Measuring system for a suspension treatment device

Abstract

The invention relates to a measuring system of a suspension treatment device (10) comprising at least one chamber (14) formed inside at least one wall (13). The measuring system comprises a temperature sensor system (20) comprising several temperature sensors attached on an outer surface of the wall (13) of the chamber (14).

Description

Technical Field

[0001] This invention generally relates to a suspension treatment process, and more specifically, to measuring temperatures associated with apparatus used for suspension treatment, such as measuring temperatures associated with cleaning devices, containers, towers, tanks, screens, and mills in slurry production processes. More particularly, this invention relates to a measurement system. Background Technology

[0002] Suspension treatment processes are involved in various industries, such as wastewater treatment, food production, or pulp production. In pulp production processes, several different types of devices are used for different process steps and for storing pulp between process steps, such as for washing, processing, or storing pulp. These devices include different types of washers, screens, containers, towers, tanks, etc., which are known to those skilled in the art. In these devices, the pulp is typically in suspension form, i.e., a mixture or solution of pulp and liquid (usually water) that is processed in the process. In these pulp production devices, it is important to have information about the flow characteristics of the pulp, the liquid level in the device, etc.

[0003] Patent application publication WO2021206601A1 discloses a slurry distribution compartment device, a slurry filtration device, and a slurry introduction method, wherein a control unit has an input of information associated with sensor readings, which are responsive to characteristics associated with slurry flow. The information associated with the sensor readings includes information about at least one of the slurry flow rate, pressure in the slurry, slurry temperature, and slurry conductivity. Examples of such sensors are, for example, pressure sensors, flow rate sensors, temperature sensors, conductivity sensors, etc. The sensors are located within the slurry compartment or at the outlet opening of the distribution compartment and are connected to the input of the control unit via a wired or wireless connection. The sensors are installed to directly measure the slurry flow. This known system does not provide an indication of stagnant flow or accumulation in the flow, nor does it provide an indication of the overall uniformity of the flow across the measured surface area of ​​the device.

[0004] One type of apparatus for pulp production is the washpress, used to clean the pulp and remove its liquid. A washpress typically comprises two rollers with a pressing nip between them, and the rollers are located in a chamber into which the pulp is fed for cleaning and pressing to remove the liquid. In a washpress, the pulp flow should be evenly distributed along the pressing nip to achieve maximum cleaning capacity and uniform pressing pressure. Stagnant flow and buildup inside the chamber can interfere with processing and, if accumulated material clumps are released into the pressing nip, can even cause roller failure. With feed flows of a specific consistency (e.g., pulp and black liquor flow) that are too large for the chamber, the washing fluid will flood the roller shafts and their bearings, causing corrosion damage. There is no easy, robust, or cost-effective technique for measuring the level of the washing fluid inside the chamber of a washpress. Summary of the Invention

[0005] The object of this invention is to create a measurement system for a suspension treatment device, wherein the disadvantages of the prior art are eliminated or at least minimized.

[0006] A particular object of the present invention is to provide a measurement system for a suspension treatment device that is simple in construction and does not require cable installation.

[0007] A particular object of the present invention is to provide a measurement system for a suspension treatment apparatus that can be installed in its location in preparation for measurement.

[0008] To achieve the above-mentioned objectives and those to be discussed later, the main feature of the measurement system of the suspension treatment apparatus according to the invention is the feature of the characterizing portion of the independent measurement system claim.

[0009] Advantageous features and embodiments of the invention are defined in the dependent claims.

[0010] According to the present invention, in the measurement system of the suspension treatment apparatus, the apparatus includes at least one chamber formed inside at least one wall, and the measurement system includes a temperature sensor system comprising a plurality of temperature sensors attached to the outer surface of the wall of the chamber.

[0011] According to an advantageous feature of the invention, in a temperature sensor system, the temperature sensor is assembled in at least one strip attached to the outer surface of the wall of the chamber.

