JP6417826B2

JP6417826B2 - Concentration system and concentration method

Info

Publication number: JP6417826B2
Application number: JP2014199360A
Authority: JP
Inventors: 聡志三輪; 英之小森
Original assignee: Kurita Water Industries Ltd
Current assignee: Kurita Water Industries Ltd
Priority date: 2014-09-29
Filing date: 2014-09-29
Publication date: 2018-11-07
Anticipated expiration: 2034-09-29
Also published as: JP2016068006A

Description

本発明は、例えば果汁、液糖、蜂蜜などの食品関連溶液のように高温での加熱により変質や変性をきたす成分を含有する溶液を濃縮するための濃縮システム及び濃縮方法に関する。 The present invention relates to a concentration system and a concentration method for concentrating a solution containing a component that is altered or denatured by heating at a high temperature, such as a food-related solution such as fruit juice, liquid sugar, and honey.

食品や飲料などの製造では例えば、果汁、液糖、蜂蜜など糖分その他特定の成分を含有する溶液（懸濁液）の濃縮工程が必要となることがある。この濃縮工程は、成分の乾固化や粉末化の前処理として、あるいは懸濁液の輸送費の低減や保管スペースの削減のためなどの目的で行われ、鮮度の維持や処理コストの低減など、その処理は極めて重要である。 In the production of foods and beverages, for example, a concentration step of a solution (suspension) containing sugar or other specific components such as fruit juice, liquid sugar, and honey may be required. This concentration process is performed as a pretreatment for drying and pulverizing the components, or for the purpose of reducing the transportation cost of the suspension and reducing the storage space, etc. The processing is extremely important.

上述したような食品プロセスにおける特定の成分を含有する生物由来の溶液を濃縮する技術としては、逆浸透膜装置を用いた濃縮（例えば、特許文献１）、多重効用缶蒸留、凍結濃縮などを用いた濃縮が知られている。また、真空エバポレーターを用いて濃縮することも公知である（例えば、特許文献２、特許文献３）。 Concentration using a reverse osmosis membrane device (for example, Patent Document 1), multi-effect can distillation, freeze concentration, etc. is used as a technique for concentrating a biological solution containing a specific component in the food process as described above. The concentration that was known is known. It is also known to concentrate using a vacuum evaporator (for example, Patent Document 2 and Patent Document 3).

特開２０１３−６３０７６号公報JP2013-63076A 特表平８−５０６７３３号公報Japanese National Patent Publication No. 8-506733 特開２００９−６２３０１号公報JP 2009-62301 A

逆浸透膜装置を利用した濃縮においては、平膜状の酢酸セルロース膜や合成高分子膜などの逆浸透膜を海苔巻状に巻装し、単位体積当たりのろ過膜面積を大きく確保したスパイラルモジュールを用いるのが一般的である。このスパイラルモジュールでは、海苔巻状に巻かれた膜面と膜面との間に極薄いスペーサが挟み込まれている。上述したような逆浸透膜装置において、被処理液はこの極薄いスペーサの隙間を流れ、ろ液は膜裏側へ透過し、溶液成分は膜面へ濃縮される。膜面へ被処理液の成分が濃縮されると浸透圧が高くなるため、この浸透圧を超えるろ過圧力を付加できる高圧ポンプを用いる必要がある。また、溶液成分が膜面に濃縮して、ろ過を妨げるのをできるだけ抑制するため、被処理液の膜面流速を高くする必要がある。すなわち、高出力の高価な送液ポンプと高いエネルギーコストが必要となる。さらに、果汁、糖液あるいは蜂蜜などの溶液は、成分の濃縮により溶液の粘度が高くなり、逆浸透膜モジュールへの極薄い被処理液の流路への通液が容易でなくなる。このため濃縮率に限界があり、最高でも４０〜５０％程度しか濃縮できないという問題があった。 Concentration using a reverse osmosis membrane device is a spiral module in which a reverse osmosis membrane, such as a flat cellulose acetate membrane or a synthetic polymer membrane, is wound in a laver winding shape to ensure a large filtration membrane area per unit volume. It is common to use. In this spiral module, an extremely thin spacer is sandwiched between the membrane surfaces wound in a laver form. In the reverse osmosis membrane apparatus as described above, the liquid to be treated flows through the gap between the extremely thin spacers, the filtrate permeates to the back side of the membrane, and the solution components are concentrated on the membrane surface. When the component of the liquid to be treated is concentrated on the membrane surface, the osmotic pressure increases. Therefore, it is necessary to use a high-pressure pump that can apply a filtration pressure exceeding the osmotic pressure. Moreover, in order to suppress as much as possible that a solution component concentrates on a film surface and prevents filtration, it is necessary to make the film surface flow rate of a to-be-processed liquid high. That is, an expensive liquid pump with high output and high energy cost are required. Furthermore, solutions such as fruit juice, sugar solution, and honey have a high viscosity due to concentration of components, and it is not easy to pass a very thin liquid to be processed to the reverse osmosis membrane module. For this reason, there is a limit to the concentration rate, and there is a problem that only about 40 to 50% can be concentrated.

