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Effect of surface finish on paste and particulate heat transfer?

I am a chem E helping to debottleneck a continuous dryer which fouls and I wonder about the impact of adding a diamond like coating or nitriding or polishing the 316 stainless steel on the heat and hydrodynamic transport

Adhesion (cohesion) of the sodium organic salt to mill finish stainless steel is very high at my operating temperature 300 F. I suspect the foulant to be the paste to soft granular form. It is highly agglomerating and forms crust if not mechanically disturbed.

The dryer is built as a heated cylinder with a single center shaft with a spiral of short blades that pass by stationary hooks, which clean the heated blades (~ 3 mm clearance).

If I only coat the cylinder interior, I imagine sliding. Is there a negative to not coating the hooks, shaft and blade? Lack of convective turnover? increased stress on the hooks?

If I coat all surfaces, can I be too slick?

Gary Holleran
buyer - Houston, Texas
2007

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I sort of picture what you are describing but not entirely, Gary. In any event electropolishing of stainless steel is often done in similar situations because it completely removes all "tooth" and can be quite effective in preventing things from sticking.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007