JPS63263381A - Method of controlling concentration of nitrogen in raw material argon - Google Patents
Method of controlling concentration of nitrogen in raw material argonInfo
- Publication number
- JPS63263381A JPS63263381A JP9674087A JP9674087A JPS63263381A JP S63263381 A JPS63263381 A JP S63263381A JP 9674087 A JP9674087 A JP 9674087A JP 9674087 A JP9674087 A JP 9674087A JP S63263381 A JPS63263381 A JP S63263381A
- Authority
- JP
- Japan
- Prior art keywords
- argon
- nitrogen concentration
- oxygen
- raw material
- nitrogen
- 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.)
- Pending
Links
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 title claims description 162
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 title claims description 150
- 229910052786 argon Inorganic materials 0.000 title claims description 81
- 229910052757 nitrogen Inorganic materials 0.000 title claims description 76
- 239000002994 raw material Substances 0.000 title claims description 42
- 238000000034 method Methods 0.000 title claims description 23
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 47
- 229910052760 oxygen Inorganic materials 0.000 claims description 47
- 239000001301 oxygen Substances 0.000 claims description 47
- 239000002826 coolant Substances 0.000 claims description 4
- 230000001276 controlling effect Effects 0.000 description 9
- 238000010586 diagram Methods 0.000 description 6
- 239000007789 gas Substances 0.000 description 6
- 238000000605 extraction Methods 0.000 description 4
- 238000009835 boiling Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000004817 gas chromatography Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 101100435268 Caenorhabditis elegans arf-1.2 gene Proteins 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04642—Recovering noble gases from air
- F25J3/04648—Recovering noble gases from air argon
- F25J3/04654—Producing crude argon in a crude argon column
- F25J3/04666—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
- F25J3/04284—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams
- F25J3/0429—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams of feed air, e.g. used as waste or product air or expanded into an auxiliary column
- F25J3/04303—Lachmann expansion, i.e. expanded into oxygen producing or low pressure column
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04406—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system
- F25J3/04412—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system in a classical double column flowsheet, i.e. with thermal coupling by a main reboiler-condenser in the bottom of low pressure respectively top of high pressure column
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04763—Start-up or control of the process; Details of the apparatus used
- F25J3/04769—Operation, control and regulation of the process; Instrumentation within the process
- F25J3/04793—Rectification, e.g. columns; Reboiler-condenser
- F25J3/048—Argon recovery
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04763—Start-up or control of the process; Details of the apparatus used
- F25J3/04769—Operation, control and regulation of the process; Instrumentation within the process
- F25J3/04848—Control strategy, e.g. advanced process control or dynamic modeling
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Separation By Low-Temperature Treatments (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、空気を原料とし酸素、窒素を蒸留する酸素精
留塔上塔の中はどから、アルゴンを生成する別の精留塔
への原料として含アルゴンガス（以下、「原料アルゴン
」という）を抜出す際の操業の制御方法に関する。Detailed Description of the Invention (Industrial Field of Application) The present invention is directed to an oxygen rectification column that uses air as a raw material to distill oxygen and nitrogen from the inside of the upper column to another rectification column that produces argon. This invention relates to a method for controlling operations when extracting argon-containing gas (hereinafter referred to as "raw material argon") as a raw material.
（従来の技術）
従来よりすでに良く知られているように、空気分離法に
よるアルゴンガスの製造はいわゆる高圧式と低圧式とが
あるが、いずれの場合にあっても、例えば第１図に示す
ように酸素精留塔上塔の中程から抜出す原料アルゴンを
さらに精製することにより製造している。(Prior Art) As is already well known, there are two types of argon gas production using the air separation method: the so-called high-pressure method and the low-pressure method. It is produced by further refining the raw material argon extracted from the middle of the upper column of the oxygen rectification column.
前記上塔内では沸点の低い窒素が塔頂に、沸点の高い酸
素が塔底に濃縮され、そして沸点が窒素より高く酸素よ
り低いアルゴンは塔の中程に集まるのである。In the upper column, nitrogen with a low boiling point is concentrated at the top of the column, oxygen with a high boiling point is concentrated at the bottom of the column, and argon, whose boiling point is higher than that of nitrogen but lower than that of oxygen, is concentrated in the middle of the column.
このように、原料アルゴンを抜出す場合、アルゴンを生
成するアルゴン精留塔の原料、つまり原料アルゴンに窒
素が多量に、例えば１１０００ｐｐ以上存在すると、ア
ルゴン精留塔の上部の窒素濃度が上昇し、塔頂より取り
出されるアルゴン中に制約量以上に窒素が混入してしま
い、またそれを防ぐべく抜出量を減少させると塔内にガ
スがたまり圧力が増加し精留塔の運転が不可能となり、
またそれを防ぐべく塔頂からガスを抜出すとその排出ガ
ス中に７０％ものアルゴンが存在し、アルゴン歩Ｉりの
低下となってしまう。In this way, when extracting raw material argon, if a large amount of nitrogen exists in the raw material of the argon rectification column that produces argon, that is, the raw material argon, for example, 11,000 pp or more, the nitrogen concentration in the upper part of the argon rectification column increases, If more nitrogen than the restricted amount gets mixed into the argon taken out from the top of the tower, and if the amount of extraction is reduced to prevent this, gas will accumulate in the tower and the pressure will increase, making it impossible to operate the rectification tower. ,
Furthermore, if the gas is extracted from the top of the tower to prevent this, as much as 70% argon will be present in the exhaust gas, resulting in a decrease in the argon rate.
しかし、原料アルゴン中のアルゴン濃度と窒素濃度には
正の関係があり、窒素濃度を制約ぎりぎり、例えば１１
０００ｐｐ＋以下できるだけ高く保持することによりア
ルゴン精留塔から回収されるアルゴンの歩留りの向上が
可能となる。However, there is a positive relationship between the argon concentration and nitrogen concentration in the raw material argon, and if the nitrogen concentration is limited, for example 11
By keeping the amount as high as possible below 000 pp+, it is possible to improve the yield of argon recovered from the argon rectification column.
ところで、原料アルゴン中の窒素濃度が低いため、連続
測定は不可能であり、１０分間に１回、所要時間１０分
のガスクロマトグラフィ分析により測定し、管理を行っ
ていた。また、その管理もオペレータの経験により３０
分間に一回程度の操作のみであり、窒素濃度を１０００
ｐｐ−以下に保つべく、非常に低濃度の安全サイドの操
業を実施し、そのためアルゴン歩留りも低かった。By the way, since the nitrogen concentration in the raw material argon is low, continuous measurement is impossible, and management is performed by measuring once every 10 minutes by gas chromatography analysis, which takes 10 minutes. In addition, its management depends on the operator's experience.
It only needs to be operated once a minute, and the nitrogen concentration can be reduced to 1000.
We operated on the safe side with very low concentrations to keep it below pp-, so the argon yield was low.
（発明が解決しようとする問題点）
本発明の目的は、原料アルゴン中の窒素濃度を限度内に
あって可及的に多量に保持すべく酸素精留塔からの原料
アルゴン中の窒素量を制御することにより、アルゴン濃
度、収率を向上させる方法を提供することである。(Problems to be Solved by the Invention) The purpose of the present invention is to reduce the amount of nitrogen in the raw argon from the oxygen rectification column in order to keep the nitrogen concentration in the raw argon within limits and as large as possible. The object of the present invention is to provide a method for improving argon concentration and yield by controlling the argon concentration.
本発明の別の目的とするところは、原料アルゴン中の窒
素濃度の連続的な間接測定を可能とし、その測定データ
により、窒素濃度を連続的に精度良く予測し酸素精留塔
からの原料アルゴンガス中の窒素濃度をある制約内に保
ち、アルゴン精留塔におけるアルゴン濃度、収率を向上
させる方法を提供することである。Another object of the present invention is to enable continuous indirect measurement of the nitrogen concentration in the raw material argon, and use the measured data to continuously and accurately predict the nitrogen concentration in the raw material argon from the oxygen rectification column. The object of the present invention is to provide a method for maintaining the nitrogen concentration in a gas within certain limits and improving the argon concentration and yield in an argon rectification column.
（問題点を解決するための手段）
かくして、本発明者らはかかる目的達成のため種々検討
を重ねたところ、まず、原料アルゴン中の窒素濃度を間
接的に連続測定する方法としては、原料アルゴン中の窒
素濃度と非常に関係の大なる連続測定容易な成分の濃度
さらには段の温度等からの推定式により間接的に連続測
定可能となることを知見した。(Means for Solving the Problems) Thus, the inventors of the present invention have conducted various studies in order to achieve this objective, and have found that a method for indirectly and continuously measuring the nitrogen concentration in raw material argon is as follows. It was discovered that the concentration of a component that has a strong relationship with the nitrogen concentration in the tank and is easy to measure continuously, and that it is possible to indirectly measure the concentration continuously using an estimation formula based on the stage temperature, etc.
また、そのようにして連続測定可能となった窒素濃度の
データにより、窒素濃度を連続的に精度良く予測する事
が可能となり、ある時間後の予測値と目標値の差にゲイ
ンをかけ、酸素精留塔の原料空気量などの操作量を求め
るなどして１分に１回程度操作する計算機制御により、
原料アルゴン中の窒素濃度をある制約範囲内に保つこと
が可能となることを知見した。In addition, with the nitrogen concentration data that can be measured continuously in this way, it is now possible to predict the nitrogen concentration continuously and with high accuracy, and by applying a gain to the difference between the predicted value after a certain time and the target value, Through computer control, operations are performed approximately once a minute, such as by determining operating variables such as the amount of raw air in the rectification column.
It has been found that it is possible to maintain the nitrogen concentration in the raw material argon within a certain constraint range.
よって、本発明の要旨とするところは、空気を原料とし
て酸素および窒素を分離する酸素精留塔上塔から原料ア
ルゴンを抜出す際における該原料アルゴン中の窒素濃度
を制御する方法であって、前記酸素精留塔の特定の段の
特定の成分の濃度または温度より前記窒素濃度を推定す
ることを特徴とする、酸素精留塔からの原料アルゴン中
の窒素濃度制御法である。Therefore, the gist of the present invention is a method for controlling the nitrogen concentration in the raw argon when the raw argon is extracted from the upper column of an oxygen rectification column that separates oxygen and nitrogen using air as the raw material, This is a method for controlling nitrogen concentration in raw argon from an oxygen rectification column, characterized in that the nitrogen concentration is estimated from the concentration or temperature of a specific component in a specific stage of the oxygen rectification column.
また、別の面力〕らは、本発明は、空気を原料として酸
素および窒素を分離する酸素精留塔上塔から原料アルゴ
ンを抜出す際における該原料アルゴン中の窒素濃度を制
御する方法であって、原料アルゴン中の窒素濃度と酸素
精留塔の操作量とから予め求めておいた応答特性の関係
から所定時間後の原料アルゴン中の窒素濃度を予測し、
この予測値と目標値の差にゲインをかけ、上記湿作量の
変更量を求めそれに応じて操作量を変更しながら連続操
作することにより、原料アルゴン中の窒素濃度を最適範
囲内に保つことを特徴とする、酸素精留塔からの原料ア
ルゴン中の窒素濃度制御法である。Furthermore, the present invention provides a method for controlling the nitrogen concentration in raw argon when the raw argon is extracted from an upper column of an oxygen rectification column that uses air as a raw material to separate oxygen and nitrogen. Then, the nitrogen concentration in the raw material argon after a predetermined time is predicted from the relationship between the response characteristics determined in advance from the nitrogen concentration in the raw material argon and the operation amount of the oxygen rectification column,
The difference between this predicted value and the target value is multiplied by a gain to determine the amount of change in the above-mentioned wet cropping amount, and the nitrogen concentration in the raw material argon is maintained within the optimum range by continuously operating while changing the operating amount accordingly. This is a method for controlling nitrogen concentration in raw argon from an oxygen rectification column.
なお、前記操作量が前記酸素精留塔上塔からの酸素抜出
量、投入原料空気量、原料を一部過冷する場合における
過冷空気量、そのための冷却媒体流量、昇圧圧力、およ
び膨張タービン入口温度から成る群から選ばれた少なく
とも１種である。Note that the manipulated variables include the amount of oxygen extracted from the upper column of the oxygen rectification column, the amount of feedstock air input, the amount of subcooled air when partially subcooling the feedstock, the flow rate of the cooling medium for that purpose, the boost pressure, and the expansion. At least one type selected from the group consisting of turbine inlet temperature.
（作用）
次に、添付図面を参照しながら、本発明をさらに詳細に
説明する。(Operation) Next, the present invention will be described in further detail with reference to the accompanying drawings.
本発明によれば、原料アルゴン中の窒素濃度を直接測定
する代わりにそれと相関の深い他の測定容易な因子を計
測の対象とするのである。According to the present invention, instead of directly measuring the nitrogen concentration in the raw material argon, other easily measurable factors that are closely correlated with it are measured.
本発明者らの研究によると、酸素精留塔全８０殿中上塔
の４２〜４９段（原料アルゴン抜出段である３６段より
、６〜１３段上の段）付近で酸素濃度、アルゴン濃度、
窒素濃度、そして温度が急変していることがわかった。According to the research conducted by the present inventors, oxygen concentration and argon concentration near the 42nd to 49th stages of the upper column (6 to 13 stages above the 36th stage, which is the raw material argon extraction stage) of the 80 fractions of the oxygen rectification column. ,
It was found that the nitrogen concentration and temperature were changing rapidly.
