Daim duab qhia no qhia txog qee qhov teeb meem uas tuaj yeem tshwm sim nrog cov ntaub ntawv polymer thiab elastomeric uas txawv ntawm cov uas tshwm sim nrog cov hlau nplaum thiab cov khoom siv.
Kev ua tsis tiav ntawm cov khoom siv polymer (yas thiab elastomeric) thiab nws cov txiaj ntsig tuaj yeem ua rau muaj kev puas tsuaj loj ntawm cov khoom siv hlau.Cov ntaub ntawv nthuav tawm piav qhia qee yam ntawm cov khoom uas cuam tshuam rau cov khoom siv polymer ntawm cov khoom siv hauv cov chaw tsim khoom.Cov ntaub ntawv no siv rau qee qhov qub txeeg qub tegO-rings, lined yeeb nkab, fiber reinforced yas (FRP) thiab kab yeeb nkab.Piv txwv ntawm cov khoom xws li nkag mus, iav kub, thiab viscoelasticity thiab lawv qhov cuam tshuam tau tham.
Thaum Lub Ib Hlis 28, 1986, Challenger space shuttle kev puas tsuaj tshwm sim rau lub ntiaj teb.Qhov tawg tau tshwm sim vim tias O-ring tsis kaw kom zoo.
Cov kev ua txhaum uas tau piav qhia hauv tsab xov xwm no qhia txog qee yam ntawm cov yam ntxwv ntawm cov khoom tsis yog hlau cuam tshuam rau cov cuab yeej siv hauv kev lag luam.Rau txhua rooj plaub, cov khoom tseem ceeb polymer tau tham txog.
Elastomers muaj lub iav hloov pauv kub, uas txhais tau tias yog "qhov kub ntawm cov khoom siv amorphous, xws li iav los yog polymer, hloov ntawm lub nkig glassy xeev mus rau lub xeev ductile" [1].
Elastomers muaj compression teeb - "txhais tau tias yog feem pua ntawm cov kab mob uas tus elastomer tsis tuaj yeem rov qab tau tom qab lub sijhawm teem tseg ntawm qhov muab extrusion thiab kub" [2].Raws li tus kws sau ntawv, compression hais txog lub peev xwm ntawm cov roj hmab kom rov qab mus rau nws cov qauv qub.Nyob rau hauv ntau zaus, lub compression nce yog offset los ntawm ib co expansion uas tshwm sim thaum siv.Txawm li cas los xij, raws li qhov piv txwv hauv qab no qhia, qhov no tsis yog ib txwm muaj.
Fault 1: Tsis tshua muaj qhov kub thiab txias (36 ° F) ua ntej tso tawm ua rau tsis txaus Viton O-rings ntawm Qhov Chaw Shuttle Challenger.Raws li tau hais nyob rau hauv ntau yam kev raug xwm txheej kev tshawb nrhiav: "Thaum qhov kub qis dua 50 ° F, Viton V747-75 O-ring tsis hloov pauv txaus los taug qab qhov qhib qhov sib txawv ntawm qhov ntsuas" [3].Lub iav hloov pauv kub ua rau Challenger O-ring tsis tuaj yeem kaw kom zoo.
Teeb meem 2: Cov ntsaws ruaj ruaj uas qhia hauv daim duab 1 thiab 2 feem ntau raug rau dej thiab chav dej.Cov ntsaws ruaj ruaj tau sib sau ua ke ntawm qhov chaw siv ethylene propylene diene monomer (EPDM).Txawm li cas los xij, lawv tab tom sim fluoroelastomers (FKM) xws li Viton) thiab perfluoroelastomer (FFKM) xws li Kalrez O-rings.Txawm hais tias qhov ntau thiab tsawg sib txawv, txhua O-rings qhia hauv daim duab 2 pib tawm tib qhov loj:
Muaj dab tsi tshwm sim?Kev siv cov ncu tuaj yeem ua teeb meem rau elastomers.Rau cov ntawv thov chav siab tshaj 250 ° F, kev nthuav dav thiab kev cog lus deformations FKM thiab FFKM yuav tsum raug coj mus rau hauv tus account hauv kev suav tsim cov khoom.Cov elastomers sib txawv muaj qee qhov zoo thiab qhov tsis zoo, txawm tias cov uas muaj tshuaj tiv thaiv siab.Txhua qhov kev hloov pauv yuav tsum tau ua tib zoo saib xyuas.
