Title of Invention	BAKING DEVICE FOR PRODUCING ENDLESS BANDS
Abstract	A baking device for producing endless strips by means of heat from above and heat from below, in which there is provided a cylindrical baking ring of metal revolving continuously one direction about its central axis and rotatably mounted outside its central axis in a stationary frame of the baking device, which baking ring has at least one surface concentric with its central axis and moves at least one endless baking surface through a stationary baking zone, which zone is provided with a heating device generating heat from above disposed above the baking surface and which zone extends in the running direction of the baking ring from a stationary loading device, which applies a pourable baking mass to the baking surface, as far as a stationary removal device for the at least partially baked strip that has formed on the baking surface from the baking mass, characterized in that, to produce the heat from below, there is provided a heating device disposed above the baking surface for inductively heating the baking ring, which heating device comprises an electric induction coil for inductively heating the baking ring.

Title of Invention

BAKING DEVICE FOR PRODUCING ENDLESS BANDS

Abstract

A baking device for producing endless strips by means of heat from above and heat from below, in which there is provided a cylindrical baking ring of metal revolving continuously one direction about its central axis and rotatably mounted outside its central axis in a stationary frame of the baking device, which baking ring has at least one surface concentric with its central axis and moves at least one endless baking surface through a stationary baking zone, which zone is provided with a heating device generating heat from above disposed above the baking surface and which zone extends in the running direction of the baking ring from a stationary loading device, which applies a pourable baking mass to the baking surface, as far as a stationary removal device for the at least partially baked strip that has formed on the baking surface from the baking mass, characterized in that, to produce the heat from below, there is provided a heating device disposed above the baking surface for inductively heating the baking ring, which heating device comprises an electric induction coil for inductively heating the baking ring.

