Lamont boiler
Posted by dullfig
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Lamont boiler January 15, 2011 04:08PM |
Registered: 15 years ago Posts: 180 |
Hi all:
I was thinking about the lamont boiler. seems like the way to go for a steam car, much easier to control. My question is about packaging it. It has that external tank that you have to put somewhere. What I was thinking, maybe instead of an external tank, you could have a double wall around the boiler that acted as the water tank. it would also recover some of the radiant heat that way.
Dan
Ps.: is there good info on designing one of these?
I was thinking about the lamont boiler. seems like the way to go for a steam car, much easier to control. My question is about packaging it. It has that external tank that you have to put somewhere. What I was thinking, maybe instead of an external tank, you could have a double wall around the boiler that acted as the water tank. it would also recover some of the radiant heat that way.
Dan
Ps.: is there good info on designing one of these?
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Re: Lamont boiler January 15, 2011 05:21PM |
Registered: 19 years ago Posts: 375 |
Dan
That would need effectively two pressure vessels, the inside and outside casings of the drum with all the complication that brings. Much better would be to put the drum in the centre of the coils like the Odfelt, Bolsover and Clarkson boilers of 100 years ago. I have been thinking on these lines for a while for a project I am hatching and it looks very possible. I think it would be practical to make a steam generator with coils, drum, combustion chamber and exhaust hood in one cylindrical casing which would make it so much easier to put the thing into a car. My plot is for about 250lbs steam per hour for a conversion on a small 1920's car, not a modern steam car. The generator would be 16 inches diameter and 24 inches tall and would go under the hood.
As ever the main problem for the Lamont is the pump for the Lamont circuit which, although it only has to pump against the back pressure of the Lamont coils, needs a gland which will manage the full system pressure and this is very hard to do if you are not a megacorporation and at the size needed for a car system. A magnetic coupling seems best at first sight but I have concluded that keeping the magnetic iron oxide crud forming inside the drum and pipes from jamming the pump magnets probably rules this option out. so we are back with pump seals. Solve that and the rest of it is easy............
There is little published information apart from the work of George Nutz from 10 years back so you are almost working from first principles on such a scheme.
Mike
Edited 1 time(s). Last edit at 01/17/2011 04:23PM by Mike Clark.
That would need effectively two pressure vessels, the inside and outside casings of the drum with all the complication that brings. Much better would be to put the drum in the centre of the coils like the Odfelt, Bolsover and Clarkson boilers of 100 years ago. I have been thinking on these lines for a while for a project I am hatching and it looks very possible. I think it would be practical to make a steam generator with coils, drum, combustion chamber and exhaust hood in one cylindrical casing which would make it so much easier to put the thing into a car. My plot is for about 250lbs steam per hour for a conversion on a small 1920's car, not a modern steam car. The generator would be 16 inches diameter and 24 inches tall and would go under the hood.
As ever the main problem for the Lamont is the pump for the Lamont circuit which, although it only has to pump against the back pressure of the Lamont coils, needs a gland which will manage the full system pressure and this is very hard to do if you are not a megacorporation and at the size needed for a car system. A magnetic coupling seems best at first sight but I have concluded that keeping the magnetic iron oxide crud forming inside the drum and pipes from jamming the pump magnets probably rules this option out. so we are back with pump seals. Solve that and the rest of it is easy............
There is little published information apart from the work of George Nutz from 10 years back so you are almost working from first principles on such a scheme.
Mike
Edited 1 time(s). Last edit at 01/17/2011 04:23PM by Mike Clark.
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Re: Lamont boiler January 15, 2011 05:58PM |
Registered: 15 years ago Posts: 180 |
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Re: Lamont boiler January 15, 2011 06:59PM |
Registered: 13 years ago Posts: 34 |
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Re: Lamont boiler January 15, 2011 07:48PM |
Registered: 19 years ago Posts: 1,441 |
Correct, control is a snap compared to a monotube. Pressure control on the burner and a simple water level control. Even a Stanley type expansion tube control would work just fine. Superheater is buried three or so coils down from the fire for better stability, although a normalizer is a good idea.
Not a double drum, or even a single drum; but a tight wound large diameter coil around the outside, like the Baker boiler.
The drum-coil is for storage and separating, not for boiling, That takes place in the coil stack.
The circulating pump flow rate should be 5-8 times the maximum evaporation rate. The more the merrier.
Read George Nutz' s splendid story of the Lamont, it has all the information one needs. Older boiler design engineering books are full of Lamont data.
Piston pumps by their very nature have packing glands and also low flow rate capacity. A centrifugal pump just like a gas car water pump, low pressure head and big volume flow.
Think canned pumps with magnetic drive. Many available commercially to provide data on how it is done,
Jim
Not a double drum, or even a single drum; but a tight wound large diameter coil around the outside, like the Baker boiler.
The drum-coil is for storage and separating, not for boiling, That takes place in the coil stack.
The circulating pump flow rate should be 5-8 times the maximum evaporation rate. The more the merrier.
Read George Nutz' s splendid story of the Lamont, it has all the information one needs. Older boiler design engineering books are full of Lamont data.
Piston pumps by their very nature have packing glands and also low flow rate capacity. A centrifugal pump just like a gas car water pump, low pressure head and big volume flow.
Think canned pumps with magnetic drive. Many available commercially to provide data on how it is done,
Jim
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Re: Lamont boiler January 15, 2011 08:59PM |
Registered: 15 years ago Posts: 180 |
Ah!
and with thick tubing around the outside, it's not a pressure vessel, but a coil of tube! then you don't need boiler inspections
hey that brings up a good point. how big does a tube have to get before inspectors start calling it a "pressure vessel"?
Dan
Edited 1 time(s). Last edit at 01/15/2011 09:01PM by dullfig.
and with thick tubing around the outside, it's not a pressure vessel, but a coil of tube! then you don't need boiler inspections
hey that brings up a good point. how big does a tube have to get before inspectors start calling it a "pressure vessel"?
Dan
Edited 1 time(s). Last edit at 01/15/2011 09:01PM by dullfig.
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Re: Lamont boiler January 16, 2011 10:30AM |
Registered: 19 years ago Posts: 1,441 |
Dan,
Now you see the point. And, it is not now a welded drum and with the right metal choice it is stronger.
It doesn't from what I was told. Maybe if it was two feet in diameter they might raise a fuss; but a 3" or 4" tube is a tube, not a pressure vessel.
Take a good look at the Baker boiler, that is just what I mean.
Jim
Now you see the point. And, it is not now a welded drum and with the right metal choice it is stronger.
It doesn't from what I was told. Maybe if it was two feet in diameter they might raise a fuss; but a 3" or 4" tube is a tube, not a pressure vessel.