General sau ntawv ntawm elastomers.Feem ntau, kev siv elastomers ntawm qhov kub siab tshaj 250 ° F thiab qis dua 35 ° F yog tshwj xeeb thiab tej zaum yuav xav tau cov tswv yim tsim.
Nws yog ib qho tseem ceeb los txiav txim siab txog cov khoom siv elastomeric siv.Fourier transform infrared spectroscopy (FTIR) tuaj yeem paub qhov txawv ntawm ntau hom elastomers, xws li EPDM, FKM thiab FFKM tau hais los saum no.Txawm li cas los xij, kev sim kom paub qhov txawv ntawm ib qho FKM los ntawm lwm qhov tuaj yeem nyuaj.O-rings ua los ntawm cov tuam txhab sib txawv tuaj yeem muaj cov khoom sib txawv, vulcanization, thiab kev kho mob.Tag nrho cov no muaj kev cuam tshuam loj heev rau compression teeb, tshuaj lom neeg tsis kam thiab cov yam ntxwv tsis tshua muaj kub.
Polymers muaj ntev, rov ua cov saw hlau molecular uas tso cai rau qee cov kua nkag mus rau lawv.Tsis zoo li cov hlau, uas muaj cov qauv crystalline, ntev molecules intertwine nrog ib leeg zoo li ib tug strand ntawm siav spaghetti.Lub cev, cov molecules me me xws li dej / chav dej thiab cov pa roj tuaj yeem nkag mus.Qee cov molecules me me kom haum los ntawm qhov sib txawv ntawm cov saw hlau ib leeg.
Failure 3: Feem ntau, cov ntaub ntawv tshawb xyuas qhov tsis ua hauj lwm pib nrog kev tau txais cov duab ntawm cov khoom.Txawm li cas los xij, lub tiaj tus, hloov tau yooj yim, roj av tswm ciab ntawm cov yas tau txais rau hnub Friday tau hloov mus rau hauv cov yeeb nkab nyuaj los ntawm hnub Monday (lub sijhawm thaij duab).Cov khoom siv tau tshaj tawm tias yog lub tsho polyethylene (PE) yeeb nkab siv los tiv thaiv cov khoom siv hluav taws xob hauv qab hauv av ntawm qhov chaw nres tsheb roj.Lub tiaj tiaj tiaj tiaj cov khoom yas uas koj tau txais tsis tiv thaiv kab.Kev nkag mus ntawm cov roj av ua rau lub cev, tsis hloov tshuaj lom neeg - cov yeeb nkab polyethylene tsis decompose.Txawm li cas los xij, nws yog qhov yuav tsum tau nkag mus rau cov kav dej uas tsis tshua muaj zog.
Fault 4. Ntau qhov chaw tsim khoom siv Teflon-coated steel kav rau kev kho dej, kev kho cov kua qaub thiab qhov chaw uas muaj cov hlau tsis huv (piv txwv li, hauv kev lag luam zaub mov).Teflon-coated kav dej muaj qhov tso cai rau dej nkag mus rau hauv qhov chaw nruab nrab ntawm cov hlau thiab hauv ob sab phlu kom ntws tawm.Txawm li cas los xij, cov kav dej muaj cov txee lub neej tom qab siv ntev.
Daim duab 4 qhia txog Teflon-lined yeeb nkab uas tau siv los muab HCl rau ntau tshaj kaum xyoo.Ib tug loj npaum li cas ntawm steel corrosion khoom accumulates nyob rau hauv annular qhov chaw ntawm lub liner thiab cov yeeb nkab steel.Cov khoom tau thawb lub hauv ob sab hauv, ua rau muaj kev puas tsuaj raws li qhia hauv daim duab 5. Corrosion ntawm cov hlau txuas ntxiv mus txog thaum cov yeeb nkab pib xau.
