JP4081199B2 - Gas extraction furnace for elemental analyzer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas extraction furnace of an element analyzer for quantitatively analyzing elements in a sample.
[0002]
[Prior art]
For example, as an element analyzer for quantitative analysis of elements such as carbon and sulfur contained in samples such as metals and ceramics, a crucible containing a weighed sample is attached to a gas extraction furnace, and the crucible is placed in a combustion space. There is a type in which an internal sample is burned, an extraction gas of an element contained in the sample is supplied to a detector by a carrier gas, and an element contained in the sample is quantitatively analyzed by, for example, an infrared absorption method.
[0003]
The gas extraction furnace used for this elemental analysis is equipped with a lower furnace body that can be moved up and down on the lower side of the furnace body provided with heating means around the combustion cylinder in order to mount a sample-weighed crucible in the furnace. Is configured .
[0004]
In the lower furnace body, a crucible base for installing the crucible, a base for placing the crucible base, and a recess formed by opening downward from the base to the lower side of the crucible base. And a metal position fixing member provided so as to be engaged with.
[0005]
By the way, in the above elemental analysis, when the weighed crucible is installed in the furnace, when the lower furnace body is lowered and the furnace body is opened, the interior of the furnace body is exposed to the atmosphere, and the inside of the combustion cylinder of the furnace body Of course, the air also flows into the recess on the lower side of the crucible base.
[0006]
This air, since lead to abnormal measurements include carbon dioxide, in order to discharge the air out of the system, typically by introducing a purge gas into the combustion cylinder prior to the start of the measurement, the A purge process for replacing the inside of the combustion cylinder with purge gas is performed.
[0007]
[Problems to be solved by the invention]
However, the atmosphere once flowing into the recess on the lower side of the crucible through a narrow gap is not easily replaced with the purge gas even if purge is performed, and the air accumulated in this recess flows into the system at the time of sample measurement and the measured value It will be variations in, while the capacity of the recess small, for the element measurement with high accuracy, the atmosphere of this small amount has a problem that a large influence on the measurement accuracy.
[0008]
[Means for Solving the Problems]
The present invention has been made to solve such a problem, and is provided with a furnace body provided with a heating means around a combustion cylinder, and a seal ring holder connected to a lower opening, and a crucible. A crucible base for mounting, a pedestal for mounting the crucible base, and a position fixing member provided so as to engage with a recess formed by opening downward from the pedestal to the lower side of the crucible base. The lower furnace body can be moved up and down relative to the furnace body so that the crucible installed on the crucible base can be inserted into the combustion cylinder through the hollow portion of the seal ring holder. And further comprising a carrier gas supply line for burning the sample in the crucible in the combustion space in the combustion cylinder of the furnace body, and detecting the extracted gas of the elements contained in the sample by the carrier gas. Supplied, the gas extraction reactor configuration the element analyzer to quantitative analysis of elements contained in the sample, wherein the seal ring retainer, purge gas supply for supplying a purge gas is also used in the carrier gas into the combustion cylinder with line is connected, at least one of the crucible base and crucible base mounting pedestal, the purge gas supplied to the purge gas supply line, a purge gas introduction stream for introduction into the crucible base lower part of the recess and it is characterized in that it provided the road.
[0009]
That is, the present invention pays attention to the fact that the gap between the crucible base and the pedestal is narrow and the purge gas is difficult to flow into the recess through this, making it difficult to purge the air accumulated in the recess. It has been made, in the present invention, provided with a purge gas introduction channel for introducing a positively in the recess of the purge gas, and than was to enable easy purging of the atmosphere, whereby the crucible base lower side since the recess is also reliably replaced purge gas, it is possible to sample measurement in the absence of air, and by extension, from the variation of the measured values does not occur, significant improvement in measurement accuracy is achieved .
[0010]
The purge gas introduction flow path is adjacent to , for example, a plurality of notches provided around the peripheral wall of the recess on the lower side of the crucible base, and a plurality of circumferential rib members erected from the crucible base mounting surface portion of the base. is formed by the rib members or between the crucible dyno surface portion in a part of said crucible base lower side circumferential plurality formed to penetrate in a recess in the recessed grooves, preferably, the purge gas introduction passage In other words, it is formed so as to face the gas supply port of the purge gas supply line.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of an elemental analyzer, where 1 is a gas extraction furnace, and as shown in FIG. 2, a furnace body 4 provided with high-frequency heating means 3 around the combustion cylinder 2, and this furnace body 4 comprises a holder 6 for an O-ring 5 connected to an opening on the lower side of 4 and a lower furnace body 9 provided with a magnetic crucible base 8 for installing a magnetic sample-receiving crucible 7.
