Milling technology dramatically reduces toxic emissions from coal-fired power plants

Techinomics, Inc manufactures high-efficiency coal pulveriser replacement parts for the coal-fired utility industry, cement production industry and lime kilns. Products include a rotating throat and ledge cover for vertical spindle mill pulverisers, stationary throats and fully automatic pyrite collection systems. Techinomics, headquartered in Pittsburgh, PA, has designed and installed rotating throat systems that are in use in coal-burning utility plants throughout the world.

The Techinomics Rotating Throat-Ledge Cover System features a patented ledge cover and inlet vane design that is claimed to provide unique and unmatched performance in several key areas. The throat design incorporates a venturi effect and converging-diverging nozzle which converts pressure to velocity, returning more over-sized coal particles back to the working zone for additional re-grinding without blowing the pyretic rock back or clogging the ports. The Techinomics design allows for a superior primary classification process. The pyretic rock, which even in pre-washed bituminous coal contains significant concentrations of mercury, is removed from the coal stream at an improved rate over conventional designs. The vane design coupled with the throat’s high-pressure drop system also allows velocity to be increased without increasing primary airflow mass, resulting in energy savings.

Recently, Techinomics released a report on late 2012 testing conducted at a major coal-fired power plant in the Western United States.  The data analysis and combined final report were issued by Consol Energy R&D Laboratory in South Park, PA.

During the study, Consol Energy analysed the pyritic rejects of two pulverisers sharing the same coal and primary air supply. One was equipped with Techinomics rotating throat technology, the second with another rotating throat technology.

Consol found that the Techinomics-equipped pulveriser consistently rejected 2-10 times more total pyritic rock during each test period. In addition, Techinomics rejects averaged less than 10% carbon (coal) content while the other pulveriser rejects contained between 30% and 35% coal content. Because of the strong correlation between pyretic rock and mercury/arsenic concentrations, significantly larger volumes of these toxic metals were removed pre-combustion by Techinomics in comparison to the competing throat technology. Consol Energy’s testing also documented Techinomics rejects having significantly higher concentrations of limestone, sandstone and silicon, substances that not only cause breathing difficulties but also equipment damage, and increase maintenance costs if not removed.

The utility plant’s testing department validated that the Techinomics technology used 7.9% less primary airflow than the other system and significantly reduced pulveriser system amperage required during the milling process. The related reduction in pulveriser system amperage usage means more than two additional megawatts of available power with Techinomics - every hour of operation.

The full report can be found at www.techinomics.com.