それゆえそれらの値と原料アルゴン中窒素濃度が関係を
持っていることが予想され、例えば４５段の酸素濃度に
ついては、第２図のような原料アルゴン中の窒素濃度と
の相関図が得られ、これより下記の推定式が得られた。Therefore, it is expected that there is a relationship between these values and the nitrogen concentration in the raw material argon, and for example, for the oxygen concentration in the 45th stage, a correlation diagram with the nitrogen concentration in the raw material argon as shown in Figure 2 can be obtained. From this, the following estimation formula was obtained.
但し、Ｃｏ１：原料＾ｒ中０□濃度（ト）同様にして、
特定段におけるアルゴン濃度、窒素濃度、温度からの原
料アルゴン中の窒素濃度推定式がそれぞれ次のようにし
て得られる：Ｃ’、ｌ＊（ｐｐｍ） ＝ｔｏ
ＨＨＨ＋ ＋ （４まただし、Ｃ’ｓｔ：原料Ａｒ
中Ｎ！濃度Ｃｐｐ−＞ｃＡｒ Ｉ特定段Ａｒｆ１度（％
）
ａａｒ、ｂｏ：定数
ＣＨＩ ｌ特定段Ｎ：濃度（％）
ａＮ！ｂ、ｌ！：定数
Ｔ ：特定段温度じＫ）
ａ７、ｂ７：定数 ≠昧
このように、本発明によれば、（１）〜（４）式のいず
れかを利用し、１０分間に一回のガスクロマトグラフィ
分析値にて補正することにより、原料アルゴン中の窒素
濃度の信転性の高い連続間接測定が可能となった。However, Co1: 0□ concentration (g) in the raw material ^r Similarly,
The equation for estimating the nitrogen concentration in the raw material argon from the argon concentration, nitrogen concentration, and temperature at a specific stage can be obtained as follows: C', l * (ppm) = to
HHH+ + (4 squares, C'st: raw material Ar
Middle N! Concentration Cpp->cAr I specific stage Arf 1 degree (%
) aar, bo: Constant CHI lSpecific stage N: Concentration (%) aN! b, l! : constant T : specific stage temperature (K) a7, b7: constant ≠ In this way, according to the present invention, gas chromatography is performed once every 10 minutes by using any of equations (1) to (4). By correcting the analytical values, it became possible to continuously and indirectly measure the nitrogen concentration in the raw material argon with high reliability.
なお、上記の特定段としては前述のように酸素、窒素濃
度などが急変する段が好ましく、その具体的段に応じ各
定数が定められる。It should be noted that the above-mentioned specific stage is preferably a stage in which oxygen, nitrogen concentration, etc. change suddenly as described above, and each constant is determined depending on the specific stage.
次に、酸素精留塔上塔からの原料アルゴンの抜出の制御
方法、つまり原料アルゴン中の窒素濃度を絶えず一定範
囲内にくるような酸素精留塔の操作方法を考察する。Next, a method of controlling the extraction of raw argon from the upper column of the oxygen rectification column, that is, a method of operating the oxygen rectification column such that the nitrogen concentration in the raw argon is constantly within a certain range will be discussed.
本発明によれば、前述のように窒素濃度の連続測定が可
能となるから、これを応用することにより、原料アルゴ
ン中の窒素濃度と投入原料空気量などの酸素精留塔の操
作量とから予め求めておいた応答特性の関係にもとすい
て所定時間後の原料アルゴン中の窒素濃度を予測し、こ
の予測値と目標値の差にゲインをかけ、上記操作量の変
更量を求めそれに応じて操作量を変更しながら連続操作
することにより、窒素濃度を最適範囲内に保つことがで
き、るのである。According to the present invention, it is possible to continuously measure the nitrogen concentration as described above, and by applying this, it is possible to calculate the nitrogen concentration in the raw argon and the operation amount of the oxygen rectification column such as the input raw material air amount. The nitrogen concentration in the raw material argon after a predetermined time is predicted based on the response characteristic relationship determined in advance, and the difference between this predicted value and the target value is multiplied by a gain to determine the amount of change in the above manipulated variable. By continuously operating while changing the operating amount accordingly, the nitrogen concentration can be maintained within the optimum range.
