JPH10307100A - Moisture adsorbing device for moisture meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the moisture content measuring accuracy and operability of a moisture meter. SOLUTION: A moisture meter is provided with a heating section which heats a sample to be measured by introducing a carrier gas, a moisture adsorbing section which adsorbs vaporized moisture from the carrier gas flowing out of the heating section, and an electronic balance section which detects the increased mass of the moisture adsorbing section. The moisture adsorbing section has a base 5b to which a carrier gas introducing tube 5a is connected and a cell main body 5d filled up with an adsorbent 5c which adsorbs the vaporized moisture and the base 5c is attached to the weighing arm 6a of the electronic balance section. In addition, the base 5b has a conical projection 5g which is put in the recessed section 5h of the cell main body 5d. A cap 5j is put on the cell main body 5d and the cap 5j has a plurality of exhaust ports 5k which are symmetrically arranged in the horizontal direction. The cap 5j is put on the cell main body 5d by putting the conical projection 5n on the bottom of the cap 5j in the recessed section 5m on the top of the main body 5d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a moisture adsorption device for a moisture meter. More specifically, the present invention relates to a moisture adsorbing device for a moisture meter which prevents external force from being applied to a measuring arm of an electronic balance for measuring the amount of moisture in a measurement sample when an adsorbent for collecting vaporized moisture is replaced.

[0002]

2. Description of the Related Art The Karl Fischer method (KF method) has been widely known as a high-precision water determination method for measuring the amount of water in a solid or liquid. KF method is iodine,
The method utilizes the fact that a Karl Fischer reagent containing sulfur dioxide, pyridine, and methanol reacts quantitatively with water. However, in the measurement of the water content by the KF method, various corrections are required depending on an object to be measured, and considerable skill is required to obtain an accurate water content. In addition, there is a problem that a special reagent or a glass container is required in the measurement.

In order to solve the above problems, a heat-drying type moisture meter has been developed. Such a heat-drying type moisture meter is, for example, as disclosed in Japanese Patent Application Laid-Open No. 7-12696, in which a gas inlet for generating a carrier gas and a carrier gas are introduced from the gas inlet. A heating unit that heats the device under test, and a moisture collection unit that collects vaporized moisture from a carrier gas derived from the heating unit,
An electronic balance unit for detecting the increased mass of the water collecting unit is provided, and the object to be measured is heated to vaporize the water in the object to be measured, and the vaporized water is collected and measured. It has the function of measuring the water content of the measured object. Here, as the moisture collecting device for such a moisture meter, one in which a carrier gas introduction tube is directly connected to a cell filled with an adsorbent has been used. However, when the carrier gas introduction tube is directly connected to the cell main body as described above, there is a problem that the measured value of the electronic balance fluctuates because the tube is twisted when the filler is replaced.

Therefore, in order to make it possible to exchange the adsorbent without affecting the tube for introducing the carrier gas, recently, as described in Japanese Patent Application Laid-Open No. Hei 7-12697, the adsorbent has to be replaced via a cell table. There has been proposed a moisture adsorbing device in which a tube and a cell main body are communicated and installed. According to such a moisture adsorption device, when the adsorbent is replaced, the cell body is separated from the cell table, the adsorbent of the cell body is replaced, and the cell body may be installed again in communication with the cell table. Although it was possible to solve the problems such as the twisting of the resulting tube and to improve the measurement efficiency, it was very effective. However, such a moisture adsorption apparatus also had the following problems.

[0005]

That is, in the moisture adsorbing device, shutting off the outside air moisture is an essential requirement for improving the measurement accuracy, but in the above moisture adsorbing device, it is necessary to satisfy such requirements. Then, the cell base and the cell main body, and the cell main body and the cap were mounted by fastening with packings (O-rings) installed in a plurality of stages. However, with such a mounting means, a large load is applied to the weighing arm of the electronic balance when the cap or the cell body is attached or detached, and as a result, the weighing value of the electronic balance fluctuates, or the electronic balance itself is damaged. Sometimes it happened. Furthermore, since the conventional cell body is made of stainless steel, there is a problem that contamination of the adsorbent and replacement time cannot be confirmed.

In view of the above, the present invention is not only configured so that the cell body can be simply separated from the cell table to which the carrier gas introduction tube is connected, but also has a large size on the weighing arm of the electronic balance when attaching or removing the cap or the cell body. An object of the present invention is to provide a moisture adsorbent for a moisture meter that is configured not to be loaded.

