JPS63478B2 - - Google Patents
Info
- Publication number
- JPS63478B2 JPS63478B2 JP59009891A JP989184A JPS63478B2 JP S63478 B2 JPS63478 B2 JP S63478B2 JP 59009891 A JP59009891 A JP 59009891A JP 989184 A JP989184 A JP 989184A JP S63478 B2 JPS63478 B2 JP S63478B2
- Authority
- JP
- Japan
- Prior art keywords
- alloy
- carbon precipitation
- treatment
- carbon
- oxide film
- 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
- 229910045601 alloy Inorganic materials 0.000 claims description 33
- 239000000956 alloy Substances 0.000 claims description 33
- 229910052799 carbon Inorganic materials 0.000 claims description 32
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 31
- 239000000463 material Substances 0.000 claims description 28
- 238000001556 precipitation Methods 0.000 claims description 25
- 239000012530 fluid Substances 0.000 claims description 15
- 229910052782 aluminium Inorganic materials 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 9
- 229930195733 hydrocarbon Natural products 0.000 claims description 8
- 150000002430 hydrocarbons Chemical class 0.000 claims description 8
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 7
- 238000005269 aluminizing Methods 0.000 claims description 7
- 239000010953 base metal Substances 0.000 claims description 7
- 230000002401 inhibitory effect Effects 0.000 claims description 7
- 229910001092 metal group alloy Inorganic materials 0.000 claims description 7
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 5
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 5
- 238000012545 processing Methods 0.000 claims description 5
- 238000005336 cracking Methods 0.000 claims description 4
- 229910000859 α-Fe Inorganic materials 0.000 claims description 4
- 230000001590 oxidative effect Effects 0.000 claims description 3
- 239000003575 carbonaceous material Substances 0.000 claims description 2
- 230000002265 prevention Effects 0.000 claims description 2
- 239000004215 Carbon black (E152) Substances 0.000 claims 1
- 229910003310 Ni-Al Inorganic materials 0.000 claims 1
- 238000000354 decomposition reaction Methods 0.000 claims 1
- 239000003112 inhibitor Substances 0.000 claims 1
- 239000002344 surface layer Substances 0.000 description 11
- 238000004519 manufacturing process Methods 0.000 description 10
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 9
- 229910000831 Steel Inorganic materials 0.000 description 9
- 229910052759 nickel Inorganic materials 0.000 description 9
- 239000010959 steel Substances 0.000 description 9
- 229910052742 iron Inorganic materials 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 6
- YNQLUTRBYVCPMQ-UHFFFAOYSA-N Ethylbenzene Chemical compound CCC1=CC=CC=C1 YNQLUTRBYVCPMQ-UHFFFAOYSA-N 0.000 description 6
- 239000005977 Ethylene Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 229910052723 transition metal Inorganic materials 0.000 description 6
- 238000004939 coking Methods 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 238000000151 deposition Methods 0.000 description 4
- 230000008021 deposition Effects 0.000 description 4
- 238000009792 diffusion process Methods 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 230000002829 reductive effect Effects 0.000 description 4
- 238000004381 surface treatment Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000000571 coke Substances 0.000 description 3
- 238000005235 decoking Methods 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 229910000851 Alloy steel Inorganic materials 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000012159 carrier gas Substances 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000006356 dehydrogenation reaction Methods 0.000 description 2
- 230000003111 delayed effect Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 150000003624 transition metals Chemical class 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 229910000885 Dual-phase steel Inorganic materials 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 150000004996 alkyl benzenes Chemical class 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910052728 basic metal Inorganic materials 0.000 description 1
- 150000003818 basic metals Chemical class 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000020335 dealkylation Effects 0.000 description 1
- 238000006900 dealkylation reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 239000012770 industrial material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 229910000765 intermetallic Inorganic materials 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- -1 or Conventionally Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000003449 preventive effect Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000007751 thermal spraying Methods 0.000 description 1
- 229930195735 unsaturated hydrocarbon Natural products 0.000 description 1
- 238000005292 vacuum distillation Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0006—Controlling or regulating processes
- B01J19/002—Avoiding undesirable reactions or side-effects, e.g. avoiding explosions, or improving the yield by suppressing side-reactions
- B01J19/0026—Avoiding carbon deposits
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
- C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
- C10B43/00—Preventing or removing incrustations
- C10B43/14—Preventing incrustations
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
- C10G9/14—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils in pipes or coils with or without auxiliary means, e.g. digesters, soaking drums, expansion means
- C10G9/16—Preventing or removing incrustation
Description
本発明はエチレン製造装置やデイレードコーキ
ング装置等のように炭化水素もしくはその誘導体
を水蒸気の存在下もしくは非存在下に加熱分解す
る場合、または合成ガス製造装置のように一酸化
炭素を含む流体を高温で取扱う場合における炭素
析出を防止し得る装置に関する。
これら装置はオーステナイト系鋼、フエライト
系鋼、オーステナイト・フエライト２相系ステン
レス鋼、低合金鋼等の材料で形成されているが、
操業中に高温流体にさらされる部分、例えば配管
（特に加熱炉管）、塔槽等に炭素が析出し、しばし
ば△Ｐの上昇、加熱効率の低下等の操業上の弊害
が生じ、謂ゆるデコーキングを頻繁に行う必要が
あつた。かかる操作は装置の定常運転の妨げとな
り、プロセスの経済性悪化の要因たることはいう
までもなく、装置の構成材料に対しても種々の不
利益をもたらすものである。
従来、これら装置における炭素析出を防止する
試みとして、例えばエチレン製造装置において微
量のH2Sを原料流体に添加することにより炭素析
出が若干抑えられるとの報告（B.L.Crynes、L.
