Steam engine lubrication

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Bentwings

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Bore is 14 mm stroke 18 mm double acting I’m picking 1000 rpm or 2000 rpm . I’ll have an air compressor thurs evening 2 gall tank 135 psi available 2.1 cut per min at 90 psi rated.
My proposed super heater is to take boiler steam out of a dome , more stack like in appearance at this point . I can see some condensation being removed as the steam vapor is being heated the super heater will have blow off capability so the moisture can be removed . My thinking. As long as pressure and temp remain high enough there should be only dry steam as long as taken ou high enough . The super heater will be pretty heavy duty . 3/16 wall 4130 is very strong from hydraulic stand point. Most likely I’ll try to maintain about 150 deg F if that is enough the unit will be independent of he main boiler using a check valve to admit boiler steam when pressure drops. At least this is my thought. I can be all wrong here as I’m not steam educated yet. I don’t really like this external idea as it introduces new mechanics and electronics obviously complexities the limitation of electric only is hampering me I believe but. Have no choice. Actually my though is to take relatively dry air from the compressor and heat it adding energy by using the inductance heater . As the heated air is used by the engines the energy gets converted into expanded volume this air would be oiled or treated as real steam since I think it will be essentially dried by the heating process. The kill condensate can be evacuated by blow off with by preset check valve or manually in other words at a certain higher pressure the checknvalv would open and clear any condensate. This would be very hot just as RR BOILERS ARE it would go into a condensate container . The steam world call these economist or condenser I think . That’s my though . Again I may be wet steam here so help me If ossible. Guess the way I see it the fire box is an external superheater. What I’m proposing is just a different way to achieve the heated dry steam . I’m right in the middle of assembling these two engines I just stepped on the #51 drill bit I dropped on the carpet last night so I now have red condensate coming out of my foot I’m installing a special check valve called a bandaide with some owdered sealant.
Dang that hurt .
I want to try and get nearly complete assembly today

byron
sorry I had to go back and read your questions I have the chilertern quad mill engine . It’s actually two twins connected together with a common flywheel . I was going to chang this but I got the flywheel to run true with the lineup rod through all the bearings so the assembly is ok for now I’ll eventually mount them on a tooling plate then the display floor. I want to be able to run various generators snd motors so the particle board is ok for now. I’m making an outer support bearing as one end of the crankshafts s longer so it overhangs some one is offered but it’s for the verticals mount quad system I have a self aligning bearing ready for mounting . This will just give added support to belt or gear drives and take load off the outer main bearing . Each main cap has a hole for an oiler so I’ll make cups for them as none that size are available. Other size I have both steam oil and machine oil in syringes I’ll add the steam displacement oiler when I’m ready for steaming . So fr it’s going together ok it’s just loaded with really small parts m2 rod cap screws m3 for most every thing else . I have two tap and drill sets for these as well as the 1/4 40 TPI ME tap . Die and drill set
 
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Hi Byron. Sorry to be blunt, but You are missing the point. Dry steam is above the condensation temperature for the pressure....
Wet steam is AT the condesation temperature for the pressure. So the moment the wet steam expands, say down a feed pipe, into a valve chamber, down an internal pipe or into a cylinder, then the pressure drops (even a tiny amount) and water vapour naturally forms. This is so the released latent heat of vaporisation can provide the work to move the gas along the pipework, etc.
Putting extra heat into the "Wet" steam (superheating), raises the temperature of the steam, and this extra heat means the steam can get through the system before condensation takes place. Most necessary for turbines, but still very advantageous for reciprocating engines.
K2
 
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Hi Byron, I have just been on the Chiltern website, and spotted their electric boiler. It has a 70 heater, is set to reach 50 psi max., and they say will just steam a single cylinder engine.
Your 4 cylinders need at least 4 times that = 2800W. Can you power that from your 110V supply?
And that is just for free running, not powering a dynamo. So I guess you'll need more wattage in your heaters.
But that is just my first guess.
K2
 
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Hi again Byron, Hope you have stopped the leak from your foot, and it has been thoroughly cleaned and steriolised.... I would not want to hear you have foot rot and need to make a new one in stainless, or some-such!
Back to your engines.
Looks like they are made for 60 psi. MAXIMUM. So do not apply more air pressure than that. You do not want to break anything, bend a con-rod, etc.
Chiltern specify their double burner 5 inch boiler for the twin cylinder vertical engine (same parts as yours) in boats. Therefore I estimate 3 to 4 kW of gas power is being supplied to heat the water, make steam and superheat the steam.
Do you have a boiler design that has that much electrical heating - or twice as much - as you are proposing to take dynamo power, as well as having 4 cylinders to feed with steam? And do you have the electrical supply?
Maybe this will be running in your workshop, not your apartment?
K2
 

