反(fan)(fan)應(ying)過程(cheng)的基本特征決(jue)定(ding)了(le)適(shi)宜(yi)(yi)的反(fan)(fan)應(ying)器(qi)形式。例如(ru)氣固(gu)相反(fan)(fan)應(ying)過程(cheng)大致是用固(gu)定(ding)床(chuang)反(fan)(fan)應(ying)器(qi)、流(liu)化(hua)床(chuang)反(fan)(fan)應(ying)器(qi)或移動(dong)床(chuang)反(fan)(fan)應(ying)器(qi)。但是適(shi)宜(yi)(yi)的選(xuan)型則需考慮反(fan)(fan)應(ying)的熱效應(ying)、對反(fan)(fan)應(ying)轉化(hua)率(lv)和選(xuan)擇(ze)率(lv)的要求、催化(hua)劑(ji)物(wu)理化(hua)學性態(tai)和失(shi)活等多種(zhong)因素。
不銹(xiu)鋼反應(ying)(ying)器的(de)(de)操作方式和加料(liao)方式也(ye)需考慮(lv)。例如(ru),對(dui)于有(you)串聯或平行(xing)副(fu)反應(ying)(ying)的(de)(de)過程,分段(duan)進料(liao)可(ke)能優于一(yi)次進料(liao)。溫度序(xu)列也(ye)是反應(ying)(ying)器選型的(de)(de)一(yi)個重要因素。例如(ru),對(dui)于放熱(re)的(de)(de)可(ke)逆反應(ying)(ying),應(ying)(ying)采用先高后(hou)低的(de)(de)溫度序(xu)列,多級、級間換(huan)熱(re)式反應(ying)(ying)器可(ke)使反應(ying)(ying)器的(de)(de)溫度序(xu)列趨于合理(li)。
下面主要介紹釜式(shi)反(fan)應器(qi)、管式(shi)反(fan)應器(qi)、塔式(shi)反(fan)應器(qi)、固定床反(fan)應器(qi)、流化床反(fan)應器(qi)。
①. 釜式反應(ying)器
釜(fu)(fu)式反(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)也(ye)稱槽式、鍋式反(fan)應(ying)(ying)(ying)(ying)(ying)器(qi),它是各類(lei)反(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)中(zhong)(zhong)結構較為簡單(dan)(dan)且應(ying)(ying)(ying)(ying)(ying)用(yong)較廣的一種(zhong)。主要應(ying)(ying)(ying)(ying)(ying)用(yong)于(yu)(yu)液(ye)(ye)(ye)-液(ye)(ye)(ye)均(jun)相(xiang)(xiang)反(fan)應(ying)(ying)(ying)(ying)(ying)過(guo)程,在(zai)氣-液(ye)(ye)(ye)、液(ye)(ye)(ye)-液(ye)(ye)(ye)非(fei)均(jun)相(xiang)(xiang)反(fan)應(ying)(ying)(ying)(ying)(ying)過(guo)程中(zhong)(zhong)也(ye)有(you)(you)應(ying)(ying)(ying)(ying)(ying)用(yong)。在(zai)化工(gong)生(sheng)產(chan)中(zhong)(zhong),既適(shi)用(yong)于(yu)(yu)間歇(xie)操(cao)作(zuo)(zuo)過(guo)程,又可單(dan)(dan)釜(fu)(fu)或多(duo)釜(fu)(fu)串聯(lian)用(yong)于(yu)(yu)連續(xu)(xu)操(cao)作(zuo)(zuo)過(guo)程,但在(zai)間歇(xie)生(sheng)產(chan)過(guo)程中(zhong)(zhong)應(ying)(ying)(ying)(ying)(ying)用(yong)最多(duo)。釜(fu)(fu)式反(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)具有(you)(you)適(shi)用(yong)的溫(wen)(wen)度(du)和(he)壓力范圍寬、適(shi)應(ying)(ying)(ying)(ying)(ying)性(xing)強、操(cao)作(zuo)(zuo)彈性(xing)大、連續(xu)(xu)操(cao)作(zuo)(zuo)時(shi)溫(wen)(wen)度(du)濃度(du)容易(yi)控制、產(chan)品質量均(jun)一等特點。但用(yong)在(zai)較高轉化率工(gong)藝要求時(shi),需要較大容積。通常在(zai)操(cao)作(zuo)(zuo)條件比較緩和(he)的情況(kuang)下使用(yong),如常壓、溫(wen)(wen)度(du)較低且低于(yu)(yu)物料沸點時(shi),應(ying)(ying)(ying)(ying)(ying)用(yong)此類(lei)反(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)最為普遍(bian)。