Full Text	Baking Device for Producing Endless Bands The invention relates to a baking device for producing endless bands by means of heat from above and heat from below, and to a facility for producing and processing endless bands, having a baking device, which produces the bands by means of heat from above and heat from below, and at least one processing station, arranged downstream of the baking device, for the bands produced by the baking device. The baking device has a cylindrical baking ring which is made of metal, revolves continuously around its central axis in one direction, and is mounted rotatably outside its central axis in the stationary machine stand of the baking device, which baking ring moves an endless baking surface through a stationary baking zone which is provided with a heating device, which is arranged at a distance above the baking surface and generates heat from above, and extends in the running direction of the baking ring from a feeder device, which applies a pourable baking mass onto the baking surface, as far as a removal device for the at least partially baked band produced on the baking surface from the baking mass. Known baking devices of this type (WO 97/34492) are heated by gas, the revolving baking ring being heated by gas burners or by infrared radiators heated by gas, which are arranged successively along its inside and along its outside, convey their heat to the baking ring and to the band resting thereon and formed from the baking mass, and convey their combustion gases to the interior of the casing of the baking device. The combustion gases are discharged upward out of the casing together with the steam which arises during the baking process in the band formed by the baking mass and is emitted from said band into the interior of the casing, and together with the air which is sucked into the casing, mainly at the lower side of the casing. The sucked-in air is firstly needed as combustion air for the operation of the gas burners or gas-heated infrared radiators, and secondly for lowering the temperature in the interior of the casing, said interior being heated by the very hot combustion gases to temperatures in the range of 600°C - 900°C for example, in accordance with the combustion temperature of the gas used in each case. In order to keep the interior of the casing to a temperature which is clearly below the combustion temperature of the gas used in each case and which corresponds essentially to the baking temperature of the particular band (for example, in the range from 200°C - 250°C), very large quantities of air exceeding the requirement with regard to combustion air have to be sucked into the casing and discharged again from the casing through its exhaust together with the combustion gases and the steam. For this purpose, a plurality of air inlet openings of relatively large overall cross section are required in the heat-insulating jacket surrounding the interior of the casing, and the exhaust of the casing has to be designed in terms of its exhaust cross section and the suction volume of its discharge fan to handle a very large volume of gas which is composed of the volume of the sucked-in air and of the volumes of combustion gases and steam which arise in the interior of the casing. In the known baking device, the revolving baking ring can be surrounded by a heat-insulating, essentially C-shaped casing jacket which, by means of its recess projecting into the interior of the baking ring, reduces the volume of the casing which is heated by the combustion gases and has to be cooled down by the admixture of air. In the known baking device, two or more baking zones may in each case be arranged laterally next to one another on the inside and on the outside of the baking ring, so that four or more bands formed in each case from baking mass are baked simultaneously on the baking ring, said bands conveying the steam arising in them during the baking process to the interior of the casing, and, as a result, increasing the volume of gas to be discharged from the casing. In the food and confectionery industry, baking devices heated by gas are generally used for producing endless bands of pourable baking masses or baking doughs, such as liquid wafer dough, which devices are provided with a rotating baking drum comprising a central, horizontally arranged hub, a circular, vertically arranged supporting disk connected integrally to the hub, and an outer, cylindrical drum jacket which is connected integrally to the supporting disk and on whose outer jacket surface an endless band is baked, which band is removed from the drum jacket and passed to a processing station immediately adjacent to the baking drum and processed in said station. The baking drum, which is driven via its central hub mounted rotatably in the machine stand, is heated by gas burners or by infrared radiators heated by gas, which are arranged along the outside and the inside of the drum jacket and along the supporting disk, in order to bake the endless band resting on the out-side of the drum jacket and to protect the supporting disk from cracks due to thermal stress, which cracks would occur, if the supporting disk were not heated, due to the high temperature differences between the heated drum jacket and the unheated supporting disk, A baking device of this type having a baking drum heated by gas is used in a facility, which is disclosed in WO 95/32630 for producing an endless wafer barld which is pliable when warm and, when warm, is divided in a band-processing device into individual fan-shaped wafer pieces which are rolled into wafer cones in a downstream rolling device. In the facility disclosed in AT patent 380 151, a thin wafer band which is pliable when warm is produced on the baking drum and in the downstream band-processing device is folded together in its longitudinal direction, or transversely thereto, into an endless, two- or multi-layered, laminated baked band which is further processed, while pliable, in a further, downstream band-processing device. In the facility disclosed in EP-Al 0 211 353, an endless wafer band which is pliable when warm is produced on the baking drum and, in the downstream band-processing device, is divided into individual wafer leaves which are further processed individually, while pliable, in a further, downstream processing device. In the baking device disclosed in US patent 3 829 593, an endless, soft band of dough which is not fully baked is produced on the baking drum and, immediately after being produced, is rolled onto a storage roll. This band of dough, which is still soft and flexible even after cooling down to room temperature, is the starting product for the dough envelopes of Chinese spring rolls which are produced by a soft filling being wrapped up several times in a rectangular leaf of dough cut out from the band of dough before the spring roll thus produced is deep-fried until the dough envelope is crispy and brown. In the facility disclosed in DE-A 24 35 110 for producing prefabricated, Chinese spring rolls, a soft band of dough which remains soft even at room temperature is produced on a baking drum and, in a processing device arranged at a distance from the baking drum, is divided into individual, square pieces of dough which are each further processed to form a prefabricated spring roll. In the processing device, a pre-cooked filling mass is applied onto a piece of dough and the piece of dough is folded around the filling mass to form a dough envelope enclosing the latter, and is rolled up. Baking devices having a rotating baking drum which is arranged upright, is driven via its horizontal central hub and is heated along its drum jacket and along its supporting disk by gas burners or by infrared radiators heated by gas, are also used in facilities for continuously producing hollow wafer rolls and small wafer rolls for the production of a thin wafer band which is pliable when warm and, in a processing station directly adjacent to the baking drum, is coiled in a helically overlapping manner to form a sleeve-shaped hollow body which is then cut into the individual hollow wafer rolls or small wafer rolls. For the production of the wafer band, a liquid wafer dough which consists mainly of water, wheatflour and sugar and, based on its flour content, contains between 25% by weight and 100% by weight of sugar, is applied to the outside of the heated, rotating baking drum where it is baked to form an endless band which is 'pliable when warm. Said band is continuously removed from the outside of the baking drum by a removal device and, in the processing station, between a rotating winding roll and a rotating winding mandrel, is continuously coiled around the winding mandrel in a helically overlapping manner to form a sleeve-shaped hollow body which is pushed axially beyond the winding mandrel by the winding process. The sleeve-shaped hollow body, which grows continuously in its longitudinal direction, is cut by a special cutting device into individual longitudinal pieces which, when cooled down to room temperature, take on a crispy, brittle and easily breakable consistency and constitute the hollow wafer rolls or small wafer rolls. In order to produce filled hollow wafer rolls or small wafer rolls, the filling mass can be inserted by a hollow winding mandrel directly into the hollow space in the sleeve-shaped hollow body formed by the baked wafer band, the hollow body then being cut, together with the filling mass contained in it, into the individual, filled hollow wafer rolls or small wafer rolls. In the baking device which is disclosed in US 4 655 125 A, an endless band which is baked on one side is produced on a small baking roll which delivers heat from below and has a roll body which is made of metal, encloses a cylindrical inner chamber and encloses a stationary, electrical induction coil which is arranged in its inner chamber and is seated on that immovable, rigid central axis on which the roll body is rotatably mounted on both sides of the induction coil. The central axis is formed by the sleeve-shaped coil former of the induction coil, which coil former bears the wire windings of the induction coil and is provided with a continuous, axial longitudinal slot in order to suppress short-circuit currents heated by it. The roll body has a cylindrical outer jacket which encloses the induction coil on its outside with a small spacing and, on its outside, bears the baking surface of the baking roll and is inductively heated by the electric induction coil. This outer jacket is designed as a water-containing hollow jacket, so that the evaporating or condensing water in its hollow space is able, by absorbing the heat of evaporation or by conveying the heat of condensation, to compensate for the differences in temperature which occur in the outer jacket during the inductive heating. The baking device does not provide any heating device which generates heat from above and, in the baking roll, would be arranged above the baking surface thereof at a distance from the baking roll. This baking device is therefore not suitable for producing endless bands by means of heat from above and heat from below. WO 92/15183 Al discloses a baking device having two small baking rolls which deliver heat from below, in which device the cake of dough produced on the first baking roll is in each case placed with its upper side downward onto the second baking roll and baked to completion thereon. The baking rolls each have a roll body which encloses a cylindrical inner chamber and have a cylindrical outer jacket made of metal and two disk-shaped side walls made of plastic. This roll body encloses a stationary, electrical induction coil which is arranged in its inner chamber and is seated on that immovable, rigid central axis on which the roll body is mounted rotatably on both sides of the induction coil. The cylindrical outer jacket, which is made of metal and encloses the induction coil on" its outside at a small distance, bears, on its outside, the baking surface of the baking roll and is inductively heated by the electrical induction coil. Neither in the first baking roll, nor in the second baking roll does this baking device have a heating device generating heat from above. This baking device is not suitable for producing endless bands by means of heat from above and heat from below. The object of the invention is to improve a baking device for producing endless bands by means of heat from above and heat from below. In order to achieve this, a baking device for producing endless bands by means of heat from above and heat from below is proposed, in which a cylindrical baking ring which is made of metal, revolves continuously around its central axis in one direction and is rotatably mounted outside its central axis in the stationary machine stand of the baking device is provided, which baking ring moves an endless baking surface through a stationary baking zone which is provided with a heating device, which