The ornamental design for a portable garment drying apparatus, as shown and described.
FIG. 1 is a front and side perspective view of a portable garment drying apparatus showing our new design in a closed position;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom view thereof;
FIG. 6 is a left side elevation view thereof;
FIG. 7 is a right side elevation view thereof;
FIG. 8 is a front elevation view thereof in which the portable garment drying apparatus is in an open position with a garment enclosure extending between detachable top and bottom parts of the apparatus; and,
FIG. 9 is a right side elevation view thereof.
The broken lines shown represent unclaimed subject matter and form no part of the claimed design.