Bentwings

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Hi Byron. Sorry to be blunt, but You are missing the point. Dry steam is above the condensation temperature for the pressure....
Wet steam is AT the condesation temperature for the pressure. So the moment the wet steam expands, say down a feed pipe, into a valve chamber, down an internal pipe or into a cylinder, then the pressure drops (even a tiny amount) and water vapour naturally forms. This is so the released latent heat of vaporisation can provide the work to move the gas along the pipework, etc.
Putting extra heat into the "Wet" steam (superheating), raises the temperature of the steam, and this extra heat means the steam can get through the system before condensation takes place. Most necessary for turbines, but still very advantageous for reciprocating engines.
K2
lease don’t worry about offending me I’m looking for information. I’m in a totally new piece of engineering. This is my new hobby. Since I really can’t get around like I’m used to. I YHINK im getting a better picture of what’s happening . Im hoping this external super heat does what i am expecting . Im going to try and get even more powerful heat capability. I have to be careful not to over load my home circuits too. I wish I had 120 easily accessible like a dryer outlet. There are two separate circuits so I YHINK im ok so far. I’ll probably have to unplug my coffee pot or maybe I can channel some radiant heat from all this steam stuff. LOL I understand hat if there is boiling water at standard pressure and 100c or 212F there will be wet steam essentially ally hot moist air or plain H2O gas it isn’t untill the temp and pressure of this gets high enough to cause only invisible steam. In other words if a “ power” port or line to the engines is taken in this area there will be dry steam not hot vapor unless the line gets cooled. I think I saw some where there was a certain max % of water in the steam for it to be considered dry steam . There was a term noted also. So if the elevated temp and pressure steam is vented you will get the invisible real steam and surrounding air i with is relative humidity will condense and become visible white wet steam we see coming off the boiling of of water on the stove. Now this is where I think I’m lacking and needing help under standing .
I just found some steam tables yikes I’ve got lots of catching up to do. I’m having a hard time just asking a question. Obviously super heated steam at some pressure /temp will have a lot of energy. So if my little engines will run 10 minutes on 2 gallons of air in the compressor tank before the pressure gets to some value say 40 psi from starting at115 psi if the super heater tank has 100 cu in at 250 psi , the little engine will be in serious need of lubrication before the SH tank gets to 40 psi due to the massive unit of heat energy how to calculate this will take time and knowledge I don’t have yet. I found a calculator on line that does in seconds if it’s the right one . I want to watch the state of union speach so I’ll sit bak for a few minutes then come back andpost this calculator . Maybe I’m just wet steam. I’d like to test this exercise if I can get everything working I’ll post a couple assembly pictures too .
byron
 

HMEL

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Bore is 14 mm stroke 18 mm double acting I’m picking 1000 rpm or 2000 rpm . I’ll have an air compressor thurs evening 2 gall tank 135 psi available 2.1 cut per min at 90 psi rated.
My proposed super heater is to take boiler steam out of a dome , more stack like in appearance at this point . I can see some condensation being removed as the steam vapor is being heated the super heater will have blow off capability so the moisture can be removed . My thinking. As long as pressure and temp remain high enough there should be only dry steam as long as taken ou high enough . The super heater will be pretty heavy duty . 3/16 wall 4130 is very strong from hydraulic stand point. Most likely I’ll try to maintain about 150 deg F if that is enough the unit will be independent of he main boiler using a check valve to admit boiler steam when pressure drops. At least this is my thought. I can be all wrong here as I’m not steam educated yet. I don’t really like this external idea as it introduces new mechanics and electronics obviously complexities the limitation of electric only is hampering me I believe but. Have no choice. Actually my though is to take relatively dry air from the compressor and heat it adding energy by using the inductance heater . As the heated air is used by the engines the energy gets converted into expanded volume this air would be oiled or treated as real steam since I think it will be essentially dried by the heating process. The kill condensate can be evacuated by blow off with by preset check valve or manually in other words at a certain higher pressure the checknvalv would open and clear any condensate. This would be very hot just as RR BOILERS ARE it would go into a condensate container . The steam world call these economist or condenser I think . That’s my though . Again I may be wet steam here so help me If ossible. Guess the way I see it the fire box is an external superheater. What I’m proposing is just a different way to achieve the heated dry steam . I’m right in the middle of assembling these two engines I just stepped on the #51 drill bit I dropped on the carpet last night so I now have red condensate coming out of my foot I’m installing a special check valve called a bandaide with some owdered sealant.
Dang that hurt .
I want to try and get nearly complete assembly today

byron
I would like to clear up some misconceptions on steam. Steam can be classified as saturated or super-heated. Both property states can exist at the same pressure except super-heated steam has the higher temperature. There are tables which define the temperatures at various pressures. Its not unusual to specify the operational pressure and the degrees of superheat the boiler is designed to produce. Basically anything above the saturation temperature is defined as superheated.

