Force circulation steam generator design

A few thoughts on this general subject:

One of the principal points of the Lamont boiler (as opposed to other forced-circulation approaches) is that it combines effective heat transfer to water, in the coils, with effective steam separation from the very high mass flow of water.

One point of high forced circulation speed is to 'scrub' any steam film effectively from the inner tube lumen at appropriate high firing rate. A proper centrifugal separator can effectively strip high mass flow of steam from the recirculating water, with the steam going up and the water going down; this is also an effective way to deal with foaming or priming with treated feedwater.

In my opinion a design like this requires a separately-fired superheater (rather than, say, relying on high saturation pressure to produce effective superheat at lower throttle pressure). I believe this was also characteristic of Lamont marine design. The enginion AG "ZEE" engine featured this approach in the much smaller form factor afforded by an ultrasupercritical design.

Also in my opinion the problems involved with varying mass flow in once-through steaming monotubes are difficult, if not practically insoluble, in applications requiring high effective mass flow. In part this involves effective heat transfer for superheat between the combustion-gas plume pattern (via a tube that may have relatively poor heat-transfer characteristics) to increasingly superheated steam that is a fairly good insulator against heat transfer. If you try to get the combined heat transfer and mass flow from a monotube that a good Lamont-style 4x-6x circulation rate setup will produce, you're likely to start getting the kind of differential heat problems the British land-speed record car suffered; that's not a prescription for the kind of longevity expected from a practical road-car steam generator.

Hi Overmod,

It sounds like you are trying to achieve a super critical (SC) boiler. I state this because of some imagine engineering to get to a super critical state with a separate super heater. This is why I might go with a separate fired super heater. Otherwise, I would just use the heat source from the basic boiler.

What I think is needed to get to SC steam is the same feed pump and generating tubes, except on steroids. So here is the scenario, impose a pump to the first stage boiler to the super critical heater. Note that you want to pump the water inside the boiler. First stage boiler for lack of knowing what to call it, is the common boiler that we build for steam automobiles today. This could be an Ofeldt, Stanley or Derr. Think about say 600 PSI - 600 Deg F steam and taking it up to near 3,000 PSI and 800 Deg F.

Back in my days with Teledyne CAE and working in the altitude test cell, the compressors did exactly that. They used the exhaust from your standard compressor (~120 PSI) and pumped it up to nearly 1,000 PSI. This is the Gas Turbine starting pressure required in certain conditions in the altitude test cell. The size of the standard compressor is decent. The HP compressor is half the size and twice to three times the weight. Hope you get the picture from this description.

I often contemplate getting to a SC boiler because of the added complexity. Is it worth it?

Can we achieve a the Land Speed Record for instance with a sub critical boiler? Can we achieve an aircraft engine? Can we achieve one of my dreams is to have a high temperature electrolysis (HTE) source feed into the burner for stellar efficiency.

Any ways...your thoughts?

To all, I'm sorry I haven't posted in a while. My wife and I have made an offer on a house that has a 50 X 90 pole barn. This will get me back into the building mode. Please, all, wish me luck to get this new house?

Kind regards,
Rick

Honestly, I have some real issues with the idea of supercritical steam in small powerplants...despite some enthusiasm thrown that way. It's going to be difficult to operate a reciprocating expander on supercritical steam. An engine designed to run with reasonable efficiency at 1,000 psi needs a cutoff that is much shorter than those found in IC engines --- meaning the inlet valve event is going to be quite brief. Given that there are practical limits on cam acceleration, the lift gets progressively smaller and the chances of wiredrawing increase, thereby cancelling out advantages of running supercritical pressures. It also gets more difficult to develop a cam geometry that will operate with minimum jerk under these conditions.

Turbines are much better suited for use with supercritical steam but they aren't necessarily a wonderful fit in an automobile. Again, despite some enthusiasm found among SACA members, it has to be remembered that turbines have a relatively narrow efficient operating speed band --- much narrower than any reciprocating engine. Stop and go traffic is going to be a killer. Probably the best way to utilize a turbine would be with some sort of electric drive setup --- a turbo-electric drive. This is certainly not a new idea, being found in US battleships and early aircraft carriers in the late WW1 era into the 1920s. Whether or nt you would want to add this much complexity and development effort to a steam plant is questionable.

