Ventilating Enclosing Hood for Head Pulley of Conveyor Belt 
Image of belt conveying head pulley diagram
Text Version
Ventilating Enclosing Hood for Head Pulley of Conveyor Belt

Totally enclosed conveyor with settling box, internal skirt board, troughing belt, return belt scraper or brush, scraper conveyor and cleanout and inspection doors. Leakage factor depends on type of construction.

Design Criteria:
Q = 250 cfm/ft2 of open area
Duct velocity = 4,200 - 4,500 fpm
he = 0.4 VPd

From American Conference of Governmental Industrial Hygienists (ACGIH®), Figure VS-50-21, Industrial Ventilation : A Manual of Recommended Practice, 23rd Edition. Copyright 1998. Reprinted with permission.