Now wet steam primarily arises in the boilers from condensate and water being entrained in the steam. To remove the water particles cyclone separators are install either on the outside of the boiler or inside the boiler drum to remove as much of the water particles as possible. The discharge of the cyclone or condensate it captures is discharged back to the boiler. Many ways to do this. The design of the cyclones take some care.. But after seeing some of the model boilers being built many do not have cyclones or superheaters.

Its a little hard to maintain saturated steam in a system but not impossible. If its critical to have dry steam the steam is passed through a superheater. There are marine systems which have separately fired superheaters. So your idea of an induction heater is workable and an interesting idea. What I suggest you do is run the steam tubing down the center of your induction coil and the walls of the tubing will stay hot. Kind of the same process as heating a bearing to install on a shaft except the boiler tube is now the part being heated with a magnetic flux. To keep it hot you might wrap the assembly with high temp insulation say something like rock wool. You could most likely hold a specified temperature very easily.

I do hope that foot of yours heals. Its not something to ignore. Take care
HMEL
 
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HMEL you have an explanation I understand, and sounds correct. But maybe you can clarify a point, as I may be a bit off-beam?
I am not a professional Steam expert, nor trained, just use my Physics and Engineering experience to "work it out".
In my understanding, any steam that carries some water vapour is considered "wet". So when the steam collected from a steam dome (even if "no" droplets of water are carried over) is expanded into a feed pipe, it can only have the entropy of the temperature of the water in the boiler and latent heat (entropy) of the conversion to steam. So any heat loss, e.g. through the lagging of the pipework, or pressure drop (even if only a fraction of a psi) must come from the total entropy, which means some steam will lose the latent heat to form vapour (aerosol droplets of water). I.E. "Wet" steam.
IMHO, therefore, I understand that any un-superheated steam is "wet". Even after water droplets from the boiler are eliminated. The only way to dry the steam is to increase the enthalpy by adding heat to the steam - away from the boiling water. This increase in temperature also causes an increase of pressure, but as it happens, we never worry about the increased pressure from the superheater. We do not add safety valves post superheater.
Is this correct? (It seems an anomaly to me).
Ta,
K2
 
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Hi Byron,
I keep reading your posts and wonder if we are on the same page...?
you suggest:
"if my little engines will run 10 minutes on 2 gallons of air in the compressor tank before the pressure gets to some value say 40 psi from starting at115 psi if the super heater tank has 100 cu in at 250 psi" ,
Having looked at the Chiltern Steam website, they run engines on MAX. 60psi SUPERHEATED STEAM. But I GUESS the steam cannot be above 350C... more likely 250C? looking at the boiler they sell for the job.
I am sure (from my basic knowledge of stress, design for money, fatigue, etc.) that their engines will not break immediately at a higher pressure, but the temperatures and pressures you put in your statement are way too high for these little model engines. Simply put: a brass engine should not exceed 200C. Chiltern sell their engines for 60psi max (before superheat, admittedly).
SO don't waste good money hitting the engine with 110psi of anything. And 250psi? that sounds like it will simply make a loud "bang" and "hissing noise" when you open the valve to your engine.
If in doubt (i am guessing a bit in some of the above) please email Chilterns for their max steam pressure, air pressure, temperature for superheat, etc. I am not even going to try calculating anything on what you suggest.
How is the build going? - between periods shovelling snow, stroking pussy, 'n all?
K2
 
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Byron, I changed my mind. (Stupid old interfering git that I am). Does this help you understand a few things?
  • bore 14mm = 0.5512"
  • stroke 18mm = 0.7087"
  • displaced volume of piston: 0.2386 x 0.7087 = 0.169 cu.in.
  • for each revolution of the crank, you'll pump 8 times that volume: so per rev = 1.353 cu.in per rev.
  • at 2000 rpm = 2706cu.in/min. (air or steam)
  • now: at 60psi, the steam (wet) will have:
  • temperature = 307deg.F,
  • total heat /lb. = 1175 BTU
  • and 1 cu.in of water will make 354 cu.in of steam.
  • Needing 2706cu.in/min. = 2706/354 = 7.6cu.in. of water to be boiled every minute, at 307F so it can be converted to steam at 60psi.
  • So this 7.6cu.in/min. of water = 7.6 cu.in./min. x 3.13 = 23.9lbs/.hour.
  • And this will need 23.9 x 1175 BTU of heat. = 28109BTU/hr.
Now to bring this into "useful" numbers for you electric heaters:
  • 3412 BTU/hr = 1kW. so you need 8.2kW if the boiler is perfectly efficient. But it won't be, so guessing you have it very well lagged, are pumping with room temp water to maintain a steady flow, and have all the pipework, engine bodies etc. lagged, the best you can achieve is possibly 80% efficiency?
  • That would mean you need over 10.3kW of electric heaters, and electric supply.
  • But only half of that if 1000rpm will suit your electric load?
Now consider: the steam as condensed.
  • Maybe 1/3rd of the heat will come out into the condenser (maybe 2/3rds? - I AM Guessing!). SO you'll have a condenser taking 7.6lbs of steam and water and need to lose 3.5~7kW of heat: Maybe plumbed into your central heating system will work?
So please have a think about the reality of your project, so you can design the components suitably.
But re-do these calcs with your own numbers first. (especially as I may have hit a wrong button on the calculator!).
Cheers!
K2
 