My suspicion is that this is the sort of application where the laws of diminishing returns eventually bite you in the rear.

Regards,

Ken

BoilerGeneralArrangementreduced.tif

Thanks Ken for your input.

Again my apologies for not posting for a while. I would like to continue showing some plans for a new land speed record boiler. We'll start with the calculator attached where I have taken some steps to generate enough BTU's needed for the record. Some discussions between Tim and myself reveal that the required value is 5M BTU in the steam. To put this figure in perspective, it is like the movie Back to the Future where Doc says "What 1.21 Gigawatts, where can you get that kind of power?"

BoilerGeneralArrangement2reduced.tif

Anyways, Ken, I attached the excel file for you to look at. I know you like to play with these things. Also, out of all the boilers or better said steam generators, I propose a unique configuration. When I say all the generator designs such as the fire tube, mono-tube, tube w/natural circulation, lamont and jet style forced circulation with separator drum. I propose a mono-tube to a separator drum. The separator drum will have natural circulation tubes. The ratio of mono tube to natural tubes will be 60 / 40. Lets say the generator is 100 feet of tubing. 60 feet will be mono-tube and 40 feet is natural circulation tubes.

I would like to call the mono-tube to a drum the Gryzyb Coil after Tony. Gerry H. is the naming person for this coil because of the use in his Steam Bus. Also, I would like to start using the terminology of a separator tube, same function with a different spin.

Note that we can't get to the BTU goal with just a generator. The use of feed water heater, economizer, generator and super heater will be required. I have attached some preliminary concepts with dimension to fit into a LSR car.

I also attached a LSR concept car that I created a long time ago. Just a thought. SteamlinerUSALSRreduced.bmp

Please don't hesitate to ask questions.

More to come...

Kind regards,
Rick

To All,

I stated above the 60 - 40 ratio, well that is the ratio I started with. After playing with my excel model, I came up with the final ratio of 3 to 1, Mono-Tube to Natural Recirculating Tube respectfully. This is the ratio I would build a prototype to validate the design. Turns out that one can get the most generation per foot with a high water mass flow in a coil. However, natural circulation coils are needed to again steam the water in the separator tube (was called separator drum).

So in operation, the feed pump or flow of the water to the separator tube needs to be higher than what the steam rate allows. Reason is you want separation when it goes into the larger volume separator tube. Hc of water is far favorable to steam. Then the water that is separated will naturally circulate in the tubes to finish of the steaming process. I would call this a Once-through Generator design. Yes, I would say that water through mono-tube and then with separated water through natural circulating coil equates to a once-through generator. Also, I would like to refer the natural circ coils as Ofeldt Coils. My intent is to use the same style coil that is in my Ofeldt Boiler for my Gentleman Speedy Roadster (currently in build).

So Dr Brown, we still don't meet the 1.21 Gigawatts needed. Tony has often told me that you can only get an engine to perform with what the boiler has to give. You can only get out of boiler what you get from the burner. The key is to improve the burner. My suggestion is to go to stages of infrared (IR). I got my eye on Scott who has demonstrated some interesting concepts to produce IR.

Two concepts that I'm currently working on, 1) is to put a ceramic IR tube in the middle of the Ofeldt coil for maximum heat to circulation coils and 2) is to have a can that a high flow pressure burner going into and out of that will emit IR. We will still use the convection, counter flow to the water feed in the Grzyb Coil.

So tonight, I'll attach some sketches to show some what of which I'm talking about.

Cheers,
Rick

Ken
As I do some real issues.
Supercritical steam 3,208 psi 705 F
The best steam cylinder oil will not hold up at that temperature.
I have read that PTFE will work up to a temperature of 2500 F in an oxygen free environment??? How it would hold up as a piston rings is unknown.
Turbine is the only way to go. There are a lot of small turbines around if installed in a housing designed for that pressure might work. I use to have two a 9” and a 16” The housings were only rated 250 PSI. Then you would need a good gear box to get the RPM you want.
Rolly

Attached is what I would build to prove out the calculations in the previously attached message. This is a scale-able design and would increase the coils proportionally with another Ofeldt-IR burner nest and make the Gryzyb Coil oval.

The design posted recently will incorporate this tube fill concept. This has been posted before. Posted again to keep the thread uniform.The calculations incorporate this concept as stated when specified as Fill.