[0007]

In order to achieve the above object, the present invention is to vaporize moisture in a measurement sample by heating, carry it with a carrier gas, and collect and detect only the vaporized moisture. A moisture adsorbing device for a moisture meter for measuring the amount of water in a measurement sample, which is connected to a measuring arm of an electronic balance for measuring the amount of water in the measurement sample, and connected to a tube for introducing the carrier gas. A table and a cell body filled with an adsorbent that collects only the vaporized water,
It has a cap for closing the cell main body, and the base and the cell main body, and the cell main body and the cap are mounted and connected to each other by fitting conical irregularities. (Claim 1)

It is preferable that the cell body is set so that the outside air can be shut off only by rotating the cap. (Claim 2) Further, it is preferable that the cell body is filled with an adsorbent whose color changes according to the water collection amount (Claim 3). In this case, the cell body is made of transparent glass. It is desirable to be made. (Claim 4)

[0009]

According to the moisture adsorbing device of the present invention, the base to which the carrier gas introduction tube is connected, the cell main body, and the cell main body and the cap are mounted only by fitting the conical irregularities. , The load is hardly applied to the weighing arm when the cell body and the cap are attached and detached. Further, in the cell body of the present invention, since it is set so that the outside air can be shut off by simply rotating the cap,
Even during such rotation, no load is applied to the measuring arm. Further, in the present invention, since the color of the adsorbent filled in the cell main body changes depending on the amount of water collected, the replacement time of the adsorbent can be determined based on the change in color, and the cell main body is made of glass. Therefore, such a change in color can be confirmed from outside the cell.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 is an embodiment using a moisture adsorption device for a moisture meter according to the present invention, and is a path and a functional block diagram of a fluid system in a moisture meter to which the moisture adsorption device of the present invention is applied. In this figure, 1 is a control section for controlling the carrier gas, 2 is a branch section for dividing the controlled carrier gas in two directions, and 3 is a heating section for introducing the carrier gas from the branch section 2 and heating and drying the measurement sample. Reference numeral 4 denotes a filter unit for removing vaporized moisture and gas generated by heating flowing out of the heating unit 3 and a carrier gas other than the vaporized moisture, and 5 denotes a carrier gas for carrying vaporized moisture discharged from the filter unit 4. A moisture adsorbing unit (moisture adsorbing device) for adsorbing only vaporized moisture from the water, an electronic balance unit 6 for detecting the increased mass of the moisture adsorbing unit 5, and drying the moisture in the carrier gas before the control unit 1 if necessary. A dry unit 1c is provided. The measuring arm 6a of the electronic balance section 6 is provided with a water mass detecting section 6c and a measuring sample measuring section 6b, so that not only the mass of vaporized water but also the mass of the measuring sample itself can be measured. The tube through which the carrier gas or the like flows is preferably made of Teflon.

The control unit 1 detects a flow rate of the carrier gas sent to the heating unit and a needle valve 1a for adjusting the flow rate of a carrier gas composed of an inert gas such as nitrogen or helium or dry air obtained by drying air. And a flow sensor 1b.
When dry air obtained by drying air is used as a carrier gas, a dry unit 1c is provided in a stage preceding the needle valve 1a.

The branch 2 is not always necessary in the moisture meter of the present invention. However, the carrier 2 accurately feeds the carrier gas to the surface of the measurement sample and completely absorbs vaporized moisture and the like.
In order to carry the carrier gas, it is preferable that the carrier gas is branched into at least two directions, preferably two or three directions, and introduced into the heating unit 3.

FIG. 2 is a sectional view of the moisture adsorbing section 5, and FIG. 3 is a perspective view showing a state in which the moisture adsorbing section 5 is attached to the measuring arm 6a. The moisture adsorbing section 5 has a table 5b to which a carrier gas introduction tube 5a is connected, and a cell body 5d filled with an adsorbent 5c for adsorbing vaporized moisture. The base 5b is provided with a connector 5e for mounting the tube 5a, a hole 5f, and a conical protrusion 5g, and the conical protrusion 5g is fitted to the cell body 5d. The base 5 b having the protrusion 5 g is attached to the measuring arm 6 a of the electronic balance 6. The cell body 5d has a recess 5h for fitting with the conical projection 5g, and is attached to the base 5b. Further, a disk 5i made of Teflon is attached to the cell body 5d, and a hole is made in the disk 5i made of Teflon so that carrier gas can flow into the cell body 5d. A cap 5j is mounted on the upper part of the cell body 5d. The cap 5j is provided with a plurality of discharge ports 5k arranged symmetrically in the horizontal direction, and is configured to communicate with a discharge port 5o provided in the recess 5m in the upper part of the main body. Note that the outlet 5o is preferably attached so as to be perpendicular to the carrier gas introduction tube 5a. The cap 5j and the cell main body 5d are attached by fitting the upper concave part 5m of the main body and the conical projection 5n at the lower part of the cap 5j. FIG. 4 is a diagram showing the state of the moisture adsorbing part at the time of measurement and at the time of non-measurement. The communication between the outlet 5k of the cap 5j and the outlet 5o of the recess 5m in the upper part of the main body is performed by rotating the cap 5j (90 (Degree direction), and as a result, the outflow of the carrier gas and the shutoff of the outside air can be easily performed. Thus, the cell body 5
d can be attached to the platform 5b or the cap 5j only by fitting the conical irregularities alone, and the tube 5a is attached to the platform 5b. Without applying external force, damage to the electronic balance can be prevented. The materials of the cell body 5d and the adsorbent 5c are not particularly limited, but the cell body 5d is desirably made of glass to facilitate determination of the replacement time of the adsorbent, and the adsorbent 5c is made of water. Those having the property that the color changes depending on the collection amount are preferable. Among such adsorbents 5c, molecular sieves are more preferable, and the most preferable one is molecular sieve 3A. Here, it is preferable that the material of the projections 5g and 5n of the base 5b and the cap 5j is made of Teflon in terms of ease of removal and adhesion.

