National Technical Reports Library

The National Technical Information Service acquires, indexes, abstracts, and archives the largest collection of U.S. government-sponsored technical reports in existence. The NTRL offers online, free and open access to these authenticated government technical reports. Technical reports and documents in its repository may be available online for free either from the issuing federal agency, the U.S. Government Publishing Office’s Federal Digital System website, or through search engines.

Details

Effect of Duct Fire on the Ventilation Air Velocity.

PB289800

Publication Date	1978
Personal Author	Hwang, C. C.; Chaiken, R. F.
Page Count	24
Abstract	In this Bureau of Mines report, a previously developed theory of reverse stratified flow in ventilated duct fires is applied to mine-related ventilation systems that use an exhaust fan to supply the forced airflows. The coupling between a fire and the ventilation airflow in a single-entry duct is analyzed to relate the air velocity in the absence of a fire to air velocity during a fire. By combining the derived coupling equations with the results of the previously developed theory of reverse stratified flow, it is possible to calculate critical flow velocities required to prevent reverse stratified flow in the event of a duct fire. The sample calculations shown agree with the few experimental results available from small-scale tunnel fires.
Keywords	Underground mining Ventilation Ducts Mine fires Air flow Mine ventilation Air circulation Airspeed Critical flow
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries
Corporate Authors	Bureau of Mines, Pittsburgh, PA. Pittsburgh Mining and Safety Research Center.
Document Type	Technical Report
Title Note	Rept. of investigations.
NTIS Issue Number	197908

Effect of Duct Fire on the Ventilation Air Velocity.

Effect of Duct Fire on the Ventilation Air Velocity.
PB289800

Publication Date	1978
Personal Author	Hwang, C. C.; Chaiken, R. F.
Page Count	24
Abstract	In this Bureau of Mines report, a previously developed theory of reverse stratified flow in ventilated duct fires is applied to mine-related ventilation systems that use an exhaust fan to supply the forced airflows. The coupling between a fire and the ventilation airflow in a single-entry duct is analyzed to relate the air velocity in the absence of a fire to air velocity during a fire. By combining the derived coupling equations with the results of the previously developed theory of reverse stratified flow, it is possible to calculate critical flow velocities required to prevent reverse stratified flow in the event of a duct fire. The sample calculations shown agree with the few experimental results available from small-scale tunnel fires.
Keywords	Underground mining Ventilation Ducts Mine fires Air flow Mine ventilation Air circulation Airspeed Critical flow
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries
Corporate Authors	Bureau of Mines, Pittsburgh, PA. Pittsburgh Mining and Safety Research Center.
Document Type	Technical Report
Title Note	Rept. of investigations.
NTIS Issue Number	197908