Thermal coating development for impulse drying
- Thermal Spray Technologies, Watertown, WI (United States)
- Sandia National Labs., Albuquerque, NM (United States)
- Institute of Paper Science and Technology, Atlanta, GA (United States)
A plasma sprayed coating has been developed for the heated surface of rolls used in a new energy-efficient paper drying process, known as ``Impulse Drying,`` which could save the US paper industry an estimated $800 million annually in reduced energy costs. Because impulse drying rolls operate at higher surface temperatures than conventional, the thermal properties of the roll surface must be carefully tailored to prevent sheet delamination. A special plasma sprayed thermal barrier coating has been developed to control thermal mass, heat transfer, and steam infiltration. A coated test platen significantly outperformed a comparable uncoated steel platen in preliminary experiments with a heavy-weight paper grade on a laboratory-scale impulse drying simulator. The coating was then tested on the roll of a pilot-scale impulse dryer. In comparison with conventional wet-pressing, linerboard that was impulse dried showed improved water removal as well as improved physical properties, such as density and specific elastic modulus. The successful prototype coating design has three plasma sprayed layers that are deposited sequentially: (1) a nickel alloy bond coat; (2) a thick 17% porous, zirconia thermal barrier; and (3) a thin, 5--7% porous, zirconia top coat.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States); Institute of Paper Science and Technology, Atlanta, GA (United States)
- DOE Contract Number:
- AC04-76DP00789; FG02-85CE40738
- OSTI ID:
- 10182860
- Report Number(s):
- SAND--92-1290C; CONF-9206135--6; ON: DE93000710
- Country of Publication:
- United States
- Language:
- English
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