DE3447432A1 - HEAT-INSULATED INDUSTRIAL STOVE AND HEAT-INSULATING COAT DAFUER - Google Patents

Description

Heat-insulated industrial furnace and heat-insulating jacket for it

The invention relates to heat-insulated industrial furnaces with a at least partially made of iron housing and an outer jacket made of insulating material and one for Thermal insulation of industrial furnaces suitable thermal insulation jacket.

Although great efforts have been made on all sides since the 1973 oil crisis Many vulcanizing, sintering, muffle and other industrial furnaces are used to save energy Heat treatment of workpieces not yet thermally insulated. This is only partly due to the fact that no simple Heat insulation was available to adapt to the various external shapes and dimensions of existing older "ovens. A major cause of this deficiency is that many industrial furnaces are heated up cyclically and before they are removed the treated workpieces have to be cooled down again. In these cases, thermal insulation would be great The disadvantage is that the cooling periods and cycle times would have been significantly lengthened overall with the inevitable consequence of a decline in productivity. Finally there was the concern that a soft, insulating Sheathing is quickly damaged and worn in rough operation, and then the replacement causes the same problems like the subsequent insulation of the ovens.

The invention is therefore based on the object of an industrial furnace of the type mentioned at the beginning, with which not only can you save energy in a simple way, but also, if necessary, the cycle time can also be shortened, as well as a heat-insulating jacket that can also be easily adapted subsequently provide.

The above object is achieved according to the invention in that the jacket is connected on the inside with permanent magnets detachably adhering to the housing.

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If, in a preferred embodiment of the invention, the jacket consists of at least one layer in the form of a supple If the blanket is made of woven, knitted or felt-like heat-resistant, fibrous material, the cut is special simply because you only have to pay attention to the rough outline of the furnace, but not to e.g. the lid that is screwed on on the outside and other surface irregularities, as these are loosely covered by the supple coat. The one with the Permanent magnets connected to the jacket have a double function, e.g. also with a hinged upper part of the furnace to secure against falling and to keep the edges of the jacket in close contact with the housing of the furnace, so that a substantially stationary layer of air is retained between this and the jacket. For this latter purpose are the permanent magnets, which e.g. can have the shape of flat, round discs with a diameter of about 1 to 3 cm especially along the edges of the mantle, taking into account their number, spacing, size and magnetic holding force, which in turn depends on the material and the temperature, depending on the conditions in the individual case.

In a preferred practical embodiment, the tear strength of the jacket and the resilience of the connection between this and the permanent magnet in relation to their holding force chosen so that you can only pull on the coat needs to loosen the permanent magnets from the housing of the furnace. Great forces do not have to be reckoned with, because the thermal insulation materials are usually very light and therefore the magnetic holding force can be so small, that the release of the permanent magnets from the furnace by pulling on the jacket is easily possible.

The proposed thermal insulation according to the invention has the other The advantage of this is that it is relatively immune to damage despite its soft surface, as it

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When objects move past normally just move or loosen the permanent magnets, and then the jacket can be adjusted again.

It goes without saying, however, that the invention can also be used for fastening relatively stiffer plate-shaped or preformed thermal insulation body on the housing of a furnace is suitable. The entire heat-insulating jacket of a furnace can be used independently of its stiffness or suppleness, consist of a single or several individual pieces and cover the surface of the furnace housing substantially completely or only partially. One becomes a partial protection Think especially when it comes down to hot parts of the oven with which people come into contact can come to cover. If energy saving is more important, the stove will be as extensive as it is practical Use allows sheath. Even with a relatively thin and light casing, energy savings are possible from about 20 to 30% possible.

In a further preferred embodiment of the invention, the proposed heat-insulating jacket consists of several layers, wherein the innermost layer has a heat ray reflective inner surface. This layer can e.g. a tear-resistant, heat-resistant, with a metallic, reflective Order provided plastic film to which the permanent magnets are glued.

In an alternative embodiment, the permanent magnets are sewn between a thin inner layer and one or more outer layers of the jacket. The innermost In this case, the layer must be so thin that the intended number of permanent magnets still has the required holding force can exercise "

In a further preferred practical embodiment, the permanent magnets are screwed or riveted to one or more Layers of the insulating jacket connected, e.g. the permanent magnet by means of a screw or a rivet can be connected through the jacket to a disk arranged on the outside thereof.

The materials used are according to the requirements to be selected on a case-by-case basis. Mineral wool, ceramic or asbestos fibers are used for the insulating jacket and felt mats such as those available under the trade name Kevlar. The latter have the advantage that they are very abrasion-resistant and therefore do not contaminate vulcanization products, for example. There is also the option of mineral wool mats to be enclosed between felt mats made of Keflar.

The permanent magnets can be SmCo magnets, AlNiCo magnets, Ferit ~ magnets or iron-neodymium magnets or other suitable permanent magnets act at least up to about 500 C, maintain sufficient magnetic holding force to hold the heat-insulating casing of the furnace.

