Abstract: The present invention pertains to an apparatus for gathering analyte. The apparatus comprises a pumping mechanism for pumping solvent at supercritical pressure. The apparatus also comprises an extraction mechanism which receives a first sample and at least a second sample separate and distinct from the first sample and extract analyte from them essentially simultaneously. The extraction mechanism is connected to the pump mechanism to receive solvent at supercritical pressure for extracting the analyte from the samples. The apparatus additionally comprises a collection mechanism for collecting analyte from the solvent after the analyte has been extracted from the samples. The collection mechanism receives the supercritical solvent having the analyte extracted from the samples from the extraction mechanism. The present invention pertains to a method for extracting analyte. The method comprises the steps of pumping solvent at a supercritical pressure.

Abstract: A variable-orifice fluid restrictor for use with a supercritical extractor or chromatograph includes an inlet line for fluid at a pressure above its critical pressure, an extended tubular probe having an inner and an outer surface and a proximal and a distal end. The proximal end of the probe is disposed toward the inlet line. The distal end of the probe includes an adjustable orifice means adapted for metering the fluid and having first and second orifice members and an adjusting stem having first and second ends. The adjustable orifice means is adjacent to the outer surface of the probe and the orifice means is adjustable with the adjusting stem. The end of the adjusting stem is located at the distal end of the probe and is adapted for moving the first orifice member with respect to the second orifice member to control the adjustable orifice for varying the restriction of fluid passing through the adjustable orifice.

Abstract: Method/apparatus for extracting substance from carrier liquid in first container into an immiscible extraction liquid of different density in second container receiving and locating the first. Substance transfers to extraction liquid at liquids admixture in second container aided by flow control and fine division of carrier liquid force supplied into extraction liquid. Separated liquids receive separator member cooperating with second container as physical barrier with only separated extraction and acquired substance at one side. Centrifuging produces three-stage dividing flow of carrier liquid on the second container wall. Moulded parts suit single use in centrifuge.

Abstract: In a piston pump for pumping liquid carbon dioxide at a temperature below 30 degrees Fahrenheit and pressures at least as high as 7500 psi at an outlet flow rate in excess of 10 milliliters per minute, the inlet to the pump and the pumphead are each cooled by thermoelectric heat exchangers that are air cooled. The pump is a cam-driven, single-plunger pump with a cam profile that enables the pumping system to avoid distructive reverse torque on the cam, gear train and drive motor after the cam passes top dead center. The volume leaving the pump is determined by measuring only pressure or other parameter related to flow and movement of the plunger. The piston of the pump is supported on both sides of the seal and the support for the piston within the pumphead are machined consentrically and colinearly to the seal gland.

Abstract: A method for extracting an organic substance from a material by extracting the organic substance with a mixed solvent which contains at least one polar solvent and at least one nonpolar solvent, by which a wide variety of organic substances can be extracted without using a halohydrocarbon at a relatively low temperature.

Abstract: A process is described whereby phenolics and other water soluble, organic materials are removed from certain aqueous refinery waste streams by an extraction process whereby the brine is contacted with a hydrocarbon solvent containing at least about 2% by weight of a trialkylamine.

Abstract: Sweetening of sour hydrocarbon feedstocks by contacting with an aqueous solution of a metal chelate as an oxidation catalyst in the presence of oxygen is hindered by the difficulty of recovering metal chelate. Extraction of the aqueous phase with a liquid secondary amine with low water solubility removes a main portion of the metal chelate, usually a mixture of polysulfonated cobalt phthalocyanines, from the aqueous phase, and subsequent recovery of the chelate from the amine extract enables a viable alternative to feed bed processes.

Abstract: An apparatus is described for carrying out solid phase microextraction and analysis of analytes in a fluid carrier in which a fiber within a housing is vibrated by a vibrating means during microextraction. The housing contains access means so that the carrier and analytes can be brought into contact with the vibrating fiber during the extraction stage. In a preferred embodiment of the present invention, the vibrating means comprises a membrane, a solenoid for vibrating the membrane, a frame, a retainer mounted on the frame for holding the solenoid, a holder for the membrane, and a retainer arm having one end connected to the retainer and the other end attached to the holder. A method for microextraction and analysis is also described in which a vibrating fiber is placed into contact with analytes to be analyzed in a suitable carrier deposited in a container for a sufficient period of time for microextraction to occur.

