JP2018122266A - Concentration system and concentration method - Google Patents

Abstract

A concentration system and a concentration method are provided for increasing the efficiency of concentration processing of an object to be processed. A concentration system (1) is a concentration system for evaporating a solvent component of a liquid object (A) to concentrate the object (A). Compression means 9 for extracting and compressing the vapor of the solvent component in the vessel 3, a heat exchanger 5 provided outside the evaporator 3 and into which the vapor compressed by the compression means 9 is introduced as a heating medium, and an evaporator. a circulation path 11 for circulating the material to be processed A in 3 to the outside, exchanging heat with the heating medium in the heat exchanger 5, and returning it to the evaporator 3 again; and a steam boiler 21 for introducing thermal energy applied to the object A, and a circulation pump 7 for pumping and circulating the object A to be processed is provided on the circulation path 11 . [Selection drawing] Fig. 1

Description

  The present invention relates to a concentration system and a concentration method.

  Conventionally, as a technique in such a field, a heat pump type concentrator described in Patent Document 1 below is known. In this concentrating device, a circulation path is formed by the heating can, the blowing pipe, the evaporator, and the return pipe. In the operation of the concentrating device, the object to be treated circulating in the circulation path is heated in the heating can to boil and the solvent component of the object to be treated evaporates. Thereafter, the liquid component and the vapor component having increased concentrations are blown into the evaporator, and the liquid component and the vapor component are separated in the evaporator to obtain a high-concentration liquid.

JP 2005-111320 A

  However, in the above-described concentration apparatus, the object to be processed boils by heating when it passes through the long tube in the heating tube. The vapor component generated by boiling pushes up the liquid component in the long pipe, so that the vapor component and the liquid component reach the blowing pipe and are blown into the evaporator. That is, circulation of the workpiece in the circulation path occurs due to boiling of the workpiece in the long pipe. Therefore, the efficiency of the circulation of the object to be processed in the circulation path may not be sufficient, and as a result, it cannot be said that the efficiency of the entire concentration process is sufficient.

  An object of this invention is to provide the concentration system and concentration method which raise the efficiency of the concentration process of a to-be-processed object.

  The concentration system of the present invention is a concentration system for concentrating a processing object by evaporating a solvent component of the processing object that is a liquid, and an evaporator in which the processing object is accommodated, and a solvent component in the evaporator Compressing means for extracting and compressing the steam to the outside, an external heat exchanger provided outside the evaporator to which the steam compressed by the compressing means is introduced as a heating medium, and an object to be processed in the evaporator is extracted to the outside A heat exchanger is used for heat exchange with the heating medium, and after that, a circulation path that circulates the heat medium to be returned to the evaporator again, and a heat energy introduction section that introduces heat energy applied to the workpiece from the outside. A circulation pump that pumps and circulates the workpiece is provided on the circulation path.

  In this concentration system, the object to be processed circulates in the circulation path by the pumping of the circulation pump. Therefore, the object to be processed efficiently circulates between the evaporator and the external heat exchanger, and the efficiency of the concentration process is increased.

  Further, the compression means may have a Roots blower, and the external heat exchanger may have a plate heat exchanger.

  By adopting a compression means having a roots blower, the processing capacity of the compression means can be increased, and by adopting an external heat exchanger having a plate heat exchanger, the heat exchange efficiency of the external heat exchanger is increased. Therefore, the efficiency of the concentration process as the whole concentration system can be improved.

  The concentration system of the present invention includes a rear stage evaporator in which an object to be processed concentrated in the evaporator is transferred and accommodated, a heating unit that heats the rear stage evaporator, a decompression unit that depressurizes the rear stage evaporator, and a rear stage. A condensing unit that cools and condenses the vapor on the movement path of the vapor of the solvent component that evaporates from the object to be processed in the evaporator and travels toward the decompression unit may be further provided.

  According to this configuration, the object to be processed in the evaporator can be further concentrated by heating and reducing the pressure in the subsequent evaporator. Vapor generated from the object to be processed in the latter stage evaporator is cooled and condensed in the condenser.

