Hood adjustment assembly and method for adjusting the position of the hood on the dryer cylinder

Abstract

The present invention comprises a hood (11), a first gap sensor (21) and a second gap sensor (22), a hood gap adjuster (12), and a hood gap controller (30), The system receives a first input signal (S1) from the first gap sensor (21) and a second input signal (S2) from the second gap sensor (22). Determine whether the first criterion for the desired food gap is met, If the first criterion is not met, determine the desired adjustment of the hood (11), A hood gap controller (30) comprises a processing circuit (31) configured to generate a control signal (C) configured to cause a determined desired adjustment to be applied to a hood gap adjuster (12), The hood gap adjuster (12) is The processing circuit (31) receives the aforementioned control signal (C), The present invention relates to a hood adjustment assembly further configured to move a hood (11) to adjust a hood gap (hg) based on a control signal (C). The present invention also relates to a computerized method, a non-temporary computer-readable storage medium, and a method for manufacturing it.

Description

[Technical Field]

[0001] This invention relates to the field of paper manufacturing, and more particularly to the adjustment of a hood on a dryer cylinder for drying paper webs. [Background technology]

[0002] In the field of papermaking, pulp is used to form a paper web, which is then transported through a series of processing steps aimed at forming and dewatering the web for papermaking. Such paper may be any type of paper, such as tissue, paper, or cardboard.

[0003] Some processing steps involve drying the paper web on a dryer cylinder where the paper web is exposed to heat to remove moisture. In some applications, a hood may be positioned on the dryer cylinder and held at a desired hood gap that is large enough to prevent the hood from coming into contact with the paper web and causing damage or rupture. The purpose of the hood is to bring about further drying of the paper web by combining the heat from the dryer cylinder with a heat transfer medium, such as hot air, which is applied to the paper web within the hood.

[0004] One known issue is that the hood gap can change during paper machine operation, due to both the expansion of hood and dryer cylinder components when exposed to heat over long periods, and the accumulation of fibers from the paper web. While the hood gap is often kept large to ensure damage to the paper web is avoided, this makes drying less energy-efficient than desired.

[0005] Therefore, in order to avoid damage to the paper web while simultaneously improving energy efficiency, the operation of the hood for the dryer cylinder needs to be improved. [Overview of the project]

[0006] The object of the present invention is to resolve, or at least minimize, the above-mentioned problems. This is achieved by the hood adjustment assembly, hood adjustment system, computerized method for adjusting the position of a hood, and method for manufacturing the hood adjustment assembly as described in the appended independent claims.

[0007] The hood adjustment assembly includes a hood configured to connect to and mount a dryer cylinder, forming a hood gap between the dryer cylinder and the hood, the hood extending in a first direction from a first end to a second end. The hood adjustment assembly also includes a first gap sensor configured to measure or detect the width of the hood gap at a first position of the hood, and a second gap sensor configured to measure or detect the width of the hood gap at a second position of the hood. The hood adjustment assembly also includes a hood gap adjuster configured to adjust the hood gap by moving the hood relative to the dryer cylinder, and the hood gap controller includes a processing circuit. The processing circuit includes, A first input signal from a first gap sensor and a second input signal from a second gap sensor, the first input signal and the second input signal receiving the first input signal and the second input signal respectively indicate the hood gap measured or detected at a first position and a second position, Based at least on the aforementioned measured or detected food gap at the first location and the aforementioned measured or detected food gap at the second location, it is determined whether the first criterion for the desired food gap is met. If the first criterion is not met, determine the desired adjustments to the food. It is configured to generate a control signal configured to apply the determined desired adjustment to the hood gap adjuster.

[0008] Furthermore, the hood gap adjuster is configured to receive the aforementioned control signals from the processing circuit and move the hood to adjust the hood gap based on the aforementioned control signals.

[0009] Preferably, the first position of the hood is at the first end and the second position of the hood is at the second end. This allows the hood gap to be detected or measured at both ends, and the hood can be adjusted so that the position of the hood is favorable at both ends. It is particularly advantageous to prevent factors such as asymmetric accumulation of fibers on the hood from making the hood gap too small at one end of the hood gap assembly, as it is important to eliminate the risk of contact between the hood and the paper web. Also, measuring or detecting at both ends ensures that excessively large gaps, which are disadvantageous from an energy efficiency standpoint, are avoided.

[0010] In some embodiments, the first and second positions of the hood are instead located at the first end, and the first and second positions are separated from each other in a second direction perpendicular to the first direction. This allows the hood gap to be measured at two or more positions at the first end. If the hood gap is too small or too large at one of these positions, the hood can be adjusted accordingly.

[0011] Preferably, the hood adjustment assembly includes at least one additional gap sensor configured to measure or detect the width of the hood gap at an additional position of the hood, and the processing circuit includes, For each additional gap sensor, an additional input signal is received from the additional gap sensor indicating the measured or detected hood gap at an additional location. Based on the aforementioned measurements or detected hood gaps at additional locations, the system is configured to determine whether the first criterion for the desired hood gap is met.

[0012] This allows for the measurement or detection of hood gaps at various locations along the hood, enabling the determination of hood adjustments to ensure the hood is positioned favorably along its entire length.

[0013] In some embodiments, the hood gap adjuster comprises a first end gap adjuster configured to adjust the hood gap at a first end of the hood, and a second end gap adjuster configured to adjust the hood gap at a second end of the hood. The processing circuit then, The desired adjustments to the hood are determined as the first end adjustment and the second end adjustment. The control signals are configured to generate a first end control signal configured to apply a first end adjustment determined to a first end gap adjuster, and a second end control signal configured to apply a second end adjustment determined to a second end gap adjuster.

[0014] This allows for individual adjustment of the hood gap at each end of the hood. This is particularly advantageous because it enables the hood to be adjusted to a position that ensures a good fit across the dryer cylinder, and allows each end of the hood to be positioned in a highly beneficial location.

