What is Urea solution?
Urea solution is a non-toxic urea solution used to chemically reduce NOx-emission from heavy-duty diesel powered vehicles. Urea solution is neither explosive nor harmful to the environment and is classified under the minimum-risk category of transportable fluids. Since Urea solution is corrosive, certain materials are required for its handling and storage.
All major trucks and buses manufacturers in Europe has models that require Urea solution. More specific Urea solution is stored in a separate tank and it is not mixed with diesel or other kind of fuel. Its use is made through a system which is called SCR Selective Catalytic Reduction .
Urea solution should meet the DIN V 70070 standard and ISO 22241-1 specifications and complies with ISO and CEFIC regulations to safeguard the correct functioning of your vehicle's SCR system.
It is very important that the Urea solution to fulfill those standards in order to achive a good function of SCR system.
What is the SCR system
- The SCR system does not affect the frequency and the cost of services, unlike the EGR system that has additional maintenance costs. More frequent oil and filters changing whilst the oil required for the EGR technology is of high quality which means high price compared to the SCR technology.
- Reduced fuel consumption. A vehicle with the SCR system and fuel discharge EURO 4 has a 2-3% less than an equivalent vehicle of EURO 3 specifications and 4-8% compared to the EGRn system.
- The SCR system allows the engine to work free without choke setting unlike the EGR and the engine is not in danger of damages due to the circulation of cold fumes, a fact very likely to happen in the EGR system.
- The transform into EURO 2 is manageable in case someone wants to sell it as a used vehicle.
Urea sulution caracteristic
- Urea solution is non-toxic and poses no serious risk to humans, animals or the environment if properly handled. The product is slightly alkaline with a pH of approximately 9.0 so should not be kept in contact with aluminum, brass, mild steel. Stainless steel and plastic tanks and fittings are recommended.
- The personal precautions when dealing withUrea solution include to avoid contact with skin and eyes. Also if it is spilled on the floor it causes a slipping hazard.
- The methods for cleaning up are to take up mechanically and collect in suitable container for disposal. Dispose of in compliance with local and national regulations. After cleaning, flush away traces with water.
- Urea solution is not flammable.
- Freezing of Urea solution starts at minus 11.5 °C
- Urea solution can be used once it has frozen. Once Urea solution has melted, it can be used without problems.
- The best way to remove crystallisation or spillage is to rinse with water. When you rinse with water be sure that the is well sealed in order to prevent any contamination of the dilution.
- If Urea solution is spilled on automotive paint you should rinse the surface with water and cleaned from paint. In case Urea solution is left to dry and crystallise on the paint, surface corrosion might take place.
Urea solution Quality
It is important to refer to the Urea solution’s quality, which should be high. The use of an additive that does not meet the requirements of DIN 70070 will cause various problems that may start from increased emission of exhausts and result in the total destruction of the catalyst.
It can also cause various problems to the engine due to the increased pressure of exhaust fumes since they can not removed correctly on time from the catalyst. This is a result of the low quality of Urea solution that reduces the size of the catalyst’s pores and deactivates the catalytic elements in the internal.
SCR System
This method combines the optimized combustion of the engine in with a system of treatment the exhaust emissions, aiming the reduction of the level of pollutant emissions such as oxide of nitrogen (NOx).The basic factor of the procedure is the use of Urea solution
This dilution is sprayed in the exhausts before they reach the catalyst. The high temperature which occurs at that point converts Urea solution into ammonia. Then; while ammonia and the inimical oxides of nitrogen pass through the catalyst, reacts with each other and converts into nitrogen and water vapours, two elements that are not harmful for the atmosphere.
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