Improves work flow and coffee quality...
I believe that the cooling tray is the unsung hero component of a coffee roaster. I'm guessing that roasters love talking about the power of their burners, the capacity of their rotating drums, their computerised control of roast profiles... however I remain in awe of how important the cooling tray is to both roasting work flow as well as the quality of the roasted coffee.
There are three important functions which the cooling tray performs. Firstly, it removes the smoke which pours out from the roasted beans as they emerge from the drum at the end of the roast. That smoke would otherwise make the roastery a hellish place to work. Secondly, the fan which draws smoke out of the roastery causes convection cooling of the beans and this is aided by mixing arms in the tray which continuously agitate the beans. Rapid cooling is important as beans can otherwise take on a baked, flattened flavour profile. Finally, the cooling tray allows the roaster to drop beans into a container so that they can be apportioned out to customers in the most efficient manner possible. There's an exit chute at the bottom right of the image above and when it's open the mixing arms cause the beans to drop down the chute. All of this occurs whilst the next batch of beans is being roasted! So you can see how work flow is dramatically improved by this unsung hero.