[0015] Preferably, the first gap sensor, the second gap sensor, and optionally the third gap sensor are also optical sensors. This provides a simple and reliable type of sensor that allows for direct measurement of the hood gap at each location. The optical sensors may be located on the hood, connected to the hood, or on a separate structure independent of the hood.

[0016] In some embodiments, the hood adjustment assembly includes a reference marking connected to the hood, and a first sensor, a second sensor, and optionally a third sensor are configured to measure or detect the width of the hood gap by detecting the reference marking. This allows the hood gap to be detected or measured by sensors located on the hood or directly on an extension component of the hood adjustment assembly or on a separate component. This reduces the risk of damage to the sensors or obstruction by fibers from the paper web, and ensures low-maintenance, stable, and reliable operation of the sensors.

[0017] Preferably, the hood gap adjuster also includes an adjuster configured to push the hood along the inclined guide in response to a control signal, with the hood resting on an inclined guide on which the hood rests. This allows the hood position to be adjusted in a reliable and easy manner with excellent control over the precise position of the hood, and very small adjustments can be made with great precision.

[0018] The present invention also encompasses a hood adjustment system comprising a first hood adjustment assembly according to the present invention, wherein the hood is a wet end hood for the dryer cylinder. The hood adjustment system also comprises a second hood adjustment assembly according to the present invention, wherein the hood is a dry end hood for the dryer cylinder. Thereafter, according to the present invention, both the wet end hood and the dry end hood for the dryer cylinder are adjusted to ensure that the hood gap is suitable for the drying operation of the paper web. This is advantageous when seeking to avoid both damage to the paper web during drying and excessive energy consumption due to a large hood gap. Thus, the system of the present invention ensures stable and efficient operation when drying paper webs.

[0019] The present invention also includes a computerized method for adjusting the position of a hood on a dryer cylinder, and this method In a processing circuit, receiving a first input signal from a first gap sensor and a second input signal from a second gap sensor, wherein the first input signal and the second input signal respectively indicate the measured or detected hood gaps at the first position and the second position of the dryer hood, and receiving; In a processing circuit, determining whether a first criterion for a desired hood gap is met based at least on the aforementioned measured or detected hood gap at the first position and the aforementioned measured or detected hood gap at the second position; In a processing circuit, determining a desired adjustment of the hood when the first criterion is not met; In a processing circuit, generating a control signal configured to apply the determined desired adjustment to a hood gap adjuster.

[0020] The method also preferably In a processing circuit, receiving an additional input signal from each of at least one additional gap sensor, wherein the additional input signal indicates the measured or detected hood gap at each additional position of the hood, and receiving; In a processing circuit, determining whether the first criterion for the desired hood gap is met based also on the aforementioned measured or detected hood gap at each additional position.

[0021] Also, the method In a processing circuit, determining the desired adjustment of the hood as a first end adjustment and a second end adjustment; In a processing circuit, generating the control signal as a first end control signal configured to apply the determined first end adjustment to a first end gap adjuster and as a second end control signal configured to apply the determined second end adjustment to a second end gap adjuster.

[0022] In some embodiments, a first criterion for a desired hood gap is that the determined hood gap exceeds a predetermined minimum hood gap. Thereby, by adjusting the hood gap adjuster so that the hood gap satisfies the first criterion, it is ensured that damage to the paper web due to contact between the hood and the paper web is avoided.

[0023] In other embodiments, a first criterion for a desired hood gap is that the determined hood gap is within a predetermined hood gap range. Thereby, by adjusting the hood gap adjuster so that the hood gap satisfies the first criterion, it is ensured that damage to the paper web due to contact between the hood and the paper web is avoided, and an overly large hood gap is avoided, thus ensuring energy efficiency.

[0024] In yet other embodiments, a first criterion for a desired hood gap is that the determined hood gap is smaller than a predetermined maximum hood gap. Thereby, by adjusting the hood gap adjuster so that the hood gap satisfies the first criterion, the process of drying the paper web between the dryer cylinder and the hood is energy efficient, and it is ensured that excessive energy use is avoided.

[0025] The present invention also, when executed by a processing circuit of a hood gap controller of a hood adjustment assembly for adjusting the position of a hood on a dryer cylinder, causes the hood adjustment assembly to In the processing circuit, receive a first input signal from a first gap sensor and a second input signal from a second gap sensor, the first input signal and the second input signal each indicating a measured or detected hood gap at a first position and a second position of the dryer hood, In the processing circuit, it is determined whether the first criterion for the desired hood gap is met, based at least on the aforementioned measured or detected hood gap at the first position and the aforementioned measured or detected hood gap at the second position. In the processing circuit, if the first criterion is not met, the desired adjustment of the hood is determined. The present invention relates to a non-temporary computer-readable storage medium for storing instructions that generate a control signal configured to apply a determined desired adjustment to a hood gap adjuster in a processing circuit.

[0026] Preferably, a non-temporary computer-readable storage medium further stores instructions, which, when executed by a processing circuit, cause the hood adjustment assembly to perform a method step of any embodiment of the present invention.

[0027] The present invention also includes a method for manufacturing a hood adjustment assembly. The method includes providing a hood suitable for connection to and mounting on a dryer cylinder to form a hood gap between the dryer cylinder and the hood, the hood extending in a first direction from a first end to a second end. The method also includes providing a first gap sensor configured to measure or detect the width of the hood gap at a first position of the hood, a second gap sensor configured to measure or detect the width of the hood gap at a second position of the hood, a hood gap adjuster configured to adjust the hood gap by moving the hood relative to the dryer cylinder, and a hood gap controller comprising a processing circuit. Furthermore, the processing circuit includes, A first input signal from a first gap sensor and a second input signal from a second gap sensor, the first input signal and the second input signal receiving the first input signal and the second input signal respectively indicate the hood gap measured or detected at a first position and a second position, Based at least on the aforementioned measured or detected food gap at the first location and the aforementioned measured or detected food gap at the second location, it is determined whether the first criterion for the desired food gap is met. If the first criterion is not met, determine the desired adjustments to the food. It is configured to generate a control signal that causes the hood gap adjuster to apply the determined desired adjustment, The hood gap adjuster is, The processing circuit receives the aforementioned control signal, The hood is further configured to move and adjust the hood gap based on the control signal.

