1 Steam Cars : Phorum
General Steam Car topics
Boiler Wrapping
Posted by: Peter Heid (IP Logged)
Date: October 23, 2002 06:25PM
<HTML>I thought I would pull this idea out for it's own thread. There would seem to be 2 possable reasons to wrap a boiler: 1) To impart strength to the shell and prevent failure. 2) To prevent personal injury and machine damage should a failure occur. Both goals can be achieved simultaneously if the wrap is of the proper material and construction. Wrapping a boiler with carbon fiber or kevlar material would seem like a very good idea, just forget about the epoxy and use sewn or wrapped material. The object you create uses the epoxy very little for strength, all the strength is in the fabric. The cloth can be sewn like a safety harness shock absorber so that each increment of expansion must break the next layer of thread in an accordian type fold. Theroetically all the energy will be expended breaking the sewn seams and the limits of the material are never reached. Kevlar thread can be used inplace of the steel wrapping wire and is much lighter for the same strength. The kevlar will not sweat when heating or cooling avoiding any condensation that might cause corrosion. The materials are reasonable enough in price and many fabrics, threads and wraps as well as tools can be found through places such as aircraft supply houses.
Peter Heid</HTML>
Peter Heid</HTML>
Re: Boiler Wrapping
Posted by: George Nutz (IP Logged)
Date: October 23, 2002 07:44PM
<HTML>Peter,
What is the coefficient of expansion of Kevlar, in preolading boiler shells it is important that the shell and the windings grow near the same rate. Also what is the strength degredation of Kevlar versus temperature---would it withstand 600 degrees F? Kevlar, at room temperature, is stronger than steel per pound but not in any way equivalent for the same diameter, I do not know if it is stronger per pound than 350,000 psi tensile strength piano wire. The modulus of elasticity of both materials should be the same as they would elastically stretch at the same rate in regards to pressure. Is the Kevlar immunable to moisture degradation over a long period of time? This old mind that has no Kevlar infomation would like to know!!
Best, George</HTML>
What is the coefficient of expansion of Kevlar, in preolading boiler shells it is important that the shell and the windings grow near the same rate. Also what is the strength degredation of Kevlar versus temperature---would it withstand 600 degrees F? Kevlar, at room temperature, is stronger than steel per pound but not in any way equivalent for the same diameter, I do not know if it is stronger per pound than 350,000 psi tensile strength piano wire. The modulus of elasticity of both materials should be the same as they would elastically stretch at the same rate in regards to pressure. Is the Kevlar immunable to moisture degradation over a long period of time? This old mind that has no Kevlar infomation would like to know!!
Best, George</HTML>
Re: Boiler Wrapping
Posted by: c benson (IP Logged)
Date: October 23, 2002 10:06PM
<HTML>My understanding is that the tension on the wire pre stresses the shell so that it is in equibrilum at around 900# The stress on each tube lengthwise around 200# or less,,,,This would be for a std welded boiler NOT // N O T the early copper shell,,,I doubt any in use but i am not sure all the covering has been taken off all the shels,,,,xxxxCan Kev'lr be put on an shrunk to pre stress the shell,,,If not ,I see the shell stretching ,,,,XXX NIMBY,,,,,,BENSON [going further into Maine]!! PS whats the wt' saving?</HTML>
Re: Boiler Wrapping
Posted by: Peter Brow (IP Logged)
Date: October 24, 2002 06:08AM
<HTML>Look out for differential expansion! One of many tedious wrinkles in steam design -- this one factors into every hot component in the system. Reference to coefficient of thermal expansion tables is a must to avoid distortion, misalignment, cracking, and failure of components, especially in innovative designs.
Peter</HTML>
Peter</HTML>
Re: Boiler Wrapping
Posted by: George Nutz (IP Logged)
Date: October 24, 2002 10:22AM
<HTML>Coburn,
In order for the shell to be in equilibrium @900psig the 1/4" shell would have to be prestressed to 40,000psi and this is not possible as the average yield stress of the low carbon shell material is in this range, the shell could be collapsed and the wire at too high a tension to have a good factor of safety. If one had three layers of .050" wire(60 turns per linear inch) this would require 170# of wire tension and a wire stress of 85,000psi(roughly as its my first cup of coffee!). It would be nice if the factors of safety of both the wire and shell were the same at operating pressure.
Each different operating pressure would have its ideal amount of wire and wire tension.
The question on weight savings is a good point as if Kevlar is slightly stronger than steel on a weight basis, then for the same compressive strength/force the difference in density would be the ratio of how much more volume of Kevlar would have to be wrapped---it would make a fatter boiler with very little weight savings. The temperature and expansion characteristics, as mentioned previously, are most important considerations.
Further into New Hampshire, George</HTML>
In order for the shell to be in equilibrium @900psig the 1/4" shell would have to be prestressed to 40,000psi and this is not possible as the average yield stress of the low carbon shell material is in this range, the shell could be collapsed and the wire at too high a tension to have a good factor of safety. If one had three layers of .050" wire(60 turns per linear inch) this would require 170# of wire tension and a wire stress of 85,000psi(roughly as its my first cup of coffee!). It would be nice if the factors of safety of both the wire and shell were the same at operating pressure.
Each different operating pressure would have its ideal amount of wire and wire tension.
The question on weight savings is a good point as if Kevlar is slightly stronger than steel on a weight basis, then for the same compressive strength/force the difference in density would be the ratio of how much more volume of Kevlar would have to be wrapped---it would make a fatter boiler with very little weight savings. The temperature and expansion characteristics, as mentioned previously, are most important considerations.
Further into New Hampshire, George</HTML>
Re: Boiler Wrapping
Posted by: Peter Heid (IP Logged)
Date: October 24, 2002 11:52AM
<HTML>One of the advantages of wrapping with fabric is that the fabric has some give to it as it will becone longer and narrower under tension. The degree of tension of the initial wrap will determine the amount of give allowed. Thats why resins and epoxies would not work as they would lock the fabric and the coefficient of thermal expansion of carbon fibers and kevlar are very low. I don't believe the materials are in any degraded by the temperatures involved or long term exposure to oil, water, fuel or most other chemicals
Peter Heid</HTML>
Peter Heid</HTML>
Re: Boiler Wrapping
Posted by: Jim Crank (IP Logged)
Date: October 24, 2002 12:31PM
<HTML>Gentlemen,
Why on earth would anyone even suggest a wrapped fire tube boiler today for a new car???? Wrapped with unobtainium or whatever.
