WO2019101520A1 - Method, device and computer program product for controlling and/or regulating a process air system - Google Patents

Abstract

In a method for controlling and/or regulating a process air system of a drying hood (12), which is assigned to a drying cylinder (14), of a machine for producing a fibrous web, feed air is fed to a wet part (18) and a dry part (22) of the drying hood via a respective feed air actuating element (20, 24) of a duct system (16), and exhaust air is discharged from the wet part and the dry part via a respective exhaust air actuating element (26, 28) of the duct system. Here, the prevailing intermediate space pressure is determined in the intermediate space between the drying cylinder and the wet part and in the intermediate space between the drying cylinder and the dry part in each case by means of at least one pressure sensor (400, 420), the respective measured intermediate space pressure is fed to a control and/or regulating device (34), and the respective intermediate space pressure is regulated automatically by means of the control and/or regulating device via a corresponding actuation of the respective feed air actuating element and/or the respective exhaust air actuating element, in such a way that the intermediate space pressure lies within a predefined value range. As an alternative or in addition, the intermediate space temperature is measured in the intermediate space between the drying cylinder and the wet part and in the intermediate space between the drying cylinder and the dry part in each case by means of at least one temperature sensor (40, 42), the respective measured intermediate space temperature is fed to a control and/or regulating device, and the respective intermediate space temperature is regulated automatically by means of the control and/or regulating device via a corresponding actuation of the respective feed air actuating element and/or the respective exhaust air actuating element, in such a way that the intermediate space temperature is kept in a temperature range between 50°C and 250°C. Devices and a computer program product for carrying out said methods are also specified.

Description

 METHOD, DEVICE AND COMPUTER PROGRAM PRODUCT FOR ESTABLISHING AND / OR CONTROLLING A PROCESS AIR SYSTEM

The invention relates to a method for controlling and / or regulating a process air system of a dryer hood, in particular a machine-glazed (MG) smooth and / or Yankee cylinder, associated dryer hood of a machine for producing a fibrous web, in particular paper , Carton or tissue web, in which a wet part and a dry part of the dryer hood via a respective Zuluftstellelement a duct system supply air supplied and discharged from the wet part and the dry part via a respective Abluftstellelement the Kanal system exhaust air. The invention further relates to a device for carrying out the method and to a computer program product for controlling and / or regulating a process air system

Paper production requires a relatively large amount of energy in the drying process. From an energetic point of view, air conditioning optimization is aimed at by keeping the energy used for drying as far as possible in the process. As a rule, heat recovery of the hood supply air takes place for heat recovery and, in particular in the case of Yankee hoods, also preheating of combustion air. In addition, heating the production halls with waste heat is the rule.

In addition, part of the circulating air has to be removed from the process air system of the drying hood of a tissue machine or of a MG smoothing and / or Yankee cylinder in order to keep the air humidity in the system at a constant level. This can be done via a controlled supply of supplementary air and with gas-heated dry hoods combustion air. The respective amounts of Extract air and supplementary air are provided via air dampers in the system

Air dampers usually have an electric or pneumatic actuator. Sensors installed on the dryer hood or in the gap between the Yankee cylinder and the dryer hood, e.g. Temperature and pressure sensors, etc., indicate whether the dryer hood blows hot air into the hall or draws cold air from the hall. The aim is to balance the two halves of the bonnet with the highest possible hood exhaust air humidity, i. at neutral air pressure so that no hot process air escapes into the hall at the gap between the Yankee cylinder and the dry hood and no cold indoor air is sucked into the dryer hood.

In the hitherto conventional methods and devices of the type mentioned above is particularly disadvantageous that the respective settings for a respective energetically optimal operation must be made manually.

The invention has for its object to provide a method and an apparatus of the type mentioned in which guaranteed in terms of energetically optimal operation of the dryer hood automatic control of the process air system of the dryer hood in the simplest and most reliable way and thus even with each change in production car - matic always optimal operation of the dryer hood is maintained.

According to the invention, this object is achieved in each case by a method having the features of claim 1, a method having the features of claim 3 or a device having the features of claim 9, or a device having the features of claim 10 and a computer program product according to FIG the features of claim 15 solved.