F.Albright著のInd.Eng.Chem.Proc.−Design
and Development.８〔１〕（1969）25）があり、
一部で実施されているが、エチレン製造装置等の
分解管内部はそもそも酸化性雰囲気であるため十
分な効果があがつていないのが実情であつた。さ
らに炭素析出を抑止し得る材料自体の研究として
は各種の純金属について軽質炭化水素を用いたコ
ーキングの実験室規模の試験が行われてはいる
が、実装置への適用は本発明者の知るかぎり現在
のところ皆無である。
実装置にあつては、前述の如き本発明で対象と
する装置内面は酸化スケールで覆われている。
Lobo等の報文（Preprint for the 5th
International Congress on Catalysis、
Amsterdam（1972））によると、炭素析出は装置
の構成材料中に含有されるFe、Ni等の遷移金属
元素によつて惹き起こされ、これらの原子や金属
粒子が常に炭素析出層上表面に浮上したように現
われることにより析出が継続されるとしている。
実際、本発明者らの検討によれば装置部材内面に
析出したコークを分析するとFe、Ni等の遷移金
属元素が検知され、炭素析出が起こるのは部材表
面のFeやNiの酸化物が還元されたり、あるいは
表面の酸化層を通してFe、Ni等の遷移金属元素
が内部から拡散して供給されることに起因すると
推測される。
このようなことから、本発明者らは前述の如き
高温流体にさらされる部材として、オーステナイ
ト系鋼材、フエライト系鋼材、オーステナイト・
フエライト２相系鋼材および５％以上のCrを含
有する低合金鋼のいずれかの母材合金に１〜10重
量％のAlを含有せしめ且つその表面に酸化皮膜
を形成したものを使用する炭素析出防止性処理装
置を提案し、出願した（特願昭55−100993）。し
かしながら、本発明者らはその後の継続的研究に
よれば、母材合金にAlを含有させただけで使用
する場合の部材表面に形成される酸化皮膜は、そ
の皮膜安定性及びFeやNi等の遷移金属の浮上を
実質的に防止するためにはAlを少くとも５％を
越えて含有せしめる必要があり、このように多量
のAlを含有せしめる場合にはδ−フエライトや
金属間化合物の晶出や析出が生じ、常温での延性
の低下や高温クリープ強度の低下、更には機械加
工性の悪化といつた弊害が生ずる問題点を有する
ものであつた。
本発明はこれら従来の問題点を解消し、延性、
高温クリープ強度、機械加工性等が優れ、しかも
前述の如き遷移金属元素の表面への浮上を防止し
得る強固で安定なAlを含有する酸化皮膜を形成
して良好な炭素析出抑止性を発揮し得る部材を具
えた処理装置を提供することを目的とするもので
ある。
本発明によれば、前述装置における少くとも高
温流体にさらされる部材がAlを1.0〜5.0重量％含
有する母材合金の表面にアルミナイジングを施し
たものであり、さらに処理時にその部材表面に
Alを含有する酸化皮膜を形成したものであるこ
とを特徴とする炭素析出抑止性処理装置が提供さ
れる。
すなわち、本発明ではAl含量を1.0〜5.0重量％
と低く抑えた母材合金と所定の表面をアルミナイ
ジングの処理を施すことにより高アルミニウム化
することにより前述の如き問題点を一挙に解決し
たものである。
通常、Alを含有しない金属、合金にAl又はAl
含有合金による表面処理を施した場合、表面層自
体のAl濃度はかなり高い（50〜100重量％）こと
から、一時的には外表面にAl2O3を主体とする酸
化皮膜が形成されるが、高温（通常500℃以上）
で長時間使用するうちに、Alの２次拡散が起り、
表面のAl濃度の低下や表面層の剥離が生ずる。
そのため、Alが貧化した部分や表面層が剥離し
た箇所から酸化が進み、FeやNiを主成分とする
酸化皮膜が生成され、それらの一部が還元された
り、内部からFeやNiが浮上拡散して表面に現わ
れ、炭化水素、一酸化炭素等からの炭素析出を促
進するようになる。
しかるに、本発明では母材合金に機械的性質及
び加工性を損わない程度にAlを含有させるとと
もに、その表面にAl又はAl含有合金による表面
処理を施すことにより、表面層と母材合金内部と
のAlの濃度差が縮まり、濃度勾配が緩和される
ため、Alの２次拡散によつて生ずる表面のAl貧
化が抑制され、しかもカーケンドール効果によつ
て惹き起こされる表面層の剥離が起りにくくな
り、高温においても表面皮膜の安定性、健全性が
長期間に亘つて保障されるものである。
そのために、母材合金に含有せしめるAlは1.0
〜5.0重量％の範囲としなければならない。すな
わち母材合金に含有させるAlが1.0重量％未満で
は実用上、高温で長時間安定な含Al酸化皮膜を
維持し得ず、逆にAlが5.0重量％を越えると機械
的性質及び加工性が劣化する。
本発明において、Alを合金化すべき母材本体
の基本金属種としては若干のフエライト相の含有
を許容するオーステナイト系鋼であればよく、例
えばFe−Cr−Ni合金等から任意に選択し得る。
また、その製造方法も鍛伸材、鋳造材あるいは粉
末成形材等から任意に選択でき、従つてその製造
方法を選ぶことにより直管部のみならず曲管部、
それらの接合部材、あるいは塔槽等に適用し得
る。
また、上記の如き母材合金に対するAl又はAl
含有合金による表面処理法としては、Al溶融浸
漬処理、Al拡散浸透処理、Al含有自溶性合金の
溶射等の適宜のアルミナイジングを適用すること
ができる。
ここで本発明で対象とする処理装置としては次
のようなものが例挙される。すなわち、ナフサ、
エタン、ガスオイル等を水蒸気とともに750〜900
℃の温度（流体温度）において加熱炉内に設けら
れた分解管中を通過せしめエチレン等の軽質不飽
和炭化水素を製造することを目的とした謂ゆるエ
チレン製造装置、減圧蒸溜残渣油等を加熱管内で
予め昇温し、コークドラム内でコークス化を行う
デイレードコーキング装置、エチルベンゼンを高
温で水蒸気とともに反応せしめてスチレンを製造
するためのエチルベンゼン脱水素反応装置、各種
アルキルベンゼンの脱アルキル化装置、原料炭化
水素（メタン、LPG、ナフサ等）に水蒸気（部
分酸化法においては酸素を加える）を加えて加熱
し、一酸化炭素と水素を生成する合成ガス製造装
置のように炭化水素もしくはその誘導体、または
一酸化炭素を含む流体を処理する場合に使用さ
れ、高温にさらされる部分、例えば加熱炉（分解
炉、反応炉、予熱炉）、トランスフアライン、蒸
溜塔、熱交換器等の従来から炭素析出（特に熱交
換器において炭素質物質が析出する謂ゆるフアウ
リングをも含む、以下の本明細書で同様）が問題
となる部分を含む装置が挙げられる。
これら装置における少なくとも高温にさらされ
て炭素析出が問題となる構成部材としては、対象
とする処理装置の使用状況、条件に応じて母材合
金を前述した本発明範囲内にて適宜選択して使用
する。これらの使用形態としては単体としてのみ
ならず、部材内壁表面に被覆するなどして複合体
として用いることもできる。
母材合金表面にアルミナイジングを施した後の
Alを含有する酸化皮膜の形成態様は適用するプ
ロセスによつて異なる。すなわち、エチレン製造