  Moreover, you may make it a back | latter stage evaporator have a stirring apparatus which stirs a to-be-processed object. With this configuration, heat from the heating unit can be efficiently applied to the object to be processed in the latter stage evaporator, so that concentration of the object to be processed in the latter stage evaporator is promoted, and finally the object to be processed. Can be made dry.

  As a specific configuration, the solvent component may be water, and the difference between the temperature of the vapor at the inlet of the compression unit and the temperature of the vapor at the outlet of the compression unit may be 10 to 15 ° C.

  The concentration method of the present invention is a concentration method for concentrating a processing object by evaporating the solvent component of the processing object that is a liquid, and the vapor of the solvent component in the evaporator in which the processing object is accommodated A step of drawing and compressing, a step of introducing the compressed vapor into an external heat exchanger provided outside the evaporator as a heating medium, and extracting an object to be processed in the evaporator to the outside and heating the medium with an external heat exchanger And a step of circulating the circulation path so as to be returned to the evaporator again, and a step of introducing heat energy applied to the object to be processed from the outside, and provided on the circulation path. The workpieces in the circulation path are pumped and circulated by the circulation pump.

  In this concentration system, the object to be processed circulates in the circulation path by the pumping of the circulation pump. Therefore, the object to be processed efficiently circulates between the evaporator and the external heat exchanger, and the efficiency of the concentration process is increased.

  ADVANTAGE OF THE INVENTION According to this invention, the concentration system and concentration method which improve the efficiency of the concentration process of a to-be-processed object can be provided.

It is a figure which shows the concentration system which concerns on embodiment. It is a figure which shows the drying part of the concentration system of FIG. It is sectional drawing which shows the back | latter stage evaporator and stirring apparatus of FIG.

  Hereinafter, embodiments of a concentration system and a concentration method according to the present invention will be described in detail with reference to the drawings.

The concentration system 1 shown in FIG. 1 is a system that concentrates the object A by evaporating the solvent component of the object A to be processed (liquid). In the following embodiment, “concentration” means not only a process for removing the solvent of the object A to be processed and increasing the concentration, but also the removal of the solvent component is continued after a part of the solute component in the object A is precipitated. And a “drying” process that removes almost all solvent components of the workpiece A. Examples of the material A to be processed by the concentration system 1 include leachate from a waste disposal site, plating solution generated by plating processing, food-based food cleaning water, water-soluble cutting oil generated by parts manufacturing, There are solutions generated during the production of chemical raw materials. Among these, the solvent component of the leachate in the waste disposal site is water. When the solvent component of the plating solution, the solvent component of the water-soluble cutting oil, the solvent component of the solution generated during the production of chemical raw materials, and the solvent component of food washing water are almost water, but contain a small amount of components other than water There is also. The concentration system 1 may eventually concentrate almost all the solvent components in the object A to be processed until the object A is in a dry state. You may concentrate so that it may become a powder form. Further, for example, the concentration may be finally concentrated to about 25% by TDS (evaporation residue) by the concentration system 1. The processing amount of the object A to be processed by the concentration system 1 may be, for example, 20 to 120 m ³ / day.

  The concentration system 1 includes an evaporator 3, a heat exchanger 5 (external heat exchanger) provided outside the evaporator 3, a circulation pump 7, and a compression means 9. The evaporator 3 accommodates an object A to be processed. The bottom of the evaporator 3 is provided with an outlet 3b for extracting the workpiece A to the outside, and a return for returning the workpiece A extracted outside to the side of the evaporator 3 is provided. A mouth 3a is provided. Further, a vapor outlet 3c for extracting the vapor in the evaporator 3 to the outside is provided at the upper part of the evaporator 3.

  The outlet 3b of the evaporator 3 is connected to the inlet of the circulation pump 7 via a line L1. The outlet of the circulation pump 7 is connected to the inlet 5a of the heat exchanger 5 via a line L2. The outlet 5b of the heat exchanger 5 is connected to the return port 3a of the evaporator 3 via a line L3. The vapor outlet 3c of the evaporator 3 is connected to the inlet of the compression means 9 via a line L4. The outlet of the compression means 9 is connected to the heating medium inlet 5c of the heat exchanger 5 via a line L6.

