• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:

    公开号:SE1000668A1
    申请号:SE1000668
    申请日:2010-06-23
    公开日:2011-12-24
    发明作者:Anders Karlstroem
    申请人:Anders Karlstroem；
    IPC主号:
    专利说明:

    95 20 25 35 40 2 is in most cases introduced into the refiners together with diluent via the center (7) of the grinding wheels and if the grinding material consists, for example, of wood ice or processed pulp from a previous refiner, this grinding material is distributed on its way to the periphery of the grinding wheels ( 8). The grinding zone (9), or as it is also called the refining zone, between the grinding wheels can have a variable grinding gap (10) along the radius (11) of the grinding wheels depending on the grinding applied to the surfaces of the grinding wheels.
    The diameter of the grinding wheels varies depending on the refinery's products and the refiners' production capacity. Previously, the grinding wheels were cast in one piece, but today it is also common to modularly manufacture the grinding wheels in a number of grinding segments (12 and 13), see Figure 1 and Figure 2. The segregant can, for example, extend from the center of the grinding wheels to its periphery or be divided into two rings. an inner (14) and an outer ring (15). The zones between the inner and outer rings are often called the "breaker bar zone" and the peripheral zone, respectively.
    The surfaces (16) of the grinding segregator are often designed in different ways with characteristic patterns in the form of booms (17) and ponds (18). The barriers act as knives and deflibrate the ice or alternatively refine the mass formed. In addition to the direct grinding zone, during HC refining, both fibers, water and steam are also transported in the ponds between the barriers. Through different pattern designs, it is possible to make the grinding segments become feeding or stopping the berm mass in order to influence the flow conditions and thereby create special pulp qualities. The frictional work to which the ice and pulp are subjected in the malting zone means that the incoming water is evaporated during HC refining. The amount of steam produced is spatially dependent, which is why both water and steam can occur together with fl ice or mass in the malt zone. It is usually assumed in this case that the water in the malting zone is bound to the fibers or the meter. No steam is generated during LC operation.
    There are also other types of grinders such as grinders or grinders where both grinding wheels rotate in the opposite direction or grinders consisting of four grinding wheels, where a rotating center in the middle has grinding wheels mounted on both sides and two stationary grinding wheels which are pressed together by means of hydraulic pistons to get two malzones.
    When producing pulp from wood ice or alternatively previously refined pulp, the milling discs are compressed so that the gap (10) of the milling zone becomes approximately 0.2-0.7 mm, depending on the type of refiner used.
    The grinding gap is a central control variable and an increase or decrease of the gap often takes place electromechanically or with the aid of hydraulic pistons which apply a hydraulic pressure (5) to one or more of the grinding wheels depending on the refiner type. This creates an axial force that is applied to the grinding wheels. The force that withstands the axial force consists in HC refining of both the force obtained by evaporation of water and the force generated by the fiber network of the grinding material. In cases where LC refining is used, Q ~ O m 20 25 60 35 40 3 is the forces caused by the increase in pressure in the aqueous phase as well as the grinding network of the grinding material which withstands the axial force. If the grinding gap is changed by, for example, 10%, the pulp quality is significantly affected.
    There are systems on the market where the temperature is measured along the grinding zone in order to visualize a temperature profile (19) or pressure profile (20) for control purposes, see Figure 3. In LC refining, it is preferably the pressure profile that is interesting to follow a. In HC refining it is usually sufficient to follow the temperature profile.
    In the event of a change in the condition in the grinding gap, production (ie alternativ ice- or pulp supply) and diluent addition, the temperature changes, which can thus be controlled.
    Several temperature and / or pressure sensors are commonly used and can be placed directly in the grinding segments or alternatively enclosed in a parallelepiped elongate rail (21) extending along the active radius (1 1) of the grinding segments (12 and 13), see Figure 1, Figure 2 and Figure 4 , according to the procedure in EP 0788 407 ~ Measurement in Malzon. Usually, the parallelepiped rail between two grinding segments is implemented in the outer ring on larger refiners, see Figure 2.
