16 December 2011
The California Air Resources Board (ARB) has reinstated the verification of Cleaire LongMile® diesel particulate filter system. This allows Cleaire to resume marketing and installation of the system to support California diesel fleet regulations.
On September 17, 2011, the ARB suspended verification of the LongMile filter following a major fire in Washington state that was caused by an uncontrolled regeneration of a LongMile unit installed on a highway truck. In order to lift the suspension, Cleaire had to satisfy a number of ARB requirements and introduced modifications to the system. The LongMile is a passively regenerated filter utilizing an oxidation catalyst positioned upstream of a sintered metal filter substrate.
While the company did not comment on the modifications, the upgraded LongMile filter includes a containment shroud around the filter substrate and a spark arrestor—components that appear to be designed to contain the molten metal and sparks within the filter unit in case of a catastrophic failure. Compared to ceramic substrates, the sintered metal substrate used in the LongMile filter is believed to be more vulnerable to failure from uncontrolled regenerations.