Design and construction solar steam sterilizer

Document Type : Research Paper

Authors

1 Mechanical Engineering Department, College of Engineering, University of Kerbala, Karbala, Iraq

2 Petroleum Engineering Department, College of Engineering, University of Kerbala, Karbala, Iraq

Abstract

Doctors, especially surgeons in remote areas, need help to overcome the problem of transmission of infection resulting from the repeated use of surgical instruments without sterilization, and that is why researchers sought to find solutions. This study presented a design and model made for a low-cost solar sterilizer. It relied on benefits from the glasshouse properties to generate the wet steam that was required for sterilization at a temperature of $121.1^{\circ} C $ and a pressure of 2.1 bar inside an aluminium pressure cylinder that was placed inside an insulated chamber, whose dimensions were 50 cm wide, 30 cm high, and 93 cm deep. Its front face was made of 10 mm-thick thermal glass. The top face was used as a frame for fixing the cylinder. The outer surface of the cylinder was coated with matte black paint to increase heat absorption. The model was tested in the absence of surgical equipment using half a litre of pure water, and it took 128 minutes to achieve steam with the properties necessary for sterilization. The test started when the temperature of the water inside the cylinder was 56.1°C. In climatic conditions in which the average intensity of solar radiation was 903  W/m\textsuperscript{2} and the average ambient temperature was 34°C. Then the performance was tested with the presence of 1.2 kg of instruments. The presence of the surgical instruments increased the time required to achieve the temperature and pressure required for sterilization by 25.78\%. And to increase the thermal enablement of the system, reflective panels were placed to reflect the solar radiation towards the surface of the cylinder. This procedure achieved a 6.2\% reduction in the time required for the sterilization requirement for steam. The tests were conducted over several days and under different conditions, each achieving the necessary steam for sterilization.

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