It amazes me that after all of your videos showing your experience and skill that people still try and tell you that you are doing it wrong. Thank you again for sharing these with us.
I'm in the motor trade. We were taught in collage that the cooling system is pressurized as for every 1psi in pressure boiling point increases by 1 degree centigrade so i agree with what you said. Beautiful engine. Poetry in motion
Keith, as someone with a peripheral academic interest in steam locomotion (both my grandfathers were LNER Drivers) you've just clarified for me the use of the water pump whilst the engine is in play. In fact more is making sense to me surrounding model steam engines just by watching this one video. Thank you. 👍🚂
My late father built static steam engines like these and had a similar boiler, which he also built. He explained all this to me, but at the time I didn’t fully understand it. Thank you so much for such a superb video. I shall now watch some more!
What I love about your videos is the knowledge you impart to the general populace regarding basics of physics that tend to be taken for granted. Models indeed.
Not only first but that was my link to the Pressure/Temperature chart in the description. This phenomena is also why pressure cookers are so popular in the western US. Up in the mountains, as the air pressure drops, the boiling point of water also drops and can really extend cooking times.
H Keith as always very well explained and to my understanding absolutely spot on. By the way to the goon who thinks you are wrong about the boiling point of water rising in temperature as the pressure increases I would sight a living example of this in every day life. The radiator cap on any car has a built in pressure release valve and over flow pipe, some cars have this going to atmosphere but most go to the header tank. (most cars have a release pressure of around 6 PSI) this is to stop the water boiling in the system by using pressure to raise the boiling point of the engine coolant thus preventing the coolant from boiling. as a consequence most cars will not boil util the water temperature is well over 110 degrees c.
Learned in science lessons at school many, many years ago that the boiling point of water rises as the pressure rises. A very good example of this is the pressurised cooling system on motor vehicles with “infernal” combustion engines. Having said that I must say I attended a very good school. The school was approved so it must have been good. Thank you for sharing your knowledge.
this is the first time I fully new what you was talking about as I have worked on supper heated steam line (fitting and welding the pipes) so I know about the relationship between steam and pressure. the rest of the video was new to me :)
Please note that steam is very dangerous due to to the amount of heat that is contained in it. (as opposed to just the temperature) A BTU (British Thermal Unit) is the amount of heat needed to raise 1 pound (pint) of water 1 degree F. So it takes 180 BTU to heat a pint from Ice water @32F to boiling water @212F. Amazingly it then takes 960 BTU to convert that pint of water @212F to steam @ 212F. If steam hits you then it condenses back into water and all that energy goes into your flesh.
Quite! Boiler bursts are almost invariably catastrophic and a high pressure steam leak in the wrong place can produce life changing injury. I think steam should be used only where absolutely necessary.
The Stuart 504 boiler and the 5A are both very nice to work with, when operated with compatible equipment. If you want to put both together, you'll need a pair of 504 boilers.
I have built steam engines for over 50 years. ALL my model engines run on compressed air, completely dodging all the lubrication bullets. I use live steam ONLY on turbines, which drive transmissions, driving electric generators. As governments fail, I see a resurgence of steam power, especially off grid. I "could" live off grid, but at 76 years old, I enjoy being grid tied. I use a tracking concentrating solar retort to make charcoal, which I use in my steam boiler (fire-tube).
Thanks for the video. I'm looking at making a 1:49 scale USS Iowa and it'll be powered with two to four steam engines of that size. I'm currently designing the diesel fired boiler and might have to increase the size I was originally planning to use
The effect of pressure on BP is basic secondary school science, I know, I taught it for nearly 40 years. 80psi is about 5 atmospheres (about 50,000 pascals), and the bp of pure water at that pressure is about 150deg C.
On a large steam engine for example on a ship the water from the turbine is recovered. There are many reasons for this but one of them is to maintain the energy as much as possible by putting water back into the boiler that is still hot. Typically somewhere around 260c and 90 bar. Not achievable in a hobby setup but it might be possible to keep the supply water up around 95c thus helping the boiler.
Soy aeromodelista y mas alla de no saber tu idioma me apaciona lo que mostras . es muy bonito . mi nombre es flavio y gracias por tus videos . desde argentina
Well presented ( Like all your videos ) thanks Keith , I use Hallett oils on all my steam locos never had any problems on the lubrication side of them , Good stuff
Hello Keith I have recently acquired a Stuart turner HB6 boiler and v-twin steam engine I have no idea how to couple the engine to the boiler as I am new to model steam units can you help ? I would like to put the unit into a steam tug .Thanks.
