Abstract: A process and a device for treating a liquid by separating out constituents contained in the liquid. Pollutants are removed or the liquid is sterilized by partial evaporization. The liquid is introduced into a vacuum tank in which a portion thereof is evaporated. The remaining liquid phase is discharged from the vacuum tank. The liquid in the vacuum tank flows under the effect of gravity on a fixed inclined or horizontal surface on which it forms a liquid film. The vapor phase emerges from the liquid film as a function of the vapor pressure defined relative to the prevailing temperature. The flow surface slopes downwardly away from the inflow of the liquid, it rises slightly or it extends horizontally.

Abstract: The invention relates to a process for evaporating a liquid containing vaporizable oxidation-sensitive compounds in an evaporator in which the liquid is brought into contact with a heated solid surface for evaporation, by a process in which direct contact between the resulting vapor phase and the heated solid surface is substantially avoided. It also directed to an evaporator composed of a heatable solid surface (16), an apparatus (2, 3) for heating the solid surface and an apparatus (10) for feeding a liquid containing vaporizable compounds to the heatable solid surface, wherein the apparatus for feeding the liquid is designed and arranged in the evaporator in such a way (12, 14, 18) that direct contact between a resulting vapor phase and the heatable solid surface is substantially avoided.

Abstract: The process for the final evaporation has at least two evaporation appliances. These appliances are coupled in series with respect to the black liquor and in parallel with the live steam (primary steam), which drives the evaporation, and with the secondary steam that is generated by the evaporation. The pressure of the primary steam that is supplied to the appliance(s) where the liquor concentration is at the highest concentration is greater than the pressure of the primary steam supplied to the other appliances where the liquor concentration is not so high.

Abstract: A is a process for removing water from an alkanesulfonic acid such as methanesulfonic acid or ethanesulfonic acid by mixing an azeotropic excess of a phenolic compound with water and the alkanesulfonic acid, then boiling off substantially all of the water, and leaving as a remnant substantially all the alkanesulfonic acid and some of the phenol. This process is particularly useful for recycling an alkanesulfonic acid for a reaction which requires the phenolic compound as one of the reagents. One such reaction is the alkanesulfonic acid catalyzed condensation reaction of a phenolic compound with an .alpha.haloketone to form a chlorinated intermediate of a dihydroxy-.alpha.-alkylstilbene such as 4,4'-dihydroxy-.alpha.-alkylstilbene (DHAMS).

Abstract: A process for separating inorganic salts from a solution of dimethyl sulfoxide, water and salts including feeding the solution plus a hydrocarbon based oil to a vacuum thin film evaporator. The DMSO and water are vaporized and condensed outside the evaporator for reuse or further purification. The salt and oil exit the evaporator as a liquid phase slurry. Water is added to the slurry to dissolve the salt and produce an aqueous phase and an oil phase which are separated. The oil phase is recycled to the thin film evaporator portion of the process.

Abstract: A large and economical type of multi-stack vertical tube evaporator (MS-VTE) having units of multiple stacks of vertical tube bundles or stages mounted in a single vessel, and having its liquid feed pumped to the uppermost VTE bundle stack or stage and having the feed then cascading downward through the lower bundle stacks in series flow, and wherein all the tube bundles are heated with the same waste steam of no or low $-value, e. g. with turbine reject steam in parallel flow under vacuum into the steam-sides of all tube bundles in the unit through a common steam conduit; and wherein the feed liquid is progressively evaporated from stage to stage or stack to stack and the vapors produced in the tubes of each bundle during the partial evaporation of the feed are separated between the stacks and condensed by parallel flow into one or more condensers.

Abstract: An evaporator system including a plurality of effects arranged in series for progressively concentrating a liquid, the effects each including: a header chamber for receiving liquid to be concentrated; a multiplicity of tubes adapted to provide evaporation of liquid from the inner surfaces of the tubes and a perforated distributor plate located in the header chamber to distribute liquid to the openings of the tubes; and wherein the evaporator system is provided with a branched wash liquid feed line for providing parallel feeding of wash liquid to the header chambers of the effects onto the distributor plates therein. Each distributor plate comprises an essentially planar plate member having a multiplicity of distributor holes therein for distributing liquid to be evaporated to the multiplicity of tubes therebelow and a series of overflow conduits for providing a flow of wash liquid through the plate to the tubes.

