純(chun)堿(jian)是最基(ji)本的(de)化(hua)(hua)工(gong)原料之一,它直接(jie)關(guan)系到(dao)國民(min)經濟(ji)的(de)發(fa)展。純(chun)堿(jian)生產過(guo)程中,氣體(ti)(ti)介質(zhi)多為NH3和CO2,液體(ti)(ti)介質(zhi)多為NaCl、NH4Cl、NH4HCO3和Cl- 濃度較高的(de)溶液,使(shi)(shi)用(yong)(yong)碳(tan)鋼(gang)、鑄鐵材質(zhi)進行(xing)碳(tan)酸化(hua)(hua)反(fan)應(ying)(ying)的(de)碳(tan)化(hua)(hua)塔小管(guan)、熱(re)母(mu)液冷(leng)卻(que)器、冷(leng)卻(que)器、結(jie)晶外冷(leng)器等(deng)主(zhu)體(ti)(ti)設備,均不(bu)耐腐蝕,腐蝕泄漏(lou)嚴(yan)重(zhong),使(shi)(shi)用(yong)(yong)壽命不(bu)超(chao)過(guo)三(san)年(nian)。1975-1977年(nian),天津堿(jian)廠(chang)和大連化(hua)(hua)學(xue)工(gong)業(ye)公司建(jian)廠(chang)進行(xing)了(le)鈦(tai)應(ying)(ying)用(yong)(yong)示范工(gong)作,碳(tan)化(hua)(hua)塔冷(leng)卻(que)管(guan)63×2mm、鈦(tai)板式換熱(re)器、鈦(tai)外冷(leng)器、鈦(tai)泵、CO2透平壓縮機轉子、Ti-6Al-4V合金(jin)葉輪等(deng)的(de)應(ying)(ying)用(yong)(yong)效果(guo)很好,這(zhe)為全行(xing)業(ye)進行(xing)用(yong)(yong)鈦(tai)技術改造和新建(jian)三(san)個(ge)年(nian)產60萬噸純(chun)堿(jian)廠(chang)起到(dao)了(le)樣(yang)板作用(yong)(yong)。
例如:某純(chun)堿(jian)廠蒸(zheng)(zheng)餾(liu)塔(ta)頂部氨(an)冷(leng)凝器(qi)應用(yong)(yong)(yong)(yong)純(chun)鈦(tai)管(guan)(guan)(guan)(guan)(guan)代替鑄(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)(tie)管(guan)(guan)(guan)(guan)(guan)。氨(an)冷(leng)凝器(qi)是(shi)純(chun)堿(jian)生產(chan)過程中(zhong),將蒸(zheng)(zheng)餾(liu)塔(ta)蒸(zheng)(zheng)出的(de)氨(an)氣進行(xing)冷(leng)凝的(de)設備,它(ta)由兩個鑄(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)(tie)冷(leng)卻(que)箱(xiang)組(zu)成,每個箱(xiang)的(de)直徑(jing)2.5m,高1.2m,箱(xiang)內(nei)原裝有Φ63×6×2986mm鑄(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)(tie)小管(guan)(guan)(guan)(guan)(guan)214根,兩個箱(xiang)共428根。管(guan)(guan)(guan)(guan)(guan)內(nei)外均用(yong)(yong)(yong)(yong)熱(re)固(gu)性酚醛(quan)清(qing)漆防腐(fu),管(guan)(guan)(guan)(guan)(guan)外介質為(wei)NH3、CO2、H2O蒸(zheng)(zheng)氣,溫(wen)度95℃左右(you)。管(guan)(guan)(guan)(guan)(guan)內(nei)走NH4Cl母液,與(yu)管(guan)(guan)(guan)(guan)(guan)外介質進行(xing)換熱(re)。在此條件(jian)下(xia),鑄(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)(tie)管(guan)(guan)(guan)(guan)(guan)腐(fu)蝕(shi)嚴(yan)重,使(shi)(shi)用(yong)(yong)(yong)(yong)一(yi)(yi)年(nian)即有部分管(guan)(guan)(guan)(guan)(guan)子(zi)腐(fu)蝕(shi)穿孔,2年(nian)已腐(fu)蝕(shi)損壞嚴(yan)重,停止使(shi)(shi)用(yong)(yong)(yong)(yong)。為(wei)解決氨(an)冷(leng)凝器(qi)內(nei)鑄(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)(tie)管(guan)(guan)(guan)(guan)(guan)嚴(yan)重腐(fu)蝕(shi)問題,將鑄(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)(tie)管(guan)(guan)(guan)(guan)(guan)全部替換為(wei)TA2鈦(tai)管(guan)(guan)(guan)(guan)(guan),規格(ge)為(wei)Φ60×2×3010mm,鈦(tai)管(guan)(guan)(guan)(guan)(guan)管(guan)(guan)(guan)(guan)(guan)端(duan)與(yu)鑄(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)(tie)花板間(jian)(jian)用(yong)(yong)(yong)(yong)O型橡膠圈密(mi)封(feng)。這是(shi)我國(guo)純(chun)堿(jian)工業第一(yi)(yi)臺(tai)蒸(zheng)(zheng)餾(liu)塔(ta)的(de)冷(leng)卻(que)小管(guan)(guan)(guan)(guan)(guan)采用(yong)(yong)(yong)(yong)純(chun)鈦(tai)管(guan)(guan)(guan)(guan)(guan)。投產(chan)使(shi)(shi)用(yong)(yong)(yong)(yong)二年(nian)多,曾抽管(guan)(guan)(guan)(guan)(guan)進行(xing)宏觀檢查,未發(fa)現腐(fu)蝕(shi)現象,預計使(shi)(shi)用(yong)(yong)(yong)(yong)壽命(ming)可(ke)達(da)20年(nian)以上,可(ke)比(bi)鑄(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)(tie)管(guan)(guan)(guan)(guan)(guan)延長10倍。由于鈦(tai)管(guan)(guan)(guan)(guan)(guan)耐腐(fu)蝕(shi),傳熱(re)效(xiao)(xiao)率保(bao)持良好(hao)(鑄(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)(tie)管(guan)(guan)(guan)(guan)(guan)在3年(nian)一(yi)(yi)個大(da)修期(qi)間(jian)(jian),其傳熱(re)效(xiao)(xiao)率前期(qi)好(hao),中(zhong)期(qi)差,后期(qi)就失效(xiao)(xiao)),管(guan)(guan)(guan)(guan)(guan)內(nei)NH4Cl母液預熱(re)回收熱(re)量,提高母液進入(ru)蒸(zheng)(zheng)餾(liu)塔(ta)的(de)溫(wen)度,可(ke)節約(yue)大(da)量蒸(zheng)(zheng)汽,經濟效(xiao)(xiao)益明顯。