JP6229596B2 - Suspension concentration system and concentration method - Google Patents

Description

The present invention relates to a related technique such as reduced-pressure concentration for concentrating various suspensions containing biological components such as fruit juice, soup, and extract under reduced pressure, and use of waste heat for the reduced-pressure concentration.

  In the production of foods and beverages, for example, there is a concentration step of concentrating a suspension of fruit juice, soup, extract and the like. This concentration process is performed as a pretreatment for drying and pulverizing the components in the suspension, or for the purpose of reducing the transportation cost and storage space of the suspension, maintaining the freshness and processing costs. Such processing, such as reduction of the amount, is an extremely important step.

  Fruit juices, soups, extracts, and the like contain biological components such as fruits, meat, seafood, and vegetables. If this biological component is treated at a high temperature for a long time, the flavor and aroma are likely to be altered. In order to prevent the flavor and aroma from changing, a vacuum distillation method capable of concentration under reduced pressure at a low temperature of less than 100 ° C., for example, a method using a vacuum evaporator, a membrane separation method for pressure filtration at room temperature, for example, a reverse osmosis membrane There is a method of using.

With regard to such related technology of concentration, it is known to use a vacuum evaporator for fruit juice production (for example, Patent Document 1 and Patent Document 2), and a sugar solution is concentrated from a cellulose-derived sugar solution using a reverse osmosis membrane. It is known (for example, Patent Document 3).

Japanese National Patent Publication No. 8-506733 JP 2009-62301 A JP2013-63076A

  By the way, since the equipment used for a production line is a metal in a vacuum evaporator, it cannot be said that the applicability with respect to what is called corrosive liquid containing acids and salts, such as fruit juice, soup, and extract, is high. Further, if the heating area and the evaporation area are increased, the evaporation efficiency can be ensured, but there are problems such as heavy equipment and a large apparatus scale and high cost.

  On the other hand, in the reverse osmosis membrane, the heat resistance of the membrane module is not sufficient, and the filtration pressure must be increased in proportion to the concentration of dissolved components in the treated water, especially the salt concentration, which requires high kinetic energy. .

  Further, in this reverse osmosis membrane, the suspension components concentrate and adhere to the membrane surface, and the amount of membrane permeate is significantly reduced. If the viscosity of the concentrate increases, it becomes difficult for the concentrate to flow in an extremely thin raw water flow path of about 1 mm or less between the membranes in the membrane module. For this reason, there is a problem that only a concentration factor of several times can be obtained.

  By the way, in the technical fields such as seawater desalination, pure water production, and water recovery from urine in a spacecraft, it is known to use a membrane distillation technique for processing to extract distilled water from raw water. The present inventor conceived that such a membrane distillation technique is applied to the concentration of a suspension, and attempted a suspension concentration experiment using this membrane distillation technique. In this experiment, for example, when membrane distillation technology is used to concentrate various suspensions containing biological components such as fruit juice, soup, and extract, new problems such as channel blockage and clogging of membrane pores have occurred. I found it and came to confirm it.

Therefore, in view of the above problems, an object of the present invention is to realize concentration of various suspensions such as fruit juice, soup, and extract using a membrane distillation technique.

In order to achieve the above object, according to one aspect of the suspension concentration system of the present invention, the apparatus includes a raw water part and a condensing part across a hydrophobic porous membrane, and the condensing part is maintained in a reduced pressure state. And the condensing part is provided with a cooling means, the suspension heated to less than 100 [° C.] is introduced into the raw water part, and the vapor of the suspension is allowed to permeate the hydrophobic porous membrane, thereby the condensing part A first valve for adjusting the flow rate of the concentrated liquid flowing in the concentrated liquid recovery line, which is installed in a concentrated liquid recovery line that collects the concentrated liquid and collects the concentrated liquid. A second valve that is installed in a circulation path for circulating a part or all of the concentrate flowing through the concentrate recovery line to the suspension introduction side of the raw water section, and adjusts the flow rate in the circulation path According to the determination result of the supply state of the suspension to the raw water section. The first valve and controls opening and closing of said second valve, said concentrate is mixed with the suspension is recycled to the raw water portion Te.

  In the suspension concentration system, the suspension may be a liquid containing biological components such as fruit juice, soup, and extract.

  In the suspension concentration system, the flow path width of the suspension may be not less than 1 [mm] and not more than 30 [mm], more preferably not less than 3 [mm] and not more than 20 [mm].

  In the suspension concentration system, the membrane surface flow velocity of the suspension is 0.01 [m / s] or more and 5 [m / s] or less, more preferably 0.05 [m / s] or more. It is good also as 2 [m / s] or less.