The Stanley restorations/replications work just fine with new piano wire wrapped boilers.
The Stanley boiler has horrible circulation and when forced, as several have found out in the past, happily lift the water off the crown sheet and warp it like a potato chip. It can't take much more than the Baker burner puts out.
Jim</HTML>
Why on earth would anyone even suggest a wrapped fire tube boiler today for a new car???? Wrapped with unobtainium or whatever.
The Stanley restorations/replications work just fine with new piano wire wrapped boilers.
The Stanley boiler has horrible circulation and when forced, as several have found out in the past, happily lift the water off the crown sheet and warp it like a potato chip. It can't take much more than the Baker burner puts out.
Jim</HTML>
Re: Boiler Wrapping
Posted by: George Nutz (IP Logged)
Date: October 24, 2002 01:51PM
<HTML>Jim & Peter,
I like this new material unobtainium, where can I get some ;o) !
The discussion is useful to me as it wakes up a few dying braincells to look at something else practical or not. Without this forum to keep me awake and thinking it would be atrophying at even a greater rate.
Peter, one thing we do not want is this stretching/plasticity of the Kevlar. An absolute no-no in my book; once two things are prestressed against each other they sould act as one piece---imagine a hard shaft press fit into a yielding crankweb, no-no-no. McMaster Carr sells some Kevlar threads and it is good to 600F(but what happens to the yield point?) and a .038" thread breaks at 130# or roughly 120,000psi tensile strength. If it was used in this theoretical case @30# tension 9 layers would have to be used to equal three layers of .050" Dia steel and the winding would be over .3" thick , the steel only half as thick. The weight of piano wire on a 23" boiler would be in the vicinity of 30-35#, hardly a place were any weight saving could be achieved plus the Kevlar has only a "good" rating for rot resistance. No thanks on that.
Piano wire has a yield strength of 90-95% of its tensile strength and in such application we never want to reach the yield point of the material, sounds like Kevlar stretches long befor reaching its maximum tensile strength.
Stresses for thought, George</HTML>
I like this new material unobtainium, where can I get some ;o) !
The discussion is useful to me as it wakes up a few dying braincells to look at something else practical or not. Without this forum to keep me awake and thinking it would be atrophying at even a greater rate.
Peter, one thing we do not want is this stretching/plasticity of the Kevlar. An absolute no-no in my book; once two things are prestressed against each other they sould act as one piece---imagine a hard shaft press fit into a yielding crankweb, no-no-no. McMaster Carr sells some Kevlar threads and it is good to 600F(but what happens to the yield point?) and a .038" thread breaks at 130# or roughly 120,000psi tensile strength. If it was used in this theoretical case @30# tension 9 layers would have to be used to equal three layers of .050" Dia steel and the winding would be over .3" thick , the steel only half as thick. The weight of piano wire on a 23" boiler would be in the vicinity of 30-35#, hardly a place were any weight saving could be achieved plus the Kevlar has only a "good" rating for rot resistance. No thanks on that.
Piano wire has a yield strength of 90-95% of its tensile strength and in such application we never want to reach the yield point of the material, sounds like Kevlar stretches long befor reaching its maximum tensile strength.
Stresses for thought, George</HTML>
Re: Boiler Wrapping
Posted by: Howard Randall (IP Logged)
Date: October 24, 2002 02:11PM
<HTML>
Kevlar is great stuff , But?
In another life, I used it to cover / incase carbon fiber battens used in the sails of ocean going racing yachts. If the batten broke, the Kevlar sleeve, a woven sock stretched over the batten and held in place by shrink wrap tubing, would save the sail from destruction until repairs could be made.
As C. B. noted, one of Stanley's achievements, 100 years ago, was the use of a light weight, relatively high pressure boiler, achieved by winding a thin shell with high strength piano wire. Critical to this design is the tensioning of the wire and the resultant pre-stressing / compression of the shell and subsequent transfer of hoop stress to the stronger wire wrap as boiler pressure rises. Use of Kevlar would have to mock this scenario. Wire "integrity" (specifications over working pressure and life, pre-tension, corrosion) and thus Kevlar integrity, is critical to boiler safety. The UK, I understand, requires inspection of steam car boilers, and this involves exposing the windings.
If nothing else, Kevlar might make a good scatter shield and allow for an open casket for those who fail to understand and heed the importance of wire integrity!
Coburn or David, did the Stanley "invent" the wire wound boiler? The Roper steam motorcycle (1860's) my father owned had an unwound fire tube boiler. Your Roper? Whitney's car?</HTML>
Kevlar is great stuff , But?
In another life, I used it to cover / incase carbon fiber battens used in the sails of ocean going racing yachts. If the batten broke, the Kevlar sleeve, a woven sock stretched over the batten and held in place by shrink wrap tubing, would save the sail from destruction until repairs could be made.
As C. B. noted, one of Stanley's achievements, 100 years ago, was the use of a light weight, relatively high pressure boiler, achieved by winding a thin shell with high strength piano wire. Critical to this design is the tensioning of the wire and the resultant pre-stressing / compression of the shell and subsequent transfer of hoop stress to the stronger wire wrap as boiler pressure rises. Use of Kevlar would have to mock this scenario. Wire "integrity" (specifications over working pressure and life, pre-tension, corrosion) and thus Kevlar integrity, is critical to boiler safety. The UK, I understand, requires inspection of steam car boilers, and this involves exposing the windings.
If nothing else, Kevlar might make a good scatter shield and allow for an open casket for those who fail to understand and heed the importance of wire integrity!