is arranged at a distance above the baking surface and generates heat from above, and extends in the running direction of the baking ring from a feeder device, which applies a pourable baking mass onto the baking surface, as far as a removal device for the at least partially baked band produced from the baking mass on the baking surface. According to the invention, this baking device is characterized in that in order to generate the heat from below, a heating device which is arranged at a distance above the baking surface and inductively heats the baking ring is provided, which device has an electric induction coil for inductively heating the baking ring. This baking device can also be integrated in a facility for producing and processing endless bands, in which there is arranged downstream of the baking device at least one processing station for the bands produced by said device. In the baking device according to the invention, in order to generate the heat from below, the revolving baking ring which bears the baking surface is inductively heated by a stationary electric induction coil which is arranged above the baking surface and at a distance therefrom. Said induction coil may be arranged above the baking surface and next to the heating device generating the heat from above or may be integrated in said heating device. In a single-track baking device having an outer baking zone and an outer baking surface arranged on the outside of the baking ring, the heating device which is arranged above the outer baking surface and at a distance therefrom and inductively heats the baking ring can be arranged, together with the heating device which is likewise arranged above the outer baking surface and at a distance therefrom, but generates the heat from above, in the exterior of the baking device surrounding the baking ring. In a single-track baking device having an inner baking zone and an inner baking surface arranged on the inside of the baking ring, the heating devices which are arranged above the inner baking surface at a distance from the baking ring and inductively heat the baking ring can be arranged in the interior of the baking device which is enclosed by the baking ring, next to the heating device which is likewise arranged above the inner baking surface at a distance from the baking ring, but generates the heat from above. By means of the design according to the invention of the baking device, the entire quantity of heat, which is required for the process of drying and baking the baking mass in contact with the baking ring and acts on each band of baking mass as heat from above or below, can be generated by one or more, electric induction coils which are provided for the inductive heating of the baking ring and mainly heat the baking ring and themselves. This applies to single-track and also to multi-track baking devices. In the single-track baking devices, the baking ring bears in each case an endless baking surface either only on the outside, or both on the inside and on the outside, which baking surface is assigned within the baking device its own baking zone for producing an endless band. In the multi-track baking devices, the baking ring bears, on the outside and on the inside, in each case two or more endless baking surfaces which are arranged next to one another and which are each assigned, within the baking device, their own baking zone for producing an endless band. The design according to the invention of the baking device permits a rapid and careful, inductive heating of the baking ring and of its respective baking surface up to that operating temperature which is appropriate for the drying and baking process and is adjusted to the endless band to be produced in each case. Both the heating-up of the baking ring to its operating temperature and the maintaining of the operating temperature of the baking ring during the continuous production of an endless band are undertaken by the inductive heating of the baking ring. For additional browning the top side of an endless band, an electrically heated infrared radiator may be arranged in the relative baking zone, in the vicinity of the band-removing device, above the baking surface bearing the endless band. when carrying out the drying and baking processes required for producing the endless bands, the heating of the baking ring and of the bands of baking mass resting on the baking surfaces thereof by the combustion adjacent to the baking ring of heating gases can be completely dispensed with in the design according to the invention of the baking device. This permits considerable simplifications and savings in the realization of a baking device according to the invention, in which, during operation of the baking device, the casing surrounding the baking ring is now heated merely by the induction coil and the inductively heated baking ring and by the infrared radiators provided, if need be, for browning the topside of the band. It is now merely necessary to remove from the casing, by suction, the baking vapors which are generated by the drying or baking process and primarily consist of the gases which arise in the baking mass during the drying or baking process and escape therefrom, such as steam, and of the volatile substances which escape from the baking mass and account for only a very small part of the volume of the baking vapors. The volume of baking vapors to be continuously removed by suction from the casing is very much smaller than the gas volume which has to be continuously removed by suction from the casing in the known baking devices which are heated by gas. In a baking device which is heated by gas, on the one hand very large amounts of air are continuously sucked into the casing from the surroundings of the baking device with the aid of the exhaust fan assigned to the exhaust channel of the casing, in order to supply the gas burners with the necessary combustion air and to continuously cool down the combustion gases generated by these gas burners, by the admixture of air, to a baking temperature of the baking mass which is far below the combustion temperature of the heating gas, and, on the other hand, the sucked-in amounts of air are continuously removed from the casing by suction together with the very large amounts of combustion gases generated by the gas burners and the baking vapors which are produced by the drying or baking process. Compared to a gas-heated baking device, in a baking device according to the invention not only can the gas burners adjacent to the baking ring be omitted together with the heating-gas pipes leading to said gas burners, but so too can the extensive, structural precautions which are required for the sucking-in of very large amounts of air into the casing and for the removal by suction of even larger amounts of gas from the casing. This permits a considerable simplification of the baking device and of the devices required for discharging the gases from the casing. The heat-insulating jacket surrounding the casing can also be of simpler design and can be realized in a more cost-effective manner in accordance with the lower operating temperatures in the interior of the casing. According to a further feature of the invention, an electric induction coil which is arranged at a distance above the baking surface of the baking ring and inductively heats the baking ring can be provided, which coil, through its intrinsic heating, also generates the heat from above for this baking surface arranged at a distance below it. This design of the baking device makes it possible to produce, by means of heat from above and heat from below, endless bands on a revolving baking ring which is heated only by an electric induction coil. The electric induction coil can be arranged in a stationary heating element adjacent to the baking ring, the heat inductively generated in the baking ring by the induction coil acting as heat from below, and the heat generated in the heating element by heating the induction coil to its operating temperature acting as heat from above on the baking mass which is in contact with the endless baking surface of the revolving baking ring. In order to inductively heat the baking ring, use may also be made of an electric induction coil which radiates heat outward in order to cool itself and in which the heat inductively generated in the baking ring by it acts as heat from below, and the heat radiated by it for cooling purposes acts as heat from above on the baking mass in contact with the baking surface of the baking ring. In this design, the heat which occurs in the induction coil during the operation of the induction coil while the baking ring is being inductively heated can be used as heat from above for the drying and baking process of the baking mass in contact with the baking ring, while the amount of heat radiated as heat from above serves for cooling the induction coil during its operation. During the course of configuring the baking device according to the invention with regard to the drying and baking process to be carried out during production of endless bands from a given baking mass, the surface temperature of the heating element producing the heat from above is determined, and the amount of heat which is available as heat from above via the heating element is generated by the heating of the induction coil and is used for cooling the induction coil. According to a further feature of the invention, a baking ring which, on its outside, moves an endless baking surface through an outer baking zone and, on its inside, moves an endless baking surface through an inner baking zone can be provided, which ring, in order to generate the heat from below, is inductively heated by an electric induction coil which is arranged at a distance above at least one of its baking surfaces. In this design of the baking device with a baking ring bearing baking surfaces on both sides, the induction coil heating it inductively is arranged, according to the invention, at a distance from and above at least one of its baking surfaces. The induction coil can be arranged next to the heating device generating the heat from above for this baking surface or can be integrated therein. According to the invention, the induction coil may be designed in such a manner that it generates the heat from above for this baking surface through its intrinsic heating, while it simultaneously generates the heat from below for all of the baking surfaces of the baking ring by inductive heating of the baking ring. According to another feature of the invention, in order to inductively heat the baking ring, an electric induction coil which engages in each case at a distance over the outside and inside of said baking ring can be provided which, by its outer section, generates the heat from above for the outside of the baking ring and, by its inner section, generates the heat from above for the inside of the baking ring. In this design of the baking device having a baking ring bearing baking surfaces on both sides, the induction coil can engage over both sides of the baking ring in each case at a distance, and can be arranged next to the heating device generating the heat from above on the particular side or can be integrated therein. According to the invention, the induction coil may be designed in such a manner that it generates the heat from above for all of the baking surfaces of the baking ring through its intrinsic heating, while it simultaneously generates the heat from below for all of the baking surfaces of the baking ring by inductive heating of the baking ring. According to a further feature of the invention, the electric induction coil can be designed as an element which is arranged at a distance above at least one baking surface of the baking ring, is curved in an arc-shaped manner, is elongated in the running direction of the baking ring and leaves the path of movement thereof free. In this connection, the electric induction coil can be designed as an element which engages in each case at a distance above the baking surfaces of the baking ring and engages around the baking ring in a C-shaped manner. According to the invention, the electric induction coil can also be designed as an element which engages in each case at a distance above the baking surfaces of the baking ring and engages completely around the baking ring. In the following', the invention will be explained in greater detail in exemplary embodiments and by reference to the drawings. In the drawings: fig, 1 shows, schematically and in an oblique projection, a multi-track facility for producing small wafer rolls, fig. 2 shows a baking device having a revolving baking ring and a first embodiment of an electric induction coil for inductively heating the baking ring, and fig. 3 shows an oblique view of a baking ring having a second embodiment of an electric induction coil for inductively heating the baking ring. Fig. 1 shows a multi-track facility for producing small wafer rolls and hollow