Lamont boiler
Posted by dullfig
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Re: Lamont boiler January 31, 2015 11:08PM |
Admin Registered: 19 years ago Posts: 2,120 |
Hi Dan
Chokes have been used in Lamont boilers at both the entrance, exit and midpoint...including some by Walter Lamont himself. The chokes are inserted to create smooth and even flow in each tube of a parallel tube boiler. The rationale is that the restriction adds an extra pressure drop across each tube, making the drop due to uneven steam generation in each tube relatively less significant; this tends to delay and prevent the establishment of a thermal short or a rapidly cycling tube. If you read some of Lamont's work he had quite a problem with surging and even backflow in tubes; apparently this cured the problem. In modern forced circulation boilers, the choke is at the tube inlet.
Regards,
Ken
Chokes have been used in Lamont boilers at both the entrance, exit and midpoint...including some by Walter Lamont himself. The chokes are inserted to create smooth and even flow in each tube of a parallel tube boiler. The rationale is that the restriction adds an extra pressure drop across each tube, making the drop due to uneven steam generation in each tube relatively less significant; this tends to delay and prevent the establishment of a thermal short or a rapidly cycling tube. If you read some of Lamont's work he had quite a problem with surging and even backflow in tubes; apparently this cured the problem. In modern forced circulation boilers, the choke is at the tube inlet.
Regards,
Ken
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Re: Lamont boiler February 01, 2015 03:31PM |
Registered: 15 years ago Posts: 73 |
Such chokes are intended to equalize flow in parallel tube Lamont configurations, just like dropping resistors were used to make parallelling power Darlington transistors work (before IGFETs, MOSFETs, etc.). The amount of the added drop should be several times the natural pressure drop difference between the tubes; if the tubes get uneven heating and thus uneven steam generation, that should be taken into account as well.
Such drops are not needed or useful in single tube configurations. As George has explained several times, you're looking for a circulation rate five times that of the water rate of the boiler; if you're making 200 lbs/hr for example, 200 lbs/hr * 5 * 1 gallon/8 lbs * 1 hr/60 minutes = 2.1 gpm. The tube size should be chosen to ensure turbulent flow (say a Reynolds number of 5000 or better yet 10000).
Since all heating occurs in the circulating tube, this means the mixture exiting the tube will be 20%(1/5) steam. At lower pressures, the specific volume (cubic feet/lb) of steam is much higher than that of water at the same temperature, so the exit velocity of the steam/water mixture will be very high. At higher pressures, the difference in specific volume goes down, and the entry/exit velocities go down somewhat.
One could make the latter part of the coil larger in diameter to decrease backpressure due to steam generation; during steam up that section might have lower velocities than desirable, however.
- Bart
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Bart Smaalders [smaalders.net]
Such drops are not needed or useful in single tube configurations. As George has explained several times, you're looking for a circulation rate five times that of the water rate of the boiler; if you're making 200 lbs/hr for example, 200 lbs/hr * 5 * 1 gallon/8 lbs * 1 hr/60 minutes = 2.1 gpm. The tube size should be chosen to ensure turbulent flow (say a Reynolds number of 5000 or better yet 10000).
Since all heating occurs in the circulating tube, this means the mixture exiting the tube will be 20%(1/5) steam. At lower pressures, the specific volume (cubic feet/lb) of steam is much higher than that of water at the same temperature, so the exit velocity of the steam/water mixture will be very high. At higher pressures, the difference in specific volume goes down, and the entry/exit velocities go down somewhat.
One could make the latter part of the coil larger in diameter to decrease backpressure due to steam generation; during steam up that section might have lower velocities than desirable, however.
- Bart
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Bart Smaalders [smaalders.net]
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Re: Lamont boiler February 03, 2015 02:23PM |
Registered: 19 years ago Posts: 215 |
Bart,
Thanks for the memories and renewal of the Lamont thread, on the old great Woodson site there may have been 20,000 good posts on the subject.
Agree with most you bring up. The last Lamont I designed was (gulp) 15 years ago for Jim and it was a 1000#/hr output boiler of high efficiency. The Lamont circuit in the mostly radiant heat area was only 55 feet of tubing and did half of all the heat transfer of the entire boiler due to the intense heat radiation. As you mentioned a single circuit was possible and no restrictors adding to the horsepower of the circulating pump was required.
The smaller Teel boat boiler was built and greatly tested and in no way could we disturb/dump/upset the Lamont pump or the collector drum from being upset with sudden boiler dumping to the atmosphere. The MOD-3 pump, after many tests and revisions could circulate 10,000#/hr without back pressure and the Lamont coil design was to limit the coil back pressure to 5psi differential. It was found that 8 amperes at 12.6 volts/100 watts could circulate 6,500#/hr. In that smaller boiler it would work without disturbance in tests to 8 volts at 5+ amperes/45 watts. At 6 volts with full firing rate the Lamont circuit could "belch" now and then. Designing a high performance single Lamont circuit requiring no more than 100 watts pump input and a 5 psi pressure head took a lot of theory and work but was most successful. As a matter of note this same MOD3 pump would satisfy the requirements of the above mentioned 1000/hr boiler without any changes. Adding restrictors on a single flow circuit would only greatly add to the small DC pump requirements. You have so correctly stated that lower pressure boilers have higher specific volumes and is why times ago tried to convince those interested in low pressure Lamonts(below 400psi) was not a viable consideration.
