Necessary fresh air ventilation flow generated in a hall

1. Entry Date

In a hall constantly emit Q = 13kg / h vapor molecular weight M = 100, with an allowable concentration Ca = 0.5g/m3 and simultaneously heat flow Q = 72100W.Temperature  inner hall to be maintained You will be = 26 ° C. To insert the explosive mixture dilution with clean outside air temperature te = 23 ° C and specific gravity Ϋ = 1.17kgf / m3.

2.Enter some output

Determining the flow of fresh air for general ventilation of the hall to meet hygiene and fire protection taking into account that the lower limit of explosive mixture of vapor and air is 1.2% in volume.

For dilute vapor

D = Q: As w / h: g / m 3 .= [m3 / h]

D = 13 x 103: 0.5 = 26 000 m3 / h

D = 26 000 m3 / h

To maintain the temperature of 26 º C

D = Q : [ ζ x Ϋ  ( ti – te )] ;  ζ = 0.24

D = 72100 : [ 0.24 x 1.17 ( 26 - 23 )]

D = 85.589 m³ /h

Q = 22.4 x ( G : M ) x ( 273 + t ) : 273    [  m³ /h ]

Q = 22.4 x ( 13 : 100 ) x ( 273 + 26 ) : 273   

Q = 22.4 x 0.13 x 1.095

Q = 3.19 m³ /h

Fresh air flow necessary to maintain concentration below the lower explosive mixture

D = Q : 1.2   x 100

D = 3.19 : 1.2 x  100

D = 285 m³ /h

Fresh air flow meets all the conditions imposed is 85,589 m3 / h.

Maximum concentration of vapor that can form in the hall is:

Cmax = 13 000: 85 589 = 0.152 g / m3

Value of 0.152 g / m3 is hygienically coverings for all dilution cases insufficient in some areas of the room