JP6236736B2 - Anomaly detection apparatus and anomaly detection method for film forming stock solution - Google Patents

Description

  The present invention relates to an abnormality detection apparatus and abnormality detection method for a hollow fiber membrane forming stock solution.

  Hollow fiber membranes (porous hollow fiber membranes) are widely used for purification of water and air. Recently, they are highly polluted, such as water treatment in sewage treatment plants and solid-liquid separation of suspended solids in industrial wastewater. It is also used for the treatment of natural water. Such a hollow fiber membrane is manufactured by discharging a film-forming stock solution containing various polymer stock solutions from a discharge means such as a spinning nozzle.

  In order to maintain the quality of the hollow fiber membrane, it is necessary to keep the state of the membrane forming raw solution discharged by the discharge means uniform. If an abnormality occurs in the film-forming stock solution due to foreign matter or bubbles mixed into the film-forming stock solution, this abnormality is accurately detected, and the production of the hollow fiber membrane is stopped. It is preferable not to use it.

  Conventionally, as one of the methods for detecting local spots (viscosity spots), which is a kind of abnormality of the film forming stock solution, the film forming stock solution is filtered through a filter having an opening smaller than the spinning hole diameter, A method has been known in which a laser beam is passed through a stock solution passing through a capillary through a capillary having an equivalent pore diameter to determine whether or not the film-forming stock solution has spots (see, for example, Patent Document 1).

  In addition to this, there is also known a method for detecting local spots in a film-forming stock solution by specifying compositional changes in the film-forming stock solution comprising a dope in which two or more kinds of polymers are dissolved from changes in viscosity and refractive index. (For example, refer to Patent Document 2).

Japanese Patent Laid-Open No. 10-267822 JP 2006-219811 A

  The method described in Patent Document 1 described above is intended only to detect a limited target of local spots in the stock solution, and the size of the local spots is about 100 μm in hand. It was necessary to use a laser beam having a small beam diameter. For this reason, it has been difficult to use this conventional method as a method for detecting a more general abnormality such as contamination of foreign substances and bubbles generated in the film forming stock solution. Further, in the refractometer used in the method described in Patent Document 2, the refraction of light generated at the interface between the prism plane exposed at a part of the tip of the detection unit of the refractometer and the liquid to be inspected is used. For this reason, it has been difficult to accurately detect bubbles and foreign matters in the film-forming stock solution. Similarly, it has been difficult to accurately detect bubbles and foreign matters in the film-forming stock solution using a viscometer.

  With the conventional abnormality detection device and abnormality detection method for the hollow fiber membrane forming solution, only a part of the abnormality that occurs in the film forming solution can be detected. Therefore, an object of the present invention is to provide an abnormality detection device and an abnormality detection method for accurately detecting other abnormalities such as mixing of foreign matters and bubbles into a membrane-forming stock solution used for manufacturing a hollow fiber membrane.

In order to achieve the above object, the present invention is an abnormality detection device that is provided in a supply line for a film-forming stock solution of a hollow fiber membrane and detects an abnormality of the film-forming stock solution in the supply line, and has an optical sensor. The optical sensor has a light emitting part that emits light toward the film forming stock solution in the supply line, and a light receiving unit that receives the light that has passed through the film forming stock solution in the supply line. An abnormality detection unit that detects an abnormality of the film-forming stock solution based on the amount of light received by the light-receiving unit, and the abnormality detection unit can detect a change in the properties of the film-forming stock solution itself. To do.

  In the present invention configured as described above, an optical sensor is used, light is emitted to a wide area of the film-forming stock solution in the supply line, and light that has passed through the film-forming stock solution is received, so The abnormality that has occurred can be detected. Unlike a configuration using a laser beam with a small beam diameter, a wide area can be detected, so various abnormalities such as contamination of foreign substances and bubbles in the membrane forming stock solution used for the production of hollow fiber membranes can be detected. It becomes possible to detect accurately.

  Further, in the present invention, the supply line has at least a part of a tube that extends linearly, and the light emitting part and the light receiving part have a length of the part of the tube in which a line connecting the light emitting part and the light receiving part extends linearly. It is preferable that they are arranged parallel to the direction axis. By comprising in this way, it becomes possible to detect the abnormality of the film forming undiluted solution exactly.

  Further, in the present invention, the supply line has at least a portion of a tube extending linearly, and the light emitting portion and the light receiving portion are the center of the portion of the tube where the line connecting the light emitting portion and the light receiving portion extends linearly. It is preferable that they are arranged so as to coincide with the axis. By comprising in this way, it becomes possible to detect the abnormality of a film forming undiluted solution more correctly.

  In the present invention, the linearly extending tube portion of the supply line includes a portion having a first diameter and a portion having a second diameter smaller than the first diameter, and the light emitting portion and the light receiving portion. Is preferably arranged so that the central axis of the portion having the second diameter of the supply line is parallel to the line connecting the light output portion and the light receiving portion. By comprising in this way, it becomes possible to detect the abnormality of a film forming undiluted solution more correctly.

  Further, in the present invention, the supply line has at least a part of a tube that extends linearly, and the light emitting part and the light receiving part have a length of the part of the tube in which a line connecting the light emitting part and the light receiving part extends linearly. It is preferable that they are arranged perpendicular to the direction axis. By comprising in this way, it becomes possible to detect the abnormality of the film forming undiluted solution exactly.

