WO2019185308A1

WO2019185308A1 - Method and device for a hydrothermal treatment, in particular of food

Info

Publication number: WO2019185308A1
Application number: PCT/EP2019/055448
Authority: WO
Inventors: Heiner GERMAN
Original assignee: German Lebensmitteltechnologie Gmbh
Priority date: 2018-03-29
Filing date: 2019-03-05
Publication date: 2019-10-03
Also published as: DE102018002806A1; DE102018002806B4

Abstract

The invention relates to a method for a hydrothermal treatment, in particular of food, using hot humid air. The following steps are carried out one after the other: a) providing the processed goods to be treated, in particular food; b) providing a processing chamber for introducing the processed goods to be treated and for discharging the treated processed goods, wherein the processing chamber has an upper and a lower region; c) loading the processing chamber with hot humid air in the form of processing vapor; d) adjusting the density gradient of the processing vapor using free convection, wherein the density of the processing vapor in the upper region of the processing chamber is lower than the density of the processing vapor in the lower region of the processing chamber; e) introducing the processed goods to be treated into one of the regions of the processing chamber; f) guiding the processed goods out of one region and into the other region, the duration of the guiding process of the processed goods to be treated equalling between 1 minute and 5 hours; and g) discharging the now treated processed goods out of the processing chamber. The invention additionally relates to a device for carrying out the method, said device being in the form of a baking tunnel oven. The advantages of the method and device according to the invention consist in using internally generated steam instead of externally generated steam to humidify the processing air and conducting the humidified processing air within the processing chamber to the location of technological need in an energy-saving manner. In this manner, the natural conduction of the warm humid air in the form of processing vapor is used.

Description

Method and device for the hydrothermal treatment, in particular of food

The present invention relates to a method and apparatus for hydro-thermal treatment, in particular food.

In many technical processes, foods are treated in particular with moist, hot air in order to produce certain technological effects. For example, at the beginning of baking, different types of bread, small bakery products and fine bakery products are subjected to a hydrothermal treatment, the so-called steaming, in order to develop pastry-typical quality features such as gloss, volume and formation. For a short time, the biscuits are exposed to moist, hot process air in order to condense certain amounts of water vapor on the surface of the biscuit. Too dry or too humid process air lead to bakery defects when sweating. In tunnel ovens, steaming takes place at the inlet of the baking tunnel, where the process air in the first tunnel section is usually moistened with externally generated steam.

Other types of bread and biscuits undergo hydrothermal treatment at the end of baking, especially if they are to be frozen after baking. In this case, pastry defects, such as splintering of the crust, can be counteracted by exposing the biscuits in the last baking section to a moist process air.

If the baking process takes place in tunnel ovens, the hydrothermal treatment of the baked goods is difficult for several reasons, which will be discussed below.

Under a tunnel oven is understood in the baking technology a particular embodiment of the continuous oven, in which the dough is guided on a movable baking surface through a heated tunnel. According to the eponymous nature of a tunnel, tunnel ovens have the following characteristics, namely tunneling ovens are stretched long, tunnel ovens have a tunnel inlet and a tun- nel outlet arranged in alignment on the opposite side, and in tunnel ovens the path of the baked goods in the oven continues to be monodirectional, ie in the case of tunnel ovens, the baked goods enter the oven in the same direction as they do leaves. Thus, the inlet direction of the baking material is equal to the outlet direction. Most tunnel ovens are further characterized in that the dough before the tunnel inlet on a movable baking surface or in bakeware, but in principle loosely placed / stored, is transported on the movable baking surface through a heated tunnel and behind the spout detached / removed from the movable baking surface. The loose application of the baking material has hitherto made it necessary to guide the baking surface horizontally through the baking tunnel.

