Stanley and White Burner Howl
Posted by Caleb Ramsby
|
Re: Stanley and White Burner Howl April 17, 2011 11:37AM |
Admin Registered: 18 years ago Posts: 2,107 |
Hi Peter,
I should have been a bit more concise, what I need is a Pyrex window in the burner housing to observe the back side of the flameholder to see what is happening to the air/fuel mix during operation. OK, you weren't trying to push me into it, but you got me thinking (a dangerous pastime, I know) and I think I just figured out how to run the larger output capacity burner and still obtain turndown ratios in the 100:1 range. Just need to redefine the parameters....as usual when trying to push the envelope.
The flashback occurs when you throttle the blower back and the air speed through the orifices drops below the flame propagation speed...and the air speed is proportional to the blower output pressure. If you could instead leave the blower output at a high enough constant pressure, you'd never get the backflash. The other variable in the equation is the surface area of the orifice(s). If you could make the stupid holes smaller, you'd be all set....
OK, after the laughing died down, turns out that isn't difficult. If you have two pieces of identical perforated stock (say 0.063 inch holes) and lay them one on top of the other so that the holes matched, you'd have a flameholder with 0.063 orifices. If you move one perforated sheet 0.063 inches you have essentially no orifices. Any fraction between 0.063 and 0 inches movement will vary the hole sizes accordingly. That is a stunningly small mechanical input to achieve that kind of change in power output.
Now, if one wanted to get really weird, attach a cylinder to one of these sheets with a massive spring loading on it, say 1,000 psi, and have the cylinder opened by steam system pressure. Below 1,000 psi the burner would be full open. Once the pressure starts to lift the spring, the burner will ramp down rapidly. To prevent total flameout a few holes on the upper sheet can be reamed out a bit so that they never reach shutoff, we can think of these as pilots.... Anyhow, this should yield an infinitely adjustable, blowback proof burner with very high output designed to maintain system pressure. With a carburetor your fuel/air ratios should be well taken care of, automatically, without the complexity of developing your own fuel injection systems (although by swiping a stock automotive MFAS that shouldn't be real hard). Hmmm...... