Xlorlangan uglevodorod (metilen xlorid) uchun bug'lashtirgichda 250 daraja ishlaydigan titanli issiqlik tayoqchasida gidrolizning oldini olish uchun ozuqa tarkibidagi ruxsat etilgan maksimal namlik (ppm) -HCl chuqurchalarining paydo bo'lishining oldini olish uchun qanday?

Metilenxlorid (CH₂Cl₂) uchun 250 daraja haroratda bug'lashtirgichda xlorli uglevodorod namlik bilan gidrolizlanadi: CH₂Cl₂ + H₂O → CH₂O + 2HCl. Titanning hosil bo'lgan xlorid kislotasi (HCl) bilan ta'siri natijasida chuqurchalar paydo bo'ladi. Chuqurlikning oldini olish uchun ruxsat etilgan maksimal namlik miqdori millionda 50 qismdir. Ushbu darajadan yuqori HCl hosil bo'lishi titanium passiv plyonkaning bardoshliligidan oshib ketadi va 100-500 soat ichida chuqurlik boshlanadi. Miqdoriy chuqurlik va namlik miqdori 250 daraja, 10 bar: Namlik (ppm)|HCl hosil qilingan (ppm ekvivalenti)|Pittingni boshlash vaqti (soat)|1000 soatdan keyin chuqur chuqurligi (µm)<10 <20 >5,000 0 10–25 20–50 2,000–5,000 0–20 25–50 50–100 500–2,000 20–50 50–100 100–200 200–500 50–150 <50 Severe >500 >1,000 50-200 150-500 200-1,000 100-500 Namlikni nazorat qilish bo‘yicha qo‘llanma Oziqlantirish namligi (ppm) Tavsiya etilgan harakat Isitgichning kutilayotgan xizmat muddati (devor 1,5 mm)<25 None >5 years 25–50 Install molecular sieve dryer 3–5 years 50–100 Dryer + acid scavenger (epoxide) 1–3 years >100 Tasma tizimini qayta loyihalash<1 year Engineering recommendation Chlorinated hydrocarbon vaporisers should be operated at 250°C with feed moisture less than 25 ppm to ensure a safety margin below the 50 ppm standard. • Install online moisture analyser with alarm at 40 ppm. The engineer controls moisture content to prevent pitting by hydrolysis of HCl.