[0012]
The crucible base 8 is formed with a fitting holding concave portion 10 of the crucible 7 and a concave portion 11 opened downward on the lower side, while the lower furnace body 9 has a metal base for placing the crucible base. 12 and a metal position fixing member 13 that engages with the lower concave portion 11 of the crucible base 8 are provided.
[0013]
The furnace body 4 is fixedly arranged on the bracket 14 in the apparatus, and the lower furnace body 9 is connected to the lifting means 15 so that the sample containing crucible 7 exchanged outside the furnace body 4 is exchanged. The O-ring holder 6 is configured to be inserted into the combustion cylinder 2 through the hollow portion.
[0014]
A dust filter 16 is arranged on the upper side of the combustion cylinder 2 and is built in a filter holder 17 which is continuously provided above the furnace body 4. Reference numeral 18 denotes a filter fixing member mounted on the upper portion of the filter holder 17, and 19 denotes a cleaning means for the combustion cylinder 2 and the dust filter 13.
[0015]
The cleaning means 19 is provided with a brush holder 22 on the cylinder rod 21 of both rod cylinders 20 and also holds a brush 23 for cleaning the combustion cylinder and a brush 24 for dust filter cleaning on the brush holder 22. Further, a nozzle member 25 is provided at the lower end portion of the brush holder 22, while a carrier gas supply line 26 is formed on the cylinder rod 21, the brush holder 22 and the nozzle member 25, and the filter fixing member 18 is formed. A cylinder receiving member is used, and the cylinder 20 is attached to the cylinder receiving member in a vertical state.
[0016]
27 is a filter heating means for indirectly heating the dust filter 13, and 28 is a gas outlet for gas (extracted gas of an element contained in the sample) generated along with combustion of the sample in the crucible 7. A gas line 30 is provided in the holder 17, and a gas line 30 for supplying the extracted gas to the detector 29 is connected to the gas outlet port 28.
[0017]
The gas line 30 includes a dust filter 31, a dehydrating means 32, and an electromagnetic valve 33. The gas purified through the dust filters 16 and 31 is dehydrated, and the clean extracted gas is detected by a detector. 30 and the elements such as carbon and sulfur contained in the sample are quantitatively analyzed by the infrared absorption method.
[0018]
34 is a means for collecting the dust dropped from the combustion cylinder 2 and the dust filter 16 by the cleaning means 19, and a gas supply line 35 for supplying a carrier gas into the combustion cylinder 2 through the hollow portion of the O-ring holder 6. It is connected to the O-ring holder 6 so that the carrier gas is also used as a dust cleaning gas, and the dust is sent to the dust collection line 36 by this carrier gas and is collected in the dust collection box 37. A pinch valve 38 is provided in the middle of the dust collection line 36 so that the extracted gas does not flow into the dust collection box 37 except during dust collection.
[0019]
In the gas extraction furnace 1 configured as described above, the carrier gas supplied from the gas supply lines 26 and 35 is also used as the purge gas, and before starting the measurement, the purge gas is introduced into the furnace for each measurement. The atmosphere in the furnace that has flowed in when the magnetic crucible 7 is mounted in the furnace is purged, and the inside of the furnace is replaced with a purge gas. In addition, you may provide the line only for purge gas.
[0020]
Since purging of the air flowing into the recess 11 of the crucible base 8 is difficult, in the present invention, as shown in FIG. 2 and FIG. Is provided with a plurality of notches (three in this embodiment, but the number is not limited) b at a portion facing the gas supply port a of the gas supply line 35 and its peripheral portion. A purge gas introduction flow path R for positively introducing purge gas into the lower recess 11 of the crucible base 8 is configured.
[0021]
According to the above configuration, the purge of the atmosphere flowing into the combustion cylinder 2 is of course easily performed, but the purge gas introduction flow path is also applied to the atmosphere flowing into the recess 11 on the lower side of the crucible base 8. Since the purge gas is positively introduced into the recess 11 through R, it is easily purged, and the entire interior of the furnace including the recess 11 of the crucible base 8 is surely replaced with the purge gas. It is possible to measure a sample in a state where no exists.
