EP0575837B1

EP0575837B1 - Dishwasher

Info

Publication number: EP0575837B1
Application number: EP93109380A
Authority: EP
Inventors: Enzo Brignone
Original assignee: Bitron SpA
Current assignee: Bitron SpA
Priority date: 1992-06-22
Filing date: 1993-06-11
Publication date: 1996-11-27
Anticipated expiration: 2013-06-11
Also published as: ES2094964T3; ITTO920530A1; EP0575837A1; DE69306177T2; DE69306177D1; ITTO920530A0; IT1259587B

Description

The present invention relates to a domestic electric appliance, in particular a dishwasher, including:

a washing tank,
a container for a substance with decalcifying properties, through which the water to be supplied to the washing tank is made to flow beforehand,
a reservoir for holding a saline substance through which water is made to flow so as to dissolve the saline substance and form a brine for regenerating the substance with decalcifying properties, and
a chamber for receiving the used brine which has flowed through the container for the substance with decalcifying properties and/or water used for rinsing the substance with decalcifying properties.

A domestic electric appliance of the type described above is known from British patent application No. 2210256.
According to this document, the chamber for receiving the used brine and the water used for rinsing the substance with decalcifying properties is disposed hydraulically upstream of the washing tank and is connected to the lower portion thereof, which is known as the sump.
The used brine and the rinsing water can thus be discharged to the sump and are then conveyed into the general waste pipe of the domestic electric appliance.
Since the used brine has corrosive properties, the sump has to be made of plastics material, unlike the other parts of the washing tank which are made of metal.
Moreover, the used brine is never completely discharged from the sump before a subsequent washing cycle. A quantity, albeit small, of used brine is thus mixed with the water supplied to the washing tank for the next washing cycle and comes into contact with the metal walls of the tank, causing corrosion problems in the long term.
In order to overcome both this and other problems the subject of the present invention is a domestic electric appliance of the type indicated above, further comprising the features specified in the characterizing portion of claim 1.
According to the invention, the used brine and the water used to rinse the substance with decalcifying properties flow from the chamber into the general waste pipe of the domestic electric appliance downstream of the washing tank, preventing corrosion problems from arising therein.
Further advantages and characteristics of the present invention will become clear from the detailed description which follows with reference to the appended drawing, provided purely by way of non-limiting example, in which:

Figure 1 shows the hydraulic system of a domestic electric appliance according to the invention, and
Figure 2 shows an alternative embodiment of the hydraulic system of a domestic electric appliance according to the invention.

In Figure 1, an air break chamber is indicated 10, a container for a substance with decalcifying properties, for example, an ion-exchange resin, is indicated 12, a salt reservoir is indicated 14, a metering chamber is indicated 16, a washing tank is indicated 18, a chamber for receiving used brine is indicated 20, and an electric pump positioned in a general waste pipe 24 of the domestic electric appliance is indicated 22.
A more detailed description of an electrical household appliance including the various components mentioned above is contained in the Applicant's Italian patent application No. TO92A000235 which is incorporated in the present description by way of reference.
When the domestic electric appliance is in operation, the water supplied from the duct 26 flows firstly into the tank 10 and most of it is then sent into the ion-exchange resin container 12 where it is decalcified.
The decalcified water is then admitted to the metering chamber 16 and then to the tank 18 from which, upon completion of the washing cycle, it is discharged through the waste pipe 24 in which the electric pump 22 is disposed.
The rest of the water supplied is sent from the tank 10 to the salt reservoir 14, where it forms a brine which is passed through the ion-exchange resin container 12 so as to regenerate the resin after it has been used to soften the water to be sent to the metering chamber 16.
Any residues of saline substances or calcareous deposits are then rinsed from the ion-exchange resin container 12 by a further flow of rinsing water from the tank 10.
The used brine and rinsing water are drained into the chamber 20, the outlet duct 28 of which joins the general waste pipe 24 of the domestic electric appliance downstream of the washing tank 18 so that the chamber 20 is disposed hydraulically in parallel therewith.
The outlet duct 28 of the chamber 20 may join the general waste pipe 24 either upstream of the electric pump 22 (as shown in Figure 1) or downstream of the electric pump 22 (as shown in Figure 2).
The latter figure shows an alternative embodiment of the hydraulic system of a domestic electric appliance according to the invention, in which the same reference numerals as those used above correspond to elements the same as or equivalent to those of Figure 1.
If the chamber 20 is positioned above the general waste pipe 24, it may be emptied, for example, by gravity. Alternatively, the portion of the general waste pipe 24 including the point at which it joins the outlet duct 28 of the chamber 20 may be shaped like a Venturi tube. In this case, the flow of liquid through this portion generates a vacuum which sucks the liquid out of the chamber 20, even if it is positioned below the general waste pipe 24.

Claims

A domestic electric appliance, in particular a dishwasher, including:
- a washing tank (18),

- a container (12) for a substance with decalcifying properties, through which the water to be supplied to the washing tank (18) is made to flow beforehand,

- a reservoir (14) for holding a saline substance, through which water is made to flow so as to dissolve the saline substance and form a brine for regenerating the substance with decalcifying properties,

- a pump (22), and

- a chamber (20) for receiving the used brine which has flowed through the container for the substance with decalcifying properties and/or water used for rinsing the substance with decalcifying properties,
characterised in that said chamber (20) is disposed hydraulically in parallel with the washing tank (18),
said pump (22) is suitable for bringing about the discharge of the content of the chamber (20) in a general waste pipe (24), and
the portion of the general waste pipe (24) including the point at which it joins the outlet duct (28) of the chamber (20) is shaped like a Venturi tube.