Abstract: Selective catalytic reduction (SCR) systems are known and are generally included in the exhaust systems of diesel engines in order to treat the exhaust gases of such engines. Such systems typically involve the introduction of a diesel exhaust fluid (DEF) into exhaust gas flowing in an exhaust passage of an engine. DEF dosing systems are limited by the amounts of DEF that can be delivered without deposits forming on surfaces of the aftertreatment system. An impaction device is dosed with DEF at a first rate based on a set of characteristics of the SCR system. A second set of characteristics, such as an available storage capacity for DEF, is determined based on a set of criteria, such as a decomposition rate of DEF. Based on the second set of characteristics, the DEF dosing rate is changed to a second rate. The dosing rate is reverted to the first rate after a second set of criteria, e.g. a lower threshold of available storage for DEF, are fulfilled.

Abstract: A selective catalytic reduction (SCR) system is provided for treating exhaust gas in an exhaust passage. The system comprises a hydrolysis catalyst located in the exhaust passage, and a diesel exhaust fluid (DEF) dosing unit configured to inject DEF onto the hydrolysis catalyst. A SCR catalyst is located in the passage downstream of the hydrolysis catalyst, and a controller controls DEF dosing by the dosing unit. The controller is configured to control the DEF dosing unit such that the DEF is injected at a modulated frequency of less than or equal to 1 Hertz. A method of treating exhaust gas in an exhaust passage using an SCR system is also provided.

Abstract: A selective catalytic reduction (SCR) system is provided for treating exhaust gas in an exhaust passage. The system comprises a hydrolysis catalyst located in the exhaust passage, and a diesel exhaust fluid (DEF) dosing unit configured to inject DEF onto the hydrolysis catalyst. A SCR catalyst is located in the passage downstream of the hydrolysis catalyst, and a controller controls DEF dosing by the dosing unit. The controller is configured to control the DEF dosing unit such that the DEF is injected at a modulated frequency of less than or equal to 1 Hertz. A method of treating exhaust gas in an exhaust passage using an SCR system is also provided.

Abstract: Selective catalytic reduction (SCR) systems are known and are generally included in the exhaust systems of diesel engines in order to treat the exhaust gases of such engines. Such systems typically involve the introduction of a diesel exhaust fluid (DEF) into exhaust gas flowing in an exhaust passage of an engine. DEF dosing systems are limited by the amounts of DEF that can be delivered without deposits forming on surfaces of the aftertreatment system. An impaction device is dosed with DEF at a first rate based on a set of characteristics of the SCR system. A second set of characteristics, such as an available storage capacity for DEF, is determined based on a set of criteria, such as a decomposition rate of DEF. Based on the second set of characteristics, the DEF dosing rate is changed to a second rate. The dosing rate is reverted to the first rate after a second set of criteria, e.g. a lower threshold of available storage for DEF, are fulfilled.

Abstract: A process for reducing nitrogen oxides in an exhaust stream, such as a vehicle exhaust stream, and apparatus for carrying out the process. The process comprises providing a first composition comprising aqueous urea, a second composition comprising ammonium carbamate and an exhaust stream comprising nitrogen oxides. A process for producing the ammonium carbamate is also provided. The second composition may be introduced into the exhaust stream (10) when the exhaust stream has a temperature below a threshold temperature and the first composition may be introduced into the exhaust stream when the exhaust stream has a temperature at or above the threshold temperature.

Abstract: A process for reducing nitrogen oxides in an exhaust stream, such as a vehicle exhaust stream, and apparatus for carrying out the process. The process comprises providing a first composition comprising aqueous urea, a second composition comprising ammonium carbamate and an exhaust stream comprising nitrogen oxides. A process for producing the ammonium carbamate is also provided. The second composition may be introduced into the exhaust stream (10) when the exhaust stream has a temperature below a threshold temperature and the first composition may be introduced into the exhaust stream when the exhaust stream has a temperature at or above the threshold temperature.

Abstract: A selective catalytic reduction (SCR) system for treating exhaust gases in an exhaust passage is provided. The system comprises a first catalyst for converting urea to ammonia, the first catalyst being located in the passage and having an upstream face and a downstream face. The upstream face is at a right angle to an axial flow path (A) through the passage. The system further comprises a second catalyst for converting NOx to nitrogen gas and water in the presence of ammonia, with the second catalyst being located in the passage downstream of the first catalyst. A diesel exhaust fluid dosing unit is located upstream of the first catalyst. The dosing unit comprises a nozzle arranged so as to inject DEF directly onto the upstream face of the first catalyst.

Abstract: The present disclosure is directed towards a clamping assembly for compressing a plurality of optical plates of a high pressure cavitation system. The clamping assembly may include a mounting frame and a housing coupled to the mounting frame. The clamping assembly may further include a holder distal the housing, the holder having the plurality of optical plates disposed therein. The clamping assembly further including a controllable clamping mechanism operably coupled to a top of the housing, the controllable clamping mechanism applying an axial force to the plurality of optical plate.

Abstract: The present disclosure is directed towards a clamping assembly for compressing a plurality of optical plates of a high pressure cavitation system. The clamping assembly may include a mounting frame and a housing coupled to the mounting frame. The clamping assembly may further include a holder distal the housing, the holder having the plurality of optical plates disposed therein. The clamping assembly further including a controllable clamping mechanism operably coupled to a top of the housing, the controllable clamping mechanism applying an axial force to the plurality of optical plate.