反(fan)(fan)應過(guo)程(cheng)的(de)(de)基本特(te)征決定了適(shi)宜(yi)的(de)(de)反(fan)(fan)應器(qi)形式(shi)。例如氣固相反(fan)(fan)應過(guo)程(cheng)大(da)致是用固定床反(fan)(fan)應器(qi)、流化床反(fan)(fan)應器(qi)或移動床反(fan)(fan)應器(qi)。但是適(shi)宜(yi)的(de)(de)選型則需考慮(lv)反(fan)(fan)應的(de)(de)熱效應、對(dui)反(fan)(fan)應轉化率(lv)和(he)選擇率(lv)的(de)(de)要求(qiu)、催(cui)化劑(ji)物理化學性態(tai)和(he)失活等多種(zhong)因素(su)。
不銹鋼反(fan)(fan)應(ying)(ying)器(qi)的(de)操作方式(shi)(shi)和加料方式(shi)(shi)也需(xu)考慮。例如(ru)，對(dui)于有串(chuan)聯或平行(xing)副反(fan)(fan)應(ying)(ying)的(de)過程(cheng)，分段進料可(ke)能(neng)優(you)于一次進料。溫度(du)序(xu)列(lie)也是(shi)反(fan)(fan)應(ying)(ying)器(qi)選型的(de)一個重要(yao)因素。例如(ru)，對(dui)于放熱的(de)可(ke)逆反(fan)(fan)應(ying)(ying)，應(ying)(ying)采用先高后低的(de)溫度(du)序(xu)列(lie)，多級、級間換熱式(shi)(shi)反(fan)(fan)應(ying)(ying)器(qi)可(ke)使反(fan)(fan)應(ying)(ying)器(qi)的(de)溫度(du)序(xu)列(lie)趨(qu)于合理(li)。
下面(mian)主要介(jie)紹(shao)釜式(shi)反(fan)(fan)(fan)應(ying)(ying)(ying)器(qi)、管式(shi)反(fan)(fan)(fan)應(ying)(ying)(ying)器(qi)、塔式(shi)反(fan)(fan)(fan)應(ying)(ying)(ying)器(qi)、固定床(chuang)反(fan)(fan)(fan)應(ying)(ying)(ying)器(qi)、流(liu)化床(chuang)反(fan)(fan)(fan)應(ying)(ying)(ying)器(qi)。
①. 釜式反應器
釜式(shi)反(fan)應(ying)(ying)(ying)器(qi)也稱槽式(shi)、鍋(guo)式(shi)反(fan)應(ying)(ying)(ying)器(qi)，它是各類反(fan)應(ying)(ying)(ying)器(qi)中結構較(jiao)(jiao)為簡單且應(ying)(ying)(ying)用(yong)較(jiao)(jiao)廣的(de)一(yi)(yi)種。主要應(ying)(ying)(ying)用(yong)于(yu)液-液均相反(fan)應(ying)(ying)(ying)過(guo)程(cheng)，在(zai)氣-液、液-液非均相反(fan)應(ying)(ying)(ying)過(guo)程(cheng)中也有(you)(you)應(ying)(ying)(ying)用(yong)。在(zai)化工生(sheng)產中，既(ji)適(shi)用(yong)于(yu)間歇操(cao)作過(guo)程(cheng)，又可單釜或多釜串(chuan)聯用(yong)于(yu)連續操(cao)作過(guo)程(cheng)，但在(zai)間歇生(sheng)產過(guo)程(cheng)中應(ying)(ying)(ying)用(yong)最多。釜式(shi)反(fan)應(ying)(ying)(ying)器(qi)具有(you)(you)適(shi)用(yong)的(de)溫度(du)(du)和壓力范圍寬、適(shi)應(ying)(ying)(ying)性(xing)強、操(cao)作彈性(xing)大、連續操(cao)作時(shi)溫度(du)(du)濃度(du)(du)容(rong)易控制、產品質(zhi)量均一(yi)(yi)等特點。但用(yong)在(zai)較(jiao)(jiao)高轉(zhuan)化率工藝要求時(shi)，需要較(jiao)(jiao)大容(rong)積。通常在(zai)操(cao)作條件(jian)比(bi)較(jiao)(jiao)緩和的(de)情況下使用(yong)，如常壓、溫度(du)(du)較(jiao)(jiao)低(di)且低(di)于(yu)物料沸點時(shi)，應(ying)(ying)(ying)用(yong)此(ci)類反(fan)應(ying)(ying)(ying)器(qi)最為普遍。
