low pressure lamont

O.K....some time ago, the bugaboo to the idea of a low pressure lamont was pointed out , that being of too much friction in the generating tubes to be efficiently overcome by the circulation pump. That unwelcomed, but grudgingly acknowledged cautionary note ( thank you George ) rooted around in my intractable knoggen for quite some time until it bumped up against an unresolved syinapse that chortled this question: Why, in a low firing, low pressure scenario is it necessary to reciriculate water through the entire system? I mean, check this out...er..uh...gentlemen...the design is not going to use super heat, not one little whisp. Also, the gasses will all be entirely convective -- the firebox being isolated from the generating tube area ( yes lots of extra tubing albeit seperated into 4 parallel sections ) Main point is that gasses will be in a downflow configuration, arranged in a tight flow path and impinging upon only the top section of each counterflow searies before reaching the next lower down. Being as the hotest heat is so is so tightly configured around the uppermost tubes, it seems that only the uppermost sections ( hairpin turn configuration ) need be recirculated. No, no.....crazy is good.

I have been doing a lot of research on this concept. But it brings up some questions. The heat transfer formula from my books and those I cab find on the internet do not cover this specific situation with turbulent boiling heat transfer in a tub.

The turbulent flow assumes a turbulent profile where at the tube surface there is laminar flow and the most turbulence is in the center. But I would expect the boiling to disrupt laminar flow at tube surface.

Anyway from the formula it seam that surface to volume ratio has the most effect on heat transfer. That would mean that going to four parallel paths using tubes of 1/2 the diameter one could double the heat transfer. Going to 1/2 the diameter would double the surface to volume ratio. But would have 1/4 the cross sectional area. Four tubes would bring the volume up to the single tube. But with double the heat transfer the tube length would need be halved. So with 4 tubes of half the diameter and length one could achieve equal heat transfer. Eight tubes doubling steam output.

There may be reasons this is impractical or maybe wrong. But it seams it would be more productive getting a once through parallel path boiler to work.

Thank you for your feedback. Much appreciated .I would actually like to go deeper into the conciderations of the many variables of heat exchange in a multi path monotube. At present I would like to focus on the main point which comes in two parts: ( Keeping in mind this is about dealing with the problem of heightened circulation friction in a low pressure lamont style monotube ) 1. Is it necessary to recirculate through the entire generating section? 2. Does the recirculated water have to be at least 5 times the feed rate?
My thinking is that the answer to both questions is - NO - neither is absolutely necessary , at least in my particular application .I guess I should state at this point that I am designing a boat boiler ( STEADY STEAMING ) and do not have to solve for high steam rates or rapid steam demand fluctuations.
O.K so...in a steady steaming application it seems to me all that is necessary is to have a ballanced oversupply of feed water running through perhaps 2/3 or 3/4 of the generating tubes and dumping into the recirculating drum. From there it could be recirculated through the ...lets say, last 1/4 of the top part of the generating tubes ( downflow gasses, upflow generating tubes in my design ) that are placed in the hotest section of the flow path. Because there would be no rapid steaming fluctuations, it doesen't seem necessary to have 5 times or more recirulation to feed rate. The recirculation rate need be only high enough to end up with enough oversupply to establish a reasonable safety margin against overheating the tubes.
Here also is another pertinant facter: In a waterwalled lamont configuration, all the generating tubes are exposed to radiant heat, and there for there is a heightened need to establish a recirculating safety margin through the entire system. It seems to follow that in a serpolit configuration where the majority of the generating tubes are being impinged by convective gasses, the intensity of radiant heat is only falling on the lower coils and so there is the zone most in need of recirculation.
To sum up; perhaps the circulation friction problem in a low pressure lamont system can be solved by three changes to the standard. 1. Shorten tube length by multi path design. 2.Restrict recirculation to the hottest tube sections only. 3. Reduce rate of recirculation. These changes might result in a lamont type boiler that, albeit is not as effecient, might just work.
Gentlemen of the jury, engineers and other assorted steam interested dude types...ready, aim, fire!