Most tunnel ovens are further characterized in the prior art in that the movable baking surface describes a continuous cycle, namely has a run-up upper part, which is loaded with dough and is surrounded only on this by the eponymous heated baking tunnel, a returning lower part which is not loaded with dough, each having a deflection of the movable baking surface behind the oven outlet (after removal of the dough) and one before the tunnel inlet (before the task of baking), whereby the continuous cycle of the movable baking surface is closed and is thermally treated only on the up-running upper part, which is why only this part is designed as a tunnel, which in turn derives the name tunnel oven.

The previous horizontal design of tunnel ovens is due to the fact that the baked goods are pushed out of the way for most types of pastry or are always loosely placed on baking trays in baking molds, but in principle always loosely. Only in the case of positively driven baked goods, as known in the production of wafers, has it hitherto been possible to move the movable baking surface through the tunnel in a different form from the usual horizontal form. In the prior art tunnel ovens are known as these are shown in Figure 1. In these tunnel ovens steam is generated externally for steaming and introduced into a steaming room 1 by means of steam pipes 2. The aim is to make baked goods with a need for steaming at the beginning of the baking process in a process air with a humidity close to the

Immerse vapor saturation. In doing so, it would be most efficient to fill the charge chamber with steam to the desired air humidity while exposing the dough to a largely quiescent moist process air. However, this is not possible with tunnel ovens since they form a largely open system in relation to the environment.

The steaming is not very effective in the prior art. The demand for steam condensate of around 25 kg per hour per 1000 kg of bread per hour is relatively small, but in practice it is exceeded by 4 to 10 times. The reason for this is that the steam introduced for steaming has a smaller density than dry air of the same temperature. Naturally, the vapor moves up from the process to be treated. For this reason, steaming in tunnel ovens is carried out in the form of pipes with openings above the process material to be treated, from which the steam flows from top to bottom of the process material. However, this has a negative effect on the treatment efficiency several times, because the process material is not fully immersed, but only flows around below the vapor outlets of steam. In addition, the speed of the flowing steam reduces the desired condensation, which results in much more steam being applied than required. In addition, the efficiency of steaming in tunnel ovens, whose process feed must be regarded as open to the system, is impaired by the fact that even small amounts of ambient air significantly reduce the dew point temperature that is important for condensation. This also means that much more steam than required must be applied.

In the further course of baking, process air with a smaller air humidity is required, for which purpose the water vapor leaving the baked goods together with the initially introduced steam must be removed from the baking chamber by means of steam chimneys 3. For energy and product opti- During baking, the introduced and discharged quantities of steam must now be regulated, which is difficult in the prior art since they influence one another.

Depending on the type of biscuit, up to 30% of the baking energy is accounted for by the external generation of the steam. This energy consumption can be avoided if, instead of the externally generated steam, the water vapor in the form of brook swirls is used instead of the externally generated steam. To do this, the baking puffs in tunnel ovens must be transported from the back of the oven where they are produced to the front part, where there is a need for steam. So far, only solutions with additional devices and additional energy expenditure are known for this transport. These also have the disadvantage that the baking steam is not always in the desired humidity in the desired part of the oven, where they should develop their technological effect.

Another portion of up to 10% of the baking energy is used to heat ambient air that enters the oven cavity at the oven inlet and oven outlet, especially during charging and discharging operations. This energy consumption can also be avoided if the baking steam is removed from the baking chamber in a controlled manner.

It is known a back-space-external solution in which the baking puffs are removed from the rear of the oven with a fan and conveyed through pipelines in the front part of the oven and introduced there again. This solution requires design effort for extraction, transport lines and introduction as well as energy expenditure for transport.

A similar back-room-external solution is known in which the baking swabs are taken from the baking chamber with a fan and returned to the baking chamber via pipelines. The baking swaths are transported by displaced or directed introduction of the baking steam into the baking chamber. The constructive and energetic effort for this solution is comparable to that of the aforementioned solution. It is known from practice also a backspace-internal solution in which a compressed air pulse is used to transport the baking steam in the back of the oven. In this solution, the effort in the compressed air installation and energy consumption.

