Can a dew point of minus 40 degrees for process gas be achieved using freeze-drying?
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Can a dew point of minus 40 degrees for process gas be achieved using freeze-drying?
This post was last edited by MTO001 on 2022-10-8 at 16:47. If the dew point of the instrument air is -40°C, and the dew point required in the refrigeration area is also -40°C, it is very difficult to meet these requirements. It is better to use instrument air for drying first, and then nitrogen for drying. Generally, in accordance with design principles, the dew point of instrument air should be the local minimum temperature minus 10 degrees; if the factory is located in the south, it may not be possible to achieve -40°C. Although the design value cannot be achieved, it is necessary to base it on the actual pressure of the instrument air supplied; this might yield better results.
The water that is discharged will freeze at 0 degrees, blocking the pipes.
1. It depends on the performance of the freeze-dryer you choose; if its operating temperature can reach below -40°C, then there will be no problem with the instrument air produced； 2. Why not consider choosing adsorption drying equipment?
Freeze-drying is a bit expensive! !
Using a cold dryer combined with an adsorption dryer, the dew point can be reduced to below -40°C
Molecular sieve adsorption dryers are typically used, with a dew point that can go below -40°C
It cannot be achieved; the dew point at the output of the cold dryer is at most around -20°C
It’s possible, but it’s not very cost-effective. The lower the dew point required by the cold dryer, the smaller the volume that can be processed, and the lower the efficiency. Therefore, a cold dryer + adsorption solution is usually adopted. .
The dew point temperature of the instrument air supply is generally required to be 10°C lower than the ambient temperature. Depending on the specific location of the facility, if a dew point temperature of -40°C is required, a cold dryer will not be sufficient; in such cases, an adsorption dryer must be used.
I also think it will freeze up and prevent water from draining. And at such low temperatures, energy consumption is also high; isn’t adsorption drying less economical?