Weekend Callout?

Mixer/ macerator unit on an agricultural 1MW CHP biogas plant

Plants always seem to go down in the middle of the night or weekends. Right? Wrong. But we notice these as they make our lives more difficult than when we’re on site and expected to deal with things. This weekend the weigh-cells on a large (3m3) mixer/ macerator vessel failed causing the feed system to stop on a Saturday morning. There were two options (1) leave it until Monday and lose 2 days feed and performance; or (2) Call ADAM.

We receievd the call at 09:35 and were on site by 10:47 (we can be that accurate). On arriving on site, we found the incorrect weigh cell readings had caused the vessel to overfill, causing upstream blockages and significant spillage (mix of fresh feed and recirculate). The system was isolated and LOTO put in place. The vessel and feed conveyors were cleaned and the blockage jetted. Once clean, the vessel was jacked up to remove the plate, bolts and nuts the weigh-cell sits on. A new plate was then positioned, spacers and cell placed on top and the new bolts torqued down to 168nm.

The leg was lowered back onto the plate, ensuring there was still a gap between weigh-cell and plate. The isolations and LOTO were removed and the vessel emptied – at which point it was noted the system did not report as empty and the vessel further inspected. On inspection it was found a significant amount of material had built up on the sides. The congealed material was jetted and the vessel flushed with water to clear. A full feed test was carried out demonstrating the correct operation and weight readings were showing. Job finished at 14:30.

Happy client.  Back up and running in less than 5 hours.  Well done ADAM.