GWRdriver

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If it hasn't been made clear already, if you aren't going to "steam" (operate on steam) you shouldn't use steam cylinder oil. It won't do its job cold, but a light mineral oil will. For all motion work, and cold running, I've used common ISO60 hydraulic oil and it's ideal - and is widely available in small containers. For steam cylinder oil, I've used Mobile 600W for decades, mostly because it's available locally (however only in 5-gal pails) and it's perfectly satisfactory, as well as are the Shell and Chevron. I would be very wary of any gear oil because those typically contain chemicals or minerals (such as sulphur) which aren't healthy for cylinder walls.

In a perfect world, when cast iron steam cylinders are correctly and adequately lubricated with steam oil, heat, oil, and oxides will eventually coat the cylinder walls with a dark rust-resistant patina. If we steamed every day or so this would be sufficient to prevent rust from forming, but for our usage a condensate purge and squirt of preservative is always a good idea.
 
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Good advice Harry. I have never been "taught" of the best procedures and oils to use, but from my work experience chose the following regime:
  • For all engines on superheated steam (all my boilers) I use a proprietary steam oil.
  • For air running I use compressed air tool lube oil.
  • After steam running I purge with WD40 and then oil with light (5W, 7.5W, or 10W) car petrol engine oil. The additive packages to prevent corrosion and cope with "cold start" conditions are the best of the various special oils. (Because Petrol engines leave the most corrosive end-of-use products that sit until the next engine start and warm-up). This is also my oil of choice for cranks, bearings, gears, slides, etc. for storage and running. 5W viscosity is as thin as light machine oil, with more and better chemical packages in it.
  • 7W lathe oil was always my choice before I checked and realised that petrol engine oil was far superior for cold storage.
  • Don't just look after "iron" engines, as brass is quite corrosive in its own way. The electro potential of the zinc in brass acts as a sacrificial material that dissolves in any moisture, in order to prevent corrosion of any other metal parts - like iron parts. Which is also a real reason to make you drain boilers after use! De-zincification of brass caused one of my water gauges to fall apart after a long period without draining the boiler. A brass part crumbled in my fingers when I spotted it leaking. It was porous and could not hold itself together, never mind take boiler pressure!
Hope that helps?
K2
 
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GWRdriver: I guess, that with high temperature (superheated steam) and thin oil films (on sliding surfaces) the oil develops lacquers, caramels, tars and some degraded oil products that form the same brown greasy film you can get on ovens and cooking utensils. Theses are an imperfect corrosion inhibitor but work (simply) in 2 ways.
  1. The film keeps water off the metal, by surface tension: the high surface energy causes any condensation water droplets to form separated blobs.. keeping some surface dry in the process, and separating the drops.
  2. Electrolytic protection. This works in 2 ways, as the film is a higher resistance so reducing any electro-potential corrosion and also by separating the water droplets so they do not develop conductive paths for electrolytic corrosion.
But as a lacquer, it is imperfect as there are microscopic-holes in the film where corrosion can start/occur.
But thanks for the experience.
This similar "lacquer" from cooking, stops the iron kitchen pans from rusting, until you wash it off! (DON'T cook in copper pans, the dissolved copper in the food will give you Alzheimers desease).
K2
 

Bentwings

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I would like to clear up some misconceptions on steam. Steam can be classified as saturated or super-heated. Both property states can exist at the same pressure except super-heated steam has the higher temperature. There are tables which define the temperatures at various pressures. Its not unusual to specify the operational pressure and the degrees of superheat the boiler is designed to produce. Basically anything above the saturation temperature is defined as superheated.

Now wet steam primarily arises in the boilers from condensate and water being entrained in the steam. To remove the water particles cyclone separators are install either on the outside of the boiler or inside the boiler drum to remove as much of the water particles as possible. The discharge of the cyclone or condensate it captures is discharged back to the boiler. Many ways to do this. The design of the cyclones take some care.. But after seeing some of the model boilers being built many do not have cyclones or superheaters.

