DRY HEAT STERILIZATION

Dry Heat Sterilization process works through the heat conduction mechanism, where heat will be absorbed by outer surface of tools sterilized and spreads to the inner surface until the sterilization temperature attained. Dry heat sterilization is usually used for materials or tools which steam can not easily penetrate or for tools made from glass.

In this method, microorganism killing works through oxidation mechanism until cell protein coagulating. Dry heat sterilization needs a longer time with higher temperature and works in a dry heat oven convection.

Working circle of dry hot sterilization machine :
1.Warming – Hot air produced through electricity mechanism and circulated at a chamber.
2.Plateau period (sterilization) begins when censor detects the attained temperature of sterilization process in chamber.
3.When all of the chamber has the same temperature so it is the end of equilibrium phase and starts “holding time” phase or sterilization.
4.Chamber cooling down, done by circulating cold air and filtrated into the chamber.

Advantages of dry heat sterilization :
1.It can sterilize several materials which can not be penetrated by steam like dry powder and oil material.
2.Non-corrosive toward metal.
3.Conduction mechanism can reach the entire non-overhauled tools surface.

Weaknesses of dry heat sterilization :
1.Penetration toward material moves slowly and not spread evenly.
2.Needs longer warming to attain sterile condition.
3.High temperature may damage rubber material and some cloth materials.

Manual instruction must be comprehensively prepared by machine supplier. The maintenance department must provide all information needed for all recommended procedure at the time of installation trial or routine maintenance. Manual instruction must be available at CSSD.
Reason: For the maintenance matter, repairing and calibration might be handled by other person, not only by the supplier.

Putting goods into the dry heat sterilization machine.
Before putting goods into the chamber, it must be heated first to the temperature of 160 C. Between one good and another there must be space to keep a good air circulation so that the thermal contact may run well and every item doesn’t stick to the chamber.