Influence of Water Temperature in Vacuum Pumps Used for Air Removal in Steam Sterilizer.

The temperature of the water used in vacuum pumps of steam sterilizers has the potential to cause failures in sterilization processes due to reduced efficiency and compromised vacuum levels. This study measured the impact of water temperature on a liquid ring vacuum pump (monobloc design) in a steam sterilizer. A sterilizer with a 566-L chamber was used for the tests. The water temperatures tested were 10°C, 20°C, 30°C, 40°C, and 50°C, and the following outcomes were analyzed: vacuum depth achieved in the drying phase (mbar), total cycle time (min), vacuum rate in the conditioning phase (mbar/s), and water consumption (L). Water temperature influenced the performance of the vacuum pump in all outcomes analyzed. Considering total cycle times, the performance with water at 10°C can be up to 50% better compared with performance with water at 50°C. The highest vacuum rates were obtained with water between 10°C and 20°C (up to 13 and 20.24 mbar/s, respectively). In cycles performed at 10°C, average water consumption was 33.3 L. In contrast, for cycles carried out at 50°C, the average water consumption increased to 94.2 L. The temperature of the water used in vacuum pumps influences the efficiency of sterilization cycles, which can result in longer cycles and higher water consumption.