Numerical Simulation Study On Working Process Of Oil Sludge Pyrolysis Furnace

Oil-containing sludge is a mixture formed by oil,sediment and water in the process of oil field mining,oil refining,transportation,use and storage.Contains a large number of harmful substances,high viscosity,difficult to settle,poor dehydration effect,with the increasing demand for oil,there will be more oily sludge produced Oiled sludge will occupy a large area of land,cause serious pollution to the soil,water and air,and even seriously affect human health,so it is necessary to deal with it effectively.Pyrolysis process technology is a kind of high efficient,clean,oily sludge treatment technology,with high added value of sludge pyrolysis process can realize resource utilization,reduction and innocuity effect,pyrolysis reaction product of non-toxic harmless and can be recycled,has great potential resource utilization,is the future trend of the development of sludge treatment.Thermogravimetric analysis of oily sludge was conducted to obtain TG and DTG curves under different experimental conditions.The pyrolysis process of oily sludge was roughly divided into four stages: water evaporation,light oil pyrolysis,heavy oil pyrolysis and final pyrolysis.The mechanism function of sludge pyrolysis is solved by proper method and relevant parameters are obtained.The reaction kinetics model was established,the thermogravimetric experimental data were fitted and calculated,and the kinetic equations of the parameters in the last three reaction stages were obtained through theoretical formula derivation.The results showed that the three stages met the reaction order of 0.8,2.0 and 1.2respectively.The internal pyrolysis process of pyrolysis furnace was studied by means of theoretical analysis and numerical simulation.The energy transfer process of pyrolysis was analyzed by means of thermodynamic calculation.Numerical simulation was used to analyze the flow field characteristics in pyrolysis furnace,and the effects of different pyrolysis temperature,furnace rotation speed and other parameters on the reaction process and pyrolysis products in pyrolysis furnace were studied.The results show that with the increase of pyrolysis temperature,the pyrolysis residue decreases,the liquid phase products rise first and then decrease,and the gas phase products become more and more.With the increase of the rotational speed of the furnace,the temperature distribution inside the furnace changes from uniform to disorder,the pyrolysis residue remains unchanged to increase significantly,the liquid phase products first stabilize and then decrease,and the production of pyrolysis gas first slowly decreases to a significant decline.With the increase of sludge inlet velocity,the temperature distribution in the furnace decreased slightly,and the effect on gas-liquid two-phase products did not change significantly.The pyrolysis residue increased with the increase of sludge inlet velocity.With the increase of fuel inlet velocity,the temperature distribution in the furnace has almost no effect,and the influence of gas-liquid two-phase products and pyrolysis residue distribution has no obvious change.In this paper,the effects of different pyrolysis temperature and furnace rotation speed on the pyrolysis process and pyrolysis products in the furnace are systematically studied,which can provide reference for the application of pyrolysis furnace in engineering practice.