PURPOSE: To prevent the. drum surface of a dryer such as a Yankee dryer from damage due to e.g. a doctor blade, by mixing water, air and a water-soluble lubricating oil in a nozzle followed by atomizing the water-soluble lubricating oil which is sprinkled on dryer surface.

CONSTITUTION: Through a delivery pipe 12 for a mixture of water and a water- soluble lubricating oil and an air delivery pipe 13, the mixture and air are forcedly fed into the pipe of a parallel-assembled sprinkling unit 19 and mixed in a nozzle 18. Then, the water-soluble lubricating oil is sprinkled in an atomized state from the nozzle onto dryer surface 20, forming a lubricating film in between the dryer surface and a doctor blade.