What really is important is less is more.

Hi Rick,

Sorry for not replying earlier, I was trying to do some proof reading on the Coats to Endurance and the Scott-Newcomb books for the Real Steam Power series. I've also been spending spare moments learning to use the Fusion 360 parametric CAD program; unfortunately, my last experience with parametric modeling was a one week course with Unigraphics, about 20 years ago. Suffice it to say that the memory has faded and the two programs aren't that similar, in any case. Anyhow, I'm coming along with that and managed to even animate a couple of model engines. Hopefully, this will let me get parts 3D printed and improve my mediocre drawings for things like Bulletin articles.

As far as a drum in a monotube, Tom Kimmel did that a while ago. His rational was that monotube control systems are complex simply because water races up and down the tube with every change in firing rate, feed water flow and throttle change --- this therefore changing the ratio of tube dedicated to steam generation versus superheating. By placing the drum just above the steam generation section, he could employ simple water level controls to regulate feed and a pressure stat to regulate firing rate ... just like a Stanley. He reports the pressure and temperature outputs were quite stable --- and this from a guy who talked about previously achieving a perfect cycle between hot water and red hot tubes on something like a 35 second interval.

To me, the cutest recirculation method was that developed by Charles French wherein the feed water pulses drove a cylinder upwards against spring tension, with the upper side of the cylinder being connected to a pair of check valves so as to constitute a pump. By employing a differential piston, he could make the volume of pumped water significantly greater than the feed water flow. It was nice in that it had no shafts extending from the unit, no electrical power draw and it guaranteed a pretty constant ratio of circulation to feed. I think much the same could be done with rotary devices such as centrifugal rotors or roller pumps.

Personally, I'd weigh in against independently fired superheaters. The US Navy did that with the M class boilers Iowa class battleships and the Midway class aircraft carriers, among other vessels. The cost and maintenance were higher and synchronizing the main and superheater burners was always trickier than expected since most control systems don't take thermal inertia into account. The navy later went to the D type boilers with uncontrolled superheaters and life got much easier. Uncontrolled is only partly true in that the superheaters were partly exposed to radiation and partly to convection --- with the ratio of convection and radiation being closely calculated. Radiant and convective superheater temperatures work in opposition to one another as flow varies, one getting hotter as the other gets cooler, having the two in series caused the output temperature to be relatively stable. Maybe it wasn't perfectly stable, but it was acceptable. From there, you could simply add a desuperheater if you wished to regulate temperature more accurately. Perhaps the neatest idea I've seen in that area was someone who suggested bypassing some of the steam flow around the first half of the superheater and recombining it downstream under the control of a thermostatic valve. This would act a lot like a Doble normalizer without injecting water into the tube so as to minimize thermal shock, risk of erosion and build up of contaminants from carryover.

One thing I think I should address is feedwater heaters. I think they are absolutely vital on total loss systems (i.e., no condenser). On the other hand, their presence in a condensing vehicle suggests something is wrong. Ideally, you regulate your condenser so as to minimize condensate depression (that's the difference in temperature between water leaving the condenser and the saturation temperature of steam at condenser pressure. We minimize condensate depression because additional cooling simply tosses additional heat energy into the atmosphere. If the condensate depression is kept to a minimum, there's very little to be gained with a feed water heater since the feed should be almost at exhaust temperature. I only mention this because I keep seeing proposals for feedwater heaters in condensing systems and I think that they are trying to control the wrong thing.

Well, the morning coffee break is over and it's time to get back to work. I'll look at the spreadsheet this evening.

Regards,

Ken

Hi Ken,
You truly are hitting on all cylinders. I must give you credit for the IR cylindrical burner shown within the Ofeldt Coils in the design above. When I posted in another thread about building the perfect boiler, you made this imaginative concept. I actually think it a good idea. At least it is something worth a trial build.

While giving out credits, Tom Kimmel gets the credit on the mono-tube to a separator tube (or drum). Yes the concept is easier to control with some type of water level device. I think the trick is to get as much steam out of the first pass through the mono-tube to the drum. That way the dealing with the water in the separator is easier. I'm sure you remember Gerry Hacket Bus that he used a mono-tube feed right over the burner. He was the one who named it the Gryzb Coil. I too had a configuration like that on my Scooter prior to a rearrangement of the tubing with a standard boiler site glass set up. I believe it worked well and caused my blow-off to trigger quicker than I expected it to. Again, because of using common tubes I couldn't tell if water was in the boiler with the site glass. It was a good learning experience.

