Abstract: A liquid purification apparatus having a main body having means to allow liquid to enter the main body is disclosed. An exit means allows exit of liquid from the main body. A solid compound is located within the main body for dissolution by the liquid. Means cooperating with the solid compound expose a substantially consistent surface area of the compound to the liquid.

Abstract: An injection nozzle for diesel engines is disclosed with a direct fuel injection into combustion air in the combustion space having a swirl. The nozzle is constructed as a hole-type nozzle with several injection openings arranged at uniform distances and distributed along the nozzle circumference. In order to further develop such an injection nozzle in a manner which permits shorter injection durations and an improved utilization of the air, an additional injection opening with a smaller diameter is constructed in each case between two adjacent larger injection openings, whereby the overall cross-sectional surface of all injection openings becomes larger without any drifting into one another of the thus formed fuel sprays.

Abstract: A process and a suitable arrangement for cooling diesel engine exhaust gases in an exhaust gas recirculation system is provided. In order to be able to avoid a contamination of the heat exchanger as well as a resulting required regenerating of the latter in the case of a cooling of the hot exhaust gas flow over a large temperature range, the cooling of the hot exhaust gas flow is carried out in at least two steps in that the exhaust gas flow flows successively through two heat exchangers which are each adapted to the corresponding cooling temperature range. By adapting the heat exchangers to specific small temperature ranges, even hot exhaust gas flows of up to 800.degree. C. can be cooled to a desired low temperature by the series connection of a corresponding number of different heat exchangers, without causing significant contaminations of the exhaust gas cooling arrangement by exhaust gas particles.

Abstract: The production of harmful substances during the operation of multi-cylinder diesel engines is reduced by separating the cylinders of the engine into two groups in combination with an exhaust gas return from one group to the other. The first group includes a plurality of the cylinders (2 to 6). The second group includes at least one cylinder (7), which is separated from the first group as far as combustion is concerned. A first fresh air suction intake (9) supplies fresh air to the group of first cylinders (2 to 6). An exhaust gas return device (24) feeds either directly or indirectly exhaust gas from the at least one second cylinder (7) through the first fresh air suction intake (9) to the group of first cylinders (2 to 6). A second fresh air suction intake (10) supplies fresh air to the second group of cylinders (7). The second fresh air suction intake (10) may also receive some exhaust gas which is then combusted by an additional fuel supply in the second fresh air suction intake (10).