Freeze drying process include which steps, learn about drying parameter

You want to learn about freeze drying techniques, product drying techniques by freeze dryers, freeze drying process or a name like that, so in this contents, MactechDryer will analyze the steps of drying products with lotus tea for readers to better understand. Thereby, you will know the right drying method for different products.

When talking about the technical process of freeze drying method for any product, we will understand that these are the general steps of a drying process on a feeze dryer. With specific drying products, they need to use different parameters such as drying temperature, pressure, time… When the dryers are not modern enough, we will have a complicated drying process, but with very modern dryer has drying process is quite simple. Below is the process of freeze drying technique analyzed to help customers understand what to do when using the dryer.

Freeze drying process include below steps:

1. Preparation of raw material: products that need to be dried include fruits, vegetables, meat and fish, liquid starch, medicinal herbs, mushrooms, etc…, before drying, there are standards or notes on product size such as reasonable thickness and thinness to make the drying process is fast, dry evenly, and the dried size meet requirements. After proper product preparation, arrange them on the tray so that the product contact with the tray surface as much as possible. The principle of heat transfer or heat transfer method on the freeze dryer is transfer heat through the surface contact, so the more contact, the faster the heat transfer.
2. Preparing the machine: this step needs to check some problems such as the drying chamber must be clean, the tray shelf surface must be clean, the condenser must drain all the water of the previous drying batch, lock the valves, check the vacuum pump by controllability on the controller…
3. Put the product into the machine, attach the sensor: after putting the drying tray containing the product into the drying chamber, the next step is to attach the sensor wires into the product core, see the instructions in the video below.
4. Parameter setting: with new generation freeze dryer, the parameters to be set will be much simpler than before. Previously, we had to install many drying stages, but now with the pressure drying controller, we only need to set 3 main parameters: sublimation pressure, freeze temperature and maximum temperature for the product, the rest of drying process will automatically calculate by software, ensure the most optimal drying process, the installation steps are included in the user manual attached to the machine.
5. Operating the machine and monitoring: after setting the appropriate parameters, or drying the next batch, you just need to select the function to restart from the beginning and the machine will start operating. The stages will go through including: 1-freezing the product to -30oC, 2- transferring to the condenser chamber to -40oC, 3- vacuuming to sublimation pressure, and 4- process heating the product, This is the stage that the ice will sublimate continuously until the product is completely dry.
6. Time to end the drying process: the freeze drying process will not end the drying process according to the preset time but according to the temperature parameter indicated on the control screen. With Mactech’s freeze dryer, on the controller, there are 4 temperature parameters: Đ – V – T -X, when all four parameters are larger 30oC, the product is completely dry. Particularly with drying probiotics, it only needs larger 20oC.
7. Checking finished products and packaging: a note with freeze-dried products is that the dryness is very high, only 0-3% humidity, so the brittleness is high, it is easy to break, especially it is very easy to absorb moisture from the air. so after drying, it is necessary to store as soon as possible, preserve it by zip plastic bag, vacuuming it, keeping it in a sealed box
8. Turn on defrost mode: after removing all the products in the machine, users need to turn on the defrost mode to thaw the ice in the condenser chamber as quickly as possible to continue drying next batch, if not in a hurry, lets it thaw naturally, save electricity.

The steps listed above are the freeze drying process for a certain product, the drying parameters may differ slightly for products with different characteristics. Customers can consult us to suitable for actual use. For more relevant information, please contact Mactech Dryer, thank you for learning about the shared content.