Study On The Stirring Performance Of Gas-liquid-solid Three-phase In The Corrosion Reactor

Artificial rutile is a high-quality substitute for natural rutile.The reduction rust method is one of the methods for preparing artificial rutile.Its advantages are less pollution and low cost.However,this method has long reaction time and low reaction efficiency.To this end,this study was commissioned by an enterprise to simulate the reduction of the rusting system and strengthen the rusting reaction process from the perspective of improving the multi-phase stirring performance of the reactor.Using similar principles and factor analysis,the effects of operating parameters such as agitator blade type,air flow,and stirring speed on the stirring performance of solid-liquid two-phase,gas-liquid two-phase,and gas-liquid-solid three-phase were studied.The main conclusions are as follows:(1)In a solid-liquid two-phase stirring system,the critical suspension rotation speeds required for a four-blade stirring blade,a three-blade stirring blade,and a six-blade stirring blade are 212 rpm,224 rpm,and 325 rpm,respectively.If the uniformity of the particles is reached between 0.9 and 1.1,then the four-blade stirring blade has a height of T/6 from the bottom of the blade and the stirring speed is 400 to 450 rpm,which can make the solid particles in a uniform suspension state.(2)The air flow is in the range of 1.0～2.5 m3·h-1,in the gas-liquid two phase stirring system.Compared with the six-blade stirring paddle,the four-blade stirring paddle has better gas-liquid dispersion performance and average bubble The diameter decreases by about 20%,and the number of local bubbles increases by about 30%.With the increase of ventilation volume,the pan-point speed also increases proportionally,and the number of local bubbles increases by about 30%.The air hole diameter of 0.01 mm had better bubble dispersion than the air hole diameter of 1 mm,and the number of air bubbles in the reactor increased significantly.(3)In the gas-liquid-solid three-phase stirring system,under the same conditions of air flow(1.0～2.5 m3·h-1),the critical suspension rotation speed is from four to four stirring blades,Three-blade mixing paddle and six-bend mixing paddle.When the shape of the stirring paddle is unchanged,the critical suspension speed increases proportionally with the ventilation.When other operating conditions remain unchanged,the relative agitation power RPD decreases with increasing ventilation,but the decrease decreases with increasing ventilation and gradually stabilizes.The critical levitation speed is almost unchanged in the two ventilation modes with a vent hole diameter of 1 mm and a vent hole diameter of 0.01 mm.Compared with the vent hole diameter of 0.01 mm,the critical suspension power of a vent diameter of 1 mm is reduced by 40%.A four-blade stirring paddle with a ventilation range of 1.0 to 2.5 m3·h-1 was used to conduct experiments in stirred reactors with diameters of 400 mm,500 mm,and 600 mm.The critical suspension speed N and the stirring were obtained by fitting.The relationship of reactor diameter D is:NL=NS(DS/DL)0.805(4)Factors affecting the stirring power include:stirring speed,diameter of the stirring blade,distance from the bottom of the stirring blade,the gas velocity of the air inlet,the density of the mixed liquid,and the acceleration of gravity.An empirical expression about power can be obtained:P=0.387ug-0.241N2.84...