また、多重効用缶蒸留を用いた濃縮においては、数段の蒸留缶を並べて、加熱蒸留する。初段で蒸留に必要な熱量を与え、後段で追加加熱することなく、初段で与えた熱量を回収しながら蒸留を繰り返すので経済的に蒸留することが可能である。しかしながら、最後段の蒸留で必要となる熱量も合わせて初段で加熱するため、初段では１００℃を超える過熱蒸気により非常に高温で加熱する必要がある。一方、食品プロセスで濃縮する生物由来の有機成分には、加熱により変質しやすいものが含まれている。その上、高温加熱により蒸発損失しやすい揮発成分なども多く含まれている。したがって、果汁や糖液や蜂蜜の中には、多重効用缶蒸留による高温濃縮が適さない場合がある、という問題点がある。 Further, in the concentration using multi-effect can distillation, several stages of distillation cans are arranged and heated and distilled. Distillation is repeated while the amount of heat necessary for distillation is given in the first stage and the amount of heat given in the first stage is recovered without additional heating in the latter stage, so that it is possible to distill economically. However, since the amount of heat required for the last-stage distillation is also heated in the first stage, it is necessary to heat at a very high temperature with superheated steam exceeding 100 ° C. in the first stage. On the other hand, organic components derived from living organisms that are concentrated in a food process include those that are easily altered by heating. In addition, it contains a lot of volatile components that easily lose evaporation due to high-temperature heating. Therefore, some fruit juices, sugar solutions, and honey have a problem that high-temperature concentration by multi-effect can distillation may not be suitable.

さらに、凍結濃縮では、例えば被処理液を−１５℃前後の温度で凍結し、生成したシャーベット状（スラリー状）の凍結物を−５℃前後の温度に保持して氷の結晶を成長させた後、遠心分離または圧搾ろ過により氷の結晶のみを分離して、分離液をさらに凍結再結晶、分離する工程を繰り返すことにより濃縮する。この濃縮技術は、インスタントコーヒーの凍結乾燥の前濃縮や、高品質の果汁濃縮に適用されるが、濃縮効率が低く大量濃縮が容易でない、濃縮限界濃度が４０％程度と低い、などの問題点がある。 Further, in the freeze concentration, for example, the liquid to be treated is frozen at a temperature of about −15 ° C., and the generated sherbet-like (slurry) frozen material is maintained at a temperature of about −5 ° C. to grow ice crystals. Thereafter, only ice crystals are separated by centrifugal separation or squeezing filtration, and the separated liquid is further concentrated by repeating the steps of freeze-recrystallization and separation. This concentration technology can be applied to pre-concentration of freeze-dried instant coffee and high-quality fruit juice concentration, but there are problems such as low concentration efficiency, difficulty in mass concentration, and low concentration limit concentration of around 40%. There is.

ところで、真空エバポレーターは、濃縮効率は良好であるが、生産ラインに用いられる装備が金属製であるため、果汁、液糖、蜂蜜など酸や塩類を含むいわゆる腐食性液体に対する適用性が高いとは言えない。また、加温面積や蒸発面積を大きくすれば、蒸発効率を確保できる反面、重装備で装置規模が大きく、高価になる、などの問題点がある。 By the way, the vacuum evaporator has good concentration efficiency, but because the equipment used in the production line is made of metal, it is highly applicable to so-called corrosive liquids containing acids and salts such as fruit juice, liquid sugar, and honey. I can not say. Further, if the heating area and the evaporation area are increased, the evaporation efficiency can be secured, but there are problems that the equipment scale is large and expensive due to heavy equipment.

このように従来は、目的成分濃度が低く、比較的多量の被処理液について、熱変質や揮発成分の損失を極力低減しながら、さらに濃縮により液粘度が増加しても高濃度まで濃縮できる簡便なシステムはなかった。 Thus, conventionally, the target component concentration is low, and it is easy to concentrate to a high concentration even if the liquid viscosity increases due to concentration, while reducing heat deterioration and loss of volatile components as much as possible for a relatively large amount of liquid to be treated. There was no such system.

本発明は、上記課題に鑑みてなされたものであり、果汁、液糖、蜂蜜などの食品関連溶液のように高温での加熱により変質や変性をきたす溶液を、変質や変性させることのない濃縮システムを提供することを目的とする。また、本発明はこのような濃縮システムを用いた濃縮方法を提供することを目的とする。 The present invention has been made in view of the above problems, and concentrates without altering or denaturing a solution that is altered or denatured by heating at a high temperature, such as food-related solutions such as fruit juice, liquid sugar, and honey. The purpose is to provide a system. Another object of the present invention is to provide a concentration method using such a concentration system.

上記課題を解決するために、第一に本発明は、被処理液を一次濃縮する逆浸透膜装置と、前記逆浸透膜により濃縮された一次濃縮液をさらに濃縮して二次濃縮液を得る膜蒸留装置とを備える濃縮システムであって、前記膜蒸留装置が、疎水性多孔質膜を挟んで原水部と凝縮部とを備え、前記凝縮部を減圧状態に維持し、かつ前記凝縮部に冷却手段を備え、加熱された一次濃縮液を前記膜蒸留装置の前記原水部に導入し、前記一次濃縮液の蒸気を前記疎水性多孔質膜に透過させることで、該一次濃縮液を濃縮して二次濃縮液を生成するものであることを特徴とする濃縮システムを提供する（発明１）。ここで前記被処理液としては、果汁、液糖、蜂蜜などの食品関連溶液が好適である（発明２）。 In order to solve the above-mentioned problems, firstly, the present invention obtains a secondary concentrated liquid by further concentrating the primary concentrated liquid concentrated by the reverse osmotic membrane, and a reverse osmotic membrane apparatus that primarily concentrates the liquid to be treated. A concentrating system comprising a membrane distillation apparatus, the membrane distillation apparatus comprising a raw water part and a condensing part across a hydrophobic porous membrane, maintaining the condensing part in a reduced pressure state, and in the condensing part The primary concentrated liquid is provided with a cooling means, and the heated primary concentrated liquid is introduced into the raw water portion of the membrane distillation apparatus, and the primary concentrated liquid is concentrated by passing the vapor of the primary concentrated liquid through the hydrophobic porous membrane. And providing a secondary concentrated liquid (Invention 1). Here, food-related solutions such as fruit juice, liquid sugar, and honey are suitable as the liquid to be treated (Invention 2).