装置の分解管もしくはエチルベンゼンの脱水素反
応のようにプロセス系内に稀釈媒体あるいは熱媒
体として水蒸気を含み、処理温度もしくは反応温
度において酸化状態に至る場合には被処理流体自
体が酸化性を有するため何らの処理を要すること
なく、処理もしくは反応開始後に部材内壁表面の
Alが酸化され、緻密な皮膜が形成される。処理
温度もしくは反応温度において被処理流体自体に
鋼材に対する酸化性がない場合もしくは少ない場
合は被処理流体をプロセス系内に導入する前に予
め内壁表面を適宜の手段で酸化しておくか、ある
いは酸化性流体を処理もしくは反応開始前に適量
流通せしめ、Alを含有する酸化皮膜が形成され
るような手段をとる。
かくして本発明では、従来から炭素析出が生ず
る部分の構成部材表面にAlを含有する酸化皮膜
が形成され、この皮膜は極めて緻密かつ堅牢で一
旦鋼材表面に形成されると物理的、化学的に安定
性を有し、炭素析出を誘発する鋼材中の各種遷移
金属が酸化皮膜によつて覆われて皮膜表面上に透
過せず、炭素析出が防止もしくは著しく低減され
ることになる。
以上のような本発明によれば、母材合金を広範
囲のオーステナイト系合金から任意に選択するこ
とができ、鍛伸材、鋳造材、あるいは粉末成形材
等製造方法も任意に選択できるため極めて凡用性
が広く、その母材合金のAl含有量は比較的少な
めに抑えられているため、延性や強度等の機械的
性質や切削加工性等が通常の工業材料とほぼ同等
に保持され、しかもアルミナイジングにより形成
される表面層と母材合金内部とのAlの濃度差が
縮まつて濃度勾配が緩和されるため、Alの２次
拡散や表面層の剥離が抑制され高温においても表
面皮膜の安定性、健全性が長期間に亘つて保障さ
れる。
従つて、本発明によれば、定期的なデコーキン
グ操作が不要となると共に継続的な運転が保証さ
れることになり製品品質が安定化される。またデ
コーキングのための余分な設備およびユーテイリ
テイが省略され、設備費の大幅な低減およびデコ
ーキング費用の節約が期待される。さらに△Ｐの
上昇が起こらず健全な運転が保証される。さらに
また、加熱炉等では管内面での析出炭素による断
熱作用がなくなるので、管外表面の温度を次第に
上昇させることなく内部流体の加熱を確保するこ
とができ、燃料の節約をはかることもできること
になる。
以下に本発明の実施例を示す。
実施例 １
耐熱合金の一種であるASTM A608、HK40
（JIS G5122 SCH22：Fe−25％Cr−20％Ni−0.4
％Ｃ）、HP（JIS G5122SCH24：Fe−25％Cr−35
％Ni）及びそれぞれの合金組成を基本としてAl
を０〜５％含有させた母材合金に表面処理として
比較的簡便なAl溶融浸漬処理によるアルミナイ
ジングを施し、機械的性質、加工性、表面層の安
定性及び耐炭素析出性につき検討した。
(1) 試験材
母材合金の化学成分組成を表１に示す。
HK40及びHPは市販の遠心鋳造材から、Alを
合金化させた材料は真空溶解にて、金型を用い
て溶製した鋳塊から試験片を採取した。表面処
理は、板状の母材試験片に695℃×10分のAl溶
融浸漬処理を施した。合金層の厚さは100〜
140μであつた。
The present invention is suitable for thermally decomposing hydrocarbons or their derivatives in the presence or absence of water vapor, such as in ethylene production equipment and delayed coking equipment, or for decomposing fluids containing carbon monoxide, such as in syngas production equipment. The present invention relates to a device that can prevent carbon deposition when handling at high temperatures. These devices are made of materials such as austenitic steel, ferritic steel, austenitic-ferritic dual-phase stainless steel, and low-alloy steel.
Carbon precipitates on parts that are exposed to high-temperature fluids during operation, such as piping (particularly heating furnace tubes), tower tanks, etc., which often causes operational problems such as increased ΔP and decreased heating efficiency. I had to caulk frequently. Such operations disturb the steady operation of the apparatus and are a factor in deteriorating the economic efficiency of the process, and also bring about various disadvantages to the constituent materials of the apparatus. Conventionally, as an attempt to prevent carbon precipitation in these devices, for example, it has been reported that carbon precipitation can be suppressed to some extent by adding a small amount of H 2 S to the raw material fluid in ethylene production equipment (BLCrynes, L.
Ind.Eng.Chem.Proc.−Design by F.Albright
and Development. 8 [1] (1969) 25).
