초록 ▼

Adsorbers used to dry air frequently contain 4A or 13X molecular sieve zeolites, which are intermittently reactivated by thermal regeneration. When the air pressure in a thermally regenerated adsorber is increased, such as during start-up, after adsorbent reloading, after apparatus repair, maintenan

Adsorbers used to dry air frequently contain 4A or 13X molecular sieve zeolites, which are intermittently reactivated by thermal regeneration. When the air pressure in a thermally regenerated adsorber is increased, such as during start-up, after adsorbent reloading, after apparatus repair, maintenance or inspection, or after repressurization following thermal regeneration, nitrogen adsorbs preferentially relative to oxygen in activated 4A and 13X molecular sieve zeolites. This produces an oxygen-enriched, high pressure gas within the adsorber vessel which emerges immediately after the adsorber is brought on line. The oxygen-enriched, high pressure gas can cause fires, explosions, and other deleterious effects in and downstream of such adsorber vessels. This invention provides thermally regenerated air driers and air drying processes using adsorbent compositions that do not adsorb nitrogen preferentially to oxygen. Thermally regenerated air driers and drying processes using such adsorbent compositions prevent the problems associated with transient oxygen enrichment.

대표청구항 ▼

An apparatus for drying air comprising: (a) at least one adsorbent chamber containing an adsorbent composition comprising one or more molecular sieve zeolites capable of adsorbing water vapor from air, wherein such composition is substantially free of molecular sieve zeolites capable of substantiall

An apparatus for drying air comprising: (a) at least one adsorbent chamber containing an adsorbent composition comprising one or more molecular sieve zeolites capable of adsorbing water vapor from air, wherein such composition is substantially free of molecular sieve zeolites capable of substantially selectively adsorbing nitrogen in preference to oxygen, (b) means for providing an air stream, connecting such air stream to such chamber to adsorb water and increasing the air pressure in such chamber at least once, (c) means for isolating such chamber from such air stream, and (d) means for heating such adsorbent composition to substantially desorb water from such adsorbent composition. A method of air drying comprising: (a) adsorbing water vapor from an air stream by contacting such air stream with an adsorbent composition comprising one or more molecular sieve zeolites capable of adsorbing water vapor from air, wherein such composition is substantially free of molecular sieve zeolites capable of substantially selectively adsorbing nitrogen in preference to oxygen, and isolating such adsorbent composition from such air stream, (b) increasing the pressure of air in contact with such adsorbent composition prior to or during at least one such adsorbing step (a), and (c) heating such adsorbent composition to desorb water.