HF-Absorb dry sorption process

In contrast to packed-bed scrubbers and the lime-­injection process, the HF-Absorb system assigns the appropriate fluorine absorption sets to the individual ceramic production kilns for eliminating fluorine from their flue gases. In other words, the extraction systems can be designed to match the specific requirements of each kiln plant: continuous or intermittent operation, for example. Additionally, this shortens the flow paths of the flue gases, hence reducing the relevant consumption of electricity. Accordingly, this means savings on piping and insulation, allows reductions in the rated ­power requirements of the necessary fans and reduces the space requirements for reactors. All in all, this lowers the overall cost of investment. The reactors can be installed beside or above the kilns or even outdoors, i.e., outside of the factory building. Of course, a centrally located flue gas cleaning system can also be installed.

Since the use of Ca(OH)2 as reagent in the dry-sorption modules yields high levels of efficiency (up to 95%), the relatively high cost of the reagent remains acceptable and economical. The resultant end product consists primarily of fluorspar and fractions of unreacted lime hydrate.

The reactors have no moving parts, cause little loss of pressure and require no manpower for maintenance and spare-part installation. The HF-Absorb system is easy to handle and cost-efficient.

An HF-Absorb system becomes particularly attractive economically, when the kilns‘ operating conditions are changed, e.g., when kilns with a continuous operating mode are replaced with an intermittent type, or when kilns are shut down during the winter time. This exposes a central absorption plant to different load levels or even temporary shutdown with resultant condensation problems and attendant conglutination of the granulated lime.

No dust filters are required for an HF-Absorb system as long as the flue gas temperature remains above the dew point (max. 350° C, or 300° C for continuous operation). The lime modules are quick and easy to install and extract on stacking pallets. The same applies to replacing spent lime modules.


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