Abstract: A venturi scrubber, which has a flow channel defined by a confuser, a throat, and a diffuser in sequence and which has a longitudinal axis. The throat has a throat wall, with nozzles for injecting scrubbing liquid into the throat. At least one insert body in the throat reduces the flow cross-section in the flow channel by at most 45%, preferably at most 30%, especially preferably at most 20%. The insert body is located preferably in a region of the longitudinal extension of the throat after the nozzles, as viewed in the direction from the confuser to the diffuser.

Abstract: A venturi scrubber, which has a flow channel defined by a confuser, a throat, and a diffuser in sequence and which has a longitudinal axis. The throat has a throat wall, with nozzles for injecting scrubbing liquid into the throat. At least one insert body in the throat reduces the flow cross-section in the flow channel by at most 45%, preferably at most 30%, especially preferably at most 20%. The insert body is located preferably in a region of the longitudinal extension of the throat after the nozzles, as viewed in the direction from the confuser to the diffuser.

Abstract: Process for treatment of gases which are exhausted through a sinter bed in a sintering plant, wherein a distinction can be made between a cold zone of the sintering plant with relatively low gas temperatures and a hot zone of the sintering plant with substantially higher gas temperatures. The gases from the cold zone of the sintering plant and the gases from the hot zone of the sintering plant are exhausted and treated as separate partial flows.

Abstract: The preliminary cleaning stage for a dust extraction installation for blast furnace gas is comprised of a large-sized cyclone which comprises a vertical pressurized tank. A gas furnace gas line arriving from the blast furnace is connected to an axial delivery device situated at the upper end of the pressurized tank. The delivery device is configured such that it introduces the blast furnace gas into the pressurized tank in an axial direction. A swirl device with guide vanes is positioned below the axial delivery device and causes the blast furnace gas which is axially introduced into the pressurized tank to swirl about the axis of the pressurized tank.

Abstract: Process for treatment of gases which are exhausted through a sinter bed in a sintering plant, wherein a distinction can be made between a cold zone of the sintering plant with relatively low gas temperatures and a hot zone of the sintering plant with substantially higher gas temperatures. The gases from the cold zone of the sintering plant and the gases from the hot zone of the sintering plant are exhausted and treated as separate partial flows.

Abstract: A method of and an apparatus for the desulfurization of an industrial flue gas wherein the recirculating scrubbing liquid is sprayed with atomization into the scrubbing zone of a column and the droplet size, degree of atomization and gas flow velocity are controlled so that the pH of the scrubbing liquid within the scrubbing zone is substantially 3 to 6, preferably 4 to 5. In the sump oxidation is carried out by the introduction of oxygen to oxidize the calcium sulfite and calcium hydrogen sulfite which is formed to calcium sulfate.

Abstract: A scrubber for flue gases from a fossil-fired power plant in which calcium sulfate dihydrate is produced by recirculating the scrubbing water suspension containing lime and introducing oxygen into the sump collection, has a discontinuously operated pump which withdraws the suspension for recovering of the solid product only discontinuously so as to maintain the solids concentration between 40 and 130 g/l.

Abstract: Calcium sulfate dihydrate in large crystal form is produced by maintaining the circulation of the lime containing scrubbing solution in the desulfurization scrubbing of flue gases from a power plant boiler so that it has a residence time of 5 to 25 hours, preferably 15 hours. The crystals are moved by passing a portion of the recirculation through a thinner in which a sludge containing crystals with a mean particle size of which 90% is in excess of 100 microns is removed. This product can be dewatered and treated with sulfuric acid and steam to convert it to the alpha semihydrate and is free from sulfite.

Abstract: A system for evacuating gases from a top blown steel making converter measures any actual value pressure in a chamber between the seal of a closure ring and duct on which this ring is mounted for movement toward and away from the converter mouth, thereby preventing perturbations from affecting the measurements and allowing accurate control of the evacuating blower to balance the rate of evacuation of the gases and the rate evolution therein in the converter at least during a portion of the blow.

Abstract: An apparatus for the handling of converter gases, especially the storage thereof, comprises a hood which fits over the mouth of a steel making converter and is connected by a duct and blower to a storage vessel. According to the invention, between the blower and the storage vessel, a cruciform junction is provided with the lower upwardly extending stretch being connected to the discharge side of the blower, the upper upwardly extending stretch being connected to a flaring pipe, one horizontal stretch being connected to the storage vessel and the other horizontal stretch to a bypass to the flaring pipe. Valves are provided for controlling the flow such that only the valuable gas is stored.

Abstract: An annular gap washer for scrubbing a gas stream with a liquid, especially for the scrubbing of blast furnace gases with water such that the adjustment of the width of the annular gap controls the pressure at the head of the blast furnace, comprises the usual housing or duct with a tapering configuration and a body axially movable in this duct and with a tapering configuration so that the annular gap is formed between this body and the duct wall. According to the invention, the base angles of the body and the duct walls are different such that the gap converges in the direction of flow of the gases, thereby reducing vibrations or oscillation of the body without interfering with scrubbing efficiency.

