【文章內(nèi)容簡介】 0160105105020512582502008303024表6—16 B型耳式支座的尺寸 支座載荷的校核計算 耳式支座實際承受的載荷按下式近似計算： 式中 D支座的安裝尺寸，mm g 重力加速度，取 D==， ＝， ， =3200，=4，=0， 將已知值代入得 因為＜[Q]=30KN，所以選用的耳式支座滿足要求。第5章 反應釜的攪拌裝置攪拌裝置由攪拌器、軸及其支撐組成。攪拌器的形式很多，根據(jù)任務說明書的要求，本次設計采用的是推進式攪拌器。推進式攪拌器的特點是能使液體產(chǎn)生激烈流動及湍流運動的性能很高。推進式攪拌器的主要運用范圍是攪拌及混合絕對粘度小于36000厘泊的各種流動性的液體，以及制成乳濁液或懸浮液。推進式攪拌器機械設計的主要內(nèi)容是：確定攪拌軸的直徑、攪拌器直徑、攪拌器與攪拌軸的連接結構。進行攪拌軸的強度設計和臨界轉(zhuǎn)速校核、選擇軸的支撐結構及材料的選用。由于介質(zhì)具有一定的腐蝕性，攪拌裝置的材料選用與反應罐主體材料相同的材料06Gr19Ni10 同一數(shù)字代號S30403。由前四章的相關設計得知反應釜凈直徑Di=1200mm，凈高H=1440mm；工作溫度：100℃；工作壓力：。 攪拌器形式的確定根據(jù)實際生產(chǎn)要求，初步設定攪拌器為兩層攪拌，采用三葉開啟渦輪式攪拌器(又稱為螺旋推進式攪拌器）。 攪拌器直徑Dj取標準值，即攪拌容器直徑的三分之一：[4] 底間距（C）即攪拌器距容器底部高度，[4]。則 因為底間距比值越小，固相完全離底懸浮臨界轉(zhuǎn)數(shù)越小，所以在滿足底層槳軸向排量的前提下，該比值盡量取得最小。但是考慮到實際生產(chǎn)中容器底部會出現(xiàn)一定量的沉積物，C值不能太??； C值太大攪拌效果不足，結合實際取C=200mm攪拌器浸入攪拌容器液面下的深度（S），攪拌器浸入液體內(nèi)的最佳深度為：[2] S= 對于雙層攪拌器，攪拌器層間距（Sp）~2范圍內(nèi)，由攪拌槳的軸向作用范圍和反應釜的高度決定攪拌槳層數(shù)。對于兩層以上的多層槳，要調(diào)整槳徑和層數(shù)取得合理的層間距，達到攪拌效果好，軸功率低的效果。故： 取Sp=400mm攪拌器和容器的幾何參數(shù)條件如表31[5]：表31 攪拌器容器幾何參數(shù)條件擋板數(shù)量無攪拌器距容器底部距離擋板寬度無攪拌器潛液深度S=960擋板與容器內(nèi)壁間距無攪拌器直徑Dj=400攪拌器槳葉數(shù)量Zj=3攪拌器槳葉的螺距表32推進式槳葉尺寸表Djdd1螺釘δ1δ1h鍵槽aP/n不大于d2bt4005090M16148951635176。19′ 攪拌軸的設計攪拌軸將電動機的動力傳遞給攪拌器。它承受的是以扭轉(zhuǎn)為主的扭—彎聯(lián)合作用。 攪拌軸軸徑的設計計算攪拌軸的材料：選用1Cr18Ni9Ti；攪拌軸的結構：用實心直軸攪拌軸功率： P= 4 Kw攪拌軸轉(zhuǎn)速： n=200r/min 表34傳動裝置各零部件的傳動效率η1類別傳動形式傳動效率η1圓柱齒輪傳動開式傳動，鑄齒（考慮軸承損失）—開式傳動，鐵齒（考慮軸承損失）單級圓柱齒輪減速器—雙級圓柱齒輪減速器—行星齒輪減速器—圓錐齒輪傳動開式傳動，鑄齒（考慮軸承損失）—開式傳動，鐵齒（考慮軸承損失）—單級圓錐齒輪減速器—雙級圓錐—圓柱齒輪減速器— 攪拌軸直徑的初步計算（1）攪拌軸直徑的設計 電機的功率＝4 ，攪拌軸的轉(zhuǎn)速＝200，文獻[1]235表111取用材料為1Cr18Ni9Ti ， []＝40，剪切彈性模量＝104，許用單位扭轉(zhuǎn)角[]＝1176。/m。 由得：=（） 利用截面法得：=（）由得： = 由于攪拌軸為實心軸，則：= 得 ≥ ?。?0mm（2）攪拌軸剛度的校核 由得： =（） 因為最大單位扭轉(zhuǎn)角max＝＜[] ＝1所以圓軸的剛度足夠?？紤]到攪拌軸與聯(lián)軸器配合，＝30可能需要進一步調(diào)整。5． 攪拌抽臨界轉(zhuǎn)速校核計算由于反應釜的攪拌軸轉(zhuǎn)速=200200，故不作臨界轉(zhuǎn)速校核計算。 攪拌器與攪拌軸的連接連接方式的選取攪拌器的軸套與攪拌軸采用鍵連接并用止動螺釘將其固定攪拌器軸套的外徑d1 取d1=70 由攪拌軸的公稱直徑d=40，查文獻[4]表1211可知見得公稱尺寸深度t=5，工作長度L=50mm。第6章 傳動裝置的選型和尺寸計算由于反應釜里的物料一定的腐蝕性，故選用隔爆型三相異步電機（防爆標志Ⅱ）。根據(jù)電機的功率＝攪拌軸轉(zhuǎn)速＝200，由文獻 1652頁表16128選用的電機型號為：Y112M4kw電動機。 減速器的選型根據(jù)電機的功率＝攪拌軸的轉(zhuǎn)速＝200、傳動比為1500/200＝（JB/T29821994），由文獻【6】1218頁表9235確定其安裝尺寸。 減速機的外形安裝尺寸由于反應釜傳來的軸向力不大，減速機輸出軸使用了C型凸緣聯(lián)軸器，且反應釜使用不帶內(nèi)置軸承的機械密封，故選用單支點機架（HG21566—95）。由攪拌軸的直徑＝40mm可知，機架的公稱直徑結構如圖6—2所示。圖6—2 WJ型無支點機架對于不銹鋼設備，本設計如下底座的結構，其上部與機架的輸出端接口和軸封裝置采用可拆相聯(lián)，下部伸入釜內(nèi)，結構與尺寸如圖63所示。