Nubwo imiyoboro y'icyuma kidashonga irangwa no kudashonga, imiyoboro y'icyuma kidashonga ishyirwa mu bidukikije byo mu mazi ihura n'ubwoko butandukanye bwa corruption mu gihe cy'ubuzima bwayo buteganijwe. Iyi corruption ishobora gutera imyuka ihumanya ikirere, igihombo cy'ibicuruzwa ndetse n'ingaruka zishobora kubaho. Ba nyir'ibikoresho byo mu mazi n'abayikoresha bashobora kugabanya ibyago byo kwangirika bashyiraho ibikoresho bikomeye by'imiyoboro bitanga corruption nziza. Nyuma y'ibyo, bagomba gukomeza kuba maso mu gihe cyo kugenzura imiyoboro iterwamo imiti, imiyoboro ya hydraulic na impulse, hamwe n'ibikoresho byo gutunganya no gupima kugira ngo barebe ko corruption idahungabanya ubuziranenge bw'imiyoboro ishyirwamo kandi ikabangamira umutekano.
Ingeso mbi ziboneka ahantu henshi, mu bwato, mu mato, no mu miyoboro y’amazi mu nyubako zo mu mazi. Iyi ngeso mbi ishobora kuba mu buryo bw’ingeso mbi cyangwa imiterere y’imyenge, imwe muri zo ikaba ishobora gusenya urukuta rw’umuyoboro igatera amazi gusohoka.
Ingaruka zo kwangirika ziba nyinshi iyo ubushyuhe bw'imikorere y'iyi porogaramu bwiyongere. Ubushyuhe bushobora kwihutisha kwangirika kwa firime y'inyuma ya okiside irinda umuyoboro, bityo bigatuma habaho kwangirika kw'imiyoboro.
Ikibabaje ni uko ingese iri mu mwobo n'imiyoboro y'amazi bishobora kugorana kuyimenya, bigatuma ubwo bwoko bw'ingese bugorana kubimenya, kubiteganya no kubishushanya. Bitewe n'izi ngaruka, ba nyiri urubuga, abarukoresha n'abashinzwe ubwitonzi bagomba kwitonda mu gihe bahitamo ibikoresho byiza byo gushyiramo imiyoboro. Guhitamo ibikoresho ni bwo buryo bwa mbere bwo kwirinda ingese, bityo kubikora neza ni ingenzi. Ku bw'amahirwe, bashobora guhitamo bakoresheje uburyo bworoshye ariko bunoze bwo gupima ingese iri mu mwobo, Umubare uhwanye na Pitting Resistance Equivalent Number (PREN). Uko agaciro ka PREN k'icyuma kaba kari hejuru, ni ko imbaraga zacyo zo kurwanya ingese ziri mu mwobo ziyongera.
Iyi nkuru izasuzuma uburyo bwo kumenya imyanda iri mu mwobo n'imyanya y'amazi ndetse n'uburyo bwo kunoza uburyo bwo guhitamo ibikoresho byo mu miyoboro y'amazi mu bijyanye no gukoresha peteroli na gaze mu mazi hashingiwe ku gaciro ka PREN k'ibikoresho.
Ingeso yo kwangirika iboneka ahantu hato ugereranije n’ingeso rusange, ikaba isa neza ku buso bw’icyuma. Ingeso yo kwangirika no gucika kw’imiyoboro y’icyuma itangira kugaragara ku miyoboro 316 y’icyuma kitagira umugese iyo icyuma gikungahaye kuri chromium nyinshi gitwikiriye oxide gicitse bitewe no guhura n’amazi yangiza, harimo n’amazi y’umunyu. Ubuzima bwo mu mazi burimo chloride nyinshi ku nkengero z’inyanja, ndetse n’ubushyuhe bwinshi ndetse n’ubwandu bw’ubuso bw’imiyoboro, byongera ubushobozi bwo kwangirika kw’iyi filime yo kwangirika.
gushonga. Gushonga kw'imyobo bibaho iyo agace k'imashini gakoresha amashanyarazi ku burebure bw'umuyoboro kangiritse, kagakora utwobo duto cyangwa imyobo hejuru y'umuyoboro. Ibyo byobo bishobora gukura uko habaho ingaruka z'amashanyarazi, bigatuma icyuma kiri mu cyuma gishonga mu mvange iri hasi mu mwobo. Hanyuma icyuma gishonga kizakwirakwira hejuru y'icyobo hanyuma gikore ogisijeni y'icyuma cyangwa ingese. Uko icyobo kigenda cyiyongera, ingaruka z'amashanyarazi ziyongera, ingese zirushaho kwiyongera, kandi zishobora gutuma urukuta rw'umuyoboro rubomoka bigatera kuva amazi.
