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Cishe ngaphansi kwanoma imuphi umgwaqo owakhiwe emashumini eminyaka amuva, amapayipi kagesi angcwatshwe cishe enziwe nge-polyethylene (HDPE) enobuningi obuphakeme. Kusukela amapayipi e-polyethylene aqala ukusetshenziselwa ukudluliswa kwegesi ngawo-1960, amapayipi e-HDPE abe yindlela ejwayelekile yokusabalalisa igesi yemvelo engaphansi komhlaba. Namuhla, eNyakatho Melika, eYurophu, nasezingxenyeni eziningi zase-Asia, i-polyethylene esebenza kahle kakhulu engu-PE100 isetshenziswa kakhulu eminye imigwaqo emisha yegesi. Lolu dumo lwalutholakala endaweni yangempela engaphakathi komhlaba, hhayi nje ezincwajaneni. Umsele wegesi ongcwatshwe phansi kumelwe usebenze ngokuphepha iminyaka engu-50 noma ngaphezulu enhlabathini enomswakama futhi enokudla okungamakhemikhali, futhi i-polyethylene ifaneleka kangcono kule ndawo kunanoma iyiphi impahla evamile yamapayipi. Insimbi nensimbi ehlanganisiwe ziyathena enhlabathini eningi futhi zidinga izembozo ezilwa nokugqwala, ukuvikelwa kwe-cathodic nokuhlolwa njalo ukuze zihlale zisebenza. Ngokuphambene nalokho, amapayipi egesi e-HDPE awanayo le nkinga. Azithinteki ngokuphelele ukugqwala okubhubhisa amapayipi ensimbi kancane kancane, ngakho izinsiza ezihambisana namazinga e-ISO 4437 ne-ASTM D2513 manje zikhetha amapayipi e-PE njengempahla ekhethwayo yamaphrojekthi amasha amaningi okuhambisa igesi.
Ukuthembela kwabantu ku-polyethylene kungaphezu nje kokumelana kwayo nokugqwala. Izihlanganisi zayo zenziwa nge-fusion welded, azihlanganiswa ngomshini. I-butt fusion iwelding amapayipi abe yinto eqhubekayo, eyingqayizivele, kuyilapho i-electrofusion ifinyelela umphumela ofanayo ezintweni ezifakwayo. Ngakho, amalunga amapayipi kagesi enziwe nge-HDPE aqinile njengodonga lwalo futhi awanawo ama-gasket, izintambo noma izivalo ezingase zikhululeke, ziguge noma zivuleke ngokuhamba kwesikhathi. Yingakho onjiniyela begesi bethi inethiwekhi ye-PE100 efakwe kahle ingafinyelela ekuqhumeni okungekho. Le nto futhi iyasebenziseka: amapayipi e-HDPE angagoba ukuze afaneleke ama-contour emgodi kanye namajika amakhulu ngaphandle kwesidingo sezinto ezengeziwe, futhi anokuvumelana nezimo okwanele ukuze amunce ukufuduka komhlaba okubangelwa ukuhlaliswa kwenhlabathi, ukuqhuma kweqhwa, nokuzamazama komhlabaiz Uma kuhlanganiswa namasu okwakha angenamgodi njengokuqhumisa okuqondisiwe, i-polyethylene isiyindlela enobungozi obuncane futhi ebiza kancane yokuletha igesi emiphakathini. Lezi zici ezine zichaza ukubusa kwayo: ukumelana nokugqwala, amalunga okuxuba angenakho ukuvuza, ukuguquguquka, nokumelana nokunyakaza komhlaba. Ezahlukweni ezilandelayo, sizohlola lezi zici ngamunye ngamunye ngombono wokusetshenziswa okusebenzayo: ukuthi zisho ukuthini emigodini, ezindaweni ezingaphansi komhlaba, futhi phakathi neminyaka engu-50 elandelayo yokusebenza.
Kungani iziphiphi zesithuthi sika-high-density polyethylene (HDPE) zisetyenziswa kakhulu emisebenzini yokuthumela nokugcina umoya wokuphuma emhlabathini? ?
