Convection/impingement oven for continuously cooking food
An improved convection/impingement oven for continuously cooking food. The oven has a wire link type belt which moves through an elongated cooking chamber. Hot air is blown on the upper surface of the food to be cooked. A separately controlled hot air source is blown on the lower surface of the food. Hot air impingement units are placed along the length of the oven and the cooking vapors are not recirculated but instead pass along the elongated cooking chamber and are exhausted at the end. Preferably a color development and sealing section has upper and lower burners which heat the food and the heat from these burners also pass the entire length of the cooking chamber before being exhausted. Also preferably steam or a water spray is used to regulate the humidity and this may be regulated in several different sections of the cooking chamber.
This is a continuation Ser. No. 08/494,716 field on Jun. 26, 1995, U.S. Pat. No. 5,560,952.
BACKGROUND OF THE DISCLOSUREThe field of the invention is cooking ovens and the invention relates more particularly to ovens of the type used to commercially bake, broil or otherwise cook meats, baked goods and other foods. With the increased use of frozen dinners, the moisture content in the meat contained in a frozen dinner has become more critical. Since microwave cooking tends to heat water, it is important that sufficient water be retained in the meat so that after it is microwaved it has the desired flavor and texture.
Many patents have been granted on continuous cooking ovens. For instance the Straub U.S. Pat. No. 3,604,336 shows a moving belt with upper and lower burners, a center exhaust duct is provided and no provision is made for moisture control of the finished product.
The Szabrak et al U.S. Pat. No. 3,721,178 also uses many burners along the length of the oven. The Nerthling U.S. Pat. No. 3,823,660 utilizes a continuous moving belt with radiant heaters above and below the food to be cooked. Burners are also used and the exhaust vent is positioned along one side of the entire length of the oven.
The Fagerstrom et al patent shows an electrical heating device over which air is passed after which it passes through channels above and below the product to be cooked. The cooking vapors are vented at points along the oven. The Caridis et al U.S. Pat. No. 3,947,241 shows a recirculating oven wherein a flame is fed into an upper chamber and then passes in a u-shaped path into the lower chamber where the product to be cooked is located. A certain amount of cooking vapors is exhausted at both ends of the oven.
A charmaker is shown in the Fetzer U.S. Pat. No. 4,026,201 which uses many rings which are heated and ride on the upper surface of the food product. The Baker et al U.S. Pat. No. 4,121,509 utilizes electric heating elements and recirculated air which passes through tubes at the end of the oven and flows against the upper and lower surface of the food to be cooked.
The Caridis et al U.S. Pat. No. 4,167,585 is similar in structure to U.S. Pat. No. 3,947,241 and is basically a recirculation system wherein water vapor is injected into the moving stream of process vapor to control the temperature and moisture content.
The Benson et al U.S. Pat. No. 4,297,942 shows a branding process utilizing an oversized screen with upper and lower burners, the heat from which it is exhausted from the branding unit. The Baker U.S. Pat. No. 4,936,286 is a small continuous broiler which has three side-by-side conveyors. The Leary et al U.S. Pat. No. 4,949,629 is a continuous cooking oven which has two very separate cooking zones, both zones utilize recirculation of the cooking vapors. Lastly, the Barkhau et al U.S. Pat. No. 4,991,497 cooks food in a closed bottom tray and utilizes air high velocity impingement nozzles to accomplish the cooking. The air is recirculated.
Although one would think that recirculation of cooking vapor would result in an efficient unit, this is not the case. Since ovens must be constructed in a manner so that they can be easily and completely cleaned, it is not practical to place an outer layer of insulation on the oven. Therefore, the large additional surface area that is required to bring about recirculation radiates more than the amount of heat saved in recirculation. Furthermore, for some products such as pork, the recirculation process results in an undesirable pink color in the meat even though it is completely cooked. Therefore, an oven which is more efficient in the use of heat would be highly desirable. Still further, it is useful to be able to cook various different types of food products requiring a wide range of controls for heat temperature and humidity.
SUMMARY OF THE INVENTIONThe present invention is for an improved convection/impingement oven for continuously cooking food. The oven is of the type having a pervious, continuous, moving belt which has an upper product supporting surface referred to as a “food supporting belt” and a return belt portion. The food supporting belt has a lower surface which permits the passage of hot air or other vapors upwardly therethrough and the passage of fat or other drippings downwardly therethrough. The food passes from a product feed end to a product discharge end through a closed elongated cooking chamber which is enclosed by a top, two sides, and a bottom. The food supporting belt and the return belt both pass through this chamber. A burner blower is supplied with outside air and feeds air to at least one burner which feeds hot air to a first manifold which is at about atmospheric pressure and has an air intake which permits atmospheric air to enter from outside the oven. A second blower then takes the atmospheric pressure hot air and increases the pressure thereof for later feeding into a low pressure hot-air manifold and from there through air impingement nozzles onto the food to be cooked. A plurality of upper air impingement nozzles are positioned above the food supporting belt and these nozzles are fed from an upper air impingement manifold which in turn is supplied from the said low pressure hot air manifold. A plurality of lower air impingement nozzles are positioned below the lower surface of the food supporting belt, and this is fed from a lower air impingement manifold which in turn is fed by the low pressure hot air manifold. Means are provided for independently controlling the flow of hot air to the upper air impingement manifold and to the lower air impingement manifold. A cooking vapor vent having an inlet positioned adjacent the product discharge of the cooking chamber comprises the only outlet for the cooking vapors. The cooking vapors move along the cooking chamber and hot air is introduced along the length of the chamber thereby causing the hot air flow, concurrently with the food-supporting surface, to move at an ever increasing rate along the cooking over. Preferably the lower hot air impingement units and the upper hot air impingement units are fed by separate burners and blowers. Also preferably a color development and sealing unit is positioned at the product feed end of the cooking chamber and upper and lower burners are played upon the food to be cooked (and preferably a branding wheel) and the heat from these two burners is passed the entire length of the cooking chamber. The color development and sealing burners are adjustable so that the direction of the flame may made from horizontal to directly downwardly. It is also preferable that a plurality of steam nozzle assemblies are positioned along the cooking chamber, preferably between the impingement units. Also, preferably the steam nozzles are separated into several discreet groups which are independently controllable so that different zones of the oven can be of different humidity and/or temperature.
The present invention is also for a process of cooking food comprising the steps of placing an object to be cooked on the upper surface of a perforate moving belt. Next, a color development and sealing flame is aimed so that the heat therefrom passes into the entrance of an elongated cooking chamber. Steam may next be introduced above and below the object to be cooked and hot air is impinged on the upper and lower surface with the temperature and force of the impinging stream of hot air from the upper nozzles being independently controlled from that from the lower nozzles. The object to be cooked is passed through at least one set of upper and lower air impingement nozzles and upper and lower stream nozzles and the finally cooked product is removed at the product discharge end.
The improved convection/impingement oven of the present invention is shown in
A cross sectional view of oven 10 is shown in
The essential feature of the present invention is the ability to separately control both the temperature and volume emitted from the upper and lower air impingement nozzles in the oven. As shown in
Turning now to
The surfaces of the cooking chamber are shown in
Returning now to
Turning now to the color development and sealing assembly, an upper color development and sealing burner 74 (see
Burners 74 and 76 may be aimed through a 90 degree arc. They may be aimed horizontally toward the cooking chamber or at any angle between horizontally to directly downwardly and upwardly respectively toward the moving belt 17. The choice of direction depends on the amount of coloring and sealing desired and the type of food being cooked. Thus the flames 75 and/or 77 may be aimed to directly impinge the surfaces of the food to be cooked, or they may merely heat the surfaces depending on how the burners 74 and 76 are aimed.
An important feature of the color development and sealing assembly is the aiming of the flames 75 and 77 toward the opening of the cooking chamber and the conveying of the heat from these flames into the cooking chamber. The portion of the cooking chamber which surrounds the branding rods is in a stair stepped shape indicated by reference character 82. The hot air is moved inwardly into the cooking chamber and not exhausted in a separate vent. The hot air carries the entire length of the cooking chamber and is not vented until it passes out of the cooking vapor vent 83 shown in
The construction of the upper and lower impingement manifolds is a very important feature of the present invention.
