Abstract: A flat transparent envelope has a rectangular, transparent cover sheet and a rectangular, preferably transparent backsheet. The cover sheet and backsheet are preferably flexible films that are joined together along at least two but no more than three of the sheet edges so that the envelope is open along at least one of the sheet edges and the edges of the joined sheets are situated in the envelope plane. The transparent cover sheet and backsheet may advantageously be entirely formed of a magnifying material.

Abstract: A flat transparent envelope has a rectangular, transparent cover sheet and a rectangular, preferably transparent backsheet. The cover sheet and backsheet are preferably flexible films that are joined together along at least two but no more than three of the sheet edges so that the envelope is open along at least one of the sheet edges and the edges of the joined sheets are situated in the envelope plane. The transparent cover sheet and backsheet may advantageously be entirely formed of a magnifying material.

Abstract: In the process and apparatus for kiln-drying of malt, at least two zones (A and B) are provided for preliminary drying and one zone (A1) is provided for secondary drying and/cooling of the malt. The unsaturated exhaust air from the secondary drying and/or cooling zone (A1) is admixed as return air with the intake air system, while in the preliminary drying zones (A and B) respectively different preliminary drying times are achieved by the degree of their loading with malt, the design of the floor surface and/or by adjusting the volume flow, the temperature and/or the moisture content of the intake air, so that during the secondary drying in the secondary drying zone (A1), a predrying process is always in operation in at least one predrying zone (A or B). Each individual zone (A, B and A1) is separated in operation as to air technology from the others.

Abstract: In the method and device for separation of harmful substances from a flue gas, in an absorption-heat exchanger arrangement both washing and also cooling of the flue gas is carried out, the flue gas being cooled below the dew point and this cooling process taking place by means of exterior air in counter flow. The flue gas is divided during its passage through the heat exchanger into at least two parallel part flows of which the first part flow is directed into a first treatment zone and the second part flow is directed into a second treatment zone. The two treatment zones are connected parallel to one another. In the first treatment zone a first absorption liquid is introduced into the flue gas which effects extensive removal of harmful substances from the flue gas, while in the second treatment zone a second absorption liquid is introduced into the flue gas, in which second absorption liquid precipitated harmful substances are soluble, to clean equipment surfaces.

Abstract: A pneumatic drive for actuating switchable devices such as valves and the like includes a cylinder and a cylinder base, the cylinder having an annular slot which extends in a plane transverse to the axis of the cylinder between an interior cylinder space and the outside. A piston is movable within the cylinder space and is connected to one end of a piston rod, the other end of the rod being coupled to the device to be actuated. A supply line communicates pressurized gas to the cylinder space to move the piston away from the cylinder base, while a spring biases the piston in the direction toward the cylinder base. An annular groove is formed in at least one of two annular surfaces which bound the annular slot in the axial direction, and a sealing ring is seated in the groove for axial movement so that the ring projects into the annular slot in response to pressurized gas communicated through a branch line into the closed end region of the groove.

Abstract: A method for the production of a tubular heat exchanger which comprises introducing the end portions of a plurality of tubes into a corresponding plurality of holes provided in troughs, substantially filling said troughs with a liquid casting resin whereupon the liquid casting resin enters the annular gaps between the holes and the tube end portions due to capillary action, to form, upon solidification of the casting resin, a tube bundle, inserting at least one tube bundle into a housing to form a tubular heat exchanger, the sidewalls of the troughs of the tube bundle forming a gap with the housing, and filling said gap with the casting resin.

Abstract: A tubular heat exchanger comprises tubes mounted between upper and lower plates employing a heat- and acid-sensitive resin at the upper plate. To prevent a fluid medium from corroding the resin, a further plate comprising an acid- and heat-resistant material is provided separating the medium from the resin, and a cooling medium is flowed through the separating space.

Abstract: A tubular heat-exchange unit and method for its manufacture comprising a plurality of heat-exchange tubes disposed in the vertical and horizontal direction in a stacked, spaced-apart relationship, the end portions of said tubes being adheringly embedded at both ends thereof in a wall of a hardened, elastic material, said wall at both ends of said tubes separating an inner zone defined by the space around said tubes from the end zones which communicate with the space within said tubes.