Freeze Dryers And Drying Processes For Materials With Low Water Content

What is this patent about?

’610 is related to the field of freeze-drying , specifically addressing the challenge of drying materials with low water content, such as candies and confections. Traditional freeze-drying processes involve freezing the material before applying a vacuum to sublimate the ice. However, this pre-freezing step may not be necessary or even desirable for materials already low in moisture, potentially leading to inefficiencies and suboptimal results.

The underlying idea behind ’610 is to eliminate the pre-freezing step in the freeze-drying process for materials with low water content (less than 20% water). Instead of freezing, the material is placed directly into the vacuum chamber, and the pressure is reduced to initiate drying. This approach leverages the fact that low-moisture materials are structurally robust enough to withstand the vacuum without prior freezing, streamlining the process and potentially improving the final product.

The claims of ’610 focus on a freeze dryer apparatus and method specifically adapted for drying materials without a pre-freezing step. The apparatus includes a vacuum chamber, a vacuum pump, a cooling system for the chamber walls, a heating system for the material, and an electronic controller. The controller is programmed to execute a drying process that involves reducing the pressure in the chamber below ambient pressure to dry the material, skipping the initial freezing phase.

In practice, the invention operates by first cooling the interior walls of the vacuum chamber to facilitate the condensation of water vapor. The material, such as candy, is then placed inside the chamber. The electronic controller then activates the vacuum pump to reduce the pressure, initiating the drying process. In some embodiments, the material is also heated to further accelerate the removal of moisture. The controller may also offer an option to repeat the drying process with another batch of material without defrosting the chamber, further enhancing efficiency.

This approach differentiates itself from traditional freeze-drying by optimizing the process for low-moisture materials . By skipping the freezing step, the invention reduces energy consumption and processing time. Furthermore, the option to heat the material before or during drying can enhance the texture and other characteristics of the final product, particularly in the case of candies, where a desirable puffed or expanded structure is often sought. The ability to run multiple batches without defrosting also improves throughput.