Corrosion reduction mechanism with outlet spiral flow guide fins

Abstract

The invention provides a corrosion reduction mechanism with outlet spiral flow guide fins and a shell-and-tube heat exchanger with the corrosion reduction mechanism. The corrosion reduction mechanismwith the outlet spiral flow guide fins comprises a spiral guide vane group, a spiral guide vane fixing flange and a spiral guide vane supporting ring, and the spiral guide vane group comprises multiple spiral guide vanes and the like. According to the corrosion reduction mechanism with the outlet spiral flow guide fins, the flow line of fluid in the flowing process from the large cross section tothe small cross section is changed from a contraction state to a spiral line state through the flow guide effect of the spiral guide vane group, boundary layer separation and secondary eddy currents which are caused by abrupt changes of the flowing cross sections can be effectively eliminated, therefore, the corrosion degree of an outlet tube of the shell-and-tube heat exchanger is reduced, and the reliability of the outlet tube is improved; and meanwhile, the spiral guide vane supporting ring can be directly welded or connected to the tube wall in a screw thread mode, the spiral guide vane fixing flange is fixed between an outlet adapter tube flange plate and an external tube flange plate through connecting nuts and bolts, installation is easy, redesigning and machining of the heat exchanger are avoided, and site modification can be directly conducted.

Description

technical field [0001] The invention belongs to the technical field of pipeline anticorrosion, and in particular relates to a corrosion reduction mechanism with outlet spiral guide fins for a shell-and-tube heat exchanger and a shell-and-tube heat exchanger with the corrosion reduction mechanism. Background technique [0002] Due to the advantages of compact structure, high heat transfer coefficient, not easy to scale, not easy to leak and easy installation, the shell-and-tube heat exchanger has become a common equipment for heat exchange between hot and cold fluids in oil refining and chemical industries; but when the shell-and-tube heat exchanger When the medium flowing inside the heat exchanger is a gas-liquid two-phase fluid or a fluid medium with volatile components, when the fluid flows from the shell or pipe body of the heat exchanger to its outlet pipe, due to the sudden change in the cross-sectional area of ​​the heat exchanger, This leads to a sharp change in the f...

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Problems solved by technology

[0002] Due to the advantages of compact structure, high heat transfer coefficient, not easy to scale, not easy to leak and easy installation, the shell-and-tube heat exchanger has become a common equipment for heat exchange between hot and cold fluids in oil refining and chemical industries; but when the shell-and-tube heat exchanger When the medium flowing inside the heat exchanger is a gas-liquid two-phase fluid or a fluid medium with volatile components, when the fluid flows from the shell or pipe body of the heat exchanger to its outlet pipe, due to the sudden change in the cross-sectional area of ​​the heat exchanger, This leads to a sharp change in the flow direction of the fluid, an increase in the flow velocity, and a decrease in the pressure of the fluid; this sharp change in flow characteristics will cause boundary layer separation and secondary eddy currents, which intensifies the corrosion process; therefore, in order to reduce the corrosion degree of the outlet pipeline To improve the service life of the equipment, it is necessary to reduce the boundary layer separation and the secondary eddy current caused by the sudden change of the flow section; therefore, a new corrosion reduction mechanism for the outlet pipeline is proposed to reduce the cost of the outlet pipeline of the shell-and-tube heat exchanger. Corrosion and improving its life are of great significance

[0003] There are many measures to reduce pipeline corrosion in the prior art, including adding corrosion inhibitors, coating protection, changing pipeline materials, and cathodic protection. , has little effect on the corrosion caused by the separation of the boundary layer and the secondary eddy current caused by the sudden change of the flow section; the existing document ZL201410155224. The spiral guide pipe with variable lift angle and the spiral guide tube with variable lift angle on both sides produce swirling flow to reduce pipeline vibration and eliminate cavitation. However, the structure of this pipeline damping device is relatively complicated, and it is difficult to apply to the shell-and-tube type The outlet pipe of the heat exchanger, and the existing documents ZL201710392415.1 and ZL201520040984.6 respectively propose a fluid spiral diversion energy-saving device for the inlet of the circulating pump and a compressor exhaust pipe and a A compressor with such an exhaust pipe, but the flow resistance loss of these two devices is relatively large, and they do not have the effect of variable cross-section flow diversion

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