Ntawm Qhov Kev Sib Txuas Tshwj Xeeb ntawm Caustic Concentration thiab Sheath Surface Temperature Puas Yog 1.6 Millimeter 316 Stainless Steel Sheath Hloov los ntawm Passive rau Active Corrosion hauv Sodium Hydroxide Service rau CIP Systems?

Cov txheej txheem engineers tsim lub tshuab hluav taws xob tso cua sov kom huv si - hauv - qhov chaw rau kev ua zaub mov, kev tsim tshuaj thiab kev tsim dej haus siv sodium hydroxide ua tus thawj saib xyuas tshuaj. CIP cov kev daws teeb meem muaj 1-3% NaOH ntawm 70-85 degree. Hauv qhov xwm txheej no, cov ntawv ua yeeb yaj kiab tsis zoo, thiab feem ntau, qhov kev tiv thaiv corrosion ntawm 316 stainless hlau yog qhov zoo. Txawm li cas los xij, ntawm qhov siab dua lossis siab dua qhov kub ntawm lub tshuab cua sov watt ntom ntom cov zaj duab xis passive tuaj yeem ua rau tawg thiab muaj zog corrosion tuaj yeem tshwm sim nrog cov nqi tshaj 1 millimeter ib xyoo. Cov phab ntsa tuab ntawm CIP cua sov yog 1.6 hli, muab kev sib haum xeeb tsim nyog ntawm kev tiv thaiv corrosion thiab thermal teb. Daim ntawv tsim cov caustic concentration thiab sheath nto kub qhov twg 1.6 hli 316 sheath hloov los ntawm passive mus rau active corrosion nyob rau hauv sodium hydroxide kev pab cuam.

316 Hloov hauv Sodium Hydroxide los ntawm Passive mus rau Active
Sodium hydroxide yog ib qho tshwj xeeb ntawm cov tshuaj alkaline hauv qhov kev coj cwj pwm ntawm 316 stainless hlau pom qhov tseeb passive - kev hloov pauv uas yog nyob ntawm ob qho tib si concentration thiab kub. Hauv cov tshuaj dilute hauv qab 5% NaOH thiab kub hauv qab 80oC, 316 nyob twj ywm nrog cov nqi corrosion tsawg dua 0.05 hli hauv ib xyoos. Raws li cov concentration loj hlob los yog kub nce, cov zaj duab xis passive yuav tsis ruaj khov. Ntawm 10% NaOH qhov hloov pauv kub yog li 90 degree. Nws txo qis rau 75C 20% NaOH. Ntawm 30% NaOH tus nqi poob rau 60 degree. Ntawm 50% NaOH, dhau 40℃qhov passive ntau yam ploj lawm. Lub plhaub saum npoo kub yog feem ntau 15-30℃siab dua li qhov ntsuas kub ntau rau lub rhaub dej kub vim yog siv watt ntom. CIP system nrog 3% NaOH thiab 80℃bulk kub nrog lub rhaub ntawm 8 W / cm² muab qhov kub ntawm qhov kub ntawm 95-105 degree. Cov txheej txheej passive ntawm 316 tuaj yeem tawg ntawm qhov kub thiab txias ntawm qhov kub thiab txias tshwm sim ntawm tus nqi ntawm 0.5-2 hli hauv ib xyoos. Active corrosion yuav puncture ib 1.6 hli sheath nyob rau hauv 1-3 xyoo, tab sis passive ua hauj lwm yuav muab 10+ xyoo ntawm kev pab cuam.

Kev hloov pauv tseem ceeb rau 1.6 hli Sheath
Kev ntsuam xyuas hluav taws xob ntawm 316 cov qauv hauv sodium hydroxide cov kev daws teeb meem ntawm CIP cov kev pabcuam ntsig txog qhov kub thiab txias tau pom tias cov kev sib xyaw ua ke hauv qab no ntawm bulk caustic concentration thiab sheath deg kub yuav ua rau passive - mus rau - nquag hloov mus rau phab ntsa 1.6 mm. Tus nqi yog rau tus qauv swaged nto polish thiab ib txwm watt ceev ntawm 6-8 W / cm².

