EP3194655B1 - Sealing strip system for a suction roll - Google Patents

Description

The invention relates to sealing strip systems for suction rolls.

A suction roll, which is used for dewatering web material, for example in paper machines, has a roll shell provided with openings and at least one suction box inside. The suction box is fixedly mounted inside the suction roll, with the roll shell provided with holes rotating around the suction box. In order to seal the suction box against the roll shell, it has sealing strips on the side, which seal the interior of the suction box against the remaining volume of the suction roll, specifically in the longitudinal direction of the suction roll. In the circumferential direction of the suction roll, the suction box is delimited at both ends by size limiters and sealed off from the roll shell.

Particular challenges in the construction and operation of suction rolls are the wear and tear of the sealing strips and the generation of noise after the sealing strips.

From the EP 0943729 B1 a sealing strip is known which is pressed by a loading element in the form of a pressure hose against the inner wall of the suction roll as long as the vacuum is built up in the suction box. During operation, the sealing strip is moved slightly away from the inner wall of the suction roll by a restoring element, also in the form of a pressure hose, so that a defined, adjustable sealing gap results. To reduce noise, it is provided that the gap between the sealing strip and the inner wall slowly widens when viewed in the running direction.

From the EP 1348805 B1 it is known to design a sealing strip with a variable sealing gap, the gap being adjusted via a strip which is height-adjustable by means of a pressure hose and which is articulated to the rear end of the sealing strip.

the EP 1344865 B1 shows a suction roll in which the inside of the suction roll in the area behind the rear sealing strip of the A microphone is attached to the suction box. If the measured sound level exceeds a limit value, countermeasures are initiated, which can consist of changing the distance between the sealing strip and the inner wall and / or changing the opening angle of the gap between the suction strip and the inner wall.

From the DE 102012213544 A1 it is known to seal a suction box laterally by a sealing strip system against the roll shell of a suction roll and to assign a device for introducing lubricating water to each sealing strip system.

From the WO 2013174573 A1 It is known to provide a plurality of electrical conductors in the form of a ribbon cable in the sealing strip, which extends over the entire length of the sealing strip in order to monitor the wear of the sealing strip. The individual conductors are embedded in the sealing strip to different depths, so that if the sealing strip is worn, they are severed one after the other. The disadvantage is that only the maximum value of the wear is known and uneven wear of the sealing strip is not recognizable.

From the DE 102005048054 A1 it is known to regulate the contact pressure of the adjusting device of the sealing strip in such a way that the entire contact pressure is kept constant. The entire contact pressure is made up of the contact pressure of the adjusting device of the sealing strip and a component generated by the vacuum inside the suction box, which acts on the sealing strip through the holes in the suction roller.

From the DE 102007027688 A1 it is known to integrate several temperature sensors into the sealing strip, which are arranged along the longitudinal extent of the sealing strip, that is, in the transverse direction of the paper machine. When a limit temperature is reached, the distance between the sealing strip and the roll shell is increased. It is also provided that the negative pressure inside the suction box is monitored. If the vacuum decreases, the sealing strip is moved again in the direction of the inner wall. Subsequently, the distance or the contact pressure or contact pressure is the Sealing strip regulated in the area between the threshold value of the temperature and the threshold value of the pressure drop. The disadvantage is that it can happen that a stable operating state occurs only slowly or not at all, or that if a threshold value cannot be reached without violating the second threshold value, no suitable countermeasures can be taken. The distance between the temperature sensors of the DE 102007027688 A1 the surface of the sealing strip facing the roll shell must be so high that it is still integrated in the material of the sealing strip until the maximum permissible wear is reached.

The object of the present invention is an improved arrangement of the temperature sensors in the interior of the sealing strip. This results in a use for the optimized dewatering of web material. To achieve the object, a sealing strip system according to claim 1 and a use according to claim 12 are proposed.

As an improvement according to the invention, it is proposed to integrate several temperature sensors into the sealing strip, these temperature sensors being inserted or integrated into the sealing strip at different depths. It is particularly advantageous that the temperature sensors can also be used for wear monitoring or measurement. This happens because the temperature sensors break as soon as they are no longer protected by the material of the sealing strip and wear out on the suction roll.

Preferably, a plurality of such temperature sensors, which are attached offset from one another in depth, are always combined in a sensor unit, with a plurality of such sensor units preferably being attached, distributed over the longitudinal direction of the sealing strip. As a result, the local temperature profile in the sealing strip and the local wear in the sealing strip can be monitored, or these data can be transmitted to a control or regulation.

A device in which the sealing strip system according to the invention can be used consists of a suction roll, in the inside of which a suction box is attached, which is laterally limited by sealing strips. Each sealing strip is preferably assigned a lubricating water supply, which, viewed in the running direction, introduces lubricating fluid in front of the sealing strip in the direction of the inside of the perforated casing of the suction roll. Each sealing strip preferably has at least one actuator, by means of which the contact pressure of the sealing strip on the inner lateral surface of the suction roll can be changed. The second, rear sealing strip, seen in the running direction, preferably additionally has a second actuator by means of which the opening angle of the gap between the sealing strip and the suction roll shell can be changed. The second, rear sealing strip, seen in the running direction, has an electroacoustic transducer, which is preferably integrated into the holder of the sealing strip and is thus protected from moisture. Provision is preferably made for the data from the sensors to be processed in a miniserver and the actuators to be controlled by the miniserver. A miniserver is a miniaturized data processing system with input and output modules and options for digital communication, in particular for wireless communication with input and output devices and other data processing systems in a network.

The temperature of the sealing strip is preferably measured for the optimized use of lubricating liquid and the use of lubricating water or the amount of lubricating water is controlled or regulated as a function of the measured temperature. For this purpose, the temperature can be measured at one or more points on the sealing strip and the amount of lubricating water introduced over the length of the sealing strip can be uniformly high in every area of the sealing strip.

If the temperature of the sealing strip is measured in several areas of the sealing strip, a local temperature profile can also be recorded in the sealing strip. The amount of lubricant introduced can advantageously be controlled or regulated separately in individual areas of the longitudinal course of the sealing strip, so that in the event of local heat generation in the sealing strip, lubricating water is only introduced in the affected area.

Since the heat in the sealing strip is created by friction on the inner surface of the suction roll and the lubricating water reduces this friction, the exact amount of lubricating water required can be introduced, which is necessary to keep the friction and thus the wear low.

For the method just described, it is necessary to detect the temperature of the sealing strip, as close as possible to the surface with which the sealing strip rubs against the inner surface of the suction roll.

It is known from the prior art to regulate the position or the contact pressure of the sealing strip as a function of the sealing strip temperature and the pressure inside the suction box.

It is preferably proposed to regulate the position or the contact pressure of the sealing strip only as a function of the pressure inside the suction box. The use of lubricants can be regulated by recording the temperature. The advantage of this is that the actuator for changing the contact pressure of the sealing strip can be made simpler, since the force exerted by the actuator can be constant over the length of the strip and there is no need to apply a negative force through the actuator, which results in a reduction in the contact pressure has to exert on the sealing strip. In addition, no clamping device is required to fix the sealing strip, which is used in other suction rolls known from the prior art in order to fix the sealing strip at a defined distance from the roll shell. In addition, the risk of non-permissible operating conditions is reduced, since an increased temperature or friction is eliminated by using lubricating water and not by changing the contact pressure, which leads to a reduction in the vacuum. In the known method according to the prior art, however, it is necessary to maintain a certain "contact pressure reserve", since otherwise it would not be possible to compensate for a temperature increase without the vacuum being weakened.

The preferred regulation means that the contact pressure of the sealing strip is regulated to this minimum, which is necessary in order to maintain the vacuum at a specified / specifiable level. In this operating state, the minimum wear required for the respective vacuum or the minimum wear that can be achieved for the respective other operating parameters of the suction roll occurs, since the wear depends on the friction and thus on the contact pressure. If this minimum wear that can be achieved is too high for any reason such as unfavorable operating parameters, contamination or a malfunction, the friction is reduced through the use of lubricating water. An additional benefit of the lubricating water is that dirt such as paper fibers can be removed from the sealing strip.

As an improvement over the prior art, the spray tube is preferably integrated into the sealing strip holder. As a result, the lubricating water can be brought in very close to the friction surface, i.e. the surface with which the sealing strip rubs on the roller shell, and the space requirement can be reduced compared to a spray pipe mounted in front of the sealing strip holder. Compared to a lubricating water system which is integrated into the sealing strip, there are the advantages that the friction surface is not reduced by the openings in the lubricating water supply and that the sealing strip has a simpler structure. A flow sensor is preferably present in the spray pipe or in the line leading to the spray pipe, which is in data connection with the mini server in order to monitor the amount of spray water used in real time. The flow rate is regulated or controlled by the miniserver, for example by adjusting a valve.