Although it has been carried out in some cases, the actual situation is that it has not been sufficiently effective because the inside of the cracking tube in ethylene production equipment and the like is an oxidizing atmosphere to begin with. Furthermore, as for research into materials themselves that can suppress carbon deposition, laboratory-scale coking tests using light hydrocarbons have been conducted on various pure metals, but the inventor is not aware of any application to actual equipment. As of now, there are none. In an actual device, the inner surface of the device as described above, which is the object of the present invention, is covered with oxide scale.
Preprint for the 5th
International Congress on Catalysis,
Amsterdam (1972)), carbon precipitation is caused by transition metal elements such as Fe and Ni contained in the constituent materials of the device, and these atoms and metal particles constantly float to the surface of the carbon deposit layer. It is said that precipitation continues by appearing like this.
In fact, according to studies conducted by the present inventors, transition metal elements such as Fe and Ni were detected when coke precipitated on the inner surface of equipment members were detected, and carbon precipitation occurs due to the reduction of Fe and Ni oxides on the surface of the member. It is assumed that this is caused by the diffusion of transition metal elements such as Fe and Ni from the inside through the oxide layer on the surface. For this reason, the present inventors have developed austenitic steel materials, ferritic steel materials, austenitic steel materials, and
Carbon precipitation using a base metal alloy containing 1 to 10% by weight of Al and forming an oxide film on the surface of either ferrite dual phase steel or low alloy steel containing 5% or more Cr. We proposed a preventive treatment device and filed an application (Japanese Patent Application No. 100993, 1983). However, according to the inventors' continued research since then, the oxide film formed on the surface of the member when using only Al in the base alloy has been found to be unstable due to the film stability and Fe, Ni, etc. In order to substantially prevent the floating of transition metals, it is necessary to contain Al in an amount exceeding at least 5%, and when such a large amount of Al is contained, crystals of δ-ferrite and intermetallic compounds must be contained. This has the problem of problems such as deterioration of ductility at room temperature, deterioration of high temperature creep strength, and further deterioration of machinability. The present invention solves these conventional problems and improves ductility and
It has excellent high-temperature creep strength, machinability, etc., and also forms a strong and stable oxide film containing Al that can prevent the above-mentioned transition metal elements from floating to the surface, exhibiting good carbon precipitation prevention properties. It is an object of the present invention to provide a processing device equipped with a member for obtaining the above-mentioned results. According to the present invention, the member exposed to at least the high-temperature fluid in the above-mentioned apparatus is one in which the surface of the base alloy containing 1.0 to 5.0% by weight of Al is aluminized, and the surface of the member is further aluminized during treatment.