Abstract: To supply supercritical fluid to an automatic supercritical fluid extractor and collect extract from the extractor, sample holding cartridges are lifted one by one in series by an elevator plug into a pressure chamber. An inlet at the top of the cartridge engages a pressure vessel inlet for the extractant so that extractant flows into the cartridge and into the space between the cartridge and inner walls of the pressure chamber. The outlets from the cartridge and pressure vessel communicate with the collector and exhaust through passageways in the plug. The plug has cleaning ports for cleaning seals and the outlet from the cartridge flows past the seals. The collector lifts vials into place and can precool the collection solvent, and later as part of the collection procedure, heat and pressurize the collector.

Abstract: Wastewaters resulting from preparation or use of paints comprising organic solvents are purified by extraction with higher monoalcohols, i.e. alcohols having at least 8 carbon atoms in the molecule.

Abstract: A preparatory supercritical extraction cartridge includes a chamber for sample having a volume in the range of 20 cubic centimeters to 2,000 cubic centimeters. An inlet and an outlet are fastened to the cartridge walls by threads and sealed to said cartridge walls With spring loaded seals so that they can be removed with a torque requirement of less than 35 pound inches. Inlet and outlet tubing are fastened to the inlet and outlet by quick release connectors.

Abstract: The invention relates to a method for extracting metals from large solution flows in liquid--liquid solvent extraction and to an apparatus for realizing the same. By employing the method and apparatus of the invention, it is possible to choose which phase is maintained continuous at the dispersion stage, while the other phase remains as drops, to prevent the aeration of the organic phase and to pump the phases further at a low circumferential speed in order to prevent emulsification. Another object of the invention is to make the dispersion removed from the settler unit spread in the settler unit over the whole transversal area thereof. The method and apparatus of the invention are particularly well suited to large copper extraction plants.

Abstract: An apparatus for automated extraction of an analyte from a sample positioned in a sample containment cell having a fluid passageway structure for communication of an extraction fluid to and from the cavity of the cell. The apparatus includes a loading tray, an oven assembly mounted proximate the loading tray, a fluid communication assembly mounted proximate the tray, a cell manipulation assembly and a controller. The cell manipulation assembly brings an inlet conduit and an outlet conduit of the fluid communication assembly into sealed relationship with the sample containment cell and uses the conduits to pick up and move the cell to and from the cell tray and oven assembly.

Abstract: A process for recovering protein, fatty and water components from a float material produced by a waste water treatment system, wherein the protein and fatty components can be further processed for inclusion in various products, such as animal feed. The recovered water component can also be further processed before discharge into a sewer system.

Abstract: To avoid deposits on the restrictor that channels extractant into a collector, a heated capillary tube pressure release restrictor, has a thermally insulated outlet end in a collecting trap substantially colder than the capillary tube. The restrictor is heated between the insulation and the capillary tube by Joulean heating. The solvent in the trap is at a pressure of 5 to 200 psi above atmospheric pressure. The thermal resistance of the insulation is selected to reduce the heat added to the extractant to a minimum and yet cause the temperature of the extractant to be in a range within which it is sufficiently hot so it does not freeze when added to the collection solvent but not so hot as to reduce partitioning of the extract and extractant before the extractant leaves the collection solvent. It has a thermal conductivity no greater than 60 BTU's per hour, per square foot, per inch for a one degree Fahrenheit difference.

Abstract: The present invention is an apparatus for extracting organic compounds from solid materials. A generator vessel has a removable closure for receiving a solid or liquid solvent which is heated with a resistive heating element to a gaseous or supercritical phase. The removable closure is unencumbered because the side wall is penetrated with an outlet for the gaseous or supercritical solvent. The generator vessel further has a pressure transducer that provides an electronic signal related to pressure of the gaseous or supercritical solvent. The apparatus of the present invention further includes at least one extraction cell having a top and a bottom and a wall extending therebetween, wherein the bottom is sealably penetrated by an inlet for gaseous or supercritical solvent received through a manifold connected to the outlet, the top having an easy-open removable closure cap, and the wall having an outlet port.

Abstract: A method of isolating purified plasmid DNA includes the steps of providing cells containing plasmid DNA and lysing the cells with an alkyldimethylphosphine oxide (APO) detergent to produce a mixture, centrifuging the cell and APO mixture, reserving a supernatant containing purified plasmid DNA and isolating the purified plasmid DNA, from the supernatant. Isolation and purification occurs in the absence of hazardous materials such as phenol and chloroform. Prior to mixing, the APO detergent is preferably combined with a strong base to produce a stable solution.