May we remember that the majority of Lamont boilers were conversions to increase the output of conventional ship boilers and several individual circuits were used , each with different lengths and different heat inputs. For a small portable car boiler this is not a consideration.
Thanks for the memories and renewal of the Lamont thread, on the old great Woodson site there may have been 20,000 good posts on the subject.
Agree with most you bring up. The last Lamont I designed was (gulp) 15 years ago for Jim and it was a 1000#/hr output boiler of high efficiency. The Lamont circuit in the mostly radiant heat area was only 55 feet of tubing and did half of all the heat transfer of the entire boiler due to the intense heat radiation. As you mentioned a single circuit was possible and no restrictors adding to the horsepower of the circulating pump was required.
The smaller Teel boat boiler was built and greatly tested and in no way could we disturb/dump/upset the Lamont pump or the collector drum from being upset with sudden boiler dumping to the atmosphere. The MOD-3 pump, after many tests and revisions could circulate 10,000#/hr without back pressure and the Lamont coil design was to limit the coil back pressure to 5psi differential. It was found that 8 amperes at 12.6 volts/100 watts could circulate 6,500#/hr. In that smaller boiler it would work without disturbance in tests to 8 volts at 5+ amperes/45 watts. At 6 volts with full firing rate the Lamont circuit could "belch" now and then. Designing a high performance single Lamont circuit requiring no more than 100 watts pump input and a 5 psi pressure head took a lot of theory and work but was most successful. As a matter of note this same MOD3 pump would satisfy the requirements of the above mentioned 1000/hr boiler without any changes. Adding restrictors on a single flow circuit would only greatly add to the small DC pump requirements. You have so correctly stated that lower pressure boilers have higher specific volumes and is why times ago tried to convince those interested in low pressure Lamonts(below 400psi) was not a viable consideration.
May we remember that the majority of Lamont boilers were conversions to increase the output of conventional ship boilers and several individual circuits were used , each with different lengths and different heat inputs. For a small portable car boiler this is not a consideration.
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Re: Lamont boiler February 03, 2015 05:55PM |
Registered: 19 years ago Posts: 1,441 |
Bart,
Yes indeed, George designed a real beauty and i was going to use a Stanley as a test bed, the old Iron Shore boiler was way too heavy and the atomizing burner liked to overheat one side of the crown sheet.
Problem was some other guy kept raising the bid on the 735 to the absurd point. He bought the car then ruined it from incompetence.
In fact, why don't you guys who want Lamonts send George a nice check and let him design it for you?
He certainly knows what he is doing. i would in a heartbeat.
Jim
Yes indeed, George designed a real beauty and i was going to use a Stanley as a test bed, the old Iron Shore boiler was way too heavy and the atomizing burner liked to overheat one side of the crown sheet.
Problem was some other guy kept raising the bid on the 735 to the absurd point. He bought the car then ruined it from incompetence.
In fact, why don't you guys who want Lamonts send George a nice check and let him design it for you?
He certainly knows what he is doing. i would in a heartbeat.
Jim
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Re: Lamont boiler February 03, 2015 11:16PM |
Registered: 15 years ago Posts: 73 |
Since the boat we're designing is intended above all for cruising/local charters, I've pretty much decided to forgo the performance advantages of a Lamont boiler. I'm really not interested in using more than 200 psig steam, and above all a quiet easy to run power plant is really the number one design criteria. I'm not interested in superheat, because I don't want to deal with the lubrication, insulation and temperature control issues. I plan on having the boiler burn either wood or diesel/waste oil; efficient cruising is important since I'd like to have a couple hundred mile range.
The engine I'm building is a single cylinder poppet valve double acting condensing uniflow based around a Detroil Diesel 149 CID cylinder liner. By using a Kitchen rudder, I can avoid reversing or stopping the engine during maneuvering and this makes the boat much easier to operate single handed.
I am intrigued by the potential of Lamont boilers, however, when it comes to lightweight high output steam plants. In my application, however, I can live w/ an extra four or five hundred pounds of weight low in the hull and I only want to fuel 200 lbs steam/hr for any length of time anyway as that already gets me past hull speed.
- Bart
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Bart Smaalders [smaalders.net]
The engine I'm building is a single cylinder poppet valve double acting condensing uniflow based around a Detroil Diesel 149 CID cylinder liner. By using a Kitchen rudder, I can avoid reversing or stopping the engine during maneuvering and this makes the boat much easier to operate single handed.
I am intrigued by the potential of Lamont boilers, however, when it comes to lightweight high output steam plants. In my application, however, I can live w/ an extra four or five hundred pounds of weight low in the hull and I only want to fuel 200 lbs steam/hr for any length of time anyway as that already gets me past hull speed.