Abstract: A method and equipment for heat-of-vaporization transfer in a heat exchanger, using steam bubbles. To achieve higher transfers at slight overheating, and with a very simple design, steam bubbles are introduced into evaporation chambers formed between heat exchanger walls, said bubbles then being deformed by said walls and rising in-between them. As they rise, the steam bubbles form a thin liquid film between themselves and the heat exchanger walls, with constrained convection inside the film. As a result excellent local conditions for heat conduction are achieved. Moreover the liquid is well mixed and by evaporation into the bubble it is cooled as far as the immediate vicinity of the heat exchanger walls.

Abstract: Fractional-volatilization separation systems and methods are disclosed which enable a stable, continuous, non-bubbling liquid flow, essentially constant surface area/volume ratio, temperature controlled, fractional volatilization of volatile/semi-volatile components in a liquid analyte or component containing sample. The fractional volatilization separator system can be utilized in small scale analytical and large scale chemical purification, concentration and desalinization applications. Continuous rapid removal of residual liquid sample can provide concentrated non-volatile component/analyte solution, and allows quick and easy washout between sequential use with different liquid samples.

Abstract: Method for bringing a gas and a liquid into contact with one another, the liquid being passed in the form of a film over an evaporator surface (1) provided with small openings and the gas being fed through the openings in the evaporator surface, which gas mixes with the liquid on the surface and absorbs vapor from the liquid, a liquid subsequently being passed in the form of a film over a condenser surface (11) provided with small openings and the gas which has absorbed vapors from the liquid film on the evaporator surface being fed through the openings in the condenser surface, at least some of the absorbed vapor condensing and being carried along with the liquid film on the condenser surface and removed.

Abstract: A method and an apparatus are provided for controlling crystallization (and thus preventing harmful fouling of heat transfer surfaces) during the treatment of black liquor. The black liquor is concentrated to a high dry solids content (at least about 70%, e.g. about 75-90%) in a falling film crystallizing apparatus (e.g. falling film evaporator). A part of the liquor flowing from the heat transfer surfaces and collected in a retention vessel (e.g. an interior volume of the evaporator) is recirculated to the heat exchange surfaces and a part of the liquor is discharged for further treatment (e.g. combustion in a recovery boiler). A part of the black liquor in the recirculation system is returned directly to the retention vessel in order to facilitate mixing and thus to bring about, in the retention vessel, crystallization of inorganic salts of the black liquor that is as complete as possible.

Abstract: Aliphatic alcohols with up to 30 and especially with 6 to 18 carbon atoms are separated from a mixture of alkyl glycosides and alcohols which are unreacted during the production of these glycosides, by single or multi-stage distillation. The alcohols are distilled off by a drop film evaporator to impoverish the reaction mixture to residual alcohol contents of 5 wt % and under. The strip load of the drop film evaporator is set to at least 1.0 m.sup.3 /h m, especially at least 1.8 m.sup.3 /h m and preferably at least 3.0 m.sup.3 /h m. It is possible to reduce the alcohol content of the product to any value between 0.1 and 5 wt % at acceptable overall cost.

Abstract: Reaction mixtures obtained in addition reactions of OH-- or NH-- carrying compounds with acetylene or propyne in the presence of alkali metal alcoholates or alkali metal amides are worked up by distilling off the vaporizable components from the reaction mixture in a thin-film evaporator. Before removal of the vaporizable components from the reaction mixture, a particularly defined polyether is added thereto.

