Development Of Microwave Sterilization Equipment For Medical Waste And Study Of Microwave Sterilization Process

The outbreak of COVID-19 has led to a surge in infected medical waste.Microwave sterilization technology is an environmentally friendly non-incineration technology for medical waste treatment.In this paper,the core sterilization technology of "microwave sterilization,steam assisted system rapid temperature rise" is used to design and build a microwave sterilization test equipment for medical waste.The microwave sterilization system is composed of microwave device and screw conveyor,which can carry out continuous dynamic microwave sterilization for medical waste.The platinum resistance temperature sensor is used to measure the steam temperature and material temperature at the outlet of the system,and the system temperature is controlled within the range of100～120℃.The microwave sterilization process of medical waste was studied in microwave sterilization test equipment.Bacillus subtilis black variety bacillus plate（ATCC 9372）was used as the test object of microwave sterilization effect,and the total number of bacterial colonies after microwave treatment was used as the test index,and the effect of microwave sterilization was judged according to the sterilization rate.Single factor experiment was designed to explore the influence of microwave power,sterilization time and moisture content on microwave sterilization effect,and orthogonal experiment was used to optimize microwave sterilization process.The results showed that the higher the microwave power,the longer the sterilization time,the higher the water content,the higher the sterilization rate of microwave.Among them,microwave sterilization time has the most significant effect on sterilization effect.Orthogonal test results show that the best conditions of microwave sterilization are: microwave power 22 kW,sterilization time 480 s,water content 90%,under this condition,the sterilization rate is 99.9996%,sterilization logarithm up to 5log10,good sterilization effect.Other test results showed that when the microwave power was 25 kW or 28 kW,the sterilization time was 480 s or 600 s,and when the water content was 90%,the sterilization rate was 100%.