- Bart
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Bart Smaalders [smaalders.net]
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Re: Lamont boiler February 04, 2015 02:17AM |
Registered: 10 years ago Posts: 79 |
Pressure on the auto water pump is good for 100psi,if one could do the machine work around the gland area that pressure could be increased.And I suppose Nuts could detail on what that gland work Teal(? if I remember correctly the guys name that worked up the pump) did, for those in doubt about that.
Though that should be straight forward enough to do for anyone who has worked with the glands on feedpumps.
It will also do 59psi differential pressure when the thermstat is closed,if you are checking on that down at the radiator shop on a regular car.You usually blow a headgasket and split the radiator at about 100psi on a IC car....most folks have the sense to stop the car before it gets to that on overheating.
Though that should be straight forward enough to do for anyone who has worked with the glands on feedpumps.
It will also do 59psi differential pressure when the thermstat is closed,if you are checking on that down at the radiator shop on a regular car.You usually blow a headgasket and split the radiator at about 100psi on a IC car....most folks have the sense to stop the car before it gets to that on overheating.
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Re: Lamont boiler February 06, 2015 10:58AM |
Registered: 10 years ago Posts: 79 |
At this point,I am running two water pumps one OEM on the diesel with radiator replaced by what steamers would call a hot tank with a vacuum jet on the evaporator just before goes into the steam separator, you guys have been talking about.
This holds the coolant temp down to something the diesel can live with(on warmup the evaporator will pull a 22in vaccum
in the hot tank).
An electric water pump is on the lamont in the tailpipe circuit for bottom cycle recirculating steam turbine...
I use the same feedpump as other steam guys on the evaporator....burn can is a little different from other lamont guys because I am using the gas turbine fuel control to cycle back and fore between idle and full speed as a two speed burner.
afterburn the soot from the diesel and touching up for blueflame temp of a standalone steam low pressure (65psi absolute) turbine.(That is double the pressure the turbocharger DIY jet engines run which were made to run with 20 to 30 psi exhaust pressure on the powerwheel in Turbocharger whatever as side note big rig or whatevery is doing about 7psi exhaust pressure on powerwheel while idling).
This holds the coolant temp down to something the diesel can live with(on warmup the evaporator will pull a 22in vaccum
in the hot tank).
An electric water pump is on the lamont in the tailpipe circuit for bottom cycle recirculating steam turbine...
I use the same feedpump as other steam guys on the evaporator....burn can is a little different from other lamont guys because I am using the gas turbine fuel control to cycle back and fore between idle and full speed as a two speed burner.
afterburn the soot from the diesel and touching up for blueflame temp of a standalone steam low pressure (65psi absolute) turbine.(That is double the pressure the turbocharger DIY jet engines run which were made to run with 20 to 30 psi exhaust pressure on the powerwheel in Turbocharger whatever as side note big rig or whatevery is doing about 7psi exhaust pressure on powerwheel while idling).
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Re: Lamont boiler May 03, 2015 07:28AM |
Registered: 15 years ago Posts: 237 |
I'm working on expanding Nutz' boiler comparison chart with more boilers and data points. I was thinking to post it here if it gets some more meat to it.
On the background of the many assurances of the Lamont's superiority in this thread, I thought it was right to mention the SES once-through. The SES was able to power a 100kW expander.
I haven't read the SAE papers, so please excuse the guesses: If the system thermal efficiency was 15% at that point, and the boiler efficiency 80%, the boiler absorbed 533 kW. This means a power to weight ratio of 10.8 kW/kg for the SES, the Lamont got 1.7 kW/kg - more than 6 times worse. However, George has said that the Lamont is capable of being fired much harder than indicated in the chart, in safety.
Edited 1 time(s). Last edit at 05/03/2015 08:28AM by sidrug.
On the background of the many assurances of the Lamont's superiority in this thread, I thought it was right to mention the SES once-through. The SES was able to power a 100kW expander.
I haven't read the SAE papers, so please excuse the guesses: If the system thermal efficiency was 15% at that point, and the boiler efficiency 80%, the boiler absorbed 533 kW. This means a power to weight ratio of 10.8 kW/kg for the SES, the Lamont got 1.7 kW/kg - more than 6 times worse. However, George has said that the Lamont is capable of being fired much harder than indicated in the chart, in safety.
Edited 1 time(s). Last edit at 05/03/2015 08:28AM by sidrug.
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Re: Lamont boiler May 03, 2015 01:55PM |
Registered: 19 years ago Posts: 1,441 |
George is right.
Please don't guess about the real improvements that SES designed into their Lamont steam generator. There was sound reasoning behind the SES design and Ken and I fully describe and summarize what they did and why in our White Paper, especially pages 15 to 17.
I regret that our paper is buried down so far on the SACA web site.
Jim
Please don't guess about the real improvements that SES designed into their Lamont steam generator. There was sound reasoning behind the SES design and Ken and I fully describe and summarize what they did and why in our White Paper, especially pages 15 to 17.
