JP6329044B2 - Concentrated can system - Google Patents

Description

  The present invention relates to a concentration can system that separates by evaporating and concentrating a mixed solution in which at least two kinds of solutions are mixed.

  In general, when a specific solution is extracted from a mixed solution in a state where a plurality of solutions are mixed, distillation is often used.

  In distillation, the concentration of a specific solution is increased by utilizing the difference in vapor pressure of each solution in a gas-liquid equilibrium state and extracting it as a gas in a state where the concentration of the specific solution to be taken out is high.

  Further, by performing this operation a plurality of times, the solution to be taken out can be concentrated to a predetermined concentration.

  Here, for example, when a polymer is produced from a chemical such as ethylene or propylene, a high concentration of 99% or more is necessary, and a rectifying column or the like among distillation columns premised on continuous distillation in order to achieve this concentration. A multistage distillation column called is used.

  However, for example, for the purpose of volume reduction of factory waste liquid or rough purification of the mixed solution, the solution to be removed is not required to have a very high concentration, and in this case, simple distillation using a batch processing concentration canister is required. Often used.

  Here, simple distillation with a concentration canister is the simplest distillation method in which the liquid mixture stored in the concentration canister is heated to evaporate and separate the evaporated gas from the remaining liquid. Widely used in processing and crude purification.

  When trying to increase the concentration of the solution after separation as much as possible by simple distillation, a method for increasing the concentration of a solution having a low boiling point by evaporating and concentrating under reduced pressure as described in Patent Document 1 has been proposed. .

Republished Patent 2004-000734

  However, in the method for recovering a fluorine-containing emulsifier described in Patent Document 1, it is possible to efficiently cope with one type of mixed solution, but there is no description for dealing with a case where a plurality of types of mixed solutions exist. There is a problem that it cannot be adequately dealt with in a factory where there is a waste liquid.

  In view of this problem, an object of the present invention is to provide a concentration can system that performs simple distillation efficiently with a single concentration can even when a plurality of types of mixed liquids are present.

  (1) A concentration can system according to the present invention is a concentration can system comprising a concentration can for evaporating and concentrating a mixed solution in which at least two kinds of solutions are mixed with a heat transfer tube provided therein. A pressure sensor installed to measure the pressure inside the concentrator, a steam supply pipe connected to the heat transfer pipe and supplying steam to the heat transfer pipe, and a pressure control valve provided on the steam supply pipe; Steam recovery for recovering the steam generated inside the concentration can, one connected to the upper part of the concentration can and the other connected to the steam supply pipe between the pressure control valve and the heat transfer pipe A heat pump installed on the steam recovery pipe, and a control unit that controls the opening of the pressure control valve according to the measured value of the pressure sensor, the control unit of the concentration can Depending on the liquid mixture And wherein the throttling the opening degree of the pressure control valve so as to be in the range of constant values.

  (2) Moreover, the concentration can system which concerns on this invention is a concentration can system as described in (1), The said heat pump is connected so that control is possible in the said control part, The said control part is a measured value of the said pressure sensor. When the value exceeds the upper limit value of the preset range, the heat pump is activated, and the opening of the pressure control valve is controlled so that the measured value of the pressure sensor does not fall below the lower limit value of the preset range. It is characterized by that.

  (3) Moreover, the concentration can system which concerns on this invention is a concentration can system as described in (1) or (2), The decompression pipe | tube connected on the said vapor | steam recovery pipe | tube between the said concentration can and the said heat pump, A depressurization control valve installed on the depressurization pipe, and the control unit is connected so as to be able to control the opening and closing of the depressurization control valve. When the upper limit value of the set range is exceeded, in addition to the operation of the heat pump, control for opening the depressurization control valve is performed.

  (4) The concentration can system according to the present invention is the concentration can system according to any one of (1) to (3), wherein the concentration can is a drain pipe for discharging condensed water generated inside the heat transfer tube. The drain pipe is provided with at least two or more branch pipes and a valve on each of the branch pipes.