[0012] According to an advantageous feature of the invention, the temperature sensor system is a bus-type temperature sensor.

[0013] According to an advantageous feature of the invention, the temperature system is configured to create a temperature map indicating temperature changes on the outer surface of the chamber wall.

[0014] According to an advantageous feature of the invention, the measurement system includes a data recording, display, and control unit that is wirelessly or via a wired connection to the temperature sensor system.

[0015] According to an advantageous feature of the invention, the suspension treatment apparatus is a cleaning press comprising two pressing rollers forming a pressing zone between the two pressing rollers, and the pressing rollers being located in a chamber on the outer surface of the chamber having a temperature sensor system arranged on the wall.

[0016] According to an advantageous feature of the invention, the cleaning press includes at least one feed stream of the suspension and at least one outlet stream of the suspension, and the temperature sensor system includes a feed temperature sensor and an outlet temperature sensor.

[0017] According to an advantageous feature of the invention, the cleaning press includes at least a partially flowing cleaning liquid configured to flow within at least one interior of the press roll and exit via at least one end of the press roll, and the temperature sensor system includes at least one roll end temperature sensor.

[0018] According to one advantageous aspect, the measurement and monitoring of the suspension treatment apparatus is based on a temperature sensor system attached to the outer surface of one or more walls of the chamber. The measurement system includes multiple temperature sensors located on the outer wall surface of the chamber of the suspension treatment apparatus.

[0019] According to one advantage, based on the measurement results of the temperature sensor system of the measurement system, a temperature map of the suspension treatment device is generated through the data recording, display, and control unit of the measurement system. The temperature map provides information on the suspension flow in the corresponding parts of the suspension treatment device, such as the feed temperature map. By continuously or in batches measuring and their corresponding temperature maps, operational trends of the suspension treatment device can also be detected. For example, temperature differences or deviations indicate stagnant suspension flow and / or accumulation in the chamber.

[0020] According to one advantageous aspect, the temperature sensor system is advantageously assembled in at least one strip, and one or more strips thus form a bus-type temperature sensor system for the measurement system. These bus-type sensors can effectively cover a large number of sensors and a large surface area. It is intended to connect multiple temperature sensors in series or parallel to form at least one measurement channel of the measurement system.

[0021] Advantageously, the bus-type temperature sensor is provided as one or more long sensor strips, wherein the temperature sensors are positioned spaced apart at desired locations. The one or more temperature sensor strips can be attached to the outer surface of the device / chamber wall by adhesive or mechanical means. Advantageously, the measurement results are transmitted to a data logging, display, and / or control unit via wired or wireless connection.

[0022] Advantageously, the temperature sensor / temperature sensor strip of the temperature sensor system is assembled to one or more locations on the outer surface of one or more walls of the chamber, with the slurry directly on the opposite side of the wall, i.e., no insulation is provided on the wall. This provides good thermal contact between the temperature sensor and the object to be measured. Additionally, advantageously, contact with other environmental elements is insulated, thus minimizing or even eliminating the influence of ambient temperature variations on the measurement.

[0023] Advantageously, the temperature sensor / temperature sensor strip of the temperature sensor system is permanently fixed to the outer surface of one or more walls of the chamber.

[0024] According to one advantageous aspect, the monitoring of the uniformity of slurry flow in the suspension treatment unit is based on a heatmap of the external surface of the feed chamber of the clean press, received from a temperature sensor system of the measurement system. Similarly, the monitoring of the uniformity of the output flow from the suspension treatment unit can utilize the same principle, i.e., based on temperature measurements from the measurement system. Temperature deviations detected based on these measurements indicate whether the suspension flow is stagnant and / or any accumulation of slurry within the chamber. Furthermore, the temperature level itself can serve as a feedback signal to optimize the compression efficiency in the pressing zone of the clean press by setting a target temperature for the process based on the received temperature measurements.