  The suspension concentration system may further include heating means for heating the suspension introduced into the raw water portion with waste heat.

In the suspension concentration system, the flow rate of the suspension is increased or decreased by controlling the opening degree of the second valve, and the membrane surface flow velocity of the suspension flowing in the raw water part is adjusted to an appropriate range. It's okay.

  The suspension concentration system further includes suspension removal means for removing the suspension from the suspension, and the suspension from which the suspension has been removed by the suspension removal means is the raw water. It may be introduced into the part.

  In the suspension concentration system, the suspension removing means may include one or both of a filter and a centrifuge.

In order to achieve the above object, according to one aspect of the suspension concentration method of the present invention, a raw water part and a condensing part are installed across a hydrophobic porous membrane, and the condensing part is maintained in a reduced pressure state. And a step of installing a cooling means in the condensing part, introducing a suspension heated to less than 100 [° C.] into the raw water part, and allowing the vapor of the suspension to permeate the hydrophobic porous membrane. And a condensate recovery line for recovering the concentrate according to a step of generating a concentrate of the suspension and a determination result of a supply state of the suspension to the raw water part. A first valve that adjusts the flow rate of the concentrated liquid that flows to the suspension, and a second valve that adjusts the flow rate of the condensed liquid that flows to the circulation path for circulating the concentrated liquid to the suspension introduction side of the raw water portion Controlling the opening and closing of the liquid, mixing the concentrated liquid with the suspension and circulating it to the raw water section It contains.

  According to the present invention, any of the following effects can be obtained.

  (1) By using a membrane distillation technique, suspensions containing fibers and particles such as fruit juice, soup, and extract can be concentrated.

  (2) Suspension of fruit juice, soup, extract, etc. is heated at a low temperature of less than 100 [° C], cooled and decompressed to promote the generation of vapor from the suspension and to promote vapor permeation through the hydrophobic porous membrane. It can be concentrated to prevent deterioration of components and flavor of suspensions such as fruit juices, soups and extracts.

  (3) It is possible to avoid inconveniences such as clogging and clogging due to suspensions containing fibers and particles such as fruit juice, soup, and extract, and efficient suspension concentration can be realized.

  (4) Applying membrane distillation technology to concentrate suspensions containing fiber and particles such as juices, soups, extracts, etc. Since this is avoided, the waste heat energy can be effectively used.

  (5) If waste heat energy is applied to membrane distillation technology, it will be possible to increase the effective use of waste heat energy and the spread of suspension concentration systems, further saving energy and cost. , Can also contribute to environmental conservation and industrial revitalization.

Other objects, features, and advantages of the present invention will become clearer with reference to the accompanying drawings and each embodiment.

It is a figure which shows an example of the concentration system which concerns on 1st Embodiment. It is a figure which shows an example of a membrane distillation apparatus. It is a figure for demonstrating the flow path width and membrane surface line | wire flow rate of the suspension liquid in a membrane distillation apparatus. It is a flowchart which shows an example of the process sequence of suspension concentration. It is a figure which shows an example of the concentration system which concerns on 2nd Embodiment. It is a figure which shows an example of the concentration system which concerns on 3rd Embodiment. It is a figure which shows an example of the concentration system which concerns on 4th Embodiment.

[First Embodiment]

  <Concentration system>

  FIG. 1 shows a concentration system according to a first embodiment. The configuration shown in FIG. 1 is an example, and the present invention is not limited to such a configuration.

  The concentration system 2 is provided with a membrane distillation apparatus 4, and a raw water line 6 is connected to the membrane distillation apparatus 4. The raw water introduced from the raw water line 6 into the membrane distillation apparatus 4 is, for example, a suspension 8, and the suspension 8 is a liquid containing biological components such as fruit juice, soup, and extract.

  In the raw water line 6, for example, a heat exchange unit 10 is installed as an example of a means for heating the suspension 8. The heat exchanging unit 10 exchanges heat of the heat medium HM heated by a waste heat source such as factory waste heat with the suspension 8. Accordingly, the suspension 8 can be heated to a low temperature of, for example, several tens [° C.] to less than 100 [° C.] and supplied to the membrane distillation apparatus 4. Waste heat such as factory waste heat can be used for heating the suspension 8, and various waste heat can be effectively used.

  The membrane distillation apparatus 4 concentrates the suspension 8 by membrane distillation and separates it into a concentrate 12 and condensed water 14. The concentrated liquid 12 is led to the concentrated liquid recovery line 16, and the condensed water 14 is led to the condensed water discharge line 18.

