JPH05281171A - Sample heating vaporizer for moisture measurement - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a sample heating vaporizer for moisture measurement, which is capable of eliminating an error due to moisture adhering to the inner surface of a container. [Structure] A heater 2 for heating a container 1 containing a sample to vaporize the water content of the sample, a carrier gas supply path 3 for supplying a dry carrier gas into the container 1, and a carrier for absorbing the water content in the container 1. In a sample heating vaporization device for moisture measurement, which is provided with a carrier gas discharge passage 5 for guiding gas to a moisture measurement device 4, the container 1 is opened at the end of the carrier gas supply passage 3 and the start of the carrier gas discharge passage 5. , A carrier gas supply / discharge device 6 for communicating the end portion and the start end portion in an airtight manner through the inner space of the container 1, and a carrier gas supply / discharge device 6 for circulating a dry carrier gas into the container 1 The preliminary purging means 7 for vaporizing and removing the water on the inner surface of the container 1 and the container 1 or the container 1 so that the container 1 is positioned in the heating space of the heater 2 after the water inside the container 1 is removed by the preliminary purging means 7. The moving means 8 for moving the heater 2 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample heating vaporizer for moisture measurement, and more particularly to a sample heating vaporizer for moisture measurement which is capable of eliminating a measurement error due to moisture in the atmosphere mixed during sample sampling.

[0002]

2. Description of the Related Art Moisture in raw materials such as plastic raw materials (plastic beads) causes a decrease in the molecular weight and foaming during polymerization and molding, and is physically caused by moisture absorption / swelling.
It is known that the electrical properties change and the quality of products varies greatly. For this reason, the moisture attached to the surface of the plastic beads is strictly controlled.

In controlling the water content of other solids or liquids in such a case, it is necessary to measure the water content of the solids or liquids. Karl Fischer's water content measurement method is the most frequently used method for measuring water content.In this method, a sample contained in a container is heated by a heater so that the amount of water vaporized from the sample is measured. ing. For this reason,
In this method, it is an important issue to minimize the influence of errors due to water mixed in during sample sampling.

In the sample vaporization and supply device for a water content measuring device described in Japanese Patent Laid-Open No. 1-216226, a terminal end of a carrier gas supply path for feeding a dry carrier gas into a container is connected to a heating chamber surrounded by a heater. , The atmosphere of the heating chamber is made dry by supplying the carrier gas previously dried to the heating chamber, then the container is inserted into the heating chamber, and the container is hermetically sealed from the end of the carrier gas supply path and the container. There is disclosed an apparatus and method for connecting a container to a starting end portion of a carrier gas discharge path that guides the water to a moisture measuring apparatus.

[0005]

By the way, in the apparatus and method described in the publication, the container containing the sample is sealed by the lid until just before it is inserted into the heating chamber. Moisture in the atmosphere mixed in the container is brought into the heating chamber as it is. As a result, for example, moisture adheres to the inner surface of the container or the surface of the sample, and in this state, the moisture is guided to the moisture measuring device via the carrier gas discharge passage, and is evaporated from the sample by heating to be guided to the moisture measuring device. Will be measured with.

Usually, the capacity of a container used for this type of moisture measurement is about 30 cc, and the inner surface thereof has a capacity of, for example, about 50 cc.
About 140 μg of water is attached. Therefore, when the sample contains a small amount of water, the amount of water mixed in the container during the sampling may not be negligible.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sample heating vaporizer for moisture measurement which can eliminate an error due to moisture mixed in a container at the time of sampling. ..

[0008]

According to the present invention, for example, as shown in FIG. 1, a heater 2 for heating a container 1 containing a sample to vaporize the water content of the sample, and a dry carrier gas in the container 1 are provided. In a sample heating vaporizer for moisture measurement, which comprises a carrier gas supply channel 3 for supplying and a carrier gas discharge channel 5 for guiding a carrier gas having absorbed moisture in a container 1 to a moisture measuring apparatus 4, to achieve the above object. , The following measures are taken.

That is, the carrier gas supply path 3 is provided in the container 1.
And a carrier gas supply / discharge device 6 for opening the end portion of the carrier gas and the start end portion of the carrier gas discharge passage 5 so that the end portion and the start end portion communicate with each other in an airtight manner through the inner space of the container 1, and the carrier gas. A preliminary purging unit 7 that circulates a dry carrier gas into the container 1 by the supply / discharge device 6 to vaporize and remove the moisture on the inner surface of the container 1, and the preliminary purging unit 7 eliminates the moisture inside the container 1. After that, the container 1 or the heater 2 is moved so as to position the container 1 in the heating space of the heater 2.

