JP4573405B2 - Diaphragm cartridge - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a diaphragm electrode for measuring the concentration of a gas to be measured dissolved in a sample solution.Used forDiaphragm cartridgeTheIt is related.
[0002]
[Prior art]
Conventionally, in order to measure the dissolved oxygen concentration, for example, as a measurement object gas dissolved in a sample solution, a so-called redox current measurement using a galvanic cell type or a polarographic method has been performed. For example, in order to improve the yield of the fermented product, and because it is necessary to grasp the physiological state of the cells in the experimental plant, the dissolved oxygen in the culture tank is measured. In the oxidation-reduction current measurement, a measurement electrode having a working electrode and a counter electrode that generates a current by a redox reaction corresponding to the oxidation-reduction reaction on the working electrode is used. A diaphragm type electrode having a gas permeable diaphragm that selectively permeates gas is widely used so that such a measurement electrode does not come into contact with, for example, interfering ions in a sample solution.
[0003]
Such oxidation-reduction current measurement is used in fields such as the environment (rivers, seawater, lakes), water treatment, aquaculture, and the like, in addition to the above-described fermentation field. In addition to measuring dissolved oxygen concentration, for example, free residual chlorine concentration measurement, dissolved ozone concentration measurement, dissolved chlorine dioxide measurement, chlorous acid (HClO₂) It can be used for concentration measurement, dissolved hydrogen concentration measurement, ammonia concentration measurement and the like.
[0004]
The schematic configuration of a conventional diaphragm electrode will be described. For example, as shown in FIG. 9, the diaphragm electrode 100 includes a main body 80 and an electrode main body 90 on the tip (lower end in the figure) side of the body 80. Have. The electrode body 90 has an electrode support tube 91, and an outer cylinder 98 connected to the lower portion of the body body 80 is provided so as to surround the outer periphery of the electrode support tube 91.
[0005]
A glass holder (glass holder) 92 is mounted on the sleeve portion 91 a below the electrode support tube 91. Further, a cathode (for example, platinum) 94 serving as a glass-sealed working electrode is attached to the front end (lower end in the figure) of the glass holder 92, and an anode serving as a counter electrode is disposed on the outer periphery of the lower end of the electrode support tube 91. (For example, lead) 93 is attached.
[0006]
And the diaphragm 4 used as a fluororesin film film etc. is provided so that the lower end opening part 99 of the outer cylinder 98 may be sealed, the outer periphery of the electrode support tube 91, the glass holder 92, and the anode 93, and the outer cylinder 98 An internal liquid (electrolytic solution) E is stored in an annular space defined between the inner peripheral portion and the inner peripheral portion. The internal liquid E comes into contact with the anode 93 and also comes into contact with the cathode 94 and the diaphragm 4 in a thin film shape so that the anode 93 and the cathode 94 are electrically connected.
[0007]
In the diaphragm type electrode, the characteristics of the diaphragm that selectively permeate the gas in the sample liquid (sample water) affect the performance of the electrode. In particular, how the membrane is stretched greatly affects its performance. For example,
(1) Adhesion between internal electrode and diaphragm
(2) Elongation of membrane surface in contact with internal electrode
(3) Dirt on the diaphragm due to sample liquid (sample water)
(4) Diaphragm breakage due to foreign matter in sample liquid (sample water)
Etc. greatly affect the electrode performance.
[0008]
Therefore, in order to maintain the normal performance of the electrode, it is necessary to replace the diaphragm when trouble occurs or periodically.
[0009]
As a method for replacing the diaphragm, there is a method in which the diaphragm itself is replaced with a new one and is stretched on the electrode body. For example, as shown in FIG. 9, the diaphragm 4 cut larger than the outer diameter of the lower end portion of the outer cylinder 98 is disposed so as to seal the lower end opening 99 of the outer cylinder 98, and the outer cylinder The portion of the lower end portion 98 that protrudes outside the outer diameter is tightened into a groove portion 76 provided on the outer periphery near the lower end portion of the outer cylinder 98 using an elastic O-ring 75 as a diaphragm fixing member.
[0010]
According to this method, the cost for the replacement of the diaphragm is only the cost of the diaphragm and is relatively inexpensive. However, it is difficult to replace a very thin diaphragm at the electrode installation site, the workability is extremely poor, and considerable skill is required. For this reason, wrinkles, deflections, etc. are likely to occur in the exchanged diaphragm, and often the diaphragm needs to be replaced several times.
[0011]
On the other hand, as shown in FIG. 10, there is a method of mounting a so-called diaphragm cartridge 1 (FIG. 11 (a)) to which a diaphragm 4 is attached in advance. That is, the diaphragm cartridge fixing member 7, which is a substantially cylindrical cap nut or the like, is configured to be attached to the lower end portion of the outer cylinder 98 by, for example, screwing, and the diaphragm cartridge 1 is configured by the diaphragm cartridge fixing member 7. It is attached to the lower end opening 99 of the outer cylinder 98. As will be described in detail later, the diaphragm cartridge 1 (FIG. 11A) has an annular holding receiving portion 21 having a shape in which the lower end side edge is cut out in an annular shape, and this annular holding receiving portion 21 is fixed to the diaphragm cartridge. The member 7 is fitted into an annular pressing portion 71 that is an annular shoulder portion that forms the edge of the lower opening 72 of the member 7. Thus, the diaphragm cartridge fixing member 7 is screwed to the lower end portion of the outer cylinder 98, whereby the diaphragm cartridge 1 to which the diaphragm 4 is attached in advance is fixed to the lower end of the outer cylinder 98.