Take a good look at the Baker boiler, that is just what I mean.
Jim
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Re: Lamont boiler January 17, 2011 05:51PM |
Registered: 19 years ago Posts: 375 |
Jim,
I've been looking again at the drawing of the Baker boiler. While I agree with your comments re the safety of a big coiled pipe vs a drum it is hard to see how the idea can be applied to a Lamont.
The Baker is a bit of a distraction as the large outer coils of pipe are only for steam storage, not for separation which goes on in the centre column which is a tall narrow drum.
If a large outer coil were used in place of a drum for a Lamont with water being drawn off from the bottom end, heated, and going in again at some higher point in the coil the water would be going in the opposite direction to the rising steam. In a vertical drum of five or more inches bore this is not a major problem but in a spirally formed pipe of even 2 inch bore it will be difficult to separate the steam. Any steam drawn down by the water flow will cause cavitation in the pump. With a flow of 5 times water usage rate the Lamont circulation rate would be 2 to 4 gallons per minute in a 250lb/hr generator so there is a lot of water to separate. I've puzzled a bit as to whether the flow could be reversed, returning the heated water to the storage coils at the bottom so water and steam are going the same direction as they would be in a monotube but this means taking water to the pump from part way up the coil, far worse problems with steam separation and the new problem of ensuring the pump intake is always below water level. I doubt this is very practical.
All a bit tricky and I think the Baker burner drawing shows that they were aware of such problems. In the Baker drawing the water level is below the heavy outer pipes which just hold steam. All the separation is going on in the centre column, which if we assume the whole boiler is 24 inches diameter, must be nearly five inches in bore and 24 inches tall. There is much more stored energy in the water held in the centre column than in the steam in the thick coils whose benefit as I see it is mainly to provide a modest reserve of steam and very effective steam/water separation because only steam should be entering the bottom of these coils. The coils of the Baker will help when the throttle is opened and the water level rises as they provide a big heat sink to evaporate rising water before it get high enough to be carried over. But I doubt that such coils could be used as the Lamont reservoir without a centre column, which brings us back to a drum.
Putting the drum in the centre is very good packaging as it uses the otherwise empty space in the centre of the coils rather than adding to the outside. The disadvantage is that the drum is relatively tall and narrow, of smallish volume and susceptible to throttle related changes in level. Large Baker-like coils on the outside add plenty of volume, but add a fair bit to the overall diameter and would be very hard to use alone without a drum. Adding them to a drum Lamont above water level would help steam separation but at the expense of significantly increased boiler diameter and complexity.
I also suspect the large centre column of the Baker is big enough to be seen as a pressure vessel not a pipe so doesn’t escape the interest of the inspectors and insurers. If we can't build a Lamont without a separation drum then making the main steam store from coiled pipe does not help much.
Mike
I've been looking again at the drawing of the Baker boiler. While I agree with your comments re the safety of a big coiled pipe vs a drum it is hard to see how the idea can be applied to a Lamont.
The Baker is a bit of a distraction as the large outer coils of pipe are only for steam storage, not for separation which goes on in the centre column which is a tall narrow drum.
If a large outer coil were used in place of a drum for a Lamont with water being drawn off from the bottom end, heated, and going in again at some higher point in the coil the water would be going in the opposite direction to the rising steam. In a vertical drum of five or more inches bore this is not a major problem but in a spirally formed pipe of even 2 inch bore it will be difficult to separate the steam. Any steam drawn down by the water flow will cause cavitation in the pump. With a flow of 5 times water usage rate the Lamont circulation rate would be 2 to 4 gallons per minute in a 250lb/hr generator so there is a lot of water to separate. I've puzzled a bit as to whether the flow could be reversed, returning the heated water to the storage coils at the bottom so water and steam are going the same direction as they would be in a monotube but this means taking water to the pump from part way up the coil, far worse problems with steam separation and the new problem of ensuring the pump intake is always below water level. I doubt this is very practical.
All a bit tricky and I think the Baker burner drawing shows that they were aware of such problems. In the Baker drawing the water level is below the heavy outer pipes which just hold steam. All the separation is going on in the centre column, which if we assume the whole boiler is 24 inches diameter, must be nearly five inches in bore and 24 inches tall. There is much more stored energy in the water held in the centre column than in the steam in the thick coils whose benefit as I see it is mainly to provide a modest reserve of steam and very effective steam/water separation because only steam should be entering the bottom of these coils. The coils of the Baker will help when the throttle is opened and the water level rises as they provide a big heat sink to evaporate rising water before it get high enough to be carried over. But I doubt that such coils could be used as the Lamont reservoir without a centre column, which brings us back to a drum.
Putting the drum in the centre is very good packaging as it uses the otherwise empty space in the centre of the coils rather than adding to the outside. The disadvantage is that the drum is relatively tall and narrow, of smallish volume and susceptible to throttle related changes in level. Large Baker-like coils on the outside add plenty of volume, but add a fair bit to the overall diameter and would be very hard to use alone without a drum. Adding them to a drum Lamont above water level would help steam separation but at the expense of significantly increased boiler diameter and complexity.
I also suspect the large centre column of the Baker is big enough to be seen as a pressure vessel not a pipe so doesn’t escape the interest of the inspectors and insurers. If we can't build a Lamont without a separation drum then making the main steam store from coiled pipe does not help much.
Mike
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Re: Lamont boiler January 18, 2011 05:17AM |
Registered: 19 years ago Posts: 1,453 |
Hi Mike & all,
When outside reserve coils are discussed, it reminds me of the "Newton Coil Boiler" at:
[oldenginehouse.users.btopenworld.com]
Scroll down to the photo of the bare tube stack on that page. I am not sure how it works, but it looks like the inner coil of 2" tubing acts as a reserve and also separates water from steam. Which coil is the riser, which is the downcomer, and which (both?) generate the steam? The only things I can figure out are that feedwater enters at the bottom, and steam exits the top.
Perhaps several similar small-tube/big-tube coil sets could be combined to get a higher steam generation rate. IE, several "fast" spirals of each, nested in the same "barrel" (cylindrical/curved) plane.
I have heard mention of natural-circulation boilers, including Bolsovers, with recirculation rates which match or exceed the Lamont's 5x. Bolsovers use about 40 generating/circulating paths and of course a central drum. No circulating pump, jet, etc needed ... though these features could perhaps be added ...
I have often wondered how well the Rider and Field boilers performed, relative to Lamont and other forced-circulation and high-output natural-circulation designs.
Rider and Field boilers are shown at:
[www.angelfire.com]
I think that good "phase separation" (water/steam separation), rapid circulation, and good reserve capacity can be achieved without drums or pressure vessels per se... needs some "thinking outside the box"...
