Water softener abstract
A dishwasher includes a door, a washing tub closable by the door,
and a water softener including an ion exchanger and a salt container.
The salt container is disposed in an area of the door and includes
a first and a second side wall, a bottom, narrow connecting walls,
a water inlet and a brine outlet. Two side walls are disposed in
the salt container, the dividing walls extending from the side walls
to the bottom, dividing the salt container into a water distribution
duct including the water inlet, a salt chamber, and a brine collecting
duct including the brine outlet. The dividing walls, each including
a respective screen surface in a region adjacent to the bottom,
separate the water inlet and a brine outlet from each other. The
screen surfaces are arranged in a v-shape relative to each other.
Water softener claims
What is claimed is:
1. A dishwasher comprising: a door; a washing tub closable by the
door; a water softener including an ion exchanger and a salt container,
the salt container being disposed in an area of the door and being
a flattened component including a first and a second side wall,
a bottom, and narrow connecting walls, the salt container including
a water inlet and a brine outlet; and a first and a second dividing
wall disposed in the salt container, the first dividing wall extending
from the first side wall to the bottom and the second dividing wall
extending from the second side wall to the bottom so as to divide
the salt container into a water distribution duct including the
water inlet, a salt chamber, and a brine collecting duct including
the brine outlet, the first and second dividing walls each including
a respective screen surface in a respective region of the respective
dividing wall adjacent to the bottom, the screen surfaces being
disposed a v-shape relative to each other, the screen surfaces separating
the water inlet and a brine outlet from each other.
2. The dishwasher as recited in claim 1 wherein the first dividing
wall includes a first support shoulder in a region of the first
dividing wall adjacent to the first side wall and the second dividing
wall includes a second support shoulder in a region of the second
dividing wall adjacent to the second side wall.
3. The dishwasher as recited in claim 1 wherein each of the respective
screen surfaces varies in height along the respective dividing wall.
4. The dishwasher as recited in claim 1 wherein at least one of
the water distribution duct and the brine collecting duct includes
a vent opening in a respective rear region as viewed in a respective
direction of flow, the respective vent opening connecting the respective
duct to ambient air via a respective vent line.
5. The dishwasher as recited in claim 4 wherein at least one of
the water distribution duct and the brine collecting duct includes
a respective air-guiding channel configured to slope upward toward
the respective vent opening when the door is closed.
6. The dishwasher as recited in claim 5 wherein each of the respective
dividing walls includes a support shoulder extending from the respective
side wall, and further comprising a respective intermediate wall
disposed between the respective support shoulder and the respective
screen surface of the dividing wall and extending from the respective
dividing wall to the respective side wall, the respective air-guiding
channel being formed by the respective intermediate wall, a portion
of the respective dividing wall, and the respective side wall.
Water softener description
[0001] Priority is claimed to German patent application DE 103
11 126.3 the subject matter of which is hereby incorporated by
reference herein.
[0002] The present invention relates generally to dishwashers,
and in particular to a dishwasher having a washing tub which is
closable by an appliance door, the appliance door including at least
two flat components that are spaced apart in at least one region;
the dishwasher further including a water softener having an ion
exchanger and a salt container, the salt container being a flat
component which includes two side walls, a bottom, and narrow connecting
walls and is located in the space between the two components of
the appliance door; and the salt container having a water inlet
and a brine outlet which are separated from each other by at least
one screen surface.
BACKGROUND
[0003] A dishwasher having an ion exchanger and a salt container
is known from German Patent Application DE 102 04 548 A1.
