Abstract: An electrically enhanced air filtration system is disclosed which uses rear fiber charging is disclosed. In particular, a fibrous filter may be placed in an upstream position within the system with one or more ionization arrays positioned downstream or to the rear of the fibrous filter in terms of airflow direction. The fibrous filter may include a grounded side and fiber side with the grounded side being upstream of the fiber side. The ionization array may include a plurality of electrodes each extending unidirectionally toward the fibrous filter.

Abstract: A cleaning apparatus may include a flow source such as a fan which creates air flow through a ventilation duct or other structure to be cleaned. A projectile source projects projectiles such as dry ice pellets proximate the structure to dislodge debris particles therefrom and introduce the dislodged debris particles into the air flow. An electrostatic precipitator removes the particles from the air flow. An upstream sensor may be used to detect the particles upstream of the electrostatic precipitator and determine if the structure is clean using a controller. A downstream sensor may be used to detect the particles downstream of the electrostatic precipitator and determine the efficiency of the electrostatic precipitator using the controller. Carbon dioxide within the air flow may also be detected.

Abstract: The present invention relates to an electrostatic filter. Particularly but not exclusively the invention relates to an electrostatic filter for removing dust particles, for example an electrostatic filter for use in a vacuum cleaner, fan or air conditioner. The electrostatic filter includes a filter medium located between a first and a second electrode, each at a different voltage during use, such that a potential difference is formed across the filter medium, wherein a property of the filter medium varies along the length of the filter medium.

Abstract: The present invention relates to an electrostatic filter. Particularly but not exclusively the invention relates to an electrostatic filter for removing dust particles, for example an electrostatic filter for use in a vacuum cleaner, fan or air conditioner. The electrostatic filter includes a filter medium located between a first and a second electrode, each at a different voltage during use, such that a potential difference is formed across the filter medium, the first and second electrodes being substantially non-porous.

Abstract: A method for removing particulate matter from a particulate-bearing gas stream includes flowing a particulate-bearing gas stream at a first volumetric flow rate to a plurality of ESP units; producing electrically charged particulate matter; collecting electrically charged particulate matter on collection electrode plates; reducing the flow through at least one of the ESP units; sequentially increasing the flow through one or more remaining ESP units in an amount so as to maintain the sum of flow through all of the ESP units at the first volumetric flow rate; subjecting the collection electrode plates in the at least one ESP unit with reduced flow to forces which dislodge the particulate matter from the collection electrode plates; collecting the dislodged particulate matter in a particulate collection receptacle; and withdrawing a gas stream of reduced particulate matter contamination.

Abstract: An oxygen generator includes a monolithic body having first and second channels extending longitudinally therein. An electrode is operatively disposed in the first channels and a counter-electrode is operatively disposed in the second channels. The second channels are formed in the monolithic body so each second channel is electrically isolated from, yet adjacent to a first channel, resulting in an alternating configuration of first and second channels. The first channels have fluid or oxygen flowing therethrough, while the second channels have the other of oxygen or fluid flowing therethrough. An output manifold, having an oxygen collection area separated from a fluid collection area, operatively engages with the monolithic body. The oxygen collection area receives substantially pure oxygen from one of the second or first channels, and the fluid collection area receives oxygen-depleted fluid from the other of the first or second channels.

Abstract: The invention relates to an electrostatic filter method and electrostatic filter for separating particles from industrial waste gases, wherein an optimal electric charging or ionization in the ionization zone are performed in a high-voltage zone and its unchanged ducts with one high-voltage supply source to ensure the subsequent particle separation in the separation zone at sufficient field strength which requires minimal energy input.

Abstract: This invention relates to an electrostatic precipitator suitable for removing industrial dust particles. This electrostatic precipitator with high efficiency includes a casing, in which the corona discharge electrode lines and the dust-collecting electrode plates, which form a plurality of sedimentation passages, are arranged in parallel and alternately. The vibration apparatuses for cleaning dust are placed respectively on the corona discharge electrode lines and the dust-collecting electrode plates. The wind shields are arranged alternately at both ends of each two adjacent sedimentation passages to form a plurality of air intake sedimentation passages and air exhaust sedimentation passages which are arranged alternately. The passages, where the wind shields are located on the side of air outlet are the air intake sedimentation passages and the air exhaust sedimentation passages with the wind shields located on the side of air inlet.

