DUST CONTROL IN GRAIN ELEVATORS 
33 
and this dust-laden air escapes through the vent to the outside of 
the building. Ventilators 01 this type are especially well adapted 
to closed bins, garners, hoppers, and inclosed equipment; they are 
sometimes used also at the head of elevator legs or the ends of con- 
veyor belts, where the air currents following the belts create a slight 
pressure which is relieved through the vent. 
Fig. 25.— Revolving ventilator 
FLOOR VENTILATORS 
Floor ventilators are installed only 
in galleries or passageways where the 
wind has a chance to blow in several 
directions beneath the floor. Install- 
ing a grating and arranging wind-deflec- 
tor plates beneath the opening afford 
a large amount of ventilation when the 
wind is deflected up through the floor 
opening. An ordinary ventilator is in- 
stalled in the roof of the gallery or 
passageway directly above the floor 
grating. 
INTERSTICE BIN VENTILATION OP BASEMENT 
In a modern large elevator, one of 
the most difficult places to ventilate is 
the basement of the storage section, 
especially if it adjoins the workhouse. 
When the storage section is large, 
ventilation from the sides is not effec- 
tive throughout the basement. Two 
modern elevators use an interstice bin as an airshaft to ventilate the 
center of the basement, the walls of the bin being extended through 
the elevator roof and covered with a cone-shaped roof. 
In one elevator, three open interstice bins, evenly distributed 
through the center of the storage section, ventilate the interior of 
the storage basement. No fans are 
used to promote the flow of air up 
through the shafts. The natural 
draft is considered sufficient. 
MECHANICAL VENTILATION 
DISC VENTILATING FANS 
Disc fans are well adapted for the 
ventilation of the basement and 
other sections of the elevator where 
natural ventilation methods can 
not be used. An air inlet or open 
areaway to the exterior is provided 
at a point where the air traveling 
from the opening to the fan passes 
through the dustiest section of the 
house. As large quantities of air 
must be handled, the larger the fan 
fig. 26— Bin vent the better. 
