Apparatus for providing large amounts of gas to a fermentation broth

Abstract

A system for delivering air to an aqueous liquid for aerobic fermentation of the aqueous liquid includes a vessel having a length to diameter ratio of less than 2:1, an aeration system including at least one sparge tube having a pore size of less than 5 microns and a porosity of greater than 50 percent in fluid communication with an interior of the vessel, at least one blower configured to deliver air at a pressure of less than 15 psig to the at least one sparge tube, and a heat exchanger in fluid communication between the at least one blower and the at least one sparge tube that cools the air to below 100° F. (37.8° C.) prior to entering the at least one sparge tube.

1 . A system for delivering air to an aqueous liquid for aerobic fermentation of the aqueous liquid, comprising:
 a vessel having a length to diameter ratio of less than 2:1;   an aeration system including at least one sparge tube having a pore size of less than 5 microns and a porosity of greater than 50 percent in fluid communication with an interior of the vessel;   at least one blower configured to deliver air at a pressure of less than 15 psig to the at least one sparge tube; and   a heat exchanger in fluid communication between the at least one blower and the at least one sparge tube that cools the air to below 100° F. (37.8° C.) prior to entering the at least one sparge tube.   
     
     
         2 . The system of  claim 1 , wherein the at least one sparge tube is constructed from a sintered, porous metal. 
     
     
         3 . The system of  claim 1 , wherein the at least one sparge tube is positioned in a lower portion of the vessel. 
     
     
         4 . The system of  claim 3 , wherein the at least one sparge tube is mounted to a sidewall of the vessel. 
     
     
         5 . The system of  claim 1 , wherein the vessel has a volume of at least 10,000 gallons. 
     
     
         6 . The system of  claim 1 , further comprising at least one filter configured to filter air delivered from the at least one blower to the at least one sparge tube. 
     
     
         7 . The system of  claim 6 , wherein the system includes a plurality of sparge tubes and a plurality of filters positioned at equidistant positions around a perimeter of the vessel such that each sparge tube of the plurality of sparge tubes is paired with a filter of the plurality of filters. 
     
     
         8 . The system of  claim 7 , wherein the plurality of sparge tubes and the plurality of filters connect at a positions external to the vessel. 
     
     
         9 . The system of  claim 6 , wherein the heat exchanger has an inlet in fluid communication with an outlet of the blower and an outlet in fluid communication with the at least one filter. 
     
     
         10 . The system of  claim 9 , further comprising flexible conduit material coupled to the at least one filter and the heat exchanger. 
     
     
         11 . The system of  claim 1 , further comprising at least one condenser in communication with an interior of the vessel and configured to condense sparge bubbles. 
     
     
         12 . The system of  claim 11 , wherein the at least one condenser is positioned at a top of the vessel. 
     
     
         13 . The system of  claim 12 , further comprising an outlet filtration assembly in fluid communication with the at least one condenser. 
     
     
         14 . The system of  claim 1 , further comprising a mixing system positioned within the interior of the vessel. 
     
     
         15 . The system of  claim 14 , wherein the mixing system includes a top impeller configured to generate a lowering force and a bottom impeller configured to generate a lifting force within the aqueous liquid. 
     
     
         16 . The system of  claim 1 , wherein the aeration system is configured to maintain a dissolved oxygen concentration of at least 10% in the aqueous liquid. 
     
     
         17 . The system of  claim 1 , wherein a distance from the at least one sparge tube to a top surface of the aqueous liquid is not more than 40 feet. 
     
     
         18 . A system for providing air to a fermentation process, comprising:
 a fermentation broth disposed in a vessel having a length to diameter ratio of less than 2:1;   an aeration system that maintains a dissolved oxygen concentration of at least 10% in the fermentation broth, the aeration system including a sparge tube in fluid communication with the fermentation broth and having a pore size of less than 5 microns and a porosity of greater than 50 percent;   at least one blower in fluid communication with the fermentation broth, the at least one blower configured to deliver air at a pressure of less than 15 psig into the vessel through the sparge tube for aerobic fermentation of the fermentation broth; and   a heat exchanger in fluid communication between the at least one blower and the sparge tube that cools the air to below 100° F. (37.8° C.) prior to entering the sparge tube.   
     
     
         19 . The system of  claim 18 , wherein the at least one blower includes a driver motor equipped with a rotor. 
     
     
         20 . The system of  claim 18 , wherein the vessel has a volume of at least 10,000 gallons. 
     
     
         21 . The system of  claim 20 , wherein the at least one sparge tube includes pores having pore sizes of 1 micron or less.