Abstract: Concentrated alcohol and distillery slop are produced from fermented beer with a reduced amount of energy by use of a multiple effect distillery slop evaporator in which evaporator vapors from one or more effects are used to strip alcohol from the fermented liquor before they are returned as heat source for the next succeeding effect, and by using vents from the partial condensation of these vapors in an evaporator effect as the principal heat and alcohol source for the rectification system. Condensed vapors from the vented evaporators and the bottom stream from the rectifier are stripped of their remaining alcohol content in a condensate stripper. The overhead stream from the condensate stripper can also be used as a heat source for an evaporator effect before being fed to the rectification system as a source of heat and alcohol.

Abstract: Distillation apparatus is disclosed which operates according to the so-called thermocompressor principle and comprises a housing in which a boiling chamber is situated to accommodate the liquid to be distilled, a heating device for heating the liquid to be distilled in the boiling chamber, a feed line for conducting the liquid to be distilled into the boiling chamber, an output line for removing the distillate from the distillation apparatus, and apparatus for imparting additional energy to the vapor that is produced from the liquid to be distilled in the boiling chamber such that the temperature of the vapor on the output side of the energy imparting apparatus is increased. According to the invention, at least one heat exchange tube is provided within the distillation apparatus through which a mixture composed of the liquid to be distilled and of the vapor produced therefrom is adapted to flow.

Abstract: A mechanical energy conversion method and system for the restoration of dissipated heat energy, contained in natural or artificial water bodies at or near ambient temperatures, to industrial process heat, mainly in the form of steam up to 200.degree.-400.degree. C. The sensible heat contained in a water body is concentrated as latent heat in low pressure water vapor which is thermo-compressed by steam ejection to an intermediate pressure level, wherefrom mechanical compression takes over, generating highly superheated output steam. The ejecting steam is not generated in a boiler, but is continuously regenerated by the compressor and routed back for repeated ejection. The compressor is driven by a heat engine whose reject heat is collected and upgraded as well. The output of heat energy is essentially equal to the sun of the heating value of the fuel consumed and the intake of latent heat and amounts thus to substantially more than the heating value of the fuel alone.

Abstract: A process for the rectification of binary liquid mixtures is disclosed wherein one component of the mixture is more volatile than the other component. A rectification column is employed having rectification, intermediate and depletion stages, with a working fluid comprised of the components to be separated being employed to furnish energy for the rectification process.

Abstract: A method for decreasing the external energy input to a fractionation system is disclosed. The method utilizes a compression zone communicating with either the overhead fraction or the bottoms fraction from a fractionation zone. The method is directed at regulating the rate of energy addition and/or removal to the fractionation zone by at least one of the fractions returned to the fractionation zone to maintain the separated fractions within the desired limits.

Abstract: Process and apparatus for extracting an organic liquid from an organic liquid solute/solvent mixture. The mixture is contacted with a fluid extractant which is at a temperature and pressure to render the extractant a solvent for the solute but not for the solvent. The resulting fluid extract of the solute is then depressurized to give a still feed which is distilled to form still overhead vapors and liquid still bottoms. The enthalpy required to effect this distillation is provided by compressing the still overhead vapors to heat them and indirectly to heat the still feed. The process is particularly suitable for separating mixtures which form azeotropes, e.g., oxygenated hydrocarbon/water mixtures. The energy required in this process is much less than that required to separate such mixtures by conventional distillation techniques.

Abstract: A new distillation equipment for alcohol which consists mainly of a brief concentrating column A, a concentrating column B, a compressor C to compress alcohol vapor generated in column B and water evaporator D heated by the compressed alcohol vapor is developed and this especially fits for a distillation source of a glue like solution obtained by alcohol fermentation because steam generated in the water evaporator D is directly blown into the solution in the concentrating column A.

Abstract: There is disclosed a process and apparatus for the fractionation of close boiling components of a multi-component system and comprised of at least two fractionation columns having a plurality of equilibrium stages wherein the vapor from a down-stream fractionation column is compressed and passed into a lower portion of a preceding fractionation column. In a particularly preferred embodiment, the compressed overhead vapor stream is passed in heat transfer relationship to a liquid stream withdrawn from the preceding fractionation column prior to introduction into the lower portion of such preceding fractionation column.

