JPH0454178B2 - - Google Patents
Info
- Publication number
- JPH0454178B2 JPH0454178B2 JP6930882A JP6930882A JPH0454178B2 JP H0454178 B2 JPH0454178 B2 JP H0454178B2 JP 6930882 A JP6930882 A JP 6930882A JP 6930882 A JP6930882 A JP 6930882A JP H0454178 B2 JPH0454178 B2 JP H0454178B2
- Authority
- JP
- Japan
- Prior art keywords
- gas
- concentration
- nitrogen monoxide
- separation tube
- molecular sieve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims description 154
- 239000007789 gas Substances 0.000 claims description 143
- 238000000926 separation method Methods 0.000 claims description 47
- 239000002808 molecular sieve Substances 0.000 claims description 26
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 claims description 26
- 239000002826 coolant Substances 0.000 claims description 18
- 238000001514 detection method Methods 0.000 claims description 9
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 7
- 239000012159 carrier gas Substances 0.000 claims description 7
- 238000000034 method Methods 0.000 claims description 7
- 238000002844 melting Methods 0.000 claims description 5
- 230000008018 melting Effects 0.000 claims description 5
- 238000009835 boiling Methods 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- CYRMSUTZVYGINF-UHFFFAOYSA-N trichlorofluoromethane Chemical compound FC(Cl)(Cl)Cl CYRMSUTZVYGINF-UHFFFAOYSA-N 0.000 claims 3
- 238000001816 cooling Methods 0.000 description 18
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 17
- 229910001873 dinitrogen Inorganic materials 0.000 description 17
- 238000005259 measurement Methods 0.000 description 4
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 150000002430 hydrocarbons Chemical class 0.000 description 3
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 229910002089 NOx Inorganic materials 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- MWWATHDPGQKSAR-UHFFFAOYSA-N propyne Chemical group CC#C MWWATHDPGQKSAR-UHFFFAOYSA-N 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
Description
【発明の詳細な説明】
本発明は、試料ガス中に微量だけ含まれるガス
濃度測定方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the concentration of a gas contained in a trace amount in a sample gas.
或る先行技術では、大気中の窒素酸化物NOx、
たとえば一酸化窒素NO、二酸化窒素NO2濃度を
測定する方法として、化学発光法による測定方法
が開発されている。この方法は、一酸化窒素が過
剰のオゾンO3中で酸化される際に600nm〜
3000nm付近の赤外光を出す第１式に示す反応式
に基づいている。 In some prior art, atmospheric nitrogen oxides NOx,
For example, a chemiluminescent method has been developed to measure the concentrations of nitrogen monoxide NO and nitrogen dioxide NO 2 . This method works when nitric oxide is oxidized in excess ozone O3 to 600nm~
It is based on the reaction formula shown in Equation 1, which emits infrared light around 3000 nm.
2NO＋O3→2NO2＋hν ……(1)
この反応は一酸化窒素に関して選択的であるた
め、二酸化窒素は300℃以下の低温コンバータに
よつて第２式に示すように一酸化窒素に還元して
測定される。 2NO+O 3 →2NO 2 +hν ...(1) Since this reaction is selective with respect to nitrogen monoxide, nitrogen dioxide is reduced to nitrogen monoxide using a low-temperature converter below 300℃ as shown in the second equation. be measured.
Ｃ＋NO2→CO＋NO ……(2)
このような化学発光法による測定装置では、こ
の装置の零調整のために、測定すべき一酸化窒素
を含まない零ガスと称される高純度窒素ガスボン
ベに充填された窒素ガスが用いられる。しかし、
市販されている一酸化窒素のいわゆる零ガスは、
10ppb以下の一酸化窒素を含むのが現状であると
ともに、この一酸化窒素ガス濃度の測定は極めて
困難である。このため、環境基準濃度付近のたと
えば20ppb前後の窒素酸化物ガス濃度の測定は、
不正確な値を示すこととなる。 C + NO 2 → CO + NO ... (2) In such a chemiluminescence measuring device, in order to zero-adjust the device, a high-purity nitrogen gas cylinder called zero gas that does not contain the nitrogen monoxide to be measured is filled. Nitrogen gas is used. but,
The so-called zero gas of nitric oxide that is commercially available is
Currently, it contains less than 10 ppb of nitrogen monoxide, and it is extremely difficult to measure the concentration of nitrogen monoxide gas. Therefore, when measuring nitrogen oxide gas concentrations near the environmental standard concentration, for example around 20 ppb,
This will indicate an incorrect value.
本発明の目的は、このような先行技術の技術的
課題を解決して、測定すべきガスを微量だけ含む
試料ガスのガス濃度を正確に得ることができるガ
ス濃度測定方法を提供することである。 An object of the present invention is to solve the technical problems of the prior art and provide a gas concentration measuring method that can accurately obtain the gas concentration of a sample gas containing only a trace amount of the gas to be measured. .