[0025] It should be noted that suspension treatment devices (such as washing presses) exist in various configurations, and their wall structures can be formed in various ways. Therefore, the appropriate location of one or more temperature sensors in the temperature sensor system is selected based on this configuration and wall structure, so that the temperature measurement results reflect the operational needs of the corresponding suspension treatment device.

[0026] According to one advantage, the temperature sensor of the measurement system is selected from sensors suitable for measuring temperature. Advantageously, the temperature sensor is a contact sensor, such as one based on the resistivity principle or capacitance. Non-contact temperature sensors in the temperature sensor system are infrared sensors, featuring point measurement, line cameras, and / or cellular measurement matrices.

[0027] According to one advantage, the temperature sensor in the measurement system is a contact bus type temperature sensor, which allows for measurement and control of the measurement signal on the same lead for several or even hundreds of sensors, thus avoiding the need for a single lead and a large number of channels for reading the measurement results. Therefore, a special structure for the sensor device is realized. As examples of these types of sensors, the Analog Devices TMP-05 / 06daisy chain or the Maxim Integrated MAX31285 with an I2C bus can be used.

[0028] According to one advantageous aspect, the temperature sensor system and / or the temperature sensor / temperature sensor strip of the temperature sensor system leads are provided with a protective cover, which is made of, for example, metal or polymer foil or a layer of material.

[0029] A series of temperature sensors (connected in parallel to form a strip) are mounted on the outer surface of the feed chamber to cover a height from below the normal liquid level to above the overflow level. The liquid level is visible as a temperature gradient on the temperature strip. The spacing between the sensors can be adjusted based on needs ranging from a few millimeters to a few centimeters, and the number of sensors at several hundred measurement points has little impact on the sensor system and setup cost.

[0030] This invention is particularly advantageous for use in conjunction with a washing press, but it is also advantageous for use with various other types of suspension treatment apparatuses, such as containers, towers, tanks, screens, and mills. Therefore, it should be understood that the term "chamber" in this specification and claims refers to different types of chamber-like portions or elements of a suspension treatment apparatus, although in practice they are usually referred to by different terms, such as container storage, bowl, tank, box, receiver, barrel, etc.

[0031] The present invention and its advantageous features and aspects offer numerous advantages and benefits: the measurement system is easy to implement, robust, and cost-effective. It provides an improved system for measuring the characteristics of the suspension flow inside the chamber of a cleaning press, the level of the cleaning fluid, etc. Furthermore, the measurement system can be used in conjunction with different types of suspension treatment devices to provide temperature information for checking and controlling various functions of these devices. According to the invention, several temperature sensors are attached to the outer surface of the chamber wall, making installation quick and cheaper compared to situations where the sensors, sensor housings, or signal transmission need to withstand direct flow conditions.

[0032] The exemplary embodiments of the invention presented in this patent application should not be construed as limiting the applicability of the appended claims. The verb "comprising" and its derivatives as used in this patent application are open-ended and do not exclude the presence of features not mentioned. Unless otherwise expressly stated, the features described herein may be freely combined with each other. Attached Figure Description

[0033] The present invention will now be described in further detail with reference to the accompanying drawings, wherein:

[0034] exist Figure 1 The diagram schematically shows an end view of an advantageous example of a washing press, which has a pulp feed located on the side of the unit.

[0035] exist Figure 2 The diagram schematically shows an end view of another advantageous example of a washing press, which has a pulp feed located in the middle of the unit.

[0036] exist Figure 3 The diagram schematically shows a side view of a favorable example of a cleaning press.

[0037] The attached figures are labeled as follows:

[0038] 10. Clean the press.

[0039] 11 and 12 press rolls

[0040] 13. The walls of the chamber

[0041] 14 chambers

[0042] 15. Slurry feed flow

[0043] 16. Slurry outlet flow

[0044] 17 portions of the cleaning fluid leaked out.