[0004] To prevent lime deposits on the dishes, it is known to soften
the raw water flowing into the washing tub of a dishwasher using
an ion exchanger. In household dishwashers, the ion exchanger generally
contains a mixed bed resin whose softening components become exhausted
and then have to be regenerated by a solution of common salt. To
accommodate a supply of salt that lasts for several regeneration
cycles, a water softener therefore contains a salt container in
addition to the ion exchanger. In commercial dishwashers, it is
generally known and a common practice to arrange the salt container
in the bottom space of the appliance housing and to fill it through
an opening in the bottom plate of the washing tub. However, this
is uncomfortable for the user because he/she must reach far into
the washing tub. An even greater disadvantage arises if a lack of
salt is noticed when the appliance is loaded. In this case, it is
first necessary to unload the lower dish rack to be able to remove
it from the washing tub, and to thereby gain free access to the
fill opening of the salt container. To avoid these disadvantages,
German Patent Application DE 102 04 548 A1 proposes to arrange the
salt container in the appliance door, thereby allowing it to be
easily filled through an opening on the inside of the door. Due
to the small amount of space between the outside door panel and
the inside door panel, such a salt container must have a very flat
design. To nevertheless allow the container to hold a quantity of
salt sufficient for about 10 to 15 regeneration cycles, the container
is designed to extend over a large area, that is, in addition to
a sufficient width, it also has a large height. This affects the
flow conditions in the salt-filled container.
[0005] In the dishwasher known from German Patent Application DE
102 04 548 A1 the salt container is divided into a salt chamber
and a water inlet by a screen which is located horizontally when
the door is closed. In the region above the salt, a brine chamber
is formed into which opens a brine outlet. In particular, if fine-grained
salt (fine salt), such as commercially available common salt, is
used for regeneration, the vertical flow through the salt chamber
leads to a heavy compaction of the salt, causing obstruction of
the screen.
[0006] In dishwashers with salt containers in the appliance housing,
it is also known to divide the salt container into a salt chamber
and a brine chamber by a screen. However, here, the brine outlet
does not open into the salt chamber, but, together with the water
inlet, into brine chamber underneath the screen. In this context,
the water inlet and the brine outlet are located on opposite sides
of the brine chamber. For regeneration, a supply amount of water
corresponding to the required quantity of brine is admitted to the
brine chamber. The salt lying on the screen is dissolved by this
raw water from below, as a result of which a brine with the desired
concentration forms in the brine chamber. The next time raw water
is introduced, this brine is forced into the ion exchanger. This
principle can only work in the case of relatively low salt heights
and screens having a very large surface area. In the case of narrow
screens and high salt heights, clogging would be inherent, as described
further above. Moreover, a relatively constant brine concentration
can only be achieved if the brine chamber volume can hold the quantity
of brine required for a regeneration cycle. In the case of the narrow
salt containers in the door, this would be at the cost of the salt
supply and is therefore not possible.
[0007] In dishwashers with salt containers in the appliance housing,
it is also known to mount two right-angled screens in the bottom
space, the screens dividing the salt container into a salt chamber
and two brine chambers, and the salt chamber extending into a so-called
"salt trench" between the two vertical screen walls. Since
the fluid flow through the salt trench is in a horizontal direction,
the salt concentration is increased. The use of such screens in
a high, flat salt container is not practicable. When the salt level
is high, the horizontal screens become clogged, and the salt is
dissolved only in the region of the salt trench. Only a small amount
of additional salt slides down over the right-angled edge, which
results in a subsequent decrease in the salt concentration. When
the salt level is low, water is also flushed through the horizontal
screens because these screens are now no longer clogged. This results
in a sharp increase in the brine concentration. Consequently, the
known screen system with salt trench causes a considerable variation
in concentration.
SUMMARY OF THE INVENTION
[0008] It is therefore an object of the present invention to provide
a dishwasher of the type mentioned at the outset whose salt container,
together with the brine chamber, can be integrated into the door
of the dishwasher, and allows producing an optimum salt concentration.
[0009] The present invention provides a dishwasher including: a
washing tub which is closable by an appliance door and a water softener
including an ion exchanger and a salt container. The salt container
is a flat component which includes two side walls, a bottom, and
narrow connecting walls and is located in a space in the region
of the door. The salt container has a water inlet and a brine outlet
which are separated from each other by at least one screen surface,
wherein dividing walls are mounted in the salt container. The dividing
walls in each case extend from the side walls to the bottom, dividing
the salt container into a water distribution duct including the
water inlet, a salt chamber, and a brine collecting duct including
the brine outlet. The dividing walls have regions which are aligned
in a v-shape relative to each other and are designed as screen surfaces
in each case only in the region adjacent to the bottom.