本発明は、高純度炭素から形成された平均細径
10Å〜20Å、60〜80メツシユの粒状のモレキユラ
シーブがそれぞれ充填された第１および第２濃縮
分離管１０，４３を準備し、
第１および第２濃縮分離管１０，４３を、一酸
化窒素の融点以下の沸点を有する液化ガスである
冷却剤１１によつて冷却し、
第１濃縮分離管１０には、キヤリアガスを供給
した試料ガスよりも充分に低濃度の一酸化窒素ガ
スを含む零ガスを得、
試料ガスと零ガスとを混合して冷却剤１１によ
つて冷却されている第２濃縮分離管４３に供給
し、その後、第２濃縮分離管４３の冷却剤１１を
取外して、第２濃縮分離管４３を加熱器５０によ
つて加熱し、そのモレキユラシーブから遊離した
一酸化窒素ガスを検出手段６に導いてモレキユラ
シーブから遊離した一酸化窒素ガスの濃度を測定
し、
さらにその後、試料ガスと、一酸化窒素ガスよ
りも高い濃度で含む標準ガスとを、予め定める混
合割合で混合して、冷却剤１１によつて冷却され
ている第２濃縮分離管４３に供給し、その後、第
２濃縮分離管４３の冷却剤１１を取外して、第２
濃縮分離管４３を加熱器５０によつて加熱し、そ
のモレキユラシーブから遊離した一酸化窒素ガス
を検出手段６に導いてモレキユラシーブから遊離
した一酸化窒素ガスの濃度を測定してその測定値
を外挿し、このステツプを、試料ガスと標準ガス
との混合割合を順次変化して複数回、繰返して行
つて、その測定値を、外挿し、
これによつて試料ガス中の一軟化窒素ガスの濃
度を正確に得ることを特徴とする一酸化窒素のガ
ス濃度測定方法でもある。 The present invention has an average small diameter formed from high purity carbon.
First and second concentration separation tubes 10 and 43 filled with granular molecular sieves of 10 Å to 20 Å and 60 to 80 mesh are prepared, respectively. It is cooled by the coolant 11, which is a liquefied gas having a boiling point of , The sample gas and the zero gas are mixed and supplied to the second concentration separation tube 43 which is cooled by the coolant 11, and then the coolant 11 of the second concentration separation tube 43 is removed and the second concentration separation tube 43 is cooled by the coolant 11. The separation tube 43 is heated by the heater 50, and the nitrogen monoxide gas liberated from the molecular sieve is guided to the detection means 6 to measure the concentration of the nitrogen monoxide gas liberated from the molecular sieve. A standard gas containing a higher concentration than nitrogen monoxide gas is mixed at a predetermined mixing ratio and supplied to the second concentration separation tube 43 cooled by the coolant 11. Remove the coolant 11 from the tube 43 and
The concentration separation tube 43 is heated by the heater 50, and the nitrogen monoxide gas released from the molecular sieve is guided to the detection means 6, the concentration of the nitrogen monoxide gas released from the molecular sieve is measured, and the measured value is extrapolated. , this step is repeated several times by sequentially changing the mixing ratio of the sample gas and standard gas, and the measured values are extrapolated, thereby calculating the concentration of mono-softened nitrogen gas in the sample gas. It is also a method for measuring the gas concentration of nitric oxide, which is characterized by accurate measurement.
以下、図面によつて本発明の実施例を説明す
る。第１図は、本発明に従う一酸化窒素ガス濃度
測定装置１の簡略化した系統図である。ガス濃度
測定装置１は、零ガス供給手段２と、試料ガス供
給手段３と、標準ガス供給手段４と、濃縮分離手
段５と、検出手段６とを含む。零ガス供給手段２
は、キヤリアガスとして窒素ガスを供給する手段
であり、窒素ガスボンベ７と、ボンベに接続され
る管路８と、管路８に介在される電磁弁９と、管
路８に接続される冷却トラツプ１０と、冷却トラ
ツプ１０を冷却するための冷却剤１１が満たされ
る容器１２と、冷却トラツプ１０に接続される管
路１３と、管路１３の冷却トラツプ１０寄りに介
在される流量調整器１４と、管路１３の流量調整
器１４の下流に介在される電磁弁１５とから成
る。 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a simplified system diagram of a nitrogen monoxide gas concentration measuring device 1 according to the present invention. The gas concentration measuring device 1 includes a zero gas supply means 2, a sample gas supply means 3, a standard gas supply means 4, a concentration separation means 5, and a detection means 6. Zero gas supply means 2
is a means for supplying nitrogen gas as a carrier gas, and includes a nitrogen gas cylinder 7, a pipe line 8 connected to the cylinder, a solenoid valve 9 interposed in the pipe line 8, and a cooling trap 10 connected to the pipe line 8. a container 12 filled with a coolant 11 for cooling the cooling trap 10; a pipe line 13 connected to the cooling trap 10; a flow rate regulator 14 interposed in the pipe line 13 near the cooling trap 10; and a solenoid valve 15 interposed downstream of the flow rate regulator 14 in the conduit 13.