FIGS. 5 to 8 are views showing the heating unit 3 and the holder 4a of the filter unit 4. FIG. here,
5 and 6 are cross-sectional views of the heating unit 3 and the holder 4a of the filter 4. The heating unit 3 includes a vertically arranged hollow cylindrical heating tube 3a. Are provided with a carrier gas inlet 3b and a carrier gas outlet 3c communicating with the filter section 4. Further, a heater is vapor-deposited on the outer periphery of the heating tube 3a, and it is preferable that the heating tube 3a and the heater to be vapor-deposited are transparent so that the state inside the heating tube 3a can be easily checked. The heating tube 3a is preferably made of glass from the viewpoint of heat resistance and the like. The carrier gas inlet 3b
Is not necessarily two directions, but may be one direction. However, when the carrier gas is branched by the branch part 2 as described above, an inlet is provided according to the number of branches. Further, it is desirable that a connecting portion between the carrier gas inlet 3b and the Teflon tube is a nylon tube. Further, as shown in FIGS. 5 and 6, a sealing material 3d is attached to a lower portion of the heating tube 3a along a bottom section 3e of the heating tube. Here, the material of the sealing material 3d is not particularly limited as long as it is heat-resistant and does not absorb moisture. However, a fluorine-based material having excellent heat resistance and adhesion and no absorption of moisture is used. Is preferred. FIG. 5 shows a state of the heating unit at the time of non-measurement, and the bottom of the heating tube 3a is sealed with a heating tube lid 3f. The projection 3g is provided on the circumference of the heating tube cover 3f, and the projection 3g pushes up the sealing material 3d at the time of joining, so that the heating tube can be sealed. On the other hand, FIG. 7 is a cross-sectional view of the heating unit 3 and the filter 4 at the time of measurement. A sample dish 3h is installed at the bottom of the heating tube 3a, and the flange 3i of the sample dish 3h pushes up the sealing material 3d. In addition, the heating tube can be hermetically sealed in the same manner as when no measurement is performed.

When measuring the measurement sample, first, the heating tube cover 3f slightly moves in the direction of arrow A, and then moves in the direction of arrow B. In this state, if the heating tube is heated and the carrier gas is allowed to flow, the entry of the outside air can be blocked by the pressure difference between the inside and the outside, so that the measurement sample can be inserted without being affected by the outside humidity. .
Next, the sample dish 3h is pushed up in the direction of arrow C, and the flange portion 3i of the sample dish 3h comes into close contact with the sealing material 3d below the heating tube 3a.

FIG. 8 is a view showing pushing up of the sample dish 3h. Here, the push-up of the sample dish 3h is performed by the push-up shaft 3j. The push-up shaft 3j is attached to the disk 3p by a screw 3o, and the disk 3p has a structure that can be moved up and down by rotation of the screw 3q. The shaft 3j includes a base shaft 3k, a shaft 3m that slides inside the base shaft 3k, and a spring 3n. By having the spring 3n, the shaft 3j can be set so that the load required for sealing is applied to the sample dish even if the stopping accuracy of the pushing position varies, and when the pushing pressure is to be increased, The pressure can be easily changed by changing the length of the screw 3o.