I too like the French inductor circulation. We need someone to build one so to get some experience with it.

Last is that I'm convinced one needs a feed water, economizer and super heater with this arrangement. This is on as you stated an open system.

Sorry, lunch is over.

Kind regards,
Rick

Hi Ken,
Another query if I may...have you any knowledge of a system that does not use a throttle valve? The feed pump and burner would control the steam to the expandor. Also, your feedback along with others on the proposed system is welcome.

This would be a Non condensing System

- Feed pump communicating with the expandor to
- Flow control valve like the Richard Smith version to
- Feed water heater (exhaust steam from expandor) to
- Economizer pancake coils in the 400 Degree F exhaust gas to
- Grzyb Coil (mono tube) w/various forms of fill to
- Seperator Pipe to
- Natural circulation Ofeldt coils to
- top of Seperator Pipe and steam to
- Super heater to
- Expandor (steam engine)

Putting the system in context, this has a specific purpose of a land speed record car.

Here is how it would work in the design above. System is cold. Feed water into the steam separator pipe using an aux pump or by spinning the vehicle's wheel till the level is adequate to start the burner and let the Ofeldt coils generate steam. There is a closed valve to the engine to initiate a starting steam pressure. Typically this valve would be open in operation. When steam pressure is enough to turn the engine, release this valve and start the ole girl running.

All this time the burner is running and heating the Grzyb coil. The feed pump is tied and tuned to the engine. When the engine turns, the water is pumped into the system via the flow control valve. This should make the engine take off. The engine should reach its maximum RPM based on the pressure the system generates. To back off the speed, reduce the flame or modulate the fire. To accelerate again, pour on the coals.

Sounds too simple doesn't it? Note that I would add in a throttle valve either in between the separator tube and the super heater or after super heater for a touring car. I'm not sure which way to go.

Kind regards,
Rick

Hi Rick,

The only way that I can see managing without a throttle valve would be by regulating feed pump flow --- you can only get out what you put in. That's about how Bill Ryan regulated the speed on his hothead go-kart. Of course, that thing is basically a Serpollet system, he has no real regulation and runs the tubes as hot as he can get them … essentially a true flash boiler. The downside is metallurgy, those tubes don't last forever under those conditions. That sort of operation seems almost necessary because I think you'd want the minimum amount of water in the boiler so that the system can be responsive to feed pump input.

As for a throttle valve, I think there's a lot to be said for putting it before the superheater. Any sort of throttling action causes the steam to desuperheat as its pressure drops while passing the restriction. If you put the throttle after the superheater, you are always desuperheating the steam to one degree or another unless the throttle is pretty wide open. If it's before the superheater, the temperature is always pretty predictable (assuming you are controlling output temperature and have a responsive control system. True, you could regulate with a throttle downstream of the superheater by measuring output temperature but now you need to run the boiler tubing hotter to compensate for the temperature drop across the throttle.

Regards,

Ken

Hi Rick,

The only way that I can see managing without a throttle valve would be by regulating feed pump flow --- you can only get out what you put in. That's about how Bill Ryan regulated the speed on his hothead go-kart. Of course, that thing is basically a Serpollet system, he has no real regulation and runs the tubes as hot as he can get them … essentially a true flash boiler. The downside is metallurgy, those tubes don't last forever under those conditions. That sort of operation seems almost necessary because I think you'd want the minimum amount of water in the boiler so that the system can be responsive to feed pump input.

As for a throttle valve, I think there's a lot to be said for putting it before the superheater. Any sort of throttling action causes the steam to desuperheat as its pressure drops while passing the restriction. If you put the throttle after the superheater, you are always desuperheating the steam to one degree or another unless the throttle is pretty wide open. If it's before the superheater, the temperature is always pretty predictable (assuming you are controlling output temperature and have a responsive control system. True, you could regulate with a throttle downstream of the superheater by measuring output temperature but now you need to run the boiler tubing hotter to compensate for the temperature drop across the throttle.

Regards,

Ken

The hothead has control issues. There is a time lag between water stop and the steam being used up. There is water reserve in the high pressure feed line.