Tsis tas li ntawd, creep tshwm sim ntawm Teflon flange nto.Creep txhais tau tias yog deformation (deformation) nyob rau hauv tas li load.Raws li nrog cov hlau, cov creep ntawm polymers nce nrog nce kub.Txawm li cas los xij, tsis zoo li steel, creep tshwm sim ntawm chav tsev kub.Feem ntau yuav, raws li tus ntoo khaub lig-section ntawm flange nto txo, cov bolts ntawm cov yeeb nkab steel yog overtightened kom txog thaum lub nplhaib tawg tshwm, qhia hauv daim duab.Cov kab nrib pleb txuas ntxiv nthuav tawm cov yeeb nkab steel rau HCl.
Failure 5: High-density polyethylene (HDPE) liners yog feem ntau siv nyob rau hauv cov roj thiab roj kev lag luam los kho corroded steel dej txhaj kab.Txawm li cas los xij, muaj cov kev cai tshwj xeeb rau liner siab nyem.Daim duab 6 thiab 7 qhia txog kev ua tsis tiav.Kev puas tsuaj rau ib lub valve liner tshwm sim thaum lub annulus siab tshaj qhov kev khiav hauj lwm siab - lub liner tsis ua hauj lwm vim yog nkag mus.Rau HDPE liners, txoj hauv kev zoo tshaj los tiv thaiv qhov tsis ua haujlwm no yog kom tsis txhob muaj kev ntxhov siab sai ntawm cov yeeb nkab.
Lub zog ntawm fiberglass qhov chaw txo qis nrog rov siv dua.Ob peb txheej yuav delaminate thiab tawg thaum lub sij hawm.API 15 HR "High Pressure Fiberglass Linear Pipe" muaj cov lus hais tias 20% kev hloov pauv hauv siab yog qhov ntsuas thiab kho qhov txwv.Tshooj 13.1.2.8 ntawm Canadian Standard CSA Z662, Petroleum thiab Gas Pipeline Systems, qhia meej tias qhov kev hloov pauv siab yuav tsum tau khaws cia qis dua 20% ntawm cov chaw tsim khoom cov yeeb nkab siab.Txwv tsis pub, tus tsim lub siab yuav raug txo kom txog li 50%.Thaum tsim FRP thiab FRP nrog cladding, cyclic loads yuav tsum raug coj mus rau hauv tus account.
Fault 6: Hauv qab (6 teev) sab ntawm cov yeeb nkab fiberglass (FRP) siv los muab cov dej ntsev yog npog nrog cov polyethylene high-density.Qhov ua tsis tiav, qhov zoo tom qab tsis ua haujlwm, thiab qhov thib peb (sawv cev rau kev tsim khoom tom qab) tau sim.Tshwj xeeb, qhov hla ntu ntawm qhov ua tsis tiav tau muab piv nrog rau ntu ntu ntawm cov yeeb nkab ua ntej ntawm qhov loj tib yam (saib daim duab 8 thiab 9).Nco ntsoov tias qhov ua tsis tiav ntawm ntu ntu muaj cov kab nrib pleb hauv intralaminar uas tsis muaj nyob hauv cov yeeb nkab fabricated.Delamination tshwm sim nyob rau hauv ob qho tib si tshiab thiab ua tsis tau tejyam kav.Delamination yog ib txwm muaj nyob rau hauv fiberglass nrog ib tug siab iav ntsiab lus;Cov ntsiab lus iav siab muab lub zog ntau dua.Lub raj xa dej tau raug kev hloov pauv loj heev (ntau dua 20%) thiab ua tsis tiav vim kev thauj khoom cyclic.
Daim duab 9. Ntawm no yog ob ntu ntxiv ntawm cov fiberglass tiav nyob rau hauv high-density polyethylene-lined fiberglass yeeb nkab.
Thaum lub sijhawm teeb tsa ntawm qhov chaw, cov ntu me ntawm cov yeeb nkab txuas nrog - cov kev sib txuas no tseem ceeb heev.Feem ntau, ob daim yeeb nkab yog butted ua ke thiab qhov sib txawv ntawm cov kav dej yog ntim nrog "putty."Cov pob qij txha yog ces qhwv nyob rau hauv ob peb txheej ntawm dav-dav fiberglass reinforcement thiab impregnated nrog resin.Sab nrauv ntawm qhov sib koom ua ke yuav tsum muaj cov txheej txheem steel txaus.
