Williams ws. Rankin
Posted by Howard Langdon
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Re: Williams ws. Rankin March 31, 2007 10:06AM |
Registered: 18 years ago Posts: 318 |
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Re: Williams ws. Rankin March 31, 2007 10:54AM |
Registered: 18 years ago Posts: 1,441 |
Howard,
Do not for any reason try to computerize a Doble F style steam generator. Why complicate what is very easy to do, with unreliable and costly electronic junk?
If the computer is MIL spec, combat certified, then that is one thing; but then they will cost more than your entire project, or even more.
The one improvement one can make is to substitute commercial thermocouple probes and easily available control modules for the old Doble style quartz rod thermostat.
One probe at the outlet of the superheater to control the secondary water flow rate and the normalizer valve.
The second thermocouple probe right before the normalizer injection point to sense if the economizer and evaporating coils are low on water, or dry, and then they shut off the fire.
Those module contacts run the power relay that controls the blower motor and the feed pump's solenoid valves. Never run high amperage current through those module contacts, or they will evaporate in a flash of sparks.
The pressure control can be any pressure switch that is suitable.
Just remember, when modern IC cars conk out on the road, 99.99% of the time, it is those damned computers that are failing.
Steam cars and boats are enough of a headache to make, why add computers when they simply are not needed or wanted. TC probes and commercial control modules work perfectly fine and are infinitely more reliable than any computer.
JC
Do not for any reason try to computerize a Doble F style steam generator. Why complicate what is very easy to do, with unreliable and costly electronic junk?
If the computer is MIL spec, combat certified, then that is one thing; but then they will cost more than your entire project, or even more.
The one improvement one can make is to substitute commercial thermocouple probes and easily available control modules for the old Doble style quartz rod thermostat.
One probe at the outlet of the superheater to control the secondary water flow rate and the normalizer valve.
The second thermocouple probe right before the normalizer injection point to sense if the economizer and evaporating coils are low on water, or dry, and then they shut off the fire.
Those module contacts run the power relay that controls the blower motor and the feed pump's solenoid valves. Never run high amperage current through those module contacts, or they will evaporate in a flash of sparks.
The pressure control can be any pressure switch that is suitable.
Just remember, when modern IC cars conk out on the road, 99.99% of the time, it is those damned computers that are failing.
Steam cars and boats are enough of a headache to make, why add computers when they simply are not needed or wanted. TC probes and commercial control modules work perfectly fine and are infinitely more reliable than any computer.
JC
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Re: Williams ws. Rankin March 31, 2007 09:35PM |
Registered: 18 years ago Posts: 318 |
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Re: Williams ws. Rankin April 02, 2007 03:34PM |
Registered: 18 years ago Posts: 1,038 |
Hi Howard.
The control would have to be designed for specific methods of control and hardware. There are simply a lot of ways to do it. I do agree with Jim, that if you just wont a Doble type control then a computer is over kill.
Wher a computer, I think, can really make a differance is bying going much futher. It would look at rate of changes. It would use differance equations to say control the fire. It would make a lot more sense with variable firing rates. You could implement a White type of control system in software. Going to a second order, looking at the rate of change of pressure and temperature you could avoid/reduce response delays.
Going even futher you could predict steam uasge by using accelerator position and engine parameters.
For example say you have a routine that takes accelerator position, cutoff, and engine RPM and sets the fuel rate using tables. Another routine is watching the same plus the temperature and pressure and their derivities and adjusts that table and firing rate as neccessary. Another routine is motering an O2 sensor and the fuel rate would adjust air intake or fan power for a clean burn. Thoes routines would basicly be running sum number of times a second.
That a simplification. Other things need to be taken into acount. I only addressed firing rate. Pressure must also be controled. Hope it gives you some ideas. A White type of control would be a good place to start.
I think where such a complex control is needed is when you are pushing the power density to it's max. David said that a Lamont can achive 60,000 BTU/HR/ft^2.
