JP2015110198A - Module unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separation membrane module unit for steam sterilization, and to provide a sterilization method for the same.SOLUTION: Individual separation membrane modules are obliquely arranged and respective modules are connected to one another in series. The steam sterilization unit can reduce cost of equipment and is excellent in operability.

Description

  The present invention relates to a separation membrane module unit suitable for steam sterilization.

  Separation membranes are used in various fields such as water treatment fields such as drinking water production, water purification, and wastewater treatment, and food industry. In water treatment fields such as drinking water production, water purification treatment, and wastewater treatment, separation membranes are used to remove impurities in water as an alternative to conventional sand filtration and coagulation sedimentation processes. In the water treatment field such as water purification treatment and wastewater treatment, the amount of treated water is large, so improvement in water permeability performance is required.The separation membrane with excellent water permeability performance reduces the membrane area, and the installation area per membrane area is reduced. By using small hollow fiber membrane modules and spiral type modules, we are trying to make the device compact and reduce equipment costs and membrane replacement costs.

On the other hand, taking a continuous fermentation apparatus using a separation membrane as an example, in order to perform production by continuous fermentation more efficiently in a continuous fermentation apparatus, the installation area per membrane area is small, and the replacement cost of the separation membrane module is low. A technique using few hollow fiber membrane modules or the like is disclosed (see Patent Document 1). In this technology, fermentation culture is performed by collecting microorganisms and cultured cells using a hollow fiber membrane as a separation membrane, collecting chemicals from the filtrate, and simultaneously holding or refluxing the microorganisms and cultured cells in the concentrate in the fermentation broth. It is possible to maintain a high concentration of microorganisms and cultured cells in the liquid. The cross-flow filtration is used to feed the fermentation broth to the hollow fiber membrane module, filter a part of it, and return it mostly to the fermenter. It was also possible to remove the soil and to continue efficient filtration for a long time.
In such continuous fermentation, it is preferable to carry out pure culture in a state where contamination with contamination is prevented. When various bacteria are mixed from the separation membrane module or the like when filtering the fermentation broth, chemical products cannot be efficiently produced due to a decrease in fermentation efficiency, foaming in the fermentation tank, or the like. Therefore, in order to prevent contamination with germs, it is necessary to sterilize the fermenter, peripheral equipment, and separation membrane before fermentation.

  Examples of sterilization methods include flame sterilization, dry heat sterilization, boiling sterilization, steam sterilization, ultraviolet sterilization, gamma ray sterilization, and gas sterilization. Note that the separation function is lost. Although there is a method of sterilizing with a drug, there is a problem of processing of the drug after sterilization or the drug remaining in the separation membrane module. Furthermore, there is concern that drug-resistant microorganisms remain.

  The shape of the separation membrane may be a flat membrane, a hollow fiber membrane, a spiral type, or the like, and if it is a hollow fiber membrane module, there are an external pressure type and an internal pressure type. In particular, the hollow fiber membrane module has a large membrane area per unit device and is considered to be an industrially useful structure, but the structure is complicated.

  In order to sterilize a separation membrane having a complicated structure without drying, steam sterilization (generally 121 ° C., 15 minutes to 20 minutes) in which water vapor at a predetermined temperature is supplied into the separation membrane module is suitable. Yes.

  When this steam sterilization is performed in equipment such as a production scale fermenter, generally, steam at a predetermined temperature and pressure, for example, saturated steam at 125 ° C. is supplied to the fermenter and peripheral equipment, and general steam sterilization is performed. Each facility is heated up to 121 ° C., which is the temperature of this, and the sterilization temperature is maintained for a predetermined time (20 minutes or more) to perform steam sterilization.

Here, considering the facilities for industrialization, it is assumed that fermentation is performed in a fermenter of several hundred m ^{3 in} a large one, but many membranes are used for filtering a fermentation broth containing a high concentration of microorganisms. An area is required, and therefore, a plurality of separation membrane modules are used. For example, when filtering the fermented liquid hundred m ^3, filterability of the fermentation liquor, such as by the performance of the separation membrane module optimal number will vary, but hundreds if large, requires a few thousand more separation membrane module Become.

  On the other hand, in the water treatment field, during filtration, the stock solution is supplied to the modules arranged in parallel to perform filtration, and at the time of washing, the modules are connected by a flushing pipe, and an open / close valve installed at a predetermined position. A technique for reducing the amount of cleaning liquid, the amount of waste liquid, and the amount of air for cleaning separation membranes by flushing the hollow fiber membrane with the modules arranged in series by the opening / closing operation is disclosed (Patent Document 2).

  For separation membrane modules used for the production of chemicals by continuous fermentation, which uses a separation membrane to produce chemicals continuously by fermentation, cross-flow filtration is used for the separation membrane modules from the separation membrane cleaning effect, resulting in operating costs. From the viewpoint of reduction, a technique of arranging separation membrane modules in series is disclosed (Patent Document 3).

JP 2008-237101A JP 2009-72708 A Japanese Patent Application No. 2012-513118

  In order to process a large amount of stock solution, a large number of separation membrane modules are required. However, it is difficult to efficiently operate and maintain a large number of modules. The operation referred to here includes not only filtration but also steam sterilization.

  The present invention provides a technique capable of processing a large amount of a stock solution and efficiently performing operation and maintenance.

(1) In order to solve the above-described problems and achieve the object, the module unit of the present invention includes:
Two or more separation membrane modules arranged above and below, wherein the separation membrane module is arranged such that an angle between the longitudinal direction and the horizontal direction is not less than 1 ° and not more than 45 ° Module,
A liquid feed line connecting in series the primary side of any one separation membrane module and the separation membrane module disposed below the separation membrane module;
A drain discharge line for feeding the drain of any one of the separation membrane modules to the separation membrane module disposed below the separation membrane module.

