Drying R-407C and R-410A refrigerant blends with molecular sieve desiccants

Conference · Thu Oct 01 04:00:00 EDT 1998

OSTI ID:653210

Cohen, A P; Tucker, D M ^[1]

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1. UOP Research Center, Des Plaines, IL (United States)

The hydrofluorocarbon (HFC) R-32 (CF{sub 2}H{sub 2}) is a component of refrigerant blends in the 407 and 410 series being tested and commercialized for use as replacements for R-502 and the hydrochlorofluorocarbon (HCFC) R-22. The molecular sieve desiccants used with chlorofluorocarbon (CFC) and HCFC mineral oil systems in the past have achieved high water capacity by excluding the refrigerant and adsorbing only the water. Unfortunately, R-32 is adsorbed on commercial type 3A molecular sieve desiccant products. The result of this adsorption is a loss of water capacity when drying R-32 compared to drying R-22 or R-502 and a reduced level of chemical compatibility of the desiccant with the refrigerant. Some compressor manufacturers are seeking a water concentration as low as 10 mg/kg (ppm[wt]) in the circulating refrigerant of polyolester-lubricated refrigerating equipment using these HFC blends. This paper compares unmodified commercial type 3A molecular sieve desiccants with a recently developed, modified 3A molecular sieve that excludes R-32. The modified 3A has better chemical compatibility with R-32 and high water capacity in liquid R-407C and R-410A. The drying rates of the two desiccants in R-407C and R-410A are similar. Data and test methods are reported on refrigerant adsorption, water capacity, drying rate, and chemical compatibility.

• OSTI ID: 653210
• Report Number(s): CONF-980123--
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
COMPATIBILITY
DESICCANTS
LUBRICANTS
MATERIAL SUBSTITUTION
MOLECULAR SIEVES
REFRIGERANTS
REFRIGERATING MACHINERY
SORPTIVE PROPERTIES