Its a little hard to maintain saturated steam in a system but not impossible. If its critical to have dry steam the steam is passed through a superheater. There are marine systems which have separately fired superheaters. So your idea of an induction heater is workable and an interesting idea. What I suggest you do is run the steam tubing down the center of your induction coil and the walls of the tubing will stay hot. Kind of the same process as heating a bearing to install on a shaft except the boiler tube is now the part being heated with a magnetic flux. To keep it hot you might wrap the assembly with high temp insulation say something like rock wool. You could most likely hold a specified temperature very easily.

I do hope that foot of yours heals. Its not something to ignore. Take care
HMEL
thanks for the encouraging words. The “ check valve worked on my foot. I have given thought to the insulation on te external heater I have Lenny of balsa and other wood available as well as automotive exhaust wrap by it self, pretty ugly so I think I’ll add a polished stainless wrap to hold it all in place . There are new induction units coming on line every day. There are a number of build sites too. I look at these to get an understanding of what is in the magic boxes and to see how they operate the external heating coils need cooling water on some I have a compact motorcycle radiator that’s brand new so I’d just need to come up with a pump. I could probably just have one 3D printed as I don’t think the water temp gets very hot . It’s what the coils encircle that gets hot. I ran into an assembly issue yesterday. The connecting rods have inner and outer bearing shells plus a flat strip acting as contact for the rod cap screws. Well the screws are m2 about 5/8” long. My new metric Allen key set apparently is not the greatest quality so the Allen hex key did not fit in the screw head so I had to sand it down just a little then there just is not much space for the rod and insert between crank webs. I used a pair of number drills in the rod holes o hold the inner bearing insert in place while I installed the upper and the bearing plate . Then you have to hold the crank in position. Not easy. I finally poked the pistons in the cylinder blocks and used them as a stand . Complicated my fingers are a lot bigger than the pets so it was a tiring day . I’ll be done today I think once the connecting rods are done I can install the crank assembly in the engine frame. Of course you have to check to make sure things keep turning freely as you assemble parts. Clearances are really tight. I’m impressed at the quality of workmanship of these tiny parts . The instructions say to assemble dry then take it apart and add sealer to the surfaces but I’m going to change that to seal it up first. If it spins over easily I’ll be home free. There are just too many small screws to be taking things spare . If I get a leak I’ll deal with it after the fact.
Untill later.

byron
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solarenergyadventures

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Byron, I changed my mind. (Stupid old interfering git that I am). Does this help you understand a few things?
  • bore 14mm = 0.5512"
  • stroke 18mm = 0.7087"
  • displaced volume of piston: 0.2386 x 0.7087 = 0.169 cu.in.
  • for each revolution of the crank, you'll pump 8 times that volume: so per rev = 1.353 cu.in per rev.
  • at 2000 rpm = 2706cu.in/min. (air or steam)
  • now: at 60psi, the steam (wet) will have:
  • temperature = 307deg.F,
  • total heat /lb. = 1175 BTU
  • and 1 cu.in of water will make 354 cu.in of steam.
  • Needing 2706cu.in/min. = 2706/354 = 7.6cu.in. of water to be boiled every minute, at 307F so it can be converted to steam at 60psi.
  • So this 7.6cu.in/min. of water = 7.6 cu.in./min. x 3.13 = 23.9lbs/.hour.
  • And this will need 23.9 x 1175 BTU of heat. = 28109BTU/hr.
Now to bring this into "useful" numbers for you electric heaters:
  • 3412 BTU/hr = 1kW. so you need 8.2kW if the boiler is perfectly efficient. But it won't be, so guessing you have it very well lagged, are pumping with room temp water to maintain a steady flow, and have all the pipework, engine bodies etc. lagged, the best you can achieve is possibly 80% efficiency?
  • That would mean you need over 10.3kW of electric heaters, and electric supply.
  • But only half of that if 1000rpm will suit your electric load?
Now consider: the steam as condensed.
  • Maybe 1/3rd of the heat will come out into the condenser (maybe 2/3rds? - I AM Guessing!). SO you'll have a condenser taking 7.6lbs of steam and water and need to lose 3.5~7kW of heat: Maybe plumbed into your central heating system will work?
So please have a think about the reality of your project, so you can design the components suitably.
But re-do these calcs with your own numbers first. (especially as I may have hit a wrong button on the calculator!).
Cheers!
K2
Hi Steamchick,
I was following through your calculations, but there was one bit that I didn't understand. In this line:
  • So this 7.6cu.in/min. of water = 7.6 cu.in./min. x 3.13 = 23.9lbs/.hour. Where does the 3.13 come from?
I did it like this: 7.6cu.in/min x .033Lb/cu.in. =.251Lbs of water per minute. .033Lbs/cu.in. is the density of water at 307 deg F @ 60 psig or 75 psia.

Now take the .251Lbs/min x 60min/hour= 15 lbs of water per hour.