A carbon precipitation inhibiting treatment device is provided, which is characterized by forming an oxide film containing Al. That is, in the present invention, the Al content is 1.0 to 5.0% by weight.
The above-mentioned problems can be solved all at once by using a base metal alloy that has a low aluminum content and by applying aluminizing treatment to certain surfaces to increase the aluminum content. Usually, Al or Al is added to metals and alloys that do not contain Al.
When surface treatment is performed using a containing alloy, the Al concentration in the surface layer itself is quite high (50 to 100% by weight), so an oxide film mainly composed of Al 2 O 3 is temporarily formed on the outer surface. However, at high temperatures (usually over 500℃)
When used for a long time, secondary diffusion of Al occurs,
A decrease in the Al concentration on the surface and peeling of the surface layer occur.
As a result, oxidation progresses from areas where Al is poor or where the surface layer has peeled off, and an oxide film containing Fe and Ni as main components is generated, some of which is reduced, and Fe and Ni float from inside. It diffuses and appears on the surface, promoting carbon precipitation from hydrocarbons, carbon monoxide, etc. However, in the present invention, the base alloy contains Al to an extent that does not impair mechanical properties and workability, and the surface is treated with Al or an Al-containing alloy, thereby forming a bond between the surface layer and the inside of the base alloy. The difference in Al concentration between the The stability and integrity of the surface film are guaranteed for a long period of time even at high temperatures. For this purpose, the Al content in the base alloy is 1.0
Must be in the range of ~5.0% by weight. In other words, if the Al content in the base alloy is less than 1.0% by weight, it is practically impossible to maintain an Al-containing oxide film that is stable at high temperatures for a long time, and conversely, if the Al content exceeds 5.0% by weight, the mechanical properties and workability deteriorate. to degrade. In the present invention, the basic metal of the base material to be alloyed with Al may be any austenitic steel that allows the inclusion of a slight ferrite phase, and may be arbitrarily selected from, for example, Fe-Cr-Ni alloys.
In addition, the manufacturing method can be arbitrarily selected from forged materials, cast materials, powder molded materials, etc. Therefore, by selecting the manufacturing method, not only straight pipe parts but also curved pipe parts,
It can be applied to those joining members, towers and tanks, etc. In addition, Al or Al for the base metal alloys as mentioned above
As a surface treatment method using a containing alloy, appropriate aluminizing methods such as Al melt immersion treatment, Al diffusion and penetration treatment, and thermal spraying of an Al-containing self-fluxing alloy can be applied. Here, the following are examples of processing devices targeted by the present invention. i.e. naphtha,
750 to 900 for ethane, gas oil, etc. with steam
The so-called ethylene production equipment aims to produce light unsaturated hydrocarbons such as ethylene by passing it through a cracking tube installed in a heating furnace at a temperature of °C (fluid temperature), heating vacuum distillation residue oil, etc. Delayed coking equipment that pre-heats in a tube and cokes in a coke drum, ethylbenzene dehydrogenation equipment that produces styrene by reacting ethylbenzene with steam at high temperatures, dealkylation equipment for various alkylbenzenes, and raw materials. Hydrocarbons or their derivatives, such as in synthesis gas production equipment that heats hydrocarbons (methane, LPG, naphtha, etc.) by adding steam (oxygen is added in the partial oxidation method) to produce carbon monoxide and hydrogen, or Conventionally, carbon deposition ( Particularly, the heat exchanger includes a device including a part where a so-called fouling in which a carbonaceous substance is deposited is a problem (the same will be said in the present specification below). In these devices, the base metal alloy is appropriately selected and used within the scope of the present invention, depending on the usage status and conditions of the target processing device, at least as a component where carbon precipitation becomes a problem when exposed to high temperatures. do. These can be used not only as a single unit but also as a composite by coating the inner wall surface of a member. After aluminizing the base alloy surface