  With this configuration, a series of separation membrane modules can be sterilized by sending steam from the end module among the separation membrane modules connected in series. Moreover, when the angle between the longitudinal direction of the separation membrane module and the horizontal direction is 1 ° or more, the drain generated during steam sterilization flows to the lower part of the module. Therefore, generation | occurrence | production of the sterilization defect by the drain retention in a module can be suppressed. Furthermore, since the drain can flow from the upper module to the lower module through the liquid feed line, the drain can be discharged collectively from the lowermost module. Moreover, the height of the whole module unit can be suppressed because the angle between the longitudinal direction of a separation membrane module and a horizontal direction is 45 degrees or less. By suppressing the height in this way, the equipment for operation and the operating cost can be reduced.

  (2) In the module unit of (1), the liquid feeding line may also serve as the drain discharge line.

  (3) The separation membrane module may include a drain discharge port arranged to face downward in the installation posture of the separation membrane module in the module unit. The drain discharge line may be connected to the drain discharge port. With this configuration, the drain can be easily discharged.

  (4) The separation membrane module may have a hollow fiber membrane, and the filling rate of the hollow fiber membrane in the separation membrane module may be 40% or more and 60% or less.

  By setting the filling rate of the hollow fiber membrane to 40% or more, the unevenness of the hollow fiber membrane can be reduced and the liquid to be filtered and the vapor can be supplied uniformly into the module. Further, by setting the filling rate to 60% or less, it is possible to spread the liquid to be filtered, steam, cleaning liquid and the like in the module.

  According to the present invention, a series of separation membrane modules connected thereto can be sterilized by feeding steam from one end of the separation membrane modules connected in series. Moreover, when the angle between the longitudinal direction of the separation membrane module and the horizontal direction is 1 ° or more, the drain generated during steam sterilization flows to the lower part of the module. Therefore, generation | occurrence | production of the sterilization defect by the drain retention in a module can be suppressed. Furthermore, since the drain can flow from the upper module to the lower module through the liquid feed line, the drain can be discharged collectively from the lowermost module. Moreover, the height of the whole module unit can be suppressed because the angle between the longitudinal direction of a separation membrane module and a horizontal direction is 45 degrees or less.

  By the above operation, according to the present invention, the scale of equipment for operation and the operation cost can be kept small.

  With respect to the separation membrane module unit, it is possible to improve the steam drainage at the time of steam sterilization, simplify the facilities for the separation membrane module unit and its peripheral equipment, and reduce the operation cost.

FIG. 1 is a schematic view of a separation membrane module according to an embodiment of the present invention. FIG. 2 is a schematic view of a separation membrane module according to another embodiment. FIG. 3 is a schematic view of a separation membrane module according to still another embodiment. FIG. 4 is a schematic view of a separation membrane module according to still another embodiment. FIG. 5 is a schematic view of a separation membrane module according to still another embodiment. FIG. 6 is a schematic view of a separation membrane module unit in which separation membrane modules are arranged obliquely. FIG. 7 is a schematic view of a separation membrane module unit in which separation membrane modules are arranged obliquely. FIG. 8 is a schematic view of a separation membrane module unit in which separation membrane modules are vertically arranged in series. FIG. 9 is a schematic view of a separation membrane module unit in which separation membrane modules are vertically arranged in parallel.

  Below, the separation membrane module unit which is one Embodiment of this invention is demonstrated. The separation membrane module unit includes two or more separation membrane modules and a pipe (line) connecting them to each other.

1. Separation membrane The separation membrane module includes a separation membrane. The separation membrane will be described. The separation membrane may have any trapping diameter such as microfiltration or ultrafiltration, and the material may be organic membrane or inorganic membrane. Since the separation membrane is washed by reverse pressure washing or chemical solution immersion, the separation membrane preferably has durability against these.

  From the viewpoints of separation performance and water permeability, and stain resistance, organic polymer compounds can be preferably used. Examples include polyethylene resins, polypropylene resins, polyvinyl chloride resins, polyvinylidene fluoride resins, polysulfone resins, polyethersulfone resins, polyacrylonitrile resins, cellulose resins, and cellulose triacetate resins. A mixture of these resins as the main component may be used.

  Polyvinyl chloride resins, polyvinylidene fluoride resins, polysulfone resins, polyethersulfone resins and polyacrylonitrile resins, which are easy to form in solution and have excellent physical durability and chemical resistance, are preferred. A vinylidene chloride resin or a resin containing the vinylidene fluoride resin as a main component is more preferably used because it has a characteristic of having both chemical strength (particularly chemical resistance) and physical strength.

  Here, as the polyvinylidene fluoride resin, a homopolymer of vinylidene fluoride is preferably used. Furthermore, the polyvinylidene fluoride resin may be a copolymer of a vinyl monomer copolymerizable with vinylidene fluoride. Examples of vinyl monomers copolymerizable with vinylidene fluoride include tetrafluoroethylene, hexafluoropropylene, and ethylene trichloride fluoride.

  As the shape of the separation membrane, any shape such as a flat membrane, a hollow fiber membrane, and a spiral type can be adopted, and any shape of an external pressure type or an internal pressure type can be adopted as long as it is a hollow fiber membrane module. be able to.

2. Separation membrane module format The separation membrane module includes a separation membrane and a housing for housing the separation membrane.