Abstract: A method for decontaminating a liquid of a contaminant having a vapor pressure which is higher than the vapor pressure of the liquid. A contaminated liquid is directed through an inclined conduit. A gas is directed into the inclined conduit, whereby the gas contacts the liquid and transports the contaminant, which has volatilized in the inclined conduit, out of the inclined conduit, thereby decontaminating the liquid. The liquid is discharged from the inclined conduit.

Abstract: An evaporator operating on falling film principle, has a shell (1) with a system (2) of evaporating tubes therein, whereby a liquid to be concentrated is fed on the outer surface of the evaporating tube system (2) and vapor is led to flow inside the tubes of the evaporating tube system (2). The evaporating tube system (2) is formed of evaporating elements, each evaporating element being formed of evaporating tubes (9) substantially on the same level. The upper ends of the tubes are connected to a common collecting chamber (8) and the lower end, respectively, to a common collecting chamber (10) in such a manner that there is a connection between both collecting chambers (8, 10) through each tube (9) between them, due to which the collecting chambers (8) of the upper end of the evaporating elements are interconnected through the upper connecting chamber (12), and respectively, the collecting chambers (10) of the lower end are interconnected through the connecting chamber (13) of the lower end.

Abstract: The use of falling-film evaporation and a concentration means such as centrifugal separation to dehydrate and concentrate a water-in-oil polymer emulsion or suspension is disclosed. In a preferred embodiment, a water-in-oil polymer composition containing less than about 25% active polymer solids is dehydrated in falling-film evaporator to produce an evaporator concentrate containing less than about 5.0% water. The evaporator concentrate then flows to a separation device such as a centrifuge, wherein oil is removed to produce a composition that is substantially a polymer and emulsifying surfactant-in-oil composition containing in excess of about 60 weight % polymer solids. The centrifuge raffinate may optionally be treated in a second separation means to capture additional polymer solids, with optional recycle of the oil-rich raffinate. The concentrated polymer composition is preferably stabilized with a steric stabilizer to produce a free flowing liquid product.

Abstract: A method for the separation and purification in a single pass of a heat or oxygen-sensitive liquid feed, such as a plant derived liquid feed mixture of fatty acids, tocopherol compounds and sterols, into a low boiling point purified fraction of Vitamin E tocopherol compounds and a high boiling point concentrate fraction of triglycerides, which method can be maintained in the presence of an inert gas to provide reduced degradation and increased purity of the Vitamin E fraction.

Abstract: Heating elements having internal spaces for a heating medium such as steam are successively submerged and withdrawn from a bath of liquid to be evaporated. Vapor boiling off the outer surfaces of the heating elements can be returned for use as heating medium. The heating elements can be a bundle of elongated tubes or a plurality of plate-type elements rotatable about a common horizontal axis.

Abstract: A thin film evaporating device includes a housing defining a space for receiving a plurality of elongated tubular evaporators. An inlet is associated with the housing for feeding a flowable heating medium to the space for heating the plurality of elongated tubular evaporators.

Abstract: A method and apparatus are disclosed for decontaminating a liquid surfactant of a dioxane having a vapor pressure which is higher than the surfactant. A contaminated liquid surfactant is directed through an inclined conduit. A gas is directed into the inclined conduit, whereby the gas contacts the surfactant and transports the dioxane contaminant, which has volatilized in the inclined conduit, out of the inclined conduit, thereby decontaminating the surfactant. The liquid surfactant is discharged from the inclined conduit.

Abstract: 1-aminopropanediol-2,3 containing 2-aminopropanediol-1,3 of less than 0.30% by weight can be prepared by the present purification process, which involves distilling a 1-aminopropanediol-2,3 containing at least 0.3% of 2-aminopropanediol-1,3 based on the weight of 1-aminopropanediol-2,3 using a distillation column, said distillation column having low pressure loss.