The formation mode of the oxide film containing Al varies depending on the applied process. In other words, if the process system contains water vapor as a diluting medium or heat medium, such as in the cracking tube of an ethylene production plant or in the dehydrogenation reaction of ethylbenzene, and an oxidized state is reached at the processing temperature or reaction temperature, the fluid to be treated will itself be oxidized. Because of its properties, no treatment is required, and the inner wall surface of the member is
Al is oxidized and a dense film is formed. If the fluid to be treated does not have or has little oxidizing property for steel materials at the treatment or reaction temperature, the inner wall surface should be oxidized by an appropriate means before the fluid is introduced into the process system, or Measures are taken to allow an appropriate amount of aqueous fluid to flow through the process or before the start of the reaction to form an oxide film containing Al. Thus, in the present invention, an oxide film containing Al is formed on the surface of the component where carbon precipitation conventionally occurs, and this film is extremely dense and robust, and once formed on the steel surface, it is physically and chemically stable. Various transition metals in the steel material that have properties and induce carbon precipitation are covered by the oxide film and do not permeate onto the surface of the film, and carbon precipitation is prevented or significantly reduced. According to the present invention as described above, the base metal alloy can be arbitrarily selected from a wide range of austenitic alloys, and the manufacturing method such as forged material, cast material, or powder molded material can also be arbitrarily selected, making it extremely easy to use. It has a wide range of uses, and because the Al content of its base alloy is kept relatively low, its mechanical properties such as ductility and strength, as well as its machinability, are maintained almost the same as ordinary industrial materials. The difference in Al concentration between the surface layer formed by aluminizing and the inside of the base alloy is reduced and the concentration gradient is relaxed, suppressing secondary diffusion of Al and peeling of the surface layer, and maintaining the surface film even at high temperatures. Stability and soundness are guaranteed over a long period of time. Therefore, according to the present invention, periodic decoking operations are not required and continuous operation is guaranteed, thereby stabilizing product quality. Additionally, unnecessary equipment and utilities for decoking are omitted, and it is expected that equipment costs and decoking costs will be significantly reduced. Furthermore, no increase in ΔP occurs and healthy operation is guaranteed. Furthermore, in heating furnaces, etc., the heat insulation effect of precipitated carbon on the inner surface of the tube is eliminated, so it is possible to ensure heating of the internal fluid without gradually increasing the temperature on the outer surface of the tube, and it is also possible to save fuel. become. Examples of the present invention are shown below. Example 1 ASTM A608, HK40, a type of heat-resistant alloy
(JIS G5122 SCH22: Fe-25%Cr-20%Ni-0.4
%C), HP (JIS G5122SCH24: Fe−25%Cr−35
%Ni) and Al based on each alloy composition
A base alloy containing 0 to 5% of aluminum was subjected to aluminizing by relatively simple Al melt dipping treatment as a surface treatment, and the mechanical properties, workability, stability of the surface layer, and carbon precipitation resistance were examined. (1) Test material Table 1 shows the chemical composition of the base alloy.
Test pieces were taken from commercially available centrifugally cast materials for HK40 and HP, and from ingots made by vacuum melting using a mold for the material alloyed with Al. For surface treatment, a plate-shaped base material test piece was subjected to Al melt immersion treatment at 695°C for 10 minutes. The thickness of the alloy layer is 100 ~
It was 140μ.
【表】【table】
【表】
(2) 機械的性質
母材の常温の機械的性質を第１図及び第２図
に示す。第１図及び第２図よりHK基、HP基
とも合金中のAl濃度が５％を越えると伸び、
絞りともほとんど０になり、延性がなくなる。
また、母材のクリープ破断性質を第３図及び
第４図に示す。第３図及び第４図よりAl濃度
が高くなるにつれ、クリープ破断強度が低下す
ることがわかる。
(3) 加工性
HK基母材のビツカース硬さを第５図に示
す。第５図よりAl濃度が６％になるとHvは
440にも達し、著しく加工性が悪化する。
(4) 表面層の安定性
表面層の安定性を試験するため、各試験片を
1100℃×30分加熱後、水冷を行う熱サイクル試
験を行つた。結果を第６図に示す。HK40は50
回目、HP（SCH24：Fe−25％Cr−35％Ni）は
20回目で表面層の剥離が始まつたが、HK−40
にAlを１〜５％合金化した材料は、軽微な酸
化増量は認められたものの、100回の熱サイク
ルによつても、表面層の剥離が認められなかつ
た。
(5) 耐炭素析出性
HK−40、HP、及びそれぞれの合金の基本
組成にAlを合金化させた材料につき、Al溶融
浸漬処理をしたものを、1100℃×1013時間大気
中時効後、ベンゼンを用いてコーキング実験を
行つた。実験方法は、試料を石英管中に設置し
て電気炉にて加熱し、一端よりベンゼンをアル
ゴン（キヤリアガス）を用いて流通させた。
コーキング実験による炭素析出結果を表２に
示す。この結果、HK−40、HP、及びAl含有
量の少ないHK＋0.5％Alで炭素析出が顕著で
あつた。[Table] (2) Mechanical properties The mechanical properties of the base material at room temperature are shown in Figures 1 and 2. From Figures 1 and 2, both HK and HP alloys elongate when the Al concentration in the alloy exceeds 5%.