[0012]
In this method, compared to the case where only the diaphragm is replaced as described above, the cost of replacement parts is high, but since the diaphragm is replaced for each diaphragm cartridge in which the diaphragm is stretched in advance, The replacement work is easy, and it has a great advantage that the work can be completed in a short time. Therefore, for example, the total cost can be reduced, such as reducing the burden on the operator or reducing the missing measurement value.
[0013]
As a method of attaching the diaphragm 4 to the diaphragm cartridge 1, for example, there is a method described in Japanese Utility Model Laid-Open No. 59-68253. That is, as a conventional diaphragm fixing method of the diaphragm cartridge 1, as shown in FIG. 11A, an outer ring 2 that is an annular member for fixing the diaphragm and an inner ring that is an annular member fitted into the outer ring 2 are used. 3 and a method for holding and fixing the diaphragm 4 is devised and implemented.
[0014]
To further explain with reference to FIG. 11B, the outer ring 2 of the diaphragm cartridge 1 has a shape in which a concave portion is provided in a substantially disk-shaped member. That is, the outer ring 2 has a cylindrical large-diameter hole 22 provided with an inner peripheral surface 24 and a cylindrical small-diameter hole 23 provided with an inner peripheral surface 25 having a smaller diameter. An annular shoulder 26 having a circular shape in plan view is formed between 22 and the small diameter hole 23, that is, in the lower end portion of the outer ring 2 in this example. The inner ring 3 has an outer diameter substantially the same as the large-diameter inner peripheral surface 24 of the outer ring 2, and has a through hole 31 having an inner peripheral surface 32 that is slightly smaller in diameter than the small-diameter hole 23 of the outer ring 2. It is a right cylindrical annular member.
[0015]
When the diaphragm 4 is fixed, the diaphragm 4 cut into a substantially circular shape having an inner diameter substantially the same as the inner diameter of the large-diameter hole 22 is separated from the upper surface 26 a of the annular shoulder 26 of the outer ring 2 and the inner ring 3. The inner ring 3 is press-fitted into the large-diameter hole 22 of the outer ring 2 so as to be sandwiched by the one annular surface (lower surface) 34. As a result, the outer peripheral surface 33 of the inner ring 3 and the large-diameter inner peripheral surface 24 of the outer ring 2 are frictionally engaged, and the annular shoulder upper surface 26a of the outer ring 2 and the lower surface 34 of the inner ring 3 are separated. 4 is compressed and held.
[0016]
[Problems to be solved by the invention]
However, the diaphragm fixing method in the conventional diaphragm cartridge 1 as shown in FIGS. 11A and 11B has the following problems.
[0017]
That is, as shown in more detail in FIG. 12, in the conventional diaphragm cartridge 1, the diaphragm 4 is held between the lower surface 34 of the inner ring 3 and the flat portion of the annular shoulder upper surface 26 a of the outer ring 2. Thus, when compressed and pressed in the thickness direction of the diaphragm 4 at the flat portion, the compressed region of the diaphragm 4 undergoes plastic deformation, and the compressed volume of the diaphragm 4 is inward (in the direction of the arrow in the figure). It will grow. As a result, as shown in FIGS. 11A and 12, the diaphragm 4 swells or wrinkles in the direction of the central axis (one-dot chain line) of the diaphragm cartridge 1. Thus, in the conventional diaphragm fixing method, it is difficult to stretch the diaphragm 4 uniformly without bending or wrinkling.
[0018]
Conventionally, in order to mount the diaphragm cartridge 1 in which the diaphragm 4 is bent on the outer cylinder 98, the diaphragm cartridge is fixed in order to bring the electrode (cathode 94) and the diaphragm 4 into close contact with each other in a state where no wrinkle is generated on the diaphragm 4. It was necessary to finely adjust the tightening of the member (cap nut) 7 to the outer cylinder 98 for each diaphragm electrode 100, and the replacement work of the diaphragm cartridge 1 was complicated. If this adjustment is not successful, each electrode may have different current sensitivities, which may lead to problems in that the quality of the electrode is impaired.
[0019]
The above-described problem becomes more remarkable when the diaphragm 4 is thick. That is, as shown in FIG. 13 (a), for example, a normal diaphragm 4 made of, for example, a FEP (tetrafluoroethylene-hexafluoropropylene copolymer) film, a so-called Teflon film or the like, generally has a thickness of about 10 to 100 μm. It is.
[0020]
On the other hand, as the diaphragm 4 of the diaphragm electrode 100 used as a dissolved oxygen sensor in a fermenter, for example, a thick diaphragm 4 having a laminated structure is used to reinforce the diaphragm 4 so as to withstand high pressure during steam sterilization of the culture tank. is there. For example, as shown in FIG. 13B, an FEP layer 4a is provided on the electrode side, and a reinforcing layer 4b in which a stainless steel mesh 4c as a reinforcing body is embedded in a silicon resin 4d is laminated on the FEP layer 4a. There is a diaphragm 4. In such a diaphragm 4, for example, the FEP layer 4 a has a thickness of about 10 μm to 100 μm, and the reinforcing layer 4 b has a thickness of 100 μm to 200 μm.
[0021]
As described above, the relatively thick diaphragm 4 is formed in the thickness direction of the diaphragm by the entire surface of the flat portions (26a, 34) of the outer ring 2 and the inner ring 3 in the conventional diaphragm cartridge 1 by having a reinforcing structure. When compressed, it is more likely to cause plastic deformation than a relatively thin diaphragm, and thus the phenomenon such as bending and wrinkling becomes more remarkable.
