Patent ID: 6966124

Claim:
A drum washing machine, comprising: a water tub, a rotary tub rotatably installed in the water tub, and a clothes-drying unit to dry clothes contained in the rotary tub, wherein the clothes-drying unit comprises: an air duct to form a closed air circulation system in cooperation with the water tub so as to circulate air through the closed air circulation system; a blower fan, a heater, and a condensing nozzle installed in the air duct; and a heat pipe to recover heat from air having a high temperature and a high humidity before the air reaches the condensing nozzle, and to combine the recovered heat with air having a low temperature and a dry state after the air having a high temperature and a high humidity passes through the condensing nozzle, wherein the air duct comprises: a first duct part arranged at a rear end of the water tub, such that the first duct part communicates with an interior of the water tub at a bottom of the rear end of the water tub, and extends upward from the bottom to a top of the rear end of the water tub along an edge of the rear end of the water tub; and a second duct part extending from the rear end to a front end of the water tub, such that the second duct part communicates at a rear end of the water tub with the first duct part, and communicates at a front end of the water tub with the interior of the water tub.