Structural Design Of Rotating Packed Bed And Unbalance Control Strategy

Rotating packed bed(RPB)is a typical process enhancement equipment.When the RPB is working,the rotor rotates at a high speed,and the gas and liquid materials undergo mass transfer and reaction in the wire mesh packing inside the rotor.The mass transfer area increases and the mass transfer efficiency improves;compared with traditional tower,RPB has the advantages of small equipment size and high mass transfer efficiency,and has broad application prospects in chemical fields such as absorption,desorption and distillation.Some reactants and reaction products contain solid particles,which are easily adhered to the wire mesh packing inside the rotor.Due to the uneven distribution of adherents,the rotor mass is usually unbalanced and vibrates,causing the rotor drive shaft to frequently squeeze the bearings and shaft seals and other components,causing material leakage.Many researchers use rotor dynamic balancing technology to try to solve this problem,but they can only achieve temporary mechanical balance.As the chemical reaction progresses,new rotor unbalanced masses will soon be produced.When the rotor generates unbalanced vibration due to particle adhesion of the filler,the prior art cannot completely eliminate the generation of unbalanced mass.Therefore,the rotor can only be stopped and clean the packing.The unbalanced vibration of the rotor caused by the unbalanced packing adhesion mass seriously affects the long-period operation and industrial application of the RPB.In order to study the effect of unbalanced mass adhesion on the rotor on the operation of the RPB,and to realize the long-period stable operation of the RPB,firstly,this paper studies the design method of RPB structure,and designs a RPB with the preparation of light magnesium carbonate from dolomite as the target process;secondly,the unbalanced response analysis of the designed RPB rotor was carried out,and the rotor unbalanced response prediction model and the bearing life prediction model were constructed.Thirdly,this paper proposes a multi-degree-of-freedom magnetic suspension spherical rotor high-gravity reactor and its corresponding control strategy.The main contents of this paper are as follows:(1)Taking the dolomite carbonization method to prepare light magnesium carbonate as the target process,the structure design of a RPB was carried out.(2)Constructed the physical model of the RPB rotor and analyzed the unbalanced response of the rotor.Orthogonal experiments were designed to study the primary and secondary relationship of the rotor unbalanced mass,rotor unbalanced mass distribution position,bearing stiffness,bearing damping and other factors on the rotor vibration response.Based on the results of the simulation experiment,the coupling relationship between the unbalanced mass of the rotor and its distribution radius and the unbalanced response of the rotor amplitude,bearing load,etc.was obtained,and the prediction model of the unbalanced response of the rotor was constructed.According to the relationship between bearing load and bearing life,the bearing life prediction model was constructed.(3)A multi-degree-of-freedom magnetic suspension spherical rotor highgravity reactor and the corresponding electromagnetic control system were proposed.Through electromagnetic action,the spherical rotor can be suspended and rotated in the spherical shell of the reactor without contact,and it avoids the problem of the drive shaft squeezing and destroying the bearing and shaft seal caused by the rotor vibration during operation.(4)The mass unbalance control mechanism of a magnetically suspended spherical rotor was studied.When the particles adhere to the packing and causes the uneven mass distribution,the spherical rotor rotates with multiple degrees of freedom,and the rotor unbalanced mass is adjusted back to the rotor rotation axis to eliminate the rotor unbalance response;a multi-degree-of-freedom magnetic suspension spherical rotor high-gravity reactor reaction process monitoring system was constructed,which can monitor the rotor imbalance,and adjust the rotor imbalance when the rotor mass imbalance occurs.In this paper,a RPB structure is designed,and a multi-degree-of-freedom magnetic suspension spherical rotor high-gravity reactor and its control method are proposed.To a certain extent,it can avoid the equipment vibration damage caused by the rotor adhesion mass imbalance,and ensure the high-gravity reactor runs stably for a long period of time.