# US 11,297,997 B2 · Dish washing machine with heat exchangers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,297,997 B2 - Document ID: US11297997B2 - Status: Granted - Kind: B2 - Application number: 15/945,279 - Filed: 2018-04-04 - Published: 2019-10-10 - Granted: 2022-04-12 - Earliest claimed: 2018-04-04 - Assignees: K.D.W. Company Limited - Applicants: Kwok Din Wong; Li Zhou - Inventors: Kwok Din Wong; Li Zhou - Web page: https://patentgrep.com/patent/US11297997B2 ## CPC - A47L 15/0081: {with vertical sliding closing doors, e.g. hood-type dishwashers} - A47L 15/22: Rotary spraying devices - A47L 15/4287: {Temperature measuring or regulating arrangements} - A47L 15/4291: {Recovery arrangements, e.g. for the recovery of energy or water} - A47L 2501/03: Water recirculation, e.g. control of distributing valves for redirection of water flow - A47L 2501/06: Water heaters - A47L: DOMESTIC WASHING OR CLEANING (brushes A46B; cleaning quantities of bottles or of other hollow articles of one kind B08B9/00; laundry D06F); SUCTION CLEANERS IN GENERAL (cleaning in general B08) ## Abstract A dish washing machine including a housing having an interior wash space for washing dishes. The housing has a liquid inlet for adding a liquid to the dish washing machine. At least one spray nozzle sprays the liquid onto dishes positioned within the interior wash space. The machine further includes a heating tank for heating the liquid which is supplied to the at least one spray nozzle for spraying onto the dishes in the interior wash space. At least one heat exchange system is within the housing. The at least one heat exchange system transfers heat from the liquid heated by the heating tank to the liquid added to the dish washing machine from the liquid inlet. ## Claims ### Claim 1 A dish washing machine comprising: a housing having an interior wash space for washing dishes, the housing having a liquid inlet for adding a liquid to the dish washing machine and a liquid outlet for removing dirty liquid from the dish washing machine; at least one spray nozzle for spraying the liquid onto dishes positioned within the interior wash space; a heating tank for heating the liquid which is supplied to the at least one spray nozzle for spraying onto the dishes in the interior wash space; at least one heat exchange system within the housing, the at least one heat exchange system transferring heat from the liquid heated by the heating tank to the liquid added to the dish washing machine from the liquid inlet; the at least one heat exchange system includes a first heat exchange system comprising a pipe having a first path therethrough and a second path therethrough; the first path being located between the liquid inlet and the heating tank; the second path being located between a drain for the interior wash space and the liquid outlet of the housing; the at least one heat exchange system further comprising a second heat exchange system; and the housing including at least one wall surrounding the interior wash space; the second heat exchange system including a fluid path adjacent the at least one wall; the liquid in the fluid path of the second heat exchange system exchanging heat through the at least one wall surrounding the interior wash space with the liquid sprayed from the at least one spray nozzle. ### Claim 2 (depends on 1) The dish washing machine of claim 1, wherein: the first path and the second path have the same center of flow axis. ### Claim 3 (depends on 1) The dish washing machine of claim 1, wherein: the first path surrounds the second path. ### Claim 4 (depends on 1) The dish washing machine of claim 1, further including: a wash tank within the housing for receiving the liquid from the heating tank and supplying the liquid to the at least one spray nozzle. ### Claim 5 (depends on 1) The dish washing machine of claim 1, wherein: the at least one spray nozzle is a plurality of spray nozzles located on a top rotating arm and a bottom rotating arm. ### Claim 6 (depends on 1) The dish washing machine of claim 1, wherein: the liquid entering the dish washing machine passes sequentially from the liquid inlet, then to the first heat exchange system, then to the second heat exchange system and then to the heating tank. ### Claim 7 (depends on 1) The dish washing machine of claim 1, wherein: the first path is located between the liquid inlet and the second heat exchange system. ### Claim 8 (depends on 1) The dish washing machine of claim 1, wherein: the at least one wall includes a top wall and a rear wall. ### Claim 9 (depends on 1) The dish washing machine of claim 1, wherein: the fluid path is through the at least one wall. ### Claim 10 (depends on 1) The dish washing machine of claim 1, further including: a bypass line located between the second path and the liquid outlet, the bypass line being located at a bypass height higher than a second path height of the second path, the bypass line maintaining liquid in the second path by a force of gravity. ### Claim 11 (depends on 10) The dish washing machine of claim 10, further including: a flow control for selectively maintaining liquid in the second path or allowing the liquid to flow to the liquid outlet, the bypass line bypassing the flow control, the flow control, when opened, allowing the liquid to flow to the liquid outlet without first passing through the bypass line. ### Claim 12 A dish washing machine comprising: a housing having an interior wash space for washing dishes, the housing having a liquid inlet for adding a liquid to the dish washing machine and a liquid outlet for removing dirty liquid from the dish washing machine; at least one spray nozzle for spraying the liquid onto dishes positioned within the interior wash space; a heating tank for heating the liquid which is supplied to the at least one spray nozzle for spraying onto the dishes in the interior wash space; at least one heat exchange system within the housing, the at least one heat exchange system transferring heat from the liquid heated by the heating tank to the liquid added to the dish washing machine from the liquid inlet; the at least one heat exchange system includes a first heat exchange system comprising a pipe having a first path therethrough and a second path therethrough; the first path being located between the liquid inlet and the heating tank; the second path being located between a drain for the interior wash space and the liquid outlet of the housing; and a bypass line located between the second path and the liquid outlet of the housing, the bypass line being located at a bypass height higher than a second path height of the second path, the bypass line maintaining liquid in the second path by a force of gravity. ### Claim 13 (depends on 12) The dish washing machine of claim 12, wherein: the at least one heat exchange system further comprises a second heat exchange system. ### Claim 14 (depends on 13) The dish washing machine of claim 13, wherein: the housing includes at least one wall surrounding the interior wash space; the second heat exchange system includes a fluid path adjacent the at least one wall; the liquid in the fluid path of the second heat exchange system exchanges heat through the at least one wall surrounding the interior wash space with the liquid sprayed from the at least one spray nozzle. ### Claim 15 (depends on 12) The dish washing machine of claim 12, further including: a flow control for selectively maintaining liquid in the second path or allowing the liquid to flow to the liquid outlet of the housing, the bypass line bypassing the flow control, the flow control, when opened, allowing the liquid to flow to the liquid outlet without first passing through the bypass line. ### Claim 16 (depends on 12) The dish washing machine of claim 12, further including: a wash tank within the housing for receiving the liquid from the heating tank and supplying the liquid to the at least one rotating spray nozzle. ### Claim 17 (depends on 12) The dish washing machine of claim 12, wherein: the at least one rotating spray nozzle is a plurality of spray nozzles located on a top rotating arm and a bottom rotating arm. ### Claim 18 (depends on 12) The dish washing machine of claim 12, wherein: wherein the first path and the second path have the same center of flow axis. ### Claim 19 (depends on 18) The dish washing machine of claim 18, wherein: the first path surrounds the second path.