Record Display for the EPA National Library Catalog

RECORD NUMBER: 25 OF 59

OLS Field Name OLS Field Data
Main Title EPA fabric filtration studies /
Author Donovan, R. P. ; Donovan, Robert P. ; Daniel, Bobby E. ; Turner., James H.
Other Authors
Author Title of a Work
Daniel, B. E.
Turner, J. H.
CORP Author Industrial Environmental Research Lab., Research Triangle Park, N.C.
Publisher Environmental Protection Agency, Office of Research and Development, Industrial Environmental Research Laboratory ; for sale by the National Technical Information Service,
Year Published 1977
Report Number EPA 600-7-77-095a
Stock Number PB-271 966
OCLC Number 318374698
Additional Subjects Air pollution control equipment ; Air filters ; Aging tests(Materials) ; Woven fabrics ; Performance evaluation ; Efficiency ; Polyester resins ; Dust filters ; Particle size distribution ; Fabric filters ; Baghouses
Internet Access
Description Access URL
http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=9100R8BY.PDF
Holdings
Library Call Number Additional Info Location Last
Modified
Checkout
Status
NTIS  PB-271 966 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 06/23/1988
Collation v. : ill. ; 28 cm.
Abstract
The report gives results of a study to determine the effects of aging on filter bags made of woven polyester. Fabric filter life can be divided into three periods: break-in, steady-state, and wear-out. During the break-in, both bag collection efficiency and the pressure drop across the bag increase. In the steady-state, performance parameters remain relatively constant until the fabric begins to fail catastrophically (bag efficiency and pressure drop both decrease), signalling the onset of the wear-out. The transition between the break-in and the steady-state can be interpreted in terms of dust buildup in or on the fabric, ending in a steady-state in which the dust arriving during a complete filtration cycle equals that leaving during the same period. Dust permanently added to the fabric filter during the break-in is at 'bulk' sites--sites which are not emptied during the shake-cleaning step of the cycle. Dust can be emitted or lost from these sites, however, as is evident from baghouse operation with clean air only and from performance measurements made after washing the fabric filter with soap and water. The report presents evidence that supports a further subdivision of the dust trapped at bulk sites into: that which is loosely bound and which affects bag pressure drop primarily; and that which is more tightly held and which influences bag collection efficiency primarily.
Notes
Prepared under program element no. EHE624. Issued Aug. 1977. Bibliography: p. 36-37. Microform.
Contents Notes
4. Bag aging effects. Fabric filter life can be divided into three periods; (1) break-in; 2) steady-state; and 3) wear-out. During the break-in period, bag collection efficiency increases, but pressure drop across the bag also increases. In the steady-state period, performance parameters remain relatively constant until the fabric begins to fail catastrophically (bag efficiency and pressure drop both decrease), signaling the onset of the wear-out period. The transition between the break-in and steady-state periods can be interpreted in terms of dust buildup in or on the fabric, ending in a steady state in which the dust arriving during a complete filtration cycle equals that leaving during the same period. Dust permanently added to the fabric filter during the break-in period is located at "bulk" sites--sites which are not emptied during the shake-cleaning step of the cycle. Dust can be emitted or lost from these sites, however, as is evident from baghouse operation with clean air only and from performance measurements made after washing the fabric filter in soap and water. The evidence presented here supports a further subdivision of the dust trapped at bulk sites into: 1) that which is loosely bound and which affects bag pressure drop primarily; and 2) that which is more tightly held and influences bag collection efficiency primarily. This preliminary classification of dust trapped at bulk sites requires more study, being based at present on only one observation of the dramatic effect of hand-washing a dust-loaded bag in soap and water. Alternative hypotheses could be equally plausible. The total quantity of dust trapped at bulk sites varies with bag operating conditions. The dependence of bag life upon the quantity of trapped dust in the fabric is not known.