Gushyira imiyoboro y'amazi mu miyoboro bishobora kwangirika cyane iyo ubuso bwayo bwo hanze bwanduye (Ishusho ya 1). Urugero, kwanduzwa n'ibikorwa byo gusudira no gusya bishobora kwangiza urwego rwa okiside isohoka mu muyoboro, bityo bigatuma habaho kandi ikiyongera kwangirika kw'imiyoboro. Ni kimwe no guhangana n'ubwandu buturuka ku miyoboro. Byongeye kandi, uko ibitonyanga by'amazi bishira, umunyu utose ugaragara ku miyoboro ukora nk'uko birinda urwego rwa okiside kandi bishobora gutera kwangirika kw'imiyoboro. Kugira ngo wirinde ubwo bwoko bw'ubwandu, komeza imiyoboro yawe isukuye uyisukura buri gihe n'amazi meza.
Igishushanyo cya 1 – Umuyoboro w'icyuma kitagira umugese wa 316/316L wandujwe na aside, amazi y'umunyu n'ibindi bintu biwurimo ushobora kwangirika cyane.
Gushwanyagurika kw'imirongo. Kenshi na kenshi, aho imyobo iherereye bishobora kumenyekana byoroshye n'uyikoresha. Ariko, gushwanyagurika kw'imirongo ntibyoroshye kubibona kandi biteza ingaruka zikomeye ku bakoresha n'abakozi. Akenshi biba ku miyoboro ifite umwanya muto hagati y'ibikoresho biyikikije, nk'imiyoboro ifatanywe uduce cyangwa imiyoboro ishyirwa ku ruhande. Iyo amazi y'amazi yinjiye mu mwobo, umuti wa ferric chloride (FeCl3) urimo aside cyane utera ingese mu mwobo uko igihe kigenda gihita utera ingese yihuta mu mwobo (Ishusho ya 2). Kubera ko imyobo ubwayo yongera ibyago byo kwangirika, gushwanyagurika kw'imirongo bishobora kubaho ku bushyuhe buri hasi cyane kuruta gushwanyagurika kw'imirongo.
Ishusho ya 2 - Ingese ishobora kuvuka hagati y'umuyoboro n'inkingi y'umuyoboro (hejuru) no mu gihe umuyoboro ushyizwe hafi y'ahandi (hasi) bitewe n'iremwa ry'umuti wa ferric chloride urimo aside nyinshi mu mwobo.
Ubusanzwe ingese y’imiyoboro isa n’ingese y’imiyoboro ibanza mu mwobo wakozwe hagati y’uburebure bw’umuyoboro n’agace gashyigikira umuyoboro. Ariko, bitewe n’ubwiyongere bwa Fe++ mu mazi ari mu mwobo, ikigega cya mbere kiba kinini kugeza ubwo gitwikiriye imvune yose. Amaherezo, ingese y’imiyoboro ishobora gutobora umuyoboro.
Uduce duto cyane ni byo bishobora gutera ingese. Kubwibyo, uduce duto tw’imiyoboro dukikije igice kinini cy’umuyoboro dukunda kugira ingaruka zikomeye kuruta uduce dufunguye, bigabanya ubuso buhuza umuyoboro n’agace gafunga. Abatekinisiye bo kubungabunga bashobora gufasha kugabanya ibyago byo kwangirika cyangwa kwangirika kw’imiyoboro bafungura buri gihe uduce dufunga kandi bakareba ubuso bw’umuyoboro niba nta ngese.
Gushonga kw'ibitunguru n'ingufu bishobora kwirindwa neza iyo uhisemo icyuma gikwiye gukoreshwa. Abashinzwe kugena imiyoboro bagomba gukora ubushakashatsi buhagije kugira ngo bagabanye ibyago byo kwangirika bitewe n'aho ikoreshwa, imiterere y'imikorere n'ibindi bintu.
Kugira ngo abapima ibintu bafashe imiterere myiza yo guhitamo ibikoresho, bashobora kugereranya agaciro ka PREN y'ibyuma kugira ngo bamenye ubushobozi bwabyo bwo guhangana n'ubushyuhe busanzwe. PREN ishobora kubarwa uhereye ku miterere y'ibinyabutabire bya alloy, harimo chromium (Cr), molybdenum (Mo), na azote (N), ku buryo bukurikira:
PREN yiyongera bitewe n'ingano y'ibintu birwanya ingese bya chromium, molybdenum na azote biri muri alloy. Isano ya PREN ishingiye ku bushyuhe bw'ibice by'ingenzi (CPT) - ubushyuhe bwo hasi cyane aho ingese igaragara - ku byuma bitandukanye bitagira ingese bifitanye isano n'imiterere ya shimi. Mu by'ukuri, PREN ingana na CPT. Kubwibyo, agaciro ka PREN kari hejuru kagaragaza ko ibice by'ingenzi birwanya ingese. Ukwiyongera guke kwa PREN kungana gusa n'ubwiyongere buto bwa CPT ugereranije n'alloy, mu gihe ukwiyongera gukomeye kwa PREN bigaragaza iterambere rikomeye mu mikorere kugeza kuri CPT iri hejuru cyane.