圖63 底座的結構 反應釜的軸封裝置設計Production of xylanase by Aspergillus awamori on plexmedium in stirred tank and airlift tower loop reactorsAbstract Aspergillus awamori was cultivated on plex medium containing wheat bran as sole carbon source in theprecultures as well as in the main cultures in stirred tank and airlift tower loop reactors. The deposition of the wheat bran particles by hamylase and xylanase produced by the fungus was investigated by monitoring the enzyme activities, the CO2 production rate, the concentrations of reducing sugars, glucose, xylose, phosphate and ammonium as well as by applying transmission electron microscopy. By applying synthetic medium in the preculture, the time lag was longer, the growth faster, the xylanase activity higher in the main culture, than by using wheat bran in the preculture. With increasing the stirrer speed the intimate contact between the pellets and the wheat bran was reduced, which caused a decrease of the growth and the xylanase production. By applying ground wheat bran, ?lamentous mycelium was formed, the growth and the substrate uptake rates increased, but the xylanase production decreased due to the less intimate contact between the fungus and the wheat bran. In the airlift tower loop reactor ?lamentous mycelium was formed due to the low speci?c power input. In spite of the high medium viscosity, high xylanaseproductivity was obtained. With ground wheat bran the particles were pletely covered by ?lamentous mycelium,medium viscosity strongly increased and as consequence the growth and xylanase production decreased. 169。 1997Elsevier Science .Keywords: Aspergillus awamori。 Wheat bran。 Stirred tank。 Airlift tower loop reactor。 Filamentous mycelium。 Pellets。Xylanase。 Amylase1 Introduction In the previous papers (Siedenberg et al., 1997a,b) Aspergillus awamori was cultivated on synthetic medium and the xylanase production was induced by xylan, which was added to the medium at different times. However, in industrial production, plex media were preferred, because of the high costs of the synthetic media andthe inductors. The most popular plex media contain agricultural byproducts, which consist of cellulose,hemicellulose, starch, pectin and several other pounds in lower concentrations (Smith and Wood, 1991). When cultivating a fungus on these plex media, several enzymes are induced., case of an Aspergillus strain cellulases, pectinglycosidases, hglucosidase, iglucosidase, igalactosidase, galactomannase, xylanase, xylobiase andvarious proteases with different activities were determined (Uhlig, 1991). Which of these enzymes will be produced in large amount, depends on the strain, medium position and cultivation conditions. It is well known that hemicelluloses, especially xylan from various sources, are excellent inductors for xylanase. Wheat (straw) bran is an inexpensive byproduct, which contains a lot of , it is one of the most popular ponents of plex media for xylanase production(Deschamps and Huet, 1985。 Ghosh et al., 1993。Hoq et al., 1994). However, the wheat bran particles suspended in the cultivation medium have tobe deposed