Next: 15Lbs/hour x 1175 BTU of heat. =17698 BTU/hour
Then: 17698/3412BTU/hour/kilowatt=5.187 kilowatts.

5187 watts/220 volts=23.5 amps.
This could be run off of a standard 30 amp electric clothes dryer outlet or an electric range outlet.
Like you said earlier, it would be less at a lower RPM.
It would also be significantly lower if the engine ran with say 50% steam cutoff.

I'm still learning this stuff, so please feel free to correct me if I missed something absurdly obvious here.
Cheers!
 

Bentwings

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Hi Steamchick,
I was following through your calculations, but there was one bit that I didn't understand. In this line:
  • So this 7.6cu.in/min. of water = 7.6 cu.in./min. x 3.13 = 23.9lbs/.hour. Where does the 3.13 come from?
I did it like this: 7.6cu.in/min x .033Lb/cu.in. =.251Lbs of water per minute. .033Lbs/cu.in. is the density of water at 307 deg F @ 60 psig or 75 psia.

Now take the .251Lbs/min x 60min/hour= 15 lbs of water per hour.

Next: 15Lbs/hour x 1175 BTU of heat. =17698 BTU/hour
Then: 17698/3412BTU/hour/kilowatt=5.187 kilowatts.

5187 watts/220 volts=23.5 amps.
This could be run off of a standard 30 amp electric clothes dryer outlet or an electric range outlet.
Like you said earlier, it would be less at a lower RPM.
It would also be significantly lower if the engine ran with say 50% steam cutoff.

I'm still learning this stuff, so please feel free to correct me if I missed something absurdly obvious here.
Cheers!
Thank you I’ll review this tonight. I’m thinking I may not have enough heating even with the third immersion heater. But again I’ll go over this again. I have done this myself already but my notes got flooded when kitty knocked a glass of water over on my table . I just got a small book of just steam tables I skimmed over it briefly today but I didn’t apply anything . It nots wet and dry steam and temps pressures and volumes. I was hoping to be almost done with engine assembly but I ran into some snags that just keep reoccurring the piston connecting rod is threaded on both ends with 1 mm difference in length. The instructions say to leave 1 mm of thread showing for the piston retaining nut . That’s not quite the thickness of the nut so it either appears not fully threaded on or on a little too far then there is a rod packing of rolled Teflon tape. Easy enough but either too loose or too tight I got all the pistons connecting rods and slide valve tubes together only to find interference with the packing nut so I had to take the rotating assembly all apart again . The connecting rod screws are m2 so really smart. I use two number drills in the rod holes for guides in assembly but there is not much room . I’m going to have dinner then have another go at it. Then I’ll do some math . My new air compressor might not be enough for a longer run . I don’t need a long continuous run but if it would run 10 min at some given rpm I’d be real happy. I have a portable air tank at the shop that’s had 150 psi in it for long times The table charts have weights for water and volumes at temps and pressures.
Anyway thanks again for the help . I review tonight

byron
 

Bentwings

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Good advice Harry. I have never been "taught" of the best procedures and oils to use, but from my work experience chose the following regime:
  • For all engines on superheated steam (all my boilers) I use a proprietary steam oil.
  • For air running I use compressed air tool lube oil.
  • After steam running I purge with WD40 and then oil with light (5W, 7.5W, or 10W) car petrol engine oil. The additive packages to prevent corrosion and cope with "cold start" conditions are the best of the various special oils. (Because Petrol engines leave the most corrosive end-of-use products that sit until the next engine start and warm-up). This is also my oil of choice for cranks, bearings, gears, slides, etc. for storage and running. 5W viscosity is as thin as light machine oil, with more and better chemical packages in it.
  • 7W lathe oil was always my choice before I checked and realised that petrol engine oil was far superior for cold storage.
  • Don't just look after "iron" engines, as brass is quite corrosive in its own way. The electro potential of the zinc in brass acts as a sacrificial material that dissolves in any moisture, in order to prevent corrosion of any other metal parts - like iron parts. Which is also a real reason to make you drain boilers after use! De-zincification of brass caused one of my water gauges to fall apart after a long period without draining the boiler. A brass part crumbled in my fingers when I spotted it leaking. It was porous and could not hold itself together, never mind take boiler pressure!
Hope that helps?
K2
great and very informative. I’ve been calculating for severa hours and keep getting different numbers, I may be just missing buttons too. I did chat with chilertern some time ago and he told me about the same try not to go to high on steam coorosion. I have 3 magnesium anodes from my boat plus’s two mor screw in zinc anodes from the boat engines all new . They worked excellently on the boat most under water parts were bronze except the drive shafts those had ring anodes changed each year even the bilges had anodes so I never had issues . Like others did . The numbers I originally noted are just pulled out of the air kinds “ what if” I just got a book of steam tables today . I didn’t know there is dry steam and wet steam . Nor under conditions it occurs . My external superheater came up as a way to add energy to the wet vapor from the boiler. I was hoping the super heater would cause the moisture to fall out of the steam from the boiler without a condenser. Just periodically blow the super heater to clear condensate. I just Ickes a number hoping the moisture would drop out as soone as the super heater was vented even slightly looks like just a dream now looking at the charts I see what you are noting. I’m planning on only using enough pressure/volume to maintain some rpm under load I picked 1k and 2k as starting pints maybe needing only 50-75 psi at the engine intakes. I’m not sure how to handle the condensate. Maybe a lubricator with a drain . In other words I’ll use only enough pressure to turn the intended load speed. I can’t imagine running full pressure on these engines. Also I was landing on tool oil when on compressed air. Steam oil only when steaming . I have some of each to start with PMResearxh ha steam oil so I can get it when needed. I’ve also got a reversing and throttle valve that I haven’t put together yet I YHINK I’ll do that first thing in the morning so it’s ready to go when the compressor arrives . Byron
Superheater. I plan on the superheater coils to surround the vessel
I’m hoping I have better luck tomorrow in the assembly . I think I’ve got the questions figured out now maybe I’m sure glad I got the lighted magnifying glass. I got a pencil size driver to day so running screws in should be easier so heat loss will be minimal I think. it will be insulated too .