Hi Scott,

You're dead on right ... verging on being too generous! It wasn't functionally all that much different than the original Serpollet, and that was also nearly uncontrolled; which is why Serpollet dropped it after a few years and went to a semi-flash boiler. I'm probably more in favor of simplicity than most people, but everything has a point of diminishing returns.

Rick,

One control system that caught my attention was designed by Osmun B. Campbell. If you'll remember, Ken Hemmelgarn talked about a converted steam car we both looked at in Ohio. That machine was horrendous, it had so many control loops running in parallel and series simultaneously that I doubt it ever did the same thing, twice. Apparently the inventor figured that was a fiasco and he designed a pretty generic forced recirculation boiler. What was interesting is that he eliminated the drum and put the recirculation pump a little bit upstream so that the suction would always be submerged. This eliminated the need for separation in the drum because the majority of the steam would be generated in the small amount of remaining tubing.

I figured you might be able to go one step further and put two suction lines on the recirc pump, a larger one for the recirculation and a smaller one a bit higher up in the tube. The feed water control would then be a differential pressure gage across the pump. If both suction lines were covered with water, the differential pressure would be high and the feed pump would be switched off. If the water level dropped below the smaller, upper line, the pump would start drawing steam and the delta P would drop, causing the differential pressure reader to start the feed pump.

I know a drum would be safer but, let's admit it, you couldn't decently fit a steam plant in most vehicles built in recent years. They've reduced mass as much as possible by making the engine compartments as small as practical (and that's ignoring the fact that turbocharging is getting ubiquitous and the engines themselves are shrinking. Every cubic inch you take out of the plant is one more little gain towards fitting the thing in a vehicle.

Regards,

Ken

Hi Guys,
Thanks for your input. During the last meet and observing and dissecting Jerry Oliver's bike, I discovered that his mono-tube goes into a separator drum. He described it as the means to eliminate scale from going into the engine. It functioned like a cyclone and acted as a steam separator along with being a particle separator. I asked him if this fills up with water and chokes the engine. His response...nope no problem. The steam temp after his mono-tube was enough to take any initial carry over and change its state to vapor. I thought what an interesting thing. This is of course the Richard Smith design to the T.

I order the plans to this from the SACA store to verify and sure enough, that's the design.

So my thought is that the separator is key to control. It provides the buffer in the water-steam region, the bell, in the TS Diagram. As you alluded to earlier, you don't know where the water transitions to steam in a tube. In fact it can vary great distances and cause the great control problems we all complain about.

However, Jerry seamed to have great control of his bike during the meet. BTW...what a wonderful looking bike that is!

Then I go back to a remark from Chuk about Carter who said to use a volume the same as the cylinder to buffer this vary concern.

Hence, my design to have this separator albeit tube to perform this function. Your thoughts?

Kind regards,
Rick

Hi Rick,

There's all kinds of separators .. cyclone, chevron, filter --- typically they are in the steam line, downstream of the drum.

The Baker boiler had no drum, but it used a larger diameter tube encircling the boiler, this tube largely acted as a storage device. This is actually what I suggested they use on the LSR car since the reserve would simplify control versus a pure monotube --- it wasn't meant to carry a lot of water, just enough to provide some control stability. I also suggested a recirculation pump in the boiler right where the Lamont coil dumps to the storage coil. Sensors on the storage coil would operate the feed water pump while a pressurestat would regulate the burner. If necessary, some sort of desuperheater would regulate output temperature. Basically, nothing much more complicated than a Lamont but with coil instead of drum storage --- to a large degree this was because the Bonneville Safety Committee has unofficially banned drums.

Regards,

Ken

X



Edited 1 time(s). Last edit at 06/30/2020 05:38AM by IronChief.

Aw geeze Ron, fireless locomotives were part of the next president's message, and now you stole my thunder!

Yep, he's right, those last 100 feet were getting a bit sketchy, but we did coast a half mile in on his boiler reserve. Actually, that worked kind of nice, didn't have to do a big blowdown in the parking lot right next to that Marmon.

Ron, hope everything is going well at the new shop.

Regards,

Ken

OK Gentlemen,

After hearing your thoughts, I would like to make a simple clarification in purpose for a separator tube.