Abstract: Purification method and apparatus for purifying a gas stream by oxygen removal. The apparatus includes primary and secondary oxygen separation zones and tubular electrically driven oxygen separation elements. There are more elements in the primary zone than the secondary zone so that low concentrations of oxygen can be obtained in a purified stream and turbulent flow conditions can also be obtained that will permit purification to very low levels. In addition, a junction is provided to connect the tubular separation elements to metallic elements such as manifolds.

Abstract: Purification method and apparatus for purifying a gas stream by oxygen removal. The apparatus includes primary and secondary oxygen separation zones and tubular electrically driven oxygen separation elements. There are more elements in the primary zone than the secondary zone so that low concentrations of oxygen can be obtained in a purified stream and turbulent flow conditions can also be obtained that will permit purification to very low levels. In addition, a junction is provided to connect the tubular separation elements to metallic elements such as manifolds.

Abstract: An electrostatic ionization system in a precipitation device for purifying a gas stream passing through it includes: an electrically conductive plate including a plurality of nozzles configured for passage of the gas stream; a sleeve positive-fittingly disposed on each nozzle; a high-voltage grid; a plurality of rod-shaped high-voltage electrodes each having an end connected to the grid and an exposed free end arranged identically centrally in a corresponding one of the nozzles, the electrodes each forming a circumferential gap and arranged at an electrical potential of the grid, wherein the free end of each of the electrodes is exposed downstream after the corresponding nozzle, wherein a wall of each sleeve is permeable to the gas stream and includes at least one of a grid, a perforated sheet and individual rods equidistantly spaced from each other and having free ends terminating in a holding ring.

Abstract: A multi-stage collector for multi-pollutant control that contains alternating narrow and wide sections with glow discharge electrodes in some narrow sections, a uniform electric field in wide sections for collecting particles charged by the glow discharge and streamer discharge electrodes in wide or narrow sections that convert and destroy harmful gaseous pollutants such as SO2, NOx and volatile organic compounds as well as convert heavy metals such as mercury into a particulate form. Steady state streamer discharge is supported by non-pulsed power supply. The streaming discharge can convert the polluting gases into nitric and sulfuric acid which can be removed by combining it with ammonia to form solid salts.

Abstract: A wet electrostatic ionization stage in an electrostatic separation device for purifying a flowing aerosal including finely dispersed particles entrained in a gas. The wet electrostatic ionization stage includes a plate disposed across a cross section of a flow channel and connected to a ground potential or reference counterpotential. The plate includes substantially identical openings through which the gas flows. The wet electrostatic ionization stage also includes a high-voltage grid disposed across the cross section of the flow channel either upstream or downstream from the plate and electrically isolated from a wall of the flow channel. The high voltage grid is coupled to a high voltage potential via a bushing disposed in the wall of the flow channel. For each opening in the plate, a rod-shaped high-voltage electrode coupled at one end to the high-voltage grid has a free end projecting centrically into the one opening.

Abstract: An air filtration device for suppressing biological pollutants for closed environments, including at least one enclosure with at least one air inlet, at which at least one perforated conducting grille is located, that has a present negative electrical potential adapted to emit electrons when air flows, so as to give negative electric charge to particles to which microorganisms adhere, at least one air passage duct being formed between at least one plate having predefined positive potential for collecting negatively charged particles to which microorganisms adhere, at least one deflector plate having a negative potential adapted to divert the particles to which microorganisms adhere, an electrical field being generated between the collector plate and the deflector plate, facing each other, the field to divert and precipitate the particles to which the microorganism adhere onto the collector plate, and an inactivator for inactivation of the microorganisms provided and at least one filtered air outlet.

Abstract: A dust-collecting electrode where at least one unit electrode between the unit electrodes facing each other includes: a ceramic dielectric body, a surface conductor disposed so as to cover at least a part of the surface of the ceramic dielectric body on the side where the unit electrodes face each other, and an internal conductive layer disposed inside the ceramic dielectric body and being electrically independent of the surface conductor. The dust-collecting electrode being capable of generating an electric field and silent discharge between the unit electrodes by applying voltage between the surface conductor of the one unit electrode and the other unit electrode and generating creeping discharge on the surface of the one unit electrode by applying voltage via the ceramic dielectric body.

