LIGHTING GP-REAR 3967829 - Caterpillar

Diesel Oxidation Catalyst (DOC)
Illustration 9 g02917116The DOC is a flow through device made of a ceramic substrate. The substrate has a catalytic coating containing precious metals applied to the DOC surface.The DOC oxidizes hydrocarbons and carbon monoxide into carbon dioxide as a result of the chemical reaction that occurs as exhaust gasses flow over the catalyst. The DOC also oxidizes soluble organic fractions, which are hydrocarbons that have attached to particulate matter.In addition, heat generated as a result of the chemical reaction also aids in the regeneration process.Diesel Particulate Filter (DPF)
Illustration 10 g02917137Unlike the DOC, which uses a catalytic process to clean the exhaust as it flows through the substrate, a DPF traps soot and ash particulates using a wall flow filter design.The soot is removed during a process called regeneration. Regeneration is a chemical process that converts soot (primarily carbon) into carbon dioxide and water in the presence of heat.NOx Reduction System (NRS)
Illustration 11 g02963458
(A) Inlet air
(B) Exhaust gas
(C) Coolant inlet
(D) Coolant outlet
(16) NRS valve
(17) Reed valve
(18) Intake manifold
(19) Exhaust manifold
(20) NRS cooler An NRS system takes out a portion of the exhaust gas and recirculates the gas to the intake side, thus reducing the amount of available oxygen and lowering the temperature of combustion, which suppresses the generation of nitrogen oxide (NOx).NRS Valve
Illustration 12 g02899317The NRS valve is a water-cooled valve. The NRS valve regulates exhaust gas flow. The degree the valve is open is detected using a lift sensor and a motor is used to set this to the degree of open calculated using signals including the engine speed.Also, passing engine coolant through the housing enables controlling temperature rise of the NRS valve.How far the NRS valve is open is detected by a contact type of position sensor that detects the movement of the motor shaft. The shaft opens and closes the valve by changing the rotation of the motor into linear motion via a screw deceleration mechanism.Intake Throttle Valve
Illustration 13 g02963319The amount of air intake is regulated by the angle of the throttle valve and the exhaust temperature is controlled when regenerating the DPF muffler.Air Flow Sensor
Illustration 14 g02963339The amount of air intake required for control of the NRS valve used to reduce NOx is measured.Exhaust Gas Temperature Sensor
Illustration 15 g02963347This is mounted on the DPF muffler and the DPF muffler DOC intake, DPF intake, and DPF discharge exhaust temperature, needed for the post processing system, are measured.Differential Pressure Sensor
Illustration 16 g02963377The differential pressure sensor is a sensor that detects the pressure differential between the inlet and the outlet of the DPF. The engine ECM calculates the amount of accumulated PM in the DPF using this signal.Seperator
Removes oil in the blowby gases that pass through the filter and the oil is returned to the oil pan. Blowby gases that pass through the filter are mixed into the intake upstream from the turbocharger.Reed Valve
Illustration 17 g02963476
(21) Valve
(22) Case
(23) Stopper The reed valves are positioned at the point where exhaust gases that have passed through the NRS valve mix with intake air and they prevent