Optimizing Paper Making Process of a Paper Machine

The present disclosure relates to paper making process, more particularly, but not exclusively, to optimization of paper making process of paper based on controlled chemical dosages.

Paper production is a complex and continuous process that involves the transformation of a mixture containing cellulosic fibers, fillers (such as inorganic powders or granules), additives, and water into continuous reels of paper by process of atmospheric and vacuum-assisted filtration (forming section), press compaction, and drying over drying cylinders and calendaring (smoothening) process. To achieve optimal production rates and paper quality, it's crucial for various components to come together seamlessly.

The efficacy of this process heavily hinges on retention, drainage, and formation aids such as coagulants or polyelectrolytes (such as synthetic cationic charge based polymers), flocculants (such as synthetic cationic or anionic charge based high molecular weight polymers) and formation aids (such as bentonite clay or colloidal Silica). These, in various proportions, are used to alter the adhesion properties of pulp slurry. These are typically added just prior to a headbox in a forming section of the paper machine. The correct dosage and application of these chemicals are essential to attain industry benchmarks like first pass retention, first pass ash retention, and back water consistency.

However, the above-mentioned process is intricately tied to the operator's observations and decisions, who must continually monitor and adjust the flow of chemicals based on the machine's production rate and the quality of the paper being produced. Each change in the machine's production rate or quality entails intervention of an operator to change the flow set point of the flow of chemicals. Unfortunately, the current testing frequency is constrained by limited manpower availability and the time required for each test, often resulting in a restricted testing capacity of 6 to 8 tests per day. This limitation in testing frequency potentially leads to compromised production efficiency and paper quality.

The information disclosed in this background of the disclosure section is for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

According to an embodiment, the present disclosure relates to a system for optimizing paper making process of a paper machine. The system described herein comprises a process device configured to receive a process parameters corresponding to characteristics of the material and chemical composition that is used in a paper making process. Further, the process device is configured to determine an optimal concentration level of a plurality of dosing additives based on the received process parameters. Finally, the process device is configured to control concentration level of the plurality of dosing additives for optimizing the paper making process based on the determined optimal concentration level.

According to an embodiment, the present disclosure relates to a method of optimizing paper making process of a paper machine. The method described herein comprises receiving a process parameters corresponding to characteristics of the material and chemical composition that is used in a paper making process. Thereafter, the method comprises determining an optimal concentration level of a plurality of dosing additives based on the received process parameters. Finally, the method comprises controlling concentration level of the plurality of dosing additives for optimizing the paper making process based on the determined optimal concentration level.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure.

Various embodiments of the present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. The term “or” is used herein in both the alternative and conjunctive sense, unless otherwise indicated. The terms “illustrative,” “example,” and “exemplary” are used to be examples with no indication of quality level. Like numbers refer to like elements throughout.

The phrases “in an embodiment,” “in one embodiment,” “according to one embodiment,” and the like generally mean that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure and may be included in more than one embodiment of the present disclosure (importantly, such phrases do not necessarily refer to the same embodiment).

The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.

If the specification states a component or feature “can,” “may,” “could,” “should,” “would,” “preferably,” “possibly,” “typically,” “optionally,” “for example,” “often,” or “might” (or other such language) be included or have a characteristic, that particular component or feature is not required to be included or to have the characteristic. Such component or feature may be optionally included in some embodiments, or it may be excluded.

In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

illustrates an environment architecturefor implementing a system that optimizes paper machine process of a paper machine, in accordance with some embodiments of the present disclosure. The environment architecturemay be constituted by a paper machineand a system. The environment architecturemay be implemented by one or more constituent elements other than the constituent elements illustrated inand the same are not explained for the sake of brevity.

In an embodiment, the paper machinemay be an industrial equipment designed to convert a mixture containing cellulosic fibers, fillers (such as inorganic powders or granules), additives, and water into continuous reels of paper. The paper machinemay be constituted by a headbox, a forming section, a press section, and a drying section (not shown in).