Preferred embodiments of the method according to the invention as well as preferred embodiments of the device according to the invention emerge from the subclaims, the present description and the drawing. In the various methods of the invention Ste

geln a process air system of a drying cylinder, in particular a MG smoothing and / or Yankee, associated dryer hood of a machine for producing a fibrous web, in particular paper, cardboard or Tissu- ebahn, each a wet part and a dry part of the dryer hood over a each air circuit supplied with hot air ("circulating air") and each air circuit is supplied via a respective Zuluftstellelement a duct system supply air and / or discharged via a respective Abluftstellelement exhaust air. In this case, a respective supply air actuating element can in particular be a supply air flap and, in the case of a respective exhaust air control element, in particular an exhaust air flap.

 In addition, a gap is provided between the drying cylinder and the wet part and the dry part in each case.

According to a first aspect of the invention, the method in question for controlling and / or regulating the process air system is characterized in that in the intermediate space of the wet part and / or in the intermediate space of the dry part by means of at least one pressure sensor, the prevailing inter-space pressure (pZ ), the respectively measured inter-space pressure (pZ) fed to a control and / or regulating device and the respective inter-space pressure (pZ) by means of the control and / or regulating device in particular via a corresponding control of the respective Zuluftstellelements and / or each exhaust air control element is automatically controlled so that the inter-space pressure (pZ) is within a predetermined range of values.

Because of this embodiment of the method, it can be achieved that the intermediate space pressure p _z always lies in a predetermined range without, as hitherto, the pressure having to be corrected by manually opening and closing flaps. As a result, staff costs can be reduced and, in addition, process stability and uniformity can be increased. In particular, it is possible for the clearance pressure (p _z ) to be so

in an interval of +/- 10 kPa, preferably of +/- 5 kPa, more preferably +/- 1 Pa around the ambient pressure.

A space pressure (p _z ), which is approximately in the range of the ambient pressure, offers great advantages for the process.

If the interspace pressure (p _z ) is higher than the ambient pressure, the hot circulating air flows from the respective wet or dry part of the drying hood into the environment, since the space between the drying hood and the drying cylinder, which is hot Convection is filled, usually not sealed against the environment. With the outflow of hot air into the environment but the process air system is lost a large amount of energy. This energy must then be returned to the air cycle, which is associated with additional costs. In addition, this is also ergonomically advantageous because the operating personnel in the vicinity of the drying cylinder is not burdened by the outflowing hot air.

On the other hand, if the intermediate pressure (p _z ) is lower than the ambient pressure, the colder ambient air is sucked into the process air system. As a result, the circulating air is cooled in the air circuit and then has to be heated, which again leads to higher costs.

The optimum state is therefore a gap pressure which corresponds approximately to the ambient pressure, since neither hot air is lost to the environment, nor cold ambient air is sucked in, and thereby the least energy must be supplied to the individual air circuits.

According to a second aspect of the invention, the relevant method for controlling and / or regulating the process air system is characterized in that in the intermediate space of the wet part and / or in the intermediate space of the dry part in each case by means of at least one temperature sensor, the interspace temperature (T _z ) measured, the respective measured gap temperature

and / or control device (34) is supplied and the respective interspace temperature (T _z ) by means of the control and / or regulating device in particular via a corresponding control of the respective Zuluftstellelements and / or the respective Abluftstellelements is automatically controlled so that the respective gap - Temperature (T _z ) in a temperature range between 50 ° C and 250 ° C, in particular in a temperature range between 100 ° C and 200 ° C, is maintained.

This second aspect solves the same problem as the first aspect with the same inventive idea, namely to replace the manual setting of the actuators by an automation based on readings from the gap. Thus, there are also the same advantages as described above.

Advantageously, it can be provided that the measurement of the respective interspace temperature (T _z ) takes place at a distance of less than 100 cm, preferably less than 50 cm, particularly preferably 20 cm or less, from a guide side and / or drive side edge of the intermediate space ,

This embodiment is advantageous because the inter-space temperature (T _z ) in the vicinity of the edge changes greatly depending on the inter-space pressure (p _z ).

Usually the temperature of the hot circulating air is very high. It is often between 300 ° C and 500 ° C.

 The temperature of the environment is much lower, and usually - depending on the quality of the hall ventilation - between 20 ° C and 50 ° C.

