Glovebox Ventilation

DOE-STD-1066-99

15.5.5 A means should be provided to safely perform required inspection, testing and

maintenance on the fire detection system installed in the glovebox.

15.5.6 Detection systems should sound local alarms and transmit remote alarms to a

continuously attended location to initiate emergency action.

15.6 Glovebox Ventilation

The criteria of this section are for gloveboxes and glovebox exhaust connections. For criteria

for filter plenums and ventilation systems beyond the gloveboxes, refer to Section 14 of this

standard.

15.6.1 Ventilation Design to Include Fire Protection Factors

15.6.1.1 Glovebox ventilation requirements should be based, in part, on the results

of the hazards analysis. Glovebox ventilation systems should be protected

against the effects of fire.

15.6.1.2 Where feasible, glovebox ventilation should incorporate a downdraft design

(that is, the ventilation inlet opening should be near the top of the box and

the exhaust opening should be near the bottom of the box). Studies have

shown that downdraft construction is best from a fire protection viewpoint,

and it should be used unless operational features dictate otherwise.

15.6.2 Exhaust Filters and Screens

Glovebox primary exhaust openings should be provided with prefilters and fire

screens to reduce vapor mist and fire propagation. The fire screens should be

stainless steel screens (8 -16 mesh) or a perforated stainless steel plate using the

same mesh opening sizes. The screens should be installed at the primary exhaust

openings.

15.6.3 Flow Rate Considerations

15.6.3.1 Glovebox ventilation flow rates in gloveboxes having an air atmosphere and

in which flammable liquids or gases are used should be sufficient to prevent

the atmosphere from reaching 25 percent of the lower flammable limit of the

material in use. Maintaining oxygen concentrations at or below 25 percent

of the lower flammability limit provides a safety factor against equipment

malfunctions, accidental leaks, etc., which could lead to increases in the

glovebox oxygen concentration.

15.6.3.2 Where hot plates or other heat sources are used in the glovebox, flow rates

higher than that stipulated above may be required in order to prevent

unacceptable overheating of the glovebox enclosure. Temperature

increases which do not exceed 15 degrees above ambient room

temperatures are, generally, acceptable.