The control would have to be designed for specific methods of control and hardware. There are simply a lot of ways to do it. I do agree with Jim, that if you just wont a Doble type control then a computer is over kill.
Wher a computer, I think, can really make a differance is bying going much futher. It would look at rate of changes. It would use differance equations to say control the fire. It would make a lot more sense with variable firing rates. You could implement a White type of control system in software. Going to a second order, looking at the rate of change of pressure and temperature you could avoid/reduce response delays.
Going even futher you could predict steam uasge by using accelerator position and engine parameters.
For example say you have a routine that takes accelerator position, cutoff, and engine RPM and sets the fuel rate using tables. Another routine is watching the same plus the temperature and pressure and their derivities and adjusts that table and firing rate as neccessary. Another routine is motering an O2 sensor and the fuel rate would adjust air intake or fan power for a clean burn. Thoes routines would basicly be running sum number of times a second.
That a simplification. Other things need to be taken into acount. I only addressed firing rate. Pressure must also be controled. Hope it gives you some ideas. A White type of control would be a good place to start.
I think where such a complex control is needed is when you are pushing the power density to it's max. David said that a Lamont can achive 60,000 BTU/HR/ft^2.
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Re: Williams ws. Rankin April 02, 2007 08:56PM |
Registered: 18 years ago Posts: 318 |
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Re: Williams ws. Rankin April 03, 2007 09:56AM |
Registered: 18 years ago Posts: 1,441 |
Howard,
You put your finger on one of the great advantages of the Lamont steam generator.
All it needs is the pressure control and the water level control for the drum.
It neatly side steps all the problems of controlling a monotube that is being forced to high levels.
Just be sure the feed pump can quickly recover the water level.
Andy,
The big problem with variable firing rate is the thermal lag before something happens. This the computer cannot foresee and things get out of hand quickly.
Doble overcame this by having a big coil stack and by using his normalizer; but if you go for minimum weight and size, then the problems magnify fast. The Lamont is a good cure.
JC
You put your finger on one of the great advantages of the Lamont steam generator.
All it needs is the pressure control and the water level control for the drum.
It neatly side steps all the problems of controlling a monotube that is being forced to high levels.
Just be sure the feed pump can quickly recover the water level.
Andy,
The big problem with variable firing rate is the thermal lag before something happens. This the computer cannot foresee and things get out of hand quickly.
Doble overcame this by having a big coil stack and by using his normalizer; but if you go for minimum weight and size, then the problems magnify fast. The Lamont is a good cure.
JC
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Re: Williams ws. Rankin April 03, 2007 12:43PM |
Registered: 18 years ago Posts: 1,038 |
Hi Jim
Forget variable firing. That is not what I was asking about. It can be ON/OFF.
The boiler I am building is vary much the same as a Lamont to control. All that is needed is the presure and water level. It is basicly a mono tube going into a stand pipe like the lamont. But it doesn't recirculate water from the drum. As I explained. At times when the water level is high it will have superheated steam going into the stand pipe where that superheat will be used to evaporate some of the water to lower the level.
It's a trade off between maybe a deposit problem and problems that can occur with the recirculation pump of the Lamont.
What I am interested in is reducing or eliminating the deposit problem when it is generating super heated steam to lower the water level. Like the Lamont there is a super heater section after the stand pipe.
I figure your experance with the Doble steam generators can help me with this.
I am thinking that what causes the solids to deposit on the tube wall has to do with tube temperature. And of course that there is no liquid at that point. But what keeps the solids from being caried with the steam.
1. The distance soids have to travle with the gas(superheated steam).
2. The tube temperature. There is less heat transfer in the superheated zone.
With any finite amount of super heat, above heat losses, the water in the stand pipe should lower. Don't need much super heat.
The super heat zone length can be very short.
I figure the tube temperature just out of the boiler can help keep the length to a minum. I am not trying to control the output steam temperature. Firing is controled by pressure and pumping by water level.
The feed pump, pumps more water then what can be completey evaporated. The pump will only run when the fire is on. When the water level is high the pump will be bypassed part of the time so the generator would start producing super heated steam. But I dont wont to completely stop pumping allowing the tube to get to hot and have deposits.
