Post-treatment System of Diesel Vehicle Exhaust Gas

DPF(Diesel Particulate Filter)

Product Technical Route

DPF(Diesel Particulate Filter)is also called DPF exhaust post treatment system.

After a long time of particulate collection, the porous medium channel of the filter will be blocked, resulting in the rise of back pressure in the exhaust system, which will affect the normal operation of the engine. Therefore, measures should be taken to remove the soot particles filtered by DPF and restore the filtering capacity of DPF. This method is called regeneration. Regeneration methods are generally divided into active regeneration and passive regeneration.


Diagram of Modified Products

The product developed by Sinocat is to reduce the emission of CO, HC and other pollutants in the exhaust through the catalytic oxidation reaction of DOC. At the same time, DOC oxidizes NO in the exhaust gas into NO2, realizing passive regeneration of CDPF(a catalytic converter coated with a layer of catalyst on the DPF substrate, namely CDPF) captured PM under appropriate temperature conditions. When the condition of active regeneration is reached, the control unit controls the fuel injection device to spray fuel in front of DOC, and the exhaust temperature is greatly increased with DOC, so that the PM in the CDPF can carry out combustion regeneration. The catalytic performance of DOC and the filtration performance of CDPF enable the tail gas to be purified.

The products of our company are tested according to the test standards of the Ministry of Ecology and Environmental Protection and industry test standards (HJ451-2008). The conversion efficiency of HC and CO by DOC of the catalyst in the system is more than 80%, the capture efficiency of particulate matter by DPF is more than 90%, and the regeneration efficiency of particulate is above 90%.

The control unit monitors the temperature of the catalyst and the pressure difference before and after CDPF, and determines whether regeneration is needed according to the carbon load and working conditions. If regeneration is required, the controller will control the active regeneration system. The system has remote online monitoring function.

In view of the actual situation of diesel vehicle emissions in use, taking into account the latitude and longitude of different regions and the environmental temperature in winter, Sinocat provides two different modification schemes. The main difference is in regeneration technology. It is to meet requirements of different vehicles.

Product Type

Fuel adaptability: Can adapt to the fifth stage of national automotive diesel (sulfur content S≤10ppm)

Product Safety Requirement


Remove the original vehicle muffler, install the product behind the engine exhaust pipe, and fix it on the vehicle frame. On the premise of ensuring the installation space of the catalytic muffler, the distance from the engine should be as short as possible. If necessary, the exhaust pipe should be insulated, and the maximum distance after insulation should not exceed 2000mm.

After the product is installed, it is guaranteed that the original safety performance of the vehicle will not be changed, and it conforms to relevant safety regulations.

Considering safety of the system, in some special circumstances, the control system will forcibly terminate the active regeneration of the product, which includes stop the active regeneration process after parking, in special occasions, such as gas stations, flammable and explosive places, etc..

(2) Structural Security

All products and accessories such as mounting bracket are made of materials that meet the strength requirements of the whole vehicle to prevent products from breaking and falling off due to violent vibration in driving. The structure and size are similar to the original car muffler, which will not affect the original safety performance of the vehicle. Good insulation measures to prevent fire or scalding caused by high temperature.