Abstract: In a method of utilizing a methane-containing biogas by feeding the methane-containing biogas to a gas engine of a gas engine/generator assembly generating electricity, the steps of passing the biogas through a membrane separating installation to divide the biogas into a first gas stream having a higher methane content than the biogas fed thereto and a second gas stream enriched in CO2, feeding the first gas stream to the gas engine as fuel, and returning the second gas stream to the source of the biogas.

Abstract: A method of utilizing a methane-containing gas by feeding the methane-containing gas to a gas engine of a gas engine/generator assembly generating electricity comprises the step of passing combustion air containing an inert gas through a membrane separating installation to reduce the content of the inert gas before feeding the combustion air to the gas engine.

Abstract: A method of utilizing a methane-containing gas by feeding the methane-containing gas to a gas engine of a gas engine/generator assembly generating electricity comprises the step of passing combustion air containing an inert gas through a membrane separating installation to reduce the content of the inert gas before feeding the combustion air to the gas engine.

Abstract: In a method of utilizing a methane-containing biogas by feeding the methane-containing biogas to a gas engine of a gas engine/generator assembly generating electricity, the steps of passing the biogas through a membrane separating installation to divide the biogas into a first gas stream having a higher methane content than the biogas fed thereto and a second gas stream enriched in CO2, feeding the first gas stream to the gas engine as fuel, and returning the second gas stream to the source of the biogas.

Abstract: In an apparatus for the treatment of liquids including foreign substances, particularly municipal and commercial waste waters, comprising a membrane separating structure having membrane elements, an inlet for receiving the liquid to be separated and passing it past the membrane elements whereby a permeant portion of the liquid permeates through the membranes and a retent portion becomes enriched with the foreign substances, and outlets for discharging the permeant portion and the retent portion, the membrane elements are arranged so as to form together flow channels extending longitudinally through the apparatus and adapted to guide the liquid straight through the flow channels along the membrane elements.

Abstract: A membrane separation device is disclosed having a cylindrical membrane support (4), which is sealed off between a top plate (26) and a bottom plate (28), whereon the cylindrical outer surface of the membranes support a membrane (6) is located, and which is surrounded by cylindrical components (14, 8) which are sealed off in the top plate and bottom plate thereby forming a cylindrical ring area (16). Permeate collection bores (20) communicate with the membrane through the membrane support and are connected with a permeate draw off connection (60). The suction side of a circulation pump (44) is connected with an enclosed inner chamber (47) formed by the cylindrical membrane support. The outer ring area is connected to the pressure side of the circulation pump and communicates with the inner chamber through a circulation channel (54). The inner chamber is connected to a infeed connection (58). The circulation pump communicates with a draw off (64) on the pressure side for the extraction of concentrate.

Abstract: A device for filtering and separating a flow medium by reverse osmosis, micro filtration, ultra filtration, or nano filtration has a pressure-tight housing having an inlet for the flow medium and a first outlet for the retentate and a second outlet for the permeate. A plurality of stacked units comprised of spaced apart membrane filter elements is provided, wherein the membrane filter elements are stacked atop one another to form a stack. The stacked units are sequentially arranged in the housing. The flow medium flows in sequence through the stacked units. Each one of the membrane filter elements includes areal outer membrane elements and an areal stabilizing element positioned between the areal outer membrane elements.

Abstract: Biologically purifying sewage which is organically loaded with substances that are difficult to decompose biologically or are not decomposable biologically has the substances that are difficult to decompose biologically or are not decomposable biologically separated and concentrated to concentrate, the concentrate preferably is treated physically and/or chemically and the treated or untreated concentrate is subjected to a biological transformation or, alternatively, the concentrate is separated from the sewage to be purified.

Abstract: A separator cell for pressure filtration and reverse osmosis includes a housing; a filtering membrane supported in the housing and having a feed side and an opposite filtrate side; a flow guide plate supported in the housing and being in a face-to-face engagement with the membrane on the feed side thereof; and a channel in the flow guide plate for guiding fluid. The channel is covered by the membrane. A feed pipe supported in the housing has an outlet and a concentrate discharge pipe supported in the housing has an inlet, both communicating with the channel. A filtrate discharge pipe is supported in the housing and has an inlet at the filtrate side of the membrane. The outlet of the feed pipe and the inlet of the concentrate discharge pipe are situated at generally diametrically opposite locations of the flow guide plate. The channel is constituted by a channel having a shape of a continuous spiral formed of a first and a second turn.

Abstract: The aeration of dispersions, especially the aeration of fiber suspensions in a flotation apparatus 1, is performed with a ring injector 2 to which air is delivered through air feed ducts 11 in the mixing section 4. The annular gap forming in the ring injector 2 is thus aerated inside and out. The center core 7, which tapers in the direction of the greatest free cross section Q4 of the ring injector 2, is provided with a fin 56 which prevents the rotation of the dispersion.

Abstract: An impact mill in which the pins of the milling tools are provided with pocket-forming vanes which are oriented substantially radially or tangentially with respect to the rotation circle of the respective tool and, downstream of the pin forming the tool, a streamlined profile is provided to reduce vortex formation and turbulence and thereby improve the energetic efficiency of the mill.

Abstract: A freeze dryer for the freeze drying of, for example, comestible products such as fruit juices and coffee, comprises a sublimation chamber having a heating plate upon which the products are disposed and an ice condenser spaced from the heating plate and upon which the moisture driven out of the product sublimes in the form of ice. According to the invention between the heating place and the ice condenser a heat pump is disposed so that the heat transferred to the ice condenser is returned via the heat pump to the heating plate.