Langh Tech Scrubbers, EGR Water Treatment for New Box Ships
Three container vessels on order at Guangzhou Wenchong Shipyard in China for Eimskip Island ehf and Royal Arctic Line A/S will be equipped with Langh Tech hybrid scrubber systems and water treatment systems for exhaust gas recirculation (EGR). The newbuilds are of a new energy-efficient design developed by Deltamarin.
The in-line scrubbers are multi-inlet installations, where the main engine and auxiliary engines are connected to the same scrubber tower. In addition, the MAN Diesel & Turbo two-stroke main engines of the newbuildings are equipped with EGR systems. EGR is a method to reduce NOx emissions to meet Tier III requirements. In the EGR process approximately one third of the exhaust gas is washed with a scrubbing unit where particles are removed from the exhaust gas before it is recycled back into the engine.
The process water used in the exhaust gas washing is continuously cleaned during EGR operation, which is where Langh Tech’s water treatment technology is applied. After being cleaned, the purified process water is fed back to the process circulation or sent overboard. Similar water treatment is also used for the process water of the SOx scrubber system. Langh Tech is the first company to combine water treatment technology for both SOx scrubber process water and EGR process water.
The Langh Tech water treatment technology is based on membrane filtration, through which the operational costs are kept low, and the amount of waste is compressed into only small amounts of dry sludge. Additionally, membrane filtration cleans the overboard discharge water far beyond MARPOL requirements.
EGR process water treatment has required long and thorough testing for MAN Diesel & Turbo, and in the end of 2016, Langh Tech received the approval from MAN Diesel & Turbo. The combined water treatment for EGR and SOx scrubber requires very good purified water quality to be fed back to the EGR. The combined water treatment system saves space onboard, and further, only one chemical compound, caustic soda (NaOH), is needed to tackle both NOx and SOx emissions. This eliminates the use of urea, which is needed when SCR technology is utilized for NOx removal.
“This is the first deal for Langh Tech for newbuildings from a Chinese shipyard. Many offers are pending and scrubber requests for newbuildings pour in,” said Laura Langh-Lagerlöf, Commercial Director of Langh Tech.
In addition to newbuildings, Langh Tech has several retrofit projects ongoing to be delivered and finished at the beginning of 2018.