Abstract: A volatile organic compound treatment apparatus including an adsorber coming into contact with a gas to be treated and adsorbing volatile organic compounds; a plurality of pairs of electrodes, divided into a plurality of groups, which generate electric discharge so that a part of the adsorber is exposed to the electric discharge; and an electric discharge control mechanism for controlling whether or not the electric discharge is generated in what pair of the electrodes by applying a voltage to every group of the pair of electrodes such that different parts of the adsorber are sequentially exposed to the electric discharge.

Abstract: An electrostatic room air cleaner includes a housing having a given profile and a plurality of electrostatic precipitation collector units arrayed in the housing with a common fan to circulate room air through the plurality of electrostatic precipitation collector units simultaneously. A total clean air delivery rate is delivered that is determined as the arithmetic sum of the clean air delivery rates of the plurality of electrostatic precipitation collector units arrayed in the housing of given profile. The greater the number of units arrayed, the smaller may be their size, and the easier they are to handle, maintain and replace.

Abstract: A separator for intended use in separating particles having a selected charge from a particle mixture entrained in or carried by a fluid flow is disclosed. The separator comprises a tubular, elongated body for receiving the fluid flow. At least one and preferably a pair of electrodes may be provided to create an electric field in at least a portion of the body through which the fluid flow passes, and at least one partition defines first and second channels for receiving the flow downstream of the portion of the body including the electric field. In one embodiment, the electrode is oriented such that a direction of an electrical field force acting on particles having a selected charge passing through the electric field is not perpendicular to a direction of gravity. A system incorporating the separator is disclosed, along with a diffuser and related methods.

Abstract: A multi-stage collector of the type used to collect particles from industrial gas. The collector can contain multiple narrow and wide zones formed by a plurality of parallel corrugated plates. Contained in the narrow zones can be elongated electrodes with sharp leading and/or trailing edges. These electrodes can provide a non-uniform electric field near their sharp edges leading to corona discharge. The corona discharge causes particulate matter in the gas flow to become charged. The region in narrow zones away from the sharp edges of the electrodes resembles a parallel plate capacitor with relatively uniform electric field. In this region, particles can be collected on the plates and on the electrode. Wide regions can contain barrier filters (bag filters) with conductive surfaces. The collector can also be used to clean inlet gas in gasification plants and to collect re-usable materials from a gas stream.

Abstract: A gas particle partitioner (GPP) removes particles from an aerosol with high efficiency and with no or minimum changes to the thermodynamic conditions and chemical composition of the gas phase of the aerosol. A permeable grid electrode surrounds a corona wire and separates an interior corona discharge area from an exterior aerosol charging zone. A particle free fluid washes the corona discharge area to minimize any transport of gas components produced by corona discharge to the aerosol. The charged particles in the aerosol are deflected by an electric field in a fractionator to selectively produce a particle free sample stream, which is then separated by a flow splitter from the aerosol.

Abstract: A size preferential electrostatic agglomerator is provided for agglomerating small particles with larger “carrier” particles. The agglomerator comprises an inlet for receiving a gas flow, a separator for separating the gas flow into flow streams based on the size of the particles therein, an ionization region for imparting an opposite electrical charge to each of the flow streams, an agglomeration region receiving the flow streams to facilitate the agglomeration of the oppositely charged particles, and an outlet for exhausting the gas flow containing agglomerated particles to facilitate collection, processing or other activity on the agglomerated particles. The present invention provides an efficient system for gathering large amounts of small particles in a gas flow.

Abstract: An electrostatic precipitator includes an upright hollow body having a lower smoke inlet and an upper smoke outlet, with a pair of spaced horizontal partitions formed in the hollow body between the inlet and outlet. A set of parallel ducts extends vertically between the partitions, and a pair of distributor frames is arranged in the hollow body, with one of the distributor frames disposed over the ducts and the other of the distributor frames disposed under the ducts. Between the distributor frames is stretched a plurality of wires that extend through respective ducts. Furthermore, each of the distributor frames is formed with a plurality of terminals to be electrically connected to one electrode of a DC high-voltage power supply, but the ducts are adapted to be electrically connected to the other electrode of the DC high-voltage power supply.

Abstract: A modular two-stage electrostatic precipitator for extracting airborne particles includes individual ionizer/collector cell modules having integrated power supplies and diagnostic systems. The cell modules are adapted to be joined blindly to one another in end-to-end nested relation through nestable end plates and in a series circuit utilizing floating electrical connectors. The module end plates provide self-correction in misalignment during a blind connection and provide sealed end plate cavities for the power supply and electrical connections. The diagnostic system provides detection for any open system circuit and/or short circuit condition and allows for trouble shooting on an individual cell module basis.