wafer rolls, in which two endless wafer bands which are pliable when warm are respectively produced on the inside and outside of a revolving baking ring 1 which is arranged upright, which wafer bands are coiled up in a band-processing station 2 by means of rolling mechanisms which are adjacent to the inside and outside of the baking ring and are only indicated schematically in fig. 1, in a helically overlapping manner to form sleeve-shaped hollow bodies which are divided into the individual small wafer rolls or hollow wafer rolls. In the vicinity of its lower apex, the baking ring 1 rests with its lower side on two drive shafts 3, 4 which are arranged at a distance from each other in the machine stand (not illustrated), bear the baking ring 1 and are driven by a driving motor 5 via an endless driving chain 6. The cylindrical baking ring 1 bears, on its outer and inner jacket surfaces la and lb, which are each concentric with respect to its central axis, a respective endless baking surface la', lb' which are assigned two stationary baking zones arranged next to each other. The baking zones are represented in fig. 1 by the strips of dough 7, 8, 9, 10 which extend in the respective baking zone from the point of pouring of the dough 8a, 9a, 10a along the circumference of the baking ring 1 as far as the band removal point 9b, 10b. In each baking zone, the band removal point 9b, 10b is arranged in the region of the front apex of the baking ring 1 above the point of pouring of the dough Ba, 9a, 10a. The wafer band baked on the baking ring 1 is removed at the band removal point 9b, 10b and supplied directly to the respective rolling mechanism. The revolving baking ring 1, and the strips of dough 7, 8, 9, 10 which are in contact with it and revolve with it, are heated by a stationary, electric induction coil 11 which extends along the path of movement of the baking ring 1 in the region of the lower half of the baking ring 1 and, for all four baking zones, generates the heat from below and heat from above which are required for baking the four strips of dough 7, 8, 9, 10. The electric induction coil 11 is of essentially flat design and has an outer half 11a extending along the outside of the baking ring 1, and an inner half lib extending along the inside of the baking ring 1. The baking ring 1, which is arranged between the two halves 11a and lib of the induction coil 11, passes through the magnetic field generated by the induction coil 11 and is inductively heated by the induction coil 11. The heat generated inductively in the baking ring 1 acts as heat from below on the strips of dough 7, 8, 9, 10 which are in contact with the two baking surfaces la', lb' of the baking ring. The heat radiated from the induction coil 11, which is heated to its operating temperature, acts, in the region of the outer half 11a of the induction coil 11, as heat from above on the two .outer strips of dough 9 and 10 and, in the region of the inner half lib of the induction coil 11, as heat from above on the two inner strips of dough 7 and 8. Fig. 2 shows a baking device 12 according to the invention having a stationary machine stand 13 in which a revolving, cylindrical baking ring 14 made of metal rests on two horizontal drive shafts 15, 16 which cause the baking ring 14 to rotate about its central axis. In the region of the vertex 17 of the baking ring 14, which is illustrated on the right in fig. 2, the stationary feeder devices 19 for the baking mass are arranged below the horizontal plane 18 which runs through the horizontally extending central axis of the baking ring 14. The stationary band-removing devices 20 are arranged above the plane 18. In each baking zone, the baking mass applied to the outside and inside of the baking ring 14 forms a continuous band which extends along the circumference of the baking ring 14 through an angular region of approximately 340° from the baking-mass feeding device 19 as far as the band-removing device 20. In that half of the machine stand 13 which is illustrated on the left in fig. 2, an electric induction coil 21 is provided as the heating device 24, which coil surrounds the baking ring 14 at a distance, is designed such that it is elongated in the direction in which the baking ring 14 revolves and has windings running essentially transversely with respect to the direction in which the baking ring 14 revolves. The induction coil 21 is connected via the electric lines 22 to a device (not illustrated) for generating the electric alternating current used for operation of the induction coil 21. The induction coil 21 may be fitted into a tubular heating element of rectangular cross section which extends along the path of movement of the baking ring 14 and is heated by the operating heat of the induction coil 21. In order to inductively heat a baking ring having a width of 400 mm and a thickness of 30 mm, use can be made of an induction coil with a heating capacity of 75 kW which is supplied with a current of 520 A and an alternating-current frequency of 1.1 kHz, Fig. 3 shows an exemplary embodiment for an electric induction coil 21 which surrounds a baking ring 14 in the region of its vertex 23, which is illustrated on the right in fig. 3, over an angular region of 90o and has windings mainly running in the direction in which the baking ring 14 revolves. Patent Claims 1, A baking device (12) for producing endless bands by means of heat from above and heat from below, in which a cylindrical baking ring (1, 14) which is made of metal, revolves continuously around its central axis in one direction and is rotatably mounted outside its central axis in the stationary machine stand (13) of the baking device (12) is provided, which baking ring moves an endless baking surface (la', lb') through a stationary baking zone which is provided with a heating device (11a, lib, 24), which is arranged at a distance above the baking surface (la', lb') and generates heat from above, and extends in the running direction of the baking ring (1, 14) from a feeder device (8a, 9a, 10a, 19), which applies a pourable baking mass onto the baking surface (la', lb'), as far as a removal device (9b, 10b, 20) for the at least partially baked band (7, 8, 9, 10) produced from the baking mass on the baking surface (la', lb'), characterized in that in order to generate the heat from below, a heating device (11, 24) which is arranged at a distance above the baking surface (la', lb') and inductively heats the baking ring (1, 14) is provided, which device has an electric induction coil (11, 21) for inductively heating the baking ring (1, 14) . 2. The baking device as claimed in claim 1, characterized in that an electric induction coil (11, 21) which is arranged at a distance above the baking surface (la', lb') of the baking ring (1, 14) and inductively heats the baking ring (1, 14) is provided, which coil, through its intrinsic heating, also generates the heat from above for this baking surface (la', lb') which is arranged at a distance below it. 3. The baking device as claimed in claim 1 or 2, characterized in that a baking ring (1) which, on its outside (la), moves an endless baking surface (la') through an outer baking zone and, on its inside (lb), moves an endless baking surface (lb') through an inner baking zone is provided, which ring, in order to generate the heat from below, is inductively heated by an electric induction coil (11) which is arranged at a distance above at least one of its baking surfaces (la', lb') . 4. The baking device as claimed in claim 3, characterized in that in order to inductively heat the baking ring (1), an electric induction coil (11) which engages in each case at a distance over the outside (la) and inside (lb) of said baking ring is provided which, by its outer section (11a), generates the heat from above for the outside (la) of the baking ring (1) and, by its inner section (lib), generates the heat from above for the inside (lb) of the baking ring (1). 5. The baking device .as claimed in one of claims 1 to 4, characterized in that the electric induction coil (11, 21) is designed as an element which is arranged at a distance above at least one baking surface (la', lb') of the baking ring (1, 14), is curved in an arc-shaped manner, is elongated in the running direction of the baking ring (1, 14) and leaves the path of movement thereof free. 6. The baking device as claimed in claim 5, characterized in that the electric induction coil (11, 21) is designed as an element which engages in each case at a distance above the baking surfaces (la', lb') of the baking ring (1, 14) and engages in a C-shaped manner around the baking ring 7. The baking device as claimed in claim 5, characterized in that the electric induction coil (11, 21) is designed as an element which engages in each case at a distance above the baking surfaces (la', lb') of the baking ring (1, 14) and engages completely around the baking ring (1, 14) . 8. A facility for producing and processing endless bands, having a baking device (12), which produces the bands by means of heat from above and heat from below, and at least one processing station (2), arranged downstream of the latter, for the bands, there being provided in the baking device (12) a cylindrical baking ring (1, 14) which is made of metal, revolves continuously around its central axis in one direction and is mounted rotatably outside its central axis in the stationary machine stand (13) of the baking device (12), which baking device moves an endless baking surface (la', lb') through a stationary baking zone which is provided with a heating device (11a, lib, 24), which is arranged at a distance above the baking surface (la', lb') and generates heat from above, and extends in the running direction of the baking ring (1, 14) from a feeder device (8a, 9a, 10a, 19), which applies a pourable baking mass onto the baking surface (la', lb'), as far as a removal device (9b, 10b, 20) for the at least partially baked band (7, 8, 9, 10) produced from the baking mass on the baking surface (la', lb'), characterized in that in order to generate the heat from below, a heating device (11, 24) which is arranged at a distance above the baking surface (la', lb') and inductively heats the baking ring (1, 14) is provided, which device has an electric induction coil (11, 21) for inductively heating the baking ring (1, 14) . 9. The facility as claimed in claim 8, characterized in that in the baking device (12) an electric induction coil (11, 21) which is arranged at a distance above the baking surface (la', lb') of the baking ring (1, 14) and inductively heats the baking ring (1, 14) is provided, which coil, through its intrinsic heating, also generates the heat from above for this baking surface (la', lb') arranged at a distance below it. 10. The facility as claimed in claim 8 or 9, characterized in that in the baking device (12) a baking ring (1) which, on its outside (la), moves an endless baking surface (la') through an outer baking zone and, on its inside (lb), moves an endless baking surface (lb') through an inner baking zone is provided, which ring, in order to generate the heat from below, is inductively heated by an electric induction coil (11) which is arranged at a distance above at least one of its baking surfaces (la', lb') . 11. The facility as claimed in claim 10, characterized in that in order to inductively heat the baking ring (1), an electric induction coil (11) which engages in each case at a distance over the outside (la) and inside (lb) of said baking ring is provided which, by its outer section (11a), generates the heat from above for the outside (la) of the baking ring (1) and, by its inner section (lib), generates the heat from above for the inside (lb) of the baking ring (1). 12. The facility as claimed in one of claims 8 to 11, characterized in that the electric induction coil (11, 21) is designed as an element which is arranged at a distance above at least one baking surface (la', lb') of the baking ring (1, 14) , is curved in an arc-shaped manner, is elongated in the running direction of the baking ring (1, 14) and leaves the path of movement thereof free. 13. The facility as claimed in claim 12, characterized in that the electric induction coil (11, 21) is designed as an element which engages in each case at a distance above the baking surfaces (la', lb') of the baking ring (1, 14) and engages in a C-shaped manner around the baking ring (1, 14) . 14. The facility as claimed in claim 12, characterized in that the electric induction coil (11, 21) is designed as an element which engages in each case at a distance above the baking surfaces (la', lb') of the baking ring (1, 14) and engages completely around the baking ring (1, 14) . 15. A baking device substantially as herein described with reference to the accompanying drawings. 16. A facility for producing and processing endless bands substantially as herein described with reference to the accompanying drawings. Dated this 31 day of October 2001