Coburn or David, did the Stanley "invent" the wire wound boiler? The Roper steam motorcycle (1860's) my father owned had an unwound fire tube boiler. Your Roper? Whitney's car?</HTML>
Re: Boiler Wrapping
Posted by: tom ward (IP Logged)
Date: October 24, 2002 09:10PM
<HTML>I suggested cabon fiber (not neccesarily Kevlar) for safety reasons. The wrapping only needs to be a loose bag in order contain the shrapnel from an explosion like the one in Ohio last year. Hopefully other safety devices would prevent an explosion in the first place. Any foolproof system can be overcome by an unfortunate fool.</HTML>
Re: Boiler Wrapping
Posted by: c benson (IP Logged)
Date: October 25, 2002 01:58AM
<HTML>I believe it was L.Copeland / ''cycle stuff of 1880 that used the wire wrap boiler ,, and before that ,,,cannons? ,,,,Copeland is documented in Scientific American XXXXX Stanley patent #737517/ apl,21 june1901 offers some detail,,,this is the copper shell boiler used on early cars,,,,Do I hear criticsm of a design thats had real close to zero failure in 100 years??? The failure is likely to come from someone not regarding the details of the originar design AND not doing the basig safety checks,,,such as testing to 5/3 working pressure ,,, this is what the old code called for AND the safety should function ,,,ie no coil bound spring etc,, now that could really test your wire,,, hohoho Ben P/S does kevelar burn??</HTML>
Re: Boiler Wrapping
Posted by: Peter Brow (IP Logged)
Date: October 25, 2002 05:57AM
<HTML>Hi Jim,
You are right, let's "keep our eyes on the prize". Firetube boilers are correct for antique cars, but we can do a lot better today, with designs giving lower cost, easier fabrication, and lighter weight for a given output.
From what I've read, the firing limit on Stanley 23" boilers is about 6 gph?
I second George's question about where to get unobtainium. :)
Peter</HTML>
You are right, let's "keep our eyes on the prize". Firetube boilers are correct for antique cars, but we can do a lot better today, with designs giving lower cost, easier fabrication, and lighter weight for a given output.
From what I've read, the firing limit on Stanley 23" boilers is about 6 gph?
I second George's question about where to get unobtainium. :)
Peter</HTML>
Re: Boiler Wrapping
Posted by: David K Nergaard (IP Logged)
Date: October 25, 2002 11:04AM
<HTML>Jim, if you have an efficient engine, do you NEED a higher firing rate than a Stanley boiler can use? Also, the circulation in a Stanley boiler can be greatly improved by using it as Delling did, mounting it on its side and firing it horizontally instead of vertically. It is heavy for its power, but it is also very easy to control and gives great short term acceleration.
As far as wire wrapping is concerned, Stanley used very thin shells. To a first order approximation, they acted as an inner tube in a radial ply tire; the wire takes almost all the stress! This is largely true in steel shelled boilers and completely so in the earlier copper shelled ones.
As near as I have been able to find out, about 20,000 Stanley boilers were used in cars sold to the public, nearly half of them copper shelled, all those used in Locomobiles and Mobiles. I have heard of only two explosive failures, both copper shelled.</HTML>
As far as wire wrapping is concerned, Stanley used very thin shells. To a first order approximation, they acted as an inner tube in a radial ply tire; the wire takes almost all the stress! This is largely true in steel shelled boilers and completely so in the earlier copper shelled ones.
As near as I have been able to find out, about 20,000 Stanley boilers were used in cars sold to the public, nearly half of them copper shelled, all those used in Locomobiles and Mobiles. I have heard of only two explosive failures, both copper shelled.</HTML>
Re: Boiler Wrapping
Posted by: Peter Heid (IP Logged)
Date: October 25, 2002 11:44AM
<HTML>Tom,
I agree with you and that was the reason for the discussion. The boiler I wish to build will probably incorporate a wrap for safety, not for structural strength as it will sit between my legs. A cloth wrap of a few layers can stop bullets so it would seem logical to choose the same or similar materials for a boiler "safety blanket". If done as an external shell with epoxy and no heat concerns, carbon fiber looks cool Too !
Peter Heid</HTML>
I agree with you and that was the reason for the discussion. The boiler I wish to build will probably incorporate a wrap for safety, not for structural strength as it will sit between my legs. A cloth wrap of a few layers can stop bullets so it would seem logical to choose the same or similar materials for a boiler "safety blanket". If done as an external shell with epoxy and no heat concerns, carbon fiber looks cool Too !
Peter Heid</HTML>
Re: Boiler Wrapping
Posted by: Jim Crank (IP Logged)
Date: October 25, 2002 12:22PM
<HTML>Peter,
Carl Guth many years ago, put a small blower on his 740 Stanley and boosted the firing rate to, if I remember correctly, 11 gph. It took only about a month before he was on the phone with the sad results. Sent a photo, the most warped crown sheet I ever saw, and well and truly burned and scaled.
Jim</HTML>
Carl Guth many years ago, put a small blower on his 740 Stanley and boosted the firing rate to, if I remember correctly, 11 gph. It took only about a month before he was on the phone with the sad results. Sent a photo, the most warped crown sheet I ever saw, and well and truly burned and scaled.
Jim</HTML>
Re: Boiler Wrapping
Posted by: Jim Crank (IP Logged)
Date: October 25, 2002 12:23PM
<HTML>Peter,
Carl Guth many years ago, put a small blower on his 740 Stanley and boosted the firing rate to, if I remember correctly, 11 gph. It took only about a month before he was on the phone with the sad results. Sent a photo, the most warped crown sheet I ever saw, and well and truly burned and scaled.
Jim</HTML>
Carl Guth many years ago, put a small blower on his 740 Stanley and boosted the firing rate to, if I remember correctly, 11 gph. It took only about a month before he was on the phone with the sad results. Sent a photo, the most warped crown sheet I ever saw, and well and truly burned and scaled.
Jim</HTML>
Re: Boiler Wrapping
Posted by: Jim Crank (IP Logged)
Date: October 25, 2002 12:33PM
<HTML>David,
Certainly, if the engine has a nice low water rate, then one does not need to boost the firing rate of a Stanley boiler. The curves I have on the Stanley, dating back to when Prof. Wendell Mason ran one on the UCLA lab dyno, went from about 19 lbs/hp/hr at high rpm and the shortest cutoff, to 35 lbs/hp/hr at slow speed, wide throttle and long cutoff. To me, this is not an efficient engine by a country mile.
Yes, on its side the boiler is a lot better, the Bower and Bell locomotive.
Kelvar is a nice scatter shield, as required by rules for the transmissions on dragsters and it works. For boiler wrapping, NO WAY!!
