In addition to useful raw materials, incinerator bottom ash consists of fine-grained combustion residues that generate a lot of dust. In order to be able to safely dispose of the residual ash after all recyclable components have been recovered, it must therefore be moistened and solidified. In addition, the product destined for the landfill must not exceed specific eluate levels.
This places considerable demands on the mixing technology. For this reason, a North American operator of waste incineration plants decided to replace its legacy mixers with a total of five ash humidifiers from BHS-Sonthofen. The single-shaft pug mills are used in 24-hour continuous operation and process up to 7.5 tons of ash per hour. The mixers are ideally suited for processing incinerator bottom ash as they ensure reliable operation and deliver high product quality. Moreover, they are efficient and allow for easy cleaning and maintenance. The self-cleaning design includes a special BHS agitator and a dead space-optimized mixing drum, which significantly increases plant availability. Thanks to their highly compact design, they also require little space.
Another advantage is their heavy-duty construction, which provides reliable protection against wear. The mixing tools of the pug mills have a special carbide hardfacing that protects them against the highly abrasive ash, thus ensuring a long service life and high availability. Being able to withstand the acid additives mixed in with the ashes, the five mixers in use at the waste incineration plants in North America are made of robust stainless steel. The design of these pug mills complies with U.S. power plant safety standards.