②. 管式反(fan)應(ying)器
管(guan)(guan)式(shi)(shi)(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)器(qi)主要用(yong)于氣相、液相、氣-液相連(lian)(lian)續(xu)反(fan)(fan)(fan)應(ying)(ying)過程,由(you)單根(直管(guan)(guan)或盤管(guan)(guan))連(lian)(lian)續(xu)或多根平行排(pai)列的(de)管(guan)(guan)子(zi)組成(cheng),一(yi)般設有(you)(you)套管(guan)(guan)或殼管(guan)(guan)式(shi)(shi)(shi)(shi)換熱裝置。操作(zuo)(zuo)時,物料自一(yi)端連(lian)(lian)續(xu)加(jia)入,在管(guan)(guan)中(zhong)連(lian)(lian)續(xu)反(fan)(fan)(fan)應(ying)(ying),從另(ling)一(yi)端連(lian)(lian)續(xu)流出(chu),便(bian)達到了要求的(de)轉化(hua)率(lv)。由(you)于管(guan)(guan)式(shi)(shi)(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)器(qi)能承受較(jiao)高的(de)壓力,故用(yong)于加(jia)壓反(fan)(fan)(fan)應(ying)(ying)尤為合適,例(li)如(ru)油脂(zhi)或脂(zhi)肪酸加(jia)氫生(sheng)產高碳(tan)醇、裂解反(fan)(fan)(fan)應(ying)(ying)用(yong)的(de)管(guan)(guan)式(shi)(shi)(shi)(shi)爐便(bian)是管(guan)(guan)式(shi)(shi)(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)器(qi)。此(ci)種反(fan)(fan)(fan)應(ying)(ying)器(qi)具有(you)(you)容積(ji)小、比(bi)表面大(da)(da)、返混少(shao)、反(fan)(fan)(fan)應(ying)(ying)混合物連(lian)(lian)續(xu)性變化(hua)、易(yi)于控制等優點。但若(ruo)反(fan)(fan)(fan)應(ying)(ying)速(su)度較(jiao)慢時,則有(you)(you)所(suo)需(xu)管(guan)(guan)子(zi)長、壓降較(jiao)大(da)(da)等不足。隨(sui)著(zhu)化(hua)工生(sheng)產越來(lai)越趨(qu)于大(da)(da)型化(hua)、連(lian)(lian)續(xu)化(hua)、自動(dong)化(hua),連(lian)(lian)續(xu)操作(zuo)(zuo)的(de)管(guan)(guan)式(shi)(shi)(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)器(qi)在生(sheng)產中(zhong)使(shi)用(yong)越來(lai)越多,某(mou)些傳統上一(yi)直使(shi)用(yong)間歇攪拌(ban)釜的(de)高分子(zi)聚合反(fan)(fan)(fan)應(ying)(ying),目前也開始改(gai)用(yong)連(lian)(lian)續(xu)操作(zuo)(zuo)的(de)管(guan)(guan)式(shi)(shi)(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)器(qi)。管(guan)(guan)式(shi)(shi)(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)器(qi)的(de)長徑比(bi)較(jiao)大(da)(da),與釜式(shi)(shi)(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)器(qi)相比(bi)在結構上差異較(jiao)大(da)(da),有(you)(you)直管(guan)(guan)式(shi)(shi)(shi)(shi)、盤管(guan)(guan)式(shi)(shi)(shi)(shi)、多管(guan)(guan)式(shi)(shi)(shi)(shi)等。