[0022]
A diaphragm that can withstand, for example, high pressure, using the diaphragm 4 having the above-described reinforcing structure by regulating the thickness of the diaphragm 4 in order to properly stretch the diaphragm 4 on the diaphragm cartridge 1. There was a limit to the practical use of the type electrode or diaphragm cartridge.
[0023]
  Accordingly, an object of the present invention is to provide a diaphragm-type electrode that can stretch the diaphragm uniformly without bending or wrinkling.Used forDiaphragm cartridgeTheIs to provide.
[0024]
  Another object of the present invention is a diaphragm type electrode capable of stretching a diaphragm uniformly without bending or wrinkling even when a thicker diaphragm such as a diaphragm provided with a reinforcing body is used.Used forDiaphragm cartridgeTheIs to provide.
[0025]
  Furthermore, another object of the present invention is to provide a diaphragm-type electrode that can attach a diaphragm without bending or wrinkle to the diaphragm-type electrode with a simple operation.Used forDiaphragm cartridgeTheIs to provide.
[0026]
[Means for Solving the Problems]
  The above object is a diaphragm electrode according to the present invention.Used forDiaphragm cartridgeTheAchieved.
[0028]
  In summary, the firstMain departureClearlyAccording toA diaphragm cartridge that can be integrally attached to and detached from a diaphragm electrode; a first fixing member having an annular recess; a second fixing member having an annular protrusion adapted to the annular recess; the annular recess and the A diaphragm compressed and held on the annular projection;The first fixing member includes a large-diameter hole opened at one end, and a small-diameter hole that is smaller in diameter than the large-diameter hole and communicates with the large-diameter hole and opens on the opposite side of the large-diameter hole. An annular member in which the annular recess is formed in a shoulder formed between the large-diameter hole and the small-diameter hole; the second fixing member has a through-hole, and has one annular surface The annular protrusion is formed, and is an annular member that is press-fitted into the large-diameter hole of the first fixing member; and the diaphragm includes the large-diameter hole and the small-diameter of the first fixing member. Compressed and held by the annular recess and the annular projection so as to block the holeA diaphragm cartridge is provided..
[0029]
  BookSecond aspect of the inventionlikeAccording toA diaphragm cartridge that can be integrally attached to and detached from a diaphragm electrode; a first fixing member having an annular recess; a second fixing member having an annular protrusion adapted to the annular recess; the annular recess and the A diaphragm compressed and held on the annular projection;The first fixing member includes a large-diameter hole opened at one end, and a small-diameter hole that is smaller in diameter than the large-diameter hole and communicates with the large-diameter hole and opens on the opposite side of the large-diameter hole. An annular member in which the annular recess is formed in a shoulder formed between the large-diameter hole and the small-diameter hole; the second fixing member has a through-hole, and has one annular surface The annular convex portion is formed in the large-diameter hole of the first fixing member, and the annular convex portion is disposed so as to fit into the annular concave portion;The diaphragm cartridge isFurther, a through hole is screwed into the large-diameter hole of the first fixing member and presses the second fixing member arranged in the first fixing member against the first fixing member. An annular fixing assisting means; the diaphragm is compressed and held by the annular recess and the annular projection so as to block the large diameter hole and the small diameter hole of the first fixing member. RuA diaphragm cartridge is provided..
[0032]
  According to each embodiment of the present invention, the annular recess and the annular projection are formed concentrically with the first and second fixing members. or,According to each embodiment of the present invention, when the depth of the annular recess is h1, the height of the annular projection is h2, and the thickness of the diaphragm is t,
  h2 ≧ h1 + t
The relationship is established. According to the preferred embodiments of the present invention, tension is always applied to the diaphragm.
[0033]
According to one embodiment of the present invention, the diaphragm has a thickness of 20 μm or more and 300 μm or less.
[0034]
Furthermore, according to another embodiment of each of the present invention, the diaphragm includes at least a selective gas permeable membrane and a reinforcing body.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the diaphragm fixing method, diaphragm cartridge, and diaphragm electrode according to the present invention will be described in more detail with reference to the drawings.
[0036]
Example 1
In this embodiment, the present invention is applied to a diaphragm electrode used for measurement of dissolved oxygen in a culture tank, that is, a dissolved oxygen electrode for fermentation (hereinafter simply referred to as “dissolved oxygen electrode”).
[0037]
FIG. 7 shows an example of a dissolved oxygen electrode to which the diaphragm cartridge 1 according to the present invention can be attached and detached. First, the schematic configuration of the dissolved oxygen electrode according to this embodiment will be described. In this embodiment, the dissolved oxygen electrode 100 has a main body body 80 having a substantially cylindrical shape. A base 81 is attached. The body 80 and the electrode base 81 are made of a metal such as stainless steel (SUS316), for example. The electrode base 81 has an upper end sleeve-shaped portion 81a filled with epoxy resin, and a pin base 84 integrally formed with a plurality of pins 83 (83a, 83b) is attached to the upper end of the epoxy resin. The pin base 84 is attached to the electrode base 81 by a pin base presser 81 b that is screwed to the sleeve-shaped portion 81 a of the electrode base 81.
[0038]
The pin 83a is electrically connected to the electrode base 81 through a lead wire 86a. The other pin 83b is electrically connected to the jack terminal 88 of the socket 87 through a lead wire 86b, which will be described in detail later.
[0039]
An electrode body 90 is provided below the body 80. As will be described later, in this embodiment, the electrode body 90 is an electrode cartridge C that is detachable from the body 80, but the present invention is not limited to this.
