Blowers, sulfur burning

Fig. 25.11. Sankey energy flow diagram for a 1000ton/day sulfur-burning double absorption sulfuric acid plant (feed gas 10% S02). A Blower B Sulphur furnace C Waste heat boiler D Catalyst bed 1 E Steam superheater F Catalyst bed 2 G Boiler H Catalyst bed 3 J Intermediate heat exchangers K Intermediate absorber L Converter bed 4 M Economizer N Final absorber O Air dryer P Acid coolers. (Courtsey Lurgi GmbH, Frankfurt, Germany.)...

The dried air is blown into the sulfur burning furnace by the acid plant s main blower. 

The blower is a steam or electricity driven centrifugal blower (Jacoby, 2004). It blows air into the sulfur burning furnace - and the furnace s offgas through the remainder of the acid plant. 0.3 to 0.5 bar pressure is required. 

A 2000 tonnes of H2S04 per day sulfur burning acid plant typically requires a 4000 to 4500 kW main blower. 

In another plant design, the air blower is arranged downstream of the drying tower to recover the heat of compression as pre-heated air to the sulfur burning furnace. This, however, required a very efQcient acid mist danister in the DT to prevent corrosion of the blower internals. 

Air ducts are provided to convey air from the air blower to the drying tower inlet and then from the drying tower to exit to the sulfur burning furnace (which is also used to bum the sulfide ores). The air ducts also convey dry air for injecting into the SO2 conversion system—either in the gas ducts or through an air injection pipe installed inside the converter. 

Air for sulfur burning is filtered through fabric and dried. It is heated by the heat of compression in the main acid plant blower then blown into the sulfur burning furnace. It is blown in behind the sulfur spray to maximize droplet-air contact. 

Figure 6.1 Etehydration of sulfur combustion air in a sulfur burning acid plant. The dried air contains 0.05 g of H20(g) per Nm of gas. The main acid plant blower is usually situated just before the sulfiir burning furnace.

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