DE6806383U - OVEN - Google Patents

Description

Utility model registration

oven

The innovation concerns an oven, namely the self-cleaning type of one.

A well-known drawback of the ovens is that pie is covered with a layer of fat and on the inside when in use Cover food particles that are hard wire and difficult to remove again. So far, aes ± sack oven has been used for cleaning Often different cleaning agents are used, but it is desirable to avoid these as much as possible by that the oven is made self-cleaning by increasing the temperature above normal oven roasting temperatures All grease and other contaminants are removed from the walls of the pit. Such self-cleaning Ovens that are based on the burning of fats and other impurities at temperatures of 480 - 670 ° C, are known. These very high temperatures of the ovens require carefully designed safety devices and, if necessary, fans to cool the outer walls hold or expensive and thick insulation.

Utility model registration G 6B 06 383.2-7401

HOOVER LIMITED

There are many ovens that are deheated in this way between the individual walls or various parts of any wall there may be a considerable difference in temperature. Z "B, Heat stratification occurs in some of the common English gas stoves on, which results in fairly low temperatures at the bottom and high temperatures in the upper part of the furnace. To Pott and to remove impurities from the lower part of the furnace by burning, the temperature in the entire furnace interior and should especially in the upper parts of the oven can be increased significantly above the value required for baking. Others in France, Germany and other European countries commonly used Ovens have a very large floor area in the oven Burner, unlike the furnace described above, produces much higher temperatures at the bottom of the furnace than on the side walls. Between different places

The temperature of the furnace wall can vary up to 205 ° C.

In a similar way, one can use electrical power from a different side heated oven temperature differences of 120 - 150 O appear.

According to the suggestion for the existing fire, at least one wall of the oven with a catalytic oxidizer Equipped in or on its surface and a fan is built in to keep the air inside aes oven circulates to reduce the temperature difference between different To reduce the steepness of the surface.

The catalyst is preferably in or on a support Ceramic or enamel or a film made of polytetrafluoroethylene firmly applied.

According to another embodiment of the innovation The fan serves a dual purpose of creating the mentioned above, relatively small temperature difference suwuai during a period of catalytic purification, as well as during reduced or all baking processes.

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In this pall the fan can be operated with two different Speeds are driven, a relatively low and quiet during baking and a higher and - "- maybe louder speed during the catalytic cleaning process. Finally, the motor driving the fan can be used can also be used to drive an auxiliary device at a third, even lower speed »

The innovation can be carried out in various ways and some particular embodiments are described below described for example:

Try a common one that is electrically heated on the sides Beckofen have shown that for a given temperature setting of the thermostat at the various Ϋ / ände des A range of temperatures is obtained in the furnace, which are approximated below:

Seen from the front the door has temperatures of 210 and U at the two upper corners and at the left corner ^; 0 ° C.

The temperature was at the two rear corners of the floor 210 and at the two front corners 160 ° C.

The back wall of the stove had sine at the top two corners Temperature of 250 and at its lower ends of 220 ° C.

The temperature on both side walls was 310 ° C at all four corners and 250 ° C at all corners of the top wall.

In the attached drawing, for example, is an embodiment of the oven after the innovation.

The door 10 of the furnace closes αen through the side walls 11, the bottom 12, the cover wall 13 and the rear wall H delimited the interior of the furnace. To heat the oven are behind each Side wall 11 electrical heating element 15 is provided. To make things easier or self-cleaning of the furnace by burning down, the walls delimiting the furnace interior, i.e. the interior

sides of the door 10, the side walls 11, the cover wall 13 and of the bottom 12 has a catalyst partially embedded in the top layer of each Y / and, like this one by the Schrax'fur 17 is indicated. In the rear wall 11 is the horizontal axis a fan 18, which is covered by a grille 19 on its front side.

By installing a fan near the back wall of the oven, which circulates the air inside the oven, the temperature at the four corners of the two side walls was not changed, but the temperature at the four corners of the door was increased ^{to 250 ° C.} On the top wall of the furnace no temperature change was observed, at each corner of the temperature remained at 250 ° C. At the two upper corners of the Hückwand of the furnace, the temperature rose depending from 250 to 310 ⁰ O, and at the bottom corners each from 220 to 250 ° 0.

At all four corners of the bottom of the furnace, the temperature rose to 310 ° C.

From these figures it can be seen that the temperature between the highest and lowest points varied during operation without a fan 150 to 310 ° G, so that a temperature difference of 16O ⁰ O was present. When operating with the VenGxiator from 250 to 310 ° C fluctuated, which corresponds to a temperature difference of only 6O ⁰ C. It can be assumed that this difference can still be reduced as development progresses.

Experiments with a gas oven, the burner of which is arranged under the floor of the oven, also have very pronounced temperature differences shown and that was in this case hottest point of 335 ° C directly above the burner, while individual points on the side walls have temperatures of only. 110 G, so that a temperature difference of approximately 225 ° C occurred. By installing a circulating air Fan, this temperature difference was considerably reduced »

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By equipping these ovens at the same time with a fan that circulates the air and with a catalytic converter Coating on some or all of the interior walls not only enables considerably lower temperatures to be used, than were previously required for self-cleaning ovens, but there is also a much lower temperature difference on. If one takes into account that a minimum temperature of 305 ° G is required for the catalytic oxidation to occur and it is assumed that the temperature difference is kept at 55 C or an even lower Y / ert the maximum temperature of the furnace need only be about 360 ° G at any point.

In this way, the maximum temperature of the oven can be significantly different from the above temperatures of 430 or 560 C and as a result, special insulation and special safety devices omitted. It should also be pointed out that the temperature difference is likely as a result of further construction and development can be reduced still further, so that the maximum temperature at some point is the inner surface for the purpose of catalytic cleaning can still be suppressed below 360.

C down-

The oxidation catalyst used on the inside of the furnace can be any of the known catalysts suitable for the occurring temperature range.

Apart from the use of the fan for the catalytic In some cases, oxidative cleaning can be done with the rinse Temperature difference also be for baking purposes of plasters.

j The fan used can be used according to the requirements j vary. In some cases a propeller fan is suitable, the one located on a row of the back wall of the stove Axis is mounted, which is driven by Einsn electric motor will. This creates an axial flow in the direction of the rear wall and a flow in the middle of the furnace

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caused by the side walls, the cover wall and the floor. If desired, the drive motor of the fan are in a circuit with a door operated switch, so that it is ensured that the fan does not circulate when the door is open. In other circumstances, a fan can be stored in a suitable housing that is connected to the inside of the furnace by a pipe,

Caution should be exercised in gas ovens, e.g. through Use of suitable partitions to ensure that the pressure difference in the vicinity of the burner Flame does not extinguish.

Expectations;

Claims (2)

Dipl.-lng. W. PAAP Dipl.-Ing. H. MITSCHERLICH Dipl.-Ing. K. GUNSCHMANN Dr. rer. not. W. KORBER PATENTANWÄLTE 8 MDNCHEN 22, Stelmdorfitra6o 10 Telephone: (0811) * 29 6otM March 28, 1969 / Bra. Utility model registration G 68 06 383.2-7401 HOOVuR LIMITED claims 1. Oven with at least one wall that is stuck in or on its surface with a catalytic oxidizer is equipped, characterized by a built-in fan (18) which circulates the air inside the furnace. 2. Oven according to claim 1, characterized in that the catalyst is in a base made of ceramic or enamel or a film made of polytetrafluoroethylene is firmly applied. The patent attorney 680?