Abstract: A variable-orifice fluid restrictor for use with a supercritical extractor or chromatograph includes an inlet line for fluid at a pressure above its critical pressure, an extended tubular probe having an inner and an outer surface and a proximal and a distal end. The proximal end of the probe is disposed toward the inlet line. The distal end of the probe includes an adjustable orifice means adapted for metering the fluid and having first and second orifice members and an adjusting stem having first and second ends. The adjustable orifice means is adjacent to the outer surface of the probe and the orifice means is adjustable with the adjusting stem. The end of the adjusting stem is located at the distal end of the probe and is adapted for moving the first orifice member with respect to the second orifice member to control the adjustable orifice for varying the restriction of fluid passing through the adjustable orifice.

Abstract: Use of polymeric two-phase systems for removing microbial contaminants from industrial lubricating agents, a method of purifying microbial contaminated lubricating agents by mixing the lubricating agent with a polymeric two-phase system, allowing the mixture to separate so as to form a top-phase containing the lubricating agent and a bottom-phase containing at least part of the microbial contaminants, and separating at least a major part of the microbially enriched bottom-phase from the top-phase, a plant for microbial purification of lubricating agents comprising a mixing tank (4) having means (7, 8) for feeding microbially contaminated lubricating agent (S) to the mixing tank, means (13) for feeding a polymeric two-phase system to the mixing tank, a stirrer (5) in the mixing tank, means (9, 10) for feeding the mixture to a separation device (6) for separating the mixture into a top-phase (T) containing lubricating agents, and a bottom-phase (B) containing microbial contaminants, and means (18) for recoverin

Abstract: An extraction column includes: one or several vertically aligned stages; fittings for inletting a phase containing a component that is desired to be extracted; fittings for inletting an extracting phase; and fittings for outletting the two phases after treatment in the column. Each stage includes two volumes, an internal one inside an outer one in fluid communication with each other via an intermediate volume. The internal volume is intended to cause mixing between the phase containing the component that is desired to be extracted, and the extracting phase. The outer volume is intended to cause the reseparation of the two phases, the one from the other after the mixing happens. The two fittings, the one high, the other low, for the two phases after their separation, are arranged in a calm zone. There is also a device for adducing the two phases from the outlet fittings of the reseparation volume to a subsequent treatment stage.

Abstract: A self-cleaning return pump system for use with a clean-in-place system for cleaning vessels includes a recirculation loop for providing flow communication including a return pump, an eductor, and a separator. The return pump is arranged to discharge a liquid through the eductor into the separator and is supplied with a substantially continuous flow of liquid from the separator. A return line provides flow communication between the vessel to be cleaned and a suction port of the eductor. The separator has a top discharge port and a bottom discharge port. The top discharge port is configured to discharge a liquid or a liquid-air mixture therefrom to the clean-in-place system. The return pump causes liquid flowing through the recirculation loop at the eductor to have sufficient dynamic head to draw liquid or a mixture of liquid and air from the vessel through the return line, into the eductor. The liquid or liquid air mixture is discharged into the separator.

Abstract: An apparatus for supercritical fluid extraction incorporates a removable extraction cartridge which in operation has insignificant pressure difference between its inside and outside walls. Because of the low pressure difference, the extraction cartridge need not have the strength to withstand significant pressure and can be made out of molded plastic for disposable use as well as stainless steel and/or machined plastic for reusability. The extraction cartridge can be removed and opened for sample access without the use of tools. The outside of the cartridge can be purged after it is installed in a heated high pressure vessel to remove contamination from its exterior. In one embodiment, the extractor includes a fraction collector for extractants, an automatic sample changer and an automatic cartridge transfer mechanism which provide completely automated extractions.

Abstract: A process for extraction of a carotenoid compound from bacterial cells containing the carotenoid compound comprising the step of bringing the bacterial cells into contact with supercritical fluid so as to extract the carotenoid compound from the cells. The process provides carotenoid compounds which can be safely used as feed additives and food additives.

Abstract: To collect analyte in a supercritical fluid extraction process, the extractant flows to a collection container under pressure. In one embodiment, the collection container contains collection solvent through which the extractant flows to partition analyte. The extractant adds to the liquid and when the collection solvent-extractant mixture rises to a heating zone, the extractant vaporizes selecively since its vapor pressure is higher than the vapor pressure of the collection solvent. When its pressure exceeds a preset valve pressure it is vented so that extractant continually leaves the collection container. After the extraction is complete, the analyte is concentrated in the collection solvent. In another embodiment, the collection vessel includes a solid material on which the analyte collects. It is removed under pressure by a solvent that is concentrated under pressure.