かかる発明（発明１、２）によれば、目的とする成分の初期濃度が数％程度と低い被処理液をまず逆浸透膜で４０〜５０％程度（容量減少相当、以下同じ）まで一次濃縮し、粘度の増加した一次濃縮液をさらに膜蒸留して７０〜８０％程度の高濃度（目的濃度）にまで濃縮することができる。しかも逆浸透膜による濃縮は加熱を必要とせず、膜蒸留では１００℃以上、好ましくは９０℃以上に加熱する必要がないので、果汁、液糖、蜂蜜などの食品関連溶液における糖分などの目的とする濃縮成分を、熱による変質や揮発成分の損失を大幅に低減させて濃縮することができる。さらに、多量の非処理液であっても効率よく処理可能であり、システム構成も簡便で運転管理も容易である。 According to the inventions (Inventions 1 and 2), the liquid to be treated having a low initial concentration of a target component of about several percent is first concentrated to about 40 to 50% (corresponding to a volume reduction, the same applies hereinafter) with a reverse osmosis membrane. The primary concentrated liquid having increased viscosity can be further subjected to membrane distillation to be concentrated to a high concentration (target concentration) of about 70 to 80%. In addition, concentration by reverse osmosis membrane does not require heating, and membrane distillation does not require heating to 100 ° C. or higher, preferably 90 ° C. or higher. Therefore, the purpose of sugar content in food-related solutions such as fruit juice, liquid sugar, and honey The concentrated component to be concentrated can be concentrated with greatly reduced heat deterioration and loss of volatile components. Furthermore, even a large amount of non-treatment liquid can be processed efficiently, the system configuration is simple, and operation management is easy.

上記発明（発明１、２）においては、前記膜蒸留装置の前記原水部に導入する前記一次濃縮液を廃熱を利用して加熱する加熱手段を備えるのが好ましい（発明３）。 In the said invention (invention 1 and 2), it is preferable to provide the heating means which heats the said primary concentrated liquid introduce | transduced into the said raw | natural water part of the said membrane distillation apparatus using waste heat (invention 3).

かかる発明（発明３）によれば、加熱手段の熱源として廃熱を活用することで熱エネルギーの有効利用を図ることができ、一層の省エネルギー化や省コスト化を図ることができるので、環境保全や産業活性化にも有効である。 According to this invention (invention 3), it is possible to effectively use heat energy by utilizing waste heat as a heat source of the heating means, and further energy saving and cost saving can be achieved. It is also effective for industrial revitalization.

また、第二に本発明は、被処理液を逆浸透膜装置により濃縮する一次濃縮工程と、前記一次濃縮工程で得られた一次濃縮液を膜蒸留装置によりさらに濃縮する二次濃縮工程とを有する濃縮方法であって、前記膜蒸留装置が、疎水性多孔質膜を挟んで原水部と凝縮部とを備え、前記凝縮部を減圧状態に維持し、かつ前記凝縮部に冷却手段を備えるものであり、前記二次濃縮工程が、加熱された一次濃縮液を前記膜蒸留装置の前記原水部に導入し、前記一次濃縮液の蒸気を前記疎水性多孔質膜に透過させることで、該一次濃縮液を濃縮して二次濃縮液を生成することを特徴とする濃縮方法を提供する（発明４）。 Second, the present invention includes a primary concentration step of concentrating a liquid to be treated by a reverse osmosis membrane device, and a secondary concentration step of further concentrating the primary concentrate obtained in the primary concentration step by a membrane distillation device. The membrane distillation apparatus includes a raw water part and a condensing part across a hydrophobic porous membrane, maintains the condensing part in a reduced pressure state, and includes a cooling means in the condensing part And the secondary concentration step introduces the heated primary concentrate into the raw water part of the membrane distillation apparatus, and allows the vapor of the primary concentrate to permeate the hydrophobic porous membrane. A concentration method is characterized in that a concentrated solution is concentrated to produce a secondary concentrated solution (Invention 4).

かかる発明（発明４）によれば、目的とする成分の初期濃度が数％程度と低い被処理液をまず逆浸透膜で４０〜５０％程度（容量濃縮相当、以下同じ）まで一次濃縮し、粘度の増加した液をさらに膜蒸留して７０〜８０％程度の高濃度（目的濃度）にまで濃縮することができる。これにより目的とする成分を熱による変質や揮発成分の損失を大幅に低減して濃縮することができる。さらに、多量の非処理液であっても効率よく処理することができる。 According to this invention (Invention 4), the liquid to be treated having a low initial concentration of the target component of about several percent is first concentrated to about 40 to 50% (equivalent to volume concentration, the same applies hereinafter) with a reverse osmosis membrane, The liquid having increased viscosity can be further subjected to membrane distillation to be concentrated to a high concentration (target concentration) of about 70 to 80%. As a result, the target component can be concentrated with greatly reduced alteration due to heat and loss of volatile components. Furthermore, even a large amount of non-treatment liquid can be processed efficiently.