冷却トラツプ１０は、第２図に示すように、た
とえば内径４mmのステンレス鋼管から形成され、
後述のモレキユラシーブ１６がたとえば10mlだけ
充填されて成る。冷却剤１１としては、たとえば
液体酸素（沸点−183.0℃）が用いられ、この冷
却剤１１が容器１２に満たされて冷却トラツプ１
０が冷却される。 As shown in FIG. 2, the cooling trap 10 is made of a stainless steel tube with an inner diameter of 4 mm, for example.
For example, 10 ml of molecular sieve 16, which will be described later, is filled. For example, liquid oxygen (boiling point -183.0°C) is used as the coolant 11, and a container 12 is filled with this coolant 11 and the cooling trap 1 is filled with the coolant 11.
0 is cooled.
前記モレキユラシーブ１６は、特殊な表面構造
をもつた高純度炭素から成り、平均細径10〜20
Å、表面積1000〜1200m2／ｇを有する可逆捕集吸
着剤であり、60〜80メツシユの粒状とされる。こ
のモレキユラシーブ１６には、たとえば商品名カ
ーボシーブ（米国、スペルコ社製）が選ばれる。
60〜80メツシユとされたカーボシーブＢをたとえ
ば内径3.2mm、管長91.5cmのカラムに充填する。
このカラム温度を30℃／minの速度で175℃から
225℃まで昇温して窒素ガスをキヤリアガスとし
たとき、炭素数１〜３の炭化水素ガスをフレーム
イオン化検出器を用いて分析した結果を第３図に
示す。第３図に示すピーク３１，３２，３３，３
４，３５，３６，３７，３８は、それぞれメタ
ン、アセチレン、エチレン、エタン、メチルアセ
チレン、アレン、プロピレン、プロパンの存在を
表す。このように、モレキユラシーブ１６は本来
無機または有機ガスの分離に用いられるものであ
る。本件発明者は、このモレキユラシーブ１６を
一酸化窒素の融点（−163.7℃）以下に冷却する
ことによつて、モレキユラシーブ１６間を流過さ
れるきわめて微量（ppbレベル）の一酸化窒素が
選択的にトラツプされることを見つけ出した。 The molecular sieve 16 is made of high-purity carbon with a special surface structure, and has an average fine diameter of 10 to 20
It is a reversible collection adsorbent having a surface area of 1000 to 1200 m 2 /g, and is in the form of granules of 60 to 80 mesh. For the molecular sieve 16, for example, Carbosieve (trade name, manufactured by Superco, USA) is selected.
Carbosieve B having a mesh size of 60 to 80 is packed into a column having an inner diameter of 3.2 mm and a tube length of 91.5 cm, for example.
The column temperature was increased from 175°C at a rate of 30°C/min.
FIG. 3 shows the results of analyzing a hydrocarbon gas having 1 to 3 carbon atoms using a flame ionization detector when the temperature was raised to 225° C. and nitrogen gas was used as a carrier gas. Peaks 31, 32, 33, 3 shown in Figure 3
4, 35, 36, 37, and 38 represent the presence of methane, acetylene, ethylene, ethane, methylacetylene, arene, propylene, and propane, respectively. In this way, the molecular sieve 16 is originally used for separating inorganic or organic gases. By cooling the molecular sieve 16 to below the melting point of nitric oxide (-163.7°C), the inventor of the present invention has discovered that by cooling the molecular sieve 16 to below the melting point of nitric oxide (-163.7°C), an extremely small amount (ppb level) of nitric oxide flowing between the molecular sieves 16 can be selectively removed. I figured out how to get trapped.
流量調整器１４によつて、窒素ガスの流量をた
とえば200ml／minに調整し、電磁弁９，１５を
開いて窒素ガスボンベ７内の窒素ガスが管路８を
介して第２図の矢符１７で示すように冷却トラツ
プ１０内を流過する際、モレキユラシーブ１６に
よつて、ボンベ７内に微量含まれる一酸化窒素ガ
スは捕捉される。これによつて窒素ガスボンベ７
内に含まれた一酸化窒素ガス濃度がたとえば1.5
〜2.5ppbであつたとすると、管路１３からミキシ
ングジヨイント１８に流入される窒素ガス中で
は、0.1ppb程度になる。 The flow rate of nitrogen gas is adjusted to, for example, 200 ml/min by the flow rate regulator 14, and the solenoid valves 9 and 15 are opened to allow the nitrogen gas in the nitrogen gas cylinder 7 to flow through the pipe line 8 to the point indicated by the arrow 17 in FIG. As shown in the figure, when flowing through the cooling trap 10, the molecular sieve 16 traps the trace amount of nitrogen monoxide gas contained in the cylinder 7. As a result, nitrogen gas cylinder 7
For example, if the concentration of nitric oxide gas contained in
If the concentration is ~2.5 ppb, it will be about 0.1 ppb in the nitrogen gas flowing into the mixing joint 18 from the pipe line 13.
