Thermal Transfer Change

adayton_2

removal of carbon/soot scale from boiler combustion chamber heat xchanger scrub & vac. How should the benefits/efficiency improvements be "visibly" or otherwise be evident? I.E., on a two pipe steam boiler burning (clean efficient flame) reasonably well for 30 years with little "real" thorough scrubbing & vaccing annualy, the only target "measure" we have is 42 minutes from 160* (aquastat) pot of boiler water to end of first steam cycle (10 ounces steam). Weil McLaine 572 Steam boiler rated for 2.75 GPH nozzle MAX(5 section boiler) currently running 2.00 GPH nozzle (possibly too underfired)(Becket Burner). AFTER thorough scrubbing & vaccing Yesterday removed substantial scale/combustion dirt from the xchange passages the time to first cycle remained at 42 minutes...... With CLEAN iron for improved heat xchange should not the time to first cycle gone down????

Alfred/Jim

brucewo1b

first cycle gone down

In reallity yes but remember it takes more energy to turn water into steam than it does to raise a few degrees so you may not notice that small of change. Yes you are underfired as most mfrs will not recogmend more that a 20 percent decrease in downfiring. In this case that would be 2.20 gal nozzle, however remember that if pump pressure has been increased then that may have already been factored in or increasing pressure on the pump could bring your nozzle up to within range. I would look at the edr of the radiators and then deside on where to fire the boiler but never more than 20 percent without mfr recogmendation.

Bruce

adayton_2

Burner used to be

30 year old standard (lower pressure) burner. New (5 year old) Beckett Burner is 100 PSI. Does this size boiler usually take 42 minutes to achieve 10 ounce steam on first cycle (from 160*F aquastat)? Weil McLaine did say not to underfire by more than 10 to 15%. word doc attached shows 572 boiler ratings. Gross IBR is 292,000 with 2.75 nozzle. Being as this is a 30 odd year old model though, I would "guess" the 2.75 was referenced to older low pressure burner packages. How does one calculate from OLD to NEW burner packages? Weil McLaine records from that era indicate two different supported burner packages. One at 2.75 nozzle and one at 1.3 nozzle. why the great difference way back then I do not know.

Alfred/Jim