本発明の濃縮システムは、被処理液をまず逆浸透膜で一次濃縮し、粘度の増加した一次濃縮液を膜蒸留してさらに濃縮するものであるので、目的とする成分の初期濃度が数％程度と低い被処理液を多量の非処理液であっても効率よく高濃度（目的濃度）にまで濃縮することができる。しかも逆浸透膜による濃縮は加熱を必要とせず、膜蒸留では１００℃以上、好ましくは９０℃以上に加熱する必要がなく、被処理液を高温にさらすことなく濃縮することができるので、果汁、液糖、蜂蜜などの食品関連溶液を目的とする成分の熱による変質や揮発成分の損失を大幅に低減することができる。 In the concentration system of the present invention, the liquid to be treated is first concentrated with a reverse osmosis membrane, and the primary concentrated solution with increased viscosity is further concentrated by membrane distillation. Even a large amount of non-processed liquid can be efficiently concentrated to a high concentration (target concentration) even if the liquid to be processed is low. Moreover, the concentration by the reverse osmosis membrane does not require heating, the membrane distillation does not require heating to 100 ° C. or higher, preferably 90 ° C. or higher, and the liquid to be treated can be concentrated without being exposed to a high temperature. It is possible to drastically reduce the deterioration of components intended for food-related solutions such as liquid sugar and honey, and loss of volatile components.

本発明の一実施形態に係る濃縮システムを示す概略図である。It is the schematic which shows the concentration system which concerns on one Embodiment of this invention. 膜蒸留装置の一例を示す概略図である。It is the schematic which shows an example of a membrane distillation apparatus. 比較例１の濃縮システムを示す概略図である。2 is a schematic view showing a concentration system of Comparative Example 1. FIG. 比較例２の濃縮システムを示す概略図である。6 is a schematic diagram showing a concentration system of Comparative Example 2. FIG. 比較例３の濃縮システムを示す概略図である。It is the schematic which shows the concentration system of the comparative example 3.

以下、本発明の一実施形態について添付図面を参照して詳細に説明する。 Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

以下、本発明について詳細に説明する。
図１は、本実施形態に係る濃縮システムを示す概略図である。図１において、被処理液Ｗの濃縮システム１は、原水ライン２の途中に一次濃縮手段としての逆浸透膜装置３と二次濃縮手段としての膜蒸留装置４とを有し、逆浸透膜装置３と膜蒸留装置４との間には加熱手段としての熱交換器５が配置されている。 Hereinafter, the present invention will be described in detail.
FIG. 1 is a schematic view showing a concentration system according to the present embodiment. In FIG. 1, the concentration system 1 of the liquid W to be treated has a reverse osmosis membrane device 3 as a primary concentration means and a membrane distillation device 4 as a secondary concentration means in the middle of a raw water line 2, and a reverse osmosis membrane device. A heat exchanger 5 serving as a heating means is disposed between 3 and the membrane distillation apparatus 4.

上記濃縮システム１において、被処理液Ｗは逆浸透膜装置３で一次濃縮されて一次濃縮液Ｗ１と膜透過水Ｗ２とに分離され、膜蒸留装置４で二次濃縮されて最終生成物である二次濃縮液Ｗ３と蒸留水Ｗ４とに分離される。 In the concentration system 1, the liquid W to be treated is primarily concentrated by the reverse osmosis membrane device 3 to be separated into the primary concentrated solution W1 and the membrane permeate W2, and is secondarily concentrated by the membrane distillation device 4 to be a final product. It isolate | separates into the secondary concentrated liquid W3 and the distilled water W4.

図２は、膜蒸留装置４の一例を示している。この膜蒸留装置４は、低温廃熱を利用して熱交換器５により加熱した一次濃縮液Ｗ１を疎水性多孔質膜を通過させて、その蒸気を減圧および低温条件下で蒸留または濃縮する膜蒸留技術を用いる。 FIG. 2 shows an example of the membrane distillation apparatus 4. This membrane distillation apparatus 4 is a membrane in which a primary concentrated liquid W1 heated by a heat exchanger 5 using low-temperature waste heat is passed through a hydrophobic porous membrane and its vapor is distilled or concentrated under reduced pressure and low temperature conditions. Use distillation techniques.

この膜蒸留装置４は疎水性多孔質膜１１が備えられており、この疎水性多孔質膜１１を挟んで原水室１２と凝縮室１３が備えられる。原水室１２は一次濃縮液Ｗ１を導入する原水部の一例であり、凝縮室１３は疎水性多孔質膜１１を通過した蒸気Ｓを凝縮する凝縮部の一例である。 The membrane distillation apparatus 4 is provided with a hydrophobic porous membrane 11, and a raw water chamber 12 and a condensing chamber 13 are provided with the hydrophobic porous membrane 11 interposed therebetween. The raw water chamber 12 is an example of a raw water portion into which the primary concentrated liquid W1 is introduced, and the condensing chamber 13 is an example of a condensing portion that condenses the vapor S that has passed through the hydrophobic porous membrane 11.

疎水性多孔質膜１１は、原水室１２に導入された一次濃縮液Ｗ１の蒸気のみを選択的に通過させる手段の一例である。この疎水性多孔質膜１１としては、耐熱性に優れていることからフッ素樹脂製多孔質膜を好適に用いることができる。この疎水性多孔質膜１１においては、一次濃縮液Ｗ１の蒸気Ｓのみを透過させ、膜透過蒸気量に対する一次濃縮液Ｗ１の浸透圧や粘度の影響を受けにくく、蒸気透過性が高く、一次濃縮液Ｗ１の懸濁成分などの濃縮を効率的に行うことができる。 The hydrophobic porous membrane 11 is an example of means for selectively allowing only the vapor of the primary concentrated solution W1 introduced into the raw water chamber 12 to pass through. As the hydrophobic porous membrane 11, a fluororesin porous membrane can be suitably used because of its excellent heat resistance. In this hydrophobic porous membrane 11, only the vapor S of the primary concentrated solution W1 is permeated, it is hardly affected by the osmotic pressure and viscosity of the primary concentrated solution W1 with respect to the membrane permeated vapor amount, has high vapor permeability, and is primarily concentrated. Concentration of the suspended component of the liquid W1 can be performed efficiently.