試料ガス供給手段３は、試料ガスボンベ１９
と、ガスボンベ１９に接続される管路２０と、管
路２０のガスボンベ１９寄りに介在される電磁弁
２１と、管路２０の電磁弁２１の下流に介在され
る流量調整器２２と、流量調整器２２と前記ミキ
シングジヨイント１８とを接続する管路２３と、
管路２３の流量調整器２２寄りに介在されるミキ
シングジヨイント２４と、管路２３のミキシング
ジヨイント２４の下流に介在される電磁弁２５と
から成る。試料ガスボンベ１９は、濃度未知の一
酸化窒素ガスを微量だけ含むガスボンベである。
流量調整器２２は、試料ガスの流量のたとえば
800ml／minに調整する。この試料ガス供給手段
３において、電磁弁２１，２５が開けられると、
管路２０，２３を介して、濃度未知の一酸化窒素
ガスを含む試料ガスがミキシングジヨイント１８
に流入される。 The sample gas supply means 3 includes a sample gas cylinder 19
, a conduit 20 connected to the gas cylinder 19, a solenoid valve 21 interposed in the conduit 20 near the gas cylinder 19, a flow regulator 22 interposed in the conduit 20 downstream of the solenoid valve 21, and a flow rate regulator a pipe line 23 connecting the vessel 22 and the mixing joint 18;
It consists of a mixing joint 24 interposed in the conduit 23 closer to the flow rate regulator 22 and a solenoid valve 25 interposed downstream of the mixing joint 24 in the conduit 23. The sample gas cylinder 19 is a gas cylinder containing only a trace amount of nitrogen monoxide gas of unknown concentration.
The flow rate regulator 22 adjusts the flow rate of the sample gas, for example.
Adjust to 800ml/min. In this sample gas supply means 3, when the solenoid valves 21 and 25 are opened,
A sample gas containing nitrogen monoxide gas of unknown concentration is passed through the pipes 20 and 23 to the mixing joint 18.
is flowing into the country.
標準ガス供給手段４は、濃度既知の一酸化窒素
ガスをたとえば350ppb含む標準ガスボンベ２６
の窒素ガスを前記ミキシングジヨイント２４に流
入させる。標準ガス供給手段４は、標準ガスボン
ベ２６と、ガスボンベ２６に接続される管路２７
と、管路２７の窒素ガスボンベ２６寄りに介在さ
れる電磁弁２８と、管路２７の電磁弁２８の下流
に介在される流量調整器２９と、さらに流量調整
器２９の下流に介在される電磁弁３０と、電磁弁
３０と前記ミキシングジヨイント２４とを接続す
る管路４１と、電磁弁３０に連接される流量計４
２とから成る。流量調整器２９は、たとえば０〜
50ml／minの範囲で流量を制御する。電磁弁３０
は、標準ガスボンベ２６からの窒素ガスを管路４
１または流量計４２に切換える。 The standard gas supply means 4 includes a standard gas cylinder 26 containing nitrogen monoxide gas of known concentration, for example, 350 ppb.
of nitrogen gas is caused to flow into the mixing joint 24. The standard gas supply means 4 includes a standard gas cylinder 26 and a pipe line 27 connected to the gas cylinder 26.
, a solenoid valve 28 interposed in the conduit 27 near the nitrogen gas cylinder 26, a flow regulator 29 disposed downstream of the solenoid valve 28 in the conduit 27, and an electromagnetic valve disposed downstream of the flow regulator 29. A valve 30, a conduit 41 connecting the solenoid valve 30 and the mixing joint 24, and a flow meter 4 connected to the solenoid valve 30.
It consists of 2. The flow rate regulator 29 is, for example, 0 to
Control the flow rate within the range of 50ml/min. Solenoid valve 30
The nitrogen gas from the standard gas cylinder 26 is passed through the pipe 4.
1 or flowmeter 42.
濃縮分離手段５は、濃縮分離管４３と、濃縮分
離管４３と前記ミキシングジヨイント１８とを接
続する管路４４と、濃縮分離管４３と検出手段６
とを接続する管路４５と、管路４４に介在される
電磁弁４６と、管路４５に介在される電磁弁４７
と、濃縮分離管４３を冷却するための冷却剤１１
が満たされた容器４８と、第１図に仮想線で示す
濃縮分離管４３を加熱するためのヒータ４９が設
けられた加熱器５０と、分岐管５７とから成る。
分岐管５７は、管路４４の電磁弁４６の直上流と
管路４５の電磁弁４７の直下流とに介在され、管
路４４寄りに電磁弁５８と、管路４７寄りにニー
ドル弁５９とを備える。このニードル弁５９によ
つて、濃縮分離管４３による抵抗と同様の抵抗が
分岐管５７に負荷される。したがつて、分岐管５
７には、電磁弁４６，４７が連動して閉じられた
とき、電磁弁５８が開かれ、ニードル弁５９が調
整されて零ガス供給手段２からのキヤリアガスが
流入され、検出手段６に供給される。濃縮分離管
４３は、前述の冷却トラツプ１０とほぼ同様に構
成され、たとえば２mmの内径を有し、前記モレキ
ユラシーブ１６がたとえば0.5mlだけ充填されて
成る。容器４８と加熱器５０とは、濃縮分離管４
３を冷却または加熱するときに交換される。 The concentration separation means 5 includes a concentration separation tube 43, a pipe line 44 connecting the concentration separation tube 43 and the mixing joint 18, and a concentration separation tube 43 and the detection means 6.
a conduit 45 connecting the two, a solenoid valve 46 interposed in the conduit 44, and a solenoid valve 47 interposed in the conduit 45.
and a coolant 11 for cooling the concentration separation tube 43.