It is particularly advantageous if the method just described is implemented with the aid of a sealing strip with the temperature sensors described above with wear detection, since the temperature is always measured very close to the surface on which the friction occurs and can thus be responded to very quickly even to the slightest temperature rises can. In addition, If individually controllable lubricating water nozzles are used, or several individually controllable spray pipes are used per sealing strip system, the lubricating water is only introduced into the area in which a local temperature rise is measured.

A preferred aspect relates to minimizing the noise level caused on the sealing strip. The sometimes very loud noise occurs when the jacket of the suction roll coming from the vacuum in the suction box, passes the second sealing strip and the vacuum in the openings in the roll jacket suddenly collapses. This sudden ventilation is counteracted according to the prior art in that the noise is reduced by gradually opening the gap between the sealing strip and the jacket of the suction roll. From the EP 1344865 B1 it is known to monitor the noise level and to take countermeasures if a threshold value is exceeded. It is preferable to measure the noise level and to regulate it to a minimum by adjusting the opening angle of the gap. The advantage of this is that the lowest possible noise level for the respective operating parameters is achieved in this way.

To form a preferred adjustment mechanism for the opening angle of the gap, which is improved over the prior art, is based on the EP 1348805 B1 Proposed to achieve the adjustment of the position of the rear end of the sealing strip not via a pressure hose, but by a motor, in particular a stepper motor or servo motor, which serves a bar, which has at least one inclined surface and is arranged below the sealing strip, in the longitudinal direction to move the sealing strip so that the height of the sealing strip can be adjusted along the inclined surface. It is advantageous that the gap can be adjusted very precisely via the motor and there is no need for clamping elements and / or stops, as are required for a pressure hose design. This preferred adjustment mechanism is therefore simpler and more exact compared to the prior art, using the position information of the stepper motor, the position of the rear end of the sealing strip can be determined at any time.

The preferred combined control method for all sub-areas includes measuring the temperature in the sealing strips, measuring the vacuum in the suction box, measuring the sound level after the second sealing strip, regulating the contact pressure of the sealing strips, regulating the amount of lubricating water and regulating the opening angle of the second sealing strip, with the contact pressure being the Sealing strips is regulated to the minimum value that is necessary to keep the vacuum in the suction box at a predefinable value, the amount of lubricating water per sealing strip is regulated depending on the temperature of the sealing strip and the opening angle of the second sealing strip is regulated in order to keep the sound level to a minimum .

Fig. 1:

Zeigt den Aufbau einer erfindungsgemäßen Dichtleiste mit erfindungsgemäßen Temperatursensoren mit Verschleißerkennung.

Fig. 2:

zeigt schematisch ein beispielhaftes erfindungsgemäßes Dichtleistensystem.

Fig. 3:

zeigt schematisch ein beispielhaftes erfindungsgemäßes Dichtleistensystem in geräuschminimierender Ausführung.

Fig. 4:

Zeigt schematisch eine besonders bevorzugte erfindungsgemäße Dichtvorrichtung einer Saugwalze.

The invention is illustrated with the aid of drawings:

Fig. 1:

Shows the structure of a sealing strip according to the invention with temperature sensors according to the invention with wear detection.

Fig. 2:

shows schematically an exemplary sealing strip system according to the invention.

Fig. 3:

shows schematically an exemplary sealing strip system according to the invention in a noise-minimizing design.

Fig. 4:

Shows schematically a particularly preferred sealing device according to the invention of a suction roll.

In Fig. 1 the sealing strip according to the invention 1.1, 2.1 is shown with integrated temperature sensors 6.1. In this particularly preferred embodiment variant, several sensor units 6 are integrated in the sealing strip 1.1, 2.1, each sensor unit 6 having four temperature sensors 6.1. With regard to the upper surface, that is to say the friction or friction surface of the sealing strip 1.1, 2.1, the temperature sensors 6.1 have different distances. The distance between two consecutive temperature sensors 6.1 is 2 mm, for example. The sensor units consist of a circuit board 6.4, temperature sensors 6.1, a microchip 6.2 with an integrated radio module and a power supply using a battery 6.3. By placing the sealing strip 1.1, 2.1 on the rotating roll shell 3, there is friction and, as a result, a rise in temperature on the sealing strip 1.1, 2.1. This change in temperature causes a change in resistance at the temperature sensors 6.1 positioned on the circuit board 6.4, the temperature being determined by the programmed microchip 6.2 from the voltage change caused thereby. If a temperature sensor 6.1 is looped through, i.e. destroyed, the signal is interrupted. As a result, the microchip 6.2 is able to calculate the exact wear on the sealing strip by interrupting the signal from the individual temperature sensors 6.1.

