Research On Gas-liquid Mass Transfer Theory And Experiment Of Falling Film Desulfurization

The development of China’s desulphurization technology is seriously restricted becauseof the expensive desulfurization dust removal equipment and high investment operating costs.Therefore, studying energy-saving efficiency desulphurization technology for China’s nationalconditions and widely using in industrial boilers is the most significant for realizing greenlow-carbon core concept. The subject aims to developing integration devices of flue gastreatment and heat recovery, and bases on the falling film reaction, using alkaline solutionstudy on the gas-liquid mass transfer of the flue gas desulfurization process, at the same time,studying the law of gas-liquid mass transfer by combining theoretical analysis withexperimental study.Obtaining mass transfer rate equation of sodium hydroxide solution absorbing SO2bytwo-film theory in the theoretical mass transfer analysis; analyzing main factors and a varietyof operating conditions by mass transfer rate equation in the desulfurization process.Carrying out the integration devices of flue gas treatment and heat recovery experimentaldesign and the experimental study of test methods; proposing and designing liquid distributorof weir trough squeezing water tongue; comparing physical properties and heat mass transfercharacteristics of polyethylene plastic, glass fiber, PSA, teflon varnished cloth, and selectingpolyethylene plastic mesh for device packing.Carrying out experimental study for the main factors of desulphurization, experimentalresults show that: as the pH value increases, the desulfurization efficiency increases, theinfluence of pH on desulfurization efficiency in low is more pronounced than in high;desulfurization efficiency decreases with the increasing SO2initial concentration; liquid-gasratio increases to improve the flue gas desulfurization efficiency, but the liquid-gas ratio is notthe bigger the better; as the fill layers increases, the desulfurization efficiency increases, thedifference of desulfurization efficiency that liquid circulation flow rate is less than4L/min ismore obvious than greater than4L/min; the higher absorption fluid of temperature, the higherthe desulfurization efficiency of system, at the same time, the system desulfurizationefficiency is still greater than70%,while absorption fluid of temperature is52℃, absorptionfluid of temperature decreases1℃and desulfurization efficiency can be increased by0.5%.Calculating physical characteristics in absorption model, carrying out gas and liquidmaterial balance mass transfer process, and the theoretical calculation and experimentalresults is compared, show that: change trend of the influence factors of desulfurization efficiency has been, the theoretical calculation and experimental values of the affect of SO2initial concentration and absorbing solution circulation flow rate is much better match.This thesis is to provide theoretical basis and valuable data for studying and developingflue gas desulfurization equipment, and to provide technical support for energy saving ofcoal-fired and gas-fired boilers.