I regret that our paper is buried down so far on the SACA web site.
Jim
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Re: Lamont boiler May 03, 2015 05:25PM |
Registered: 15 years ago Posts: 237 |
Thanks for the pointer, it rang a bell and it turns out I have downloaded it, from some thread here I guess. Will read.
That storeroom by the way, you would have to know exactly what you are looking for. One short line of title, and I am supposed to be tempted to pay money? Should be an "abstract" for each article.
That storeroom by the way, you would have to know exactly what you are looking for. One short line of title, and I am supposed to be tempted to pay money? Should be an "abstract" for each article.
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Re: Lamont boiler May 03, 2015 06:36PM |
Registered: 15 years ago Posts: 237 |
Ok, so the SES was a Lamont? (Quote from white paper: "A seriously compact design wat that developed during the Clean Air Car program by SES Corporation. Their coil stack was arranged at a 45' angle to the long axis of the generator, providing a 40% increase in heating surface compared to a straight concentric coil arrangement. Combined with extended surface tubing and using the Lamont system, a very compact and highly efficient steam generator was realized by SES." )
I thought it was a once-through, so did Peter Brow (quote:" As far as I know, the SES boiler was a "once-through" type, no liquid recirculation. Water in one end, steam out the other. Chuk's looking into "Lamontizing" it though; I think that will work well. " )
So did Ken Helmick, before this paper (quote: "Peter is right,the SES boiler is a once through monotube. At least, I talked to one of the guys who built it and he assured me that was the case. No recirculation." )
I have never seen the drum in an illustration either. So please forgive the mistake.
- edited to remove unwanted emoticons, showing up when using " and ) together.
- edited to add "squeeze, bubble, whoosh, drip."
lol.
Edited 2 time(s). Last edit at 05/03/2015 06:41PM by sidrug.
I thought it was a once-through, so did Peter Brow (quote:" As far as I know, the SES boiler was a "once-through" type, no liquid recirculation. Water in one end, steam out the other. Chuk's looking into "Lamontizing" it though; I think that will work well. " )
So did Ken Helmick, before this paper (quote: "Peter is right,the SES boiler is a once through monotube. At least, I talked to one of the guys who built it and he assured me that was the case. No recirculation." )
I have never seen the drum in an illustration either. So please forgive the mistake.
- edited to remove unwanted emoticons, showing up when using " and ) together.
- edited to add "squeeze, bubble, whoosh, drip."
lol.Edited 2 time(s). Last edit at 05/03/2015 06:41PM by sidrug.
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Re: Lamont boiler May 04, 2015 12:33PM |
Registered: 19 years ago Posts: 1,441 |
Correct, the SES was NOT a Lamont, it was a forced circulation monotube. What we should have said was : " When combined with extended surface tubing AND the Lamont system, a very compact and highly efficient steam generator would be realized." I'll change the wording on our paper.
We added their excellent tubing arrangement to the Lamont system for obvious control reasons when really forced hard.
Jim.
We added their excellent tubing arrangement to the Lamont system for obvious control reasons when really forced hard.
Jim.
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Re: Lamont boiler May 04, 2015 08:47PM |
Registered: 19 years ago Posts: 1,268 |
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Re: Lamont boiler May 04, 2015 09:53PM |
Registered: 19 years ago Posts: 1,519 |
Is there a transition zone with the SES, if not then its defined with this steam table
[www.engineeringtoolbox.com]
[www.engineeringtoolbox.com]
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Re: Lamont boiler May 05, 2015 12:27PM |
Registered: 19 years ago Posts: 1,441 |
Bill,
The shape or bulk of the whole assembly depends on where you intend to install it. Almost any shape works, unless one really gets wild.
Honestly I never used to consider the cubic foot size of the whole generator; but the evaporation rate per sq ft of the tubing. Then considered the burner and then what it was going into as an assembled unit.
Even the standard Doble style can evaporate 22-28 lbs/sq/ft/hr when pushed hard. I wouldn't be surprised if the one Ken and I like could do in the 30-40 pound range. The extended surface tubing has been measured as being 8-12 times per sq ft better than smooth tubing, so things get even more compact.
When designing a vehicle generator, there is so much you can play with, you really can tailer it almost any way you want.
Jeremy,
Are you thinking about where the phase change and various steam conditions take place? I personally have never seen a book that tells anything about small forced circulation monotubes and how they operate.
Of course in the original SES generator there are transition zones. Cool intake-preheat--boiling with phase change from water to steam-wet steam-drying-superheating. All forced circulation monotubes work that way. The Lamont uses that drum for separation, then takes the steam off the top and runs it through the buried superheater.
Jim
The shape or bulk of the whole assembly depends on where you intend to install it. Almost any shape works, unless one really gets wild.
Honestly I never used to consider the cubic foot size of the whole generator; but the evaporation rate per sq ft of the tubing. Then considered the burner and then what it was going into as an assembled unit.
