Abstract: A high-voltage electrostatic precipitator is powered by a transformer supported below the high-voltage electrodes. A lead-in conductor extends from the transformer to the electrodes through a screen-covered aperture in the precipitator housing. Purging gas is directed through the aperture to prevent accumulation of particulates on the lead-in conductor.

Abstract: A system and process are provided for recovering copper from a contaminated copper-bearing source such as copper smelter flue dust. The copper-bearing source is leached in an acidic solution to produce a liquor containing dissolved copper and dissolved contaminants. Simple copper sulfides are precipitated from the liquor by reacting the liquor with chalcopyrite and sulfur dioxide. Copper is recovered from the precipitated sulfides.A novel process is provided for precipitating simple copper sulfides from a solution containing both dissolved copper and dissolved contaminants. The solution is combined with precipitation product such that substantially all ferric iron contained in the solution is reduced to ferrous iron. The ferric-free solution is reacted with chalcopyrite solids and sulfur dioxide to precipitate the dissolved copper as simple copper sulfides.

Abstract: Total organic carbon can be determined for each one of a plurality of discrete aqueous samples containing halide ion by means of an apparatus comprising a reactor (13), and a pump (12) and flowline (11) for introducing a continuous flow into the reactor (13) of a solution that contains an oxidizing agent and mercuric monohalide ion without forming an insoluble precipitate. The solution to be introduced into the reactor (13) is prepared by mixing the oxidizing agent with a solution containing mercuric monohalide ion; and the solution containing mercuric monohalide ion is formed by adding a quantity of mercuric halide and a quantity of mercuric nitrate to an aqueous solution containing nitric acid, where the molar concentration of the mercuric halide is at least equal to the molar concentration of the mercuric nitrate.

Abstract: In a system for controlling electric power supplied to corona-generating electrodes in an electrostatic precipitator (10), an opacity-sensitive transducer (20) produces an output signal proportional to the opacity of the flue gas exiting from the precipitator (10). The signal from the transducer (20) is compared in comparators (304 and 305) with pre-set upper and lower limits defining a permissible opacity range for the flue gas. When the signal from the transducer (20) exceeds the pre-set upper limit or falls below the pre-set lower limit, automatic voltage controllers (40) are activated to control the power supplied to the corona-generating electrodes in order to restore the flue gas opacity to the permissible opacity range.

Abstract: A slurry electrowinning apparatus includes a tank (10) in which are mounted alternating, spaced-apart anode (18) and cathode (20) electrodes. An inlet opening (60) is formed in a side of the tank (10) for introducing a copper-bearing electrolyte to the tank (10). An overflow opening (76) is also formed in a side of the tank (10) such that a solution level (62) is maintained in the tank (10) which is above the inlet opening (60). Baffles (64) are mounted within the tank (10) for evenly distributing the slurry within the tank (10) between the anodes (18) and cathodes (20). Both the anodes (18) and the cathodes (20) are supported within the tank (10) by electrode guides (22) such that a high pressure contact between the electrodes (18, 20) and the main electrical bussing (78) is provided.

Abstract: A humidifier comprises a conduit (20), a rotatable fan assembly (30) mounted in the conduit (20) for causing an air stream to flow through the conduit (20), and a counter-rotatable water slinger assembly (40) mounted coaxially with and downstream of the fan assembly (30) for centrifugally ejecting water into the conduit (20). A cylindrical mist-forming member (60) affixed to the fan assembly (30) for rotation therewith extends downstream therefrom so as to surround the water slinger assembly (40). Water ejected centrifugally from the water slinger assembly (40) is sheared by the mist-forming member (60) into a mist of fine water droplets, which become entrained in the air stream passing through the conduit (20).

Abstract: A machine for baking thin wafers of the type which are foldable to form fortune cookies includes an oven, a parallel chain conveyor that moves continuously in a plurality of horizontal runs through the oven, and a plurality of baking units carried by the conveyor. Each baking unit consists of two associated platens mounted in movable face-to-face parallelism. The wafers are baked in cupped containers which are carried by one of the platens and which are sealed by the other platen during baking. Following a baking period, the platens are inverted. A mechanism is provided to remove baked wafers from the inverted platens. Finally, a mechanism is provided to carry the removed wafers to discharge from the machine.

