Design And Key Technology Research Of Sulfur Burner

Sulfur dioxide?SO₂?is an important auxiliary material of sulfite sugar process,plays an important role in the clarification of juice and decolorization and quality assurance of sugar.At present,the main equipment to produce SO₂ is closed jet combustion type sulphur burning furnace in the sugar industry.This method can obtain high combustion quality and pure SO₂,however,it's easy to generate sublimed sulfur and SO₃ in the process of enterprise production,which leads to control precision reduction,pipe blockage and other issues.It has seriously affected the efficiency of sugar and increased the production cost.So,it's of great significance to design new style sulfur burner to improve efficiency,reduce cost and resource conservation.Firstly,under the condition that the daily consumption of sulfur is 0.5 tons,the stagnation temperature is 425K and the stagnation pressure is 0.45MPa,based on the Venturi principle and injector structure principle,designing the air-liquid sulfur injector and the influence of the pressure on the injection efficiency is analyzed.According to the theoretical calculation,the geometric size and assembly dimension of the sulfur injector are determined and the optimum pressure is 0.51724MPa.Secondly,the structure design of the convective boiling burner is simulated by Fluent.Based on the design goals of air and powder mixing and stable fluidization,convective boiling air chamber,burner air distribution plate and the combustion chamber are designed.Furthermore,the structure model of fluidized boiling burner is determined.Results show isobaric air chamber structure,two wind structure model with annular cross baffle is reasonable.When inletl wind speed is 0.8m/s,inlet2 wind speed is 0.5m/s,sulfur air ratio reach 1:1.0273,sulfur powder can be fully fluidized.Moreover,the effects of the apparent wind speed,the initial thickness of the fluidized bed,the initial volume fraction of the fluidized bed and the particle size of the sulfur particles on the fluidization of the particles are analyzed.On the basis of the above analysis,the PDF non-adiabatic model is used to simulate the combustion of sulfur particles in the designed boiling combustor,and the effects of excess air coefficient,air temperature and oxygen concentration on the combustion are analyzed.The results show that appropriate apparent wind velocity,initial thickness of the fluidized bed and particle size are beneficial to the stable fluidization;when the excess air coefficient is 1.5,the sulfur burns sufficiently and the fraction of sublimed sulfur?SO3 of outlet is small.The air temperature has a great influence on the combustion of sulfur powder.Appropriate increase in temperature is beneficial to the formation of SO₂;under the condition that the inlet air flow rate is constant,the increase of oxygen concentration has little influence on the combustion,and to some extent,it breaks the fluidization and it's not conducive to the formation of SO₂.The boiling combustion designed by this paper capacity reaches 1 tons/day,when air coefficient is 1,the air temperature is 600K for optimal production conditions,the mole fraction of S,SO₂,SO₃ of burner outlet is 0.15%,14.3%,0.037%,better than the measured value of industrial sulfur burning.Last,cold spray test and the fluidization experiment are carried out based on the sulfur jet burner and fluidized boiling burner.The results shows that the injector can work stably under different conditions;air pressure P,tube throat diameter D and distance between nozzle outlet section and throat inlet section L have a certain effect on the ejector efficiency and air-liquid mixing state.Moreover,eject distance is long and air liquid ratio is up to 123,which is not conducive to full combustion.The fluidization test results are similar to the simulation results,particle size and inlet air flow have a great influence on the convection,but the bed material quality affects the stability of fluidization.Under certain circumstances,the sulfur powder is fully fluidized.Design and experimental research of high temperature sulfur ejector and the flow boiling sulfur burner shows that sulfur ejector and flow boiling sulfur burner as SO₂ preparation equipment is feasible,and the boiling burner has solved the problems of sublimed sulfur and the generation of SO₃ of current burning furnace at a certain extent.This paper's work provides a new idea for obtaining SO₂ in the sugar industry and provides a reference to further optimize the sulfur burning furnace structure,which has a certain guiding significance and pragmatic value.