按塔(ta)內件結(jie)構可分為(wei):板(ban)式(shi)(shi)塔(ta)和(he)填料塔(ta)。塔(ta)設備盡管(guan)(guan)其(qi)用(yong)途各異,操作條(tiao)件也各不相同,但就其(qi)構造(zao)而言(yan)大同小(xiao)異,主要由塔(ta)體(ti)、支(zhi)座(zuo)(zuo)(zuo)、內部構件及附件組成。根據塔(ta)內部構件的(de)結(jie)構可以(yi)將其(qi)分為(wei)板(ban)式(shi)(shi)塔(ta)和(he)填料塔(ta)兩(liang)大類。塔(ta)體(ti)是塔(ta)設備的(de)外殼,由圓(yuan)筒(tong)和(he)兩(liang)封頭組成;封頭可以(yi)是半球形(xing)、橢圓(yuan)形(xing)、碟形(xing)等;支(zhi)座(zuo)(zuo)(zuo)是將塔(ta)體(ti)安裝在基礎上的(de)連接(jie)部分,一(yi)般(ban)采用(yong)裙式(shi)(shi)支(zhi)座(zuo)(zuo)(zuo),有圓(yuan)筒(tong)形(xing)和(he)圓(yuan)錐形(xing)兩(liang)種(zhong),常采用(yong)圓(yuan)筒(tong)形(xing)。裙座(zuo)(zuo)(zuo)與塔(ta)體(ti)采用(yong)對接(jie)焊(han)接(jie)或搭接(jie)焊(han)接(jie)連接(jie),裙座(zuo)(zuo)(zuo)的(de)高度由工藝要求的(de)附屬設備(如再沸器、泵(beng))及管(guan)(guan)線(xian)的(de)布置情況而定。
1. 板式塔(plate column)
在(zai)(zai)板式塔(ta)(ta)中裝有一定數量的塔(ta)(ta)盤,液體借自(zi)身的重量自(zi)上(shang)而下沉向(xiang)(xiang)塔(ta)(ta)底(在(zai)(zai)塔(ta)(ta)盤板上(shang)沿塔(ta)(ta)徑橫向(xiang)(xiang)流(liu)動),氣體靠壓差自(zi)下而上(shang)以鼓泡的形式穿過塔(ta)(ta)盤上(shang)的液層升向(xiang)(xiang)塔(ta)(ta)頂。在(zai)(zai)每層塔(ta)(ta)盤上(shang)氣、液兩相密切接觸(chu),進行傳質,使兩相的組分濃度沿塔(ta)(ta)高呈階梯式變化,如(ru)圖4.1所示。

