A method for controlling urea injection in an exhaust aftertreatment system includes injecting urea at a flow rate upstream of the first catalytic reduction device; measuring a level of nitrogen oxides downstream of the first catalytic reduction device and upstream of the second catalytic reduction device; controlling the flow rate of the urea injection until the measured level of nitrogen oxides fulfils a predetermined condition; if the measured level of nitrogen oxides is decreasing in response to reducing the flow rate of the urea injection, reducing the flow rate of the urea injection, and controlling a flow rate of urea injection using the second urea injector upstream of the second catalytic reduction device according to the measured level of nitrogen oxides downstream of the first catalytic reduction device and upstream of the second catalytic reduction device.

In general, one aspect disclosed features an in-davit run kit for a lifeboat, the kit comprising: a water container comprising a first connector; a hose configured to connect with the first connector; and a second connector configured to connect to the hose, wherein the second connector is in fluid communication with a water cooling system of the lifeboat; wherein the in-davit run kit allows a water pump of the lifeboat to draw water from the water container into the water cooling system of the lifeboat.

Devices and methods for reducing emissions, e.g., hydrocarbons, NOx, carbon dioxide (CO.sub.2), and carbon monoxide (CO) from an internal combustion engine burning a hydrocarbon fuel. The devices include a mixture of tourmaline, quartz, and a holographic film within a non-metallic housing. The device containing the mixture and the holographic film is then charged. After charging the device, treating hydrocarbon fuel is taught by exposing the hydrocarbon fuel to the charged device before combustion of the hydrocarbon fuel in an internal combustion engine.

An insulated exhaust gas conduit system includes a first exhaust gas conduit, a second exhaust gas conduit, a first insulation sleeve, and a second insulation sleeve. The first exhaust gas conduit has a first exhaust gas conduit end portion. The second exhaust gas conduit has a second exhaust gas conduit end portion that is configured to engage with the first exhaust gas conduit end portion. The first insulation sleeve comprising includes a first insulation sleeve and a first insulation sleeve heat shield. The first insulation sleeve insulation layer is disposed around the first exhaust gas conduit. The first insulation sleeve heat shield is disposed around the first insulation sleeve insulation layer. The first insulation sleeve extends beyond the first exhaust gas conduit end portion. The second insulation sleeve includes a second insulation sleeve insulation layer and a second insulation sleeve heat shield.

An aftertreatment system for reducing constituents of an exhaust gas having a sulfur content includes: an oxidation catalyst; a filter disposed downstream of the oxidation catalyst; and a controller configured, in response to determining that the filter is to be regenerated and a desulfation condition being satisfied, to: cause a temperature of the oxidation catalyst to increase to a first regeneration temperature that is greater than or equal to 400 degrees Celsius and less than 550 degrees Celsius; cause the temperature of the oxidation catalyst to be maintained at the first regeneration temperature for a first time period; and after the first time period, cause the temperature of the oxidation catalyst to increase to a second regeneration temperature equal to or greater than 550 degrees Celsius.

The present invention shows an exhaust gas aftertreatment system comprising at least a first route and a second route arranged in parallel in an exhaust gas stream, wherein the first route and the second route are provided with exhaust gas aftertreatment subsystems. The exhaust gas aftertreatment subsystems of the first route and the second route use different exhaust gas aftertreatment technologies.

An internal combustion engine arrangement includes an internal combustion engine, a catalytic converter, and a controller. The controller is configured to determine a maximum H.sub.2 production capacity of the catalytic converter. The catalytic converter is arranged downstream of the internal combustion engine. The controller is configured and adapted to determine the maximum H.sub.2 production capacity of the catalytic converter based on a first function that correlates an H.sub.2 production of the internal combustion engine with first internal combustion engine parameters.

An auxiliary system with purge control automatically supplies diesel exhaust fluid (DEF) to an onboard DEF tank of a diesel engine to enable prolonged unattended operation. The system includes an auxiliary DEF tank, an auxiliary DEF supply line, a controller, a pump, an air inlet, and a three-way valve configured to switch the pump inlet between the auxiliary DEF tank and air. In response to low-level DEF, the pump delivers DEF through the supply line to replenish the onboard DEF tank. The controller may automatically calculate onboard DEF tank volume based on the delivered volume of DEF, and DEF level data received from an ECM, to enable replenishment control regardless of engine make and model. In response to high-level DEF, engine stoppage, or other system fault, the controller switches the valve to air and runs the pump for a predetermined time to purge DEF from the supply line. The auxiliary system may be skid-mounted, portable, and configured to supply DEF to multiple diesel engines.

An exhaust aftertreatment system for an internal combustion engine includes an outer casing having an exhaust gas inlet and an exhaust gas outlet between which a fluid flow path for exhaust gases is provided, a selective catalytic reduction unit provided in the fluid flow path for reducing nitrogen oxides, a reductant dosing device for adding reductant to the exhaust flow upstream of the selective catalytic reduction unit, and a rotatable mixer device for mixing the reductant with exhaust gases upstream of the selective catalytic reduction unit, an air inlet valve provided upstream of the mixer device for introducing air into the fluid flow path, and an electric motor arranged for rotating the mixer device to create a suction of air into the fluid flow path via the air inlet valve.

A system, apparatus, and method are provided for preventing the accumulation of particulate matter such as combustion soot on sensors positioned in exhaust gas conduits of internal combustion engines. In an embodiment, the apparatus includes a device for deflecting soot deposits from sensor surfaces. In an embodiment, the apparatus includes a device employing a surface acoustic wave generator for dislodging soot accumulation or measuring soot accumulations to trigger burn-off events. In an embodiment, an injector injects pressurized bursts of gas toward a sensor surface to dislodge particulate matter. In an embodiment, charged electrodes attract charged particles of soot from the exhaust gas flow to form deposits that are then subject to burn-off events.