Abstract: A retractable bat which comprises an internal structure coupled to a sleeve comprising foam, wherein the sleeve comprising foam surrounds and protects the internal structure, wherein the internal structural member comprises a sleeve rod and an inner rod that may be detachably coupled to movable threads inside the sleeve rod.

Abstract: An outer finned tube includes a tube body, an outer wall of the tube body is provided with outer fins spirally arranged in an extension direction of the tube body; grid fins are arranged between two adjacent spiral parts of the outer fins correspondingly; two ends of each grid fin are connected to the two adjacent spiral parts of the corresponding outer fin respectively; a gap is kept between each grid fin and the outer wall of the tube body; and the plurality of grid fins are spaced in the extension direction of the tube body. An enhancing cavity is formed in an area defined by the outer wall of the tube body, inner walls of the grid fins and the outer fins in an encircling way, which can form a larger degree of superheat, provides a nucleation point for a boiling/condensation process and improves a heat exchange performance.

Abstract: A method for sealing a high-temperature heat pipe includes: (1) necking and reducing two ends of the heat pipe separately, so as to obtain a necked end and a reduced end; (2) sealing the necked end by laser welding or electron beam welding; (3) placing the heat pipe in an inert gas glove box, and pouring a working medium without impurities into the heat pipe; (4) heating the heat pipe, connecting the reduced end to a vacuum pump, pumping gas inside the heat pipe by the vacuum pump to vacuumize the heat pipe, such that pressure in an inner cavity of the heat pipe reaches a target pressure, and flattening the reduced end; and (5) sealing an opening of the flattened reduced end by electron beam welding or laser welding, so as to obtain the high-temperature heat pipe.

Abstract: A method for sealing a high-temperature heat pipe includes: (1) necking and reducing two ends of the heat pipe separately, so as to obtain a necked end and a reduced end; (2) sealing the necked end by laser welding or electron beam welding; (3) placing the heat pipe in an inert gas glove box, and pouring a working medium without impurities into the heat pipe; (4) heating the heat pipe, connecting the reduced end to a vacuum pump, pumping gas inside the heat pipe by the vacuum pump to vacuumize the heat pipe, such that pressure in an inner cavity of the heat pipe reaches a target pressure, and flattening the reduced end; and (5) sealing an opening of the flattened reduced end by electron beam welding or laser welding, so as to obtain the high-temperature heat pipe.

Abstract: An outer finned tube includes a tube body, an outer wall of the tube body is provided with outer tins spirally arranged in an extension direction of the tube body; grid fins are arranged between two adjacent spiral parts of the outer fins correspondingly; two ends of each grid fin are connected to the two adjacent spiral parts of the corresponding outer fin respectively; a gap is kept between each grid fin and the outer wall of the tube body; and the plurality of grid fins are spaced in the extension direction of the tube body. An enhancing cavity is formed in an area defined by the outer wall of the tube body, inner walls of the grid fins and the outer tins in an encircling way, which can form a larger degree of superheat, provides a nucleation point for a boiling/condensation process and improves a heat exchange performance.