Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
  • F24C7/00—Stoves or ranges heated by electric energy
  • F24C7/06—Arrangement or mounting of electric heating elements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
  • F24C15/00—Details
  • F24C15/005—Coatings for ovens

Definitions

• the present invention relates to an oven with a metallic oven muffle that can be closed at the front by a door, the muffle walls of which are associated with heating elements for heating the cooking space to above about 180 ° C. or the items to be cooked therein, with a protective layer covering the muffle walls at least on the inside .
• Such an oven is generally known, the oven muffle being provided with an enamel layer.
• the enamel coating serves on the one hand as an anti-corrosion layer and on the other hand as an anti-oxidation layer. Furthermore, the enamel layer improves the cleanability of the oven muffle and increases the surface hardness. Finally, the look of the oven muffle is determined by the enamel.
• the object of the present invention is therefore to improve the performance properties of the oven muffle in an oven according to the preamble of claim 1.
• the thickness of the protective layer is less than about 30 microns, in particular less than 20 microns and preferably between about 5 and 10 microns.
• the thickness of the protective layer is less than about 30 microns, in particular less than 20 microns and preferably between about 5 and 10 microns.
• the sol-gel layer can, for example, be applied to the muffle walls in a simple immersion process.
• the low baking temperatures of about 450 to 500 ° C. are favorable in the sol-gel technique compared to the enamel technique.
• the applied sol-gel layers are also suitable for the temperatures typical for cooking processes.
• the hard layer preferably has a thickness of 5 to 10 ⁇ m.
• a sol-gel functional layer is provided on the hard sol-gel layer.
• Different areas of the muffle walls can be equipped with special properties. These properties can be, for example, a particularly simple cleanability, a special sliding behavior or catalytic properties.
• the functional layer is advantageously implemented as a layer approximately 10 ⁇ m, in particular approximately 2 to 3 ⁇ m thick. Due to the sol-gel technology, the applied layers, despite their small thickness, have great stability and great adhesion both on top of one another and on the metal.
• the protective layer is transparent and the inside of the muffle wall serves as a reflector. This is particularly advantageous when cooking with the help of heat radiation in the infrared range or in the visible light range.
• Such transparent layers can be easily represented as sol-gel layers.
• the protective layer can be realized as an anodized, in particular hard anodized, aluminum oxide layer.
• This oxide layer is particularly characterized by its excellent hardness and smoothness.
• a particularly good heat transfer from the heating element to the muffle wall or to the cooking space and an excellent heat distribution in this respect can be achieved in that the muffle wall has an insulating protective layer in the ⁇ m range to which the heating element is applied directly by means of thick-film technology.
• the heating element can also be implemented using more complex coating processes, for example thin-film technology. Due to the thin protective layers, only slight stresses occur in the oven muffle when the oven muffle is heated up, despite the different thermal expansion coefficients of the protective layer and the muffle wall. The thickness of the muffle wall can therefore also be reduced to, for example, approximately 0.4 mm.
• the oven muffle is supported from the outside by a stabilizing frame. This is particularly important if the thickness of the muffle wall is only about 0.3 to 0.5 mm. This almost halving the wall thickness of the oven muffle compared to the previously known prior art further improves the heating-up times and the heat distribution. In addition, material can be saved due to the low material thickness. In addition, the weight of the oven muffle is significantly reduced.
• the stabilizing frame is essentially formed by oven insulation. On the one hand, this must be sufficiently flexible to be able to participate in the spatial enlargement of the oven muffle when heating up, and on the other hand it must be stiff enough to be able to sufficiently stabilize the thin-walled oven muffle.
• Fig. 4 in perspective views from the front of the oven muffle after various process steps for its manufacture.
• Fig. 1 shows a rectangular oven muffle 1 made of stainless steel with five muffle walls 3. These are the two side walls, a bottom and a top wall and a rear wall.
• the loading opening of the oven muffle 1 moves around a muffle flange 5.
• the oven muffle 1 is produced in one piece using a hydroforming process. In this deep-drawing process, in contrast to conventional mechanically deep-drawn parts, the oven muffle does not have defects such as uneven and large changes in wall thickness, visible traces of drawing and a bead, as well as reduced surface quality and reduced shape accuracy.
• sol-gel technology a muffle inside 7 and a muffle outside 9 are coated with a sol-gel layer 11 in a dipping or spraying process (FIG. 2).
• a solution becomes a colloid by controlled condensation methods System created on the micrometer scale (gel).
• This gel is compressed by drying as a result of solvent removal and then cured in a suitable manner or baked at a temperature of about 450 to 500 ° C.
• the sol-gel layer is particularly firmly bonded to the substrate via chemical compounds.
• the resulting sol-gel layer is about 10 ⁇ m thick and forms a hard surface with electrical insulation properties on both sides of the stainless steel muffle wall 3. Furthermore, it forms a tarnish and oxidation protection for the stainless steel.
• functional layers are applied to the sol-gel hard layer on different areas of the inside of the socket 7.
• the sol-gel functional layers in particular provide non-stick, sliding and catalytic properties.
• the sol-gel functional layers have a thickness of approximately 3 ⁇ m.
• the protective layer formed from the two sol-gel layers 11 is so transparent that the heat radiation relevant to the preparation of food can penetrate the protective layer in the infrared or visible light range and can be optimally reflected by the stainless steel surface into the interior of the muffle (Fig . 2). If necessary, a transparent or opaque coloring of the layers is also possible.
• heating conductors 13 are applied to the sol-gel hard layer on the muffle outside using thick-film technology (FIG. 3). Due to the particularly thin insulation layer between the heating conductor 13 and the muffle wall 3, a particularly favorable and uniform heat transfer is possible.
• the heating conductors 13 can be supplied with electrical voltage via conductor connections 15.
• the oven muffle 1 is finally in a muffle insulation 17 made of fiber-free insulation material, e.g. Perlite, embedded.
• the oven jacket 1 the wall thickness of which is only 0.4 mm, is stabilized by the insulation jacket.
• the insulation shell 17 is designed to be sufficiently flexible so that it does not tear during the thermal expansion of the oven muffle 1 during heating during a baking process.