第３図は、上述の関係を図示するもので、現時点（ｔ、
）でＬ時間後のモデル予測値を算出し、それに現時点で
のモデル誤差を上乗せし、これと目標値との差をとり、
その差にゲイン（Ｋ）をかけることにより、酸素精留塔
の操作量を変更するのである。このときの操作量として
は、酸素精留塔上塔からの酸素抜出量、投入原料空気量
、原料を一部過冷する場合における過冷空気量、そのた
めの冷却媒体流量、昇圧圧力、および膨張タービン入口
温度から成る群から選ばれる。FIG. 3 illustrates the above-mentioned relationship, and shows the current time (t,
), calculate the model predicted value after L hours, add the current model error to it, take the difference between this and the target value,
By multiplying the difference by a gain (K), the operating amount of the oxygen rectification column is changed. The manipulated variables at this time include the amount of oxygen extracted from the upper column of the oxygen rectification column, the amount of feedstock air input, the amount of subcooled air when partially subcooling the feedstock, the flow rate of the cooling medium for that purpose, the boost pressure, and selected from the group consisting of: expansion turbine inlet temperature;
この場合、各操作量による原料アルゴン中の窒素濃度Ｖ
（ｉ）の予測式は次のようにして求められる。In this case, the nitrogen concentration V in the raw material argon depending on each manipulated variable
The prediction formula (i) is obtained as follows.
例えば、第４図に示す破線のモデルを自己回帰モデル式
とした場合、高圧式の例を考えると、次の通りである。For example, if the model indicated by the broken line in FIG. 4 is an autoregressive model equation, then considering an example of a high voltage equation, the equation is as follows.
ただし、？ ＝１ｏｇＣ’Ｈ１
ｕｌ：酸素抜出１ （Ｎｒｒｒ／ｈｒ）ｕｔ：昇圧圧力
（ｋｇ／ａｄ）
ｕ３：冷却媒体流量（Ｎｎ？／ｈｒ）
ｕ、二過冷空気ｆｆ１（〜 ）
ｕｓ：原料空気量 （〃）
・・・・（５）
Ｃｊｔ ｂＪ＋ Ｃｊｔ ｄｊ＋ Ｃｊｔ ｆｊ ’
定数＋１ｙｌ ｎｌ＋ ｎ２Ｉ ｎ３１ ｎ４１
ｎＳ＋鵬、曽！ｌＩｌコ１ｍ４１１１．：定数（整数）
したがって、本発明によれば、このようなモデルにより
現在の各操作量がそのままホールドされるとして、Ｌ時
間後の出力を計算し、上記連続測定窒素から考えられる
モデル誤差を上乗せし推定し、目標値との偏差にゲイン
（Ｋ）をかけ各操作量の変更量を求め１分に１回程度設
定操作する。however,? =1ogC'H1 ul: Oxygen removal 1 (Nrrr/hr) ut: Boost pressure (kg/ad) u3: Cooling medium flow rate (Nn?/hr) u, 2 supercooled air ff1 (~ ) us: Raw material air amount (〃) ...(5) Cjt bJ+ Cjt dj+ Cjt fj'
Constant +1yl nl+ n2I n31 n41
nS+Peng, Zeng! lIlko1m4111. : constant (integer)
Therefore, according to the present invention, assuming that each current manipulated variable is held as is by such a model, the output after L time is calculated, and the model error considered from the above continuous measurement nitrogen is added and estimated, and the target is calculated. The deviation from the value is multiplied by a gain (K) to determine the amount of change in each manipulated variable, and the setting operation is performed approximately once a minute.
なお、低圧式酸素精留塔にあっても原料アルゴン中のＮ
ｔｙ度予測式は次のように同様に考えられる。Note that even in a low-pressure oxygen rectification column, N in the raw argon
The ty degree prediction formula can be similarly considered as follows.
ただし、ｕ、： 膨張タービン入口温度（０Ｋ）ａ’
Ｊ＋ ｔｌ’ｊ＋ ｅ＋、、 ｆ’ｊ＋ ｇ’ｊ ’定
数膨張タービン入口温度が操作量として加わる事となる
。However, u: Expansion turbine inlet temperature (0K) a'
J+ tl'j+ e+,, f'j+ g'j 'The constant expansion turbine inlet temperature is added as a manipulated variable.
次に、実施例によって本発明をさらに詳細に説明する。Next, the present invention will be explained in more detail with reference to Examples.