Ngaphambi kokufaka, onjiniyela begesi kumelwe benze izinqumo ezimbili ezithinta ukuphila kwenethiwekhi yamapayipi ngokuqondile: uhlobo lwezinto ezibonakalayo nobukhulu bodonga. Amapayipi e-PE (polyethylene) ahlukaniswa ngokususelwa "kuMandla Amancane Adingekayo" (MRS), okuyikhono lokumelana nokucindezelwa okuzungezile iminyaka engama-50 ku-20 °C (ngokusho kwe-ISO 9080). PE80 has a MRS ka 8.0 MPa, kuyilapho PE100 has 10.0 MPa; Ngakho-ke, nge efanayo udonga ukushuba, PE100 SDR11 igesi amapayipi babe ukusebenza ephakeme okuthiwa futhi ukumelana namandla kakhulu kancane ufa ukusabalalaindlela ukwehluleka esibucayi kakhulu ngoba gas pipelines wangcwatshwa. Ngenxa yalesi sizathu, amapayipi kagesi e-PE100 SDR11 abe ukucushwa okuzenzakalelayo kwamapayipi kagesi aphansi aphansi asanda kwakhiwa, kuyilapho i-PE80 iqhubeka isetshenziswa kumanethiwekhi amadala aphansi. Ukukhethwa kwezinto ezibonakalayo kanye ne-SDR (standard dimension ratio) kufanele futhi kuhambisane nemithetho yamanje yegesi: iYurophu isebenzisa i-ISO 4437/EN 1555, kanti eNyakatho Melika isebenzisa i-ASTM D2513.
Kusetyenziswa kwezinye izinhlangano zokuthumela nekugcina igasi emhlabathini, isibonelo sesibili sokuziphatha kukuphakanyiswa kwesithunzi. SDR (Isilinganiso se-Diameter Yendawo) sibhalwa njengesilinganiso sendawo yokuqanda kunesithunzi, futhi isilinganiso sakhe sokuphakanyiswa kwenziwa ngokusebenzisa lefomula: MOP = 2 × MRS ÷ (C × (SDR − 1)), apho i-MOP yisiphiwo esikhulu sokusebenza futhi i-C yisiphakamiso sokusebenza. Indawo yokugcina igasi iyasebenzisa i-C = 2, ngakho-ke isiphiwo sokusebenza se-Pipe ye-Gas ye-PE100 SDR11 siyizinkambo ezingu-10 bar; ngakolunye uhlangothi, izipha yezindawo ze-SDR17 noma ze-SDR17.6 (ezincane kakhulu, nezincane ukuthenga) ziyasebenza kahle kwezinye izindawo zokuthumela nekugcina ngokuphakanyiswa okuncane. Ngaphezu kwalokho, kunezifaktor ezimbili zokulungisa ozokubhekwa phansi kwezinye izindaba, kodwa abazihlukanisi. Okokuqala kukufaktor yokuplaninga, okuxhasa umthelela wokuphambana kwezandla ngokuphakanyiswa kwezinkambo ezingu-50 (i-C = 2, futhi i-49 CFR 192 yase-US ibeka isilinganiso esikhulu se-0.4) ukukhindza ukuphambana kwezandla kwezinkambo ezingu-50. Okwesibili kukulungiswa kokuchaza kwesikhathi, ngoba konke okubhalwe kuyabaseka ku-20°C: uma isikhathi siphakanyiswa phezu kwe-20°C, i-MOP kufanele ikhangelwe ngokulungiswa kokuchaza kwi-ISO 4437-5 (kuya kuma-40°C); uma isilinganiso sokulungiswa siningi kune-siphiwo sokusebenza esidingekayo, kufanele isipha esincane kakhulu se-SDR sikhethwe (okusho ukuthi isithunzi kufanele sikhiphe kakhulu). Kuma-mediumpressure main pipelines, isiphiwo esiphelile kufanele kube i-Pipe ye-Gas ye-PE100 SDR11, futhi i-SDR yakho, ifaktor yokuplaninga, nokulungiswa kokuchaza kwezikhathi kuyaphakanyiswa ngokuphelele ngokulinganisa nezisilinganiso zezikhathi.
Ukukhokha kwezifundo zokuhlinzekwa kwezilayini zokugcina amanzi e-HDPE ?