凝縮室１３には減圧装置１４が接続され、凝縮室１３の壁面には冷却部１５が備えられている。凝縮室１３とともに原水室１２が減圧装置１４により減圧されて減圧状態に維持され、冷却部１５は接触する蒸気Ｓを凝縮する程度の温度に図示しない冷却手段により冷却されている。 A decompression device 14 is connected to the condensation chamber 13, and a cooling unit 15 is provided on the wall surface of the condensation chamber 13. The raw water chamber 12 is decompressed by the decompression device 14 together with the condensing chamber 13 and is maintained in a decompressed state, and the cooling unit 15 is cooled by a cooling means (not shown) to a temperature to condense the vapor S in contact therewith.

上記被処理液Ｗとしては、果汁、液糖、蜂蜜などの糖分を含む食品関連溶液が好適である。ここで、被処理液Ｗは、糖分などの目的とする濃縮成分の初期濃度が１０％以下、特に２〜７％程度である。 As said to-be-processed liquid W, the food related solution containing sugars, such as fruit juice, liquid sugar, and honey, is suitable. Here, in the liquid W to be treated, the initial concentration of the target concentrated component such as sugar is 10% or less, particularly about 2 to 7%.

次に上述したような膜蒸留装置４を備えた濃縮システム１の作用について説明する。 Next, the operation of the concentration system 1 provided with the membrane distillation apparatus 4 as described above will be described.

まず、被処理液Ｗは、逆浸透膜装置３で一次濃縮される。ここで被処理液Ｗは、膜透過水Ｗ２が分離排出されることで４０〜５０％程度まで濃縮され、粘度等が増加した一次濃縮液Ｗ１が得られる。特に、食品プロセスでは、水温が高いことがあるため、あらかじめ貯槽や熱交換器において、逆浸透膜モジュールの許容温度に調整しておくのが好ましい。上記逆浸透膜装置３としては、スパイラル式や中空管式（チューブラー式）や中空糸式などのモジュールが適用することができる。また、逆浸透膜装置３を構成する膜としては、酢酸セルロース膜や合成高分子膜、例えば、芳香族ポリアミドやポリスルホンやポリビニルアルコールなどを適用することができる。 First, the liquid W to be treated is primarily concentrated by the reverse osmosis membrane device 3. Here, the liquid W to be treated is concentrated to about 40 to 50% by separating and discharging the membrane permeated water W2, and a primary concentrated liquid W1 having an increased viscosity or the like is obtained. Particularly in food processes, the water temperature may be high, so it is preferable to adjust the temperature to the allowable temperature of the reverse osmosis membrane module in a storage tank or heat exchanger in advance. As the reverse osmosis membrane device 3, modules such as a spiral type, a hollow tube type (tubular type), and a hollow fiber type can be applied. Moreover, as a film | membrane which comprises the reverse osmosis membrane apparatus 3, a cellulose acetate film | membrane and a synthetic polymer film, for example, aromatic polyamide, polysulfone, polyvinyl alcohol, etc. are applicable.

そして、この一次濃縮液Ｗ１を熱交換器５へ送液する。ここで、この一次濃縮液Ｗ１は熱交換器５により所定の温度に熱交換される。熱交換器５は工場廃熱など、廃熱源で加熱された熱媒体の熱で一次濃縮液Ｗ１に熱交換する。これにより一次濃縮液Ｗ１は、例えば、１００℃未満、好ましくは４０〜９０℃、特に５０℃〜８０℃程度になるように温度調整され、後段の膜蒸留装置４に供給される。このように被処理液Ｗを膜蒸留装置４における濃縮に好適な温度に加熱するのに工場廃熱などの廃熱を利用することができ、各種の廃熱の有効利用が図られる。 Then, the primary concentrated liquid W1 is sent to the heat exchanger 5. Here, the primary concentrated solution W1 is heat-exchanged to a predetermined temperature by the heat exchanger 5. The heat exchanger 5 exchanges heat with the primary concentrated liquid W1 by heat of a heat medium heated by a waste heat source such as factory waste heat. Thus, the temperature of the primary concentrated liquid W1 is adjusted to be, for example, less than 100 ° C., preferably about 40 to 90 ° C., particularly about 50 ° C. to 80 ° C., and supplied to the membrane distillation apparatus 4 at the subsequent stage. In this way, waste heat such as factory waste heat can be used to heat the liquid W to be treated to a temperature suitable for concentration in the membrane distillation apparatus 4, and various waste heat can be effectively used.

そして、温度調整されるとともに一次濃縮により粘度の増加した一次濃縮液Ｗ１を膜蒸留装置４に送液し、二次濃縮して蒸留水Ｗ４を分離し二次濃縮液Ｗ３を得る。 Then, the primary concentrated liquid W1 whose temperature is adjusted and whose viscosity has been increased by the primary concentration is sent to the membrane distillation apparatus 4 and subjected to secondary concentration to separate the distilled water W4 to obtain the secondary concentrated liquid W3.

ここで膜蒸留装置４では、以下のようにして二次濃縮を行う。すなわち、凝縮室１３を減圧下に維持しておくことで、疎水性多孔質膜１１の孔を通過した蒸気Ｓが引き込まれる。 Here, the membrane distillation apparatus 4 performs secondary concentration as follows. That is, by maintaining the condensation chamber 13 under reduced pressure, the vapor S that has passed through the holes of the hydrophobic porous membrane 11 is drawn.