4 vertical [or coiled] standpipes, 2" ID each, could have the same storage and flow-separation capacity as a single drum of 4" ID, if properly plumbed together. Even more, smaller-bore pipes, IE, 16 pipes of 1" ID, etc, could do the same. Of course the connections, fabrication, and cost/benefit analysis get more complex with more/smaller reserve/separation pipes...
Height/diameter ratio of tube stack can become an issue with a water-level steam car boiler; consider the effect of the boiler tilting while going up or down steep hills. Some tubes can drain and burn out, and/or water level can rise too high in other tubes, feeding water into the steam outlet (priming)... thus breaking the engine...
George Nutz's Lamont articles, and his posts on the subject which are archived in the back pages of this Forum, are treasure troves of valuable and thought-provoking information.
Peter
Edited 3 time(s). Last edit at 01/18/2011 06:12AM by Peter Brow.
When outside reserve coils are discussed, it reminds me of the "Newton Coil Boiler" at:
[oldenginehouse.users.btopenworld.com]
Scroll down to the photo of the bare tube stack on that page. I am not sure how it works, but it looks like the inner coil of 2" tubing acts as a reserve and also separates water from steam. Which coil is the riser, which is the downcomer, and which (both?) generate the steam? The only things I can figure out are that feedwater enters at the bottom, and steam exits the top.
Perhaps several similar small-tube/big-tube coil sets could be combined to get a higher steam generation rate. IE, several "fast" spirals of each, nested in the same "barrel" (cylindrical/curved) plane.
I have heard mention of natural-circulation boilers, including Bolsovers, with recirculation rates which match or exceed the Lamont's 5x. Bolsovers use about 40 generating/circulating paths and of course a central drum. No circulating pump, jet, etc needed ... though these features could perhaps be added ...
I have often wondered how well the Rider and Field boilers performed, relative to Lamont and other forced-circulation and high-output natural-circulation designs.
Rider and Field boilers are shown at:
[www.angelfire.com]
I think that good "phase separation" (water/steam separation), rapid circulation, and good reserve capacity can be achieved without drums or pressure vessels per se... needs some "thinking outside the box"...
4 vertical [or coiled] standpipes, 2" ID each, could have the same storage and flow-separation capacity as a single drum of 4" ID, if properly plumbed together. Even more, smaller-bore pipes, IE, 16 pipes of 1" ID, etc, could do the same. Of course the connections, fabrication, and cost/benefit analysis get more complex with more/smaller reserve/separation pipes...
Height/diameter ratio of tube stack can become an issue with a water-level steam car boiler; consider the effect of the boiler tilting while going up or down steep hills. Some tubes can drain and burn out, and/or water level can rise too high in other tubes, feeding water into the steam outlet (priming)... thus breaking the engine...
George Nutz's Lamont articles, and his posts on the subject which are archived in the back pages of this Forum, are treasure troves of valuable and thought-provoking information.
Peter
Edited 3 time(s). Last edit at 01/18/2011 06:12AM by Peter Brow.
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Re: Lamont boiler January 18, 2011 06:35AM |
Registered: 19 years ago Posts: 375 |
Thanks Peter -- interesting one that Newton boiler-- if it had the thick coil outside and the thinner inside as the Lamont circuit with the pump drawing from the bottom of the big coil and feeding to the top via the 1/2 inch pipe would the water run down and the steam go up? A steeper pitch on the big coil would help and maybe the thin pipe could extend down a turn or two within the top of the big coil to the approximate running water level. I guess it would just have to be tried. Feedwater would go into the pump as well. The tube benders would enjoy making the big coil! Plenty to think about.
I do think the Lamont is better able to avoid tube burnout than any natural circulation generator - anyway it's more interesting to work on the unknown rather than follow an old recipe. I'm quite open to suggestions though which is why I'm on this forum and getting a coil to work in place of a drum is a worthwhile objective if it can be done. I'll try drawing it up then you chaps can shoot me down before I commit to metal.
I did a few sums on contained volume versus weight for a length of 2 " sch 40 pipe and for a 5 inch sch 80 drum - it would perhaps be 10 or 20 percent lighter with the pipe for a given capacity which is of interest to me as weight is critical for this project as is overall diameter of the boiler where 19" inches is my limit.
Thanks for your thoughts on this.
Mike
Edited 1 time(s). Last edit at 01/18/2011 06:43AM by Mike Clark.
I do think the Lamont is better able to avoid tube burnout than any natural circulation generator - anyway it's more interesting to work on the unknown rather than follow an old recipe. I'm quite open to suggestions though which is why I'm on this forum and getting a coil to work in place of a drum is a worthwhile objective if it can be done. I'll try drawing it up then you chaps can shoot me down before I commit to metal.
I did a few sums on contained volume versus weight for a length of 2 " sch 40 pipe and for a 5 inch sch 80 drum - it would perhaps be 10 or 20 percent lighter with the pipe for a given capacity which is of interest to me as weight is critical for this project as is overall diameter of the boiler where 19" inches is my limit.
Thanks for your thoughts on this.
Mike
Edited 1 time(s). Last edit at 01/18/2011 06:43AM by Mike Clark.
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Re: Lamont boiler January 18, 2011 07:29AM |
Registered: 15 years ago Posts: 663 |
A similar stand pipe arangement with no recurlation simply pumps water through tube only boiler into the lower end of the stand pipe. Saturated steam is taken from the top of the stand pipe.
I have thought of several controls for this type of boiler. But the simplest follows the white system sastem idea. Presure low pump on. Water high fire on. With the fire on superheated steam will eventually be entering the standpipe below the water level. The superheat will transfer to the water in the standpipe. Being at saturation pressure that wile vaporize some water lowering the water level.
I have thought of several controls for this type of boiler. But the simplest follows the white system sastem idea. Presure low pump on. Water high fire on. With the fire on superheated steam will eventually be entering the standpipe below the water level. The superheat will transfer to the water in the standpipe. Being at saturation pressure that wile vaporize some water lowering the water level.
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Re: Lamont boiler January 18, 2011 10:08AM |
Registered: 15 years ago Posts: 180 |
all:
i think because of all these steam separation problems, and the heat conduction problems bubbles present, is that steam powerplants are going (or are already?) to supercritical water. If your boiler was full of supercritical water (like a Benson boiler), and then you had a valve that reduced the pressure to produce steam when you needed it, most of the problems inherent in the boiler would go away, other than your boiler tube being able to withstand 3200 psi.
Dan
i think because of all these steam separation problems, and the heat conduction problems bubbles present, is that steam powerplants are going (or are already?) to supercritical water. If your boiler was full of supercritical water (like a Benson boiler), and then you had a valve that reduced the pressure to produce steam when you needed it, most of the problems inherent in the boiler would go away, other than your boiler tube being able to withstand 3200 psi.
