A DISHWASHER COMPRISING A MICROFILTER

[0001] The present invention relates to a dishwasher comprising a microfilter.

[0002] The microfilter used in a dishwasher clogs due to the residues adhering thereon after consecutive washings. This decreases, after a while, the washing performance of the dishwasher and makes the filtration system dysfunctional. To prevent this, the user is required to remove and clean the microfilter at certain periods. But many users either never clean the microfilter or cannot replace it properly after the cleaning. The microfilter not being cleaned or its erroneous assembly causes the washing performance to decrease. For this reason, in the state of the art, various solutions have been developed for the microfilter to self-clean.

[0003] In the state of the art, a washing receptacle is situated at the lower portion of the washing tub, wherein the water in the washing tub is collected during the washing process and in the middle of which the microfilter is placed. The circulation pump which is used to return the water collected in the washing receptacle to the washing tub is connected to the washing receptacle by means of a suction hose one end of which opens to the pump, the other to the washing receptacle. Moreover, a supply hose is connected which provides the water to be taken into the washing tub from the mains with one end being connected to the mains and the other end of which opens to the washing receptacle.

[0004] Since the circulation pump sucks the water in the washing receptacle by means of the suction hose, residues entering into the microfilter

accumulate at the inner part of the washing receptacle located at the side of the wall thereof to which the suction hose is connected more than the other side. The water taken from the mains by the supply hose does not provide the cleaning of the residues adhering to this wall, on the contrary sticks them to the wall of the microfilter.

[0005] The aim of the present invention is the realization of a dishwasher

comprising a microfilter which can be cleaned without requiring user intervention.

[0006] The dishwasher realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof, comprises a control unit which, just before or after any one of the washing steps, provides the water which is insufficient for washing and rinsing to be directed onto the microfilter by water inlet hole and after to be discharged by the circulation pump.

[0007] Little amount of water is sufficient for the microfilter cleaning process. It is sufficient to fill the receptacle up to the upper level of the microfilter. The said amount is directly proportional to the dimensions and the capacity of the dishwasher. Today, in the household dishwashers the said amount is between 0.5 and 1.5 liters.

[0008] In an embodiment of the present invention, the cleaning of the microfilter is realized just after the main washing step. The water taken from the mains is discharged after being passed through the microfilter.

[0009] In another embodiment of the present invention, the cleaning of the

microfilter is realized before the main washing step.

[0010] In another embodiment of the present invention, the cleaning of the

microfilter is realized before the rinsing step.

[001 1] In another embodiment of the present invention, while the microfilter is being cleaned, the circulation pump is operated simultaneously.

[0012] In another embodiment of the present invention, the water inlet hole to which the supply hose is connected, is in nozzle form. Thus, by increasing the speed of the water coming from the supply hose due to mains pressure and thus by the water hitting the outer surface of the microfilter faster, the residues accumulated on the other side of the same surface are provided to be removed from the microfilter.

[0013] By means of the present invention, the residues accumulated on the inner surface of the microfilter are provided to be cleaned by the water flow to which the microfilter is subjected at the opposite direction from the other side of the same surface. Thus, the microfilter is cleaned by pushing the residues adhering to the inner surface of the microfilter by means of the water moving through the supply hose to the chamber when water is taken into the washing tub from the mains. The washing performance is increased since the residues fallen from the microfilter after the cleaning process and the water used for the cleaning are directly discharged through the circulation pump.

[0014] By means of the present invention, less residue accumulates on the

microfilter surface. Moreover, the residues accumulated are provided to be dispersed almost homogeneously on all the surfaces of the microfilter.

Thus, the decrease in the washing performance of the dishwasher after consecutive washings is prevented.

[0015] A dishwasher realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

[0016] Figure 1 - is the schematic view of a dishwasher.

[0017] The elements illustrated in the figures are numbered as follows:

1. Dishwasher

2. Washing tub

3. Receptacle

4. Circulation pump

5. Microfilter

6. Supply hose

7. Suction hose

8. Water inlet hole

9. Suction hole

10. Control unit

[0018] The dishwasher (1 ) of the present invention comprises a washing tub (2) wherein items to be washed are placed, a receptacle (3) located at the lower portion of the washing tub (2), wherein the water in the washing tub (2) is collected during the washing process, a microfilter (5) located in the middle of the receptacle (3), which allows the passing of the water which passes from the washing tub (2) to the receptacle (3) but which holds the residues carried by the water, a circulation pump (4) which returns the water accumulated in the receptacle (3) to the washing tub (2), a suction hose (7) one end of which opens to the circulation pump (4), the other to the receptacle (3), a suction hole (9) to which the end of the suction hose (7) which opens into the receptacle (3) is mounted, and which opens to the receptacle (3) wall facing the microfilter (5) such that the water accumulated in the receptacle (3) can pass to the suction hose (7), and a supply hose (6) one end of which is connected to the water intake line and the other end of which opens to the receptacle (3).