1, a heater 50 provided with a heater 49 for heating the concentration separation tube 43 shown in phantom lines in FIG. 1, and a branch tube 57.
The branch pipe 57 is interposed immediately upstream of the solenoid valve 46 in the conduit 44 and immediately downstream of the solenoid valve 47 in the conduit 45, with a solenoid valve 58 closer to the conduit 44 and a needle valve 59 closer to the conduit 47. Equipped with. This needle valve 59 applies resistance to the branch pipe 57 similar to the resistance caused by the concentration separation pipe 43 . Therefore, branch pipe 5
7, when the solenoid valves 46 and 47 are closed in conjunction with each other, the solenoid valve 58 is opened and the needle valve 59 is adjusted so that the carrier gas from the zero gas supply means 2 flows in and is supplied to the detection means 6. Ru. The concentration separation tube 43 is constructed in substantially the same manner as the cooling trap 10 described above, has an inner diameter of, for example, 2 mm, and is filled with the molecular sieve 16 in an amount of, for example, 0.5 ml. The container 48 and the heater 50 are connected to the concentration separation tube 4
3 is replaced when cooling or heating.
検出手段６は、化学発光法に基づく窒素酸化物
測定機５１と、前記管路４５に接続される流量計
５２と、流量計５２と窒素酸化物測定機５１とを
接続する管路５３と、管路５３の途中で分岐され
る分岐管５４と、分岐管５４に介在される流量計
５５と、流量計５５の上流に設けられた電磁弁５
６とから成る。 The detection means 6 includes a nitrogen oxide measuring device 51 based on a chemiluminescence method, a flow meter 52 connected to the pipe 45, and a pipe 53 connecting the flow meter 52 and the nitrogen oxide measuring device 51. A branch pipe 54 branched in the middle of the pipe line 53, a flow meter 55 interposed in the branch pipe 54, and a solenoid valve 5 provided upstream of the flow meter 55.
It consists of 6.
以下に述べるステツプによつてガス濃度が測定
される。ステツプ１では、試料ガス供給手段３か
ら測定すべき一酸化窒素ガスを含む試料ガスが濃
縮分離管４３に流過される。このとき、濃縮分離
管４３は冷却剤１１によつて一酸化窒素の融点以
下に冷却されている。したがつて試料ガス中に微
量だけ含まれる一酸化窒素ガスは、濃縮分離管４
３に充填されたモレキユラシーブ１６によつて捕
捉される。このため、この試料ガスをたとえば５
分間濃縮分離管４３を流過させることによつて、
一酸化窒素ガスはモレキユラシーブ１６表面で濃
縮される。この濃縮分離管４３を流過した後、試
料ガスの一部は測定機５１に流入され、試料ガス
の残部は分岐管５４から排気される。 Gas concentration is measured by the steps described below. In step 1, a sample gas containing nitrogen monoxide gas to be measured is passed from the sample gas supply means 3 to the concentration separation tube 43. At this time, the concentration separation tube 43 is cooled by the coolant 11 to a temperature below the melting point of nitrogen monoxide. Therefore, the trace amount of nitric oxide gas contained in the sample gas is removed from the concentration separation tube 4.
3 is captured by the molecular sieve 16 filled with 3. For this reason, this sample gas is
By passing through the concentration separation tube 43 for a minute,
Nitric oxide gas is concentrated on the surface of the molecular sieve 16. After passing through the concentration separation tube 43, a portion of the sample gas flows into the measuring device 51, and the remaining sample gas is exhausted from the branch tube 54.
ステツプ２では、電磁弁４６，４７が閉じら
れ、濃縮分離管４３は、容器４８に換えて加熱器
５０によつてたとえば250℃で４分間加熱される。
これによつてモレキユラシーブ１６表面で捕捉さ
れ濃縮されていた一酸化窒素ガスが遊離される。 In step 2, the solenoid valves 46 and 47 are closed, and the concentration separation tube 43 is heated, for example, at 250 DEG C. for 4 minutes by the heater 50 instead of the container 48.
As a result, the nitrogen monoxide gas that has been captured and concentrated on the surface of the molecular sieve 16 is liberated.
ステツプ３では、電磁弁４６，４７が開けら
れ、キヤリアガスとして零ガス供給手段２からの
窒素ガスが濃縮分離管４３を流過し、ステツプ２
によつて遊離された一酸化窒素ガスを窒素酸化物
測定機５１に流入させ、一酸化窒素ガス濃度が測
定される。 In step 3, the electromagnetic valves 46 and 47 are opened, and the nitrogen gas from the zero gas supply means 2 flows through the concentration separation pipe 43 as a carrier gas.