    The design of the grinding segments has proven to be of greater importance for how the temperature profile along the active radius looks, which is why it is difficult to decide in advance where the temperature sensors (22) and / or pressure sensors (22) are to be placed in the rail (21).
    Outside the malzone, there are instruments that can be placed in the blast line out from the generator where the dry content of the flowing mass stream can be calculated using algorithms connected to NIR (Near Infra Red) measurements. These are used as standard for controlling the dry matter with the help of the dilution water.
    The pulp quality is not measured immediately after each raffin butter, but rather when the pulp has been completely processed in the raffinates. This usually takes place after the so-called latency cyclist, where the fibers in the pulp are allowed to straighten for about 20 minutes before being passed on to a paper machine or other equipment. The sampling rate of the pulp quality can vary between 20 to 30 minutes depending on how many process lines each pulp analyzer has to handle.
    According to the literature, temperature netting has proven to be an unusually robust technology also for direct control in HC refining US2000 / 6024309 because measuring the temperature profile in the grinding zone has shown that when production, diluent supply and grinding gap change, the temperature profile is dynamically affected. The dynamic change is suitably illustrated by studying Figure 5a, where a step change of the dilution water affects the temperature profile in different ways depending on where along the radius (11) the course of events is viewed. As the diluent supply increases, the temperature (23) decreases before the temperature maximum (24). After the temperature maximum ÖO QS 20 30 35 4 the temperature increases (25). The reason for this is that the incoming water cools the returning steam at the same time as the forward steam is heated.
    When production increases, it usually means that the entire temperature profile (19) rises to another level (26), see Figure 5b. This usually also applies when the grinding gap (10) decreases, which is equivalent to the electromechanical pressure alternatively the hydraulic pressure (5) being applied to the grinding wheels via the hydraulic pistons. Experiments have also been carried out where the appearance of the pro curl shifts spatially from (19) to (32), see Figure 5c.
    In traditional control concepts for raffinator control, one often wants to control the specific energy, E, ie the ratio between the raffin's motor load, and fl is fl fate (30) F p alternatively only the motor load, the dry content out of the refiner, C for each individual raffnor, below indicated by subindex p for primary refiner and secondary refiner respectively, see below. Mass-related variables (37), for example Canadian standard freeness, CSF, which are analyzed according to the so-called latency cyclist (3 8), see Figure 6 which shows a simplified fl fate scheme is often controlled manually without any automated control concept. The elements in the output vector Y are thus affected by the elements in the input vector U which usually contain hydraulic pressure (5) Phydn diluted water fl fate (29) F D, and fl ice fl fate (30) FP depending on whether the primary or secondary driver is considered.
    Y _ Ep _ _ 811 ,, 812 ,, 813 ,, Phydr ”_ _ E, _ _ 811, 812, Phydr, p- Cp _GpUp * 821, 822 823 FD”, YS_ [CÄ_GSUS_ 821, 822, FD, l I 'P FR) where G represents transfer fi irilction matrices with its elements gy- which describe the dynamics of the system. The mass properties (3l) from each refiner are not controlled and thus vary depending on what is de facto happening in each refiner's malzone. The linear function G provides a simplification of what the process dynamics look like because the dynamics are strongly non-linear and we will return to this below.
    Raffin butter processes usually consist of series-connected refiner steps; one called the primary step (34) and one called the secondary step (35), including a process step involving a rejektrafñnörßó), see Figure 6. Sometimes a different structure can occur with parallel solutions, which makes the control concepts complex and difficult to overview.