③. 塔式反(fan)應器
塔(ta)(ta)式(shi)反(fan)(fan)(fan)應(ying)(ying)器(qi)的(de)(de)長徑比(bi)介于釜(fu)式(shi)和管(guan)式(shi)之間。主(zhu)要用(yong)于氣(qi)(qi)(qi)-液(ye)(ye)反(fan)(fan)(fan)應(ying)(ying),常(chang)用(yong)的(de)(de)有(you)鼓(gu)泡(pao)塔(ta)(ta)、填料塔(ta)(ta)、板式(shi)塔(ta)(ta)。最常(chang)用(yong)的(de)(de)是鼓(gu)泡(pao)塔(ta)(ta)式(shi)反(fan)(fan)(fan)應(ying)(ying)器(qi),底部裝(zhuang)有(you)氣(qi)(qi)(qi)體(ti)(ti)分布(bu)器(qi),殼外裝(zhuang)有(you)夾套或(huo)(huo)其他形式(shi)換熱(re)(re)(re)(re)器(qi)或(huo)(huo)設(she)(she)有(you)擴(kuo)大段、液(ye)(ye)滴(di)捕集器(qi)等(deng)。反(fan)(fan)(fan)應(ying)(ying)氣(qi)(qi)(qi)體(ti)(ti)通過分布(bu)器(qi)上(shang)的(de)(de)小孔以(yi)鼓(gu)泡(pao)形式(shi)通過液(ye)(ye)層進(jin)行化學(xue)反(fan)(fan)(fan)應(ying)(ying),液(ye)(ye)體(ti)(ti)間歇或(huo)(huo)連(lian)續(xu)(xu)(xu)加(jia)入,連(lian)續(xu)(xu)(xu)加(jia)入的(de)(de)液(ye)(ye)體(ti)(ti)可以(yi)和氣(qi)(qi)(qi)體(ti)(ti)并流或(huo)(huo)逆流,一般采用(yong)并流形式(shi)較多。氣(qi)(qi)(qi)體(ti)(ti)在(zai)塔(ta)(ta)內為分散(san)相,液(ye)(ye)體(ti)(ti)為連(lian)續(xu)(xu)(xu)相,液(ye)(ye)體(ti)(ti)返(fan)混程(cheng)(cheng)度較大。為了提高氣(qi)(qi)(qi)體(ti)(ti)分散(san)程(cheng)(cheng)度和減少液(ye)(ye)體(ti)(ti)軸向循環,可以(yi)在(zai)塔(ta)(ta)內安置水(shui)平多孔隔板。當(dang)吸(xi)收或(huo)(huo)反(fan)(fan)(fan)應(ying)(ying)過程(cheng)(cheng)熱(re)(re)(re)(re)效應(ying)(ying)不大時,可采用(yong)夾套換熱(re)(re)(re)(re)裝(zhuang)置,熱(re)(re)(re)(re)效應(ying)(ying)較大時,可在(zai)塔(ta)(ta)內增設(she)(she)換熱(re)(re)(re)(re)蛇(she)管(guan)或(huo)(huo)采用(yong)塔(ta)(ta)外換熱(re)(re)(re)(re)裝(zhuang)置,也可以(yi)利用(yong)反(fan)(fan)(fan)應(ying)(ying)液(ye)(ye)蒸(zheng)發的(de)(de)方法帶走(zou)熱(re)(re)(re)(re)量。
④. 固(gu)定床反應器
固定床(chuang)(chuang)(chuang)板反(fan)應(ying)(ying)器是(shi)指流體(ti)(ti)(ti)通過(guo)靜止不動的固體(ti)(ti)(ti)物料所形成的床(chuang)(chuang)(chuang)層(ceng)(ceng)而進(jin)行化(hua)學反(fan)應(ying)(ying)的設備。以氣-固反(fan)應(ying)(ying)的固定床(chuang)(chuang)(chuang)反(fan)應(ying)(ying)器最常(chang)見。固定床(chuang)(chuang)(chuang)反(fan)應(ying)(ying)器根(gen)據床(chuang)(chuang)(chuang)層(ceng)(ceng)數的多(duo)少又可分為(wei)單(dan)段式(shi)(shi)和多(duo)段式(shi)(shi)兩種(zhong)類型。