Heated hoses
The globally operating hose specialist, with headquarters at the place of the same name at Rehau in the German province of Upper Franconia supplies the entire high-tech hose systems for the Bosch exhaust gas purifier for the utility vehicle industry. When normal consumers can soon also order their diesel cars with the highly effective nitrogen extraction system, REHAU will once again become a leader of innovation. The Schöbel team has also conceived the hoses for the much more difficult requirements in cars. Not only technology freaks will be interested in why the unusual requirements made such demands on the engineers with regard to cars and HGVs.
The solution is the problem
In the new SCR process (SCR stands for "Selective Catalytic Reduction"), a 33 percent solution of urea called "AdBlue" is injected into the SCR catalyser to convert most of the unwanted nitrogen oxides into water vapour and nitrogen. This solution was the problem: "AdBlue" is extremely aggressive and freezes at just eleven degrees below zero. However, due to the development work conducted at REHAU, the use of clean diesel engines was made possible. The heated, urea-resistant hoses ensure unimpeded travel even in the most stringent winter. The intelligent hoses withstand temperatures from minus 35 degrees to plus 100 degrees. Apart from the environmental effects, there are other incentives for the operators of HGV fleets. In many countries, tax or toll relief is granted for the blue trucks. Lorries carrying the urea in a supplementary tank, at a price of 50 cents per litre, (nearly all new utility vehicles are supplied with "AdBlue" technology) also saves up to five percent in diesel consumption according to the manufacturer Bosch. The obvious reason: until now, the engines were not optimally adjusted to avoid producing too much nitrogen oxides. However, with "AdBlue" optimum engine management is possible.
Diesel hybrid dream
On the car market, it is particularly the stricter exhaust gas regulations in the USA that ensure that the automotive industry is working under high pressure on the use of "AdBlue". As diesel engines are increasingly used in cars, the new exhaust gas technology certainly has a potential to make the compression ignition engine popular on markets in which it has been viewed more sceptically. The plastics specialist has also been a driving force here and mastered great technical obstacles. In contrast to HGVs, much less space is available in cars for the exhaust gas equipment. Internally heated hose systems with extremely small cross-sections were developed for this reason.
There is another problem for car applications: the space required for the urea tank, which is attached relatively simply to the exterior of HGVs. Also, car drivers themselves should not have additional work to do with "AdBlue". The urea fill should therefore be sufficient to last until the next servicing. Nevertheless, Michael Schöbel is convinced that "AdBlue" diesel technology is well able to compete with hybrid petrol technology - initially in the USA. For engineer Schöbel, a combination of economical diesel engines with hybrid drives would be "simply a dream". If this could be achieved by designers, it would be a revolution with a bang on the car market, also made audible by the intelligent hoses from REHAU.