• 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:
    A method for controlling an oxygen-bleaching process of lignocellulosic pulp to a desired degree of delignification. The pulp is passed at a substantially constant temperature into a bleaching reactor wherein the pulp has a substantially constant level at its outlet. The hydrostatic pressure is measured and the quantity of oxygen fed into the reactor is adjusted to reach a desired degree of delignification.
    公开号:SU1542423A3
    申请号:SU853974051
    申请日:1985-11-06
    公开日:1990-02-07
    发明作者:Мальмстен Эркки
    申请人:Раума-Репола Ой (Фирма)；
    IPC主号:
    专利说明:

    This invention relates to methods for regulating the process of oxygen bleaching of cellulose.
    The purpose of the invention is to improve the quality of bleaching.
    Figure 1 shows an example implementation of this method; figure 2 - the results of the experiments; FIG. 3 shows the operability of the control method.
    In the diagram (Fig. 1), a settler 1, an oxygen mixer 2, a reactor 3, a pressure sensor 4, a dispenser 5, a differential relay 6, an alkali flow meter 7, a second differential relay 8, pH measuring circuit 9, flow meters 10 and 11, a device 12 are indicated. density control, additional differential relays 13 and 14, temperature controller 15 and steam flow meter 16.
    The method is carried out as follows.
    The incoming pulp is passed through the thickness control device 12 and the flow meter 10 into the scrubber (settler) 1, then alkali is introduced into the pulp, then the pulp is pumped through the oxygen mixer 2 to the lower end of the reaction tower 3, which is heated to normal pressure. pulp to a predetermined level using steam.
    Oxygen bleached pulp flows out through the upper edge of the reactor 30 At the lower end of the reactor 3 there is a pressure sensor 4 and a corresponding measuring circuit that controls the hydrostatic pressure in the reactor at a predetermined level by changing the oxygen supply to the metering device 5 using a differential relay 6. At change the oxygen consumption g relay
    (Y)
    WITH

    sn
    31
    8 sets a new flow rate in alkali flow meter 7, therefore the ratio of alkali to oxygen in the incoming pulp remains at a predetermined level. The reactor is equipped with a pH sensor with an appropriate pH meter 9, with which the differential relay 8 is adjusted. The pH measurement equipment can also be such that for all flow rates (flow is the actual mass flow) determined by flow meter 1 1 taking into account the density, measured



    The lignin yield is determined by IBC. The results of the experiments are presented in figure 2 and in table 1.
    From these results, a correlation is seen between the decrease in the lignin content and the hydrostatic pressure.
    EXAMPLE 2, The installation produces sodium sulfite pulp from Canadian spruce and pine, and the proportion of pine is about 80%. The lignin concentration in the pulp is determined by IBC. Product quality and product data
    The sensor 12, was supported by the automation of the productivity of the process carried out continuously for 18 hours, is given in Table 2.
    alkali to oxygen ratio set by means of relays 13 and pH meter 9. The change in the set hydrostatic pressure value is made through the flow meter 10 and relay 14. The main level of the set hydrostatic pressure and the effect of performance on the hydrostatic pressure level and installation
    0-100%; curve 2 - performance 0-30 t / g 0-100%; curve 3 - the hardness of the pulp to the reactor 1-10 IBC 0-100%; curve 4 - oxygen consumption
    thirty
    35
    40
    pH meter 9 (differential settings of 25–1–5 kg / min; curve 5 — hardness of pulsed relays 13 and 14) are determined based on measurements of the decomposition of lignin in the installation. In addition, the temperature of the supplied pulp is controlled by the controller 15, and the steam consumption is measured by the meter 16.
    In addition, the hydrostatic pressure in the reactor can be measured at different levels, and the pressure ratios obtained can be used for regulation. To control the bleaching process carried out under pressure, you can use a method that measures the pressure difference at the upper and lower ends of the reactor. Of course, in the process that takes place under pressure, the excess pressure must be kept exactly constant so that its changes cannot affect the amount of hydrostatic pressure, otherwise these effects must be taken into account.
