Roaster, overbed water

Roaster Overbed Water Heat Removal (Gas Purification) Equipment Requirements... 

To further increase the capacity of the roaster to obtain the rates required to produce 86,000 t/y of marketable metal, the addition of more overbed water and the installation of a fiflh serpentine cooling coil in the bed were considered. 

The first option was simple and easy to implement, but it would increase the cooling load on the gas purification section. The second option would produce more steam, but it could crowd the roaster bed and impose tighter time limits on future routine shutdowns because of the increase in the fixed rate of bed cooling. Calculations indicated that the steam produced in the first option would be sufficient to meet the demands of the leaching plant, and consequently, the use of additional overbed water was adopted as the preferred strategy. 

The recently replaced gas purification section was already operating outside its design parameters because of the extra heat load placed on the system as a result of increasing the overbed water usage in the roaster. The plate heat exchangers of the humidifying tower/wash... 

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