  Further, in the present invention, the supply line has at least a portion of a tube extending linearly, and the light emitting portion and the light receiving portion are such that the line connecting the light emitting portion and the light receiving portion is relative to the longitudinal axis of the supply line. It is preferable that they are arranged so as to be inclined. By configuring in this way, it is possible to monitor the type of the film-forming stock solution flowing through the supply line in addition to accurately detecting the abnormality of the film-forming stock solution.

  In the present invention, the optical sensor is preferably an optical fiber sensor. With this configuration, inspection light can be transmitted with high efficiency even with a small bent portion, and the light emitting unit, the light receiving unit, and the elements constituting the light emitting unit and the light receiving unit can be freely arranged. The degree can be increased.

Further, the present invention is an abnormality detection device that is provided in a supply line for a film-forming stock solution of a hollow fiber membrane and detects an abnormality of the film-forming stock solution in the supply line, and has an optical sensor. A light-emitting unit that receives light with respect to the film-forming stock solution in the line, and a light-receiving unit that receives light reflected by the film-forming stock solution in the supply line. An abnormality detection unit that detects an abnormality of the film forming stock solution based on the amount of received light is provided, and the abnormality detecting unit can detect a change in the properties of the film forming stock solution itself . By comprising in this way, it becomes possible to detect various abnormalities, such as mixing of a foreign material and a bubble into the membrane forming stock solution used for manufacture of a hollow fiber membrane, accurately.

  Further, in the present invention, the supply line is connected to discharge means for discharging the membrane-forming stock solution supplied from the supply line to spin the hollow fiber membrane, and the light emitting part and the light receiving part are discharged from the supply line. It is preferably arranged immediately before the upstream side of the means. By comprising in this way, it becomes possible to detect correctly the abnormality of the film forming stock solution which generate | occur | produces in a supply line.

  In the present invention, the light emitting part and the light receiving part are arranged outside the supply line, and at least the part corresponding to the light emitting part and the part corresponding to the light receiving part of the supply line are formed of a material that transmits light. It is preferable that By comprising in this way, it becomes possible to detect the abnormality of the film forming undiluted solution exactly.

  Moreover, in this invention, it is preferable that the light emission part and the light-receiving part are provided so that it may protrude in a supply line, and may be arrange | positioned so that a film-forming stock solution may be directly contacted. By comprising in this way, it becomes possible to detect the abnormality of the film forming undiluted solution exactly.

  Further, in the present invention, the abnormality detection unit is based on the intensity of the light received by the light receiving unit, at least of bubbles, foreign matter, gelled material, undissolved material, and property change of the film forming stock solution itself. It is preferable to detect one.

Further, the present invention is an abnormality detection method for detecting an abnormality of a film forming raw solution in a supply line when supplying the film forming raw solution of a hollow fiber membrane through a supply line. The light is incident from the optical sensor, passes through the film-forming stock solution, the light is received by the light sensor, the intensity of the light received by the light sensor is measured, and the film-forming stock solution is measured based on the measured amount of light. An abnormality is detected , and the detection of the abnormality of the film forming stock solution is characterized in that a change in properties of the film forming stock solution itself can be detected . By using an optical sensor, unlike a laser beam having a small beam diameter, a wide area can be detected, and various kinds of contaminants such as foreign substances and bubbles are mixed in a film-forming stock solution used for manufacturing a hollow fiber membrane. Abnormalities can be accurately detected.

Further, the present invention is an abnormality detection method for detecting an abnormality of a film forming raw solution in a supply line when supplying the film forming raw solution of a hollow fiber membrane through a supply line. The light is incident from the optical sensor, reflected from the film forming stock solution, the light is received by the light sensor, the intensity of the light received by the optical sensor is measured, and the film forming stock solution is measured based on the measured amount of light. Abnormality is detected, and the abnormality of the film-forming stock solution can be detected by detecting the property change of the film-forming stock solution itself . By doing in this way, it becomes possible to detect accurately various abnormalities, such as mixing of a foreign material and a bubble into the membrane forming stock solution used for manufacture of a hollow fiber membrane.

  In the present invention, the abnormality detection method preferably detects at least one of bubbles, foreign matter, gelled material, undissolved material, and property change of the film forming stock solution itself.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to detect correctly the abnormality of the membrane forming stock solution used for manufacture of a hollow fiber membrane.

It is the schematic which shows the structure of the hollow fiber membrane manufacturing process which concerns on this invention. It is a figure which shows 1st Embodiment of the abnormality detection apparatus of the film-forming stock solution which concerns on this invention. It is a figure which shows the example of the signal measured by the abnormality detection apparatus of the film-forming stock solution which concerns on this invention. It is a figure which shows 2nd Embodiment of the abnormality detection apparatus of the film forming stock solution which concerns on this invention. It is a figure which shows 3rd Embodiment of the abnormality detection apparatus of the film-forming stock solution which concerns on this invention. It is a figure which shows 4th Embodiment of the abnormality detection apparatus of the film-forming stock solution which concerns on this invention. It is a figure which shows 5th Embodiment of the abnormality detection apparatus of the film-forming stock solution which concerns on this invention. It is a figure which shows 6th Embodiment of the abnormality detection apparatus of the film-forming stock solution which concerns on this invention.