  A first valve 20-1 is installed in the concentrated liquid recovery line 16, and the concentrated liquid 12 is taken out from the membrane distillation apparatus 4 by opening this valve 20-1. A concentrated liquid circulation line 22 is connected between the concentrated liquid recovery line 16 and the raw water line 6, and the concentrated liquid circulation line 22 is provided with a second valve 20-2. The concentrate circulation line 22 is an example of a circulation path for circulating the concentrate 12 to the raw water side.

  When the amount of raw water supplied from the raw water line 6 is small, the valve 20-2 is opened, the concentrated liquid 12 is returned to the suspension 8 on the raw water side, mixed, and circulated through the membrane distillation apparatus 4.

  <Membrane distillation apparatus 4>

  FIG. 2 shows an example of the membrane distillation apparatus 4. This membrane distillation apparatus 4 is a membrane distillation technique that heats the suspension 8 using low-temperature waste heat and distills or concentrates the vapor of the suspension 8 that has passed through the hydrophobic porous membrane under reduced pressure and low-temperature conditions. Use.

  The membrane distillation apparatus 4 includes a hydrophobic porous membrane 24, and a raw water chamber 26 and a condensing chamber 28 with the hydrophobic porous membrane 24 interposed therebetween. The raw water chamber 26 is an example of a raw water portion into which the suspension 8 is introduced, and the condensing chamber 28 is an example of a condensing portion that condenses the vapor that has passed through the hydrophobic porous membrane 24.

  The hydrophobic porous membrane 24 is an example of means for selectively allowing only the vapor of the suspension 8 introduced into the raw water chamber 26 to pass through. For example, a fluororesin porous membrane is used for the hydrophobic porous membrane 24. This fluororesin porous membrane is excellent in heat resistance. This hydrophobic porous membrane 24 allows only the vapor 30 of the suspension 8 to permeate, is less affected by the osmotic pressure and viscosity of the suspension 8 with respect to the membrane permeated vapor amount, has high vapor permeability, and concentrates the suspension. Can be done efficiently.

  A decompression device 32 is connected to the condensation chamber 28, and a cooling unit 34 is provided on the wall surface of the condensation chamber 28. The raw water chamber 26 is decompressed by the decompression device 32 together with the condensing chamber 28 and is maintained in a decompressed state, and the cooling unit 34 is cooled to a temperature that condenses the vapor 30 that is in contact therewith. Vapor 30 that has passed through the hydrophobic porous membrane 24 is drawn into the condensing chamber 28 maintained under reduced pressure. The steam 30 contacts the cooling part 34 of the condensation chamber 28 and condenses. That is, in the cooling unit 34, the condensed water 14 is generated when the steam 30 is condensed.

  In this case, since the condensing chamber 28 is maintained in a reduced pressure state, it has a function of lowering the boiling point of the suspension 8 as well as a function of drawing the steam 30. Thereby, the vapor | steam 30 produced from the suspension 8 becomes remarkable, and the vapor | steam amount which permeate | transmits the hydrophobic porous membrane 24 increases. As a result, the steam 30 entering the condensing chamber 28 contacts the cooling unit 34 and condenses under reduced pressure to become condensed water 14. That is, since a large amount of the vapor 30 is condensed from the suspension 8 and converted into the condensed water 14, the suspension 8 in the raw water chamber 26 is efficiently concentrated. Accordingly, a large amount of the concentrated liquid 12 is generated from the raw water chamber 26 and is recovered in the concentrated liquid recovery line 16.

  In this membrane concentration, when the suspension 8 is concentrated to obtain the concentrated solution 12, the flow path width and the membrane surface line flow rate of the suspension 8 are extremely important. The channel width is a size such as a channel diameter effective for allowing the suspension 8 to pass therethrough. On the other hand, the membrane surface linear flow velocity is a linear velocity given by the value obtained by dividing the flow rate of the suspension 8 by the effective cross-sectional area in the apparatus, and is apparently the velocity of the suspension 8. Specifically, it is the average flow rate of the suspension 8 parallel to the membrane surface of the hydrophobic porous membrane 24.

  FIG. 3 shows the flow of the suspension 8 in the membrane distillation apparatus 4 as an example. In FIG. 3, the distance from the surface of the hydrophobic porous membrane 24 to the surface of the raw water chamber 26 facing the surface of the hydrophobic porous membrane 24 is the flow path width W. The value obtained by dividing the flow rate of the suspension 8 by the cross-sectional area of the raw water chamber 26 is the membrane surface flow velocity V. Since the suspension 8 which is raw water is concentrated while flowing through the membrane distillation apparatus 4, the suspension and dissolved component concentration P contained in the raw water becomes high, and thus it becomes difficult to flow through the flow path 35 of the raw water chamber 26. . Q shows the transition of the suspension and dissolved component concentration P. When the suspended matter and the dissolved component concentration P are increased, there is a problem that the channel is blocked or the membrane pores are clogged. As a result of intensive studies to solve such problems, it has been found that these problems can be solved if the flow path width W and membrane surface line flow velocity V of the suspension 8 are adjusted to an appropriate range according to the quality of the raw water. It was issued. That is, the flow path width W and the membrane surface flow velocity V of the suspension 8 vary depending on the quality of the raw water, for example, the shape, softness, concentration, and dissolved components of the suspended matter. Specifically, for example, sugar, amino acids, proteins, etc. Therefore, the appropriate range is preferably confirmed by a concentration test. Based on this concentration test, the appropriate range for this application is generally as follows.