The nitrogen monoxide gas liberated by the nitrogen monoxide gas is allowed to flow into the nitrogen oxide measuring device 51, and the nitrogen monoxide gas concentration is measured.
ステツプ４では、試料ガス供給手段３からの測
定すべき一酸化窒素ガスを含む試料ガスと、標準
ガス供給手段からの流量調整器２９によつて流量
が調整された標準ガスとがミキシングジヨイント
２４によつて混合されて濃縮分離管４３に流過さ
れる。このとき、濃縮分離管４３は前述のステツ
プ１と同様に冷却されているので、混合されたガ
ス中に含まれている一酸化窒素ガスは、濃縮分離
管４３に充填されたモレキユラシーブ１６によつ
て捕捉される。この冷却濃縮操作をたとえば５分
間行ない、濃縮分離管４３を流過された後、混合
されたガスの一部は測定機５１に流入され、混合
されたガスの残部は分岐管５４から排気される。 In step 4, the sample gas containing nitrogen monoxide gas to be measured from the sample gas supply means 3 and the standard gas whose flow rate has been adjusted by the flow rate regulator 29 from the standard gas supply means are mixed at the mixing joint 24. The mixture is mixed by the filter and passed through the concentration separation tube 43. At this time, the concentration separation tube 43 is cooled in the same way as in step 1 described above, so the nitrogen monoxide gas contained in the mixed gas is removed by the molecular sieve 16 filled in the concentration separation tube 43. Captured. This cooling and concentration operation is carried out for, for example, 5 minutes, and after passing through the concentration separation pipe 43, a part of the mixed gas flows into the measuring device 51, and the remainder of the mixed gas is exhausted from the branch pipe 54. .
ステツプ５では、ステツプ２と同様の操作が行
なわれる。 In step 5, the same operation as in step 2 is performed.
ステツプ６では、零ガス供給手段２からの窒素
ガスがキヤリアガスとして濃縮分離管４３を流過
し、窒素酸化物測定機５１に流入され、一酸化窒
素ガス濃度が測定される。 In step 6, the nitrogen gas from the zero gas supply means 2 passes through the concentration separation tube 43 as a carrier gas, flows into the nitrogen oxide measuring device 51, and the nitrogen monoxide gas concentration is measured.
前述のステツプ４における試料ガスと標準ガス
との混合割合が順次変化されてステツプ４〜６が
繰り返される。したがつて、この混合割合によつ
て、濃度未知の試料ガスに添加される一酸化窒素
ガス濃度は、たとえば0.1，0.2，0.3ppbと変化さ
れる。 The mixing ratio of the sample gas and standard gas in step 4 described above is sequentially changed, and steps 4 to 6 are repeated. Therefore, depending on this mixing ratio, the concentration of nitrogen monoxide gas added to the sample gas of unknown concentration is changed to, for example, 0.1, 0.2, or 0.3 ppb.
このようにステツプ１〜６の手順によつて一酸
化窒素ガス濃度が測定され、得られた測定値を外
挿することによつて試料ガス中に含まれる一酸化
窒素ガス濃度が正確に測定される。ただし、この
外挿されたガス濃度は濃縮された一酸化窒素ガス
濃度であるので、試料ガスボンベ１９中の濃度に
換算する必要がある。 In this way, the nitric oxide gas concentration is measured according to steps 1 to 6, and by extrapolating the obtained measurement values, the nitric oxide gas concentration contained in the sample gas can be accurately measured. Ru. However, since this extrapolated gas concentration is the concentrated nitrogen monoxide gas concentration, it is necessary to convert it to the concentration in the sample gas cylinder 19.
本件発明者は、第４図に示すように濃縮分離管
４３における冷却濃縮時間を変化させたときの一
酸化窒素ガス濃度との関係を得ている。これによ
ると、第４図から明らかなように、試料ガスの冷
却濃縮時間と一酸化窒素ガス濃度とは、直線性を
示す。したがつて、前述の濃縮された一酸化窒素
ガス濃度から容易に試料ガスボンベ１９中に極め
て微量だけ含まれる一酸化窒素ガス濃度が求めら
れる。 As shown in FIG. 4, the inventor of the present invention has obtained a relationship with the nitrogen monoxide gas concentration when the cooling concentration time in the concentration separation tube 43 is varied. According to this, as is clear from FIG. 4, the cooling concentration time of the sample gas and the nitrogen monoxide gas concentration exhibit linearity. Therefore, the concentration of the nitrogen monoxide gas contained in the sample gas cylinder 19 in an extremely small amount can be easily determined from the concentration of the concentrated nitrogen monoxide gas described above.
上述の実施例では、冷却剤１１として液体酸素
が用いられたけれども、本発明の他の実施例とし
ては、液体空気が用いられてもよい。 Although liquid oxygen was used as the coolant 11 in the embodiments described above, liquid air may be used in other embodiments of the invention.