Even the standard Doble style can evaporate 22-28 lbs/sq/ft/hr when pushed hard. I wouldn't be surprised if the one Ken and I like could do in the 30-40 pound range. The extended surface tubing has been measured as being 8-12 times per sq ft better than smooth tubing, so things get even more compact.
When designing a vehicle generator, there is so much you can play with, you really can tailer it almost any way you want.
Jeremy,
Are you thinking about where the phase change and various steam conditions take place? I personally have never seen a book that tells anything about small forced circulation monotubes and how they operate.
Of course in the original SES generator there are transition zones. Cool intake-preheat--boiling with phase change from water to steam-wet steam-drying-superheating. All forced circulation monotubes work that way. The Lamont uses that drum for separation, then takes the steam off the top and runs it through the buried superheater.
Jim
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Re: Lamont boiler May 06, 2015 05:08PM |
Registered: 19 years ago Posts: 1,519 |
Jim I cant find any fault with your comment. I also think a Lamont boiler would work well with a solid fuel burner because it has reserve capacity.
If I wasn't so heavily invested in a flash steam engine (where the working cylinder is the boiler) I would use the Lamont boiler. Im just not sure what expander I would use (most likely a uniflow).
The steam drum on a Lamont would be of a larger diameter at the top and use the heat exchangers zone be of a smaller diameter. to give additional reserve capacity. So the drum would look like a "T". Also the circulation pumps would be no problem for my selection.
I don't think it would be a bad design, but I would not use the design until after my work with flash steam is complete.
Jeremy
If I wasn't so heavily invested in a flash steam engine (where the working cylinder is the boiler) I would use the Lamont boiler. Im just not sure what expander I would use (most likely a uniflow).
The steam drum on a Lamont would be of a larger diameter at the top and use the heat exchangers zone be of a smaller diameter. to give additional reserve capacity. So the drum would look like a "T". Also the circulation pumps would be no problem for my selection.
I don't think it would be a bad design, but I would not use the design until after my work with flash steam is complete.
Jeremy
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Re: Lamont boiler May 06, 2015 05:47PM |
Registered: 15 years ago Posts: 641 |
Hello everyone:
Having a recent experience with a Lamont-style steam generator I feel that I can contribute an opinion (whether right or wrong):
My effort used a high aspect ratio separation tower which provided the usual hotwell for the saturated steam/hot feedwater. More importantly it utilized a substantially taller upper section which included gravity separation as well as deviation fins to promote the maximum separation of water from the steam.
The result is, I was able to throttle the full output from this generator to atmospheric with zero water inclusion. I continue to believe that the Lamont-style of boiler is the best choice for enthusiast projects.
Best to All,
B.
Edited 2 time(s). Last edit at 05/06/2015 05:51PM by Bill Hinote.
Having a recent experience with a Lamont-style steam generator I feel that I can contribute an opinion (whether right or wrong):
My effort used a high aspect ratio separation tower which provided the usual hotwell for the saturated steam/hot feedwater. More importantly it utilized a substantially taller upper section which included gravity separation as well as deviation fins to promote the maximum separation of water from the steam.
The result is, I was able to throttle the full output from this generator to atmospheric with zero water inclusion. I continue to believe that the Lamont-style of boiler is the best choice for enthusiast projects.
Best to All,
B.
Edited 2 time(s). Last edit at 05/06/2015 05:51PM by Bill Hinote.
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Re: Lamont boiler May 30, 2015 10:06AM |
Registered: 11 years ago Posts: 202 |
I've been going back through the Lamont threads and would like more information on the International Harvester jet pump recirculation boiler design. I don't understand how recirculation is maintained with variable feed water flow. There must be a bypass scheme. A quote on a similar Lamont design:
"I think I finally have the final objection overcome in my forced recirc boiler scheme. The feed pump still uses the compressibility difference between steam or water at the desired level in the drum to either start or stop the flow of feed water to the boiler through a jet recirculation pump. The new pump modification recirculates water from the drum through the jet pump when the water level is high although not adding new feed water. This means there is flow through the jet pump 100 percent of the time.
The jet pump nozzle has also been modified to incorporate a spring loaded needle valve. The valve is forced closed by a combination of spring pressure and boiler drum pressure, although there is a minimum clearance to prevent total closure. The feed will start to open the needle valve when the pressure reaches the setpoint above the steam drum pressure, probably somewhere in the neighborhood of 150-200 psi. This regulated needle valve will maintain a reasonably steady pressure drop across the nozzle even as flow rate changes with the engine driven pump speeds; guaranteeing a reasonbly high level of efficiency.
None of this requires much additional hardware but is a matter of more fully integrating the system components.
The biggest issue at this point is regulation of the blower for the burner. I'm considering a variable ratio sheave with the output speed controlled by the boiler drum pressure rather than the usual centrifugal weights. Below setpoint pressure the sheave will have the highest step-up ratio and as the setpoint is reached the belt drive will progressively slow the fan down. Not that I am against electric motors, but I'd rather restrict their use to startup as much as possible and use mechanical systems for normal operation. This way, in case of an electrical failure I could have provisions for manual startup (OK, it's sweaty work but that just makes my doctor happy) and then proceed normally until electrical repairs can be made.
