Optimal Design Of Chloromethane Reactor

Methylene chloride reactor is the core equipment for the production of methane chloride.Its heat and mass transfer performance directly affect the conversion of methanol and the capacity of methane chloride.In this paper,methylene chloride reactor as the research object,the process analysis,simulation and structure optimization and other aspects of the study,the main research content and results are as follows:(1)On the basis of methyl chloride reactor of methanol synthesis of methyl chloride process principle and operating mode,analyzes the temperature,pressure and gas tube side velocity distribution uniformity on the influence of the methanol conversion,it is concluded that the methanol conversion along with the increase of temperature,pressure,present the change trend of decrease after increases first,and in 290-300 ℃,high methanol conversion during 0.36-0.38 MPa.In addition,according to the technical standards of pressure vessels and the performance requirements of the reactor in terms of gas distribution,heat transfer,high pressure resistance and corrosion resistance,the main design parameters of the reactor are formulated.(2)Influence factor analysis results based on methanol conversion and formulation of design parameters,design of methyl chloride reactor integral structure for column tubular fixed bed reactor to improve the axial backmixing airflow problem,design conical gas distributor and staggered distribution plate-ring baffle plate by the shell side of the gas velocity distribution uniformity and efficiency of fluid flow and heat transfer performance.(3)The distribution of gas velocity along the pipe is analyzed by numerical simulation.Aiming at the problems of insufficient distribution capacity of conical gas distributor and large deviation of radial velocity in the nozzle plane,a new structure scheme of bird-cage type distributor is proposed.After using the new scheme,the radial limit velocity deviation of the orifice plane is reduced from8.9m/s to 3.5m/s,and the optimization effect is obvious.Further study on the influence of structural parameters of the bird cage gas distributor on the uniformity of gas velocity distribution shows that: when the crack ratio is 0.436,the width of the crack is 3.2mm,the height ratio and the diameter ratio are 0.157 and 0.286 respectively,the radial limit velocity deviation of the nozzle plane is small,and the groove flow and flow dead zone are not easy to form on the nozzle plane.(4)Based on the computational fluid dynamics and chemical thermodynamics theory,the opening of the disk-annular baffle was studied.It was concluded that the opening at the pipe bridge of the baffle could effectively reduce the flow dead zone at the back root of the baffle and improve the uniformity of temperature field and pressure field.It is found that the pressure drop and heat transfer capacity of the shell side decrease with the increase of the opening aperture when the plate spacing remains constant.The pressure drop and heat transfer capacity of the shell side decrease with the increase of plate spacing when the aperture of the hole remains unchanged.The pressure drop and heat transfer capacity of the shell side are smaller when the aperture of the hole is 8mm and the tube spacing is 305mm.