Flame

Flame is burning and incandescent vapors and gases. The brightness of a flame depends on the presence of solid incandescent particles or heavy vapors within it. In the absence of solid particles, a flame is transparent, pale, and produces little light (e.g., the flame of burning alcohol or sulfur). A pale flame can be made luminous by introducing fine particles of solid bodies into it. Certain volatile substances color the flame (e.g., potassium salts give a violet color, sodium a bright yellow, barium a green, and strontium a red). The structure of a gas flame: 1) the inner cone—there is no combustion, the temperature is low, and air content is 62%; 2) the middle cone is formed by burning illuminating gas mixed with air; 3) a luminous tip does not form if the air supply is abundant. In these main parts of the flame, Bunsen distinguishes 6 following places for chemical reactions: 1. The base of the flame (a'), the temperature here is low—a place for testing volatile substances regarding their ability to color the flame. 2. The place for melting (β)—the highest temperature, about 1,560°, for testing fusibility and volatility. 3. The lower oxidizing flame (γ)—a place for oxidizing oxides dissolved in beads. 4. The upper oxidizing flame (δ)—for oxidizing large samples of substances that do not require a high temperature for their oxidation. 5. The lower reducing flame (ε)—for reduction on charcoal and in beads. 6. The upper reducing flame—for the reduction of metals and obtaining their deposits. The influence of flame as a source of thermal and radiant energy on the living organism is significant. Under the conditions of various labor processes associated with flame, it is difficult to separate the temperature factor from the radiant energy factor—they combine in their effect on humans. The physiological effect of any flame (wood, coke, coal, iron) depends on the wavelength of the radiation. Long-wave infrared rays exert mainly a thermal effect, while short-wave ultraviolet rays exert a chemical effect and cause inflammatory phenomena of the skin—erythema (Leites). All occupational hazards of various hot workshops (glass production, metallurgical, etc.) are associated with the effect of infrared rays on the organism, with the exception of metal welding industries, where the effect of ultraviolet rays predominates. The intensity of the flame's effect on the organism increases with temperature. Thermal radiation causes the dilation of peripheral blood vessels, the result of which is a lowering of blood pressure and an increase in pulse rate. Professional cataracts in glassblowers are caused by the action of long-wave rays (Leites).