  In the concentration process in the steady operation of the concentration system 1, the workpiece A in the evaporator 3 is extracted from the outlet 3 b by driving the circulation pump 7 and introduced into the heat exchanger 5 through the lines L 1 and L 2. Is done. Thereafter, in the heat exchanger 5, the workpiece A is heated by heat exchange between the workpiece A and a high-temperature heating medium. The workpiece A heated by the heat exchanger 5 is returned again to the evaporator 3 through the line L3.

As described above, in the concentration system 1, the circulation path 11 of the workpiece A is formed by the evaporator 3, the line L1, the circulation pump 7, the line L2, the heat exchanger 5, and the line L3. In the circulation path 11, the workpiece A is pumped by the circulation pump 7 provided on the circulation path 11, so that the circulation flow of the workpiece A as described above occurs. The circulation pump 7 may perform inverter control or number control of the flow rate of the workpiece A. During the steady operation, the circulation amount of the workpiece A in the circulation path 11 may be, for example, 100 to 600 m ³ / h. The raw water of the object A to be treated is preliminarily heated by the preheater 17 from the outside of the concentration system 1, and then merged with the line L <b> 1 through the line L <b> 61 and introduced into the evaporator 3 through the circulation path 11. The

  As the object A circulates the circulation path 11 as described above, the temperature of the object A increases. As the temperature of the workpiece A rises, the solvent component of the workpiece A evaporates in the evaporator 3 and vapor of the solvent component is generated. The steam in the evaporator 3 is drawn out through the steam outlet 3 c by driving the compression means 9. In this way, the processing object A repeats the circulation of the circulation path 11, whereby the solvent component of the processing object A is gradually removed and the processing object A is concentrated.

  The steam drawn out from the evaporator 3 is introduced into the compression means 9 through the line L4, and after being increased in pressure and temperature by the compression means 9, it is introduced into the heating medium inlet 5c of the heat exchanger 5 through the line L6. Here, the compression means 9 is a device that compresses the fluid sucked from the inlet and discharges it from the outlet. The compression means includes a blower, a fan, a blower, a compressor, a vacuum pump, and the like. The fan includes a turbo fan, and the blower includes a high-pressure blower. The steam introduced into the heat exchanger 5 is used as a heating medium that performs heat exchange with the workpiece A as described above.

  A part of the steam as the heating medium is condensed in the heat exchanger 5, and the condensate and surplus steam are discharged from the heating medium outlet 5 d of the heat exchanger 5. Among these, the condensate is temporarily introduced into the condensate tank 13 through the line L7, and the surplus steam is joined to the line L4 through the line L57 and again introduced into the compression means 9. In addition, the condensate generated by the condensation of the vapor in the line L6 is also introduced into the condensate tank 13 via the line L62, the drain tank 19, and the line L63. The non-condensed vapor stored in the condensate tank 13 is discharged out of the concentration system 1 through the line L65. On the other hand, the condensate stored in the condensate tank 13 is extracted by the condensate pump 15 and introduced into the preheater 17 described above. Since this condensate has a higher temperature than the raw water of the object A, it is used as a high heat source for heating the raw water. That is, in the preheater 17, the raw water is preliminarily heated as described above by heat exchange between the condensate and the raw water. The condensate discharged from the preheater 17 is discharged out of the concentration system 1 through the line L67 and collected.

  Furthermore, the concentration system 1 is a steam boiler 21 (thermal energy introduction unit) that generates steam and supplies it to the evaporator 3 in order to give thermal energy to the workpiece A from the outside of the circulation path 11 when starting up. It has. At the time of starting the concentration system 1 or the like, the high-temperature steam generated by the steam boiler 21 is introduced into the evaporator 3 through the line L71. The steam generated in the steam boiler 21 is steam. When heat energy is introduced from the steam boiler 21, particularly when the concentration system 1 is started up, the temperature of the workpiece A in the evaporator 3 rises, and vapor of the solvent component is generated, and the steam is converted into a heat exchanger. 5, a cycle in which the workpiece A is heated in the circulation path 11 starts up early. In addition, the introduction of steam from the steam boiler 21 to the evaporator 3 is not limited to when the concentration system 1 is started, and can also be performed when the thermal energy for the above cycle is insufficient for some reason during steady operation. .