  And in this membrane distillation apparatus 4, the flow path width W of the suspension 8 should just be 1 [mm] or more and 30 [mm] or less, More preferably, it is 3 [mm] or more and 20 [mm]. The following. Further, the membrane surface flow velocity V of the suspension 8 is, for example, 0.01 [m / s] or more and 5 [m / s] or less, more preferably 0.05 [m / s] or more and 2 [m / s]. / S].

  Such a value has been confirmed by the inventor's device and concentration experiment, and solves the above-described problems when the membrane distillation technique is used for concentration of the suspension 8. Therefore, if such conditions are set, blockage of the flow path of the hydrophobic porous membrane 24 due to fiber components and coarse particles contained in the suspension 8 can be prevented, and the vapor permeation function is not impaired, and the suspension is suspended. It was confirmed that the concentration efficiency of the liquid 8 can be increased.

  In this case, the membrane surface flow velocity V of the suspension 8 is related to the concentration efficiency of the suspension 8. Therefore, when the supply raw water amount of the suspension 8 from the raw water line 6 is small, the valve 20-2 is opened, and the valve 20-1 is squeezed to reduce the passage amount, whereby the concentrate 12 is removed from the raw water line 6 side. The addition liquid obtained by adding the concentrated liquid 12 to the suspension 8 is circulated through the membrane distillation apparatus 4 as raw water. Thereby, the circulation amount of the suspension 8 flowing into the raw water chamber 26 can be adjusted, the membrane surface line flow velocity can be increased, and it can be controlled to a predetermined value. In this case, the concentrate 12 may be returned to the inlet of the raw water chamber 26 described later and circulated to the raw water chamber 26.

  Further, when the amount of raw water supplied from the raw water line 6 is large, for example, the valve 20-2 is opened, and the concentrated liquid 12 is added from the concentrated liquid recovery line 16 to the suspension 8 on the raw water line 6 side. It is also possible to circulate through the membrane distillation apparatus 4.

  FIG. 4 shows a processing procedure for concentrating the suspension 8. This processing procedure is an example of the method for concentrating a suspension according to the present invention.

  In this processing procedure, when the suspension 8 is concentrated, the condensation chamber 28 of the membrane distillation apparatus 4 is decompressed and the cooling unit 34 is maintained at a low temperature (S11).

  The suspension 8 flowing in the raw water line 6 is heated at a low temperature by heat exchange in the heat exchange unit 10 (S12). In this low-temperature heating, for example, the suspension 8 is heated to a temperature of several tens [° C.] to less than 100 [° C.].

  The vapor 30 generated from the heated suspension 8 is caused to flow from the raw water chamber 26 to the condensing chamber 28 through the hydrophobic porous membrane 24 (S13).

  The vapor 30 that has passed through the hydrophobic porous membrane 24 is cooled and condensed by the cooling unit 34 of the condensing chamber 28, becomes condensed water 14, and is discharged from the condensed water discharge line 18 (S 14).

  Then, it is determined whether the raw water supply amount of the suspension 8 supplied to the raw water chamber 26 is appropriate (S15). If the raw water supply amount is appropriate (YES in S15), the concentrate 12 concentrated in the raw water chamber 26 is sent out from the concentrate recovery line 16 (S16). Thereby, the concentrated liquid 12 of the suspension 8 is recovered.

  If the raw water supply amount is small (NO in S15), the valve 20-2 is opened, the concentrated liquid 12 is caused to flow into the concentrated liquid circulation line 22, returned to the suspension 8 of the raw water line 6, and the raw water increased in the concentrated liquid 12 = Suspension 8 + Concentrated liquid 12 is supplied to the raw water chamber 26 (S17), and processing from S13 onward is performed. Thereby, the concentrate 12 is similarly collected.

<Effect of the first embodiment>

  (1) As described above, by using the membrane distillation technique, the suspension 8 containing fiber and particles can be concentrated by the membrane distillation technique.

  (2) In the first embodiment, the above-described problems can be solved, and an excellent concentration function not obtained by the conventional vacuum evaporator method or membrane separation method can be obtained.

