Astell has described key features and functions which can be used to enhance the cooling of its autoclaves.
Thermal sterilisation, in which microbes and biological materials are heated to temperatures above 121°C, is only part of the autoclave process. Temperatures need to drop before items can be removed from the instrument, and this can be enhanced in multiple ways.
A cooling fan blows air across the surface of the autoclave chamber vessel, stripping heat from the external surface and, in turn, removing it from within the autoclave chamber. This budget-friendly method provides faster cooling than passive heat dissipation but relies on the chamber’s external surface being exposed to the atmosphere, and so is not compatible with features such as insulation materials or chamber jackets.
Some autoclaves generate sterilising steam by heating water within the chamber vessel. Removing this water after sterilisation, will help speed the cooling process. Astell’s Ecofill system transfers the water to an external reservoir to accelerate cooling as well as enabling the heat energy to be reused in future cycles.
The intrinsic relationship between temperature and pressure means that vacuum pumps can be excellent tools for autoclave cooling. Reducing the pressure within the autoclave chamber after sterilization lowers the boiling point of moisture inside the chamber. This causes the moisture to evaporate, effectively removes heat from the autoclave. Additionally, this process helps dry items inside the autoclave, which is particularly beneficial for sterilizing fabric-wrapped or porous materials.
Encapsulating the autoclave chamber vessel within another vessel—or jacket—allows a flow of water to pass over its external surfaces. As with the cooling fan method, this strips heat from the chamber vessel's outer surface but, unlike the fan, the chamber vessel does not need to be directly exposed to air. This allows the water-cooling jacket to be enclosed within a layer of insulation, minimising heat loss during sterilisation and making the autoclave more energy-efficient.
Once water passes through the jacket and absorbs heat from the vessel, it can be drained away. A more efficient approach is to recycle the coolant water by allowing it to cool in an unpressurized vessel before recirculating it. Cooling can be further enhanced by adding fresh cool water to the system.
At the pinnacle of autoclave cooling, an internal chamber fan generates airflow that accelerates heat dissipation from all items inside the chamber. One key advantage of this method is its compatibility with other cooling systems, such as the cooling jacket and vacuum cooling. When combined with additional cooling hardware, autoclaves equipped with internal chamber fans can achieve cooling speeds up to 70% faster than those without dedicated cooling equipment. This can effectively double an autoclave’s throughput and make the difference between requiring one or two autoclaves in high-demand environments.
From the simple, low-cost solution of a cooling fan to the advanced setup of a cooling jacket and internal chamber fan, there is a wide array of autoclave cooling solutions that can be built into an autoclave. Find more information here.