Dan
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Re: Lamont boiler January 18, 2011 12:41PM |
Registered: 19 years ago Posts: 1,441 |
All,
Please, everyone sit down and carefully read George's paper again. You are reading and fantasizing things into this that do not exist in the real world.
The coil-drum is for water STORAGE, not boiling, and that is why it is OUTSIDE the casing and the fire. That is the reserve that the monotube does not have for long.
The reference to the Baker is only for illustration of possible coil location and nothing else, OK?
Water is pumped from the bottom of the coil-drum, through the evaporating-helical coils and tangentially into the top of the drum. If a coil is used, then one welds a vertical tee on the top end of the coil and that is where the centrifugal separator is located. Enough height and baffles to prevent splashing over. Steam is taken off the top of the separator and then into the superheater and on out to the engine. The actual angle the Lamont may or probably not be in, is so small it simply doesn't matter in vehicle use.
Feed water goes from the feed pump into the economizer coils first and then into the drum-coil unit. Just like George illustrated.
The driven circulating pump is sized to flow at least five times and better more like eight to ten times the maximum evaporation rate. THAT is where and why the great evaporation rate is obtained. The faster the flow rate the greater the heat transfer rate and it is water not steam, basic thermodynamics. Natural or assisted circulation water tube boilers do not have an equal evaporation rate than the correctly designed Lamont per square foot of heating surface. They are good; but not that good.
The control is super simple and NOT like the White by any means. Pressure shuts off the burner and either a conductivity probe or even a simple expansion tube water level control just like a Stanley is all you need, NOTHING else. Maintain the water level in the drum-coil section, PERIOD. Forget computers and rate systems, that is just not needed.
A Doble style normalizer would be nice, as the superheater could then be sized for the desired temperature plus a tiny bit more at FULL flow rate. Then as added protection with low flow rates, the normalizer could hold the outlet to a precise temperature. Buried like it should be provides good stability and increased thermal hysteresis.
The White is an all mechanical flow rate proportioning system for both fuel and water for a monotube steam generator of minimum size with a fierce burner. It has no association to the Lamont at all.
If the Lamont is actually to be built and not just talked about, then hire George to design it. He is very reasonable and accurate as hell.
He did one for me to replace a bad Stanley boiler in a 735 car. Half the heating surface area of an equivalent Doble style monotube, half the size overall, and half the weight and good for 1200 pounds per hour. With finned tubing we could have reduced the size a lot more.
Jim
Please, everyone sit down and carefully read George's paper again. You are reading and fantasizing things into this that do not exist in the real world.
The coil-drum is for water STORAGE, not boiling, and that is why it is OUTSIDE the casing and the fire. That is the reserve that the monotube does not have for long.
The reference to the Baker is only for illustration of possible coil location and nothing else, OK?
Water is pumped from the bottom of the coil-drum, through the evaporating-helical coils and tangentially into the top of the drum. If a coil is used, then one welds a vertical tee on the top end of the coil and that is where the centrifugal separator is located. Enough height and baffles to prevent splashing over. Steam is taken off the top of the separator and then into the superheater and on out to the engine. The actual angle the Lamont may or probably not be in, is so small it simply doesn't matter in vehicle use.
Feed water goes from the feed pump into the economizer coils first and then into the drum-coil unit. Just like George illustrated.
The driven circulating pump is sized to flow at least five times and better more like eight to ten times the maximum evaporation rate. THAT is where and why the great evaporation rate is obtained. The faster the flow rate the greater the heat transfer rate and it is water not steam, basic thermodynamics. Natural or assisted circulation water tube boilers do not have an equal evaporation rate than the correctly designed Lamont per square foot of heating surface. They are good; but not that good.
The control is super simple and NOT like the White by any means. Pressure shuts off the burner and either a conductivity probe or even a simple expansion tube water level control just like a Stanley is all you need, NOTHING else. Maintain the water level in the drum-coil section, PERIOD. Forget computers and rate systems, that is just not needed.
A Doble style normalizer would be nice, as the superheater could then be sized for the desired temperature plus a tiny bit more at FULL flow rate. Then as added protection with low flow rates, the normalizer could hold the outlet to a precise temperature. Buried like it should be provides good stability and increased thermal hysteresis.
The White is an all mechanical flow rate proportioning system for both fuel and water for a monotube steam generator of minimum size with a fierce burner. It has no association to the Lamont at all.
If the Lamont is actually to be built and not just talked about, then hire George to design it. He is very reasonable and accurate as hell.
He did one for me to replace a bad Stanley boiler in a 735 car. Half the heating surface area of an equivalent Doble style monotube, half the size overall, and half the weight and good for 1200 pounds per hour. With finned tubing we could have reduced the size a lot more.
Jim
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Re: Lamont boiler January 18, 2011 03:22PM |
Registered: 19 years ago Posts: 1,771 |
Forced cycle boilers.
Herreshoff boilers 1880 and engines were 50 years before Lamont. The boilers are typically not shown as they should be with the drum and pumps. At MIT you can find drawings with the auxiliary circulating pumps driven by a single cylinder engine. The pumps were piston type. Water level was controlled manually by the engineer. In the artists drawing of the sawmill you can see the steam to the engine is taken off the top of the drum but the circulating pumps are not shown. It should not be credited to Lamont as George stated in his paper the idea was originally proposed and tested by Martin Benson in 1856 forty years before Herreshoff and 60 years before Lamont. Herreshoff was the first to make commercial use of the work with over 100 boats being built.
Herreshoff boilers 1880 and engines were 50 years before Lamont. The boilers are typically not shown as they should be with the drum and pumps. At MIT you can find drawings with the auxiliary circulating pumps driven by a single cylinder engine. The pumps were piston type. Water level was controlled manually by the engineer. In the artists drawing of the sawmill you can see the steam to the engine is taken off the top of the drum but the circulating pumps are not shown. It should not be credited to Lamont as George stated in his paper the idea was originally proposed and tested by Martin Benson in 1856 forty years before Herreshoff and 60 years before Lamont. Herreshoff was the first to make commercial use of the work with over 100 boats being built.
