Abstract: An arrangement drives volatile impurities from ground water and ground through which it flows by producing a negative pressure in a well shaft extending to a region of a contaminated ground water by supplying a gas in an air chamber arranged above a water level in the well shaft. The arrangement includes partitions separating a well shaft region with a water permeable shaft wall for water suction from the ground and a well shaft region for resupply of the water into the ground. The partitions are formed as a pipe. A suction pump is arranged in the water suction region of the shaft and has an outlet, and a closed water receiving chamber is arranged underneath a nozzle body. The outlet of the suction pipe is connected with the water receiving chamber.

Abstract: An arrangement for cleaning contaminated ground water and the ground through which it passes with a shaft extending to the region of the ground water to be cleaned has a shaft wall including a plurality of water permeable and water impermeable wall portions with one of the water impermeable wall portions located between water permeable wall portions, a tightly inserted partition located above a ground water level in the one water impermeable wall portion and having an opening, a throughgoing passage extending in the opening and forming a part of a flow path of a ground water and ending above a ground water level in the well shaft, a circulating pump arranged in the well shaft for circulating the ground water along the flow path, and a filter arranged in the well shaft in the flow path of the ground water circulated by the circulating pump.

Abstract: An apparatus for cleaning and aeration of open bodies of water includes a floating structure partially extending above a water surface and having at least one opening in its lower region through which, water flows into the apparatus, and a fan arranged in the upper region of the floating structure for creating vacuum that enables flow of water inside of the floating structure. An air receiving space is defined inside of the floating structure. A perforated plate which is located below a water surface established in the floating structure, limits the air receiving space from above. The air receiving space is connected with atmosphere by a gas conducting conduit.

Abstract: An arrangement for driving out volatile impurities from a ground water with a well shaft extending to the region of the ground water to be purified, the arrangement comprises an element for producing a negative pressure in the well shaft and supplying a gas underneath a water level in the well shaft, an element for providing a plurality of capillary openings in an upper sieve wall portion of the well shaft at least in a purification region between a gas inlet and a water level in the well shaft to enhance a laminary flow of ground water with relatively high speed, the capillary openings forming a greater free throughflow surface than a remaining portion of the well shaft.

Abstract: An aerating apparatus or aerator for expelling the impurities from ground water, especially for ground water under an overpressure, in which the impurities are expelled by generating a partial vacuum in an aeration shaft in the vicinity of ground water to be purified and by feeding fresh air below the water level in the aeration shaft, the aeration shaft is closed on its upper end with a pressurized receiving chamber. The pressurized receiving chamber permits fresh air to be brought in at an air pressure balancing the ground water pressure. Moreover a vacuum generator producing the partial vacuum is located in the pressurized receiving chamber.

Abstract: To expel volatile contaminants from a liquid body, outer air is introduced into a perforated container arranged below the liquid surface and having an open bottom by the action of a suction blower creating an underpressure above the liquid surface. Air bubbles exiting through the perforated top wall of the container entrain the volatile contaminants and expel the same into the underpressure area. The air receiving perforated container is either suspended on a float or fixedly arranged relative to the bottom of the receptacle.

Abstract: Driving of volatile impurities from a ground by mans of air is performed by aspirating an afterflow air and impurities containing gases which penetrated through a permeable wall of a shaft in a ground, at one or several locations in regions of expected high gas contents, air afterflow passages are extended to these regions for supplying the afterflow air, and an adjustable afterflow resistance is arranged in the passages for influencing a negative pressure value and a flow speed in these regions.

Abstract: A sealing device particularly suitable for sealing pistons of working cylinders and for sealing two machine components which can slide against one another is disclosed. A conventional sealing element consisting of low-friction, but not very elastic material, such as PTFE plastic material, and resting on an elastic support, is used. The cross-section of the sealing element in a direction of the sliding motion is U-shaped and encircles the support. The dimensions of the support and the sealing element are determined such that the support exerts prestress forces on the sealing element which try to bend the rim areas of the sealing element outward against the sliding surface for the sealing element. Consequently, an additional force component, directed toward the sliding surface, results for the pressure force which is exerted on the sealing element by the support and functions as a sealing force.