Oxy-acetylene

Ethyne is the starting point for the manufacture of a wide range of chemicals, amongst which the most important are acrylonitrile, vinyl chloride, vinyl acetate, ethanal, ethanoic acid, tri- and perchloro-ethylene, neoprene and polyvinyl alcohol. Processes such as vinylation, ethinylation, carbonylation, oligomerization and Reppe processes offer the possibility of producing various organic chemicals cheaply. Used in oxy-acetylene welding. 

Oxygen enrichment of steel blast furnaces accounts for the greatest use of the gas. Large quantities are also used in making synthesis gas for ammonia and methanol, ethylene oxide, and for oxy-acetylene welding. 

Hot RF and - DC plasma, are discharge, plasma jets Oxy-acetylene flames Low pressure microwave plasma, holt filament. Low pressure DC or RF glow discharge Thermal decomposition... 

Electric arc welding, flame-cutting using oxy-acetylene, propane or butane flames, or such flames burning in air. 

A high-pressure air compressor drew its air from an area where oxy-acetylene welding was taking place. Small amounts of copper acetylide formed on a bronze valve and exploded. 

One of the interesting properties of PBPCP [187] was its fast heat dissipation characteristics and so it was tested by the well-known oxy-acetylene panel test (ASTM 285-70) for ablative materials. Figure 13 shows the survival of a flower for 100 s. kept on the 6.35-mm asbestos fiber-reinforced hexamine-cured panel. The ablation rate value of this material was 3.2 x 10 in/s in comparison with 3.6 x 10 in/s for asbestos-phenolic. As the char content of PBPCP was only 27% compared with 60% for conventional phenolics, mechanisms involving transpiration processes rather than heat blocking by char formation might be playing a greater role in this case [188]. 

Figure 13 Oxy-acetylene panel test showing the survival of a flower kept on the asbestos-CNSL polymer composite of thickness 6.35 x 10 m.

More bearings are destroyed during their installation than fail in operation. Installation with a heavy hammer is the usual method in many plants. Heating the bearing with an oxy-acetylene burner is another classical method. However, the bearing does not stand a chance of reaching its... 

An alkyne is a hydrocarbon that contains a carbon-carbon triple bond. Acetylene.. H—C= C—H, the simplest alkyne, was once widely used in industry as the starting material for the preparation of acetaldehyde, acetic acid, vinyl chloride, and other high-volume chemicals, but more efficient routes to these substances using ethylene as starting material are now available. Acetylene is still used in the preparation of acrylic polymers but is probably best known as the gas burned in high-temperature oxy-acetylene welding torches. 

Acetylenes contain at least one triple bond. The triple bond is even more reactive than a double bond and, therefore, acetylene is used industrially to make other compounds used in rubber and plastics. Acetylene burns in oxygen to produce a very hot flame used for welding and metal cutting (oxy-acetylene torch). 

Harding HE, McLaughlin AIG, Doig AT Clinical, radiographic, and pathological studies of the lungs of electric arc and oxy-acetylene welders. Lancet 2 394—398, 1958... 

Oxygen also is a component of oxy-hydrogen flame and oxy-acetylene flame for welding and glass blowing. 

Dunkle notes (Ref 15) that one of the recent works described a deceleration of the detonation wave in oxy-acetylene mixtures by crossed electric and magnetic fields, which makes an interesting comparison with the acceleration of the shock wave in argon electrically as reported by R.M. Parrick ... 

Thus gas detonations initiate condensed explosives (if at all) by some direct heat transfer process. In oxy-acetylene detonations, the equilibrium temperature (CJ temp) is quite high 4500°K... 

The writer (unpublished results) was able to initiate Lead Azide pellets of ca 2.5 g/cc density with oxy-acetylene detonations. However ca 1.2 g/cc PETN pellet could not be initiated under these conditions. Gordeev et al [Nauchn-Tekhn Probl Goreniya Vzryva (1965) p 12 CA 64 1894 (1966)] succeeded in initiating liquid mixtures of tetranitromethane (TNM) and benzene with stoichiometric methane-oxygen detonations. For 1.5 vol parts of TNM 1 vol p of benz the initial pressure, P0, of the detonating gas mixture had to be greater than 2 atm to initiate the liquid. Initiation delays decreased as P0 increased delays were 350, 10 0 psec for P0 of 2, 12 24 atm. For 4 1 by vol TNM/benz initiation of the liquid was observed for Po>0.7 atm. At Po 0.7 atm the initiation delay for this liquid mixture was 70 jusec... 

Oxy-acetylene flame is a very useful tool in modem industry as it can cut through steel slabs and weld them together again. In the oxy-acetylene flame, oxygen and acetylene from separate cylinders are fed into a blow torch. The gases are mixed thoroughly and burnt at the tip of the blow torch. The products of this combustion are carbon dioxide, water vapour and heat. 

A combination of faulty equipment and careless working led to an extremely violent explosion during oxy-acetylene cutting work. The oxygen cylinder was nearly empty... 

The latter permits spectral scanning of the entire fluorescence spectrum using boxcar averaging. In Figure 15 is shown a comparison of the normal CH flame emission from an oxy-acetylene slot torch and the laser induced fluorescence spectrum. The CH was... 

Figure 15. Comparison of CH flame emission and laser-excited fluorescence spectrum in an oxy-acetylene slot torch...

Laser induced fluorescence is particularly well suited to combustion chemistry, as a sensitive "in-situ" probe for free radicals in flames or under more controlled conditions in laboratory flash photolysis, discharge flow tube, or shock tube experiments. Using laser-saturation fluorescence previous studies from this laboratory (J ) have shown that C2(a3n ) is present in high concentrations in the hot region of an oxy-acetylene flame. C2(a-,n and X1 ) reacts with 0 .(2,3 4) One of the products of this reaction (and/or the reaction of C2H+02) is CC0.(2) In the present study, we report C20()rn.-f, i 7 fluorescence excitation spectra, A"3 , lifetimes and quenching rate constants, and... 

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