  FIG. 1 is a schematic view showing the configuration of a hollow fiber membrane production process according to the first embodiment of the present invention. As shown in FIG. 1, the hollow fiber membrane forming process according to the first embodiment of the present invention includes a stock solution preparation unit 10, a stock solution storage unit 20, an abnormality detection device 30, a discharge unit 40, a coagulation bath unit 50, The cleaning unit 60, the disassembly unit 70, the drying unit 80, and the winding unit 90 are included. The stock solution preparation means 10 is composed of a melting pot or the like, and the stock solution preparation means 10 and the stock solution storage section 20 are connected by a film-forming stock solution supply line by piping. The stock solution storage unit 20 is composed of a tank or the like, and a supply line by piping is provided from the stock solution storage unit 20 toward the discharge means 40. An abnormality detection device 30 is provided in the middle of the supply line from the stock solution storage unit 20 toward the discharge means 40, and detects an abnormality of the film forming stock solution. The discharge means 40 is, for example, a spinning nozzle, and discharges the raw film forming solution into the form of a hollow fiber. The film-forming stock solution discharged from the discharge means 40 is immersed in the coagulating liquid in the coagulating bath part 50 filled with the coagulating liquid, and solidifies to form a hollow fiber membrane. Thereafter, the hollow fiber membrane is wound around the winding unit 90, and from the coagulation bath unit 50, a cleaning unit 60 for cleaning the hollow fiber membrane, a decomposition unit 70 for decomposing and removing impurities, and a drying unit for drying the hollow fiber membrane. 80 passes one after another, and is finally taken up by the take-up unit 90.

  The stock solution preparing means 10 is a means for preparing a film forming stock solution for forming a porous film. This film-forming stock solution contains a film-forming resin, a pore-opening agent, and a solvent.

  As the film-forming resin, it is possible to use an ordinary resin generally used for forming a porous film. For example, polysulfone resin, polyether sulfone resin, sulfonated polysulfone resin, polyvinylidene fluoride resin, polyacrylonitrile resin, polyimide resin, polyamideimide resin, polyesterimide resin and the like can be mentioned. Among these resins, it is preferable to use a polyvinylidene fluoride resin excellent in chemical resistance. Moreover, about these resin, only 1 type may be used and 2 or more types may be used together.

  As the pore-opening agent, for example, a hydrophilic polymer resin such as monool-based, diol-based, triol-based, or polyvinylpyrrolidone represented by polyethylene glycol can be used. Among these, it is preferable to use polyvinyl pyrrolidone excellent in the thickening effect. About these pore-opening agents, only 1 type may be used and 2 or more types may be used together.

  The solvent is not particularly limited as long as it can dissolve these film-forming resins and pore-opening agents, but dimethyl sulfoxide, N, N-dimethylacetamide, and dimethylformamide can be used as examples. Among these, it is preferable to use N, N-dimethylacetamide, which can efficiently dissolve the film-forming resin. About these solvents, only 1 type may be used and 2 or more types may be used together.

  A film-forming stock solution is prepared with these film-forming resins, pore-opening agents, and solvents, but arbitrary components can be added as long as the control of phase separation of the film-forming stock solution is not hindered. For example, a resin other than the pore opening agent and other additives can be added.

  In the stock solution preparation means 10, a film-forming stock solution is prepared by adding a film-forming resin and a pore-opening agent to the solvent described above, stirring to dissolve, and defoaming by decompression treatment. In the present embodiment, as the stock solution preparation means 10, specifically, a melting pot is used.

  The film-forming stock solution adjusted by the stock-solution preparing means 10 is then sent to a stock-solution storing unit 20 constituted by a tank through a supply line (film-forming stock solution piping) and stored in the stock-solution storing unit 20. The stock solution storage unit 20 temporarily stores the film-forming stock solution prepared by the stock solution preparing unit 10 before sending it to the discharge unit 40, and stably supplies the uniform film-forming stock solution to the discharge unit 40. is there. The film-forming stock solution is fed to the stock solution storage unit 20 through this supply line using a pump (not shown) or the like.

  The stock solution stored in the stock solution storage unit 20 is then sent to the discharge means 40 through the supply line. An abnormality detection device 30 to be described later is provided in the middle of the supply line from the stock solution storage unit 20 toward the discharge means 40. The discharge means 40 is a means for producing a hollow fiber membrane by discharging the membrane forming raw solution, and specifically, a spinning nozzle can be used. As an example of a spinning nozzle, do not use a spinning nozzle that discharges so as to apply a film-forming stock solution to the outside of a reinforcing support such as a hollow knitted string or braid made of various fibers, or a reinforcing support. In addition, there is a spinning nozzle that discharges only the film-forming stock solution into a cylindrical shape. It is also possible to use a spinning nozzle that discharges a plurality of membrane-forming stock solutions concentrically to form a porous hollow fiber membrane in which a plurality of porous membrane layers are laminated. In this case, in order to send each film-forming stock solution to the spinning nozzle, a plurality of stock solution preparation means, stock solution storage units, and film-forming stock solution pipes are used. Further, in this case, by providing an abnormality detection device in each of the plurality of film-forming stock solution supply lines, it is possible to easily know which supply line of the film-forming stock solution is abnormal. In addition, although the spinning nozzle was mentioned as an example, it is also possible to use the discharge nozzle used for manufacture of a flat film besides this.

  The raw film forming solution discharged by the discharging means 40 is immersed in the coagulating liquid in the coagulating bath 50. When the film-forming stock solution is immersed in the coagulation liquid, the coagulation liquid diffuses into the film-forming stock solution, and the film-forming resin and the pore-opening agent coagulate while causing phase separation, thereby forming a porous film. . As the coagulation bath portion 50, a conventionally used one can be used.