Edited 3 time(s). Last edit at 09/21/2013 09:24AM by richard orr.

What your proposing sounds very much like a Baker boiler, where circulation was natural instead of forced. Any one have any experience with a Baker, always been curious how well that design worked.

Keith

It has been a while sence I have looked at a Baker boiler, but if memory serves, wasn't it a type of natural recirculating boiler that used the dynamic flow of the heated water to acheive recirculation? The system I am imagining is one of forced circulation.and I suppose I should not even refer to it as a "Lamont type" as it only recirculates through the hottest portion of the generating tubes and at a much lower ratio of feed to recirculation then does a Lamont. Basicly the design would pump feed water through the economiser and 2/3 or 3/4 of the generating tubes up to the point well into the transition zone.and then dup into the recirculation drum as saturated steam and having a small margin of oversupply feedwater. Steam quality could be discerned by a temp. gague at the dumping point. Water is then recirculated by a pump through the hottest section of the generating tubes.With a sight gague the feedwater oversupply could be balanced with the recirculating tubes simply by maintaining water level by adjustment of feed pump and fireing rate.
By recirculating through a much shorter portion of the generating tubes at a lower rate then that of a Lamont -say two times the rate of feed - and deviding tubes into a parrallel of 4, it would create less friction for the recirculation pump to overcome. I would leave the tube diameter of the parallel tubes just the same as the rest of the generating system assuming that the velocity of the lower pressure steam is plenty high enough to scower the heat exchange surface.



Edited 1 time(s). Last edit at 09/22/2013 08:17AM by richard orr.

Richard,

If you want to see how a Baker was made look in our Bulletin or the Newsletter or better yet, buy the repro Baker catalog from the Club stores. As to the real Lamont, George Nutz wrote a definitive paper on it.

I had a Baker in my 735 Stanley and it worked just fine. The original Baker burner was full of holes and backfired constantly so a new one was made only with one 3" venturi like a White. It used the original grate; but with a sheet of stainless under it with many fine holes in it ti try to even out the mixture distribution. It yodeled magnificently.
The only problem with it was the guy who made it did not include the rotary blowdown on top where you could index it and blow each circuit down hard, so eventually it clogged up.

I am very curious why anyone would want to use a Lamont at low pressure in a boat, when a Yarrow water tube is so good, especially when the firebox is outside the helical coil and only provides convective heat transfer. Rolly can comment on this better than I can.
The Lamont was perfect for intense radiative firing and provides a serious reduction in size and weight compared to a Doble type and has the wonderful advantage of greatly simplified control needs.

Jim

Jim, thank you for your feedback. You da man. Let me clearify, I am not going for a Baker boiler but rather a screw-together, off-the-shelf boiler, driven by the same insentives as another long time poster...Steamerandy I think. However, if I were going for a weld-up, the Yarrow is a beaut -straight forward simplicity of design. I'd want to set it up like a big un though and have cleaning ports through the mud drums or something; light years beyond my moth eaten pocket book .
Far be it for me to say this to you, but as you well know, designing is always a trade off of principals - whatcha gonna put in ye ol' shopping bag?. I am designing for a large sidewheeler and so, compared to what you guys are up against with steam cars my options are so wide open it could be termed a LUXLUXURY of design The boat has a flat bottom - no worries about weight. It'll run on switch grass, bamboo and, who knows,... old tennis shoes scaveneged from the dumpster in back of the Goodwill... so no worries about fuel.
In two months we will be a family of eight and so tops on my list is S A F E T Y as the wife would be kinda upset if I blew up the kids. We're in for a long trip up the Mississipp. What I want is durability which to me is simplicity spelled sideways. I'm building a 12" x 11" grasshopper direct connect by pitmans to the sidewheels .It wants me to feed it low pressure.
My choice of boilers...Lawd, lets just call me crazy and get it over with. I have it in my mind to do it with a screw together monotube and prove to all those who say I can't that indeed I can. I've been thinking about it for a long time and you guys have been loads of help.
As far as isolating the fire from the generating tubes, it's iniffecient by a facter of four, I know. But if your looking for a margin of safety when catastrophy is measured in seconds...well GREAT CEASER'S SUSPENDERS there it is. I'll buy more pipe.
The rocket stove burner design is ideal for fuel such as switch grass, capable of attaining a high heat and an exceptionally clean burn ( clean burn...gonna be a growing issue with solid fuel ) ... so.no sooting. Da be a good teng, mon.
There it is, Jim, from the nutshell of my mind, outa the box and onto you .

