Perform regular vacuum pump maintenance

Make sure your freeze dryer is compatible with the eutectic temperature of your sample(s)

First and foremost, ensure your sample is compatible with your freeze dry system before you use the unit. A good rule of thumb is to plan for your most challenging sample and choose a system based on that need.

It's not possible to modify a freeze dryer’s condenser temperature.

The condenser temperature should be 10 to 15°C below the sample’s eutectic point. Low freezing point solvents, for instance, should not be used on -50°C units.

Certain acids should not be used with bare stainless steel and should only be used with PTFE models. Systems that reach -84°C are ideal for lyophilizing samples with low eutectic temperatures (like those that contain acetonitrile).

Systems that reach -105°C can handle samples containing small amounts of ethanol.

Perform regular Vacuum Freeze Dryer pump maintenance

Have you ever had problems with your freeze dryer not pulling sufficient vacuum?

If so, you're not alone—it's one of the most common freeze dry troubleshooting issues. The good news is that performing regular pump maintenance can help solve the problem, both reducing immediate downtime and increasing unit life in the long term.

After you’ve ensured you have the appropriate lyophilizer for your samples (see above), do the same for your pump: standard rotary vane pumps work well for aqueous based solutions, and hybrid or combination pumps are best suited for use with solvents or acids.

A low maintenance option, the scroll pump, is a new offering, which does not use oil at all.

In some cases, secondary acid or solvent traps can be used to extend the life of your vacuum pump by providing an additional barrier between the lyophilizer and the pump.

Dry ice traps are also available if you don't have the appropriate temperature differential between the eutectic temperature of your sample and the collector temperature.

Last but certainly not least, make sure to change the oil in your vacuum pump every 1,000 hours (or sooner if your application warrants). If in doubt, check the appearance of the oil. If it's cloudy or darker than an iced tea color, it needs to be changed.

Note that some pumps, such as hydrocarbon free scroll pumps, can pull a deep vacuum for freeze drying without using oil. If you've chosen a scroll pump, make sure to change the scrolls after every 40,000 hours of use.

Clean the freeze dryer after each run

It's necessary to defrost and drain the condenser after each standard run.

If using acids, note that you'll also need to neutralize the chamber.

Regardless of the sample used, you must rinse and wipe down any components that may have come into contact with chemicals to reduce the risk of damage. Don't let water—especially chemically contaminated water—sit on the stainless, acrylic or rubber components of your freeze dryer. If you wanna konw more information, please click https://www.gf-machine.com/product/vacuum-freeze-dryer/