Abstract: A dissolved gas flotation apparatus and process for removing oils and other contaminants from produced water generated in the production of crude petroleum and natural gas. The invention is particularly designed for offshore applications, where space is limited and natural gas is readily available. The invention includes a vessel for receiving and maintaining a liquid level therein and a circulating pump for introducing tiny flotation gas bubbles into the vessel. Natural gas is used as a blanket gas for the vessel and as a source of gas fed into the pump, wherein the gas is mixed with the pumped liquid. The liquid/gas mixture is transferred into the vessel, wherein the gas releases from the liquid, thereby forming tiny, finely dispersed gas bubbles.

Abstract: An apparatus and method for clarifying a contaminated fluid mixture containing contaminating fluid, principal liquid and solids. The apparatus comprises a vertically standing cylindrical vessel for separating the contaminants from the principal liquid; a preliminary separator for tangentially introducing the contaminated fluid into the vessel; sparging tubes to aerate the contaminated fluid mixture, thereby separating the contaminating fluid from the principal liquid and solids; and a reservoir for collecting the contaminating fluid. The reservoir and preliminary separator are located in the upper portion of the vessel. The sparging tubes are located in the lower portion of the vessel.

Abstract: An apparatus for clarifying a contaminated fluid mixture containing contaminating fluid, principal liquid and solids, comprising a vertically standing cylindrical vessel for separating the contaminants from the principal liquid; a preliminary separator for tangentially introducing the contaminated fluid into the vessel; sparging tubes to aerate the contaminated fluid mixture, thereby separating the contaminating fluid from the principal liquid and solids; and a reservoir for collecting the contaminating fluid. The reservoir and preliminary separator are located in the upper portion of the vessel. The sparging tubes are located in the lower portion of the vessel.

Abstract: The method of the present invention comprises introducing a contaminated fluid mixture containing solids, liquid and contaminating fluid into a preliminary separator to separate the contaminating fluid from the principal liquid and solids; tangentially introducing the contaminated fluid mixture into a vertical cylindrical vessel in a circular motion to further separate the contaminating fluid from the principal liquid and solids; introducing air into the contaminated fluid mixture to further separate the contaminating fluid from the liquid and solids; maintaining the circular flow of the contaminated fluid mixture within the vessel to separate the fluid into contaminating fluid, clean liquid and solid contaminants; collecting the contaminating fluid in a reservoir; removing the contaminating fluid from the reservoir; and, discharging the clean liquid from the vessel.