Hi Richard, I have thought a bit about this you said about kids blowing up. In the boiler, I feel that the failure rate is secondary to the failure mode.
One way to ensure a more benign failure mode is to reduce tube diameter. This has two effects.
1) The rate of steam released to atmosphere is less because the narrow tubes choke the flow.
2) There is less water in the tubes for the same surface area, so less steam is released to the atmosphere.

Richard,
Who says you can't screw a monotube or any other boiler together??? All those couplings on top of a White coil stack are left and right hand threaded couplings that screw each coil to the next one.

For a boat and i sure have steamed on quite a few, lack of any fuss is important and so is eliminating the need for a fancy control system with any of the electrics a monotube will want and a low center of gravity.
If it were my boat, I would sure build a Yarrow type of water tube boiler and weld it together. Big deep firebox and so easy to keep clean and they make steam like crazy. A boiler with a long time constant between anything going wrong and getting to the point where you need to do something about it.
Low pressure? Then make the bottom headers from big pipe and screw cap ends for cleaning. Stanley water level control with a manual override and a nice gauge glass.
Ask Rollie.
Jim

richard orr Wrote:
What I want
> is durability which to me is simplicity spelled
> sideways. I'm building a 12" x 11" grasshopper
> direct connect by pitmans to the sidewheels .It
> wants me to feed it low pressure.
> My choice of boilers...Lawd, lets just call me
> crazy and get it over with. I have it in my mind
> to do it with a screw together monotube and prove
> to all those who say I can't that indeed I can.
> I've been thinking about it for a long time and
> you guys have been loads of help.

Richard:

You're probably aware of this successful project already--but here's the link anyway:

[www.youtube.com]

--really like the engine, the walkiing beam concept lends itself to the use of the Marshall valve gear. The drive to the paddles seems to approximate what you have in mind.

I'm not very happy with him firing it on propane--and carrying a spare tank along in the transom! Great way to get blown to hell IMO!

There's lots of info on this project if you look around the 'net.

FWIW

Bill



Edited 1 time(s). Last edit at 02/08/2014 03:19PM by Bill Hinote.

Bill,
Propane on any boat is about as stupid as they get.
Saw a nice 40' yacht blow to bits outside the Santa Barbara harbor, three killed, four badly burned.
Remember Wayne Nutting's disaster?
Jim

Jim Crank Wrote:
-------------------------------------------------------
> Bill,

> Remember Wayne Nutting's disaster?

Y, Stanley steamer in a parade converted to propane. He carried a spare tank and it was a hot day and vented.

SACA banned propane for quite some while after that event.

B.

More:

IMO propane is great for small vehicle projects such as bicycles, karts or motorcycles. It combines ease of control with clean burning character without excess effort. Also, the "open-air" nature of these eliminates locations where propane can accumulate and cause disasters.

Once we get into larger projects like autos or boats, propane becomes less desirable. Solid-fuel firing or (especially for autos) the use of liquid fuels with so many developed and documented burners such as steam atomizing or spinning-cup types makes propane a non-contender.

BH

That is NOT what caused the Nutting disaster. Let's get this right once and for all.
The pilot was burning propane, not the main burner. Fran Duveneck and I were doing the same thing and after the disaster we both instantly went back to the original Stanley pilot system.