Sodium Hydroxide Concentration ( Nyhav %) Passive to Active Transition Temperature Minimum Sheath Surface Temperature for Active Corrosion Safe Bulk Temperature for 1.6 mm Sheath at 8 W/cm2 (25℃rise) Expected Corrosion Rate in Active Regime
1 – 2% >100℃100℃75℃0.3 ~ 0.7 hli / xyoo
2 - 3% 95 - 100℃95 - 100℃Txog 70 - 75℃0.5 - 1.0 mm / xyoo
3 - 5% 85 - 95℃85 - 95℃Mus txog 60 - 70℃0.8 - 1.5 mm / xyoo
5 - 7% 75 - 85℃75 - 85℃Mus txog 50 - 60℃1.0 - 2.0 mm / xyoo
7 - 10% 65 - 75℃65 - 75℃Mus txog 40 - 50℃1.5 - 3.0 mm / xyoo
10 - 15% 55 - 65℃55 - 65℃Mus txog 30 - 40℃2.0 - 4.0 mm / xyoo
> 15% < 55 degrees CBelow 55°C Not safe at any useful temperature>3.0mm / xyoo
Rau CIP system nrog qhov kub thiab txias ntawm 80℃thiab 2% NaOH siv 1.6 hli sheath ntawm 8 W / cm2, qhov kub ntawm lub plhaub yog nyob ib ncig ntawm 105 degree, siab tshaj qhov hloov pauv ntawm 100 degree. Active corrosion yuav tshwm sim thiab sheath yuav perforate nyob rau hauv 1-2 xyoo. Txo qhov ceev ntawm watt mus rau 4 W / cm², txo qhov kub ntawm qhov chaw nce mus rau 12-15℃thaum lub sheath kub nyob ntawm 92-95 degree, uas yog qis dua 100℃pib. Qhov kev hloov no tso cai rau 5-10 xyoo ntawm kev pabcuam lub neej.

1.6 Millimeter Sheath Safe Operating Envelope Nyob rau hauv Caustic CIP Service
Cov lus hauv qab no muab qhov siab tshaj plaws tso cai bulk sodium hydroxide concentration rau 1.6 hli 316 sheath ntawm ntau qhov kub thiab watt ntom. Rau qee qhov ntsuas qhov tseem ceeb, qhov kub ntawm lub plhaub tau khaws cia tsawg kawg 5℃hauv qab qhov passive - mus rau - kub hloov pauv.

Kev daws qhov kub thiab txias Watt Density 4 W / cm2 (12℃nce) Watt Density 6 W / cm2 (18℃sawv) Watt Ceev 8 W / cm2 (25℃sawv) Watt ceev 10 W / cm2 (32℃sawv) 60℃Safe mus rau 10% NaOH Safe mus txog 7% NaOH Safe mus txog 7% NaOH 65℃Safe mus rau 8% NaOH Ib xees nyab xeeb rau 5 NaOH Safe mus rau 3% NaOH Safe mus rau 2% NaOH 70℃Safe mus rau 6% NaOH Safe mus txog 4% NaOH Safe mus txog 2% NaOH Tsis muaj kev ruaj ntseg tshaj 1% 75oC Tsis zoo siab tshaj 5% NaOH max 5%, mus txog % NaOH nyab xeeb tshaj 3%.℃Kev nyab xeeb txog li 4% NaOH nyab xeeb txog 2% NaOH tsis nyab xeeb siab dua 1.5% Tsis nyab xeeb 85℃nyab xeeb txog 3% NaOH txog 1.5% NaOH nyab xeeb Tsis nyab xeeb Tsis nyab xeeb
90℃Safe mus txog 2% NaOH Tsis muaj kev nyab xeeb siab dua 1% Tsis zoo Tsis muaj kev nyab xeeb
Rau ib tug raug CIP voj voog ntawm 80℃nrog 2% NaOH, ib tug 1.6 hli 316 sheath muaj kev ruaj ntseg nkaus xwb ntawm watt ntom ntawm 4 W / cm2 los yog tsawg dua. Ntawm qhov kev lag luam watt ceev ntawm 8 W / cm² lub rhaub yuav nyob rau hauv kev ua haujlwm corrosion thiab lub neej kev pab cuam ntawm 1-3 xyoos yuav tsum tau kwv yees ntau dua li qhov feem ntau xav tias 5-10 xyoo.

