FIG. 1 is a front and top perspective view of a portable fan, showing my new design;
FIG. 2 is a rear and bottom perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a right side elevational view thereof;
FIG. 7 is a top plan view thereof;
FIG. 8 is a bottom plan view thereof; and,
FIG. 9 is an enlarged view of a portion indicated with numeric 9 in FIG. 2.
The dash dot dash lines in FIGS. 2 and 9 are for the purpose of depicting the cut line of the enlarged view and form no part of the claim. The dashed broken lines in the figures illustrate portions of the portable fan that form no part of the claimed design.