  The porous film formed in the coagulation bath unit 50 is then sent to the cleaning unit 60 and cleaned. The washed porous membrane is sent to the decomposition unit 70, and the hydrophilic polymer remaining in the membrane is decomposed and removed. Thereafter, the porous film is dried in the drying unit 80 and wound around the winding unit 90. As the cleaning unit 60, the disassembling unit 70, the drying unit 80, and the winding unit 90, those conventionally used can be used.

  FIG. 2 is a schematic view showing a main part of the first embodiment of the abnormality detection device according to the present invention. The light output unit 302 and the light receiving unit 303 of the optical fiber unit 301 are arranged on the left and right of the supply line 305, and a cross section of the supply line 305 is shown in the center. This portion of the supply line 305 is formed by a linearly extending cylindrical tube, and the line connecting the light output portion 302 and the light receiving portion 303 of the optical fiber unit 301 is the longitudinal axis of the portion of this linearly extending tube. It arrange | positions so that it may become perpendicular | vertical with respect to it. The light receiving unit 303 is connected to the abnormality detection unit 304 via an amplifier unit (not shown).

  The optical fiber sensor used in this embodiment includes an optical fiber unit 301 and an amplifier unit (not shown), and in particular, a transmission type optical fiber sensor is used. An end portion of an optical fiber that guides light from a light source (not shown) is provided in the light exit portion 302, and light is emitted from the light exit portion 302. The beam diameter of the light emitted from the end of the optical fiber is larger than the laser light used in the prior art, and this light spreads at a predetermined angle from the end of the optical fiber. For this reason, unlike a laser beam having a small beam diameter, a wide area can be set as a detection target. The light receiving unit 303 receives the light emitted from the light output unit 302 and sends a signal to the amplifier unit. The amplifier unit amplifies the signal of the light received by the light receiving unit 303, thereby measuring the amount of light received by the light receiving unit 303. Based on the amount of light received by the light receiving unit 303, the abnormality detection unit 304 detects an abnormality of the film forming stock solution. As the optical fiber unit 301 constituting the optical fiber sensor, FU-77 manufactured by Keyence Corporation or E32-T11N manufactured by OMRON Corporation can be used, and FS-N11MN manufactured by Keyence Corporation or OMRON Corporation as an amplifier. E3X-DA11AN made by the company can be used. The optical fiber used for the optical fiber sensor is preferably made of plastic from the viewpoint of ease of handling.

  In each embodiment, as an optical sensor, an optical fiber as an optical transmission body that can transmit inspection light with high efficiency even if it has a small bent portion, from the viewpoint of the degree of freedom of arrangement of the light emitting portion and the light receiving portion. In addition to this, an optical sensor comprising a light emitting part having a light guide element such as a light emitting element and a quartz rod, and a light receiving part having a light guide element such as a light receiving element and a quartz rod is used. May be. Moreover, you may use the sensor structure which guides light directly to a detection target with a lens etc., without using a light guide.

  The abnormality detection unit 304 monitors the amount of light received by the light receiving unit 303 of the optical fiber unit 301 and analyzes the change in the absolute value with time to detect an abnormality in the film forming stock solution. It may be configured by a dedicated device for the purpose of detecting an abnormality, and a similar function may be realized by installing software in a personal computer.

  The light output unit 302 and the light receiving unit 303 of the optical fiber unit 301, which are a part of the transmission type optical fiber sensor, are arranged with the supply line 305 of the film-forming stock solution interposed therebetween. In the first embodiment, a transparent resin pipe is used for the supply line 305 in the portion where the light exiting portion 302 and the light receiving portion 303 of the optical fiber unit 301 are disposed. Specific examples of preferable transparent materials include transparent nylon resins, polyolefin resins, fluorine resins (PFA, ETFE, etc.), transparent fluorine rubber, polyurethane and the like. With the arrangement shown in FIG. 2, the light emitted from the light exit portion 302 of the optical fiber unit 301 arranged outside the pipe passes through the transparent pipe and the film-forming stock solution flowing inside the pipe, and the light Light is received by the light receiving unit 303 of the fiber unit 301. In the first embodiment, the light output unit 302 and the light receiving unit 303 of the optical fiber unit 301 are in a non-contact state with respect to the film forming stock solution.

  In the abnormality detection apparatus shown in FIG. 2, the entire linearly extending pipe of the supply line 305 is a transparent resin pipe. However, the portion where the light from the light exit unit 302 enters the supply line 305 and the receiving / supplying line 305 are arranged. It is also possible to provide a transparent window at a portion where the light that has passed through is emitted, and make the other supply lines opaque.

  In the first embodiment, a film-forming stock solution in which bubbles or foreign substances, a gel-like material or an undissolved material in the film-forming stock solution is mixed, or a film-forming stock solution that has become cloudy due to a change in properties is supplied. When flowing through the line 305, the light emitted from the light exit part 302 passes through the wall of the transparent resin pipe, and bubbles, foreign substances, gel-like or undissolved substances contained in the film-forming stock solution in the supply line 305, Scattered by cloudiness of the film-forming stock solution. As a result, the light receiving unit 303 is not compared with the case where a normal film-forming stock solution in which bubbles, foreign matter, gel-like material or undissolved material is not mixed, and no property change occurs, flows through the supply line 305. The amount of light received will be reduced. The film-forming stock solution flows along the supply line 305 between the light exiting portion 302 and the light receiving portion 303 toward the discharge means, so that the amount of light received by the light receiving portion 303 is air bubbles, foreign matter, gel-like substances, It is affected by the passage of undissolved material and cloudy stock solution, and changes with time.