A mini server with a radio module is positioned outside the suction roll and receives the data from the sensor units 6 via radio. The miniserver is preferably connected to a network and the data can be visualized via an output device such as a computer, tablet computer, laptop or mobile phone.

The sealing strip 1.1, 2.1 has at least one sensor unit 6, preferably the sealing strip 1.1, 2.1 has several sensor units 6 in order to be able to measure the temperature at several points on the sealing strip 1.1, 2.1.

In Fig. 2 a sealing strip system 1 according to the invention is shown, which is preferably used as the first sealing strip system 1 of a suction box 4, viewed in the direction of movement of the roller jacket 3. The sealing strip system 1 consists of a sealing strip 1.1 which is movably received in the groove of the sealing strip holder 1.2. In the groove below the sealing strip 1.1 there is an adjusting hose 1.3 designed as a pressure hose. In front of the sealing strip 1.1, the sealing strip holder 1.2 is provided with a lubricating water system which has spray nozzles 1.4 via which the lubricating water is preferably conveyed through Spray tube 1.5 integrated into the sealing strip holder 1.2 is introduced. At least one sensor unit 6 is preferably integrated or inserted into the sealing strip 1.1. The contact pressure with which the sealing strip 1.1 is pressed against the inside of the roll shell 3 can be changed via the pressure in the contact hose 1.3.

In Fig. 3 a sealing strip system 2 according to the invention is shown, which is preferably used as a second sealing strip system 2 of a suction box 4, viewed in the direction of movement of the suction roll. The sealing strip system 2 consists of a sealing strip 2.1 which has a web along the lower front edge which is movably received in the groove of the sealing strip holder 2.2. An adjusting hose 2.3 is located in the groove below the web of the sealing strip 2.1. In front of the sealing strip 2.1, the sealing strip holder 2.2 is provided with a lubricating water system which has spray nozzles 2.4 via which the lubricating water is introduced through a spray pipe 2.5 which is preferably integrated in the sealing strip holder 2.2. At least one sensor unit 6 is preferably integrated or inserted into the sealing strip 2.1. The contact pressure with which the sealing strip 2.1 is pressed in the front area against the inside of the roll shell 3 can be changed via the pressure in the contact hose 2.3. The sealing strip 2.1 has a curved upper surface so that the upper surface rests against the roll shell 3 in its front region and forms a gradually increasing gap with the roll shell 3 in the rear region. The width of this gap can be adjusted by a height-adjustable strip 2.7, which can move the rear end of the sealing strip 2.1 closer to the roll shell 3 or away from it. The height-adjustable strip 2.7 is guided along an upwardly sloping groove of a strip 2.6 which can be displaced in the longitudinal direction of the sealing strip 2.1. The displaceable strip 2.6 can be designed as a slide which is displaced in the groove of the sealing strip holder 2.2 by an adjusting spindle driven by the motor. One Longitudinal displacement of the displaceable bar 2.6 leads to the height-adjustable bar 2.7 being displaced upwards along the groove. It is also conceivable to make the bar 2.6 fixed and to adjust the height of the height-adjustable bar 2.7 along the groove by longitudinally displacing it. Since there are many possibilities to convert the rotational movement of a stepping motor into a linear movement of an actuator, it should be generally stated that the distance from the rear end of the sealing strip 2.1 to the roll shell 3 can be changed by a motor and can be kept in the respective position.

In the sealing strip holder 2.2, a symbolically represented sound sensor 7 or a pickup is preferably attached, which is used to measure the noise level on or after the sealing strip 2.1. The preferred regulation method provides that the opening angle of the gap between the sealing strip 2.1 and the roll shell 3 is regulated in such a way that the noise level is reduced to a minimum.

As a generalization, it can be stated that instead of the pressure hoses 1.3, 2.3, other adjustment devices known from the prior art can also be used on the sealing strip 1.1 and the front area of the sealing strip 2.1. For example, clamping devices can be present in addition to the pressure hoses in order to fix the sealing strip in its position temporarily or after a stable, optimal operating state has been reached. In addition, as from the EP 0943729 B1 It is known to have an additional pressure hose which acts on the sealing strip in the opposite direction to the first pressure hose (adjustment hose) in order to be able to "pull" it away from the roll shell.