  (3) As is clear from the first embodiment, the membrane distillation technique used exclusively for seawater desalination, pure water production, water recovery from urine in a spacecraft, etc. is applied to the suspension 8 It can be applied to concentration, overcomes the above problems, can efficiently concentrate the suspension 8, and can recover the concentrated solution 12.

  (4) In the first embodiment, the heat medium HM passed through the heat exchanging unit 10 is heated using waste heat energy obtained from a waste heat source. Since the heat of the heating medium HM is heat-exchanged to heat the suspension 8 at a low temperature, its effective use can be expanded, such as application of waste heat energy to membrane distillation technology, and further energy saving and Cost savings can be achieved, contributing to environmental conservation and industrial revitalization.

  (5) Since the insides of the raw water chamber 26 and the condensing chamber 28 including the hydrophobic porous membrane 24 are depressurized, the boiling point of the suspension 8 heated at a low temperature lowers under this depressurization, whereby the suspension 8 Evaporation from water is promoted. Since the treatment is performed under such reduced pressure, the suspension 8 may be heated at a relatively low temperature of less than 100 [° C.], and various types of waste heat such as factory waste heat can be used for heating the suspension 8. Can be used effectively as a heat source.

  (6) When the suspension 8 supplied to the raw water chamber 26 is small, the concentrated liquid 12 can be circulated to the inlet of the raw water chamber 26 or the raw water line 6 to increase the supply amount of the raw water to the raw water chamber 26. Further, the membrane surface flow velocity of the suspension 8 in the raw water chamber 26 can be increased, and furthermore, the membrane surface flow velocity suitable for the concentration of the suspension and the passage of vapor to the hydrophobic porous membrane 24 can be controlled. Membrane concentration can be performed.

[Second Embodiment]

  As shown in FIG. 5, the concentration system 2 includes a mesh filter 36 which is an example of a suspension removing unit on the pretreatment side of the membrane distillation apparatus 4, and the permeation treatment by the mesh filter 36 is performed by the membrane distillation of the membrane distillation apparatus 4. You may combine with a process. In FIG. 5, the same parts as those in FIG.

  In the concentration system 2, the suspension 8 is supplied from the raw water line 6 to the mesh filter 36 installed at the front stage of the membrane distillation apparatus 4. By filtration through the mesh filter 36, the filtrate 38 obtained from the suspension 8 is introduced into the membrane distillation apparatus 4 through the suspension line 40. A concentrated liquid circulation line 22-1 is provided between the concentrated liquid recovery line 16 and the suspension line 40, and a concentrated liquid circulation line 22-2 is provided between the concentrated liquid recovery line 16 and the raw water line 6. The circulation line 22-1 is provided with the valve 20-2, and the concentrate circulation line 22-2 is provided with the valve 20-3.

  Similar to the membrane distillation apparatus 4, the mesh filter 36 is provided with a concentrated liquid recovery line 42, and the concentrated liquid recovery line 42 is provided with a valve 20-4. A concentrated liquid circulation line 22-3 is provided between the concentrated liquid recovery line 42 and the raw water line 6, and a valve 20-5 is installed in the concentrated liquid circulation line 22-3.

  According to this embodiment, the suspension 8 is filtered by the mesh filter 36, and the filtrate 38 obtained from the mesh filter 36 can be supplied to the membrane distillation apparatus 4, and the concentrated liquid 12 concentrated from the filtrate 38 can be supplied. Is recovered by the membrane distillation apparatus 4.

  In the treatment in which the mesh filter 36 is placed in advance, the suspension of about several [%] to several tens [%] can be removed from the suspension 8 which is raw water by filtration of the mesh filter 36. By removing the suspension, the membrane distillation apparatus 4 can reduce the influence of the suspension such as blockage of the channel and clogging of the membrane pores.

  In this case, the opening of the mesh filter 36 may be selected according to the size of a suspended component such as a suspension contained in the raw water suspension 8. In the opening of the mesh filter 36 assuming a suspension containing biological components such as fruit juice, soup, extract, etc., for example, the suspension 8 may be 10 [μm] or more and several [mm] or less, More preferably, it is 50 [μm] or more and about 2000 [μm], but in any case, if removal of the suspended matter is assumed, the opening may be selected depending on the size.

  Also in the second embodiment, the heat exchange unit 10 is provided in the raw water line 6 as in the first embodiment, and the heat of the heating medium HM heated by waste heat is exchanged with the suspension 8. The suspension 8 heated at a low temperature may be introduced into the raw water chamber 26.

