Appeared in the 1st Edition of World of Drying Magazine
The rotary processing dryer/cooler does much of the heavy lifting in the industrial processing industry. Rotary dryers/coolers process a multitude of material in a wide range of industries, (agricultural, chemical and mineral materials, among others). And flights, fin-like pieces attached to the interior of the unit’s drum, are the heavy-lifter’s “lifter.”
Flights, specifically lifting flights, are used in both rotary dryers and coolers to maximize heat transfer between the material and the drying or cooling air. They pick up or “lift,” the material as the drum rotates, and shower it through the air stream, a phenomenon known as “veiling.”
This veiling action is comparable to that of a clothes dryer, with the material tumbling, sifted through the hot or cool air that is being pumped through the unit. Similar to your clothes dryer at home, if the material did not fall through the air stream, it would not evaporate the moisture and thus not dry or cool.
In addition to aiding in the drying or cooling of material, flights have another function – as the scooping motion occurs, this prevents material from sliding on the bare shell. Think of the sliding motion on the bare metal shell as rubbing sandpaper on the shell. After some amount of time this “sanding,” will thin the shell and cause a hole, or worse, rip the shell due to loss of metal and structure strength. Flighting can help prevent this damage and extend the life of your shell and other components.
Newer to the scene of flighting technology is the use of a 3D printing.
Optimus Solutions has been working with 3D flight design and printing since 2018, and uses this technology to assist customers from all industries meet and exceed their company’s production goals.
But how do 3D flights accomplish this – and why are they so important?
To begin to answer this, Tom Zhang, PhD, PE of Optimus Solutions asks the question, “Suppose that 3D printing didn’t exist?”
“You’re at a plant, and you want to change your flighting. Someone tells you ‘we can make it better.’ But how do how do you know it is better? Before 3D printing, you had to make your best guess, draw up the flights, have them manufactured, shutdown the unit, install the proto-type flights, start up the unit and measure your output. If you were wrong, do it again! There was only trial and error.”
“Before 3D flights, trial and error was the only way – you shut down production and install and test your proto-type flights. Imagine how much that would cost in flight development and loss of production in shutting down the unit. For some industries, that approaches millions of dollars.”
But now, with a 3D-printed models, changes can be tested on a smaller-scale unit outside the current production system. The proto-typing costs are significantly lower and the company’s production isn’t interrupted. Once a winning solution is developed and manufactured installation can be scheduled during a normal shutdown. Questions are answered, the solution is known, and money is saved. Everybody wins.
“We decrease trial and error, you don’t have to shut down during our study, and we have experience in 3D flighting,” concluded Zhang. The big “value added,” is no shutdown and minimum development costs.
3D flighting is a cutting-edge, important avenue to help companies improve production. As the flighting increases the efficiency of units and extends the “wear,” of the metal components, plants are able to improve their process and thus their production in more tons per hour.
Click the video to see an original flighting design (left) and an improved flighting design (right) created by Optimus Solutions through use of 3D printing technology. This particular flighting study is estimated to save Optimus’ customer $100,000 a year. https://youtu.be/tU-RIgJzED4