    Examples of control concepts available on the market today are described in a dissertation from Mid Sweden University, “Quality Control of Single Stage Double Disc Chip Reajining í Joar Lidén, 2003 and US2005 / 0263259 where control concepts based on Model Productive Control, MPC, are used for large complex systems .O 20 25 60 35 40 5 comprehensive fl your refiner lines but also individual refiner lines and refiners. However, these concepts have not been based on the fact that measurement is obtained directly from the template zone via, for example, temperature profiles as in US2000 / 6024309, but focus mainly on available process variables that are measured outside the operator.
    In connection with a number of research initiatives, off-line experiments have been carried out to predict the pulp quality based on raffin butter line one with the help of so-called “Auto Regressive Moving Average eXogenous” (ARMAX) models. These are based on known sister identification systems, see Lennart Ljung's System identification, Theory for the user, 2nd edition, Prentice Hall, New Jersey (1999), and are a subset of a number of sister identification tools available on the market. The off-line experiments resulted in the article “Cleaning zone temperature control: A good choice for pulp quality control Karin Eriksson and Anders Karlström, IMPC09, 2009 where the dynamic effects on pulp quality were studied using a new type of ARMAX modulation that can still be characterized as state models that are easy to translate to transfer functions G if desired. The purpose was to investigate whether one can get any empirical correlation at all between pulp quality and step changes in dilution fl fate, production and hydraulic pressure from a primary refiner. The lasting result of the research effort was that the prediction of the pulp quality became somewhat better when information about the temperature profile of the primary offspring butter was included in the vector U.
    All refiners are different due to construction, type of grinding segments and nonlinearities in the process, which has been documented in “Reining models for control purposes” (2008), Anders Karlström, Karin Eriksson, David Sikter and Mattias Gustavsson, Nordic Pulp and Paper journal. The model that describes HC refining. The model thus assumes that the temperature and / or the absolute pressure is measured along a segment, preferably along the outer ring in the raffin butter where the actual refining takes place, in order to mathematically tighten both the material balance and the energy balance in the raffle and thus calculate the grinding gap, see the Swedish patent application 0502784-2.
    What distinguishes the model from previous rudimentary attempts to describe the physics around the grinding process itself is that it calculates both the reversible thermodynamic work and the irreversible refining work carried out on the fi brers.
    However, the model does not show that the variations in the temperature profile are affected by the raw material mixture that is fed into the process, nor does it show how the distribution of the energy input in the primary and secondary stages is to be carried out.
    Ongoing research shows that the understanding of how the refiners are to be loaded is central for the operators to be able to quickly and easily change the operating conditions in the event of raw material changes. Description of the invention Technical problem: A comprehensive material on electronic control by means of dry matter measurement, grinding gap measurement and temperature measurement including safety systems to prevent aggregation of grinding segments has been reported in the literature. Documents concerning raff butter control with the help of pulp quality measurement are, however, surprisingly underrepresented. This has meant that sufficient data has not been made available to carry out an overall analysis of how the raw material mixture affects the refining conditions. However, it has been established that the raw material has a major impact on the quality of the pulp and attempts have been made to find empirical connections for how the operating conditions in the refineries are to be handled.
    Measurement systems for pulp quality are often built up of both hardware in the form of, for example, samplers from the process and image analysis systems for fiber characterization.
    The latter is linked to software that calculates mass actions that form the basis for, for example, Medium Fiber Length (MFL) calculations. The Canadian Standard Freeness (CSF) dewatering measure is usually also represented by the pulp quality measurement systems.
    Some results show that measurement of pulp quality variables with such equipment often shows a clear deviation from actual conditions obtained during the direct refining of the fibers.
    Usually a refiner line consists of at least two serially connected raffinates, often referred to as primary and secondary raffinates. These can be run in a variety of ways dynamically while different work points can be used. This thus means that the pulp quality is formed in both the primary and secondary stages, which has not been taken into account in rule-related patents previously published.
    Since the mass quality measurement takes place according to the so-called latency cycle (38) in Figure 6, it can be difficult to determine which energy input should be used in the primary and secondary meters to achieve a specified rnass quality.
