Document B8nENpr9vMjmV6gp7Y8Dr4ZDJ

Heating Ventilating Air Conditioning Guide 1938 violent air motion will sustain them in air long enough for them to be breathed. This means that, in hygenic problems, the engineer is con cerned mostly with suspensions of particles comparable to the common Fig. 1. Sizes and Characteristics of' Air-Borne Solids bacteria in size. A notable exception to this size limitation is the common hay-fever producing pollen such as that from rag-weed. Pollen grains may be anything from fragments 15 microns in diameter to whole pollens 25 microns or more in size. Since the lower limit of visability to the 80 Chapter 4. Air Pollution Table 1 Approximate Limits' of Inflammability of Single Gases and Vapors 1A in Air at Ordinary Temperatures and Pressures1 Gas ob Vapoe dweh Loot in Pee Cent Higher Limit Volume in Peb Cent Hydrogen.................................... Ammonia..... --.............:............. Hydrogen sulphide.................... Carbon disulphide.................... Carbon monoxide...................... Methane............... -.......;.........--' Methane (turbulent mixture).. Ethane...-.-................................ Propane.--................................... Butane.--.......... ................. -..... Pentane.-........... -..............--...... Ethylene....... .............................. Acetylene.................... -.............. Acetylene (turbulent mixture) Benzene--................................... Toluene-............. -...................... Cyclohexane............................... Methyl cyclohexane.................. Methyl alcohol........................... Ethyl alcohol.............................. Ethyl ether.................................. Benzine.... ..........-...................... Gasoline.---- ..... ---- --------........ Water gas.................................... Ethylene oxide-......................... Acetaldehyde....... ...................... Furfural (125 C)._............ :........ Acetone........ .............................. Acetone (turbulent mixture)__ Methyl ethyl ketone........... :..... Methyl formate_____!.......--...... Ethyl formate............................. Methyl acetate..............'. ..... Ethyl acetate.......................:...... Propyl acetate............................ Butyl acetate (30 C)._.............. Ethyl nitrite......... .................. .... Methyl chloride-....................... Methyl bromide.--................. Ethyl chloride............................. Ethyl bromide..--!--....... ............ Ethylene dichloride.-...... .......... Dichlorethylene....................... ... Vinyl chloride............................ Pyridine (70 C).......................... Natural gas______:..................... Illuminating gas......................... Blast-furnace gas._..................... 4.1 16.0 4.3 1.0 12.5 5.3 5.0 3.2 2.4 1.9 1.45 3.0 3.0 2.3 1.4 1.4 1.3 1.2 7.0 4.0 1.7 1.1 1.4 6 to 9 .3.0 4.0 2.0 3.0 2.5 2.0 6.0 3.5 4.1. 2.5. 2.0 1.7 3.0 8.0 13.5 4.0 ' 7.0 6.0 10.0 4.0 1.8 4.8 5.3 35.0 74.0 27.0 46.0 50.0 74.0 14.0 15.0 12.5 9.5 8.5 7.5 29.0 7.0 7.0 _8_._3- , 19.0 26.0 6:0 55 to 70 80.0 57.0 11.0 12.0 20.0 16.5 14.0 11.5 v ........ ... 19.0 14.5 - 15.0 11.0 16.0 13.0 22.0 12.5 13.5 31.0 74.0 . ^Limits of Inflammability of Gases and -Vapors. by H. F. Coward-and G. W. Jones, (U. S. Burrau of Mtncs, Bulletin No. 279, 1931). 81 y