The answer to this question is very simple: the atomized droplets may only reach the walls of the tower when they are dry.

In industry, this is achieved by making the tower large, but laboratory systems are far too small to allow the droplets to travel a long distance.

If you have a small tower available, the only option is to optimize the spray nozzle to produce smaller droplets and lower productivity. A high temperature in the upper part of the tower can also help a little.

We have had similar problems when we sprayed

16-20 metric tons/h (wet) finely divided starch agglomerate into a diam 950 mm flash dryer. at 160 C air temperature. When the incoming agglomerate's moisture content VS surface increases¨so the risk of adhesion on the inside of the dryer increases. In particular when the quantity and/or moisture content varied and/or an unwanted large whirlwind occurred, we solved it by reducing the moisture and quantity variation, as well as limiting the speed of the whirlwind. Also, the spray speed decreased slightly. The possible capacity of the dryer increased significantly.

Hi Vadim Verlotski sir,

Thank you for the help. I have tried with both at lab and pilot (industrial scale also). At lab scale, yield was not even 10%. But in pilot scale, I still got something (I mean yield was okay but not higher as desired at least 40-50%). We also tried to increase the temperature to enhance the drying, reduced the nozzle size. But still that one problem was persistent that it was sticking to chamber wall and on scraping peeling off like a film. and thus yield is coming less than expected. So, I am confused on how to avoid it, what agent i can add so that its film forming nature can be reduced?

Thanks for reading and help sir.

Regards

Hi Nemo Ivarson sir,

Thank you for sharing your experience.

Even we tried to increase the temperature up to 200 degrees C and reduce the nozzle size, but at lab scale, it was not of much help. There was no significant effect on the yield.I cross checked with research papers but have not found anything which explains about the yield, etc.

Sir it would be great if you can share your research paper or something similar that I can go through.

Thank you

Regards

Unfortunately, we are not done with any papers yet.

But I agree with Vadim Verlotski. The answer to this question is very simple

the atomized droplets can only reach the walls of the tower when they are dry. THAT should be your focus.

Depending on what resources you have available, you will have different options to avoid hitting the wall with something wet. The size and shape of the dryer is of course the most obvious. Airspeed and air flow patterns are trickier. likewise the size, shape and behavior of the nozzle. The fluid's temperature, viscosity, if its non-newtonianian fluid etc etc. The list is long. Some make little difference others need a combination.

Unless standard fixes work. It will be a very time-consuming to find a solution.