Cov ntaub ntawv tsis yog xim hlau xws li liners thiab fiberglass yog viscoelastic.Txawm hais tias tus cwj pwm no nyuaj los piav qhia, nws cov kev tshwm sim yog tshwm sim: kev puas tsuaj feem ntau tshwm sim thaum lub sij hawm teeb tsa, tab sis kev xau tsis tshwm sim tam sim ntawd."Viscoelasticity yog ib yam khoom ntawm cov khoom uas nthuav tawm ob qho tib si viscous thiab elasticity thaum deformed.Cov ntaub ntawv viscous (xws li zib ntab) tiv thaiv shear flow thiab deform linearly nyob rau lub sijhawm thaum muaj kev ntxhov siab.Elastic cov ntaub ntawv (xws li steel) yuav deform tam sim ntawd, tab sis kuj sai sai rov qab mus rau lawv cov qub xeev tom qab kev ntxhov siab raug tshem tawm.Cov ntaub ntawv Viscoelastic muaj ob yam khoom thiab yog li nthuav tawm lub sijhawm sib txawv deformation.Elasticity feem ntau tshwm sim los ntawm kev ncab ntawm daim ntawv cog lus raws cov dav hlau crystalline hauv cov khoom tawg, thaum viscosity tshwm sim los ntawm kev sib txawv ntawm cov atoms lossis cov molecules hauv cov khoom siv amorphous ” [4].
Fiberglass thiab yas Cheebtsam yuav tsum tau saib xyuas tshwj xeeb thaum lub sij hawm installation thiab tuav.Txwv tsis pub, lawv yuav tawg thiab kev puas tsuaj yuav tsis tshwm sim kom txog rau thaum ntev tom qab kuaj hydrostatic.
Feem ntau tsis ua hauj lwm ntawm fiberglass linings tshwm sim vim kev puas tsuaj thaum lub sij hawm installation [5].Kev kuaj hydrostatic yog tsim nyog tab sis tsis pom kev puas tsuaj me me uas yuav tshwm sim thaum siv.
Daim duab 10. Qhia ntawm no yog sab hauv (sab laug) thiab sab nraud (txoj cai) cuam tshuam ntawm cov yeeb nkab fiberglass ntu.
Qhov tsis zoo 7. Daim duab 10 qhia txog kev sib txuas ntawm ob ntu ntawm cov kav dej fiberglass.Daim duab 11 qhia txog ntu ntu ntawm kev sib txuas.Sab nrauv ntawm cov yeeb nkab tsis muaj zog txaus thiab kaw, thiab cov yeeb nkab tawg thaum lub sij hawm thauj mus los.Cov lus pom zoo rau kev txhim kho cov pob qij txha yog muab rau hauv DIN 16966, CSA Z662 thiab ASME NM.2.
High-density polyethylene kav yog lub teeb yuag, corrosion-resistant, thiab feem ntau yog siv rau cov pa roj thiab cov kav dej, nrog rau cov hoses tua hluav taws ntawm cov chaw ua haujlwm.Feem ntau qhov ua tsis tiav ntawm cov kab no cuam tshuam nrog kev puas tsuaj tau txais thaum lub sijhawm ua haujlwm khawb av [6].Txawm li cas los xij, kev loj hlob qeeb qeeb (SCG) tsis ua haujlwm kuj tuaj yeem tshwm sim ntawm qhov kev ntxhov siab tsawg thiab tsawg heev.Raws li cov lus ceeb toom, "SCG yog ib qho kev ua tsis tau zoo hauv cov kav dej hauv av polyethylene (PE) nrog lub neej tsim ntawm 50 xyoo" [7].