Also viewing
Further details of construction of the steam nozzle assembly is shown in
Another important feature of the present invention is the single pass operation where the only significant venting of cooking vapor is through cooking vapor vent 83 which includes a damper 99 and an air blower, not shown, positioned upwardly from damper 99. Air is thus drawn upwardly through vent 83 and is exhausted and is not recirculated.
As the food 41 passes along the cooking chamber, it tends to draw heat out of the cooking vapors 21. Thus, although the temperature may be as high as 1000 to 1600 degrees Fahrenheit near the product feed end of the cooking chamber it decreases along the chamber. For example, it may drop to 800, 600, 400 and 300 degrees in some instances, along the chamber so that as the food warms, the cooking temperature difference between the product and the cooking vapors 21 decreases. This characteristic optimizes the cooling operation and reduces the possibility of overcooking in a manner not possible in the typical over or a recirculating oven which remains at a relatively constant temperature.
Also shown in
Control panel 103 is shown in
The present embodiments of this invention are thus to be considered in all respects as illustrative and not restrictive: the scope of the invention being indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.
Claims
1. A process for continuously cooking foodstuff while being able to provide excellent control of the properties of the cooked foodstuff, said process comprising the step of:
- placing a foodstuff to be cooked on an upper surface of a perforate, moving belt;
- heating at least one surface of the foodstuff to be cooked with a color development and sealing flame;
- aiming said color development and sealing flame so that the heat therefrom passes into the entrance of an elongated cooking chamber surrounding said moving belt, said cooking chamber having a product feed and a product discharge;
- passing said foodstuff to be cooked through a plurality of cooking phase assemblies for introducing hot air to produce cooking vapors and moving the cooking vapors concurrently along said elongated cooking chamber and said cooking vapors increasing in velocity along said cooking chamber as the foodstuff to be cooked moves from the product feed to the product discharge, the cooking phase assemblies being in communication with a heat source, the heat source being remote from the color development and sealing flame and the elongated oven;
- venting said cooking vapors from said cooking chamber near the product discharge; and
- removing the resulting cooked product from the moving belt.
2. A process for continuously cooking foodstuff while being able to provide excellent control of the properties of the cooked product, said process comprising the steps of:
- placing an object to be cooked on an upper surface of a perforate, moving belt;
- heating at least one surface of the object to be cooked with a color development and sealing flame;
- aiming said color development and sealing flame so that the heat therefrom passes into the entrance of an elongated cooking chamber surrounding said moving belt, said cooking chamber having a product feed and a product discharge;
- introducing steam above and below said object to be cooked after said object has passed said color development and sealing flame;
- impinging the lower surface of said object to be cooked with hot air from below said moving belt at a first temperature and velocity;
- impinging the upper surface of said object to be cooked with hot air from above said moving belt at a second temperature and velocity, said introducing and said two impinging steps forming a cooking phase assembly for introducing hot air and each of said cooking phase assemblies producing cooking vapors, the cooking phase assemblies being in communication with a heat source, the heat source being remote from the color development and sealing flame and the elongated oven;
- passing said object to be cooked through a plurality of said cooking phase assemblies while moving the cooking vapors concurrently along said elongated cooking chamber without and recirculation of the cooking vapors, and said cooking vapors increasing in velocity along said cooking chamber as the object to be cooked moves from the product feed to the product discharge;
- venting said cooking vapors from said cooking chamber near the product discharge; and
- removing the resulting cooked product from the moving belt.
3. The method of claim 1 wherein the cooking vapors are vented without recirculation.
4. A process for continuously cooking foodstuff while being able to provide excellent control of the properties of the cooked foodstuff, said process comprising the steps of:
- placing a foodstuff to be cooked on an upper surface of a perforate, moving belt;
- heating at least one surface of the foodstuff to be cooked with a color development and sealing flame;
- aiming said color development and sealing flame so that the heat therefrom passes into the entrance of an elongated cooking chamber surrounding said moving belt, said cooking chamber having a product feed and a product discharge;
- passing said foodstuff to be cooked through a plurality of impingement nozzles for introducing hot air to produce cooking vapors and moving the cooking vapors concurrently along said elongated cooking chamber and said cooking vapors increasing in velocity along said cooking chamber as the foodstuff to be cooked moves from the product feed to the product discharge, the impingement nozzles receiving hot air from a heat source external to the elongated cooking chamber;
- venting said cooking vapors from said cooking chamber near the product discharge; and
- removing the resulting cooked product from the moving belt.
