Abstract: The pulse voltage for the electrode (12) of a dust separator (10) is generated by a thyristor circuit (19) to be transferred to a dust separator through a transformer (16). It being possible that voltage arcings take place at the dust separator (10), there is the risk, in case of a blocked thyristor (20) that from the secondary of the transformer (16) a high voltage is produced at thyristor (20) to destroy the thyristor. To avoid such an occurrence, a detector (27) is provided which is only responsive to sudden voltage drops whereupon the thyristor (20) is enabled to become conductive so that the energy of the secondary circuit may be discharged to the storage capacitor (24) in the primary circuit.

Abstract: An electrostatic precipitator wherein a gaseous carrier medium is caused to pass through one or more electrostatic filters to be relieved of the major percentage of impurities. The thus purified carrier medium is caused to flow through a tapering funnel-shaped section of the outlet wherein the lower layer of the flow is caused to enter an elongated horizontal slit-shaped aperture leading to a chamber which narrows in the direction of flow of carrier medium therein and discharges into a first conduit for evacuation of the lower layer. The upper layer enters a polygonal or cylindrical second conduit at a level above an adjustable flat or otherwise configurated partition which extends into the funnel-shaped section at the intake end of the second conduit and whose inclination can be changed to vary the size of the aperture leading to the chamber.

Abstract: The hoppers of several dust precipitators are connected to a common readily accessible monitoring station by discrete conduits each of which has a first open end at a preselected level in the respective hopper, a second open end at the monitoring station and an intermediate portion extending above the corresponding preselected level. Suction which normally prevails in the hoppers tends to maintain closed pivotable flaps for the second open ends of the conduits. If the dust in a hopper accumulates to or rises above the respective preselected level, the corresponding flap is opened by a counterweight and such movement of the flap entails the generation of a signal which is used to evacuate dust from the corresponding hopper and/or to actuate an alarm for the convenience and attention of the persons in charge.

Abstract: The operation of one or more full-size electrostatic filters for removing solid impurities from gaseous carrier media is regulated automatically as a function of variations of breakdown potential of a miniature electrostatic filter which is installed in the path of the contaminated gaseous carrier medium. The regulation is such that the potential which is applied to the corona discharge electrode(s) of the full-size filter(s) is very close to but continuously below the breakdown potential. This eliminates the periods of idleness of the full-size filter(s) by preventing arcing because the applied potential does not reach the breakdown value at which the electrostatic field collapses.

Abstract: A fire-proof rescue system for high-rise buildings comprises an upright rail fixed to a face of the building and a rescue cabin movable upwardly and downwardly of the building and having a gear engageable with the rail. The system further includes a gear transmission unit, a cable drum with a cable thereon, and a deflecting roller mounted above the rail and operative for taking up the cable from the cable drum.

Abstract: A rescue system for a multi-floor building includes an upright climb rail assembled of profiled rail sections defining two lateral cooling channels and an upright tooth rack extending around the entire length of the rail; a rescue cabin includes a projecting frame insertable into a front guiding slot in the rail and supporting a driving gear engaging the upright tooth rack; the frame of the cabin overlaps safety windows provided on each floor of the building and has an entrance opening facing the windows.

Abstract: A funnel includes an upper portion which comprises at least two separate parts separably connected to each other so as to define a first interior and lower portion defining a second interior. The first and lower portions are sealingly and separably connected to each other so that the first and second interiors thereof define together the interior of the funnel.

Abstract: Waste gas is contacted with a solution of a salt from a pollutant of the gas. This solution is obtained from another stage of the process used for cleansing or purifying the gas. The resulting mixture of gas and solution is subjected to vaporization so as to obtain a dry gaseous substance constituted by the waste gas and the evaporated solvent for the salt. The gaseous substance thus formed contains crystals of the salt as well as the pollutant present in the original waste gas. The salt crystals and other solid particles are removed from the gaseous substance in the form of a dry solids mixture. The gaseous substance is subsequently mixed with an absorption fluid such as an ammonia solution in order to wash out and redissolve any salt crystals which may remain in the gaseous substance and in order to remove the pollutant present in the original waste gas from the gaseous substance.

Abstract: A sprinkler system having a pressurized sprinkler conduit which is separated from a water supply by a normally closed valve, and a fire alarm system having a circuit which is connected with this valve and opens the same in response to the detection of a fire by the circuit, is operated by detecting the absence of electrical energization of the fire alarm circuit, and thereupon operating the sprinkler system as a function of pressure losses in the sprinkler conduit rather than as a result of the operation of the fire alarm system.