Fault 8: SCG tau tsim hauv qhov hluav taws kub hose tom qab siv ntau tshaj 20 xyoo.Nws pob txha muaj cov yam ntxwv hauv qab no:
SCG tsis ua hauj lwm yog tus cwj pwm los ntawm tus qauv tawg: nws muaj qhov me me deformation thiab tshwm sim vim muaj ntau lub nplhaib concentric.Thaum thaj tsam SCG nce mus txog kwv yees li 2 x 1.5 ntiv tes, cov kab nrib pleb nthuav tawm sai heev thiab cov yam ntxwv macroscopic tsis pom tseeb (Daim duab 12-14).Cov kab yuav muaj kev hloov pauv ntau dua 10% txhua lub lim tiam.Cov pob qij txha HDPE qub tau raug tshaj tawm tias muaj kev tiv thaiv tsis ua haujlwm vim qhov kev hloov pauv ntau dua li qub HDPE pob qij txha [8].Txawm li cas los xij, cov chaw uas twb muaj lawm yuav tsum xav txog kev tsim SCG li HDPE hluav taws hoses hnub nyoog.
Daim duab 12. Daim duab no qhia tau hais tias qhov twg T-txoj haujlwm sib tshuam nrog cov yeeb nkab loj, tsim kom muaj qhov tawg uas qhia los ntawm xub liab.
Rice.14. Ntawm no koj tuaj yeem pom ze ntawm qhov tawg ntawm T-shaped ceg mus rau lub ntsiab T-shaped yeeb nkab.Muaj qhov pom tseeb tawg ntawm sab hauv.
Intermediate Bulk Containers (IBCs) yog tsim rau khaws cia thiab thauj cov tshuaj me me (Daim duab 15).Lawv ntseeg tau tias nws yooj yim tsis nco qab tias lawv qhov kev ua tsis tiav tuaj yeem ua rau muaj kev phom sij loj.Txawm li cas los xij, MDS ua tsis tiav tuaj yeem ua rau poob nyiaj txiag tseem ceeb, qee qhov kev tshuaj xyuas los ntawm cov kws sau ntawv.Feem ntau qhov ua tsis tiav yog tshwm sim los ntawm kev tuav tsis raug [9-11].Txawm hais tias IBC zoo li yooj yim los tshuaj xyuas, cov kab nrib pleb hauv HDPE tshwm sim los ntawm kev tuav tsis raug yog qhov nyuaj rau kev kuaj xyuas.Rau cov thawj tswj hwm cov cuab yeej cuab tam hauv cov tuam txhab uas nquag tuav cov thawv ntim khoom uas muaj kev phom sij, kev tshuaj xyuas sab nraud thiab sab hauv yog qhov yuav tsum tau ua.nyob rau hauv lub tebchaws United States.
Ultraviolet (UV) kev puas tsuaj thiab kev laus yog muaj nyob rau hauv cov polymers.Qhov no txhais tau tias peb yuav tsum ua tib zoo ua raws li O-ring cia cov lus qhia thiab xav txog qhov cuam tshuam rau lub neej ntawm cov khoom siv sab nraud xws li qhib lub tso tsheb hlau luam thiab cov pas dej hauv pas dej.Thaum peb yuav tsum tau ua kom zoo dua (tsawg kawg) kev siv nyiaj txiag, qee qhov kev tshuaj xyuas ntawm cov khoom sab nraud yog qhov tsim nyog, tshwj xeeb tshaj yog cov uas raug tshav ntuj (Daim duab 16).
Cov yam ntxwv xws li iav hloov kub, compression teeb, nkag mus, chav tsev kub creep, viscoelasticity, qeeb tawg propagation, thiab lwm yam. txiav txim siab qhov kev ua tau zoo ntawm cov yas thiab elastomeric qhov chaw.Txhawm rau kom muaj txiaj ntsig zoo thiab ua haujlwm tau zoo ntawm cov khoom tseem ceeb, cov khoom no yuav tsum raug coj mus rau hauv tus account, thiab cov polymers yuav tsum paub txog cov khoom no.
Cov kws sau ntawv xav ua tsaug rau cov neeg tau txais kev pom zoo thiab cov npoj yaig sib qhia lawv qhov kev tshawb pom nrog kev lag luam.
1. Lewis Sr., Richard J., Hawley's Concise Dictionary of Chemistry, 12th edition, Thomas Press International, London, UK, 1992.