[0019] The dishwasher (1 ) furthermore comprises a water inlet hole (8) to which the end of the supply hose (6) which opens into the receptacle (3) is connected, which is located on the receptacle (3) wall, which faces the outer surface (DY) of the microfilter (5). The water inlet hole (8) and the suction hole (9) are situated on the receptacle (3) wall facing the outer surface (DY) of the microfilter (5) (Figure 1 ).

[0020] After passing over the microfilter (5) the water sucked by the circulation pump (4) reaches the suction hole (9) and is directed to the washing tub (2) by passing through the circulation pump (4) after passing through the suction hose (7). When water is taken from the mains, the water passing through the supply hose (6) reaches the receptacle (3) by passing through the water inlet hole (8) and enters into the receptacle (3) by hitting the microfilter (5) just in front of the water inlet hole (8). Thus, the residues remaining on the inner surface (IY) of the microfilter (5) at the water suction direction when the circulation pump (4) operates, leave the inner surface (IY) of the microfilter (5) by the water taken into the receptacle (3) at a direction opposite to the water suction direction hitting the outer surface (DY) of the microfilter (5).

[0021] While the dishwasher (1 ) operates, the water accumulated in the

receptacle (3) is sucked by means of the circulation pump (4) and sent to the propellers. While the water accumulated in the receptacle (3) is sucked by means of the circulation pump (4), residues carried by the water accumulate on the inner surface (IY) of the microfilter (5) in the middle of the receptacle (3). In this case, the residues accumulated on the inner surface (IY) of the microfilter (5) by the water being sucked by the circulation pump (4) when the circulation pump (4) operates, are moved away from the inner surface (IY) of the microfilter (5) by the water taken from the mains hitting the outer surface (DY) of the microfilter (5) right after flowing at the opposite direction to the suction direction of the circulation pump (4). Thus, the residues accumulated on the inner surface (IY) of the nnicrofilter (5) are moved away from the inner surface (IY) by the water taken from the mains hitting the outer surface (DY) of the microfilter (5) and thus providing the microfilter (5) to be cleaned without user

intervention.

[0022] The dishwasher (1 ) comprises a control unit (10) which runs a washing program having various washing steps such as pre-washing, main washing, first rinsing, second rinsing and regeneration step which is applied when needed.

[0023] The control unit (10), before or after any one of the washing steps,

provides the water which is insufficient for washing or rinsing to be directed onto the microfilter (5) through the water inlet hole (8) and then to be discharged by the circulation pump (4). By means of the said microfilter (5) washing process, the microfilter (5) is provided to be cleaned by removing the residues adhering onto the microfilter (5). The said water amount is approximately between 0.5 and 1.5 liters. The receptacle (3) being empty during the microfilter (5) washing process increases the performance of the process. When the water level in the receptacle (3) increases, the microfilter (5) remains in the water, accordingly it gets difficult for the water taken by the water inlet hole (8) to hit the microfilter (5) surface. For this reason, during the microfilter (5) washing process, an amount of water which is sufficient to fill the receptacle (3) up to a level above the microfilter (5) is used.

[0024] In an embodiment of the present invention, the said microfilter (5) washing process is performed after the main washing step. In this embodiment, first rinsing step performed with cold/warm water is cancelled, the microfilter (5) washing process is realized at least once between the main washing and the second rising (with hot water) steps. By cancelling the first rinsing, both energy saving is provided and water consumption is reduced.

[0025] In another embodiment of the present invention, the said microfilter (5) washing process is performed before the main washing step.

[0026] In another embodiment of the present invention, the said microfilter (5) washing process is performed before the rinsing step.

[0027] In another embodiment of the present invention, during the said microfilter (5) washing process, the water is directed onto the nnicrofilter (5) through the inlet hole (8) and the circulation pump (4) is operated simultaneously by the control unit (10). Thus, the residues which leave the microfilter (5) by the hitting of the water sprayed through the water inlet hole (8), are discharged by means of the circulation pump (4) without settling at the bottom of the receptacle (3).

[0028] In another embodiment of the present invention, during the said microfilter

(5) washing process, the water directed onto the microfilter (5) through the water inlet hole (8) is directed to the propellers before being discharged.

[0029] In another embodiment of the present invention, the water inlet hole (8) is in nozzle form narrowing towards the inside of the receptacle (3). Thus, the speed of the water taken from the mains by means of the supply hose

(6) is provided to be taken into the receptacle (3) and to hit the outer surface (DY) of the microfilter (5).

[0030] It is to be understood that the present invention is not limited to the

embodiments disclosed above and a person skilled in the art can easily introduce different embodiments. These different embodiments should be considered within the scope of the claims of the present invention, too.