SCR post-processing system mainly includes urea solution supply system, urea solution injection system and SCR post-processor. Specific parts are Adblue pump
, nozzle, tank, post-processor, level sensor, NOx sensor, temperature sensor, an electromagnetic valve, pipe, nozzle cooling water pipes and tank heating pipes. the pump, nozzle, urea solution tank, these three parts should pay special attention to the maintenance.
Urea Solution Pump Maintenance
Urea Solution pump is the driving force of urea hydraulic movement, SCR system important implementation of the components. When the ECU issued a normal working state instructions, the pump takes a certain amount of urea solution from the tank, while the urea tube filled with stable pressure. When the diesel engine stops, the ECU sends out the end of the work instructions, pump urea solution circuit should be pumped back to the urea tank, to ensure that the urea pipe, especially the urea nozzle to keep clean. Urea solution pump equipped the electric heating system.When the temperature is low, make sure that the urea does not freeze in the pump.
Urea solution pump main maintenance is to replace the main filter, the main filter replacement frequency: 30000-40000 km/time, depending on the specific conditions of use and the environment. Urea pump into the urea, urea back to the internal connector also has a filter, depending on the running conditions need to regularly clean or replace.
The way of replacing the main filter
We introduce the two ways of replacing the main filter based on DeNOx2.2 urea pump, DeNOx6.5 urea pump
1. Open the urea solution pump filter cap
2. Remove the old filter adjusting part
3. Remove the old filter
4. Fix the new filter adjusting part to the new urea solution filter
Urea solution nozzle maintenance
The nozzle is the executive part of the SCR system for quantitative injection of urea solution. The nozzle module has three SAE standard push-in connectors. The smaller SAE standard male plug (5/16 ") is the urea nozzle connector and the other two (3/8") is the nozzle cooling water inlet and outlet.
The maintenance of the urea solution nozzle requires the removal of the urea nozzle and the pipe to the inlet of the processor at every 30,000 km. Check whether there is crystallization near the nozzle and its piping. Each nozzle must be replaced with a nozzle pack. Urea tank, liquid level sensor, urea pipe, and cooling water pipe maintenance.
Urea solution level temperature sensor with urea tank water heating pipe and urea filter, integrated into the urea box, the main test urea inside the urea temperature and urea level.
Urea Solution tank maintenance
1. daily maintenance need to always check the urea level to see if the urea is sufficient.
2. urea tank to be regularly cleaned, the liquid level sensor filter regularly cleaned or replaced to protect the filter without impurities without crystal blockage channel, according to the operating conditions to select the cleaning time.