If it keep the length to say 5" would I have a deposit problem. Would 10" inches be a problem. Do you think deposits can be eleminated. The tube diameter if 1/4 or 5/16" .020 wall. It a small boiler with around 90' of tubeing.
Andy
Forget variable firing. That is not what I was asking about. It can be ON/OFF.
The boiler I am building is vary much the same as a Lamont to control. All that is needed is the presure and water level. It is basicly a mono tube going into a stand pipe like the lamont. But it doesn't recirculate water from the drum. As I explained. At times when the water level is high it will have superheated steam going into the stand pipe where that superheat will be used to evaporate some of the water to lower the level.
It's a trade off between maybe a deposit problem and problems that can occur with the recirculation pump of the Lamont.
What I am interested in is reducing or eliminating the deposit problem when it is generating super heated steam to lower the water level. Like the Lamont there is a super heater section after the stand pipe.
I figure your experance with the Doble steam generators can help me with this.
I am thinking that what causes the solids to deposit on the tube wall has to do with tube temperature. And of course that there is no liquid at that point. But what keeps the solids from being caried with the steam.
1. The distance soids have to travle with the gas(superheated steam).
2. The tube temperature. There is less heat transfer in the superheated zone.
With any finite amount of super heat, above heat losses, the water in the stand pipe should lower. Don't need much super heat.
The super heat zone length can be very short.
I figure the tube temperature just out of the boiler can help keep the length to a minum. I am not trying to control the output steam temperature. Firing is controled by pressure and pumping by water level.
The feed pump, pumps more water then what can be completey evaporated. The pump will only run when the fire is on. When the water level is high the pump will be bypassed part of the time so the generator would start producing super heated steam. But I dont wont to completely stop pumping allowing the tube to get to hot and have deposits.
If it keep the length to say 5" would I have a deposit problem. Would 10" inches be a problem. Do you think deposits can be eleminated. The tube diameter if 1/4 or 5/16" .020 wall. It a small boiler with around 90' of tubeing.
Andy
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Re: Williams ws. Rankin April 05, 2007 08:51PM |
Registered: 18 years ago Posts: 318 |
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Re: Williams ws. Rankin April 19, 2007 08:22PM |
Registered: 18 years ago Posts: 318 |
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Re: Williams ws. Rankin April 20, 2007 10:53AM |
Registered: 18 years ago Posts: 1,441 |
Hi Howard,
The experimental Lear steam generator I used in the race car was an extended surface, parallel circut design. Control was by a normalizer with two TC probes, one in the outlet of the superheater and one right before the normalizer injection point. And the usual feed bypass for pressure control.
The unit produced 5500 lbs/hr at 1200 psi and 1100°F with an 8,500,000 BTU burner I designed. Nothing radical, just pushed to the limit.
The air blower drew 400 amps at 24 volts; but who cares, the run was only for ten minutes total and I had ample battery capacity for running at Bonneville.
JC
The experimental Lear steam generator I used in the race car was an extended surface, parallel circut design. Control was by a normalizer with two TC probes, one in the outlet of the superheater and one right before the normalizer injection point. And the usual feed bypass for pressure control.
The unit produced 5500 lbs/hr at 1200 psi and 1100°F with an 8,500,000 BTU burner I designed. Nothing radical, just pushed to the limit.
The air blower drew 400 amps at 24 volts; but who cares, the run was only for ten minutes total and I had ample battery capacity for running at Bonneville.
JC
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Re: Williams ws. Rankin April 20, 2007 02:29PM |
Registered: 18 years ago Posts: 1,259 |
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Re: Williams ws. Rankin April 20, 2007 07:40PM |
Registered: 18 years ago Posts: 1,441 |
Bill,
The steam generator and burner weight was about 570 pounds.
The turbine put out 350 hp at 85,000 rpm.
This calculates out at about a 15 pound water rate, just what Bob Barbor said a single stage impulse turbine could do. Thus I think along the lines of two stage turbines for the car.