Abstract: A flow of fermenting liquor from a fermentor is separated into a yeast concentrate flow, which is recirculated to the fermentor, and a yeast-free flow which is separated in a simple evaporator unit into a first ethanol-enriched vapor flow and a first liquid bottom flow. The first vapor flow is treated to produce the desired ethanol while a major part of the first liquid bottom flow is recirculated to the fermentor. A minor, residual part of the latter flow is fed to a stripping unit where it is separated into a second ethanol-enriched vapor flow and a second liquid bottom flow exhausted of ethanol.

Abstract: This process provides an efficient means for distillative separation of a gas mixture at a temperature below ambient without requiring either a dual pressure or low pressure distillation column. The process comprises supplying the gas at an elevated pressure to a single pressure distillation column, work-expanding the column overhead gas to drive a heat pump compressor, compressing any of several gases in the heat pump compressor so as to effect phase change heat transfer between condensing column reflux and boiling column bottom product, and separately withdrawing the depressurized gaseous separation products.

Abstract: Process and apparatus for extracting an organic liquid from an organic liquid solute/solvent mixture. The mixture is contacted with a fluid extractant which is at a temperature and pressure to render the extractant a solvent for the solute but not for the solvent. The resulting fluid extract of the solute is then depressurized to give a still feed which is distilled to form still overhead vapors and liquid still bottoms. The enthalpy required to effect this distillation is provided by compressing the still overhead vapors to heat them and indirectly to heat the still feed. The process is particularly suitable for separating mixtures which form azeotropes, e.g., oxygenated hydrocarbon/water mixtures. The energy required in this process is much less than that required to separate such mixtures by conventional distillation techniques.

Abstract: An energy efficient distillation method is provided which is particularly adapted for use on a dairy farm, and which comprises a distilland evaporating receptacle, a distillate condensing receptacle, and a conduit interconnecting the evaporating receptacle and the condensing receptacle. A vacuum pump is provided for drawing a partial vacuum within the evaporating receptacle, and a vapor compression refrigeration system is provided which includes condenser coils disposed to heat and vaporize the distilland while it is within the evaporating receptacle, and evaporator coils for cooling and condensing the vaporized distilland in the condensing receptacle. A cooling distribution system is also provided whereby a variable portion of the cooling potential of the refrigeration system may be selectively directed to each of the condensing receptacle, a distillate receiver tank, or to a bulk milk container as utilized on a dairy farm or the like.

Abstract: A liquid containing a solvent to be evaporated is fed to a concentration chamber which is fluidly connected to an evaporation chamber maintained at a reduced pressure. A vapor compression means withdraws solvent vapor from the evaporation chamber, compresses the vapor and forces the compressed vapor to a liquification chamber. Regulator means responsive to the density of the liquid remaining within the concentration chamber will regulate the rate of solvent evaporation to provide a concentrate suitable for recycling.A method of operating the still of this invention utilizes the technique of increasing the compressor capacity until the compressor begins to surge and then reducing the capacity a fixed amount to provide the desired efficiency.

Abstract: An energy-efficient water evaporation process uses a falling film evaporator having a plurality of substantially vertical and equidistant heat exchange elements made of a synthetic polymeric material. Each evaporating surface is in contact with a liquid spreading means, and each heat exchange element is heated by steam having a condensation temperature slightly higher than the boiling point of the aqueous solution from which water is being evaporated. Steam formed by evaporation of water either is recompressed and reintroduced as heating steam in a single-stage process or is used as heating steam for another stage, operating at a lower temperature and pressure, in a multistage process. Heating steam condenses to fresh water, which is recovered. This process is operated at a low feed rate, preferably below 45 Kg of incoming aqueous solution per linear meter of horizontal width of each evaporating surface, and is capable of providing a 50% fresh water recovery per pass from sea water.