Imbonerahamwe ya 1 igereranya agaciro ka PREN k'ibyuma bitandukanye bikunze gukoreshwa mu ikoreshwa rya peteroli na gaze mu mazi. Igaragaza uburyo ibipimo bishobora kongera cyane ubudahangarwa bw'ingese binyuze mu guhitamo imashini yo mu bwoko bwa alloy yo mu rwego rwo hejuru. PREN yiyongera gato gusa iyo ivuye ku cyuma cya 316 ijya kuri 317. Kugira ngo imikorere irusheho kwiyongera, icyuma cya 6 Mo super austenitic stainless steel cyangwa 2507 super duplex stainless steel ni byiza cyane.
Ubucucike bwinshi bwa nikeli (Ni) mu byuma bidashonga nabwo butuma habaho ubudahangarwa bw'ingufu. Ariko, ubucucike bwa nikeli mu byuma bidashonga si igice cya PREN equation. Uko byagenda kose, akenshi ni byiza kugaragaza ibyuma bidashonga bifite ubucucike bwinshi bwa nikeli, kuko iki kintu gifasha kongera gusimbuza ubuso bugaragaza ibimenyetso bya corruption. Nikeli ikomeza austenite kandi ikarinda martensite kubaho iyo igonze cyangwa ikonje ikurura umuyoboro ukomeye wa 1/8. Martensite ni crystalline phase idakenewe mu byuma igabanya ubudahangarwa bw'icyuma bidashonga na corruption iterwa na chloride. Ubucucike bwinshi bwa nikeli nibura 12% muri 316/316L nabwo ni byiza mu bikorwa birimo hydrogen ifite umwuka mwinshi. Ubucucike buke bwa nikeli busabwa ku byuma bidashonga bya 316/316L mu bipimo ngenderwaho bya ASTM ni 10%.
Ingeso mbi zishobora kubaho ahantu hose ku miyoboro ikoreshwa mu bidukikije byo mu mazi. Ariko, ingeso mbi zishobora kubaho cyane mu duce twanduye, mu gihe ingeso mbi zishobora kubaho cyane mu duce dufite icyuho gito hagati y’umuyoboro n’ibikoresho byo kuwushyiraho. Hakoreshejwe PREN nk'ishingiro, igikoresho gishobora guhitamo imashini nziza y’imiyoboro kugira ngo kigabanye ibyago byo kwangirika k’ubwoko ubwo aribwo bwose.
Ariko, ibuka ko hari izindi mpinduka zishobora kugira ingaruka ku byago byo kwangirika. Urugero, ubushyuhe bugira ingaruka ku kudakomera kw'icyuma kidashonga. Ku birere bishyushye byo mu mazi, imiyoboro 6 ya molybdenum super austenitic cyangwa 2507 super duplex stainless steel igomba gusuzumwa cyane kuko ibi bikoresho bifite ubudahangarwa bwiza ku kwangirika kw'aho hantu no kwangirika k'umuvuduko wa kloride. Ku birere bikonje, umuyoboro wa 316/316L ushobora kuba uhagije, cyane cyane niba haragaragajwe amateka yo gukoreshwa neza.
Ba nyiri puratifomu zo mu mazi n'abazikoresha bashobora gufata ingamba zo kugabanya ibyago byo kwangirika nyuma yo gushyiraho imiyoboro. Bagomba gukomeza gusukura imiyoboro no kuyisukura buri gihe kugira ngo bagabanye ibyago byo kwangirika. Bagomba kandi kugira abatekinisiye bashinzwe kubungabunga imiyoboro bafungura udukingirizo mu gihe cy'igenzura risanzwe kugira ngo barebe niba hari kwangirika kw'imiyoboro.
Bakurikije intambwe zavuzwe haruguru, ba nyiri urubuga n'abarukoresha bashobora kugabanya ibyago byo kwangirika kw'imiyoboro y'amazi n'ibindi bijyana nayo mu nyanja, bakongera umutekano n'imikorere myiza, mu gihe bagabanya amahirwe yo gutakaza ibicuruzwa cyangwa kurekura imyuka ihumanya ikirere.
Brad Bollinger is the Oil and Gas Marketing Manager for Swagelok Company.He can be reached at bradley.bollinger@swagelok.com.
Ikinyamakuru cy’ikoranabuhanga rya peteroli ni ikinyamakuru cy’ingenzi cy’Umuryango w’Abahanga mu by’Ingufu za Peteroli, gitanga ibisobanuro n’ingingo z’ingenzi ku iterambere mu ikoranabuhanga mu bushakashatsi no mu gutunganya, ibijyanye n’inganda za peteroli na gaze, ndetse n’amakuru yerekeye SPE n’abanyamuryango bayo.