The Stanley boiler, in a Stanley car, wrapped with pre stressed piano wire, just as they designed it, is safe and relatively light weight for that type of boiler. It's the people that are not content with 60 mph on their Stanleys and think 80 is better, that ought to watch out about overfiring that boiler.
Jim</HTML>
Certainly, if the engine has a nice low water rate, then one does not need to boost the firing rate of a Stanley boiler. The curves I have on the Stanley, dating back to when Prof. Wendell Mason ran one on the UCLA lab dyno, went from about 19 lbs/hp/hr at high rpm and the shortest cutoff, to 35 lbs/hp/hr at slow speed, wide throttle and long cutoff. To me, this is not an efficient engine by a country mile.
Yes, on its side the boiler is a lot better, the Bower and Bell locomotive.
Kelvar is a nice scatter shield, as required by rules for the transmissions on dragsters and it works. For boiler wrapping, NO WAY!!
The Stanley boiler, in a Stanley car, wrapped with pre stressed piano wire, just as they designed it, is safe and relatively light weight for that type of boiler. It's the people that are not content with 60 mph on their Stanleys and think 80 is better, that ought to watch out about overfiring that boiler.
Jim</HTML>
Boiler insulation vs. wraping
Posted by: Caleb Ramsby (IP Logged)
Date: October 25, 2002 05:27PM
<HTML>On the old fire tube boilers for cars and such, is there any insulation to inhibit heat loses? It seams that there would be a slightly diminished convection rate since the outer shell is wraped with wire and since wire is round, it would have a decreased surface area to surface area contact. The radiant heat would also be somewhat captured between the wires to a certain point.
At full pressure for one hour what do you think the heat loses are for one of Stanelys fire tube boilers?
I would think that since the wires need to expand that any adhesive or restrictive insulation would be a bad idea. How about a few layers of high temp reflective foil, wraped with some thick fiberglass spray then a backup kevlar webbing that would stay cool. The reflective foil laying loosely on the boiler and spray over that, then the kevlar on the outside.
After doing a little research in my 1948 ASM Metals Handbook I became highly aware that almost all properties of structual integrity decrease to about half of that when cold when the metal reachs 1000 F. Any higher than that and the fall off is very rapid!
If the fire tube boilers indead don't have insulation it is very posible that they wanted the wires to stay realativly cool so that they would stay strong.
Does anyone know what the average temp. of the wires on the fire tube boilers is when at full pressure?
This is all very interesting!
Caleb Ramsby
Back from driving 45 hours to move 6000# boat through snow in the U.P. of Michigan to Wisconsin! What a trip!</HTML>
At full pressure for one hour what do you think the heat loses are for one of Stanelys fire tube boilers?
I would think that since the wires need to expand that any adhesive or restrictive insulation would be a bad idea. How about a few layers of high temp reflective foil, wraped with some thick fiberglass spray then a backup kevlar webbing that would stay cool. The reflective foil laying loosely on the boiler and spray over that, then the kevlar on the outside.
After doing a little research in my 1948 ASM Metals Handbook I became highly aware that almost all properties of structual integrity decrease to about half of that when cold when the metal reachs 1000 F. Any higher than that and the fall off is very rapid!
If the fire tube boilers indead don't have insulation it is very posible that they wanted the wires to stay realativly cool so that they would stay strong.
Does anyone know what the average temp. of the wires on the fire tube boilers is when at full pressure?
This is all very interesting!
Caleb Ramsby
Back from driving 45 hours to move 6000# boat through snow in the U.P. of Michigan to Wisconsin! What a trip!</HTML>
Re: Boiler insulation vs. wraping
Posted by: Pat Farrell (IP Logged)
Date: October 26, 2002 02:53AM
<HTML>Caleb, The Stanley boilers are insulated with about 1 " thick fiberglass insullation. After wrapping the boiler with insullation, the insullation is then topped with either a metal cover or another fire proof covering depending on the year on manufacture. The wire is given some air circulation in the loose fiberglass insulation to prevent rusting. The wire should not get any hotter than the steam inside at 550 pounds. My guess is it would be below 500 degrees F.. The super heated steam goes out hotter than that but that is after it passes through the super heater. When a boiler is accidentally ran without water, the temperature easily exceeds 500 degrees F. The copper tubes are the first things to melt out. Without any fire in it, our Stanleys will still be hot (150 degrees), after 24 hours of sitting idle in a garage. You get a faster steam up with hot water!</HTML>
Re: Boiler insulation vs. wraping
Posted by: Peter Brow (IP Logged)
Date: October 26, 2002 04:13AM
<HTML>The Stanley literature sez that factory insulation on Stanley boilers was 1/2" of asbestos sheet (hope there's no EPA or OSHA guys lurking here). Modern practice of 1" of glass or ceramic fiber is better. The steam tables book was handy, so: boiling point of water at 500 psia is 467°F; at 550 psia it is 477°F. Add a few degrees for psig figures. Shell probably runs hotter than this on the road due to heat conduction from the tube sheets (heat exchanger metal is always hotter than the heated fluid during firing). Then again, pressure/temp drop while steaming should compensate somewhat.
Peter</HTML>
Peter</HTML>
Re: Boiler Wrapping
Posted by: Peter Brow (IP Logged)
Date: October 26, 2002 05:02AM
<HTML>11 gph, Ay Carumba! Well, at least he got an "A" for ambition! That would be too much for a 30" boiler, let alone a 23"!</HTML>
Re: Boiler Wrapping
Posted by: Peter Brow (IP Logged)
Date: October 26, 2002 05:48AM
<HTML>Jim and David,
Didn't Delling have a somewhat different side-fired boiler? I seem to recall seeing a diagram of it once, with straight vertical water tubes running between flattish drums at top and bottom. Arrows showed circulation up the tubes closest to the burner, with the tubes at the exhaust end acting as downcomers. Sort of a sideways, crossflow, circulated, and inside-out version of a Stanley boiler.
Would installing/firing a Stanley boiler sideways cause problems with unequal heating/expansion of top & bottom tubes under some conditions?
