Patent Application
20180283809
This invention relates generally to the field of direct-contact heat exchange. More particularly, we discuss the process of direct contact heat exchange between fouling or corrosive liquids and cooling fluids.
The art of direct-contact heat exchange has been a part of the human experience since the discovery of cooking. More recently, direct-contact heat exchange is used in industry for warming and cooling gases, liquids, and solids. Direct-contact heat exchange is designed to maximize the contact surface area between the media exchanging heat. In general, this goal is accomplished by maximizing the amount of solid surface area of the exchanger. However, when the heat exchange process produces solids that can foul the flow paths of the exchanger, or reactive intermediates that can corrode or otherwise react with the surface of the exchanger, maximization of exchanger surface area is counter-productive. No effective system or method for conducting heat exchange of these fouling and reactive liquids is available.
U.S. Pat. No. 3,496,996 to Osdor teaches an apparatus for providing large surface area direct contact between a liquid and another fluid. The surface area of the exchanger is maximized to provide the most surface exchange between a liquid and a fluid. The present disclosure differs from this disclosure in that the amount of contact with the exchanger itself is maximized, rather than minimized. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
U.S. Pat. No. 3,988,895 to Sheinbaum teaches power generation from hot brines. A multi-tray exchanger is utilized that maximizes heat exchange with the brine. The present disclosure differs from this disclosure in that the amount of contact with the exchanger itself is maximized, rather than minimized, in spite of the brine solution in use. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
A device and a method for conducting a heat exchange process is disclosed. A direct-contact heat exchanger is provided comprising a process inlet, a coolant inlet, and an interior surface. A process stream is provided to the process inlet to be cooled in the heat exchange process by direct contact with a coolant stream that is provided to the coolant inlet. The coolant stream comprises a liquid or a gas. The heat exchange process comprises a phase change from liquid to gas, a sensible heat transfer, or a combination thereof. The cooling process leads to chemical reactions, solids formation in the bulk phase, or a combination thereof. The use of the direct-contact heat exchanger minimizes such reactions on the interior surface. In this manner, the heat exchange process is conducted.
The cooling stream may comprise a liquid refrigerant that vaporizes by contact with the feed liquid, a gas refrigerant, or a combination thereof. The coolant inlet may comprise a pressure-drop device and the cooling stream, comprising a liquid refrigerant, is vaporized by passing through the pressure drop device into the direct-contact heat exchanger. The pressure-drop device may comprise a valve, turbine, nozzle, orifice, or combinations thereof.
Solids formation in the bulk phase may produce solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, or combinations thereof.
The process stream may comprise soot, dust, minerals, microbes, wastewater, acids, bases, immiscible liquids, paper pulp, metal hydrides, solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, other sulfides, other sulfates, chlorides, or combinations thereof.
The direct-contact heat exchanger may comprise a spray tower, bubble contactor, mechanically agitated tower, or combinations thereof.
The coolant inlet may comprise a gas distributor, bubble plate, sparger, nozzle, or combinations thereof.
The coolant stream may be soluble in the process stream, with the process stream pre-cooled to produce a pre-chilled process stream, and the coolant stream thus less soluble in the pre-chilled process stream. A temperature of the pre-chilled process stream may be near a freezing point of the pre-chilled process stream. A portion of the coolant stream may be dissolved into the product stream and the process stream further cooled to near a freezing point of the process stream, causing the coolant stream to become insoluble in the process stream, whereby the process stream is removed.
In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through use of the accompanying drawings, in which:
It will be readily understood that the components of the present invention, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the invention, as represented in the Figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of certain examples of presently contemplated embodiments in accordance with the invention.
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In some embodiments, the cooling stream comprises a liquid refrigerant that vaporizes by contact with the feed liquid, a gas refrigerant, or a combination thereof.
In some embodiments, the coolant inlet comprises a pressure-drop device and the cooling stream, comprising a liquid refrigerant, is vaporized by passing through the pressure drop device into the direct-contact heat exchanger, and wherein the pressure-drop device comprises a valve, turbine, nozzle, orifice, or combinations thereof.
In some embodiments, solids formation in the bulk phase produces solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, or combinations thereof.
In some embodiments, the process stream comprises soot, dust, minerals, microbes, wastewater, acids, bases, immiscible liquids, paper pulp, metal hydrides, solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, other sulfides, other sulfates, chlorides, or combinations thereof.
In some embodiments, the direct-contact heat exchanger comprises a spray tower, bubble contactor, mechanically agitated tower, or combinations thereof.
In some embodiments, the coolant inlet comprises a gas distributor, bubble plate, sparger, nozzle, or combinations thereof.
In some embodiments, the coolant stream is soluble in the process stream, the process stream is pre-cooled to produce a pre-chilled process stream, and the coolant stream is less soluble in the pre-chilled process stream. In some embodiments, a temperature of the pre-chilled process stream is near a freezing point of the pre-chilled process stream. In some embodiments, a portion of the coolant stream is dissolved into the product stream and the process stream is further cooled to near a freezing point of the process stream, causing the coolant stream to become insoluble in the process stream, whereby the process stream is removed.
In some embodiments, the coolant inlet comprises a material that inhibits adsorption of gases, prevents deposition of solids, or a combination thereof. In some embodiments, this material comprises ceramics, polytetrafluoroethylene, polychlorotrifluoroethylene, natural diamond, man-made diamond, chemical-vapor deposition diamond, polycrystalline diamond, or combinations thereof.
In some embodiments, the liquid refrigerant comprises ethane, methane, propane, R14, nitrogen, oxygen, argon, helium, xenon, other light gases, aliphatic hydrocarbons, aromatic hydrocarbons, other refrigerants, or combinations thereof. In some embodiments, the gas refrigerant comprises ethane, methane, propane, R14, nitrogen, oxygen, argon, helium, xenon, other light gases, aliphatic hydrocarbons, aromatic hydrocarbons, other refrigerants, or combinations thereof.
This invention was made with government support under DE-FE0028697 awarded by The Department of Energy. The government has certain rights in the invention.