以上のように本発明によれば、第１および第２
濃縮分離管１０，４３は、一酸化窒素の融点以下
の沸点を有する液化ガスである冷却剤１１によつ
て冷却するようにしたので、モレキユラシーブに
よつて一酸化窒素ガスを確実に捕捉することがで
きる。これによつて第１濃縮分離管１０では、キ
ヤリアガス中の一酸化窒素ガスを充分に低濃度に
除去することができ、零ガスを得ることが可能と
なる。また第２濃縮分離管４３では、試料ガスに
含まれている一酸化窒素ガスを全て捕捉すること
が可能となる。こうして測定精度の向上を図るこ
とができる。 As described above, according to the present invention, the first and second
Since the concentration separation tubes 10 and 43 are cooled by the coolant 11, which is a liquefied gas having a boiling point below the melting point of nitric oxide, the molecular sieve can reliably capture the nitric oxide gas. can. As a result, in the first concentration separation tube 10, the nitrogen monoxide gas in the carrier gas can be removed to a sufficiently low concentration, making it possible to obtain zero gas. Furthermore, the second concentration separation tube 43 can capture all the nitrogen monoxide gas contained in the sample gas. In this way, measurement accuracy can be improved.
さらに本発明では、試料ガスよりも高い濃度で
一酸化窒素ガスを含む標準ガスを用い、試料ガス
と標準ガスとを予め定める混合割合で混合して、
第２濃縮分離管４３に供給して一酸化窒素ガスを
捕捉し、その後、第２濃縮分離管４３を加熱して
一酸化窒素ガスを遊離させて濃度測定し、こうし
て得られた測定値を外挿するようにしたので、試
料ガス中の一酸化窒素ガスの濃度を、さらに正確
に得ることが可能になる。 Furthermore, in the present invention, a standard gas containing nitric oxide gas at a higher concentration than the sample gas is used, and the sample gas and the standard gas are mixed at a predetermined mixing ratio,
The nitrogen monoxide gas is captured by supplying it to the second concentration separation tube 43, and then the second concentration separation tube 43 is heated to liberate the nitrogen monoxide gas to measure its concentration, and the measured value thus obtained is externally stored. Since the sample gas is inserted, it becomes possible to obtain the concentration of nitrogen monoxide gas in the sample gas more accurately.
特に本発明では、試料ガスと標準ガスとの混合
割合が順次変化されて、その一酸化窒素ガスの濃
度の測定動作が複数回繰返され、その測定値が外
挿されるので、試料ガス中の一酸化窒素ガスの濃
度を、そのような外挿された測定値に基づいて、
高精度で測定することが可能である。一般に、一
酸化窒素は、炭化水素とは異なり、活性炭に吸着
しにくい特性を有しており、しかもその一酸化窒
素の濃度は、極めて低濃度、たとえばppbのレベ
ルであり、このような、一酸化窒素ガスの低濃度
のものを、高精度で測定することは、本発明の特
許請求の範囲に記載されている構成によつて、始
めて可能になる。 In particular, in the present invention, the mixing ratio of the sample gas and the standard gas is sequentially changed, and the operation of measuring the concentration of nitrogen monoxide gas is repeated multiple times, and the measured value is extrapolated. Based on such extrapolated measurements, the concentration of nitric oxide gas is
It is possible to measure with high precision. In general, unlike hydrocarbons, nitric oxide has the property of being difficult to adsorb onto activated carbon, and the concentration of nitric oxide is extremely low, for example on the ppb level. Measuring low concentrations of nitrogen oxide gas with high precision becomes possible for the first time with the configuration described in the claims of the present invention.
第１図は本発明に従う一酸化窒素ガス濃度測定
装置１の簡略化した系統図、第２図は零ガス供給
手段２の冷却トラツプ１０の一部を示す断面図、
第３図は本発明に従うモレキユラシーブ１６を用
いて炭素数１〜３の炭化水素ガスを分離してフレ
ームイオン化検出器を用いて分析した結果を示す
グラフ、第４図は濃縮分離管４３における冷却濃
縮時間と一酸化窒素ガス濃度との関係を示すグラ
フである。
１……ガス濃度測定装置、２……零ガス供給手
段、３……試料ガス供給手段、４……標準ガス供
給手段、５……濃縮分離手段、６……検出手段、
７……窒素ガスボンベ、１０……冷却トラツプ、
１１……冷却剤、１２，４８……容器、１６……
モレキユラシーブ、１９……試料ガスボンベ、２
６……標準ガスボンベ、４３……濃縮分離管、５
０……加熱器、５１……窒素酸化物測定機。
FIG. 1 is a simplified system diagram of the nitrogen monoxide gas concentration measuring device 1 according to the present invention, and FIG. 2 is a sectional view showing a part of the cooling trap 10 of the zero gas supply means 2.
FIG. 3 is a graph showing the results of separating a hydrocarbon gas having 1 to 3 carbon atoms using the molecular sieve 16 according to the present invention and analyzing it using a flame ionization detector. It is a graph showing the relationship between time and nitric oxide gas concentration. DESCRIPTION OF SYMBOLS 1... Gas concentration measuring device, 2... Zero gas supply means, 3... Sample gas supply means, 4... Standard gas supply means, 5... Concentration separation means, 6... Detection means,
7...Nitrogen gas cylinder, 10...Cooling trap,
11... Coolant, 12, 48... Container, 16...