    For a long time it has been believed that it is possible to control the character of the mass and thereby indirectly the final mass quality after the secondary stage with the help of only the specific energy. This is of course a simplified truth which has been documented and commented on in “Towards Improved Control of TMP Purification Processes”, Karin Eriksson, 2009, Dept. Of Signals and Systems, Chalmers Univ. Of Technology.
    Usually, in situ measurement has not been installed in the refractory males zones, which has been a problem for a long time. Technology for measuring temperature and pressure in the mold zone has, however, reached the market and now research results are beginning to be used to optimize processes, which is part of this patent application.
    The problem you have, when temperature and pressure measurements are not available, is that you do not know how to distribute the energy input to the generators. This can be in the form of parallel refiners and / or serial refiners, as is the case for primary and secondary refiners, for example. Usually, both refiners are loaded to the maximum without caring about the process from a system optimization perspective.
    Ongoing research shows that the temperature profile and / or pressure problems react differently depending on the grinder, grinding segment pattern, where in the grinding zones the fibers are processed the longest but also on which raw material mixture is run into the primary refiner. However, it has not previously been connected, classified and used, for example, the temperature profiles in the primary and secondary meters in a well-thought-out way based on raw material changes. An example of a problem according to the above reasoning is that it has proved difficult to know, without having in situ measurement from the refining zone, how serially connected refiners should be loaded in the best possible way at different raw material compositions in order to quickly arrive at optimal operating conditions in order to produce acceptable mass.
    Another problem that has not been taken into account in previous years is that the raw material variations also affect the dry content in the refiners' malt zones. In the past, the operators have been satisfied that the pulp quality is within a certain specification, usually stated in the form of CSF and / or MFL. The spread can be quite large, which is shown in Figure 7. It is of course desirable to minimize this large work window (39) to a smaller well-specified work window (40), which to date has been difficult to implement.
    In raw material changes, it has been assumed that, for example, physical dry matter measurement in the blow line from the primary stage alone will be sufficient to take care of changes in the raw material moisture, but as we have found, the local dry matter along the malzone radius can vary considerably and thus affect residence time and final pulp quality. This of course affects the final pulp quality as the residence time of the fibers thus varies, which means that it is not enough to measure the dry matter content from the primary refiner and / or the secondary refiner.
    In addition to raw material reductions, all controllable process conditions, such as increased production, dilution water supply and hydraulic pressure (grinding gap), affect the active volume in the grinding zone. As a result, a complex pattern of process conditions arises. These must of course be controlled in some way, which has proven to be difficult because you usually follow each individual process variable in time domain, ie as a function of time, and then it is very difficult to see how the raw material fl actuations affect and differ from normal process disturbances, see Figure 8 .
    No results have yet been published where both the primary and secondary meters are equipped with measuring rails for temperature and / or pressure measurement, which proved to be an important part of the technical solution below. The solution: The present invention is the solution to these problems and relates to a method that uses robust temperature and / or pressure measurement directly in the grinding zone combined with available measurement signals from the process to control an entire refinery line during raw material conversions. The operator line is comprised of at least two connected operators called primary and secondary operators. It can also be parallel connectors. The mentioned raw material changes are most often associated with the introduction of different amounts of sawmill ice together with freshly cut ice, but other variants with mixed freshly cut ice from different tree species may also occur.
    To get a good characterization of the process conditions, it is not enough to measure the malzone temperature alone in the primary refiner. Instead, the temperature and / or pressure profiles from both the primary and secondary refiner must be used as both refiners are affected by raw material changes and thus also affect the pulp quality in different ways. In cases where the maximum temperature is used to control the process, it is thus important to measure at your points outside the radius to reach the said maximum. In some cases, the shrimp carrier may also be included if it significantly affects the final product, ie the pulp quality.