  Specifications such as length, filling rate, and type of separation membrane of the separation membrane modules included in one separation membrane module unit may be the same or different. However, for example, when the filling rate is different for each module, the crossflow flux in each module is different, so that the cleaning effect of the separation membrane obtained by the shearing force of the crossflow is different in each module. It is also necessary to set the filtration rate of the module individually. Furthermore, since managing different modules takes more time than managing the same type of modules, it is preferable that the specifications of each module are the same from the viewpoint of production management.

(1) Configuration of Separation Membrane Module The separation membrane module only needs to be able to separate the filtrate (that is, the permeate) from the liquid to be filtered (that is, the stock solution). Filtration includes total volume filtration and cross flow filtration. In cross flow filtration, a filtrate and a concentrated liquid are obtained from the filtrate. Specifically, in total filtration, a separation membrane module includes a housing; and a separation membrane that is housed in the housing and separates a liquid to be filtered (that is, a stock solution) into a filtrate (that is, a permeate). Further, there may be an additional outlet for discharging the membrane cleaning liquid or the like. On the other hand, in the case of cross-flow filtration, the separation membrane module includes a casing; a separation membrane that is housed in the casing and separates a liquid to be filtered (that is, a stock solution) into a filtrate (that is, a permeate) and a concentrated liquid; A filtrate inlet for supplying the filtrate to the primary side of the separation membrane from the outside of the casing; a filtrate outlet for discharging the filtrate outside the casing; and a concentrate outlet for discharging the concentrate outside the casing; Prepare. The filtrate inlet and the concentrate outlet are preferably provided in the vicinity of both ends in the longitudinal direction of the casing.

  The “primary side” is a side to which a liquid to be filtered (that is, a stock solution) is supplied in a space partitioned by a separation membrane, and the “secondary side” is the opposite. That is, the primary side indicates the inside of the membrane in the internal pressure type hollow fiber membrane module, and the outside of the membrane in the external pressure type hollow fiber membrane module. “Primary side” and “secondary side” may be rephrased as “supply side” and “transmission side”, respectively.

  A specific configuration of the separation membrane module will be described with reference to the drawings, taking an external pressure hollow fiber membrane module as an example.

  The hollow fiber membrane module 11 of FIG. 1 includes a cylindrical case 3 having both ends opened, an upper cap 6, a lower cap 7, and a plurality of hollow fiber membranes 2 housed in the cylindrical case 3.

  The cylindrical case 3, the upper cap 6 and the lower cap 7 correspond to a housing.

  The cylindrical case 3 is a cylindrical case having both ends open, and on the side surface, a filtrate inlet 8 is provided in the vicinity of the lower end in the height direction of the cylindrical shape, and in the vicinity of the upper end in the height direction. A concentrate outlet 10 is provided. Further, nozzles 8 a (22 a) and 10 a protrude from the filtrate inlet 8 and the concentrate outlet 10, respectively.

  The upper cap 6 is attached to the upper end of the cylindrical case 3. The upper cap 6 is provided with a first filtrate outlet 91. The lower cap 7 is attached to the lower end of the cylindrical case 3. The lower cap 7 is provided with a second filtrate outlet 92. Nozzles 91 a and 92 a protrude from the filtrate outlets 91 and 92. In the present embodiment, the filtrate inlet 8 also serves as the drain outlet 22. Moreover, the to-be-filtrated liquid inlet 8 functions also as an air supply port.

  In this embodiment, both ends of the hollow fiber membrane 2 are open. However, the present invention is not limited to this, and the hollow fiber membrane only needs to have at least one of the two end faces opened. In this embodiment, the upper end and the lower end of the hollow fiber membrane 2 are bundled by hollow fiber membrane focusing members 41 and 42, respectively. In FIG. 1, the hollow fiber membrane bundle is fixed in the cylindrical case 3 by fixing both hollow fiber membrane focusing members 4 in the cylindrical case 3. The hollow fiber membrane focusing members 41 and 42 are formed of a so-called potting agent. In addition, the hollow fiber membrane focusing members 41 and 42 are bonded and fixed in a cylindrical container or the like, if necessary, and fixed inside the cylindrical case 3 using a sealing material such as an O-ring or packing. Thus, the hollow fiber membrane 2 and the hollow fiber membrane focusing members 41 and 42 may be of a cartridge type, and the hollow fiber membrane bundle may be fixed in the cylindrical case 3.

  In the hollow fiber membrane module 11, for example, in the case of total filtration, the liquid to be filtered is supplied from the liquid inlet 8 to the inside of the cylindrical case 3, specifically, to the outside (primary side) of the hollow fiber membrane 2. The The permeate that has passed through the hollow fiber membrane 2 flows into the upper cap 6 from the open upper end of the hollow fiber membrane 2, and then flows out from the first filtrate outlet 91 to the outside of the hollow fiber membrane module 11. Further, the permeate can flow into the lower cap 7 from the open lower end of the hollow fiber membrane 2, and the permeate flowing into the lower cap 7 in this way passes through the second filtrate outlet 92 to the hollow fiber membrane module. 11 to the outside. Since the hollow fiber membrane focusing members 41 and 42 are liquid-tightly fixed to the inner wall of the cylindrical case 3 (that is, to the inner wall of the housing), the permeated liquid, the liquid to be filtered, and the concentrated liquid are not mixed with each other. Isolated.

  The hollow fiber membrane module 12 of FIG. 2 is bundled by a small bundle focusing member 5 with the lower end of the hollow fiber membrane 2 closed, and is replaced with a cylindrical case 3 and a lower cap 7. Except that 31 and the lower cap 71 are provided, the configuration is almost the same as that of FIG. The members already described are given the same reference numerals and the description thereof is omitted.

