Adjusting air Beckett AWG / Burnham V - 84

Reply

  #1  
Old 02-07-16, 05:42 AM
Member
Thread Starter
Join Date: Feb 2016
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
Adjusting air Beckett AWG / Burnham V - 84

Well, I'm just getting into this. Don't have all the tools yet but I do have thermometer (thermocouple on a Fluke meter), a new Bacharach spot tester, appropriate boiler brush, a pressure gauge, and a Dwyer 460 draft gauge.

I first changed the spin-on oil filter and before doing anything else, I checked the draft (at flue and over fire) and stack temp. The drafts were fine at 0.3 in the stack and 0.1 in the boiler. But the net stack temp was about 525 degrees -- a little hot no? I checked the air settings, they were at 2 for the band and 10 for the shutter. I then checked the fuel pressure and found it to be correct at 140 psi (I used a known good pressure gauge). I next removed the Beckett AWG burner from the boiler (to allow easier access to parts) and removed, cleaned, and re-adjusted air tube, burner head (a V1), electrodes, etc. I also replaced nozzle, a Delavan solid cone 1.10 gph (at 100psi) 60 degree, and replace the oil pump strainer and gasket. Everything was set up to Burnham specs (pretty much the same as Beckett specs and pretty much the same as I found everything except I moved nozzle line assembly forward by 3/16 in. consistent with Burnham specs).

Everything went together just fine (very easily now that everything is clean) and start-up was perfect. The flame looks great to this laymen. I re-checked draft figures and they were unchanged and, after running 5 minutes plus, net stack temps were unchanged at 525 degrees.

I now used spot tester and found no evidence of smoke, a "0" on the Bacharach scale. So I closed down the shutter a little from 10 to 6 and tested again. No smoke, same stack temp. I eventually went to 1.5 on the band and 0 on the shutter and still no smoke and same stack temps. At this point I quit and decided to re-set back to specs (2 on band, 10 on shutter) and write this post. Unfortunately, I do not have a CO2 gauge yet (gonna get the old fashioned Bacharach hour glass thing if I can find one in used in good shape) so I don't have any CO2 numbers.

What could be going on here? Am I missing something?
 
Sponsored Links
  #2  
Old 02-07-16, 06:47 AM
Member
Join Date: May 2006
Location: upstate New York
Posts: 399
Received 0 Votes on 0 Posts
adjust

Hi, you mean -.01 and -.03 draft correct? If not, the first thing would be to reduce the very high draft. Are you sure you're using the smoke tester correctly? Try to pull back the plunger while you hold your finger over the end of the sampling tube.
If you can pull it very far, you're leaking somewhere. Take your test sample with 10 full, slow strokes. Good luck, Steve
 
  #3  
Old 02-07-16, 09:14 AM
Member
Thread Starter
Join Date: Feb 2016
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
Yes, my draft figures are negative 0.3 in the stack and negative 0.1 over the fire. The Bacharach spot tester is brand new. Suction is good with no leaks. I think there is just too much air feeding the fire even with reductions that I tried.
 
  #4  
Old 02-07-16, 11:07 AM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,493
Received 33 Votes on 25 Posts
You have twice written that your draft readings were 0.1 over fire and 0.3 at the flue. Steve asked if you meant 0.01 and 0.03, figures that are one-tenth of what you state.

I don't know what Beckett or Burnham recommends but you may very well have excessive draft and need to adjust the barometric damper.

You ARE taking the flue draft reading between the boiler and the barometric damper, correct?
 
  #5  
Old 02-07-16, 11:54 AM
Member
Thread Starter
Join Date: Feb 2016
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
Got It

Well, well, well. Who whudda thought that the burner cover could have so much of an effect on air flow? Since you have to remove the cover to do the adjustments, I assumed that putting the cover on after making the air adjustments would have a minor effect for which you would then perhaps make a minor adjustment. But no. The effect of the cover (the metal one, not the new plastic one) is dramatic.

With cover off, I found that the band had to be decreased to 0 (from the OEM-recommended 2 setting) with the shutter set at 10, in order to obtain a positive smoke test. Placing the cover on at that point produced substantial soot (a 7 score). In short, I found that I had to go back all the way to the OEM-recommended settings (band 2, shutter 10) with the cover on to remove all traces of smoke! Of course this took a few iterations of checking soot/smoke, removing cover, making minor adjustment, replacing cover, taking soot sample, etc., Clearly it would be absurd to take any combustion measurements on this burner / boiler combination with the burner cover off.

Good lesson learned. And yes, the bloody draft numbers are -0.01 over fire, -0.03 over breech.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: