Solvent vessels must be purged before maintenance personnelenter in order to ensure that: (1) sufficient oxygen is availablefor breathing; (2) vapor concentrations are below the flash point;(3) vapor concentrations are below the Occupational Safetey andHealth Administration (OSHA) limits if breathing apparatus is notto be used. Assuming that a 8 m^3 fixed-roof solvent tank has justbeen drained of all liquid and that the vapor phase is initiallysaturated at 22 degrees celsius, estimate the length of purgenecessary with 2 m^3/min of gas at 0.1 MPa and 22 degrees celsiusto reach the OSHA 8-hr exposure limit.
(a) Choloroform 50 ppm