Sigh, time to start working on feed pump patterns to go with the engine patterns."
Has this scheme been built? Are more details available?
Lohring Miller
"I think I finally have the final objection overcome in my forced recirc boiler scheme. The feed pump still uses the compressibility difference between steam or water at the desired level in the drum to either start or stop the flow of feed water to the boiler through a jet recirculation pump. The new pump modification recirculates water from the drum through the jet pump when the water level is high although not adding new feed water. This means there is flow through the jet pump 100 percent of the time.
The jet pump nozzle has also been modified to incorporate a spring loaded needle valve. The valve is forced closed by a combination of spring pressure and boiler drum pressure, although there is a minimum clearance to prevent total closure. The feed will start to open the needle valve when the pressure reaches the setpoint above the steam drum pressure, probably somewhere in the neighborhood of 150-200 psi. This regulated needle valve will maintain a reasonably steady pressure drop across the nozzle even as flow rate changes with the engine driven pump speeds; guaranteeing a reasonbly high level of efficiency.
None of this requires much additional hardware but is a matter of more fully integrating the system components.
The biggest issue at this point is regulation of the blower for the burner. I'm considering a variable ratio sheave with the output speed controlled by the boiler drum pressure rather than the usual centrifugal weights. Below setpoint pressure the sheave will have the highest step-up ratio and as the setpoint is reached the belt drive will progressively slow the fan down. Not that I am against electric motors, but I'd rather restrict their use to startup as much as possible and use mechanical systems for normal operation. This way, in case of an electrical failure I could have provisions for manual startup (OK, it's sweaty work but that just makes my doctor happy) and then proceed normally until electrical repairs can be made.
Sigh, time to start working on feed pump patterns to go with the engine patterns."
Has this scheme been built? Are more details available?
Lohring Miller
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Re: Lamont boiler May 31, 2015 11:07PM |
Registered: 15 years ago Posts: 488 |
Hi Lohring,
Centrifugal blowers are very naturally regulated with louvers or baffles. Shut off completely and they draw almost no current. Big airflow, big current. Not sure of your design parameters and turndown targets, but I had to log in on phone. Don't let that one give too much grief. Keith
Centrifugal blowers are very naturally regulated with louvers or baffles. Shut off completely and they draw almost no current. Big airflow, big current. Not sure of your design parameters and turndown targets, but I had to log in on phone. Don't let that one give too much grief. Keith
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Re: Lamont boiler June 01, 2015 10:11AM |
Registered: 11 years ago Posts: 202 |
I think you misunderstood. The quote was from someone working on a jet pump for the circulation in the boiler patent below. It was patented by Charles French. I don't understand how you can get enough recirculation with variable flow from the feed pump. I was also very interested if the person I quoted had actually built a Lamont with a jet pump.
Lohring Miller
Lohring Miller
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Re: Lamont boiler June 01, 2015 11:21AM |
Registered: 15 years ago Posts: 641 |
Lohring:
The answer lies in the fact that there is a separate circulation pump in addition to the FW pump. The circ pump is fed water from the bottom of the separation tower and typically runs at a fixed speed. When designed properly to the desired flow rate an electrically driven unit consumes surprisingly little power.
The FW pump circuit is typically switched on/off by a water level sensor placed in the separation tower immediately adjacent to the outflow from the Lamont coil. One possible further refinement would be a backup water level sensor placed somewhat lower which would shut the burner off in the case of reduced or disrupted FW flow (a common scenario when a vehicle is driven slowly for exetended periods).
Hope this helps.
B.
The answer lies in the fact that there is a separate circulation pump in addition to the FW pump. The circ pump is fed water from the bottom of the separation tower and typically runs at a fixed speed. When designed properly to the desired flow rate an electrically driven unit consumes surprisingly little power.
The FW pump circuit is typically switched on/off by a water level sensor placed in the separation tower immediately adjacent to the outflow from the Lamont coil. One possible further refinement would be a backup water level sensor placed somewhat lower which would shut the burner off in the case of reduced or disrupted FW flow (a common scenario when a vehicle is driven slowly for exetended periods).
Hope this helps.
B.
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Re: Lamont boiler June 01, 2015 03:13PM |
Registered: 19 years ago Posts: 238 |
Hi Lohring
The patent you quote has some details for the performance of this generator in use with a 25hp engine which I think relates to the International Harvester tractor as detailed in US1685279. There are pictures on the web of 3 different prototypes of the tractor but have no idea how well it worked.
Brian
The patent you quote has some details for the performance of this generator in use with a 25hp engine which I think relates to the International Harvester tractor as detailed in US1685279. There are pictures on the web of 3 different prototypes of the tractor but have no idea how well it worked.