It is preferably also possible to provide an adjustment mechanism for adjusting the sealing strip 1.1 and the front area of the sealing strip 2.1, as is used in the rear area of the sealing strip 2.1. There is no need to use an adjusting hose. Since, in contrast to the rear area of the sealing strip 2.1, the front area and the Sealing strip 1.1 can be brought into contact with the roll shell 3, it is necessary to make the contact pressure controllable or regulatable. The contact pressure can be regulated by a controllable holding torque of the motor, or it can be regulated indirectly by a resilient element which is located between the actuating element and the sealing strip. If the sealing strip is already in contact with the roll shell, a further adjustment of the actuator via the resilient element can exert an increasing force with increasing deformation of the resilient element, with which the sealing strip is pressed against the roll shell. It is advantageous that the actuator can also be positioned in such a way that there is a narrow gap between the sealing strip and the roll shell.

In Fig. 4 the structure of a suction box 4 with two sealing strip systems 1, 2 according to the invention is shown schematically. The direction of movement of the roll shell 3 is indicated by an arrow. The front first sealing strip system 1 as seen in the direction of movement is according to FIG Fig. 2 executed, the rear second sealing strip system 2 seen in the direction of movement is according to Fig. 3 executed. As in Fig. 4 The two sealing strip systems 1, 2 can be seen to form the lateral delimitation of the suction box 4. In the interior of the suction box 4, there is thus an area 4.1 that is sealed off from the rest of the interior of the suction roll.

As shown symbolically, a pressure sensor 5 for measuring the negative pressure or vacuum in the sealed area 4.1 is located inside the suction box 4. Alternatively, the negative pressure in the suction box 4 can also be determined in or by the vacuum pump, which is used to generate the vacuum in the sealed area 4.1.

The first sealing strip system 1 has a temperature sensor system 16 for determining the temperature of the sealing strip 1.1, which is preferably implemented as a plurality of sensor units 6 according to FIG Fig. 1 is executed.

The second sealing strip system 2 has a temperature sensor system 26 for determining the temperature of the sealing strip 2.1, which is preferably implemented as a plurality of sensor units 6 integrated into the sealing strip 2.1 according to FIG Fig. 1 is executed. The second sealing strip system 2 also has a sensor for recording noise, which is preferably designed as a sound sensor 7 integrated in the sealing strip holder 2.2.

The first sealing strip system 1 has an adjustment mechanism for changing the position of the sealing strip 1.1, which preferably comprises an adjusting hose 1.3. The setting pressure of the sealing strip 1.1 and / or the distance between the sealing strip 1.1 and the roll shell 3 can be controlled and / or regulated via the adjustment mechanism. The first sealing strip system 1 has a lubricating water supply, the amount of lubricating water introduced being controllable and / or regulatable. The lubricating water supply is preferably designed as a spray tube 1.5 integrated in the sealing strip holder 1.2.

The second sealing strip system 2 has an adjustment mechanism for changing the position of the front area of the sealing strip 2.1, which preferably comprises an adjusting hose 2.3. The adjustment pressure of the front area of the sealing strip 2.1 and / or the distance between the front area of the sealing strip 2.1 and the roll shell 3 can be controlled and / or regulated via the adjustment mechanism. The second sealing strip system 2 has a second adjustment mechanism for changing the position of the rear area of the sealing strip 2.1, which preferably comprises a stepper motor. The opening angle between the rear area of the sealing strip 2.1 and the roll shell 3 can be controlled and / or regulated via the second adjustment mechanism.

The second sealing strip system 2 has a lubricating water supply, the amount of lubricating water introduced being controllable and / or regulatable. The lubricating water supply is preferably designed as a spray pipe 2.5 integrated in the sealing strip holder 2.2.

The preferred control method consists in a first variant in the detection of the negative pressure or vacuum in the suction box 4, the contact pressure or the distance to the roll shell 3 of the first sealing strip 1.1 and the contact pressure or the distance to the roll shell 3 of the front area of the second sealing strip 2.1 are regulated in such a way that the minimum contact pressure or that maximum distance is set which is permissible to maintain the vacuum in the interior of the suction box 4 at the desired level. The contact pressure or the distance can be varied jointly for both sealing strips 1.1, 2.1, for example by applying the same pressure to the pressure hoses 1.3, 2.3.

