Abstract: A process and apparatus are used for purifying dust- and pollutant-containing exhaust gases, which are first subjected in a first stage to a dry purification in a mass separator and are subsequently subjected in a second stage to an electrostatic purification in an electrostatic precipitator. In the second stage the exhaust gases are passed through one or more fields provided with liquid-wetted collecting electrodes, which define gas passages. The electrostatic precipitator also has an overflow trough and a collecting trough for each collecting electrode. Liquid supplied to the overflow trough flows onto the collecting electrode and then is collected in the collecting trough.

Abstract: The process for cleaning collecting surfaces of dedusting electrostatic precipitators includes the steps of introducing a coarse-grained cleaning dust into the dedusting electrostatic precipitator, collecting at least the cleaning dust electrostatically in the dedusting electrostatic precipitator and periodically removing the cleaning dust so collected from the collecting surfaces to form a collected dust. To provide a more complete cleaning, the cleaning dust is fed into a gas-flowless space above the fields containing the collecting electrodes and the cleaning dust is distributed in the gas-flowless space according to the cleaning requirements. An apparatus for performing the above cleaning process is also described.

Abstract: A process and an apparatus for the electrostatic purification of dust- and pollutant-containing exhaust gases in multiple-field precipitators are proposed. The exhaust gases are first subjected in a first stage to an electrostatic purification under dry conditions in gas passages defined by platelike collecting electrodes and are subsequently passed in a second stage through one or more fields defined by liquid-wetted collecting electrodes, which define gas passages. The liquid which is supplied in the second stage at the top ends of the collecting electrodes is laterally discharged from the precipitator and the substantially dry dust which is still collected in the second stage is fed to dust-receiving means.

Abstract: Centrifugal separator and a granular bed filter are arranged one over the other in a common cylindrical housing to constitute a unit for separating solid particles from a gas stream. For more effective separation of solid particles within a structure having a given overall volume, the gas inlet pipe is rectangular in cross-section and has a height amounting to 60 to 80% and a width amounting to 20 to 30% of the height H and a gas guide is provided in the gas outlet pipe and extends parallel to the axis of the pipe. This will result in an optimum matching of the separation of solid particles affected by centrifugal force and in the granular bed in close succession in the single structural unit.

Abstract: Disclosed is an improved process for the production of a sulfur trioxide conditioning gas, which consists in compensating the faulty "ambient gas temperature" in a simple and effective manner, such that all of the subsequent functions can take place at the established optimum temperature and can no longer be adversely affected by fluctuations in the ambient air temperature.

Abstract: A horizontal-flow granular filter is provided at its bottom part with openings through which pistons are displaceable in an up-and-down movement to loosen the granular bed during back-flushing of the filter. This reduces the energy cost of cleaning and the tendency toward abrasive deterioration of the granule while also ensuring an improved cleaning action.

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: 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.