  (5) Further, in the concentration can system according to any one of (1) to (4), in the concentration can system according to the present invention, when there are a plurality of types of the mixed solution, the control unit controls the mixed solution. The range of the pressure value of the concentrating can set in advance is set in accordance with each of the liquid mixtures.

  According to the concentration can system described in (1), it is possible to efficiently extract a specific solution by evaporation concentration using the difference in vapor pressure of the mixed solution even in simple distillation using the concentration can. It becomes.

  According to the concentration can system described in (2), it is possible to reduce the supply of new steam and reduce running costs by using the steam collected by the heat pump as much as possible for the evaporation of the solution. .

  According to the concentration can system described in (3), in the concentration can system using a heat pump, the amount of the liquid mixture inside the concentration can gradually decreases and the heat input from the heat pump gradually increases. The pressure increases. However, by opening the depressurization control valve, the pressure inside the concentrator can be maintained within a preset range for a long time, and more efficient evaporation and concentration can be achieved.

  According to the concentration can system described in (4), even when a plurality of different mixed liquids are evaporated and concentrated in one concentration can system, the evaporated solution is respectively transferred to another tank or the like by a separate branch pipe. It can be stored.

  According to the concentration can system described in (5), even when a plurality of mixed liquids are evaporated and concentrated in one concentration can system, the operation can be performed in an optimum pressure range according to the properties of each of the mixed liquids. It becomes possible.

It is a figure which shows the schematic diagram of the concentration can system which concerns on 1st embodiment. It is a schematic diagram which shows the operation time at the time of operation | movement of the concentration can system which concerns on 1st embodiment, and the measured value of a pressure sensor. It is a figure which shows the schematic diagram of the concentration can system which concerns on 2nd embodiment. It is a schematic diagram which shows the operation time at the time of operation | movement of the concentration can system which concerns on 2nd embodiment, and the measured value of a pressure sensor.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Such an embodiment is merely an example for facilitating understanding of the invention, and does not limit the present invention unless otherwise specified.

  In the present specification and drawings, elements having substantially the same functions and configurations are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not shown.

  (First embodiment)

  First, the structure of the concentration can system 100 which concerns on 1st embodiment is demonstrated.

  The concentrating can system 100 includes a concentrating can 10 that stores the mixed liquid therein, and a steam supply pipe 12 that is connected to the concentrating can 10 and supplies steam.

  Further, the mixed solution is sent into the concentration can 10 through the mixed solution supply pipe 14.

  A heat transfer tube 16 is installed inside the concentration can 10, and is connected to the inside of the heat transfer tube 16 so that steam from the steam supply tube 12 is sent.

  One end of the circulation pipe 18 is connected to the lower portion of the concentration can 10, and the other end is connected to the upper portion of the concentration can 10. The circulation pipe 18 is provided with a circulation pump, and the mixture liquid can be sent from the lower part of the evaporator 10 to the upper part of the evaporator 10 and showered on the heat transfer pipe 16 by the circulation pump.

  The circulation pipe 18 is connected to a solution discharge pipe 20 for discharging the concentrated solution, and the circulation pipe 18 and the solution discharge pipe 20 can be discharged from the solution discharge pipe 20. A valve is installed on each downstream side of the connecting portion.

  A vacuum tube 22 provided with a vacuum pump is connected to a portion of the steam collecting condensate collected downstream of the heat transfer tube 16 and outside the concentration can 10.

  A pressure sensor 24 for measuring the pressure inside the concentration can is installed above the concentration can 10. The measurement value of the pressure sensor 24 is sent to the control unit 26, and the control unit 26 supplies steam according to the measurement value. It is installed so that the opening degree of the pressure control valve 28 installed on the pipe 12 can be adjusted.

  In addition to the vacuum tube 22, a drain pipe 30 is connected to a portion of the steam collecting water collected downstream of the heat transfer pipe 16 and outside the concentration can 10. Are branched, and a first drain valve 32 and a second drain valve 34 are installed in each branched pipe.

