The devices, systems, and methods described herein relate generally to separation of solids and liquids. More particularly, the devices, systems, and methods described herein relate to separations utilizing a screw press.
Separations of solids and liquids is a challenge in nearly every industry. The challenge is greatly increased in cryogenic situations, where the solids involved are at extreme low temperatures and sublimate directly to gases at ambient pressures. Filter assemblies capable of handling these temperatures, maintaining higher pressure, and still effectively separating the solids and the liquids would be beneficial.
Devices, systems, and methods for concentrating a slurry are disclosed. A concentrator is utilized, including a cylindrical vessel containing a cylindrical filter and a screw. The cylindrical vessel includes a fluid inlet, a fluid outlet, and a product outlet. The cylindrical vessel has a first inner diameter and a longitudinal axis. The cylindrical filter consists of a flat coil compression spring. The flat coil compression spring has a geometric center located on the longitudinal axis. The flat coil compression spring has a second outer diameter and a second inner diameter. The second outer diameter is smaller than the first inner diameter such that a space between an outer side wall of the flat coil compression springand an inner wall of the cylindrical vessel forms a fluid plenum. The fluid outlet is adjacent to the fluid plenum. The screw passes through the cylindrical filter along the longitudinal axis. An outer edge of the screw has a first outer diameter. The first outer diameter is substantially the same as the second inner diameter such that the outer edge of the screw is adjacent to an inner side wall of the flat coil compression spring without contact.
A slurry may be passed through the fluid inlet of the cylindrical vessel. The slurry may include a solid and a liquid. The slurry may be conveyed by the screw along an interior of the cylindrical filter. Any two concentric coils of the flat coil compression spring may be spaced such that the solid is prevented from passing between the any two concentric coils of the flat coil compression spring. The slurry may be concentrated to produce a concentrated slurry by restricting the product outlet such that a back pressure is created in the cylindrical vessel. The back pressure causes a portion of the liquid to pass between the any two concentric coils of the flat coil compression spring into the fluid plenum and out the fluid outlet. The concentrated slurry may pass out the product outlet. The spacing of the any two concentric coils of the flat coil compression spring may be modified by compressing or decompressing the flat coil compression spring in place.
The liquid may include water, hydrocarbons, liquid ammonia, liquid carbon dioxide, cryogenic liquids, or a combination thereof. The hydrocarbons may include 1,1,3-trimethylcyclopentane, 1,4-pentadiene, 1,5-hexadiene, 1-butene, 1-methyl-1-ethylcyclopentane, 1-pentene, 2,3,3,3-tetrafluoropropene, 2,3-dimethyl-1-butene, 2-chloro-1,1,1,2-tetrafluoroethane, 2-methylpentane, 3-methyl-1,4-pentadiene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-methylpentane, 4-methyl-1-hexene, 4-methyl-1-pentene, 4-methylcyclopentene, 4-methyl-trans -2-pentene, bromochlorodifluoromethane, bromodifluoromethane, bromotrifluoroethylene, chlorotrifluoroethylene, cis 2-hexene, cis-1,3-pentadiene, cis-2-hexene, cis-2-pentene, dichlorodifluoromethane, difluoromethyl ether, trifluoromethyl ether, dimethyl ether, ethyl fluoride, ethyl mercaptan, hexafluoropropylene, isobutane, isobutene, isobutyl mercaptan, isopentane, isoprene, methyl isopropyl ether, methylcyclohexane, methylcyclopentane, methylcyclopropane, n,n-diethylmethylamine, octafluoropropane, pentafluoroethyl trifluorovinyl ether, propane, sec-butyl mercaptan, trans-2-pentene, trifluoromethyl trifluorovinyl ether, vinyl chloride, bromotrifluoromethane, chlorodifluoromethane, dimethyl silane, ketene, methyl silane, perchloryl fluoride, propylene, vinyl fluoride, or combinations thereof.
The solid may include carbon dioxide, nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, hydrogen cyanide, water, mercury, hydrocarbons, pharmaceuticals, soot, dust, minerals, microbes, precipitated salts, or a combination thereof.
The product outlet may be equipped with a plunger, the plunger restricting the product outlet. The plunger may have a heating element.
The back pressure may be created by a combination of a feed pressure of the slurry passing through the fluid inlet and a conveyance pressure on the slurry from the screw conveying the slurry through the product outlet.
The cylindrical vessel may have a gas outlet.
The flat coil compression spring may have a heating element.
The flat coil compression spring may have different thicknesses at the outer side wall and the inner side wall.
The flat coil compression spring may be made of stainless steel, carbon steel, brass, ceramics, plastics, polymers, or combinations thereof.
The any two concentric coils of the flat coil compression spring may be spaced between 0.001 and 3 mm apart.
The method may be implemented by a computer that controls one or more motors, pumps, valves, heaters, coolers, actuators, or combinations thereof.
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.
Separation of solids from liquids is a challenge, especially in cryogenic situations. Cryogenic separations are at extreme low temperatures, require stable above-ambient pressure, and should still effectively separate the liquids and solids. The devices, systems, and methods disclosed herein overcome these challenges. Further, the devices, systems, and methods disclosed herein are not limited to cryogenic situations. Rather, they can be used in general solid-liquid separations. Throughout this disclosure, the term “concentration” is used interchangeably with the terms “separation” and “thickening.” The devices, systems, and methods disclosed separate solids and liquids. In some instances, this is a substantially complete separation, resulting in a liquid-free or substantially liquid-free solid. In other instances, the separation involves a removal of only a portion of the liquids, commonly referred to as concentrating or thickening of the slurry. The term slurry includes any pastes or other solid-liquid mixtures.
Concentration herein involves the utilization of cross-flow filtration of a slurry conveyed by a screw. The cross-flow filter consists of the flat coil compression spring and compressing or decompressing the flat coil compression spring in place results in a variable gap between concentric coils. This gap is chosen to prevent solids from passing through the gap, but allowing the liquids to pass through the gap. By providing a back pressure by restriction of the outlet at the end of the screw, a portion of the liquid is forced through the gaps, resulting in a concentrated slurry.
The use of a flat coil compression spring rather than a typical porous filter plate has several immediately apparent benefits. The plates are much more easily constructed with tight specifications. Spacers can be used and their thicknesses varied to vary the gap widths with minimal costs. An overall larger surface area becomes available for liquid passage without losing solids through the gaps along with the liquid. Solid plates tolerate thermal cycling better than porous plates, especially when the plates are attached to other objects with different expansion and contraction coefficients. Other benefits will become apparent as the figures are detailed, below.
Referring now to the Figures,
Cylindrical vessel 108 includes a filtering section 110 and a melting section 112. The filtering section 110 includes a fluid inlet 126, a fluid outlet 130, a gas outlet 128, a screw 114, and a cylindrical filter 122. The screw 114 is rotated by a rotor 116. The cylindrical filter 122 is a flat coil compression spring held pressed together by end caps 118 and 120. Cylindrical filter 122 has an inner diameter 144 and an outer diameter 142, with an outer side wall 141 and an inner side wall 143. The outer diameter of the screw is substantially the same as the inner diameter 144 of the cylindrical filter 124 such that the outer edge of the screw is adjacent to the inner side wall 143 of the cylindrical filter 124 but does not contact the inner side wall 143. The melting section 112 acts as the product outlet for the filtering section 110. The melting section 112 includes a plunger (internal—not shown) controlled by a piston 136, as well as a gas outlet 132, a liquid outlet 134, and a heating element (not shown). The outer shell of the filter section 110 has an inner diameter greater than the outer diameter 142 of the cylindrical filter 124. The space between the outer side wall 141 of the cylindrical filter 124 and the inside of the outer shell of the filter section 110 is a fluid plenum 146. The fluid outlet 130 is adjacent to the fluid plenum 146.
A longitudinal axis 109 runs through the center of the rotor 116, and out through piston 136. The geometric center of the cylindrical filter 124 is along the longitudinal axis 109. The spaces between concentric coils of the cylindrical filter 124 in the cylindrical filter 122 are shown in
In this exemplary embodiment, the slurry 150 consists of a liquid, such as isopentane, and a solid, such as solid carbon dioxide. The slurry 150 passes through the fluid inlet 126 and is conveyed by the screw 114 through the cylindrical filter 122 to the melting section 112. The plunger is moved in or out by piston 136 to maintain a back pressure inside the cylindrical filter 122. The back pressure causes a portion of the isopentane to pass through the spaces between the concentric coils of cylindrical filter 124 and into the fluid plenum 146. The portion of the isopentane 152, now substantially free of solid carbon dioxide, passes out the fluid outlet 130. Removal of the isopentane from the slurry 150 produces a concentrated slurry of solid carbon dioxide, which passes into the melting section past the plunger. The concentrated slurry is melted in the melting section 112 and leaves through liquid outlet 134 as liquid carbon dioxide 158. Any carbon dioxide gas 154 evolved in the filtering section 110 exits gas outlet 128. Any carbon dioxide gas 156 evolved in the melting section 112 exits gas outlet 132.