[0040]
The electrode main body 90 has an elongated cylindrical shape, and is usually made of a metal such as stainless steel (SUS316), and an electrode support tube 91, and a glass holder (glass) mounted in a sleeve 91a below the electrode support tube 91. Holder) 92. An anode 93 made of lead is attached as a counter electrode to the outer peripheral portion of the lower end of the electrode support tube 91, and a cathode 94 made of platinum encapsulated in glass as a working electrode is attached to the lower end (tip) of the glass holder 92. Silver-silver chloride can also be used as the anode 93.
[0041]
At the upper end of the electrode support tube 91, a plug 85, which is integrally formed with a pin 85a and made of, for example, a fluororesin, is screwed. The pin 85 a is electrically connected to the cathode 94 through a lead wire 96 passed through the electrode support tube 91.
[0042]
A connecting tube 89 is disposed between the inner peripheral surface of the cylindrical body 80 and the electrode support tube 91. The connection pipe 89 is attached to the body 80 by screwing with the lower end of the body 80 at the upper end thereof. Further, the lower outer peripheral portion of the connection tube 89 and the upper inner peripheral portion of the outer cylinder 98 disposed on the outer periphery of the electrode support tube 91 are screwed together. As a result, the body 80 and the outer cylinder 98 are integrally connected via the connection pipe 89. The connecting pipe 89 and the outer cylinder 98 are made of a metal such as stainless steel (SUS316), for example. Further, a socket 87 formed of, for example, a fluororesin or the like, in which a jack 87a is integrally formed, is screwed to the inner peripheral portion of the upper end of the connection pipe 89. The jack 87a can be electrically connected to the pin 85a of the plug 85.
[0043]
In addition, the inner periphery of the upper end of the connection tube 89 and the outer periphery of the upper end of the electrode support tube 91 are screwed together.
Accordingly, the electrode support tube 91 is detachably attached to the body 80 via the connection tube 89.
[0044]
The upper end of the diaphragm cartridge fixing member 7 having a substantially cylindrical shape is screwed to the outer peripheral portion of the lower end of the outer cylinder 98 disposed on the outer periphery of the electrode support tube 91. With this diaphragm cartridge fixing member 7, the diaphragm cartridge 1 including the selective gas permeable diaphragm 4 that transmits at least the measurement target gas is mounted in the lower end opening 99 of the outer cylinder 98.
[0045]
That is, as shown in more detail in FIG. 8, in the dissolved oxygen electrode 100 of the present embodiment, a screw portion 98 a is formed on the outer peripheral portion of the lower end of the outer tube 98, and the upper portion of the substantially cylindrical diaphragm cartridge fixing member 7 is formed. A threaded portion 73 formed around the periphery is screwed together. The annular shoulder forming the edge of the lower opening 72 of the diaphragm cartridge fixing member 7 serves as an annular pressing portion 71 that holds the diaphragm cartridge 1 on the outer cylinder 98. An annular holding receiving portion 21 that is an annular notch provided on the outer periphery of the lower end of the outer ring 2 of the diaphragm cartridge 1 described later in detail is fitted into the annular pressing portion 71.
[0046]
When the diaphragm cartridge 1 is fixed to the lower end opening 99 of the outer cylinder 98, the diaphragm cartridge 1 is disposed in the lower end opening 99 of the outer cylinder 98, and the annular holding receiver 21 is an annular shape of the diaphragm cartridge fixing member 7. The diaphragm cartridge fixing member 7 is screwed to the lower end portion of the outer cylinder 98 so as to be fitted to the pressing portion 71. Thus, the diaphragm cartridge 1 in which the diaphragm 4 is properly stretched in advance is fixed to the lower end of the outer cylinder 98.
[0047]
By mounting the diaphragm cartridge 1, the diaphragm 4 seals the lower end opening 99 of the outer cylinder 98, the outer periphery of the electrode support tube 91, the glass holder 92 and the anode 93, the inner periphery of the outer cylinder 98, and the diaphragm 4. The internal liquid (electrolytic solution) E is stored in an annular space formed between the diaphragm cartridge 1 and the diaphragm cartridge 1. The internal liquid E comes into contact with the anode 93 and also comes into contact with the cathode 94 and the diaphragm 4 in a thin film shape so that the anode 93 and the cathode 94 are electrically connected. An O-ring 74 is disposed on the outer periphery of the lower end opening 99 of the outer cylinder 98, and seals the space in which the internal liquid E is stored after the diaphragm cartridge 1 is mounted.
[0048]
Next, with reference to FIG.1 and FIG.2, schematic structure of the diaphragm cartridge 1 which can be attached or detached to the dissolved oxygen electrode 100 of a present Example is demonstrated.
[0049]
In the diaphragm cartridge 1 of this embodiment, as shown in FIG. 1, the diaphragm 4 is sandwiched and fixed by an outer ring 2 as a first fixing member and an inner ring 3 as a second fixing member. As shown in more detail in FIG. 2, the outer ring 2 of the diaphragm cartridge 1 includes a large-diameter inner peripheral surface 24, and includes a large-diameter hole 22 opened on the upper side in the figure and a small-diameter inner peripheral surface 25. And a small diameter hole 23 communicating with the large diameter hole 22 to form an annular member penetrating the substantially disk-shaped member. Thus, an annular shoulder 26 is formed between the large diameter hole 22 and the small diameter hole 23. Further, an annular holding receiving portion 21 having a shape in which an edge is cut out in an annular shape is formed on the outer periphery on the lower side of the outer ring 2 in the drawing. As described above, the annular holding portion 21 of the cartridge fixing member 7 is engaged with the annular holding portion 71.
[0050]
The inner ring 3 has a disk-shaped member by a through hole 31 having an outer diameter substantially the same as the diameter of the large-diameter hole 22 of the outer ring 2 and slightly smaller than the diameter of the small-diameter cylindrical hole 23 of the outer ring 2. The annular member penetrated.