JC
Edited 1 time(s). Last edit at 04/21/2007 12:23PM by James D. Crank.
The steam generator and burner weight was about 570 pounds.
The turbine put out 350 hp at 85,000 rpm.
This calculates out at about a 15 pound water rate, just what Bob Barbor said a single stage impulse turbine could do. Thus I think along the lines of two stage turbines for the car.
JC
Edited 1 time(s). Last edit at 04/21/2007 12:23PM by James D. Crank.
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Re: Williams ws. Rankin April 20, 2007 08:08PM |
Registered: 18 years ago Posts: 318 |
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Re: Williams ws. Rankin April 22, 2007 08:01PM |
Registered: 18 years ago Posts: 318 |
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Re: Williams ws. Rankin May 05, 2007 07:56PM |
Registered: 18 years ago Posts: 318 |
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Re: Williams ws. Rankin May 07, 2007 02:18PM |
Registered: 18 years ago Posts: 835 |
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Re: Williams ws. Rankin May 08, 2007 08:51AM |
Registered: 18 years ago Posts: 1,441 |
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Re: Williams ws. Rankin May 09, 2007 08:29PM |
Registered: 18 years ago Posts: 318 |
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Re: Williams ws. Rankin May 10, 2007 09:25AM |
Registered: 18 years ago Posts: 1,441 |
Hi Howard,
SAAB had the idea of converting that Sonnett sports car of theirs to steam, whether they were serious about it or just curious, I can't tell you. This was back in the first hysteria period about pollution.
The engine was a most compact five cylinder barrel engine that used a swash plate drive, and the engine was mounted vertically over the differential of that front drive little car.
Such a package naturally led to a central rotary inlet valve, I think the exhaust was unaflow, if I recall correctly. Anyhow, the valve was made from pure boron nitride, because it was self lubricating. I don't think they used any oil injection for piston lubrication, because of their steam generator design.
Somewhere I have a nice brochure that Dr. Platell gave me when he visited us when we were building the race car. Now I have to find it.
I think there was an S.A.E. paper on the car, you might try to find it and read it.
This conversion had some serious engineering in it and the condenser design was a big improvement over the usual fin and tube type, much more area in the same size package.
Their one bad idea was a steam generator that had almost a hypodermic 1mm ID tubing design with many, many, tubes in parallel. I recall telling Dr. Platell that they are going to have serious control problems with so many tubes in parallel. They did. Somewhat the same problem that the Brits are going to have with that crazy steam generator they now have for their race car, uncontrolled water flow conditions leading to rapid tube burnout.
The SAAB steam still exists and is the property of Dr. Platell now. He bought it from the company when he retired.
JC
Edited 1 time(s). Last edit at 05/10/2007 10:04AM by James D. Crank.
SAAB had the idea of converting that Sonnett sports car of theirs to steam, whether they were serious about it or just curious, I can't tell you. This was back in the first hysteria period about pollution.
The engine was a most compact five cylinder barrel engine that used a swash plate drive, and the engine was mounted vertically over the differential of that front drive little car.
Such a package naturally led to a central rotary inlet valve, I think the exhaust was unaflow, if I recall correctly. Anyhow, the valve was made from pure boron nitride, because it was self lubricating. I don't think they used any oil injection for piston lubrication, because of their steam generator design.
Somewhere I have a nice brochure that Dr. Platell gave me when he visited us when we were building the race car. Now I have to find it.
I think there was an S.A.E. paper on the car, you might try to find it and read it.
This conversion had some serious engineering in it and the condenser design was a big improvement over the usual fin and tube type, much more area in the same size package.
Their one bad idea was a steam generator that had almost a hypodermic 1mm ID tubing design with many, many, tubes in parallel. I recall telling Dr. Platell that they are going to have serious control problems with so many tubes in parallel. They did. Somewhat the same problem that the Brits are going to have with that crazy steam generator they now have for their race car, uncontrolled water flow conditions leading to rapid tube burnout.