  In the form of FIG. 2, the upper end of the hollow fiber membrane 2 is bundled with the hollow fiber membrane focusing member 41 in an open state. The hollow fiber membrane focusing member 41 is liquid-tightly fixed in the vicinity of the upper end of the cylindrical case 3 as in the embodiment of FIG. On the other hand, the lower end of the hollow fiber membrane 2 is divided into 1 to 300 small bundles 2a, each small bundle 2a is bundled by a small bundle focusing member 5, and the lower end is closed.

  Note that, at the lower end, the small bundle 2a is not fixed to the casing and can move freely. For reinforcement, each small bundle 2a may include a thread-like or rod-like member having high strength and low elongation, such as a steel wire or an aramid fiber cord.

  The cylindrical case 31 has the same configuration as that of the cylindrical case 3 except that it does not include an inlet to be filtered. The lower cap 71 has the same structure as the lower cap 7 in FIG. 1, but the structure corresponding to the filtrate outlet 92 in the lower cap 7 functions as the filtrate inlet 8, the drain discharge port 22, and the air supply port. To do.

  In the hollow fiber membrane module 12 of FIG. 2, for example, in the case of cross-flow filtration, the liquid to be filtered passes between the plurality of small bundles 2 a from the liquid inlet 8, specifically inside the cylindrical case 31. Is supplied to the outside (primary side) of the hollow fiber membrane 2. The permeate that has permeated through the hollow fiber membrane 2 flows into the upper cap 6 from the open upper end of the hollow fiber membrane 2 and then flows out from the first filtrate outlet 91 to the outside of the hollow fiber membrane module 12. The concentrate that has not permeated through the hollow fiber membrane 2 flows out from the concentrate outlet 10 to the outside of the hollow fiber membrane module 12. Since the hollow fiber membrane focusing member 41 is liquid-tightly fixed to the inner wall of the cylindrical case 31 (that is, to the inner wall of the housing), the permeated liquid, the liquid to be filtered, and the concentrated liquid are isolated so as not to mix with each other. The

  Note that the configuration of FIG. 1 and the configuration of FIG. 2 can be combined. That is, in the configuration of FIG. 1, one end of the hollow fiber membrane 2 may be closed. For example, the hollow fiber membrane 2 of FIG. 1 bundled with the hollow fiber membrane focusing members 41 and 42 is accommodated in a casing including the cylindrical case 31, the upper cap 6, and the lower cap 71 of FIG. The hollow fiber membrane focusing member 42 may block the lower end of the hollow fiber membrane 2. In this case, the cylindrical case 3 may not be fixed to the hollow fiber membrane focusing member 42, and a gap may be provided between the cylindrical case 31 and the hollow fiber membrane focusing member 42.

  In any of the above-described configurations, at the end of the membrane that is to be closed, the curved portion of the yarn bundle that is bent in a U shape may be bundled by the closing member or the focusing member.

  Furthermore, as shown in FIGS. 3 and 4, the drain discharge port 22 may be provided separately from the filtrate inlet 8.

  Specifically, the separation membrane module 13 in FIG. 3 has the same configuration as the separation membrane module 1 in FIG. 1 except that the tubular case 3 is provided instead of the tubular case 3. The cylindrical case 32 includes a filtrate inlet 8 and a drain outlet 22 provided separately in the vicinity of the lower end thereof. The position of the to-be-filtrated liquid inlet 8 may be close to the drain outlet 22 in the circumferential direction of the cylindrical case, or may be separated.

  Further, the separation membrane module 14 of FIG. 4 has the same configuration as the separation membrane module 12 of FIG. 2 except that it includes a cylindrical case 33 instead of the cylindrical case 31. The cylindrical case 33 includes a drain discharge port 22 at the lower end thereof. Moreover, in the structure of FIG. 4, the position of the to-be-filtrated liquid inlet 8 and the drain discharge port 22 may interchange.

  Further, the separation membrane module 15 of FIG. 5 has the same configuration as the module 12 of FIG. 2 except that the filtrate inlet 8 (drain discharge port 22) is provided at an eccentric position. 1, 3 and 4, the drain discharge port 22 is provided at an eccentric position. This effect will be described later.

  The more specific structure of the member demonstrated above and the member which the separation membrane module can further be provided are demonstrated.

(2) Rectifying member The separation membrane module may include a rectifying member for rectifying the flow in the separation membrane module in the housing. The rectifying member is, for example, a cylindrical member, and is disposed in the vicinity of the upper end of the housing (for example, in the vicinity of the upper ends of the cylindrical case 3 and the cylindrical case 31).

  The separation membrane may be fixed to the casing or the rectifying component with an adhesive or the like. Further, the separation membrane may be a cartridge type. That is, the separation membrane may be detachable from the housing or the rectifying component.

(3) Housing The cylindrical case 3, the upper cap 6 and the lower cap 7 preferably have heat resistance against steam sterilization. For example, as materials for these members, heat-resistant resins such as polysulfone, polycarbonate, and polyphenylene sulfide are used alone or in combination. Moreover, aluminum, stainless steel, etc. are preferable as materials other than resin. Preferred materials further include composite materials such as a resin-metal composite, glass fiber reinforced resin, and carbon fiber reinforced resin.

  The shape of the housing is not particularly limited, but a housing having a cylindrical body is preferable. The shape of the body portion does not have to be a cylinder, and can be changed in consideration of ease of manufacture of the housing, minimization of dead space in the separation membrane module, and the like.