この場合、凝縮室１３が減圧状態に維持されるので、蒸気Ｓを引き込む機能だけでなく、一次濃縮液Ｗ１の沸点をより降下させる機能を有する。これにより、一次濃縮液Ｗ１から生じる蒸気Ｓが顕著となり、疎水性多孔質膜１１を透過する蒸気量が増大する。この結果、原水室１２で二次濃縮液Ｗ３が得られる。つまり、一次濃縮液Ｗ１から多くの蒸気Ｓが凝縮して二次濃縮液Ｗ３に変換されるので、原水室１２の一次濃縮液Ｗ１が効率的に濃縮される。したがって、原水室１２から多くの二次濃縮液Ｗ３が生成され、濃縮液回収ライン１６から回収される。 In this case, since the condensing chamber 13 is maintained in a reduced pressure state, not only the function of drawing in the steam S but also the function of lowering the boiling point of the primary concentrated liquid W1. Thereby, the vapor | steam S produced from the primary concentrated liquid W1 becomes remarkable, and the vapor | steam amount which permeate | transmits the hydrophobic porous membrane 11 increases. As a result, the secondary concentrated liquid W3 is obtained in the raw water chamber 12. That is, since much steam S is condensed from the primary concentrate W1 and converted into the secondary concentrate W3, the primary concentrate W1 of the raw water chamber 12 is efficiently concentrated. Therefore, a lot of secondary concentrated liquid W3 is generated from the raw water chamber 12 and recovered from the concentrated liquid recovery line 16.

一方、蒸気Ｓは凝縮室１３の冷却部１５に触れ凝縮して水滴Ｌが生じる。この結果、冷却部１５では蒸気Ｓが結露して蒸留水Ｗ４が凝縮水排出ライン１７から排出される。 On the other hand, the vapor S touches the cooling unit 15 of the condensation chamber 13 and condenses, and water droplets L are generated. As a result, the steam S is condensed in the cooling unit 15, and the distilled water W <b> 4 is discharged from the condensed water discharge line 17.

このような膜蒸留において、一次濃縮液Ｗ１を濃縮し、二次濃縮液Ｗ３を得る上で、一次濃縮液Ｗ１の流路幅および膜面線流速は重要である。流路幅は、一次濃縮液Ｗ１を通過させるに有効な流路径などの大きさである。これに対し、膜面線流速は、一次濃縮液Ｗ１の流量を装置内の有効断面積で割った値で与えられる線速度であり、見かけ上、一次濃縮液Ｗ１の速度である。具体的には、疎水性多孔質膜１１の膜面に平行な一次濃縮液Ｗ１の平均流速である。 In such membrane distillation, the primary concentrated solution W1 is concentrated to obtain the secondary concentrated solution W3, and the flow path width and membrane surface line flow rate of the primary concentrated solution W1 are important. The channel width is a size such as a channel diameter effective for allowing the primary concentrated solution W1 to pass through. On the other hand, the membrane surface line flow velocity is a linear velocity given by a value obtained by dividing the flow rate of the primary concentrate W1 by the effective cross-sectional area in the apparatus, and is apparently the velocity of the primary concentrate W1. Specifically, the average flow velocity of the primary concentrated liquid W1 parallel to the membrane surface of the hydrophobic porous membrane 11 is shown.

そして、この膜蒸留装置４では、一次濃縮液Ｗ１の流路幅ｗは例えば、１〔ｍｍ〕以上、３０〔ｍｍ〕以下であればよく、より好ましくは３〔ｍｍ〕以上、２０〔ｍｍ〕以下とする。また、一次濃縮液Ｗ１の膜面線流速Ｖは例えば、０．０１〔ｍ／ｓ〕以上、５〔ｍ／ｓ〕以下とし、より好ましくは０．０５〔ｍ／ｓ〕以上、２〔ｍ／ｓ〕とすればよい。 And in this membrane distillation apparatus 4, the flow path width w of the primary concentrate W1 should just be 1 [mm] or more and 30 [mm] or less, for example, More preferably, it is 3 [mm] or more and 20 [mm]. The following. The membrane surface flow velocity V of the primary concentrated liquid W1 is, for example, not less than 0.01 [m / s] and not more than 5 [m / s], more preferably not less than 0.05 [m / s] and not more than 2 [m]. / S].

この膜蒸留装置４において、被処理液Ｗは７０〜８０％程度の高濃度（目的濃度）にまで濃縮する。したがって、膜蒸留装置４は必要に応じて多段、例えば、２段〜１２段、望ましくは３段〜１０段として、目的とする濃縮濃度となるまで濃縮するとともにエネルギー回収率を高めることができる。 In this membrane distillation apparatus 4, the liquid W to be treated is concentrated to a high concentration (target concentration) of about 70 to 80%. Therefore, the membrane distillation apparatus 4 can be concentrated in multiple stages, for example, 2 to 12 stages, preferably 3 to 10 stages, as necessary, until it reaches the desired concentration, and the energy recovery rate can be increased.

このようにして得られる二次濃縮液Ｗ３は、逆浸透膜装置３による一次濃縮では加熱を必要とせず、膜蒸留装置４では１００℃以上、好ましくは９０℃以上に加熱されず、被処理液Ｗを高温にさらすことなく濃縮することができるので、目的とする成分の熱による変質や揮発成分の損失を大幅に低減することができる。さらに、被処理液Ｗが多量であっても効率よく処理可能であり、システム構成も簡便で運転管理も容易である。 The secondary concentrated solution W3 thus obtained does not require heating in the primary concentration by the reverse osmosis membrane device 3, and is not heated to 100 ° C. or higher, preferably 90 ° C. or higher in the membrane distillation device 4, and the liquid to be treated Since W can be concentrated without being exposed to a high temperature, it is possible to greatly reduce alteration of the target component due to heat and loss of volatile components. Furthermore, even if the liquid W to be processed is large, it can be processed efficiently, the system configuration is simple, and the operation management is easy.

