1.1Basic performance characteristics

Pressure steam sterilization cabinet is divided into pre-vacuum type and lower exhaust type according to the different vacuum generation principle of the original cold air in the cabinet.The fundamental difference between the pre-vacuum type and the lower exhaust type is that the way of removing the cold air inside the cabinet is changed from passivity to initiative, that is, from being pushed out by the steam from top to bottom by gravity to be pulled out by the vacuum pump.The operation methods of pre-vacuum pressure steam sterilization cabinet can be divided into two categories: one is the pre-vacuum method that USES a single vacuum to reduce the cold air in the cabinet to the required degree; The other is the pulsating vacuum method, which USES multiple vacuums to reduce the cold air in the cabinet to the required degree.

1.2Comparison with lower exhaust pressure steam sterilization cabinet

1)The cold air in the cabinet is removed thoroughly compared with the lower exhaust type, thus the effect temperature is increased and the whole sterilization cycle is shortened obviously.

2)The oxygen in the cabinet decreases and the action time is shortened. Therefore, even if the action temperature is raised to a higher level, such as 132~134℃ and 4min, the damage to articles is lighter than that of the lower exhaust sterilization at 121℃ and 20min.

3)Compared with the lower exhaust sterilization cabinet, it can save energy, reduce labor intensity, and be less affected by the factors such as packaging and goods placement.

4)Compared with the lower exhaust sterilization cabinet, the structure is complex and the manufacturing cost is high. One – time vacuum, vacuum pump and cabinet chamber seal requirements are very high, increase the maintenance work.

5)It can produce small loading effect, that is, when the loading amount is too small, the residual gas can surround the small loading amount to form a barrier, and prevent the steam from penetrating, which can cause the failure of sterilization.