Chav Kawm B Fires Tsis Muaj Feem cuam tshuam "Txuj Ci" cov roj zoo li roj av -}}} muaj ntau koomTshwj Xeeb Tshaj Tawm(Dej {- soluble solvents, siab - viscosity greases) lossis tshwm sim hauvkaw qhov chaw(Kev tso tsheb hlau luam hauv av, ntim kev cob qhia) qhov chaw ua npuas dej tsis tiav. Cov xwm txheej no tau thov ntau dua li "ua npuas ncauj yuav tsum tawm tsam los ntawm cov roj av, lossis siv cov neeg ua haujlwm los ntawm cov tshuaj lom neeg lom. Lub affer 3% series yog engineed rau cov kis tawv no, nrog cov ntsuas tsis zoo rau cov kev tshaj tawm tshwj xeeb cov cwj pwm thiab cov chaw kaw qhov teeb meem zais.
1. Cov tsis muaj tseeb: Ua rau cov xwm txheej tshwj xeeb
Txhua qhov metric ntawm Afff 3% cov chaw nyob hauv qhov mob ntawm kev tshaj xov xwm tshwj xeeb thiab kaw chaw- tsis muaj kev ua haujlwm. Ntawm no yog li cas txhua tus qauv haum:
| Qauv Parieter | Afff 3% (-1 degree) | Afff 3% (-16 Qib) | Afff 3% (-35 degree) | Lub luag haujlwm hauv cov xwm txheej tshwj xeeb |
|---|---|---|---|---|
| Cov nro | 16.2 mn / m (anti -} yaj) | 17.3 mn / m (siab - kua nplaum) | 18.7 mn / m (txias - adhesion) | Resusts tsom tawg; clings kom tuab roj |
| Kis cov coefficient | 6.2-6.4 mn / m (nrawm -} ceev) | 3.5-3.3 mn / m (grease - cling) | 4.2-4.3 mn / m (txias - cling) | Npog cov chaw nruj heev; lo rau viscous media |
| Ph ntau | 7.6–8.3 | 7.6–8.3 | 7.6–8.3 | Nruab nrab kom tsis txhob muaj cov kuab tshuaj |
| VOC cov ntsiab lus | <0.1% | <0.1% | <0.1% | Muaj kev nyab xeeb rau kev kaw chaw (tsis muaj tshuaj lom) |
| 25% lub sijhawm tawm | 2.9 (1 ± 20%) min | 2.5 (1 ± 20%) Min | 3.2 (1 ± 20%) min | Khaws cov dej noo kom txias tuab, cua sov - pteined greases |
2. Tshwj xeeb xov xwm 1: Dej {- soluble polar cov kuab tshuaj (ethanol, methanol, acetone)
Sab hauv qab polar cov tshuaj sib xyaw nrog dej - Lawv yaj kev ua npuas dej, tig mus rau lub voj voog ntawm "thov, rhuav tshem, rov ua haujlwm." Lub affff 3% series tiv taus kev sib cais los ua cov pam vov.
- Qhov Zoo Tshaj: AFFF 3% (-16 Qib)Its balanced surface tension (17.3 mN/m) and neutral pH (7.6–8.3) prevent solvents from breaking down the foam's film. A Chinese methanol factory had a 40m² acetone spill in 2024: acetone's high water solubility would have dissolved traditional foam in 30 seconds, but AFFF 3% (-16℃) formed a stable blanket that lasted 2.5 minutes. The 3.5–3.8 mN/m spreading coefficient ensured the foam clung to the solvent's surface (no pooling), and the low VOCs let crews work in the factory's semi-confined space without respirators.The factory reported zero re-ignitions-unlike a 2022 incident, where traditional foam required 4 re-applications and exposed crews to toxic fumes (VOCs >1.5%).
3. Tshwj Xeeb Tshaj Tawm 2: Siab - viscosity greases & roj (asphalt, cov roj roj hnyav)
Tuab, nplaum me me (piv txwv li, molten asphalt, muaj roj|Tsis txhob ntws tawm los yog daim ntawv ua npuas ncauj, ua npuas dej tsis sib xws, tawm hauv hotspots. Lub AFFF 3% series 'siab - kua nplaum} kua nplaum ua kom daws qhov no.
Zoo Tshaj: AFff 3% (-35 degree) (thaj chaw txias) / afff 3% (-16 degree) (qib kub)
- Txias - cheeb tsam asphalt nroj tsuag: Ib haiv neeg asphalt cov neeg asphalt siv Afff 3% (-35 degree) rau Molten Asphalt Hluav Taws Xob (-20℃cia). Asphalt's viscosity (10, 000+ CP ntawm chav temp) thiab cov qauv ua npuas ncauj thiab cov neeg ua npuas ncauj. Thaum lub sijhawm 2024 hluav taws, cov ua npuas ncauj tsim cov pam tas li 60m² ntawm molten Aslhalt, txias nws los ntawm 280℃mus rau 120℃(hauv qab ntawm nws lub ntsej muag) hauv 4 feeb.
- Lub Chaw Haujlwm Kub Kub Frease: Lub tshuab German lub paj tau txais roj rau Afff 3% (- 16 degree). Nws tau txais kev sib piv tau ua rau muaj kev ua npuas dej ua npuas ntev uas tau ua npuas dej, tsis muaj zawv zawg. Lub 2.5 - feeb Siv cov dej ntws kom txias kom txias cov roj ua npuas dej kom txias rau hauv 1 feeb, xav tau 2 daim ntawv thov.
4. Cov xwm txheej nyuaj: kaw / chaw tso tsheb hauv av (hauv av hauv av tso tsheb hlau luam, ntim kev cob qhia)
Kev kaw thaj chaw ntxiab fumes thiab txwv maneuverability - cov tsoos foams 'siab heev cov khoom lag luam tsis muaj zog, thiab kis tawm qeeb qeeb tawm. Lub afff 3% series ua ntej kev nyab xeeb thiab nrawm ntawm no.
- Zoo tshaj plaws haum: afff 3% (-1 degree)Nws<0.1% VOC content and fast spreading make it ideal for underground tanks. A U.S. gas station had an underground gasoline tank leak (15m² confined space) in 2024: crews used AFFF 3% (-1℃) with a small portable sprayer. The foam's 16.2 mN/m surface tension let it spread through the tank's narrow access points in 25 seconds, covering the entire leak. Air tests showed VOC levels 98% below OSHA limits-crews worked without full-face respirators.Traditional foam (VOCs 1.8%) would have forced evacuations and required 30 minutes of ventilation before crews could enter-delaying suppression by 1 hour.
5. Vim li cas cov tsoos foams swb cov xwm txheej no
Lub affff 3% series kho cov khoom siv tsoos ua npuas tsis tuaj yeem:
| Cav | Tsoos Ua Npuas Ncej Kev Ua npuas dej | Afff 3% series daws |
|---|---|---|
| Ncauj Lus Qhia Sab Nraud | Zaj duab xis rhuav tshem hauv 30-60 vib nas this | Zaj duab xis tawm tsam kev xaus rau 2.5+ min |
| Siab - viscosity cling | Swb rau hauv 1-2 feeb | Clings rau 4+ Min (khaws cia txias) |
| Kaw cov chaw fumes | VOCs >1.5% (lom rau cov neeg ua haujlwm) | Vocs<0.1% (safe for unmasked work) |