SCR technology is essentially a device for treating diesel exhaust gas. That is, at high temperatures, ammonia or urea is used as a reducing agent, and nitrogen oxides are used as an oxidant. The oxidation-reduction reaction occurs to generate nitrogen and water vapor. Such products don’t cause pollution to the environment.
At a suitable temperature, first mix urea and fresh water thoroughly and stir evenly to form a mixed solution of about 40%, which is injected into the urea storage cabinet for the next reaction, and then the solution in the storage cabinet is transported to the In the measurement module, the zirconium dioxide sensor transmits the information to the computer. The computer compares the measured value sent by the sensor with the estimated value of nitrogen oxide, sends out instructions to the urea solution, takes out an appropriate amount of urea solution and mixes it with hot air, and turns it into a mist. Inject evenly into the exhaust pipe of the diesel engine.
At present, ship exhaust pollution control is mainly divided into four categories: improving fuel quality, using alternative fuels, processing during combustion, and after-treatment of exhaust gas. From the perspective of improving fuel quality, the use of high-quality fuel will inevitably lead to an increase in fuel costs, and the use of alternative fuels has disadvantages in equipment technology. From the perspective of treatment technology, the use of in-combustion treatment technology alone cannot currently meet the IMO emission standards, while the use of exhaust gas aftertreatment technology can achieve the MARPOL Convention Annex VI amendment formulated by IMO even when low-cost heavy oil is burned. Therefore, the current exhaust pollutant emission reduction strategy is usually exhaust gas after-treatment technology.
SCR denitrification combined with flue gas scrubbing and desulfurization has good adaptability to the marine environment and good matching performance with diesel engines.
Urea pump’s application is embodying here.In the application of SCR system, it is necessary to inject the urea solution quickly, accurately and at high pressure through the JONSN precision micro gear pump to effectively purify the exhaust gas.
The purification of exhaust gas has made an effective contribution to environmental protection and improving the quality of life in large port cities, thereby reducing nitrogen oxides and fine dust particles. For this purpose, a urea solution that can be injected into the exhaust gas of a diesel engine is used. These systems are called Selective Catalytic Reactions (SCR): using reducing agents (such as Urea/AdBlue® or DEF), NOX can be further processed in an exhaust catalytic converter connected downstream of the engine. First, the DEF is decomposed with ammonia and water. Subsequently, ammonia reacts with nitrogen oxides in the exhaust gas, and NOX is decomposed into nitrogen and water.
The injection of urea solution must be permanent, rapid, high-pressure, and accurately adapted to the specific exhaust gas volume generated, especially when the load changes or performance requirements change. Reliability is also needed: if the SCR system fails, ships will no longer be allowed to enter the port.
At present, JONSN precision micro gear pump suppliers have been successfully applied to leading enterprises in the Shanghai Hudong Shipyard, China Shipbuilding Industry Corporation, etc., supporting cooperation for many years, stable and reliable performance, and have obtained Japan Classification Society certification.