I can see a lot of experimenting with this thing but that what this is for .
 
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Hi Steamchick,
I was following through your calculations, but there was one bit that I didn't understand. In this line:
  • So this 7.6cu.in/min. of water = 7.6 cu.in./min. x 3.13 = 23.9lbs/.hour. Where does the 3.13 come from?
I did it like this: 7.6cu.in/min x .033Lb/cu.in. =.251Lbs of water per minute. .033Lbs/cu.in. is the density of water at 307 deg F @ 60 psig or 75 psia.

Now take the .251Lbs/min x 60min/hour= 15 lbs of water per hour.

Next: 15Lbs/hour x 1175 BTU of heat. =17698 BTU/hour
Then: 17698/3412BTU/hour/kilowatt=5.187 kilowatts.

5187 watts/220 volts=23.5 amps.
This could be run off of a standard 30 amp electric clothes dryer outlet or an electric range outlet.
Like you said earlier, it would be less at a lower RPM.
It would also be significantly lower if the engine ran with say 50% steam cutoff.

I'm still learning this stuff, so please feel free to correct me if I missed something absurdly obvious here.
Cheers!
You are probably right, I just v grabbed some data from a book to show how to do the calcs... missed the correct units I guess!
Still, 5 kW is still more than most UK. Domestic circuits.... hard-wired cookers excepted.
I don't know what Baron has, 110V, 220V, or 240V.
K2
 

Bentwings

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You are probably right, I just v grabbed some data from a book to show how to do the calcs... missed the correct units I guess!
Still, 5 kW is still more than most UK. Domestic circuits.... hard-wired cookers excepted.
I don't know what Baron has, 110V, 220V, or 240V.
K2
I spent a bunch of time before bed time last night and I just couldn’t get the engine displacement to come out to what I originally noted , well about 3AM I woke up with a start. I grabbed my trusty middle of the night note book. I had made a real dumb simple mistake engine displacement is bore radius squared time stroke time number of cylinders o in this cas double acting so 8 cylinders effectively. I had been using bore square not radius squared . No excuse.
I took the easy way and found an online calculator that automatically calculates in imperial even with metric input .
So this gives 1.353 cu in per revolution

s 1k equals 1,353 cu in per minute at some pressure to be determined.
The compressor has 2 gal tank and is rated 2.1cu ft per min at 90 psi. A gal is 231 cu in so it looks like I’d be using just over 1 gallon per min if I ran at 90 psi which is probably too high . If I ran at say 50 psi it looks like I could run quite a long time before the compressor would even kick on then almost indefinitely. Not that I would I didn’t go into the steam tables yet. I want to try and get as much assembled today as I can. I’ll do the throttle valve first. So that’s out of the way. I see that PM Research has some small pressure gages so I think a gage on the engine intake line might not be a bad idea I’ll need something better for the super heater. Ashcroft makes all kinds of gages. Industrial quality and reasonably priced.

