Win a copy of Compost Teas for the Organic Grower this week in the Composting forum!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education experiences global resources the cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • r ranson
  • Anne Miller
  • paul wheaton
  • Joseph Lofthouse
stewards:
  • Mike Jay
  • Jocelyn Campbell
  • Devaka Cooray
garden masters:
  • Steve Thorn
  • Dave Burton
  • Dan Boone
gardeners:
  • Joylynn Hardesty
  • Mandy Launchbury-Rainey
  • Mike Barkley

Clearance From The Top Of The Heat Riser to Steel boiler or Masonry?

 
pollinator
Posts: 118
7
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Still working on my final design for a 5" or 6" batch box rocket water heater/bell and was wondering what is the recommended clearance between the top of the heat riser and a masonry bell top or water boiler?

Would a mild steel boiler cope with the exit temps from a heat riser?

Many thanks in advance for any help.
 
gardener
Posts: 2993
Location: Southern alps, on the French side of the french /italian border 5000ft high Southern alpine climate.
129
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
John, Peter says a good practice is to make the top gap a foot. On a 5 incher, i've gone down to 3 inches gap, between heat riser and cast iron top.

I'd say, use the same gap as your diameter, if it's refractory masonry. If it's the boiler, it could most certainly cope, if cooled by water. The only problem i envision placing it over the heat riser. Condensation of the gases against the cooled metal. And steam flashing.
 
John Harrison
pollinator
Posts: 118
7
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thanks for your quick and helpful response Satamax. Would you suggest the same gap for the boiler as for the masonry?
 
Won't you please? Please won't you be my neighbor? - Fred Rogers. Tiny ad:
permaculture bootcamp - learn permaculture through a little hard work
https://permies.com/wiki/bootcamp
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!