The present invention relates to warewashing using a re-circulating warewashing machine.
In a re-circulating warewashing machine, wash water and rinse water are directed into and stored in a sump of the re-circulating warewashing machine and then pumped into the wash arms in subsequent wash cycles. For the initial wash cycle, detergent is added to water to create wash water for use during the initial wash cycle, and the wash water is directed into and stored in the sump of the warewashing machine for use in subsequent wash cycles. Fresh water, which may include an optional rinse aid, is as rinse water during each of the rinse cycles, and the rinse water is also directed into and stored in the sump of the warewashing machine. During subsequent wash and rinse cycles, the wash water and the rinse water are directed into and stored in the sump of the dishwashing machine for use as wash water in the subsequent wash cycles. The rinse water displaces a proportional amount of water in the sump, which flows into a drain, thereby diluting the sump water. Because the wash water is diluted with the rinse water, detergent should be added to the water stored in the sump for use in subsequent wash cycles. However, less detergent than is needed initially is needed for use in subsequent wash cycles since the sump water includes detergent from previous wash cycles. Because the sump water is used in several wash cycles, the sump water can become very soiled over time.
High soil levels in the sump water can lead to re-deposition of soils on wares and decreases the detersive action of the chemicals added to the wash water. Therefore, it is desired to direct the soiled water out of sump so that it can be replaced with relatively cleaner water resulting in lower soil levels in wash water for subsequent cycles.
In one aspect of the invention, a sump assembly of a re-circulating warewashing machine having a rinse cycle and a wash cycle includes a sump, a divider, a drain, a first water level, and a second water level. The sump has a top, a bottom, and a cavity in which water used in the re-circulating warewashing machine is stored. The water includes rinse water from the rinse cycle and soiled water from the wash cycle. During the rinse cycle, the rinse water is proximate the top of the sump and the soiled water is proximate the bottom of the sump. The divider defines a first portion and a second portion of the cavity. The first portion is in fluid communication with the second portion, and the drain has an opening and is in fluid communication with the second portion. The first water level is approximately level with the opening of the drain. As the rinse water enters the first portion of the cavity, the second water level is approximately above the opening of the drain in the first portion. The second water level directs soiled water proximate the bottom of the sump from the first portion into the second portion where the soiled water is directed into the drain thereby replacing soiled water with rinse water in the sump during the rinse cycle.
In another aspect of the invention, a sump assembly of a re-circulating warewashing machine having a rinse cycle and a wash cycle includes a sump, a divider, a drain, a first water level, and a second water level. The sump has a top, sides, a bottom, and a cavity in which water used in the re-circulating warewashing machine is stored. The water includes rinse water from the rinse cycle and soiled water from the wash cycle. During the rinse cycle, the rinse water is proximate the top of the sump and the soiled water is proximate the bottom of the sump. The divider has a partition extending from opposing sides of the sump proximate the top of the sump toward proximate a middle of the sump. The partition defines a gap between the divider and the bottom of the sump and defines a first portion and a second portion of the cavity. The first portion and the second portion are in fluid communication via the gap interconnecting the first portion and the second portion. The drain has an opening and is in fluid communication with the second portion. The first water level is approximately level with the opening of the drain. As the rinse water enters the first portion of the cavity, the second water level is above the opening of the drain in the first portion. The rinse water raises the first water level to the second water level in the first portion, and the drain maintains approximately the first water level in the second portion. The rinse water exerts a pressure on the soiled water in the first portion thereby directing the soiled water in the first portion through the gap and into the second portion where the soiled water is directed into the drain until approximately the first water level returns in the first portion thereby replacing soiled water with rinse water in the sump during the rinse cycle.
In another aspect of the invention, a sump assembly of a re-circulating warewashing machine having a rinse cycle and a wash cycle includes a sump, a drain, a divider, a first water level, and a second water level. The sump has a top, a bottom, and a cavity in which water used in the re-circulating warewashing machine is stored. The water includes rinse water from the rinse cycle and soiled water from the wash cycle. During the rinse cycle, the rinse water is proximate the top of the sump and the soiled water is proximate the bottom of the sump. The drain has an opening. The divider defines a first portion and a second portion of the cavity and has a top with an aperture proximate the opening of the drain. The first portion is in fluid communication with the second portion, and the second portion is in fluid communication with the opening of the drain. The first water level is approximately level with the opening of the drain. As the rinse water enters the first portion of the cavity, the second water level is above the opening of the drain in the first portion. The second water level covers the aperture of the divider and fills the second portion proximate the opening of the drain to create a siphon directing soiled water proximate the bottom of the sump from the first portion into the second portion where the soiled water is directed into the drain thereby replacing soiled water with rinse water in the sump until the aperture is no longer covered with water in the first portion proximate the first water level.
In another aspect of the invention, a method of disposing of soiled water from a sump of a re-circulating warewashing machine having a rinse cycle and a wash cycle includes dividing the sump into a first portion and a second portion. The first portion and the second portion are in fluid communication, and the second portion is in fluid communication with a drain. Soiled water is directed from the wash cycle into the sump, and the soiled water is stored in the sump at a first water level. Rinse water from the rinse cycle is directed into the first portion of the sump proximate the top of the sump increasing the first water level to a second water level in the first portion. The drain maintains the first water level in the second portion. The second water level directs the soiled water proximate the bottom of the sump from the first portion into the second portion where it is directed into the drain until approximately the first water level returns in the first portion.
Preferred embodiment inserts constructed according to the principles of the present invention are designated by the numerals 100, 200, and 300 in the drawings.
The term “water” is used herein to refer to the wash water and the rinse water, including any additives such as detergents, sanitizers, and/or rinse aids, used in a re-circulating warewashing machine and then directed into and stored in the sump of the re-circulating warewashing machine for use as wash water in subsequent wash cycles. The water may also include soils removed from the wares during the wash and rinse cycles.
An example of a suitable re-circulating warewashing machine 400 having a sump 405 is shown in
Generally, during the rinse cycle and before the wash cycle, the rinse water is proximate the top of the sump and the soiled water is proximate the bottom of the sump. This can be attributed to several factors including the rinse water enters the sump from the top of the sump, the rinse water has a higher temperature than the soiled water, and the rinse water includes less soil than the soiled water. During the wash cycle, the rinse water and the soiled water is mixed together into soiled water. To keep the water in the sump as clean as possible for longer periods of time, it is desired to remove the more soiled water proximate the bottom of the sump from the sump so that less soiled water is mixed with the rinse water for use as wash water in subsequent wash cycles. This can be accomplished using the present invention.
In one aspect of the present invention, the insert 100 is a four-sided rectangular insert having a back 101, a first side 102, a second side 103, and a top 104 configured and arranged to fit within a cavity 117 of a sump 115 of a re-circulating warewashing machine. The sides 102 and 103 are parallel to one another and the back 101 interconnects the edges on one side of the sides 102 and 103 creating a space between the sides 102 and 103 approximately the length of the back 101. The top 104 interconnects the back 101 and the top edges of the sides 102 and 103. The back 101 extends upward beyond the top 104 forming a flange 101a, and the top 104 extends outward beyond the sides 102 and 103 forming flanges 104a and 104b, respectively. The top 104 includes an optional notch 105 on the side opposite the back 101. The insert 100 does not include a front or a bottom so there is a front opening 106 and a bottom opening 107 allowing access to a cavity 108 defined by the insert 100. The insert 100 is shown in
The insert 100 is shown in a typical sump in
The insert 100 fits within the cavity 117 and divides the cavity 117 into a first portion 117a and a second portion 117b. To insert the insert 100 in the sump 115, front opening 106 is placed proximate the third side 116c of the sump and the back 101 is placed proximate the middle of the cavity 117. The flange 104a rests on top of the first side 116a and the flange 104b rests on top of the second side 116b. The back 101 is proximate the middle of the sump 117 and extends from the first side 116a to the second side 116b proximate the top but does not extend all the way to the bottom 118 of the sump 115. Thus, there is a gap 125 proximate the bottom 118 of the sump 117. The back 101 acts as a partition between the first portion 117a and the second portion 117b with the gap 125 interconnecting the first portion 117a and the second portion 117b proximate the bottom 118 of the cavity 117 since the back 101 does not extend all the way to the bottom 118. An optional strainer 126 may be placed proximate the first portion 117a to prevent large soils from entering the remainder of the sump 117.
In operation, as shown in
In another aspect of the present invention, as shown in
The outlet portion 211 is preferably a flexible conduit having a longitudinally extending bore 211 d and may include one or more portions. A first portion 211a is operatively connected to the top 201b and is in fluid communication with the cavity 203 via the aperture 204 of the top 201b and the bore 211d of the outlet portion 211. A second portion 211b interconnects the first portion 211a and a third portion 211c with the bore 211d extending through each of the portions. The portions 211a, 211b, and 211c may be connected using clamps 213. The outlet portion 211 is preferably flexible so that it curves upward from the inlet portion 201 and then downward into the drain 220 in an upside down U-shape, as shown in
The drain 220 includes a drain bore inlet 221a, which is an opening into the drain 220, proximate the top 224 in fluid communication with a drain bore outlet 221b proximate the bottom 223 of the drain 220. As shown in
The insert 200 divides the cavity 217 into a first portion 217a, which is outside of the insert 200, and a second portion 217b, which is inside of the insert 200 within its cavity 203. Because of the apertures 202 in the inlet portion 201, the cavity 203 of the insert 200 is in fluid communication with the cavity 217 of the sump and sump water may flow between the cavities 217 and 203.
In operation, as shown in
In another aspect of the present invention, as shown in
As shown in
The insert 300 is placed over the drain 320 so that the top of the drain 320 is within the cavity 305 and the top 302 contacts the spacers 324. The spacers 324 create a space between the drain 320 and the insert 300 so that the top 302 does not cover the drain bore inlet 323a. The insert 300 defines a first portion 317a and a second portion 317b in the cavity 317 of the sump 315. The first portion 317a being outside of the insert 300, and the second portion 317b being within the cavity 305 of the insert 300. The sides 301 do not extend fully to the bottom of the sump 315 creating a gap 325, which interconnects the first portion 317a and the second portion 317b.
In operation, as shown in
A test was conducted to determine the amount of soluble soil in the water in a sump of an automatic, re-circulating warewashing machine without an insert and with an insert. The insert 100 was used.
Salt was used to represent a soluble soil in the sump water. Five grams of salt was added to the sump water before each wash cycle. The soil levels were determined after each rinse cycle using a conductivity sensor. The graph in
As shown in the graph in
Although the preferred embodiments are referred to and shown as inserts for retrofitting the sump of a re-circulating warewashing machine, it is recognized that the inserts may be incorporated into the sump and integral with the sump rather than being separate components inserted into the sump. For example, the insert 100 could be integral with the sump 115. It is also recognized that the inserts may be incorporated into the drain and integral with the drain rather than being separate components inserted into the sump. For example, the inserts 200 and 300 could be integral with the drains 220 and 320, respectively.
Each of the inserts 100, 200, and 300 increases the amount of rinse water incorporated into the sump water because more of the soiled water is directed out of the sump. By drawing out the soiled water proximate the bottom of the sump, the amount of food soil is reduced. The resulting reduction in food soils, which retard the detersive effects of detergent, will increase the performance of the warewashing machine. In addition, the increased incorporation of the hot rinse water decreases the energy use by the sump heater. Among the advantages, the present invention decreases the soil levels and decreases the energy use.
Any time an inlet stream of rinse water enters a sump proximate a drain, and the density is such that it does not promote mixing of the rinse water and the soiled water, a divider such as an insert or any other suitable apparatus that will provide a siphon to a controlled level can be used to decrease residence time by increasing the replacement rate. The residence time is the amount of time the soiled water is in the sump, and the replacement rate is the rate at which the soiled water is replaced with rinse water.
The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
This application is a divisional of U.S. patent application Ser. No. 11/332,021, filed Jan. 13, 2006, entitled, “Sump Assembly For A Re-Circulating Warewashing Machine,” the entire disclosure of which is incorporated herein by reference in its entirety for all purposes.
Number | Date | Country | |
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Parent | 11332021 | Jan 2006 | US |
Child | 12398293 | US |