Washing machine and controlling method thereof

Abstract

A washing machine that can shorten the drying time by improving the drying efficiency of the washing machine. A washing machine includes a tub, a drum rotatably installed inside of the tub, a condensing duct formed on an inner wall of the tub, a heating duct provided outside the tub, a duct heater provided inside the heating duct, a fan configured to circulate air in the drum, the condensing duct, and the heating duct and a controller configured to rotate the drum at a first rotational speed so as to tumble laundry contained in the drum while controlling the duct heater to heat the air circulated by the fan. The controller may rotate the drum at a second rotational speed, which is higher than the first rotational speed to separate water from the laundry contained in the drum while controlling the duct heater to heat the circulating air.

What is claimed is: 
     
         1 . A washing machine, comprising:
 a tub;   a drum rotatably installed inside of the tub;   a condensing duct formed on an inner wall of the tub;   a heating duct provided outside the tub;   a duct heater provided inside the heating duct;   a fan configured to circulate air in the drum, the condensing duct, and the heating duct; and   a controller configured to rotate the drum at a first rotational speed so as to tumble laundry contained in the drum while controlling the duct heater to heat the air circulated by the fan,   wherein the controller rotates the drum at a second rotational speed, which is higher than the first rotational speed, to separate water from the laundry contained in the drum while controlling the duct heater to heat the circulating air.   
     
     
         2 . The washing machine of  claim 1  further comprising:
 a condensation conduit to connect an external water source to the condensing duct; and 
 a condensation valve provided on the condensation conduit to adjust supply of water to the condensing duct. 
 
     
     
         3 . The washing machine of  claim 2 , wherein the controller controls the duct heater to heat the circulating air, and controls the condensation valve to block the supply of water to the condensing duct while rotating the drum at the second rotational speed to separate the water from the laundry contained within the drum. 
     
     
         4 . The washing machine of  claim 2 , wherein the controller controls the duct heater to heat the circulating air, and controls the condensation valve to allow the supply of water to the condensing duct while rotating the drum at the first rotational speed to tumble the laundry contained within the drum. 
     
     
         5 . The washing machine of  claim 2 , wherein the controller rotates the drum at the first rotational speed alternately in a first direction and a second direction so that the laundry contained in the drum tumbles, and time for rotating the drum in the first direction differs from time for rotating the drum in the second direction. 
     
     
         6 . The washing machine of  claim 1 , wherein the condensing duct includes a rear groove formed inside a rear wall of the tub having a cylindrical shape, and a cover for partitioning the inside of the rear groove from the inside of the tub. 
     
     
         7 . The washing machine of  claim 6 , wherein the condensing duct is formed along a portion of a sidewall of the tub having the cylindrical shape. 
     
     
         8 . The washing machine of  claim 6 , wherein the condensing duct has a horseshoe shape. 
     
     
         9 . The washing machine of  claim 7 , wherein both ends of the condensing duct are formed with inlets to connect the condensing duct with the inside of the tub. 
     
     
         10 . The washing machine of  claim 1 , further comprising:
 a filter to filter foreign substances contained in the air sucked into the heating duct;   a washing water nozzle to spray water on the filter;   a washing water conduit to connect an external water source to the washing nozzle; and   a washing water valve configured to adjust the supply of the water to the washing nozzle provided on the washing water conduit, and   wherein the controller is configure to rotate the drum at a third rotational speed which is higher than the first rotational speed and lower than the second rotational speed while controlling the washing water valve to allow the supply of the water to the washing nozzle.   
     
     
         11 . The washing machine of  claim 1  further comprising:
 a pulsator provided inside the rear of the drum having a cylindrical shape and rotating independently of the drum, and wherein 
 the controller rotates the drum at the first rotational speed, and rotates the pulsator the same as the drum at a fourth rotational speed while controlling the duct heat and the fan to heat the air circulating in the drum and the condensing duct and the heating duct, 
 wherein the fourth rotational speed is higher than the first rotational speed. 
 
     
     
         12 . A controlling method of a washing machine including a tub, a drum rotatably provided inside the drum, comprising:
 rotating the drum at a first rotational speed so as to tumble laundry contained in the drum while controlling a duct heater to heat air circulated by a fan, and   rotating the drum at a second rotational speed, which is higher than the first rotational speed, to separate water from the laundry contained in the drum while controlling the duct heater to heat the circulating air.   
     
     
         13 . The method of  claim 12 , wherein rotating the drum at the first rotational speed includes allowing supply of water to the condensing duct while heating the heating duct and circulating the air and rotating the drum at the first rotational speed so as to tumble the laundry contained in the drum. 
     
     
         14 . The method of  claim 12 , wherein rotating the drum at the first rotational speed includes rotating the drum alternately in a first direction and a second direction so that the laundry contained in the drum tumbles, and wherein time for rotating the drum in the first direction differs from time for rotating the drum in the second direction. 
     
     
         15 . The method of  claim 12 , wherein rotating the drum at the second rotational speed includes, blocking the supply of water to the condensing duct while rotating the drum at the second rotational speed to separate the water from the laundry contained within the drum. 
     
     
         16 . A washing machine, comprising:
 a tub;   a drum rotatably installed inside of the tub;   a condensing duct formed on an inner wall of the tub;   a condensation conduit to connect an external water source to the condensing duct;   a condensation valve provided on the condensation conduit to adjust the supply of water to the condensing duct;   a heating duct provided outside the tub;   a duct heater provided inside the heating duct;   a fan circulating air in the drum, the condensing duct, and the heating duct; and   a controller electrically connected with the drum motor, the condensation valve, the duct heater, and the fan, and   wherein the condensing duct includes a rear groove formed inside a rear wall of the tub having a cylindrical shape, and a cover for partitioning the inside of the rear groove from the inside of the tub.   
     
     
         17 . The washing machine of  claim 16 , wherein the condensing duct is formed along a portion of a sidewall of the tub having the cylindrical shape. 
     
     
         18 . The washing machine of  claim 17 , wherein both ends of the condensing duct are formed with inlets to connect the condensing duct with the inside of the tub. 
     
     
         19 . The washing machine of  claim 16 , wherein the controller rotates the drum at the second rotational speed to separate water from laundry contained within the drum while controlling the condensation valve to block the supply of water to the condensing duct and controlling the duct heater to heat the air circulated by the fan. 
     
     
         20 . The washing machine of  claim 16 , wherein the controller rotates the drum at the first rotational speed to tumble the laundry contained within the drum while controlling the condensation valve to block the supply of water to the condensing duct and controlling the duct heater to heat the air circulated by the fan.