Plate type compact air preheaters
Our compact heat exchangers consist of stacked metal plates that enable the recuperation of heat between two gaseous fluids, for example hot flue gas and cold combustion air.
The plate packages of our designs are typically arranged in one or several hot stages and a cold stage. The direction of flow is arranged either in a counter- or crossflow.
The use of metal sheets represents a technical optimum between structural stability and beneficial heat transfer properties. Solutions with highest efficiency needs and flue gas exit temperatures below the dew point can be equipped with inox metal sheets at the cold stage of the air preheater.
This concept allows for maximum thermal efficiency and thus maximized savings as well as reliable operation and longevity.
The mechanical design is customized to fit the particularities and process parameters of the existing plant, depending on the plant layout.
The thermal design is done according to the rule of FDBR and VDI, allowing reliable and safe performance. Efficiency gains lie in the range of 0,6%-points for each 10 K of stack temperature reduction. This can lead to efficiency gains of more than 10% for initial installation and more than 5% for retrofits, respectively.
Our design can replace a variety of outdated heat exchanger types, including DEKA cast iron type, conventional tubular type, OCAP type, rotating type or pump-around systems.
Compact, integrated DeNOx systems
Regulatory constraints require plant operators to keep their NOx emissions low. The industrial standard to achieve a reduction of NOx in a plant’s flue gas can is a Selective Catalyst Reaction (SCR) system. The flue gas enters a chamber and is forced to stream through a structure of catalyst blocks where the NOx in the flue gas will selectively react with an aqueous ammonia or urea solution to harmless compounds such as water and nitrogen. The NOx conversion depends heavily on the process temperature.
Our compact DeNOx system allows the installation after upstream particle filters that might have cooled down the flue gas already. The installation of the equipment is facilitated by a weight reduction compared to conventional DEKA cast iron type pre-heaters of up to 50%. Due to a higher heat transfer rate, the mounting space can be reduced significantly, allowing also for easier handling on-site. The energy consumption for re-heating the flue gas in order to reach an optimum reaction temperature is reduced by a factor of 10.
BD Heat's patented design uses cost-efficient, vortex generating mixers for the direct injection of an aqueous ammonia solution. The turbulent mixing process quickly distributes the solution evenly in the reaction chamber, thus leading to increased conversion rates and reduced ammonia slip rates.
Installing a compact DeNOx Systems will allow our customers to achieve high NOx removal rates of up to 97% during plant operation.