  For example, the temperature of the steam supplied from the steam boiler 21 to the evaporator 3 is 100 to 130 ° C. During steady operation of the concentration system 1, for example, when the temperature in the evaporator 3 is 95 to 98 ° C., steam supply from the steam boiler 21 to the evaporator 3 is executed, and the temperature of the outlet of the compression means 9 is 110 ° C. In the above case, the supply of steam from the steam boiler 21 to the evaporator 3 is stopped. Further, when the concentration system 1 is started, the supply of steam from the steam boiler 21 to the evaporator 3 is started after the start of the concentration system 1. The steam supply is stopped.

  In the concentration system 1, the workpiece A is concentrated to a predetermined concentration by the circulation of the circulation path 11, then extracted from the circulation path 11 and transferred to the buffer tank 23.

  Here, the timing of transfer to the buffer tank 23 will be described. In the circulation path 11, the workpiece A is circulated in the heat exchanger 5 outside the evaporator 3 and heated. Therefore, it is necessary that the workpiece A is a liquid and the solute component in the workpiece A is completely dissolved. In addition, if the concentration of the object to be processed A is too high, the solute component of the object to be processed A may be deposited in the circulation path 11 (for example, in the flow path of the heat exchanger 5) to block the path. Therefore, in the concentration process by the circulation path 11, the concentration of the object to be processed A is monitored, and when the object to be processed A reaches a specified concentration, the object to be processed A is transferred from the circulation path 11 to the buffer tank 23. . In addition, at least the above-mentioned specified concentration needs to be lower than the concentration at which the solute component of the workpiece A is deposited. In the concentration system 1, the concentration process by the circulation path 11 is executed until the concentration of the workpiece A reaches the specified concentration, and then the drying process by the drying processing unit 27 described later is executed.

  As a means for detecting the concentration of the object A to be processed in the circulation path 11, a specific gravity meter may be provided on the circulation path 11 to detect the specific gravity that is an index of the concentration of the object A to be processed. In this case, when the specific gravity is equal to or higher than a predetermined value, the workpiece A is transferred to the buffer tank 23. Further, for example, the amount of raw water of the object A to be processed introduced into the evaporator 3 and the amount of condensate collected from the line L67 are measured, and the concentration of the object A is detected based on these amounts. May be.

  Specifically, a line L72 branched from the line L2 is provided for transferring the workpiece A to the buffer tank 23, and an open / close valve V72 and a pump P72 are provided on the line L72. When the concentration of the object A to be processed in the circulation path 11 reaches a specified value, the object A is extracted from the line L2 and transferred to the buffer tank 23 by opening the opening / closing valve V72 and driving the pump P72. The An amount of the processing object A corresponding to the processing object A extracted from the line L2 is supplied to the line L1 through the above-described line L61.

(Dry processing part)
Further, the concentration system 1 includes a drying processing unit 27 provided at the subsequent stage of the buffer tank 23. As shown in FIG. 2, the drying processing unit 27 includes a post-stage evaporator 29, a steam jacket 29 a (heating unit), a condenser 31 (condensing unit), a decompression unit 33, and a cooling tower 35. doing. The workpiece A stored in the buffer tank 23 is moved from the buffer tank 23 to the raw water metering tank 24 through the line L73 and measured by driving the pump P73. Thereafter, the raw water measuring tank 24 is transferred to and accommodated in the post-stage evaporator 29 of the drying processing unit 27.

  The steam jacket 29a is provided around the lower portion of the post-stage evaporator 29, and steam is supplied from the steam boiler 21 to the steam jacket 29a through a line L74. When the steam supplied from the steam boiler 21 condenses in the steam jacket 29a, the condensation heat of the steam is applied to the post-stage evaporator 29, and the post-stage evaporator 29 is heated. The condensate generated by the condensation of the steam in the steam jacket 29a is extracted from the bottom of the steam jacket 29a, returned to the steam boiler 21 through the line L75, and reused as a steam source.