Abstract: A distillation process for recovering concentrated ethanol from an aqueous fermentate comprises fractionation of components of the aqueous fermentate under reduced pressure with vapor recompression and recovery of waste heat in a manner which obviates the need for substantial external sources of heat to operate the fractionation apparatus. The process includes a preliminary enrichment of the fermentate to separate volatile components, the enrichment also including recompression of a vapor phase and utilization of waste heat. The compression means used during enrichment and fractionation are run by engines which produce the recoverable waste heat. The utilization of vapor recompression and the use of waste heat to dry solid matter separated during the enrichment of the fermentate, for preheating the fermentate and for heating other process streams provides an energy efficient manner in which to recover ethanol from a fermentate.

Abstract: The distillation apparatus includes an upstanding closed boiler which receives a fluid mash, a mixture including alcohol and water, and has a plurality of heating means, including a pre-heat means, to boil the mash and produce a vapor at the top thereof; two heat exchangers are located at the bottom of the boiler; one is heated by fluid from a compressor and one is heated by exhaust gases from an internal combustion engine which drives the compressor. The fluid mash is removed from the boiler at a first point, passed through a solar panel and returned to the boiler at a higher level; the fluid mash is removed from the boiler at a second point, where new mash is added, and both used as the coolant for the engine; when the fluid has cooled the engine it is then passed over an enclosed coil which carries exhaust gases from the engine. It is then returned to the boiler at a higher level; exhaust gases from the engine are injected directly into the fluid mash adding heat thereto.

Abstract: Concentrated alcohol and distillery slop are produced from fermented beer with a reduced amount of energy by employing a vapor recompression distillery slop evaporator in which evaporator vapors are used to strip alcohol from the fermented liquor before they are returned as the heat source for evaporation. Vents in the evaporator permit passage of uncondensed vapors used to drive the evaporator to a rectifier, in which they constitute the principal heat and alcohol source. Condensed vapors from the evaporator and the bottom stream from the rectifier are stripped of their remaining alcohol content in a condensate stripper, which is also driven by the recompressed vapors from the evaporator. This prevents dilution of the slops and the additional energy cost that would be necessary if the water content of these streams had to be removed in the slop evaporator.

Abstract: Method and apparatus for purifying or reclaiming liquid desiccant comprising heating a water rich desiccant to form dilute desiccant vapor; partially condensing said vapor to produce a purified desiccant equal in strength to the feed stream, reintroducing a first stream of said vapor by sparging into the means of heating said desiccant and cooling a second stream of said vapor thereby refluxing condensible desiccant and venting non-condensible gases, and recovering condensed vapor for use elsewhere.

Abstract: A method and apparatus for high volume distillation of impure liquid comprises evaporating the impure liquid in an evaporator to form a vapor at a temperature above the freezing point and below the boiling point of said liquid at atmospheric pressure and at a pressure not exceeding a pressure corresponding to the evaporation temperature under saturated conditions; compressing the vapor; passing a portion of the compressed vapor through an expansion engine to do work upon and motivate the engine and to produce shaft energy, whereby the vapor expands and cools; bypassing the expansion engine with the remainder of the compressed vapor and admixing the remainder directly with the expanded vapor from the expansion engine in a mixing chamber; adding work to the expansion engine to supplement the work done by the vapor expanding therethrough to make up for work lost when the remainder of the compressed vapor bypassed the expansion engine and for other work lost; cooling the admixed vapor in heat transfer relation wi

Abstract: There is disclosed a process and apparatus for the fractionation of close boiling components of a multi-component system and comprised of at least two fractionation columns having a plurality of equilibrium stages wherein the vapor from a downstream fractionation column is compressed and passed into a lower portion of a preceding fractionation column. In a particularly preferred embodiment, the compressed overhead vapor stream is passed in heat transfer relationship to a liquid stream withdrawn from the preceding fractionation column prior to introduction into the lower portion of such preceding fractionation column.