[0028] Many further benefits and advantages of the present invention will be readily apparent to those skilled in the art, considering the detailed description below. [Brief explanation of the drawing]

[0029] [Figure 1] A plan view from the operating side of a hood adjustment system comprising two hood adjustment assemblies according to the present invention is disclosed. [Figure 2] A side view and plan view of the hood adjustment assembly are disclosed. [Figure 3a] A side view and plan view of a first embodiment of a sensor for a hood adjustment assembly is disclosed. [Figure 3b] The sensor shown in Figure 3a, along line BB, is disclosed. [Figure 4a] A side view and plan view of a second embodiment of the sensor for the hood adjustment assembly is disclosed. [Figure 4b] The sensor shown in Figure 4a, along line DD, is disclosed. [Figure 5a] A top view of a first embodiment of the hood of the hood adjustment assembly is disclosed. [Figure 5b] A top view of a second embodiment of the hood of the hood adjustment assembly is disclosed. [Figure 6a]A perspective view of the hood gap adjuster of the hood adjustment assembly is disclosed. [Figure 6b] A hood gap adjuster having a first guide and a first roll of the hood in a side view is schematically disclosed. [Figure 7] A controller for a hood adjustment assembly, operably connected to a sensor and a hood gap adjuster, is schematically disclosed. [Figure 8] The operation of the sensor, processing circuit, and hood gap adjuster of the hood adjustment assembly is schematically disclosed. [Figure 9] The steps of the method according to the first embodiment of the present invention are disclosed in general terms. [Figure 10] Other embodiments of this method are disclosed in general terms. [Modes for carrying out the invention]

[0030] Next, the present invention will be described in more detail with reference to the attached drawings.

[0031] All figures are schematic and not necessarily to scale, and generally show only the parts necessary to illustrate each embodiment, with other parts being omitted or merely suggested. Any reference numerals appearing in multiple drawings refer to the same object or feature throughout the drawings unless otherwise indicated.

[0032] The present invention relates to assemblies, systems, and methods for adjusting a hood in the drying process of a paper machine. The paper machine itself is not disclosed in detail and does not form part of the present invention. Rather, the present invention is suitable for use in any type of paper machine in which a dryer cylinder is used to dry a paper web and the dryer cylinder is arranged together with a hood. Typically, the hood is used to conserve the heat released from the dryer cylinder during operation and to circulate hot air to improve drying and reduce the moisture content of the paper web. The paper machine itself may be used to produce any type of paper, tissue, or cardboard. The dryer cylinder itself may be any type of dryer, such as a TAD (through-air dryer) cylinder or a Yankee cylinder.

[0033] As used herein, the term “operably connected” should be understood as a part of the invention being electronically connected (i.e., so that signals can be transmitted and / or received via wired or wireless connections) and / or so that motion or force can be transmitted from one part to the other.

[0034] As used herein, the term “operating side” refers to the side of the paper machine from which the paper machine is controlled, with the other side being referred to as the “driving side.”

[0035] The term "wet end" should be understood as the end of the paper web with a higher moisture content, while the term "dry end" refers to the end with a lower moisture content. Therefore, when two hoods are applied to a dryer cylinder, the paper web passes through the wet end hood before reaching the dry end hood.

[0036] Where various embodiments are described herein, it should be understood that features from any embodiment may be freely incorporated into any of the other embodiments, provided that they are technically feasible and such combination is not expressly stated to be inappropriate or undesirable.

[0037] Embodiments of hood adjustment assembly and hood adjustment system Figure 1 discloses a plan view from the operating side of a hood adjustment system 100 comprising two hood adjustment assemblies 10 according to a first embodiment of the present invention. Of the two hood adjustment assemblies 10, one is a wet end assembly W and the other is a dry end assembly D, but their features are similar or identical, and it should be understood that what is described below for any hood adjustment assembly 10 is applicable to both the wet end assembly W and the dry end assembly D. In any paper machine, the hood adjustment assembly 10 according to the present invention may be applied to only one hood or to both, and thus may form a system 100 of two hood adjustment assemblies 10.

[0038] Each hood adjustment assembly 10 comprises a hood 11 extending from a first end 11A to a second end 11B in a first direction D1, which is lateral, i.e., perpendicular to the direction of transport of the paper web (see Figure 5) when the hood 11 is attached to the paper machine. The hood 11 is configured to be attached to the dryer cylinder 200, as is well known in the art. Typically, the hood 11 is attached so as to at least partially cover the dryer cylinder 200, such that the paper web being transported on the dryer cylinder 200 is covered by the hood 11. A hood gap hg is formed between the hood 11 and the dryer cylinder 200.

[0039] The hood 11 is held at its first end 11A and second end 11B, respectively, by a first guide 14 and a second guide 15, the first guide 14 may be an inclined guide and the second guide 15 may be a horizontal guide. The purpose of the guides 14, 15 is typically to allow the hood 11 to rest on them by positioning the rolls 16, 17 of the hood 11 on the guides 14, 15 so that the hood 11 can slide on the guides 14, 15 when the hood 11 is adjusted or released. A hood gap adjuster 12 is positioned in conjunction with the first guide 14 so as to adjust the hood gap hg by moving the hood 11 by pushing the roll 16 along the first guide 14. This will be described in more detail below with reference to Figure 6. It is advantageous that the second guide 15 is a horizontal guide as it allows for secure holding of the hood.

