Cartridge service life is not appreciably affected at relative humidities below 50%. However, performance is severely compromised when the humidity exceeds 65%. Experimental values are compared from those calculated from the adsorption isotherm, Mecklenburg and modified Wheeler equations. Calculations indicate that temperature does not play a significant role in service life predictions.

The theory of solvent vapor adsorption of activated carbon is reviewed. Calculated and experimental cartridge service life values are compared using various breathing rates, relative humidities, concentrations and solvent vapors. Cartridge service life (the 10% breakthrough time) can be estimated from the emperical expression: t 10% = 2.4 X 10(6) WC (A + BT)/C 2/3 MQ Carbon weight (wc), relative solvent volatility (a, b and t) concentration (C), molecular weight (M) and breathing rate (Q) all play a vital role in cartridge performance predictions.

No abstract

No abstract

The service life of organic vapor cartridges was determined for ten vapors at concentrations between 50 and 3000 ppm. The breakthrough time (tb) conformed to the empirical expression tb = aCf, where C is the concentration in ppm and a and be are constants. The average value for b at 10% breakthrough was -0.67 +/- 0.17. The service life is inversely proportional to flow rate for acetone and benzene.