| In recent years,the pollution problem caused by oily sludge has become more and more serious,which has adverse effects on the natural environment and human health.Due to its high viscosity and difficulty in dehydration,higher requirements are put forward for cleaning technology.Therefore,it is of great significance to research and develop a high-efficiency oily sludge cleaning system.At present,domestic research on oily sludge focuses on the influence mechanism of single experimental factors.It lacks detailed research that the influence on various factors,the determination of optimal process parameters and the overall system.The chemical cleaning technology,oxidation cleaning technology and oil sludge cleaning system are detailedly analyzed and summarized in this paper.Firstly,the single factor of the chemical treatment and the oxidation cleaning are experimentally studied to determine the best range of experiment parameters.The influencing factors of chemical cleaning technology include temperature,chemical concentration and liquid-solid ratio.And the influencing factors of oxidation cleaning technology include cleaning time,gas flow,pH value and liquid-solid ratio.Secondly,through the response surface method,the interaction between experimental multiple factors is studied to obtain the optimal parameters.In the experiment,the residual oil rate of sediment is used as an evaluation index.Finally,the design of a high-efficiency combined oily sludge treatment system is presented in this paper.At the same time,based on the results and the best conditions of experiment,the pre-treatment equipment and the major cleaning equipment are calculated and designed in detail.In the experiment of chemically cleaning oily sludge,NaOH is the best cleaning agent through selecting of reagents.The appropriate range for each parameter is determined by the single factor experiment,the cleaning temperature range is 70~90°C,NaOH concentration range is 0.50~1.00 g/L,and the liquid-solid ratio range is 7.5:1~12.5:1.The response surface methodology is employed to design experiment scheme,and the best parameters are acquired by analysis as the cleaning temperature of 78.68℃,the chemical reagent concentration of 0.84 g/L and the liquid-solid ratio of 9.40:1.And the simulated the residual oil rate is 3.85%,the average residual oil rate of experimental results is 3.96%.In the experiment of oxidation technology cleaning oily sludge,the oxidation experiment combined with stirring and ozone flotation is selected by scheme comparison.The appropriate range for each parameter is determined by the single factor experiment,the cleaning time range is 40~60 min,the gas flow range is 0.6~1.0 L/min,the pH value range is 7~9,and the liquid-solid ratio range is 4:1~6:1.The response surface methodology is employed to design experiment scheme,and the best parameters are gotten by analysis as the cleaning time of 42 min,the gas flow rate of 0.92 L/min,the pH value of 9,the liquid-solid ratio of 6:1.And the simulated the residual oil rate is 1.00%,the average residual oil rate of experimental results is 1.04%.In this paper,according to the optimization study of the experiment,a set of treatment process combining mechanical separation with chemical cleaning is calculated and designed,which can improve the cleaning efficiency of oily sludge and shorten the treatment cycle.The dimensions of the compound hydrocyclone and the cavity structure are detailed calculated.The diameter of the cylinder is 300 mm and the wall thickness is 3 mm.Another major device,the cleaning tank with the length-diameter ratio of 1.8 is also designed crefully.The diameter of the cylinder is 1800 mm,the length of the cylinder is 3240 mm and the wall thickness is 6 mm.At the same time,gas distributor and mixing equipment are added to the tank to ensure full contact between bubbles and sludge. |
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