A quick aside is that my earlier change of terminology from "Separator Drum" to "Separator Tube" is because of your recommendation to the us guys thinking about the LSR record attempt. Ken, this was your comment. Also some terminology is to replace a mono-tube generator to a drum as a Gryzb Coil and any natural circulation coil as an Ofeldt Coil. This is like calling a Fire Tube Boiler a Stanley Boiler. And I would like to give Ron credit for the values I use on the excel spread sheet attached earlier. They turn out to be pretty good numbers for calculating BTU per square feet steam generation.

The clarification is on the purpose of control volume of some sorts after either a mono-tube or a forces circulation single tube. Originally and mentioned above the purpose was anticipated to be a steam separator. After the comments immediately above, I think it more of a buffer or even accumulator is a better word for it. This will provide the reserve that we are all familiar with on Stanley(s) and Ofeldt(s). Also it provides a means for control, more predictable is more approx.

More clarification is the direction I'm seriously considering for a LSR boiler prototype build. I realize that a forced circulation system is the current steam generator design believed to be the best. My actual experience is with Tony's Bike where I road it up and down his street. That thing has torque. It put out. However, think about check valves and pumps and their reliability. This is why I built an Ofeldt and followed Tony's Ofeldt, then Ron's Ofeldt and Ross along with Ken Hemmelgard (sp). As a compromise to improve the Ofeldt, I suggest a mono-tube to a tube (Gryzb Coil) and some natural re-circulation coils (Ofeldt Coil) to replace the forced circulation concept. After a few trys with the tube calculation model, I settle on a 3 to 1 tube length ratio for Grzyb Coil to Ofeldt Coil. Note this does not include the economizer coil or any feed water heating.

Got to get back to work...thoughts welcome.

Kind regards,
Rick

Throttling superheat is the term. Somehow you have this backwards.

Steam Pressure Reduction - Industrial Professionals ...
[Search domain www.cheresources.com/invision/topic/11487-steam-pressure-reduction/] [www.cheresources.com]
When you reduce the steam pressure through any throttling device (control valve, orifice), the steam at the outlet of the throttling device will be superheated.

Karl Petersen

Rick, I'm finally back and plan on getting my steam generator built. I'll be getting with my brother tomorrow and hopefully putting up a lot of information. Pricing and cost estimates, and sourcing materials will be needed then finding someone to help build and test the generator. We finally have the money to start doing this as well as looking into building the actual engine. But the engine is a whole 'nother can of worms.
I'm hoping someone in the club can recommend a decent source for materials such as the tubing. The recirculating pump will have to be custom made since it will be specialized.
The bearings can be lubricated with krytox and the pump will be internal and turned using an external motor and high temp magnets and insulation. This way there won't be a shaft going from high internal pressure to low external. No leakage and sealing problems.
Hopefully with the help of phorum members we can end up with an efficient and compact steam generator.

SteveW

Forced circulation steam generator.

About twenty years ago I had been working on a pump design in my spare time or should I say when I need a brake from building my Stanley.

At this time the size and output of the pump was not the issue, as I have no need for a forced circulation steam generator at this time. I wanted to learn the best way to build a pump.

My first criteria was to have a safe pump, one that could with stand three times boiler pressure. The other problem is the expansion of the parts at maximum temperature and how it affects the bearings and seals. I first thought was to cast the whole pump in Invar, very low expansion up to 600F. Looking into this I found the cost much to high for a small quantity of castings.

I decided to use an Invar core, as I wanted to cool the area around the seal. The seal is a big power loss on a small pump. It can be, as much as the pump loads I believe.

Anyway my first pump casting in cast in ductile Iron. I can get a two-inch impeller in side and the housing will stand a pressure of 4000 PSI, It is a centrifugal design with a involute expansion cavity.

My first test with a two-inch impeller, I can get a maximum pump pressure of 9 PSI at 3450 RPM. My maximum out put is six GPM at seven feet at 8 PSI. 1-1/2 GPM at sixteen feet at 9 PSI.

My friend is trying to get me a speed controller and a higher RPM motor to do a study over a wider range of RPM

Do to other projects I sent all the casting and my pump to Tom.

