The devices, systems, and methods described herein relate generally to melting of solids. More particularly, the devices, systems, and methods described herein relate to melting of solids that sublimate at ambient pressures.
Cryogenic solids of various varieties have phase diagrams that do not permit transitions between solid and liquid phases at ambient or near-ambient pressures. Handling these materials as solids is a challenge, as they require the solids handling be done under high pressure conditions, which is logistically difficult and costly. Devices, systems, and methods capable of handling cryogenic materials with minimal solids handling would be beneficial.
Devices, systems, and methods for melting solids are disclosed. A vessel includes a solids inlet, a plunger, one or more fluid jets, and a fluid outlet. Solids are passed through the solids inlet into the vessel. The plunger is positioned adjacent to the solids inlet to provide a variable gap between the plunger and the solids inlet. The variable gap provides a restriction producing a back pressure at the solids inlet. Hot fluid is injected into the vessel by fluid jets. The one or more fluid jets enter the vessel and end adjacent to the variable gap.
The solids inlet may direct the solids into the variable gap. The one or more fluid jets may direct the hot fluid into the variable gap. The hot fluid may melt at least a portion of the solids. At least a portion of the solids may be the same compound as the hot fluid.
The solids may include water, hydrocarbons, ammonia, solid acid gases, or a combination thereof. The solid acid gases may include solid forms of carbon dioxide, nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, or a combination thereof.
The hot fluid may include water, hydrocarbons, liquid ammonia, liquid acid gases, cryogenic liquids, or a combination thereof. The liquid acid gases may include liquid forms of carbon dioxide, nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, or a combination thereof.
The solids inlet may be fed by a screw press. The solids inlet may be fed by a pump.
The one or more fluid jets may be made of stainless steel, carbon steel, brass, ceramics, plastics, polymers, or a combination thereof.
The one or more fluid jets may pass through the plunger. The plunger may include a heating element. The plunger may be moved by a piston.
In order that the advantages of the described devices, systems, and methods will be readily understood, a more particular description of the described devices, systems, and methods 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 described devices, systems, and methods and are not therefore to be considered limiting of its scope, the devices, systems, and methods 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 described devices, systems, and methods, 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 described devices, systems, and methods, as represented in the Figures, is not intended to limit the scope of the described devices, systems, and methods, as claimed, but is merely representative of certain examples of presently contemplated embodiments in accordance with the described devices, systems, and methods.
Many cryogenic solids act in ways seemingly contradictory to what we expect from solids. Normally, solids melt into a liquid, which then vaporizes into a gas. Many cryogenic liquids, such as carbon dioxide and other acid gases, have phase diagrams that, at ambient pressures, will sublimate from solid directly to gas. In materials handling, liquids are simple to transport when compared to both solids and gases. Gases require large equipment to transport similar masses in comparison to liquid. Solids have to be moved by conveyance devices that are, with only a few exceptions, open to ambient pressures. The devices, systems, and methods disclosed herein overcome these challenges by avoiding the issue entirely. Cryogenic solids, or any solids that can be melted, are passed into a vessel through a restricted inlet. The restriction, a plunger, provides a back pressure on the solids both to produce a steady flow rate of solids entering the vessel, but also because the back pressure keeps the solids in the solid phase in the inlet. Losing pressure may produce gases, which can be dangerous. A hot liquid is added via fluid jets adjacent to the variable gap through which the solids pass. This not only melts the solids, producing a warm liquid, but the jets prevent chunks of solids from making an irregular sealing surface between the plunger and the solids inlet. This would result in channeling, allowing hot liquid backflow into the solids inlet. The jets also make the gap turbulent, making heat transfer more efficient. The outlet of the vessel can also be restricted, maintaining the vessel at the appropriate pressure for the liquid produced.
Referring now to the Figures,
A slurry 150 enters screw press 104 through slurry inlet 118. In this example, the slurry 150 consists of a liquid, such as isopentane, and a solid, such as solid carbon dioxide. The slurry 150 is conveyed through the screw press 104 by screw 122, driven by rotor 124. The slurry 150 is pushed through the outlet 130 and through the gap inlet 132. The restriction of gap inlet 132 by plunger 106 causes a back pressure that has several benefits. The back-pressure drives the isopentane out of the slurry and through filter 138. The liquid collects in the fluids outlet plenum 134 and leaves as a substantially pure isopentane stream 154. Some portion of the isopentane and the solid carbon dioxide may leave in the gas phase through gas outlet 116 as gas stream 152. The restriction meters the solid carbon dioxide through gap inlet 132 at a controlled rate. The slurry 150 has substantially all the liquid driven from it, resulting in a stream of substantially pure solid carbon dioxide passing through gap inlet 132. This stream is met by a hot liquid stream 160 that is jetted into the space adjacent to gap inlet 132. In this example, the hot liquid stream 160 is a liquid carbon dioxide stream. A sufficient amount of the hot liquid stream 160 is provided through fluid jets 108 to melt the solids, resulting in a warm liquid stream 156 that passes out of fluid outlet 114. The jetting also causes turbulent flow, making more efficient melting, and breaks up any chunks of solids as they pass through gap inlet 132, making the solids seal the gap inlet 132 against hot liquid channeling.
Referring now to
Referring now to
Solids 350 are passed into vessel 302 through solids inlet 304. In some embodiments, these are provided by a solids pump (not shown). Solids 350 passes through the inlet gap 332, providing a back pressure as well as metering the solids into the vessel 302. Hot fluid 360 is injected into the vessel through fluid jets 308. Hot fluid 360 melts solids 350 and the resulting warm fluid 356 passes out of fluid outlet 314.
Referring to
Referring to
In some embodiments, the solids may include ice, hydrocarbons, ammonia, solid acid gases, or a combination thereof. Solid acid gases include solid forms of carbon dioxide, nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, or a combination thereof.
In some embodiments, the warm fluid may include water, hydrocarbons, liquid ammonia, liquid acid gases, cryogenic liquids, or a combination thereof. Liquid acid gases include liquid forms of carbon dioxide, nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, or a combination thereof.
In some embodiments, the one or more fluid jets may be made of stainless steel, carbon steel, brass, ceramics, plastics, polymers, or a combination thereof. In some embodiments, the one or more fluid jets may move towards and away from the adjacent variable gap, varying a distance between the one or more fluid jets and the variable gap. This provides finer control of the melting process, allowing for more or less melting as the process requires. In conjunction with moving the plunger closer and further from the solids inlet, the composition and pressure can be maintained and varied as desired.
This invention was made with government support under DE-FE0028697 awarded by the Department of Energy. The government has certain rights in the invention.