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Re: Lamont boiler January 18, 2011 08:50PM |
Registered: 19 years ago Posts: 215 |
Rolly,
It has been a few years for me to respond to anyone in regards to the great Lamont boiler which my original paper was published in 1998. All of what you say(as you are always the great authority to be kindly in all things steam) but I take exception to your know it all remarks. If you carefully re-read my 1998 paper it begins with a tribute to Martin Benson of 1856 and the tribute to Herreshoff for his great experiments. Why do you take me to criticism when my first article gave that information and tributes to the precursers of the modern very high output Lamont boiler that you take me to task for? Must you always be foremost and greatest authority on all things steam. I admire your very great fabrication and copying abilities but sadly you know nothing of things of vastly difficult steam and theoretical heat transfer. Sorry old friend but you failed to remember in your zest to be critical to remember my original tributes to these previous experimentors and developers of rather simple forced recirulation boilers. Lamont brought them to modern fruition in huge high efficiency plants as his heat transfer knowledge at his time was far superior to the great Benson and Herrishoff designs. So don't take me to task as I had stated long ago what you try and correct me on. .
For others considering a central drum Lamont it is a feasable design;my very first 2GPH fired Lamont had a central 6" drum but in order for it to be classified as an unfired pressure vessel its outside diameter was close wound with tubing circulated with saturated water/steam to classify it such. The problem with this is now the boiler had two parallel Lamont coils of very different heat inputs, diameters and flow rates. Balancing the two for there different lengths/heat inputs/inner flow rates working off the same centrifugal pump was a very difficult task but possible. Without exaggeration the first boiler design took many hundreds of hours of theoretical heat transfer work both inside and outside the tubing to insure its safety. For small boilers I would much prefer a monotube Lamont coil that is designed for great safety and a minimum or recirculating pump horsepower when 12 volt power is limited such as in a car. If I remember correctly from tests done years ago the Nutz/Teel pump circulated about 2000#/hr when generating a steam output of 400#/hr---we did this with our pump design with a variable voltage supply down to 6 amperes @ 10 volts DC or 60 watts or recirculation pump energy required, about 1/8th DC motor horsepower. At 12 volts and 10 amperes I believe we could recirculate over 4000#/hr that would be useful for a 800-1000#/hr boiler firing at 10-12GPH kerosine. Dozens of tests, many under temperature and pressure conditions verified the efficiency of this system. It is Lamont that under more modern cercustances brought this design to perfection.
Thanks Jim Crank for the compliments, Georgen
It has been a few years for me to respond to anyone in regards to the great Lamont boiler which my original paper was published in 1998. All of what you say(as you are always the great authority to be kindly in all things steam) but I take exception to your know it all remarks. If you carefully re-read my 1998 paper it begins with a tribute to Martin Benson of 1856 and the tribute to Herreshoff for his great experiments. Why do you take me to criticism when my first article gave that information and tributes to the precursers of the modern very high output Lamont boiler that you take me to task for? Must you always be foremost and greatest authority on all things steam. I admire your very great fabrication and copying abilities but sadly you know nothing of things of vastly difficult steam and theoretical heat transfer. Sorry old friend but you failed to remember in your zest to be critical to remember my original tributes to these previous experimentors and developers of rather simple forced recirulation boilers. Lamont brought them to modern fruition in huge high efficiency plants as his heat transfer knowledge at his time was far superior to the great Benson and Herrishoff designs. So don't take me to task as I had stated long ago what you try and correct me on. .
For others considering a central drum Lamont it is a feasable design;my very first 2GPH fired Lamont had a central 6" drum but in order for it to be classified as an unfired pressure vessel its outside diameter was close wound with tubing circulated with saturated water/steam to classify it such. The problem with this is now the boiler had two parallel Lamont coils of very different heat inputs, diameters and flow rates. Balancing the two for there different lengths/heat inputs/inner flow rates working off the same centrifugal pump was a very difficult task but possible. Without exaggeration the first boiler design took many hundreds of hours of theoretical heat transfer work both inside and outside the tubing to insure its safety. For small boilers I would much prefer a monotube Lamont coil that is designed for great safety and a minimum or recirculating pump horsepower when 12 volt power is limited such as in a car. If I remember correctly from tests done years ago the Nutz/Teel pump circulated about 2000#/hr when generating a steam output of 400#/hr---we did this with our pump design with a variable voltage supply down to 6 amperes @ 10 volts DC or 60 watts or recirculation pump energy required, about 1/8th DC motor horsepower. At 12 volts and 10 amperes I believe we could recirculate over 4000#/hr that would be useful for a 800-1000#/hr boiler firing at 10-12GPH kerosine. Dozens of tests, many under temperature and pressure conditions verified the efficiency of this system. It is Lamont that under more modern cercustances brought this design to perfection.
Thanks Jim Crank for the compliments, Georgen
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Re: Lamont boiler January 19, 2011 11:10AM |
Registered: 19 years ago Posts: 1,771 |
I’m sorry George but I don’t find any thing critical in my post toward you or your work.
I pointed out in my post it was you in your paper that gave credit to Benson and Herrishoff designs.
Rolly
There were others as well.
E.M. White in the late 1890 who built a forced cycle boiler with parallel flow circulation.
I pointed out in my post it was you in your paper that gave credit to Benson and Herrishoff designs.
Rolly
There were others as well.
E.M. White in the late 1890 who built a forced cycle boiler with parallel flow circulation.
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Re: Lamont boiler January 19, 2011 11:32AM |
Registered: 19 years ago Posts: 215 |
Rolly,
I apologize for misreading your post, yes you did quote the Benson and Herreshoff work from my paper, and as I origanally read it your mention of that was a separate remark to put down the work of Lamont. Unfortunately neither Benson nor Herreshoff had the more modern steels and great .advancements in heat transfer theory that Lamont had---he was a most gifted and talented engineer and the thread title is Lamont. Why don't you start a thread on Herreshoff and his brilliance in ship and steam power designs, lots of good stuff could come out of such a thread.
Sorry for the misunderstanding, Georgen
I apologize for misreading your post, yes you did quote the Benson and Herreshoff work from my paper, and as I origanally read it your mention of that was a separate remark to put down the work of Lamont. Unfortunately neither Benson nor Herreshoff had the more modern steels and great .advancements in heat transfer theory that Lamont had---he was a most gifted and talented engineer and the thread title is Lamont. Why don't you start a thread on Herreshoff and his brilliance in ship and steam power designs, lots of good stuff could come out of such a thread.
Sorry for the misunderstanding, Georgen
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Re: Lamont boiler January 19, 2011 11:34AM |
Registered: 19 years ago Posts: 1,441 |
Rolly,
According to the book in my library "Modern Marine Engines, Boilers and Screw Propellers" by Emory Edwards, 1881, pages 130-131, the Herreshoff coil boiler was not operated like the Lamont at all. At this late remove, it is as good a reference as one needs today. It is an esoteric argument anyhow. Only the pure Lamont should be considered today.