②. 管(guan)式反應器
管(guan)(guan)式(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)主要用(yong)(yong)于(yu)(yu)氣相(xiang)(xiang)、液相(xiang)(xiang)、氣-液相(xiang)(xiang)連(lian)續(xu)(xu)反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)過程，由單(dan)根（直管(guan)(guan)或盤(pan)管(guan)(guan)）連(lian)續(xu)(xu)或多根平(ping)行排(pai)列的(de)(de)(de)管(guan)(guan)子(zi)(zi)組成，一(yi)(yi)般設有(you)套(tao)管(guan)(guan)或殼(ke)管(guan)(guan)式(shi)(shi)換熱裝(zhuang)置。操(cao)作(zuo)時，物料自一(yi)(yi)端(duan)連(lian)續(xu)(xu)加入(ru)，在管(guan)(guan)中連(lian)續(xu)(xu)反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)，從另一(yi)(yi)端(duan)連(lian)續(xu)(xu)流出，便達到了要求的(de)(de)(de)轉化(hua)率。由于(yu)(yu)管(guan)(guan)式(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)能承受較(jiao)高的(de)(de)(de)壓力，故用(yong)(yong)于(yu)(yu)加壓反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)尤為合(he)(he)適，例如油脂(zhi)或脂(zhi)肪酸加氫生產(chan)高碳醇(chun)、裂解反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)用(yong)(yong)的(de)(de)(de)管(guan)(guan)式(shi)(shi)爐(lu)便是管(guan)(guan)式(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)。此種反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)具有(you)容積小、比表面大、返混少、反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)混合(he)(he)物連(lian)續(xu)(xu)性變化(hua)、易于(yu)(yu)控制等優點。但若反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)速(su)度較(jiao)慢(man)時，則有(you)所需(xu)管(guan)(guan)子(zi)(zi)長、壓降較(jiao)大等不足。隨著化(hua)工生產(chan)越(yue)來(lai)越(yue)趨于(yu)(yu)大型化(hua)、連(lian)續(xu)(xu)化(hua)、自動(dong)化(hua)，連(lian)續(xu)(xu)操(cao)作(zuo)的(de)(de)(de)管(guan)(guan)式(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)在生產(chan)中使(shi)用(yong)(yong)越(yue)來(lai)越(yue)多，某些(xie)傳統上一(yi)(yi)直使(shi)用(yong)(yong)間歇攪拌釜(fu)(fu)的(de)(de)(de)高分子(zi)(zi)聚(ju)合(he)(he)反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)，目(mu)前也開始改用(yong)(yong)連(lian)續(xu)(xu)操(cao)作(zuo)的(de)(de)(de)管(guan)(guan)式(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)。管(guan)(guan)式(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)的(de)(de)(de)長徑比較(jiao)大，與釜(fu)(fu)式(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)(ying)(ying)(ying)器(qi)相(xiang)(xiang)比在結構上差異較(jiao)大，有(you)直管(guan)(guan)式(shi)(shi)、盤(pan)管(guan)(guan)式(shi)(shi)、多管(guan)(guan)式(shi)(shi)等。
