Rau Titanium Sheath Heater Uas Muaj Qee Lub Sijhawm Qhuav -Tawm (10 feeb hauv ib lub lis piam) hauv 5% Sulfuric Acid Tank, Dab tsi yog Qhov Ntau Tshaj Plaws Qhuav -Tawm Cov Txheej Txheem Ua Ntej Oxide Spalls thiab Tube Thins Ntau dhau?

Titanium is passivated in 5% sulphuric acid (H 2 SO 4 ) at 80°C by a passive oxide coating. There is occasional dry-out, where the liquid level falls below the heater, exposing the hot titanium to air. The quick temperature increase (from 80°C to >200 degree) ua rau thermal expansion mismatch ntawm oxide nplai thiab hlau, uas ua rau spalling. Txhua qhov qhuav - tawm tshem tawm ib txheej nyias ntawm oxide thiab qee cov hlau hauv paus. Kev ua kom nyias nyias tom qab ib ncig ntawm 50 qhuav- tawm ntu yog 0.1–0.2 hli. Perforation ntawm 1.2 hli phab ntsa tuaj yeem tsim tom qab 200 qhov tshwm sim.

Qhuav-tawm cov xwm txheej thiab ntau qhov thinning

Qib 2 titanium 5% H₂SO₄ ntawm 80℃10- feeb qhuav-tawm txheej xwm:

Qhuav-Tawm Cov Txheej Txheem Cov Hlau Loss (mm) Cov Phab Ntsa Tseem Ceeb (1.2 hli pib) Oxide Condition
1.20 Tag nrho 0 0
10 0.02–0.05 1.15–1.18 Me me spalling 25 0.05–0.10 1.10–1.15 Nruab nrab spalling 50 0.10–0.20 1.00–1.10 Qhov tseem ceeb thinning 100 0.20–{10}}–1.00Severe thinning 200 0.40–{0.{0. 500 1.00–2.00 Perforated Failed Effect of Acid Concentration thiab Qhuav-Tawm Sijhawm

H₂SO₄ Concentration (%) Qhuav-Tawm Sijhawm (min) Hlau Loss ib qho xwm txheej (µm) Cov Txheej Txheem rau 0.5 mm Poob 5 5 2-4 125-250 5 10 4-8 60-125 5 30 8-15 30-60 10 10 6-12 40-80 20 10 10-20 25-50 Qhuav-Out Management Guide

Qhov siab tshaj plaws tau tso cai rau ib xyoos xav tau tus naj npawb ntawm qhuav- tawm cov xwm txheej hauv ib xyoos Kev Pom Zoo Ua Haujlwm 50 (5 xyoo)<10OK
10-25 xyoo 50 xyoo (2-5 xyoos) ntxiv lub tswb qis
25–50 50 (1–2 xyoos) Nws pib refill Tsis kam txais Re-tsim lub tank qib tswj
Cov Lus Qhia Engineering:

Rau cov tank sulfuric acid hloov lub rhaub tom qab 50 qhuav- tawm qhov xwm txheej. Qee zaus qhuav- tawm ua ntej hloov lub rhaub. Nruab lub tswb qis ntawm 20% siab tshaj qhov siab ntawm lub rhaub kom tiv thaiv kom qhuav. Tus kws tshaj lij tswj xyuas qhov qhuav- tawm zaus kom tsis txhob muaj oxide spalling thiab thinning ntau dhau.