  The post-stage evaporator 29 and the condenser 31 communicate with each other via a line L76. A line L76 connects the upper part of the post-stage evaporator 29 and the upper part of the condenser 31. A mist catcher 32 that catches and removes mistakes may be provided on the line L76. Furthermore, the decompression means 33 is connected to the upper part of the condenser 31 via the line L77. The decompression means 33 can decompress the condenser 31 and the post-stage evaporator 29 communicated with the condenser 31 by evacuation. Here, the decompression means 33 is a device that compresses the fluid sucked from the inlet and discharges it from the outlet. The decompression means 33 includes a blower, a fan, a blower, a compressor, a vacuum pump, and the like. In the present embodiment, it is assumed that a vacuum pump is employed as the decompression means 33. Further, a cooling water pipe 31 a is provided inside the condenser 31. The cooling water supplied from the cooling tower 35 circulates in the cooling water pipe 31a.

  When the steam jacket 29a, the decompression means 33, and the cooling tower 35 are driven in the drying processing unit 27 having the above-described configuration, the workpiece A in the rear evaporator 29 is heated by the steam jacket 29a and the decompression means. The pressure is reduced by 33. Evaporation of the solvent component of the workpiece A is promoted by heating / depressurizing the workpiece A. The vapor of the solvent component evaporated from the object A to be processed in the post-stage evaporator 29 moves toward the decompression means 33 through a movement path constituted by the line L76, the condenser 31, and the line L77. At this time, in the condenser 31 on the moving path, the vapor of the solvent component contacts the cooling water pipe 31a and is cooled. The vapor condenses by this cooling, and the solvent component that has become liquid is discharged out of the concentration system 1 through the condenser 31 and collected. By the above operation, the solvent component is removed from the workpiece A in the post-stage evaporator 29, and the concentration of the workpiece A proceeds.

(Agitator)
In order to make the concentration of the object A to be processed by the drying processing unit 27 more efficient, a stirring device for stirring the object A in the latter stage evaporator 29 may be provided in the latter stage evaporator 29. FIG. 3 is a cross-sectional view illustrating an example of the post-stage evaporator 29 including a stirring device. The post-stage evaporator 29 in this example has a cylindrical shape extending in a direction orthogonal to the paper surface of FIG. Inside the post-stage evaporator 29, a stirring device 39 that rotates about the cylindrical axis C of the post-stage evaporator 29 is provided. The stirring device 39 includes a shaft 41 extending on the cylindrical axis C, and a partition plate 43 that is attached to the shaft 41 in a posture orthogonal to the shaft 41 and forms a substantially triangular shape.

  A plurality of partition plates 43 are arranged at predetermined intervals in the direction orthogonal to the plane of FIG. 3, and partition the internal space of the rear evaporator 29 into a plurality of spaces in the direction of the cylindrical axis C. The partition plate 43 rotates together with the shaft 41. Furthermore, the stirring device 39 has a stirring blade 47 that rotates together with the shaft 41. The stirring blade 47 rotates together with the shaft 41 while sliding on the inner wall surface of the post-stage evaporator 29.

  When the shaft 41 is rotated by a predetermined power source, the partition plate 43 and the stirring blade 47 described above rotate together in the rear evaporator 29. The workpiece A accommodated in the post-stage evaporator 29 is heated by the steam jacket 29a while being stirred up and stirred above the liquid level by the heat transfer tube 45 and the stirring blade 47, so that it is efficiently concentrated. To go. When the concentration of the object to be processed A increases, the object to be processed A may adhere to the inner wall surface of the post-stage evaporator 29 due to its viscosity, but the object to be processed A is attached by the steam jacket 29a via the inner wall surface. It is heated efficiently. Further, the workpiece A attached to the inner wall surface of the post-stage evaporator 29 is scraped off by the stirring blade 47. When the processing object A is concentrated to a predetermined concentration in the rear evaporator 29, the processed object A that has been subjected to the concentration treatment is recovered from the rear evaporator 29 as a final concentrated processing object.

  In this way, in addition to heating and depressurization of the processing object A in the post-stage evaporator 29, the processing object A is efficiently concentrated by performing stirring by the stirring device 39. In addition, it is possible to remove almost all solvent components in the object to be processed and concentrate the object to be processed until it is in a dry state. For example, concentration (drying) until the object to be processed is finally powdered. ) Is also possible. Further, for example, it is possible to finally concentrate to a concentration rate of about 25% with TDS (evaporation residue). The residue left in the post-stage evaporator 29 is recovered as the processing target A after the concentration process.