(4) Converging member A member that bundles the hollow fiber membranes with the hollow fiber membrane converging members 41 and 42 open, and a member that closes and bundles the hollow fiber membranes such as the small bundle converging member 5 together with the converging member. Call it. An adhesive is preferably used as the focusing member.

  As the adhesive, a synthetic resin having a cured type D durometer hardness of about 50 or more and 80 or less is preferably used. Type D durometer hardness is measured according to JIS-K6253 (2004).

  When the hardness is 50 or more, there is a difference between the primary side and the secondary side of the separation membrane, such as when high-pressure saturated steam is introduced from the separation membrane primary side during filtration, back-pressure washing, and steam sterilization. Even when pressure is applied, deformation of the hollow fiber membrane focusing member 4 can be suppressed to a small level. As a result, the occurrence of peeling between the hollow fiber membrane and the converging member can be suppressed, and the concern that the hollow fiber membrane 2 breaks and leaks is reduced.

  The hardness of 80 or less also reduces the risk of damage to the hollow fiber membrane. In the portion of the surface of the focusing member where the hollow fiber membrane protrudes, the corners of the focusing member and the hollow fiber membrane come into contact with each other. When vibration of the hollow fiber membrane occurs during filtration or back pressure washing, the corners of the converging member and the outer surface of the hollow fiber membrane may come into strong contact, but in this case, the hardness is 80 or less. As a result, damage and breakage of the hollow fiber membrane can be suppressed.

  As the adhesive for the hollow fiber membrane focusing member 4 and the small bundle focusing member 5 as described above, it is preferable to use a synthetic resin such as an epoxy resin or a polyurethane resin that is a general-purpose product, is inexpensive, and has little influence on water quality. .

(5) Separation membrane filling rate The separation membrane filling rate of the separation membrane module will be described by taking a hollow fiber membrane module as an example. Here, the filling rate of the hollow fiber membrane in the hollow fiber membrane module is obtained by the following formula 1.

  The filling rate of the hollow fiber membrane in the hollow fiber membrane module can be appropriately determined according to the purpose and situation of use. Specifically, the filling rate is preferably 30% or more and 60% or less. In the present embodiment, since the hollow fiber membrane modules are arranged obliquely, connected in series, and steam sterilization is performed, the filling rate of the hollow fiber membrane is preferably 40% or more, and 45% More preferably.

  The reason is as follows. When the hollow fiber membrane module is installed obliquely, the hollow fiber membrane is biased in the vertical direction in the housing, and this bias may affect the temperature rise during sterilization and the flow of the cross flow. For this reason, it is preferable that the hollow fiber membrane is packed in the housing to minimize the gap so that the bias does not increase in the housing. Therefore, it is preferable to set the filling rate of the hollow fiber membrane higher than usual.

  Further, the hollow fiber membrane may be held by a holding plate or the like so that the hollow fiber membrane is not biased in the housing. The holding member such as a holding plate preferably has heat resistance against steam sterilization, and preferably has a structure that does not have a concave portion so that steam drain does not stay.

  Other reasons why the filling rate is preferably 30% or more will be described below. Since the membrane area per module increases as the filling rate increases, the filtration efficiency improves. When the filling rate is 30% or more, the cross-sectional area other than the hollow fiber membrane can be kept small in the hollow fiber membrane module, so that the membrane surface linear velocity can be increased without increasing the circulation flow rate. That is, since a linear velocity suitable for filtration can be obtained without requiring a large circulation pump, equipment cost and operating power can be suppressed. Further, since the circulation flow rate is small, it is possible to use a thin pipe, and as a result, it is possible to suppress the cost of the pipes and valves such as an automatic valve.

  When the filling rate of the hollow fiber membrane is 60% or less, the steam in sterilization, the liquid to be filtered in the filtration operation, and the cleaning liquid in the cleaning are sufficiently easily distributed in the module.

  In addition, since the filling rate is 60% or less, microorganisms can be easily discharged out of the module, so that clogging of the membrane can be easily suppressed. If the filling rate is 60% or less, it is easy to insert the hollow fiber membrane bundle into the housing. Furthermore, the adhesive constituting the converging member is likely to permeate between the hollow fiber membranes, and the manufacture is easy.

3. Arrangement of Separation Membrane Module A specific example of the configuration of the module unit is shown below. The module unit is a separation membrane module having two or more separation membrane modules, the separation membrane modules being disposed obliquely; any one separation membrane module and the separation being disposed below the separation membrane module A liquid feed line that connects the primary side with the membrane module in series, and a drain discharge line that feeds the drain of any one of the separation membrane modules into the separation membrane module disposed below the separation membrane module.

  Usually, the separation membrane module is often long in one direction like a cylinder or a rectangular parallelepiped. When a plurality of such separation membrane modules are installed so that the length direction is parallel to the vertical direction (vertically placed) and connected in series, arranging the separation membrane modules in the vertical direction increases the overall height of the facility. The length is equal to or greater than (length of each separation membrane module) × (number of stacked modules).

  On the other hand, the present inventors have found that the facility height can be suppressed by arranging the separation membrane module so that the longitudinal direction thereof is oblique with respect to the vertical direction.

  6 and 7 exemplify a module unit including an external pressure type hollow fiber membrane module, the present invention is not limited to this, and can be applied to various separation membrane modules.

  The module unit 101 shown in FIG. 6 is a module connection pipe that connects a plurality of separation membrane modules 1A, 1B, and 1C, separation membrane modules 1A and 1B, and separation membrane modules 1B and 1C in series. (An example of a liquid feeding line) 23 is provided.