Brian
|
Re: Lamont boiler June 02, 2015 08:14AM |
Registered: 11 years ago Posts: 202 |
Bill Hinote Wrote:
-------------------------------------------------------
> Lohring:
>
> The answer lies in the fact that there is a
> separate circulation pump in addition to the FW
> pump. The circ pump is fed water from the bottom
> of the separation tower and typically runs at a
> fixed speed. When designed properly to the
> desired flow rate an electrically driven unit
> consumes surprisingly little power.
>
> The FW pump circuit is typically switched on/off
> by a water level sensor placed in the separation
> tower immediately adjacent to the outflow from the
> Lamont coil. One possible further refinement
> would be a backup water level sensor placed
> somewhat lower which would shut the burner off in
> the case of reduced or disrupted FW flow (a common
> scenario when a vehicle is driven slowly for
> exetended periods).
>
> Hope this helps.
>
> B.
I don't see any seperate pump in the drawings or a mention of it in the patent text. Water from the feed pump flows through the economiser and evaporating coils into the jet pump. The pump circulates water from the tank thriugh tubes around the combustion chamber. This pattern is a little different from the standard Lamont, but the use of the jet pump is what interests me. If this scheme works, it would solve a lot of the issues with the recirculating pump. I couldn't find any more information on the international harvester tractor the boiler was used in.
Lohring Miller
Lohring Miller
-------------------------------------------------------
> Lohring:
>
> The answer lies in the fact that there is a
> separate circulation pump in addition to the FW
> pump. The circ pump is fed water from the bottom
> of the separation tower and typically runs at a
> fixed speed. When designed properly to the
> desired flow rate an electrically driven unit
> consumes surprisingly little power.
>
> The FW pump circuit is typically switched on/off
> by a water level sensor placed in the separation
> tower immediately adjacent to the outflow from the
> Lamont coil. One possible further refinement
> would be a backup water level sensor placed
> somewhat lower which would shut the burner off in
> the case of reduced or disrupted FW flow (a common
> scenario when a vehicle is driven slowly for
> exetended periods).
>
> Hope this helps.
>
> B.
I don't see any seperate pump in the drawings or a mention of it in the patent text. Water from the feed pump flows through the economiser and evaporating coils into the jet pump. The pump circulates water from the tank thriugh tubes around the combustion chamber. This pattern is a little different from the standard Lamont, but the use of the jet pump is what interests me. If this scheme works, it would solve a lot of the issues with the recirculating pump. I couldn't find any more information on the international harvester tractor the boiler was used in.
Lohring Miller
Lohring Miller
|
Re: Lamont boiler June 02, 2015 09:40AM |
Registered: 19 years ago Posts: 1,771 |
The C.A. French concept is interesting in theory. We discussed this back in 2007; I think it was Ken whom first posted the patent drawings.
The problem with it is the injector working with the hot boiler water. If you’ve ever used one you would know they have a hard time starting if ever on hot water. They like sucking cold water. And they’re temperamental at best. The other thing is I have never seen one work above 300 PSI.
I have used them on all my marine boilers for feed water. They don’t always pick up the first time.
Rolly
The problem with it is the injector working with the hot boiler water. If you’ve ever used one you would know they have a hard time starting if ever on hot water. They like sucking cold water. And they’re temperamental at best. The other thing is I have never seen one work above 300 PSI.
I have used them on all my marine boilers for feed water. They don’t always pick up the first time.
Rolly
|
Re: Lamont boiler June 02, 2015 11:13AM |
Registered: 19 years ago Posts: 238 |
Patent US1731458 A ihas a feed pump with free piston and ejector working together. There are other patents showing just a circulating pump.
Being from an agricultural back ground the tractor is of interest to me and it is surprising the resources International must have invested in the prototypes before scrapping the project.
Brian
Found on the net an article copied from December 1927 issue of Railway Mechanical Engineer showing the IH Locomotor with drawings of the 8cyl uni flow engine and 300hp steam generator. The generator drawing shows an injector assisting circulation. Funny how the patent terminology is ejector and in this drawing it is injector.
Hope this answers the question about wether any working systems were built.
Edited 1 time(s). Last edit at 06/02/2015 12:11PM by Brian McMorran.
Being from an agricultural back ground the tractor is of interest to me and it is surprising the resources International must have invested in the prototypes before scrapping the project.
Brian
Found on the net an article copied from December 1927 issue of Railway Mechanical Engineer showing the IH Locomotor with drawings of the 8cyl uni flow engine and 300hp steam generator. The generator drawing shows an injector assisting circulation. Funny how the patent terminology is ejector and in this drawing it is injector.
Hope this answers the question about wether any working systems were built.
Edited 1 time(s). Last edit at 06/02/2015 12:11PM by Brian McMorran.
|
Re: Lamont boiler June 02, 2015 12:29PM |
Registered: 19 years ago Posts: 1,771 |
Brian
I don’t see and ejector, and the text only describe a feed pump.
The power plant just described is of the
closed type, in which a relatively fixed quantity
of water is being continuously circulated,
only enough "make-up" water being added
from time to time to replace unavoidable
losses. The water is supplied to the boiler
by the feed pump 22 which is driven at
constant speed from the auxiliary engine and
is of sufficient capacity, to take care of the
maximum, load on the boiler.