Abstract: A device and method for controlling particulate air pollutants of the present invention combines filtration and electrostatic collection devices. The invention includes a chamber housing a plurality of rows of filter elements. Between the rows of filter elements are rows of high voltage discharge electrodes. Between the rows of discharge electrodes and the rows of filter elements are grounded perforated plates for creating electrostatic precipitation zones.

Abstract: The present invention describes a method and an arrangement for purifying the intake air of a gas turbine of solid particles and liquid droplets. According to the invention air is taken into the system of intake air passages (1, 2, 4) of the gas turbine and the particles contained in the intake air are collected by means of at least one plate filter (3) to which a collection voltage has been connected. In order to enable and enhance collection, the air is taken into at least one charging chamber (2) arranged at a distance prior to the plate filters (3) in the flow direction of the air, where an electric field is formed between at least two electrodes (5, 7) by connecting a voltage between the electrodes which exceeds the collection voltage, whereby powerful charging of the particles and at least partial removal of the water contained in the air are effected.

Abstract: A multi-stage particulate matter collector of the type used to collect particles from waste industrial gas. The collector can contain multiple narrow and wide zones formed by a plurality of parallel corrugated plates. Contained in the narrow zones are elongated electrodes with sharp leading and/or trailing edges. These electrodes provide a non-uniform electric field near their sharp edges leading to corona discharge. The corona discharge causes particulate matter in the gas flow to become charged. The region in narrow zones away from the sharp edges of the electrodes resembles a parallel plate capacitor with relatively uniform electric field. In this region, particles can be collected on the plates and on the electrode. Wide regions can contain barrier filters (bag filters) with conductive surfaces. The electric field is also relatively uniform in this region causing electrostatic collection on the plates and filter surface.

Abstract: A device for cleaning gases includes a housing and a plurality of electrostatic filter units. Each of the filter units have a tube-shaped covering, and the housing has an intake opening at one end and an outlet opening at the other end for gas flow. The filter units have an essentially airtight arrangement within the housing. The filter units combine to form a filter assembly arranged inside the housing such that the assembly can be inserted and removed from the housing in one piece.

Abstract: This invention relates to an apparatus and method to electrostatically charge or neutralize particles conveyed in a pneumatic stream. More particularly the invention is drawn to an apparatus that has at least two longitudinal chambers separated from each other with a plate electrode. Within each chamber is at least one corona charging electrode with multiple discharge points and at least one power level zone. The apparatus divides a single gas stream into a multiple streams where corona discharge polarizes or neutralizes particles with a similar or dissimilar polarity causing coalescing or separation of the particles as they exit the charging chambers.

Abstract: A device for the treatment of a flowing gas, such as an exhaust gas, includes at least one pair of smooth electrodes that are arranged opposite each other so that they form between them a discharge space through which a gas flows. For each pair of electrodes, at least one electrode is coated with a dielectric material on a side facing the discharge space. At least one electrode has one or more thickened areas facing the discharge space. The one or more thickened area has at least one opening through which the gas can flow. A device may be used in the cleaning of exhaust gases from internal combustion engines of motor vehicles as well as the cleaning of waste gases of power plants or waste incinerating plants.

Abstract: An electronic air cleaner assembly (1) for attachment to an air handling unit AHU (2) of an air-conditioning system has a housing (10) containing a plurality of electrostatic filter cells (20). One side wall (11) of the housing (10) is pivotally mounted to a side (5) of the AHU (2) by hinges (30) and the opposite side wall (12) is releasably attached to the opposite wall (6) of the AHU (2) by a releasable locking device (42,44). Wheels (46) are provided on the housing (10) to assist in moving it from a closed position to an open position which allows access to the heat exchanger coil(s) (4) of the AHU (2). The electrostatic filter cells (20) may be readily removed either through the open front face or through one of the walls of the housing (10) for checking and maintenance.

Abstract: A method for controlling mass flow of a hydrocarbon feed stream to a steam reformer said stream consisting of hydrogen and of natural gas, naphtha, off-gas, LPG, or a mixture hereof, and

Abstract: A particulate control system which includes a collector such as an electrostatic precipitator (ESP) is improved by incorporation of a collector, such as an electrostatically enhanced separator (EES) connected parallel with the collector and wherein the output flow from the collector is split and a portion of the output flow from the collector is directed through the separator. The input flow to the collector may also be split so that a portion is directed to the separator as well as the collector. A bleed line may also be employed to connect the separator to the collector resulting in a bleed flow from the separator to the collector.