[0051]
Although not limited, the outer ring 2 can be made of metal. In this embodiment, it is made of stainless steel (SUS316). Moreover, the inner ring 3 is not limited, but is manufactured using polysulfone resin in this embodiment. The inner ring 3 can be made of a metal such as stainless steel in the same manner as the outer ring 2.
[0052]
More specifically, in this embodiment, the inner diameter of the large diameter hole 22 of the outer ring 2 is 12.1 mm, and the inner diameter of the small diameter hole 23 is 8.2 mm. The inner ring 3 has an outer diameter of 12.2 mm, and the through hole 31 has an inner diameter of 7.8 mm. Further, the height of the large-diameter hole 22 of the outer ring 2 is 2 mm, and the diaphragm cartridge 1 formed by the outer ring 2 and the inner ring 3 in a state where the diaphragm 4 is fixed by the inner ring 3 as will be described in detail later. The height of the inner ring 3 is set so that the upper surface is substantially coplanar.
[0053]
  When the diaphragm 4 is fixed by the outer ring 2 and the inner ring 3, the diaphragm 4 is cut into a substantially circular shape having substantially the same diameter as the inner diameter of the large-diameter hole 22 of the outer ring 2, and the annular shoulder 26 of the outer ring 2 is cut. Place. Then outside~ sideInside the large-diameter hole 22 of the ring 2~ sidePress-fit the ring 3.
[0054]
In the diaphragm cartridge 1 of the present embodiment, an annular recess 27 having a circular shape in plan view is provided on the upper surface 26a of the annular shoulder portion 26 of the outer ring 2 at the approximate center in the width direction of the annular shoulder portion upper surface 26a. Further, one annular surface (lower surface in the drawing) 34 of the inner ring 3 is provided with an annular convex portion 35 having a circular shape in plan view, which fits the annular concave portion 27 provided in the outer ring 2.
[0055]
When fixing the diaphragm 4, the diaphragm 4 cut out to a predetermined size is placed on the annular shoulder 26 of the outer ring 2, and the inner ring 3 is inserted into the large-diameter side cylindrical hole 22 of the outer ring 2. The diaphragm 4 is compressed in a linear (annular) compression region formed by the annular concave portion 27 of the outer ring 2 and the annular convex portion 35 of the inner ring 3. Thus, the large-diameter inner peripheral surface 24 of the outer ring 2 and the outer peripheral surface 33 of the inner ring 3 are frictionally engaged, and the diaphragm 4 is held by the annular concave portion 27 and the annular convex portion 35. The two large diameter holes 22 and the small diameter holes 23 are stretched so as to be blocked.
[0056]
Further explanation will be given with reference to FIG. 3. The diaphragm 4 has an annular recess 27 provided in the outer ring 2 and an annular protrusion provided in the inner ring in a state where the inner ring 3 is fitted into the outer ring 2. The compression is performed only in the linear (annular) region (compression region) P facing the portion 35. In regions (non-compressed regions) S, S located across the compression region P in the width direction of the annular shoulder 26, the diaphragm fixing side surface 34 of the inner ring 3 is in contact with the diaphragm 4, and is not compressed. .
[0057]
In order to achieve such conditions, the relationship between the depth h1 of the annular recess 27 provided in the outer ring 2, the height h2 of the annular projection 35 provided in the inner ring 3, and the thickness t of the diaphragm 4 is
h2 ≧ h1 + t
It is preferable that
[0058]
However, the diaphragm 4 is substantially compressed and fixed only in the compression region P. When the diaphragm 4 is fixed, the diaphragm 4 is not prevented from entering the region P, and plastic deformation of the diaphragm 4 is prevented. The diaphragm 4 may be held in the region S as long as it does not occur.
[0059]
Thus, by making the area | region which compresses the diaphragm 4 with the outer side ring 2 and the inner side ring 3 linear (annular), the area to which the diaphragm 4 is compressed can be minimized. Thereby, it is possible to prevent the diaphragm 4 from being plastically deformed and extending toward the inside of the diaphragm cartridge 1, that is, toward the center of the diaphragm cartridge 1 indicated by a one-dot chain line in FIG. 3. It is possible to prevent the diaphragm 4 from being bent and wrinkled.
[0060]
Further, with the configuration of this embodiment, when the annular convex portion 35 of the inner ring 3 presses the diaphragm 4 against the annular concave portion 27 of the outer ring 2, the diaphragm 4 enters the annular concave portion 27. As a result, the tension toward the outside from the center of the diaphragm cartridge 1 acts uniformly on the circular diaphragm 4 (in the direction of the arrow in FIGS. 3 and 4), and the diaphragm 4 can be in a uniform stretched state.
[0061]
  The diaphragm 4 usually has an appropriate stretchability, and the diaphragm cartridge 1 of this embodiment in which the diaphragm 4 is stretched in a uniform stretched state is attached to the outer cylinder by the diaphragm cartridge fixing member 7.98 is attached to the cathode, while the diaphragm 4 is slightly stretched.94 is completely adhered. Since the diaphragm 4 is bent and stretched without wrinkles in the diaphragm cartridge 1 of the present embodiment, the diaphragm cartridge fixing member (cap nut) 7 prevents wrinkles from being generated in the diaphragm 4 when the diaphragm cartridge 1 is mounted. It is not necessary to finely adjust the tightening by the respective dissolved oxygen electrodes 100.
[0062]
Of course, since the thickness of the diaphragm 4 varies, the present invention does not limit the depth h1 of the annular recess 27 provided in the outer ring 2 and the height h2 of the annular projection 35 provided in the inner ring 3. However, by adjusting appropriately, it can be applied to the diaphragm 4 having any thickness from the thin diaphragm 4 to the thick diaphragm 4.
