Solvent heat transfer system, cooling product on the Freeze dryer

The current solvent cooling system /solvent heat transfer system/ is probably no longer strange to users of large freeze dryers, specifically 10kg or more. However, with small dryers of 3kg and 5kg, only MactechDryer are currently fully applied, the rest of the small machines on the market today are still indirect heat transfer with the disadvantage of slow heat transfer. To clearly identify this problem, Customers need to know the different characteristics when looking at the drying tray shelf.

Most small manufacturing facilitys and individuals buying for use often care more about price than the technical characteristics of the equipment. Not to mention expensive sublimation dryers, even for common dryer groups such as hot air dryers and cold dryers, cheap dryers are more popular, but cheap dryers have very thin walls, poor insulation, simple heat control, uneven drying, slow drying, waste of electricity…many problems that users have encountered when buying cheap products.

With Freeze drying machine, the solvent cooling system (solvent heat transfer system) is extremely important because it directly affects product quality, drying quickly, transferring cold quickly, transferring heat quickly, so the drying quality will be higher and better than indirect cooling. The image above is a common characteristic of dryers with indirect cooling, the tray shelf is only a very thin 2mm stainless steel plate. The solvent cooling system is completely different. See the images below.

To cool with heat transfer solvents, you simply understand that inside each shelf supporting the tray in the drying chamber, there will be a stream of cold liquid solvent circulating continuously connected to the dryer’s condenser, then the cold transfer rate is very quickly and very evenly on the drying trays. When you first turn on the dryer for the initial cooling stage, you will see a lot of ice and snow clinging to the tray shelf. That is the tray shelf will be cold very quickly from the start of the drying process.

Solvent heat transfer system is a required cooling system on freeze dryers in particular and other multi-shelf product cooling systems in general. However, due to low price competition, many other dryers are on the market is not currently applied. Customers choosing household freeze dryers, 3kg, 5kg dryers should note this. Normally, the drying time is about 25 – 30 hours for fruits, but with indirect cooling, the time is extended by 4-8 hours, so it will cost more operating costs for the user, and it is also easier to frustrates users.

The image above is a 50kg freeze dryer with 32 drying trays, the tray shelf is divided into 2 column as shown to effectively distribute the refrigerant solvent evenly, the large chamber on the left is the product drying chamber, the small chamber on the right is the water condensation chamber, these two parts should be separated so that the systems do not affect each other during the product drying process. Through the picture above, you will clearly see that with solvent cooling, inside the drying chamber there will be a pipe carrying solvent into and out of the drying chamber, which is an easily recognizable feature of the system.

Customers need advice on how to choose an effective dryer, how to dry suitable products, please contact Mactech Vietnam so we can quickly provide information. Thank you for learning the sharing content.