Abstract: A dissolving tank for dissolving a large amount of gas in a liquid and including a generally horizontally disposed tray (28) (29) mounted within the tank (2) (21) to divide the tank (2) (21) into an upper reaction zone (36) and a lower discharge zone (38). The tray (28) (29) has formed therein both a central opening (34) (35) for fluid communication between the discharge zone (38) and the reaction zone (36) and peripheral openings (32) (33) which allow any liquid which collects on the tray (28) (29) to flow from reaction zone (36) to discharge zone (38). The dissolving tank further includes liquid feed means (10) positioned within the tank (2) (21) below the tray (28) (29) to discharge liquid upwardly through the central opening (34) (35) of the tray (28) (29) and into the reaction zone (36). The dissolving tank further includes liquid distribution means (14) mounted within the tank (2) (21) above the tray (28) (29) and having flared sidewalls (15) and a vertically-oriented distribution orifice (16).

Abstract: Total organic carbon in an aqueous sample containing halide ion is determined by preparing an aqueous solution containing an oxidizing agent and mercuric monohalide ion without forming an insoluble precipitate, introducing the sample into the solution so formed, irradiating the solution and sample with ultraviolet energy to oxidize organic matter in the sample to produce carbon dioxide, sparging the carbon dioxide so produced from the solution, and measuring total carbon in the carbon dioxide. The aqueous solution is prepared by mixing the oxidizing agent with a solution containing mercuric monohalide ion, which is formed by adding a quantity of mercuric halide and a quantity of mercuric nitrate to an aqueous solution containing nitric acid, where the molar concentration of the mercuric halide is at least equal to the molar concentration of the mercuric nitrate.

Abstract: The following disclosure teaches ways and means for clarifying raw sewage and thickening secondary sewage sludge. The disclosed apparatus comprises a tank having upper and lower feedwells disposed therein. Raw sewage is introduced into the lower feedwell and flows into the lower part of the tank to be clarified therein, and secondary sludge is aerated and introduced into the upper feedwell so that it flows therefrom and thickens in the upper part of the tank by flotation type thickening.

Abstract: An improved precipitator voltage control system including an automatic voltage control (AVC) circuit, a firing circuit, an alarm circuit, a power-saving circuit, a remote set-point control circuit and a power supply, all of which are mounted on a single, readily interchangeable circuit board. The automatic voltage control circuit includes a highly responsive spark detection subcircuit which causes the transformer/rectifier voltage to be reduced to zero at the end of the half-cycle in which a spark occurs and then causes the voltage to remain at zero for a short period of time after which voltage is reapplied in a dual ramp manner causing it to rapidly reach a level below the precipitator arcing potential and then increase at a slower rate to the threshold of sparking. The firing circuit drives silicon-controlled rectifiers (SCRs) through optical couplers which provide several thousand volts of circuit isolation.

Abstract: In a system for filtering fibers and particulates from a gas stream, a fiber separator (10) is disposed to remove fibers in gross quantity from the gas stream. A corona charging apparatus (20) is disposed downstream of the fiber separator (10) to impart electric charge to particulates and to fibers that escape removal from the gas stream by the fiber separator (10). An electrostatic filter medium (30), which may advantageously be mounted on the cylindrical wall of a drum filter, is disposed downstream of the corona charging apparatus (20) to remove electrically charged particulates and fibers from the gas stream. The corona charging apparatus (20) comprises at least one fiber-rejecting corona discharge electrode (21 or 25). The fiber-rejecting electrode (21) comprises a shielding portion (22) facing upstream and a corona discharge portion (23) facing downstream in the gas stream.

Abstract: A quick-coupling locking mechanism is provided comprising a C-shaped attachment means (2) which is secured to a service module (C) of any type and a toggle linkage assembly which is secured to a service vehicle (B). The C-shaped attachment means (2) is formed to define a lifting hook (3) at its top and a holding hook (4) at its bottom. The linkage assembly includes a horizontal lifting bar (5) for engagement with the lifting hook (3) and a horizontal holding bar (6) for engagement with the holding hook (4). The linkage assembly is selectively operable to move the lifting bar (5) into secure engagement with the lifting hook (3) to raise the service module (C) such that the holding hook (4) is brought into engagement with the holding bar (6). The linkage assembly further includes separating means (21) responsive to the movement of the assembly to force the lifting bar (5) away from the holding bar (6) to lock the lifting bar (5) and the holding bar (6) into secure engagement with the attachment means (2).