The object of the present invention is therefore to provide an energy-efficient method for the hydrothermal treatment, in particular of foods. A further object of the invention is the provision of a device for carrying out the method.

The object of the present invention is achieved by the provision of a method and a device which overcome the disadvantages of the prior art.

The present invention is a method for hydrothermal treatment according to the features of the main claim. Advantageous developments are characterized in the dependent subclaims.

The present invention thus provides a process for the hydro-thermal treatment, in particular of foods with moist, warm air, wherein the following steps are carried out successively:

a) providing the processed goods to be treated, in particular food;

b) providing a process space for introducing the process goods to be treated and for discharging the processed process goods, the process space having an upper and a lower area;

c) loading the process room with moist, warm air in the form of process swaths;

d) setting a density gradient of the process swaths using free convection, wherein the density of the process swaths in the upper area of the process space is smaller than the density of the process swaths in the lower area of the process space;

e) bringing the process goods to be treated into one of the areas of the process area; f) guiding the process goods from one area to the other area, the time duration of the management of the process items to be treated being between 1 minute and 5 hours;

g) Application of the now treated process goods from the process area.

Preferred is a method according to the invention, wherein the process goods are water-containing process goods.

Particularly preferred is a method according to the invention, wherein the moisture and / or the density and / or the temperature of the process swath is measured in the upper and / or lower region of the process space.

Furthermore, it is preferred according to the invention that, during the execution of the method, process swaths are at least partially derived from the upper region of the process chamber.

In particular, a method is preferred in which the process material to be treated is introduced into the upper region of the process space, which leads process material from the upper region into the lower region of the process space and discharges the treated process material from the lower region of the process space.

Also particularly preferred is a method in which the process material to be treated is introduced into the lower region of the process space, which leads process material from the lower region into the upper region of the process space and discharges the treated process material from the upper region of the process space.

Furthermore, a method according to the invention is preferred, wherein the process space has at least one entry area for introducing the process items to be treated and / or at least one exit area for discharging the processed process items and / or at least one movable carrier for the process items, preferably in the form a conveyor belt, and / or at least one device for introducing the process swaths into the process space and / or at least one device for deriving water vapor from the process space and / or at least one device for spatially vertical separation of a part of the process space.

Very particularly preferred is a method according to the invention, wherein the process space has the shape of a tunnel oven or a baking chamber.

The present invention also provides an apparatus for carrying out the method according to the invention, in particular a tunnel oven, with the features of the independent claim. Advantageous developments are characterized in the dependent subclaims.

The subject of the present invention is thus a tunnel oven whose baking surface has a height difference between the tunnel inlet and the tunnel outlet.

According to the invention, a tunnel oven is preferred, wherein the baking surface between the oven inlet and the oven outlet has a gradient at an angle of 0.5 to 4.0 degrees, preferably 0.7 to 2.0 degrees.

Also preferred is a tunnel oven according to the invention, wherein the baking surface between the oven inlet and the oven outlet has a pitch with an angle of 0.5 to 4.0 degrees, preferably of 0.7 to 2.0 degrees.

According to the invention, a tunnel baking oven is furthermore preferred, with the baking steam being taken from the baking space at the oven inlet, being led outside the baking chamber and being supplied in a freely convective manner to a separate loading space upstream of the baking tunnel.

Furthermore, a tunnel oven according to the invention is preferred, wherein the baking chamber has at least one device for the controlled introduction of externally generated steam into the baking chamber. Also preferred according to the invention is a tunnel oven, wherein the baking chamber has at least one device for the controlled discharge of baking steam from the baking chamber.

Also preferred is an inventive tunnel oven, wherein the baking chamber has at least one device for controlling the free-convective flow of convection within the oven.

Particularly preferred according to the invention is a tunnel oven, wherein the baking chamber has at least one device for measuring and controlling the air humidity.

Furthermore, a tunnel baking oven is very particularly preferred, wherein the baking chamber has at least one device for measuring and regulating the pressure.