[0022]
In the above embodiment, the notch b is formed in the concave peripheral wall 8a of the crucible base 8 to constitute the purge gas introduction flow path R. However, the purge gas is composed of a number of slits, simple through holes, combinations thereof, and the like. The introduction flow path R can be configured.
[0023]
As shown in FIG. 4, a plurality of parts for placing the crucible base 8 on the metal base 12 for placing the crucible base without forming the notch b or the like in the concave peripheral wall 8 a of the crucible base 8. A plurality of arc-shaped rib members 39 can be erected to form the purge gas introduction flow path R between the adjacent rib members 39.
[0024]
Alternatively, instead of the rib member 39, as shown by the phantom line in FIG. 4 , the purge gas introduction flow may be formed by forming a groove-like recess 40 partially entering the recess 11 on the crucible base mounting surface portion of the base 12. The path R can be configured, and the purge gas introduction flow path R may be configured by appropriately combining them.
[0025]
【The invention's effect】
As described above, the present invention pays attention to the fact that the narrow gap between the crucible base and the pedestal makes it difficult to purge the air flowing into the concave portion of the downward opening on the lower side of the crucible base. The purge gas introduction flow path for positively introducing the purge gas into the concave portion is provided, and the air flowing into the concave portion on the lower side of the crucible base is surely replaced with the purge gas. Sample measurement can be performed in a state where no is present, and as a result, variations in measurement values do not occur, and a significant improvement in measurement accuracy has been achieved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an elemental analyzer.
FIG. 2 is a cross-sectional view of a gas extraction furnace.
FIG. 3 is a perspective view of a crucible base in which a purge gas introduction flow path is formed by a notch.
FIG. 4 is a configuration diagram of a purge gas introduction channel according to another embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 3 ... Heating means, 4 ... Furnace main body, 7 ... Crucible, 8 ... Crucible base, 8a ... Recessed peripheral wall, 9 ... Lower furnace body, 11 ... Recessed part on the crucible base lower side , 12 ... Base, 13 ... Position fixing member, 29 Detecting device 35 Purge gas supply line a Purge gas supply port R Purge gas introduction channel

Claims (4)

A heating means around the combustion tube, and the lower furnace body which the seal ring retainer and continuously provided to the opening of the pedestal to the crucible base and placing the crucible stand for for mounting the crucible and this A lower furnace body provided with a position fixing member provided so as to engage with a recess formed by opening downward from the base to the lower side of the crucible base, and the lower furnace body is attached to the crucible base. The installed crucible is configured to be movable up and down with respect to the furnace main body so that the crucible can be inserted into the combustion cylinder through the hollow portion of the seal ring holder, and further includes a carrier gas supply line. in the combustion space of the combustion cylinder of, from which by burning the sample in the crucible, the extraction gas of the elements contained in the sample is supplied to the detector by the carrier gas, it was constructed an element contained in the sample to quantitatively analyze In gas extraction reactor of the analyzer,
A purge gas supply line is connected to the seal ring holder for supplying a purge gas that is also used as the carrier gas into the combustion cylinder.
Wherein at least one of the crucible base and crucible base mounting pedestal, the purge gas supplied to the purge gas supply line is provided with a purge gas introduction channel for introducing into the crucible base lower part of the recess Gas extraction furnace for elemental analysis equipment. The purge gas introduction flow path, gas extraction furnace elemental analyzer according to claim 1, which is formed from outs plurality of cut that was opened in the recess peripheral wall around said crucible base lower side. The purge gas introduction flow path, between the rib member adjacent the crucible Dyno surface portion of the pedestal erected circumferential plurality of rib members or the crucible dyno surface portion in a part of said crucible base lower side The gas extraction furnace of the elemental analysis apparatus according to claim 1, wherein the gas extraction furnace is formed by a plurality of circumferential groove-shaped recesses formed so as to enter into the recesses of the elemental analyzer. The gas extraction furnace of an elemental analyzer according to any one of claims 1 to 3 , wherein the purge gas introduction flow path is formed facing a gas supply port of the purge gas supply line .

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