rear of the booth.
Notice that the difference between the overall height and the sidewall height is significantly different. This has the effect of reducing most of the paint booth ceiling to just barely over the top of the aircraft fuselage. The airflow in the booth is sized for the lower cross-sectional area. Often this airflow is 50-65% of the airflow required in a paint barn. This very fact helps control the laminar nature of the paint booth airflow. The difference in the overall height and the sidewall height also allow for significant structural advantages. This difference is often 25-35 ft in depth, and if a truss is designed using that depth of section, the truss is incredibly rigid.
Notice from Figure 1 that the two main trusses require that a lateral truss support it from the sides. This geometry means that only four footings are required to support the main structure. Two are at the rear behind the filter chamber. The other two are on each side of the booth under the transverse truss. The front end of the two main trusses is cantilevered to the face of the booth.
One of the main design efforts for a paint booth is the location of the mechanical equipment. In this case, the low roof of the booth makes an ideal place to store the mechanical equipment.There is plenty of headroom and a wide area available.
Even off-the-shelf air make-up units can be arranged to provide the smaller amounts of airflow that this booth requires. The combined airflow is then ducted to the front plenum doors for distribution into the paint booth. The weight of the mechanical equipment and its access platforms are carefully located to be as close as possible to the very stiff and stable structure of the filter chamber.