Abstract: An annular-gap washer especially for scrubbing of industrial gases, comprises a central body which is axially shiftable in a housing defining an all-around clearance with the body. The clearance forms an annular gap through which the gas stream and water droplets from a spray nozzle axially spaced from the gap, are accelerated and brought into intimate contact. According to the invention at least over part of the gap, the mixture is subjected to an electrostatic field having generally radial field lines.

Abstract: A washer having a controlled-gap scrubber is connected to the gas outlet of a pressure blast furnace and an expansion turbine for the recovery of energy is connected downstream of the controlled-gap washer unit while a bypass is connected across the turbine. The system has operating regions A and B on a diagram in which the gas pressure is plotted along the ordinate and the volume rate of flow of gas from said blast furnace is plotted along the abscissa, the region A being defined between the turbine-insertion and the turbine-operating characteristic curves plotted on the diagram, the region B being defined between the turbine-operating characteristic curve and the corrected blast-furnace characteristic curve. The pressure in the blast furnace where the operating point is in region A while the gas traverses the turbine is controlled by varying the gap width of said control-gap washer unit in response to the pressure.

Abstract: Converter exhaust gases in a steel-refining plant are used for the recovery of energy, e.g. for the production of electrical energy. The steel-refining process is carried out in a closed converter maintained at a pressure of from 1 to several atmospheres gauge above ambient pressure. The converter exhaust gases at such elevated pressure is subjected to washing, preferably in the exhaust-gas stack or duct and the washed converter exhaust gases from several refining processes is stored and supplied to a gas consumer, e.g. an electrical generating plant, at a rate which is independent of the blowing period.

Abstract: The gases emerging from a high-pressure gas furnace are subject to coarse particle separation and then to washing and scrubbing with water before driving an expansion turbine which has a gas bypass so that the turbine can be cut off. The scrubbing water recycled to the scrubber when the turbine is cut off, is permitted to traverse a cooler of the washing-water recovery unit but, when the turbine is operative, the scrubbing water bypasses the cooler. The water introduced into the scrubber can thus have a temperature of about 25.degree. C. when the turbine is bypassed and about 50.degree. C. when it is effective.

Abstract: The gas-cleaning apparatus for a blast furnace operating under pressure using a differential-pressure washing arrangement whereby the differential-pressure washer comprises at least one annular gap with an annular-gap passage and an axially adjustable body received in the annular gap washer. The nozzle is disposed upstream of the annular-gap washer to spray the washing liquid into the gas which is accelerated through the annular gap. The position of this body is controlled in response to the gas pressure within the head of the blast furnace. The annular gap of the washer diverges in the direction of flow of the gas and the body has a complementary shape so that the gap width remains generally constant although its flow cross section increases with the diameter of the annular gap in the direction of flow of the gas.

Abstract: Stack gas is first passed through a coarse-particle separator and then a prescrubbing tower. Then this gas, which is under pressure, is passed through a pair of differential-pressure (annular-gap) washers. The output side of one of the washers is connected directly to a droplet separator at the output of the system. The outlet of the other washer is connected through a turbine driving an electric generator and having its output side in turn connected to the droplet separator. The control body of at least the washer which is connected directly to the droplet separator is adjustable so as to maintain a constant backpressure in the system at the blast furnace from which the stack gas comes. The washer connected to the turbine is set up to pass at least four times as much of the gas as the other washers so that most of the gas passes through the turbine, undergoing a pressure drop that is transformed into the work of driving the turbine and generates electricity.

Abstract: An apparatus for cleaning the exhaust gas of a high-pressure blast furnace comprises a coarse-particle separator, a prewasher and a differential-pressure annular gap washer traversed in succession by the gases. The exhaust gases can be passed through a main duct provided with an expansion turbine or through a bypass duct around the expansion turbine. The expansion turbine unit controls the back pressure at the blast furnace while a separate control circuit is provided to operate the differential-pressure washer with optimum efficiency. A quick-closing valve in the turbine-supply line and a quick-opening valve in the bypass line permits rapid switchover, a pressure-control valve in the bypass line maintains a constant backpressure at the blast furnace when the expansion turbine unit is shut down.

Abstract: Stack gas is first passed through a coarse-particle separator and then a prescrubbing tower. Then this gas, which is under pressure, is passed through a pair of Venturi washers. The output side of one of the washers is connected directly to a droplet separator at the output of the system. The outlet of the other Venturi washer is connected through a turbine driving an electric generator and having its output side in turn connected to the droplet separator. The control body of at least the washer which is connected directly to the droplet separator is adjustable so as to maintain a constant back pressure in the system at the blast furnace from which the stack gas comes. The Venturi washer connected to the turbine is set up to pass at least four times as much of the gas as the other Venturi washers so that most of the gas passes through the turbine, undergoing a pressure drop that is transformed into the work of driving the turbine and generates electricity.

Abstract: Dust-laden waste gases from a converter and from ancillary equipment are exhausted by respective blowers through a first and a second duct to a main and a secondary scrubbing station whence the purified gases escape through respective chimneys. The first duct is provided with two cascaded washing stages, the upstream stage being operable to throttle or block the flow of gases therethrough. An annular cowl for the interception of peripherally escaping converter gases is connected to a third duct which joins the first duct at a location between the two washing stages but is also connectable through a switching valve to the second duct.