【導讀】帶攪拌的夾套反應釜是化學、醫(yī)藥及食品等工業(yè)中常用的典型反應設備之一。體物料混勻，促進其反應的設備。它主要由攪拌容器、攪拌裝置、傳動裝置、軸封裝置、支座、人孔、工藝接管和一些附件組成。夾套反應釜分罐體和夾套兩部分，主要有封頭和筒體組成，多為中、低。有電動機、減速器、聯(lián)軸器和傳動軸等組成；軸封裝置一般采用機械密封或填料密封；準，以實現(xiàn)工藝要求的加熱、蒸發(fā)、冷卻及低高速的混配反應功能。隨之反應過程中的壓力要求對容器的設計要求也不盡相同。照相應的標準加工、檢測并試運行。不銹鋼反應釜根據(jù)不同的生產(chǎn)工藝、操作條件等。反應釜可采用SUS304、SUS316L等不銹鋼材料制造。加熱、冷卻可采用夾套、半管、盤管、米勒板等結構，加熱方式有：蒸汽、電。加熱、導熱油，以滿足耐酸、耐高溫、耐磨損、抗腐蝕等不同工作環(huán)境的工藝需要。反應釜按材質及用途可分為不銹鋼反應釜,搪玻璃反應釜。有他的適用范圍和優(yōu)缺點。其主要類型有以下幾種：

　　

【正文】 ious 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 to soluble pounds to be used by the fungus. The aim of the presented project was to investigate the interaction between the mold and the wheat bran and the deposition of the wheat bran by 立方米攪拌裝置 (反應釜 )設計畢業(yè)設計 the enzymes produced by the fungus in stirred tank and airlift tower loop reactors at various operating conditions. and methods Strain, preculture and main cultures Aspergillus awamori CBS was used for the investigations. The strain was maintained at 4176。C on potatodextroseagar. New stock cultures were obtained by use of spores from the old stock cultures and incubating them at 30176。C for 7 isolated spores from stock cultures were used to inoculate the medium of the precultures. A total of 50 volume parts of the plex medium were inoculated with 1 volume part of preculture. For the preparation of the spore suspensions (Siedenberg et 1997a). Aspergillus awamori CBS was used for the investigations. The strain was maintained at 4176。C on potatodextroseagar. New stock cultures were obtained by use of spores from the old stock cultures and incubating them at 30176。C for 7 isolated spores from stock cultures were used . Bioreactors Shake ?asks, a 2l bioreactor with working volume (Biostat M Braun Diessel International Melsungen), a 30l Bioreactor with 20 lworking volume (Biostat B20, Braun Diessel International,Melsungen) and a 100l airlift tower loop (ATL)reactor with 65 l working volume (TCI, University of Hannover) were used for cultivations. For description of the reactors and their operation (Siedenberg et al., 1997b). . Process monitoring The online and offline analyses for the process monitoring were described already in Siedenberg et al. (1997b). In addition to these methods。 the wheat bran was investigated with transmission electron microscopy (Adolph et al., 1996) and with ?uorescence microscopy (Freudenberg et al.,1996). 3. Results . Culti6ations in the stirred tank reactor . Deposition of wheat bran The deposition of wheat bran was investigated under following standard operation conditions: Precultures were incubated in shaked ?ask cultures at 150 rpm, 30176。C, for h. Main cultures were performed in a stirred tank reactor with 7104 spores ml ? 1, at a stirrer speed of 300rpm, temperature: 25176。C, pH and aeration rate:1 vvm. In the cultivation medium the wheat bran is the sole carbon source and the source of the growth factors and the inductors. The wheat bran consists of 28% hemicellulose, 9% % cellulose, % lignin and 3% pectin (Anderson and Clydesdale, 1980。 Weizenkleie, 1995). The fungus used these sole energy and carbon sources for growth by deposing them with particular enzymes. During the deposition of the wheat bran no cellulase and pectinase activitiy, but only hamylase and xylanase could be detected. On account of the presence of the solid wheat bran and because of the adherence of the fungus to the wheat bran as well as by the inclusion of the fungus by the wheat bran (Adolph et al., 1996), it was not possible to determine the fungal cell mass concentration in the culture. However, because of the close relationship between the growth rate and the CO2 production rate (CPR), the cell mass can be estimated by the integration of the CPR over the time. 立方米攪拌裝置 (反應釜 )設計畢業(yè)設計 According to the transmission electonmicro scopic investigations, the fungus grew inside the bran. It used the mechanical damage of the bran to evade it. In particular, the layer between the inner and the outer pericarp was colonized. After the dissolution of the pectincontaining structures and the peration into this space, the fungus ?lled the wheat bran with dense et al. (1996) have shown, that inside of large pellets and clumps no mRNA could be observed. Thus no protein synthesis occurred. It is somewhat unexpected, that the cells in the dense mycelium inside the wheat bran shell still were provided with suf?cient oxygen and nutrient to produce xylanase. Before the xylanase appeared in the medium, it could be already detected within the cytoplasma and at the plasma membrane by immunogold assay. After 50 h the xylanase appeared on the surface of the wheat bran fragments and at the wheat branhyphaeinterface as well (Adolph et al., 1996). The concentrations of orthophosphate and ammonium, originating partly from the nutrient salt and partly from the wheat bran, were consumed during the ?rst 60 h and than increased again, as the older hyphae started to starve and lyse Their ?nal concentrations surpassed their starting concentrations in the nutrient medium. The difference of their ?nal and original concen trations is a measure for their share originating from the wheat bran. . In?uence of the preculture The preculture was prepared with spores in the plex medium containing wheat bran as sole carbon source. The spores needed for their germination the carbon source from the wheat bran. For this purpose they adhered to the surface of the wheat bran and developed within 24 h to hyphae. The largest part of the fungal cell mass formed pellets and were bound to the wheat bran. The duration of the germination and the peration of the hyphae into the wheat bran as well as the fungal morphology were independent of the spore concentration. . In?uence of the stirrer speed The investigations were carried out under standard operation conditions, except the stirrer speed, which was maintained at 300, 500 and 750rpm, respectively. By changing the stirr