阅读说明：本技术 用于造纸机或纸板机的湿端的监测系统和方法 (Monitoring system and method for the wet end of a paper or board machine ) 是由 M·瓦尔克宁 于 2020-02-03 设计创作，主要内容包括：本发明涉及一种用于造纸机或纸板机的湿端的监测系统(10)。该系统包括：至少一个灯具(19),用于照亮供应到网(13)上的纸浆(16)；至少一个图像传感器(11),其在机器的湿端处放置在流浆箱(15)上方,用于捕获从流浆箱(15)供应的纸浆(16)在网部中沿网(13)的移动方向的活动性；以及,计算设备(12,22),至少一个图像传感器(11)被配置为向其发送用于确定关于纸浆(16)的活动性数据的图像信息,计算设备(12,22)被配置为基于所确定的活动性数据来调整造纸机或纸板机和/或监测系统的设置。本发明还涉及一种用于通过根据本发明的监测系统(10)监测造纸机或纸板机的湿端的方法,该方法包括基于所确定的活动性数据来调整造纸机或纸板机和/或监测系统(10)的设置。(The invention relates to a monitoring system (10) for the wet end of a paper or board machine. The system comprises: at least one light (19) for illuminating the pulp (16) supplied onto the wire (13); at least one image sensor (11) placed above the headbox (15) at the wet end of the machine for capturing the mobility of the pulp (16) supplied from the headbox (15) in the direction of movement of the wire (13) in the wire section; and a computing device (12, 22), to which the at least one image sensor (11) is configured to send image information for determining activity data about the pulp (16), the computing device (12, 22) being configured to adjust settings of the paper or board machine and/or the monitoring system based on the determined activity data. The invention also relates to a method for monitoring the wet end of a paper or board machine by means of a monitoring system (10) according to the invention, which method comprises adjusting the settings of the paper or board machine and/or the monitoring system (10) on the basis of the determined activity data.)

1. A monitoring system (10) for the wet end of a paper or board machine, characterized in that the system (10) comprises:

at least one light (19) for illuminating the pulp (16) supplied onto the wire (13),

-at least one image sensor (11) placed above the headbox (15) at the wet end of the machine for capturing the mobility of the pulp (16) supplied from the headbox (15) in the wire section in the direction of movement of the wire (13); and

a computing device (12, 22), to which at least one image sensor (11) is configured to send image information for determining activity data about the pulp (16), the computing device (12, 22) being configured to control settings of the paper or board machine and/or the monitoring system based on the determined activity data.

2. A monitoring system (10) according to claim 1, wherein the image sensor (11) captures the activity of the pulp (16) at an angle of not more than 45 ° to the surface of the wire (13).

3. The monitoring system (10) according to claim 1 or 2, wherein the activity is an amplitude, a scale, an activity duration or a combination of these in a predetermined area.

4. The monitoring system (10) according to any one of claims 1 to 3, wherein the computing device (12) is an integrated part of the image sensor (11), or wherein the computing device (22) is connected to the image sensor in a wired or wireless manner for receiving image information.

5. A monitoring system (10) according to any of claims 1-4, wherein the determined activity data is used to adjust the settings of the headbox (15) and the foil (18) in the paper or board machine.

6. The monitoring system (10) according to any one of claims 1 to 5, wherein the determined activity data is used to adjust settings of at least one image sensor (11) in the monitoring system (10).

7. The monitoring system (10) according to any one of claims 1 to 6, wherein the determined activity data is used to adjust settings of at least one light fixture (19) in the monitoring system (10).

8. A method for monitoring a wet end of a paper or board machine, the method comprising:

illuminating at least one portion of the pulp (16) supplied onto the wire (13) by means of at least one lamp (19),

monitoring the at least one portion of the pulp (16) supplied onto the wire (13) by means of at least one camera (14) placed above the headbox (15) to determine activity data of the pulp,

comparing the determined activity data with an activity data reference to determine deviating activity data, an

Adjusting settings of the paper or board machine and/or the monitoring system based on the determined activity data.

9. The method of claim 8, comprising adjusting settings of the headbox (15) based on the determined activity data.

10. Method according to claim 8 or 9, comprising adjusting settings of a foil (18) of the paper or board machine based on the determined activity data.

