• 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:SU950182A3
    申请号:SU802892752
    申请日:1980-02-29
    公开日:1982-08-07
    发明作者:Пройссер Герхард；Рихтер Клаус；Шульце Мартин
    申请人:Крупп-Копперс Гмбх(Фирма)；
    IPC主号:
    专利说明:

    The invention relates to methods for controlling the processes of separation of mixtures in extraction distillation columns and can be used in the processes for producing aromatic hydrocarbons.
    A known method for controlling the process of separation of a mixture in an extraction column by changing the flow, θ of the flow of the coolant into the boiler depending on its flow rate and regulating the flow ratio of the initial mixture and solvent [1].
    The closest in technical ) 5 essence to the invention is a method for regulating the process of separation of the mixture in the extraction column by changing the flow of coolant in the boiler of the column depending on 20 on the flow rate and quality of the initial mixture, temperature and pressure of the bottom of the column, the composition of the product in the column [2], The disadvantage these methods is that they do not provide 25 maximum performance and high quality separation of the mixture.
    The purpose of the invention is to improve the quality of separation of the mixture by increasing the accuracy of regulation.
    This goal is achieved in that the coolant flow is bypassed, while the flow rate of the main coolant flow is regulated depending on the flow rate of the initial mixture, and the bypass flow rate is dependent on a parameter characterizing the state of the product in the column.
    As a parameter characterizing the state of the product in the column, use the temperature, temperature difference or composition of the product, measured in the upper part of the column.
    In addition, the main flow of the coolant is 80-90%, mainly 90%, and the bypass flow of 10-20%, mainly 10%, of the total flow of the coolant.
    Figure 1 presents the regulation scheme of the extraction-distillation column; figure 2 is a graph of the hydrocarbon content of the extract (toluene) in the raffinate depending on the temperature of the liquid available on the measuring plate.
    The method is as follows. ''
    The extractant is supplied to the head of the extraction column 1 through a cooler 2 and pipe 3. The cooling medium necessary for cooling the extractant, for example water, is supplied to the cooler 2 through pipe 4 and again discharged through pipe 5. At that, 5 a meter can be installed in pipe 3 6 temperature, which determines the temperature of the extractant flowing through the extraction column 1, and the obtained measured · 10 .my regulator value 23 rakhonny value can be transmitted through a pulse wire 7 to a flow regulator 8, which by means of a valve 9 controls the flow of coolant flowing through the pipe 4. In some cases, the extractant can also be cooled by means of an air radiator. In this case, the temperature meter 6 regulates the cooling effect of the corresponding fan, so that the extractant is supplied to the extraction column 1 also with the required temperature.
    The separated mixture of substances (initial product) is introduced into the middle part of the extraction distillation column 1 through a heater 10 and a pipe 11. The heat carrier required for heating the mixture of substances is supplied to the heater 10 through a pipe 12 and is again discharged through a pipe 13. Similar to a control system In this case, the extractant in the pipe 11 also incorporates a temperature meter 14, the measured value of which is transmitted through the pulse pipe 15 to the flow controller 16. The latter through the valve 17 controls the supply of heat in the pipe 12.
    To heat the extraction distillation column 1, a riboiler 18 is provided in its lower part, which can be included as a direct-flow riboiler and / or as a circulating riboiler of the lower part of the column. The extractant containing the extractable substance is then discharged, for example, from the lowermost plate or from one of the lower plates of the extraction column 1, the discharge being carried out through a pipe 19, and the withdrawn substance is supplied to the hose 20 of the reboiler 18, in which it is subjected to the required heating. After that, the heated product through the pipe 21 is returned back to the extraction distillation column 1, and the product is introduced again under a blank plate.
    'The coolant supply to the riboiler 18 of the extraction distillation column 1 is regulated as follows.