Abstract: The method of recovering water by vaporizing aqueous solutions employs a heat pump circuit having a compressor, condensor, extention valve and evaporator for a heat transfer medium. The circulation channel for a gas stream which is capable of absorbing water vapor includes a gas washing station into which is sprayed the aqueous solution to be vaporized. The gas stream is guided past the condensor of the heat pump which acts as a heater and the heated gas is delivered into the gas washing station where is absorbs water. The water saturated gas stream is fed past the evaporator which acts as a refrigerating device and the water contents from the gas stream is condensed on the evaporator and returned into a galvanizing bath for example.

Abstract: In a new type of evaporator both a stream of cooling liquid and vapor are produced simultaneously. The cooling liquid is then used to compress and condense the vapor in an ejector-condenser. Heat of vaporization is recaptured in the ejector-condenser and recycled back to the evaporator, thus leading to high thermal efficiency.

Abstract: A process and still for removing substantially all water from an alcohol-containing solution. The solution is distilled in a rectification column under reduced pressure of about 40 mm Hg or less, and the distillate later collected and condensed having a water content of about 2% by volume or less. Heating for distilling the original solution and cooling for condensing the distilled alcohol vapors are supplied to the system by an external, closed-loop heat pump.

Abstract: A process and apparatus especially suited for distilling alcohol from aqueous fermentation liquors wherein liquid vapors from a body of a liquid mixture (4) which is to be distilled pass from a container (2) holding the liquid mixture to a vapor heating chamber (8) disposed above the container where the vapors are heated by solar radiation and/or heat exchange with a source of process heat. The vapors are then withdrawn from the vapor heating chamber, compressed, passed in heat exchange relation with the liquid mixture and introduced into a reflux column (15) disposed in the interior of the body of liquid to be distilled near the center of the container. An aqueous fraction (24) is collected from the bottom of the reflux column, and an alcohol vapor fraction is withdrawn from the top of the reflux column and further condensed in heat exchange contact with the liquid mixture to produce an alcohol fraction (32).

Abstract: The apparatus comprises a container closed to free communication with the atmosphere, and means for maintaining therein a body of crude volatile liquid at a predetermined surface level with an evacuated space thereabove containing a low pressure mixture of evaporated volatile liquid vapor and incondensible gas, an array of heat conducting tubes immersed in said body of crude liquid with their lower ends entering into a closed drum member, a fan blower arranged to maintain a pressure differential for heating said mixture by compression and friction and impelling it into the upper ends of the tubes, whereby through heat exchange the vapor is condensed to liquid and passes into the drum member together with incondensible gas.

Abstract: The present invention relates to a process for providing make-up heat in a mechanical vapour recompression evaporator (1, 8, 9).It includes using the evaporation vapour created in another evaporator (5) called make-up evaporator.The invention finds particular application in the dairy industry.

Abstract: Process for distillatively separating a liquid mixture containing at least two miscible volatile components having different boiling points using low-grade heat and, if necessary, low-grade cooling. Distillation is carried out at a pressure sufficiently low to cause the mixture at the bottom of the distillation column to boil below the temperature of the low-grade heat supplied and condensation of at least a portion of the vapor fraction is carried out at a pressure which permits using available cooling liquid. Condensed liquid is returned as reflux to the distillation column at a temperature and pressure essentially equal to the temperature and pressure prevailing near the top of the column. The progressive increase of vapor recompression in the system makes it possible to provide an increasing proportion of the energy to the system in the form of electrical energy, up to the total energy requirement.

Abstract: The latent heat of condensation released by condensing a process vapor is captured in a fluid contained in a latent heat recirculating system; the captured heat is returned by the fluid to the body of process liquid for continued vaporization.

Abstract: Disclosed is a method and apparatus for the concentration of a solution of a "dissolved" material in a "solvent" without the input of any outside heat and by the furnishing of only work, the latter having a value close to the theoretical work of unmixing.

Abstract: A method and closed system for high volume distillation of impure liquids comprises evaporating the impure liquid in an evaporator to form a vapor at a temperature above the freezing point and below the critical point, preferably the boiling point, of the liquid at ambient pressure and at a pressure not exceeding a pressure corresponding to the evaporation temperature under saturated conditions; compressing the vapor in compression means which preferably has a compression ratio variable in the range 1.

