Patent Application
20120263442
1. Field of the Invention
The subject invention relates to an oven apparatus having a modular construction for curing paint on the surface of a vehicle body utilizing radiant and convection heat.
2. Description of the Prior Art
Ovens having a modular construction for curing paint on the surface of a vehicle are known in the art. One such oven is illustrated in U.S. Pat. No. 6,990,749 to Roesler et al. wherein a plurality of oven modules, each having an interior, extend along an axis and have a length. Further, it is known in the art to include radiant tubes in paint curing ovens for heating vehicle bodies and reflectors for reflecting radiant heat at the vehicle bodies. One such oven is illustrated in U.S. Pat. No. 6,769,909 issued to Glen N Schwartz. Moreover, it is known for ovens to include convection return air assemblies having an outer surface and disposed in the interior of an oven. One such oven is illustrated in U.S. Pat. No. 5,588,830 issued to Josefsson et al. The prior art includes separate reflector and convection return air assemblies.
The invention provides for such an oven apparatus having a convection return air assembly with a reflective outer surface for reflecting radiant heat from the radiant tubes at the vehicle body.
Thus several advantages of one or more aspects of the invention are that it provides for an inexpensive, easily-assembled, easily-maintained and compact structure for reflecting heat from radiant heating tubes at a vehicle body and for removing return air from an oven interior. The invention uses fewer parts and requires less time to assemble than the separate return air and reflector assemblies of the prior art, therefore reducing capital and assembly expenses and providing for a structure that is easier to assemble. Further, the fact that the invention uses fewer parts than the prior art makes the invention less prone to error during assembly and operation and also easier to maintain. Moreover, the integrated assembly of the invention uses significantly less space in the oven interior than the prior art, therefore providing for a more compact assembly.
Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, an oven apparatus 24 for a curing paint on the surface of a vehicle body 26 having an upper part 20 and a lower part 22 and a vehicle interior 28 is generally shown.
The oven apparatus 24 includes a plurality of oven modules 30, wherein each of the oven modules 30 extends along an axis A and has a length B. It should be appreciated that the length B of each oven modules 30 can vary depending on its drying application. Each oven module 30 includes a fixed end 32 and an expanding end 34, wherein the expanding end 34 accommodates axial expansion and contraction caused by heat in the oven modules 30. Each of the oven modules 30 is disposed in serial relationship with one another, and combinations of oven modules 30 define zones 36, 38, 40 corresponding to different baking applications. In the enabling embodiment, one and a half oven modules 30 define a heat-up zone 36, one and half oven modules 30 define an equalization zone 38, and three oven modules 30 define a hold zone 40. It should be appreciated that more or fewer oven modules 30 can be used to comprise different zones 36, 38, 40 to accommodate various paint drying processes.
Each of the oven modules 30 includes a base 42. A structural member 44 is disposed below the base 42 to define a base cavity 46 between the base 42 and the structural member 44. A base insulating material 48 is disposed in the base cavity 46 for restricting heat loss from the base 42. It should be appreciated that various types of insulation could be disposed in the base cavity 46. Further, each of the oven modules 30 includes a pair of walls 50 extending up from the base 42. Each wall 50 includes an interior shell 52, an outer shell 54 and a wall cavity 56 therebetween. In the enabling embodiment, the outer shell 54 and the interior shell 52 each have a shell interior 134. However, it should be appreciated the outer and interior shells 54, 52 could be solid panels. Each of the walls 50 has a wall top end 58 and a wall bottom end 60, where the bottom end engages the base 42. The wall top ends 58 form an L-shape and extends parallel to the base 42 to define a ceiling 62. In the enabling embodiment, the walls 50 and ceiling 62 are constructed of aluminized sheet metal for heat and corrosion resistance. However, it should be appreciated that other wall 50 materials could be used. A shell insulating material 64 is disposed in the shell interior 134 of the outer and interior shells 54, 52 as well as in the wall cavity 56 to define three layers of insulation for restricting heat loss from the walls 50 and the ceiling 62. The seams of the shell insulating material 64 are staggered for reducing concentrated areas of heat on the wall 50 and ceiling 62. The L-shaped top ends 58 advantageously prevent air from escaping from the upper corners of the oven modules 30. Further, the interior shell 52 is seal-welded at all joints to prevent oven air from escaping.