Abstract: A thin film flow-down type concentrating apparatus for concentrating a heat susceptible raw liquid with heated steam to high concentration without spoiling the flavor or deteriorating the quality by alternately laminating raw liquid plates and steam plates 20, in which the width of the raw liquid heating passage 18 is gradually narrowed from the raw liquid inlet to the concentrate outlet. As a result, if the volume of the raw liquid decreases due to evaporation and separation of the moisture in the raw liquid, scorching is prevented. Besides, by the steam generated from the raw liquid, in order to prevent increase of the flow velocity of the concentrate going toward the concentrate exit, the plate intervals of the raw liquid heating passage is gradually widened from the raw liquid inlet toward the concentrate outlet.

Abstract: A solution of cellulose is formed by moving a premix of a tertiary amine N-oxide, water and cellulose through a thin-film evaporator using a bladed rotor under treatment conditions which specify, inter alia, an area of heated surface (1 m.sup.2 to 125 m.sup.2), a blade speed (2.5 to 8 m/sec), a pressure (25 to 100 mb) and a temperature (90.degree. to 135.degree. C.).

Abstract: A rotary evaporator is described utilizing a magnetically driven fluorocarbon cylinder, operating within a solvent container, to create a thin solvent film for rapid evaporation without the usual requirement for rotating the entire solvent container assembly. Infra-red heating is employed for efficient evaporation rates. Solvent heating is controlled during evaporation by a single temperature probe, turning the infra-red heater on and off on demand of the probe. Over heating of the product is prevented by maintaining a solvent residue at or near the conclusion of an evaporation.

Abstract: Reprocessing mixtures which contain organic solvents and constituents of low volatility and may contain water: includes introducing the mixture into a concentration apparatus of a solvent recovery system, concentrating the mixture in the concentration apparatus by evaporating off a portion of a readily volatile fraction and feeding this readily volatile fraction to a separation column. A portion of the concentrated mixture from the concentration apparatus is conducted away into a separation apparatus where the constituents of low volatility are separated off from the concentrated mixture and ejected from the solvent recovery system. The concentrated mixture is conducted away, freed from the constituents of low volatility, from the separation apparatus.

Abstract: A film-type evaporator has an upright container, a heating system arranged on the outside of its jacket, a rotor rotating in the container and an upper part with a vapor chamber and droplet separator. In the upper area of the rotor the product is fed onto the inner container wall and runs down in the form of a thin film in which evaporation takes place. Circulation evaporation with a high thickening capacity is made possible in that the container has an unheated lower part constructed as a receiving flask in which the product is collected and a central part with the heating system, on whose inner wall film-type evaporation takes place, and in that the tubular rotor extends into the lower part and is constructed as a circulating pump, which delivers the product from the lower part on the inside of the tubular rotor into its upper area and centrifugally delivers it there to the inner wall of the central part.

Abstract: A concatenable module for a multiple-effect still has a chamber encompassed by four walls and two baffles, where one baffle is shared with the preceeding effect and the other the subsequent effect. Heat exchanger tubes mount into an accumulator which is sealed to a baffle, an aperature in the baffle at the accumulator allows vapors and fluids to flow between modules.A distribution plug seals the top end of a heat exchanger tube while carrying distilland through internal channels until it reaches a ring channel which carries distilland in evenly around the plug. A gap below the ring channel between the plug and tube allow distilland to flow evenly on the tube as it leaves the plug.

Abstract: The invention relates to a thin-film evaporator equipped with a heatable tubular evaporator body in whose product charged interior a driven rotor is disposed which is equipped with essentially radially oriented vanes. The invention is formed from an evaporator body of at least one thick-wall graphite tube with a plurality of essentially axially extending bores disposed in the tube walls, each one of the bores open at the tube ends into an annular channel which is in communication with a connecting pipe stub for a heating medium.

Abstract: Liquid to be evaporated by the indirect transfer of heat from a heating medium within plate type heat exchange elements is distributed over outer surfaces of the plate type elements by means of one or more brushes mounted for movement over the heating surface. Horizontally and vertically moving brush assemblies are described and shown.

