Research On Vibratory Fluidization Heat Exchanger Of Blast Furnace Slag

Blast furnace slag is the main solid by-product of blast furnace iron-smelting,and it is a high quality waste heat resource.At present,in the recovery process of waste heat from blast furnace slag,the slag particles generally go through two stages of cooling process,one is cooling in the centrifugal granulation chamber,and the other is cooling in the heat exchanger.In order to solve the problems of slag particle bonding and accumulation during these two stages,we study the application of VFB to the second stage of heat transfer.This paper is supported by the national key R&D project(2017YFB0603602-03).Our main findings are as follows:(1)Based on Lagrange equation,a 3-d OF harmonic forced vibration dynamic model of a VFB was established.Based on the theoretical calculation of vibration parameters,a vibration fluidization heat transfer system was developed.Vibratory fluidization heat exchange system is mainly composed of VFB device,heating device,air cooling device and control device.Each device works together to achieve the goal of high efficiency heat exchange of blast furnace slag.(2)We analyze the dynamic characteristics of the VFB,including modal analysis and harmonic response analysis,and obtain the modal shape and natural frequency of the structure,along with the deformation,stress and response information of the VFB unit under the working frequency.These lay the foundation for subsequent experimental tests.(3)The vibratory fluidization experiment includes bonded vibration test,vibratory fluidization test and vibratory fluidized flow visualization test to study various vibration parameters’ influence on slag particle fluidization and produce the minimum fluidization gas velocity and bed pressure drop.Results show that the vibration not only effectively restrains slag bonding,but also facilitates bed fluidization.In other words,compared with the common fluidized bed,a vibratory fluidized bed can help slag particles reach good fluidization states with less air flow.We carry out research along three dimensions: system design and manufacture,finite element simulation and experimental test.We conduct a preliminary exploration of the application of VFB to waste heat recovery of blast furnace slag,verify the feasibility of VFB,and lay a foundation for the industrial application of VFB.