  FIG. 3 is a diagram showing an example of the waveform of the output voltage of the optical fiber sensor used in this embodiment. The horizontal axis is the time axis, and the vertical axis indicates the voltage. Under normal conditions, that is, when the normal film-forming stock solution without bubbles, foreign matter, gel-like material or undissolved material is passing through the supply line 305, and the level of bubbles, foreign matter, or film-forming stock solution A change in voltage level appears when the gel-like material, undissolved material, or cloudy film-forming stock solution passes through the supply line 305. If bubbles, foreign matter, gel-like material, undissolved material, or cloudy film-forming stock solution reaches between the light-emitting part 302 and the light-receiving part 303, the light emitted from the light-emitting part 302 is changed to bubbles, foreign matter, gel-like substance, Since the amount of light scattered by the dissolved matter and white turbidity and received by the light receiving unit 303 of the optical fiber unit 301 decreases, the output voltage of the optical fiber sensor also decreases. After that, when the film-forming stock solution passes bubbles, foreign matters, gels and undissolved materials, and the cloudy film-forming stock solution passes through, the amount of light received by the light receiving unit 303 of the optical fiber unit 301 is also recovered. The output voltage of the optical fiber sensor also returns to the normal value.

  As described above, by monitoring the output voltage of the optical fiber sensor, that is, the amount of light received by the optical fiber sensor, it is possible to detect abnormality of the film forming stock solution flowing through the supply line. When the abnormality detection device 30 detects an abnormality in the membrane forming stock solution, the collection as the product is stopped before the abnormality occurs in the hollow fiber membrane that is the product, and after the abnormality is not detected in the film forming stock solution, It is preferable to resume the product collection after waiting for the process stay time of the film-forming solution to the product collection unit to elapse. By doing in this way, it can avoid collecting the hollow fiber membrane manufactured from the membrane forming stock solution in which abnormality was detected as a product. Since it is not possible to exclude the possibility that foreign matter is mixed in the supply line from the abnormality detection device 30 to the discharge means 40 after confirming that there is no abnormality in the abnormality detection device 30, the discharge is performed from the discharge means 40. In order to accurately ensure that there is no abnormality in the film-forming stock solution, the abnormality detection device 30 of the present invention is arranged in the supply line from the stock solution storage unit 20 to the discharge means 40 in the vicinity immediately upstream of the discharge means 40. Preferably it is done.

  In addition to the abnormalities that occur in the film-forming stock solution, the characteristics of the film-forming stock solution itself change in addition to abnormalities such as the generation and mixing of bubbles and foreign matters that cause light scattering, and the generation of gel-like and undissolved materials. Thus, an abnormality that causes light absorption may occur. Even in such a case, since the amount of light received by the light receiving unit 303 of the optical fiber unit 301 is reduced, it is possible to detect an abnormality similarly. Therefore, it is possible to accurately detect various abnormalities that may occur in the film forming stock solution based on the amount of light received by the light receiving unit 303.

  As described above, according to the first embodiment, by using the abnormality detection device having the optical fiber sensor, it is possible to accurately detect various abnormalities of the membrane forming stock solution used for manufacturing the hollow fiber membrane. .

  FIG. 4 is a schematic view showing a second embodiment of the abnormality detection device according to the present invention. The basic configuration of the second embodiment is the same as that of the first embodiment, but the arrangement of the optical fiber units is different. A description of portions common to the first embodiment is omitted. As shown in FIG. 4, the light emitting unit 302 and the light receiving unit 303 of the optical fiber unit 301, which are part of the transmission type optical fiber sensor, are arranged on the left and right of the supply line 305, and the cross section of the supply line 305 is shown in the center. Has been. The supply line 305 in this portion is formed by a linearly extending tube, and the line connecting the light output portion 302 and the light receiving portion 303 of the optical fiber unit 301 is perpendicular to the longitudinal axis of the linearly extending tube portion. It is arranged to become.

  Unlike the first embodiment, the end portions of the light output portion 302 and the light receiving portion 303 of the optical fiber unit 301 of the second embodiment are arranged in a protruding manner in the piping of the supply line 305. By doing in this way, in 2nd Embodiment, the light emission part 302 and the light-receiving part 303 of the optical fiber unit 301 are in the state which contacted the film-forming stock solution. Since the end portions of the light exiting portion 302 and the light receiving portion 303 protrude into the piping of the supply line 305, it is not necessary to provide a transparent portion in the piping. In addition, unlike the first embodiment, since the wall surface of the supply line 305 does not exist between the light exiting portion 302 and the light receiving portion 303 of the optical fiber unit 301, the amount of light received by the light receiving portion 303 than in the first embodiment. Increases and the S / N ratio also improves. Also in the second embodiment, the output voltage from the optical fiber sensor and the abnormality detection method based on the output voltage are the same as those in the first embodiment, and thus the description thereof is omitted.

