Incident alert
LOCATION:
ASPHALT/COATING PLANT
ACTIVITY:
PRODUCTION AND PROCESSING
SUB ACTIVITY:
ASPHALT & COATED STONE
TITLE
Bag House Filter Fire
COUNTRY OF ORIGIN
United Kingdom
ACCIDENT / INCIDENT DETAILS
This bag house filter caught fire on the morning of the 2 August 2008. The plant had operated normally the previous day however a faulty exhaust fan was identified by the plant operator when he noticed an amp change on the control panel. This fault was immediately reported and an electrical engineer tested the fan motor who could find no defects. As a precaution the site replaced the drive belts as worn belts can effect fan efficiency.
On investigation it was established that all test and inspection requirements for the plant were met in full including a recent burner service and electrical systems check. However blinding of the filter bags had not been identified. The plant magnehelic gauges which indicate pressure across the bag house were inoperative. These gauges are not currently part of any on site test or inspection.
This incident has many similarities to the Runcorn Fire in February 2008, the following actions must be implemented.
ACCIDENT / INCIDENT IMAGES
Click image to enlarge
Click image to enlarge
LEARNING POINTS / ACTIONS TAKEN
The National Engineering Manager for Asphalt has forwarded the following recommendations:
1. The plant burner must be sequenced with the main fan to ensure that it cannot be lit without it running.
2. Ensure that at all times the bag filter temperature instrument is working correctly. Whilst these normally fail safe i.e. open circuit they should be checked every 6 months. The protection system should be set at 180 deg C for alarm and fuel cut off at 190 deg C.
3. The bag filter differential pressure instrument (Magnahelic) must be functioning correctly. Where copper/ Nylon pipes are used they should be cleaned out on a regular basis (every 6 months maximum or earlier if required).
4.Under no circumstances should the burner protection equipment/ system i.e. purge/ ignition/ flame failure (Honeywell/ Landis & Gyre) be bypassed.
LEARNING POINTS / ACTIONS IMAGES
Go back to search critera