Claims
- 1. In a dishwasher which utilizes multiple fluid fills for sequentially washing and rinsing food ware items during a complete cycle, said dishwasher having a wash chamber including rack means for receiving and supporting food ware therein and a sump at the bottom of said chamber for containing fluid therein; primary spray means including a wash pump operable in a recirculating mode for recirculating and spraying fluid onto food ware items to remove food soil particles therefrom and carry food soil particles to the sump; a drain system having a drain pump inlet adjacent the bottom of said sump, a drain outlet communicating with a drain, and a drain pump operable in a draining mode for pumping fluid and food soil particles therein from said pump to said drain outlet at intervals between successive fluid fills; and soil collector means for continuously collecting and removing food soil particles from fluid in said sump during said recirculating mode; the improvement comprising:
- (a) said soil collector means comprising a soil collecting circuit having a circuit inlet connected to receive fluid from said sump, a return outlet located within said wash chamber, and a portion, independent of said primary spray means and said wash chamber, in fluid communication with said circuit inlet and said return outlet;
- (b) said portion including a relatively fine screen soil collecting filter for removing food soil particles from fluid circulating through said soil collecting circuit to be retained within said portion during said recirculating mode, said filter having its upstream side in position to have collected soil particles flushed therefrom to said sump during said draining mode;
- (c) flow direction control means for establishing bi-directional fluid flow between said sump and said portion, said control means being operable for directing fluid and food soil particles in a first direction from said sump to said portion during said recirculating mode, and being operable for directing fluid and debris in a second direction from said portion to said sump during said draining mode; and
- (d) means for selectively controlling said dishwasher to operate said primary spray means and said drain system in either a recirculating mode or in a draining mode.
- 2. The combination of claim 1 wherein said portion includes a soil collector body for retaining food soil particles separate from said wash chamber during said recirculating mode, and said filter is positioned between said collector body and said return outlet.
- 3. The combination of claim 2 wherein:
- said soil collector body includes a debris outlet which constitutes a common fluid channel with said portion; and
- said soil collecting circuit includes a nozzle which directs fluid flowing therethrough into said common fluid channel during said recirculating mode.
- 4. The combination of claim 3 further comprising spray jet means, associated with said primary spray means, for directing a jet of fluid from said primary spray means upon said soil collecting filter, thereby continuously backflushing said soil collecting filter during said recirculating mode and said draining mode, thereby preventing build-up of food soil particles on said filter and assisting in the draining of food soil particles from said portion during said draining mode.
- 5. The combination of claim 4 wherein said flow direction control means includes valve means in said soil collecting circuit and said drain system for directing fluid flow from said sump through said soil collecting circuit to said portion during said recirculating mode and from said portion thence to said drain system to said sump in said draining mode.
- 6. The combination of claim 5 wherein said drain system further comprises means cooperating with said drain pump for grinding food soil particles carried by fluid pumped through said drain pump such that food soil particles are ground during said recirculating mode and during said draining mode, whereby all food soil particles flowing to said drain outlet from said sump have passed through said grinding means at least once.
- 7. The combination of claim 6 wherein said grinding means includes a drain impeller mounted within said drain pump such that upon controlled operation of said wash pump and drain pump said impeller can be rotated in a forward direction during said recirculating mode thereby pumping fluid from said sump through said nozzle, said common fluid channel and said soil collector body, or rotated in a reverse direction during said draining mode such that fluid is discharged from said soil collector body through said common fluid channel to said sump and therefrom to said drain means.
- 8. The combination of claim 7 wherein said primary spray means further includes a housing portion integral with said drain system and said soil collecting circuit and positioned below said spray arms, said housing portion having:
- a circular recess sized to receive said drain impeller;
- a first trough extending from said circular recess and integral with said drain system and said soil collecting circuit such that fluid entering said drain inlet during said recirculating mode is pumped through said first trough to said nozzle and said common fluid channel; and
- a second trough extending from said circular recess and integral with said drain system such that fluid entering said drain pump inlet during said draining mode from said sump is pumped through said circular recess and through said second trough to said drain outlet.
- 9. The combination of claim 8 wherein said second trough intersects said circular recess to form a stator member, said stator member extending from an outer peripheral wall of said circular recess toward said drain impeller thereby forming a constriction such that, as said impeller operates in a forward direction, said constriction causes a slight positive pressure in said second trough so that fluid in said circular recess does not flow through said second trough.
- 10. The combination of claim 8 wherein said drain pump inlet further includes a drain inlet plate disposed above said impeller and having a central opening concentric with said impeller such that fluid entering said drain inlet during said recirculating mode and said draining mode flows downwardly to said impeller.