Abstract: A method of preparing an extract from hops comprises contacting the hops to be extracted with carbon dioxide in the liquid state to dissolve the matter to be extracted in the liquid carbon dioxide, heating the solution of extract to evaporate carbon dioxide from the solution of extract, compressing and condensing the evaporated carbon dioxide vapor to re-form liquid carbon dioxide, and re-cycling the liquid carbon dioxide to contact the material to be extracted. At least part of the heat evolved from the carbon dioxide vapor after its compression and during its change of state from vapor to liquid carbon dioxide is used to cause the change of state of the liquid carbon dioxide in the solution of the extract to evaporate the carbon dioxide from the solution of the extract.A plant for the preparation of an extract of hops by extraction with liquid carbon dioxide is also disclosed together with modifications of the plant to enhance the recovery of hop oils or to obtain a separate extraction of the hop oils.

Abstract: A mechanical energy conversion method and system for the restoration of dissipated heat energy, contained in natural or artificial water bodies at or near ambient temperatures, to industrial process heat, mainly in the form of steam up to 200.degree.-400.degree. C. The sensible heat contained in a water body is concentrated as latent heat in low pressure water vapor which is thermo-compressed by steam ejection to an intermediate pressure level, wherefrom mechanical compression takes over, generating highly superheated output steam. The ejecting steam is not generated in a boiler, but is continuously regenerated by the compressor and routed back for repeated ejection. The compressor is driven by a heat engine whose reject heat is collected and upgraded as well. The output of heat energy is essentially equal to the sum of the heating value of the fuel consumed and the intake of latent heat and amounts thus to substantially more than the heating value of the fuel alone.

Abstract: A process for fractionating two or more compounds in which the stripping section of the fractionator is maintained at a first pressure and the rectifying section of the fractionator is maintained at a higher pressure. Overhead vapors from the stripping section are compressed in a heat pump where the vapor temperature and pressure are raised, and the heated and compressed vapors are then fed to the bottom of the rectifying section. Overhead vapors from the rectifying section, at a higher temperature than the bottoms from the stripping section, are heat exchanged with stripping section bottoms to condense overhead vapors and to supply reboiling heat to the stripping section.

Abstract: A process is described for the removal of acid gases and ammonia from dilute aqueous solutions. This is achieved by two separate and successive distillations. In the first distillation, substantially all of the acid gases and free ammonia are removed. In the second distillation, substantially all of the fixed ammonia is removed. Exemplary aqueous solutions are waste waters from coke oven and coal conversion plants.

Abstract: A vapor compression distillation apparatus and method are provided wherein scaling tendencies are eliminated. The raw feedwater has acid added to it in an amount sufficient to convert the carbonates and/or bicarbonates therein to carbon dioxide. The heated acidified feedwater is then deaerated to remove the carbon dioxide and other non-condensible gases. The deaerated water flows to the evaporator through a line having a valve therein controlled by the liquid level in the deaerator to maintain such level constant even though the tube side of the evaporator is being operated at a pressure less than that of the deaerator. This permits the evaporation to take place under a partial vacuum and at a boiling temperature of less than 212.degree. F. even though the deaerator is operated at atmospheric pressure. Vent steam from the evaporator is added to the deaerator to further preheat the feedwater, and as a sparging or stripping agent to aid in the elimination of carbon dioxide and other non-condensible gases.

Abstract: A vapor compression distiller having a shell for enclosing a pair of heat exchange tube bundles each having one end connected to a steam chest and its other end connected to a condensate collecting chamber. A vapor compressor has its inlet connected to the shell and the outlet to one steam chest which is coupled to a second steam chest through a steam ejector for elevating the inlet pressure to the second heat exchange tube bundle. A half partition extends across the lower end of the vessel and between the wells to divide the lower portion of the vessel into two sections which are in communication across the upper end of the vessel. One well is connected to receive fresh feed liquid and the other includes a density sensor to discharge a portion of the concentrate to therein maintain a desired concentrate level and each well is connected to a spray nozzle manifold disposed in its respective shell section.