  Each of the separation membrane modules 1A, 1B, and 1C has the same configuration as the hollow fiber membrane module 12 of FIG. However, any of the modules described above can be applied to the configurations of FIGS.

  The separation membrane module 1A is disposed at the lowermost position, the module 1B is disposed above 1A, and the module 1C is disposed above 1B. As described above, when the separation membrane modules are stacked in the vertical direction, the pipes connecting the separation membrane modules can be shortened rather than arranging them in the horizontal direction, and the energy required for operation can be reduced.

  Further, the angle between the longitudinal direction of the separation membrane modules 1A, 1B, 1C (the height direction of the cylindrical case: indicated by a one-dot chain line in the figure) and the horizontal direction (indicated by a dotted line in the figure) is 1 °. It is preferably 45 ° or less and more preferably 5 ° or more and 30 ° or less.

  The “angle” is an acute angle among the angles between a straight line parallel to the longitudinal direction of the module and a straight line parallel to the horizontal direction.

  If the angle is 1 ° or more, retention of drain in the separation membrane module during steam sterilization can be suppressed, and sterilization defects can be effectively suppressed. The greater the angle (the closer the longitudinal direction is to the vertical), the greater the draining speed (that is, the draining speed). In particular, since the drain of the upper separation membrane module collects in the lower separation membrane module, there is a concern that the temperature rise performance is lowered in the lower separation membrane module and the lower flow path. When there are many connected in series, so much drain flows into the bottom separation membrane module, so by increasing the angle between the longitudinal direction and the horizontal direction of the separation membrane module, It is preferable to expedite drainage by increasing the speed.

  On the other hand, when the angle is smaller, the height HU of the separation membrane module unit can be reduced, so that the equipment cost and the operation cost can be reduced. Furthermore, labor can be reduced in maintenance such as replacement of the separation membrane module. For this reason, it is preferable that the inclination of the obliquely arranged separation membrane module is minimized, and an example thereof is the above-described range of 1 ° to 45 °.

  In FIG. 6, the angles RA, RB, and RC between the longitudinal direction and the horizontal direction of all the modules 1A, 1B, 1C in the unit 101 are the same. However, the angles of the plurality of separation membrane modules included in one module unit may be different from each other.

  For example, the unit 102 in FIG. 7 has the same configuration as the unit 101 in FIG. 6 except that the modules are arranged so that the longitudinal direction of each module is zigzag with the longitudinal direction of the adjacent module.

  Moreover, at least two modules among the modules connected in series should just show the angle within the above-mentioned numerical range.

  In other words, a separation membrane module showing an angle deviating from the above numerical range may be further connected to the module showing the angle within the above numerical range. That is, in the module unit, the angle between the longitudinal direction and the horizontal direction is 1 °, and the first separation membrane module arranged so that the angle between the longitudinal direction and the horizontal direction is 1 ° or more and 45 ° or less. The second separation membrane module arranged so as to be 45 ° or less and above the first separation membrane module, and the primary side of the first separation membrane module and the second separation membrane module are connected in series. And a liquid feed line for connecting the primary side of the separation membrane module in series. Another separation membrane module showing a different angle may be connected between the first separation membrane module and the second separation membrane module.

  In addition, the position of the separation membrane module in one unit may be shifted in the horizontal direction or may be overlapped. Further, when one unit is viewed from above, the longitudinal directions of the plurality of separation membrane modules included in the unit may be parallel to each other or cross each other.

  The angle of the module may be determined by performing a steam heating test in advance before actually using the module. In the steam heating test, for example, heating steam is fed into the module from the concentrate outlet 10 of the upper module 1C, so that the module 1B passes through the filtrate inlet 8 of the module 1C and the concentrate outlet 10 of the lower module 1B. In the same manner, the heating steam is fed to the lower module 1A. If the temperature of the separation membrane module, particularly the lower part of each module, can be raised to a predetermined sterilization temperature by this experiment, the angle of each module is appropriate. On the other hand, if there is a module that cannot sufficiently raise the temperature, it may be considered to increase the angle of the separation membrane module.

  In order to discharge the drain without retaining it, the drain outlet of the module is preferably provided at the lowest position in the installation posture of the module. If the module is installed so that the longitudinal direction of the module is along the vertical direction, the drain outlet of the separation membrane module is provided near the vertical axis of the module (that is, near the center in the end view) at the lower end of the module. That's fine. However, when the module is installed obliquely, the drain outlet is preferably provided at an eccentric position. In other words, a drain discharge port may be provided at a place where drain easily collects in the housing. Thus, when the separation module is disposed obliquely, the drain is discharged without stagnation. The specific configuration is as shown in FIG. 1, FIG. 3, FIG. 4, and FIG.

  For example, it is assumed that three cylindrical separation membrane modules having a diameter of 159 mm and a length of 1500 mm are connected in series. At this time, as shown in FIG. 6 or FIG. 7, if the module is disposed at an angle, the height of the separation membrane module unit can be suppressed to about 1.5 m.

  The module connection pipe 23 only needs to be able to connect the primary side of each module. 6 and 7, the module connection pipe 23 connects the drain discharge nozzle 22a of the upper module to the concentrate discharge nozzle 10a of the lower module. When any of the modules described above is applied, the module connection pipe 23 may be connected to the same position.