③. 塔式反(fan)應(ying)器
塔(ta)(ta)(ta)式(shi)(shi)(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)器(qi)(qi)的(de)長徑比介(jie)于釜式(shi)(shi)(shi)(shi)和(he)(he)管式(shi)(shi)(shi)(shi)之(zhi)間。主要用(yong)于氣-液(ye)反(fan)(fan)(fan)應(ying)(ying)，常用(yong)的(de)有(you)鼓(gu)泡(pao)塔(ta)(ta)(ta)、填料塔(ta)(ta)(ta)、板式(shi)(shi)(shi)(shi)塔(ta)(ta)(ta)。最常用(yong)的(de)是鼓(gu)泡(pao)塔(ta)(ta)(ta)式(shi)(shi)(shi)(shi)反(fan)(fan)(fan)應(ying)(ying)器(qi)(qi)，底(di)部裝(zhuang)有(you)氣體(ti)分布器(qi)(qi)，殼外裝(zhuang)有(you)夾套(tao)或(huo)(huo)其(qi)他(ta)形(xing)式(shi)(shi)(shi)(shi)換(huan)(huan)熱(re)(re)(re)器(qi)(qi)或(huo)(huo)設有(you)擴大(da)段、液(ye)滴捕集器(qi)(qi)等(deng)。反(fan)(fan)(fan)應(ying)(ying)氣體(ti)通過分布器(qi)(qi)上(shang)的(de)小孔以(yi)鼓(gu)泡(pao)形(xing)式(shi)(shi)(shi)(shi)通過液(ye)層進行化學反(fan)(fan)(fan)應(ying)(ying)，液(ye)體(ti)間歇或(huo)(huo)連續加(jia)入，連續加(jia)入的(de)液(ye)體(ti)可以(yi)和(he)(he)氣體(ti)并(bing)流或(huo)(huo)逆流，一般(ban)采用(yong)并(bing)流形(xing)式(shi)(shi)(shi)(shi)較(jiao)多(duo)。氣體(ti)在塔(ta)(ta)(ta)內為分散相，液(ye)體(ti)為連續相，液(ye)體(ti)返(fan)混程(cheng)(cheng)度(du)較(jiao)大(da)。為了提高氣體(ti)分散程(cheng)(cheng)度(du)和(he)(he)減少液(ye)體(ti)軸向循環，可以(yi)在塔(ta)(ta)(ta)內安(an)置水平多(duo)孔隔板。當吸收或(huo)(huo)反(fan)(fan)(fan)應(ying)(ying)過程(cheng)(cheng)熱(re)(re)(re)效應(ying)(ying)不大(da)時，可采用(yong)夾套(tao)換(huan)(huan)熱(re)(re)(re)裝(zhuang)置，熱(re)(re)(re)效應(ying)(ying)較(jiao)大(da)時，可在塔(ta)(ta)(ta)內增設換(huan)(huan)熱(re)(re)(re)蛇管或(huo)(huo)采用(yong)塔(ta)(ta)(ta)外換(huan)(huan)熱(re)(re)(re)裝(zhuang)置，也可以(yi)利用(yong)反(fan)(fan)(fan)應(ying)(ying)液(ye)蒸發的(de)方法帶走(zou)熱(re)(re)(re)量。
④. 固定床反應器(qi)
固(gu)定(ding)(ding)床(chuang)(chuang)(chuang)(chuang)板反應(ying)(ying)(ying)器(qi)是(shi)(shi)指流體通過(guo)靜止(zhi)不動(dong)的(de)(de)固(gu)體物(wu)料所(suo)形(xing)成的(de)(de)床(chuang)(chuang)(chuang)(chuang)層而(er)進行化(hua)(hua)學(xue)反應(ying)(ying)(ying)的(de)(de)設備。以氣-固(gu)反應(ying)(ying)(ying)的(de)(de)固(gu)定(ding)(ding)床(chuang)(chuang)(chuang)(chuang)反應(ying)(ying)(ying)器(qi)最常見。固(gu)定(ding)(ding)床(chuang)(chuang)(chuang)(chuang)反應(ying)(ying)(ying)器(qi)根據床(chuang)(chuang)(chuang)(chuang)層數(shu)的(de)(de)多少又可分為單段(duan)(duan)式和(he)多段(duan)(duan)式兩種類(lei)型。