If the inter-space pressure (p _z ) is above the ambient pressure, as described above, hot circulating air flows from the intermediate space into the environment. This happens inter alia via the driver side and / or drive side edge of Gap. Thus, this hot air flows to the ang

past a high temperature of i.d.R. > 300 ° c.

If the inter-space pressure (p _z ) is below the ambient pressure, ambient air is drawn in again via the edge, among other things, and the temperature sensors attached there show a low temperature, generally <50 ° C.

If the intermediate pressure (p _z ) and the ambient pressure are approximately the same, there is no - or only very little - exchange of air between the space and the environment. The temperature in the edge area will then be set in an intermediate range, which is usually between 50 ° C and 250 ° C, in particular between 100 ° C and 200 ° C.

In this respect, the same invention idea is again realized by the second aspect of the invention, as achieved by the first, namely by reducing or preventing the exchange of air, a reduction in the energy requirement.

In further preferred embodiments of the method, the temperature measurement can be carried out by using at least one temperature sensor installed in the insulation of the drying hood.

It may be advantageous that for controlling the respective interstitial temperature (T _z) at a measured respectively at low interstitial temperature (T _z) and the respective Zuluftstellelement automatically opened (at a measured respectively to high clearance temperature T _z ) the respective Zuluftstellelement is automatically throttled.

In this case, according to a preferred practical embodiment of the method according to the invention for measuring the respective gap Temperature (T _z ) in the intermediate space of the wet part and / or the

several, in particular four, temperature sensors used, being used as the measured value in each case the sensor value with the highest temperature.

 These multiple sensors may, for example, be arranged along the circumferential direction of the drying cylinder. In this way it can be checked at various points whether air escapes from the intermediate space or is sucked in. By choosing the highest measured value as the temperature value, it is ensured that the control already becomes active when hot air escapes at least at one point. A likewise possible variant of the method, in which the lowest measured temperature is selected, or an average value or the median leads to a different behavior of the control, which, however, may also be advantageous.

Furthermore, it may be advantageous that the channel system comprises a common supply air supply channel to the Zuluftstellelementen, which is supplied with a supply air blower with supply air and in which at least one supply air pressure sensor is provided, wherein by means of at least one Zuluft- Pressure sensor measured values supplied to a control and / or regulating device and the applied pressure is influenced by the control and / or regulating device in particular via a corresponding control of the Zuluftgebläses and is kept in particular constant. This possibility can be used advantageously both for methods according to the first aspect and the second aspect of the invention.

If, as a result of a control intervention, one of the two feed elements opens, and as a result supply air increasingly flows into one of the two air circuits, a pressure drop can occur in the common supply air feed channel. In turn, this can lead to unplanned supply of fresh air flowing through the other of the two delivery elements into the other air circulation, where the flow conditions are disturbed. By using a pressure measurement in common seed supply air supply channel connected to a control of Z

this disadvantage can be avoided.

In the methods according to the various aspects of the invention, preference is often given to using only the supply air control elements or only the exhaust air control elements in the control or regulation. However, there may also be cases in which both types of control elements are addressed.

 Thus, for example, it can happen that an air supply control element is completely closed and still there is an overpressure in the associated interspace, which is indicated by the pressure sensors or by the temperature sensors as "high temperature". In that case, the exhaust air release element can be opened further in order to move the sensor values back into the desired range.

 Similarly, there may be occurrences that a Zuluftstellelement is fully open, but still prevails in the space oppression. In this case, can be further controlled via an at least partial closing of the exhaust element.

The various devices according to the invention for controlling and / or regulating a process air system of a dryer hood, in particular a MG smoothing and / or Yankee cylinder, associated dryer hood of a machine for Fierstellung a fibrous web, in particular paper, cardboard or Tissu- ebahn include each

a duct system with one air circuit each for supplying a wet part and a dry part with hot air.

 In addition, the duct system comprises a supply air control element associated with the wet part of the dryer hood and a supply air control element which is assigned to the dry part of the dryer hood and via which supply air can be supplied to the respective air circuit,

and / or the channel system comprises an exhaust air actuating element assigned to the wet part of the drying hood and / or a dry part of the drying hood associated exhaust air control element, via the jewe

 Exhaust air is discharged.

 In addition, the elements of the drying hood are positioned so that a gap is provided between the drying cylinder and the wet part and the dry part.