What is particularly advantageous about this preferred control method is that the energy requirement of the roller is minimized, since the vacuum is maintained with a minimal contact pressure, which results in high savings.

It is also conceivable to regulate the contact pressure or the distance separately for both sealing strips 1.1, 2.1, if necessary using definable additional control rules, for example by pressing the more heavily worn strip less than the even less worn strip.

In the first variant of the control method, a temperature sensor system 16, 26 for detecting the sealing strip temperature of each sealing strip 1.1, 2.1 is preferably also present. The amount of lubricating water used for sealing strip 1.1 is controlled or regulated as a function of the measured values of the temperature sensor system 16 and the amount of lubricating water used for sealing strip 2.1 is controlled or regulated as a function of the measured values of the temperature sensor system 26. The regulation of the amount of lubricant as a function of the temperature of the sealing strip 1.1, 2.1 can also be used or advantageous without the aforementioned regulation of the contact pressure.

What is particularly advantageous about this preferred control or regulation method is that the water requirement is minimized and This means that significantly less water is used than with conventional spray pipes.

As an extension of the first variant, the second variant of the preferred regulation also measures the noise level after or on the second sealing strip system 2 and, depending on the measured value, the distance between the rear area of the sealing strip 2.1 and the roll shell 3 and thus the opening angle of the gap between the sealing strip 2.1 and Roller shell 3 regulated, so that there is a minimum noise level. This method can also be used advantageously separately from the method described above, since the noise generation on conventional sealing strips can be up to 110 dBA and can therefore be hazardous to health. The constant noise optimization reduces this potential risk and also advantageously creates a working environment that is as quiet as possible and therefore pleasant.

The opening angle of the gap can advantageously also be regulated or controlled in such a way that the frequency of the noise is changed, in particular towards lower frequencies. Since the possible disruptive effect of a noise is generally significantly increased by its tonality, which must be taken into account when forming an assessment level by adding a tonality bonus to the measurement result, the opening angle of the gap can advantageously also be regulated or controlled in such a way that the frequency of the noise is changed according to predetermined patterns or stochastically in order to reduce the tonality.

Since a paper machine usually has a large number of suction rolls, the regulation or control of the noise emissions of all suction rolls is preferably carried out by a central data processing system, in particular a mini server, in order to prevent the noise emissions from two or more suction rolls from reaching a maximum in the same frequency range at the same time to have. Provision is preferably made for all measured values of all sensors to be transmitted to a mini server, preferably wirelessly, in which the Rules and regulations are stored, which can optionally be changed by a program or a user. The miniserver uses the measured values to determine the correcting variables required to control the actuators. The miniserver is preferably connected to a display and input device, in particular wirelessly, in order to display the operating parameters or to allow manual changes.

What is particularly advantageous about the particularly preferred embodiment of the present invention is that the intelligent system for controlling all essential parameters within a suction roll, which is centrally monitored, preferably by a mini server and can be changed either by the system or by the user depending on one another, is as energy-efficient and as possible ensures quiet operation and enables preventive maintenance. The system is based on components equipped with sensors such as sealing strip, pressure hose, sealing strip holder and spray tube, which preferably provide constant information about the process that cannot be viewed and / or controlled from the outside, preferably via radio / WLAN, and thus provide information about the operating status of the Suction roll.

Claims (15)

1. A sealing ledge system for use as intended in a suction roll for dewatering sheet material, wherein the sealing ledge system (1, 2) is used to laterally seal at least one suction box (4) on the inside of the suction roll and comprises at least one sealing ledge (1.1, 2.1), wherein the sealing ledge (1.1, 2.1) is designed to seal off the suction box (4) from the roll shell (3) of the suction roll and the sealing ledge (1.1, 2.1) has a surface which faces the inner side of the roll shell (3) when the sealing ledge system (1, 2) is used in the suction roll, wherein at least two temperature sensors (6.1) are included or inserted in at least one sealing ledge (1.1, 2.1),

