Freeze drying controller, pressure controlled drying method

Mactech has now updated its freeze-drying program to a new generation, ensuring faster drying times and easier parameter settings for initial use. This guide will show you how to use and understand the advantages of this pressure-based temperature controller.

In the section on freeze-drying principles or freeze-drying processes, we will understand the steps involved in a drying process. Below are the steps that require setting appropriate parameters on the temperature-pressure controller:

• Step 1 is the freezing stage, which involves freezing the dried product to a temperature of -20°C to -30°C for a specific period, usually 4-8 hours depending on the thickness of the product. Therefore, two parameters must first be set for the freezing process: temperature and freezing time.
• Step 2 involves cooling the condenser chamber, setting the condenser chamber temperature parameters, usually -35°C to -45°C.
• Step 3 involves selecting the drying mode: either stage drying or pressure drying. We typically use pressure drying (temperature controlled by pressure) to optimize the drying process. The software automatically handles the drying process without requiring user intervention in increasing the product temperature.
• Step 4 involves setting the sublimation pressure value, usually 20-40 Pa. This is the operating threshold value of the heat control. That is, when the actual pressure in the drying chamber is always lower than this threshold, the machine will continuously supply heat to the product to ensure the fastest possible sublimation. When the actual pressure in the drying chamber exceeds the set threshold, the machine stops supplying heat until the pressure drops below the appropriate threshold. This heating method optimizes drying time, drying as quickly as possible. As long as the actual pressure in the drying chamber remains sufficiently low, the machine will continuously heat, promoting the most efficient sublimation of the ice.
• Step 5 involves setting the maximum drying temperature for a specific product. For common products like fruits, vegetables, meat, fish, and medicinal herbs, a temperature of 30-40°C is usually set. For more specialized products like probiotics, a lower temperature of around 15-30°C is more suitable. This temperature represents the maximum heat that the product can withstand and ensures the correct temperature range for each type of product.
• Step 6 involves setting the remaining parameters; these are fixed parameters that we don’t need to change each time we use the machine or change the product being dried.

The video above provides the most intuitive user guide to help customers easily set drying parameters each time they use the machine. To move between setting steps, simply press the MODE button. To change parameters such as temperature, pressure, and time, simply press the increase or decrease buttons. Mactech freeze dryers always come with complete, intuitive user manuals and continuous support from our experienced technical team.

Based on the above information, customers now have a better understanding of what a pressure-controlled temperature controller is. For more advice on drying specific products, please contact Mactech for further information. Thank you for reading this information.