Research On The Manufacturing Process Of Large Fixed Tube Sheet Reactor

With the continuous development of chemical industry,various chemical reaction devices have appeared according to different chemical reactions.Fixed tubesheet reactor is a chemical reactor comparatively widely used in chemical industry and other process industries.With the expansion of production scale and capacity of chemical industry and the improvement of manufacturing level of chemical process equipment,this kind of chemical reactor is continuously being developed towards the trend of large-scale.Large fixed tubesheet reactor is widely and widely used in process industry,especially in industrial production of maleic anhydride.Maleic anhydride is an important organic chemical raw material and fine chemical product.It is the third anhydride in the world,next only to phthalic anhydride and acetic anhydride.Among them,the key equipment of producing maleic anhydride,or maleic anhydride reactor is a large fixed tubesheet reactor.A typical example of large fixed tubesheet maleic anhydride reactor with a capacity of 50kt/a in Yunnan Dawei Hengyuan chemical Co.,Ltd.was researched as an object in this thesis.The body structure characteristics of maleic anhydride reactor,the key manufacturing techniques,and various tests and inspections after its manufacture were taken as the keystone.The whole manufacturing process,technical principle,theoretical basis and manufacturing quality assurance of maleic anhydride reactor were analyzed,concluded and summarized.The main research contents and achievements are as follows:1.In allusion to the structural characteristics of tubesheet in large fixed tubesheet reactor,through the measures such as controlling the flatness of the tubesheet,adopting reasonable splicing grooves,carrying non-destructive test and heat treatment etc.,the key problems of welding process and preventing welding deformation control technique of tubesheet assembly in large fixed tubesheet reactor were tackled.These measures can be taken to control the irregularity within 3 mm after the tubesheet welding and make its manufacturing quality better than the design requirements.2.In allusion to the characteristics of many heat exchange pipe holes and higher requirements in the tubesheet of large fixed tubular plate reactor,through adopting numerical control programming to lead holes,using three drilling machines to optimize the circular arrangement and then utilizing the processing technique of drilling holes before reaming holes,the processing technique and machining precision control of the pipe holes were investigated,finally which could make the tubesheet meet the requirements and improving efficiency.3.Through reasonably setting supports and auxiliary devices,the assembly technique of the upper tubesheet(floating tubesheet),the lower tubesheet and 26180 reactive tubes in the maleic anhydride reactor were investigated,which could make the assembly of the main body of maleic anhydride reactor be successfully fulfilled.4.Through making a reasonable construction scheme,special hoisting frock design and hoisting scheme,group pairs,hoisting frock design,manufacture and test of the maleic anhydride reactor were investigated,which successfully ensured the equipment manufacturing schedule.5.In allusion to the maleic anhydride reactor as a large fixed tubesheet reactor,from the discussion of the process scheme to the implementation,its quality inspection control of the reactor(including the welding quality inspection between the reactive tubes and the tubesheet,leakage detection of ammonia and helium,molten salt leakage detection at 370°C and the whole hydraulic pressure test of the reactor)were investigated.The quality inspection and control of the large maleic anhydride reactor were realized by making a reasonable inspection and test scheme.Through the manufacturing technique researches on a typical example of large fixed tubesheet reactor or maleic anhydride reactor,the farther cognition of large fixed tubesheet reactor was obtained.These research achievements provided a technical guarantee for the manufacture,use and management of the entire large fixed tubesheet reactor.These schemes lay a solid foundation for the manufacturing quality of large fixed tubesheet reactor and have certain guiding significance for the actual manufacture and ensuring its manufacturing quality of large fixed tubesheet reactor,moreover make this type of reactor be further consummated and improved on the basis of the existing technique.