Full Text

Baking Device for Producing Endless Bands
The invention relates to a baking device for producing endless bands by means of heat from above and heat from below, and to a facility for producing and processing endless bands, having a baking device, which produces the bands by means of heat from above and heat from below, and at least one processing station, arranged downstream of the baking device, for the bands produced by the baking device.
The baking device has a cylindrical baking ring which is made of metal, revolves continuously around its central axis in one direction, and is mounted rotatably outside its central axis in the stationary machine stand of the baking device, which baking ring moves an endless baking surface through a stationary baking zone which is provided with a heating device, which is arranged at a distance above the baking surface and generates heat from above, and extends in the running direction of the baking ring from a feeder device, which applies a pourable baking mass onto the baking surface, as far as a removal device for the at least partially baked band produced on the baking surface from the baking mass.
Known baking devices of this type (WO 97/34492) are heated by gas, the revolving baking ring being heated by gas burners or by infrared radiators heated by gas, which are arranged successively along its inside and along its outside, convey their heat to the baking ring and to the band resting thereon and formed from the baking mass, and convey their combustion gases to the interior of the casing of the baking device. The combustion gases are discharged upward out of the casing together with the steam which arises during the baking process in the band formed by the baking mass and is emitted from said band into the interior of the casing, and together with the

air which is sucked into the casing, mainly at the lower side of the casing. The sucked-in air is firstly needed as combustion air for the operation of the gas burners or gas-heated infrared radiators, and secondly for lowering the temperature in the interior of the casing, said interior being heated by the very hot combustion gases to temperatures in the range of 600°C - 900°C for example, in accordance with the combustion temperature of the gas used in each case. In order to keep the interior of the casing to a temperature which is clearly below the combustion temperature of the gas used in each case and which corresponds essentially to the baking temperature of the particular band (for example, in the range from 200°C - 250°C), very large quantities of air exceeding the requirement with regard to combustion air have to be sucked into the casing and discharged again from the casing through its exhaust together with the combustion gases and the steam. For this purpose, a plurality of air inlet openings of relatively large overall cross section are required in the heat-insulating jacket surrounding the interior of the casing, and the exhaust of the casing has to be designed in terms of its exhaust cross section and the suction volume of its discharge fan to handle a very large volume of gas which is composed of the volume of the sucked-in air and of the volumes of combustion gases and steam which arise in the interior of the casing. In the known baking device, the revolving baking ring can be surrounded by a heat-insulating, essentially C-shaped casing jacket which, by means of its recess projecting into the interior of the baking ring, reduces the volume of the casing which is heated by the combustion gases and has to be cooled down by the admixture of air. In the known baking device, two or more baking zones may in each case be arranged laterally next to one another on the inside and on the outside of the baking ring, so that four or more bands formed in each case from baking mass are baked simultaneously

on the baking ring, said bands conveying the steam arising in them during the baking process to the interior of the casing, and, as a result, increasing the volume of gas to be discharged from the casing.
In the food and confectionery industry, baking devices heated by gas are generally used for producing endless bands of pourable baking masses or baking doughs, such as liquid wafer dough, which devices are provided with a rotating baking drum comprising a central, horizontally arranged hub, a circular, vertically arranged supporting disk connected integrally to the hub, and an outer, cylindrical drum jacket which is connected integrally to the supporting disk and on whose outer jacket surface an endless band is baked, which band is removed from the drum jacket and passed to a processing station immediately adjacent to the baking drum and processed in said station. The baking drum, which is driven via its central hub mounted rotatably in the machine stand, is heated by gas burners or by infrared radiators heated by gas, which are arranged along the outside and the inside of the drum jacket and along the supporting disk, in order to bake the endless band resting on the out-side of the drum jacket and to protect the supporting disk from cracks due to thermal stress, which cracks would occur, if the supporting disk were not heated, due to the high temperature differences between the heated drum jacket and the unheated supporting disk,
A baking device of this type having a baking drum heated by gas is used in a facility, which is disclosed in WO 95/32630 for producing an endless wafer barld which is pliable when warm and, when warm, is divided in a band-processing device into individual fan-shaped wafer pieces which are rolled into wafer cones in a downstream rolling device. In the facility disclosed in AT patent 380 151, a thin wafer band which is

pliable when warm is produced on the baking drum and in the downstream band-processing device is folded together in its longitudinal direction, or transversely thereto, into an endless, two- or multi-layered, laminated baked band which is further processed, while pliable, in a further, downstream band-processing device. In the facility disclosed in EP-Al 0 211 353, an endless wafer band which is pliable when warm is produced on the baking drum and, in the downstream band-processing device, is divided into individual wafer leaves which are further processed individually, while pliable, in a further, downstream processing device. In the baking device disclosed in US patent 3 829 593, an endless, soft band of dough which is not fully baked is produced on the baking drum and, immediately after being produced, is rolled onto a storage roll. This band of dough, which is still soft and flexible even after cooling down to room temperature, is the starting product for the dough envelopes of Chinese spring rolls which are produced by a soft filling being wrapped up several times in a rectangular leaf of dough cut out from the band of dough before the spring roll thus produced is deep-fried until the dough envelope is crispy and brown. In the facility disclosed in DE-A 24 35 110 for producing prefabricated, Chinese spring rolls, a soft band of dough which remains soft even at room temperature is produced on a baking drum and, in a processing device arranged at a distance from the baking drum, is divided into individual, square pieces of dough which are each further processed to form a prefabricated spring roll. In the processing device, a pre-cooked filling mass is applied onto a piece of dough and the piece of dough is folded around the filling mass to form a dough envelope enclosing the latter, and is rolled up.
Baking devices having a rotating baking drum which is arranged upright, is driven via its horizontal central hub and is

heated along its drum jacket and along its supporting disk by gas burners or by infrared radiators heated by gas, are also used in facilities for continuously producing hollow wafer rolls and small wafer rolls for the production of a thin wafer band which is pliable when warm and, in a processing station directly adjacent to the baking drum, is coiled in a helically overlapping manner to form a sleeve-shaped hollow body which is then cut into the individual hollow wafer rolls or small wafer rolls. For the production of the wafer band, a liquid wafer dough which consists mainly of water, wheatflour and sugar and, based on its flour content, contains between 25% by weight and 100% by weight of sugar, is applied to the outside of the heated, rotating baking drum where it is baked to form an endless band which is 'pliable when warm. Said band is continuously removed from the outside of the baking drum by a removal device and, in the processing station, between a rotating winding roll and a rotating winding mandrel, is continuously coiled around the winding mandrel in a helically overlapping manner to form a sleeve-shaped hollow body which is pushed axially beyond the winding mandrel by the winding process. The sleeve-shaped hollow body, which grows continuously in its longitudinal direction, is cut by a special cutting device into individual longitudinal pieces which, when cooled down to room temperature, take on a crispy, brittle and easily breakable consistency and constitute the hollow wafer rolls or small wafer rolls. In order to produce filled hollow wafer rolls or small wafer rolls, the filling mass can be inserted by a hollow winding mandrel directly into the hollow space in the sleeve-shaped hollow body formed by the baked wafer band, the hollow body then being cut, together with the filling mass contained in it, into the individual, filled hollow wafer rolls or small wafer rolls.
In the baking device which is disclosed in US 4 655 125 A, an