11. The method according to any one of claims 8 to 10, comprising adjusting settings of at least one camera (14) in the monitoring system (10) based on the determined activity data.

12. The method according to any one of claims 8 to 11, comprising adjusting a setting of at least one luminaire (19) in the monitoring system (10) based on the determined activity data.

13. The method according to any one of claims 8 to 11, comprising illuminating and monitoring the pulp supplied onto the wire in at least two sections of the wire, and determining activity data of these at least two sections to be compared with an activity reference, and adjusting settings of the paper or board machine and/or the monitoring system based on the determined activity data.

Technical Field

The invention relates to a system for monitoring a wet end in a paper or board machine and a method for monitoring a wet end in a paper or board machine.

Background

Pulp (e.g., paper or paperboard pulp) is formed at the wet end of paper and board machines. The mobility of the pulp will affect the final quality of the paper and board product and the amount of energy used to dewater the product. By monitoring the activity and controlling the settings of the paper or board machine accordingly, it is possible to find such settings of the machine that the activity of the pulp will be kept at a desired level and of the type required, whereby a good quality of the end product is obtained. Cameras for monitoring activity are usually fixed in various beams or beam structures extending above the pulp for monitoring the pulp from above and/or to the side of the wire section for monitoring the pulp from the side. However, the quality of the image captured by a camera monitoring the pulp from above may be impaired by upward splashing of the pulp from the paper and board machine, thereby blurring the camera lens. This makes it difficult to provide a good quality image of the pulp and thus to accurately determine its mobility. Furthermore, it may not be possible to place the camera on the wire side of the paper machine, for example, due to lack of space and web variations. However, it is advantageous to monitor the activity of the pulp in order to meet the strict quality specifications of the end product and to achieve an optimal drying energy level.

Disclosure of Invention

The object of the invention is to provide and propose a novel system for monitoring the wet end of a paper or board machine, and a method for monitoring the wet end. The monitoring system and method according to the invention are characterized by what will be presented in the independent claims, and the dependent claims relate to advantageous embodiments of the invention.

The invention relates to a system for monitoring the wet end of a paper or board machine. The system comprises at least one light for illuminating the pulp fed onto the wire; at least one image sensor placed above a head box at the wet end of the machine for imaging the mobility of the pulp fed from the head box in the wire section in the direction of movement of the wire; and a computing device to which the image sensor is configured to transmit image information for determining pulp activity data, the computing device being configured to control settings of the paper or board machine and/or the monitoring system based on the determined activity data.

In an advantageous embodiment the image sensor captures the activity of the pulp at an angle of not more than 45 ° to the wire surface. In an advantageous embodiment, the activity is an amplitude, a scale, an activity duration or a combination of these in a predetermined area. In an advantageous embodiment, the computing device is an integrated part of the image sensor, or the computing device is connected to the image sensor in a wired or wireless manner for receiving the image information. In an advantageous embodiment the determined activity data are used for controlling the settings of the headbox and/or the foil (blade) in a paper or board machine. In an advantageous embodiment, the determined activity data is used for controlling settings of at least one image sensor in the monitoring system. In an advantageous embodiment, the determined activity data is used for controlling settings of at least one luminaire in the monitoring system.

Furthermore, the invention relates to a method for monitoring the wet end of a paper or board machine. The method comprises illuminating at least one area of the pulp supplied onto the wire by at least one lamp; monitoring the at least one area of the pulp supplied onto the wire by means of at least one camera placed above the headbox for determining activity data of the pulp in said area; comparing the determined activity data with activity reference data to determine deviating activity data; and adjusting settings of the paper or board machine and/or the monitoring system based on the determined activity data.

In an advantageous embodiment the method comprises adjusting settings of a headbox of a paper or board machine based on the determined activity data. In an advantageous embodiment the method comprises adjusting the settings of the foil of the paper or board machine based on the determined activity data. In an advantageous embodiment, the method comprises adjusting settings of at least one camera in the monitoring system based on the determined activity data. In an advantageous embodiment, the method comprises adjusting a setting of at least one luminaire in the monitoring system based on the determined activity data. In an advantageous embodiment the method comprises illuminating and monitoring the pulp supplied onto the wire in at least two areas on the wire and determining activity data of the at least two areas to be compared with reference activity data, and adjusting settings of the paper or board machine and/or the monitoring system based on the determined activity data.