- 11. The combination of claim 5 wherein said valve means comprises a flap valve for selectively diverting fluid flow from said drain pump to said soil collector body during said recirculating mode or to said drain outlet during said draining mode.
- 12. The combination of claim 1 or 10 wherein said primary spray means comprises a wash pump inlet in fluid communication with said sump for supplying fluid to said wash pump, a main screen enclosing and separating said wash pump inlet from said sump, and spray arms rotatably mounted above and in fluid communication with said wash pump; and said soil collecting circuit includes conduit means enclosing said return outlet and extending to said wash pump inlet at a location between said main screen and said wash pump inlet.
- 13. The combination of claim 12 wherein said conduit means includes shroud means positioned beneath said spray arms and being contiguous with said main screen.
- 14. The combination of claim 13 wherein said shroud means comprises:
- an inner disc member mounted to said spray arms and capable of rotation therewith;
- means forming a spray jet associated with said inner disc portion and communicating with said wash pump to receive fluid therefrom, said spray jet means oriented to direct a spray of fluid upon an exterior surface of said soil collecting filter; and
- an outer annular member mounted to said main screen to form a watertight seal therewith and having an inner periphery forming a labyrinth seal with said inner disc.
- 15. The combination of claims 10 or 11 wherein said return outlet is in fluid communication with said wash chamber.
- 16. The combination of claim 15 wherein said primary spray means includes spray arms mounted above and in fluid communication with said recirculating pump, said spray arms including said spray jet means; and said soil collector body is positioned beneath said spray arms such that said spray jet means directs a jet downwardly upon an exterior surface of said soil collecting filter.
- 17. The combination of claim 16 further comprising a pump housing concentric with and located beneath said spray arms within said sump, said housing enclosing said wash pump, said drain pump, and said soil collector body.
- 18. The combination of claim 11 wherein:
- (a) said wash chamber includes means defining an opening in the bottom thereof;
- (b) said soil collector body has a hollow interior and is attached to said wash chamber bottom opening so as to cover the underside thereof; and
- (c) said soil collecting filter further comprises a fine mesh screen at the interface between said soil collector body hollow interior and said wash chamber opening.
- 19. The combination of claim 18 further comprising means extending toward said drain pump inlet from said debris outlet for guiding food soil particles directly from the former to the latter, to minimize dispersion of the discharged debris into said wash chamber sump.
- 20. The combination of claim 2 wherein said soil collector body is positioned below an average static fluid level in the wash chamber for retaining the collected food soil debris in said soil collector body during interruption of the operation of the warewashing machine while the fluids are therein.
- 21. A method of washing soiled food ware supported on racks in a chamber of a dishwasher, comprising the steps of:
- filling a sump at the bottom of said chamber with a wash solution, thereby initiating a soil collecting cycle;
- spraying said food ware and flushing soil therefrom to said sump by pumping said solution under pressure from said sump through spray arms with a recirculating pump, thereby forming a soil laden solution in said sump;
- ingesting said soil laden solution from said sump during said soil collecting cycle and passing said soil laden solution through a soil collecting circuit independent of said recirculating pump;
- filtering soil particles from said soil laden solution in said circuit to collect and retain said filtered particles within said circuit thereby preventing reentrance of said filtered particles into said chamber during said soil collecting cycle and returning supernatant from said circuit for recirculation by said spray arms; and
- upon completion of said soil collecting cycle, emptying said circuit of collected soil particles into said sump for draining the solution and said soil particles therefrom.
- 22. A method according to claim 21 including the additional step of first filtering said solution pumped through said recirculating pump by means of a first filter, and wherein said filtering in said circuit is accomplished with a second filter finer in mesh than said first filter.
- 23. A method according to claim 22 wherein said supernatant from said circuit is returned for recirculation to said recirculating pump at a location downstream of said first filter.
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of U.S. Application Ser. No. 165,467, filed July 2, 1980, now abandoned, which is a continuation-in-part of U.S. Application Ser. No. 974,342, filed Dec. 29, 1978, now abandoned.
US Referenced Citations (42)
Non-Patent Literature Citations (3)
Entry |
"A Dishwasher Designed for Dependability", Appliance, May 1978, p. 44. |
Page from a General Electric Dishwasher Service Manual. |
"Removing Solids From Process Liquids", Plant Engineering, Nov. 24, 1977, p. 80. |
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
165467 |
Jul 1980 |
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Parent |
974342 |
Dec 1978 |
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