  One end of a steam recovery pipe 36 is connected to the upper part of the concentration can 10, and the other end is connected to the steam supply pipe 12 between the concentration can 10 and the pressure control valve 28. A heat pump 38 is provided on the steam recovery pipe 36.

  The heat pump 38 is a blower or a compressor. However, the heat pump 38 may be anything as long as it can compress and send air.

  Next, operation | movement of the concentration can system 100 is demonstrated, referring FIG.

  FIG. 2 is a schematic diagram showing changes in pressure with the internal pressure of the concentration can 10 measured by the pressure sensor 24 as the vertical axis and the operation time of the concentration can system 100 as the horizontal axis.

  When the operation of the concentrated can system 100 is started, first, the mixed solution is sent to the concentrated can 10 through the mixed solution supply pipe 14.

  Next, after the pressure in the concentration can 10 is reduced to a predetermined level by the vacuum tube 22 having a vacuum pump, the mixed solution is circulated by a circulation tube 18 having a circulation pump and showered from the upper part of the heat transfer tube 16.

  Steam is sent to the inside of the heat transfer pipe 16 through the steam supply pipe 12, and a part of the mixed liquid evaporates by heating the mixed liquid showered from the top to the outside of the heat transfer pipe 16. On the other hand, the steam inside the heat transfer tube 16 is condensed and discharged through the drain tube 30.

  Vapor generated by evaporation of a part of the mixed liquid is accumulated inside the concentration can 10 and the pressure inside the concentration can 10 gradually increases (from point A to point B in FIG. 2).

  The control unit 26 performs control to gradually reduce the opening degree of the pressure control valve 28 when the pressure value inside the evaporator 10 measured by the pressure sensor 24 exceeds a preset lower limit value of the pressure. As a result, the pressure increase inside the evaporator 10 becomes moderate (from point B to point C in FIG. 2).

  Next, when the pressure value measured by the pressure sensor 24 exceeds the preset upper limit value, the control unit 26 activates the heat pump 38, and the pressure measured by the pressure sensor 24 determines the opening degree of the pressure control valve 28. Control is performed to gradually reduce the pressure within a range that does not fall below a preset lower limit value.

  As a result, the amount of steam supplied from the outside of the concentrating can system 100 is reduced, and the steam used for concentrating the liquid mixture is mainly the steam recovered by the heat pump 38. For this reason, the pressure value measured by the pressure sensor 24 decreases (from point C to point D in FIG. 2).

  The control unit 26 performs control to reduce the opening degree of the pressure control valve 28, but when the operation time of the concentrating can system 100 elapses, the pressure value measured by the pressure sensor 24 gradually increases due to heat input from the heat pump 38. (D point to E point in FIG. 2).

  When the pressure value measured by the pressure sensor 24 is likely to exceed the preset upper limit value, the concentration can system 100 stops operating and ends the concentration of the mixed solution (point E in FIG. 2).

  The effect of this first embodiment is that the pressure of the solution mixed with the liquid mixture is maintained by maintaining the pressure value measured by the pressure sensor 24, that is, the pressure inside the concentration can 10 within a preset range. By making maximum use of the difference in pressure, it is possible to concentrate with high efficiency even with simple distillation.

  In addition, it is possible to realize high energy efficiency by using the recovered steam by the heat pump 38 in preference to the steam supplied from the outside.

  (Second embodiment)

  The difference of the configuration of the second embodiment from the first embodiment will be described.

  In the concentrating can system 200 according to the second embodiment, the depressurizing pipe 40 is connected to the heat pump 38 from the connection portion with the concentrating can 10 on the steam recovery pipe 36, and the depressurizing pipe 40 is depressurized. A control valve 42 is installed.

  The decompression control valve 42 is connected to the control unit 26 so that the opening degree can be controlled by the control unit 26.

  The decompression pipe 40 is connected to a condenser and a vacuum pump so that the pressure inside the concentration can 10 can be released even when the concentration can 10 is in a reduced pressure state (the condenser and the vacuum pump are not shown).

  Next, the operation of the second embodiment will be described with reference to FIG.