  FIG. 5 is a schematic view showing a third embodiment of the abnormality detection apparatus according to the present invention. The basic configuration of the third embodiment is the same as that of the first embodiment, but instead of using the transmission type optical fiber sensor as in the first and second embodiments described above, a reflection type optical fiber sensor is used. 306 is used. The reflection type optical fiber sensor 306 includes a light emitting unit 307 and a light receiving unit 308 mounted in one housing, and is different from a transmission type optical fiber sensor in which a light emitting unit and a light receiving unit are arranged so as to sandwich a measurement target. The light is emitted from the light emitting unit 307 toward the measurement target, and the light reflected by the measurement target is received by the light receiving unit 308.

  Since the reflection type optical fiber sensor 306 used in the third embodiment emits light from the outside of the supply line 305 and receives the reflection of this light outside the supply line 305, it is the same as in the first embodiment. In addition, the portion of the supply line 305 that transmits the light emitted from the light exit unit 307 and transmits the light reflected by the film forming stock solution to the light receiving unit 308 is formed of a transparent material. As shown in FIG. 5, a portion of the supply line 305 that is part of the linearly extending pipe may be transparent, or a window may be provided in the part of the linearly extending pipe, and the window portion may be transparent. Good. Also in the third embodiment, the output voltage from the optical fiber sensor and the abnormality detection method based on the output voltage are the same as those in the first embodiment, and thus description thereof is omitted.

  FIG. 6 is a schematic view showing a fourth embodiment of the abnormality detection device according to the present invention. The basic configuration is the same as that of the first embodiment, and a transmissive optical fiber sensor is used. However, the shape of the supply line 305 and the arrangement of the light output unit 302 and the light receiving unit 303 of the optical fiber unit 301 are different. In the fourth embodiment, the supply line 305 has two bent portions that are each bent by 90 degrees, and is a tube that extends linearly between the first bent portion and the second bent portion. A part is provided. In the fourth embodiment, the line connecting the light exiting portion 302 and the light receiving portion 303 of the optical fiber unit 301 is parallel to the longitudinal axis of the linearly extending tube portion. A light emitting unit 302 and a light receiving unit 303 are arranged. In particular, it is preferable that the line connecting the light output portion 302 and the light receiving portion 303 of the optical fiber unit 301 coincides with the central axis of the linearly extending tube portion. Of the supply line 305, the side where the light exiting portion 302 of the optical fiber unit 301 is provided and the side where the light receiving portion 303 of the optical fiber unit 301 is provided are formed of a transparent material such as glass (quartz glass, barium fluoride, etc.). Has been.

  In the first and second embodiments described above, the width of the film-forming stock solution between the light output unit 302 and the light receiving unit 303 is substantially the same as the diameter of the linearly extending tube portion of the supply line. However, by arranging the light emitting unit 302 and the light receiving unit 303 of the optical fiber unit 301 as in the fourth embodiment, it becomes possible to pass through the film forming stock solution for a longer time, improving noise resistance, It becomes possible to improve the accuracy of detection.

  Moreover, it is known from the fluid dynamics that bubbles or foreign matters mixed in the fluid tend to gather at a high flow velocity in the fluid flow. In the linearly extending pipe portion of the supply line as shown, the flow velocity near the central axis of the linearly extending tube is faster than the flow velocity near the inner wall surface of the linearly extending tube. Therefore, by making the line connecting the light output portion 302 and the light receiving portion 303 of the optical fiber unit 301 coincide with the central axis of this linearly extending tube portion, it is possible to detect the abnormality of the film forming stock solution more accurately. It becomes possible. Also in the fourth embodiment, the output voltage from the optical fiber sensor and the abnormality detection method based on the output voltage are the same as those in the other embodiments, and thus the description thereof is omitted.

  In the fourth embodiment as well, as in the second embodiment, the light output portion 302 and the light receiving portion 303 of the optical fiber unit 301 are projected into the supply line 305 so as to be in direct contact with the film forming stock solution. It doesn't matter. In addition, the bending portion before and after the linearly extending tube portion is bent at an angle other than 90 degrees as long as it does not interfere with the arrangement of the light emitting portion 302 and the light receiving portion 303 of the optical fiber unit 301. It doesn't matter.

  FIG. 7 is a schematic view showing a fifth embodiment of the abnormality detection apparatus according to the present invention. The fifth embodiment is similar to the fourth embodiment described above, except that a part of the linearly extending tube portion in the fourth embodiment has a smaller diameter. . In the fifth embodiment, the central axis of the small diameter portion of the linearly extending tube portion and the line connecting the light output portion 302 and the light receiving portion 303 of the optical fiber unit 301 are parallel to each other. . In particular, it is preferable that the central axis of the portion having a small diameter coincides with the line connecting the light output portion 302 and the light receiving portion 303 of the optical fiber unit 301.

  In terms of fluid dynamics, in the linearly extending tube portion as in the fifth embodiment, the flow velocity of the portion having a small diameter is faster than the flow velocity of the portion having a large diameter. Therefore, by detecting an abnormality such as a bubble in this portion, it is possible to accurately detect the abnormality of the film forming stock solution. Also in the fifth embodiment, the output voltage from the optical fiber sensor and the abnormality detection method based on the output voltage are the same as in the other embodiments, and thus the description thereof is omitted.