The subject matter of the present invention is furthermore a device for carrying out the method according to the invention in the form of a back chamber with the features of the additional independent claim. Advantageous further developments are indicated in the dependent subclaim.

According to the invention, a baking chamber is preferred, the baking chamber having at least one heating device of the baking chamber and at least one device for loading the interior of the baking chamber with moist, warm air and / or for discharging the moist, warm air and a device for receiving the process material, characterized in that the baking chamber in the interior further comprises at least one device for guiding the process material through the interior of the baking chamber. It is inventively provided that the device for guiding the baking stock is configured, for example in the form of a lift.

Particularly preferred is a baking chamber, wherein the baking chamber in the interior further comprises at least one device for guiding the heating device through the interior of the baking chamber. It is advantageous that the heating device and the process material are guided by means of a device to be used together.

The present invention will be explained in more detail with the attached drawings. It shows:

Fig. 1 is a cross-sectional view of a tunnel oven according to the prior art;

2 shows a cross-sectional view of a first embodiment of a tunnel oven according to the invention;

3 shows a cross-sectional view with a bottom view of a second embodiment of a tunnel oven according to the invention; and

4 shows a cross-sectional view of a third embodiment of a tunnel oven according to the invention.

definitions

For the purposes of the invention, the term "hydrothermal" is understood to mean a treatment of process products in air at different temperatures and in different concentrations of water vapor. The air is heated or heated. The energy required for heating can be generated by any method known in the art. In general, however, the term "hydrothermal" may also refer to fluids other than water vapor. It is thus possible, by means of the described method according to the invention, to treat process goods other than food and also fluids other than water. Such fluids can be substances such as carbon dioxide or ammonia, and suitable process materials can then be minerals, rocks or building materials and materials of all kinds.

For the purposes of the present invention, the term "process material" means any type of product which requires modification or refinement of a hydrothermal treatment. In the context of the invention, process goods in the form of foods are particularly preferred. Such suitable foods are, for example, cereals or cereal products, such as oatmeal, corn products or the like. These products are modified by hydrothermal processes, improving the shelf life or digestibility of the products. In the sense of the invention, however, processed goods are preferably baked goods of all kinds, ie mixtures and doughs from the usual raw materials for the respective baked goods, which are subjected to a baking process.

The term "process space" in the sense of the invention means a space in which the hydrothermal process according to the invention can be carried out. Decisive for the design of the process space according to the invention is that the process space has a height which enables moist, warm air introduced into or formed in the process space to be distributed in such a way that a natural moisture fall within of the room without the need for an artificial air movement within the process space. As a result of the properties of the moist, warm air prescribed by the laws of nature, an enrichment of air with higher humidity is achieved in the upper region of the process space. Natural convection then forms the required air humidity gradient of the process air within the process area. Of course, in the process room further devices may be present, which serve for heating or for feeding or introducing or introducing and / or for feeding or discharging the moist, warm air. The process space also has corresponding devices which guide the process goods through the density gradient as required. Such devices may be conveyor belts, lifting devices and the like, which are known in the art.

Furthermore, the term "process swath" in the context of the invention means a structure of moist, warm air, which is formed by the fact that the air present in the process space is enriched with water vapor and spreads out in the process space. The water vapor can first be introduced or introduced into the process space from the outside. However, the water vapor can also be formed in the interior of the process space, for example by water from the process material through supplied heat is evaporated. In this case too, process swaths are formed which are required for carrying out the process according to the invention. Process steam thus denotes warm air with different air humidity for carrying out the process according to the invention.

The present invention thus relates to a process for the hydro-thermal treatment, in particular of foods with moist, warm air. The result of the treatment is, for example, a bread or pastry with the typical quality characteristics of gloss, volume and puffiness. The use of other foods, such as cereal products in the form of grains or oatmeal, results in the digestion or refining of foods. For example, this enzyme is deactivated, which can lead to better digestibility or extended shelf life. Also high molecular carbohydrates can be digested with it. In all areas of application, the method according to the invention can be used.