[0010] Due to the inventive design of the salt container, a nearly
constant brine concentration is achieved independently of the salt
level. This is possible because the salt is compacted downward due
to the inclined, converging regions of the dividing walls. Since
the screens are located near the bottom, the flow passes only through
this compacted region, and addition salt can always slide down from
above.
[0011] In an embodiment, the dividing walls have a support shoulder
in the region adjacent to the side walls. In this manner, the level-dependent
pressure on the salt is markedly reduced in the region of the screens.
Thus, the brine concentration only depends on structural and therefore
freely selectable parameters such as screen height, angle of inclination
of the inclined walls, width of the trench, and flow rate of the
water.
[0012] Moreover, in an embodiment the screen surfaces vary in height
along the respective dividing wall. Thus, if the salt container
has narrowings due to design requirements, changes in the salt density
in the screen region can be compensated for.
[0013] In a further embodiment the water distribution duct and/or
the brine collecting duct are provided with a vent opening in the
rear region as viewed in the direction of flow, the vent opening
connecting the respective duct to the ambient air via a vent line.
Since a salt container mounted in the door is filled with salt through
an opening which is oriented in a vertical direction when the dishwasher
is in operation (with the door closed), the salt container cannot
be completely filled with water. For this reason, an air cushion
forms in the upper region of the container from where very fine
bubbles are carried away during brine exchange. Moreover, trapped
air is already present in the raw water itself This air clogs the
screen and causes concentration variations in the brine.
[0014] In an embodiment the water distribution duct and/or the
brine collecting duct each have an air-guiding channel which slopes
upward toward the vent opening when the door is closed. Due to this,
the air bubbles are carried away to the vent openings in a simple
manner. In an expedient embodiment, provision is made for the air-guiding
channel to be formed by an intermediate wall which is located between
the screen surface and the support shoulder and extends from the
dividing wall to the side wall, and by a section of the dividing
wall and of the side wall.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Exemplary embodiments of the present invention are shown
in the drawings in purely schematic way and will be described in
more detail below. In the drawings:
[0016] FIG. 1 shows a schematic sectional view of a dishwasher;
[0017] FIG. 2 shows a perspective view of a salt container;
[0018] FIGS. 3 3a show a partial section through a simplified
embodiment of salt container as viewed in the X direction; and
[0019] FIG. 4 shows a partial section through salt container including
a vent, with the right side wall removed.
DETAILED DESCRIPTION
[0020] FIG. 1 shows a program-controlled household dishwasher having
a washing tub 3 which includes a drain pain 4 and is located in
a housing 1 and which can be closed by a door 2 at the front. The
two-panel door 2 is composed of an inside door panel 5 and an outside
door panel 6 and is supported at its bottom section on the appliance
body in such a manner that it can pivot about a horizontally extending
axis 7. A lower spray arm is denoted by 8 and two dish racks are
referred to by 9. The supply of wash water to spray arm 8 via a
circulating pump is sufficiently known and therefore not shown in
the drawings. The same applies to the supply of water to the washing
tub 3 and to the drainage of the drain pan 4 via a drain pump.
[0021] To be able to use softened wash water in at least one program
cycle, the dishwasher 1 is equipped with an integrated water softener.
This water softener includes an ion exchanger 13 and a container
which is intended to hold the regenerant NaCI and is therefore referred
to as "salt container 12" hereinafter. The raw water is
supplied from a water line system of the dishwasher via a valve-controlled
water connection. Ion exchanger 13 is located in housing 1 underneath
drain pan 4; salt container 12 is mounted in door 2 in the space
between inside door panel 5 and outside door panel 6. A brine outlet
line 10 runs from salt container 12 to the ion exchanger. Water
is supplied from a reservoir in a water bag via a water supply line
11. Lines 10 11 are designed as flexible hose connections at least
in the moving portion of the door.
[0022] FIG. 2 is a detail view of salt container 12. The salt container
is made of plastic (polypropylene) and composed of two side walls
14 which have a large surface area and of which the wall 14.1 facing
the inside door panel 5 is provided with a closable salt fill opening
9. The two side walls 14 are completed by narrow connecting walls
15 and a likewise narrow bottom 16 (shown in FIGS. 3a and 4) into
a flat container which has a cuboidal shape in the lower region
from where it tapers towards fill opening 9 in a trapezoidal shape.
