An exhaust gas post treatment system for an internal combustion engine, in particular a heavy fuel oil-powered engine, including an SCR catalyst, using ammonia as a reducing agent for the denitration of the exhaust gas, and a device positioned upstream of the SCR catalyst by which ammonia or an ammonia precursor substance, which is converted to ammonia, introduced upstream of the SCR catalyst. Downstream of the SCR catalyst an exhaust gas scrubber is positioned, by which excess ammonia, contained in the exhaust gas leaving the SCR catalyst, together with sulfur oxides, can be scrubbed out of the exhaust gas forming ammonium salts while maintaining a pH value of approximately 6. For the control thereof, a bypass around the SCR catalyst can be provided as a westgate, or comprising an additional SCR catalyst.

A connection head for being arranged in an orifice of a fluid tank with a return cavity in the form of a radial duct is provided. The return cavity overcomes the problems of the formation of air bubbles in the tank and enhances the functioning of the sensor in the tank.

A NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst composition comprises a support material, one or more platinum group metals disposed on the support material, and a NO.sub.x storage material.

An exhaust gas purifying system includes: a NOx trapping agent (2) which adsorbs nitrogen oxide when an excess air ratio of exhaust gas is more than 1, and releases nitrogen oxide when the excess air ratio is 1 or less; a NOx purifying catalyst (13) which reduces nitrogen oxide to nitrogen; and an oxygen concentration controller which controls oxygen concentration in the exhaust gas. When the excess air ratio of the exhaust gas is more than 1, nitrogen oxide is adsorbed to the NOx trapping agent (2). When the excess air ratio of the exhaust gas is 1 or less, the oxygen concentration controller controls the oxygen concentration of the exhaust gas at an inlet of the NOx purifying catalyst between 0.8 and 1.5% by volume, so that the NOx purifying catalyst reduces nitrogen oxide released from the NOx trapping agent.

Provided is a method for producing an inexpensive, high-performance AEI type zeolite and an AEI type zeolite having a Si/Al ratio of 6.5 or less by using neither an expensive Y type zeolite as a raw material nor dangerous hydrofluoric acid. The method for producing an AEI type zeolite having a Si/Al ratio of 50 or less includes: preparing a mixture including a silicon atom material, an aluminum atom material, an alkali metal atom material, an organic structure-directing agent, and water; and performing hydrothermal synthesis of the obtained mixture, in which a compound having a Si content of 20% by weight or less and containing aluminum is used as the aluminum atom material; and the mixture includes a zeolite having a framework density of 14 T/1000 Å.sup.3 or more in an amount of 0.1% by weight or more with respect to SiO.sub.2 assuming that all Si atoms in the mixture are formed in SiO.sub.2.

An aftertreatment system (100) connected downstream an internal combustion engine arrangement (102) for receiving exhaust gases conveyed from the internal combustion engine arrangement (102) during operation thereof, wherein the aftertreatment system comprises first and second catalytic devices in series, wherein a gap is there between.

An internal combustion engine (1), with an engine regulating device (3) and an exhaust gas aftertreament device (16) with an SCR catalytic converter (4) for the reduction of at least one NO.sub.x component, and with a catalytic converter regulating device (6), wherein the engine regulating device (3) is prescribed a target value for an NO.sub.x mean value of the NO.sub.x component of the exhaust gases, which mean value results at an outlet point (7) of the exhaust gas aftertreatment device (16) in relation to a predefinable time period, and the engine regulating device (3) is configured at least in one operating mode to continuously calculate an NO.sub.x reference value for the catalytic converter regulating device (6) with consideration of No.sub.x components which have already been emitted and the predefined target value, which reference value is selected in such a way that the predefined target value results at the outlet point of the exhaust gas aftertreatment device (16) at the end of the predefinable time period when the calculated NO.sub.x reference value of the catalytic converter regulating device (6) is fed as NO.sub.x setpoint value to the regulating means.

An exhaust gas purification device includes a diesel particulate filter (DPF) for capturing particulate matter (PM) in an exhaust gas, a selective catalytic reduction (SCR) device for reducing NOx in the exhaust gas, detecting units for detecting the DPF electrostatic capacity, an estimating unit for estimating the inside temperature of the DPF based on the electrostatic capacity, and a controlling unit for executing forced DPF regeneration. A lower limit temperature is defined as a temperature to trigger PM combustion, and an upper limit temperature is defined as a temperature to avoid filter erosion. The controlling unit executes the forced regeneration with an amount of fuel supplied for causing the inside temperature to reach the lower limit temperature, when the inside temperature is at or above the SCR activation temperature, and executes the forced regeneration with another amount of fuel supplied for causing the inside temperature to reach the upper limit temperature, when the inside temperature is below the SCR activation temperature.

To provide an exhaust purifying system and a method for controlling the exhaust purifying system that avoid occurrence of clogging, breakage, or the like of a reducing agent injection valve caused by the solidification of a reducing agent and prevent reduction in the efficiency of reducing agent recovery processing and exhaust gas purification. An exhaust purifying system and a method for controlling the exhaust purifying system according to an aspect of the present invention is configured to detect the injection valve temperature of the reducing agent injection valve according to detection of turn-off of an ignition switch for stopping the internal combustion engine or detection of an injection stop of the reducing agent injection valve, whichever is earlier, calculate the waiting time until reducing agent recovery processing starts based on the injection valve temperature, and permits the reducing agent recovery processing under condition of the detection of turn-off of the ignition switch and an elapse of the waiting time.

The invention is characterized by a rotary external housing and the attachment of the movable blades to the inner side of said housing, and by the attachment of the fixed (or static) blades to a shaft or other static central element, irrespective of whether compression or expansion occurs in one or more stages. The proposed attachment eliminates the radial gap in the region that transfers maximum energy to the fluid, thereby drastically reducing the problems due to stalling at the boundary layer. In this way, there is no drop in the mechanical performance of small axial turbines and compressors with a less favorable ratio of radial gap to housing diameter, an aspect that has prevented more generalized use thereof. The fixed blades, by not transferring energy to the fluid and decelerating the rotation thereof, encounter fewer stalling problems than movable blades.