なお、膜透過水Ｗ２と蒸留水Ｗ４は、必要に応じて、用水、例えば、逆浸透膜及びモジュールや、膜蒸留ユニットの洗浄水、あるいは、希釈水などに用いて、資源の有効利用を図ることができる。 The membrane permeated water W2 and the distilled water W4 are used as service water, for example, reverse osmosis membranes and modules, washing water for the membrane distillation unit, or dilution water as required, so as to effectively use resources. be able to.

以上、本発明の実施形態について説明してきたが、本発明は上記実施形態に限らず種々の変形実施が可能である。例えば、濃縮システムの構成としては、逆浸透膜装置３及び膜蒸留装置４をそれぞれ複数段としてもよい。また、この濃縮システムにおいて、被処理液Ｗは食品プロセス水に限らず、医薬やその他の産業分野のプロセス水を濃縮するのにも適用することができる。 As mentioned above, although embodiment of this invention has been described, this invention is not restricted to the said embodiment, A various deformation | transformation implementation is possible. For example, as a configuration of the concentration system, the reverse osmosis membrane device 3 and the membrane distillation device 4 may each have a plurality of stages. In this concentration system, the liquid W to be treated is not limited to food process water, but can be applied to concentrate process water in medicine and other industrial fields.

以下の具体的実施例により本発明をさらに詳細に説明する。 The following specific examples further illustrate the present invention.

＜実施例１＞
図１に示す構成を有する濃縮システムを用い、Ｂｒｉｘ値（糖度）７％の糖水溶液（被処理液Ｗ）を逆浸透膜装置３でＢｒｉｘ値４０〜５０％程度まで一次濃縮し、熱交換器５でこの一次濃縮液Ｗ１を加熱し、膜蒸留装置４において８０℃、８０ｋＰａで濃縮してＢｒｉｘ値７４％の二次濃縮液Ｗ３を得た。 <Example 1>
Using the concentrating system having the configuration shown in FIG. 1, an aqueous sugar solution (liquid W to be treated) having a Brix value (sugar content) of 7% is primarily concentrated by the reverse osmosis membrane device 3 to a Brix value of about 40 to 50%. The primary concentrated liquid W1 was heated at 5 and concentrated at 80 ° C. and 80 kPa in the membrane distillation apparatus 4 to obtain a secondary concentrated liquid W3 having a Brix value of 74%.

＜実施例２＞
図１に示す構成を有する濃縮システムを用い、Ｂｒｉｘ値８％の蜂蜜水溶液（被処理液Ｗ）を逆浸透膜装置３でＢｒｉｘ値４０〜５０％程度まで一次濃縮し、熱交換器５でこの一次濃縮液Ｗ１を加熱し、膜蒸留装置４において５２℃、８０ｋＰａで濃縮してＢｒｉｘ値６２％の二次濃縮液Ｗ３を得た。この二次濃縮液Ｗ３に成分の焦げはなく、褐変着色は認められなかった。 <Example 2>
Using the concentration system having the configuration shown in FIG. 1, an aqueous honey solution (treatment liquid W) having a Brix value of 8% is primarily concentrated by the reverse osmosis membrane device 3 to a Brix value of about 40 to 50%. The primary concentrated liquid W1 was heated and concentrated at 52 ° C. and 80 kPa in the membrane distillation apparatus 4 to obtain a secondary concentrated liquid W3 having a Brix value of 62%. The secondary concentrated liquid W3 was not burnt and no browning was observed.

＜比較例１＞
図３に示すように逆浸透膜装置２１、２２、２３を３段に連続させた構成を有する濃縮システム２０を用い、Ｂｒｉｘ値７％の糖水溶液（被処理液Ｗ）を濃縮したところ、２段目の逆浸透膜装置２２で、濃縮液の粘性が高くなりすぎ、濃縮液Ｗ５を得ることができなかった。なお、図３中においては図１と同一の構成には同一の符号を付している。 <Comparative Example 1>
As shown in FIG. 3, a sugar aqueous solution (treatment liquid W) having a Brix value of 7% was concentrated using a concentration system 20 having a configuration in which reverse osmosis membrane devices 21, 22, and 23 are continuously arranged in three stages. In the reverse osmosis membrane device 22 in the stage, the viscosity of the concentrated liquid became too high, and the concentrated liquid W5 could not be obtained. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals.

＜比較例２＞
図４に示すように多重効用缶３１、３２、３３を３段に連続させた構成を有する濃縮システム３０を用い、Ｂｒｉｘ値３９％の蜂蜜希釈液（被処理液Ｗ）を濃縮して濃縮液Ｗ６を生成したが、１段目の多重効用缶３１の加熱蒸気管の表面温度が高いため、加熱蒸気管付近の糖水溶液が焦げて、褐変着色が起き、品質劣化が起きた。なお、図４中においては図１と同一の構成には同一の符号を付している。 <Comparative example 2>
As shown in FIG. 4, using a concentration system 30 having a configuration in which multiple effect cans 31, 32, 33 are continuously arranged in three stages, a honey dilution liquid (processed liquid W) having a Brix value of 39% is concentrated to a concentrated liquid. Although W6 was produced, since the surface temperature of the heating steam pipe of the first stage multi-effect can 31 was high, the aqueous sugar solution in the vicinity of the heating steam pipe was burnt, browning coloration occurred, and quality deterioration occurred. In FIG. 4, the same components as those in FIG. 1 are denoted by the same reference numerals.