5. The method of claim 4 wherein the heat source comprises a burner fed with air and a combustible fuel.
6. The method of claim 5 wherein a burner blower is supplied with outside air and feeds air to at least one burner which feeds hot air to a first manifold that is about atmospheric pressure and has an air intake that permits atmospheric air to enter from outside the elongated cooking oven.
7. The method of claim 6 wherein a second blower increases the pressure of the hot air for feeding into a low-pressure, hot-air manifold associated with the impingement nozzles and from the impingement nozzles onto the foodstuff to be cooked.
8. The method of claim 4 wherein the elongated cooking oven further include a plurality of steam impingement nozzles in communication with a source for steam.
9. The method of claim 7 wherein the elongated cooking oven further includes a plurality of steam impingement nozzles in communication with a source for steam.
10. The method of claim 7 wherein the cooking vapors are vented without recirculation.
11. The method of claim 4 wherein the elongated cooking chamber has a detachable hood, which exposes the moving belt when detached.
12. The method of claim 11 wherein the hood is substantially free of insulating material.
13. A process for continuously cooking foodstuff while being able to provide excellent control of the properties of the cooked product, said process comprising the steps of:
- placing an object to be cooked on an upper surface of a perforate, moving belt;
- heating at least one surface of the object to be cooked with a color development and sealing flame;
- aiming said color development and sealing flame so that the heat therefrom passes into the entrance of an elongated cooking chamber surrounding said moving belt, said cooking chamber having a product feed and a product discharge;
- introducing steam above and below said object to be cooked after said object has passed said color development and sealing flame;
- passing said object to be cooked through a plurality of impingement nozzles for impinging at least an upper or lower surface of the foodstuff while moving the resulting cooking vapors concurrently along said elongated cooking chamber without any recirculation of the cooking vapors, and said cooking vapors increasing in velocity along said cooking chamber as the object to be cooked moves from the product feed to the product discharge, the impingement nozzle assemblies receiving heat from a heat source external to the elongated cooking chamber;
- venting said cooking vapors from said cooking chamber near the product discharge; and
- removing the resulting cooked product from the moving belt.
14. A process for continuously cooking foodstuff while being able to provide excellent control of the properties of the cooked foodstuff, said process comprising the steps of:
- placing a foodstuff to be cooked on an upper surface of a perforate, moving belt;
- heating at least one surface of the foodstuff to be cooked with a color development and sealing flame;
- aiming said color development and sealing flame so that the heat therefrom passes into the entrance of an elongated cooking chamber surrounding said moving belt, said cooking chamber having a product feed and a product discharge;
- passing said foodstuff to be cooked through a plurality of impingement nozzles for introducing heat to produce cooking vapors and moving the cooking vapors concurrently along said elongated cooking chamber and said cooking vapors increasing in velocity along said cooking chamber as the foodstuff to be cooked moves from the product feed to the product discharge, the impingement nozzles receiving hot air from a heat source comprising a burner fed with air and a combustible, the burner being external to the interior chamber of the elongated cooking chamber and in communication with the interior via at least one manifold;
- venting said cooking vapors from said cooking chamber near the product discharge; and
- removing the resulting cooked product from the moving belt.
15. The method of claim 14 wherein the cooking vapors are vented without recirculation.
16. The method of claim 14 wherein the elongated cooking chamber has a detachable hood that exposes the moving belt when detached.
17. The method of claim 16 wherein the hood is substantially free of insulating material.
18. The method of claim 14 wherein a manifold for communicating hot air to the impingement nozzles is disposed substantially below the moving belt.
19. The method of claim 18 wherein the manifold communicates with a plurality of impingement nozzles that impinge a foodstuff from above the moving belt.
