Dab tsi yog qhov siab tshaj plaws ntawm Silica Concentration (ppm) nyob rau hauv 25% Sodium Hydroxide Solution ntawm 90℃los tiv thaiv kev tsim ntawm Sodium Titanate Scale uas Insulates Qib 2 Titanium Heater Tube?

Silica (SiO2) interacts with titanium in 25% sodium hydroxide at 90°C to create sodium titanate (Na2TiO3) and sodium silicate scale. These scales have a relatively low thermal conductivity (0.5–1.5 W/m·K). Silica The maximum concentration of silica allowed to prevent the formation of insulating scale is 50 ppm. A scale thickness of >0.1 mm in 500 hours at >50 ppm yog tsim, ua rau muaj kev poob siab ntawm kev hloov pauv kub.

Silica Concentration vs. Quantitative Scale Formation

90℃rau 500 teev hauv 25% NaOH:

Silica (ppm) Scale Thickness (µm) Scale Composition Reduction ntawm tshav kub hloov (%)
0 0 Tsis muaj 0 10 5–15 Sodium silicate 2–{4}}–40 Mixed silicate/titanate 5–15 50 40–80 Sodium titanate predominate 15–{10}}–150 Thick titanate 30–{13}}– 300 silica titanate kub kam rau ua

Kub (degree) Max Silica rau<0.1 mm Scale (ppm)Recommended Max (ppm) Silica Control Guide 70 100 75 80 75 50 90 50 30 100 30 20

Ntsuas Silica (ppm) Pom Zoo Ua Haujlwm Cia Siab Nplai Thickness (microns / xyoo)
<20 No <20
20–50 Monitor Monthly 20-80 50-100Dilute or filter solution 80-150 >100 Replace solution >150
Pom zoo rau Engineering

Rau 25% NaOH ntawm 90 degree, silica concentration yuav tsum tau khaws cia qis dua 30 ppm. Txhawm rau tiv thaiv kev kis kab mob silica, siv dej deionised rau dilution. Tus engineer tswj cov silica los tiv thaiv kev tsim ntawm insulating sodium titanate nplai.