Abstract: A regenerable process for removing SO.sub.2 from a gas comprising contacting the gas with an aqueous suspension of gelatinous aluminum hydroxide.

Abstract: A comprehensive multiple rapper control system controls rapping intensity with enhanced accuracy, controls a large number of rappers in any desired sequence with intensity control for each individual rapper, and includes alarm circuitry for reliably indicating open circuited and short circuited conditions in the rapper coils or in the electrical connections to the rapper coils. For enhanced accuracy, a short boost pulse of full lift energy is applied immediately prior to a lift pulse of controlled energy. The boost pulse overcomes initial rapper plunger sticking forces so that total rapper plunger lift accurately reflects the electrical energy supplied during the subsequent controlled pulse. Advantage is taken of the relatively constant boost pulse which is supplied to every rapper in the system regardless of the energy supplied during the control pulse to provide an alarm circuit. Current through each rapper plunger lift coil is sensed during at least a portion of the boost pulse.

Abstract: Sulfur dioxide is scrubbed from boiler flue gases in a double-loop alkali scrubber, one a quencher loop and the other an absorption loop. Preferably, the reagent flow of the two loops is isolated so that none of the reagent from the quencher loop is cycled to the absorber loop. A substantial portion of the make-up water for the quencher loop is received from the absorber loop and solids are concentrated in a dewatering system which includes a hydroclone.

Abstract: Moveable and fixed vertically depending, longitudinally spaced baffles are mounted perpendicular to the direction of gas flow on the roof of large generally horizontal runs of flues carrying dust laden gas as a cost-effective way to reduce gravitational dust dropout.

Abstract: A jacking device for use with a thread bar having a plurality of couplers and nuts spaced longitudinally thereon. The jacking device is arranged to permit movement thereof longitudinally past the respective couplers and nuts while permitting utilization of the nuts by threaded movement thereof on the thread bar for supporting different portions of the jacking device relative to the thread bar in effecting the desired jacking operation. The jacking device may be utilized to climb the thread bar and, alternatively, may be utilized to pull the thread bar and lift a load associated therewith. The jacking device includes biased chuck elements movably carried to permit passing of the couplers and nuts and selective support thereof on the nuts in effecting the controlled jacking operation.

Abstract: An electrostatic precipitator rapping system of the type which lifts weights and then allows the weights to fall to impact on precipitator elements to impart particulate-dislodging vibration thereto. The system includes a rotating drive shaft and a plurality of individual rapping mechanisms disposed along the drive shaft. Each rapping mechanism includes a driving assembly affixed to the drive shaft and a driven assembly mounted for pivotal movement. A means attached to the driven assembly lifts a weight as the driven assembly pivots in one direction towards a release position and allows the weight to fall to impact as the driven assembly pivots in the other direction towards a resting position.

Abstract: A shop assembled drag-type conveyor is provided with means for shortening its length and width and the conveyor is placed in assembled, but shortened form in a dust hopper of an electrostatic precipitator. When the conveyor is in place it is lengthened to its operating length and its width is expanded and attached to the side walls of the dust hopper with a minimum of on-site construction.

Abstract: Parameters for optimum operation of a pulsed multisection electrostatic precipitator are disclosed: It has been discovered that superior particulate collection can be achieved by a combination of pulse and conventional DC voltages. The pulse rise time and decay time are made short enough so that adverse sparking conditions do not develop. The base voltage (conventional DC voltage) is adjusted in coordination with the superposed pulse characteristics (pulse voltage, pulse frequency and pulse shape) to maintain an average current through the collected dust layer just below or at that value which would cause electrical breakdown of the dust layer. Base voltage may actually be below normal corona starting voltage in some cases. The pulse produces instanteously very high ion densities and electric field strengths. In one design of precipitator, alternate sections are pulsed, with the other alternate sections functioning as collecting sections and merely having DC base voltage applied thereto.

Abstract: A wetted parallel plate collecting electrode arrangement which increases the maximum electric field intensity possible without having water draining off the lower edges of the collecting electrodes forming small droplets which are accelerated towards the opposite electrodes. An electrically conductive partition plate maintained at a voltage intermediate the voltages on the electrodes is disposed between the lower edges of oppositely charged electrodes and extends above and below the lower edges of the electrodes. Preferably, the partition plate is electrically "floating" and receives its voltage due to the effects of the electric field between the collecting electrodes.

Abstract: An equilateral derrick structure such as for use in erecting chimneys and the like, wherein a plurality of horizontal members, upright diagonal brace members, and vertical column members are interconnected by a plurality of connectors to provide a desired three-dimensional framework derrick. The horizontal members may define a first kind of structural element, the brace members may define a second kind of structural element differing from the first kind, and the column members may define a third kind of structural element differing from each of the first and second kinds. The connectors may be formed as unitary members having a center portion defining a right circularly cylindrical hole for receiving corresponding right circularly cylindrical column members. The connectors may further define outwardly projecting flanges for connection of the horizontal members and diagonal brace members thereto.

Abstract: A corrosion resistant electrostatic precipitator has an array of tubular collector electrodes with a cylindrical casing, the tubular collector electrodes and casing each having a surface resistivity of the order 10.sup.6 ohms. The walls of the collector tubes, in preferred form, are a lamina comprising, in order from the inner surface outwardly, an innermost resin impregnated with graphite followed by a conductive metal mesh, another layer of resin impregnated with graphite, a fiberglass veil (corrosion resistant barrier), a layer of fiberglass mat, a layer of fiberglass roving, another layer of fiberglass mat, another layer of fiberglass roving, and finally an outer layer of fiberglass mat. The wall of the cylindrical casing is also a lamina whose make-up is generally similar but not identical to the walls of the collector tubes. Means are provided for grounding the conductive metal mesh which is embedded in the collector walls and in the casing wall.

Abstract: Amber glass is made by melting a soda-lime glass-forming batch in which at least 1 percent of the silica content is provided by lignite fly ash.

Abstract: A modular gas and liquid contact member is formed of a plurality of extended surface sheet members with means associated with at least the peripheral margins thereof warping the sheets and maintaining the sheets in an undulated array. In a preferred form of the invention, the means for warping and maintaining the sheet members in the undulated array comprises a plurality of through bolts and spacers of varying lengths threaded on the through bolts and contacting opposed surfaces of adjacent sheet members.