單段(duan)(duan)式一般為高徑比不大(da)的(de)(de)圓筒(tong)(tong)體，在圓筒(tong)(tong)體下部裝有柵板等板件，其上為催化(hua)(hua)劑床(chuang)(chuang)(chuang)(chuang)層，均勻地堆(dui)置一定(ding)(ding)厚度的(de)(de)催化(hua)(hua)劑固(gu)體顆粒。單段(duan)(duan)式固(gu)定(ding)(ding)床(chuang)(chuang)(chuang)(chuang)反應(ying)(ying)(ying)器(qi)結構簡(jian)單、造價便宜、反應(ying)(ying)(ying)器(qi)體積利用率高。多段(duan)(duan)式是(shi)(shi)在圓筒(tong)(tong)體反應(ying)(ying)(ying)器(qi)內(nei)設有多個催化(hua)(hua)劑床(chuang)(chuang)(chuang)(chuang)層，在各床(chuang)(chuang)(chuang)(chuang)層之間可采(cai)用多種方式進行反應(ying)(ying)(ying)物(wu)料的(de)(de)換熱。其特(te)點是(shi)(shi)便于控制調(diao)節反應(ying)(ying)(ying)溫度，防止(zhi)反應(ying)(ying)(ying)溫度超出(chu)允許范圍(wei)。
⑤. 流化床反應器
細小的固(gu)(gu)體(ti)(ti)顆粒(li)(li)被(bei)流(liu)(liu)(liu)動(dong)著的流(liu)(liu)(liu)體(ti)(ti)攜(xie)帶，具(ju)有流(liu)(liu)(liu)體(ti)(ti)一(yi)樣(yang)自由流(liu)(liu)(liu)動(dong)的性質，此(ci)種現象稱(cheng)為固(gu)(gu)體(ti)(ti)的流(liu)(liu)(liu)態(tai)化。一(yi)般(ban)把(ba)反(fan)(fan)應(ying)器(qi)和(he)在(zai)其中呈(cheng)(cheng)流(liu)(liu)(liu)態(tai)化的固(gu)(gu)體(ti)(ti)催(cui)化劑(ji)顆粒(li)(li)合(he)在(zai)一(yi)起，稱(cheng)為流(liu)(liu)(liu)化床(chuang)(chuang)(chuang)反(fan)(fan)應(ying)器(qi)。流(liu)(liu)(liu)化床(chuang)(chuang)(chuang)反(fan)(fan)應(ying)器(qi)多用于(yu)氣(qi)-固(gu)(gu)反(fan)(fan)應(ying)過(guo)程。當原料(liao)氣(qi)通過(guo)反(fan)(fan)應(ying)器(qi)催(cui)化劑(ji)床(chuang)(chuang)(chuang)層(ceng)(ceng)時(shi)，催(cui)化劑(ji)顆粒(li)(li)受(shou)氣(qi)流(liu)(liu)(liu)作(zuo)用而懸(xuan)浮起來呈(cheng)(cheng)翻滾沸騰狀，原料(liao)氣(qi)在(zai)處于(yu)流(liu)(liu)(liu)態(tai)化的催(cui)化劑(ji)表面(mian)進行化學反(fan)(fan)應(ying)，此(ci)時(shi)的催(cui)化劑(ji)床(chuang)(chuang)(chuang)層(ceng)(ceng)即(ji)為流(liu)(liu)(liu)化床(chuang)(chuang)(chuang)，也叫沸騰床(chuang)(chuang)(chuang)。流(liu)(liu)(liu)化床(chuang)(chuang)(chuang)反(fan)(fan)應(ying)器(qi)的形式很(hen)多，但(dan)一(yi)般(ban)都由殼體(ti)(ti)、內部構件、固(gu)(gu)體(ti)(ti)顆粒(li)(li)裝卸設備及氣(qi)體(ti)(ti)分布、傳熱、氣(qi)固(gu)(gu)分離裝置等構成(cheng)。流(liu)(liu)(liu)化床(chuang)(chuang)(chuang)反(fan)(fan)應(ying)器(qi)也可根據床(chuang)(chuang)(chuang)層(ceng)(ceng)結構分為圓筒式、圓錐(zhui)式和(he)多管式等類(lei)型。
不同類型反應器在工業生(sheng)產中的適用(yong)情(qing)況見表6.2。不同結構形式的反應器在工業裝置中的應用(yong)舉例見表6.3。