The SAAB steam still exists and is the property of Dr. Platell now. He bought it from the company when he retired.
JC
Edited 1 time(s). Last edit at 05/10/2007 10:04AM by James D. Crank.
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Re: Williams ws. Rankin May 13, 2007 08:05PM |
Registered: 18 years ago Posts: 318 |
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Re: Williams ws. Rankin May 13, 2007 11:12PM |
Registered: 18 years ago Posts: 1,259 |
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Re: Williams ws. Rankin May 14, 2007 08:52AM |
Registered: 18 years ago Posts: 1,441 |
Hi Howard-Bill,
Rotary inlet valves for steam engines has historically been a trap and a failure for many steam car enthusiasts, and many who should have known better, tried them. They look so attractive at first glance.
There has always been two main failure points with them, massive leakage after about half an hour that is monumental, and a demand for more oil than any other valve to even live that long. Even for those who tried graphite or ceramic valves.
Several gas engine makers tried them in the past, and the only ones to succeed were the Cross, Aspin, and Junkers-Wankel for a WW-II torpedo engine. But; in a gas engine, the inlet conditions are light years easier than in a high pressure steam engine.
There is a very good book on the subject: "Rotary Valve Engines" by Hunter, Wiley & Sons, unfortunately very hard to get now.
The best thing is to just not get excited about them and bite the bullet and use a poppet valve.
JC
Edited 1 time(s). Last edit at 05/14/2007 09:39AM by James D. Crank.
Rotary inlet valves for steam engines has historically been a trap and a failure for many steam car enthusiasts, and many who should have known better, tried them. They look so attractive at first glance.
There has always been two main failure points with them, massive leakage after about half an hour that is monumental, and a demand for more oil than any other valve to even live that long. Even for those who tried graphite or ceramic valves.
Several gas engine makers tried them in the past, and the only ones to succeed were the Cross, Aspin, and Junkers-Wankel for a WW-II torpedo engine. But; in a gas engine, the inlet conditions are light years easier than in a high pressure steam engine.
There is a very good book on the subject: "Rotary Valve Engines" by Hunter, Wiley & Sons, unfortunately very hard to get now.
The best thing is to just not get excited about them and bite the bullet and use a poppet valve.
JC
Edited 1 time(s). Last edit at 05/14/2007 09:39AM by James D. Crank.
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Re: Williams ws. Rankin May 14, 2007 04:54PM |
Registered: 18 years ago Posts: 373 |
Darracq more or less bankrupted themselves in 1912-13 by introducing a useless rotary valve car - the boss Alexandre Darracq lost his business over this although the company survived. Here is a link on gas engine rotary valves.
[www.dself.dsl.pipex.com]
Mike
[www.dself.dsl.pipex.com]
Mike
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Re: Williams ws. Rankin May 14, 2007 05:35PM |
Registered: 18 years ago Posts: 835 |
Yes I tried it also
However it did work as the seal floated and oil flowed around the out side of the tube valve and fuel was direct injected into the cylinder. Ford had an intrest in it and did a study on it.They said they were looking for a clean air engine and this was still internal combustion same-o same-o. External combustion is the only way. The rest is history pat# 5,326,294
Harry
However it did work as the seal floated and oil flowed around the out side of the tube valve and fuel was direct injected into the cylinder. Ford had an intrest in it and did a study on it.They said they were looking for a clean air engine and this was still internal combustion same-o same-o. External combustion is the only way. The rest is history pat# 5,326,294
Harry
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Re: Williams ws. Rankin May 14, 2007 08:00PM |
Registered: 18 years ago Posts: 1,259 |
Hello Harry,
That was the patent number of your stern drive. I still like the Arneson drive though, just throw the fish over the stern and instant fillet. A friend of mine had one, but the women didn't like that big uncovered prop in the back as it looked too dangerous. Out of sight and out of mind was more acceptable.