[0010]

In the present invention, the carrier gas supply / discharge device 6 communicates with the container 1 in an airtight manner through the end portion of the carrier gas supply passage 3, the start end portion of the carrier gas discharge passage 5 and the inner space of the container 1, By circulating the carrier gas inside the container 1 by the preliminary purging means 7, for example, moisture in the atmosphere mixed in the container 1 at the time of sample sampling can be absorbed by the carrier gas and discharged to the outside of the container 1.

Then, after that, the moving means is operated to move the container or the heater to position the container 1 in the heating space of the heater 2. By heating the container 1 by the heater 2, the moisture of the sample is vaporized and the carrier It is absorbed by the gas and sent to the moisture measuring device 4.

[0012]

EXAMPLE A sample heating vaporizer for moisture measurement according to an example of the present invention shown in the schematic view of FIG.
Heater 2 for heating the sample to vaporize the water content of the sample, and container 1
A carrier gas supply path 3 for supplying a dry carrier gas therein and a carrier gas discharge path 5 for guiding the carrier gas, which has absorbed moisture in the container 1, to the moisture measuring device 4 are provided.

The moisture measuring device 4 is not particularly limited,
A Karl Fischer automatic moisture meter was used. Further, this sample heating vaporization device for moisture measurement is configured to supply a carrier gas in which the end portion of the carrier gas supply path 3 and the start end portion of the carrier gas discharge path 5 are communicated to the container 1 in an airtight manner through the inner space of the container 1. Exhaust device 6 and a preliminary purge in which a dry carrier gas is circulated in the container 1 by the carrier gas supply / exhaust device 6 to vaporize moisture on the inner surface of the container 1 and absorb the carrier gas to remove it from the inside of the container 1. Means 7 and moving means 8 for moving the container 1 so as to position the container 1 in the heating space of the heater 2 after removing water inside the container 1 by the preliminary purging means 7 are provided.

As shown in the sectional views of FIGS. 2 (a) and 2 (b), the container 1 has a bottomed cylindrical main body 1a, a lid 1b fitted on the top thereof, and a main body 1a. A sealing member 1c including an O-ring that hermetically seals a gap between the lid and the lid 1b.
And a passage 1d that vertically passes through the central portion of the lid 1b.
The airtight film 1e that covers the upper surface of the lid 1b, the pressing lid 1f that is screwed onto the upper portion of the lid 1b to bring the airtight film 1e into close contact with the upper surface of the lid 1b, and the central portion of the pressing lid 1f. And a passage 1g that penetrates vertically.

The material of the airtight film 1e is not particularly limited as long as it has airtightness, and can be made of, for example, rubber, a metal foil such as an aluminum foil, and the like. In order to reduce the amount, it is recommended to select a material that does not easily adsorb water on the surface. Therefore, in this example, the airtight film 1e made of aluminum foil was used.

The structure of the heater 2 is not particularly limited, and the heater 2 may be formed in a tubular shape, for example, but in this embodiment, the container can be easily moved from the preliminary purge means 7 to the heating space of the heater 2. In order to make the
The container 1 is placed on the upper side thereof.

Further, the heat source of the heater 2 is not particularly limited, but in order to simplify the structure of the heater 2, electric heat is used here. As shown in FIG. 1, the carrier gas supply path 3 is led out from a cylinder 11 filled with nitrogen gas used as a carrier gas, and a shutoff valve 12 and a zeolite filter are housed in order from the cylinder 11 to the end. 13, a dehydrator 14 containing silica gel, a flow rate adjusting valve 15, a flow meter 16, a gas valve 17 and a flow path switching valve 18 are interposed.

As shown in FIG. 2, the carrier gas supply passage 3
The end portion of (1) is inserted into the start end portion of the carrier gas discharge passage 5 to form a nozzle 19 having an inner-outer double pipe structure. The tip of the nozzle 19 is obliquely cut so as to easily break through the airtight film 1e of the container 1.

As shown in FIG. 1, the carrier gas discharge path 5
Is extended from the nozzle 19 to the moisture measuring device 4, and a heat retention heater 20 is attached so that moisture contained in the carrier gas does not condense on the way.

The carrier gas supply / discharge device 6 includes an insertion device 10 (driving device shown in FIG. 1) for lowering the nozzle 19 and inserting it into the container 1 after the container 19 is placed on the nozzle 19 and the table 9. (Only a motor is shown), and an airtight board 21 for maintaining airtightness between the container 1 and the nozzle 19 when the nozzle 19 is inserted.

As shown in FIG. 2, the airtight board 21 is a disk-shaped main body 21a, a nozzle insertion hole 21b vertically penetrating the central portion of the main body 21a, and a bottom surface of the main body 21a. A sealing member 21c composed of an O-ring which is abutted on the upper surface of the pressing lid 1f of No. 1 so as to surround the passage 1g.
And a sealing member 21d, which is fitted and supported on the peripheral surface of the nozzle insertion hole 21b, slidably fits the nozzle 19 and includes an O-ring that is fitted in an airtight manner.