Abstract: Water containing dissolved compounds is preheated, and is then pressurized in stages of water pressure, while receiving a quantum of steam. Scale-forming compounds in the water are thermally precipitated, and clarified post-thermal water is formed. This is flash vaporized in stages corresponding to the stages of water pressure, and the flashed vapors are compressed to form each said quantum of steam. Alternately, the flashed vapors themselves comprise each said quantum of steam, by being induced into the water as it flows through an eductor means. Flash-cooled, post-thermal water, substantially devoid of scale-forming compounds, is employed as such, or more generally is evaporated to form fresh water and an end concentrate of dissolved compounds.

Abstract: A continuous distillation apparatus and method, the apparatus including separate stripping and rectifying sections in tandem, each of which are segregated into a plurality of vapor/liquid contact stages. The rectifying section is operated at a higher temperature than the stripping section by compressing vapor from the stripping section prior to introducing the vapor into the rectifying section. Thermal energy is conserved during the distillation process by transferring thermal energy from the rectifying section to the stripping section with a plurality of heat pipes.

Abstract: A process for separating two close-boiling chemical compounds by fractionation wherein a vapor stream removed from the overhead receiver is superheated by indirect heat exchange and is then further heated by compression. The thus-heated high pressure stream is cooled by heat exchange against the overhead vapor and split into at least two portions. One portion of the high pressure stream is passed through a reboiler at an intermediate point in a fractionation column. Preferably, both portions of the high pressure stream are subcooled and returned to the overhead receiver except for the overhead product drawn off.

Abstract: Distillation apparatus in which a group of heat-transfer tubes are each driven to wobble about a vertical axis which passes through a wobbling center. A stream of fluid is directed to flow down inside each tube. The fluid stream tends to cling to the inner surface of the tube away from the wobbling center while it revolves with respect to the tube in response to the wobbling motion. The revolving flow stream wipes the inside surface of the tube to form a thin film which offers low heat resistance to facilitate the evaporation, carries away the residue by its lateral motion and carries the reflux downward with little restriction.

Abstract: A vapor compression distiller has a vertically oriented cylindrical tank and a heat exchanger having a plurality of groups of heat exchange tubes disposed one above the other. Internal baffling channels vapor through the groups of heat exchange tubes in a serial relation commencing with the vertically lowest group. Feed liquid is distributed from the upper end of the vessel downwardly over the surfaces of the tubes. This causes the evaporation of a first portion of the feed liquid and a condensation of the vapor. The evaporated and unevaporated portions of the feed liquid pass downwardly past the heat exchange tubes with the unevaporated portion collecting in a liquor well at the lower end of the vessel and the vapor passes upwardly along the sides of the vessel heat exchanger and outwardly to a compressor, the outlet of which is connected to the vapor inlet of the system.

Abstract: Thin-layer evaporators are described in which evaporation cylinders and a cylindrical vapor-collection vessel of the same height are mounted to expand in parallel between horizontal base and top plates joined by a vertical jacket surrounding the cylinders and vessel and confining together with the plates a steam jacket. Rotors in the cylinders apply thin layers of the substance to be dried to the inner surfaces of the cylinders, from the tops of which vapors are discharged to the top of the vessel. A collecting conduit leads vapor from the bottom of the vessel to a compressor that delivers the compressed vapor to join a supply of super-heated steam passing into the steam jacket. Droplets separated in the vessel are discharged from the vessel through an outflow conduit. Solids and/or concentrates fall out of the evaporation cylinders into a clearing chamber from which they are evacuated into a trap by a rotary scoop.