[0063]
As an example, when using a diaphragm 4 (product number OCT-5011 manufactured by Toa Denpa Kogyo Co., Ltd.) made of FEP (tetrafluoroethylene-hexafluoropropylene copolymer) having a thickness t of 50 μm, the outer ring 2 The depth h1 of the annular recess 27 provided on the inner ring 3 is 150 μm, and the height h2 of the annular projection 35 provided on the inner ring 3 is 200 μm, so that the present invention preferably operates and is uniform in a state free from bending and wrinkling. The diaphragm 4 could be stretched around the diaphragm cartridge 1.
[0064]
For example, the present invention can be applied to the case where a thick diaphragm 4 having a selective gas permeable membrane and a reinforcing body is used. As an example, as shown in FIG. 13B, a gas selective permeation layer 4a (thickness 50 μm) manufactured by FEP and a reinforcing layer 4b (thickness) in which a stainless steel mesh 4c is coated with a silicon resin 4d as a reinforcing body. And a diaphragm 4 (product number OCA00002 manufactured by Toa Denpa Kogyo Co., Ltd.) having a thickness t of 150 μm was used. In this case, when the depth h1 is 150 μm and the height h2 is 300 μm, the present invention preferably works. Similarly to the case where the thin diaphragm 4 is used, the diaphragm 4 is uniformly distributed without bending or wrinkling. The cartridge 1 could be stretched.
[0065]
The present invention can be applied without being particularly limited to the thickness of the diaphragm 4. For example, it is suitable for fixing a diaphragm 4 for a diaphragm electrode generally having a thickness of 5 μm to 500 μm. In particular, compression by a flat portion has been conventionally performed, such as a diaphragm 4 having a selective gas permeable membrane layer having a thickness of about 10 μm to 100 μm and a reinforcing layer having a reinforcing body and a thickness of about 100 μm to 200 μm. This is effective for fixing a relatively thick diaphragm 4 having a thickness of 20 μm or more and 300 μm or less, which is easy to cause plastic deformation.
[0066]
  As described above, in the diaphragm cartridge 1 of this embodiment, the area where the diaphragm 4 is compressed by the outer ring 2 and the inner ring 3 is linear, and the diaphragm 4 is directed outward from the center.USince the outer ring 2 and the inner ring 3 are nipped and fixed so that the tension works, the diaphragm 4 can be uniformly stretched on the diaphragm cartridge 1 without bending and wrinkling, RegularIntervalThe diaphragm cartridge 1 on which the membrane is stretched can be attached to the diaphragm electrode 100. Thereby, the adhesion between the diaphragm 4 and the cathode 94 is always kept good by exchanging the diaphragm cartridge 1, the current sensitivity and stability of the dissolved oxygen electrode 100 are extremely good, and the quality of the electrode 100 is stabilized.
[0067]
Example 2
Next, another embodiment of the diaphragm cartridge that can be attached to and detached from the dissolved oxygen electrode 100 described in Embodiment 1 will be described. For the explanation of the dissolved oxygen electrode 100, the explanation in Example 1 is used. Elements having the same functions and configurations as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
[0068]
In the above-described first embodiment, the diaphragm 4 is described as being fixed by the outer ring 2 and the inner ring 3 press-fitted into the large-diameter hole 22 of the outer ring 2, but the present invention is not limited to this. It is not something.
[0069]
As shown in FIG. 5A, in this embodiment, a diaphragm fixing washer ring 5 having an annular projection 55 for fixing the diaphragm 4 is used as the second fixing member, and the outer ring 3 has a large diameter. A diaphragm fixing ring screw 6 is used as a fixing auxiliary means that is screwed into the hole 22 and presses the washer ring 5 against the outer ring 3.
[0070]
Further description will be made with reference to FIG. 5B. The large-diameter inner peripheral surface 24 of the large-diameter hole 22 of the outer ring 2 that is substantially the same as that of the first embodiment includes a screw portion 28. The diaphragm fixing washer ring 5 has a through hole 51 having an outer diameter slightly smaller than the diameter of the large diameter hole 22 of the outer ring 2 and an inner diameter slightly smaller than the inner diameter of the small diameter cylindrical hole 23 of the outer ring 2. .
The diaphragm fixing ring screw 6 has, on the lower outer peripheral surface 63 thereof, a screw portion 65 that engages with a screw portion 28 provided on the large-diameter inner peripheral surface 24 of the large-diameter hole 22 of the outer ring 2. Yes. Similarly to the washer ring 5, the ring screw 6 has a through hole 61 having a diameter slightly smaller than the diameter of the small diameter hole 23 of the outer ring 2.
[0071]
According to the present embodiment, the outer ring 2 has the annular recess 27 on the upper surface 26 a of the annular shoulder 26, as in the first embodiment. Further, the diaphragm fixing washer ring 5 is provided with an annular convex portion 55 corresponding to the annular concave portion 27 provided in the outer ring 2 on one annular surface (lower surface in the figure) 54.
[0072]
When the diaphragm 5 is fixed, the diaphragm 4 is cut into a substantially circular shape having the same diameter as the large-diameter hole 22 of the outer ring 2 and placed on the annular shoulder 26 of the outer ring 2. Next, the washer ring 5 for securing the diaphragm is placed on the diaphragm 4 at a position where the annular protrusion 55 matches the annular recess 27 of the outer ring 2. Thereafter, the diaphragm fixing ring screw 6 is screwed into the large-diameter hole 28 of the outer ring 2. Accordingly, the diaphragm fixing washer 5 is pressed toward the outer ring 2, and the diaphragm 4 is sandwiched and fixed by the annular convex portion 55 of the washer 5 and the annular concave portion 27 of the outer ring 2. As a result, as in the first embodiment, the diaphragm 4 is substantially compressed only in the linear (annular) compression region formed by the annular concave portion 27 and the annular convex portion.