    It is generally known that refiners can be controlled with a cascade control. An extended control system, comparable to that described in “Quality Control of a Newsprint TMP Cleaning Process based on Cleaning Zone Temperature Measurements”, David Sikter, 2007, Dept. of Signals and Systems, Chalmers University of Technology, can for example be a concept where information on the temperature profiles in both the primary and secondary operators is used in a more complex control concept. Each refiner in such a MIMO (Multi-Input-Multi-Output) system thus has at least one dry content control and one temperature control. In total, the entire process line, if it consists of two series-connected refiners, will be controlled as a MIMO system with at least four insigrials and four output signals. If the maximum temperature (TW) along the profile is controlled, a process description as follows is obtained for each refiner Y: |: Tmax: |: GU: {gll z0: |:}) hydr} C “z 0 gzz FD where the hydraulic pressure Bud, and the dilution water fl FD is considered as an element in an input signal vector U and the variables T m and the dry content C belong to the output vector Y.
    The advantage of this description is that the antidiagonal elements in the transfer function matrix G become negligible because the effect of the dilution water T on T max is negligible while grinding gap changes do not affect the dry content so much. This description can then be easily transferred to a control-wording formulation for each refractor.
    Note that in this solution we indicate TW as the maximum temperature that can be measured by the parallelepiped elongated rail (21) and its temperature sensors (22), see Figure 4. This means that in cases where a sensor breaks, one of the adjacent sensors will represent T, W. Consequently, from a control perspective, this means that T ma, does not necessarily reflect the exact physical maximum temperature along the radius of the grinding zone.
    It is of course the case that the distribution of energy between the primary and secondary refiners must be based on which pulp can be accepted instead of grinding the pulp to the limit of the refiners' capacity, as is the case today in most refiner processes.
    In addition to being able to guarantee smoother quality, the purpose is also to minimize the risk of machine breakdown, etc. This is most conveniently done by defining a work window (40), see Figure 7, which sets the boundary conditions for the process. Figure 7 shows two pulp quality variables and their desired work windows. One can also extend the reasoning to include specific work windows that reproduce process-oriented information such as engine load or TW as above. Thus, instead of, as before, seeing each operator as an individual process, we want to see the entire process line in the work window in this document. Work windows are therefore described on the basis of variables obtained in the primary and secondary refiners. This enables a study of how the process conditions are affected in, for example, raw material changes. Below is an example: By, for example, visualizing TW in the secondary refiner against T ma, in the primary refiner, see Figure 9, you can obtain a more comprehensive picture of what happens with different raw material changes. For the sake of clarity, the terms R21 and R22, respectively, have been introduced in all figures after Figure 8 to describe the primary refiner and the secondary refiner, respectively.
    In Figure 9, the populations obtained for the different raw materials are referred to as 4la and 42a, respectively, and it is clear that they are distinct from each other. This is of great interest because TW is used in future control concepts instead of motor loads whose populations for the same raw materials, 41b and 42b, respectively, cannot be distinguished from each other, see Figure 10.
    It has not previously been known that the temperature shows such a clear class division for different raw materials and process conditions. It is particularly noteworthy that a comparison between the motor loads of the secondary and primary raffiners in Figure 10 does not have the same character as Figure 9, which further supports the claim that one must have in situ measurement in the raffering zone to access local connections. This fact that the engine loads can not be linked to any raw material variation is certainly one of the reasons why it has not been possible to make a class division based on raw material composition before.
    Thus, by using the work window for T ma, the operator can use the work window to adjust the distribution between the primary and secondary refiners and quickly return to the same process conditions, for example when starting up the refiners after a production stop.
    Now that this is known, the question naturally arises as to whether it is possible to control a system, according to the mathematical description above, so that production can be set quickly so that the various operating conditions are achieved.
    By implementing simple PID controls for controlling T ma, with the help of the hydraulic pressure, we get an idea of which control errors, ie the difference between the setpoint (SP) and the actual value (PV), that we can expect to get. In Figure ll we find that the control error in TW can be expected to end up in the range +/- 1 degree Celsius.
