Example If we have an equilibrium concentration of 25 mgm3 a

Example: If we have an equilibrium concentration of 25 mg/m^3, an initial concentration of 300 mg/m^3, a dilution volume flow rate of 2,000CFM, and a time constant of 30 minutes, what will be the concentration after 90 minutes? 6. With an initial concentration of 25 ppm and an equilibrium concentration of 300 ppm, if the time constant for the room is 90 minutes, what will be the concentration after 30 minutes?

Solution

C (30) = Co * exp( -t/tau) + Ceq ( 1- exp( -t/tau))

putting all values,

C( 30) = 25 * exp( -30/90) + 300*(1- exp( -30/90))

solving it.

concentration after 30 min ,
C(30) = 102.95 ~ 103 ppm