In an exemplary embodiment, the headbox may a component from which the paper making process is initiated. Initially, a pulp slurry is introduced into the paper machineby using the headbox. The headbox may distribute the pulp slurry evenly onto a moving wire mesh (also, referred as forming fabric).

In an exemplary embodiment, the forming section may be a section where the pulp slurry from the headbox may be spread across the forming fabric and water may be drained through the forming fabric by gravity and vacuum assistance. This process involved in the forming section may form a continuous wet paper web with the desired fiber orientation and uniformity.

In an exemplary embodiment, the wet paper web leaving the forming section may contain a significant amount of water. In the press section, the wet paper web may be passed through a series of press rolls that may remove more water by mechanical pressure. The wet paper web may be compressed between the rolls, reducing its moisture content.

In an exemplary embodiment, the drying section may be a section where partially dewatered paper may be introduced from the press section. The partially dewatered paper may pass over a series of steam-heated cylinders that evaporate the remaining water from the partially dewatered paper, further increasing its dryness. The drying section may consist of several cylinders arranged in groups to provide controlled drying conditions. After the drying section, some additional process may be performed in order to prepare continuous reels of paper.

In an embodiment, the systemmay be constituted by a process device, a dosing pump, a mixer, a charge analyzer unit, a turbidity tester unit, and a server. At least one constituted elements of the systemmay communicate with the paper machine.

In an embodiment, the process devicemay be constituted by a control unitand input/output (I/O) interface. The control unitmay comprise, but not limited to, a Programmable Logic Controller (PLC), a Human Machine Interface (HMI), relays, sensors, switches, and/or a communication device.

The I/O interfacemay include communication protocols/methods such as, without limitation, audio, analog, digital, monaural, Radio Corporation of America (RCA) connector, stereo, IEEE® 1394 high speed serial bus, serial bus, Universal Serial Bus (USB), infrared, Personal System/2 (PS/2) port, Bayonet Neill Concelman (BNC) connector, coaxial, component, composite, Digital Visual Interface (DVI), High Definition Multimedia Interface (HDMI®), Radio Frequency (RF) antennas, S Video, Video Graphics Array (VGA), IEEE® 802.11b/g/n/x, Bluetooth, cellular e.g., Code Division Multiple Access (CDMA), High Speed Packet Access (HSPA+), Global System for Mobile communications (GSM®), Long Term Evolution (LTE®), Worldwide interoperability for Microwave access (WiMax®), Dedicated Short-Range Communications (DSRC), or the like.

In an embodiment of the present disclosure, the process devicemay be in communication with a Distributed Control System (DCS) (not shown in) of the paper machineusing a wired or wireless communication protocol and may receive training process parameters for training the process device. The training process parameters from the DCS corresponds to parameters that influence the outcomes of retention (from the press section), drainage (from the drying section), and formation (from the forming section). The process devicemay be equipped with Artificial Intelligence/Machine Learning (AI/ML) based programs that autonomously learn the intricate inter-relationships existing among training process parameters and desired results, specifically focusing on the retention, the drainage, and the formation qualities. Once the process devicemay be trained, the process devicemay evaluate the current state of process parameters and the desired retention, drainage, and formation results. Subsequently, the process deviceadjust and control the dosages of chemicals used in the paper making process.

In an another embodiment of the present disclosure, the process devicemay receive the process parameter information for evaluation from a plurality of sensors (not shown in). The plurality of sensors may be in communication with the paper machine. The plurality of sensors may comprise, not limited to, a Total Suspension Solid (TSS) sensor, a conductivity sensor, and a pH sensor. In an embodiment, the plurality of sensors may be a part of the process device. In an alternative embodiment, the plurality of sensors may be communicably connected with the process device.

The TSS sensor is a device that may be used to measure concentration of suspended solid particles in a backwater of the paper making process. The backwater may refer to water that may be drained or separated from the paper slurry as it undergoes dewatering and drainage in the forming section of the paper machine. As water drains through the fabric due to gravity and vacuum assistance, the water is collected and referred to as backwater. The backwater may contain various dissolved and suspended materials, including fibers, fillers, chemicals, and other contaminants. The backwater forms a significant recirculated component of headbox slurry and hence measurement of its TSS is vital significance and a macro-indicator of paper machine forming section's performance. Measurement of filtrate turbidity of headbox stock is a leading indicator of the TSS of backwater.

