Abstract: In an electrostatic precipitator which is supplied with energy in the form of d.c. voltage pulses or of a d.c. voltage and superposed pulses, the energy supply is optimized and reverse corona discharges are avoided by use of a method in which energy at the highest possible rate is supplied to the electrostatic precipitator during the pulsing period and the total energy consumption of the electrostatic precipitator required to achieve in the pure gas a predetermined maximum dust content is minimized in that the pulse parameters are optimized and the application of pulses is interrupted for the longest possible non-pulsing time which is consistent with the predetermined maximum dust content of the pure gas.

Abstract: The discharge end of the rotary kiln (24) is surrounded by and gas-tightly sealed to a stationary kiln head (2), which contains a rigid, cooled, inclined grate (1). A container (3) for collecting oversize is mounted on the kiln head (2) and is provided at its discharge end with a gate valve (4). The collecting container (3) is surrounded by and gas-tightly sealed to an outer container (5) and is provided with a gas-tight flap valve (6) and with a fitting (7) for a gas-tight connection to a transport container (8). Under the grate (1) the kiln head (2) constitutes a buffer bin (9) for the particles falling through the grate. The buffer bin (9) is succeeded by a batching bin (10), which is provided with a gas-tight upper shutoff valve (11). On its discharge side, the batching bin (10) is provided with a gas-tight lower shutoff valve (12) and with a fitting (13) for a gas-tight connection to a transport container (14).

Abstract: Disclosed is a method for the operation of an electrostatic precipitator so as to provide a pure gas having a predetermined dust content with a minimum consumption of energy. Characteristics for the operation with an unpulsed voltage are recorded for different dust resistivities. Each characteristic has then associated with it that k value with which a pure gas having a predetermined dust can be achieved with a minimum energy consumption. During operation, the actual characteristic is compared with the recorded characteristics and that k value is selected which is associated with the recorded characteristic which coincides with the actual characteristic or is next below the actual characteristic. The actual characteristic is determined in predetermined intervals, the duration of which is determined in dependence on the speed with which the operating conditions may be expected to change.

Abstract: A catalyst is produced in two stages in that prefabricated carrier bodies are impregnated with solutions which contain vanadium and alkalies. When the impregnated carrier bodies have been dried, the conversion activity of the catalyst is increased further in that the catalyst is activated under oxidizing conditions at a temperature of 700.degree. to 1000.degree. C.

Abstract: Disclosed is an electrofilter for the removal of dust from gases under a pressure of up to 30 bar and a temperature up to 500.degree. C. The electrofilter has a vertical cylindrical pressure casing having a lower chamber for the accommodation of the precipitating electrodes and spray electrodes, an upper chamber for the connection of the gas ducts and the disposition of the insulators, as well as a funnel-shaped dust collector. The upper chamber is divided horizontally and vertically by walls to permit a double-filter effect, and to thermally insulate the insulators from the flowing-gas chamber.

Abstract: Sponge iron is produced by a direct reduction of iron oxide containing materials in a rotary kiln, the material discharged from the rotary kiln is separated into sponge iron and material which contains surplus carbon, the carbon-containing material is burnt in a fluidized bed reactor containing a circulating fluidized bed, and the heat generated by the combustion is recovered and utilized to produce electric power. To ensure a utilization of the surplus energies of the rotary kiln process and to minimize the contents of SO.sub.2, NO.sub.

Abstract: A solvent-containing composition for the cleaning of equipment used to mix and handle reactive multicomponent mixtures of high viscosity, which react to form polymers. In order to improve the capacity of the solvent to dissolve the more or less polymerized mixtures, the solvent contains a chain-terminating agent. For binary systems containing liquid polysulfide polymers, the solvent contains a chain-terminating agent or chain-degrading agent containing mercapto group-containing compounds of the general formula R--SH or disulfide or polysulfide group-containing compounds of the general formula R--S.sub.n --R, in which formulas n.gtoreq.2 and R represents equal or difficult alkyl residues, aryl residues or substituted alkyl or aryl residues. For binary polyurethane systems, the solvent contains chain-terminating compounds which in their molecule contain a Zerewitinoff-active hydrogen atom and have the general formula HY--R.sup.1, wherein ##STR1## where R.sup.2 =H or alkyl and R.sup.

Abstract: An electrostatic precipitator is fed high voltage pulses by a pulse generating circuit including a high voltage transformer and a first thyristor switch connected in series with a primary winding of the transformer. Magnetic saturation of the core of the high voltage transformer is prevented by recurrently short circuiting the primary winding of the transformer by means of a second thyristor switch connected in parallel to the primary winding. The second thyristor switch is closed for a period of time extending from a first instant following a high voltage pulse crest to a second instant at or before the start of a pulse generating cycle subsequent to the pulse crest.

Abstract: The reactor for the gasification of the fuel in a fixed bed comprises a rotary distributor, which is disposed over the fixed bed and includes at least one outlet structure for the fuel. The outlet structure consists of a tube, which is formed at its lower end with two arcuate cutouts through which the fuel flows out approximately at right angles to the direction of movement of the tube. Each cutout lies in a plane which includes an angle of about 25.degree. to 50.degree. with the horizontal. The outlet end of the tube has preferably the same elevation on the leading and trailing sides of the tube.

Abstract: Linear vibratory motion is imparted to two mutually opposite plates, which are connected to each other. As a result, conveying impulses are applied to solid particles. To permit chemical or physical processes to be carried out with fluids flowing in cocurrent or countercurrent streams and to effect a transfer of material or heat at a high rate during the vibratory conveyance or to disintegrate or compact the solid particles, conveying pulses are imparted to the particles by both plates and the solids occupy in a state of rest only part of the free space between the two plates.