Drawings

The invention will be described in more detail hereinafter with reference to the accompanying drawings, in which:

fig. 1 shows a side view of a monitoring system for determining pulp activity at the wet end of a paper machine according to an advantageous embodiment of the invention;

FIG. 2 shows a side view of a monitoring system for determining pulp activity at the wet end of a paper machine according to an advantageous embodiment of the invention;

FIG. 3 shows a simplified view of a cross-section of the pulp shown in FIG. 1 in the direction A of FIG. 1;

FIG. 4 shows a monitoring system for determining pulp activity at the wet end of a paper machine according to an advantageous embodiment of the present invention;

FIG. 5 shows a top view of the monitoring system of FIG. 4;

FIG. 6 shows a monitoring system for determining pulp activity at the wet end of a paper machine according to an advantageous embodiment of the present invention;

FIG. 7 shows a top view of the monitoring system of FIG. 6; and

fig. 8 shows a monitoring method according to an advantageous embodiment of the invention in the form of a flow chart.

Detailed Description

The web forming section of a paper machine comprises a headbox and a wire section; a board machine may comprise several such web forming sections. The upstream portion of the paper machine may be referred to as the wet end of the paper machine. The wet end comprises not only the grinding and mixing of the pulp and the web forming section, but also the pressing section. The wet end is followed by the dry section and the dry end of the machine. After reeling, the finished board may be cut into rolls by a slitter.

Starting from the headbox of the web forming section, the pulp is sprayed onto the wire in the form of a uniform jet over the entire width of the wire. In this context, the term "pulp" also includes the term "pulp suspension". By adjusting the settings of the headbox and its feed pipes, the properties of the pulp can be influenced. These are adjusted to make the pulp jet uniform in its consistency and fine particle distribution. Furthermore, by adjusting the flow rate, orientation and turbulence of the pulp jet, the basis weight distribution and fiber orientation can be influenced. In the wire section, the pulp is dewatered to dry the formed web sufficiently for further processing in the press section. More than 90% of the water contained in the pulp in the headbox is removed on the lower and upper wires of the wire section. The cohesion of the web is provided by the bonds between the fibers and by the surface tension.

By measuring the activity and analyzing the measurement results, the settings of the headbox and its feed pipe and the foil below the wire can be adjusted/controlled, for example by comparing with earlier measurement results or stored thresholds for different activity types/activities and corresponding headbox settings used. By adjusting the settings, for example by changing the mixing ratio, a more uniform consistency and fine particle distribution can be achieved. Furthermore, by adjusting the flow rate, orientation and turbulence of the stock jet from the headbox, the basis weight distribution and fiber orientation of the stock can be influenced. By adjusting the settings, it is thus possible to find suitable settings for the headbox and/or the foil to achieve the desired pulp mobility, whereby it is more possible to achieve a good quality product. The activity measured from the pulp may be, for example, the amplitude in the predetermined area, a measure of the activity, the duration of the activity or a combination of these. The adjustable properties of the foil may comprise, for example, the height and/or angle of the foil.

In addition to controlling/changing the settings of the headbox and its feed pipes and foils below the wire by measuring the activity of the pulp and analyzing the measurements, it is also possible to adjust the settings/positions of one or more active cameras and/or lamps in the monitoring system, whereby said one or more active cameras and/or lamps can be placed on the side of the wire, above the headbox, at the edge of the headbox and/or above the wire.

