By Dr.-Ing. Axel Müller and Dipl.-Ing. Thomas Rolland, Thomas Magnete GmbH, Herdorf/Germany

Thomas engineers have been working hard to realize the robust, compact dosing unit P1300 able to supply liquids Independent from the engine to make Diesels clean – even under cold conditions.

As dirty Diesel cars and trucks may be regarded as belonging to history, today’s challenge of engineers is to choose the right system for the individual vehicle. Environmental protection, legal requirements and performance of the engines seem to be a contradiction, but they have to be brought into line. High torque and low CO2-emission and clean exhaust gas at the same time is no implicitness. It is a result of complex mechatronic systems.

Similar principles apply to the transport industry and mobile machinery sector, where diesel-powered units are the norm. Among the harmful pollutants generally associated with diesel engines are nitrogen oxides and particles of soot. By applying Selective Catalytic Reduction, nitrogen oxides are converted to non-harmful nitrogen and water. This requires a precise dosing of reactants like Diesel Exhaust Fluid [DEF or AdBlue®] directly into the exhaust gas. The precision enables a very effective over-all exhaust gas aftertreatment system and avoids unwanted chemicals in the exhaust gas.

German engineering specialist Thomas develops and produces a wide range of state-of-the-art metering units and pumps used in this field of application. Drawing on more than fifty years‘ experience in the area of electromagnets and more than thirty years‘ Expertise in metering pumps, the family-run Company located in Herdorf, middle of Germany, has now introduced a new generation of innovative metering systems, callaed P1300. These units are capable of measuring and delivering the required quantity of liquids with pinpoint accuracy. What is more, these pumps can operate in extreme conditions – without the risk of damage. The new generation of metering pumps has been thoroughly tested to ensure full functionality in all possible working conditions. In addition it has undergone endurance tests to fulfill the requirements of long service lives associated with trucks – achieving a consistently high quality as regards metering accuracy. The P1300 pump is available in various designs with a range of hydraulic and electrical connections, which makes it the perfect choice for a host of applications.

Alongside AdBlue®, Thomas’ family of metering pumps are also capable of supplying fuels. Therefore, they are particularly suited to systems used in the thermal management of the exhaust system. These systems also call for precision metering, the prime objective being to use just as much fuel as needed really. Hence, such systems allow to achieve fully working exhaust aftertreatment systems even under cold ambient temperatures and cold start conditions that have to be proven for the recent, more realistic, driving cycles. By using engine independent dosing of fuels into the exhaust, no energy is wasted and the overall fuel consumption is brought down.

Thomas offers a highly integrated product with the metering unit not only delivering the fuel but also generating the required operating pressure. Furthermore, the metering unit is extremely reliable, as it is designed to prevent uncontrolled flow over lifetime. In contrast to systems that separate the tasks of metering and delivery, this highly integrated unit can be operated without the need for additional components such as sensors, valves, and injectors. As a result, the number of electrical and hydraulic interfaces can be greatly reduced, which helps to scale back the overall system costs. Thus, the innovative P1300 is the basis for resolving this seeming contradiction of Diesel engines showing Performance and clean exhaust gas.

(Source: OEM&Lieferant, Edition 01/2017)