In the Herreshoff, water was pumped by the feed pump into the two concentric beehive coils connected in series. The wet steam then went to a separator drum on the outside of the boiler, then to the superheating coil on top, then out to the engine. The water in the drum, which had a water glass, was discharged overboard, into the condenser, or back to the inlet of the main feed pump by a small separate pump. All manually controlled then. It did NOT operate like the Lamont at all.
What Lamont did was recognize that a rapid flow of only water in the tubes next to the fire would give greatly enhanced evaporation rates, much improved safety from tube burnout, and a much simpler control system demand and if needed, could be forced to high rates of evaporation with complete safety. The Lamont is superior in these respects to the Doble style of steam generator. It also provides a greatly enhanced reserve which the Doble steam generator does not have except for a few moments, like two blocks!!
The circulating pump is exactly like the centrifugal water pump on a normal IC car. High flow rate and modest pressure differential. It poses no design problems.
George in his paper on the Lamont did indeed give source and credit to the previous people like the Herreshoffs who used a fast steaming coil boiler in some of their steam yachts.
I think you should re-read his paper again with great care and not jump to conclusions that may mislead people not familiar with this style of steam generator. What is important is not the creation of a coil boiler, which many did invent around that same time; but the greatly increased flow rate of only water in the coils next to the fire, which did offer great improvements, as noted above.
Not compliments as such George, only the truth.
Jim
Edited 2 time(s). Last edit at 01/19/2011 11:50AM by Jim Crank.
According to the book in my library "Modern Marine Engines, Boilers and Screw Propellers" by Emory Edwards, 1881, pages 130-131, the Herreshoff coil boiler was not operated like the Lamont at all. At this late remove, it is as good a reference as one needs today. It is an esoteric argument anyhow. Only the pure Lamont should be considered today.
In the Herreshoff, water was pumped by the feed pump into the two concentric beehive coils connected in series. The wet steam then went to a separator drum on the outside of the boiler, then to the superheating coil on top, then out to the engine. The water in the drum, which had a water glass, was discharged overboard, into the condenser, or back to the inlet of the main feed pump by a small separate pump. All manually controlled then. It did NOT operate like the Lamont at all.
What Lamont did was recognize that a rapid flow of only water in the tubes next to the fire would give greatly enhanced evaporation rates, much improved safety from tube burnout, and a much simpler control system demand and if needed, could be forced to high rates of evaporation with complete safety. The Lamont is superior in these respects to the Doble style of steam generator. It also provides a greatly enhanced reserve which the Doble steam generator does not have except for a few moments, like two blocks!!
The circulating pump is exactly like the centrifugal water pump on a normal IC car. High flow rate and modest pressure differential. It poses no design problems.
George in his paper on the Lamont did indeed give source and credit to the previous people like the Herreshoffs who used a fast steaming coil boiler in some of their steam yachts.
I think you should re-read his paper again with great care and not jump to conclusions that may mislead people not familiar with this style of steam generator. What is important is not the creation of a coil boiler, which many did invent around that same time; but the greatly increased flow rate of only water in the coils next to the fire, which did offer great improvements, as noted above.
Not compliments as such George, only the truth.
Jim
Edited 2 time(s). Last edit at 01/19/2011 11:50AM by Jim Crank.
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Re: Lamont boiler January 19, 2011 12:17PM |
Registered: 19 years ago Posts: 1,771 |
Jim
In around 1986 to 1990 I had the opportunity and privilege from Bill Hart to have access to all the Herreshoff drawings. MIT has all of his work with the exception of five sailboat hulls.
You would need to study his drawings. The coiled boilers were all single pass forced cycle boilers, there were two pumps as shown in the White drawing I posted. One was a circulating pump and one a feed water pump; none that I can remember had a superheater. At that time pipe and tube was made in five-foot sections from sheet metal wrapped around a mandrel and welded, then each section was welded together. When a Herreshoff boiler lost a tube and the engineer was killed it put an end to the coil boiler. But by that time a large fleet of the fastest torpedo boats were all over the world.
There is no doubt that Lamont brought the forced cycle boiler into the modern age. But to call all forced cycle boilers Lamont is not appropriate in my mind.
Rolly
In around 1986 to 1990 I had the opportunity and privilege from Bill Hart to have access to all the Herreshoff drawings. MIT has all of his work with the exception of five sailboat hulls.
You would need to study his drawings. The coiled boilers were all single pass forced cycle boilers, there were two pumps as shown in the White drawing I posted. One was a circulating pump and one a feed water pump; none that I can remember had a superheater. At that time pipe and tube was made in five-foot sections from sheet metal wrapped around a mandrel and welded, then each section was welded together. When a Herreshoff boiler lost a tube and the engineer was killed it put an end to the coil boiler. But by that time a large fleet of the fastest torpedo boats were all over the world.
There is no doubt that Lamont brought the forced cycle boiler into the modern age. But to call all forced cycle boilers Lamont is not appropriate in my mind.
Rolly
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Re: Lamont boiler January 19, 2011 12:25PM |
Registered: 15 years ago Posts: 663 |
Hi George.
Good to see you posting again.
I have a question on the area calculations in your paper. The White and Double boilers were contionus coils producing super heated steam. While in a Lamont you have the evaporation and super heater coils seperated. When you figure evaperation rate per square foot was the total heating surfaces included or any estimation of just evaporation areas done. It seams an unfair comparison to use the total surface area of the White or Double against the generator section area of the Lamont.
Good to see you posting again.
I have a question on the area calculations in your paper. The White and Double boilers were contionus coils producing super heated steam. While in a Lamont you have the evaporation and super heater coils seperated. When you figure evaperation rate per square foot was the total heating surfaces included or any estimation of just evaporation areas done. It seams an unfair comparison to use the total surface area of the White or Double against the generator section area of the Lamont.
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Re: Lamont boiler January 19, 2011 01:08PM |
Registered: 19 years ago Posts: 1,441 |
Rolly,
Yes, that rolled and welded tube idea is simply astounding. Gas welded or forge welded? No one seems to know. Or was there even gas welding in those days?
Those three were really something, were they not. I love the story about James and his Stirling powered bicycle catching his pants on fire.
Or their steam car escapades. Fascinating people and stunning yacht designers with great talent.
In that book, the flat coil on top of the boiler is called a superheater. Seems more like a drying coil as the two beehive coils produced wet steam, according to the books.
Amazon has a reproduction of the book for sale.
Nobody should call all forced circulation boilers or steam generators, Lamont. Or they certainly should not.
Only the high flow rate recirculating coil steam generator with the exact circuit that George illustrated is called the Lamont. The rest are assisted circulation boilers as far as I am concerned, or forced circulation monotube like the Doble and White.
Jim
Yes, that rolled and welded tube idea is simply astounding. Gas welded or forge welded? No one seems to know. Or was there even gas welding in those days?
