Gas Removal by vacuum from aqueous flows with and without high solids concentrations

Gas Removal Tower This patented process and hardware (US Patent 6,218,174) replaces a forced air stripping tower with a closed system vacuum removal of dissolved gases, in turn replacing chemical addition requirements. In the installation shown, continuous removal of carbon dioxide and hydrogen sulfide (~200-300 mg/L as S) from an anaerobic mixed liquor (18-30,000 mg/L TSS) replaced a nominal 1/4 - 1/2 ton per day requirement for lime addition, eliminating both the initial chemical handling and the resulting sludge created by its addition.

Gas Removal Platform Vacuum System The hydrogen sulfide was converted to elemental sulfur and returned as inert material to the downstream treatmetn system and the carbon dioxide vented to atmosphere, stabilizing the system pH at nominally 7.25 SUS, up from 5.2 - 6.5 before installation.  The unit shown has the design capacity to remove 65-75 scfm of dissolved gases at 100-125 mbar from the recirculating flow of ~350 gpm while preventing air contact with the recirculating flow.  Power consumption of the system is ca. 6.5 kw continuously (1/2 each for vacuum and recirculation) with chemical consumption at 1 lb. of rebar scrap per month and 125-250 gallons per day of dilution/flushing water for the vacuum system to dispose of the elemental sulfur generated.