The outer shell 54 has an outer shell inner surface 70 and an outer shell outer surface 72 and the interior shell 52 has an interior shell inner surface 74 and an interior shell outer surface 76. A pair of C-shaped channels 78 are disposed on opposing sides of each of the oven modules 30. The C-shaped channels 78 extend along the length B of the module and engage the base 42 and the structural member 44 and the outer shell outer surface 72. The C-shaped channels 78 are used to provide support during shipping and installation.
A plurality of rectangular shaped openings 80 are axially spaced across the ceiling 62 of the oven modules 30. A corresponding rectangular shaped explosion relief plug 82 is sealingly disposed in each of the openings 80. In the enabling embodiment, the explosion relief plug 82 includes three seals, however it should be appreciated that any number of seals could be used.
As best shown in
An oven interior 98 of each oven module 30 is defined by the base 42, walls 50 and the ceiling 62. A pair of U-shaped radiant heating tubes 100 are disposed in each of the oven modules 30 for heating the oven interior 98. Each of the radiant heating tubes 100 includes a first tube leg 102 entering one of the oven module 30 ends 32, 34 at a 45 degree angle. The radiant heating tube 100 then extends axially along the oven module 30 length B to form a U-shaped portion 104 adjacent one of the ends 32, 34 of the oven module 30. A second tube leg 106 extends back along the oven length B and exits the oven module 30 adjacent to the first tube leg 102. The first tube leg 102 of each of the radiant heating tubes 100 is positioned lower than the second tube leg 106 of the radiant heating tube 100. Each of the radiant heating tubes 100 has a tube outer surface 92 and a wall thickness of at least 0.25 inches for explosion resistance. In the enabling embodiment, each of the radiant heating tubes 100 is constructed of steel with raw steel exposed for providing emissivity in the range of 0.85 to 0.90. However, It should be appreciated that the radiant heating tubes 100 could be constructed of other materials to vary the emissivity of their outer surfaces 92.
As best shown in
Upon exiting the oven module 30, the second tube leg 106 defines an exhaust outlet 118. A heat exchanger 120 is disposed outside of each of the oven modules 30 and is in fluid communication with the exhaust outlet 118 and the natural gas burner 108 for transferring heat from the exhaust air from the exhaust outlet 118 to the air entering the burner inlet 110 of the natural gas burner 108 to provide for a more efficient heating process. As best shown in
A plurality of upper convection ducts 126 are disposed in at least one of the oven modules 30 adjacent to the walls 50 and the ceiling 62 of each of the oven modules 30. The upper convection ducts 126 are connected to the convection air heater 122 for directing heated convection air at the upper part 20 of the vehicle body 26 and for directing heat at the vehicle interior 28 to equalize the temperature profile of the vehicle body 26. It should be appreciated that one or more ceiling fans could be located in the oven interior 98 to provide convection heat, wherein the motors of the ceiling fans are disposed outside of the oven modules 30.
A pair of convection return air assemblies 128 are disposed in each of the oven modules 30 on opposing sides and adjacent to the walls 50 and the base 42. The convection return air assemblies 128 extend axially along the length B of each of the oven modules 30. A plurality of return air ducts 130 are disposed on the convection return air assembly 128 for removing exhaust air from the oven interior 98. Each convection return air assembly 128 has a return air outer surface 94. The return air outer surface 94 of the convection return air assembly 128 is reflective for reflecting radiant heat from the radiant tubes at the lower part 22 of the vehicle body 26 for increased heating efficiency. The return air outer surface 94 extends from a first outer surface end 66 to a pair of bends 132 to a second outer surface end 68 to partially surround the radiant heating tubes 100 for directing radiant heat at the lower part 22 of the vehicle body 26.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings and may be practiced otherwise than as specifically described while within the scope of the appended claims. That which is prior art in the claims precedes the novelty set forth in the “characterized by” clause. The novelty is meant to be particularly and distinctly recited in the “characterized by” clause whereas the antecedent recitations merely set forth the old and well-known combination in which the invention resides. These antecedent recitations should be interpreted to cover any combination in which the inventive novelty exercises its utility. The use of the word “said” in the oven apparatus claims refers to an antecedent that is a positive recitation meant to be included in the coverage of the claims whereas the word “the” precedes a word not meant to be included in the coverage of the claims. In addition, the reference numerals in the claims are merely for convenience and are not to be read in any way as limiting.