    In the pipeline 22, through which the required coolant is supplied to the riboiler 18, a flow regulator 23 with a valve 24 is installed. The flow regulator 23 is connected via a pulse wire 25 to a flow meter 26, which is built into the pipeline 11. The amount of a mixture of substances (initial product) flowing through this wire to the extraction distillation column 1, in this case it is determined by a flow meter 26 and is adjustable like a temperature sensor 35, which acts on the valve 24, and the amount of the initial product can tune by means of valve 27. The control range of the flow controller 23 according to the invention is set so that approximately 8090% of the total heat supplied through line 28 in the form of an appropriate heat transfer fluid is supplied through line 22 and valve 24 to the riboiler 18. The remaining amount of heat reaches the bypass line 29 in the form of a heat carrier used. A flow regulator 30 with a valve 31 is built into the bypass pipe 29. The flow regulator 30 is connected to the measuring device 33 by means of a pulse wire 32. In this case, the measuring point 3 4 is located on. one of the upper plates of the extraction distillation column 1. As mentioned above, as a solid device 33, a measuring instrument or a gas chromatograph can be used. The temperature of the liquid measured on the control plate 35, or when using a chromatograph, the concentration of the extracted substance is transferred to the flow controller 30 by means of a pulse wire 32 as an adjustable value. The flow controller 30 by means of a valve 31 controls the flow of coolant passing through the bypass pipe 29 to the riboilera 18, such In this way, a smaller part of the total amount of heat supplied to the extraction column 1 is controlled.
    Additionally, the flow controller 30 and the flow controller 23 can be interconnected by means of a pulse wire 36. This creates an additional possibility of regulation, in which the regulatory effect of the flow controller 30 by the pulse wire 36 is shifted proportionally (in a strongly weakened form) to the set value of the flow controller 23. Thanks to this, fine control is always carried out in the optimal control range. For example, the flow controller 30 65 can be adjusted so that a control pulse is turned on when the amount of heat determined by the flow controller 30 exceeds a certain limit value, for example 20% of the total heat. In this case, this control pulse is transmitted to the flow controller 23 through the pulse wire 36 and causes a corresponding increase in the heat supply to the riboiler 18 through the pipe 22. If necessary, this kind of control can also be performed in the opposite direction. In this case, when a certain limit value is exceeded in the flow controller 23, the corresponding control pulse is transmitted to the flow controller 30.
    In addition, to ensure a constant ratio of the amounts of extractant and the starting product by means of the flow meter 26, it is possible to control the supply of extractant to the extraction column 1 through the pipe 3. Moreover, the value measured by the flow meter 26 is additionally transmitted to the flow controller 37 through the pulse wire 38, and the controller flow affects the valve 39.
    In this case, the raffinate is discharged from the extraction column 1 through the pipeline 40, and the extract through the pipeline 41. Their further processing is carried out by known methods.
    The amount of heat supplied through the pipe 22 can be adjusted to a certain unregulated value, so that in this case there may be no regulation carried out depending on the value measured by the flow meter 26. This is possible, in particular, when starting the installation or in the case when the shared mixture of substances does not have significant fluctuations in the input quantities, temperatures and chemical composition. In addition, the amount of heat supplied through the bypass pipe 29 can be supplied to a special riboilera, and this pipeline and this special riboiler can work with a different heat carrier other than the heat carrier of the riboiler 18. In practice, in the usual case, instead of one single riboilera, several on the bottom of the extraction column, and they can be adjusted in a similar way. Temperature measurement can be carried out on two different control plates instead of measuring on one measuring plate 35, and the determined temperature difference is used as an adjustable value, which is transmitted to the flow controller 30.