Hard to beat Stanley boilers for acceleration & simple control. I just wonder whether the (continuous) power/weight ratio & fabrication cost are acceptable for a modern road vehicle. For original Stanley cars, though, nothing else should be considered.
On Stanley water rates:
"The [Stanley 20 hp] engine weighs 265 pounds. A stock engine under test-block run has frequently operated with a steam consumption of 16 to 17 lb. per hp-hr., a remarkable result from so small an engine."
(The Journal of the Society of Automotive Engineers, May 1918, page 17)
Of course this was a brand-new engine, and Prof. Mason's results may be more representative of the older Stanley engines on the road today. Also, the above quote is from an article by a Stanley Motor Carriage Company employee (John Sturgess), so consider the source and the word "frequently".
And surely we can do better than 16-17 lbs/hp/hr with improved engine designs.
Peter</HTML>
Didn't Delling have a somewhat different side-fired boiler? I seem to recall seeing a diagram of it once, with straight vertical water tubes running between flattish drums at top and bottom. Arrows showed circulation up the tubes closest to the burner, with the tubes at the exhaust end acting as downcomers. Sort of a sideways, crossflow, circulated, and inside-out version of a Stanley boiler.
Would installing/firing a Stanley boiler sideways cause problems with unequal heating/expansion of top & bottom tubes under some conditions?
Hard to beat Stanley boilers for acceleration & simple control. I just wonder whether the (continuous) power/weight ratio & fabrication cost are acceptable for a modern road vehicle. For original Stanley cars, though, nothing else should be considered.
On Stanley water rates:
"The [Stanley 20 hp] engine weighs 265 pounds. A stock engine under test-block run has frequently operated with a steam consumption of 16 to 17 lb. per hp-hr., a remarkable result from so small an engine."
(The Journal of the Society of Automotive Engineers, May 1918, page 17)
Of course this was a brand-new engine, and Prof. Mason's results may be more representative of the older Stanley engines on the road today. Also, the above quote is from an article by a Stanley Motor Carriage Company employee (John Sturgess), so consider the source and the word "frequently".
And surely we can do better than 16-17 lbs/hp/hr with improved engine designs.
Peter</HTML>
Re: Boiler insulation vs. wraping
Posted by: c benson (IP Logged)
Date: October 26, 2002 10:50AM
<HTML>If //IF the shell were 1/4 '' I doubt the transfer of heat would go more than 3/4 lengthwise in the shrll,,,tho the uneven temp would add a strain to that area,,,just a thot' Cheers Ben</HTML>
Re: Boiler insulation vs. wraping
Posted by: Peter Brow (IP Logged)
Date: October 27, 2002 02:48AM
<HTML>Hi Ben,
Yep, that sounds right, and come to think of it, note the thick steel bands on the shells at the ends ... at least in the Eckels blueprints for new construction ... wonder if those do more than anchor & locate the wire windings, like reinforcing a thermally-stressed area too?
Peter</HTML>
Yep, that sounds right, and come to think of it, note the thick steel bands on the shells at the ends ... at least in the Eckels blueprints for new construction ... wonder if those do more than anchor & locate the wire windings, like reinforcing a thermally-stressed area too?
Peter</HTML>
Re: Boiler insulation vs. wraping
Posted by: Pat Farrell (IP Logged)
Date: October 27, 2002 03:05AM
<HTML>In rolling the tubes into the tube sheets, there is a lot of outward stress that the bands hold in. Without the bands on the outside ends of the boiler, the rolled in tubes would not be as tight when rolled cold. And when the boiler is up to temperature, there is even more stress on the end bands, from the copper tubes expanding more than the steel tube sheet. And when the temperatures get too high, "scortched boiler", the tube sheet turns into the potatoe chip that Jim Crank mentioned. There is just no where for all that extra metal to go but to curl up. Yes, those end bands do hold a lot in!</HTML>
Re: Boiler Wrapping
Posted by: Peter Heid (IP Logged)
Date: October 28, 2002 04:52PM
<HTML>I never thought this post would stay alive this long and bring so much information and contoversy to light. I would never design a boiler that must be wrapped for structrual intgerity and I cannot recomend this course of action for anyone else either. I think the Stanley boiler is a marvel of ingeniuty and was a great development for its time. I do not reccomend the use of an explosion shield as such. If the unknowing people learned my steam engined vehicle included a shield to protect those around it from parts of an expolding boiler they would assume there is a chance of explosion. I would also restrain from indicating anything around the boiler is there for human protection as any failure to protect would result in unfriendly litigation. A cloth shield can be cut by flying parts effectively eliminating most of the margin of safety regardless of the material used.
Kevlar 49 as commerically introduced by Dupont in 1972 has a tensile strength of 43,000 psi and a modulus of elasticity of 19,000,000 psi. Carbon fiber has a tensile strength of 470,000 psi and is available as tow or a yarn/thread of material in 3000, 6000 and 12,000 fibers per strand. Most carbon fiber cloth is woven from the 3000 tow. The 12,000 tow is available in spools of 4 pounds or about 2500 yards for around $140.00 US. Carbon fiber material is formed by intense heat at a few thousand degrees and is resistant to heat below the formation temperature. I have not seen strengths listed for elevated temperatures but I believe there is little change in strength at temperatures below 1000 degrees F..
Peter Heid</HTML>
Kevlar 49 as commerically introduced by Dupont in 1972 has a tensile strength of 43,000 psi and a modulus of elasticity of 19,000,000 psi. Carbon fiber has a tensile strength of 470,000 psi and is available as tow or a yarn/thread of material in 3000, 6000 and 12,000 fibers per strand. Most carbon fiber cloth is woven from the 3000 tow. The 12,000 tow is available in spools of 4 pounds or about 2500 yards for around $140.00 US. Carbon fiber material is formed by intense heat at a few thousand degrees and is resistant to heat below the formation temperature. I have not seen strengths listed for elevated temperatures but I believe there is little change in strength at temperatures below 1000 degrees F..
Peter Heid</HTML>
Re: Boiler Wrapping
Posted by: Rolly Evans (IP Logged)
Date: October 28, 2002 05:10PM
<HTML>Peter Heid
I seem to remember some one building a Pinto engine out of carbon fiber, with only a steel plate being used on the bottom of cylinder head and the top of the pistons. with hopes of all plastic engines some day.