endless band which is baked on one side is produced on a small baking roll which delivers heat from below and has a roll body which is made of metal, encloses a cylindrical inner chamber and encloses a stationary, electrical induction coil which is arranged in its inner chamber and is seated on that immovable, rigid central axis on which the roll body is rotatably mounted on both sides of the induction coil. The central axis is formed by the sleeve-shaped coil former of the induction coil, which coil former bears the wire windings of the induction coil and is provided with a continuous, axial longitudinal slot in order to suppress short-circuit currents heated by it. The roll body has a cylindrical outer jacket which encloses the induction coil on its outside with a small spacing and, on its outside, bears the baking surface of the baking roll and is inductively heated by the electric induction coil. This outer jacket is designed as a water-containing hollow jacket, so that the evaporating or condensing water in its hollow space is able, by absorbing the heat of evaporation or by conveying the heat of condensation, to compensate for the differences in temperature which occur in the outer jacket during the inductive heating. The baking device does not provide any heating device which generates heat from above and, in the baking roll, would be arranged above the baking surface thereof at a distance from the baking roll. This baking device is therefore not suitable for producing endless bands by means of heat from above and heat from below.
WO 92/15183 Al discloses a baking device having two small baking rolls which deliver heat from below, in which device the cake of dough produced on the first baking roll is in each case placed with its upper side downward onto the second baking roll and baked to completion thereon. The baking rolls each have a roll body which encloses a cylindrical inner chamber and have a cylindrical outer jacket made of metal and

two disk-shaped side walls made of plastic. This roll body encloses a stationary, electrical induction coil which is arranged in its inner chamber and is seated on that immovable, rigid central axis on which the roll body is mounted rotatably on both sides of the induction coil. The cylindrical outer jacket, which is made of metal and encloses the induction coil on" its outside at a small distance, bears, on its outside, the baking surface of the baking roll and is inductively heated by the electrical induction coil. Neither in the first baking roll, nor in the second baking roll does this baking device have a heating device generating heat from above. This baking device is not suitable for producing endless bands by means of heat from above and heat from below.
The object of the invention is to improve a baking device for producing endless bands by means of heat from above and heat from below.
In order to achieve this, a baking device for producing endless bands by means of heat from above and heat from below is proposed, in which a cylindrical baking ring which is made of metal, revolves continuously around its central axis in one direction and is rotatably mounted outside its central axis in the stationary machine stand of the baking device is provided, which baking ring moves an endless baking surface through a stationary baking zone which is provided with a heating device, which is arranged at a distance above the baking surface and generates heat from above, and extends in the running direction of the baking ring from a feeder device, which applies a pourable baking mass onto the baking surface, as far as a removal device for the at least partially baked band produced from the baking mass on the baking surface. According to the invention, this baking device is characterized in that in order to generate the heat from

below, a heating device which is arranged at a distance above the baking surface and inductively heats the baking ring is provided, which device has an electric induction coil for inductively heating the baking ring. This baking device can also be integrated in a facility for producing and processing endless bands, in which there is arranged downstream of the baking device at least one processing station for the bands produced by said device.
In the baking device according to the invention, in order to generate the heat from below, the revolving baking ring which bears the baking surface is inductively heated by a stationary electric induction coil which is arranged above the baking surface and at a distance therefrom. Said induction coil may be arranged above the baking surface and next to the heating device generating the heat from above or may be integrated in said heating device. In a single-track baking device having an outer baking zone and an outer baking surface arranged on the outside of the baking ring, the heating device which is arranged above the outer baking surface and at a distance therefrom and inductively heats the baking ring can be arranged, together with the heating device which is likewise arranged above the outer baking surface and at a distance therefrom, but generates the heat from above, in the exterior of the baking device surrounding the baking ring. In a single-track baking device having an inner baking zone and an inner baking surface arranged on the inside of the baking ring, the heating devices which are arranged above the inner baking surface at a distance from the baking ring and inductively heat the baking ring can be arranged in the interior of the baking device which is enclosed by the baking ring, next to the heating device which is likewise arranged above the inner baking surface at a distance from the baking ring, but generates the heat from above.

By means of the design according to the invention of the baking device, the entire quantity of heat, which is required for the process of drying and baking the baking mass in contact with the baking ring and acts on each band of baking mass as heat from above or below, can be generated by one or more, electric induction coils which are provided for the inductive heating of the baking ring and mainly heat the baking ring and themselves. This applies to single-track and also to multi-track baking devices. In the single-track baking devices, the baking ring bears in each case an endless baking surface either only on the outside, or both on the inside and on the outside, which baking surface is assigned within the baking device its own baking zone for producing an endless band. In the multi-track baking devices, the baking ring bears, on the outside and on the inside, in each case two or more endless baking surfaces which are arranged next to one another and which are each assigned, within the baking device, their own baking zone for producing an endless band.
The design according to the invention of the baking device permits a rapid and careful, inductive heating of the baking ring and of its respective baking surface up to that operating temperature which is appropriate for the drying and baking process and is adjusted to the endless band to be produced in each case. Both the heating-up of the baking ring to its operating temperature and the maintaining of the operating temperature of the baking ring during the continuous production of an endless band are undertaken by the inductive heating of the baking ring. For additional browning the top side of an endless band, an electrically heated infrared radiator may be arranged in the relative baking zone, in the vicinity of the band-removing device, above the baking surface bearing the endless band.

when carrying out the drying and baking processes required for producing the endless bands, the heating of the baking ring and of the bands of baking mass resting on the baking surfaces thereof by the combustion adjacent to the baking ring of heating gases can be completely dispensed with in the design according to the invention of the baking device. This permits considerable simplifications and savings in the realization of a baking device according to the invention, in which, during operation of the baking device, the casing surrounding the baking ring is now heated merely by the induction coil and the inductively heated baking ring and by the infrared radiators provided, if need be, for browning the topside of the band. It is now merely necessary to remove from the casing, by suction, the baking vapors which are generated by the drying or baking process and primarily consist of the gases which arise in the baking mass during the drying or baking process and escape therefrom, such as steam, and of the volatile substances which escape from the baking mass and account for only a very small part of the volume of the baking vapors. The volume of baking vapors to be continuously removed by suction from the casing is very much smaller than the gas volume which has to be continuously removed by suction from the casing in the known baking devices which are heated by gas. In a baking device which is heated by gas, on the one hand very large amounts of air are continuously sucked into the casing from the surroundings of the baking device with the aid of the exhaust fan assigned to the exhaust channel of the casing, in order to supply the gas burners with the necessary combustion air and to continuously cool down the combustion gases generated by these gas burners, by the admixture of air, to a baking temperature of the baking mass which is far below the combustion temperature of the heating gas, and, on the other hand, the sucked-in amounts of air are continuously removed from the casing by suction together with the very large

amounts of combustion gases generated by the gas burners and the baking vapors which are produced by the drying or baking process.
Compared to a gas-heated baking device, in a baking device according to the invention not only can the gas burners adjacent to the baking ring be omitted together with the heating-gas pipes leading to said gas burners, but so too can the extensive, structural precautions which are required for the sucking-in of very large amounts of air into the casing and for the removal by suction of even larger amounts of gas from the casing. This permits a considerable simplification of the baking device and of the devices required for discharging the gases from the casing. The heat-insulating jacket surrounding the casing can also be of simpler design and can be realized in a more cost-effective manner in accordance with the lower operating temperatures in the interior of the casing.
According to a further feature of the invention, an electric induction coil which is arranged at a distance above the baking surface of the baking ring and inductively heats the baking ring can be provided, which coil, through its intrinsic heating, also generates the heat from above for this baking surface arranged at a distance below it.
This design of the baking device makes it possible to produce, by means of heat from above and heat from below, endless bands on a revolving baking ring which is heated only by an electric induction coil. The electric induction coil can be arranged in a stationary heating element adjacent to the baking ring, the heat inductively generated in the baking ring by the induction coil acting as heat from below, and the heat generated in the heating element by heating the induction coil to its operating