Bill Marsh and I drove Wayne's Stanley the weekend before and it was leaking propane then.
Wayne had a huge propane tank behind his shop to fire his heat treating furnace. He filled the propane pilot tank clear full of liquid propane, totally ignoring the fact that you leave a 20% empty space on top by using that fill valve, which had a tube extending down inside the tank. When it spits liquid you stop filling. Wayne did not stop; but made sure it was totally full of liquid. We watched him do this and both Bill and I told him he was just looking for a disaster. He got mad and told us to mind our own business and he would fill the tank like he always filled the tank.

The tank sat in the tonneau behind the front seat right over the hot cylinders. It was a blistering hot day at Knots Berry Farm with no wind at all and the Stanley was creeping along in the parade.
The safety valve was relieving the pressure in the propane tank BECAUSE Wayne had NOT filled it correctly, he had left no room for expansion.
The tonneau was full of raw propane gas, just like when I drove it the weekend before. It smelled to high heaven of propane.

Bill Shutz's wife and kids were riding in the Stanley and she lit a cigarette. The newspaper photos showed a huge ball of flame with only a small sector of the tires showing on the bottoms. Wayne and his wife died from burns and the three in the back seat were also very badly burned.

That White that burned down on the London to Brighton. The idiot had taken the White fuel tank out and put in a propane tank with a rubber hose going to the burner, at full tank pressure. In that early model White the fuel tank sat right along side the steam generator.
A friend of mine was on the other side of the fence when it blew up and got photos. I helped the VCC analyze why this happened. Pure stupidity.
Both SACA and the VCC banned propane except for hand torches for firing up after this, that should still be in force and observed.
Jim

Jim Crank Wrote:
-------------------------------------------------------
>> The tonneau was full of raw propane gas, just like
> when I drove it the weekend before. It smelled to
> high heaven of propane.
>
>You are a lucky chap Jim!

Mike

Indeed. Both Bill and I were invited to ride in that parade the following weekend; but I was then desperately searching for a Delling that was supposed to be in Watts in an old warehouse.
That tonneau absolutely reeked of propane after our drive the weekend before. I opened both rear doors while it was still outside and firmly shut off that tank. Should have dumped some of it when Wayne wasn't looking.
Jim

Jim
Hear is my ¼ scale model of the late 1907 white generator. All screwed together with right and left hand threads.
Rolly

Jim Crank Wrote:
-------------------------------------------------------
> Bill,
> Propane on any boat is about as stupid as they
> get.
> Saw a nice 40' yacht blow to bits outside the
> Santa Barbara harbor, three killed, four badly
> burned.
> Remember Wayne Nutting's disaster?
> Jim

This thread is getting a little off topic, sorry. The Low pressure Lamont should not use propane for a fuel. The Northwest Steam Society requires an annnual boiler inspection for our Stanleys before we can participate in their activities. (When is the last time that you know of a Stanley boiler blowing up?) However, most of NWSS steam boats run from propane bottles that are surrounded with hot water so that the tanks don't ice up. Just about every year they have a malfunction where the occupants have to jump overboard because by the tanks being heated, their propane tanks have vented propane and caught the pool of propane afire. The boats quickly become a bathtubs filled with propane and overboard is the only escape for their passengers. The Northwest Steam Society members are chasing the wrong witches. They should instead, be banning propane as a fuel source, as the rest of us should also do.

Pat,
Not the least off topic, this is just what our forum is so good for and why we have it. This propane thing is a serious matter.
What the boat guys do is something we have no control over; but propane fired things at SACA meets is sure something we most certainly can control. The NWSS boats sound like a good things to avoid, talk about asking for it!!!.
Firing up torches are fine unless you want to fuss with a gasoline blowtorch, or use your gas headlight's acetylene tank and torch. Anything else: "Thanks for coming now take your contraption home."

Only the one Stanley boiler deliberately blown at the factory long ago. Bulging and the wire going tink-tink yes, immediately shut down and blown dry. A local nitwit who was a rolling hazard.

Rollie, Now can you be conned into building full size White coil stacks??
Jim

Rolly Wrote:
-------------------------------------------------------
> Jim
> Hear is my ¼ scale model of the late 1907 white
> generator. All screwed together with right and
> left hand threads.
> Rolly

I'm very interested in your scale boiler. How was it fired? How did you control the temperature and pressure?