実施例
前述の制御方法で操作量を酸素抜出量とし、原料アルゴ
ン中の窒素濃度と操作量とから予め求めておいた応答特
性の関係から所定時間後の原料アルゴン中の窒素濃度を
予測し、この予測値と目標値の差にゲインをかけ、上記
操作量の変更量を求めそれに応じて操作量を変更しなが
ら連続操作した。このとき、第２図におけるし＝４５分
、に＝０．５、目標値を４００ｐｐｍとし、制御テスト
した。なお、原料アルゴン中の窒素濃度は第２図の関係
によって推定した。Example Using the control method described above, the manipulated variable is set as the amount of oxygen extraction, and the nitrogen concentration in the raw material argon after a predetermined time is predicted from the relationship between the response characteristics determined in advance from the nitrogen concentration in the raw material argon and the manipulated variable. The difference between this predicted value and the target value was multiplied by a gain to obtain the amount of change in the manipulated variable, and continuous operation was performed while changing the manipulated variable accordingly. At this time, a control test was carried out using the conditions of 45 minutes in FIG. 2, 0.5 and a target value of 400 ppm. Note that the nitrogen concentration in the raw material argon was estimated based on the relationship shown in FIG.
結果を第５図および第６図にグラフにまとめて示す。The results are summarized in graphs in FIGS. 5 and 6.
制御前は平均１９０ｐｐ−であった原料アルゴン中窒素
濃度は４００ｐｐ−まで上昇し、また制御前は、窒素濃
度１１０００ｐｐ以上となることが１２％程度存在して
いたのに対し、はとんど上限を超えることがなくなった
。The nitrogen concentration in the raw material argon, which was 190 pp- on average before the control, increased to 400 pp-, and before the control, the nitrogen concentration was 11,000 pp or more in about 12% of cases, but it is almost at the upper limit. It is no longer possible to exceed.
また、アルゴン歩留りにおいても７４．５％がら７６％
にまで約１．５％の向上が達成された。In addition, the argon yield increased from 74.5% to 76%.
An improvement of approximately 1.5% was achieved.
（発明の効果）
以上、本発明を説明してきたが、本発明によれば原料ア
ルゴン中の窒素濃度の連続的測定を可能にし、その測定
データにより制御系を作成し、窒素濃度を制約内で最大
に保ち、アルゴン収率を１゜５％向上させることができ
る。(Effects of the Invention) The present invention has been explained above.According to the present invention, it is possible to continuously measure the nitrogen concentration in raw material argon, create a control system based on the measured data, and keep the nitrogen concentration within constraints. The argon yield can be improved by 1.5%.
第１図は、酸素精留塔の模式的説明図：第２図は、原料
アルゴン中の窒素濃度と４５段の酸素濃度との相関を示
すグラフ；
第３図は、本発明にかかる原料アルゴン中の窒素濃度の
制御方法の説明図；
第４図は、酸素精留塔の各操作量からの原料アルゴン中
の窒素濃度を推定するモデルの構造の説明図；および
第５図および第６図は、本発明の実施例の結果を示すグ
ラフである。
出願人 住友金属工業株式会社（外１名）代理人 弁理
士 広 瀬 章 一
本！凹
：＃２国
４５ａｆｉ Ｏｘ （％ン
手続補正書（自局）
１．事件の表示
昭和６２年特許願第９６７４０号
２、発明の名称
原料アルゴン中の窒素濃度制御法
３、補正をする者
事件との関係 特許出願人
住所 大阪市東区北浜５丁目１５番地
名称 （２１１）住友金属工業株式会社 （外１名）４
、代理人
住所 〒１０１東京都千代田区内神田２丁目９番１４号
寄木ビル 電話（０３） ２５４−７７６７６、補正
の内容
（１）明細書第７真１６〜１７行目の「酸素精留塔全８
０殿中上塔の」をｒｍｍ精精留塔上塔全８０段中に訂正
する。
（２）明細書第８頁２行目のＶ第２図」をｒ第２図（ａ
） Ｊに訂正する。
（３）明細書第９頁８行目「このように、本発明・・・
」の前に次の文を挿入する。
ｒ また、４３段の温度については、第２図（ｂ）のよ
うな原料アルゴン中の窒素濃度との相関図が（ｉ）られ
、これより下記の推定式が得られた。
−０，３０３丁−５３，２
Ｃ′□（ｐｐｍ） ＝１０ ・・・（４
）゛同様にして、この特定段における酸素濃度、アルゴ
ン濃度、窒素濃度からの原料アルゴン中の窒素濃度制御
法が次のように得られる：Ｃ’ｎｔ（ｐｐｍ） ＝１０
・・・（３）’ただしく１）”〜（４）
式において
ａ’ｏｚ、ｂ’０２、”Ａｒｓ ｂ’Ａｒ、ａ’Ｎｌ、
ｂ’ｓｚ：定数であり、他の記号は（１１〜（４）式の
場合と同様である。
また、４０段の温度については第２図（Ｃ）のような原
料アルゴン中の窒素濃度との相関図が得られ、これより
下記の推定式が得られた。
同様にしてこの特定段における酸素濃度、アルゴン濃度
、窒素濃度からの原料アルゴン中の窒素濃度推定式が次
のように得られる：ただし上の（１）”〜（４どにおい
て、”０２ｓ ｂ″Ｏ！％ Ｃ”０２％ ａ”Ａｒｓ
１３’ｓｒｓ Ｃ’Ａｒ、 ａ’Ｈ２゜ｂＺＺＳＣ”ｎ
ｚ：定数
であり、他の記号は、（１）〜（４）式と同様である。
１（４）明細書第９頁９行日の「（１）〜（４）式」を
「（１）〜（４）式、（１）〜（４）°式、および（１
）１〜（４）”式ｊに訂正する。
（５）明細書第９頁９行目の「第２図」を「第２図（ａ
） Ｊに訂正する。
（６）明細書筒１４頁１４行目の「示すグラフ；」を１
示すグラフ、第２図Φ）は、該濃度と４３段の温度の相
関を示すグラフ、第２図（Ｃ）は該濃度と４０段の温度
の相関を示すグラフ；１に訂正する。
（７）図面「第２図」をｒ第２図（ａ）漠に訂正する。
（８）図面に別紙の第２図Φ）および第２図（Ｃ）を追
加する。