如果按(an)其塔板(ban)上(shang)氣、液(ye)流(liu)向不同還可分為以下(xia)幾種。
①. 氣(qi)(qi)、液(ye)(ye)(ye)呈(cheng)(cheng)錯流(liu)(liu)的(de)(de)塔(ta)(ta)板(ban)。氣(qi)(qi)、液(ye)(ye)(ye)呈(cheng)(cheng)錯流(liu)(liu)的(de)(de)塔(ta)(ta)板(ban)上(shang)裝有降(jiang)(jiang)液(ye)(ye)(ye)管,液(ye)(ye)(ye)體自上(shang)板(ban)的(de)(de)降(jiang)(jiang)液(ye)(ye)(ye)管落下,進入塔(ta)(ta)板(ban)之后,沿著塔(ta)(ta)板(ban)橫向(xiang)流(liu)(liu)過,經塔(ta)(ta)板(ban)的(de)(de)降(jiang)(jiang)液(ye)(ye)(ye)管流(liu)(liu)入下一(yi)塊(kuai)塔(ta)(ta)板(ban)(受液(ye)(ye)(ye)槽)。一(yi)般受液(ye)(ye)(ye)槽和對應降(jiang)(jiang)液(ye)(ye)(ye)管寬度(du)是一(yi)樣的(de)(de)。而氣(qi)(qi)體則通過塔(ta)(ta)板(ban)的(de)(de)開(kai)孔(kong),與液(ye)(ye)(ye)體呈(cheng)(cheng)錯流(liu)(liu)方(fang)式傳質(zhi)和傳熱。氣(qi)(qi)、液(ye)(ye)(ye)呈(cheng)(cheng)錯流(liu)(liu)方(fang)式的(de)(de)塔(ta)(ta)板(ban)在(zai)生(sheng)產上(shang)用得最多,根據其氣(qi)(qi)、液(ye)(ye)(ye)接觸元件形式的(de)(de)不同,又(you)可分為泡(pao)罩型(xing)塔(ta)(ta)板(ban)、篩孔(kong)型(xing)塔(ta)(ta)板(ban)、浮閥型(xing)塔(ta)(ta)板(ban)和噴射型(xing)塔(ta)(ta)板(ban)。
②. 氣(qi)、液(ye)呈逆流(liu)(liu)的(de)塔(ta)(ta)板。塔(ta)(ta)板結構(gou)簡單(dan),不設溢(yi)流(liu)(liu)管(guan),氣(qi)、液(ye)從塔(ta)(ta)板縫中(zhong)上下穿(chuan)流(liu)(liu)而(er)過(guo),在(zai)板上的(de)流(liu)(liu)體為上升(sheng)蒸汽所攪動(dong)而(er)形(xing)成泡沫,進行兩相間的(de)傳(chuan)質,這(zhe)類塔(ta)(ta)板的(de)塔(ta)(ta)有柵板塔(ta)(ta)、穿(chuan)流(liu)(liu)式波紋篩板塔(ta)(ta)。
③. 氣(qi)、液呈并流的塔(ta)(ta)板。氣(qi)、液呈并流的塔(ta)(ta)板在(zai)每一塊塔(ta)(ta)板上(shang),氣(qi)、液呈并流接觸(chu)方式,對整個塔(ta)(ta)氣(qi)、液呈逆流操作方式。
板(ban)(ban)(ban)(ban)(ban)(ban)(ban)式(shi)塔(ta)(ta)按有(you)(you)無(wu)降(jiang)液(ye)管塔(ta)(ta)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)可(ke)分為(wei)(wei)兩類:有(you)(you)降(jiang)液(ye)管塔(ta)(ta)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)(錯(cuo)流(liu)式(shi)),包括篩(shai)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)、浮(fu)閥(fa)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)、泡罩(zhao)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)、導向篩(shai)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)、舌形(xing)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)、多(duo)降(jiang)液(ye)管塔(ta)(ta)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)等;無(wu)降(jiang)液(ye)管塔(ta)(ta)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)(逆流(liu)式(shi)),包括穿流(liu)篩(shai)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)、穿流(liu)柵板(ban)(ban)(ban)(ban)(ban)(ban)(ban)、波紋(wen)穿流(liu)塔(ta)(ta)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)等。板(ban)(ban)(ban)(ban)(ban)(ban)(ban)式(shi)塔(ta)(ta)的結構(gou)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)式(shi)塔(ta)(ta)的主要(yao)部件是塔(ta)(ta)板(ban)(ban)(ban)(ban)(ban)(ban)(ban),塔(ta)(ta)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)有(you)(you)許多(duo)形(xing)式(shi)。圖4.2所示為(wei)(wei)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)式(shi)塔(ta)(ta)塔(ta)(ta)板(ban)(ban)(ban)(ban)(ban)(ban)(ban)結構(gou)。

2. 填料(liao)塔(packed column)
填料塔(ta)(ta)中裝填一定高度的填料,液體自塔(ta)(ta)頂沿(yan)填料表面向下(xia)流(liu)動(dong),作為(wei)連續相(xiang)的氣體自塔(ta)(ta)底向上流(liu)動(dong),與液體進行逆流(liu),兩相(xiang)組分(fen)的濃度沿(yan)塔(ta)(ta)高呈連續變化。可根據(ju)工藝(yi)特點(dian)、介質的特性選用(yong)不(bu)同類型的填料,如拉西環、鮑爾(er)環等(deng)。填料塔(ta)(ta)結(jie)構示意(yi)圖(tu)如圖(tu)4.3所示。

典型填(tian)(tian)料(liao)(liao)塔的(de)工作原理(li)圖(tu)如圖(tu)4.4所示(shi)。塔體(ti)(ti)為一圓筒,筒內堆放(fang)一定高(gao)度(du)的(de)填(tian)(tian)料(liao)(liao)。操作時(shi),液(ye)體(ti)(ti)自塔上部進(jin)入,通過液(ye)體(ti)(ti)分布器(qi)均(jun)勻噴灑(sa)于塔截面(mian)上,在(zai)填(tian)(tian)料(liao)(liao)表面(mian)呈膜狀(zhuang)流下(xia)(xia)。填(tian)(tian)充(chong)高(gao)度(du)較高(gao)的(de)填(tian)(tian)料(liao)(liao)塔可(ke)將填(tian)(tian)料(liao)(liao)分層(ceng)(ceng)(ceng),各層(ceng)(ceng)(ceng)填(tian)(tian)料(liao)(liao)之間設置(zhi)液(ye)體(ti)(ti)再分布器(qi),收集上層(ceng)(ceng)(ceng)流下(xia)(xia)的(de)液(ye)體(ti)(ti),并將液(ye)體(ti)(ti)重(zhong)新均(jun)布于塔截面(mian)。氣體(ti)(ti)自塔下(xia)(xia)部進(jin)入,通過填(tian)(tian)料(liao)(liao)層(ceng)(ceng)(ceng)中的(de)空隙由塔頂排(pai)出(chu),離開填(tian)(tian)料(liao)(liao)層(ceng)(ceng)(ceng)的(de)氣體(ti)(ti)可(ke)能挾帶(dai)少量液(ye)沫,必要時(shi)可(ke)在(zai)塔頂安裝除沫器(qi)。

