The system to clean exhaust gas emissions from an IC motor has a nitrogen oxide accumulator, and desulfurizing operating in full and partial modes according to registered temperatures

The assembly to clean an exhaust gas from an internal combustion motor, has an accumulator to take nitrogen oxides to purify the exhaust gas containing nitrogen oxides and polluted with sulfur. The desulfurizing uses two modes, where one completely desulfurizes the accumulator in a main stage and the other gives a partial desulfurizing action. For the partial mode, a minimum temperature is selected in advance at the weakest for the accumulator, and the shortest desulferizing time for the main stage. To clean a motor exhaust gas, the minimum temperature (T4) for a partial desulferizing is 600 deg C, and the minimum temperature (T5) for the main desulferizing is 680 deg C. Meters monitor the times of the two stages, to give a durable register of the duration of both stages during desulfurizing. The capacity of the nitrogen oxide accumulator and the quantity of sulfur sent to it since the last main desulferizing action are controlled, and a main desulfurizing process is triggered as necessary if the capacity of the accumulator or the quantity of delivered sulfur breach given threshold values. A partial desulfurizing action is started if the quantity of delivered sulfur since the last partial mode breaches the partial desulfurizing threshold, but is lower than the threshold for the main operating mode. After the last main desulfurizing action, an interval is determined until the next main cleaning, and the intermediate partial actions are set as a fraction of the interval between the main stages. When a main or partial desulfurizing action is started, the accumulator temperature is registered and a heater is activated if the temperature is below the minimum level. On normal working, the heating temperature for combustion (T2) is set, which is lower than the desulfurizing temperature. The accumulator heating is interrupted while the accumulator temperature drops below a temperature (T1) where the heating stops, which is lower than the minimum heat starting temperature. The partial desulfurizing is switched into a main mode if the accumulator temperature is at the required level and if a sufficient quantity of sulfur has been fed through since the last main desulfurizing process. The partial or main desulfurizing actions can be started without the necessity of desulfurizing as long as the accumulator temperature is at the level for a main desulfurizing action. The desulfurizing actions are stopped when the temperatures drop below the operating levels. A blocking