As shown in FIG. 1, the preliminary purging means 7 is provided.
Includes a table 9 that is horizontally rotatable and a table drive device 22 that drives the table 9 to rotate.
The containers 1 arranged at appropriate intervals in the circumferential direction are sequentially moved to a predetermined position below the nozzle 19 of the carrier gas supply / discharge device 6.

Further, the preliminary purging means 7 is provided with a cover 23 surrounding the table 9 and the container 1 placed on the table 9 as necessary, and the dehydrator 14 is provided in the preliminary purging chamber 24 formed in the cover 23. Gas supply path 3 downstream of
The carrier gas can be introduced through the branch passage 25 branched from the. A flow rate adjusting valve 26 and a flow meter 27 are interposed in this branch path 25.

The moving device 8 may be configured to move the heater 2 toward the container 1, but in order to prevent the residual heat of the heater 2 from being brought into the preliminary purge chamber 24, the container 1 Support frame 8a for supporting the support frame 8a
A chuck 8b for fixing the container 1 supported by the solenoid 8c, a solenoid 8c for driving the chuck 8b, and a drive device 8d for reciprocating the solenoid 8c between the preliminary purging means 7 and the heater 2 are provided, and the container 1 is held on the table 9 by the table 9a. Is moved from above to the heater 1.

The sample heating vaporizer for moisture measurement is provided with a pre-purge channel 28 for allowing a carrier gas to flow from the channel switching valve 18 to the moisture measuring apparatus 4 in advance. In this sample heating vaporization apparatus for moisture measurement, first, a carrier gas is caused to flow to the moisture measurement apparatus 4 through the prepurge channel 28 to stabilize the moisture measurement apparatus 4 in a dry state, and at the same time, the carrier gas is passed through the branch channel 25. The gas is caused to flow into the preliminary purge chamber 24 to keep the preliminary purge chamber 24 in a dry state. The bripurge flow path 28 is closed after the inside of the moisture measuring device 4 is stabilized in a dry state.

Simultaneously with or after the above-mentioned pre-purge, the nozzle 19 is lowered by the insertion device 10 toward the container 1 placed at a predetermined position on the table 9, and the nozzle 19 is
Then, the container 1 and the nozzle 19 are connected in an airtight manner by breaking through the airtight film 1e and pushing the lower end of the nozzle 19 into the container 1.

Thereafter, the dry carrier gas is introduced into the container 1 through the carrier gas supply passage 3 for about 10 to 30 seconds to vaporize the water mixed in the container 1 and absorb the water. The carrier gas is discharged to the moisture measuring device 4 through the carrier gas discharging passage 5, and preliminary purging for drying the inside of the carrier gas supplying passage 3, the container 1, the carrier gas discharging passage 5 and the moisture measuring device 4 is performed. The pre-purging time is set to be short when the water content on the surface of the sample is small or the sample is easily scattered.

Thereafter, while the nozzle 19 is still connected to the container 1, the container 1 is transferred from the table 9 onto the heater 2 by the moving device 8 while passing the carrier gas through the container 1, and the container 2 is mounted by the heater 2. Water is vaporized from the sample in the container 1 by heating. The carrier gas containing the moisture is sent to the moisture measuring device 4 via the carrier gas discharge passage 5.

Since the water present in the container 1 is removed from the system by circulating the carrier gas in advance, the water measuring device 4 contains only the water vaporized from the sample by the heater 2. The carrier gas will be sent. Therefore, it is possible to perform the measurement without an error due to the water mixed in the container 1 other than the water contained in the sample to be measured.

The heater 2 may be operated before the container 1 is placed, or may be operated after the container 1 is placed. Although the airtight film 1e is made of aluminum foil in the above embodiments, the airtight film 1e is made of silicon rubber in other embodiments of the present invention. Other configurations, operations, and effects are the same as those of the above-described embodiment, and thus the description thereof will be omitted to avoid duplication.

In order to determine the influence of the material of the airtight film 1e on the error in each of the above-mentioned examples, Table 1 shows the measurement results in each case. As is clear from Table 1, the measured value when using silicone rubber is about three times that when using aluminum foil. The cause is that many fine irregularities are present on the surface of the silicone rubber, and therefore, when the inside of the container 1 is dried by the carrier gas, the moisture on the inner surface of the container body 1a is sufficiently dried, but the surface of the silicone rubber is This is because water is captured and remains on many minute irregularities, and this vaporizes during heating and vaporization.

[0032]

[Table 1]

Further, the airtight film 1e was made of aluminum foil, and the moisture content was measured by omitting the procedure of drying the inside of the container 1 in advance with the carrier gas. As a result, as shown in the column of Comparative Example in Table 2, the carrier gas was previously prepared. Compared with the case where the procedure for drying the inside of the container 1 is performed, about 95 to 128 μg has a large measured value,
Further, it can be seen that the dispersion of the measured values is large.