Rolly</HTML>
I seem to remember some one building a Pinto engine out of carbon fiber, with only a steel plate being used on the bottom of cylinder head and the top of the pistons. with hopes of all plastic engines some day.
Rolly</HTML>
Re: Boiler Wrapping
Posted by: George Nutz (IP Logged)
Date: October 28, 2002 05:16PM
<HTML>Peter(OT),
Now if only you had told me that 7 years ago I could have prestressed my banjo rims with carbon fiber from coming apart!! Talk about stresses, there can be a 5,000# tensile(and relateed bending ) load on this poor 11" wooden hoop pulling on the banjo head---banjos and steam cars are from the same era. Where can I get 100 feet for cheap??
Best, as always, George</HTML>
Now if only you had told me that 7 years ago I could have prestressed my banjo rims with carbon fiber from coming apart!! Talk about stresses, there can be a 5,000# tensile(and relateed bending ) load on this poor 11" wooden hoop pulling on the banjo head---banjos and steam cars are from the same era. Where can I get 100 feet for cheap??
Best, as always, George</HTML>
Re: Boiler Wrapping
Posted by: Peter Heid (IP Logged)
Date: October 28, 2002 08:40PM
<HTML>Rolly,</HTML>
Re: Boiler Wrapping
Posted by: Peter Heid (IP Logged)
Date: October 28, 2002 08:43PM
<HTML>Rolly,
Yes there was a 2.0 litre pinto engine developed from plastic. It was a ford project with some plastics company on board also. Somewhere I have a Popular Mechanics mag detailing the project. Never heard another thing about it, I figured it melted or caught fire.
Peter Heid</HTML>
Yes there was a 2.0 litre pinto engine developed from plastic. It was a ford project with some plastics company on board also. Somewhere I have a Popular Mechanics mag detailing the project. Never heard another thing about it, I figured it melted or caught fire.
Peter Heid</HTML>
Re: Boiler Wrapping
Posted by: c benson (IP Logged)
Date: October 28, 2002 09:42PM
<HTML>Hi,,,I recall a feature article in PLASTICS WORLD around 1971,,,,talking of a plastic / ceramic engine ,, the deizel boys [mack autocar cummins,,as I recall ]] were envolved the focus was to run at around 1800deg,,,cant recall which scale ,,,,,all fuzzy memory,,to me, ranks w/ my wellknown [?] regards for juce brakes an' electric stuff,,Sorry Dave,,,you are ok its them lil lectron thin's I cant see ,,,,ONLY FEEL GGGRRR!! The black racer,,NO ELECTRIC,, [ Gasoline !! Torch to start]],,,Lectro atom field wont stop me,,hahaha,,, Oh yeh, the Flat Earth Scociety WILL meet again next year as usual,,,here in Maine,,,,,Cheers - Ben at home in Maine,,, at last,,,</HTML>
Re: Boiler Wrapping
Posted by: Peter Brow (IP Logged)
Date: October 29, 2002 08:34AM
<HTML>Rolly and Peter,
This is the Ford Polimotor "plastic engine" of the early/mid 1980s (circa 1984-5). I too have a Popular Science article on the thing, somewhere in the mixed-up files of the Miskatonic Library here. Try a search engine for Ford Polimotor, and you'll find a few tantalizing tidbits of info on the web.
The engine used metal cylinder sleeves, metal combustion chamber tops, metal piston crowns, bearings, valves & seats, and a stock 2.3L Pinto crankshaft. Darn near everything else in the engine, including the block, conrods, piston skirts, etc was fiber-reinforced plastic. The exact type of plastic escapes me at the moment. Very little metal was used outside of the crankshaft; just small/thin metal parts to shield against direct contact with combustion, and on mechanical wear surfaces.
This experimental engine was reportedly a great success, several were built and used very successfully in racing. HP & RPMs were dramatically higher than in the metal original, and it was quite smooth-running and durable and something like 1/3 the weight. This was one of my prime inspirations to build a polymer-intensive steam car engine.
The achilles heel was the cost. The engines were practically hand-built and would have been very pricey in production compared to mass-produced metal production engines. They tried but just couldn't scope out a way to mass-produce the plastic parts competitively, so Ford canned further research. When the few racing engines finally burned out, that was the end of it.
However the developers noted that in limited production, the tooling and fabrication methods actually made it easier and cheaper to build than a limited-production metal engine (with small-batch custom castings, forgings, and machine jobs) -- that is, for those with the unusual skills and knowledge needed. But virtually no engine shop would be able to handle such an exotic project, which is probably why it was never duplicated to my knowledge.
Weird stuff like fiber orientation for load transfer, resin/fiber ratios, resin wetting, layup, mold closing, bubble exclusion, mold-integrated component positioning jigs, etc are as incomprehensible as quantum physics or UFO engineering to most 20th/early21st century engine builders, trained, experienced, and focused as they are on metalworking. Some engine shops might know a surfboard builder, EAA guy, or body wizard who can whip up custom carbon/epoxy valve covers or oil pans for them, but that is about all, high-load polymer working parts get pretty freaky, and the idea is so obscure that it just never pops up in the first place. If they want exotic structural or loaded stuff, they'll go with CNC'ed alloy billet and feel pretty daring about it. The plastic engine was (and still is) just way too far ahead of its time. Pretty amazing that it was built in the mid-1980s.
It was also noted that the crankshaft could have been made of fiber-reinforced polymer with thin metal journal inserts, which would have upped rpms/hp even more and saved a bunch more weight, but they stuck with the stock metal crank because of budget & time limitations. They were really pushing the technological envelope as it was.
Peter</HTML>
This is the Ford Polimotor "plastic engine" of the early/mid 1980s (circa 1984-5). I too have a Popular Science article on the thing, somewhere in the mixed-up files of the Miskatonic Library here. Try a search engine for Ford Polimotor, and you'll find a few tantalizing tidbits of info on the web.
The engine used metal cylinder sleeves, metal combustion chamber tops, metal piston crowns, bearings, valves & seats, and a stock 2.3L Pinto crankshaft. Darn near everything else in the engine, including the block, conrods, piston skirts, etc was fiber-reinforced plastic. The exact type of plastic escapes me at the moment. Very little metal was used outside of the crankshaft; just small/thin metal parts to shield against direct contact with combustion, and on mechanical wear surfaces.