    The graph shown in FIG. 2 shows what effect the temperature of the extraction column has on the composition of the raffinate. In this case, toluene should be separated from non-aromatic components in the form of an extract, while the latter should be enriched in the raffinate. The efficiency of extraction distillation is the greater, the lower the toluene content in raffic nate. In this case, extraction distillation is carried out in a column having 60 plates, with the extractant (formylmorphine -N) being introduced at the head and the starting product being introduced into the column at the 33rd plate from above. In order to investigate the relationship between the temperature of the liquid present on the top plate of the column and the corresponding toluene content in the raffinate, the amount of heat supplied to the bottom of the extraction distillation column is gradually increasing. At the same time, each time the temperature of the liquid is measured on the eighth plate on top and the corresponding toluene content in the liquid (in the raffinate phase). The curve shows that when the temperature of the liquid increases, the toluene content in the liquid increases very steeply (in the raffinate phase /. In the temperature range 145-152.5 ° C, the toluene content in the raffinate increases only from about 2 wt.% To about 4 wt.%. In the range 164-165 ° C t toluene content increases, in contrast to about 17 wt.% to about 26 wt.%. based on this, we can conclude that the success of the extractive distillation decisive influence current regulation supplied koliches heat, which helps maintain the temperature in the upper part of the extraction distillation column in a range in which the temperature gradient has the greatest value, i.e., the temperature change is large, which is necessary to change the toluene content in the raffinate by 1%: On the contrary, if a certain value is exceeded temperature, the temperature gradient decreases so much that the toluene content in the raffinate can hardly ·· change due to changes in temperature on the control plate.
    For this example, this means that in order to maximize the yield, the toluene content in the raffinate must be maintained in the range
    2-4 wt.% ·, As a result of which the amount of heat supplied to the bottom of the extraction distillation column must be controlled so that the temperature of the liquid on the control plate is maintained in the range of 145-152.5 ° C.
    To obtain comparative data, the temperature of the liquid, measured 5 on the control plate (the eighth plate on top), was used as an adjustable value of the total amount of heat supplied to the bottom of the extraction distillation column 10. Despite the use of conventional regulators and optimal tuning of the control system, it was not possible, however, to maintain the temperature of the liquid on the control plate-15 ke within the indicated range. Moreover, sinusoidal temperature fluctuations appeared, as a result of which the toluene content in the raffinate varied in the range of 2-9 wt.%. After that, depending on the temperature of the liquid measured on the control plate, only 10-11% of the total heat supplied to the extraction column 5, while the remaining bulk of the supplied heat was set as a constant value. With this setting, the toluene content in the raffinate for a long period of time was maintained in the range of 2.43.6 forest%.
    权利要求:
    Claims (2)
    [1]
    cooler 2 and pipe 3. Cooling means necessary for cooling the extractant, such as water, is supplied to cooler 2 through pipe 4 and again discharged through pipe 5. In this case, a temperature meter b can be installed in pipe 3, which determines the temperature of the extractant flowing through the extraction column 1, and the obtained measured value can be transmitted through the impulse wire 7 to the flow controller 8, which by means of the valve 9 controls the flow of the coolant, I flow it via line 4. In some instances, cooling of extractant may be carried out also by airy radiator. In such a case, the temperature meter 6 controls the cooling effect of the respective fan, so that the extractant is supplied to the extraction column 1 also at the desired temperature. The separable mixture of substances (initial product) is introduced into the middle part of the extraction distillation column 1 through the heater 10 and pipe 11. The heat carrier required for heating the mixture of substances leads to the heater 10 through pipe 12 and again discharged through pipe 13. Similarly to the control system in this case, the extractant is also embedded in the pipeline 11 with the temperature meter 14, the measured value of which is transmitted through the pulse pipe 15 to the flow controller 16. The latter, by means of a valve 17, controls the supply of heat in conduit 12. A reboiler 18 is provided in the lower part of the section to heat the extraction distillation column 1, which can be switched on as a continuous reboiler and / or as a circulating reboiler for the lower part of the column. The extractant containing the extractable substance is removed, for example, from the extreme lower plate or from one of the lower plates of the extraction column 1, the removal being carried out via conduit 19, and the withdrawn substance is fed to reboiler hose 20, in which