Abstract: A reusable apparatus for multiphase, multistage countercurrent liquid separation is presented. The apparatus is particular useful in progressive multistage separation of target microorganisms from background organisms and materials with precise transfer, air exclusion, homogeneous mixing, isolation from the ambient atmosphere, in the absence of valves and at ow cost. The structure has at least one chamber in which a piston-like sliding bottom is sealingly moved or braked and includes internal structure for mixing, preferably a magnetic-stainless steel ball which can be reciprocated from the outside to mix the liquid contents. Motion of the bottom is limited by stops. A number of ways to actuate the apparatus are taught.

Abstract: A process for the separation of naphthalenesulfonate-based carbonyl condensates from water is provided. The process comprises contacting a mixture comprised of water and a naphthalenesulfonate-based carbonyl condensate (preferably a material selected from the group consisting of formaldehyde condensates of naphthalenesulfonic acids, formaldehyde condensates of lower-alkyl substituted naphthalenesulfonic acids, and mixtures of two or more of such materials) with a liquid organic phase comprised of a lipophilic non-quaternary amine to form an aqueous phase depleted with respect to said mixture of naphthalenesulfonate-based carbonyl condensate and a liquid organic phase enriched in naphthalenesulfonate-based carbonyl condensate. The process further comprises separating said aqueous phase depleted with respect to said mixture of naphthalenesulfonate-based carbonyl condensate and said liquid organic phase enriched with respect to naphthalenesulfonate-based carbonyl condensate.

Abstract: Methods and apparatus for extracting an analyte from a sample using a field-portable extraction instrument. The preferred embodiment of the extraction instrument includes an extraction fluid source, a sample container, a valve element, a nozzle, and a collection trap vessel. The methods of the present invention include the steps of inserting the sample into the sample container, attaching the sample container to the instrument, and providing a quantity of pressurized extraction fluid from the pressurized extraction fluid source into the sample container to initiate the extraction process. Extraction is facilitated by directing the extraction fluid into the sample at a rapid flow rate such that the sample and extraction fluid are vigorously mixed and a sample/solvent mixture is created. The valve element is then operated to isolate the extraction fluid source and to fully close the sample container.

Abstract: Gel formulations including a polydimethylsiloxane-polyethyleneoxide copolymer gelled with dibenzylidine sorbitol in the presence of water or alcohol, The gel formulations are useful for facilitating the separation of blood serum or plasma from the cellular portion of blood or as a thermoreversible shear sensitive substance.

Abstract: A blood collection assembly with gel formulations including a polydimethylsiloxane-polyethyleneoxide copolymer gelled with dibenzylidine sorbitol in the presence of water or alcohol. The gel formulations are useful for facilitating the separation of blood serum or plasma from the cellular portion of blood or as a thermoreversible shear sensitive substance.

Abstract: Method for forming blood compatible, shear sensitive gel formulations including a polydimethylsiloxane-polyethyleneoxide copolymer gelled with dibenzylidine sorbitol in the presence of water or alcohol. The gel formulations are useful for facilitating the separation of blood serum or plasma from the cellular portion of blood or as a thermoreversible shear sensitive substance.

Abstract: Gel formulations including a polydimethylsiloxane-polyethyleneoxide copolymer gelled with dibenzylidine sorbitol in the presence of water or alcohol. The gel formulations are useful for facilitating the separation of blood serum or plasma from the cellular portion of blood or as a thermoreversible shear sensitive substance.

Abstract: A serum:plasma separator is provided containing a tackifier having a softening point of 70.degree. to 150.degree. C. and a partition-forming material. The separator prevents hemocyte from remaining in a serum portion after blood separation and prevents migration of a component having a concentration gradient between clot and serum, even when separated blood components are stored as they are in place in a tube for the separation of blood, whereby correct examination results can be obtained. The serum:plasma separator hardly undergoes a form change at room temperature and under heat and hardly shows a viscosity change even after a long period of time. Further, the serum:plasma separator has an excellent thixotropic nature free from a change in temperature, excellent cohesion and excellent adhesion to a blood separation tube. There is also provided a tube for the separation of serum:plasma from clot;hemocyte, which contains the above serum:plasma separator.

Abstract: In a non-agitated, countercurrent flow type liquid-liquid contacting tower, trays consisting of column plates and dams are installed horizontally inside the tower shell alternately in vertical direction with a suitable interval. The column plate share a part of the cross-section of the tower to provide a flow channel or channels for the liquids, and the dam extends from the end of the column plate vertically downward and has openings near the column plate. The liquid-liquid contactor has high contacting efficiency, and thus relatively small sized apparatus can have a large treatment capacity. Because the apparatus has no moving element, maintenance is easy.