The reduction of area becomes almost 0, and the ductility disappears. Further, the creep rupture properties of the base material are shown in FIGS. 3 and 4. It can be seen from FIGS. 3 and 4 that as the Al concentration increases, the creep rupture strength decreases. (3) Workability Figure 5 shows the Vickers hardness of the HK base material. From Figure 5, when the Al concentration becomes 6%, Hv is
It reaches as high as 440, which significantly deteriorates workability. (4) Stability of the surface layer To test the stability of the surface layer, each specimen was
A thermal cycle test was conducted in which the sample was heated at 1100°C for 30 minutes and then cooled with water. The results are shown in Figure 6. HK40 is 50
The second time, HP (SCH24: Fe-25%Cr-35%Ni) is
The surface layer started to peel off at the 20th time, but HK-40
In the material alloyed with 1 to 5% Al, a slight increase in weight due to oxidation was observed, but no peeling of the surface layer was observed even after 100 thermal cycles. (5) Resistance to carbon precipitation HK-40, HP, and materials made by alloying Al with the basic composition of each alloy were subjected to Al melt immersion treatment, and after aging in air at 1100°C for 1013 hours, benzene A caulking experiment was conducted using The experimental method was to place a sample in a quartz tube, heat it in an electric furnace, and flow benzene from one end using argon (carrier gas). Table 2 shows the carbon deposition results from the coking experiment. As a result, carbon precipitation was remarkable in HK-40, HP, and HK+0.5% Al, which has a low Al content.
【表】
試料予備酸化 1100℃×1013hr（大気中）
コーキング実験 原料：ベンゼン 0.45ｇhr
条件：800℃×3hr（キヤリアガスとしてアルゴ
ン使用）
炭素析出量は、試験片の実験前後の重量変化を
試験片の幾何学表面積で除して求めた。
以上の実施例から、炭素析出を起こしにくくす
るためには、最低1.0重量％のAlを母材中に必要
とし、実用材料としての機械的性質を確保するた
めには、最高5.0重量％のAl濃度に制限されるこ
とが理解される。[Table] Sample pre-oxidation 1100℃ x 1013hr (in air) Coking experiment Raw material: Benzene 0.45ghr Conditions: 800℃ x 3hr (argon used as carrier gas) It was calculated by dividing by the geometric surface area. From the above examples, it is clear that a minimum of 1.0% by weight of Al is required in the base material to prevent carbon precipitation, and a maximum of 5.0% by weight of Al is required to ensure mechanical properties as a practical material. It is understood that the concentration is limited.
第１図はHK基合金のAl含有量と機械的性質と
の関係図である。第２図はHP基合金のAl含有量
と機械的性質との関係図である。第３図はHK基
合金のAl含有量とクリープ破断特性との関係図
である。第４図はHP基合金のAl含有量とクリー
プ破断特性との関係図である。第５図はHK基合
金のAl含有量とビツカース硬さ（５点平均）と
の関係図である。第６図は各試料の1100℃×30分
（大気炉中）→水冷を１サイクルとする熱サイク
ル試験を実施したときの試料の重量変化図であ
る。
FIG. 1 is a diagram showing the relationship between Al content and mechanical properties of HK-based alloys. FIG. 2 is a diagram showing the relationship between Al content and mechanical properties of HP-based alloys. FIG. 3 is a diagram showing the relationship between Al content and creep rupture properties of HK-based alloys. FIG. 4 is a diagram showing the relationship between Al content and creep rupture properties of HP-based alloys. FIG. 5 is a diagram showing the relationship between the Al content and the Vickers hardness (average of 5 points) of the HK-based alloy. FIG. 6 is a diagram showing the weight change of each sample when a thermal cycle test was carried out for each sample in which one cycle was 1100°C x 30 minutes (in an atmospheric furnace) → water cooling.