單(dan)段式(shi)(shi)一(yi)般為(wei)高徑比不大的圓(yuan)筒(tong)體(ti)(ti)(ti),在(zai)(zai)圓(yuan)筒(tong)體(ti)(ti)(ti)下部裝有(you)柵板等板件,其上為(wei)催化(hua)劑(ji)床(chuang)(chuang)(chuang)層(ceng)(ceng),均勻地堆置一(yi)定厚度的催化(hua)劑(ji)固體(ti)(ti)(ti)顆(ke)粒(li)。單(dan)段式(shi)(shi)固定床(chuang)(chuang)(chuang)反(fan)應(ying)(ying)器結構簡單(dan)、造價便宜、反(fan)應(ying)(ying)器體(ti)(ti)(ti)積利用率高。多(duo)段式(shi)(shi)是(shi)在(zai)(zai)圓(yuan)筒(tong)體(ti)(ti)(ti)反(fan)應(ying)(ying)器內設有(you)多(duo)個催化(hua)劑(ji)床(chuang)(chuang)(chuang)層(ceng)(ceng),在(zai)(zai)各床(chuang)(chuang)(chuang)層(ceng)(ceng)之間(jian)可采用多(duo)種(zhong)方式(shi)(shi)進(jin)行反(fan)應(ying)(ying)物料的換熱。其特點是(shi)便于控制調節(jie)反(fan)應(ying)(ying)溫度,防止反(fan)應(ying)(ying)溫度超出允許范圍。
⑤. 流化床反應器
細(xi)小的固體(ti)顆(ke)(ke)粒(li)被流(liu)(liu)動著的流(liu)(liu)體(ti)攜帶(dai),具有(you)流(liu)(liu)體(ti)一(yi)樣自由(you)流(liu)(liu)動的性(xing)質(zhi),此(ci)種(zhong)現象稱(cheng)為固體(ti)的流(liu)(liu)態化(hua)(hua)(hua)(hua)。一(yi)般(ban)把反(fan)應(ying)(ying)(ying)器(qi)和在其中呈流(liu)(liu)態化(hua)(hua)(hua)(hua)的固體(ti)催(cui)化(hua)(hua)(hua)(hua)劑顆(ke)(ke)粒(li)合在一(yi)起(qi),稱(cheng)為流(liu)(liu)化(hua)(hua)(hua)(hua)床(chuang)反(fan)應(ying)(ying)(ying)器(qi)。流(liu)(liu)化(hua)(hua)(hua)(hua)床(chuang)反(fan)應(ying)(ying)(ying)器(qi)多(duo)(duo)用于氣(qi)-固反(fan)應(ying)(ying)(ying)過(guo)程(cheng)。當(dang)原料(liao)氣(qi)通過(guo)反(fan)應(ying)(ying)(ying)器(qi)催(cui)化(hua)(hua)(hua)(hua)劑床(chuang)層時,催(cui)化(hua)(hua)(hua)(hua)劑顆(ke)(ke)粒(li)受氣(qi)流(liu)(liu)作(zuo)用而(er)懸浮(fu)起(qi)來呈翻(fan)滾(gun)沸騰(teng)狀(zhuang),原料(liao)氣(qi)在處于流(liu)(liu)態化(hua)(hua)(hua)(hua)的催(cui)化(hua)(hua)(hua)(hua)劑表(biao)面進行化(hua)(hua)(hua)(hua)學反(fan)應(ying)(ying)(ying),此(ci)時的催(cui)化(hua)(hua)(hua)(hua)劑床(chuang)層即為流(liu)(liu)化(hua)(hua)(hua)(hua)床(chuang),也叫沸騰(teng)床(chuang)。流(liu)(liu)化(hua)(hua)(hua)(hua)床(chuang)反(fan)應(ying)(ying)(ying)器(qi)的形式(shi)很(hen)多(duo)(duo),但一(yi)般(ban)都由(you)殼(ke)體(ti)、內(nei)部構件、固體(ti)顆(ke)(ke)粒(li)裝卸(xie)設備及氣(qi)體(ti)分(fen)(fen)布、傳熱、氣(qi)固分(fen)(fen)離(li)裝置等構成(cheng)。流(liu)(liu)化(hua)(hua)(hua)(hua)床(chuang)反(fan)應(ying)(ying)(ying)器(qi)也可根據床(chuang)層結(jie)構分(fen)(fen)為圓(yuan)筒(tong)式(shi)、圓(yuan)錐(zhui)式(shi)和多(duo)(duo)管式(shi)等類型(xing)。
不(bu)同類(lei)型(xing)反應(ying)器在(zai)(zai)工業生產中的(de)適用(yong)情況見表6.2。不(bu)同結構形式(shi)的(de)反應(ying)器在(zai)(zai)工業裝置中的(de)應(ying)用(yong)舉例見表6.3。