Hi this was a very interesting video thank you for posting it. I don’t know anything about steam engines but one thing I do know about is gas.propane gas in the red cylinder is far better because it keep a good constant pressure in all weathers. But the gas in the blue cylinder is rubbish in cooler weather.
Great video about boiler vs engine. ISTR some steam locomotives didn't work out very well simply because the fire grate and boiler were too small compared to the engine. While they could develop full power for a short while, they were 'boiler limited' in that as soon as they started working hard, pressure would fall off and they'd slow to a stop. And I'd just add that if a boiler has a superheater, that helps in reducing condensate. Not a substitute for a properly matched boiler, but a sort of side-effect of having a super-heater.
Not only does boiling point rise in proportion to increased pressure, it drops in proportion to decreasing pressure. Water will boil at lower temperatures at the top of high mountains due to lower atmospheric pressure, also your blood will boil instantly at body heat when exposed to the vacuum of space due to the complete absence of atmospheric pressure.
In the situation with the test boiler, you were getting very wet steam or a lot of the steam was condensing before it got to the engine. Steam temperature rises directly as the steam pressure rises, it is not a direct 1 for 1 rise though. Here is a temperature/pressure table from Global Supply Line for saturated water/steam. 1 bar/14.5 psi = 100C/212 F 10 bar/145.04 psi = 179 C/354.2 F
@@keithappleton this question lead me down the rabbit hole I didn't even know TH-cam had. There are people who actually do make classy looking model steam engines, like the one in this video, and also generate DC power off of it to power their homes. I guess I didn't realize this was a thing.
just thought of something (as I live in Finland) dose cold weather effect the efficiency of a steam engine??? here I have seen temps as low as -33C but this year it's been warmer only as low as -20C
Possibly. The efficiency of a steam engine is based on the change in pressure between the input and exhaust. Most full-size steam engines use a condenser that is kept at a vacuum to lower exhaust pressure, significantly improving efficiency. The condenser is maintained at a vacuum primarily by the condensing action of the steam itself: as the steam turns into liquid, its volume reduces dramatically, maintaining vacuum in the condenser. If the condenser is colder, the steam condenses faster, maintaining a better vacuum and therefore higher efficiency. However, most model steam engines either don't use a condenser, or they use a vented condenser without a vacuum. I guess changes in atmospheric pressure would have a small effect on efficiency, but nothing close to the effect of drawing 25inHg of vacuum in your condenser.
That is a very interesting question. According to thermodynamic theory, efficiency is only related the temperature difference, but with a steam engine being mostly uninsulated, it seems that a lot of energy could be lost before being fully utilized.
Yes, it has impact. Firstly, the longer the feed line, the more the steam will cool down before reaching the engine. This steam will not be able to expand as much in the engine as otherwise, causing a lower output. A poorly insulated engine will have the same effect, condensation instead of expansion. In a perfect world, without losses, you can pass on the steam to more cylinders, intermediate- and low pressure cyls, LP turbines, boiler feed water heaters, etc, and this way get a very high plant efficiency.
For the temperature you could add a super heater, basically you just run the steam from the regulator valve through the fire of the coal or gas burner and the water problem should be away.
Thank you for your information. The Stuart 500 range of boilers already have superheater built in, please watch a few more of my 2000 videos for a wealth of information covering the subject of your comment . . . . .
Keith, how do you match the burner size, the capacity of the boiler, and the engine. Im attempting to get into building a steam powered launch and want to make sure that I have a good power plant. A friend of mine purchased a steam powered tugboat that ran out of pressure within 5 minutes. We assumed that the burner was not getting the water hot enough or quickly enough to replace the steam. Any suggestions?