Claims (1)
炭素を含む流体を高温で処理する装置であつて、
少くともこの高温流体にさらされる部材がAlを
1.0〜5.0重量％含有する母材合金の表面にアルミ
ナイジングにより高アルミニウム含有層を形成し
たものであることを特徴とする炭素析出抑止性処
理装置。 ２ 炭化水素もしくはその誘導体、または一酸化
炭素を含む流体を高温で処理する装置であつて、
少くともこの高温流体にさらされる部材がAlを
1.0〜5.0重量％含有する母材合金の表面にアルミ
ナイジングにより高アルミニウム含有層を形成
し、処理時にその表面にAlを含有する酸化皮膜
を形成したものであることを特徴とする炭素析出
抑止性処理装置。 ３ Alを含有する酸化皮膜が処理開始前に酸化
性ガスにより部材表面に形成されたものである特
許請求の範囲第２項記載の炭素析出抑止性処理装
置。 ４ Alを含有する酸化皮膜が処理開始直後に被
処理流体により部材表面に形成されたものである
特許請求の範囲第２項記載の炭素析出抑止性処理
装置。 ５ 母材合金が若干のフエライト相の含有を許容
するオーステナイト系合金である特許請求の範囲
第２項乃至第４項のいずれかに記載の炭素析出抑
止性処理装置。 ６ 母材合金がFe−Cr−Ni−Al合金である特許
請求の範囲第５項記載の炭素析出抑止性処理装
置。 ７ 外面側が母材合金層、内面側が高アルミニウ
ム含有層よりなり、外面側から加熱され、内面側
に炭素質物質が接するものである特許請求の範囲
第２項乃至第６項のいずれかに記載の炭素析出抑
止性処理装置。 ８ 管内側壁が高アルミニウム含有層を有する分
解管から形成された炭化水素分解装置である特許
請求の範囲第７項記載の炭素析出抑止性処理装
置。[Scope of Claims] 1. An apparatus for treating a fluid containing hydrocarbons or derivatives thereof, or carbon monoxide at high temperatures,
At least the parts exposed to this high temperature fluid contain Al.
1. A treatment device for inhibiting carbon precipitation, characterized in that a high aluminum content layer is formed on the surface of a base alloy containing 1.0 to 5.0% by weight by aluminizing. 2. A device that processes fluids containing hydrocarbons or derivatives thereof, or carbon monoxide at high temperatures,
At least the parts exposed to this high temperature fluid contain Al.
A carbon precipitation inhibitor characterized by forming a high aluminum content layer on the surface of a base alloy containing 1.0 to 5.0% by weight by aluminizing, and forming an oxide film containing Al on the surface during treatment. Processing equipment. 3. The carbon precipitation inhibiting treatment apparatus according to claim 2, wherein the oxide film containing Al is formed on the surface of the member by an oxidizing gas before the start of the treatment. 4. The carbon precipitation inhibiting treatment apparatus according to claim 2, wherein the oxide film containing Al is formed on the surface of the member by the fluid to be treated immediately after the start of the treatment. 5. The carbon precipitation inhibiting treatment device according to any one of claims 2 to 4, wherein the base metal alloy is an austenitic alloy that allows the inclusion of some ferrite phase. 6. The carbon precipitation inhibiting treatment device according to claim 5, wherein the base metal alloy is a Fe-Cr-Ni-Al alloy. 7. According to any one of claims 2 to 6, the outer surface side is composed of a base material alloy layer and the inner surface side is a high aluminum content layer, heated from the outer surface side, and in contact with a carbonaceous material on the inner surface side. Carbon precipitation prevention treatment equipment. 8. The carbon precipitation inhibiting treatment device according to claim 7, which is a hydrocarbon decomposition device formed from a cracking tube whose inner wall has a high aluminum content layer.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP989184A JPS60155293A (en) | 1984-01-23 | 1984-01-23 | Treating apparatus protected against deposition of carbon |
| FR8500924A FR2558484B1 (en) | 1984-01-23 | 1985-01-23 | CARBON RESISTANT TREATMENT APPARATUS |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP989184A JPS60155293A (en) | 1984-01-23 | 1984-01-23 | Treating apparatus protected against deposition of carbon |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60155293A JPS60155293A (en) | 1985-08-15 |
| JPS63478B2 true JPS63478B2 (en) | 1988-01-07 |
Family
ID=11732753
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP989184A Granted JPS60155293A (en) | 1984-01-23 | 1984-01-23 | Treating apparatus protected against deposition of carbon |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS60155293A (en) |
| FR (1) | FR2558484B1 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5725386A (en) * | 1980-07-23 | 1982-02-10 | Jgc Corp | Carbon deposition-preventing apparatus |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2496705A1 (en) * | 1980-12-19 | 1982-06-25 | Manoir Fonderies Acieries | PROTECTIVE METHOD MAINSTALLY AGAINST THE COKEFACTION OF REFRACTORY ALLOY SURFACES IN CONTACT WITH REAGENTS IN PYROLYSIS FURNACES AND OVENS OBTAINED THEREBY |
| JPS57153734A (en) * | 1981-03-17 | 1982-09-22 | Jgc Corp | Apparatus capable of preventing carbon deposition |
| DE3201816A1 (en) * | 1982-01-21 | 1983-09-08 | JGC Corp., Tokyo | DEVICE FOR TREATING HYDROCARBONS AT HIGH TEMPERATURES WITHOUT CARBON DEPOSITION |
-
1984
- 1984-01-23 JP JP989184A patent/JPS60155293A/en active Granted
-
1985
- 1985-01-23 FR FR8500924A patent/FR2558484B1/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5725386A (en) * | 1980-07-23 | 1982-02-10 | Jgc Corp | Carbon deposition-preventing apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2558484A1 (en) | 1985-07-26 |
| FR2558484B1 (en) | 1992-08-14 |
| JPS60155293A (en) | 1985-08-15 |
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