backbto the assembly line
Byron
 

Bentwings

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I spent a bunch of time before bed time last night and I just couldn’t get the engine displacement to come out to what I originally noted , well about 3AM I woke up with a start. I grabbed my trusty middle of the night note book. I had made a real dumb simple mistake engine displacement is bore radius squared time stroke time number of cylinders o in this cas double acting so 8 cylinders effectively. I had been using bore square not radius squared . No excuse.
I took the easy way and found an online calculator that automatically calculates in imperial even with metric input .
So this gives 1.353 cu in per revolution

s 1k equals 1,353 cu in per minute at some pressure to be determined.
The compressor has 2 gal tank and is rated 2.1cu ft per min at 90 psi. A gal is 231 cu in so it looks like I’d be using just over 1 gallon per min if I ran at 90 psi which is probably too high . If I ran at say 50 psi it looks like I could run quite a long time before the compressor would even kick on then almost indefinitely. Not that I would I didn’t go into the steam tables yet. I want to try and get as much assembled today as I can. I’ll do the throttle valve first. So that’s out of the way. I see that PM Research has some small pressure gages so I think a gage on the engine intake line might not be a bad idea I’ll need something better for the super heater. Ashcroft makes all kinds of gages. Industrial quality and reasonably priced.

backbto the assembly line
Byron
this spell check is just devastating my posts. I’m goingvto look into disabling it. It seems that no matter how well I proof read it just crests it’s own issues later. I did get the compressor today we had it up and running by 2pm. It still has not kicked on since then it’s got almost 120 psi in the tank. The recovery time is spectacular. It only took a couple minutes when we tested it . It’s so quiet that my kitty doesn’t even startle . My son is goingvto put a hook up hose together for me. Otherwise I just need some 1/4” I’d hose and a couple clamps.
I did make some progress with the engine assembly . There are two different assembly drawings one is the new style engine the other is a different twin cyl engine one way or another I’ll get it . I have the right parts for the twin engines it’s just the assembly drawing makes it confusing. I’m just folding the odd drawing up and putting it away, save for reference .
I got some blue lock tite so parts would not be too hard to service. I’ve used this for years and never had issues. I put just a tiny drop in the piston attaching nut m 3 as is the piston. Well the stuff wicks even better than thin superglue . It stuck the piston on really tight then the m3 nut threads were full of it . I had to run a tap through both to clean them out . Not a big deal but very time consuming . Just getting the tap started was tough not the nut and the piston then I re tapped all m3 holes in the frames as screws were very tight in most I was able to run the tap out with my driver fill but I didn’t think it was a good idea to try and start the tap with the drill . It’s just asking for cross thread or broken tap. My son said he would mak oiler tubes for the main bearing caps this week otherwise I can u my little medical syringes . They work very well . So far the rotating assemblies are moving without issue. I did get the throttle revers control assembled. That’s just a spool valve with a slot in it and in and out ports with fittings o once the air manifold is done I’ll be ready to run on air for now .
By the way thanks for the numbers. I saw some ofvthe demonology you used on the steam tables so I’ll look into that further.
once this machine is running I YHINK the first test will be to run it untill the compressor comes on and check the pressure. From this I think I’ll be able to get a better handle on how much volume and at what pressure I can run at. Then I can get a better idea of how much water I need to boil to maintain operating conditions . Then I have to look at the aluminum base plate so the engines are dead flat and even. I’m goingvto have to remount one engine as it is so the flywheel connection works correctly . I’d really prefer a flex coupling there instead. I just saw a short flex coupling for tight spaces so I’ll Perdue that one too.
Byron
 

Bentwings

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Thanks for clas on how steam works I’ll save this and apply as I go.
one thing I question is engine displacement. I was told not to forget the piston length or thickness. I don’t understand this. The piston goes up and down each stroke so the volume displaced is just the volume changed above the piston in hydraulics we consider the ro diameter both volume and area but for this the rod is pretty small 2 mm I’ll measure the piston thickness and hav it handy later .
So here is the formula we use in auto world
1/2 bore squared times stroke times number of cylinders

boe is 14 mm
Stroke is 18 mm
Number of cylinders I’d four , but it’s double acting so essentially eight strokes .
I found an online calculator that does all the conversion from metric to imperial automatically

Doing this . Total displacement is 1.353 cu in
22.167cc
0.022 liter
From here we can multiply by rpm to get cu in per minute or length of time.
I’ll have a pressure gage on the intake line so I cn monitor pressure the engine is getting at what ever speed it is running

if I load the engine I’ll be able to monitor pressure required per load value , torque for example or generator toe volts amps output . Since pressure gages are pretty inexpensive I could monitor exhaust pressure too since I could connect a turbine to the exhaust . Temp is more difficult but the trusty infrared gun is quick . I have an immisitivity table too for various materials pipes can be made from.
as you can see this is rapidly becoming a complicated science project.
being retired and essentially immobile I have plenty of time on my hands. My TV HAS NOT BEEN ON FOR MONTS EXCEPT WHEN KITTY STEPS ON CONTROLLER

so now I’m going to try and get into translation of the neat facts presented in the first part of the questions that were asked of me . I’ll be on loose rocks here as I’ll be out of my education level. But I’m not opposed to learning .
Byron
 
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