[0045] 18. Shaft of the press roller

[0046] 19 bearings

[0047] 20 Temperature Sensor System

[0048] 215 Feed Temperature Sensor

[0049] 216 Outlet Temperature Sensor

[0050] 217 Roll end temperature sensor

[0051] 30 data logging, display and control units

[0052] N pressing zone Detailed Implementation

[0053] In the following description, the same reference numerals denote corresponding components unless otherwise mentioned, and it should be understood that the examples are readily modified to suit different uses and conditions.

[0054] exist Figure 1 The diagram schematically shows an end view of an example suspension treatment apparatus, in which the suspension treatment apparatus is a washing press 10 with a feed inlet on the side. The washing press 10 includes two press rolls 11, 12, with a pressing zone N for pressing the pulp between the two press rolls. The press rolls 11, 12 have perforated housings. The pulp feed flow 15 is arranged on the side of the washing press, which is located on an outer longitudinal side of each press roll (i.e., the opposite side relative to the pressing zone N). A chamber 14 is arranged below the press rolls 11, 12, into which the pulp feed flow 15 is guided from the side. The chamber 14 includes a wall 13. A portion of the liquid contained in the pulp is pressed into the interior of the press rolls 11, 12 by penetrating the housings of the press rolls 11, 12, as a partially discharged washing liquid 17. This liquid is removed from the ends of the press rolls 11, 13. Figure 3 ). Slurry outflow 16 as Figure 3 As shown. A temperature sensor system 20 is arranged on the outer surface of the wall 13 of the chamber 14. A data recording, display, and control unit 30 is wirelessly ( Figure 1 ) or via wired connection ( Figure 2 ) Connect to temperature sensor system 20.

[0055] exist Figure 2 The diagram schematically illustrates an end view of an example suspension treatment apparatus, in which the suspension treatment apparatus is a washing press 10 with a feed inlet in the middle. Unless otherwise stated, the components and elements of the washing press 10 according to this embodiment correspond to those according to... Figure 1 The components and elements of the embodiment. The pulp feed flow 15 is arranged in the middle of the washing press, which is located below the pressing zone N. As shown, the pulp feed flow 15 can be configured to distribute the pulp into the chamber 14. A temperature sensor system 20 is arranged on the outer surface of the wall 13 of the chamber 14. A data recording, display and control unit 30 is connected via a wired connection ( Figure 2 or wireless ( Figure 1 ) Connect to temperature sensor system 20.

[0056] exist Figure 3 The diagram schematically shows a side view of an example suspension treatment device, in which the suspension treatment device is a cleaning press 10. The cleaning press 10 includes two press rolls 11, 12, with a pressing zone N for pressing the pulp between the two press rolls. One of the two press rolls 11, 12... Figure 3As shown in the figure. The press rolls (11; 12) include a shaft 18 with a bearing 19. The press rolls (11; 12) have a perforated housing. The pulp feed flow 15 is shown below the press rolls (11; 12) in the figure, and the pulp outlet flow 16 is shown above the press rolls in the figure. The pulp feed flow 15 flows into a chamber 14, which includes a wall 13. By penetrating the housing of the press rolls (11; 12), a portion of the liquid contained in the pulp is pressed in the pressing zone N ( Figure 1-2 ) is pressed into the inside of the press rollers (11; 12), as part of the outflowing washing liquid 17 ( Figure 1-2 The liquid is removed from the ends of the press rolls (11; 12) at a partial outflow point. A temperature sensor system 20 is arranged on the outer surface of the wall 13 of the chamber 14. The temperature sensor system 20 includes a feed temperature sensor 215, an outlet temperature sensor 216, and a roll end temperature sensor 217. In this example, a data logging, display, and control unit 30 is wirelessly connected to the temperature sensor system 20. The temperature measurement result of the feed temperature sensor 215 indicates the operating characteristics of the slurry flow and possible accumulation and / or blockage. The temperature measurement result of the outlet temperature sensor 216 indicates the operating characteristics of the slurry flow. Based on the difference between the measurement results of the feed temperature sensor 215 and the measurement results of the outlet temperature sensor 216, the amount of liquid removed and the pressing efficiency can be detected. The measurement result of the roll end temperature sensor 217 indicates the liquid level in the outlet and the liquid level that may overflow into the bearings.