以上Figure 1 is a schematic explanatory diagram of an oxygen rectification column; Figure 2 is a graph showing the correlation between the nitrogen concentration in the raw argon and the oxygen concentration at the 45th stage; Figure 3 is a graph showing the correlation between the nitrogen concentration in the raw argon and the oxygen concentration in the 45th stage; An explanatory diagram of the method for controlling the nitrogen concentration in the argon; Figure 4 is an explanatory diagram of the structure of a model that estimates the nitrogen concentration in the raw argon from each operation amount of the oxygen rectification column; and Figures 5 and 6. is a graph showing the results of Examples of the present invention. Applicant: Sumitomo Metal Industries, Ltd. (1 other person) Representative: Patent attorney Akira Hirose Ippon! Concave: #2 Country 45afi Ox (% N Procedural Amendment (Own Bureau) Relationship with Patent Applicant Address 5-15 Kitahama, Higashi-ku, Osaka Name (211) Sumitomo Metal Industries, Ltd. (1 other person) 4
, Agent address: Yosegi Building, 2-9-14 Uchikanda, Chiyoda-ku, Tokyo 101 Telephone: (03) 254-77676 Contents of amendment (1) "Oxygen rectification tower" in line 16-17 of line 7 of the specification Total 8
0 in the upper column of the rectification column is corrected to 80 stages in total in the upper column of the rmm rectification column. (2) Figure 2 (a) on page 8, line 2 of the specification.
) Correct to J. (3) Page 9, line 8 of the specification: “In this way, the present invention...
Insert the following sentence before ``. r Regarding the temperature of the 43rd stage, a correlation diagram (i) with the nitrogen concentration in the raw argon as shown in FIG. 2(b) was obtained, and the following estimation formula was obtained from this. -0,303 blocks -53,2 C'□(ppm) =10...(4
) Similarly, the method for controlling the nitrogen concentration in the raw argon from the oxygen concentration, argon concentration, and nitrogen concentration at this particular stage is obtained as follows: C'nt (ppm) = 10
・・・(3) 'Just do it 1)''～(4)
In the formula a'oz, b'02, "Ars b'Ar, a'Nl,
b'sz: constant, other symbols are the same as in equations (11 to (4)). Also, regarding the temperature of the 40th stage, the nitrogen concentration in the raw material argon and the A correlation diagram was obtained, and from this the following estimation formula was obtained. Similarly, the equation for estimating the nitrogen concentration in the raw material argon from the oxygen concentration, argon concentration, and nitrogen concentration at this particular stage can be obtained as follows. :However, in (1)” to (4) above, “02s b”O!% C”02% a”Ars
13'srs C'Ar, a'H2゜bZZSC"n
z: a constant; other symbols are the same as in formulas (1) to (4). 1 (4) Expressions (1) to (4) on page 9, line 9 of the specification are changed to “formulas (1) to (4), (1) to (4)°, and (1)
) 1 to (4) "Formula j." (5) Change "Figure 2" on page 9, line 9 of the specification to "Figure
) Correct to J. (6) In the 14th line of page 14 of the specification cylinder, set “Graph to show;” to 1
The graph shown in FIG. 2 Φ) is a graph showing the correlation between the concentration and the temperature at the 43rd step, and FIG. 2 (C) is a graph showing the correlation between the concentration and the temperature at the 40th step; corrected to 1. (7) The drawing “Figure 2” has been vaguely corrected in Figure 2 (a). (8) Add attached Figure 2 Φ) and Figure 2 (C) to the drawings. that's all
Claims (4)
精留塔上塔から原料アルゴンを抜出す際における該原料
アルゴン中の窒素濃度を制御する方法であって、前記酸
素精留塔の特定の段の特定の成分の濃度または温度より
前記窒素濃度を推定することを特徴とする、酸素精留塔
からの原料アルゴン中の窒素濃度制御法。(1) A method for controlling the nitrogen concentration in raw argon when extracting the raw material argon from an upper column of an oxygen rectification column that separates oxygen and nitrogen using air as a raw material, the method comprising: A method for controlling nitrogen concentration in raw argon from an oxygen rectification column, characterized in that the nitrogen concentration is estimated from the concentration or temperature of a specific component in the stage.
