In April, 2010, California South Coast Air Quality Management District (SCAQMD) passed Rule 1155, requiring all industries that operate baghouses and dust collectors with 7500 ft2 or more of filter area to install particulate monitors for filter leak detection and to have no visible emissions.
Asphalt plant operators were concerned with the new rule. In prior years, many plants tried to be proactive by installing other charge sensing devices, triboelectric broken bag detectors, and opacity monitors. The experiences were all similar. Batch processing with high moisture and sticky particulates caused repeated unreliable measurements and false alarms, significantly hampering production. Frequent maintenance and confusing set up and were also common.
SCAQMD agreed to an extension of the rule for the asphalt industry to provide time to determine if reliable technology was available for hot mix asphalt processes. Blue Diamond Materials volunteered their Inglewood, CA, plant for a test. Having learned that FilterSense DynaCHARGE™ particulate monitoring technology had proven reliable in many other moist and demanding processes (such as chemical spray dryers and carbon black raw production), a system was installed at their Inglewood plant.