For example, the settings of the camera may be adjusted by changing the angle of the camera relative to the mesh and/or by electronically adjusting the pass band of the filter of the camera and/or in the case of a color camera by changing its filter (e.g., blue, green, red or a combination of these). The angle of the camera can also be adjusted in the cross direction so that a single camera can be used to image, i.e. scan, the entire width of the web, if desired. At each position in the lateral direction it is required that the settings of the luminaire are adjusted to correspond to the field of view selected for the camera. Typically, the active camera captures images of the pulp at an angle of less than 90 °; for example, a camera placed above the headbox and a camera placed at a low level on the side of the wire capture images at an angle of about/no greater than 45 ° to the wire. When the field of view is adjusted based on pulp activity data, for example when the camera captures images of activity targets that are closer or further than before and whose activity has been found to deviate from, based on the activity measurements made, a more accurate activity measurement than before can be achieved. For example, if the analysis of the measurements shows that the amplitude of the activity is very low, or the activity is only found in the area very close to the active camera, which first measures the activity of the pulp on the wire at an angle of substantially about 45 °, may be adjusted to reduce its field of view to any value, e.g. less than 30 ° or between 0 ° and 45 °, depending on the measurements and the position of the camera. With the new field of view, the measure of activity amplitude can be made more accurate than before, and/or images of different areas can be captured with the same camera. For example, when foils are arranged at several different positions below the wire, it may be necessary to capture images of different areas, and if the activity measurements have for example suggested that adjusting one foil based on the activity measurements does not result in the desired change in pulp activity, the camera may be arranged to capture images of each of these areas in an alternating manner after the change in activity in the pulp caused by the foil as the pulp travels over the wire, and that adjusting the next foil will be necessary, and will require activity data measured after the previous foil to adjust them. Alternatively, for example, if the analysis of the activity measurements shows that there is activity in a given zone, the activity cameras that first capture the activity of the pulp on the web at an angle of substantially about 7 ° may be adjusted to increase their field of view to any angle between, for example, 10 ° or 8 ° to 45 °, depending on the measurement, whereby the activity may be better focused on the center of the imaging zone, i.e. the captured image. Logically, the field of view can be adjusted to be larger or smaller based on the measurements as desired. By switching to the infrared mode, information about activity different from the visible range can be obtained in the same way as using different filters. The settings of the luminaire may be adjusted based on the activity data, for example by changing the angle of incidence (direction) of the central beam of the luminaire with respect to the mesh, and/or by changing the position of the luminaire in the x, y and/or z direction, and/or by changing the intensity, wavelength and/or beam width of the light. The angle of incidence of the central beam of the luminaire with respect to the mesh may be adjusted in a range between e.g. 15 ° and 30 °. By adjusting the illumination based on the measured pulp activity data, the illumination of the activity may be improved or changed to better show the activity, or by changing the settings of the illumination, such activity, which cannot be detected at all or which may not be detected well, may be detected without changing the lighting settings.

Fig. 1 shows a side view of a monitoring system 10 for determining pulp activity at the wet end of a paper machine according to an advantageous embodiment. At least one camera 14 is mounted above the headbox 15, which in this embodiment is a so-called smart camera comprising an image sensor 11 and a computing device 12 for analyzing image data (i.e. image information) captured by the image sensor 11 and for analyzing the activity of the pulp 16 fed from the headbox 15 onto the wire 13. The computing device 12 includes at least one memory for storing computer programs and image data, a processor for executing the computer programs, one or more types of data transmission components for receiving and transmitting data. The computing device 12 is connected to the image sensor 11 in such a way that image data can be transferred from the image sensor 11 to the computing device 12. Further, the camera 14 may comprise a display for displaying, for example, image data or measurement results, as well as other components such as data input components, different types of software, etc.

At least one lamp 19 is mounted on the side of the headbox 15 for illuminating the pulp 16 travelling on the wire 13 at a given angle z for imaging. This angle is formed between the centre line of the light beam generated by the luminaire 19 and the plane surface formed by the mesh 13, and is preferably typically, for example, 15 ° to 40 °, for example 15 ° to 30 °, or for example 20 °. The lighting angles of the lamps 19 placed above the same headbox can be equal or different from each other. Also, the light fixtures may illuminate different points or the same point on the pulp 16 but at different angles.

Thus, the at least one camera 14 mounted above the headbox 15 is configured to image the pulp 16 travelling on the wire 13. The image sensor 11 captures the pulp 16 at an angle alpha. The image α is the angle formed between the centre line 17 of the field of view of the image sensor 11 and the plane surface formed by the mesh 13, and it is typically less than 45 °, advantageously 30 ° to 40 °, for example 35 °. On this image data captured at angle α, the computing device 12 takes the necessary measurements to determine the activity of the slurry 16. The foils 18 are arranged below the mesh 13 and they may be controlled or their settings may be adjusted to induce a desired turbulence (activity) in the slurry 16. The activity data may be compared by the computing device 12 with predetermined activity data entered in the computing device, such as previous measurement data or thresholds set for activity and corresponding headbox settings used. These comparisons can be used to determine the adjustments needed for feeding the pulp 16 from the headbox 15 or for the foils to change the mobility of the pulp 16. The direction of travel of the pulp 16 is away from the headbox 15, as indicated by the arrow in fig. 1. The camera that captures pulp activity may be referred to as an activity camera. The predetermined activity data compared to the measured activity data and the thresholds set for the activity and the corresponding headbox adjustments used may be referred to as activity data references or activity reference data.