Passive Operation Design Hloov
Peb tsim kev hloov kho tuaj yeem ua kom ruaj khov ua haujlwm tsis tas yuav hloov cov khoom siv hauv cov txheej txheem CIP uas yuav txwv tsis pub siv 1.6 hli 316 sheath rau hauv kev ua haujlwm corrosion (piv txwv li, caustic concentrations lossis kub): Thawj txoj hauv kev yog txhawm rau nce qhov ntev ntawm cov khoom kom txo tau cov watt ntom. Doubling qhov ntev (1 m mus rau 2 m) txo qhov kub ntawm qhov kub ntawm 25℃mus rau 12℃thiab rov qab mus rau kev ua haujlwm tsis zoo thaum lub zog watt raug txo los ntawm 8 W / cm2 txog 4 W / cm 2 . Qhov kev hloov kho thib ob yog txhawm rau txhim kho kev ncig ntawm lub rhaub dej. Rau tib lub watt ntom ntom, qhov kub ntawm qhov saum npoo tuaj yeem raug txo mus rau 8-10℃ntawm qhov nrawm ntawm 2-3 m / s siv lub twj tso kua mis CIP. Qhov kawg hloov pauv yog qhov sib ntxiv ntawm cov tshuaj tiv thaiv corrosion rau cov tshuaj caustic. Silicates los yog phosphates ntawm 100 mus rau 200 ppm tuaj yeem ruaj khov rau cov yeeb yaj kiab passive ntawm 316 thiab nce qhov kev hloov pauv kub ntawm 10 mus rau 20 degree. Tab sis cov kev hloov no tej zaum yuav tsis txaus rau CIP systems uas yuav tsum tau 5% NaOH ntawm 80oC. Nyob rau hauv cov xwm txheej no tus engineer yuav tsum qhia meej txog kev siv cov nickel{29}}raws li alloy xws li Alloy 600 los yog Alloy 825, uas yog passive nyob rau hauv caustic tov txog li 50% concentration ntawm kub tshaj 100℃. Tus nqi ntawm kev hloov kho los ntawm 316 mus rau Alloy 825 feem ntau yog 2-3 zaug ntau dua, tab sis kev pab cuam lub neej nce ntawm 1-2 xyoos mus rau 10-15 xyoo. Nco ntsoov qhia tus neeg muag khoom thaum qhia txog lub tshuab cua sov rau CIP kev pabcuam: qhov siab tshaj plaws ntawm caustic, qhov kub thiab txias thiab lub sijhawm xav tau. Thaum ib lub chaw tsim khoom qhia 316 rau 5% NaOH ntawm 85 deg C yam tsis muaj kev xav txog kev hloov pauv hloov pauv lossis derating rau watt ntom, qhov ntawd tsis tsim nyog cov lus qhia. Qhov kev hloov ntawm passive mus rau active corrosion nyob rau hauv sodium hydroxide yog sai sai thiab muaj nuj nqi ntawm kub. A 316 sheath ntawm 1.6 hli tuab ua haujlwm qis dua qhov pib yuav nyob mus li kaum xyoo; ib qho kev khiav hauj lwm tsuas yog dhau nws yuav ua tsis tiav hauv 18 lub hlis. Qhov tseeb thermal tsom xam ntawm sheath nto kub yog tsim nyog rau kev txhim khu kev qha specification.