In another embodiment, no melter is used as the slurry consists of a liquid, such as water, and a solid, such as ore. Different ores have wildly different particle sizes. The gap between plates could therefore range from 0.001 mm to as high as 3 mm.
Referring to
Referring to
In some embodiments, the cylindrical vessel includes a fluid inlet, a fluid outlet, a product outlet, a cylindrical filter, and a screw. The cylindrical vessel has a first inner diameter and a longitudinal axis. The cylindrical filter has a flat coil compression spring. The flat coil compression spring has a geometric center located on the longitudinal axis and the flat coil compression spring has a second outer diameter and a second inner diameter. The second outer diameter is smaller than the first inner diameter such that a space between an outer side wall of the flat coil compression springand an inner wall of the cylindrical vessel forms a fluid plenum. The fluid outlet is adjacent to the fluid plenum. The screw passes through the cylindrical filter along the longitudinal axis. An outer edge of the screw has a first outer diameter. The first outer diameter is substantially the same as the second inner diameter such that the outer edge of the screw is adjacent to an inner side wall of the flat coil compression springwithout contact.
In some embodiments, the liquid includes water, hydrocarbons, liquid ammonia, liquid carbon dioxide, cryogenic liquids, or a combination thereof. In some embodiments, the -methyl-1-ethylcyclopentane, 1-pentene, 2,3,3,3-tetrafluoropropene, 2,3-dimethyl-1-butene, 2-chloro-1,1,1,2-tetrafluoroethane, 2-methylpentane, 3-methyl-1,4-pentadiene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-methylpentane, 4-methyl-1-hexene, 4-methyl-1-pentene, 4-methylcyclopentene, 4-methyl-trans-2-pentene, bromochlorodifluoromethane, bromodifluoromethane, bromotrifluoroethylene, chlorotrifluoroethylene, cis 2-hexene, cis-1,3-pentadiene, cis-2-hexene, cis-2-pentene, dichlorodifluoromethane, difluoromethyl ether, trifluoromethyl ether, dimethyl ether, ethyl fluoride, ethyl mercaptan, hexafluoropropylene, isobutane, isobutene, isobutyl mercaptan, isopentane, isoprene, methyl isopropyl ether, methylcyclohexane, methylcyclopentane, methylcyclopropane, n,n-diethylmethylamine, octafluoropropane, pentafluoroethyl trifluorovinyl ether, propane, sec-butyl mercaptan, trans-2-pentene, trifluoromethyl trifluorovinyl ether, vinyl chloride, bromotrifluoromethane, chlorodifluoromethane, dimethyl silane, ketene, methyl silane, perchloryl fluoride, propylene, vinyl fluoride, or combinations thereof.
In some embodiments, the solid includes carbon dioxide, nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, hydrogen cyanide, water, mercury, hydrocarbons, pharmaceuticals, soot, dust, minerals, microbes, precipitated salts, or a combination thereof.
In some embodiments, the product outlet includes a plunger, the plunger restricting the product outlet. In some embodiments, the plunger further comprises a heating element.
In some embodiments, the back pressure is created by a combination of a feed pressure of the slurry passing through the fluid inlet and a conveyance pressure on the slurry from the screw conveying the slurry through the product outlet.
In some embodiments, the cylindrical vessel has a gas outlet. In some embodiments, the slurry has entrained gases that separate from the slurry, pass between the concentric coils of the spring, and pass out the gas outlet.
In some embodiments, the flat coil compression spring has a heating element.
In some embodiments, the flat coil compression spring has different thicknesses at the outer side wall and the inner side wall. For example, the inner side wall may be machined to have raised edges that effectively reduce the gap available to liquid to pass between concentric coils of the spring. However, behind this raised edge, the coils are smooth and a larger space is presented, allowing the passage of liquid to be unimpeded.
In some embodiments, the flat coil compression spring is made of stainless steel, carbon steel, brass, ceramics, plastics, polymers, or combinations thereof.
In some embodiments, the any two concentric coils of the flat coil compression spring are spaced between 0.001 and 3 mm apart.
In some embodiments, the cylindrical vessel is oriented horizontally. In other embodiments, the cylindrical vessel is oriented vertically, either facing up or down. In other embodiments, the cylindrical vessel is oriented at an angle between fully horizontal and fully vertical.
This application is a continuation-in-part of U.S. patent application Ser. No. 15/385,056, filed Dec. 20, 2016, which is hereby incorporated by reference herein in its entirety.
This invention was made with government support under DE-FE0028697 awarded by the Department of Energy. The government has certain rights in the invention.
Number | Date | Country | |
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Parent | 15385056 | Dec 2016 | US |
Child | 15810935 | US |