精留塔上塔から原料アルゴンを抜出す際における該原料
アルゴン中の窒素濃度を制御する方法であって、原料ア
ルゴン中の窒素濃度と酸素精留塔の操作量とから予め求
めておいた応答特性の関係から所定時間後の原料アルゴ
ン中の窒素濃度を予測し、この予測値と目標値の差にゲ
インをかけ、上記操作量の変更量を求めそれに応じて操
作量を変更しながら連続操作することにより、原料アル
ゴン中の窒素濃度を最適範囲内に保つことを特徴とする
、酸素精留塔からの原料アルゴン中の窒素濃度制御法。(2) A method for controlling the nitrogen concentration in the raw argon when the raw argon is extracted from the upper column of an oxygen rectification column that separates oxygen and nitrogen using air as the raw material, the nitrogen concentration in the raw argon and the oxygen The nitrogen concentration in the raw material argon after a predetermined time is predicted from the relationship between the response characteristics determined in advance from the manipulated variable of the rectification column, and the difference between this predicted value and the target value is multiplied by a gain to change the manipulated variable. A method for controlling the nitrogen concentration in raw argon from an oxygen rectification column, which is characterized by keeping the nitrogen concentration in raw argon within an optimal range by determining the amount of nitrogen and performing continuous operation while changing the operating amount accordingly. .
たは温度より原料アルゴン中の窒素濃度を推定する、特
許請求の範囲第２項記載の方法。(3) The method according to claim 2, wherein the nitrogen concentration in the raw argon is estimated from the concentration or temperature of a specific component in a specific stage of the oxygen rectification column.
量、投入原料空気量、原料を一部過冷する場合における
過冷空気量、そのための冷却媒体流量、昇圧圧力、およ
び膨張タービン入口温度から成る群から選ばれた少なく
とも１種である、特許請求の範囲第２項または第３項記
載の方法。(4) The manipulated variables include the amount of oxygen extracted from the upper column of the oxygen rectification column, the amount of input feedstock air, the amount of subcooled air when partially subcooling the feedstock, the flow rate of the cooling medium for that purpose, the boost pressure, and 4. The method according to claim 2 or 3, wherein the temperature is at least one selected from the group consisting of: expansion turbine inlet temperature;
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9674087A JPS63263381A (en) | 1987-04-20 | 1987-04-20 | Method of controlling concentration of nitrogen in raw material argon |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9674087A JPS63263381A (en) | 1987-04-20 | 1987-04-20 | Method of controlling concentration of nitrogen in raw material argon |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63263381A true JPS63263381A (en) | 1988-10-31 |
Family
ID=14173094
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9674087A Pending JPS63263381A (en) | 1987-04-20 | 1987-04-20 | Method of controlling concentration of nitrogen in raw material argon |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63263381A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0609814A1 (en) * | 1993-02-01 | 1994-08-10 | Praxair Technology, Inc. | Process for maximizing the recovery of argon from an air separation system at high argon recovery rates |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5413469A (en) * | 1977-07-01 | 1979-01-31 | Hitachi Ltd | Controlling method for air separation plant |
| JPS5560164A (en) * | 1978-10-25 | 1980-05-07 | Hitachi Ltd | Method of automatically operating coarse argon tower |
-
1987
- 1987-04-20 JP JP9674087A patent/JPS63263381A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5413469A (en) * | 1977-07-01 | 1979-01-31 | Hitachi Ltd | Controlling method for air separation plant |
| JPS5560164A (en) * | 1978-10-25 | 1980-05-07 | Hitachi Ltd | Method of automatically operating coarse argon tower |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0609814A1 (en) * | 1993-02-01 | 1994-08-10 | Praxair Technology, Inc. | Process for maximizing the recovery of argon from an air separation system at high argon recovery rates |
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