<Effects of Second Embodiment>

  (1) When the mesh filter 36 is used in combination, the suspension 8 containing the suspension at a high concentration and the suspension 8 containing a coarse solid at a high concentration can be efficiently concentrated. it can.

  (2) If the concentrate obtained by the mesh filter 36 is returned to the suspension 8 of raw water on the inlet side of the mesh filter 36 and circulated as the suspension 8, the recovery rate of the concentrate 12 from the suspension 8 Can be increased.

[Third Embodiment]

  In the concentration system 2, instead of the mesh filter 36, a system may be configured by combining a centrifuge 44 as shown in FIG. 6. In FIG. 6, the same parts as those in FIG.

  In the concentration system 2, a centrifuge 44 is installed as an example of a suspension removing means in the front stage of the membrane distillation apparatus 4, and the suspension 8 is supplied to the centrifuge 44 from the raw water line 6. The permeate 46 separated from the suspension 8 by the centrifuge 44 is introduced into the membrane distillation apparatus 4 through the suspension line 40. Other configurations are the same as those in FIG.

  According to this embodiment, the suspension 8 is pretreated by the centrifuge 44, and the permeate 46 obtained by the centrifuge 44 can be supplied to the membrane distillation apparatus 4. The concentrated liquid 12 concentrated from the above is recovered by the membrane distillation apparatus 4.

  If pretreatment is performed with such a centrifuge 44, a suspension of several [%] to several tens [%] can be removed from the suspension 8, which is raw water, by allowing the centrifuge 44 to pass through. By removing this suspension, the influence of the suspension can be reduced in the membrane distillation apparatus 4 also by the centrifuge 44.

  In this case, the opening of the centrifuge 44 may be selected according to the size of the suspended component such as the suspension contained in the raw water suspension 8. Even in the centrifugal separator 44 assuming a suspension 8 containing a biological component such as fruit juice, soup, extract, etc., the opening is 10 [μm] or more and several [mm] or less, for example. What is necessary is just to be 50 [μm] or more and about 2000 [μm], but in any case, if the removal of the suspended matter is assumed, the opening may be selected depending on the size.

  The centrifugal force of the centrifuge 44 may be adjusted in accordance with the properties of the suspension 8 that is raw water, and the suspension 8 contains a biological component such as fruit juice, soup, extract, etc. Assuming that the maximum value is 4000 [G] to 5000 [G] or less, more preferably from several hundred [G] to 3000 [G], in any case, the removal of the suspended matter is assumed. The centrifugal force may be selected.

  Also in the third embodiment, as in the first embodiment, the raw water line 6 includes the heat exchanging unit 10, and heat of the heating medium HM heated by waste heat is exchanged with the suspension 8. The suspension 8 heated at a low temperature may be introduced into the raw water chamber 26.

<Effect of the third embodiment>

  (1) When the centrifuge 44 is used in this way, the suspension 8 containing the suspension at a high concentration and the suspension 8 containing the coarse solid at a high concentration can be efficiently concentrated. Can do.

  (2) If the concentrate obtained by the centrifuge 44 is returned to the suspension 8 of the raw water on the inlet side of the centrifuge 44 and circulated as the suspension 8, the same as in the second embodiment, The recovery rate of the concentrated liquid 12 from the suspension 8 can be increased.

[Fourth Embodiment]

  As shown in FIG. 7, the concentration system 2 may be configured by combining a mesh filter 36 and a centrifuge 44. In FIG. 7, the same parts as those in FIG. 5 or FIG.

  In the concentration system 2, a centrifuge 44 is installed in front of the membrane distillation apparatus 4, and a mesh filter 36 is installed in front of the centrifuge 44. Suspension 8 that is raw water is supplied from the first raw water line 6-1, and similarly, the suspension 8 is supplied to the second raw water line 6-2.

  The filtrate separated from the suspension 8 by the filtration of the mesh filter 36 is recovered from the concentrate line 48-1 by opening the valve 20-6 as the concentrate 12 described above. The concentrated liquid 12 is led from the concentrated liquid line 48-2 to the suspension line 40 by opening the valve 20-7, and introduced into the raw water chamber 26 of the membrane distillation apparatus 4 together with the permeated liquid of the centrifuge 44. The In this case, the recovery of the concentrate 12 obtained by the mesh filter 36 or the supply to the membrane distillation apparatus 4 can be adjusted by the opening degree of the valves 20-6 and 20-7. Further, if the valve 20-7 is opened and the valve 20-6 is closed, the filtrate 38 obtained by the filtration of the mesh filter 36 can be added only to the suspension line 40.