Abstract: Collecting electrodes extend vertically in dust-collecting electrostatic precipitators, which are horizontally traversed by gas. Each collecting electrode comprises a plurality of profiled sheet metal strips which are suspended from the roof structure and are hooked into each other at their vertical longitudinal edges. The collecting electrodes also comprise at least one lower transverse connector. Two adjacent collecting electrodes define a gas passage which contains centrally disposed corona electrodes. Each sheet metal strip is substantially W-shaped in cross-section defining shallow dust-collecting pockets and comprises portions which are inclined alternately in opposite directions with respect to the direction of gas flow and portions which are parallel to the direction of gas flow and disposed between the inclined portions. The edge portions extend also parallel to the direction of gas flow and are reversely bent through 180.degree.

Abstract: The liquid sulfur which contains H.sub.2 S is sprayed in a steel vessel and the liberated gases which are rich in H.sub.2 S are withdrawn. A degasification accelerator is added to the liquid sulfur. The steel vessel contains at least two chambers, which communicate with each other and are connected in series. Sulfur at temperatures in the range from 140.degree. to 160.degree. C. is supplied to the first chamber. Sulfur is withdrawn from the second chamber and is cooled to temperatures of 120.degree. to 135.degree. C. outside the vessel. The liquid sulfur which has been cooled is sprayed in the gas space of the first chamber. The sulfur is caused to remain in the steel vessel for a dwelling time of 12 to 32 hours. The gas spaces of the chambers are scavenged with an oxygen-free inert gas. The sulfur is withdrawn from the vessel and sprayed in the gas space of one of the chambers about 30 to 50 times until the dwelling time of the sulfur in the vessel has expired.

Abstract: The fuel constitutes a fixed bed in the reactor, which is provided in its lower portion with a rotating grate, which is adapted to be speed-controlled. The gasifying agents consisting of oxygen, steam and/or carbon dioxide are introduced through the rotating grate into the fixed bed. Under the action of the rotating grate the incombustible mineral constituents are delivered as solid ash to a lock chamber container. The speed of the rotating grate is controlled in dependence on the temperature in the lock chamber container. The speed will be decreased when the temperature in the lock chamber container exceeds a desired value, and increased when the temperature is too low. The desired temperature in the lock chamber container is taken into account as a range, which varies with time. The speed can be controlled by hand or can be automatically controlled with the aid of a computer. The rate at which oxygen as a gasifying agent is supplied to the reactor is also taken into account in the speed control.

Abstract: A separator for collecting solid particles from a gas stream by centrifugal force comprises a vertical cylindrical housing having a coaxial top gas discharge pipe, a lower gas supply line extending coaxially into the housing, and a solids outlet which is laterally disposed in the lower portion of the housing. That separator has its gas supply line closed at its upper end and merging into at least one duct by which a vertically rising gas stream is deflected into a substantially horizontal direction that is tangential to the gas supply line.

Abstract: In a method of periodically heating a product separator of a plant for producing anhydride or maleic anhydride, a PA or MA product is deposited on cooling surfaces of the product separator. To melt the product, the cooling surfaces are indirectly heated by means of a heated liquid, which is circulated through the product separator. The liquid heat transfer medium is indirectly heated with steam in a heater for the heat transfer medium. At least during the time of the largest steam demand, most of that steam is taken from a steam accumulator, which is charged with steam supplied from the plant for producing PA or MA. The charging of the steam accumulator is effected to at least a substantial degree during the time in which the heater for the heat transfer medium is out of operation or is operated under a low load.

Abstract: The moist ores are dried in direct contact with hot dry tail gas from a contact process plant for producing sulfuric acid. The dried ores are roasted, the SO.sub.2 -containing gases produced by the roasting are processed in the contact process plant to produce sulfuric acid, and the tail gases from the contact process plant are heated up with surplus heat from the contact process plant. These heated tail gases are used to dry the moist ores.

Abstract: A gas-distributing device for use in a gas passage which flares like a diffuser, particularly a passage leading to an electrostatic precipitator, formed by a set of components consisting of perforated sheet metal panels, carrying and connecting elements, in which the carrying elements have no wide end faces extending at right angles to the direction of flow so that the variations of the gas velocity over the entire flow area can be distinctly reduced. Besides, the set of components can be manufactured at lower total costs and the perforated sheet metal panels, which are connected by the connecting element to the carrying elements consisting of flat bar strips, is simplified.

Abstract: In the proposed process of sorting metal particles in dependence on their chemical composition the melting point and/or the melting temperature range are used to identify the particles. A radiation pyrometer integrally combined with a laser is used for this purpose and only a fraction of a second is required to test a given particle. A graph shows the melting temperatures of the metals and alloys frequently occurring in shredded scrap.

Abstract: Linear vibratory motion is imparted to two mutually opposite plates, which are connected to each other. As a result, conveying impulses are applied to solid particles. To permit chemical or physical processes to be carried out with fluids flowing in cocurrent or countercurrent streams and to effect a transfer of material or heat at a high rate during the vibratory conveyance or to disintegrate or compact the solid particles, conveying pulses are imparted to the particles by both plates and the solids occupy in a state of rest only part of the free space between the two plates.

Abstract: In a process of producing coarse pure potassium chloride crystals from feed solutions containing potassium chloride and other impurities, comprising cooling the solution under a vacuum in a plurality of stages connected in series, withdrawing by means of a conveyor the potassium chloride which has been crystallized in each stage, withdrawing the water vapors, collecting crystalline potassium chloride from the solution, drying the crystalline potassium chloride and separating the same into several fractions, compacting the fine fraction and cooling and aminating the end product, the potassium chloride content of the feed solution is increased in that potassium chloride from one or more of the stages containing solution at a low temperature is recycled to the feed solution before the latter enters the first stage.