Abstract: A pulp mill has zero or minimum liquid discharges. The large amounts of liquid that must be processed to achieve this result are handled utilizing a multiple effect evaporator provided with heat from a steam exhaust of a condensing type steam turbine. Super heated steam from the recovery and bark boilers is fed to the turbine to generate electricity for the production of bleaching chemical and other uses in the mill. Three or four steam exhausts having different composite temperature and pressure values are taken from the turbine and used where most suitable in the pulp mill. For evaporation of bleach plant effluent the steam taken from the turbine preferably has a pressure of about 1-3 psia and a temperature of about 120.degree.-140 .degree. F, and has no significant adverse affect on power generation.

Abstract: Sulphur dioxide is separated from the flue gases of a cellulose pulp mill by absorbing it into a sodium sulphite solution. Sulphur dioxide is regenerated from the sodium bisulphite solution produced by an evaporation-crystallization method utilizing thermo-compressor evaporation technique. A lamella evaporator is utilized as the evaporator-crystallizer, the evaporator being divided into separate compartments for ease of cleaning the lamella surfaces. The recovered concentrated sulphur dioxide can be used wherever desired, for example for the production of chlorine dioxide.

Abstract: A silver nitrate feed solution containing nitrites and nitric acid is treated to produce a low-nitrite silver nitrate product solution. In the process, the temperature of the feed solution is established in the range of from about 80.degree. C. to about the boiling point of the feed solution. The feed solution is introduced into a vessel having a stripping zone containing a contacting element and is dispersed over the contacting element. The feed solution is flowed counter to and intimately contacted in the stripping zone with a motive gas to strip nitrites from solution and form a low-nitrite silver nitrate product solution.

Abstract: A process for simultaneously exchanging material and for exchanging heat, material change being effected between a gas phase and at least one liquid phase by contact and passage in opposite directions of the gas phase and of the at least one liquid phase and heat exchange being effected between a compartment (I) and another compartment (II). In compartment (I) a plurality of spacer plates defining material exchange passages are arranged and the material exchange is effected by causing the at least one liquid phase to flow over a substantially vertical or inclined wall of a corrugated spacer plate having perforations and by causing at least a fraction of the gas phase to traverse simultaneously said perforations in a substantially ascending direction to contact said at least one liquid phase. The heat exchange is effected by circulating a heat exchange fluid in the compartment (II) which has a common wall with the compartment (I).

Abstract: Polyether glycols, especially poly(tetramethylene ether) glycol (PTMEG) having a narrow molecular weight distribution of about 1.25 to 1.80, or dispersity of 1.05 to 1.90, are made by a process involving distilling the low molecular weight fraction in unit operations including at least one short-path distillation evaporator. Two short-path distillation evaporators, in series, are desirable if significant narrowing of the PTMEG is required. In these units, PTMEG is subjected to temperatures in the range of 270.degree.-400.degree. C. with the hold-up time varying between 10-200 seconds. The required vacuum to force the separation of the low molecular weight PTMEG varies between 0.001 mm and 1.0 mbar. PTMEG residue from the distillation unit is also characterized by its low water content and low concentration of oligomeric cyclic ethers.

Abstract: Polyether glycols, especially poly(tetramethylene ether) glycol (PTMEG) having a narrow molecular weight distribution of about 1.90 to 2.07, or dispersity of 1.50 to 1.90, are made by a process wherein the low molecular weight fraction in unit operations using at least one short-path distillation evaporator. In these units, PTMEG is subjected to temperatures in the range of 150.degree.-190.degree.C. with the hold-up time varying between 10-200 seconds. The required vacuum to force the separation of the low molecular weight PTMEG varies between 0.001 mm and 1.0 mbar. PTMEG residue from the distillation unit is also characterized by its low water content and low concentration of oligomeric cyclic ethers.

Abstract: A film-type evaporator has a vapor chamber, a rotor rotating therein, at least one evaporating surface extending outwards from the rotor axis and a heating chamber rotating therewith and sealed with respect to the vapor chamber. The starting product is fed onto the evaporating surface close to the rotor axis and spreads outwards in film-like manner due to the centrifugal force on the evaporating surface. A uniform film thickness is achieved in that the evaporating surface is a curved blade surface, which is formed by a generatrix substantially parallel to the rotor axis and whose axial extension is limited by upper and lower stop ledges, and that the concave side of the evaporating surface is directed in the circumferential direction of rotation of the rotor.

Abstract: Apparatus and method for evaporating a liquid includes a casing; a plurality of vertically extending plate-type heating elements within the casing, each heat element having an outer surface and an inner surface and a vertical edge, the heat elements being spaced and forming an open channel along the vertical edge between adjacent elements; a distributor above the heating elements for distributing the liquid over the elements; an inlet connected to the heating elements for introducing a heating medium and for generating vapor from the liquid; and a wall-like device mounted within the casing facing the spaces between the heating elements for collecting and guiding the vapor generated in the evaporator. Preferably, the wall-like element includes a droplet separating device formed by vertically elongated spaced elements having a substantially U-shaped cross-section with inwardly pointing vertical edges.

Abstract: An apparatus for thickening liquids with solid contents has a container receiving the liquid and a vapor outlet and a heater, which is positioned in the liquid column in the container. The heater is constructed as a rotor rotating in the container and is formed from a plurality of substantially parallel plates arranged with a limited axial spacing and extending outwards from the rotor axis, every second space between adjacent plates forming a heating chamber sealed with respect to the liquid, while the spaces located between the same close to the rotor axis and on the circumference thereof are open towards the container interior.

Abstract: In a thin film evaporator for the evaporation of solutions, colloids, suspensions, or the like, to concentrates, which has a heatable cylindrical evaporator casing coupled with a rotary drive, which evaporator casing has a feed inlet at one end, in the form of a feed distributor that runs on bearings and is coupled with a rotary drive, and at the other end has a concentrate discharge, the axis of the evaporator casing is arranged horizontally. The distal end of the feed distributor can reach the inside surface of the evaporator casing to within less than 2 cm. Wiper elements can work together with the effective surface of the evaporator casing. This thin film evaporator makes possible an optimal setting of the retention time of the process material to be treated in the evaporator casing and has the effect that the thickness of the layer of the process material changes very little over the entire axial length.

Abstract: Film-type evaporator for thickening liquid products with a container having a vapor outlet, a drive shaft introduced into the latter from above for a rotating rotor with at least one conically upwardly widening heating surface, onto whose inside the product is fed in the vicinity of the smaller diameter and the product spreads in film-like manner towards the larger diameter and is fed there as a concentrate into the container, and on whose outside is guided the heating medium supplied and removed through the hollow drive shaft.

Abstract: An evaporation assembly for concentrating liquids having an evaporation area for conveying a liquid to be concentrated and a heating system for heating and concentrating the liquid conveyed through the evaporation area. The evaporation area includes a liquid inlet for introducing liquid to be concentrated into the evaporation area, and a liquid and vapor outlet for conveying the liquid through the evaporation area. A vapor circulating system is coupled between the liquid inlet end and the liquid and vapor outlet of the evaporation area for increasing the velocity of the liquid to be concentrated for impeding or removing precipitated particles or deposits from the heat exchange surfaces.

Abstract: A falling film evaporator includes a chamber having a top and bottom tube plate; a plurality of vertical tubes each having an interior and exterior surface and extending through the chamber and being supported by the top and bottom tube plates; an inlet at the chamber for feeding heating medium into the chamber; a distributor above the tubes for feeding liquid to be evaporated into the tubes and for causing the liquid to be distributed as a falling film along the interior surface of the tubes so as to evaporate the liquid and generate vapor as the liquid passes in heat exchanging relationship with a heating medium present at the exterior surface of the tubes; a vapor space defined by a circumferential wall below the tubes; a plurality of vertically elongated spaced elements having a substantially U-shaped cross-section with inwardly pointing vertical edges for receiving the evaporated liquid and the vapor, the elements being arranged in a circumferential wall below the tubes within the vapor space spaced from

Abstract: Fatty alcohols are separated from a solution containing alkyl polyglycosides (APGs) and alcohols, wherein the alcohols and the alkyl groups of the APGs contain 10-18 C atoms and wherein the mean degree of polymerization of the (APGs) is 1.05-1.4 by distilling said solution at 160.degree.-200.degree. C. under a pressure of 0.1-20 hPa in a thin layer evaporator having a Reynolds number of 30-18,000.