  In the mesh filter 36, the concentrated residue 50 is obtained by filtering the suspension 8, and this concentrated residue 50 is recovered from the concentrated residue recovery line 52. In this case, when the suspension 8 contains many suspensions, the suspension is removed from the suspension 8 as a concentrated residue 50 by filtration through a mesh filter 36, and the suspension 8 is subjected to membrane distillation. It can be introduced into the apparatus 4, the influence of the suspension on the membrane distillation apparatus 4 can be avoided, and efficient concentration can be performed.

  In the centrifuge 44, the concentrate 12 is separated from the suspension 8, and is recovered from the concentrate recovery line 42 by opening the valve 20-4. The concentrate 12 is supplied to the mesh filter 36 by opening the valve 20-5 from the concentrate circulation line 54, and can be mixed with the suspension 8 in the mesh filter 36.

  Thus, by combining the membrane distillation apparatus 4, the mesh filter 36, and the centrifuge 44, the concentrated liquid 12 can be recovered from the suspension 8, and the condensed water 14 and the concentrated residue 50 can be taken out.

  Also in this embodiment, even in the mesh filter 36 or the centrifuge 44 that assumes a suspension 8 containing a biological component such as fruit juice, soup, extract, etc. [Μm] or more and several [mm] or less, more preferably 50 [μm] or more and about 2000 [μm]. What is necessary is just to select an opening according to size. Moreover, what is necessary is just to set about the centrifugal force of the centrifuge 44 similarly to 3rd Embodiment.

  Further, depending on the concentration and properties of the suspended substance in the suspension 8, a microfiltration membrane or an ultrafiltration membrane may be used instead of the mesh filter 36 or the centrifuge 44, and these may be used as the mesh filter 36 or the centrifuge. 44 may be used in combination with either one or both.

  Also in the fourth embodiment, the raw water line 6 includes the heat exchanging unit 10 as in the first embodiment, and heat of the heating medium HM heated by waste heat is exchanged with the suspension 8. The suspension 8 heated at a low temperature may be introduced into the raw water chamber 26.

<Effect of the fourth embodiment>

  (1) If the mesh filter 36 and the centrifuge 44 are used in combination, the suspension 8 containing a suspension at a high concentration or the suspension 8 containing a coarse solid at a high concentration is converted into a solid. The suspension 8 can be concentrated more efficiently.

(2) If the concentrate obtained by the mesh filter 36 and the centrifuge 44 is returned to the raw water suspension 8 on the inlet side of the mesh filter 36 and circulated as the suspension 8, the second or third implementation The recovery rate of the concentrated liquid 12 from the suspension 8 that exceeds the effect of the form can be further increased.

<Example 1>

  In this example, Satsuma mandarin was squeezed out after squeezing, and about 40 [%] of the pulp suspension was removed from this liquid, which was used as raw water. When this suspension 8 was measured with a refractometer, the raw water sugar content was 9%.

  This suspension 8 was subjected to membrane distillation concentration using the membrane distillation apparatus 4 described above, with the raw water channel width set to 5 [mm] and the membrane surface flow velocity 0.5 [m / s].

  According to this example, no blockage of the raw water channel was confirmed. When the concentrate was measured with a refractometer, it could be concentrated to a sugar content of 52%.

<Example 2>

  In Example 2, the same suspension 8 as in Example 1 was used. That is, after squeezing Satsuma mandarin, it was sieved, and about 40 [%] of pulp suspension was removed as raw water. The suspension 8 has a raw water sugar content of 9%.

  In Example 2, the raw water channel width was set to 0.5 [mm] and the membrane surface line flow velocity was set to 5 [m / s], and membrane distillation concentration was performed.

  In Example 2, although the raw water flow path was clogged, the concentrated solution was measured with a refractometer, and although it was concentrated to a sugar content of 10.5 [%], the sugar content of Example 1 described above was reached. There wasn't. That is, the raw water flow path width 0.5 [mm] and the membrane surface flow velocity 5 [m / s] affect the concentration efficiency, and the suspension 8 flow passage width and membrane surface flow velocity are adjusted. It was confirmed that a concentrated concentration was obtained by controlling the amount of suspension 8 introduced.

[Other Embodiments]

  (1) In the above embodiment, the condensing chamber 28 is installed adjacent to the hydrophobic porous membrane 24. However, the condensing chamber 28 is disposed at a position spaced from the hydrophobic porous membrane 24, and the hydrophobic porous membrane is arranged. It is good also as a structure which guides the vapor | steam 30 which passed 24 to the condensation chamber 28, and condenses.

  (2) In the above embodiment, the raw water line 6 is provided with the heat exchanging unit 10 and the waste heat is guided to the heat exchanging unit 10 with the heat medium HM and is exchanged with the suspension 8. As described above, it may be installed on the membrane distillation apparatus 4 side or on the waste heat source side. That is, a configuration may be employed in which the suspension guided by the raw water line 6 is exchanged with waste heat to the heat exchange unit provided on the waste heat source side, and the suspension 8 is heated at a low temperature.