4). Steam sterilization In steam sterilization, steam is preferably introduced from the nozzle above the module and discharged from the nozzle below so that the steam drain generated by heat exchange can be easily discharged. Therefore, it is only necessary to supply steam from the upper module among the modules connected in series. In particular, in the case of the diagonally arranged unit, the drain of the upper module (that is, upstream in the steam flow direction) collects in the lower part of the module vertical, and the steam flows in the other part. If the drain amount is large, it may be difficult to raise the temperature of the drain flow path portion to a predetermined temperature or higher for steam sterilization. Therefore, it is important to improve drainage. The amount of drain that is generated varies depending on the outside air temperature, the separation membrane module and the surrounding piping, the state of heat insulation of the equipment, and the like. As described above, an appropriate angle or the like can be confirmed by conducting a steam heating test in advance.

  At the time of steam sterilization, steam may be supplied from the primary side of the separation membrane module, or steam may be supplied from the secondary side. The external pressure hollow fiber membrane may be sterilized by supplying steam from the primary side and raising the temperature of the primary side to a predetermined temperature. Furthermore, depending on the type of membrane, steam may be ventilated from the primary side to the secondary side, and the secondary side may be sterilized.

<Reference form 1>
Usually, the separation membrane module is often arranged vertically (so that the longitudinal direction is along the vertical direction). This is because the case where the liquid to be filtered is filled from below and the inside of the module housing is filled is less likely to form a gas-phase pool such as air in the module, and the film area can be effectively used by filling with the liquid to be filtered. . Moreover, it is because foaming of a to-be-filtered liquid can be suppressed and the cell contained in a to-be-filtered liquid is hard to be damaged.

  On the other hand, in order to efficiently sterilize a large number of separation membrane modules, it is conceivable to connect the separation membrane modules in series and sterilize a series of separation membrane modules all together. In order to improve drain discharge efficiency in such a series arrangement, it is considered preferable to place the modules vertically.

  However, when a plurality of separation membrane modules are connected in series, and the separation membrane modules are arranged in the vertical direction, the overall height of the facility is (length of individual separation membrane modules) x (number of stacked) That's it. In other words, the height of the entire facility is increased, and a large facility is required to maintain it. In addition, there is a concern that a liquid feed pump capable of realizing a large liquid feed pressure is required and the operation cost increases. Furthermore, since work at a high place occurs, maintenance is also difficult.

  For example, if three cylindrical separation membrane modules with a diameter of 159 mm and a length of 1500 mm are arranged in series and vertically in the length direction, a supply line to the separation membrane module and a liquid feed line between the separation membrane modules, etc. In consideration, the height of the separation membrane unit is about 5 m (see FIG. 8).

<Reference form 2>
On the other hand, when the separation membrane modules having the same dimensions as those of the reference embodiment 1 are arranged in parallel, the height of the unit is about 2 m (see FIG. 9).

  However, when the separation membrane modules are connected in parallel, it is necessary to provide each of the separation membrane modules with a steam supply line and a steam drain discharge line. Therefore, many valves and the like are required, and the piping is complicated. As a result, the liquid pressure loss particularly in cross flow filtration increases. Furthermore, during steam sterilization, these valves must be linked automatically.

  Hereinafter, the effects of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

(1) Preparation of external pressure type hollow fiber membrane (a) Melt vinylidene fluoride homopolymer having a mass average molecular weight of 47,000 and γ-butyrolactone at a temperature of 170 ° C. at a rate of 38% by mass and 62% by mass, respectively. did. A hollow fiber membrane having a spherical structure is obtained by discharging this polymer solution from a die while accompanying γ-butyrolactone as a hollow portion forming liquid and solidifying in a cooling bath composed of an 80% by mass aqueous solution of γ-butyrolactone at a temperature of 20 ° C. Produced.

  (B) Next, 14% by mass of vinylidene fluoride homopolymer having a mass average molecular weight of 284,000, 1% by mass of cellulose acetate propionate (manufactured by Eastman Chemical Co., CAP482-0.5), N-methyl- A polymer solution was prepared by mixing and dissolving 2-pyrrolidone at 77% by mass, T-20C at 5% by mass, and water at 3% by mass at a temperature of 95 ° C. This membrane-forming stock solution is uniformly applied to the surface of the hollow fiber membrane having the spherical structure obtained in the above (a), and immediately solidified in a water bath to form a three-dimensional stitch structure on the spherical structure layer. A hollow fiber membrane provided was prepared. The hollow fiber membrane thus obtained was brought into contact with 125 ° C. saturated water vapor for 1 hour.

(C) The average pore diameter of the treated water side surface of the hollow fiber membrane obtained in (b) above was 0.04 μm. Moreover, when the pure water permeation rate was evaluated about the hollow fiber membrane obtained by said (b), it was 5.5 * 10 < ^-9 > m < ³ > / m < ² > / s / Pa. The amount of water permeation was measured using purified water at a temperature of 25 ° C. by a reverse osmosis membrane at a head height of 1 m.

(2) Production of External Pressure Type Hollow Fiber Membrane Module Using the hollow fiber membrane produced in (1) above, a separation membrane module having the structure of FIG. 5 was produced.

Specifically, the hollow fiber membrane was bundled with a potting agent (polyurethane manufactured by Sanyu Rec Co., Ltd., SA-7068A / SA-7068B, and mixed at a weight ratio of 64: 100). Moreover, the hollow fiber membrane was opened by cutting off a part of the potting agent at the upper end of the hollow fiber membrane. The hollow fiber membranes thus bundled were fixed in a stainless steel casing to form a module.
In addition, the size of a housing | casing used the thing with an internal diameter of 159 mm and length 1500mm.

Example 1
A separation membrane module was produced according to the procedure (2) above so that the filling rate of the hollow fiber membrane in the housing was 40%. The three separation membrane modules thus obtained were arranged as shown in FIG. 6 to obtain a separation membrane module unit. The inclination of the separation membrane module was 3 °.

