南华大学机械工程学院毕业设计
J外部清理，刷油漆。
5.4 主要件的热处理
a 筒体内筒纵焊缝焊接后，按620℃+_14℃消除应力热处理。
B椭圆头为整体热冲压成型，成型前的加热温度为960℃+_14℃成型后的
正火热处理温度为930℃+_20℃。堆焊过渡层按560℃+_10℃消除应力热处理。
5.5主要检验要求
a对主要受压件及耐腐蚀包括板材，管材，圆钢，锻件，焊材进行复查。 b焊缝错边量；衬里纵焊缝小于1mm，内筒总焊缝小于1.5mm
c对筒体与封头的深环焊缝，返修焊缝，均应100％RT检验，100％UT复
检，100％MT检验。
d封头热成型和正火热处理后，应进行100％UT，MT检验。
e堆焊过渡层后进行UT，PT检验，堆焊面层后进行UT，PT，FT检验。 f设备在水压试验后，对有关焊缝进行MT，PT检验。 g设备主要螺栓MT检验。
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南华大学机械工程学院毕业设计
参考文献：
[1] 《化学工程师手册》,机械工业出版社 .1999，10 [2] 《化工设备结构图集》，化学工业部设备设计技术中心站
[3] 刘道德 《化工设备的选择与设计》，第三版 中南大学出版社，2002.6 [4] 王明浑 主编《化工单元过程设计》，第二版，化东理工大学出版社2004.12 [5] 祁存谦 丁楠 吕树申 主编 《化工原理》，化学工业出版社，2002.2
[6] 郑津洋 董其伍 桑芝富 主编 《过程设备设计》 第二版，化学工业出版社 2005.7 [7] 刘湘秋 编著 《常用压力容器手册》机械工业出版社2004.6 [8] GB 150-1998
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附录一 外文原稿
Influence of osmotic distillation on membrane absorption for the
treatment of high strength ammonia wastewater
WANG Guan—ping ，SHI Han—chang ，SHEN Zhi—song2 (1．Environment
Simulation and Pollution Control State Key Joint Laboratory，Department of Environmental Science and Engineering，Tsinghua University，Beijing 100084，China．E—mail：wgpO0@mails．tsinghua．edu．cn；2．Jiangsu Institute of Microbiology，Wuxi 214063，China)
Abstract：0smotic distillation(OD)was found to be a coupled process in membrane absorption(MA)for the treatment of high strength ammonia wastewater．As a result．ammonia could not be concentrated in absorption solution(AS)as expected．The inhibition of the coupled OD in MA process was investigated as welI as various factors affecting the inhibition．The results indicated that the coupled OD can be effectively inhibited by heating concentrated solution and cooling dilute solution．It was also found that experimentaI minimum inhibition temperature difference(MITD)between concentrated and dilute solutions was
different when using polyvinylidene fluoride(PVDF) and
polypropylene(PP)membranes respectively，which could be ascribed to materiaI properties，such as OD and membrane distillation(MD)coefficients of the membranes．Experimental MITDs were found to be higher than theoreticaI MITDs
which were calculated using a simplified method．
Keywords：membrane absorption；osmotic distillation；high strength．ammonia wastewater
Introduction
Ammonia is a major pollutant in water pollution in China， an d the treatment of hi gh strength ammonia wastewater is still a difficult problem in wastewater treatment． A novel technique，membrane absorption(MA)，has been introduced by some researchers(Rajalo，1994；Qin，1996) to treat high strength
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南华大学机械工程学院毕业设计
ammonia wastewater．MA is also known as gas—filled memb ran e absorption， gas memb rane or memb rane ab sorption—desorption， which is a memb rane process comb ining desorption and ab sorption process together (Winston，1992)．The pivotal part of the process is the hydrophobic microporous memb ran e that consists of a gas layer separating two aqueous solutions(Fig．1)．The two solutions can not be mixed together unless the pressure difference across the memb rane is higher than the expel pressure．Volatile solute like amm onia can pass across the memb rane pores， but liquid and nonvolatile solutes are completely retained．
A pilot scale study was conducted in laboratory for the treatment of high strength ammonia wastewater by using MA process(Wang，2002)．We used equipments as those shown in Fig．2，and(1)was a H2SO．solution reservoir and(7) was an amm onia wastewater reservoir． Hi【gh efficiency of amm onia removal was achieved in the study：the ammonia concentration in wastewater could be reduced from 2000 mg／L to less than 15 mg／L with ammonia transfer flux of 8 g／(m2· h)，and more than 99％ of amm onia could be recovered in the absorption solution(AS)．
It was found that the volume of the AS expanded continuously in the process，which led to impossibility of ammonia condensation in the AS． e measure flux of water permeation was 150 g／(m2。h)and it was caused by osmotic distillation(OD)．OD，also known as isothermal membrane distillation(MD)，was investigated widely among researchers (Werner，1996)． e driving force of OD was vapor pressure diflference． and it was originated from a concentration difference(△C) of solutions between the two sides of memb rane． In the MA process， 2 gNH3-N／L ammonia solution Was circulated on the feed side，and 10％ (w／w) H2S04 solution on the absorption side． erefore，the water vapor pressure on the feed side was higher than that on the AS side．which leaded to the transfer of water vapor from the feed to the AS，an d it was an unwan ted process in MA for ammonia recovery·
If the volume of AS tank was 300 ml and the initial volume of 10％ H2S04 was 250 ml，H2SO．could be reacted completely within 1 3．5 h but the tank would be
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南华大学机械工程学院毕业设计
fully filled by “leaked”water after 4 h．As shown in Table 1．theoretically we can get 13．14％ (NH4)2SO,solution without OD after 13．5 h and there would be no residual H2SO,in the final solution．But with the coupled OD process，the AS tank was filled up after 4 h and we could only get 3．31％ (NH4)2SO4 solution with 5．89％ residual H2SO ．
It was clear that the coupled OD leads to two disastrous results in MA process for the treatment of high strength ammonia wastewater． Firstly， the ammonia removed from wastewater could not be concentrated in the AS． Theoretically，ammonia could be concentrated from 2 gNH3N／L to 12％ (NH4)2SO4 when the AS is 10％ H2SO4．But actually，(NH4)2SO,concentration was less than 4％ when the AS tank was filled up by“leaked”water．Secondly，the system might be forced to stop running if such a dilute (NH4)2SO4 solution with residual H2SO4 could not be easily reused in industry ．
1 Experimental Polypropylene(PP) hollow fiber memb rane and polyvinylidene
fluoride(PVDF)flat sheet memb rane(Table 2)were used in the experiments．
As shown in Fig．2，the osmotic agent(NaCl solution of varied concentration)and the feed agent(pure water)were circulated co—currently along two sides of the memb ran e．In this paper，the inside of the PP hollow fiber memb rane is called lumen side，and the outside of the fibers is called shel1 side．HFMC was made by potting 75 pieces of fibers into a glass shel1．The packing method of fibers was random and memb rane area was 141 cm2．
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