Abstract: A method is disclosed for processing industrial waste waters and, in particular, blow down water from thermal electric plants. The water is processed to concentrate the salts contained therein and to obtain a concentrated brine which can then be passed to a thermal evaporator and/or solar evaporation ponds. The water is processed by the addition of magnesium hydroxide and carbon dioxide in amounts sufficient to precipitate the calcium as calcium carbonate, thereby obtaining a water reduced in calcium content and increased in magnesium content from the industrial waste water. The treated water is processed to recover a purified water from a brine, preferably by reverse osmosis. Calcium hydroxide is added to the brine generated by the reverse osmosis process in an amount sufficient to precipitate magnesium hydroxide therefrom which can be recycled to supply the magnesium hydroxide used in pre-treatment of the water prior to the reverse osmosis process.

Abstract: A method and apparatus for high volume distillation of impure liquid comprises evaporating the impure liquid in an evaporator to form a vapor at a temperature above the freezing point and below the boiling point of said liquid at atmospheric pressure and at a pressure not exceeding a pressure corresponding to the evaporation temperature under saturated conditions; compressing the vapor; passing a portion of the compressed vapor through an expansion engine to do work upon and motivate the engine and to produce shaft energy, whereby the vapor expands and cools; bypassing the expansion engine with the remainder of the compressed vapor and admixing the remainder directly with the expanded vapor from the expansion engine in a mixing chamber; adding work to the expansion engine to supplement the work done by the vapor expanding therethrough to make up for work lost when the remainder of the compressed vapor bypassed the expansion engine and for other work lost; cooling the admixed vapor in heat transfer relation wi

Abstract: A method and closed system for high volume distillation of impure liquids comprises evaporating the impure liquid in an evaporator to form a vapor at a temperature above the freezing point and below the critical point, preferably the boiling point, of the liquid at ambient pressure and at a pressure not exceeding a pressure corresponding to the evaporation temperature under saturated conditions; compressing the vapor in compression means which preferably has a compression ratio variable in the range 1.

Abstract: Substantial energy savings are realized in an aromatic extraction process wherein a vapor sidestream is removed from the solvent stripper, compressed and used to provide the heat necesary for distillation in the solvent stripper.

Abstract: The recovery of dimethylacylamides from solutions which are formed during the production of fibres is particularly economical if the solution is concentrated in a separating column to produce a sump product having a DMA content of 30 to 90% at pressures of more than 300 Torr, using the evaporation heat of the head product for heating the column, with the aid of a compressor and then separating the sump product which is concentrated in DMA by distillation.

Abstract: A vapor compression type distillation unit is provided for distilling brackish water or seawater wherein high heat transfer rates are achieved in a vertical shell and tube type vaporizer while avoiding carry-over normally resulting from excessive foaming and its entrainment of liquid droplets in the vapor. A pool of liquid is maintained at the lower end of the vaporizer to be fed into the tubes with the level of the liquid being relatively low so that most of the length of the tube is filled with a frothy mixture conducive to high heat transfer rates. The mixture of vapor and liquid discharged from the upper ends of the tubes is caused to flow laterally and then downwardly through a downtake passage communicating with the lower end of the vaporizer. A vapor outlet is provided intermediate the ends of the downtake passage in such a manner that the vapor must change its direction of flow, preferably substantially 180.degree.

Abstract: A unique combination of specially chosen entrainers, e.g., pentanes and cyclohexane, and high-pressure azeotropic distillation conditions, e.g., 100-200 psig., provides an economically efficient separation of a C.sub.2 -C.sub.5 alkyl alcohol, e.g., isopropanol, from its aqueous mixture; and also results in the production of a useable steam having a sufficient pressure, e.g., from 10 psig. to 30 psig. Preferably, said azeotropic distillation is conducted in the substantial absence of oxygen, e.g., less than 1 wppm.

Abstract: A double-effect evaporator comprises a first and a second effects and an external steam ejector, each of the effects having feed-liquid spray means, a bundle of heat-transfer tubes below the spray means and extending between headers, and a concentrated liquid collector. The first effect heat-transfer tubes extend perpendicularly to the second effect tubes. A suction port of the ejector opens into the second effect evaporation chamber. A diffuser of the ejector extends in parallel to the second effect heat-transfer tubes. A discharge port of the ejector opens into the inlet header of the first effect. The first effect evaporation chamber is connected with a duct straight to the inlet header of the second effect.