Molecular sieve, 19...Sample gas cylinder, 2
6...Standard gas cylinder, 43...Concentration separation tube, 5
0... Heater, 51... Nitrogen oxide measuring device.
Claims (1)
Å、60〜80メツシユの粒状のモレキユラシーブが
それぞれ充填された第１および第２濃縮分離管１
０，４３を準備し、 第１および第２濃縮分離管１０，４３を、一酸
化窒素の融点以下の沸点を有する液化ガスである
冷却剤１１によつて冷却し、 第１濃縮分離管１０には、キヤリアガスを供給
した試料ガスよりも充分に低濃度の一酸化窒素ガ
スを含む零ガスを得、 試料ガスと零ガスとを混合して冷却剤１１によ
つて冷却されている第２濃縮分離管４３に供給
し、その後、第２濃縮分離管４３の冷却剤１１を
取外して、第２濃縮分離管４３を加熱器５０によ
つて加熱し、そのモレキユラシーブから遊離した
一酸化窒素ガスを検出手段６に導いてモレキユラ
シーブから遊離した一酸化窒素ガスの濃度を測定
し、 さらにその後、試料ガスと、一酸化窒素ガスよ
りも高い濃度で含む標準ガスとを、予め定める混
合割合で混合して、冷却剤１１によつて冷却され
ている第２濃縮分離管４３に供給し、その後、第
２濃縮分離管４３の冷却剤１１を取外して、第２
濃縮分離管４３を加熱器５０によつて加熱し、そ
のモレキユラシーブから遊離した一酸化窒素ガス
を検出手段６に導いてモレキユラシーブから遊離
した一酸化窒素ガスの濃度を測定してその測定値
を外挿し、このステツプを、試料ガスと標準ガス
との混合割合を順次変化して複数回、繰返して行
つて、その測定値を、外挿し、 これによつて試料ガス中の一酸化窒素ガスの濃
度を正確に得ることを特徴とする一酸化窒素のガ
ス濃度測定方法。[Claims] 1. Average fine diameter of 10 Å to 20 Å formed from high-purity carbon.
Å, first and second concentration separation tubes 1 each filled with 60 to 80 mesh granular molecular sieves.
0 and 43 are prepared, the first and second concentrating separation tubes 10 and 43 are cooled with a coolant 11 which is a liquefied gas having a boiling point below the melting point of nitrogen monoxide, and the first concentrating separation tube 10 is obtains a zero gas containing nitrogen monoxide gas at a sufficiently lower concentration than the sample gas supplied with the carrier gas, and performs a second concentration separation process in which the sample gas and the zero gas are mixed and cooled by the coolant 11. After that, the coolant 11 of the second concentration separation tube 43 is removed, the second concentration separation tube 43 is heated by the heater 50, and the nitrogen monoxide gas liberated from the molecular sieve is detected by the detection means. 6 to measure the concentration of nitrogen monoxide gas liberated from the molecular sieve, and then mix the sample gas with a standard gas containing a higher concentration than nitrogen monoxide gas at a predetermined mixing ratio and cool it. The refrigerant 11 is supplied to the second concentration separation tube 43 which is cooled by the refrigerant 11, and then the refrigerant 11 of the second concentration separation tube 43 is removed and the second concentration separation tube 43 is cooled.
The concentration separation tube 43 is heated by the heater 50, and the nitrogen monoxide gas released from the molecular sieve is guided to the detection means 6, the concentration of the nitrogen monoxide gas released from the molecular sieve is measured, and the measured value is extrapolated. , this step is repeated several times by sequentially changing the mixing ratio of the sample gas and standard gas, and the measured values are extrapolated, thereby determining the concentration of nitric oxide gas in the sample gas. A method for measuring the gas concentration of nitric oxide, which is characterized in that it can be obtained accurately.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6930882A JPS5951347A (en) | 1982-04-23 | 1982-04-23 | Measurement of gas concentration |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6930882A JPS5951347A (en) | 1982-04-23 | 1982-04-23 | Measurement of gas concentration |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5951347A JPS5951347A (en) | 1984-03-24 |
| JPH0454178B2 true JPH0454178B2 (en) | 1992-08-28 |
Family
ID=13398798
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6930882A Granted JPS5951347A (en) | 1982-04-23 | 1982-04-23 | Measurement of gas concentration |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5951347A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102087179B (en) * | 2011-01-20 | 2012-11-14 | 北京雪迪龙科技股份有限公司 | Infrared gas analysis pretreatment system |
| JP2014059204A (en) * | 2012-09-18 | 2014-04-03 | Taiyo Nippon Sanso Corp | Gas sampling device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4845286A (en) * | 1971-10-11 | 1973-06-28 | ||
| JPS533393A (en) * | 1976-06-30 | 1978-01-13 | Ebara Mfg | Method and apparatus for n20 analysis |
-
1982
- 1982-04-23 JP JP6930882A patent/JPS5951347A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5951347A (en) | 1984-03-24 |
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