The conductivity sensor is a device that may measure concentration of suspended solids and dissolved solids present in backwater. The conductivity sensor may work on a principle that the ability of a solution to conduct electricity is directly related to the presence of ions. These ions originate from dissolved salts, minerals, and other substances present in the water. In the context of backwater analysis, the conductivity sensor may determine the concentration of suspended and dissolved solids, which can indicate the level of contamination, salinity, or overall water quality. The sensor typically consists of electrodes that come into contact with the water and measure the ease with which an electric current passes through it. The higher the conductivity, the greater the amount of dissolved ions.

The pH sensor is a device that may measure the acidity or alkalinity of the backwater at any given point in the paper making process. In particular, the pH sensor may consist of an electrode system, including a glass electrode sensitive to hydrogen ions and a reference electrode that provides a stable comparison voltage. When immersed in backwater, the Ph sensor may generate an electrical signal proportional to the hydrogen ion activity, which is then converted into a pH value.

In an embodiment of the present disclosure, the process devicemay further receive information related to a charge density or zeta potential of suspended particles present in a filtrate at a time of paper making from the charger analyzer unit.

The filtrate may refer to liquid that is extracted from headbox water in the paper making process. The filtrate is the liquid portion that drains or is separated from the pulp slurry during the forming section of the paper machine, specifically, as the pulp slurry is spread over the forming fabric and the initial dewatering takes place. It is the water that is separated from the pulp slurry as it undergoes mechanical pressing and gravity-driven drainage on the paper machine.

In an embodiment, the charge analyzer unitmay be a device or an instrument to assess charge density and electrostatic interactions among suspended particles present in the filtrate extracted from the headbox water. The charge analyzer unitmay work on the principal of electrochemistry, utilizing electrodes and sensors to measure the electrical properties of the filtrate. By subjecting the filtrate to an electric field, the charge analyzer unitmay determine the overall charge on the suspended particles, indicating whether the charge may be predominantly cationic or anionic. In an embodiment, the charge analyzer unitmay measure zeta potential, providing data on the potential difference between the liquid medium and the particles surface layer.

In an embodiment, the charge analyzer unitmay be configured to continuously extract a filtrate from the headbox of a paper machine, analyze the electrical properties of the filtrate, and provide a measured charge density value as a process parameter to the process device. The charge analyzer unitmay be implemented as a device or an instrument designed to assess charge density and electrostatic interactions among suspended particles present in the filtrate extracted from the headbox water.

In an embodiment, the charge analyzer unitmay operate based on the principles of electrochemistry, utilizing electrodes and sensors to measure the electrical characteristics of the filtrate. In an implementation, the charge analyzer unitmay subject the filtrate to an electric field and determine the overall charge on the suspended particles. Based on the measurement, the charge analyzer unitmay identify whether the charge is predominantly cationic or anionic.

In an embodiment, the charge analyzer unitmay be configured to measure zeta potential, which represents the potential difference between the liquid medium and the surface layer of the suspended particles. The measured charge density value obtained from the charge analyzer unitmay be transmitted to the process device, where it may be utilized as a key process parameter.

In an embodiment of the present disclosure, the process devicemay further receive the turbidity value of the headbox water from the turbidity tester unit. The detailed functioning of the turbidity tester unitmay be further explained with reference toin forthcoming paragraphs of the present disclosure.

In an embodiment, after receiving process parameters such as pH value, conductivity value, total suspended solids (TSS) concentration value, charge density value, and turbidity value, the process devicemay be configured to compare the received process parameters with predefined reference values. In an embodiment, the predefined reference values may be stored in at least one database or memory of the process device. The predefined reference values correspond to optimal operating conditions determined based on at least one of prior experimentation, industry standards, or machine learning models trained on historical process data.

The process device, based on the comparison, may be configured to identify deviations in the received process parameters from the predefined reference values. In response to identifying such deviations, the process devicemay be configured to determine corrective measures for adjusting the concentration levels of a plurality of dosing additives.

