What's next for controlling airborne silica sand?
U.S. metalcasters are finding themselves in the crosshairs of new measures meant to enforce and improve compliance with workplace safety standards and reduce worker injuries and illnesses.
In September 2022, the U.S. Occupational Safety and Health Administration (OSHA) announced significantly expanded criteria to its Severe Violator Enforcement Program (SVEP) that includes more substantial consequences for employers that violate OSHA requirements.
Of note, Directive Number CPL 02-00-169 singles out high-emphasis hazards such as silica exposure as an area where OSHA will be stepping up enforcement through enhanced penalties, mandatory inspections and public disclosures.
In the February 2023 issue of Foundry Management & Technology magazine, Scott Harris of Solex Thermal Science expands on the new enforcement protocols, as well as how metalcasters see it impacting their business.
Of note, Harris discusses a driving force behind these ongoing concerns is that existing equipment in many foundries are not making it easy for them to meet current regulations. For example, vibrating fluid beds introduce direct contact between the air being used to conduct the heat transfer and the sand product — thereby leading to silica dusting that escapes the equipment.
In contrast, "moving bed heat exchangers (MBHE) are emerging as a preferred solution for metalcasters looking to source a more effective method to dually manage temperature control and silica exposure," writes Harris.
"Since air is not used in the cooling process and the required heat transfer is realized within a gravity-fed layout, the sand is not subject to agitation and particle degradation – thereby minimizing dust and subsequent emissions."
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