[0034]

[Table 2]

[0035]

As described above, according to the present invention,
Since the inside of the container is dried with a carrier gas in advance and then heated by a heater to vaporize the water content of the sample, it is possible to eliminate the measurement error due to the water content in the air mixed in the container at the time of sampling the sample, and it is possible to achieve high accuracy. You can measure.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of the present invention.

FIG. 2 is a cross-sectional view of the container of the present invention.

[Explanation of symbols]

 1 Container 1e Airtight Membrane 2 Heater 3 Carrier Gas Supply Channel 4 Moisture Measuring Device 5 Carrier Gas Discharge Channel 6 Carrier Gas Supply / Discharge Device 7 Preliminary Purge Means 8 Moving Means 9 Table 10 Insertion Device

[Procedure amendment]

[Submission date] April 16, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 7

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

The sample heating vaporizer for moisture measurement is provided with a pre-purge flow channel 28 for allowing a carrier gas to flow from the flow channel switching valve 18 to the moisture measurement device 4 in advance. In this sample heating vaporization apparatus for moisture measurement, first, a carrier gas is caused to flow to the moisture measurement apparatus 4 through the prepurge channel 28 to stabilize the moisture measurement apparatus 4 in a dry state, and at the same time, the carrier gas is passed through the branch channel 25. The gas is caused to flow into the preliminary purge chamber 24 to keep the preliminary purge chamber 24 in a dry state. The prepurge channel 28 is closed after the inside of the moisture measuring device 4 is stabilized in a dry state.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

The heater 2 may be operated before the container 1 is placed, or may be operated after the container 1 is placed. In the above embodiment, the airtight film 1e is the metal foil.
For example, although it is made of aluminum foil, in another embodiment of the present invention, the airtight film 1e is made of silicon rubber. Other configurations, operations, and effects are the same as those of the above-described embodiment, and thus the description thereof will be omitted to avoid duplication.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiji Funaki 68 Ninodancho Nittadan, Kichijoin, Minami-ku, Kyoto City Kyoto Electronics Industry Co., Ltd.

Claims (7)

[Claims] 1. A heater (2) for heating a container (1) containing a sample to vaporize the water content of the sample, and a carrier gas supply path (3) for supplying a dry carrier gas into the container (1). ,
In a sample heating vaporizer for moisture measurement, which is equipped with a carrier gas discharge passage (5) that guides the carrier gas that has absorbed moisture in the container (1) to the moisture measurement device (4), the carrier gas supply passage ( A carrier gas supply / discharge device (3) that opens the end portion and the start end portion of the carrier gas discharge path (5) to allow the end portion and the start end portion to communicate with each other in an airtight manner through the inner space of the container (1) ( 6), and a preliminary purging means (7) for circulating the dry carrier gas in the container (1) by this carrier gas supply and discharge device (6) to vaporize and remove water on the inner surface of the container (1), After removing the water inside the container (1) by the preliminary purging means (7), move the container (1) or the heater (2) so that the container (1) is located in the heating space of the heater (2). transportation
(8) A sample heating vaporizer for moisture measurement, comprising: 2. The preliminary purging means (7) comprises a table (9) on which a container (1) containing a sample is placed, and the carrier gas supply / discharge device (6) is provided on the table (9).
The insertion device (10) for inserting the end portion of the carrier gas supply passage (3) and the start end portion of the carrier gas discharge passage (5) into the container (1) after the (1) is placed thereon. The sample heating vaporizer for moisture measurement described. 3. The moving means (8) is a preliminary purging means.
Transfer the container (1) from (7) to the heater (2) with the end of the carrier gas supply passage (3) and the start end of the carrier gas discharge passage (5) communicating with the container (1). The sample heating vaporizer for moisture measurement according to claim 1 or 2, which is configured to: 4. The moving means (8) contains a heater (2) in a container.
The sample heating vaporizer for moisture measurement according to claim 1 or 2, which is configured to be moved to the position (1). 5. The tubular nozzle of claim 1, wherein the end portion of the carrier gas supply passage (3) and the start end portion of the carrier gas discharge passage (5) are bundled together or constitute an inner / outer double tubular nozzle. A sample heating vaporizer for moisture measurement according to any one of claims. 6. An airtight membrane (1e), wherein the container (1) is pierced on one surface thereof by a terminal end of a carrier gas supply passage (3) and a starting end of a carrier gas discharge passage (5) or one of these.
A sample heating vaporizer for moisture measurement according to any one of claims 1 to 5. 7. The sample heating vaporizer for moisture measurement according to claim 6, wherein the airtight film (1e) is made of aluminum foil.