BACKGROUND
The present invention relates to industrial ovens.
Industrial ovens are heated chambers used for a variety of industrial applications, including, but not limited to, drying, curing, or baking components, parts or final products. Industrial ovens can be used for large or small volume applications, in batches or continuously with a conveyor line, and for a variety of temperature ranges, sizes and configurations.
Such ovens are used in many different applications including, but not limited to, chemical processing, food production, metal processing, and the electronics industry.
SUMMARY
Industrial ovens often include wall panels that provide both structural support and thermal insulation such that heat transfer between the interior of the oven and the outside environment is reduced. One source of heat transfer through the wall panels is the through-metal of each wall panel's support structure. The through-metal is positioned such that heat may conduct from the interior surface of the oven to the outside surface of the oven and to the environment via the through-metal.
Reducing the amount of through-metal is a solution to reducing heat transfer through the wall panel. However, prior art wall panels have been unable to realize a minimum amount of through-metal while maintaining the structural rigidity of the oven wall panels. Often, in reduced through-metal wall panels, bowing occurs along the length of the panel causing decreased structural rigidity and an unsightly appearance. Thus, the industrial oven industry has a long standing need for a wall panel for an industrial oven with a minimal amount of through-metal that maintains an acceptable structural rigidity.
In one embodiment, the invention provides a panel for an oven. The panel includes an outer wall, an inner wall, and a rail that interconnects the outer wall and the inner wall. The rail includes an outer beam coupled with the outer wall, an inner beam coupled with the inner wall, and a plurality of rungs connecting the outer beam and the inner beam. The rail has a first end portion, an intermediate portion, and a second end portion that together define a total length of the rail. The intermediate portion includes all of the rungs such that there are no rungs on either of the first or second end portions. The first end portion and the second end portion together define at least about 33 percent of the total length of the rail and the intermediate portion defines no more than about 67 percent of the total length of the rail.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an oven that includes panels embodying the invention.
FIG. 2 is a partial exploded view of two panels of the oven of FIG. 1.
FIG. 3 is an enlarged view of a portion of the panel at 3-3 of FIG. 2.
FIG. 4 is an enlarged view of a portion of the panel at 4-4 of FIG. 2, with insulation removed for clarity.
FIG. 5 is a perspective view of a rail.
FIG. 6 is an enlarged view of a portion of the rail at 6-6 of FIG. 5.
FIG. 7 is a perspective view of another embodiment of a rail.
FIG. 8 is a schematic representation of a rail.
DETAILED DESCRIPTION
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
FIG. 1 shows an oven 10 that includes a frame 14, access doors 18, controls 22, and multiple panels 26 or wall panels (i.e. insulated panels). The illustrated oven 10 is an industrial oven and may be used for heat processing or other known applications (e.g. curing paint, continuous run, adhesive curing, tempering, food-grade heat processing, non-food grade heat processing, etc.).
The illustrated frame 14 includes frame or support members 30 that provide additional structural support to the oven 10. In other embodiments, the oven 10 need not include the frame 14 and may be formed substantially only by the panels 26. In addition, the frame 14 may include other components or frame members 30 that are not shown.
The illustrated oven 10 has a rectangular footprint. In other embodiments, the frame 14 may be arranged differently or may have a different footprint. In addition, the panels 26 may be arranged differently to fit a specific space or application as is well known by those skilled in the art.
The illustrated access doors 18 are connected to the frame 14 with hinges 34 such that they are movable between a closed position (FIG. 1) that inhibits access to an oven interior and an open position that provides access to the oven interior. The access doors 18 are insulated to inhibit heat transfer from the oven interior to an oven exterior. In other embodiments, more or less that two access doors 18 may be provided. For example, access doors 18 may be provided at two opposite ends of the oven 10. In addition, the access doors 18 may be a different style (e.g. sliding doors or other door arrangements as are known by those skilled in the art). Furthermore, the access doors 18 may be constructed similarly to the panels 26, or the access doors 18 may be a panel 26 movable between the open position and the closed position.
The illustrated controls 22 control the oven 10 such that the desired heat processing is performed in the oven 10. Oven controls and terminals are well known to those skilled in the art and will not be discussed further.