Also, the orientation, angle, brightness, and/or other settings of the camera 14 and light fixture 19 may be adjusted/changed based on activity data determined by the computing device 12.

Fig. 2 shows a side view of a monitoring system 20 for determining the activity of pulp at the wet end of a paper machine according to an advantageous embodiment of the invention. Above the headbox 25 at least two cameras 21a, 21b are mounted, each comprising an image sensor, although in this embodiment two cameras are provided, the number of cameras may also be only one, or three or more, depending on e.g. the width of the wire 23 and the pulp 26 thereon. In this context, width refers to the direction perpendicular to the direction of travel of the web and pulp. The cameras 21a, 21b are connected to the computing device 22 in a wired or wireless manner. The computing device 22 is configured to process the image data, i.e. image information, sent by the cameras 21a, 21b to the computing device 22 to measure the activity of the pulp 26 supplied by the headbox 25 onto the wire 23. The computing device 22 includes at least one memory for storing computer programs and image data, a processor for executing the computer programs, one or more types of data transmission components for receiving and transmitting data. The computing device 22 is connected to the cameras 21a, 21b in such a way that image data can be transmitted from the cameras 21a, 21b to the computing device 22 in a wired or wireless manner. Further, the computing device 22 may include a display for displaying image data or measurements, as well as other components such as data input components, different types of software, and so forth. The computing device 22 communicates with the cameras 21a, 21b via a data transmission network, for example via WLAN (wireless local area network), bluetooth, or GSM, CDMA or WCDMA technology or future technology, or other data network technology.

Furthermore, at least one luminaire 22 is mounted at the edge of the headbox 25 to illuminate the pulp 26 travelling on the wire 23 for imaging. The luminaire 22 illuminates the pulp 26 at an angle x. The angle x is the angle formed between the central beam of the luminaire 22 and the planar surface formed by the mesh 23. As mentioned above, these illumination angles are generally less than 45 °, advantageously 15 ° to 30 °, for example 20 °. The lighting angles of the lamps 22 placed above the same headbox may be equal or different from each other. The light fixture may illuminate different points or the same point on the pulp 26 but at different angles.

The cameras 21a, 21b mounted above the headbox 25 are thus configured to capture the pulp 26 travelling on the wire 23 to determine the activity of the pulp 26. The image sensors 21a, 21b capture images of the pulp 26 at angles β and γ. The angle β is an angle formed between the center line 24a of the field of view of the image sensor of the camera 21a and the plane surface formed by the mesh 23, and the angle γ is an angle formed between the center line 24b of the field of view of the image sensor of the camera 21b and the plane surface formed by the mesh 23. Similarly, these angles are generally less than 45 °, advantageously 30 ° to 40 °, for example 35 °. The viewing angles of cameras placed on top of the same headbox can be equal or different from each other. The cameras 21a, 21b may capture different points of the pulp 26 or the same point but at different angles. On the image data, the computing device 22 takes the required measurements to determine the activity of the pulp 26. A foil 28 is placed under the wire 23 to adjust the mobility of the pulp 26. The activity data may be compared by the computing device 22 to predetermined activity data on the computing device and corresponding adjustments to stored thresholds and usage; based on these comparisons, the required adjustments in the supply of pulp 26 from the headbox 25 and/or the foil 28 can be determined for changing/adjusting the activity. The direction of travel of the pulp 26 is away from the headbox 25, as indicated by the arrow in fig. 2.

In addition to adjusting the supply of pulp 26 from the headbox 25 and/or foil 28, the orientation, angle, wavelength and/or other settings of the cameras 21a, 21b and the luminaire 22 may also be adjusted/changed based on activity data determined by the computing device 22. However, the orientation, angle and/or other settings of the cameras 21a, 21b and luminaires 22 are adjusted/changed based on the activity data to improve the quality of the activity measurements, rather than to adjust the activity, although higher quality activity measurements may also actually affect the activity adjustment.