[0040] Figure 2 more clearly discloses a hood adjustment assembly 10, showing a first gap sensor 21 configured to measure or detect the width of the hood gap hg at a first position P1 of the hood 11. The present invention also includes a second gap sensor 22 (see Figures 5a-5b) configured to measure or detect the width of the hood gap at a second position P2 of the hood 11. Additional sensors may be included, as will be further described below. Sensors 21, 22 are preferably optical sensors, but other types of sensors are also possible within the scope of the present invention.

[0041] Figures 3a to 3b disclose one embodiment of a first gap sensor 21 configured to directly measure or detect a hood gap hg, namely, the first gap sensor 21 is positioned on the hood 11 facing the dryer cylinder 200 and is positioned to detect or measure the distance from the first gap sensor 21 to the surface of the dryer cylinder 200. The first gap sensor 21 is shown with wires 32 providing a connection to a controller 30 and a processing circuit 31 contained therein, but alternatively, the connection between the first gap sensor 21 and the controller 30 can be wireless. Preferably, the first gap sensor 21 is positioned in a recess or notch within the hood 11 so that the first gap sensor 21 protrudes from the hood 11. In the embodiments of Figures 3a to 3b, the first gap sensor 21 is held so as to be coplanar with the surface 11C of the hood 11, but in other embodiments, the first gap sensor 21 can be held so that the distance from the first gap sensor 21 to the dryer cylinder 200 is greater than the hood gap hg. The heat insulating material 33 is preferably provided on the first gap sensor 21 to prevent heat from affecting the first sensor 21 and, in some cases, damaging the first sensor 21.

[0042] Figures 4a-4b disclose another embodiment of the first gap sensor 21, in which the first gap sensor 21 is instead held by a frame 34 so as to extend from the hood 11. This is advantageous in preventing damage to the first gap sensor 21 and also in preventing obstruction of the first gap sensor 21 by fibers from the paper web adhering to the sensor 21 during use. In Figures 4a-4b, the reference marking 220 is provided on a machine frame 210 having a surface that is connected to the hood 11 and has a reference marking 220 which may be related to the position of the dryer cylinder 200. In some embodiments, the first gap sensor 21 and the reference marking 220 are held coplanar with the surface of the hood 11 and the surface of the dryer cylinder 200, respectively, but in other embodiments they may be held in other positions, and the resulting hood gap hg may be determined by a processing circuit based on the hood gap hg measured or detected from the first gap sensor 21. In this embodiment, the positions of the first gap sensor 21 and the reference marking 220 may also be reversed, such that the first gap sensor 21 is located on the machine frame 210 and the reference marking 220 is located on the frame 34. One particular advantage of providing the first gap sensor 21 according to this embodiment is that it is easily accessible from outside the hood 11, thus facilitating maintenance and replacement of the first gap sensor 21.

[0043] The above description of the first gap sensor 21 is equally applicable to the second gap sensor 22 and any additional sensors 23 used in conjunction with the present invention. The sensors 21, 22, and 23 may be similar, identical, or different from one another, as long as they can be operably connected to the processing circuit 31 so as to be able to measure or detect the hood gap hg and transmit a signal indicating the measured or detected hood gap.

[0044] When the hood adjustment assembly 10 is used in a paper machine equipped with a dryer cylinder 200, the hood gap hg between the dryer cylinder 200 and the hood 11 must be large enough to allow the paper web to be transported on the dryer cylinder 200 without touching the hood 11, in order to avoid damage or breakage of the paper web. The hood gap hg should also not be excessively large, as this would make the energy efficiency of the hood 11 undesirably low, increasing energy consumption and thereby increasing the cost of paper production. Typically, the desired hood gap is a preset value or range, which may include a minimum hood gap to avoid damage to the paper, a maximum hood gap to avoid energy loss, or a range that includes both the minimum and maximum hood gaps. During use, the hood gap changes due to both the accumulation of fibers from the paper web on the dryer cylinder or hood, and the thermal expansion of the dryer cylinder and hood when used at high temperatures. Such thermal expansion increases from the start of the machine until it reaches maximum expansion, and is then maintained until the machine is stopped or the operating temperature changes. Based on the desired hood gap, a first criterion is determined (usually pre-set, but in some embodiments, based on operating parameters such as temperature and operating time and / or parameters of the hood and dryer cylinder itself). As long as the first criterion is met, i.e., as long as the detected or measured hood gap hg is within the range of the desired hood gap, above the minimum hood gap, or below the maximum hood gap, the first criterion is met and no adjustment of the hood 11 is necessary. If the first criterion is not met, adjustment of the hood is required to correct this.

[0045] Therefore, the present invention also includes a processing circuit 31 and a hood gap controller 30 (see FIG. 7) operably connected to sensors 21, 22 and hood gap adjuster 12. The processing circuit 31 is configured to receive a first input signal S1 from the first gap sensor 21 and a second input signal S2 from the second gap sensor 22, and the first and second input signals S1, S2 respectively represent the measured or detected hood gap hg at the first position P1 and the second position P2.

[0046] FIG. 5a discloses an embodiment in which the first gap sensor 21 and the second gap sensor 22 are provided at the first end 11A of the hood, that is, on the operating side of the hood adjustment assembly 10. The first position P1 and the second position P2 are separated from each other in a second direction D2 perpendicular to the first direction D1, that is, in the vertical direction when the hood adjustment assembly 10 is connected and attached to the dryer cylinder 200 of the paper machine.

[0047] By arranging the sensors 21, 22 at the same end of the hood 11, a reliable determination of the hood gap hg becomes possible, and a desired hood gap hg can be reliably obtained when adjusting the hood 11. Additional gap sensors 23 may be provided at both the first end 11A and the second end 11B. In some embodiments, the hood gap measured or detected by some or all of the additional gap sensors 23 is used to determine whether the first criterion is met. This will be further described below with reference to the method embodiments. The additional gap sensors 23 may be any suitable number of additional gap sensors 23 i , where 1 < i < N. FIGS. 5a - 5b show four additional gap sensors 231, 232, 233, 234 that measure or detect the hood gap hg at additional positions P3 given as P31, P32, P33, P34 in FIGS. 5a - 5b i , where 1 < i < N.

