Method And Apparatus For Abating Fugitive Emissions From A Volatile Liquid Storage Tank

Abstract

A fugitive emissions abatement system for use a storage tank 4 with a floating roof assembly 10 comprises a roof structure 12, a first peripheral seal 70 slidably engaging an interior surface 4A of the tank 4 to form an annular gas chamber 60 intermediate the first peripheral seal 70 and the liquid level 50 within the tank 4, and an aperture 78 in the first peripheral seal 70 coupled to the first end 82 of a fluid conduit 80. The second end 81 of the fluid conduit 80 may be coupled to the inlet of a gas mover 88 so that operation of the gas mover 88 draws gas from the annular gas chamber 60 through the fluid conduit 80 so that it can be delivered to a processing apparatus that may include, but is not limited to, a compressor, a vessel, a heat exchanger and / or an incinerator.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention is directed to an apparatus and a method to abate fugitive emissions from a volatile liquid storage tank. The present invention is directed to an improved floating roof assembly to abate fugitive emissions from a volatile liquid storage tank.[0003]2. Description of the Related Art[0004]Storage tanks are used to store volatile liquids including oil and other liquid hydrocarbons, produced brines, organic and non-organic chemicals, solvents, etc. Storage tanks may also be used to store sewage and other mixtures related to public utilities. In some storage tanks, the roof is not fixed, but instead it is adapted to be buoyantly supported by the liquid stored in the tank, and to rise and fall with the level of the liquid stored it the tank. The floating roof assembly may be buoyantly supportable within the interior of a liquids storage tank. For example, the floating roof assembly may be adapted with iso...

AI Technical Summary

Benefits of technology

"The present invention provides a method and apparatus for abating fugitive emissions from a volatile liquid storage tank. Specifically, the invention provides a floating roof assembly with an annular gas chamber and fluid conduits for capturing and processing fugitive emissions. The captured emissions can then be directed to a processing apparatus for further treatment. The invention can effectively reduce emissions from a floating roof assembly and provide a safer workplace."

Problems solved by technology

A conventional floating roof assembly may comprise one or more peripheral seals to obstruct evaporating gasses from escaping the tank and entering the atmosphere, but it is difficult to seal a conventional floating roof assembly against the interior of a tank that may exceed, for example, 100 meters in diameter.

The large size of the tank and the movable floating roof assembly makes machining close tolerances prohibitively expensive, and factors such as ambient wind direction and speed, ambient and stored liquid temperature, and uneven solar heating make conventional seals unusable on large floating roof-equipped tanks.

These peripheral seals generally slow and reduce, rather than substantially prevent, fugitive gas emissions.

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