In particular, subsequent to identifying the deviations, the process devicemay be further configured to analyze at least one of the magnitude of the identified deviations and determine corrective measures based on the analysis. The corrective measures may be determined using at least one of control algorithms, predictive models, or rule-based logic configured to compute an optimal quantity of each dosing additive required for correction.

Upon determining the required adjustments, the process devicemay be configured to determine an optimal concentration level for each dosing additive based on the calculated adjustments.

After determining the optimal concentration level, the process devicemay generate at least one control signal. After generation of the at least one control signal, the process devicemay transmit the at least one control signal to at least one dosing pump. The at least one control signal may be configured to regulate the dosing of the plurality of additives in real-time to achieve the determined optimal concentration levels. The process devicemay be further configured to continuously monitor the updated process parameters after executing the dosing adjustments and dynamically respond to further deviations, thereby implementing a closed-loop feedback mechanism for real-time process optimization.

In an embodiment, the at least one dosing pumpmay be in communication with the process device. Based on this communication, the at least one dosing pumpmay provide accurate and controlled delivery of dosing additive based on the at least one control signal received from the process device. In particular, the at least one dosing pumpmay be configured to determine amount of a plurality of dosing additives based on the at least one control signal received from the process device. After determining the amount of the plurality of dosing additive, the at the least one dosing pumpmay be configured to transmit the amount of the plurality of dosing additives in a controlled manner to the mixer. In an embodiment, the communication ability of the at least one dosing pumpmay facilitate controlled delivery of the dosing additive for the paper making process based on real-time process conditions and requirements.

In an embodiment, the dosing additives may be, not limited to, one or more coagulants, one or more flocculants, and formation aid chemicals. Each dosing additive may be associated with different dosing pump.

In an embodiment of the present disclosure, the dosing additives may be injected into the mixer. The mixermay be placed before the headbox of the paper machine. The mixermay perform efficient mixing of the dosing additive in order to provide efficient paper making process. The detailed functioning of the mixermay be further explained with reference toin forthcoming paragraphs of the present disclosure.

In an embodiment, the process devicemay be in communication with the server. The process devicemay utilize functionality of serversuch as scalability, flexibility, and centralized data storage and may enable a seamless aggregation of data from multiple devices outside the environment architecture, even when located in diverse geographical locations. This unified approach empowers comprehensive analysis of trends and Key Performance Indicators (KPIs), thereby empowering the process deviceto make more informed and strategic decisions for end users. Further, with the adoption of functionality of the server, the process devicemay ensure minimal to zero data redundancy, high accessibility, and real-time insights, accessible from virtually anywhere with an internet connection. The integration of the process deviceand the servermay create a harmonious synergy between edge computing real-time processing and cloud data analysis.

Moving to, which illustrate a turbidity tester unit(same as the turbidity tester unitof), in accordance with some embodiments of the present disclosure. Theillustrates a first view of the turbidity tester unitand theillustrates a second view (opposite to the first view) of the turbidity tester unit. The turbidity tester unitmay perform operation of measurement of the filtrate turbidity of the headbox water and communicate the measured filtrate turbidity to the process device.

In an embodiment, a representation of the components of the turbidity tester unitalong with their abbreviations may be shown below in Table 1.

In an embodiment, the turbidity tester unitmay perform an operation in order to provide indications for advance prediction of the trend of falling or raising retention values and provides early opportunity to correct the dosages pro-actively without actually waiting for the consistency results of the headbox and backwater. The operation of the turbidity tester unitmay be as described below:

In an embodiment, prior to initiating an operation on a filtrate unit, a hose pipe connection may be established from flow pipe to the filtrate unitand from the filtrate unitto a drain.

Upon initiating the operation, a first operation may be performed. In the first operation, a pulp inlet valve and a pulp flushing valve may be opened. The opening of these valves may allow the introduction of a flushing fluid to wet the pulp and remove any residual stagnation from a previous test. The flushing process ensures that any leftover pulp or contaminants from a previous cycle may be expelled.