Clothing dryer including drain pump and method for controlling the same

Abstract

The disclosure of a clothing dryer may comprise: a first water container in which condensate generated as a drying cycle is performed is stored, a drain pump driven by a brushless direct current motor, and a controller configured to: alternately drive the drain pump at a first rotational speed and stop the drain pump a predetermined number of times in response to a start of a bubble removal cycle to remove bubbles from the condensate stored in the first water container, and start a drainage cycle in which the drain pump is operated at a second rotational speed which is greater than the first rotational speed for a predetermined driving period in response to termination of the bubble removal cycle.

What is claimed is: 
     
         1 . A clothing dryer, comprising:
 a first water container in which condensate generated as a drying cycle is performed is stored;   a drain pump driven by a brushless direct current motor; and   a controller configured to:
 alternately drive the drain pump at a first rotational speed and stop the drain pump a predetermined number of times in response to a start of a bubble removal cycle to remove bubbles from the condensate stored in the first water container; and 
 start a drainage cycle in which the drain pump is operated at a second rotational speed which is greater than the first rotational speed for a predetermined driving period in response to termination of the bubble removal cycle. 
   
     
     
         2 . The clothing dryer of  claim 1 , wherein
 a direction in which the condensate is introduced into an inlet portion of the drain pump and a direction in which the condensate is discharged through a discharge portion of the drain pump are parallel to a direction in which a rotation shaft of the drain pump extends, and   the rotation shaft is perpendicular to a lower surface of the clothing dryer.   
     
     
         3 . The clothing dryer of  claim 2 , wherein the controller is further configured to:
 operate the drain pump at a primary first rotational speed during a first operation time to perform a first bubble removal cycle so that, a level of the condensate in the first water container is lowered, and a level of the condensate from the discharge portion is raised to a first predetermined height, by the condensate being pumped by the drain pump from the discharge portion, and   stop operation of the drain pump during a first rest time to lower the level of the condensate from the discharge portion.   
     
     
         4 . The clothing dryer of  claim 3 , wherein
 the controller is further configured to:
 operate the drain pump at a secondary first rotational speed during a second operation time to perform a second bubble removal cycle so that, the level of the condensate in the first water container is lowered, and the level of the condensate from the discharge portion is raised to a second predetermined height, by the condensate being pumped by the drain pump from the discharge portion, in response to termination of the first bubble removal cycle, and 
 stop operation of the drain pump during a second rest time to lower the level of the condensate from the discharge portion, and 
   the secondary first rotational speed is greater than or equal to the primary first rotational speed.   
     
     
         5 . The clothing dryer of  claim 4 , wherein
 the first predetermined height and the second predetermined height are lower than a height to which the condensate is to be raised when the condensate in the first water container is drained from the first water container by operation of the drain pump, and   the first predetermined height is lower than or equal to the second predetermined height.   
     
     
         6 . The clothing dryer of  claim 1 , wherein the second rotational speed includes:
 a primary second rotational speed corresponding to a rotational speed to pump the condensate from the first water container to a second water container in a main body of the clothing dryer, and   a secondary second rotational speed corresponding to a rotational speed to pump the condensate from the first water container to an outside of the clothing dryer.   
     
     
         7 . The clothing dryer of  claim 2 , further comprising:
 a connector connected to an end of the discharge portion to guide the condensate from the first water container to a second water container, or to guide the condensate from the first water container to an outside of the clothing dryer.   
     
     
         8 . The clothing dryer of  claim 7 , wherein the controller is further configured to:
 identify, from a position sensor in the connector, a location where the condensate is to be discharged, and   determine to operate the drain pump at one of a primary second rotational speed and a secondary second rotational speed based on the identified location where the condensate is to be discharged.   
     
     
         9 . The clothing dryer of  claim 4 , wherein the primary first rotational speed and the secondary first rotational speed are 1300 rpm to 3000 rpm. 
     
     
         10 . The clothing dryer of  claim 1 , wherein the second rotational speed is less than or equal to 3300 rpm. 
     
     
         11 . The clothing dryer of  claim 1 , wherein the controller is further configured to: start the bubble removal cycle in response to a level of the condensate in the first water container exceeding a threshold level. 
     
     
         12 . A method of a clothing dryer comprising a first water container in which condensate generated as a drying cycle is performed is stored, a drain pump driven by a brushless direct current motor, and a controller, the method comprising:
 by the controller,
 alternately driving the drain pump at a first rotational speed and stopping the drain pump a predetermined number of times in response to a start of a bubble removal cycle to remove bubbles from the condensate stored in the first water container; and 
 starting a drainage cycle in which the drain pump is operated at a second rotational speed which is greater than the first rotational speed for a predetermined driving period in response to termination of the bubble removal cycle. 
   
     
     
         13 . The method of  claim 12 , wherein
 a direction in which the condensate is introduced into an inlet portion of the drain pump and a direction in which the condensate is discharged through a discharge portion of the drain pump are parallel to a direction in which a rotation shaft of the drain pump extends, and   the rotation shaft is perpendicular to a lower surface of the clothing dryer.   
     
     
         14 . The method of  claim 13 , wherein the bubble removal cycle includes a first bubble removal cycle including:
 operating the drain pump at a primary first rotational speed during a first operation time to raise a level of the condensate from the discharge portion to a first predetermined height, and   stopping operation of the drain pump during a first rest time to lower the level of the condensate from the discharge portion.   
     
     
         15 . The method of  claim 14 , wherein the bubble removal cycle includes a second bubble removal cycle starting in response to termination of the first bubble removal cycle, the second bubble removal cycle including:
 operating the drain pump at a secondary first rotational speed during a second operation time to raise the level of the condensate from the discharge portion to a second predetermined height, and   stopping operation of the drain pump during a second rest time to lower the level of the condensate from the discharge portion.   
     
     
         16 . The method of  claim 15 , wherein
 the first predetermined height and the second predetermined height are lower than a height to which the condensate is to be raised when the condensate is drained from the first water container by operation of the drain pump, and   the first predetermined height is lower than or equal to the second predetermined height.   
     
     
         17 . The method of  claim 12 , wherein the second rotational speed includes:
 a primary second rotational speed corresponding to a rotational speed to pump the condensate from the first water container to a second water container in a main body of the clothing dryer, and   a secondary second rotational speed corresponding to a rotational speed to pump the condensate from the first water container to an outside of the clothing dryer.   
     
     
         18 . The method of  claim 17 , wherein the clothing dryer further includes a connector connected to an end of a discharge portion of the drain pump to guide the condensate from the first water container to a second water container, or to guide the condensate from the first water container to an outside of the clothing dryer, the method further including:
 by the controller,
 identifying, from a position sensor in the connector, a location where the condensate is to be discharged; and 
 determining to operate the drain pump at one of the primary second rotational speed and the secondary second rotational speed based on the location where the condensate is to be discharged. 
   
     
     
         19 . The method of  claim 15 , wherein the primary first rotational speed and the secondary first rotational speed are 1300 rpm to 3000 rpm, and
 the second rotational speed is less than or equal to 3300 rpm.   
     
     
         20 . The method of  claim 12 , further comprising: by the controller, starting the bubble removal cycle in response to a level of the condensate in the first water container exceeding a threshold level.