Liquid Phase Molecular Sieve Dehydration
This Liquid Phase Design passes a liquid stream of wet alcohol or solvent through a column filled with molecular sieve beads.
As the liquid passes through the bed of sieve beads, the water molecules are sucked into the beads due to polar attraction. As the bulk liquid continues through the column, more of the water is adsorbed onto the internal surfaces of the molecular sieve, until essentially all of the water is removed and the dried alcohol (or solvent) exits the column.
This process continues until the sieve becomes saturated with water, at which time the molecular sieve must be changed, or regenerated.
Regenerating the sieve typically involves 1) draining the liquid, 2) heating the sieve beads, 3) purging the gas either at pressure or under vacuum, and lastly, 4) cooling the sieve.
Wintek’s Internally Heated Short Path(SP) Design
Wintek’s unique MSDUL Liquid Phase Molecular Sieve design utilizes internal heating for temperature swing regeneration, which offers the following advantages:
- Very Dry Product to less than 10 ppm
- Low energy consumption
- Very high product recovery due to the low purge gas requirements: >99% recovery
- Very high thermal efficiency with the short gas path for thermal transfer
- High thermal efficiency means shorter regeneration cycle
- A shorter regeneration cycle enables higher processing rates
- Packaged units are fully piped and wired
- Fully automated, reducing operator
Externally Heated MSDUs
In Externally Heated MSDU Designs, the heating the mole sieve beads is performed by purging hot dry gas (generally Nitrogen) through the bed, or by circulating a hot gas with a partial purge.
Externally heated designs suffer from long regeneration times due to the low heat content of the nitrogen being used to heat and cool the bed and the relatively large amount of energy required to change the temperature of the beds.
This design also suffers from higher emissions, even though condensers are used, due to relatively high purge gas rates which are exhausted with saturated vapors.