Abstract: A water desalination apparatus which is constructed of a main housing which includes a condensation chamber and a vapor chamber located above the condensation chamber. Brackish water is to be supplied into the vapor chamber with this brackish water to produce a vapor which is to be removed by a centrifugal compressor arrangement into the condensation chamber. The condensed brackish water from the vapor chamber is to flow through a mass of thin-walled tubes to be eventually discharged into the ambient. The exterior wall of these tubes is located within the condensation chamber and it is on the walls of these tubes that the distilled water vapor is to collect and condense and flow from the condensation chamber to a collection source.

Abstract: A system for continuously recovering renewable volatile compounds by boiling points from waste organic solvent with minimum energy loss, and an improved thin membrane distillation apparatus for efficient distillation of renewable volatile compounds from waste organic solvent and enforced discharge of the residue or sludge. The waste treatment system includes a thin membrane distillation apparatus, a cooling unit, a first distillation unit, and a second distillation unit connected in this sequence. Alternatively, the system includes two thin membrane distillation apparatus, a reduced pressure distillation unit, and a normal pressure distillation unit connected in this sequence. The thin membrane distillation apparatus includes a decompression chamber, a waste inlet, an outlet for volatile compound, an air-tight chamber, and a breaking mechanism with a screw head movable into the air-tight chamber.

Abstract: A wiped film evaporation process for reducing the amount of residual organic polyisocyanate, especially toluene diisocyanate, in a polyurethane prepolymer reaction product mixture. An inert sweeping gas is added to the evaporation process, preferably after first passing through a holdup volume of the prepolymer which has passed through the evaporation zone.

Abstract: A process for the production of tocopherols (T) and tocotrienols (T3) from palm fatty acid distillates (PFAD). The process includes converting free fatty acids and glycerides in PFAD into alkyl esters, then separating T and T3 from the alkyl esters and other impurities. The T and T3 are concentrated by ion-exchange and further concentrated by distilling the resulting product. Specific catalysts and optimum temperatures for the process are included. The resulting purified tocopherols and tocotrienols are useful substances, exhibiting antioxidant and physiological activities.

Abstract: A film evaporator formed by a cylindrical body section (50) with a heating jacket (53) and angled scraping blades (84) mounted on a rotatable shaft (76) to move the thickened material downwardly through the evaporator. Below the body section (50) is an inverted frusto-conical section (62) containing inclined scraping blades (86) also mounted on the shaft (76) and a smaller diameter lower body section (64) through which the thickened product can be discharged by a screw (93) of opposite hand to the scraping blades (84). The screw (93) is carried on a lower shaft (88) which is journalled to the shaft (76) so that the shafts can be rotated independently and in opposite directions.

Abstract: Concentration of solutions containing methanol and either dimethyl carbonate or methyl t-butyl ether may be effected by a composite membrane including a dibromobutane cross-linked poly(4-vinyl pyridine) bonded to a porous layer of polyacrylonitrile on a polyester backing.

Abstract: A solvent-containing biological material specimen is dried in a vacuum chamber with solvent evolving during the drying cycle being condensed in a refrigerated cold trap. During the drying cycle, communication of the drying chamber with the vacuum pump with which the chamber is evacuated, selectively is established or interdicted in response to raising or lowering of the vacuum condition in the chamber with respect to an initially set predetermined vacuum condition. Evolving of solvent from the specimen proceeds during interdiction by way of "cryopumping" due to the differential in pressure between the chamber and the refrigerated trap. Thus maximized solvent recovery in the trap is achieved, and carry over of solvent to the vacuum pump wherein its presence would be contaminating of the pump oil is for practical purpose eliminated.