In the first step of the process, the process material to be treated is prepared. This can be an applied dough for bread or pastry or another food.

In the next step, a suitable process space is provided. This process space is used for introducing the process goods to be treated and for discharging the processed process goods. According to the invention, it is necessary for the process space to have an upper and a lower area.

In the next step, the process room is now loaded with moist, warm air in the form of process steam. For this purpose, steam is either introduced from the outside by means of appropriate devices in the process space or generated directly in the interior of the process chamber, for example by heating water or in the further course of the process moist process material and thereby evaporated.

In the next step, a density gradient of the process swaths must now be set using free convection inside the process space. Due to the known physical laws, the density of the process swaths is in the upper range of the process space is smaller than the density of the process swaths in the lower area of the process area. This sets the process climate (moist, warm air) required for carrying out the method according to the invention inside the process space.

Now, in the next step, the process goods to be treated are introduced into one of the areas of the process area. This introduction can take place by means of a lock-type loading station, whereby the process goods can be guided on a belt. However, the process items can also be inserted into the process space in baking molds arranged side by side. In this step of the method according to the invention, it is crucial in which area of the process space the process goods have to be introduced. For example, there are bakery products which require an intake of particularly moist air at the beginning of the process. This is the case with most breads. These process goods are first introduced into the upper area of the process area. If the process material is, for example, a lye cake, an initially high level of air humidity in the process stream is negative for the baking result. Therefore, such process goods are first introduced into the less humid, lower area of the process space.

In the next step, the process material is led from the area in which it was introduced into the process area in the other area. Depending on the process material, the duration of the process to be treated is between 1 minute and 5 hours. The duration of time, in turn, depends on the nature of the process material and the desired result of the treatment.

In the final step, the processed process material is now removed from the process area. The treated process material can now be further processed or consumed.

Particularly preferred is a method according to the invention, wherein the moisture and / or the density and / or the temperature of the process swath is measured in the upper and / or lower region of the process space. The determination of these parameters or the setting thereof is different for the respective process material and can be determined by a person skilled in the art in a simple manner. Furthermore, it is preferred according to the invention that, during the execution of the method, process swaths are at least partially derived from the upper region of the process chamber. This leads to the fact that the energy of the process can be guided within the process and thereby reduced. This leads to an energy-efficient process.

The subject matter of the present invention is thus an energy-saving method for the treatment of, in particular, foods with warm, moist air, which uses internally generated water vapor for moistening the process air and transports the process swaths solely by natural buoyancy.

The subject matter of the invention is a tunnel oven, the design of which saves energy by constructively minimizing and optimizing the air exchange between the oven and the surrounding area and, in addition, by using the steam in the steaming room 1 instead of externally generated steam 2.

The invention further provides a method with which energy is saved by, on the one hand in a windrowing space 1 instead of externally generated steam 2, the baking steams are used to recover the laden and in the other hand, the air exchange between the process space and the environment constructively minimized and is optimized in terms of control technology.

The energy saving succeeds according to the invention without additional effort for devices and energy for the transport of the baking steam, as the transport force of the buoyancy of the moist baking steam is used internally for baking space. This is possible because process swaths at the same temperature have only 75% of the dry air density.

The new and inventive idea of the present invention lies in the fact that it shapes the course of the movable baking surface in the baking tunnel of the tunnel oven by a moderate gradient so that the free, loose baking good does not slip on the one hand and the desired baking surface on the other hand. climatic and energy-saving effects are achieved. This is both new and inventive for the baking industry.