  (3) The condensed water 14 obtained by membrane concentration from the suspension 8 may be used for industrial water or beverages.

As described above, the most preferred embodiment of the suspension concentration system and concentration method has been described. The present invention is not limited to the above description. Various modifications and changes can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the embodiments for carrying out the invention. It goes without saying that such modifications and changes are included in the scope of the present invention.

According to the suspension concentration system and concentration method of the present invention, a suspension containing biological components such as fruit juice, soup, and extract can be efficiently concentrated by membrane concentration. Can be widely used as.

2 Concentration System 4 Membrane Distillation Device 6 Raw Water Line 6-1 First Raw Water Line 6-2 Second Raw Water Line 8 Suspension 10 Heat Exchanger 12 Concentrated Liquid 14 Condensed Water 16 Concentrated Liquid Recovery Line 18 Condensed Water Discharge Line 20-1 1st valve 20-2 2nd valve 20-3, 20-4, 20-5, 20-6, 20-7 Valve 22, 22-1, 22-2, 22-3 Concentrated liquid circulation Line 24 Hydrophobic porous membrane 26 Raw water chamber 28 Condensing chamber 30 Steam 32 Depressurizer 34 Cooling unit 35 Channel 36 Mesh filter 38 Filtrate 40 Suspension line 42 Concentrated liquid recovery line 44 Centrifuge 46 Permeate 48-1 48-2 Suspension line 50 Concentrated residue 52 Concentrated residue recovery line 54 Concentrated liquid circulation line

Claims (9)

It has a raw water part and a condensation part across a hydrophobic porous membrane,
Maintaining the condensing part in a decompressed state, and providing the condensing part with cooling means;
Suspension heated to less than 100 [° C.] is introduced into the raw water part, and vapor of the suspension is allowed to permeate the hydrophobic porous membrane and condensed in the condensing part, and the suspension is concentrated. Producing liquid ,
A first valve installed in a concentrate recovery line for recovering the concentrate and adjusting a flow rate of the concentrate flowing through the concentrate recovery line;
A second valve that is installed in a circulation path for circulating a part or all of the concentrate flowing through the concentrate recovery line to the suspension introduction side of the raw water section, and that adjusts a flow rate in the circulation path; ,
And controlling the opening and closing of the first valve and the second valve according to the determination result of the supply state of the suspension to the raw water section, and mixing the concentrate with the suspension A suspension concentration system, characterized by being circulated in the raw water section .   The suspension concentration system according to claim 1, wherein the suspension is a liquid containing biological components such as fruit juice, soup, and extract.   The flow path width of the suspension is 1 [mm] or more and 30 [mm] or less, more preferably 3 [mm] or more and 20 [mm] or less. A suspension concentration system as described in 1.   The membrane surface flow velocity of the suspension is 0.01 [m / s] or more and 5 [m / s] or less, more preferably 0.05 [m / s] or more and 2 [m / s] or less. The suspension concentration system according to any one of claims 1 to 3, wherein the suspension concentration system is provided.   The suspension concentration system according to any one of claims 1 to 4, further comprising heating means for heating the suspension introduced into the raw water section with waste heat. The flow rate of the suspension is increased or decreased by controlling the opening degree of the second valve, and the membrane surface flow velocity of the suspension flowing in the raw water portion is adjusted to an appropriate range. The suspension concentration system according to claim 5.   Furthermore, a suspension removing means for removing the suspension from the suspension is provided, and the suspension from which the suspension has been removed by the suspension removing means is introduced into the raw water portion. The suspension concentration system according to any one of claims 1 to 6.   The suspension concentration system according to claim 7, wherein the suspension removing means includes one or both of a filter and a centrifuge. Suspension heated below 100 [° C.] by installing a raw water part and a condensing part across a hydrophobic porous membrane, maintaining the condensing part under reduced pressure, and installing a cooling means in the condensing part Introducing the liquid into the raw water part;
Allowing the vapor of the suspension to pass through the hydrophobic porous membrane and condensing in the condensing unit to produce a concentrated liquid of the suspension;
A first valve that adjusts a flow rate of the concentrate to flow to a concentrate recovery line for recovering the concentrate according to a determination result of a supply state of the suspension to the raw water portion; The raw water is mixed by controlling the opening and closing of a second valve for adjusting the flow rate of the condensate flowing in a circulation path for circulating the concentrate on the introduction side of the suspension, and mixing the concentrate with the suspension. A process of circulating to the part ,
A method for concentrating a suspension, comprising:

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