Looking to make a steam engine that can run a pump which circulates water through pipes in a floor as radiant heat. Any suggestions. All off of a wood burning stove. Let me know. Thanks
When you look at the amount of horse power - mouse power that is generated from a model steam engine, you are going to need a big engine to run your pump. The problem then becomes how big a boiler do you need. I think you will have a large enough boiler that it will have to be certified. Try looking for Amish information. They do use some steam driven items. Another way to look at what you need: lets drive a piston off the flywheel driven by the steam piston. That piston with a check valve can be a pump to pump your heating water. What flow in GPM of heated do you want to pump? For starts lets say the engine is running at 50 rpm. What size pump piston will you need to pump the requires GPM? lets go for 5 GPM. 5 gal/min x min/50 gal, => 1/10 gal /rev. 1 gal = 268.8 cu in we need 26.8 cu in /rev. cyl vol = pi x rad squared x l , lets have a 2 inch stroke. rad squared = vol/pi x 2 , => rad = 2.065. So you will need a 4 inch diameter cyl . Now the question is how much force will be needed to push the water through valves and piping. When I was a senior engineer at a power plant I used a Crane Handbook for piping loss. Good Luck
I am shocked - shocked, I say, to hear that the physics of steam applies to model steam engines as well as full-size steam engines. I am going to write a very stern letter to Newton, or Curtiss, or whoever invented physics, and demand a full refund.
It amazes me that after all of your videos showing your experience and skill that people still try and tell you that you are doing it wrong. Thank you again for sharing these with us.
I'm in the motor trade. We were taught in collage that the cooling system is pressurized as for every 1psi in pressure boiling point increases by 1 degree centigrade so i agree with what you said. Beautiful engine. Poetry in motion
Keith, as someone with a peripheral academic interest in steam locomotion (both my grandfathers were LNER Drivers) you've just clarified for me the use of the water pump whilst the engine is in play. In fact more is making sense to me surrounding model steam engines just by watching this one video. Thank you. 👍🚂
My late father built static steam engines like these and had a similar boiler, which he also built. He explained all this to me, but at the time I didn’t fully understand it. Thank you so much for such a superb video. I shall now watch some more!
What I love about your videos is the knowledge you impart to the general populace regarding basics of physics that tend to be taken for granted. Models indeed.
Not only first but that was my link to the Pressure/Temperature chart in the description.
This phenomena is also why pressure cookers are so popular in the western US. Up in the mountains, as the air pressure drops, the boiling point of water also drops and can really extend cooking times.
A really useful video for the tyro steamer like me: your knowledge and advice is very much appreciated.
thank you }:-)))
Sehr gute Arbeit. Danke für all die schönen Videos. DieStuart No 5 läuft sehr gut!
H Keith as always very well explained and to my understanding absolutely spot on. By the way to the goon who thinks you are wrong about the boiling point of water rising in temperature as the pressure increases I would sight a living example of this in every day life. The radiator cap on any car has a built in pressure release valve and over flow pipe, some cars have this going to atmosphere but most go to the header tank. (most cars have a release pressure of around 6 PSI) this is to stop the water boiling in the system by using pressure to raise the boiling point of the engine coolant thus preventing the coolant from boiling. as a consequence most cars will not boil util the water temperature is well over 110 degrees c.
Learned in science lessons at school many, many years ago that the boiling point of water rises as the pressure rises. A very good example of this is the pressurised cooling system on motor vehicles with “infernal” combustion engines. Having said that I must say I attended a very good school. The school was approved so it must have been good. Thank you for sharing your knowledge.
Thank You. That was extremely informative.
Glad you enjoyed it!
this is the first time I fully new what you was talking about as I have worked on supper heated steam line (fitting and welding the pipes) so I know about the relationship between steam and pressure.
the rest of the video was new to me :)
Please note that steam is very dangerous due to to the amount of heat that is contained in it. (as opposed to just the temperature) A BTU (British Thermal Unit) is the amount of heat needed to raise 1 pound (pint) of water 1 degree F. So it takes 180 BTU to heat a pint from Ice water @32F to boiling water @212F. Amazingly it then takes 960 BTU to convert that pint of water @212F to steam @ 212F.
If steam hits you then it condenses back into water and all that energy goes into your flesh.
Quite! Boiler bursts are almost invariably catastrophic and a high pressure steam leak in the wrong place can produce life changing injury. I think steam should be used only where absolutely necessary.
Great work mate 👏
Thank you }:-)))
The Stuart 504 boiler and the 5A are both very nice to work with, when operated with compatible equipment. If you want to put both together, you'll need a pair of 504 boilers.
I have built steam engines for over 50 years. ALL my model engines run on compressed air, completely dodging all the lubrication bullets.
I use live steam ONLY on turbines, which drive transmissions, driving electric generators.