    Example 1 In order to establish the relationship between the hydrostatic pressure in the bleaching reactor and the decomposition of lignin, experiments were carried out on an installation whose scheme is shown in Fig. 1. The cellulose pulp used in the experiments is a sodium sulfate liquor pulp, which is obtained from Canadian spruce and pine, and the proportion of pine is approximately 80%. Discharges after the reactor) 1-10 IBC 0-100%.
    During the first hours of operation, the pulp consumption in the reactor varies several times (curve 2).
    The control system maintains the set point of the hydrostatic pressure controlled by curve 1, while the oxygen supply is controlled by curve 4, as well as the alkali supply, and the oxygen / alkali ratio is 1/2. Despite the 40% performance change, the hardness of the oxygen-bleached pulp is almost unchanged.
    In the final stage of the industrial experiment (Fig. 3), the control system works reliably when the hardness of the pulp entering the reactor 45 is doubled (curve 3). Even so, the control system maintains the hardness of the oxygen bleached pulp at the same constant level.
    This method allows you to adjust the process of oxygen bleaching, and also provides a simple
    50
    55
    and reliable oxygen bleaching management.
    权利要求:
    Claims (2)
    [1]
    1. Method of regulating the process of oxygen bleaching of cellulose
    productivity of the process, carried out continuously for 18 h, is given in table 2.
    The efficiency of the regulation method is shown in FIG. 3, where curve 1 is the hydrostatic pressure.
    0-100%; curve 2 - performance 0-30 t / g 0-100%; curve 3 - the hardness of the pulp to the reactor 1-10 IBC 0-100%; curve 4 - oxygen consumption
    1-5 kg / min; curve 5 - the hardness of the
    1-5 kg / min; curve 5 - the hardness of the
    after reactor) 1-10 IBC 0-100%.
    During the first hours of operation, the pulp consumption in the reactor varies several times (curve 2).
    The control system maintains the set point of the hydrostatic pressure controlled by curve 1, while the oxygen supply is controlled by curve 4, as well as the alkali supply, and the oxygen / alkali ratio is 1/2. Despite the 40% performance change, the hardness of the oxygen-bleached pulp is almost unchanged.
    In the final stage of the industrial experiment (Fig. 3), the regulation system works reliably when the hardness of the pulp entering the reactor doubles (curve 3). Even so, the control system maintains the hardness of the oxygen bleached pulp at the same constant level.
    This method allows you to adjust the process of oxygen bleaching, and also provides a simple
    and reliable oxygen bleaching management.
    Invention Formula
    1. Method of regulating the process of oxygen bleaching of cellulose
    adjusting the flow of alkali depending on the pH of the cellulosic suspension in the reactor after mixing it with alkali and oxygen, characterized in that, in order to determine the quality of bleaching, the hydrostatic pressure in the reactor is additionally measured, and the flow rate of galeoch, oxygen or soot
    The cost of oxygen to alkali is controlled by the amount of mismatch between the measured and the set hydrostatic pressure values.
    [2]
    2. Method pop. 1, characterized by the fact that the hydrostatic pressure is measured in the upper and lower parts of the reactor. Table 1
    Table 2
    Steam
    - &
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    §one
    alkali
    Bleached hotel
    figure 1
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    38,035, 030
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    t 60
    70
    Decreased lignin content,%
     §
    Editor I. 1 1makova Tehred L.Oliynyk
    Order 292 Circulation 326 Subscription
    VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5
    $ 2
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    Proofreader M. Maksimishinets
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    同族专利:
    公开号 | 公开日
    FI71178C|1988-05-18|
    ES548535A0|1986-12-01|
    FR2572742B1|1988-06-03|
    SE8505246D0|1985-11-06|
    FI844390A0|1984-11-08|
    IT1186185B|1987-11-18|
    US4840703A|1989-06-20|
    DE3538618A1|1986-07-10|
    FR2572742A1|1986-05-09|