The invention is explained in more detail below with reference to the drawing.

Fig "1 side view of a with a heat insulating Mantle protected industrial furnace,

FIG. 2 is a plan view of an expanded part of the heat-insulating jacket according to FIG. 1,

3 shows a cross section through a jacket according to FIG. 2 in the area of a sewn-in permanent magnet j,

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Pig. 4 another embodiment of a heat insulating Jacket with permanent magnets fixed inside by gluing,

5 shows a cross section through a heat insulating jacket with permanent magnets fastened by screws.

Ih Fig. 1, an industrial furnace 10 is shown schematically, which consists of a lower part and an upper part that can be pivoted open about a hinge axis 12. The lower part and the upper part of the furnace 10 are each covered individually with an adapted heat-insulating jacket. The designated 14 The mat-shaped jacket of the lower part is placed in a ring around the furnace. Dar with 16 designated coat of the In the example, the upper part is cut like a hood. The sheaths 14 and 16 are each connected on their inside with numerous button-shaped permanent magnets 18, which are mainly arranged along the edges of the jacket and for their easily detachable attachment to the ferromagnetic housing of the furnace 10 are used. Considering the load acting on the individual permanent magnets 18 can, as shown in FIG. 2, be provided that For example, more permanent magnets 18 are arranged on the upper peripheral edge of the jacket 14 than on the lower edge. Of course permanent magnets 18 will normally also be attached in the central area of the jacket.

Figures 3 to 5 show examples of different types of attachment for the permanent magnets 18. In the embodiment according to FIG between an inner layer 22 that is as thin as possible and a comparatively thick, heat-insulating outer layer 24 of the jacket 14 or 16 sewn. In the embodiment according to FIG. 4, the permanent magnet 18 is on the inner layer 22 of the Jacket 14 or 16 glued on. The inner layer 22 can

have an inward-facing metallic surface that Reflects heat rays.

The embodiment according to FIG. 5 shows a jacket 14 or 16 consisting of three layers 26, 28, 30, with the middle, thick layer 28 can consist of mineral wool, for example, which is resistant to abrasion between the inner and outer and tear resistant layers 26 and 28 is included. The layers 26 and 30 do not even need special thermal insulation properties since the function of thermal insulation essentially falls to the middle layer 28. The outer Layer 30 is isolated from the hot oven by the inner layers 26 and 28 and can therefore consist of a less heat resistant material like this one. The permanent magnets 18 are provided with a threaded hole and are fastened to the jacket 14 or 16 by means of a screw 32 passed through the jacket 14 or 16 from the outside, a washer 34 provides support for the screw head.

It is understood that both the external shapes shown and the mounting options shown for the Permanent magnets 18 represent only exemplary embodiments of the invention, to those within the scope of the inventive concept the further design options available to the person skilled in the art are added.

If, in practical use of the furnace, it is important to achieve short cycle times, the procedure according to the invention is as follows: that after inserting the workpieces to be treated, the furnace with a magnetically attached heat-insulating jacket is heated and heated during the treatment time. At least during part of the cool-down period can then The cooling time can be shortened by removing the insulating jacket from the furnace housing.

Claims (10)

PATENT CLAIMS 1. Thermally insulated industrial furnace with an at least partially Housing made of iron and an outer jacket made of heat-insulating material, thereby characterized in that the jacket (14, 16) on the inside with releasably adhering permanent magnets to the housing (10) (18) is connected. 2. Thermally insulating jacket for at least partially outside of iron existing industrial furnaces, characterized that it is connected on the inside with several permanent magnets (18). 3. Coat according to claim 2, characterized in that it consists of at least one layer (24) in the form of a supple blanket made of woven, knitted or felt-like, heat-resistant, fibrous Material consists. 4. Coat according to claim 2 or 3, characterized in that it consists of several layers (22, 24; 26, 28, 30) and its innermost layer (22 or 26) is a heat radiation reflective having inner surface. 5. Sheath according to one of claims 2 to 4, characterized in that the permanent magnets (18) with their surface exposed to the inside of the jacket (14, 16). 6. Sheath according to one of claims 2 to 5, characterized in that the permanent magnets (18) on the inside of the jacket (14, 16) only by one like that thin layer (22) are covered, that their magnetic holding force at the furnace temperature to hold the jacket sufficient. 7. Sheath according to claim 6, characterized in that the permanent magnets between one sewn thin inner layer (22) and one or more outer layers (24) of the jacket (14, 16) are. 8. Sheath according to one of claims 2 to 6, characterized in that the permanent magnets (18) are glued to its innermost layer (22). 9. Sheath according to one of claims 2 to 8, characterized in that the permanent magnets (18) are riveted to at least one of its layers (24, 28, 30) or connected by means of screws (32). 10. Process for the cyclical operation of an industrial furnace with a heat-insulating jacket connected to permanent magnets according to one of claims 1 to 9, characterized characterized in that the jacket in each case before or during the heating of the furnace on its housing attached and detached during at least a portion of the cool down period.