Connecting walls are provided with openings on both sides in the
lower regions, the openings having pipe connectors 17 18 integrally
formed thereon. Water supply line 11 is connected to the front connector
18; brine outlet line 10 is connected to the rear connector 17.
[0023] FIGS. 3 and 3a show the interior of a simplified embodiment
of the salt container. The salt container is divided by two dividing
walls 19 into a water distribution duct 20 including the water inlet,
a salt chamber 21 and a brine collecting duct 22 including the
brine outlet. Dividing walls 19 are designed as angle sections,
each extending over nearly the full width of salt container 12.
The dividing walls are made as separate parts and connected to salt
container 12 by welding. Alternatively, salt container 12 and dividing
walls 19 can also be integrally injection-molded as a single piece;
which, however, is difficult to accomplish because of problems during
the removal from the mold. Due to the angular shape, the first legs
23 act as support shoulders which are aligned parallel to the bottom
16 of salt container 12. The free edges 24 of these legs contact
the side walls 14. The other legs 25 contact the bottom 16 of salt
container 12 with their free edges 26. The latter legs are provided
with about 0.2 mm wide slits 27 only in the region adjacent to bottom
16; the slits in each case forming a screen, or seive, surface 28.
In the exemplary embodiment shown, the screen slits 27 have a constant
height. However, the height can also vary, which is useful especially
if salt container 12 has installation-related constrictions above
the region between legs 25 (salt trench). The two legs 23 and 25
of a dividing wall 19 from an angle a greater than 90.degree.. Accordingly,
the lower legs 25 of the two dividing walls 19 are aligned in a
v-shape relative to each other, forming a salt trench 29 of trapezoidal
cross section; the narrower of the two parallel sides (bases) being
formed by bottom 16.
[0024] FIG. 4 shows an embodiment of a salt container 12 which
is provided with a vent. To this end, horizontal legs 23 of the
dividing walls 19 are provided with openings 30 which are in communication
with the ambient air via vent lines 31. The openings 30 are in each
case arranged at the sink end of the flow gradient in the respective
duct (water distribution duct 20 and brine collecting duct 22 respectively).
In the case of water distribution duct 20 this is the end opposite
water inlet 18; in the case of brine collecting duct 22 this is
the end at brine outlet 17. Moreover, in both ducts 20 22 provision
is made for an air-guiding channel 33 that slopes upward toward
the vent opening. For this purpose, intermediate walls 32 are mounted
between the screen surfaces 28 and the support shoulders (legs 23).
The intermediate walls extend from the legs 25 of the dividing walls
to the respective side walls 14. Thus, the air-guiding channels
33 are formed by the upwardly sloping intermediate walls 32 the
adjacent sections of dividing walls 19 and by the adjacent sections
of side walls 14. The air-guiding channels 33 ensure that small
bubbles move up the slopes due to buoyancy and with the assistance
of the fluid flow, and are carried off through openings 30 via vent
lines 31 into the ambient environment.
[0025] To carry out a regeneration cycle, the supply amount of
water required for this is fed from the water bag via water supply
line 11 into water distribution duct 20. Thus, initially, the brine
present in brine collecting duct 22 is forced into ion exchanger
13. However, since this amount of brine is not sufficient for regeneration,
additional brine must be produced. To this end, additional water
is forced from water distribution duct 20 through left screen 28.1
into salt trench 29 and from there through right screen 28.2 into
brine collecting duct 22. In the process, the water dissolves the
salt located between the screens 28 and is converted to brine. The
concentration of this brine is nearly constant because the fluid
flow, and thus the dissolution of salt, is primarily limited to
the region between screens 28. Due to the v-shaped, inclined arrangement
of the legs 25 of dividing walls 19 the salt is compacted in the
region of screens 28. Moreover, it is ensured that addition salt
constantly slides down from the space above salt trench 29. Pressure
exerted by the salt volume present above salt trench 29 is supported
by the support shoulders (legs 23). After the supply of water has
been completely emptied, a residual amount of water remains in water
distribution duct 20 and a residual amount of brine remains in
brine collecting duct 22. These residual amounts of water and brine
are transported into ion exchanger 13 during the next regeneration
cycle. |