[0048] FIG. 5b discloses another embodiment in which the first gap sensor 21 is at the first end 11A and the second gap sensor 22 is at the second end 11B, such that the first gap sensor 21 and the second gap sensor 22 are provided at different ends of the hood 11. By providing the first and second sensors 21, 22 at different ends of the hood 11, the hood gap hg across the entire hood 11 is reliably determined, and adjustment of the hood 11 when the first criterion is not met reliably matches the hood gap to a desired hood gap. Similar to the embodiment of FIG. 5a, an additional gap sensor 23 i is provided at an additional position P3 i , where 1 < i < N.

[0049] In all embodiments of the present invention, an additional gap sensor 23 may be provided at a position between the first end 11A and the second end 11B to detect or measure the hood gap hg at various positions from the first end 11A to the second end 11B in the first direction D1.

[0050] Figure 6a more clearly discloses a hood gap adjuster 12 in one embodiment in which the adjuster 12C is provided in the form of a fork 12C coupled to the hood 11 such that the movement of the fork 12C results in a corresponding movement of the hood 11. Preferably, the fork 12C is coupled to a roll 16. In this embodiment, the adjuster 12C is coupled to an actuator 12D which has a hydraulic cylinder operably connected to the fork 12C by a rod 12G. In other embodiments, the actuator 12D may instead comprise an electric or pneumatic motor or pneumatic system, and other types of actuators 12D are also possible as long as they can move the fork 12C. The hood gap adjuster 12 is operably connected to a processing circuit 31 and is configured to receive a control signal C from the processing circuit 31 and move the hood 11 to adjust the hood gap hg based on this control signal C. This is achieved in the first embodiment by configuring the hood gap adjuster 12 to move adjuster 12C by extension or retraction of a hydraulic cylinder 12D so that the hood 11 is pushed along a first guide (see Figure 6b), thereby adjusting the hood gap hg. The actuator 12D (see also Figure 7) is preferably controlled by a control signal C from the processing circuit 31. The actuator preferably comprises an electric motor, a pneumatic motor, a hydraulic cylinder, or a pneumatic cylinder, as described above. Similar to the hood gap sensors 21, 22, and 23, the hood gap adjuster 12 may be operably connected to the processing circuit 31 by a wired or wireless connection. In other embodiments, adjuster 12C may be implemented in a manner other than as a fork, as long as the function of pushing the first roll 16 along the first guide 14 is achieved. The hood gap adjuster 12 also preferably comprises a mechanical stopper 12F that prevents the hood 11 from moving when the actuator 12D is not operating, i.e., when no further adjustment is being made.

[0051] Figure 6b shows a hood gap adjuster 12 having an adjuster 12C coupled to the first roll 16 for moving the first roll 16 along the first guide 14. The first guide 14 may be inclined as shown in Figure 6b, but alternatively, the first guide 14 may have horizontal and inclined portions that allow adjustment in both horizontal and vertical directions and allow opening of the hood for maintenance purposes. Preferably, the roll 16 is configured to be locked in place by the hood gap adjuster 12 when not being acted upon by the actuator 12D for moving the adjuster 12C. This lock is preferably achieved by a mechanical stopper 12F as described above. This prevents the hood 11 from falling onto the dryer cylinder 200 in the event of power loss or other malfunction of the hood adjustment assembly 10.

[0052] Figure 7 discloses a controller 30 of the hood adjustment assembly 10, and also shows a first gap sensor 21, a second gap sensor 22, and an optional additional gap sensor 23, which are operably connected to a processing circuit 31 of the controller 30 so that they can transmit signals S1, S2, S3 indicating the measured or detected hood gap. A gap adjuster 12 is also shown, to which the processing circuit can transmit a control signal C so that the actuator 12E of the gap adjuster 12 adjusts the position of the hood 11. In some embodiments, the processing circuit 31 transmits the control signal C directly to the gap adjuster 12, while in other embodiments, the processing circuit 31 is directly connected to the actuator 12E.

[0053] Therefore, the processing circuit 31 is configured to receive a first input signal S1 from the first gap sensor 21 and a second input signal S2 from the second gap sensor 22. Preferably, the processing circuit analyzes the hood gap detected or measured from each of the sensors 21 and 22 and determines whether a first criterion is met based on the measured or detected hood gap at a first position P1 and a second position P2. If the first criterion is met, no adjustment is necessary, and the processing circuit 31 waits for new signals from the sensors 21 and 22. However, if the first criterion is not met, the processing circuit 31 determines a desired adjustment of the hood 11 to a position where the first criterion is met. A control signal C is then generated, configured to cause the hood gap adjuster 12 to apply the determined desired adjustment. This control signal C is transmitted to the hood gap adjuster 12, which receives the control signal C and moves the hood 11 to adjust the hood gap hg based on the control signal C.

[0054] In some embodiments, the hood gap adjuster 12 comprises a first end gap adjuster 12A located at the first end 11A of the hood 11 and a second end gap adjuster 12B located at the second end 11B of the hood 11. The first and second end gap adjusters 12A, 12B are preferably similar or identical, but in some embodiments, they may differ in design or operation as long as they can satisfy the function of adjusting the hood 11 in response to a control signal C. In embodiments having the first and second gap adjusters 12A, 12B, the control signal C is generated as a first end control signal configured to apply a first end adjustment determined to the first end gap adjuster 12A and a second end control signal configured to apply a second end adjustment determined to the second end gap adjuster 12B. This is further described below in embodiments of the method.

[0055] In embodiments comprising at least one additional gap sensor 23, the processing circuit 31 is also configured to receive additional input signals from each additional gap sensor if the additional input signal indicates a measured or detected hood gap at an additional location, and to determine whether a first criterion for a desired hood gap is met, also based on the aforementioned measured or detected hood gap at the additional location.