   characterised in that

   at least one temperature sensor (6.1) has a larger distance than the other(s) from that surface of the sealing ledge (1.1, 2.1) which faces the inside of the roll shell (3) when used as intended.
2. The sealing ledge system of claim 1, characterised in that at least one sensor unit (6) is included or inserted in at least one sealing ledge (1.1, 2.1), wherein said sensor unit (6) comprises a circuit board (6.4) having at least two, preferably at least four, temperature sensors (6.1), wherein each temperature sensor (6.1) has a distance from that surface of the sealing ledge (1.1, 2.1) which faces the roll shell (3) when used as intended that is different from that of the other temperature sensors (6.1) of the sensor unit (6).
3. The sealing ledge system of claim 2, characterised in that each sensor unit (6) comprises a power supply, preferably a battery (6.3), and a microchip (6.2) having a radio module.
4. The sealing ledge system of any one of claims 1 to 3, characterised in that the sealing ledge system (1, 2) comprises sealing ledge holders (1.2, 2.2), wherein each sealing ledge (1.1, 2.1) is inserted into a sealing ledge holder (1.2, 2.2), wherein at least one spray pipe (1.5, 2.5) is included in at least one sealing ledge holder (1.2, 2.2), wherein openings in the sealing ledge holder (1.2, 2.2), preferably having jets (1.4, 2.4) arranged therein, extend from the spray pipe (1.5, 2.5) to an outer side of the sealing ledge holder (1.2, 2.2).
5. The sealing ledge system of any one of claims 1 to 4, characterised in that the sealing ledge system comprises sealing ledge holders (1.2, 2.2), wherein each sealing ledge (1.1, 2.1) is inserted into a sealing ledge holder (1.2, 2.2), wherein at least one adjusting member, via which the distance of the sealing ledge (1.1, 2.1) from the roll shell (3) is adjustable when used as intended, is present in at least one sealing ledge holder (1.2, 2.2), wherein the position of the adjusting member can be adjusted, and a desired position thereof maintained via a motor.
6. The sealing ledge system of claim 5, characterised in that the adjusting member comprises a member slidable in a longitudinal direction of the sealing ledge (1.1, 2.1) which has at least one oblique surface, wherein the sealing ledge (1.1, 2.1) or a height-adjustable member connected to the sealing ledge (1.1, 2.1) is guided along said oblique surface.
7. The sealing ledge system of any one of claims 5 and 6, characterised in that the sealing ledge (2.1) has a first section and a second section, wherein the adjusting member acts upon the second section of the sealing ledge (2.1), so that the distance of the second section of the sealing ledge (2.1) from the roll shell (3) can be adjusted so as to be different from the first section of the sealing ledge (2.1) when used as intended.
8. The sealing ledge system of claim 7, characterised in that the adjustment pressure on the roll shell (3) of the first section of the sealing ledge (2.1) can be adjusted using an adjustment tube (2.3) when used as intended.
9. The sealing ledge system of claim 7, characterised in that an adjusting member, via which the distance of the first section of the sealing ledge (2.1) from the roll shell (3) can be adjusted, is also present in the first section of the sealing ledge (2.1), wherein the position of the adjusting member can be adjusted, and a desired position thereof maintained, via a motor.
10. The sealing ledge system of any one of claims 5 to 9, characterised in that a spring-elastic member is mounted between the sealing ledge (1.1, 2.1) and the adjusting member.
11. The sealing ledge system of any one of claims 4 to 10, characterised in that an acoustic sensor (7) is included in or mounted on the sealing ledge holder (2.2).
12. Use of a suction roll having the sealing ledge system of any one of claims 1 to 11 for dewatering sheet material, characterised in that a device for introducing lubrication water is associated with at least one sealing ledge (1.1, 2.1), wherein the amount of lubrication water introduced is regulated or controlled depending on the temperature of the respective sealing ledge (1.1, 2.1), which is measured by at least one temperature sensor (6.1).
13. The use of claim 12, characterised in that the negative pressure inside the suction box (4) is recorded as the current pressure and the adjustment pressure of the sealing ledges (1.1, 2.1), or the distance of the sealing ledges (1.1, 2.1) from the roll shell (3) is regulated or controlled depending on the current pressure.
14. The use of any one of claims 12 to 13, characterised in that the wear of the sealing ledges (1.1, 2.1) is recorded or monitored during operation by detecting signal disruptions by the temperature sensor (6.1) as the wear progresses.
15. The use of any one of claims 12 to 14, characterised in that the noise level is recorded after or at the rear, second sealing ledge system (2) as seen in the direction of movement of the roll shell (3), and the opening angle of the gap between the rear area of the sealing ledge (2.11) and the roll shell (3) is regulated or controlled depending on the recorded noise level.

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