  FIG. 8 is a schematic view showing a sixth embodiment of the abnormality detection device according to the present invention. The basic configuration of the sixth embodiment is the same as that of the first embodiment described above, but in the first embodiment, the line connecting the light emitting unit 302 and the light receiving unit 303 of the optical fiber unit 301 is a straight line of the supply line 305. Whereas the light exiting portion 302 and the light receiving portion 303 are arranged so as to be perpendicular to the longitudinal axis of the portion of the tube extending in general, in the sixth embodiment, the light exiting portion of the optical fiber unit 301 is arranged. The line connecting 302 and the light receiving unit 303 is arranged so as to be inclined with respect to the longitudinal axis of the linearly extending tube portion of the supply line 305. In the first embodiment, the change in the amount of light received by the light receiving unit 303 based on reflection or absorption of light due to abnormality in the film forming stock solution is monitored, whereas in the sixth embodiment, further, It is also possible to monitor the change in the amount of light received by the light receiving unit 303 based on the change in light refraction caused by the change in the refractive index of the film forming stock solution. In FIG. 8, the thickness of the tube of the supply line 305 is shown large for easy understanding of light refraction, but the actual thickness of the tube of the supply line 305 is thinner than that shown in the figure.

  FIG. 8A shows an example of an abnormality detection device that operates when a normal film-forming solution is supplied to the discharge means 40 via a supply line. From the relationship between the refractive index of the film-forming stock solution and the material of the supply line, the light-receiving unit 303 is positioned at a position where the amount of light received by the light-receiving unit 303 is maximized by the refraction of light caused by the refractive index of the normal film-forming stock solution. Is preferably positioned. Using the optical fiber unit 301 arranged in this way, it is possible to detect an abnormality in the film forming stock solution as in the above-described embodiments.

  On the other hand, FIG. 8B shows an example of an abnormality detection device that operates when a film-forming stock solution having a refractive index different from the refractive index of a normal film-forming stock solution is supplied to the discharge means 40 via the supply line. ing. Since the refractive index of the film-forming stock solution flowing in the supply line is different from the refractive index of the normal film-forming stock solution, the degree of refraction of the light emitted from the light-emitting unit 302 changes, and the amount of light received by the light-receiving unit 303 also decreases. To do. Further, this decrease is not temporary unlike the above-described mixing of bubbles and foreign matters, and remains constantly reduced while different film-forming stock solutions are being supplied. Therefore, by monitoring the amount of light received by the light receiving unit 303, from the behavior of the measured value, not only detection of abnormality of the film forming stock solution due to mixing of bubbles or foreign matters, but also the film forming stock solution flowing in the supply line It is possible to monitor the type of the item. Also in the sixth embodiment, the output voltage from the optical fiber sensor and the abnormality detection method based on the output voltage are the same as those in the other embodiments, and thus the description thereof is omitted.

  The preferred embodiments of the present invention have been described above, but it is also possible to configure an abnormality detection apparatus using a plurality of optical fiber sensors by appropriately combining these embodiments. For example, the first embodiment and the sixth embodiment are combined to use two optical fiber sensors, and for the first optical fiber sensor, a line connecting the light emitting unit 302 and the light receiving unit 303 of the optical fiber unit 301. Is arranged perpendicular to the longitudinal axis of the linearly extending tube portion of the supply line 305, and the light exiting portion 302 and the light receiving portion 303 are arranged so that the light exiting portion of the optical fiber unit 301 for the second optical fiber sensor. The light exiting portion 302 and the light receiving portion 303 may be arranged so that the line connecting the portion 302 and the light receiving portion 303 is inclined with respect to the longitudinal axis of the linearly extending tube portion of the supply line 305. In this case, an abnormality in the film forming stock solution is detected by the measurement by the first optical fiber sensor, and the role is shared so that the type of the film forming stock solution is detected by the measurement by the second optical fiber sensor. Is preferred.

  According to the present invention, it is possible to accurately detect various abnormalities such as contamination of foreign substances and bubbles in the membrane-forming stock solution used for the production of hollow fiber membranes. Stop sampling as a product before the abnormality occurs in the hollow fiber membrane, and after the abnormality is no longer detected in the membrane forming stock solution, wait for the process stay time of the membrane forming stock solution from the detection unit to the product sampling unit From this point, it is possible to resume product collection. Also, increase the discharge amount of the film-forming stock solution from the time when the abnormality is detected, perform the replacement operation of the film-forming stock solution until no abnormality is detected, and return to normal conditions from the time when no abnormality is detected in the film-forming stock solution. It is also possible to perform a process return operation such as that described above, and it is possible to suppress a loss of condition stabilization accompanying the stop / restart of the process. Furthermore, if abnormalities in the film-forming stock solution continue even after the above-mentioned measures are taken, it is not an abnormality in the film-forming stock solution due to a sudden cause, but a major problem or fundamental problem related to equipment or raw materials. Since it is suspected to be caused, it is possible to minimize the process loss by stopping the manufacturing process and checking the process.

  Further, the application of the present invention is not limited only to the detection of abnormality in the hollow fiber membrane forming stock solution, and may be used, for example, to detect abnormality in the supply line of the spinning solution of acrylic fiber and acetate fiber. . Moreover, you may use for the abnormality detection in the supply line of melt | dissolved raw materials, such as polyester and nylon manufactured by melt spinning.

