A test stand for the evaluation of high efficiency mist eliminators

High efficiency mist eliminators (HEME) are airstream filtering elements primarily used to remove liquid and solid aerosols. HEME elements are designed to reduce aerosol load on downstream high efficiency particulate air filters and to have a liquid particle removal efficiency of 99.5% for aerosols as small as 1 μm in size. The test stand described herein is designed to evaluate the loading capacity and filtering efficiency of a single HEME element. The loading capacity was determined with or without use of a water spray cleaning system to wash the interior surface of the element. The HEME element is challenged with a liquid waste surrogate using Laskin nozzles and large dispersion nozzles. The waste surrogate used was a highly caustic solution with both suspended and dissolved solids representative of actual exposures at mixed, hazardous, and radiological, waste treatment facilities. The filtering efficiency performance was determined by challenging the element with a dried waste surrogate aerosol and di-octyl phthalate intermittently during the loading process. Capabilities of the test stand and representative results obtained during testing are presented.