Allweiler pumps in exhaust gas treatment systems in ships
As environmental regulations become more stringent, waste gas treatment systems are growing in importance. H+H Umwelt- und Industrietechnik GmbH of central Germany has been using Allweiler progressing cavity pumps as a core component of these systems since 2003. The company has been manufacturing catalytic waste gas treatment systems since 1998. Originally they focused on applications in block heating stations and industrial plants. But stricter environmental regulations introduced in Scandinavia and in the Baltic Sea in 2004 have boosted demand for shipborne systems. Introduction of a NOx tax in Norway has further increased demand. NOx-reduction systems are used on ships for the propulsion system’s heavy oil motor and for auxiliary equipment like power generators. The first of these systems produced by H+H was commissioned in 2005. Since 2004, the company has been the global market leader for maritime Selective Catalytic Reduction systems (SCR) with a market share of approximately 80%. Currently about 600 of these single systems, known by the name “EcoMarin”, are operational on 160 ships.
According to the company's founders, Alexander Hommen and Michael Heck, the success of H+H is based on four factors. First is their global service. Approximately 20 agents and service centers ensure rapid reactions regardless of where a ship is currently located. Second, the company delivers fully assembled, fully tested systems that are ready for immediate deployment. 'We provide turnkey systems, including a complete maintenance package, such as a catalyst replacement plan,” according to M. Heck. And H+H is fast – the third factor in its success. 'We design every system ourselves, configure it for the specific ship it will be used in, and assemble the whole thing here.' The company's years of experience with catalytic processes are the foundation of their strategy. Even before the company was founded, three of the four managing directors were active in this area. Fourth, fast and reliable suppliers are essential to making this approach work.
Progressing cavity pumps from Allweiler AG, a Colfax business unit, play a major role in the finished products. These pumps feed urea to the SCR system’s dosing panels. The urea is heated to a high temperature in the waste gas. The resulting ammonia serves as a reducing agent in the system. Due to the difficulty of storing ammonia, it is not possible to simply keep the material onboard the ship in 'ready-to-use' form.
Allweiler pumps continuously circulate urea in a closed loop; excessive amounts of the material are fed back into the tank. A major advantage of these pumps is their pulsation-free pumping characteristics. Even when starting, they do not produce pressure surges that could damage the system.