Rolly
I don’t see and ejector, and the text only describe a feed pump.
The power plant just described is of the
closed type, in which a relatively fixed quantity
of water is being continuously circulated,
only enough "make-up" water being added
from time to time to replace unavoidable
losses. The water is supplied to the boiler
by the feed pump 22 which is driven at
constant speed from the auxiliary engine and
is of sufficient capacity, to take care of the
maximum, load on the boiler.
Rolly
|
Re: Lamont boiler June 02, 2015 01:46PM |
Registered: 19 years ago Posts: 238 |
Hi Rolly
Item 35 on the drawing you posted. Quote from patent; "Hot water from the preheater enters` the outer evaporator. coil through an ejector 35 where it picks up additional Water from the storage drum 38"
"An auxiliary circulating pump 41 is operated by shock from the feed pump 22 and is connected in. the pipe 40 to assist in the circulation through the evaporator. A free piston or plunger 42 in this pump is moved in lone direction or on its discharge stroke by shock from the feed pump with-the delivery side of which it is in direct communication.v The plunger is-moved in the opposite direction or `on its intake stroke by a spring f3 during the interval that the pump 22 is making its intake stroke. It will be understood that the pump 41 and ejector 35 mutually cooperate to produce the same result and that either may be used without the other in many instances."
Also here is the drawing from the railcar article with the injector indicated.
Brian
Item 35 on the drawing you posted. Quote from patent; "Hot water from the preheater enters` the outer evaporator. coil through an ejector 35 where it picks up additional Water from the storage drum 38"
"An auxiliary circulating pump 41 is operated by shock from the feed pump 22 and is connected in. the pipe 40 to assist in the circulation through the evaporator. A free piston or plunger 42 in this pump is moved in lone direction or on its discharge stroke by shock from the feed pump with-the delivery side of which it is in direct communication.v The plunger is-moved in the opposite direction or `on its intake stroke by a spring f3 during the interval that the pump 22 is making its intake stroke. It will be understood that the pump 41 and ejector 35 mutually cooperate to produce the same result and that either may be used without the other in many instances."
Also here is the drawing from the railcar article with the injector indicated.
Brian
|
Re: Lamont boiler June 02, 2015 02:34PM |
Registered: 19 years ago Posts: 1,771 |
Yes Brian
I stand corrected. Both generators are using an injector to circulate the water through the forced circulation coil. I’m doubtful this would ever work.
The second one is listed as 500 psi.
Both use a piston pump for feed water. The second one uses a centripetal pump shown is circulating water out of the condenser back to the hotwell.
Fun stuff
Rolly
I stand corrected. Both generators are using an injector to circulate the water through the forced circulation coil. I’m doubtful this would ever work.
The second one is listed as 500 psi.
Both use a piston pump for feed water. The second one uses a centripetal pump shown is circulating water out of the condenser back to the hotwell.
Fun stuff
Rolly
|
Re: Lamont boiler June 02, 2015 02:56PM |
Registered: 19 years ago Posts: 238 |
Hi Rolly
Truly fun stuff working out what was real and what were dreams.
Found this little web site
which shows the same circuit in relation to the Coats steam car.
[modernsteampower.wordpress.com]
Brian
Truly fun stuff working out what was real and what were dreams.
Found this little web site
which shows the same circuit in relation to the Coats steam car.
[modernsteampower.wordpress.com]
Brian
|
Re: Lamont boiler June 03, 2015 07:38AM |
Registered: 11 years ago Posts: 202 |
Rolly Wrote:
-------------------------------------------------------
> The C.A. French concept is interesting in theory.
> We discussed this back in 2007; I think it was Ken
> whom first posted the patent drawings.
> The problem with it is the injector working with
> the hot boiler water. If you’ve ever used one
> you would know they have a hard time starting if
> ever on hot water. They like sucking cold water.
> And they’re temperamental at best. The other
> thing is I have never seen one work above 300 PSI.
>
> I have used them on all my marine boilers for feed
> water. They don’t always pick up the first time.
>
> Rolly
I got the feeling from an old discussion that someone was trying to use an injector as the circulating pump in a Lamont boiler. Are there any reports on that effort or others?
Lohring Miller
-------------------------------------------------------
> The C.A. French concept is interesting in theory.
> We discussed this back in 2007; I think it was Ken
> whom first posted the patent drawings.
> The problem with it is the injector working with
> the hot boiler water. If you’ve ever used one
> you would know they have a hard time starting if
> ever on hot water. They like sucking cold water.
> And they’re temperamental at best. The other
> thing is I have never seen one work above 300 PSI.
>
> I have used them on all my marine boilers for feed
> water. They don’t always pick up the first time.
>
> Rolly
I got the feeling from an old discussion that someone was trying to use an injector as the circulating pump in a Lamont boiler. Are there any reports on that effort or others?
Lohring Miller
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