How to lower the vacuum degree of freeze dryer

The vacuum freeze dryer is an integrated device of pre-freezing and drying, which can quickly freeze the material into a solid state at low temperature, and then sublime into water vapor in a vacuum state, and capture the water vapor into ice through a cold trap, so as to obtain low-temperature dried material. Freeze drying machine has a wide application, but we may meet some problems in use. For example, what should be done if the vacuum degree  cannot be lowered?

Causes:  

1. Too high pump temperature: it may be that the pump valve plate or inner cavity of the laboratory freeze dryer is scratched and worn, and the displacement of the rotor shaft causes one-sided wear.

2. Pump oil problem:

* The oil level is too low and the sealing is not tight;

*The oil is polluted and is creamy yellow;

*The oil level is normal, but the oil circuit is blocked, and the oil amount in the pump chamber is not proper.

3. Air leakage of the pump: the sealing ring and the gas ballast valve gasket are damaged or not pressed tightly, and the exhaust valve plate is damaged, resulting in poor sealing.

4. The air inlet filter is blocked.

Solutions:

1. Reassemble after repair.

2. Refuel; change the oil; check the oil intake of the oil circuit and the oil valve.

3. Replace the sealing ring or valve plate according to the specific situation of the failure of the pilot freeze dryer.

4. Remove it and clean.

The industrial freeze dryer can achieve a faster drying speed only by improving the heat transfer and mass transfer efficiency and increasing the surface area of the freeze-dried material per unit volume at the same time.