Abstract: A separator assembly (30) for an evaporator comprises an ensemble of spaced-apart corrugated vanes (31) mounted in a hollow cylindrical configuration at the outlet (22) of the evaporator. The spacing between adjacent vanes (31) is such as to prevent line-of-sight passage of vapor between adjacent vanes (31) from the outer wall (33) to the inner wall (34) of the ensemble. The upper end of the ensemble of vanes (31) is secured to an annular support member (32), which is secured to the evaporator circumjacent the outlet (22). A closure member (40) is secured to the lower end of the ensemble. The annular support member (32) and the closure member (40) prevent vapor from leaving the evaporator via any path other than tortuous path between adjacent vanes (31) in a direction from the outer wall (33) to the inner wall (34). Droplets entrained in the vapor passing through the separator assembly (30) impinge upon the vanes (31) and are thereby separated from the vapor.

Abstract: A rotary rake structure for use in a settling tank comprises a torque transmitting member and a pair of rake arms. The torque transmitting member is mounted in the tank for rotation about a vertical axis. Each rake arm comprises one or more upper chords and one or more lower chords, the two rake arms being symmetrically disposed on opposite sides of the vertical axis of rotation along a transverse axis generally perpendicular to the axis of rotation. The upper and lower chords of each rake arm are fixedly positioned with respect to each other by truss members. The upper chords of both rake arms are attached to the torque transmitting member so as to permit pivotal motion of each rake arm in a plane containing the transverse axis and the vertical axis of rotation. Scraping devices depend from the lower chords for raking sediment at the bottom of the tank when the rake arms are rotated by the torque transmitting member. The end of each lower chord adjacent the axis of rotation terminates in a flange.

Abstract: A coke guide fumes control system includes a hood overlying a coke guide and apparatus for continuously evacuating the hood during a coke pushing operation. Several types of apparatus are illustrated. Some types are self-contained, including blowers and filter mechanisms mounted on the coke guide hood. The fumes and dusts from the pushing operation are evacuated through the filter mechanism under suction established by the blower, and the purified air pulled through the blower is exhausted to atmosphere. Alternatively, the hood can include slot-like nozzles cooperating with the blower to generate an air curtain which is directed down the sides of the coke guide to prevent the escape of contaminants through openings typically provided in the sides of such coke guide.

Abstract: Disclosed is a process provided for increasing the fuel value of off-gas (20) recovered from oxygen blowing steel converters (10, 100). Carbon is introduced into an off-gas capture hood (22) to react with carbon dioxide therein to form carbon monoxide. A carbon dioxide curtain (61) is formed which surrounds the inlet end of the gas capture device (22) to prevent air from entering the capture device. Carbon dioxide is drawn from the carbon dioxide curtain (61) into the capture device (22) to mix with the gases therein.

Abstract: A process and system are provided for recovering copper from chalcopyrite concentrate. The chalcopyrite is ground to a mean particle size of about 1.5-5 microns. The ground chalcopyrite is then divided into a first stream and a second stream. The first stream is leached in a leach solution containing at least about 100 gpl sulfuric acid and about 10-30 gpl ferric iron to produce a copper sulfate solution containing about 40-75 gpl dissolved copper and less than about 5 gpl ferric iron. The second stream of ground chalcopyrite is combined with the copper sulfate solution and with sulfur dioxide such that the combination reacts to precipitate dissolved copper from the copper sulfate solution as simple copper sulfides and to produce a liquor containing dissolved ferrous iron. The simple copper sulfides are then separated from the ferrous iron liquor.

Abstract: A process and system to dry wet sewage sludge with hot sand and to burn the dried sludge. The sand is heated in a heating device by burning dried sludge, and the hot sand is mixed with wet sludge in a drying device. Thereby moisture is driven from the wet sludge to dry it. The dried sludge and sand are separated, and the sand returned to the heating device while the dried sludge is burned to heat the sand.

Abstract: A rotary rake structure for use in a settling tank comprises a torque transmitting member and a pair of rake arms. The torque transmitting member is mounted in the tank for rotation about a vertical axis. Each rake arm comprises one or more upper chords and one or more lower chords, the two rake arms being symmetrically disposed on opposite sides of the vertical axis of rotation along a transverse axis generally perpendicular to the axis of rotation. The upper and lower chords of each rake arm are fixedly positioned with respect to each other by truss members. The upper chords of both rake arms are attached to the torque transmitting member so as to permit pivotal motion of each rake arm in a plane containing the transverse axis and the vertical axis of rotation. Scraping devices depend from the lower chords for raking sediment at the bottom of the tank when the rake arms are rotated by the torque transmitting member. The end of each lower chord adjacent the axis of rotation terminates in a flange.