DESCRIPTION OF SYMBOLS 10 Stock solution preparation means 20 Stock solution storage part 30 Abnormality detection apparatus 301 Optical fiber unit 302 Light emission part 303 Light reception part 304 Abnormality detection part 305 Supply line 306 Reflection type optical fiber sensor 307 Light emission part 308 Light reception part 40 Discharge means 50 Coagulation bath part 60 Cleaning 70 Disassembling unit 80 Drying unit 90 Winding unit

Claims (17)

An abnormality detection device that is provided in a supply line of a membrane forming stock solution of a hollow fiber membrane and detects an abnormality of the membrane forming stock solution in the supply line,
An optical sensor, the optical sensor comprising:
A light output part that emits light toward the film-forming stock solution in the supply line;
A light receiving portion that receives the light that has passed through the film-forming stock solution in the supply line;
The abnormality detection device includes an abnormality detection unit that detects an abnormality of the film forming stock solution based on the amount of light received by the light receiving unit ,
The anomaly detection unit is an anomaly detection device capable of detecting a change in properties of the film-forming stock solution itself . The abnormality detection device according to claim 1, wherein the abnormality detection unit analyzes a temporal change in the amount of light. The abnormality detection device according to claim 2, wherein the time change is a continuous time change. The supply line has at least a portion of a tube extending linearly, and the light emitting portion and the light receiving portion have a length of a tube portion in which a line connecting the light emitting portion and the light receiving portion extends linearly. The abnormality detection device according to any one of claims 1 to 3, wherein the abnormality detection device is disposed so as to be parallel to the direction axis. The supply line has at least a portion of a tube extending linearly, and the light emitting portion and the light receiving portion have a center of a portion of the tube where the line connecting the light emitting portion and the light receiving portion extends linearly. The abnormality detection device according to claim 1 , wherein the abnormality detection device is disposed so as to coincide with an axis. The linearly extending tube portion of the supply line has a portion having a first diameter and a portion having a second diameter smaller than the first diameter, and the light emitting portion and the light receiving portion are: 6. The device according to claim 1 , wherein a central axis of a portion having the second diameter of the supply line and a line connecting the light emitting unit and the light receiving unit are arranged in parallel. The abnormality detection device described. The supply line has at least a portion of a tube extending linearly, and the light emitting portion and the light receiving portion have a length of a tube portion in which a line connecting the light emitting portion and the light receiving portion extends linearly. The abnormality detection device according to claim 1 , wherein the abnormality detection device is disposed so as to be perpendicular to the direction axis. The supply line has at least a portion of a tube extending linearly, and the light emitting portion and the light receiving portion have a line connecting the light emitting portion and the light receiving portion with respect to the longitudinal axis of the supply line. The abnormality detection device according to claim 1 , wherein the abnormality detection device is disposed so as to be inclined. An abnormality detection device that is provided in a supply line of a membrane forming stock solution of a hollow fiber membrane and detects an abnormality of the membrane forming stock solution in the supply line,
An optical sensor, the optical sensor comprising:
A light output part that emits light toward the film-forming stock solution in the supply line;
A light receiving unit that receives the light reflected by the film-forming stock solution in the supply line;
The abnormality detection device includes an abnormality detection unit that detects an abnormality of the film forming stock solution based on the amount of light received by the light receiving unit ,
The anomaly detection unit is an anomaly detection device capable of detecting a property change of the film-forming stock solution itself . The supply line is connected to discharge means for discharging the membrane-forming stock solution supplied from the supply line to spin the hollow fiber membrane,
10. The abnormality detection device according to claim 1 , wherein the light output unit and the light receiving unit are disposed immediately upstream of the discharge unit of the supply line. The light emitting part and the light receiving part are arranged outside the supply line, and at least a part corresponding to the light emitting part and a part corresponding to the light receiving part of the supply line are made of a material that transmits the light. The abnormality detection device according to claim 1 , wherein the abnormality detection device is formed. 11. The abnormality detection device according to claim 1 , wherein the light emitting unit and the light receiving unit are provided so as to protrude into the supply line and are arranged so as to be in direct contact with the film forming stock solution. . The abnormality detection unit further based on the intensity of the light which the light receiving unit has received, to detect air bubbles in the film-forming stock solution, foreign material, gel-like product, undissolved, at least one, according to claim 1 The abnormality detection device according to any one of 1 to 12 . The abnormality detection apparatus according to claim 1 , wherein the optical sensor is an optical fiber sensor. When supplying the membrane-forming stock solution of the hollow fiber membrane by a supply line, an abnormality detection method for detecting an abnormality of the membrane-forming stock solution in the supply line,
Incident light from an optical sensor to the film forming stock solution flowing in the supply line,
The light that has passed through the film-forming stock solution is received by the optical sensor,
Measure the intensity of light received by the optical sensor,
Based on the measured amount of light, an abnormality of the film forming stock solution is detected ,
The abnormality detection method for detecting an abnormality of the film-forming stock solution can detect a property change of the film-forming stock solution itself . When supplying the membrane-forming stock solution of the hollow fiber membrane by a supply line, an abnormality detection method for detecting an abnormality of the membrane-forming stock solution in the supply line,
Incident light from an optical sensor to the film forming stock solution flowing in the supply line,
The light reflected from the film forming stock solution is received by the optical sensor,
Measure the amount of light received by the light sensor,
Based on the measured amount of light, an abnormality of the film forming stock solution is detected ,
The abnormality detection method for detecting an abnormality of the film-forming stock solution can detect a property change of the film-forming stock solution itself . The abnormality detecting method further bubbles of the film-forming stock solution, foreign material, gel-like product, undissolved substances, detecting at least one abnormality detection method according to claim 15 or 16, wherein.

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