Flame Temperatures of Combustible Gas-Oxygen Mixtures 11. It. L t i i m
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G. W. SHERMAN, Engineering Experiment Station, P u r d u e Universit,y, LafuyelLe, Ind.
~lleasurentent of the maximum flame lentperalures oblairiable from mixtures oj 550, 800, and 1005 B. t. u. (198.7, 201.6, and 253.5 Cal.) city gases with oxygen show that they lie between 3410" K., the temperalure of llie oxy-acetylene flame, and 2933" K., the lernperatare of tlie oxy-hydrogen flame.
M
ATllE~1A'~ICALestimates oi flame tenqicraturcs are accurate to t.he same cxtent that the frmd:t-
mental bases and data upon which these estimates are made are accurate. Since tlier~nochemical and thermophysical data on gases at high teniperatures are not only incomplete but dilficult to obtain, the inathcmatical estimates of flame temperatures will always be a t variance wit,li measured values until such data have becn succesxfully gatliered. In a recent book hy Hchiile (16) the latest data on gaseous ciinibustion have hecn correlated. Goodenougli and Felbeck (7) liave also investigated theoretical temperatures thoroughly, hut their methods of calculation are somewha.t involved. By taking into account the heat dissipated in the dissociation of molecular hydrogen into the atomic iorm, of water vapor into hydrogen and oxygcn, and of carbon dioxide into carbon monoxide and oxygen, tho mathematieal approximations approach very neatly the ineasorcd values. Sample calculations based on t.he references cited d l be included for coinparison. This report, howcvcr, deals essentially with t.he measurement of nonluminous flame temperatures, and, while some error is no doubt present owing to calihratioii of the instruinents used, the error remains constant tlirougliout the work and so gires a relative measure among the various gases. In investigating tlie use of low calorific gases for welding purposes, a project carried out at Purdue University for the TJtilities Research Commission, Inc., the measurenmt of flame temperatures of these gases was iiicliided as a part
nf the research. The results gireii are tlie actual valuee detcrmined by tlie method of line rerersnl which will be deserihed in more detail in this article. Mamy data on flame teniperatures of air and oxygeneiiriclied air mixtures of oomrrion coinbustible gases have hcen gathered in recent years, particularly by the United States l ~ u r t ~ aofu Mines (0,I S ) . KO data, other than those published by Ileniiing a i d Tingwaldt (8) in 1928 on tlie oxy-acetylene flame, have been given on straight oxygencombustible gas flame temperatures. The values given by Potbmann (14)seem t o be erratic, and those of Joos (10) for oxy-acetylene are low, because of added water vapor.
HISTOR~CAL In 1902 I