temperature acting as heat from above on the baking mass which is in contact with the endless baking surface of the revolving baking ring. In order to inductively heat the baking ring, use may also be made of an electric induction coil which radiates heat outward in order to cool itself and in which the heat inductively generated in the baking ring by it acts as heat from below, and the heat radiated by it for cooling purposes acts as heat from above on the baking mass in contact with the baking surface of the baking ring. In this design, the heat which occurs in the induction coil during the operation of the induction coil while the baking ring is being inductively heated can be used as heat from above for the drying and baking process of the baking mass in contact with the baking ring, while the amount of heat radiated as heat from above serves for cooling the induction coil during its operation. During the course of configuring the baking device according to the invention with regard to the drying and baking process to be carried out during production of endless bands from a given baking mass, the surface temperature of the heating element producing the heat from above is determined, and the amount of heat which is available as heat from above via the heating element is generated by the heating of the induction coil and is used for cooling the induction coil.
According to a further feature of the invention, a baking ring which, on its outside, moves an endless baking surface through an outer baking zone and, on its inside, moves an endless baking surface through an inner baking zone can be provided, which ring, in order to generate the heat from below, is inductively heated by an electric induction coil which is arranged at a distance above at least one of its baking surfaces.
In this design of the baking device with a baking ring bearing

baking surfaces on both sides, the induction coil heating it inductively is arranged, according to the invention, at a distance from and above at least one of its baking surfaces. The induction coil can be arranged next to the heating device generating the heat from above for this baking surface or can be integrated therein. According to the invention, the induction coil may be designed in such a manner that it generates the heat from above for this baking surface through its intrinsic heating, while it simultaneously generates the heat from below for all of the baking surfaces of the baking ring by inductive heating of the baking ring.
According to another feature of the invention, in order to inductively heat the baking ring, an electric induction coil which engages in each case at a distance over the outside and inside of said baking ring can be provided which, by its outer section, generates the heat from above for the outside of the baking ring and, by its inner section, generates the heat from above for the inside of the baking ring.
In this design of the baking device having a baking ring bearing baking surfaces on both sides, the induction coil can engage over both sides of the baking ring in each case at a distance, and can be arranged next to the heating device generating the heat from above on the particular side or can be integrated therein. According to the invention, the induction coil may be designed in such a manner that it generates the heat from above for all of the baking surfaces of the baking ring through its intrinsic heating, while it simultaneously generates the heat from below for all of the baking surfaces of the baking ring by inductive heating of the baking ring.
According to a further feature of the invention, the electric

induction coil can be designed as an element which is arranged at a distance above at least one baking surface of the baking ring, is curved in an arc-shaped manner, is elongated in the running direction of the baking ring and leaves the path of movement thereof free. In this connection, the electric induction coil can be designed as an element which engages in each case at a distance above the baking surfaces of the baking ring and engages around the baking ring in a C-shaped manner. According to the invention, the electric induction coil can also be designed as an element which engages in each case at a distance above the baking surfaces of the baking ring and engages completely around the baking ring.
In the following', the invention will be explained in greater detail in exemplary embodiments and by reference to the drawings. In the drawings: fig, 1 shows, schematically and in an oblique projection, a multi-track facility for producing small wafer rolls, fig. 2 shows a baking device having a revolving baking ring and a first embodiment of an electric induction coil for inductively heating the baking ring, and fig. 3 shows an oblique view of a baking ring having a second embodiment of an electric induction coil for inductively heating the baking ring.
Fig. 1 shows a multi-track facility for producing small wafer rolls and hollow wafer rolls, in which two endless wafer bands which are pliable when warm are respectively produced on the inside and outside of a revolving baking ring 1 which is arranged upright, which wafer bands are coiled up in a band-processing station 2 by means of rolling mechanisms which are adjacent to the inside and outside of the baking ring and are only indicated schematically in fig. 1, in a helically overlapping manner to form sleeve-shaped hollow bodies which are divided into the individual small wafer rolls or hollow

wafer rolls. In the vicinity of its lower apex, the baking ring 1 rests with its lower side on two drive shafts 3, 4 which are arranged at a distance from each other in the machine stand (not illustrated), bear the baking ring 1 and are driven by a driving motor 5 via an endless driving chain
6. The cylindrical baking ring 1 bears, on its outer and inner
jacket surfaces la and lb, which are each concentric with
respect to its central axis, a respective endless baking
surface la', lb' which are assigned two stationary baking
zones arranged next to each other. The baking zones are
represented in fig. 1 by the strips of dough 7, 8, 9, 10 which
extend in the respective baking zone from the point of pouring
of the dough 8a, 9a, 10a along the circumference of the baking
ring 1 as far as the band removal point 9b, 10b. In each
baking zone, the band removal point 9b, 10b is arranged in the
region of the front apex of the baking ring 1 above the point
of pouring of the dough Ba, 9a, 10a. The wafer band baked on
the baking ring 1 is removed at the band removal point 9b, 10b
and supplied directly to the respective rolling mechanism.
The revolving baking ring 1, and the strips of dough 7, 8, 9, 10 which are in contact with it and revolve with it, are heated by a stationary, electric induction coil 11 which extends along the path of movement of the baking ring 1 in the region of the lower half of the baking ring 1 and, for all four baking zones, generates the heat from below and heat from above which are required for baking the four strips of dough
7, 8, 9, 10. The electric induction coil 11 is of essentially
flat design and has an outer half 11a extending along the
outside of the baking ring 1, and an inner half lib extending
along the inside of the baking ring 1. The baking ring 1,
which is arranged between the two halves 11a and lib of the
induction coil 11, passes through the magnetic field generated
by the induction coil 11 and is inductively heated by the

induction coil 11. The heat generated inductively in the baking ring 1 acts as heat from below on the strips of dough 7, 8, 9, 10 which are in contact with the two baking surfaces la', lb' of the baking ring. The heat radiated from the induction coil 11, which is heated to its operating temperature, acts, in the region of the outer half 11a of the induction coil 11, as heat from above on the two .outer strips of dough 9 and 10 and, in the region of the inner half lib of the induction coil 11, as heat from above on the two inner strips of dough 7 and 8.
Fig. 2 shows a baking device 12 according to the invention having a stationary machine stand 13 in which a revolving, cylindrical baking ring 14 made of metal rests on two horizontal drive shafts 15, 16 which cause the baking ring 14 to rotate about its central axis. In the region of the vertex 17 of the baking ring 14, which is illustrated on the right in fig. 2, the stationary feeder devices 19 for the baking mass are arranged below the horizontal plane 18 which runs through the horizontally extending central axis of the baking ring 14. The stationary band-removing devices 20 are arranged above the plane 18. In each baking zone, the baking mass applied to the outside and inside of the baking ring 14 forms a continuous band which extends along the circumference of the baking ring 14 through an angular region of approximately 340° from the baking-mass feeding device 19 as far as the band-removing device 20. In that half of the machine stand 13 which is illustrated on the left in fig. 2, an electric induction coil 21 is provided as the heating device 24, which coil surrounds the baking ring 14 at a distance, is designed such that it is elongated in the direction in which the baking ring 14 revolves and has windings running essentially transversely with respect to the direction in which the baking ring 14 revolves. The induction coil 21 is connected via the electric

lines 22 to a device (not illustrated) for generating the electric alternating current used for operation of the induction coil 21. The induction coil 21 may be fitted into a tubular heating element of rectangular cross section which extends along the path of movement of the baking ring 14 and is heated by the operating heat of the induction coil 21.
In order to inductively heat a baking ring having a width of 400 mm and a thickness of 30 mm, use can be made of an induction coil with a heating capacity of 75 kW which is supplied with a current of 520 A and an alternating-current frequency of 1.1 kHz,
Fig. 3 shows an exemplary embodiment for an electric induction coil 21 which surrounds a baking ring 14 in the region of its vertex 23, which is illustrated on the right in fig. 3, over an angular region of 90o and has windings mainly running in the direction in which the baking ring 14 revolves.