Abstract: A centrifugal extractor comprising several superimposed stages (E1, E2, E3) has a fixed casing (10) within which rotate at high speed bowls (22) driven by a common vertical shaft (18). An immiscible light liquid and heavy liquid are emulsified and injected into a separating compartment (32) defined by each of the bowls (22) by ducts (54) forming ejectors and which are formed in the lower wall of the corresponding bowl. The light phase passes upwardly from one stage to the next by annular passages (46) surrounding the shaft (18), while the heavy phase redascends by gravity in return channels (44) formed in the fixed casing. This avoids turbulence in the separating compartments (32) and there is a reduction of the risks of clogging as a result of solid particles being present in the heavy phase.

Abstract: A serum separating sealant having a specific gravity at 20.degree. C. of 1.035 to 1.065, a viscosity of 100 to 400 Pa.S and a yield stress of 100 to 400 dyne/cm.sup.2 and comprising:(A) 100 parts by weight of a polymer having specific gravity at 20.degree. C. of 0.94 to 1.06 and a viscosity of 10 to 140 Pa.S, derived from an alkyl acrylate or alkyl methacrylate monomer having the formula (I): ##STR1## wherein R.sup.1 denotes H or CH.sub.3, R.sup.2 denotes an alkyl group having 1 to 18 carbon atoms;(B) 0.5 to 10 parts by weight of at least one component selected from silica and bentonite; and(C) 0.01 to 2 parts by weight of at least one surfactant selected from the group consisting of:(C-1) fluorocarbon-based surfactants;(C-2) polyester modified alkylpolysiloxane based surfactants.

Abstract: The invention concerns a method and an interface valve for the purpose of the separation of fluids where the separation process proceeds under control and quasi static and quickly on an extended surface and affords minimal expenditure of energy. By inserting the separating fluid 1c in layers into the fluid 1a, 1b that is to be separated, a separating layer T develops the surface tension of which is causing the separation of the fluids 1a, 1b.

Abstract: Apparatus and method are described for processing waste into a clean fuel. The waste comprises organic and inorganic portions. A float tank is filed with a liquid, e.g., water, of a selected depth. The waste is introduced into the liquid and separates into its organic portion, which floats near the surface of the liquid, and into its inorganic portion, which falls towards the bottom of the tank. The liquid depth is selected to be sufficiently large to permit the separation of the organic and inorganic portions. Then the organic and inorganic portions are removed. Sufficient liquid is extracted from the separated organic portion to provide the clean fuel. The fuel, illustratively, is formed as pellets. In a further aspect of this invention, further liquid is added to the separated organic portion to form a mixture thereof, which is pulped to provide a slurry thereof of a relatively high moisture content. Liquid is extracted by mechanical means, e.g.

Abstract: Apparatus for stop flow membrane probe analysis which apparatus is especially suitable for on-line analysis, the apparatus necessarily including five parts. The first part is a reservoir for containing an extractant. The second part is a flow control unit, being a pump or valve, the flow control unit connected to the reservoir, the flow control unit being of the type that can be turned on and off. The third part is a flow through membrane probe, the flow through membrane probe being connected to the flow control unit. The fourth part is a detector, the detector being connected to the flow through membrane probe. The fifth part is a switch for turning the flow control unit on and off so that the apparatus can be used for stop flow analysis. Preferably, the detector is also connected with the reservoir so that the extractant flowing through the probe and detector can be. recycled back to the reservoir. The probe is immersed into a process stream.

Abstract: A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated or lipophilic crown ether or fluorinated dithiocarbamate. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

Abstract: A process is provided for separating alkyl carbonate from a feedstock comprising at least one alkyl carbonate and at least 0.01 percent by weight water comprising extracting the alkyl carbonate from the feedstock in a liquid-liquid extraction step comprising an extraction solvent selective for extracting alkyl carbonates relative to water in an amount sufficient to extract a substantial amount of the alkyl carbonates from the feedstock. The extraction solvent substantially comprises hydrocarbon boiling at a temperature ranging from about 50.degree. F. to about 700.degree. F. at atmospheric pressure and having a specific gravity ranging from about 0.50 to about 1.00.

Abstract: A novel process and related apparatus for removing common contaminants from used motor oil. Propane, butane or a similar solvent is mixed with the contaminated oil to form a solution. This solution is agitated and then given time to settle thus allowing gravitational separation of asphaltic pollutants. The solution is then percolated through a columned filter to remove heavy metallic contaminants and the solvent recovered by heating the solution.

