Abstract: A system and method for producing flat tubes is described and illustrated. The flat tubes can be produced from at least one strip of endless band material having at least one wall part and an inner part formed with corrugations on a roller train provided with roller pairs, with the strip running in a longitudinal direction through the rollers and being shaped. The inner part of the flat tube can be formed with corrugations placed between the shaped wall parts, after which the closure of the flat tube is carried out. Production of the flat tubes can include forming spaced apart band thinning lines running in the longitudinal direction of the strip, and forming corrugation peaks and corrugation troughs at the band thinning lines.

Abstract: The invention relates to a cooling fluid cooler for motor vehicles having a soldered cooling network (1) made of flat tubes (101) and ribs (102), produced from very thin aluminum sheets (a, b, c), and having header or loop-around chambers (3) at the ends of the flat tubes (101) for the cooling fluid flowing in the flat tubes (101), said chambers being cooled by cooling air flowing through the ribs (102). The cooling fluid cooler has exceptional cooling power and a light weight. This is achieved according to the invention in that each flat tube (101) is made of at least two formed sheet metal strips (a, b, c), wherein at least the one sheet metal strip (a, b) forms the wall of the flat tube and the other sheet metal strip forms a wavy internal insert (c) forming channels (10) in the same, and that the ratio of the constriction factor on the cooling fluid side to the constriction factor on the cooling air side is approximately in the range of 0.20 to 0.

Abstract: An installation for soldering or for heat-treating workpieces (1) under a protective gas atmosphere, includes a workpiece transportation apparatus (2), an entrance (3) into the installation and an exit (4) out of the installation, a combustion-gas or heating-gas stream (B) which is conducted separately from the protective-gas stream (S) and brings the protective-gas stream (S) to operating temperature, and comprising an insulating means (5) which surrounds the installation. A considerable amount of energy is saved in that the combustion-gas or heating-gas stream (B) and the protective-gas stream (S) have approximately corresponding heat capacities and can be conducted through the installation in counterflow.

Abstract: In a method for purifying exhaust gases in particular from lean-burn internal combustion engines having an exhaust-gas converter with a heat exchanger and catalysts arranged in inflow and/or outflow passages, the heat exchanger exhaust gas which flows in is heated by heat exchange with exhaust gas which flows. The incoming exhaust gas enters the inflow passages without encountering any obstacle susceptible to blockages, and flows through the inflow passages to a diversion region. Heat is fed to the exhaust gas by means of a burner. The burner is operated with fuel, air and engine exhaust gas in such a way that it supplies either an oxidizing or a reducing exhaust gas. Burner exhaust gas is admixed to the gas which emerges from the inflow passages and, together with this gas, enters the outflow passages, where nitrogen oxides are removed from it by a deNOxing catalyst present in the outflow passages.

Abstract: The invention relates to a cooling fluid cooler for motor vehicles having a soldered cooling network (1) made of flat tubes (101) and ribs (102), produced from very thin aluminum sheets (a, b, c), and having header or loop-around chambers (3) at the ends of the flat tubes (101) for the cooling fluid flowing in the flat tubes (101), said chambers being cooled by cooling air flowing through the ribs (102). The cooling fluid cooler has exceptional cooling power and a light weight. This is achieved according to the invention in that each flat tube (101) is made of at least two formed sheet metal strips (a, b, c), wherein at least the one sheet metal strip (a, b) forms the wall of the flat tube and the other sheet metal strip forms a wavy internal insert (c) forming channels (10) in the same, and that the ratio of the constriction factor on the cooling fluid side to the constriction factor on the cooling air side is approximately in the range of 0.20 to 0.

Abstract: The invention relates to an installation for soldering or for heat-treating workpieces (1) under a protective gas atmosphere, comprising a workpiece transportation apparatus (2), comprising an entrance (3) into the installation and an exit (4) out of the installation, comprising a combustion-gas or heating-gas stream (B) which is conducted separately from the protective-gas stream (S) and brings the protective-gas stream (S) to operating temperature, and comprising an insulating means (5) which surrounds the installation. A considerable amount of energy is saved in that, according to the invention, the combustion-gas or heating-gas stream (B) and the protective-gas stream (S) have approximately corresponding heat capacities and can be conducted through the installation in counterflow. The invention also proposes a process which is favourable in terms of energy.

Abstract: A system and method for producing flat tubes is described and illustrated. The flat tubes can be produced from at least one strip of endless band material having at least one wall part and an inner part formed with corrugations on a roller train provided with roller pairs, with the strip running in a longitudinal direction through the rollers and being shaped. The inner part of the flat tube can be formed with corrugations placed between the shaped wall parts, after which the closure of the flat tube is carried out. Production of the flat tubes can include forming spaced apart band thinning lines running in the longitudinal direction of the strip, and forming corrugation peaks and corrugation troughs at the band thinning lines.

Abstract: A heat exchanger including at least one collecting tank for input and output of a first heat transfer medium, a plurality of plastic tubes receiving the first heat transfer medium from the at least one collecting tank and outputting the first heat transfer medium to the at least one collecting tank, and a plurality of metal heat exchange elements between the tubes and in heat exchange contact with the tubes and a second heat transfer medium. At least some of the heat exchange elements are incorporated in the tube walls, with wave crests and troughs embedded in furrows of the walls. The heat exchanger is manufactured by heating the heat exchange element to plasticize the tubes at least at the contact sites between the tubes and the heat exchange elements, and then producing intimate contact between the tube and the heat exchange element.

Abstract: In a method for purifying exhaust gases in particular from lean-burn internal combustion engines having an exhaust-gas converter with a heat exchanger and catalysts arranged in inflow and/or outflow passages, the heat exchanger exhaust gas which flows in is heated by heat exchange with exhaust gas which flows. The incoming exhaust gas enters the inflow passages without encountering any obstacle susceptible to blockages, and flows through the inflow passages to a diversion region. Heat is fed to the exhaust gas by means of a burner. The burner is operated with fuel, air and engine exhaust gas in such a way that it supplies either an oxidizing or a reducing exhaust gas. Burner exhaust gas is admixed to the gas which emerges from the inflow passages and, together with this gas, enters the outflow passages, where nitrogen oxides are removed from it by a deNOxing catalyst present in the outflow passages.