    When the maximum temperature in the primary and secondary refiners is controlled, we see that it is excellent to control the process to a predetermined working point if you know where you want to place it in a preselected work area (43), see Figure 12, which roughly corresponds to the specified work area (40 ) in Figure 7. Thus, since a class division can take place as above, the residence time variations can also be reduced in the malzones, which means that a more even pulp quality and a smaller working window (40) are obtained compared to what is normally the case (39).
    A consequence of controlling T ma, in both operators will also be that engine load variations will be reduced, see Figure 13, which shows two obtained populations 44 and 45 for two different raw material compositions.
    The main purpose of the invention is thus to describe a procedure, which with great reliability can present an on-line based tool that defines optimal work areas that are linked to different raw material qualities while you can choose within which area to run the raff butter between them.
    The invention is based on the fact that the temperature profile and / or the absolute pressure profile can be measured in the grinding zones of the primary and / or secondary operators.
    The method of the present invention is not limited to any particular device for reading temperature or pressure in the grinding zone. However, such devices are known from, for example, Swedish patent 9601420-4. The invention is also not limited to the embodiment shown, but it can be varied in various ways within the scope of the claims. ÖO 95 20 25 60 35 12 Description of drawing pad: Figure 1: Section of a stationary grinding wheel that presses against a rotating grinding wheel.
    Figure 2: Two grinding segments with intermediate parallelepiped elongate rail for measuring temperature and / or pressure.
    Figure 3: Temperature profile and pressure profile as a function of the malzone radius.
    Figure 4: Parallel pipedong elongated rail with discreetly placed temperature and / or pressure sensors.
    Figure Sa: The appearance of the temperature profile before and after an increase in the dilution water supply.
    Figure 5b: Appearance of the temperature profile before and after an increase in production.
    Figure 5c: Appearance of the temperature profile before and after a template segment change.
    Figure 6: Schematic figure of how two refractors are connected to a latency cyclist with subsequent pulp quality analyzer. The figure also includes a shrimp refiner.
    Figure 7: Description of a pulp quality work window characterized by Freeness (CSF) and mean fiberlength fl vlF L).
    Figure 8: Freeness (CSF) versus time.
    Figure 9: Example of Tmax for secondary refiners versus T max for primary refiners for two different ice assemblies to the refiner line.
    Figure 10: Example of engine load for secondary versus inner versus engine load for primary fl inner for two different fl ice compositions to refiner line one.
    Figure ll: Obtained control error, ie. the difference between setpoint (SP) and actual value (PV) for Tmax when controlling the process.
    Figure 12: Example of reducing the process work window T max (secondary refiner) versus Tmax (primary refiner) when the process TW is controlled. 13 Figure 13: Example of reduction of the process working window motor load (secondary driver) versus motor load (secondary driver) when the process T max is controlled.
    权利要求:
    Claims (1)
    [1]
    A method for controlling a set comprising at least two refractors, wherein each of these at least two refiners measures at least one measuring variable with respect to temperature or pressure in a set of spatially separated measuring points and where maximum variable values are obtained from the measuring variable values in the set points for both the at least two refiners, characterized in that the regulation comprises controllable variables that are regulated so that the maximum variable values strive for setpoints that are refinanced between the refiners based on a work window that spans at least two variables from the refiners. A method of regulation according to claim 1, characterized in that the controllable variables comprise at least either of the hydraulic pressure or the predicted water fl fate. A method for control according to claim 1 or 2, characterized in that the measuring variable refers to temperature. A method for regulation according to claim 1 or 2, characterized in that the measuring variable refers to pressure. A method for regulation according to claims 1-4, characterized in that the method is applied to two successively alternatively two parallel arranged generators. A device for regulating a set comprising at least two sensors, wherein each of these at least two sensors at least one measuring variable with respect to temperature or pressure is measured by a set of spatially separated sensors and where maximum variable values are obtained from the measuring variable values in the sets of sensors for both the two sensors. by the device receiving controllable variables that are regulated so that the maximum variable values strive against setpoints that are interoperable with each other based on a well-specified work window that spans at least two variables from the operators. A control device according to claim 6, characterized in that the controllable variables comprise at least either of the hydraulic pressure or the dilution water fl. A control device according to claim 6 or 7, characterized in that the sensors - measure temperature. A device for control according to any one of claims 6-8, characterized in that the sensors measure pressure. A device for control according to any one of claims 6-9, characterized in that the device regulates two consecutive or alternatively two arranged arrangers.
