Water circulation apparatus and method for drum washing machine

Abstract

A water circulation apparatus and method of a drum washing machine is disclosed. The water circulation apparatus includes a tub, a drain hose connected to the tub, a muddiness detecting sensor detecting a degree of muddiness of wash water being discharged through the drain hose after being used for rinsing laundry, a drain pump located in the drain hose to pump the wash water being discharged through the drain hose, a circulation hose connected to the drain hose at a discharge side of the drain pump to supply the wash water into a drum, a supply valve located at a connecting portion between the drain hose and the circulation hose to selectively supply the wash water pumped by the drain pump to the drain hose of a drain port side or to the circulation hose, and a controller controlling operations of the drain pump and the supply valve.

1 . A water circulation apparatus of a drum washing machine, comprising:
 a tub;   a drain hose connected to the tub;   a muddiness detecting sensor detecting a degree of muddiness of wash water being discharged through the drain hose after being used for rinsing laundry;   a drain pump located in the drain hose to pump the wash water being discharged through the drain hose;   a circulation hose connected to the drain hose at a discharge side of the drain pump to supply the wash water into a drum;   a supply valve located at a connecting portion between the drain hose and the circulation hose to selectively supply the wash water pumped by the drain pump to the drain hose of a drain port side or to the circulation hose; and   a controller controlling operations of the drain pump and the supply valve.   
   
   
       2 . The apparatus according to  claim 1 , further comprising: a drain valve located at a connecting portion between the tub and the drain hose to drain the wash water used for rinsing the laundry. 
   
   
       3 . The apparatus according to  claim 1 , wherein the drain hose is connected to a lower side of the tub. 
   
   
       4 . The apparatus according to  claim 1 , wherein the muddiness detecting sensor is located in the drain pump or the drain hose at the tub side. 
   
   
       5 . A water circulation method of a drum washing machine comprising:
 draining wash water used for rinsing laundry after a rinsing cycle;   measuring a degree of muddiness of the wash water to compare the measured degree of muddiness of the wash water with a target value;   circulating the wash water if the measured degree of muddiness of the wash water is less than or equal to the target value; and   draining the wash water if the measured degree of muddiness of the wash water is greater than the target value.   
   
   
       6 . The method according to  claim 5 , wherein the circulating the wash water comprises actuating a drain pump and opening a port of a supply valve at a circulation hose side. 
   
   
       7 . The method according to  claim 5 , wherein the draining the wash water comprises actuating a drain pump and opening a port of a supply valve at a drain hose side of a drain port side. 
   
   
       8 . A water circulation apparatus of a drum washing machine comprising:
 a tub;   a drain hose connected to the tub;   a drain pump located in the drain hose to pump wash water being discharged through the drain hose;   a circulation hose connected to the drain hose at a discharge side of the drain pump to supply the wash water into a drum; and   a supply valve located at a connecting portion between the drain hose and the circulation hose to selectively supply the wash water pumped by the drain pump to the drain hose at a drain side or to the circulation hose.   
   
   
       9 . The apparatus according to  claim 8 , further comprising: a drain valve located at a connecting portion between the tub and the drain hose to drain the wash water. 
   
   
       10 . The apparatus according to  claim 8 , wherein the drain hose is connected to a lower side of the tub.