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Buschjost valves keep SCR-catalytic converters in trucks running: Nitric oxide? No thank you!

Innovative technical solutions which contribute to protecting the environment are always a special challenge for Buschjost’s employees. “The slogan 'The future’s green' is a central component of Buschjost’s philosophy”, explains Ognjen Starovic, Head of Sector Business, who is responsible for a project at Buschjost which helps to substantially reduce nitric oxide emissions in heavy goods vehicles.

“If necessary, Buschjost can help trucks to function reliably from the hottest Nevada deserts to the polar regions, with considerably reduced nitric oxide emissions,” he says, referring to a Buschjost valve which has made it possible for SCR catalytic convertors in heavy goods vehicles to function reliably over long periods of time. “If modern truck engines are made to operate at maximum performance and with the lowest possible consumption, very high nitric oxide emissions occur, which are subject to an aftertreatment process in a so-called 'SCR catalytic convertor' and separated into nitrogen and water”, Starovic explains, adding: “SCR stands for Selective Catalytic Reduction and is an important technology which allows the necessary reduction in emissions to the boundary values of the Euro 4, 5 and 6 exhaust emission standards to be achieved.”

An SCR catalytic convertor can only reduce nitrogen if urea is injected before the catalytic convertor. “And this is the problem in daily operations”, Starovic points out, “because the urea freezes at a temperature of -11 degrees Celsius and in winter must therefore be kept at the right temperature.” On the other hand, there are limits to how much the urea can be warmed up without reducing its effectiveness.

The solution is to feed the coolant from the truck’s cooling system through the urea tank. “The servo-actuated Buschjost valve effectively acts as a thermostat which ensures that the temperature of the urea remains within the ideal range”, says Starovic.  Although such valves have been in serial production at Buschjost since 2004, this market is only just getting started. According to Ognjen Starovic: “The next few years will see exhaust emission standards being further tightened all over the world. Our valve is designed to be very variable and can be easily integrated into a wide range of assemblies – the market potential is therefore enormous.”

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