The tunnel oven according to the invention has a height difference between tunnel inlet and tunnel outlet. In a first embodiment (FIG. 2), the baking surface to the oven outlet shows a gradient. As a result, the baking flocks are guided freely convectively into the front part of the baking chamber or into a separate loading space upstream of the baking tunnel. The backwash recovered in this way replaces externally generated steam in baked goods with a need for steaming. This saves energy for baking. In a further embodiment (FIG. 3), the baking surface to the oven outlet shows a gradient. As a result, the baking flocks are freely convected in the back of the oven, where they are recovered to achieve technological effects. The air exchange of the baking chamber with the environment is minimized, thereby saving energy for baking.

The following examples illustrate the invention in more detail, without limiting the scope of the invention.

The tunnel oven is designed in different embodiments, as shown in FIGS. 2 to 4. A common inventive feature of the embodiments is a baking surface with a height difference between the tunnel inlet and the tunnel outlet.

In the first exemplary embodiment according to FIG. 2, the baking surface for the oven outlet shows a gradient, as a result of which the baking flocks are conveyed into the front part of the baking chamber inside the baking space and are used specifically for steaming in the steaming room 1 instead of externally generated steam 2. During loading and unloading operations, the baking puffs can be e.g. B. be prevented with curtains 8 at the unwanted exit from the oven. The first embodiment of the tunnel oven according to the invention is suitable for pastries with Beschwadungsbedarf such as baguettes, wheat bread and wheat cookies 9. FIG. 3 shows a further embodiment of a tunnel oven according to the invention. For baked goods which, like wheat and rye mix bread, require a dry baking chamber climate for the formation of pastry-typical properties for a short time after being soaked, the presented transport principle is used in a variation of the embodiment according to FIG. In this variation, the pastry is passed through a separate Beschwadungsraum, then on a ventilated transport route and only then in the baking tunnel. The baking puffs are taken from the back of the baking tunnel, guided parallel to the transport route and then introduced into the upstream steaming room. The Fül treatment of separate Beschwadungsraums with baking steam is done as well as in the other embodiments free convection.

In a further embodiment, which is shown in Figure 4, the baking surface to the furnace outlet shows a slope, whereby the baking swirls are promoted due to their buoyancy internally in the back of the baking chamber and recovered there to achieve technological effects. This embodiment of the tunnel oven according to the invention is particularly suitable for laked or whipped types of biscuits as well as for certain fine baked goods and frozen bakery products 10, for which a smooth, shiny pastry surface or a cohesive, non-chipping pastry crust is desired.

The tunnel oven according to the invention creates the condition for fol lowing control concept for energy and quality optimization during baking.

In the first embodiment, as shown in FIG. 2, a first control circuit controls that the rear part of the baking chamber is protected against the ingress of air from the environment and at the same time the baking oven is supplied with baking steam. It consists of an air humidity sensor 4 and a throttle valve 5, which regulates the escape of the baking steam from the baking chamber into the wind chimney 3. The flap is closed at the start of production and opens when the setpoint is exceeded later. There is a second control circuit consisting of an air humidity sensor 6 and a steam valve 7 for externally generated steam. The second control circuit regulates the humidity required for the pastry. Above all, the steam valve opens to fill the steam room with steam at the start of production and later if it falls below the setpoint.

In the further embodiment of the tunnel oven according to the invention, as shown in Figure 3, controls a single control circuit that the front part of the oven is protected against air intake from the environment and that at the same time the rear of the tunnel oven with the desired humidity from baking steam is supplied. It consists of a humidity sensor 4 and a throttle valve 5, which regulates the escape of the baking steam from the baking chamber into the windrower 3. The

Damper is closed at the beginning of the production and opens on later exceeding of the nominal value.

The advantages of the method and the devices according to the invention are to use internally generated steam instead of externally generated steam for humidifying the process air and to promote the humidified process air within the process space energy-saving to the place of technological need. The natural convection of the moist, warm air is used, which results from the different density of moist and dry air. Process swaths are directed within a process space in such a way that the optimum treatment conditions which are required for the respective process material can be achieved in a technologically simple manner.