With reference to FIGS. 1-4, the illustrated panels 26 are coupled to the frame 14 and other panels 26 to form oven walls 38. Each panel 26 includes an outer wall 42 that defines at least a portion of the oven exterior, an inner wall 46 that defines at least a portion of the oven interior, two engagement members 50, each defined by the opposing inner and outer walls 42, 46 at opposite edges of the panel 26, and two rails 54 that interconnect the outer wall 42 and the inner wall 46 adjacent the engagement members 50. Insulation 58 is disposed between the outer wall 42 and the inner wall 46 to inhibit heat transfer through the panel 26. The illustrated insulation 58 is a mineral wool although many other types of insulation 58 may be used. In the illustrated embodiment, the panels 26 substantially cover three sides and the top of the oven 10. In other embodiments, the panels 26 may cover more or less oven sides than illustrated.
As best seen in FIGS. 3 and 4, the illustrated outer wall 42 includes a first or outer surface 62 defining a portion of the oven exterior and a second or inner surface 66 facing the oven interior relative to the oven exterior. The illustrated inner wall 46 includes a first or inner surface 70 defining at least a portion of the oven interior and a second or outer surface 74 facing the oven exterior relative to the oven interior.
Each panel 26 includes two engagement members 50, and in the illustrated embodiment a first engagement member 50 is a female engagement member 78 and a second engagement member 50 is a male engagement member 82. One edge of each panel 26 includes the female engagement member 78 (FIG. 3) and the other edge includes the male engagement member 82 (FIG. 4) such that multiple panels 26 may be coupled together (see FIG. 2). The male engagement member 82 of a first panel 26 engages and overlaps with the female engagement member 78 of a second panel 26. In this way, multiple panels 26 are coupled together to form the oven walls 38. In other embodiments, both the first and second engagement members 50 may be male engagement members 82 or female engagement members 78. In addition, the first engagement member 50 may be a male engagement member 82 and the second engagement member 50 may be a female engagement member 78. In still other embodiments, the engagement members 50 may be constructed differently in order that the first panel 26 couples to the second panel 26 and is held substantially rigid with respect to the first panel 26. Furthermore, each panel 26 may have more or less than two engagement members 50.
With reference to FIG. 3, the female engagement member 78 is formed by bending or wrapping the inner and outer walls 42, 46 at one edge. The outer wall 42 is bent or wrapped toward the oven interior such that the outer surface 62 remains substantially planar at the female engagement member 78. The inner wall 46 is bent or wrapped toward the oven exterior such that the inner surface 70 remains substantially planar at the female engagement member 78. Bent portions form the female engagement members 78 and include a receiving portion or chamber 86 that receives respective portions of a rail 54 such that the inner wall 46 and the outer wall 42 are coupled together, as will be discussed further below.
With reference to FIG. 4, the male engagement member 82 is formed by bending or wrapping the inner and outer walls 42, 46 at the edge opposite the female engagement member 78. The outer wall 42 is depressed or offset toward the oven interior and bent or wrapped toward the oven interior such that the outer surface 62 at the male engagement member 82 is substantially offset from a plane containing the remainder of the outer surface 62 of the outer wall 42. The inner wall 46 is depressed or offset toward the oven exterior and bent or wrapped toward the oven exterior such that the inner surface 70 at the male engagement member 82 is substantially offset from a plane containing the remainder of the inner surface 70 of the inner wall 46. Bent portions form the male engagement member 82 and include the receiving portion or chamber 86 that receives respective portions of a rail 54 such that the inner wall 46 and the outer wall 42 are coupled together. The male engagement member 82 is offset from the inner and outer walls 42, 46 such that the female engagement member 78 fits over and overlaps the male engagement member 82 in an interlocking arrangement. In other embodiments, the rail 54 may be formed as a single piece with the engagement members 50. In addition, each panel 26 may include more or less than two rails 54.
