Effect of input gas SO3 concentration on output acid temperature

6 Effect of Input Gas SO3 Concentration on Output Acid Temperature 

Of course, output acid temperature will increase if mass% H2SO4 in output acid is allowed to increase with increasing volume% SO3 in H2SO4 making tower input gas. Fig. 24.4. This is the case when input acid flowrate and mass% H2SO4 are kept constant while volume% SO3 in input gas increases. This is usual industrial practice. 

5 mass% H2SO4.1.5 mass% H2O input acid 99.0 mass% H2SO4.1.0 mass% H2O output acid 350 K input acid and output gas 480 K input gas 

The above discussion indicates that acid is heated by Reaction (1.2) as it cycles through the H2SO4 making tower. It is evident from this that the recycling acid must be cooled to prevent the system from overheating. 

This is done by passing the acid through water cooled  

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