LIST OF REFERENCE NUMBERS

1 steam room

2 supply line for externally generated steam

3 windcheater

4 humidity sensor at the rear

5 throttle

6 humidity sensor front

7 steam valve

8 curtain

9 types of pastries requiring steaming

10 types of pastry without the need for steaming

Claims

claims

1. A process for the hydrothermal treatment, in particular of foodstuffs with moist, warm air, wherein the following steps are carried out in succession:

a) providing the processed goods to be treated, in particular food;

b) providing a process space for introducing the processed goods to be treated and for discharging the processed process goods, the process space having an upper and a lower area;

c) loading the process room with moist, warm air in the form of process puffs;

d) setting a density gradient of the process swaths using free convection, the density of the process swaths in the upper area of the process area being smaller than the density of the process swaths in the lower area of the process area;

e) bringing the process goods to be treated into one of the areas of the process area;

(f) transferring the processed goods from one area to the other, the time taken for the management of the processed products to be treated being between 1 and 5 hours;

g) Application of the now treated process materials from the process area.

2. Method according to claim 1, characterized in that the process goods are water-containing process goods.

3. The method according to claim 1 or 2, characterized in that measuring the moisture and / or the density and / or the temperature of the process swath in the upper and / or lower region of the process space.

4. The method according to any one of the preceding claims, characterized in that during the implementation of the Process at least partially derived from the upper area of the process space.

5. The method according to at least one of the preceding claims, characterized in that one introduces the process material to be treated in the upper region of the process space, the process material from the upper region in the lower region of the process space leads and the treated process material from the lower region of the Process space.

6. The method according to any one of claims 1 to 4, characterized in that one introduces the process material to be treated in the lower region of the process space, the process material from the lower area leads into the upper area of the process space and the treated process material at the top of the process chamber.

7. The method according to claim 1, wherein the process space has at least one entry area for introducing the process items to be treated and / or at least one exit area for dispensing the processed process items and / or at least one movable carrier for the process goods, preferably in the form of a conveyor belt, and / or at least one device for introducing steam into the process space and / or at least one device for diverting the process swath from the process space and / or at least one device for spatially vertical separation a portion of the process space has.

8. The method according to at least one of the preceding claims, characterized in that the process space has the shape of a tunnel baking oven or a baking chamber.

9. tunnel oven, for performing a method according to at least one of the preceding claims, wherein the baking surface has a difference in height between the tunnel inlet and tunnel outlet.

10. Tunnel baking oven, according to claim 9, characterized in that the baking surface between the oven inlet and the oven outlet has a slope at an angle of 0.5 to 4.0 degrees, preferably from 0.7 to 2.0 degrees or that the baking surface between the kiln inlet and the kiln outlet has a slope at an angle of 0.5 to 4.0 degrees, preferably from 0.7 to 2.0 degrees.

11. Tunnel oven according to one of the preceding claims,

characterized in that the baking flocks taken at the oven inlet the baking chamber, out of the oven and fed to the baking tunnel upstream, separate Beschwadungsraum are fed freely convection.

12. tunnel oven according to one of the preceding claims,

characterized in that the baking chamber has at least one device for the controlled introduction of externally generated steam into the baking chamber.

13. tunnel oven, according to one of the preceding claims,

characterized in that the baking space has at least one device for the controlled discharge of baking steam from the baking space and / or has at least one device for controlling the free-convective flow of steam inside the baking space.

14. tunnel oven according to one of the preceding claims,

characterized in that the baking chamber has at least one device for measuring and regulating the humidity and / or has at least one device for measuring and regulating the pressure.

15. baking chamber, for performing a method according to any one of claims 1 to 8, wherein baking chamber at least one Be heating device of the baking chamber and at least one device for loading the interior of the baking chamber with moist, warm air and / or for discharging the moist, warm air and a device for receiving the process material, characterized in that the baking chamber inside at least one Vorrich- device for guiding the process material through the interior of the baking chamber and that optionally has inside the baking chamber at least one device for guiding the heating device through the interior of the baking chamber.