The size of the gap in the devices of the various aspects of the invention may vary depending on the design. Often it will be between 10mm and 50mm, preferably between 20mm and 30mm.

The various devices according to the invention are in each case particularly suitable for carrying out the respective method according to the invention.

In principle, any combination of the various methods according to the two aspects of the invention may also be provided.

According to the first aspect of the invention, the relevant device for controlling and / or regulating the process air system is characterized in that at least one pressure sensor is provided for measuring the intermediate pressure (p _z ) of the wet part and / or the dry part. The respective pressure sensor is connected to a control and / or regulating device and the control and / or regulating device is set up such that the intermediate pressure (p _z ) by means of a corresponding control of the respective Zuluftstel- lel element and / or the respective Abluftstellelements so it can be regulated that the respective inter-space pressure (p _z ) is or can be kept within a predetermined value range.

According to the second aspect of the invention, the relevant device for controlling and / or regulating the process air system is characterized in that in each case at least one temperature sensor (40 or 42) is provided for measuring the intermediate pressure. space temperature (T _z ) of the wet part and / or the Trock

is. The respective temperature sensor is connected to a control and / or regulating device, and the control and / or regulating device is set up so that the respective interspace temperature (T _z ) with a corresponding control of the respective Zuluftstellelements and / or of the respective Abluftstel lelements is regulated so that the respective interspace temperature (T _z ) in a temperature range between 50 ° C and 250 ° C, preferably in a temperature range between 100 ° C and 200 ° C, can be maintained.

Preference is given to the measurement of the respective

for measuring the respective interspace temperature (T _z ) of the wet part and / or the dry part in each case a plurality, in particular four, temperature sensors are provided.

Furthermore, it may be advantageously provided that in each case at least one temperature sensor is provided for measuring the respec conditions interspace temperature (TZ), in the insulation of the drying hood, in particular the

Nässeils and / or the dry part is installed.

In a further preferred embodiment, it can be provided

at least one, preferably all, temperature sensors are provided at a distance of less than 100 cm, preferably less than 50 cm, particularly preferably 20 cm or less, from a driver-side and / or drive-side edge of the intermediate space and thus also of the wet or dry part ,

It should be noted that the connection of the pressure and / or temperature sensors to a control and / or regulating device can take place in various ways. Advantageously, this connection can take place wirelessly, or via cables, in particular via high-temperature cables, which are especially suitable for the temperature conditions in the environment of a drying hood. For a device according to both the first and the second}

 The invention may advantageously be provided that the channel system comprises a common supply air supply to the Zuluftstellelementen, wherein in this supply air supply channel at least one supply air pressure sensor is provided and / or at least one supply air blower is provided to the common air supply Supply supply with supply air.

The Zuluftstellelemente or flaps and Abluftstellelemente or flaps nen can be provided, for example, with electric and / or pneumatic actuators.

In principle, any combination of the various devices according to the two aspects of the invention can also be provided. The control and / or regulating device will usually comprise or consist of a computer.

With regard to the computer program product, the object is achieved by a computer program product which, when executed on the computer of a control and / or regulating device of a device according to one of claims 9 to 14, controls and / or regulates a process air system according to one of claims 1 to 8 causes.

Because of the solutions according to the invention, the two hood halves of the dryer hood can be balanced with the hood exhaust air humidity being as high as possible and, in particular, driven with neutral air pressure so that no hot process air enters the hall at the gap between the MG smoothing and / or Yankee cylinder and the dryer hood outlet and no cold indoor air is sucked into the dryer hood. The relevant control elements no longer have to be dogged. be changed, but are now according to the invention au

provides.

The invention will be explained in more detail below on the basis of exemplary embodiments with reference to the drawing; in this show:

1 is a schematic representation of an exemplary embodiment of an apparatus for controlling and / or regulating a process air system of a drying hood according to one aspect of the invention,

1 shows a schematic representation of an exemplary embodiment of a device 10 for controlling and / or regulating a process air system of a drying hood 12 according to an aspect of the invention.

