October 23, 2020 at 6:04 pm #2258
We have 4 50 SGs that have been in operation since January, 2019 with run hours that vary from 5900 hours to 3700 hours. The engines came with HUG emissions control systems.
Since commissioning, the average ammonia injection rate has nearly doubled (from 7.5 gal/hr to 13.5 gal/hr), the CO has more than tripled (2.5 ppm to 8.1 ppm) and the d/p across the catalyst has increased by 5%. The HUG maintenance manual states to clean the catalyst ‘as required’.
What are the experiences of other users? Are these the symptoms that are seen with a dirty catalyst? How often are other users cleaning their catalysts? Do you clean them yourself or hire it out to a 3rd party?
Thanks in advance for any feedback.
MikeOctober 26, 2020 at 8:57 pm #2259Steven OsgoodParticipant
At Portwest ward we check / clean the catalyst at the 4000 hour interval. We have not seen the size of the indications you talk about, just an increase in DP.
We have just completed the 8K maintenance intervals, and blew out / vacuumed each of the catalyst beds.October 27, 2020 at 2:32 pm #2260Jeremy SaarParticipant
We clean them annually and inspect the HUG controls and injection systems. We started off cleaning them based on hours but found some engines with less hours had more ash then engines with higher hours.
We do the cleaning ourselves and use a combination of high volume air nozzles from Exair and a vacuum cleaner. You should see some major improvement if you clean them.October 27, 2020 at 2:51 pm #2263ajluhmannParticipant
We have silencer packing depositing on our first ROM layer. We inspect those quarterly as required by our air permit. However we recently experienced a DP across our SCR due to the silencer packing. Keep in mind that our facility is 34SG’s with the silencers ahead of the SCRs. To clean these off we use a HEPA vacuum with a soft bristle nozzle.
If you are entering the SCR enclosure, you should make sure your PPE is appropriate. One of the components of the ROM layer is Vanadium Pentoxide. You dont want to ingest this or get it on your skin. There is also Vermiculite found in the expansion mats. For our entry into the SCR enclosure we have to suit up using our full body haz mat suit plus a respirator and goggles.
We’ve also had good luck with consulting Miratech with any SCR/Urea questions. They have several ex-HUG employees working with for them and we have found them to be quite knowledgeable with regards to troubleshooting our HUG system.
Miratech Contact – David Bonner – firstname.lastname@example.org – 918-442-2499
October 27, 2020 at 7:05 pm #2266
- This reply was modified 1 month ago by ajluhmann.
As a follow up to my first post – we just opened up the SCR that has 5700 hours on it for the first time and we found a lot of debris in the later sections of the SCR. I’ve attached a picture of the section between the ROM and OXI layers.
Based on the soot we see in the HUG sample filters, we were expecting excessive soot build up in the SCR to be causing the degraded performance, but we were very surprised when we saw very little soot. Is this similar to what other users find during their inspections? Have other users found the expansion mats to break free?
MikeOctober 27, 2020 at 7:54 pm #2268
I am having technical difficulties posting a picture to the forum. If you would like to see a picture from our catalyst inspection, please send me an e-mail.
MikeOctober 28, 2020 at 10:45 am #2270
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