  In the above concentration system 1, each line L1-L77 etc. is a conveyance path formed with a tubular body, for example, in order to convey each conveyance target object, such as gas and liquid. In each line, the specification (for example, material, thickness, heat insulation characteristics, inner cross-sectional area, etc.) of the pipe body may be determined according to the purpose. Each line is provided with valves such as on-off valves and switching valves, and pumps as necessary. By appropriately controlling the operation of such valves and pumps, it is possible to control to which line the conveyance object is advanced at the branching portion of the line. Each line and the equipment such as the evaporator 3 and the heat exchanger 5 are provided with sensors (a thermometer, a flow meter, a pressure gauge, etc.) as necessary. In order to realize each function as described above of the concentration system 1, the above-described valves, pumps, sensors, and the like provided in each part may be appropriately operated.

(Concentration method)
In the concentration method of the object A to be processed using the concentration system 1 described above, the vapor of the solvent component in the evaporator 3 is drawn out and compressed, and the compressed vapor is introduced into the heat exchanger as a heating medium. A step of extracting the object in the evaporator 3 to the outside, exchanging heat with the heating medium in the heat exchanger 5, and then circulating the circulation path 11 so as to be returned to the evaporator 3 again. And a step of introducing heat energy applied to the object to be processed A from the outside, and the object to be processed A in the circulation path 11 is pumped and circulated by the circulation pump 7 provided on the circulation path 11. Is done.

  The specific concentration method is as follows. The raw water of the workpiece A is preliminarily heated by the preheater 17, introduced into the line L <b> 1 of the circulation path 11 through the line L <b> 61, and introduced into the evaporator 3. The workpiece A is pumped by the circulation pump 7 and circulates in the circulation path 11. That is, the workpiece A is extracted to the outside of the evaporator 3 through the line L1 and sent to the heat exchanger 5. The workpiece A is heated by exchanging heat with the heating medium in the heat exchanger 5, and then returned to the evaporator 3 through the line L3.

  The object to be processed A is heated by passing through the heat exchanger 5 through circulation in the circulation path 11, the solvent component of the heated object to be processed A is evaporated, and vapor of the solvent component is generated in the evaporator 3. . This vapor is drawn out of the evaporator 3 through the line L4 by the compression means 9 and compressed. The compressed steam is introduced into the heat exchanger 5 through the line L6 and functions as the above-described heating medium. In addition, when the solvent component of to-be-processed object A is water, the temperature of to-be-processed object A in the evaporator 3 in this process is about 100 degreeC.

  Note that, when the concentration system 1 is started, high temperature steam is supplied from the steam boiler 21 to the evaporator 3 while the workpiece A circulates in the circulation path 11. Thereby, since heat energy is given to the to-be-processed object A on the circulation path 11, the to-be-processed object A in the evaporator 3 rises in temperature as mentioned above, and the vapor | steam of a solvent component generate | occur | produces, the said vapor | steam Functions as a heating medium for the heat exchanger 5, and the cycle in which the workpiece A is heated in the circulation path 11 starts up early. Thereafter, when the temperature of the outlet of the compression means 9 exceeds a predetermined reference value, the supply of steam from the steam boiler 21 is stopped, and then the operation proceeds to steady operation. Thereafter, steam supply from the steam boiler 21 may be unnecessary. Further, when the thermal energy for the above cycle is insufficient during steady operation for some reason, the steam supply from the steam boiler 21 may be executed again.

  Thereafter, when the processing object A reaches a predetermined concentration, the processing object A is transferred to the drying processing unit 27 via the buffer tank 23. In the drying processing unit 27, the steam jacket 29 a, the decompression unit 33, and the cooling tower 35 are driven, and the workpiece A in the rear stage evaporator 29 is heated by the steam jacket 29 a and decompressed by the decompression unit 33. The Evaporation of the solvent component of the workpiece A is promoted by heating / depressurizing the workpiece A. The vapor of the solvent component evaporated from the object A to be processed in the post-stage evaporator 29 moves toward the decompression means 33 through a movement path constituted by the line L76, the condenser 31, and the line L77. At this time, in the condenser 31 on the moving path, the vapor of the solvent component contacts the cooling water pipe 31a and is cooled. The vapor condenses by this cooling, and the solvent component that has become liquid is stored in the condenser 31. The liquid solvent component stored in the condenser 31 is discharged from the bottom of the condenser 31 to the outside of the concentration system 1. By the above operation, the solvent component is removed from the workpiece A in the post-stage evaporator 29, and the concentration of the workpiece A proceeds.