Landscapes

• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Baking, Grill, Roasting (AREA)
• Muffle Furnaces And Rotary Kilns (AREA)
• Electric Stoves And Ranges (AREA)
• Cookers (AREA)
• Control And Other Processes For Unpacking Of Materials (AREA)
• Electric Ovens (AREA)
• Special Wing (AREA)
• Meat, Egg Or Seafood Products (AREA)

Priority Applications (1)

Applications Claiming Priority (3)

Related Child Applications (1)

Publications (2)

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Family Applications (2)

Family Applications Before (1)

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Family Cites Families (16)

• 1998
  • 1998-03-27 DE DE19813787A patent/DE19813787A1/de not_active Withdrawn
• 1999
  • 1999-03-26 ES ES02017745T patent/ES2237637T3/es not_active Expired - Lifetime
  • 1999-03-26 TR TR2000/02585T patent/TR200002585T2/xx unknown
  • 1999-03-26 WO PCT/EP1999/002061 patent/WO1999050601A1/fr not_active Application Discontinuation
  • 1999-03-26 EP EP02017745A patent/EP1255083B1/fr not_active Expired - Lifetime
  • 1999-03-26 AT AT99917868T patent/ATE232952T1/de not_active IP Right Cessation
  • 1999-03-26 DE DE59904331T patent/DE59904331D1/de not_active Revoked
  • 1999-03-26 KR KR1020007010578A patent/KR20010034651A/ko not_active Application Discontinuation
  • 1999-03-26 PL PL99343159A patent/PL343159A1/xx not_active IP Right Cessation
  • 1999-03-26 JP JP2000541465A patent/JP2002510029A/ja active Pending
  • 1999-03-26 DE DE59911624T patent/DE59911624D1/de not_active Expired - Lifetime
  • 1999-03-26 ES ES99917868T patent/ES2193696T3/es not_active Expired - Lifetime
  • 1999-03-26 EP EP99917868A patent/EP1064502B1/fr not_active Revoked
• 2000
  • 2000-09-27 US US09/671,826 patent/US6392203B1/en not_active Expired - Lifetime

Non-Patent Citations (1)

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