Lohring Miller

Lohring
The white model is not setup with a burner, I use it as a display model, along with many other models.
I belong to the New England model Engineering society. Here are some photos at the Cabin Expo last year. Look at the second row.
[www.neme-s.org]
Rolly

Jim Crank Wrote:
-------------------------------------------------------
> Pat,
> Not the least off topic, this is just what our
> forum is so good for and why we have it. This
> propane thing is a serious matter.
> What the boat guys do is something we have no
> control over; but propane fired things at SACA
> meets is sure something we most certainly can
> control. The NWSS boats sound like a good things
> to avoid, talk about asking for it!!!.
> Firing up torches are fine unless you want to fuss
> with a gasoline blowtorch, or use your gas
> headlight's acetylene tank and torch. Anything
> else: "Thanks for coming now take your contraption
> home."

Jim and others:

It's time for me to disagree about a carte blanche ban on propane. This would eliminate the possibility of many small, "garage-level" projects that might be fueled by propane because the use of liquid or solid fuels instead could place the potential success beyond the average enthusiast.

It should be possible to establish a set of operating parameters which might ensure against the possibility of disaster.

If everyone agrees, maybe we should start a thread on propane firing for steam power. I could just start it, but would like some positive input to encourage it.

Come on guys, this is a worthwhile subject and I want all to participate. As Jim Crank has said, this is what forums like these are really all about. Personally, I don't want to lose access to propane for firing my puny projects because of the "idiot factor" which we can filter out.

BH

I agree with Bill
Rolly , I think your model White Steam Generator is Fantastic.

A few things to keep in mind when working with propane
Propane is HEAVIER than air, so any leaks or venting will settle down into compartments, hulls, etc. This can lead to FATAL results.

So use open and well vented configurations

Natural Gas has similar advantages of using propane however it is LIGHTER than air. So it will dissipate quicker than propane The down side is that Natural Gas has less energy per volume when compared with propane.

Do not smoke within 25 feet of any potential fuel source. From what I read that was the final mistake of the Wayne Nutting incident.
[eaglerockhistory.org]

Follow guidelines to prevent even coming close to over filling your propane tanks. they need room for expansion
Read and follow other safety rules

The Horseless Carriage Club of America prohibits the use of propane as a fuel for their owners' cars. I am not aware of any rules of SACA,Inc prohibiting the use of propane as a fuel for their owners' steam cars. There are a lot of choices other than propane to fuel a steam car. Personally I perfer using the fuel with the most BTU s per gallon of fuel, and to me that is kerosene. I support the HCCA in the prohibition of propane. My steam cars are already enough of a fire wagon with out someone next to me burning them up with his propane fired vehicle.

Great looking coil stack Rolly. Nice simple bender.

How about a simple set of propane rules? Outdoor turkey fryers may not need one of these, but perhaps whenever there is means for containment one of these are required? I didn't realize natural gas was lighter than air, a plus. I suppose knowing that should effect where such said detectors are mounted.

I agree with Bill, a carte blanch ban would be a discouragement for viable developments.
-Keith

edit:changed detector(s) are or could be detector is.......a nit



Edited 1 time(s). Last edit at 02/11/2014 04:05AM by kdc2.

I've read the account of this "Nutting" accident several times and it doesn't make sense. He over filled the tank, there was a continual propane odor in proximity of the tank and someone lit a cigarette and the whole thing went up etc.

First of all, propane has no odor, there is an oforant added to the LPG called ethyl mercaptan, simply smelling the odorant does not guarnatee the presence of the gas. It's common that this chemical is leaked around the valve on the exterior surfaces during the filing process.

The danger of overfilling a tank is having a release of the gas through thr relief valve when the pressure exceeds 250psi, which it can easily do in normally warm ambient teperatures.. This event is a fast release and reseating of the valve- not a slow release over a long period of time.