Abstract: Aqueous mixtures of hydrophilic and hydrophobic molecules are separated by adding to the aqueous mixture a second aqueous solution containing 95 mole percent of an alkyldimethylphosphine oxide and 5 mole percent of a phospholipid at 0-10.degree. C. followed by warming to 12-20.degree. C. and separating the resulting two layers.

Abstract: An apparatus for receiving chemical compounds carried in a high pressure effluent fluid stream from supercritical fluid extraction. The apparatus includes a heated conduit connected to supercritical fluid extraction device through which an effluent stream flows. The exit port of the heated conduit is located within the airspace of a decompression zone which is free of liquid. A liquid solvent chamber is provided in open communication with the downstream end of the decompression zone into which the effluent stream flows for the recovery of chemical compounds therein.

Abstract: Extraction of valeric and/or caproic acid from an aqueous solution containing adipic acid and/or methyl glutaric acid using an organic solvent is enhanced by carrying out the process using an extraction-enhancing acid, such as acetic or isobutyric acid, which is soluble in the organic solvent.

Abstract: A mixer-settler is provided which is modulatable and permits use, manipulation and maintenance within a tight, shielded enclosure using a telemanipulator. The mixer-settler is constituted by several modules (M1, M2, M3), which can be reciprocally dismantled by using tight connecting means (19, 20, 21). The inlets and outlets (17, 18) for the heavy and light phases are located on the front face (40) of each module. Regulating members (9, 10, 11) issue onto the upper surface of each module close to the front face (40). Preferably, shield windows (12) make it possible in each case to see the interphase of a stage comprising a mixing chamber (1) and a settling chamber (2). This is completed by a motorization assembly (3) placed above the module. Application to the treatment of radioactive liquids.

Abstract: A material extraction nozzle for separating a mixture of materials having different densities, comprising: a nozzle body shell having an outer surface with a tangentially located material inlet at an upper portion thereof and an inner surface defining in part a frustrum of a cone; a substantially conical diffuser section having an outer surface terminating in an apex, the diffuser section axially aligned within the nozzle body shell in a spaced relation therewith so as to form an extraction chamber with the inner surface of the nozzle body shell and the outer surface of the substantially conical diffuser section; an extracted material outlet port positioned axially through the substantially conical diffuser section; and at least one rejected material capillary outlet located below the apex of the diffuser section.

Abstract: In a process for industrial fractionation of polymers using an extraction column and a homogeneous extraction agent a homogeneous feed is supplied to a region of the extraction column which is nearer the upper end thereof when the feed has a greater density than the extraction agent and which is nearer the lower end thereof when the feed has a lower density than the extraction agent. An apparatus for carrying out this process consists advantageously, instead of a pulsed sieve plate column as hitherto, of an unpulsed filling body column which leads to a better separation because a back mixing is avoided in favourable manner.

Abstract: The invention provides a process for the extraction of indoles which comprises the steps of firstly extracting indoles from an indoles containing mixture with formamide or a formamide-containing solution and subsequently contacting the extract with at least one organic solvent selected from the group consisting of ethers, aromatic hydrocarbons and halogenated hydrocarbons to recover indoles with the organic solvent. This process is applicable to an industrial scale extraction of indoles, because the extraction solvent system has a high extraction selectivity of indoles, is required in a small amount with almost no losses through the extraction and recovery steps and can be used repeatedly.

Abstract: A method for the removal and recovery of paint overspray in a water wash spray booth is disclosed. The method uses a circulating agitated dispersion of an organic solvent component in water which collects the paint overspray. The dispersion containing the overspray is permitted to phase separate into an organic phase and an aqueous phase. The organic phase is further treated such as by distillation to separate the paint solids from an organic solvent portion which contains the original organic solvent component and the organic solvents associated with the paint. The organic solvent portion can be recycled and reused in the circulating dispersion and the paint solids can be recovered for further use such as a filler for adhesives or can be disposed of.

Abstract: A method and apparatus for mixing two different phases in a liquid-liquid extraction process and for separating the phases employs a spiral stirrer having two tubular coils for creating homogeneous circulation throughout a mixer. The stirrer rotates at a relatively slow speed to create an upward flow from bottom to top of the mixer near the mixer periphery and a downward flow in the middle of the mixer. The mixer has a flow reversing profile ring and is designed to prevent aeration and formation of an emulsion.