FIG. 9 is a sectional view of the filter section 4.
In this figure, the filter 4 has a holder 4a, an insertion portion 4b, a filter body 4c, and activated carbon 4d filled in the filter body 4c. Filter body 4
c has a hole 4e communicating with the insertion portion 4b, and a mesh plate 4f is provided at the bottom of the filter body 4c. A heater 4q is deposited on the outer periphery of the holder 4a. The material of the holder 4a and the heater 4q is preferably made of glass from the viewpoint of facilitating checking of the filter for contamination. In addition, in order to enable highly accurate measurement, it is preferable to change the activated carbon every day.
A lid 4g is provided above the holder 4a, and a tube joint 4o and a tube 4p for passing a carrier gas are provided above the lid 4g. The replacement of the filter main body is performed as shown in FIG. 10, and the fixing of the filter main body 4c by attaching the holder 4a and the lid 4g is performed, as shown in FIG.
By engaging the lead grooves 4i provided on the side surfaces of the first and second members. By adopting such a fixing method, the filter body 4c can be replaced very easily.
When removing the lid 4g at the time of replacement,
Is not twisted, so there is no pain due to cracks etc. due to twisting of the surface of the tube 4p, and the tube 4p is covered with a lid 4g.
The lid 4g can be removed from the holder 4a while being attached to the, and the workability is greatly improved. 4g of lid
Has a groove 4k for mounting the O-ring 4j. The upper portion of the filter body 4c is formed in a flange shape, and the flange portion 4n and the O-ring 4j attached to the groove 4k on the back of the lid 4g are in close contact. In the upper part of the filter body 4c, a mesh plate 4 is provided in the gap between the flange part 4n and the lid 4g.
m and an O-ring 4r between 4a and 4c.

[0018]

As described above, according to the present invention, the base of the moisture adsorbing device, the cell main body, and the cell main body and the cap are mounted and communicated only by fitting the conical concave and convex. The cell body and the cap can be attached and detached without applying a load to the weighing arm. In addition, despite such a simple mounting method, the moisture adsorbing device of the present invention has an excellent outside air blocking effect, and in such a fitting portion, leakage of a carrier gas carrying vaporized moisture or the like occurs. Therefore, it is possible to measure the water content with extremely high accuracy. Further, in the cell main body of the present invention, the switching between the discharge of the carrier gas and the shutoff of the outside air is performed only by the rotation of the cap attached to the upper part of the cell main body, so that the switching can be easily performed without applying a load to the measuring arm. it can. Further, in the present invention, the adsorbent filled in the cell main body changes its color depending on the amount of water collected, and the cell main body is made of glass, and the color change of the adsorbent can be changed from outside the cell. Since it is possible to confirm, it is possible to easily determine the time to replace the adsorbent, and the measurement accuracy of the moisture meter is improved.

[Brief description of the drawings]

FIG. 1 is a path and a block diagram of a fluid system of a moisture meter.

FIG. 2 is a cross-sectional view illustrating an example of a moisture adsorption unit.

FIG. 3 is a perspective view showing an embodiment of a moisture adsorption unit.

FIG. 4 is a cross-sectional view illustrating an example of a moisture adsorption unit during measurement and during non-measurement.

FIG. 5 is a cross-sectional view illustrating an example of the heating unit (when not measuring).

FIG. 6 is an explanatory sectional view showing an example of a heating unit.

FIG. 7 is a cross-sectional view illustrating an example (at the time of measurement) of a heating unit.

FIG. 8 is an explanatory diagram of a sample dish pushing-up mechanism during measurement.

FIG. 9 is a cross-sectional view illustrating an example of a filter unit.

FIG. 10 is an explanatory diagram of a method of replacing a filter body according to the present invention.

FIG. 11 is an explanatory view of a method of replacing the filter body of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control part 2 Branch part 3 Heating part 3a Heating tube 3d Sealing material 3f Heating tube lid 3h Sample dish 4 Filter 5 Water absorption part 5b Base 5c Adsorbent 5d Cell body 5j Cap 5k Discharge port 6 Electronic balance part

Claims (4)

[Claims] 1. A moisture adsorbing device for a moisture meter that vaporizes moisture in a measurement sample by heating, carries the moisture with a carrier gas, and collects and detects only the vaporized moisture to measure the moisture content in the measurement sample. It is joined to a measuring arm of an electronic balance for measuring the amount of water in the measurement sample, a table to which a tube for introducing the carrier gas is connected, and filled with an adsorbent for collecting only the vaporized water. Cell body,
A water absorption device for a moisture meter, comprising: a cap for closing the cell main body, wherein the base, the cell main body, and the cell main body and the cap are mounted and connected to each other by fitting conical concave and convex. apparatus. 2. The moisture adsorption device for a moisture meter according to claim 1, wherein the cell main body is set so as to be able to shut off the outside air only by rotating the cap. 3. The moisture analyzer according to claim 1, wherein the color of the adsorbent filled in the cell body changes according to the amount of moisture collected. 4. A moisture meter according to claim 3, wherein said cell body is made of transparent glass.