Those three were really something, were they not. I love the story about James and his Stirling powered bicycle catching his pants on fire.
Or their steam car escapades. Fascinating people and stunning yacht designers with great talent.
In that book, the flat coil on top of the boiler is called a superheater. Seems more like a drying coil as the two beehive coils produced wet steam, according to the books.
Amazon has a reproduction of the book for sale.
Nobody should call all forced circulation boilers or steam generators, Lamont. Or they certainly should not.
Only the high flow rate recirculating coil steam generator with the exact circuit that George illustrated is called the Lamont. The rest are assisted circulation boilers as far as I am concerned, or forced circulation monotube like the Doble and White.
Jim
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Re: Lamont boiler January 19, 2011 01:09PM |
Registered: 19 years ago Posts: 215 |
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Re: Lamont boiler January 19, 2011 02:20PM |
Registered: 15 years ago Posts: 663 |
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Re: Lamont boiler January 19, 2011 03:10PM |
Registered: 16 years ago Posts: 358 |
Hi Rolly, George, Jim,,Hey good to get the fogg cleared here,,and glad to hear from George again,,Defining the details and clearing the misconseptions is all god,,Seems these designs are so far apart in time,,what could have been if they were all in a decade,, Seems like the car stuff spans 30-50 years,,,and the boat and powerplant is triple that,, A good healthy discussion,,,and echo ,, memories of that dinner table at MtWashington/not to ever be forgotten,,,,,, George,,should you forget why U are there,,,It's been o -to minus 5 for 2 weeks,,mornings, and below freezing days,,today is 33but not to worry,,its forcast for +2 by friday,,and the 1885 soapstone stove is fine,,,Cheers,,Ben
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Re: Lamont boiler January 19, 2011 04:12PM |
Registered: 19 years ago Posts: 215 |
Ben,(off topic)
God bless you my good friend and the memories of you and I meeting Jim Crank at Mt. washington and the absolute energy at that back dinner table was electrifying, still raises the hair on my arms(none on my head to raise!) That you and Jim and Frazier had such an infinite knowledge of just about every old car and its history was a pleasure beyond description, one of the great steam moments of my life, it was enthralling. The electric energy must have risen to about 1000 volts that evening at that table and no one around us had the slightest idea of what we were experiencing. Incredible moments!
Glad I am down in Florida as I would have died a few years ago on the New Hampshire hideaway from the work just to get thru the winters. Tough to survive all alone without help up there.
On Topic: the reason for not developing a Lamont with an inner drum is the drum connection problems become very complicated, especially when the drum is tight wound with a separate Lamont coil to label it "non-fired". If one has the room for an external drum then all of this becomes a rather simple matter. Ease of fabrication is a big consideration for the amatuer machinest and builder and the ultimate can be left to those with greater talents and monies to have the work done by others.
Best to you Ben, George
God bless you my good friend and the memories of you and I meeting Jim Crank at Mt. washington and the absolute energy at that back dinner table was electrifying, still raises the hair on my arms(none on my head to raise!) That you and Jim and Frazier had such an infinite knowledge of just about every old car and its history was a pleasure beyond description, one of the great steam moments of my life, it was enthralling. The electric energy must have risen to about 1000 volts that evening at that table and no one around us had the slightest idea of what we were experiencing. Incredible moments!
Glad I am down in Florida as I would have died a few years ago on the New Hampshire hideaway from the work just to get thru the winters. Tough to survive all alone without help up there.
On Topic: the reason for not developing a Lamont with an inner drum is the drum connection problems become very complicated, especially when the drum is tight wound with a separate Lamont coil to label it "non-fired". If one has the room for an external drum then all of this becomes a rather simple matter. Ease of fabrication is a big consideration for the amatuer machinest and builder and the ultimate can be left to those with greater talents and monies to have the work done by others.
Best to you Ben, George
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Re: Lamont boiler January 19, 2011 04:32PM |
Registered: 15 years ago Posts: 180 |
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Re: Lamont boiler January 19, 2011 04:55PM |
Registered: 19 years ago Posts: 375 |
Andy,
Doble's methods are explained by him in JN Walton's book "Doble Steam Cars, Buses Lorries and Railcars". Surface areas of helical coils that are closely packed as where they surround the inside of the furnace are taken as 1.4 times the area of the furnace wall that they cover, rather than the actual area of the coil. In this way the area counted is less than the actual area to allow for the fact that heat is only hitting one side of the pipe. Spiral coils which get hot gas all round are credited with their true area. Doble may have had some more elaborate sums to account for whether the spirals are staggered or lined up above one another but he doesn't say. He also writes on furnace volume and on gas flow through spiral economiser sections.
Doble gives guide figures and the logic behind them for the pipe sizes, wall thicknesses and length needed for an 850lb /hr generator and also advises on flow rates in feet per second for water and for steam in various sections of the generator. Scaling it down for a smaller generator is not so easy as to get the preferred flow rate the pipe sizes get small, particularly for the first part of the economiser section where the temperature is low. There are some web based flow calculators which avoid the need for elaborate maths, which in my case is a very good thing! Doble does not talk of linear or turbulent flow but his suggested flow rates always get into the turbulent zone - an instance where his practical experience provided the answer. It's a worthwhile book to read, mainly for this information although this part of the book is just one chapter.
Interesting topic and I'm pleased to see George Nutz in action. I've read all the papers G, but what happened next?:
It would be great to have follow up on the Lamont generators which were built after your paper.
Mike
Mike
Doble's methods are explained by him in JN Walton's book "Doble Steam Cars, Buses Lorries and Railcars". Surface areas of helical coils that are closely packed as where they surround the inside of the furnace are taken as 1.4 times the area of the furnace wall that they cover, rather than the actual area of the coil. In this way the area counted is less than the actual area to allow for the fact that heat is only hitting one side of the pipe. Spiral coils which get hot gas all round are credited with their true area. Doble may have had some more elaborate sums to account for whether the spirals are staggered or lined up above one another but he doesn't say. He also writes on furnace volume and on gas flow through spiral economiser sections.
Doble gives guide figures and the logic behind them for the pipe sizes, wall thicknesses and length needed for an 850lb /hr generator and also advises on flow rates in feet per second for water and for steam in various sections of the generator. Scaling it down for a smaller generator is not so easy as to get the preferred flow rate the pipe sizes get small, particularly for the first part of the economiser section where the temperature is low. There are some web based flow calculators which avoid the need for elaborate maths, which in my case is a very good thing! Doble does not talk of linear or turbulent flow but his suggested flow rates always get into the turbulent zone - an instance where his practical experience provided the answer. It's a worthwhile book to read, mainly for this information although this part of the book is just one chapter.
