Information
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Patent Grant
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6458281
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Patent Number
6,458,281
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Date Filed
Wednesday, February 7, 200123 years ago
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Date Issued
Tuesday, October 1, 200222 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
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CPC
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US Classifications
Field of Search
US
- 210 767
- 210 167
- 210 196
- 210 197
- 210 499
- 210 409
- 210 791
- 134 111
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International Classifications
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Abstract
The invention relates to a method for separating solid particles from a liquid in a dish-washer. For the separation a filter (19) of expanded metal is provided, which forts openings (21) the bounding surfaces (22) of which are inclined in relation to the plane of the filter. The liquid with particles entrained therein is directed towards descending bounding surfaces in the filter for guiding the liquid flow through the filter under separation of the particles from the liquid.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for separating solid particles from a liquid in a dish-washer.
The invention is proposed primarily for a granule dish-washer with a condenser in order to separate granules from the condensation water
However, the method according to the invention can be applied also to the separation of food residues from circulating liquid in a dish-washer in order to facilitate the cleaning of a filter used for this separation.
2. Problem Involved
Granules which during a previous dish washing step have collected in the condenser may be carried along by the condensation water to the drain and eventually may clog the filter and as a Consequence thereof prevent the outflow of the condensation water.
BRIEF SUMMARY OF THE INVENTION
The purpose of the invention is to provide a method of the kind referred to above wherein granules entrained in the condensation water are returned to the liquid tank for use in following dishwashing operations.
For this purpose the invention provides a method for separating solid particles from a liquid in a dish-washer, wherein there is provided for said separation a filter of expanded metal which forms openings the bounding surfaces of which are inclined in relation to the plane of the filter, and wherein the liquid with particles entrained therein is directed towards descending bounding surfaces in the filter for guiding the liquid flow through the filter under separation of the particles from the liquid.
BRIEF DESCRIPTION OF THE DRAWING
Embodiments of the invention will be described in order to explain the invention in more details reference being made to the accompanying drawing in which
FIG. 1
is a diagrammatic side view of a granule dishwasher,
FIG. 2
is a perspective view of a condenser in the dish-washer,
FIG. 3
is an enlarged fragmentary plan view of a filter consisting of expanded metal and mounted in the condenser,
FIG. 4
is a cross sectional view along line IV—IV in
FIG. 3
,
FIG. 5
is a diagrammatic view illustrating the function of the filter consisting of expanded metal, and
FIG. 6
is a diagram disclosing the dishwashing cycle in the granule dish-washer.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1
discloses diagrammatically a granule dish-washer which in a typical embodiment comprises a cabinet
10
for receiving the goods
11
to be cleaned. A number of spray nozzles
12
are provided in the cabinet, and the lower portion of the cabinet forms a liquid tank
13
. On the outside of the cabinet a condenser
14
is mounted which is permanently connected with the interior of the cabinet by upper and lower sleeve couplings
15
,
16
, The condenser has a connection
17
for supply of cooling water at the top and a closable outlet
18
connected to the lower sleeve coupling
16
for draining off cooling water at the bottom via a filter
19
mounted in the sleeve coupling
16
. The filter slopes downwards towards the mouth of the sleeve coupling
16
. The central portion
20
of the condenser forms a venturi tube for producing an injection effect in the condenser while cooling water is being supplied through the connection
17
.
The filter
19
consists of expanded metal according to
FIGS. 3 and 4
, i.e. a close-meshed net with openings
21
, which is made by tensioning (expanding) a slotted metal sheet. The openings
21
are defined by bounding surfaces
22
which are inclined in relation to the plane of the filter as will be seen in FIG.
4
. The filter is mounted in the sleeve coupling
16
in such a way that liquid which enters the coupling
16
from the condenser meets descending bounding surfaces
22
of the filter as will be seen in
FIG. 5
wherein liquid arriving from the condenser is indicated by arrows
23
.
A dishwashing cycle in a granule dish-washer is illustrated in
FIG. 6
wherein the several steps are marked on a time axis. In a first step
24
, the dish washing step, liquid at about 65° C. together with granules is pumped from the tank
13
to the nozzles
12
, and the jets emanating therefrom are directed towards the goods
11
to be washed, and then the liquid and accompanying granules are returned to the tank in order to be circulated again in the manner described.