Fig. 3 shows a reduced cross-sectional view of the pulp 16 of fig. 1 in the direction a, i.e. towards the headbox 15 and transversely to the direction of travel of the pulp 16. As shown in fig. 3, the mobility 32 of the pulp 16 varies in different portions across the width of the pulp 16. In this context, the activity 32 refers to the deviation of the pulp 16 from the base plane.

Fig. 4 shows a monitoring system 40 for determining the activity of pulp 46 at the wet end of a paper machine according to an advantageous embodiment. The lighting fixtures used in the monitoring system are not shown. In addition to the active camera 41 mounted above the headbox 45, the monitoring system 40 also comprises a camera for capturing the activity of the pulp on both sides of the wire 43. In this embodiment, both a low level of mobility camera 42a (on the left hand side of the wire 43 as viewed from the headbox 45), 42b (on the right hand side of the wire as viewed from the headbox 45), and a high level of mobility camera 44a (on the left hand side of the wire 43 as viewed from the headbox 45), 445 (on the right hand side of the wire 43 as viewed from the headbox 45) are provided on the sides. The low level activity cameras 42a, 42b capture the activity of the pulp (not shown) supplied onto the wire 42 substantially at the level of the wire 43, i.e. on a horizontal line or, for example, at an angle of less than 15 °. The high level activity cameras 44a, 44b capture the activity of the pulp on the wire 43 at a higher level than the low level activity cameras 42a, 42b, for example at an angle less than 90 ° but greater than 15 ° (e.g. 45 °). In this embodiment, the angle is also determined in the same manner as shown in fig. 1 and 2; that is, the angle is formed between the centerline of the field of view of the image sensor of the activity camera and the planar surface formed by the mesh 43.

The number of cameras is not limited to the number shown in the figure, but it may also be only one, or three or more, depending on e.g. the width of the wire 43 and the pulp thereon. The cameras 41, 42a, 41b, 44a, 44b are connected to a computing device (not shown) in a wired or wireless manner, as shown in fig. 2, or they are so-called smart cameras, as shown in fig. 1. A foil 48 is provided under the wire 43 for adjusting the mobility of the pulp. Furthermore, based on the comparison made by the computing device, the required adjustment in the feed of pulp from the headbox 45 and/or the foil 48 may be determined to change/adjust the activity. The direction of travel of the wire 43 is away from the headbox 45, as indicated by the arrow in fig. 4. The direction of travel of the wire is always the same as the direction of travel of the pulp. Fig. 5 shows the monitoring system 40 of fig. 4 in a top view.

Fig. 6 shows a monitoring system 60 for determining the activity of pulp 66 at the wet end of a paper machine according to an advantageous embodiment. In addition to the active camera 61 and the lamps 66 mounted on the headbox 65, the monitoring system 60 also comprises cameras and lamps 67 on both sides of the wire 63 for capturing pulp activity, but it is also possible to provide cameras and/or lamps on only one side of the wire 63. In this embodiment, a low-level mobility camera 62a (on the left-hand side of the wire 63 as viewed from the headbox 65), 62b (on the right-hand side of the wire 63 as viewed from the headbox 65) and a high-level mobility camera 64a (on the left-hand side of the wire 63 as viewed from the headbox 65), 64b (on the right-hand side of the wire 63 as viewed from the headbox 65) are all provided on the sides of the wire 63. The low level activity cameras 62a, 62b capture the activity of the pulp (not shown) supplied onto the wire 62, substantially at the level of the wire 63, i.e. in the horizontal plane or at an angle of less than 15 °, for example. The high level of activity cameras 64a, 64b capture pulp activity on the wire 63 from a higher level than the low level of activity cameras 62a, 62b, for example at an angle of less than 90 ° but more than 15 ° (e.g. 45 °). In this embodiment, the illumination angle is also less than 45 °, i.e. about 15 ° to 30 °. In this embodiment, the viewing angle and the illumination angle are determined in the same manner as shown in fig. 1 and 2; that is, the angle is formed between the center line of the field of view of the image sensor of the active camera and the planar surface formed by the mesh 63, and the illumination angle between the center beam of the light fixtures 66, 67 and the planar surface formed by the mesh 63.