[0056] In an embodiment comprising a first end gap adjuster 12A and a second end gap adjuster 12B, the processing circuit 31 is also configured to determine a desired adjustment of the hood as a first end adjustment and a second end adjustment, and to generate a control signal C as a first end control signal C1 configured to apply the first determined end adjustment to the first end gap adjuster 12A and a second end control signal C2 configured to apply the second determined end adjustment to the second end gap adjuster 12B.

[0057] Figure 8 discloses the operation of a hood adjustment assembly 10 in which a first gap sensor 21 measures or detects the width of the hood gap hg at a first position P1 of the hood 11 (301), and a second gap sensor 22 further measures or detects the width of the hood gap hg at a second position P2 of the hood 11 (302). A processing circuit 31 is configured to receive the measured or detected width of the hood gap hg from sensors 21, 22 303. The processing circuit 31 may then optionally analyze the measured or detected width of the hood gap hg and form a combined hood gap based on them. However, in some embodiments, the processing circuit may instead be configured to determine whether a first criterion is met without first analyzing the information received from the sensors.

[0058] The processing circuit 31 determines whether a first criterion is met based on at least one measurement or detected hood gap hg from sensors 21, 22 (305). If the first criterion is indeed met, the processing circuit 31 waits for a new signal from sensors 21, 22 corresponding to the detection or measurement of the width of the hood gap hg again. In some embodiments, sensors 21, 22 are configured to measure the hood gap hg at predetermined intervals, and in other embodiments, the hood gap hg may be measured continuously. In yet another embodiment, the processing circuit 31 may be operably connected to sensors 21, 22 so that measurements at sensors 21, 22 are performed only when requested by the processing circuit 31.

[0059] If the first criterion is not met, the processing circuit 31 determines a desired adjustment of the hood 11 (306). In embodiments where the hood gap adjusters 12 at both ends are not independent of each other, the processing circuit 31 determines one desired adjustment to be performed simultaneously at both ends of the hood 11. In embodiments where the first end gap adjuster 12A can function independently of the second end gap adjuster 12B, the processing circuit 31 may instead determine a first end adjustment and a second end adjustment for each of the first and second end gap adjusters 12A, 12B. The processing circuit 31 then generates a control signal C which may include a first end control signal C1 and a second end control signal C2 (307). The control signal C is then transmitted from the processing circuit 31.

[0060] The hood gap adjuster 12, or the first end gap adjuster 12A and the second end gap adjuster 12B, are configured to receive a control signal C from the processing circuit 31 (308) and to apply a desired adjustment to move the hood 11 based on the control signal C (309).

[0061] The hood adjustment system 100 is formed by two hood adjustment assemblies 10 according to any embodiment of the present invention, one of which is a first hood adjustment assembly W for the wet end and the other is a second hood adjustment assembly D for the dry end.

[0062] Computerized Method Embodiment Figure 9 discloses a first embodiment of the computerized method of the present invention. Step 401 includes receiving a first input signal S1 from a first gap sensor 21 in the processing circuit 31, and step 402 includes receiving a second input signal S2 from a second gap sensor 22 in the processing circuit 31. The first and second input signals indicate the measured or detected hood gap at a first position P1 and a second position P2 of the dryer hood 11, respectively.

[0063] In the optional step 403, the processing circuit 31 may analyze the measured or detected hood gap at the first position P1 and the second position P2.

[0064] Step 404 includes determining in the processing circuit 31 whether a first criterion for a desired hood gap is met, based at least on the aforementioned measured or detected hood gap at the first position P1 and the aforementioned measured or detected hood gap at the second position P2.

[0065] If the first criterion is met, the method is repeated from step 401.

[0066] If the first criterion is not met, the processing circuit 31 determines the desired adjustment of the hood in step 405. Step 406 then includes the processing circuit 31 generating a control signal C configured to cause the hood gap adjuster 12 to apply the determined desired adjustment.

[0067] FIG. 10 discloses an embodiment of an alternative method according to various embodiments of the present method. Note that any method step shown as optional in FIG. 10 may be freely combined with the steps disclosed in FIG. 9 with only minor modifications, as will be apparent to those skilled in the art.

[0068] In an embodiment comprising at least one additional sensor 23, the method comprises, in a processing circuit 31, at least one additional gap sensor 23 i from each of 1 < i < N an additional input signal S i and an optional step 407 of receiving, where N indicates the number of additional sensors, an additional input signal S i which represents the measured or detected hood gap at each additional position P i of the hood 11, 1 < i < N. In such an embodiment, the optional step 403 as well as steps 404 and 405 are preferably carried out based on the measured or detected hood gap at each additional position P i .

[0069] In an embodiment comprising a first end gap adjuster 12A and a second end gap adjuster 12B, the method preferably comprises, in a processing circuit 31, an optional step 408 of determining a desired adjustment of the hood 11 as a first end adjustment and a second end adjustment, and, in the processing circuit 31, a first end control signal C1 configured to apply the first end adjustment determined for the first end gap adjuster 12A and a second end control signal C2 configured to apply the second end adjustment determined for the second end gap adjuster 12B, and an optional step 409 of generating a control signal C.

[0070] Here, step 404 of determining whether a first criterion is met will be described in more detail with reference to various embodiments of the present invention.

[0071] When determining whether the first criterion is met, the processing circuit 31 may individually compare each measured or detected hood gap (i.e., the first position P1, the second position P2, and optionally an additional position Pi) with the first criterion for the desired hood gap. If at least one of the measured or detected hood gaps does not meet the first criterion, it is determined that the first criterion is not met. Alternatively or additionally, the processing circuit 31 may analyze the measured or detected hood gaps in an optional step 403 and determine at least one combined hood gap based on the measured or detected hood gaps. Such a combined hood gap may be the mean, median, minimum value of the measured or detected hood gaps, maximum value of the measured or detected hood gaps, or formed by these or other combinations, etc. In some embodiments, the combined hood gap may also include a measured or detected hood gap at an earlier point in time so that the combined hood gap is the combined hood gap over time. In this way, a gradual change in the measured or detected hood gap may be determined and used to determine whether adjustment of the hood 11 is necessary.