  In the processing by the drying processing unit 27, the temperature in the post-stage evaporator 29 is set to 40 to 60 ° C., for example. The temperature in the rear-stage evaporator 29 may be controlled by automatically adjusting the flow rate of the steam to the steam jacket 29a and the degree of decompression of the rear-stage evaporator 29. By setting the temperature in the post-stage evaporator 29 to a relatively low temperature as described above, the workpiece A adheres strongly to the inner wall surface of the post-stage evaporator 29 or the workpiece A is denatured (for example, carbonized) by the high temperature. Can be suppressed. Further, since the inside of the post-stage evaporator 29 is depressurized by the depressurizing means 33, the solvent component of the workpiece A is sufficiently evaporated even at the comparative low constant temperature as described above. In the drying processing unit 27, for example, almost all solvent components in the object to be processed A may be removed and the object to be processed A may be concentrated to a dry state. For example, the object to be processed A is finally powdered. You may concentrate so that it may become a shape. Further, in the drying processing unit 27, for example, the concentration may be finally about 25% with TDS (evaporation residue).

In the concentration system 1 and the concentration method described above, it is preferable to employ a Roots blower as the compression means 9. In general, since the roots blower can increase the capacity (work rate [W]), the use of the roots blower as the compression means 9 increases the amount of heat that can be supplied to the heat exchanger 5 per unit time. be able to. Thereby, the heating efficiency of the to-be-processed object A by the heat exchanger 5 becomes high, and by extension, the efficiency of the concentration process by the concentration system 1 improves. When a roots blower is employed, when the solvent component of the workpiece A is water, the motor capacity of the compression means 9 may be 55 to 220 kW, for example. Moreover, the suction | inhalation air volume of the compression means 9 is good also as 1350-8100m < ³ > / h, for example.

Moreover, as the heat exchanger 5, it is preferable to employ a plate heat exchanger. The plate heat exchanger has a structure in which the flow path of the high-temperature fluid and the flow path of the low-temperature fluid are alternately stacked with the heat transfer plate interposed therebetween, so that the heat transfer area between the heating medium and the workpiece A Can be increased. In the plate heat exchanger, the heat transfer area can be increased relatively freely. Therefore, also by this structure, the heating efficiency of the to-be-processed object A by the heat exchanger 5 becomes high, and the efficiency of the concentration process by the concentration system 1 improves. When a plate heat exchanger is employed, the heat transfer area of the heat exchanger 5 may be, for example, 45 to 250 m ² . Also, in the unlikely event that the solute component of the object to be processed A is precipitated in the heat exchanger 5, the plate-type heat exchanger can easily clean the flow path because of its structure. From the viewpoint of improving the maintainability of the heat exchanger 5, it is preferable to employ a plate heat exchanger.

  Further, when the solvent component of the workpiece A is water, the difference between the steam temperature at the inlet of the compression means 9 and the steam temperature at the outlet of the compression means 9 is 10 to 15 ° C. Is preferred. The temperature difference of the steam as described above may be realized by adjusting the pressure ratio of the steam by the compression means 9 (ratio of the outlet pressure to the inlet pressure of the compression means 9) and setting the pressure ratio within a predetermined range. By raising the temperature of the steam by the compression means 9 to 10 to 15 ° C., the temperature of the heating medium of the heat exchanger 5 can be increased, and even with this configuration, the heating efficiency of the object A to be processed by the heat exchanger 5 is increased. Increases the efficiency of the concentration process.

  Further, by adjusting the balance between the compression characteristic of the steam by the compression means 9, the heat exchange characteristic by the heat exchanger 5, and the conveyance characteristic of the workpiece A by the circulation pump 7, the steam boiler can be started early after the start-up. The operation in which the steam supply from 21 is stopped and the steady operation is performed while the steam supply is stopped is possible. That is, it is possible to supply steam from the steam boiler 21 to the evaporator 3 only when the concentration system 1 is started, and to eliminate the need for steam supply from the steam boiler 21 in the subsequent steady operation.