The number of cameras or light fixtures is not limited to those shown in fig. 6; that is, it may be only one, three or even more, depending on, for example, the width of the wire 63 and the pulp thereon. The cameras 61, 62a, 61b, 64a, 64b and the luminaires 66, 67 are connected to a computing device (not shown) in a wired or wireless manner, as shown in fig. 2, or the cameras are so-called smart cameras, as shown in fig. 1, whereby the luminaires 66, 67 may be connected to the cameras in a wired or wireless manner. A foil 68 is provided below the wire 63 for adjusting the mobility of the pulp. Furthermore, based on the comparison made by the computing device, the required adjustments in the supply of pulp from the headbox 65 and/or in the foil 68 may be determined to change/adjust the activity, as well as to change and/or adjust the adjustments/settings/functions of the cameras 61, 62a, 61b, 64a, 64b and/or the luminaires 66, 67, so that the monitoring system 60 may capture the activity of the pulp in a more accurate and/or versatile manner. As indicated by the arrows in fig. 6, the direction of travel of the wire 63 is away from the headbox 65, the direction of travel of the wire always being the same as the direction of travel of the pulp. Fig. 7 shows the monitoring system 60 of fig. 6 in a top view.

Fig. 8 shows a flow diagram 80 of a system for monitoring the wet end of a paper machine according to an advantageous embodiment of the invention. In a first step 81, at least one area of the pulp supplied onto the wire is illuminated by at least one lamp. The lamps may be on the side of the wire, above the headbox, above the edge of the headbox, or above the wire in front of the headbox. In a second step 82 at least one camera placed above the headbox is used to monitor at least one of said areas of pulp supplied onto the wire to determine data about pulp activity. However, it is possible that at least one camera for monitoring activity is placed on the side of the wire, above the edge of the headbox, above the wire in front of the headbox, instead of above the headbox, or in case of at least two or more cameras, at least one of the cameras is placed at a different location than at least one other camera for monitoring the pulp. In a third step, the determined activity data is compared with an activity data reference for determining deviating activity data by a computing device, which may be part of the camera or a separate device. In a fourth step 84, settings of the paper or board machine and/or the monitoring system are adjusted based on the activity data. For example, when the activity data is found to deviate in step 83, settings of the paper or board machine and/or the monitoring system may be adjusted based on the activity data.

In the method, the settings of the headbox may be adjusted based on the activity data. By adjusting the settings of the headbox, the settings of the headbox itself and its supply pipe can be changed and thereby the properties of the pulp are influenced. By adjusting the flow rate, orientation and turbulence setting of the pulp jet, the square mass distribution and fiber orientation can be influenced. Similarly, the arrangement of the foils can be adjusted in the method to make the pulp uniform in terms of consistency and distribution of the fine particles. Furthermore, settings of the at least one camera and the luminaire may be controlled based on activity data determined in the method.

Thus, the monitoring system according to the invention may comprise only the activity capturing camera, i.e. the activity camera, above the headbox, or the monitoring system according to the invention may comprise, in addition to the activity camera above the headbox, a low-level activity camera on one or both sides of the wire (and pulp), or the monitoring system according to the invention may comprise, in addition to the activity camera above the headbox, a high-level activity camera on one or both sides of the wire (and pulp), or the monitoring system according to the invention may comprise, in addition to the activity camera above the headbox, a low-level and high-level activity camera on one or both sides of the wire (and pulp).

The camera and light fixture may be fastened to various frames or supports made of, for example, metal, and placed above the headbox. Alternatively, it is also possible to mount the camera and the lamp directly on top of the headbox, or to provide a camera beam above the headbox to receive the camera and the lamp. Similarly, various frames, supports or arms made of, for example, metal may be provided for cameras or light fixtures placed on the sides of the mesh. The frame, support, arm or beam may be used to fix the correct field of view and position of the camera, for example, relative to the mesh, and the correct lighting angle and position of the light fixture relative to the mesh. The camera used in the system for monitoring the wet end may be a so-called pinhole camera or the camera may comprise a so-called pinhole lens, since the degree of contamination of the camera lens area may be relatively high at the wet end.

The field of view of the active camera relative to the wire can be chosen relatively freely according to the activity or target to be measured, but typically the active camera is captured at an angle of less than 90 ° and the camera above the headbox and the low level camera are captured at an angle of less than 45 ° relative to the wire.

It is obvious that the invention is not limited solely to the above-described embodiments, but it can be modified within the scope of the appended claims.