＜比較例３＞
図５に示すように、図１において逆浸透膜装置３を用いずに濃縮システム４０を構成し、Ｂｒｉｘ値７％の糖水溶液（被処理液Ｗ）を熱交換器５で加熱し、膜蒸留装置４において８０℃、８０ｋＰａで濃縮してＢｒｉｘ値３５％まで濃縮しようとしたが、液粘性の上昇とともに単位時間当たりの蒸留量が少なくなり、現実的でない大きなサイズの装置でなければ不可能であることが想定できた。 <Comparative Example 3>
As shown in FIG. 5, the concentration system 40 is configured without using the reverse osmosis membrane device 3 in FIG. The device 4 tried to concentrate at 80 ° C. and 80 kPa to concentrate to a Brix value of 35%. However, the amount of distillation per unit time decreased as the liquid viscosity increased, and this would not be possible unless the device was unrealistically large. I was able to assume that there was.

本発明の濃縮システムおよび濃縮方法によれば、果汁、液糖、蜂蜜などの食品関連溶液のように高温での加熱により変質や変性をきたす溶液を、変質や変性させることなく濃縮することができ、食品プロセス溶液の濃縮技術として広く利用することができる。 According to the concentration system and concentration method of the present invention, a solution that is altered or denatured by heating at a high temperature, such as a food-related solution such as fruit juice, liquid sugar, and honey, can be concentrated without being denatured or denatured. It can be widely used as a technology for concentrating food process solutions.

１…濃縮システム
２…原水ライン
３…逆浸透膜装置（一次濃縮手段）
４…膜蒸留装置（二次濃縮手段）
５…熱交換器（加熱手段）
１１…疎水性多孔質膜
１２…原水室
１３…凝縮室
１４…減圧装置
１５…冷却部
１６…濃縮液回収ライン
Ｗ…被処理液
Ｗ１…一次濃縮液
Ｗ２…膜透過水
Ｗ３…二次濃縮液
Ｗ４…蒸留水
Ｓ…蒸気 DESCRIPTION OF SYMBOLS 1 ... Concentration system 2 ... Raw water line 3 ... Reverse osmosis membrane apparatus (primary concentration means)
4 ... Membrane distillation device (secondary concentration means)
5 ... Heat exchanger (heating means)
DESCRIPTION OF SYMBOLS 11 ... Hydrophobic porous membrane 12 ... Raw water chamber 13 ... Condensing chamber 14 ... Depressurization device 15 ... Cooling part 16 ... Concentrated liquid recovery line W ... To-be-processed liquid W1 ... Primary concentrated liquid W2 ... Membrane permeated water W3 ... Secondary concentrated liquid W4 ... Distilled water S ... Steam

Claims

果汁、液糖あるいは蜂蜜の食品関連溶液である被処理液を一次濃縮する逆浸透膜装置と、
前記逆浸透膜により濃縮された一次濃縮液をさらに濃縮して二次濃縮液を得る膜蒸留装置と
を備える濃縮システムであって、
前記膜蒸留装置が、疎水性多孔質膜を挟んで原水部と凝縮部とを備え、
前記凝縮部を減圧状態に維持し、かつ前記凝縮部に冷却手段を備え、
加熱された一次濃縮液を前記膜蒸留装置の記原水部に導入し、前記一次濃縮液の蒸気を前記疎水性多孔質膜に透過させることで、該一次濃縮液を濃縮して二次濃縮液を生成するものであることを特徴とする濃縮システム。 A reverse osmosis membrane device that primarily concentrates a liquid to be treated, which is a food-related solution of fruit juice, liquid sugar, or honey ;
A membrane distillation apparatus that further concentrates the primary concentrate concentrated by the reverse osmosis membrane to obtain a secondary concentrate,
The membrane distillation apparatus comprises a raw water part and a condensing part across a hydrophobic porous membrane,
Maintaining the condensing part in a decompressed state, and providing the condensing part with cooling means;
The heated primary concentrated liquid is introduced into the raw water section of the membrane distillation apparatus, and the primary concentrated liquid is concentrated by allowing the vapor of the primary concentrated liquid to permeate the hydrophobic porous membrane. A concentrating system characterized in that

前記膜蒸留装置の前記原水部に導入する前記一次濃縮液を廃熱を利用して加熱する加熱手段を備えることを特徴とする請求項１に記載の濃縮システム。 The concentration system according to claim 1, further comprising heating means for heating the primary concentrated liquid introduced into the raw water portion of the membrane distillation apparatus using waste heat.

果汁、液糖あるいは蜂蜜の食品関連溶液である被処理液を逆浸透膜装置により濃縮する一次濃縮工程と、
前記一次濃縮工程で得られた一次濃縮液を膜蒸留装置によりさらに濃縮する二次濃縮工程と
を有する濃縮方法であって、
前記膜蒸留装置が、疎水性多孔質膜を挟んで原水部と凝縮部とを備え、前記凝縮部を減圧状態に維持し、かつ前記凝縮部に冷却手段を備えるものであり、
前記二次濃縮工程が、加熱された一次濃縮液を前記膜蒸留装置の前記原水部に導入し、該一次濃縮液の蒸気を前記疎水性多孔質膜に透過させることで、該一次濃縮液を濃縮して二次濃縮液を生成することを特徴とする濃縮方法。 A primary concentration step of concentrating a liquid to be treated which is a food-related solution of fruit juice, liquid sugar or honey with a reverse osmosis membrane device;
A secondary concentration step of further concentrating the primary concentrate obtained in the primary concentration step with a membrane distillation apparatus,
The membrane distillation apparatus comprises a raw water part and a condensing part across a hydrophobic porous membrane, maintains the condensing part in a reduced pressure state, and comprises a cooling means in the condensing part,
In the secondary concentration step, the heated primary concentrate is introduced into the raw water part of the membrane distillation apparatus, and the primary concentrated solution is allowed to pass through the hydrophobic porous membrane by passing the vapor of the primary concentrate through the hydrophobic porous membrane. A concentration method comprising producing a secondary concentrate by concentration.