[0057] Based on the measurement results of the temperature sensor system of the measurement system, a temperature map of the suspension treatment device is generated in the data recording, display and control unit 30 of the measurement system.

[0058] The measurement system of the pulp production apparatus 10 is based on a temperature sensor system 20, which includes multiple temperature sensors attached to the outer surface of one or more walls 13 of the chamber 14.

[0059] In temperature sensor system 20, temperature sensors are advantageously assembled in at least one strip, and one or more strips thus form a bus-type temperature sensor system for the measurement system. Advantageously, the bus-type temperature sensor system provides one or more long sensor strips, wherein the temperature sensors are positioned spaced apart at desired locations. One or more temperature sensor strips may be attached to the outer surface of the wall of the device / chamber by adhesive or mechanical means. Advantageously, the temperature sensors / temperature sensor strips of temperature sensor system 20 are assembled to one or more locations on the outer surface of the wall 13 of chamber 14, wherein the adhesive is directly on the other side of the wall 13, i.e., no insulation is provided on the wall. Advantageously, the temperature sensors / temperature sensor strips of temperature sensor system 20 are permanently fixed to the outer surface of the wall 13 of chamber 14.

[0060] In the above description, although some functions and elements have been described with reference to certain features, these functions and elements may be performed by other features, regardless of whether they are described. Although features have been described with reference to certain embodiments or examples, those features may also exist in other embodiments or examples, regardless of whether they are described.

[0061] The invention has been described above with reference only to some advantageous examples, but it is not strictly limited thereto. Many modifications and variations can be made within the inventive concept.

Claims

1. A measurement system for a suspension treatment apparatus (10), the apparatus comprising at least one chamber (14) formed inside at least one wall (13), characterized in that, The measurement system includes a temperature sensor system (20) comprising a plurality of temperature sensors attached to the outer surface of the wall (13) of the chamber (14), the temperature sensor system (20) being configured to create a temperature map indicating temperature changes on the outer surface of the wall (13) of the chamber (14), the temperature map being configured to indicate stagnant suspension flow and / or accumulation in the chamber (14).

2. The measurement system according to claim 1, characterized in that, In the temperature sensor system (20), the temperature sensor is assembled in at least one strip, which is attached to the outer surface of the wall (13) of the chamber (14).

3. The measurement system according to claim 1 or 2, characterized in that, The temperature sensor system (20) is a bus-type temperature sensor.

4. The measurement system according to claim 1 or 2, characterized in that, The measurement system includes a data recording, display, and control unit (30) that is wirelessly or via a wired connection to the temperature sensor system (20).

5. The measurement system according to claim 1 or 2, characterized in that, The suspension treatment device (10) is a cleaning press, which includes two pressing rollers (11, 12) forming a pressing zone (N) between the two pressing rollers, and the pressing rollers (11, 12) are located in the chamber (14), and the temperature sensor system (20) is arranged on the wall (13) of the outer surface of the chamber.

6. The measurement system according to claim 5, characterized in that, The cleaning press includes at least one feed stream of the suspension and at least one outlet stream of the suspension, and the temperature sensor system (20) includes a feed temperature sensor (215) and an outlet temperature sensor (216).

7. The measurement system according to claim 5, characterized in that, The cleaning press includes at least a partially flowing cleaning liquid (17) configured to flow inside at least one of the press rolls (11; 12) and out via at least one end of the press rolls (11; 12), and the temperature sensor system (20) includes at least one roll end temperature sensor (217).

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