it is subjected to the required heating . Thereafter, the heated product returns to the extraction distillation column 1 through conduit 21, at which time the product is introduced again under a blank plate. The supply of heat carrier to riboler 18 of the extraction distillation column 1 is adjusted as follows. In conduit 22, through which the required coolant is supplied to the reboiler 1B, a flow controller 23 is installed with a valve 24. The flow regulator 23 is connected by means of a pulsed wire 25 to a flow meter 26, which is embedded in the pipe 11. The amount of the mixture of substances (starting product j through this wire to the extraction distillation column 1, in this case is determined by the flow meter 26 and is the adjustable value of the flow controller 23, which acts on the valve 24, and the amount of the initial product is It can be installed by means of valve 27. The control range of flow regulator 23 according to the invention is set in such a way that approximately 8090% of the total amount of heat supplied through conduit 28 in the form of a suitable heat transfer fluid is supplied through conduit 22 and valve 24 to the reboiler 18. The remaining amount of heat reaches the bypass pipe 29 in the form of a used coolant. In the bypass pipe 29, a flow controller 30 is installed with a valve 31. A flow controller 30 is pulsed the wires 32 are connected to the measuring device 33. Here, the measuring point 34 is located on. one of the upper plates of the extraction distillation column 1. As can be seen from the above, a temperature measuring device or a gas chromatograph can be used as a measuring instrument 33. The temperature of the liquid measured on the control plate 35, or using a chromatograph, the concentration of the extracted substance is transmitted to the flow controller 30 by means of a pulse wire 32 as an adjustable quantity. The flow control valve 30 controls the flow of heat-transfer fluid through the bypass pipe 29 to the reamer 18 via valve 31 so that a smaller part of the total heat supplied to the extraction column 1 is controlled. Additionally, the flow controller 30 and the flow controller 23 They can be interconnected by means of a pulsed wire 36. This creates an additional possibility of control, in which the regulating effect of the flow controller 30 by the pulse wire 36 is displaced proportionally (in a greatly weakened form) to the specified value of the flow controller 23. Due to this, fine adjustment is always carried out in the optimum adjustment range. For example, the flow controller 30 can be adjusted so that a control pulse is activated when the amount of heat detected by the flow controller 30 exceeds a certain limit value, for example, 20% of the total amount of heat. In this case, this regulating impulse is transmitted to the regulator 23 of the flow through the impulse wire 36 and there causes a corresponding increase in the supply of heat to the reboiler 18 through the pipe conduit 22. If necessary, this kind of control can be carried out in the opposite direction. In such a case, if a certain limit value is exceeded in the flow controller 23, the corresponding control pulse is transmitted to the flow controller 30. In addition, to ensure a constant ratio of the amounts of the extractant and the starting product, the flow meter 26 can be controlled by supplying the extractant to the extraction column 1 through line 3. In this case, the value measured by the flow meter 26 is additionally transmitted to the flow regulator 37 pulse wire 38, and the flow controller acts on the valve 39. In this case, the raffinate is discharged from the extraction column 1 through pipe 40, and the extract through pipe 41. Their further processing is It is realized by known methods. The amount of heat supplied through conduit 22 may be adjusted to a certain unregulated value, so that in this case there may be no regulation, depending on the value measured by the flow meter 26. This is possible, in particular, when the unit is started up or when the divided mixture does not have significant fluctuations in the quantities, temperatures and chemical composition. In addition, the amount of heat supplied through the circumferential conduit 29 can be supplied to a special reboiler, and this pipeline and this special reboiler can work with another coolant other than the heat sink of the reboiler 18. In practice, in the usual case instead of one single reboiler several may be located at the bottom of the extraction column, and they can be adjusted in a similar way. The temperature measurement can be carried out on two different control plates instead of on a single measuring plate 35, with a detectable temperature difference being used. as an adjustable value, which is transmitted to the flow controller 30. The graph shown in Figure 2 shows the effect the temperature of the extraction column has on the composition of the raffinate. In this case, toluene should be separated from the non-aromatic constituents as an extract, while the latter should be enriched in the raffinate. The efficiency of extraction distillation is the greater, the lower the toluene content in the raffinate. In this case, extraction distillation is carried out in a column having 60 plates, the extractant (formylmorphine-N) is introduced into the head part, and the starting product is introduced into the column on the 33rd plate from the top. In order to investigate the relationship between the temperature of the liquid present on the top plate of the column and the corresponding toluene content in the raffinate, the amount of heat supplied to the bottom of the extraction distillation column is gradually increased. At the same time, the temperature of the liquid on the eighth plate on top and the corresponding toluene content in the liquid (in the raffinate phase) are measured each time. The curve shows that as the temperature of the liquid increases, the toluene content in the liquid increases very abruptly (in the raffinate phase. In the temperature range 145-152.5 ° C, the toluene content in the raffinate increases only from about 2 wt.