I am a little supprized at the present activity with rotary valves given the research and success Ricardo had with the Burt Mc Collum sleeve valve. I am planning a somewhat modified one in my engine for the second stage. The modifications are necessary to make it work with my engines physical configuration not due to any perceived deficiency with the B-M systen as it is.
Best ------ Bill G.
That was the patent number of your stern drive. I still like the Arneson drive though, just throw the fish over the stern and instant fillet. A friend of mine had one, but the women didn't like that big uncovered prop in the back as it looked too dangerous. Out of sight and out of mind was more acceptable.
I am a little supprized at the present activity with rotary valves given the research and success Ricardo had with the Burt Mc Collum sleeve valve. I am planning a somewhat modified one in my engine for the second stage. The modifications are necessary to make it work with my engines physical configuration not due to any perceived deficiency with the B-M systen as it is.
Best ------ Bill G.
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Re: Williams ws. Rankin May 15, 2007 12:35PM |
Registered: 18 years ago Posts: 835 |
Right Bill
engine pat # 5,315,967
The other won't reverse or manouver well ,however it makes a nice blender.
Did a steam rotary valve years ago. It was a hollow taper with a slot and did not weare or seize. It did leak a little. Jim is right a poppet valve is best. I also like a bump valve in some cases.
Harry
engine pat # 5,315,967
The other won't reverse or manouver well ,however it makes a nice blender.
Did a steam rotary valve years ago. It was a hollow taper with a slot and did not weare or seize. It did leak a little. Jim is right a poppet valve is best. I also like a bump valve in some cases.
Harry
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Re: Williams ws. Rankin May 15, 2007 02:08PM |
Registered: 18 years ago Posts: 1,259 |
Harry,
I am considering using a bump valve in the high pressure stage of 3,500 psia. There is a need for a fixed short cutoff for this stage as control will be from throttle or exhaust pressure.
Do you think a bump valve will make the thousands of miles necessary for a car? Are they noisy like a tappet?
Best ------- Bill G.
I am considering using a bump valve in the high pressure stage of 3,500 psia. There is a need for a fixed short cutoff for this stage as control will be from throttle or exhaust pressure.
Do you think a bump valve will make the thousands of miles necessary for a car? Are they noisy like a tappet?
Best ------- Bill G.
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Re: Williams ws. Rankin May 15, 2007 02:44PM |
Registered: 18 years ago Posts: 835 |
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Re: Williams ws. Rankin May 15, 2007 05:09PM |
Registered: 18 years ago Posts: 1,259 |
Hello Harry,
Peter Brow and I were discussing how the old VW's had a unique and endearing sound because of the distinct tappet noise they made. The cats always seemed to know which VW was which and came running when the thing rounded the block. So some noise with character is OK and probably a plus.
What kind of cutoffs and valve lifts were you using? What happened to the stainless ball?
Best Regards ------- Bill G.
Peter Brow and I were discussing how the old VW's had a unique and endearing sound because of the distinct tappet noise they made. The cats always seemed to know which VW was which and came running when the thing rounded the block. So some noise with character is OK and probably a plus.
What kind of cutoffs and valve lifts were you using? What happened to the stainless ball?
Best Regards ------- Bill G.
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Re: Williams ws. Rankin May 15, 2007 06:31PM |
Registered: 18 years ago Posts: 835 |
HI Bill,
when the seat and the ball are the same hardness one will beat up the other untill it leaks. The silicon nitrite ball on a stainless seat is always improving itself. Bump valves donot like to small a clearance volume. About 8-1 compression is about it. A short cutoff is good if your valve dia is ok. A bump valve engine is a high rpm engine and good for constant speed.Cuttof from 3% up to 8%. The Long cutoffs can be a bear to start.
Harry
when the seat and the ball are the same hardness one will beat up the other untill it leaks. The silicon nitrite ball on a stainless seat is always improving itself. Bump valves donot like to small a clearance volume. About 8-1 compression is about it. A short cutoff is good if your valve dia is ok. A bump valve engine is a high rpm engine and good for constant speed.Cuttof from 3% up to 8%. The Long cutoffs can be a bear to start.
Harry
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