To couple the first panel 26 to the second panel 26, the male engagement member 82 of the first panel 26 is received within the female engagement member 78 of the second panel 26. The male and female engagement members 78, 82 interlock along the length of the engagement members 50 to provide a secure coupling and a uniform appearance. A void 88 formed between the rails 54 of the first and second connected panels 26 is filled with insulation 58 to inhibit heat transfer through the void 88. In other embodiments, the male engagement member 82 and the female engagement member 78 may interlock along less than the entire length of the engagement members 50. In addition, the arrangement of the engagement members 50 may be different.
The illustrated rail 54 (FIG. 5) is formed as a single piece and includes two vertical beams 90 and five rungs 94. The illustrated vertical beams 90 include base portions 96, and connecting portions 98. When assembled with a panel 26, the connecting portions 98 are received in the respective receiving portions 86 of the engagement members 50 such that they are coupled to the inner and outer walls 42, 46. The illustrated base portions 96 are substantially perpendicular to the connecting portions 98 such that the base portions 96 and the connecting portions 98 provide structural rigidity to the rail 54. The rail 54 is coupled to the engagement member 50 by inserting the connecting portions 98 into the respective receiving portions 86 and sliding the rail 54 along the length of the engagement member 50 such that the rail 54 is received within the receiving portions 86 over substantially the full length of the rail 54. The illustrated vertical beams 90 are about nine feet long. In other embodiments, the vertical beams 90 may be more or less than nine feet long depending on the size of the panel 26 and the oven 10. In addition, the rail 54 may couple to the engagement member 50 in a different way, may be formed with the engagement member 50, and/or may be a different length than the engagement member 50. Furthermore, the base portions 96 may be arranged at different angles with respect to the connecting portions 98.
The rail 54 illustrated in FIGS. 5 and 6 is constructed from a stamped blank of steel, or other suitable material, that initially may have one rung 94 spaced about every twelve inches. Each illustrated rung 94 is about one inch wide. To produce the finished rail 54, all the rungs 94 except the five central rungs 94 can be clipped to remove the rungs 94 thereby minimizing the total amount of through-metal in the rail 54. The rungs 94 may be clipped as shown in FIGS. 5 and 6 wherein a small protrusion 102 remains extending from the vertical beam 90, or may be clipped flush to the vertical beam 90 as illustrated in FIG. 7. Alternatively, the stamping may be done such that only the five central rungs 94 (or another amount of centrally-located rungs 94) are originally produced (see FIG. 7). One advantage to clipping the initially formed rungs 94 is the ability to produce rails 54 of varying length with a single blank stock. For example, if the stamped blank is twenty feet long, a rail 54 of nine feet or eighteen feet may be made out of the same twenty foot blank. The extra rungs 94 are clipped off to eliminate the through-metal and provide a finished rail 54 of the desired length.
Referring to FIGS. 5-8, the finished rail 54 includes a first end portion 106, an intermediate portion 110, and a second end portion 114. The first end portion 106 is defined from a first end 118 of the rail 54 to a first edge 122 of the rung 94 closest to the first end 118. The intermediate portion 110 is defined from the first edge 122 of the rung 94 closest to the first end 118 to a second edge 126 on the rung 94 closest to a second end 130 of the rail 54 opposite the first end 118. The second end portion 114 is defined from the second edge 126 of the rung 94 closest to the second end 130 to the second end 130. The first and second end portions 106, 114 are characterized in that there are no rungs 94 in the first end portion 106 or the second end portion 114. Only the intermediate portion 110 includes any rungs 94 or through-metal of any kind. Removing the rungs 94 and all through-metal from the first end portion 106 and the second end portion 114 yielded the unexpected result of a stronger panel that was more resistant to bowing or warping. In this way, the inventor has found that the counter-intuitive solution of removing through-metal has fortified the rail 54 against the current problems with bowing and warping due to heat transfer. Until now, a larger amount of through-metal at locations closer to the ends of the rail 54 was thought necessary to retain the structural integrity and rigidity of the panels 26.
In the illustrated embodiment, a total length L of the rail 54 is about nine feet. The first end portion 106 defines about twenty-two percent of the total length L and is about two feet long. The illustrated second end portion 114 defines about thirty-three percent of the total length L and is about three feet long. As such, in the illustrated embodiment, the first end portion 106 and the second end portion 114 combine to define about fifty-five percent and about five feet of the total length L. The illustrated intermediate portion 110 defines about forty-five percent and about four feet of the total length L. In other embodiments, the rail 54 may have a total length L more or less than about nine feet.
