Method and apparatus for mixing fluids

Abstract

A method for entraining and mixing gas with liquids within a conduit or drop structure, comprising the channeling of one or more liquid flows into spiral flows of predetermined radius (radii), reducing the predetermined radius (radii) to increase the centrifugal forces acting upon the spiral flow(s) as the spiral flow(s) enter the conduit, and allowing gas access to the conduit to mix with and entrain within the spiral flow within the conduit or drop structure. The method can facilitate the mixing of gas with one or more fluid flows and / or reduce the release of gas emissions from the fluid(s) into the surrounding environment.

Description

[0001]This application claims the benefit ofis a continuation-in-part <?insert-end id="INS-S-00001" ?>of U.S. patent application Ser. No. 09 / 561,999 filed May 1, 2000, now U.S. Pat. No. 6,419,843 <?insert-start id="INS-S-00002" date="20080701" ?>B2 <?insert-end id="INS-S-00002" ?>which claimed the benefit of provisional patent application No. 60 / 135,476 filed May 24, 1999.FIELD OF USE[0002]The invention relates generally to applications whereby it is desirous to introduce or reintroduce gas with liquid flowing through pipes, and / or mix two fluids within a pipe. In particular, this method can be used, but is not so limited, to mix and entrain air and other odorous gas emissions into sewage to reduce odorous gas emissions and to reduce hydrogen sulfide corrosion and abrasive wear in waste water conveyance, collection and treatment systems.BACKGROUND OF THE INVENTION[0003]Throughout past decades, sewers have been utilized to efficiently transport waste water or sewag...

AI Technical Summary

Benefits of technology

[0009]It, therefore, is an object of this invention to provide a method for reducing gas emissions of a fluid through the entraining and mixing of gas with the liquid.

[0011]Another object of this invention is to provide a method for use in sewer drop structures that significantly reduces odorous gas emissions from the sewer.

[0012]A further object of the invention is to reduce hydrogen sulfide corrosion in waste water conveyance, collection and treatment systems.

[0013]A benefit of this invention is the improved way in which the method helps to protect conveyance or collection systems from abrasive wear.

[0014]Another benefit is the way the invention in particular improves the quality of wastewater by wastewater aeration.

[0016]The method creates an accelerated fluid flow sufficient to create substantial intimate contact with the vortex form and conduit wall throughout the fluid flow's descent in the maintenance hole. This intimate contact creates frictional forces that reduce the kinetic energy of the flow and inhibit turbulent flow. The reduction in turbulent flow in turn reduces the release of gases, including hydrogen sulfide. In addition, the spiral flow in the conduit creates an air core with reduced pressure in the center of the conduit, inhibiting the escape of any hydrogen sulfide gas into the environment and encouraging the reintroduction of any escaped gas back into the spiral flow and the energy dissipating pool.

Problems solved by technology

One problem that occurs during the transport of sewage is the release of sulfides from the sewage.

Unfortunately, in most practical applications, sewage contains a significant amount of potentially volatile dissolved molecular hydrogen sulfide gas.

Thus, while drop structures can reintroduce dissolved oxygen into the sewage flow, lowering the level of hydrogen sulfide gas, they can also cause the release of hydrogen sulfide gas.

The hydrogen sulfide emissions often cause corrosion with the drop structures and adjacent sewer lines, and cause odor problems even the most elegant, pristine neighborhoods.

Two problems remain to be solved when applying this known method of using a vortex form in a drop structure for sewage flows.

First, the upstream flow velocities within the influent line are usually not large enough to create a stable spiral flow on the vertical wall of a typical maintenance hole.

Thus, the flow, rather than continuing to spiral down the cylindrical wall of the maintenance hole, will generally revert to a turbulent descending flow similar to waterfall, losing the effective energy dissipation of the spiral flow and releasing significant amounts of hydrogen sulfide gas into the air.

Second, quite often the maintenance hole is used for additional lateral influent connections at elevations lower than the main influent pipe.

Consequently, the lateral influent connections disrupt the spiral flow and create a turbulent waterfall of sewage to the bottom of the maintenance hole, again releasing significant amounts of hydrogen sulfide gas into the air.

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