[0072] A first criterion for a desired hood gap may be defined as whether the measured or detected hood gap at the first and second positions P1, P2, and optionally additional positions Pi and / or combined hood gaps, is above a predetermined minimum hood gap, below a predetermined maximum hood gap, or within a predetermined hood gap range.

[0073] Embodiment of the manufacturing method A method for manufacturing a hood adjustment assembly 10 includes providing a hood 11 suitable for connection and mounting to a dryer cylinder 200 so as to form a hood gap hg between the dryer cylinder 200 and the hood 11, and also includes providing a first gap sensor 21 configured to measure or detect the width of the hood gap at a first position of the hood 11, and a second gap sensor 22 configured to measure or detect the width of the hood gap at a second position of the hood 11. The method also includes providing a hood gap adjuster 12 configured to adjust the hood gap by moving the hood 11 relative to the dryer cylinder 200, and providing a hood gap controller 30 comprising a processing circuit 31. The processing circuit 31 is configured to perform steps of a computerized method according to any embodiment of the present specification.

[0074] Further embodiments In one aspect of the present invention, when performed by the processing circuit 31 of the hood gap controller 30, the hood adjustment assembly is: In the processing circuit, a first input signal from a first gap sensor and a second input signal from a second gap sensor are received, the first input signal and the second input signal respectively indicating the hood gap measured or detected at a first position and a second position of the dryer hood. In the processing circuit, it is determined whether the first criterion for the desired hood gap is met, based at least on the aforementioned measured or detected hood gap at the first position and the aforementioned measured or detected hood gap at the second position. In the processing circuit, if the first criterion is not met, the desired adjustment of the hood is determined. A non-temporary computer-readable storage medium is provided in the processing circuit for storing instructions that generate a control signal configured to apply a determined desired adjustment to the hood gap adjuster.

[0075] The non-temporary computer-readable storage medium may further store instructions, when executed by the processing circuit 31, that cause the hood adjustment assembly to perform any of the method steps of the embodiments described in relation to Figures 9 to 10.

[0076] It is generally advantageous if the controller 30 is configured to automatically perform the above-described procedure by executing a computer program 31. Therefore, the controller 30 may then include a memory unit, i.e., a non-volatile data carrier, which stores the computer program 31, including software for causing a processing circuit in the form of at least one processor within the controller 30 to perform the operations referred to in this disclosure when the computer program 31 is executed on at least one processor. Thus, in one or more embodiments, the present invention may include a computer program loadable onto a non-volatile data carrier communicably connected to a processor, the computer program including software for performing the method according to any embodiment of the method presented in relation to Figures 9-10 when the computer program is executed on the processor. Furthermore, the present invention may include a non-volatile data carrier containing the computer program.

[0077] It should be noted that the features from the various embodiments described herein can be freely combined unless such combination is explicitly stated to be inappropriate.

Claims

1. A hood adjustment assembly for adjusting the position of a hood on a dryer cylinder, wherein the hood adjustment (10) assembly is A hood (11) is configured to be attached to the dryer cylinder (200) so as to form a hood gap (hg) between the dryer cylinder (200) and the hood (11), and extends in a first direction (D1) from a first end (11A) to a second end (11B), A first gap sensor (21) is configured to measure or detect the width of the hood gap (hg) at a first position (P1) of the hood (11), A second gap sensor (22) is configured to measure or detect the width of the hood gap (hg) at a second position (P2) of the hood (11), A hood gap adjuster (12, 12A, 12B) is configured to adjust the hood gap (hg) by moving the hood (11) relative to the dryer cylinder (100), A hood gap controller (30) equipped with a processing circuit (31) is provided, The processing circuit (31) The first input signal (S1) from the first gap sensor (21) and the second input signal (S2) from the second gap sensor (22) are received, and the first and second input signals (S1, S2) indicate the measured or detected hood gap (hg) at the first position (P1) and the second position (P2), respectively. Based on the measured or detected food gap (hg) at least at the first location (P1) and the measured or detected food gap (hg) at the second location (P2), it is determined whether the first criterion for the desired food gap is met. If the first criterion is not met, determine the desired adjustment of the hood (11), A control signal (C) is generated, configured to cause the hood gap adjusters (12, 12A, 12A) to apply the determined desired adjustment. The aforementioned hood gap adjusters (12, 12A, 12B) The processing circuit (31) receives the control signal (C), A hood adjustment assembly further configured to move the hood (11) to adjust the hood gap (hg) based on the control signal (C).

2. The hood adjustment assembly according to claim 1, wherein the first position (P1) of the hood (11) is at the first end (11A), and the second position (P2) of the hood (11) is at the second end (11B).

3. The hood adjustment assembly according to claim 1 or 2, wherein the first position (P1) and the second position (P2) of the hood (11) are located at the first end (11A), and the first position (P1) and the second position (P2) are separated from each other in a second direction (D2) perpendicular to the first direction (D1).

4. The processing circuit (31) further comprises at least one additional gap sensor (23) configured to measure or detect the width of the hood gap (hg) at an additional location (P3) of the hood (11), For each additional gap sensor (23), an additional input signal (S3) is received from the additional gap sensor (23) indicating the measured or detected hood gap (hg) at the additional position (S3). A hood adjustment assembly according to any one of claims 1 to 3, configured to determine whether the first criterion for the desired hood gap is met, based on the measured or detected hood gap (hg) at the additional location (P3).

