Study On The Design And Sterilization Of Hydrogen Peroxide Vapour (HPV) Generator

Sterilization is a very important part in aseptic filling process,which can directly affect the quality of products.As a new type of green disinfection method,hydrogen peroxide vapour（HPV）sterilization technology has been applied in aseptic filling production maturely in foreign countries,but it is still in the start stage in China.And there is a big gap of the equipment for producing HPV in home and abroad.Therefore,it is of great significance to develop a new type of HPV generator for improving our aseptic packing technology.This paper designed and manufactured HPV generator and studied process parameters and operating condition on the gemicidal efficacy by experiment.The main research contents were as follows:1.This study choosed jet device atomize hydrogen peroxide solution according to the operational principle of venturi-tube.Utilized compressed air mix with hydrogen peroxide solution in the jet to spray the solution,and then heated the atomized mixed fluid in heater to prepare HPV.The main structure,mixed heating system,flowrate and temperature control system of the generator were studied and designed.The jet was designed by theoretical analysis and verified by atomization test.At the same time,the heater with total power of 6 kW,which was connected by a 2 kW heater and a 4 kW heater in series,was selected according to our calculation.2.The gemicidal efficacy of HPV inactivating Bacillus subtilis on the inner surface of Polyethylene terephthalate（PET）bottles in “non preheating-sterilization-non dry”condition was studied with single-factor and response surface method.The results of single-factor method showed that: The H₂O₂ flowrate and time were positively correlated to the gemicidal efficacy.The sterilization effect was obviously enhanced with the increase of H₂O₂ flowrate and the extension of sterilization time.While the steam temperature was negatively correlated to the gemicidal efficacy.With the increase of temperature,the decomposition of hydrogen peroxide aggravated sterilization effect.Under this condition,it was concluded that interaction between H₂O₂ flowrate and sterilization time had a great influence on the sterilization effect according to the results of regression analysis.And the optimum process parameters were H₂O₂ flowrate 16 m L/min,treatment time 10 s and steam temperature 120℃,under which condition,the reduction of Bacillus subtilis could be up to 6.85-log（CFU/mL）.3.The gemicidal efficacy of HPV inactivating Bacillus subtilis on the inner surface of PET bottles in “50℃ preheating-sterilization-50℃ dry”condition was studied.Three factors and three levels of H₂O₂ flowrate（10,13,16 m L/min）,treatment time（4,7,10 s）and steam temperature（120,140,160℃）were validated by single factor experiments.The analysis results showed that the interaction of H₂O₂ solution flow and sterilization time on the sterilization effect was very significant.And the optimum process parameters were draw that H₂O₂ flowrate of 14.24 m L/min,treatment time of 9.05 s and steam temperature of 120℃ according to the results of regression analysis.Under this result,the predicted reduction of Bacillus subtilis was 5.45-log（CFU/mL）,and the reduction in experiment was 5.39-log（CFU/mL）.In order to ensure thorough sterilization,the gemicidal efficacy of HPV was further studied by improving the flowrate of H₂O₂ solution.And ultimately it was concluded that the gemicidal efficacy was significantly enhanced with the increase of H₂O₂ flowrate.This paper provided a new method for the design of HPV generator.Based on analysis of the process parameters and gemicidal efficacy of HPV,it was proved that HPV had advantages of high efficiency and low dosage.HPV sterilization has a good application value in industrial development of aseptic filling.