As governments fail, I see a resurgence of steam power, especially off grid. I "could" live off grid, but at 76 years old, I enjoy being grid tied.
I use a tracking concentrating solar retort to make charcoal, which I use in my steam boiler (fire-tube).
Thanks for the video. I'm looking at making a 1:49 scale USS Iowa and it'll be powered with two to four steam engines of that size. I'm currently designing the diesel fired boiler and might have to increase the size I was originally planning to use
The effect of pressure on BP is basic secondary school science, I know, I taught it for nearly 40 years. 80psi is about 5 atmospheres (about 50,000 pascals), and the bp of pure water at that pressure is about 150deg C.
On a large steam engine for example on a ship the water from the turbine is recovered. There are many reasons for this but one of them is to maintain the energy as much as possible by putting water back into the boiler that is still hot. Typically somewhere around 260c and 90 bar. Not achievable in a hobby setup but it might be possible to keep the supply water up around 95c thus helping the boiler.
I've been planning a model steam ship, and one of my design goals is to be able to recover the water and pump it back into the boiler automatically.
This is great information. Thank you.
Glad it was helpful!
Keith another great little educational video. I hope you're doing well and safe over there.
Great explanation, thanks for the demonstration as well.
Soy aeromodelista y mas alla de no saber tu idioma me apaciona lo que mostras . es muy bonito . mi nombre es flavio y gracias por tus videos . desde argentina
Well presented ( Like all your videos ) thanks Keith , I use Hallett oils on all my steam locos never had any problems on the lubrication side of them , Good stuff
Excellent. Thank you. Why dont you add a super heater to your system?
Glad it was helpful }:-)))
Fascinating. I love learning from you. --dunc
Very inormative❤
Glad you liked it }:-)))
Hello Keith I have recently acquired a Stuart turner HB6 boiler and v-twin steam engine I have no idea how to couple the engine to the boiler as I am new to model steam units can you help ? I would like to put the unit into a steam tug .Thanks.
Hello John, I can only offer limited tech support to my Patreon subscribers: www.patreon.com/keithappleton
Is there a formula to a the engines displacement and the boiler size? Like lbs/hr required (engine) and lbs/hr generation (boiler)?
Hi this was a very interesting video thank you for posting it. I don’t know anything about steam engines but one thing I do know about is gas.propane gas in the red cylinder is far better because it keep a good constant pressure in all weathers. But the gas in the blue cylinder is rubbish in cooler weather.
Propane is not popular for Steam Models in this country owing to it's higher pressure.....
Great video about boiler vs engine. ISTR some steam locomotives didn't work out very well simply because the fire grate and boiler were too small compared to the engine. While they could develop full power for a short while, they were 'boiler limited' in that as soon as they started working hard, pressure would fall off and they'd slow to a stop.
And I'd just add that if a boiler has a superheater, that helps in reducing condensate. Not a substitute for a properly matched boiler, but a sort of side-effect of having a super-heater.
Interesting, tutorial movie! Cheers, Fabrizio
Although it might not solve your problem, it might be a good idea to install insulation around the cylinder.
not really worth the effort in small model steam engines, as it is ineffective . . . I have tried it in the past ....
Very Good, Thank You.
Not only does boiling point rise in proportion to increased pressure, it drops in proportion to decreasing pressure. Water will boil at lower temperatures at the top of high mountains due to lower atmospheric pressure, also your blood will boil instantly at body heat when exposed to the vacuum of space due to the complete absence of atmospheric pressure.
In the situation with the test boiler, you were getting very wet steam or a lot of the steam was condensing before it got to the engine. Steam temperature rises directly as the steam pressure rises, it is not a direct 1 for 1 rise though. Here is a temperature/pressure table from Global Supply Line for saturated water/steam. 1 bar/14.5 psi = 100C/212 F 10 bar/145.04 psi = 179 C/354.2 F
Is there an electrical generator that operates from a model sized steam engine like this?
You could use a car Alternator or A Dynamo.
@@keithappleton this question lead me down the rabbit hole I didn't even know TH-cam had. There are people who actually do make classy looking model steam engines, like the one in this video, and also generate DC power off of it to power their homes. I guess I didn't realize this was a thing.
