I claim the ornamental design for a hand dryer, as shown and described.
FIG. 1 is a front elevational view of a hand dryer embodying my/our new design;
FIG. 2 is a front perspective view thereof;
FIG. 3 is a left elevational view thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
The rear view of the hand dryer does not from any part of the claimed design and the broken lines are for environmental purposes only and form no part of the claimed design.