FIG. 4 according to the second embodiment and FIG. 2 according to the first embodiment are the same up to point D, but in the second embodiment, the pressure of the pressure sensor 24 rises due to heat input by the heat pump 38 and is set in advance. When the pressure exceeds the upper limit value (point E1), the control unit 26 opens the depressurization control valve 42 to reduce the pressure inside the concentration can 10, and the pressure inside the concentration can 10 is within a preset range. The operation of the concentration can system 200 is continued while maintaining the temperature (point E1 to point E2 in FIG. 4).

  This makes it possible to concentrate the mixed solution for a longer time under an efficient pressure in order to use the difference in vapor pressure of each solution, and to enable the operation of the more efficient concentration can system.

  In both the first embodiment and the second embodiment, the concentration can system separates different solutions from a plurality of types of mixed liquids and can be stored in separate tanks (tanks and the like are not shown). It is preferable to have a drain pipe branch and a valve so that each can be used properly.

  1 and 2 show two drain pipes having a first drain valve 32 and a second drain valve 34, it is preferable to have more drain pipes and respective valves as necessary.

  In both the first embodiment and the second embodiment, the pressure value measured by the pressure sensor 24 is matched to the properties of the mixed solution so that a plurality of mixed solutions having different properties can be efficiently concentrated. It is preferable to set an upper limit value and a lower limit value.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings.

  It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention can be used as a concentration can system for concentrating a mixture under reduced pressure.

10: Concentration can, 12: Steam supply pipe, 14: Mixture supply pipe, 16: Heat transfer pipe, 18: Circulation pipe, 20: Solution discharge pipe, 22: Vacuum pipe, 24: Pressure sensor, 26: Control unit, 28: Pressure control valve, 30: Drain pipe, 32: First drain valve, 34: Second drain valve, 36: Steam recovery pipe, 38: Heat pump, 40: Pressure relief pipe, 42: Pressure relief control valve, 100: Concentration can system , 200: Concentrated can system

Claims (5)

In a concentration can system comprising a concentration can for evaporating and concentrating a mixed solution in which at least two kinds of solutions are mixed by a heat transfer tube provided therein,
A pressure sensor installed in the concentration canister and measuring the pressure inside the concentration can;
A steam supply pipe connected to the heat transfer pipe and supplying steam to the heat transfer pipe;
A pressure control valve provided on the steam supply pipe;
Steam recovery for recovering the steam generated inside the concentration can, one connected to the upper part of the concentration can and the other connected to the steam supply pipe between the pressure control valve and the heat transfer pipe Tube,
A heat pump installed on the steam recovery pipe;
A control unit for controlling the opening of the pressure control valve according to the measurement value of the pressure sensor,
The said control part restrict | squeezes the opening degree of the said pressure control valve so that the pressure of the said concentration canister may be in the range of the value preset according to the said liquid mixture, The concentration can system characterized by the above-mentioned. The heat pump is connected so as to be controllable by the control unit,
The control unit activates the heat pump when the measurement value of the pressure sensor exceeds an upper limit value of a preset range, and the measurement value of the pressure sensor is within a range that does not fall below a lower limit value of the preset range. The concentration can system according to claim 1, wherein control is performed to reduce the opening of the pressure control valve. A depressurization pipe on the steam recovery pipe and connected between the concentrating can and the heat pump;
A depressurization control valve installed on the depressurization pipe,
The control unit is connected so as to be able to control the opening and closing of the depressurization control valve, and the control unit operates the heat pump when the measured value of the pressure sensor exceeds an upper limit value of a preset range. In addition, the concentration can system according to claim 1 or 2, wherein control for opening the depressure control valve is performed. The concentration can is provided with a drain pipe for discharging condensed water generated inside the heat transfer pipe,
The concentration can system according to any one of claims 1 to 3, wherein the drain pipe includes at least two or more branch pipes and a valve on each of the branch pipes. In the case where there are a plurality of types of the mixed solution,
5. The control unit according to claim 1, wherein a range of the pressure value of the concentrating can set in advance according to the mixed liquid is set according to each of the mixed liquids. The concentration can system of any one of Claims.

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