  Saturated steam at 125 ° C. was introduced from the side nozzle of the uppermost separation membrane module to the primary side of the separation membrane module, and a steam heating test of the separation membrane module unit was performed. On the secondary side, steam sterilization was performed with the valve provided at the filtrate outlet sealed. Vapor drain was discharged from the lower nozzle of the lowermost separation membrane module. A steam trap was provided at the tip of the lower nozzle of the lowermost separation membrane module so that a saturated steam pressure of 125 ° C. could be maintained while discharging steam drain. However, for 3 minutes after the start of steam ventilation, the lower nozzle tip of the lowermost separation membrane module did not pass through the steam trap and was blown with steam so as to be open to the atmosphere. In the lowermost separation membrane module with the largest drain amount, a thermocouple was installed on the inner surface of the case in the vertical downward direction at the center of the case body, and the temperature during steam heating was measured. A thermocouple was also installed at the center of the hollow fiber membrane bundle, and the temperature during steam heating was measured.

  As a result, each thermocouple temperature was 121 ° C. or more 5 minutes after the start of steam aeration. This result satisfied a temperature of 121 ° C. under general steam sterilization conditions.

(Example 2)
A separation membrane module was produced according to the procedure (2) so that the filling rate of the hollow fiber membrane was 55%. The three separation membrane modules thus obtained were installed as shown in FIG. 6, and the same operation as in Example 1 was performed.

  As a result, 7 minutes after the start of steam aeration, the thermocouple temperature showed 121 ° C. or higher, which satisfied the temperature of 121 ° C. under general steam sterilization conditions.

(Example 3)
A separation membrane module was produced according to the procedure (2) above so that the filling rate of the hollow fiber membrane was 30%. The three separation membrane modules thus obtained were installed as shown in FIG. 6, and the same operation as in Example 1 was performed.

  As a result, 7 minutes after the start of steam aeration, the thermocouple temperature showed 121 ° C. or higher, which satisfied the temperature of 121 ° C. under general steam sterilization conditions.

Example 4
A separation membrane module was produced according to the procedure (2) so that the filling rate of the hollow fiber membrane was 65%. The three separation membrane modules thus obtained were installed as shown in FIG. 5 and the same operation as in Example 1 was performed.

  As a result, 9 minutes after the start of steam aeration, the thermocouple temperature showed 121 ° C. or higher, and the temperature of 121 ° C. under general steam sterilization conditions was satisfied.

(Example 5)
A separation membrane module was produced according to the procedure (2) above so that the filling rate of the hollow fiber membrane in the housing was 40%. The three separation membrane modules thus obtained were arranged as shown in FIG. 6 to obtain a separation membrane module unit. The inclination of the separation membrane module was 1 °.

  Saturated steam at 125 ° C. was introduced from the side nozzle of the uppermost separation membrane module to the primary side of the separation membrane module, and a steam heating test of the separation membrane module unit was performed. On the secondary side, steam sterilization was performed with the valve provided at the filtrate outlet sealed. Vapor drain was discharged from the lower nozzle of the lowermost separation membrane module. A steam trap was provided at the tip of the lower nozzle of the lowermost separation membrane module so that a saturated steam pressure of 125 ° C. could be maintained while discharging steam drain. However, for 3 minutes after the start of steam ventilation, the lower nozzle tip of the lowermost separation membrane module did not pass through the steam trap and was blown with steam so as to be open to the atmosphere. In the lowermost separation membrane module with the largest drain amount, a thermocouple was installed on the inner surface of the case in the vertical downward direction at the center of the case body, and the temperature during steam heating was measured. A thermocouple was also installed at the center of the hollow fiber membrane bundle, and the temperature during steam heating was measured.

  As a result, each thermocouple temperature was 121 ° C. or more 7 minutes after the start of steam aeration. This result satisfied a temperature of 121 ° C. under general steam sterilization conditions.

  According to the apparatus of the present invention, steam sterilization of a plurality of separation membrane modules arranged in series can be performed with a simple apparatus configuration.

11-15, 1A, 1B, 1C, 10A, 10B, 10C Hollow fiber membrane module 2 Hollow fiber membranes 3, 31, 32, 33 Cylindrical cases 41, 42 Hollow fiber membrane focusing member 5 Small bundle focusing member 6 Upper cap 7 Lower cap 8 Filtrate inlet 22 Drain outlet 8a Filtrate nozzle 22a Drain outlet nozzles 91, 92 Filtrate outlet 92a Filtrate outlet nozzle 10 Concentrate outlet 10a Concentrate outlet nozzle

Claims (4)

Two or more separation membrane modules arranged above and below, wherein the separation membrane module is arranged such that an angle between the longitudinal direction and the horizontal direction is not less than 1 ° and not more than 45 ° Module,
A liquid feed line connecting in series the primary side of any one separation membrane module and the separation membrane module disposed below the separation membrane module;
A module unit comprising: a drain discharge line that feeds the drain of any one separation membrane module into the separation membrane module disposed below the separation membrane module. The module unit according to claim 1, wherein the liquid feeding line also serves as the drain discharge line. The said separation membrane module is provided with the drain discharge port arrange | positioned so that it may face downward in the installation attitude | position of the said separation membrane module in the said module unit. The said drain discharge line is connected to the said drain discharge port. 3. The separation membrane module unit according to 2. The separation membrane module has a hollow fiber membrane;
The filling rate of the hollow fiber membrane in the separation membrane module is 40% or more and 60% or less.
The separation membrane module unit according to any one of claims 1 to 3.

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