5. The aforementioned hood gap adjusters (12, 12A, 12B) A first end gap adjuster (12A) configured to adjust the hood gap (hg) at the first end (11A) of the hood (11), The hood (11) comprises a second end gap adjuster (12B) configured to adjust the hood gap (hg) at the second end (11B) of the hood (11), The processing circuit (31) The desired adjustments of the hood (11) are determined as a first end adjustment and a second end adjustment. The hood adjustment assembly according to any one of claims 1 to 4, wherein the control signal (C) is configured to generate a first end control signal configured to cause the first determined end adjustment to be applied to the first end gap adjuster (12A), and a second end control signal configured to cause the second determined end adjustment to be applied to the second end gap adjuster (12B).

6. The hood adjustment assembly according to any one of claims 1 to 5, wherein the first gap sensor (21) and the second gap sensor (22), and optionally the third gap sensor (23), are optical sensors.

7. A hood adjustment assembly according to any one of claims 1 to 5, further comprising a reference marking connected to the hood (11), wherein the first sensor (21) and the second sensor (22), and optionally the third sensor (23), are configured to measure or detect the width of the hood gap (hg) by detecting the reference marking.

8. The hood adjustment assembly according to any one of claims 1 to 7, wherein the hood gap adjuster (12) also comprises an adjuster (12C) configured to move the hood (11) along the inclined guide (14) in response to the control signal (C).

9. A hood adjustment system comprising a first hood adjustment assembly (10) according to any one of claims 1 to 8, wherein the hood (10) is a wet end hood (W) for a dryer cylinder (200), and a second hood adjustment assembly (10) according to any one of claims 1 to 8, wherein the hood (11) is a dry end hood (D) for a dryer cylinder.

10. A computerized method for adjusting the position of the hood on the dryer cylinder, In the processing circuit (31), a first input signal (S1) from the first gap sensor (21) and a second input signal (S2) from the second gap sensor (22) are received, wherein the first and second input signals (S1, S2) indicate the measured or detected hood gap (hg) at the first position (P1) and second position (P2) of the dryer hood (200), respectively. In the processing circuit (31), it is determined whether a first criterion for a desired hood gap is met, based at least on the measured or detected hood gap at the first position (P1) and the measured or detected hood gap at the second position (P2). In the processing circuit (31), if the first criterion is not met, the desired adjustment of the hood (11) is determined, A method comprising generating a control signal (C) in a processing circuit (31) configured to cause the hood gap adjuster (12) to apply the determined desired adjustment.

11. The processing circuit (31) receives an additional input signal (S3) from each of at least one additional gap sensor (23), wherein the additional input signal (S3) indicates the measured or detected hood gap (hg) at each additional position (P3) of the hood (11). The method according to claim 10, further comprising: in the processing circuit (31), determining whether the first criterion for the desired hood gap is met, also based on the measured or detected hood gap (hg) at each additional position (P3).

12. In the processing circuit (31), the desired adjustment of the hood (11) is determined as a first end adjustment and a second end adjustment, The method according to claim 10 or 11, further comprising: in the processing circuit (31), generating the control signal (C) as a first end control signal configured to apply the determined first end adjustment to the first end gap adjuster (12A), and as a second end control signal configured to apply the determined second end adjustment to the second end gap adjuster (12B).

13. The method according to any one of claims 10 to 12, wherein the first criterion for the desired food gap is that the determined food gap exceeds a predetermined minimum food gap.

14. The method according to any one of claims 10 to 12, wherein the first criterion for the desired food gap is that the determined food gap is within a predetermined minimum food gap range.

15. The method according to any one of claims 10 to 12, wherein the first criterion for the desired food gap is that the determined food gap is less than a predetermined maximum food gap.

16. When performed by the processing circuit (31) of the hood gap controller (30) of the hood adjustment assembly (10) for adjusting the position of the hood (11) on the dryer cylinder (200), the hood adjustment assembly is: In the processing circuit (31), a first input signal (S1) from the first gap sensor (21) and a second input signal (S2) from the second gap sensor (22) are received, respectively, indicating the hood gap measured or detected at a first position (P1) and a second position (P2) of the dryer hood (11). In the processing circuit (31), a determination is made as to whether the first criterion for the desired hood gap is met, based on the measured or detected hood gap at least at the first position (P1) and the measured or detected hood gap at the second position (P2). If the first criterion is not met, the processing circuit (31) determines the desired adjustment of the hood (11). A non-temporary computer-readable storage medium that stores instructions for generating a control signal (C) configured to cause the hood gap adjuster (12) to apply the determined desired adjustment to the processing circuit (31).

17. The non-temporary computer-readable storage medium according to claim 16, further storing an instruction, when executed by the processing circuit, that causes the hood adjustment assembly to perform a step according to any one of claims 11 to 15.

18. A method for manufacturing a hood adjustment assembly, To provide a hood (11), which is suitable for connecting and mounting to the dryer cylinder (200) so as to form a hood gap (hg) between the dryer cylinder (200) and the hood (11), and which extends in a first direction (D1) from a first end (11A) to a second end (11B), To provide a first gap sensor (21) configured to measure or detect the width of the hood gap (hg) at a first position (P1) of the hood (11), To provide a second gap sensor (22) configured to measure or detect the width of the hood gap (hg) at a second position (P2) of the hood (11), To provide a hood gap adjuster (12) configured to adjust the hood gap (hg) by moving the hood (11) relative to the dryer cylinder (200), The provision includes providing a hood gap controller (30) equipped with a processing circuit (31), The processing circuit (31) The system receives a first input signal (S1) from the first gap sensor (21) and a second input signal (S2) from the second gap sensor (22), respectively, indicating the measured or detected hood gap at the first position (P1) and the second position (P2). Based on the measured or detected food gap at least at the first position (P1) and the measured or detected food gap at the second position (P2), it is determined whether the first criterion for the desired food gap is met. If the first criterion is not met, determine the desired adjustment of the hood (11), The system is configured to generate a control signal (C) that causes the hood gap adjuster (12) to apply the determined desired adjustment, The hood gap adjuster (12) The processing circuit (31) receives the control signal (C), A method further configured to move the hood (11) to adjust the hood gap (hg) based on the control signal (C).

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