In the second step
25
the granules are separated from the liquid and only liquid at 65° C. is circulated in order to rinse the goods. Then, a final rinsing step
26
with clean water at 85° C. is initiated in order to heat and disinfect the goods, and this water is allowed to flow into tank
13
in order to be mixed with the liquid therein the volume of which as a consequence thereof will increase existing surplus being drained off to an outlet conduit via an overflow carrying away solid particles, grease etc. from the surface layer in the tank.
During dish washing and rinsing liquid and granules will enter the condenser
14
because the condenser is permanently connected with the interior of the cabinet, an insignificant amount of liquid being collected in the sleeve coupling
16
below the filter
19
because the outlet
18
is kept closed during these operations. Moreover, some granules adhere to the walls of the condenser by the surface tension of the liquid.
When the final rinsing step
26
has been terminated the machine in its entirety is warm inside and also the goods that have been cleaned are warm. The interior of the cabinet is filled with hot steam. This must be removed before the cabinet is opened for removing the goods, which is effected in a following step
27
by cooling water being sprayed into the condenser
14
at the connection
17
and being allowed to pass through the condenser to the sleeve coupling
16
where the water is drained off through the outlet conduit
18
now open. At the passage through the venturi tube
20
of the condenser, the cooling water provides an injector effect generating a suction through the condenser so that steam is sucked from the interior of the cabinet into the condenser through the sleeve coupling
15
. When moving downwards through the condenser the steam will condense. The condensate is drained off together with the cooling water through the conduit
18
. Granules which during the dish washing and rinsing steps
24
,
25
,
26
due to surface tension of the liquid have adhered to the surfaces in the condenser may be entrained in the condensation water, and it is of course desired to retrieve these granules for use in following dish washing cycles. Therefore, they are prevented from being carried along by the water to the outlet
18
by the filter
19
the openings of which are sufficiently small in order that the granules cannot pass therethrough. The water hits the filter from the left as seen in
FIGS. 4 and 5
so that it rams the descending inclined bounding surfaces of the filter openings
21
in order to be guided through the openings of the filter and be drained off through the outlet
18
while accompanying granules as well as the granules which have collected on the filter during previous operations will be repelled towards the interior of the cabinet as illustrated in
FIG. 5
in order to be received by the tank
13
for reuse in following dish washing steps.
In the embodiment described the filter of expanded metal is mounted in connection with a condenser but it can also be mounted in the circulation system of the granule dish-washer in order to separate granules from liquid circulating in step
24
with granules entrained therein. In that case the filter can be mounted in inclined position in a conduit for the liquid with granules entrained therein so that granules trapped by the filter will roll from the filter through a side outlet connecting to the filter surface, into a drained collection container while the liquid separated from granules passes through the filter and continues to circulate for effecting rinsing with liquid, step
25
. The separated granules can then be returned to the liquid for reuse in the dish washing step
24
.
A filter of expanded metal preferably is provided also in the overflow from the tank
13
in the dish-washer the outflow from the tank being directed towards the descending bounding surfaces of the filter in the manner described above. Solid particles such as food residues which are separated from the liquid by means of the filter and collect on the surface thereof then can be easily removed from the filter by rinsing the filter with liquid in a direction opposite to that of the outflow from the tank such that this rinsing flow hits the ascending surfaces of the filter. As a consequence thereof the rinsing flow will have a component directed from the surface of the filter, which lifts collected material from the surface of the filter so that the rinsing flow more easily removes the material from the filter.
Claims
- 1. A method for separating-solid particles from a liquid in a dishwasher comprising the steps of:(a) providing a separation filter formed from expanded metal having openings formed there through, said openings being defined by bounding surfaces of said expanded metal, said bounding surfaces being inclined with respect to the plane of the filter; and (b) positioning said filter within said dishwasher such that liquid with particles entrained therein is directed downwards toward descending surfaces of said bounding surfaces in the filter so as to guide the liquid flow through the filter and separate the particles from the liquid.
- 2. The method according to claim 1 wherein the liquid with particles entrained therein comprises dishwashing liquid with dishwashing granules entrained therein and wherein said separation filter separates said dishwashing granules from said liquid so that said dishwashing granules may be reused in a subsequent dishwashing procedure.
- 3. The method according to claim 1 wherein the liquid with particles entrained therein comprises cooling and condensation water escaping from a condenser in a granule dishwasher and wherein said separation filter separates said granules from said cooling and condensation water.
- 4. The method according to claim 1 wherein particles collected on the separation filter are removed there from by means of a liquid flow directed towards ascending bounding surfaces of the separation filter.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4998548 |
Lagerstrand |
Mar 1991 |
A |