It need apprx. 50cm /20" of a cupperpipe to build a superheater... 😊
www.blackgates.co.uk
thank you
You're welcome.
just thought of something (as I live in Finland) dose cold weather effect the efficiency of a steam engine???
here I have seen temps as low as -33C but this year it's been warmer only as low as -20C
Possibly. The efficiency of a steam engine is based on the change in pressure between the input and exhaust. Most full-size steam engines use a condenser that is kept at a vacuum to lower exhaust pressure, significantly improving efficiency. The condenser is maintained at a vacuum primarily by the condensing action of the steam itself: as the steam turns into liquid, its volume reduces dramatically, maintaining vacuum in the condenser. If the condenser is colder, the steam condenses faster, maintaining a better vacuum and therefore higher efficiency.
However, most model steam engines either don't use a condenser, or they use a vented condenser without a vacuum. I guess changes in atmospheric pressure would have a small effect on efficiency, but nothing close to the effect of drawing 25inHg of vacuum in your condenser.
That is a very interesting question. According to thermodynamic theory, efficiency is only related the temperature difference, but with a steam engine being mostly uninsulated, it seems that a lot of energy could be lost before being fully utilized.
Yes, it has impact. Firstly, the longer the feed line, the more the steam will cool down before reaching the engine. This steam will not be able to expand as much in the engine as otherwise, causing a lower output. A poorly insulated engine will have the same effect, condensation instead of expansion. In a perfect world, without losses, you can pass on the steam to more cylinders, intermediate- and low pressure cyls, LP turbines, boiler feed water heaters, etc, and this way get a very high plant efficiency.
For the temperature you could add a super heater, basically you just run the steam from the regulator valve through the fire of the coal or gas burner and the water problem should be away.
Thank you for your information. The Stuart 500 range of boilers already have superheater built in, please watch a few more of my 2000 videos for a wealth of information covering the subject of your comment . . . . .
@@keithappleton I just found your channel a few days ago I will definitely keep watching 😁
Keith, how do you match the burner size, the capacity of the boiler, and the engine. Im attempting to get into building a steam powered launch and want to make sure that I have a good power plant. A friend of mine purchased a steam powered tugboat that ran out of pressure within 5 minutes. We assumed that the burner was not getting the water hot enough or quickly enough to replace the steam. Any suggestions?
Trial and error, it all depends on the size of the Engine, Boiler and Gas Burner.
Looking to make a steam engine that can run a pump which circulates water through pipes in a floor as radiant heat. Any suggestions. All off of a wood burning stove. Let me know. Thanks
Not really, I generally make model steam engines . . . why not put a water boiler on the stove and circulate the hot water through the pipes?
Using thermosiphon?
When you look at the amount of horse power - mouse power that is generated from a model steam engine, you are going to need a big engine to run your pump. The problem then becomes how big a boiler do you need. I think you will have a large enough boiler that it will have to be certified. Try looking for Amish information. They do use some steam driven items.
Another way to look at what you need: lets drive a piston off the flywheel driven by the steam piston. That piston with a check valve can be a pump to pump your heating water. What flow in GPM of heated do you want to pump? For starts lets say the engine is running at 50 rpm. What size pump piston will you need to pump the requires GPM? lets go for 5 GPM. 5 gal/min x min/50 gal, => 1/10 gal /rev. 1 gal = 268.8 cu in we need 26.8 cu in /rev. cyl vol = pi x rad squared x l , lets have a 2 inch stroke. rad squared = vol/pi x 2 , => rad = 2.065. So you will need a 4 inch diameter cyl . Now the question is how much force will be needed to push the water through valves and piping. When I was a senior engineer at a power plant I used a Crane Handbook for piping loss. Good Luck
so, basically it's a bad idea to try to run a steam engine on a boiler who's diameter is less than the steam engine's cylinder diameter?
❤😊
Finally, wd40 being used for its true and honest purpose. The nasa engineers would be grateful to you.
Water displacer 40
I am shocked - shocked, I say, to hear that the physics of steam applies to model steam engines as well as full-size steam engines. I am going to write a very stern letter to Newton, or Curtiss, or whoever invented physics, and demand a full refund.
not sure why the sarcasm. physics don't always scale, so it's completely non-obvious
What about a 10KW engine driven by solar? Does anyone make 10kw engines?
I make models . . . .
@@keithappleton what's wrong with using small steam engines? why don't people use them? I saw someone in India was manufacturing them maybe.
⭐️😊👍
And there was me thinking it's was 1 gramme of water for the last 80 years.......
No use of your “special stuff” mix this time?