From what I've read of the account, there was a leak in the system, and the cigarette lighter provided a source of ignition and the gas that had accumulated in the confined area ignited everything around it. The ensuing heat caused the tank to pop off which would have happened anyway no matter the liquid level. Had nothing to do with over-filling a propane tank, this was caused by a leak in the piping.

I agree propane has no place on or around an open-fired steamplant. The argument is made that propane is used for motor fuel applications and campers etc and with a very good safety record. The major difference here is the open fire associated with a steam boiler. It is a perfect source of ignition and any accidental or automatic release of propane has a very high probablity of resulting in a fire.

Rollie,
Now can you be conned into building full size White coil stacks??
Jim
Jim
There already is a guy building the early version of the white generator of the eleven coil stack that had the smaller tubing.

Tom can wing nice coils, all he would need is the ones to go by. They would not be the 0.072 diameter as originally used.
I would use 3/8 A-106 0.675OD pipe or 0.750 4130 tube with the correct wall size.
Rolly

Bill,
There are are lots of very small RAY type atomizing oil burners around that one can adapt, also from commercial space heaters, steam cleaners, etc.. Investigate.
Propane settling on the garage floor and finding the water heater will definitely make a big impression on one.
Yes it is used in cars and campers and when it is, the plumbing is to AGA standards.

Doug, Very hot day, no breeze at all, Stanley just creeping along, propane IS heavier than air and filled the tonneau BECAUSE Wayne deliberately overfilled the tank and the heat caused it to naturally expand and vent. Hell, I watched him do it and was told to mind my own business.
The tonneau was filled with propane, just look at that ball of fire. The ignition source was Mrs. Shutz lighting her cigarette in the back seat.
What was infuriating was the usual stupid reporter making up the story to be even more lurid than it was.

It stinks too, otherwise how could Bill and I not help but notice it that weekend before. I know all about the odorizer added to natural gas. Ethyl-mercaptan or eu d' Stanley or whatever you want to call it, propane stinks.
Yes, it did vent from the safety valve, we looked for leaks the weekend before with soapy water and found none, just wanting to help Wayne out. Bill and I liked Wayne very much and were concerned about the very strong propane odor in the tonneau. The propane WAS venting from the safety valve, there was no other leak..

We were there, none of you were, so please no second guessing. It was a horrible disaster and two nice people got burned to death and three others were badly burned, isn't that enough.
Jim

Rolly
Those are real nice windings. Nice to see something that doesn't look like a bird's nest, not that the latter doesn't work - just not as fun to look at. Am surprised about the use of propane on NWSS boats as I thought it has been long held to be a bad idea on boats due to it's tendency to collect in the bildg.

The stink that is added to propane dissapates to the air long before the propane does. In 1963, while attending college, I lived in a travel trailer at the gas station where I worked. I turned on the oven to cook a dinner, but before I could find a match to light the oven, I was distracted by a gas customer . Quickly returning, I turned the oven valve off, but the trailer was already filled with propane stink. I openned every window and door and let it vent for about 90 minutes. The propane stink was all gone by then and it appeared it was now safe to light the oven. I left all of the windows and doors open while I lit my match. The explosion blew me back 10 feet and I had first degree burns on my arms and face and no head hair left at all. All the cupboard doors in the kitchen blew open at the same time. When I lit my match, there was no propane odor left, but it was still as dangerous as anything could ever be. Please remember, "Just because you cannot smell the propane, it doesn't mean that it isn't there". This lesson could save someone's life.

All files from this thread

File Name	File Size		Posted by	Date
Finished Model-3.jpg	527.8 KB	open | download	Rolly	02/10/2014	Read message
Top white boiler.JPG	137.9 KB	open | download	Rolly	02/10/2014	Read message
Small.jpg	165.1 KB	open | download	Rolly	02/10/2014	Read message
Combustion support ring -2.JPG	132.2 KB	open | download	Rolly	02/10/2014	Read message
tube bender.JPG	801.6 KB	open | download	Rolly	02/10/2014	Read message
small Serpollet burner.jpg	825.1 KB	open | download	Mike Clark	02/20/2014	Read message