Thereafter, the device 10 for controlling and / or regulating a process air system comprises a drying cylinder 14, in particular a MG smoothing and / or Yankee cylinder 14, associated dryer hood 12 of a machine for producing a fibrous web, in particular paper, cardboard or Tissuebahn, a channel system 16 with an air circuit 180 for supplying a Nässeils 18 and an air circuit 220 for supplying a dry part 22 with hot air. Advantageously, as also shown in Figure 1, in each of the air circuits 180, 220 there is a respective blower 36, 38, e.g. Compressor or fan 36, 38 provided, and a burner 44, 46. With suitable burners 44, 46, the circulating air can be heated to temperatures between 300 ° C and 500 ° C.

In addition, the channel system 16 comprises a wet part 18 of the dryer hood 12 associated Zuluftstellelement 20 and the dry part 22 of the dryer hood 12 associated Zuluftstellelement 24 via the respective air circuit 180, 220 supply air can be fed The channel system 16 in Figure 1 also includes a nasal

hood 12 associated Abluftstellelement 26 and a dry part 22 of the drying hood 12 associated Abluftstellelement 28 via the from the respective air circuit 180, 220 exhaust air can be discharged.

The wet end 18 and the dry part 22 of the dryer hood 12 are arranged so that between you and the drying cylinder 14, a gap 60, 62 is gebil det. This gap 60, 62 is often 20 mm, but it may also be larger or smaller, preferably between 10 mm and 50 mm.

 In the embodiment according to FIG. 1, sensors 40, 400, 42, 420 are provided both in the wet part 18 and in the dry part 22. This may, as described in the first aspect of the invention, be pressure sensors 400, 420. Alternatively, they may also be temperature sensors 40, 42, as described in the second aspect. It can also be quite possible that pressure sensors 400, 420, as well as temperature sensors 40, 42 are used in the drying hood.

 The sensors 40, 400, 42, 420 are connected to a control and / or regulating device 34, for example via high-temperature cables or other suitable connections. This control and / or regulating device 34 is usually installed on a computer or includes this. Such a computer usually has a suitable computer program product installed in accordance with an aspect of the invention.

 Although only one sensor 40, 400, 42, 420 per part of the drying hood 12 is shown in FIG. 1, it should be noted that in advantageous installations, several, e.g. 2 or 4, pressure and / or temperature sensors per part of the drying hood 12 may be provided. These can be arranged, for example, along the circumferential direction of the drying cylinder 14.

The control and / or regulating device 34 is designed so that it can control some or all adjusting elements 20, 24, 26, 28, so that they can be automatically opened and / or closed. The supply air to the two Zuluftstellelementen 20, 24 is here sannen supply air supply channel 32 to the Zuluftstellelementen 20, 24 out. An air blower 52 supplies the common supply air supply channel 32, and thus the entire duct system 16 with supply air.

It may be provided in advantageous embodiments that this supply air after the supply air fan 52 and before the Zuluftstellelementen 20, 24 is still heated. This can happen through a heat exchanger (not shown in FIG. 1). It is particularly advantageous if the energy for heating this supply air is wholly or partly taken from the exhaust air which is removed from the air circuits 180, 220 by the exhaust air control elements 26, 28. In many installations, this exhaust air has a temperature of 150 ° C to 300 ° C, often 200 ° C +/- 25 ° C.

LIST OF REFERENCES

10 device

 12 drying hood

 14 drying cylinders

 16 channel system

 18 wet part

 20 Zuluftstellelement

 22 dry part

 24 supply air actuator

 26 exhaust air actuator

 28 exhaust air actuator

 30 supply air pressure sensor

 32 Supply air supply channel

 34 control and / or regulating device

36 hot air blower

 38 hot air blower

 40 temperature sensor

 42 temperature sensor

 44 burners

 46 burners

 50 exhaust fan

 52 supply fan

 60, 62 interspace

180, 220 air circulation

400, 420 pressure sensor

Tz supply air temperature

Claims

 claims 1. A method for controlling and / or regulating a process air system of a drying cylinder (14), in particular a MG smoothing and / or Yankee cylinder, associated drying hood (12) of a machine for producing a fibrous web, in particular paper, Carton or tissue web, in which a wet part (18) and a dry part (22) of the drying hood (12) via a respective air circuit (180, 220) are supplied with hot air and each ment circuit (180, 220) via a respective Zuluftstellele element (20 or 24) of a duct system (16) supply air supplied and / or exhaust air is discharged via a respective Abluftstellelement (26 or 28) between the drying cylinder (14) and the wet part (18) and the dry part (22) a gap (60, 62) is provided and wherein in the intermediate space (60) of the wet part (18) and / or in the intermediate space (62) of the dry part (22) in each case by means of at least one pressure sensor (400, 420) of the prevailing gap pressure (p _z ) besti mmt, the respectively measured interspace pressure (p _z ) is fed to a control and / or regulating device (34) and the respective interspace pressure (p _z ) is supplied by means of the control and / or regulating device (34), in particular via a corresponding activation of the respective supply air control element (20 or 24) and / or of the respective exhaust air control element (26 or 28) is automatically controlled such that the inter-cylinder pressure (p _z ) is within a predetermined value range. 2. The method according to claim 1,  Thereby, the gap pressure (pz) is controlled or controlled so as to be within an interval of +/- 10 kPa, preferably +/- 5 kPa, more preferably +/- 1 Pa, around the ambient pressure. 3. A method for controlling and / or regulating a process air system of a drying cylinder (14), in particular a MG-smoothing and / or Yankee, associated drying hood (12) of a machine for producing a fibrous web, in particular paper, cardboard or tissue web, in which a wet part (18) and a drying part (22) of the drying hood (12) are supplied with hot air via a respective air circuit (180, 220) and wherein each air circuit (180, 220) via a respective Zuluftstellele- element (20 or 24) of a duct system (16) supply air supplied and / or exhaust air is discharged via a respective Abluftstellelement (26 or 28), in particular according to at least one of the preceding claims, wherein between the drying cylinder (14) and the wet part (18) and the drying part (22), a gap (60, 62) is provided and wherein in the intermediate space (60) of the wet part (18) and / or in the intermediate space (62) of the dry part (22) measured by means of at least one temperature sensor (40 or 42), the interspace temperature (T _z ), the respective measured interspace temperature (T _z ) of a control and / or regulating geleinrichtung (34) supplied and the respective that for controlling the respective interspace temperature (T _z ) at a respectively measured low interspace temperature (T _z ), the respective supply air control element (20 or 24) is automatically opened and at a respectively measured interspace temperature ( T _z ) the respective Zuluftstellelement (20 or 24) is throttled automatically. By means of the control and / or regulating device (34), in particular via a corresponding control of the respective Zuluftstellelements (20 or 24) and / or the respective Abluftstellele- ment (26 or 28) is automatically regulated so that d space temperature (T _z ) in a temperature range between 50 ° C and 250 ° C, in particular in a temperature range between 100 ° C and 200 ° C, is maintained. 4. The method according to claim 3, characterized in that the measurement of the respec conditions interspace temperature (T _z ) at a distance of less than 100cm, preferably less than 50cm, more preferably 20cm or less of a driver side and / or drive side edge of the intermediate space (60 , 62). 5. The method according to claim 3 or 4, characterized in that at least one temperature sensor (40 or 42) installed in the insulation of the drying hood (12) is used to measure the respective interspace temperature (T _z ). 6. The method according to any one of claims 3 to 5, Characterized in that for controlling the respective gap temperature (T _z ) at a respectively low measured intermediate space temperature (T _z ), the respective Zuluftstellelement (20 bzw.24) automatically open and at a respectively too high measured Interspace temperature (T _z ) the respective Zuluftstellelement (20 or 24) is automatically throttled. 7. The method according to any one of claims 3 to 6, characterized in that for measuring the respective gap temperature (T _z ) in the intermediate space (60, 62) of the Naßils (18) and / or the dry part (22) each have several, in particular re four, temperature sensors (40, 42) is used, where _< because the sensor value is used with the highest temperature. 