Rolly

Rolly, I remember seeing you posting that pump and schematic. Thank you for reposting it and the information. What I plan on doing shouldn't give me as much problem on strength and sealing. I am looking at having a pump inside the reserve tank with a external magnetic coupling to drive it. Between new insulations and ultra high temperature magnets I think it might work. You can now buy a magnet that will work up to at least 600F and possibly more. I'll have to recheck to see whats now available.
SteveW

The attached picture is basically the layout for the proposed steam generator my brother and I have been working on. It still needs a lot more calculations done and what materials will be best to use within our budget. Given the efficiency of steam engines I am guessing that 200 to 400 hp output from the boiler will be plenty with 800 psi and 800 F . I want to try for 80% efficiency or more within reason.
Thanks for any input

SteveW

Very good drawing and explanation thanks

Mike

Steve your coil arrangement is all wrong, as well as the scale of your combustion chamber from what I can tell.

Doble’s book by Walton gives all the formulas he used for calculating combustion volume per gal of fuel. (around page 157.) I found from my own experiments these to be on the tight size as I think Besler did as well as his combustion chamber on the 200 HP generator for the airplane was larger as well.

For 200 HP you will need to burn 1,200,000 BTU per hour. Min. per 80% boiler efficiency. I don’t think I have ever achieved that.

The forced circulation coil should surround the outside of a lined combustion chamber the lining being 310 SS combustion grade stainless. 95% or more of the heat will pass right through it. The liner will give a much cleaner fuel burn.

The forced circulation pump should take water from the drum through the forced circulation coil and back to the drum. This has nothing to do with the generator feed pump.

Rolly

Rolly, I'll get you a better diagram and double check ours. This should show what you described.
SteveW

I've checked and the diagram should be showing it as you described.
I have a question about the hp though. Isn't it 2550 btu / horsepower? If so 1,200,000 btu should give around 400hp or 320 at 80% efficient.
Thanks
Steve

You must be using a Percheron or Clydesdale that can only pull a single feral plow,
I’m using a Shire that can pull a four feral plow.

Your tube layout as shown is Laminar flow of the gases not Turbulent fllow.