20. The method of claim 18 wherein the manifold communicates with a plurality of impingement nozzles that impinge the foodstuff from below the moving belt.
21. The method claim 18 wherein a manifold for communicating hot air to the impingement nozzles is disposed substantially below the moving belt and the manifold communicates with impingement nozzles that impinge a foodstuff from above and below the moving belt.
22. The method of claim 14 wherein the heat source comprises a burner fed with air and a combustible fuel.
23. The method of claim 22 wherein a manifold for communicating hot air from the heat source to the impingement nozzles is disposed substantially below the moving belt and the manifold communicates with impingement nozzles that impinge a foodstuff from above and below the moving belt, and wherein the elongated cooking chamber has a detachable hood, which exposes the moving belt when detached.
24. The method of claim 23 wherein the hood is substantially free of insulating material.
25. A process for continuously cooking foodstuff while being able to provide excellent control of the properties of the cooked product, said process comprising the steps of:
- placing an object to be cooked on an upper surface of a perforate, moving belt;
- heating at least one surface of the object to be cooked with a color development and sealing flame;
- aiming said color development and sealing flame so that the heat therefrom passes into the entrance of an elongated cooking chamber surrounding said moving belt, said cooking chamber having a product feed and a product discharge;
- introducing steam above and below said object to be cooked after said object has passed said color development and sealing flame;
- passing said object to be cooked through a plurality of impingement nozzles for impinging at least an upper or lower surface of the foodstuff while moving the resulting cooking vapors concurrently along said elongated cooking chamber without any recirculation of the cooking vapors, and said cooking vapors increasing in velocity along said cooking chamber as the object to be cooked moves from the product feed to the product discharge, the impingement nozzle assemblies receiving heat from a source external to the interior of the elongated cooking chamber;
- venting said cooking vapors from said cooking chamber near the product discharge; and
- removing the resulting cooked product from the moving belt.
26. The method of claim 25 further comprising a burner blower is that supplied with outside air and feeds air to at least one burner which feeds hot air to a first manifold that is about at atmospheric pressure and has an air intake that permits atmospheric air to enter from outside the elongated cooking oven.
27. The method of claim 26 wherein a second blower increases the pressure of the hot air for feeding into a low-pressure, hot-air manifold associated with the impingement nozzle assemblies and from the impingement nozzles assemblies onto the foodstuff to be cooked.
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- Declaration of R. Craig Miller Providing Details of prior art for “Brander Heated Oven”.
- Declaration of Richard Naess Providing Details of prior art for “Brander Heated Oven”.
- Declaration of Edgar W. Averill Providing Details of prior art for “Brander Heated Oven”.
- Ervin, Cohen & Jessup LLP, Attorneys for Plaintiffs; Complaint for: 1)Professional Negligence 2)Breach of Fiduciary Duty 3)Constructive Fraud 4)Fraudulent Concealment; Demand for Jury Trial; Aug. 1, 2003; Orange County; California; 11 pages.
- Lewis Brisbois Bisgaard & Smith LLP, Attorneys for Defendants; Answer to Complaint filed Aug. 1, 2003; Case No. 03 CC 09811, Assigned to the Honorable Andrew P. Banks; Aug. 27, 2003; Orange County; California; 6 pages w/ proof of service by mail.
- Ervin, Cohen & Jessup LLP, Attorneys for Plaintiffs; Plaintiff's Separate Statement of Disputed and Undisputed Facts in Opposition to Defendant's Motion for Summary Judgement; Case No. 03CC09811, Hon. Andrew P. Banks Aug. 13, 2004; 17 pgs.
Type: Grant
Filed: Jan 16, 2003
Date of Patent: Sep 11, 2007
Inventors: R. Craig Miller (Huntington Beach, CA), Richard W. Naess (Laguna Beach, CA)
Primary Examiner: Joseph Pelham
Attorney: Ganz Law, P.C.
Application Number: 10/347,543
International Classification: A23L 1/01 (20060101); F24C 1/04 (20060101); F27B 9/24 (20060101); F27B 9/36 (20060101);