    NO163910B|1990-04-30|
    IT8522761D0|1985-11-08|
    SE463106B|1990-10-08|
    FI71178B|1986-08-14|
    JPH024718B2|1990-01-30|
    AT391718B|1990-11-26|
    ATA310985A|1990-05-15|
    FI844390L|1986-05-09|
    ZA858415B|1986-07-30|
    BR8505604A|1986-08-12|
    ES8701263A1|1986-12-01|
    SE8505246L|1986-05-09|
    JPS61113889A|1986-05-31|
    NO854446L|1986-05-09|
    NO163910C|1990-08-08|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE1417503A1|1952-10-22|1968-10-31|Scholler Dr Jur Heinrich|Process for the production of pulp|
    US3579417A|1969-05-12|1971-05-18|Improved Machinery Inc|Continuous digester wood chip level control|
    US3832276A|1973-03-07|1974-08-27|Int Paper Co|Delignification and bleaching of a cellulose pulp slurry with oxygen|
    SU445033A1|1973-05-25|1974-09-30|Предприятие П/Я Г-4132|Apparatus for controlling pressure in a continuous viscose receiving apparatus|
    SE399966B|1973-10-17|1978-03-06|Mo Och Domsjoe Ab|WAY TO REGULATE THE QUANTITY OF CHEMICAL SUBSTANCE IN CELLULOSA INDUSTRY AND RELATED INDUSTRIES|
    US4192708A|1974-09-05|1980-03-11|Mo Och Domsjo Aktiebolag|Method for controlling the addition of active chemical for delignifying and/or bleaching cellulose pulp suspended in a liquor containing chemicals reactive with the delignifying and/or bleaching chemical|
    US4198266A|1977-10-12|1980-04-15|Airco, Inc.|Oxygen delignification of wood pulp|
    SE421019B|1980-08-26|1981-11-16|Kamyr Ab|PROCEDURE FOR CHEMICAL REGULATION IN THE TREATMENT OF A SUBSTANCE, SPECIAL MASS, WITH GAS|US4946555A|1989-01-19|1990-08-07|Canadian Liquid Air Ltd./Air Liquide Canada|Apparatus and method for measuring vent gas flow rates and parameters in pulp and paper processing|
    US5188708A|1989-02-15|1993-02-23|Union Camp Patent Holding, Inc.|Process for high consistency oxygen delignification followed by ozone relignification|
    US5525195A|1989-02-15|1996-06-11|Union Camp Patent Holding, Inc.|Process for high consistency delignification using a low consistency alkali pretreatment|
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    US5217574A|1989-02-15|1993-06-08|Union Camp Patent Holdings Inc.|Process for oxygen delignifying high consistency pulp by removing and recycling pressate from alkaline pulp|
    US5085734A|1989-02-15|1992-02-04|Union Camp Patent Holding, Inc.|Methods of high consistency oxygen delignification using a low consistency alkali pretreatment|
    US5211811A|1989-02-15|1993-05-18|Union Camp Patent Holding, Inc.|Process for high consistency oxygen delignification of alkaline treated pulp followed by ozone delignification|
    US5164043A|1990-05-17|1992-11-17|Union Camp Patent Holding, Inc.|Environmentally improved process for bleaching lignocellulosic materials with ozone|
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    US5164044A|1990-05-17|1992-11-17|Union Camp Patent Holding, Inc.|Environmentally improved process for bleaching lignocellulosic materials with ozone|
    US5173153A|1991-01-03|1992-12-22|Union Camp Patent Holding, Inc.|Process for enhanced oxygen delignification using high consistency and a split alkali addition|
    US5403441A|1992-11-13|1995-04-04|Union Camp Patent Holding, Inc.|Method for controlling an ozone bleaching process|
    US5554259A|1993-10-01|1996-09-10|Union Camp Patent Holdings, Inc.|Reduction of salt scale precipitation by control of process stream Ph and salt concentration|
    US5672247A|1995-03-03|1997-09-30|Union Camp Patent Holding, Inc.|Control scheme for rapid pulp delignification and bleaching|
    US5736004A|1995-03-03|1998-04-07|Union Camp Patent Holding, Inc.|Control scheme for rapid pulp delignification and bleaching|
    SE510740C2|1996-11-26|1999-06-21|Sunds Defibrator Ind Ab|Oxygen delignification control|
    US6153050A|1998-03-24|2000-11-28|Noranda Forest Inc.|Method and system for controlling the addition of bleaching reagents to obtain a substantially constant percentage of pulp delignification across the first bleaching/delignifying stage|
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    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    FI844390A|FI71178C|1984-11-08|1984-11-08|Procedure for controlling oxygen bleaching process|
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