Sulfur burning atomizers

The number of moles of sulfur burned equals the number of moles of sulfur dioxide produced. The atomic weight of sulfur is 32 and molecular weight of sulfur dioxide is 64. Therefore ... 

Sulfur dioxide is manufactured mostly by combustion of sulfur or its iron sulfide mineral, pyrite, FeS2, in air. The flame temperatures for such combustion of sulfur in the air are usually in the range 1,200 to 1,600°C. Many types of sulfur burners are available and are used to produce sulfur dioxide. They include rotary-kiln, spray, spinning-cup and air-atomizing sulfur burners. Selection and design of burners depend on quality of sulfur to be burned, and rate and concentration of sulfur dioxide to be generated. Pyrites or other metal sulfides may be burned in air in fluid-bed roasters to form sulfur dioxide. 

Fig. 3.3. Burner end of sulfur burning furnace. Atomized molten sulfur droplets are injected into the furnace through steam-cooled lances. Dry combustion air is blown in through the circular openings behind. The sulfur is oxidized to S02 by Reactions (3.1) and (3.2). Atomization is done by spiral or right angle flow just inside the burner tip.

Sulfur burning furnaces are 2 cm thick cylindrical steel shells lined internally with 30 to 40 cm of insulating refractory, Fig. 3.3. Air and atomized molten sulfur enter at one end. Hot S02, 02, N2 gas departs the other into a boiler and steam superheater (Fig. 3.4). Some furnaces are provided with internal baffles. The baffles create a tortuous path for the sulfur and air, promoting complete sulfur combustion. Complete sulfur combustion is essential to prevent elemental sulfur condensation in downstream equipment. 

Total sulfur in air, most of which is sulfur dioxide, can be measured by burning the sample in a hydrogen-rich flame and measuring the blue chemiluminescent emission from sulfur atom combination to excited S2 (313). Concentrations of about 0.01 ppm can be detected. 

Spent Acid or Burning. Burners for spent acid or hydrogen sulfide are generally similar to those used for elemental sulfur. There are, however, a few critical differences. Special types of nozzles are required both for H2S, a gaseous fuel, and for the corrosive and viscous spent acids. In a few cases, spent acids maybe so viscous that only a spinning cup can satisfactorily atomize them. Because combustion of H2S is highly exothermic, carehil design is necessary to avoid excessive temperatures. 

CO oxidation catalysis is understood in depth because potential surface contaminants such as carbon or sulfur are burned off under reaction conditions and because the rate of CO oxidation is almost independent of pressure over a wide range. Thus ultrahigh vacuum surface science experiments could be done in conjunction with measurements of reaction kinetics (71). The results show that at very low surface coverages, both reactants are adsorbed randomly on the surface CO is adsorbed intact and O2 is dissociated and adsorbed atomically. When the coverage by CO is more than 1/3 of a monolayer, chemisorption of oxygen is blocked. When CO is adsorbed at somewhat less than a monolayer, oxygen is adsorbed, and the two are present in separate domains. The reaction that forms CO2 on the surface then takes place at the domain boundaries. 

A block diagram for tlie double-absorption sulfuric acid process is gi en in Fig. 8.6.1. Atomized molten sulfur is burned in a horizontal, brick-... 

When burning in the air. each atom of sulfur takes on two atoms of oxygen to make one molecule of sulfur dioxide gas (SO,). 

In some parts of the world, there is more acid in the rain than normal. This type of rain is called acid rain. Scientists believe that one cause of acid rain is sulfur dioxide. Sulfur dioxide is a type of air pollution produced by burning fuels that contain sulfur atoms. When... 

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