Patent Claims
1, A baking device (12) for producing endless bands by means
of heat from above and heat from below, in which a
cylindrical baking ring (1, 14) which is made of metal,
revolves continuously around its central axis in one
direction and is rotatably mounted outside its central
axis in the stationary machine stand (13) of the baking
device (12) is provided, which baking ring moves an
endless baking surface (la', lb') through a stationary
baking zone which is provided with a heating device (11a,
lib, 24), which is arranged at a distance above the
baking surface (la', lb') and generates heat from above,
and extends in the running direction of the baking ring
(1, 14) from a feeder device (8a, 9a, 10a, 19), which
applies a pourable baking mass onto the baking surface
(la', lb'), as far as a removal device (9b, 10b, 20) for
the at least partially baked band (7, 8, 9, 10) produced
from the baking mass on the baking surface (la', lb'),
characterized in that in order to generate the heat from
below, a heating device (11, 24) which is arranged at a
distance above the baking surface (la', lb') and
inductively heats the baking ring (1, 14) is provided,
which device has an electric induction coil (11, 21) for
inductively heating the baking ring (1, 14) .
2. The baking device as claimed in claim 1, characterized in
that an electric induction coil (11, 21) which is
arranged at a distance above the baking surface (la',
lb') of the baking ring (1, 14) and inductively heats the
baking ring (1, 14) is provided, which coil, through its
intrinsic heating, also generates the heat from above for
this baking surface (la', lb') which is arranged at a
distance below it.

3. The baking device as claimed in claim 1 or 2, characterized in that a baking ring (1) which, on its outside (la), moves an endless baking surface (la') through an outer baking zone and, on its inside (lb), moves an endless baking surface (lb') through an inner baking zone is provided, which ring, in order to generate the heat from below, is inductively heated by an electric induction coil (11) which is arranged at a distance above at least one of its baking surfaces (la', lb') .
4. The baking device as claimed in claim 3, characterized in that in order to inductively heat the baking ring (1), an electric induction coil (11) which engages in each case at a distance over the outside (la) and inside (lb) of said baking ring is provided which, by its outer section (11a), generates the heat from above for the outside (la) of the baking ring (1) and, by its inner section (lib), generates the heat from above for the inside (lb) of the baking ring (1).
5. The baking device .as claimed in one of claims 1 to 4, characterized in that the electric induction coil (11, 21) is designed as an element which is arranged at a distance above at least one baking surface (la', lb') of the baking ring (1, 14), is curved in an arc-shaped manner, is elongated in the running direction of the baking ring (1, 14) and leaves the path of movement thereof free.
6. The baking device as claimed in claim 5, characterized in that the electric induction coil (11, 21) is designed as an element which engages in each case at a distance above the baking surfaces (la', lb') of the baking ring (1, 14) and engages in a C-shaped manner around the baking ring

7. The baking device as claimed in claim 5, characterized in that the electric induction coil (11, 21) is designed as an element which engages in each case at a distance above the baking surfaces (la', lb') of the baking ring (1, 14) and engages completely around the baking ring (1, 14) .
8. A facility for producing and processing endless bands, having a baking device (12), which produces the bands by means of heat from above and heat from below, and at least one processing station (2), arranged downstream of the latter, for the bands, there being provided in the baking device (12) a cylindrical baking ring (1, 14) which is made of metal, revolves continuously around its central axis in one direction and is mounted rotatably outside its central axis in the stationary machine stand
(13) of the baking device (12), which baking device moves an endless baking surface (la', lb') through a stationary baking zone which is provided with a heating device (11a, lib, 24), which is arranged at a distance above the baking surface (la', lb') and generates heat from above, and extends in the running direction of the baking ring (1, 14) from a feeder device (8a, 9a, 10a, 19), which applies a pourable baking mass onto the baking surface (la', lb'), as far as a removal device (9b, 10b, 20) for the at least partially baked band (7, 8, 9, 10) produced from the baking mass on the baking surface (la', lb'), characterized in that in order to generate the heat from below, a heating device (11, 24) which is arranged at a distance above the baking surface (la', lb') and inductively heats the baking ring (1, 14) is provided, which device has an electric induction coil (11, 21) for inductively heating the baking ring (1, 14) .

9. The facility as claimed in claim 8, characterized in that in the baking device (12) an electric induction coil (11, 21) which is arranged at a distance above the baking surface (la', lb') of the baking ring (1, 14) and inductively heats the baking ring (1, 14) is provided, which coil, through its intrinsic heating, also generates the heat from above for this baking surface (la', lb') arranged at a distance below it.
10. The facility as claimed in claim 8 or 9, characterized in that in the baking device (12) a baking ring (1) which, on its outside (la), moves an endless baking surface (la') through an outer baking zone and, on its inside (lb), moves an endless baking surface (lb') through an inner baking zone is provided, which ring, in order to generate the heat from below, is inductively heated by an electric induction coil (11) which is arranged at a distance above at least one of its baking surfaces (la', lb') .
11. The facility as claimed in claim 10, characterized in that in order to inductively heat the baking ring (1), an electric induction coil (11) which engages in each case at a distance over the outside (la) and inside (lb) of said baking ring is provided which, by its outer section (11a), generates the heat from above for the outside (la) of the baking ring (1) and, by its inner section (lib), generates the heat from above for the inside (lb) of the baking ring (1).
12. The facility as claimed in one of claims 8 to 11, characterized in that the electric induction coil (11, 21) is designed as an element which is arranged at a distance above at least one baking surface (la', lb') of

the baking ring (1, 14) , is curved in an arc-shaped manner, is elongated in the running direction of the baking ring (1, 14) and leaves the path of movement thereof free.
13. The facility as claimed in claim 12, characterized in that the electric induction coil (11, 21) is designed as an element which engages in each case at a distance above the baking surfaces (la', lb') of the baking ring (1, 14) and engages in a C-shaped manner around the baking ring (1, 14) .
14. The facility as claimed in claim 12, characterized in that the electric induction coil (11, 21) is designed as an element which engages in each case at a distance above the baking surfaces (la', lb') of the baking ring (1, 14) and engages completely around the baking ring (1, 14) .

15. A baking device substantially as herein described with reference to the accompanying drawings.
16. A facility for producing and processing endless bands substantially as
herein described with reference to the accompanying drawings. Dated this 31 day of October 2001

Documents:

in-pct-2001-1499-che-abstract.pdf

in-pct-2001-1499-che-claims duplicate .pdf

in-pct-2001-1499-che-claims original.pdf

in-pct-2001-1499-che-correspondence others.pdf

in-pct-2001-1499-che-correspondence po.pdf

in-pct-2001-1499-che-description complete duplicate.pdf

in-pct-2001-1499-che-description complete original.pdf

in-pct-2001-1499-che-drawings.pdf

in-pct-2001-1499-che-form 1.pdf

in-pct-2001-1499-che-form 26.pdf

in-pct-2001-1499-che-form 3.pdf

in-pct-2001-1499-che-form 5.pdf

in-pct-2001-1499-che-other documents.pdf

in-pct-2001-1499-che-pct.pdf

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Patent Number

208054

Indian Patent Application Number

IN/PCT/2001/1499/CHE

PG Journal Number

31/2007

Publication Date

03-Aug-2007

Grant Date

06-Jul-2007

Date of Filing

31-Oct-2001

Name of Patentee

FRANZ HAAS WAFFELMASCHINEN-INDUSTRIE AKTIENGESELLSCHAFT ,WIEN

Applicant Address

PRAGERSTRASSE 124, A-1210 WIEN.

Inventors:

#	Inventor's Name	Inventor's Address
1	HAAS FRANZ	GERSTLGASSE 25, A-1210 WIEN.
2	HAAS JOHANN	SEITWEG 5, A-3400 KLOSTERNEUBURG.
3	KOLETNIK ERICH	ANZENGRUBERGASSE 7, A-3400 KLOSTERNEUBURG.

PCT International Classification Number

A21B5/03

PCT International Application Number

PCT/AT00/00086

PCT International Filing date

2000-04-10

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	A 795/99	1999-05-04	Austria