    类似技术:
    公开号 | 公开日 | 专利标题
    EP1743068B1|2018-06-06|System and method for controlling a thermo-mechanical wood pulp refiner
    CA2707683C|2016-06-14|An apparatus for washing and dewatering pulp, a system for controlling such an apparatus, and a method for processing pulp in such an apparatus
    SE1000668A1|2011-12-24|Procedure for controlling pulp quality from refiners for varying raw material mixtures
    SE506687C2|1998-02-02|Method and apparatus for controlling the grinding process in a refiner
    EP2221680B1|2012-04-04|Configurable multivariable control system
    US7809462B2|2010-10-05|Power savings method for rotating pulp and paper machinery
    EP2488695B1|2016-09-21|Procedure and system for refining a fibrous material with improved energy efficency and pulp quality
    CA2744638C|2016-01-26|Procedure and system for control of a refiner to improve energy efficiency and pulp quality
    SE0901588A1|2011-04-26|Procedure for controlling pulp quality from refiners
    SE0900916A1|2010-12-07|Procedure for minimizing the difference between temperature profiles in refiners with two grinding zones
    Karlström et al.2016|Pulp property development Part III: Fiber residence time and consistency profile impact on specific energy and pulp properties
    Luukkonen et al.2012|Mechanical Pulping: Low consistency refining of mechanical pulp: Relationships between refiner operating conditions and pulp properties
    SE532558C2|2010-02-23|Procedure for limiting process conditions in refiners to prevent fiber cutting and breakage of mill segments
    WO1996011284A1|1996-04-18|Process for controlling a drying plant and arrangement therefor
    RU2340854C1|2008-12-10|Method of drying period rating for products containing free and bound moisture when drying mode is changed
    Isokangas et al.2005|Optimisation of wood losses in log debarking drum
    Huhtanen2007|Numerical study on refiner flows: Determination of refining efficiency and pulp quality by mixing analogy
    JP5778136B2|2015-09-16|How to control wood pulp production in a chip refiner
    CA2784502A1|2011-06-30|Procedure for controlling the pulp quality from refiners
    Ferritsius et al.2018|TMP properties and refining conditions in a CD82 chip refiner. Part I: Step changes of process variables, description of the tests
    SE530528C2|2008-07-01|Pulp refiner grinding gap calculating system, comprises separate or combined pressure and temperature sensors for providing data combinable with material and process variables
    WO2013095203A1|2013-06-27|Procedure for controlling pulp quality from refiners
    CA2633275A1|2007-07-12|Rapid sampling assembly for thermo-mechanical pulp control application
    Forsman et al.0|Project report: Multivariable Control of the Grinding Process Brief version
    同族专利:
    公开号 | 公开日
    SE535283C2|2012-06-12|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    CN111705534A|2020-06-04|2020-09-25|北京创源基业自动化控制技术研究所|Grinding disc of straw decomposition machine|
    WO2013095203A1|2011-12-20|2013-06-27|Karlstroem Anders|Procedure for controlling pulp quality from refiners|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    SE1000668A|SE535283C2|2010-06-23|2010-06-23|Procedure for controlling pulp quality from refiners in varying raw material mix|SE1000668A| SE535283C2|2010-06-23|2010-06-23|Procedure for controlling pulp quality from refiners in varying raw material mix|
    [返回顶部]