Abstract: A ceramic honeycomb nitrogen purification device is provided including a source gas, a set of gaseous nitrogen passages, a set of oxygen disposal passages, an electroded oxygen conducting ceramic membrane, an electrical power source, an oxygen sensor, and nitrogen purification control circuitry. The source gas includes gaseous nitrogen. The set of gaseous nitrogen passages defines respective source nitrogen input openings and purified nitrogen output openings. The set of oxygen disposal passages defines disposed oxygen output openings, wherein a plurality of the gaseous nitrogen passages are exclusively dedicated to individual ones of the oxygen disposal passages.

Abstract: Improved apparatus and methods for the treatment of boiler flue gas with sulfur trioxide conditioning agent include the beneficial use of catalytic converters that can be located immediately adjacent the injection site for their sulfur trioxide output, that can be individually sized and manufactured for variable required conditioning agent outputs, that can be individually controlled and can provide substantially improved conversion efficiency and that can provide an efficient, flexible, effective and relatively inexpensive multi-boiler flue conditioning system.

Abstract: An electronic air cleaner includes a housing having a fluid inlet and a fluid outlet for creating a fluid stream through the housing. Inside the housing is provided a set of first parallel conductive plates and a set of second parallel conductive plates, herein the first and second plates ar interspersed in an alternating fashion. An ionizer is provided on each of the second plates, and a source of negative high voltage is connected to each of the first plates. Particulate matter can be removed from the air stream in a method using the above-described electrostatic air cleaner.

Abstract: An integrated jet scrubber and particulate collection device for removing sulfur oxides and other contaminants from combustion flue gas and also for removing particulates from this gas, such operations occurring in a single, integrated unit or assembly. In some instances, this combination device may be located in the lower portion of a chimney or stack.

Abstract: Novel photographic processing compositions including a polymeric oxime viscosity-increasing reagent for processing an exposed film unit to provide a photographic image. While this photographic image may be in black-and-white or in color and prepared by any of the heretofore known systems, of particular interest are color diffusion transfer systems for preparing a color image viewable without separation of any of the components or layers of the photographic product. The invention also includes a novel class of polymeric oximes which may be employed in such compositions.

Abstract: In a color diffusion-transfer photographic element comprising a support carrying at least two color image forming units, each comprising a selectively sensitized silver halide emulsion layer and a color image-forming material contained in either said silver halide emulsion layer or a layer adjacent to said silver halide emulsion layer, there is provided an intermediate layer between two of said color image-forming units or protective overcoating layer comprising a polymer of at least one monoacrylate or monomethacrylate of an aliphatic polyhydric alcohol.

Abstract: A photographic element comprising a support, a layer containing certain photographically useful fragments and a layer containing a dye mordant composition comprising a polymer having recurring units of the formula: ##STR1## wherein: A comprises polymerized units of ethylenically unsaturated monomers;R is H or alkyl;R.sup.1 is H, alkyl or is a group containing at least one atomatic nucleus;Q is a linking group;Y is H or an inert group;X is a leaving group;E and F are the atoms necesary to complete a 5-7 membered heterocyclic ring;N is 0 to 2;M is 1 to 3;P is 0 or 1;X is 0 to 90 weight percent; andY is 10 to 100 weight percent of the polymer.The polymeric mordants covalently bond with dyes or dye precursors and are especially useful in diffusion transfer processes.

Abstract: A dry, activator sheet for a dry, thermal silver dye bleach process comprises a support having thereon a non-volatile, diffusible acid, a substituted heterocyclic thiazoline, oxazoline, imidazoline or imidazolidine silver halide complexing agent and a non-hydrolyzable polymer vehicle having an effective pH up to 6.0 and a melting point lower than 200.degree. C. The activating sheet is useful to bleach a silver image containing a bleachable dye.

Abstract: A dry, activator sheet for a dry, thermal silver dye-bleach process, in the absence of a silver dye-bleach catalyst, comprises a support having thereon a nonvolatile, diffusible acid and a non-hydrolyzable polymeric vehicle having an effective pH up to 4.0 and a melting point lower than 200.degree. C. The activator sheet is useful to bleach a silver image containing a bleachable dye.