In another embodiment, a rail with a total length of about six feet includes a first end portion and a second end portion that together define about thirty-three percent of the total length of the rail, and an intermediate portion that defines about sixty-seven percent of the total length of the rail. As such, the rail with the total length of about six feet includes the first end portion and the second end portion that are each about one foot in length and the intermediate portion that is about four feet in length.
In still another embodiment, a rail with a total length of about twelve feet includes a first end portion and a second end portion that together define about sixty-seven percent of the total length of the rail, and an intermediate portion that defines about thirty-three percent of the total length of the rail. As such, the rail with the total length of about twelve feet includes the first end portion and the second end portion that are each about four feet in length and the intermediate portion that is about four feet in length.
Regardless of the total length L, the first and second end portions 106, 114 combine to define at least about thirty-three percent of the total length L and the intermediate portion 110 defines no more than about sixty-seven percent of the total length L. In addition, while the illustrated embodiments show the intermediate portion 110 to be about four feet in length, the intermediate portion may be more or less than about four feet in length. Furthermore, the first end portion 106 may have a substantially equal length or a substantially different length from the second end portion 114. In other embodiments, the first end portion 106 and the second end portion 114 may combine to define at least about fifty percent of the total length L while the intermediate portion 110 may define no more than about fifty percent of the total length L (e.g., an eight foot rail having a four foot long intermediate portion).
The illustrated intermediate portion 110 includes five rungs 94. Each rung 94 has a width W of about one inch and connects from the base portion 96 of the outer or first vertical beam 90 to the base portion 96 of the inner or second vertical beam 90. The illustrated rail 54 is formed from 20 gauge steel such that the thickness T of each rung 94 is about 0.06 inches. As such, each rung 94 presents a cross-sectional area (T×W) of about 0.06 square inches of through-metal and all five rungs 94 present about 0.3 square inches in cross-section of total through-metal. In other embodiments, a different metal and gauge may be used. In addition, more or less than five rungs 94 may be included in the intermediate portion 110. Furthermore, other embodiments may include up to 1.0 square inch in cross-section of total through-metal. In still other embodiments, the rail 54 may include up to 1.5 square inches in cross-section of total through-metal.
With reference to FIG. 8, the illustrated rail 54 defines a space 134 (L×D as viewed from the front as in FIG. 8) between the base portion 96 of the first vertical beam 90 and the base portion 96 of the second vertical beam 90. The protrusions 102 are shown in broken lines and may or may not be present. Regardless of whether the protrusions 102 are present, the protrusions 102 do not define through-metal such that the space 134 is defined between the base portions 96 of the vertical beams 90 and includes the protrusions 102 if present as illustrated in FIG. 8. The space 134 is split into a first end surface area 138, a second end surface area 142, and an intermediate surface area 146 corresponding to the space 134 between the base portions 96 in the respective portions 106, 114, 110. The rungs 94 in the intermediate portion 110 define a through-metal surface area 150 (W×D×total number of rungs) that is about eleven percent of the intermediate surface area 146. Again, the protrusions 102 do not define any through-metal, through-metal surface area, or through-metal cross-sectional area. The first end surface area 138 and the second end surface area 142 include no through-metal (zero percent through-metal surface area 150). In other embodiments, the intermediate portion 110 may include a through-metal surface area 150 that may be up to about fifteen percent of the intermediate surface area 146. In still other embodiments, the intermediate portion 110 may include a through-metal surface area 150 that may be up to about twenty percent of the intermediate surface area 146.
A total surface area 154 (L×D) is defined by the combination of the first end surface area 138, the second end surface area 142, and the intermediate surface area 146. The through-metal surface area 150, in the illustrated embodiment is about five percent of the total surface area 154. In other embodiments, the through-metal surface area 150 may be up to about seven percent of the total surface area 154. In still other embodiments, the through-metal surface area 150 may be up to about ten percent of the total surface area 154.
Various features and advantages of the invention are set forth in the following claims.
Patent Application
20090188483
