Liquid compost aerator and method of using same

Abstract

A compost aerator for aerating a compost/liquid mixture. The aerator has a aerator pump located downstream from a liquid inlet. The aerator pump has a plurality of impellers mounted on a rotor which spins within a circular channel though which the liquid flows. The liquid is propelled through the channel by the impellers and, as the area of the channel decreases downstream from the impellers caused by the increase in diameter of the rotor, the velocity of the liquid increases. Air enters the channel upstream from the impellers and is drawn with the liquid through the channel. The diameter of the rotor then decreases significantly thereby causing the area of the liquid carrying channel to increase suddenly downstream of the widest portion of the rotor. Turbulence occurs in this area and bubbles are formed which are released from the outlet of the compost aerator into the compost/liquid mixture to perform aeration for bacterial breakdown.

I claim:  
     
         1 . Air entrainment apparatus to entrain air in liquid comprising a liquid inlet for supplying liquid to a liquid conveying channel, an air inlet to allow the entry of air to said liquid conveying channel, said air being introduced into said liquid in said liquid conveying channel and a vortex generator downstream from said point of introduction of said air and said liquid to said liquid conveying channel, said vortex generator being operable to cause turbulence in said liquid conveying channel and to create bubbles in said liquid, said liquid forming an annular portion within said liquid conveying channel adjacent to said vortex generator.  
     
     
         2 . Air entrainment apparatus as in  claim 1  wherein said vortex generator includes a skirt, said skirt having an upstream diameter and a downstream diameter, said downstream diameter being wider than said upstream diameter.  
     
     
         3 . Air entrainment apparatus as in  claim 2  wherein said skirt has a skirt diameter at the most downstream position of said skirt, said skirt diameter being the widest portion of said skirt.  
     
     
         4 . Air entrainment apparatus as in  claim 3  wherein the area of said liquid carrying channel increases immediately downstream of said skirt diameter.  
     
     
         5 . Air entrainment apparatus as in  claim 4  and further comprising a rotor, said rotor including a plurality of liquid transporting impellers, said impellers being operable to move said liquid downstream in said liquid carrying channel.  
     
     
         6 . Air entrainment apparatus as in  claim 5  wherein said vortex generator rotates with said rotor.  
     
     
         7 . Air entrainment apparatus as in  claim 5  wherein said vortex generator is stationary.  
     
     
         8 . Air entrainment apparatus as in  claim 4  and further comprising a pump, said pump moving said liquid downstream in said liquid carrying channel.  
     
     
         9 . Air entrainment apparatus as in  claim 6  wherein said vortex generator is integral with said rotor.  
     
     
         10 . Method of creating turbulence in a liquid/air mixture for aerobic bacteria breakdown comprising the steps of conveying liquid through a liquid carrying channel, allowing air to enter said liquid in said liquid carrying channel from an air inlet, reducing the cross-sectional area of said liquid carrying channel by positioning a vortex generator having a skirt with a diameter increasing from an upstream to a downstream position and allowing said liquid carrying channel to increase in cross-sectional area immediately downstream of the widest diameter of said skirt of said vortex generator.  
     
     
         11 . Method as in  claim 10  wherein said liquid is conveyed through said liquid carrying channel by an impeller.  
     
     
         12 . Method as in  claim 10  wherein said liquid is conveyed through said liquid carrying channel by a pump.  
     
     
         13 . Method as in  claim 11  wherein said impeller is mounted on a rotor and said rotor is rotated with said impeller.  
     
     
         14 . Method as in  claim 13  and further comprising rotating said skirt with said rotor.  
     
     
         15 . Method as in  claim 13  and further comprising maintaining said skirt stationary during rotation of said rotor.