  The effect by the concentration system 1 and the concentration method of this embodiment is demonstrated.

  According to the concentration system 1 and the concentration method using the same, the workpiece A circulates in the circulation path 11 by the pumping of the circulation pump 7, so that the workpiece A is interposed between the evaporator 3 and the heat exchanger 5. It circulates efficiently, the heating efficiency of the to-be-processed object A is improved, and the efficiency of the concentration process by the concentration system 1 is improved. Moreover, since the heating efficiency of the to-be-processed object A by the circulation path 11 is improved, the heat energy which should be provided to the to-be-processed object A from the steam boiler 21 is also suppressed small. Furthermore, as described above, it is possible to supply steam from the steam boiler 21 to the evaporator 3 only when the concentration system 1 is started, and to eliminate the need for steam supply from the steam boiler 21 in the subsequent steady operation. Become.

  The present invention can be implemented in various forms including various modifications and improvements based on the knowledge of those skilled in the art including the above-described embodiments. Moreover, it is also possible to configure a modification of the example using the technical matters described in the above-described embodiment. You may use combining the structure of each embodiment suitably. For example, in the embodiment, an example in which a roots blower is employed as the compression unit 9 is described, but the present invention is not limited to this, and various compression units can be employed. Moreover, although embodiment demonstrates the example which employ | adopts a plate-type heat exchanger as the heat exchanger 5, it is not limited to this, A various heat exchanger can be employ | adopted.

  DESCRIPTION OF SYMBOLS 1 ... Concentration system, 3 ... Evaporator, 5 ... Heat exchanger (external heat exchanger), 7 ... Circulation pump, 9 ... Compression means, 11 ... Circulation path, 21 ... Steam boiler (thermal energy introduction part), 29 ... Subsequent evaporator, 29a ... steam jacket (heating unit), 31 ... condenser (condensing unit), 33 ... decompression means, 39 ... stirring device, 45 ... heat transfer tube (heating unit), A ... workpiece.

Claims (6)

A concentration system for concentrating the object to be processed by evaporating a solvent component of the object to be processed, which is a liquid,
An evaporator in which the workpiece is accommodated;
Compression means for extracting and compressing the vapor of the solvent component in the evaporator to the outside;
An external heat exchanger provided outside the evaporator and into which the steam compressed by the compression means is introduced as a heating medium;
A circulation path for extracting the object to be processed in the evaporator to the outside and exchanging heat with the heating medium in the external heat exchanger, and then circulating back to the evaporator again;
A thermal energy introduction unit that introduces thermal energy applied to the object to be processed from outside the circulation path,
A concentration system, wherein a circulation pump for pumping and circulating the object to be processed is provided on the circulation path. The compression means has a roots blower,
The concentration system according to claim 1, wherein the external heat exchanger includes a plate heat exchanger. A post-stage evaporator in which the object to be processed concentrated in the evaporator is transferred and stored;
A heating section for heating the post-stage evaporator;
Decompression means for decompressing the inside of the latter stage evaporator,
A condensation section that further cools and condenses the vapor on the movement path of the vapor of the solvent component that evaporates from the object to be processed in the rear-stage evaporator and travels toward the decompression unit. Concentration system.   The concentration system according to claim 3, wherein the post-stage evaporator includes a stirring device that stirs the workpiece. The solvent component is water;
The concentration system according to any one of claims 1 to 4, wherein a difference between the temperature of the steam at the inlet of the compression means and the temperature of the steam at the outlet of the compression means is 10 to 15 ° C. A concentration method for concentrating the object to be processed by evaporating a solvent component of the object to be processed, which is a liquid,
Extracting and compressing the vapor of the solvent component in the evaporator containing the object to be processed, and
Introducing the compressed vapor as a heating medium into an external heat exchanger provided outside the evaporator;
Extracting the object to be processed in the evaporator to the outside, exchanging heat with the heating medium in the external heat exchanger, and circulating the circulation path so as to be returned to the evaporator again;
A step of introducing thermal energy applied to the object to be processed from outside the circulation path,
The concentration method, wherein the object to be treated in the circulation path is pumped and circulated by a circulation pump provided on the circulation path.

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