% To about 4 wt.%. in the range of 164-165 ° C., the toluene content increases, on the contrary, from approximately 17% by weight to approximately 26% by weight. Based on this, it can be concluded that the successful regulation of extraction distillation is decisive heat, which helps to maintain the temperatures in the upper part of the extraction distillation column in such a range that the temperature gradient has the highest value, i.e., the temperature change required to change the toluene content in the raffinate by 1%. On the contrary, if a certain temperature value is exceeded then the temperature gradient is reduced so much that the content of the toluene in the raffinate can hardly vary due to the change in temperature on the control plate. In the context of this example, this means that in order to maximize the yield, the toluene content in the raffinate should be maintained in the 2–4 wt.% Range, resulting in the amount of heat supplied to the bottom of the extraction distillation column. must be adjusted so that the temperature of the liquid on the control plate is maintained in the range of 145-152. To obtain comparative data, the fluid temperature measured on the control plate (the eighth plate on top, was used as a controlled amount of the total amount of heat supplied to the bottom of the extraction distillation column. Despite the use of conventional regulators and optimal adjustment of the control system, however, it was not possible to maintain fluid temperature on the control plate within the specified range. Moreover, there were sinusoidal temperature fluctuations, as a result of which The toluene content in the raffinate varied in the range of 2–9 wt.% Thereafter, depending on the temperature of the liquid measured on the control plate, only 10–11% of the total heat supplied to the extraction column was regulated, while the remainder The amount of heat supplied was set as a constant value. With this setting, the toluene content in the raffinate was maintained for a long period of time in the range of 2.43 .6.%. Claim 1. The method of controlling the process of separating the mixing of an extraction distillation column by changing the flow of the heat carrier supplied to the column booster and maintaining the cost ratio of the ORIGINAL mass and solvent, in order to improve the quality of separation of the mixture by increasing the accuracy of regulation , the carrier heat is bypassed, the flow of the main coolant flow is controlled depending on the flow rate of the initial mixture, and the flow rate of the bypass flow is controlled depending on the steam meter Hsfakterizuyuschego state of the product in the column. 2. The method according to claim 1, characterized in that the temperature, temperature difference or composition of the product measured in the upper part of the column is used as a parameter characterizing the state of the product in the column. 3. Method according to claim 1, characterized in that the main coolant flow is 80-90%, preferably 90%, and the bypass flow - 10-20%, mostly 10%, of the total flow of the coolant. Sources of information taken into account in the examination 1.Golub tnikov V.A. and others. Automation of production processes and automated control systems in the chemical industry. M., Himi, 1978, p. 156.
    [2]
    2. USSR author's certificate number 753442, cl. B 01 D 3/42, 1978.
    l

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    同族专利:
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    引用文献:
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    US3953300A|1972-11-29|1976-04-27|Snam Progetti, S.P.A.|Process for separating a high purity vinyl aromatic hydrocarbon from hydrocarbon mixtures containing the same|
    NL7306022A|1973-05-01|1974-11-05|
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    US3881994A|1974-04-11|1975-05-06|Universal Oil Prod Co|Distillation column reboiler control system|
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    DE2430711A1|1974-06-26|1976-01-08|Kloeckner Werke Ag|Evaporation of water or aqs solutions - to make boiler feed water using steam produced by cooling a blast furnace for heating|
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    FR2388580B1|1977-04-29|1982-01-08|Inst Francais Du Petrole|JPH0130522B2|1981-12-28|1989-06-20|Idemitsu Kosan Co|
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    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    DE2916175A|DE2916175C2|1979-04-21|1979-04-21|
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