This experimental engine was reportedly a great success, several were built and used very successfully in racing. HP & RPMs were dramatically higher than in the metal original, and it was quite smooth-running and durable and something like 1/3 the weight. This was one of my prime inspirations to build a polymer-intensive steam car engine.
The achilles heel was the cost. The engines were practically hand-built and would have been very pricey in production compared to mass-produced metal production engines. They tried but just couldn't scope out a way to mass-produce the plastic parts competitively, so Ford canned further research. When the few racing engines finally burned out, that was the end of it.
However the developers noted that in limited production, the tooling and fabrication methods actually made it easier and cheaper to build than a limited-production metal engine (with small-batch custom castings, forgings, and machine jobs) -- that is, for those with the unusual skills and knowledge needed. But virtually no engine shop would be able to handle such an exotic project, which is probably why it was never duplicated to my knowledge.
Weird stuff like fiber orientation for load transfer, resin/fiber ratios, resin wetting, layup, mold closing, bubble exclusion, mold-integrated component positioning jigs, etc are as incomprehensible as quantum physics or UFO engineering to most 20th/early21st century engine builders, trained, experienced, and focused as they are on metalworking. Some engine shops might know a surfboard builder, EAA guy, or body wizard who can whip up custom carbon/epoxy valve covers or oil pans for them, but that is about all, high-load polymer working parts get pretty freaky, and the idea is so obscure that it just never pops up in the first place. If they want exotic structural or loaded stuff, they'll go with CNC'ed alloy billet and feel pretty daring about it. The plastic engine was (and still is) just way too far ahead of its time. Pretty amazing that it was built in the mid-1980s.
It was also noted that the crankshaft could have been made of fiber-reinforced polymer with thin metal journal inserts, which would have upped rpms/hp even more and saved a bunch more weight, but they stuck with the stock metal crank because of budget & time limitations. They were really pushing the technological envelope as it was.
Peter</HTML>
Re: Boiler Wrapping
Posted by: Howard Randall (IP Logged)
Date: October 29, 2002 12:10PM
<HTML>George, I think I can help you out!
Remember that in another life, I worked with these materials. See www.fiberspar.com for details. Fiberspar makes fiber re-inforced pipe for oil and gas field applications operating at up to 2500 PSI.
If you are serious, I can ask. The manufacturing facility is near by.
I would normaly ask for the first born for my services, but for you, a tune on a carbon fiber re-inforced banjo in Carol's kitchen will suffice!</HTML>
Remember that in another life, I worked with these materials. See www.fiberspar.com for details. Fiberspar makes fiber re-inforced pipe for oil and gas field applications operating at up to 2500 PSI.
If you are serious, I can ask. The manufacturing facility is near by.
I would normaly ask for the first born for my services, but for you, a tune on a carbon fiber re-inforced banjo in Carol's kitchen will suffice!</HTML>
Re: Boiler Wrapping
Posted by: Ron Parola (IP Logged)
Date: November 03, 2002 11:13PM
<HTML>Polymotor inc. they were to have an engine to run at indy, One of the main problems they had (they said) was grounding the spark plugs, so what happened??? Drag racers were using plastic connection rod a few years ago,(top fuel) turns out that with nitro the impact loads were too high, they weren't breaking rods, but cranks!! The aluminum rods flex a bit and absorb shock ,the plastic ones didn't. And the alloy rods get thown away after a few passes anyway. As an aside folks in England were suppling carbon fibre pushrods for your Norton, problem was they are porous and absorbed engine oil, it didn't hurt the rods but they became heaver than the hollow alloy or even steel ones, and coating them addedweight also. RP</HTML>
Re: Boiler Wrapping
Posted by: David K Nergaard (IP Logged)
Date: November 04, 2002 11:29AM
<HTML>Kevlar having a Youngs Modulus of only 19,000,000 means that it will stretch more than a steel shell under a given pressure, NOT the desired result. The modulus of the wrapping should be at least as high as the shell's. What is the modulus of carbon fibre?</HTML>
Re: Boiler Wrapping
Posted by: Peter Heid (IP Logged)
Date: November 20, 2002 01:15PM
<HTML>David,
The listings in the book "Successful Composite Techniques 3rd Ed", Keith Noakes, 1999, Osprey Publishing lists the specific modulus of steel at 1.2, kevlar at 2.0, carbon at 3.8, high modulus carbon at 5.6 and ultrahigh modulus carbon at 8.2. But one should keep in mind the specific strength of the materials also and these are in the same order; 1.5, 4.0, 4.3, 2.6, and 1.5.
Peter Heid</HTML>
The listings in the book "Successful Composite Techniques 3rd Ed", Keith Noakes, 1999, Osprey Publishing lists the specific modulus of steel at 1.2, kevlar at 2.0, carbon at 3.8, high modulus carbon at 5.6 and ultrahigh modulus carbon at 8.2. But one should keep in mind the specific strength of the materials also and these are in the same order; 1.5, 4.0, 4.3, 2.6, and 1.5.
Peter Heid</HTML>
Re: Boiler Wrapping
Posted by: David K Nergaard (IP Logged)
Date: November 20, 2002 07:23PM
<HTML>In Re Delling boilers: the ones used in the cars were vertical water tube boilers with very heavy drums top and bottom. Not easy to make in large sizes as they used bolted joints.
For the 'busses, they used a Stanley type on its side, with a side way burner that only fired the lower two thirds of the boiler, venturi openings jets etc. at the top. This gave a much larger stored energy than the water tube type, important in a start-stop kind of driving inherent in a 'bur route.</HTML>
For the 'busses, they used a Stanley type on its side, with a side way burner that only fired the lower two thirds of the boiler, venturi openings jets etc. at the top. This gave a much larger stored energy than the water tube type, important in a start-stop kind of driving inherent in a 'bur route.</HTML>
Re: Boiler Wrapping
Posted by: Peter Brow (IP Logged)
Date: November 21, 2002 05:51AM
<HTML>David: thanks for the info on the Delling bus boilers. I had only known about the car type. Delling data is pretty scarce.