8. The method according to any one of claims 1 to 7,  characterized in that the channel system (16) comprises a common supply air supply channel (32) to the Zuluftstellelementen (20, 24), which is supplied with a Zuluftgebläse (52) with supply air and in which at least one supply air pressure sensor (30) wherein the values measured by means of the at least one supply air pressure sensor (30) are fed to a control and / or regulating device (34) and the applied pressure is supplied by the control and / or regulating device (34) in particular via a corresponding one Control of the supply air blower (52) is influenced and in particular is kept constant. 9. Device (10) for controlling and / or regulating a process air system of a drying cylinder (14), in particular a MG-smoothing and / or Yankee cylinder, associated drying hood (12) of a machine for producing a fibrous web, in particular paper, cardboard - or tissue web, in particular for carrying out the method according to one of claims 1 to 2, with a channel system (16) comprising  in each case an air circuit (180, 220) for supplying a wet part (18) and a dry part (22) with hot air and a Zuluftstellele- element (20) associated with the wet part (18) of the drying hood (12) and a Zuluftstellelement (24) associated with the drying part (22) of the drying hood (12), via which supply air can be supplied to the respective air circuit, and or an exhaust air control element (26) assigned to the wet part (18) of the dryer hood (12) and / or an exhaust air control element (28) associated with the dry part (22) of the dryer hood (12), via which exhaust air can be discharged from the respective air circuit is wherein between the drying cylinder (14) and the nose: an intermediate space (60, 62) is provided in the dry part (22) and in each case at least one pressure sensor (400 or 420) for measuring the interspace pressure (p _z ) of the wet part (18) and / or the dry part (22 ), the respective pressure sensor (400 or 420) is connected to a control and / or regulating device (34) and the control and / or regulating device (34) is set up such that the inter-space pressure (p _z ) by means of a corresponding control of the respective Zuluftstellele- element (20 or 24) and / or the respective Abluftstellelements (26 or 28) is controllable so that the respective gap pressure (p _z ) can be kept within a predetermined range of values. 10. Device (10) for controlling and / or regulating a process air system of a drying cylinder (14), in particular a MG-smoothing and / or Yankee cylinder, associated drying hood (12) of a machine for producing a fibrous web, in particular paper, cardboard - or tissue web, in particular for carrying out the method according to one of claims 3 to 8, with a channel system (16) comprising  in each case an air circuit (180, 220) for supplying a wet part (18) and a dry part (22) with hot air and  a Zuluftstellele element (20) associated with the wet part (18) of the drying hood (12) and a supply air actuating element (24) which is assigned to the drying section (22) of the drying hood (12) and via which supply air can be supplied to the respective air circuit; or an exhaust air control element (26) associated with the wet part (18) of the dryer hood (12) and / or an exhaust air control element (28) associated with the dry part (22) of the dryer hood (12), via which exhaust air can be discharged from the respective air circuit . wherein a gap (60, 62) is provided between the drying cylinder (14) and the wet part (18) and the drying part (22), and in each case at least one temperature sensor (40 or 42) for measuring the intermediate the temperature (T _z ) of the wet part (18) and / or (22) is provided, the respective temperature sensor (40 bzw.42) is connected to a control and / or regulating device (34) and the control and / or Control device (34) is arranged so that the respective inter-room temperature (T _z ) by means of a corresponding control of the respective Zuluftstellelements (20 bzw.24) and / or the respective Abluftstellstellelements (26 bzw.28) is so regulated in that the respective interspace temperature (T _z ) can be maintained in a temperature range between 50 ° C and 250 ° C, preferably in a temperature range between 100 ° C and 200 ° C. 11. The device according to claim 10, characterized in that a plurality of, in particular four, temperature sensors (40 or 42) are respectively provided for measuring the respective interspace temperature (T _z ) of the wet part (18) and / or the dry part (22). 12. Device according to claim 10 or 11, characterized in that for measuring the respec conditions interspace temperature (T _z ) in each case at least one in the insulation of T rockenhaube (14), in particular of the Naßtils (18) and / or the tail part (22) built-temperature sensor (40 or42) is provided. 13. Device according to one of claims 10 to 12, characterized in that at least one, preferably all temperature sensors (40, 42) at a distance of less than 100cm, preferably less than 50cm, more preferably 20cm or less of a leader side and / or drive side edge of the space ( 60, 62) are provided. 14. Device according to one of claims 9 to 13,  characterized in that the channel system (16) comprises a common supply air supply channel (32) to the Zuluftstellelementen (20, 24), wherein in this supply air supply channel (32) at least one air supply pressure sensor (30) is provided and / or at least one supply air blower (52) is provided to supply the common supply air supply channel (32) with air. 15. computer program product,  characterized in that when it is carried out on the computer of a control and / or regulating device of a device according to one of claims 9 to 14 thereby a control and / or regulation of a process air system according to one of claims 1 to 8 is effected ,