Even though duct work is our bread and butter and what the majority of my work day consists of. We often get projects that are along the same lines, but just different enough that some extra thought and attention is needed. Case and point, the project I had for the last few days has been to fabricate an exhaust hood for a drying machine inside a small screen printing shop. I won't even pretend to know exactly what the machine does, the customer drew up what he wanted and I am making it to those specifications. Simple. Here's some pics.
Below is the wide shot of the hood. The customer wanted a rectangular box with pieces angled inside that would deflect the air to the center 4" collar.There are no welds, everything is done with the Pittsburgh machine, break, hammer and rivets.
This picture just gives a clearer view of the depth of the piece and a look at the collar in the center. The total dimensions were 62" wide, 6" deep and 12" in height with a 4" collar cut into the top middle.
Here is a shot looking inside at the angled pieces that will deflect the air toward the center of the hood. It's tough to see, but I also added a 1/4" 90 degree lip around the bottom edge for some stability. Even though the hood is for a smaller application, the width of the hood will make it weaker in the middle and prone to bowing or popping. The angle will give it just enough strength to keep it stable when the machine is running and keep any noise to a minimum.