Top Secret LL Boiler Spy Photos

Sting wrote:snip.. I am not sure you will enjoy my jaded comments regarding this design. So let me answer your quest for discussion on water tube boilers with a question. You have been kind to my questions and comments - I think I may skirt your patience if I vent mine - well here goes. snip

I did enjoy your comments and you make excellent points, thanks Sting. To answer your question, yes I have operated water tube type boilers, but never one designed quite like this... a better mousetrap? We shall see!

Brock, as far as copying the Anthratube design we did consider that, however much more complex to build and not going to sell for $4,000. So it is all a trade off. We think we have come up with a design that will last a good long while without problems and will be economical to own. Time will tell on both those counts.

My choice for a boiler design would be something based on the AA or AHS design but with a dual burn column. This would permit two or three BTU production capabilities. The lowest for summertime domestic hot water production using only one of the burn columns and higher BTU production when the larger or both were used. Perhaps a design with more than one internal blower that lights the larger coal column with gases from the smaller one. I'd also design it with more intelligent electronics. An integrated controller that uses PID control algorithms. Such algorithms could eliminate boiler water overshoot and outfires. It would also be easy to add outdoor reset boiler water temperature control. What I'm suggesting may be beyond the design capabilities of any current coal appliance maker but properly done I believe it would be a winner.

In addition making ash containment and disposal more automated and convenient would be a huge plus. What you are proposing is a product that breaks no new ground. It's just your version of an standard design with LL's reputation, quality control and customer service. I fully acknowledge it may be your only prudent business choice.

Yanche that sounds like a boiler id love to own. It also sounds like a boiler that would require me to take out a second mortgage to afford

I'm not in the market for a boiler, I'm very happy with mine. Back when I was looking I thought of the outdoor units for wood burning, I have no firewood and they were not all a pressurized vessel. I also looked at a corn burner that could take barley, the corn price was up and the mill told me they don't always have barley so I will keep that for drinking purposses only. If their was a unit that would burn coal, wood pellets and grain, that would be a high selling point in my book.That would have a big BTU swing . The auger would be great but the extra $$$ may cause some to look the other way. Keep the 's comming and good luck.

If you all look closely the unit has a tube ash scaper built in so as to not have a dirty job theme as sting has illuded to. This unit is a tube and plate hybrid so it isn't a true tube boiler and as Matt said hopefully a better mouse trap that incorporates the best of both worlds.

To transfer the 100,000 BTU of heat to the water you'll
need about 15 to 17 square ft of surface that is exposed to
the primary heat source. The loop back is helpful in removing
heat, but not as important as the primary surfaces. It looks
to me like you have enough primary surface.

You have some areas that are going to be a bear to weld
and if leaks are found during pressure testing could be almost impossible to get to.
I'm sure this is not news to you.

Good luck

Hey Matt, what is the estimated heat transfer surface area. Was it more efficient to make the head longer versus taller. Looks like you gained tremendous area with the double pass setup and left no place for the ash to stick with the angled plates. Looks better every time I look.

If I remember correctly we ended up with almost 20 sq ft surface area. I have a 200,000 BTU modine unit as a test load, so we are going to run the snot out of this poor thing, Berwick will have a slight case of global warming in our neighborhood.

Yanche, I still want to build a design similar to what you described, you hit it right on the head when you mentioned business considerations for what we are doing now. Maybe we can get you to come up and consult for a little brainstorming session on the "high end" LL boiler model.

Thanks for your comments tsb, we will be pressure testing on Saturday so if you hear some cussin out your way you'll know the score.

My concern, would be for a potential crack to form at the entrance to the second pass heat exchanger (If I understand the concept and flow of heat). There appears to be a significant difference in length between the yellow and blue lines. With continuous slight heating and cooling, there will be a differential of expansion and contraction, leading to a crack at the corner. How many thermal cycles would it take, would be a guess. Any way to replace the right angle bend with a more gradual U-shape? A radius-ed (sp?) corner is much more difficult to fabricate. The same caution applies to the final bend in the flue gas channel.

I ain't-no engineer. Got no formal book-learnin'. So, I don't know nuthin' and anything.

john

Update on the surface area just reran my calculations with more accurate ones for the current form factor, 18.26 sq ft primary and 14.197 sq ft secondary. I have been over the design several times since fabricating the inner head and some changes will be made to make for better ASME compliance. I met with Pete Axeman yesterday and he helped critique our first effort. So far we are not making any drastic changes.

Thanks for your comments John, the concern for cracking is not an issue just look inside a plate type EFM boiler and you will see a simipar difference in expansion distances at the exit by the plates. We of course will stand behind the boiler with free corrections for any development induced issues such as cracks.

Thanks for the feedback, we are having fun a look forward to a possible lighting of the boiler some time in the next week. Some delays have been expereinced becasue we are waiting for availability of ASME certified welders.

Latest activity includes running the completed first prototype under a slight load (to damn hot to run it at full blast! ) A few pics to update you all on progress. Still heading for boiler availability this fall. Tow models now in work a smaller unit for the single burner (110K Pocono Feeder) and this unit for the double 110K BTU feeder.

Supply temp at Modine unit is 158*F return temp is 132*F, pressure is 5psig, no instrumentation on supply and return pressure to get accurate flow and BTU data. Flue temp is approx 150* (in pipe) at idle and 250* at 1/2 fire. Will keep you posted as performance data is collected.

Few more pics of the fun we are having, don't worry high limit will be functional before any serious heat is applied! Just running unit off timer at this point.

Cab you show me how EZ it is to clean?

Good question Sting, water tube boilers are not common among the coal stoker population (Harman is the only other active model I know of) and probably for the reason of cleaning, we plan to burn this unit all summer to see how much fly ash collects wit this design.

There is a flat plate that fits the tubes and slides back and forth, the hole on each side will have a rod attached with a spring handle for heat isolation( side will be depending on left or right side config). This will keep the tubes clean and efficient, given the large amount of surface area we are figuring this to be an effective set up, time will tell. Also, the second pass ends in the base (just before exiting to the flue) and has a sliding door that raises up to allow easy vacuuming of the fly ash that will collect in the base. Will post some pics when I assemble the second prototype base.

Matthaus wrote:Good question Sting, water tube boilers are not common among the coal stoker population (Harman is the only other active model I know of) and probably for the reason of cleaning, we plan to burn this unit all summer to see how much fly ash collects wit this design.

There is a flat plate that fits the tubes and slides back and forth, the hole on each side will have a rod attached with a spring handle for heat isolation( side will be depending on left or right side config). This will keep the tubes clean and efficient, given the large amount of surface area we are figuring this to be an effective set up, time will tell. Also, the second pass ends in the base (just before exiting to the flue) and has a sliding door that raises up to allow easy vacuuming of the fly ash that will collect in the base. Will post some pics when I assemble the second prototype base.

And the other reason why over the fire Horizontal water tubes boilers are not popular in coal fired units is you Just built in a self sprinkler system when the fly ash starts to eat threw the water tubes over the stoker fire especially in the summer time when a lot of folks shut down the boiler until heating season comes around again . That gives the sulfur acid in the fly ash time to work on them water tubes.When heating season comes around again you now have a auto fire extinguisher system built right in . Just look at what happens to the water loops in stoker stoves and there made of SS. I guess it will be OK if you give extra grates with the boiler purchase because you will need to replace them as well as the tubes when the water hits the hot grates they will crack nicely. But who am I to say your the expert .