[0073]
Also in this embodiment, preferably, the relationship between the depth h1 of the annular recess 27, the height h2 of the annular projection, and the thickness t of the diaphragm 4 is
h2 ≧ h1 + t
And
[0074]
  As described above, also in the configuration of the present embodiment, the region where the diaphragm 4 is compressed is linear, and the diaphragm 4 is directed outward from the center.USince the tension is fixed so as to work, the same effect as in the first embodiment can be obtained.
[0075]
Example 3
In each of the above-described embodiments, the diaphragm fixing method of the present invention is embodied in a diaphragm cartridge. As described above, when the diaphragm for replacement of the diaphragm electrode is formed into a cartridge, the operability for mounting the diaphragm is remarkably improved. However, the principle of the present invention can be applied to a diaphragm type electrode other than the diaphragm cartridge type. Next, several embodiments in which the diaphragm fixing method according to the present invention is applied to a diaphragm type electrode other than the diaphragm cartridge type will be described. In addition, about the whole structure of the diaphragm type electrode 100, the description in Example 1 is used, and the same code | symbol is attached | subjected to the element which has the same structure and function, and detailed description is abbreviate | omitted.
[0076]
As shown to Fig.6 (a), the fixing ring 120 provided with the cyclic | annular recessed part 127 is used as a 1st fixing | fixed part of the structure similar to the outer side ring 2 (FIG. 2) in Example 1. FIG. In addition, as a second fixing portion that performs substantially the same function as the inner ring 3 (FIG. 2) described in the first embodiment, an edge portion 99a of the lower end opening 99 of the outer cylinder 98 is used, and this edge portion 99a. An annular projection 130 is provided on the surface. The fixing ring 120 is fitted to the edge 99a in the same manner as the relationship between the outer ring 2 and the inner ring 3 in the first embodiment. Then, a ring fixing member 170 having the same configuration as that of the diaphragm cartridge fixing member 7 (FIG. 8) in the first embodiment is screwed through a screw portion 98a provided on the outer peripheral surface of the lower end portion of the outer cylinder 98. The annular holding receiving portion 121 of the fixing ring 120 and the annular pressing portion 171 of the ring fixing member 170 are fitted, and the fixing ring 120 is fixed to the lower end of the outer cylinder 98.
[0077]
  When the diaphragm 4 is fixed, for example, the diaphragm 4 cut out to an appropriate size is disposed on the annular shoulder upper surface 126a of the fixing ring 120, and the fixing ring 120 is fitted to the edge 99a. The fixing member 170 is screwed to the lower end portion of the outer cylinder 98. Accordingly, the annular recess 127 provided on the upper surface 126a of the annular shoulder 126 of the fixing ring 120 and the annular protrusion 13 provided on the edge 99a.0Thus, the diaphragm 4 can be pinched and fixed.
[0078]
Alternatively, as shown in FIG. 6 (b), as a fixing auxiliary means having the same function as that of the diaphragm fixing ring screw 6 (FIG. 5b) described in the second embodiment, a lower portion of the outer cylinder 98 is provided. The edge 99a of the end opening 99 is used. Further, as the first fixing portion, the same structure as that of the outer ring 2 (FIG. 5b) in the second embodiment is used, and the fixing ring 120 provided with the annular recess 126 is used, and the second fixing portion is used in the second embodiment. The diaphragm fixing washer ring 150 having the same configuration as that of the diaphragm fixing washer ring 5 and having an annular convex portion 155 is used. A screw portion 128 is provided on the inner peripheral surface 124 on the large diameter side of the fixing ring 120, and a screw portion 163 that is screwed to the screw portion 128 is provided on the outer peripheral portion of the lower end of the outer cylinder 98.
[0079]
When the diaphragm 4 is fixed, for example, the diaphragm 4 cut out to an appropriate size is arranged on the annular shoulder upper surface 126a of the fixing ring 120, and the diaphragm fixing washer ring 150 is formed on the annular recess 127 and the annular recess 127. It arrange | positions so that the convex part 155 may fit. Next, the lower end edge 99a of the outer cylinder 98 and the fixing ring 120 are screwed together. Thereby, the diaphragm can be pinched and fixed by the annular concave portion 127 and the annular convex portion 155.
[0080]
  Thus, even when the principle of the present invention is applied to a diaphragm electrode other than the diaphragm cartridge removable type, the region for compressing the diaphragm 4 is linear. Furthermore, the diaphragm 4 is directed outward from the center.USince it is compressed and held so that tension acts, the diaphragm 4 can be stretched uniformly in a state without bending or wrinkling. As a result, the current sensitivity and stability of the diaphragm electrode 100 of this embodiment are extremely good, and the quality of the diaphragm electrode 100 is stabilized.
[0081]
In each of the above-described embodiments, the present invention has been described on the assumption that the diaphragm electrode is a dissolved oxygen electrode for fermentation (dissolved oxygen electrode). However, the present invention is not limited to this, for example, free residual Electrode for measuring chlorine concentration, electrode for measuring dissolved ozone concentration, electrode for measuring dissolved chlorine dioxide concentration, chlorous acid (HClO₂) It can be suitably embodied in a concentration measurement electrode, a dissolved hydrogen concentration measurement electrode, an ammonia concentration measurement electrode, and the like.
[0082]
【The invention's effect】
  As explained above, the present inventionAccording toThe diaphragm used for the diaphragm electrode can be uniformly stretched without bending or wrinkling. Further, according to the present invention, even when a thicker diaphragm is used, the diaphragm can be uniformly stretched without bending or wrinkling. Furthermore, according to the present invention, the diaphragm without deflection and wrinkle can be attached to the diaphragm electrode by a simple operation.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an embodiment of a diaphragm cartridge according to the present invention.
FIG. 2 is an exploded cross-sectional view of the diaphragm cartridge of FIG.
3 is an enlarged cross-sectional view of a diaphragm fixing portion in the diaphragm cartridge of FIG. 1. FIG.
4 is a plan view of the diaphragm cartridge for explaining the tension applied to the diaphragm in the diaphragm cartridge of FIG. 1. FIG.
5A is a sectional view of another embodiment of the diaphragm cartridge according to the present invention, and FIG. 5B is an exploded sectional view thereof.
FIGS. 6A and 6B are enlarged cross-sectional views showing another embodiment of the diaphragm fixing portion of the diaphragm electrode according to the present invention.
FIG. 7 is a cross-sectional view showing a schematic configuration of an embodiment of a diaphragm electrode according to the present invention.
8 is a cross-sectional view showing in more detail a diaphragm fixing part of the diaphragm type electrode of FIG. 7;
FIG. 9 is an enlarged cross-sectional view of a diaphragm fixing portion for explaining an example of a diaphragm fixing method in a conventional diaphragm electrode.
FIG. 10 is an enlarged sectional view of a diaphragm fixing portion for explaining another example of a diaphragm fixing method in a conventional diaphragm electrode.
11A is a sectional view showing an example of a conventional diaphragm cartridge, and FIG. 11B is an exploded sectional view thereof.
12 is a cross-sectional view showing in more detail a diaphragm fixing part of the diaphragm cartridge of FIG. 11. FIG.
FIG. 13 is a diagram showing a schematic configuration of a diaphragm type electrode using a diaphragm having (a) a normal diaphragm and (b) a reinforcing body, respectively.
[Explanation of symbols]
1 Diaphragm cartridge
2 Outer ring (first fixing member)
3 Inner ring (second fixing member)
4 diaphragm
5 Diaphragm fixing washer ring (second fixing member)
6 Diaphragm fixing ring screw (fixing auxiliary means)
7 Diaphragm cartridge fixing member
22 Large diameter hole
23 Small hole
26 Annular shoulder
27 Annular recess
35 Annular convex
55 Annular projection
80 Body
90 Electrode body
91 Electrode support
92 Glass holder
93 Anode
94 Cathode
98 outer cylinder
100 Dissolved oxygen electrode (diaphragm electrode)
E Internal solution (electrolyte)
P compression area
S Uncompressed area

Claims (7)

A diaphragm cartridge that can be integrally attached to and detached from the diaphragm electrode,
A first fixing member having an annular recess;
A second fixing member having an annular protrusion that fits into the annular recess;
A diaphragm compressed and held in the annular recess and the annular projection;
Have
The first fixing member includes a large-diameter hole opened at one end, and a small-diameter hole that is smaller in diameter than the large-diameter hole and communicates with the large-diameter hole and opens on the opposite side of the large-diameter hole. An annular member in which the annular recess is formed in a shoulder formed between the large-diameter hole and the small-diameter hole;
The second fixing member is an annular member having a through hole, the annular convex portion is formed on one annular surface, and press-fitted into the large-diameter hole of the first fixing member,
The diaphragm, the first of the large-diameter hole and the small-diameter hole and septum membrane cartridge wherein the annular recess and said being held in compression in the annular projection to interrupt you, wherein the fixing member . A diaphragm cartridge that can be integrally attached to and detached from the diaphragm electrode,
A first fixing member having an annular recess;
A second fixing member having an annular protrusion that fits into the annular recess;
A diaphragm compressed and held in the annular recess and the annular projection;
Have
The first fixing member includes a large-diameter hole opened at one end, and a small-diameter hole that is smaller in diameter than the large-diameter hole and communicates with the large-diameter hole and opens on the opposite side of the large-diameter hole. An annular member in which the annular recess is formed in a shoulder formed between the large-diameter hole and the small-diameter hole;
The second fixing member has a through hole, the annular convex portion is formed on one annular surface, and the annular convex portion is formed in the annular concave portion in the large-diameter hole of the first fixing member. An annular member arranged to fit,
The diaphragm cartridge is further screwed into the large-diameter hole of the first fixing member, and presses the second fixing member disposed in the first fixing member against the first fixing member. , Having an annular fixing auxiliary means having a through hole,
The diaphragm, the first of the large-diameter hole and the small-diameter hole and septum membrane cartridge wherein the annular recess and said being held in compression in the annular projection to interrupt you, wherein the fixing member . The diaphragm cartridge according to claim 1 or 2, wherein the annular recess and the annular projection are formed concentrically with the first and second fixing members. When the depth of the annular recess is h1, the height of the annular projection is h2, and the thickness of the diaphragm is t,
h2 ≧ h1 + t
The diaphragm cartridge according to any one of claims 1 to 3 , wherein the relationship is established. The diaphragm cartridge according to any one of claims 1 to 4 , wherein tension is always applied to the diaphragm. The diaphragm cartridge according to any one of claims 1 to 5 , wherein the diaphragm has a thickness of 20 µm or more and 300 µm or less. The diaphragm cartridge according to any one of claims 1 to 6 , wherein the diaphragm includes at least a selective gas permeable membrane and a reinforcing body.

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