Abstract: Suitable masking compounds for masking the undesired color side densities of image dyes produced from color couplers are those of the following formula ##STR1## in which R.sup.1 represents hydrogen or one or more substituents such as halogen, alkyl, aryl, a heterocyclic group alkoxy, hydroxyl, amino, acylamino, sulfo, sulfonyl, carboxyl or carbamyl or condensed carbocyclic or heterocyclic ring.R.sup.2 represents alkyl, aryl, a heterocyclic group carboxyl or esters or amide derived from carboxylX represents a dye group optionally containing a solubilizing group.On development with black-and-white or color-forming developers the dye group is released imagewise and is removed by aqueous processing baths leaving back a positive color or masking image.

Abstract: Photographic elements, diffusion transfer assemblages and processes are described which employ a novel nondiffusible compound having a novel releasable azo dye. The dyes are azophenols, or precursors of azophenols, and have electron withdrawing groups in each of the positions ortho to the phenolic hydroxy group.

Abstract: Color photographic elements containing silver halide and incorporated colored and color-forming materials are described. These elements have (a) a layer containing a yellow dye or yellow dye precursor that is bleachable by a mild silver-dye-bleach procedure and (b) at least one other layer, spectrally sensitized to green light, which contains a color-forming coupler which forms magenta dye upon reaction with oxidized color developer. Such elements, when they are processed by a process have improved graininess and yield sharper images. The novel process comprises the steps:A. develop in black and white developer,B. apply non-fixing silver-dye-bleach solution,C. rinse,D. fog and color developE. washF. bleach and fix.A "positive" colored image results.

Abstract: A dye-releasing mechanism is described which employs a nondiffusible dye-releasing compound having a dye or dye-precursor moiety attached thereto through a sulfonamido cleavage linkage so that a diffusible sulfonamide dye or dye-precursor will be released upon oxidation and subsequent alkaline hydrolysis of the compound.

Abstract: Photographic elements, diffusion transfer assemblages and processes are described which employ a novel nondiffusible compound having a releasable 1-arylazo-4-isoquinolinol dye moiety. The compound contains:(a) in the ortho position of the arylazo moiety a metal chelating group, a salt thereof or a hydrolyzable precursor thereof; and(b) a ballasted carrier moiety which is capable of releasing the diffusible azo dye under alkaline conditions. The dye is transferred imagewise to an image-receiving layer where it is contacted with metal ions to form a metal-complexed azo dye transfer image of excellent stability.

Abstract: Improved diffusion transfer products having a light-reflecting layer which includes a U V absorber dispersed in the layer.

Abstract: Photographic elements, diffusion transfer assemblages and processes are described which employ a novel nondiffusible compound having a releasable azo dye moiety. The compound has the formula: ##STR1## wherein: G is a metal chelating group (or a salt or hydrolyzable precursor thereof) or a group which together with a ##STR2## IS CAR (bonded through the oxygen); G.sup.1 is a hydroxy group (or a salt of hydrolyzable precursor thereof);Z is an electron withdrawing group;Z' is alkyl, aryl or N(R).sub.2 (R being H, alkyl or aryl);Car is a ballasted carrier moiety; andT is 0 or 1.The dye can be transferred imagewise to an image-receiving layer where it can be contacted with metal ions to form a metal-complexed azo dye transfer image of excellent stability. The retained dye image in the photographic element can also be bleached, fixed and metallized to form a color transparency or a motion picture film.

Abstract: Photographic elements, diffusion transfer assemblages and processes are described which employ a novel nondiffusible compound having a releasable pyridylazopyrazole or pyrimidylazopyrazole dye moiety. The compound contains in the ortho position of the azopyrazole moiety a metal chelating group, a salt thereof or a hydrolyzable precursor thereof, and a ballasted carrier moiety which is capable of releasing the diffusible azo dye under alkaline conditions. The dye is transferred imagewise to an image-receiving layer where it is contacted with metal ions to form a metal-complexed azo dye transfer image of excellent stability.

Abstract: Photographic elements, diffusion transfer assemblages and processes are described which employ a novel nondiffusible compound having a releasable 2-(5-nitro-2-pyridylazo)-1-naphthol dye moiety. The compound contains a ballasted carrier moiety which is capable of releasing the diffusible azo dye under alkaline conditions. The dye is transferred imagewise to an image-receiving layer where it is contacted with metal ions to form a metal-complexed azo dye transfer image of excellent stability.