Relationship Between Physical Configuration of Hood and Velocity for Local Exhaust Systems

DOI Web Site Web Site PubMed 1 Citations Open Access
  • ISHIDAO Toru
    Department of Environmental Management, School of Health Sciences, University of Occupational and Environmental Health
  • ISHIMATSU Sumiyo
    Department of Environmental Management, School of Health Sciences, University of Occupational and Environmental Health
  • HORI Hajime
    Department of Environmental Management, School of Health Sciences, University of Occupational and Environmental Health

Bibliographic Information

Other Title
  • 局所排気装置における外付け式フードの形状と風速の関係
  • キョクショ ハイキ ソウチ ニ オケル ソトツキケ シキ フード ノ ケイジョウ ト フウソク ノ カンケイ

Search this article

Description

The hood performance of a local exhaust ventilation system is determined by the capture velocity and the air flow rate. The equation proposed by Dalla Valle has been widely used to speculate this relationship. However, Dalla Valle used different formulae for slot and plain opening (rectangular) hoods, and the calculated values near the boundary between the slot and plain opening by these formulae do not always match each other. In this study, we measured capture velocity of four hoods by changing the distance from the hood face for different aspect ratios. We also tried to develop an empirical formula to express a relationship that could be applied to both types of hoods. As a result, it was found that the relationship between air velocity in front of exterior hoods and air flow rate could be expressed as the sum of two exponential functions with distance. In addition, when the hood aspect ratio was less than 9 the values of the capture velocity calculated by the proposed equation were in good agreement with the experimental ones.

Journal

  • Journal of UOEH

    Journal of UOEH 33 (4), 331-336, 2011

    University of Occupational and Environmental Health, Japan

Citations (1)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top