Rolly

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IMG_1355.JPG	125.9 KB	open | download	Rick.H	06/17/2019	Read message
IMG_1357.JPG	141.7 KB	open | download	Rick.H	06/17/2019	Read message
IMG_1358.JPG	112.1 KB	open | download	Rick.H	06/17/2019	Read message
IMG_1359.JPG	121.5 KB	open | download	Rick.H	06/17/2019	Read message
IMG_1360.JPG	120.4 KB	open | download	Rick.H	06/17/2019	Read message
tube bender.JPG	801.6 KB	open | download	Rolly	06/18/2019	Read message
Finished Model-3.jpg	527.8 KB	open | download	Rolly	06/18/2019	Read message
Small.jpg	165.1 KB	open | download	Rolly	06/18/2019	Read message
Finished-2.jpg	217 KB	open | download	Rolly	09/05/2019	Read message
White.jpg	193.5 KB	open | download	Rolly	09/05/2019	Read message
Forced Cir generator-2.jpg	39.5 KB	open | download	Rolly	09/05/2019	Read message
Marine economizer.jpg	51.4 KB	open | download	Rolly	09/10/2019	Read message
Marine Boiler.jpg	48.1 KB	open | download	Rolly	09/10/2019	Read message
TS Diagram - High Efficiency Boiler.gif	60.8 KB	open | download	Rick.H	09/11/2019	Read message
Single IR Burner Design reduced.jpg	364.8 KB	open | download	Rick.H	10/16/2019	Read message
Single IR Burner Design2 reduced.jpg	502.2 KB	open | download	Rick.H	10/16/2019	Read message
Single IR Burner Design3 reduced.jpg	253.6 KB	open | download	Rick.H	10/16/2019	Read message
2019 Fall SACA Presentation.xlsx	30.7 KB	open | download	Rick.H	01/21/2020	Read message
Boiler General Arrangement reduced.tif	405.2 KB	open | download	Rick.H	01/21/2020	Read message
Boiler General Arrangement 2 reduced.tif	430.1 KB	open | download	Rick.H	01/21/2020	Read message
Steamliner USA LSR reduced.bmp	953.9 KB	open | download	Rick.H	01/21/2020	Read message
rankine_ts.jpg	130.5 KB	open | download	Rick.H	01/22/2020	Read message
Single IR Burner Design reduced.jpg	364.8 KB	open | download	Rick.H	01/27/2020	Read message
Single IR Burner Design2 reduced.jpg	502.2 KB	open | download	Rick.H	01/27/2020	Read message
Single IR Burner Design3 reduced.jpg	253.6 KB	open | download	Rick.H	01/27/2020	Read message
Boundary Layer Concept reduced.jpg	609 KB	open | download	Rick.H	01/27/2020	Read message
Tube Stages.jpg	252.4 KB	open | download	Rick.H	01/27/2020	Read message
Drawing Circulation pump for .75 IPS.jpg	126 KB	open | download	Rolly	02/03/2022	Read message
P5050002.JPG	854.9 KB	open | download	Rolly	02/03/2022	Read message
Boiler schematic for Steam Club@2x.png	968.1 KB	open | download	SteveW	02/05/2022	Read message
200 HP design.jpg	736.9 KB	open | download	Rolly	02/06/2022	Read message
Boiler schematic for Steam Club@2x.png	968.1 KB	open | download	Rick.H	02/14/2022	Read message
Tesla_valve_cross-section.png	12 KB	open | download	Rick.H	02/18/2022	Read message
IMAGE 31.png	504 KB	open | download	frustrated	02/18/2022	Read message
Pole Barn.jpg	934.4 KB	open | download	Rick.H	02/21/2022	Read message
HEAT FLOW 2.png	37.9 KB	open | download	frustrated	02/24/2022	Read message
Good burn 6 GH.JPG	41 KB	open | download	Rolly	02/25/2022	Read message
Burner pan - 2.JPG	197.2 KB	open | download	Rolly	02/25/2022	Read message
another great burn.JPG	131.4 KB	open | download	Rolly	02/25/2022	Read message
Tube Layout-1.jpg	147.6 KB	open | download	Rolly	02/25/2022	Read message
combustion chamber.jpg	344.6 KB	open | download	Rolly	02/25/2022	Read message
Boiler schematic for Steam Club@2x.png	968.1 KB	open | download	Rick.H	02/25/2022	Read message
Newcomb v SES.png	57.6 KB	open | download	frustrated	02/28/2022	Read message
McInerney.png	54.7 KB	open | download	frustrated	02/28/2022	Read message
Endurance burner.png	136.7 KB	open | download	frustrated	03/03/2022	Read message
My Code boiler.jpg	32.4 KB	open | download	Rolly	03/16/2022	Read message
ADforcedRecirc.jpg	37.3 KB	open | download	Karl Petersen	12/01/2022	Read message
Penberthy.jpg	188.6 KB	open | download	Rolly	12/02/2022	Read message
ADforcedRecirc Increased.jpg	207.6 KB	open | download	Rick.H	12/05/2022	Read message
33-Mono Tube vs Hybrid.png	85.8 KB	open | download	Rick.H	12/05/2022	Read message
16-Steam-Car-British-Boiler-Diagram.jpg	318.3 KB	open | download	Rick.H	12/05/2022	Read message
Mono tube-water tube Concept reduced.jpg	763.9 KB	open | download	Rick.H	12/05/2022	Read message
Mono tube-water tube Configuration reduced.jpg	974.5 KB	open | download	Rick.H	12/05/2022	Read message
Mono tube-water tube Topview reduced.jpg	487.6 KB	open | download	Rick.H	12/05/2022	Read message
IMAGE 177.png	479 KB	open | download	frustrated	12/07/2022	Read message
Clean out .JPG	395.7 KB	open | download	Rolly	12/07/2022	Read message
DSC_0011.JPG	423.6 KB	open | download	Rolly	12/07/2022	Read message
Finished Baker Boiler.JPG	616.7 KB	open | download	Rolly	12/07/2022	Read message
US1550943-0.jpg	994.7 KB	open | download	Rolly	12/07/2022	Read message
pat1617586.pdf	387.5 KB	open | download	frustrated	02/20/2023	Read message
pat2571540.pdf	358.9 KB	open | download	frustrated	02/20/2023	Read message
pat4847043.pdf	787.3 KB	open | download	frustrated	02/21/2023	Read message
CIRC SYSTEM 26 APR 2023.png	471.9 KB	open | download	frustrated	04/26/2023	Read message