Interesting topic and I'm pleased to see George Nutz in action. I've read all the papers G, but what happened next?:
It would be great to have follow up on the Lamont generators which were built after your paper.
Mike
Mike
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Re: Lamont boiler January 19, 2011 05:17PM |
Registered: 19 years ago Posts: 375 |
Yes - back to Lamont.
George - the ease of fabrication was the reason I proposed the inside drum but should I go that way I would accept that it be classified as a pressure vessel. I think the connections could be made top and bottom ends rather than through the wall of the drum. An external drum is very hard to fit into the car which is very small.
I'm still thinking about the Jim's "big spiral" which would be much easier to get insured and generally preferable to a drum. Jim - I well understand that the Lamont does not boil in the spiral or drum through the application of heat, but it does the moment pressure is released by opening the throttle so the separation issue is a real one with water going one way and bubbles of steam the other. As you said a centrifugal separator could be the answer.
Mike
Edited 2 time(s). Last edit at 01/19/2011 05:27PM by Mike Clark.
George - the ease of fabrication was the reason I proposed the inside drum but should I go that way I would accept that it be classified as a pressure vessel. I think the connections could be made top and bottom ends rather than through the wall of the drum. An external drum is very hard to fit into the car which is very small.
I'm still thinking about the Jim's "big spiral" which would be much easier to get insured and generally preferable to a drum. Jim - I well understand that the Lamont does not boil in the spiral or drum through the application of heat, but it does the moment pressure is released by opening the throttle so the separation issue is a real one with water going one way and bubbles of steam the other. As you said a centrifugal separator could be the answer.
Mike
Edited 2 time(s). Last edit at 01/19/2011 05:27PM by Mike Clark.
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Re: Lamont boiler January 19, 2011 07:26PM |
Registered: 19 years ago Posts: 657 |
Hey Mike,
The Lane had a hybrid system. Having the burner on the bottom, above that a firetube boiler with 1" flues then above that was a contraflow economizer/boiler made of brass tubing(with maybe some steel at the hotter lower section).
The water came in at the top of the tubing(pancake wound) and steam and water left it into a centrifugal seperator that sent the water and steam(seperately) into the firetube boiler. The steam was taken only from the firetube boiler.
Yarrow conducted some very interesting experiments in regards to a natural circulation boiler. He found that cold downcomers were not required as odd as this may sound. What he discovered is that once circulation was established he could cease applying heat to the riser and apply it to the downcomer and circulation would continue!
You can find these experiments in "Steam Boilers: Their History and Development" which has been legally scaned by google. Here is the link, Yarrows experiments begin around page 225.
[books.google.com]
There is some very fascinating stuff in there.
Caleb Ramsby
The Lane had a hybrid system. Having the burner on the bottom, above that a firetube boiler with 1" flues then above that was a contraflow economizer/boiler made of brass tubing(with maybe some steel at the hotter lower section).
The water came in at the top of the tubing(pancake wound) and steam and water left it into a centrifugal seperator that sent the water and steam(seperately) into the firetube boiler. The steam was taken only from the firetube boiler.
Yarrow conducted some very interesting experiments in regards to a natural circulation boiler. He found that cold downcomers were not required as odd as this may sound. What he discovered is that once circulation was established he could cease applying heat to the riser and apply it to the downcomer and circulation would continue!
You can find these experiments in "Steam Boilers: Their History and Development" which has been legally scaned by google. Here is the link, Yarrows experiments begin around page 225.
[books.google.com]
There is some very fascinating stuff in there.
Caleb Ramsby
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Re: Lamont boiler January 20, 2011 01:35PM |
Registered: 19 years ago Posts: 215 |
Dan,
Yes, the circulation ratio as chosen by Lamont has a sufficient Reynolds Number for very turbulent flow and the steam "bubbles" are swept off the tube surface. There is always a thin laminar flow boundary thickness even if it is a few thousandths of an inch thick. In the Lamont it is thin enough and the temperature rise and thickness of this boundary layer can easily be computed; the whole concept of the Lamont coils in the hottest boiler sections is to keep the tube OD temperature to within a few hundred degrees of the very turbulent water-steam flowoing thru it. I have always chosen to keep the temperature rise at maximum boiler output of the combined laminar film plus temperature rise across the tubing thickness to 100-150F so that common steel can be used in the hottest sections. As an example let us have an inside turbulent flow temperature of 550F(1050psi) plus 150F= 700F outside tube temperature. Common SA-53 steel tubing has almost its full strength at 700F as it does at room temperature. Unlike other forced flow boilers that have been mentioned the Lamont always has this minimum flow ratio no matter what the boiler output. Several attempts were made in the past to use a steam powered recirculation pump or even a venturi/injector circulator but they never totally protected this very high heat input section under all conditions. It only takes a few seconds of non-circulation to creat overheat of the tube OD temperature. The nice thing(as I have mentioned so many times over so many years) is that there is never any buildup of mineral salts or oil carbon on the inside of this highly heated tube.
Thus an evaporation rate of 20-35 #steam/hour for the entire boiler surface becomes possible with great safety. Please feel free to read my hundred or so posts over the past many years to get a greater understanding of this wonderful Lamont system.
Hope this helps, Georgen
Yes, the circulation ratio as chosen by Lamont has a sufficient Reynolds Number for very turbulent flow and the steam "bubbles" are swept off the tube surface. There is always a thin laminar flow boundary thickness even if it is a few thousandths of an inch thick. In the Lamont it is thin enough and the temperature rise and thickness of this boundary layer can easily be computed; the whole concept of the Lamont coils in the hottest boiler sections is to keep the tube OD temperature to within a few hundred degrees of the very turbulent water-steam flowoing thru it. I have always chosen to keep the temperature rise at maximum boiler output of the combined laminar film plus temperature rise across the tubing thickness to 100-150F so that common steel can be used in the hottest sections. As an example let us have an inside turbulent flow temperature of 550F(1050psi) plus 150F= 700F outside tube temperature. Common SA-53 steel tubing has almost its full strength at 700F as it does at room temperature. Unlike other forced flow boilers that have been mentioned the Lamont always has this minimum flow ratio no matter what the boiler output. Several attempts were made in the past to use a steam powered recirculation pump or even a venturi/injector circulator but they never totally protected this very high heat input section under all conditions. It only takes a few seconds of non-circulation to creat overheat of the tube OD temperature. The nice thing(as I have mentioned so many times over so many years) is that there is never any buildup of mineral salts or oil carbon on the inside of this highly heated tube.
Thus an evaporation rate of 20-35 #steam/hour for the entire boiler surface becomes possible with great safety. Please feel free to read my hundred or so posts over the past many years to get a greater understanding of this wonderful Lamont system.
Hope this helps, Georgen
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