2. Internet qhov chaw: https://promo.parker.com/promotionsite/oring-ehandbook/us/en/ehome/laboratory-compression-set.
3. Lach, Cynthia L., Cov nyhuv ntawm qhov kub thiab txias O-Ring Surface Treatment ntawm Sealing Ability ntawm Viton V747-75.NASA Technical Paper 3391, 1993, https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940013602.pdf.
5. Cov Kev Cai Zoo Tshaj Plaws rau Canadian Cov Roj thiab Cov Hluav Taws Xob (CAPP), "Siv Reinforced Composite (Non-Metallic) Pipeline," Lub Plaub Hlis 2017.
6. Maupin J. thiab Mamun M. Failure, Risk and Hazard Analysis of Plastic Pipe, DOT Project No. 194, 2009.
7. Xiangpeng Luo, Jianfeng Shi thiab Jingyan Zheng, Mechanisms of Slow Crack Growth in Polyethylene: Finite Element Methods, 2015 ASME Pressure Vessels and Piping Conference, Boston, MA, 2015.
8. Oliphant, K., Conrad, M., thiab Bryce, W., Fatigue of Yas Dej Pipe: Kev Tshawb Fawb Txog Kev Tshawb Fawb thiab Kev Pom Zoo rau Kev Tsim Nyog ntawm PE4710 Yeeb Nkab, Kev Tshaj Tawm Txog Kev Ua Haujlwm ntawm Lub Koom Haum Plastic Yeeb Nkab, Tsib Hlis 2012.
9. CBA/SIA Cov Lus Qhia rau Kev Cia Dej Hauv Cov Thawv Nruab Nrab Nruab Nrab, ICB Issue 2, Kaum Hli 2018 Online: www.chemical.org.uk/wp-content/uploads/2018/11/ibc-guidance-issue-2- 2018-1.pdf.
10. Beale, Christopher J., Txoj Kev, Charter, Ua rau IBC Leaks hauv Tshuaj Cog - Kev Ntsuam Xyuas Kev Ua Haujlwm, Kev Sib Tham No. 154, IChemE, Rugby, UK, 2008, online: https://www.icheme.org/media/9737/xx-paper-42.pdf.
11. Madden, D., Caring for IBC Totes: Tsib Lub Tswv Yim Kom Ua Kom Kawg, muab tso rau hauv Bulk Containers, IBC Totes, Sustainability, posted on blog.containerexchanger.com, September 15, 2018.
Ana Benz yog Chief Engineer ntawm IRISNDT (5311 86th Street, Edmonton, Alberta, Canada T6E 5T8; Xov tooj: 780-577-4481; Email: [email tiv thaiv]).Nws tau ua haujlwm ua tus kws tshaj lij, tsis ua haujlwm thiab tshuaj xyuas tshwj xeeb rau 24 xyoo.Nws qhov kev paub dhau los suav nrog kev kuaj xyuas siv cov txheej txheem tshuaj ntsuam xyuas qib siab thiab teeb tsa cov phiaj xwm tshuaj xyuas cov nroj tsuag.Mercedes-Benz ua haujlwm rau kev lag luam tshuaj, petrochemical cov nroj tsuag, chiv thiab cov nroj tsuag npib tsib xee thoob ntiaj teb, nrog rau cov nroj tsuag roj thiab roj.Nws tau txais kev kawm tiav qib siab hauv cov khoom siv engineering los ntawm Universidad Simon Bolivar hauv Venezuela thiab kawm tiav qib siab hauv cov khoom siv engineering los ntawm University of British Columbia.Nws tuav ob peb Canadian General Standards Board (CGSB) cov ntawv pov thawj tsis muaj kev puas tsuaj, nrog rau API 510 ntawv pov thawj thiab CWB Group Level 3 certification.Benz yog ib tug tswv cuab ntawm NACE Edmonton Executive ceg rau 15 xyoo thiab yav tas los ua haujlwm hauv ntau txoj haujlwm nrog Edmonton ceg Canadian Welding Society.
NINGBO BODI SEALS CO., LTD tsim txhua yamFFKM YOG, FKM ORING KITS ,
Txais tos tiv tauj peb ntawm no, ua tsaug!
Post lub sij hawm: Nov-18-2023