Peter</HTML>
Peter</HTML>
Re: Boiler insulation vs. wraping
Posted by: Mathew Kurien (IP Logged)
Date: July 18, 2004 05:21AM
<HTML>Kindly let me know what is the recommended temperature on the boiler skin of three pass wetback design firetube boiler. The boiler is insulated with rockwool 50mm high density mineral wool with a conductivity of 0.045W/mdegc at 100degc. The manufacturer says the surface temp on cladded surfaces will be between 50-60degc in an ambient of 20degc. The endusers are complaining it is too hot. The ambient temp in reality is 25-30degc.
How best can one explain this situation, and that the too hot issue is not detrimental. Appreciate your advice.
Best regards.
Mathew
<a href="mailto:ramsbergenheighmer@yahoo.com?subject=Boiler insulation vs. wraping">Caleb Ramsby</a> wrote:
>
> On the old fire tube boilers for cars and such, is
> there any insulation to inhibit heat loses? It seams that
> there would be a slightly diminished convection rate since
> the outer shell is wraped with wire and since wire is round,
> it would have a decreased surface area to surface area
> contact. The radiant heat would also be somewhat captured
> between the wires to a certain point.
>
> At full pressure for one hour what do you think the heat
> loses are for one of Stanelys fire tube boilers?
>
> I would think that since the wires need to expand that any
> adhesive or restrictive insulation would be a bad idea. How
> about a few layers of high temp reflective foil, wraped with
> some thick fiberglass spray then a backup kevlar webbing that
> would stay cool. The reflective foil laying loosely on the
> boiler and spray over that, then the kevlar on the outside.
>
> After doing a little research in my 1948 ASM Metals Handbook
> I became highly aware that almost all properties of structual
> integrity decrease to about half of that when cold when the
> metal reachs 1000 F. Any higher than that and the fall off is
> very rapid!
>
> If the fire tube boilers indead don't have insulation it is
> very posible that they wanted the wires to stay realativly
> cool so that they would stay strong.
>
> Does anyone know what the average temp. of the wires on the
> fire tube boilers is when at full pressure?
>
> This is all very interesting!
>
> Caleb Ramsby
>
> Back from driving 45 hours to move 6000# boat through snow in
> the U.P. of Michigan to Wisconsin! What a trip!</HTML>
How best can one explain this situation, and that the too hot issue is not detrimental. Appreciate your advice.
Best regards.
Mathew
<a href="mailto:ramsbergenheighmer@yahoo.com?subject=Boiler insulation vs. wraping">Caleb Ramsby</a> wrote:
>
> On the old fire tube boilers for cars and such, is
> there any insulation to inhibit heat loses? It seams that
> there would be a slightly diminished convection rate since
> the outer shell is wraped with wire and since wire is round,
> it would have a decreased surface area to surface area
> contact. The radiant heat would also be somewhat captured
> between the wires to a certain point.
>
> At full pressure for one hour what do you think the heat
> loses are for one of Stanelys fire tube boilers?
>
> I would think that since the wires need to expand that any
> adhesive or restrictive insulation would be a bad idea. How
> about a few layers of high temp reflective foil, wraped with
> some thick fiberglass spray then a backup kevlar webbing that
> would stay cool. The reflective foil laying loosely on the
> boiler and spray over that, then the kevlar on the outside.
>
> After doing a little research in my 1948 ASM Metals Handbook
> I became highly aware that almost all properties of structual
> integrity decrease to about half of that when cold when the
> metal reachs 1000 F. Any higher than that and the fall off is
> very rapid!
>
> If the fire tube boilers indead don't have insulation it is
> very posible that they wanted the wires to stay realativly
> cool so that they would stay strong.
>
> Does anyone know what the average temp. of the wires on the
> fire tube boilers is when at full pressure?
>
> This is all very interesting!
>
> Caleb Ramsby
>
> Back from driving 45 hours to move 6000# boat through snow in
> the U.P. of Michigan to Wisconsin! What a trip!</HTML>
Re: Boiler insulation vs. wraping
Posted by: zahedian (IP Logged)
Date: July 27, 2004 11:21AM
<HTML>DEAR SIR
WE WANT TO BUY SOME FIRE TUBE BOILERS WIHT WOODEN FUEL
THAT PRODUCE STEAM PRESSURE 14-15BARG AND 4.3GCAL/HR
PLEASE GUIDE ME AND IF POSSIBLE SEND ME SOM TECHNICAL INFORMATION AND PICTURES AND PRICE
THANKING YOU INADVANCE
ZAHEDIAN</HTML>
WE WANT TO BUY SOME FIRE TUBE BOILERS WIHT WOODEN FUEL
THAT PRODUCE STEAM PRESSURE 14-15BARG AND 4.3GCAL/HR
PLEASE GUIDE ME AND IF POSSIBLE SEND ME SOM TECHNICAL INFORMATION AND PICTURES AND PRICE
THANKING YOU INADVANCE
ZAHEDIAN</HTML>
Re: Boiler insulation vs. wraping
Posted by: zahedian (IP Logged)
Date: July 27, 2004 11:21AM
<HTML>DEAR SIR
WE WANT TO BUY SOME FIRE TUBE BOILERS WIHT WOODEN FUEL
THAT PRODUCE STEAM PRESSURE 14-15BARG AND 4.3GCAL/HR
PLEASE GUIDE ME AND IF POSSIBLE SEND ME SOM TECHNICAL INFORMATION AND PICTURES AND PRICE
THANKING YOU INADVANCE
ZAHEDIAN</HTML>
WE WANT TO BUY SOME FIRE TUBE BOILERS WIHT WOODEN FUEL
THAT PRODUCE STEAM PRESSURE 14-15BARG AND 4.3GCAL/HR
PLEASE GUIDE ME AND IF POSSIBLE SEND ME SOM TECHNICAL INFORMATION AND PICTURES AND PRICE
THANKING YOU INADVANCE
ZAHEDIAN</HTML>
Re: Boiler insulation vs. wraping
Posted by: nainamohamed meerangani (IP Logged)
Date: October 29, 2004 01:23PM
<HTML>kindly send us detailed insulation on boiler
With best regards
Meeran
Asmacs</HTML>
With best regards
Meeran
Asmacs</HTML>
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