Yini okufanele sizenze ukuze sizivikele isikhungo sezilayini zokugcina amanzi e-HDPE? Ukukhokha kwezifundo zokuhlinzekwa kusobala kumazwi amane, okuyizindlela eziningi zokubhukudza: izihlangothi zokugqibela, ukulayisha kwemithambo yezilayini, ukuzimisa imithambo, nokukhetha i-SDR (Standard Draw Reduction). Lezi zinkinga zingasolwa ngokuphelele ngezindlela eziphelele.
Iziphulo zokufaka kuzoba phakade emhlabeni wonke. Izinhlamvu zokufaka okungafanele: Ukulinganisa okungafanele kwesilinganiso sokufaka noma isikhathi sokufaka kungasiza ukuthi izihlangothi ziboneke njengalokho kodwa zihlwayele ngokuhamba kwezinsizakalo zemhlabani; ngakho ke kufanele ukufaka kwenziwe ngokuphelele ngokulandela izitabhu zezinhlamvu eziphathelene ngeziquketho. Ukufaka okungafanele kwezindawo zokubeka: Uma kubekwa umsindo, amathambo amabi nezindawo ezingavumelekile kungasiza ukuthi ubumbane bwezinhlobo zibhekwe; ngakho ke kufanele abe usebenzise izinhlobo ezincinci nezinhlobo ezifakwe ngokuphelele ekubekenini nokubekwa emva kwezinhlobo. Ukuphakanyiswa okungafanele kwesikhathi sokuphakanyisa: Konke okubekwa kufanele kuphakanyiswe ukuze kufanele kweziquketho; izindlela zingahambelwa futhi noma izinyathelo zingahlanganiswe. Ukukhetha okungafanele kwe-SDR: Phambi kokubeka okubekwa, kufanele ukhethwe ukuthi kubekwe i-SDR11 noma i-SDR17.6 ngokwesilinganiso sokusebenza esihlukile. Ngokuphatha lezi zinkambo ezi-4, ukubeka okuphelele nokuphatha okuphelele kwezinhlobo zesiqondiso se-HDPE kungakhathaliseka.
Ukubeka kwezinhlobo zesiqondiso se-HDPE: Ukuchazwa kwezinhlobo zokubeka ngokubeka kwezindawo zokubeka nokubeka ngaphandle kwezindawo zokubeka ?
Kufanele kuchazwe indlela yokufaka umkhondo wokugcina amanzi we-HDPE okuhambisana nezimo zokusebenza kuleli leli. Ukufaka ngokuvula umkhondo uyasebenza kubantu bakwesibhakabhaka esihlwayini; indlela yokufaka ngokuphambuka kwemithambo (HDD) iyakwenzela ukuthi kubhekwe emaphetheni nasezilalweni ngaphandle kokuthi kubhekwe isibhakabhaka. Isiqephu se-HDPE sisebenza ngokuzenzakalela kumsebenzi wokufaka ngaphandle kokuvula: izinyathelo zemikhondo emva kokugxilwa ngokushisa ziyabuyela ezinkulu, kusukela ukuthi zibeke kumaphepha futhi zizobuyela umkhondo ojulile ongena ngaphandle kokuthi kubhekwe isibhakabhaka.
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Indlela |
Isicelo |
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Vula umsamo |
Izisebenzo zesibhakabhaka esihlwayini |
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Ukuphambuka kwemithambo |
Ukubhekwa emaphetheni, ukubhekwa eziphalweni |
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Ukuvula umkhondo |
Ukubuyisela umkhondo |
Ukubhukha kwe-pipe kuyisibonelo sokubhukha kwe-pipe yekhanda elidala, futhi ukuthintela ipipe entsha ye-HDPE ekuphakathini kwezinye, ngakho-ke ukuthintela kugcina isikhundla esingaphakathi kwesikhundla sokusebenza. Amasiko amasha ase-pipeline ayasebenzisa indlela yokuthintela, i-HDD (High-Density Die-Drying) isetshenziswa xa kufinyelelwa izimpilo, ngakho-ke ukubhukha kwe-pipe kusetyenziswa kakhulu xa kubhukhwa ipipe. Izindaba zombili ziyasebenzisa izinkambo zokusebenza ze-HDPE—ngokuvamile, ubukhulu bokuthintela kwe-pipe, ubukhulu bokuthintela kwezincwadi, nokuthakazelwa kwezincwadi zokuthakazela okufanayo nezincwadi zepipe—ngakho-ke ipipe ye-gas ye-HDPE iyabona ubukhulu bakhe ngokungafani na-ke xa kuthintelwa noma kuthintelwa ngokungathinteli.
Imibuzo eyisifundisa ngokuvamile ngamapipa e-gas e-HDPE: Imibuzo eyisifundisa ngokuvamile ngabaprofesiwe nabathengisi
Imibuzo yokuqala. Iyiphi ipipa ye-HDPE esetshenziswa ekhanda lomkhosi wezinye?
Amaphipha wezinye zokugcina amanzi ngaphansi kwelwandle nezinye zokusebenza kusendlini zisebenzisa amaphipha we-polyethylene aye-PE80 noma PE100 (ngokuvamile abahlanu noma abamnyama nesitripu sobuhlanu) futhi ziyafanele kumistanda we-ISO 4437/EN 1555 (umistanda we-ASTM D2513 usebenziswe eNorth America). Amaphipha we-PE100 ayenakho umkhawulo wokubaluleka okuncikishwayo (MRS) we-10 MPa futhi yizindlela ezibalulekileyo zokusebenzisa kumaphipha amasha we-mediun-pressure: ngokufanana kwezithambo, zinakho uphawu lwe-pressure eliphakeme kanye nokuthintana kakhulu kwe-slow crack propagation.
Umbuzo 2. Yini i-SDR (Standard Draw Ratio) esifunekayo kumaphipha we-HDPE wezinye zokugcina amanzi?
Lokhu kuyiphakade kubukhulu be-pressure yokusebenza. Uma ifaktor yesigni ye-gas C = 2, i-pressure eyavamile yomphipha we-PE100 SDR11 yingaphezu kwe-10 bar; i-SDR11 iyasebenza kumaphipha amasha we-mediun-pressure kanye nokwenza umphipha ngaphandle kwezindawo zokuphatha izinto. Kuma-networks amancane, amaphipha we-SDR17.6 angaphezulu kwezithambo kanye nokuncane kwezindleko zinakwenzeka; uma ubukhulu be-zithambo bephika kude kwe-20°C, kufanele kwenziwe ukunciphisa uphawu lwe-pressure ngokwemistanda ye-ISO 4437-5.
Umbuzo 4. Ingakwenzekani ukufaka izilayini zokugcina amanzi ze-HDPE ngendlela engafakwanga emhlabathini?
Yebo. Iteknoloji yokufaka ngendlela yokuhambisa ngokuphelele (HDD) iyasebenziswa kakhulu ukufaka izilayini zokugcina amanzi ze-HDPE ngaphansi kwemilonga, amanzi, nokwekwe: iziqephu zesilayini zihlanganiswa ngokufaka ngokuphelele ngokuchitha kwezinkampani kanye noma zihlakazwa emhlabathini. Umphumela wokuthi isilayini sikhula kakhulu kusiza ukuthi sifanele kumhlabathi wokufaka; ukungabikho kwezinqamulelo zokubamba kusiza ukuthi akukho amanzi asuka ngokuhlakaza—lokho okungakwenzeka ngokusebenzisa izilayini zokubamba ezikhulayo.
Umbuzo 5. Kuphi umahluko phakathi kokufaka ngokuphelele ngokuchitha kwezinkampani nokufaka ngokuphelele ngokuchitha kwezilayini?
Imibono yombili ingakwakha amaphuzu okugqamisa okuphakanyiswa ngokupheleleyo nesikhundla sokubambisana esifanayo nesikhundla sokubambisana kwe-pipe, ngaphandle kokudinga kwezinkothi zokubambisana noma amaphuzu. Ukubambisana ngokupheleleyo kusebenzisa isithelo sokuchaza ukuchaza amaphepha we-pipe futhi kubambisana—kuyasebenza kubizwa kwezimpilo zokubambisana nezimpilo zokubambisana kwezimpilo, kuyisikhathi esinye futhi kuyisikhathi esihlukile, kodwa kudinga isithelo sokubambisana ngokupheleleyo futhi abasebenzi abaqinisekile. Ukubambisana ngokuchaza kusebenzisa umthwalo wokuchaza owenziwe ngokupheleleyo kusuka kwezinkothi ukuchaza i-pipe ngokupheleleyo—kuyasebenza kubizwa kwezinkothi zokubambisana, ukulungisa, nokusebenza emaphakathini amancane.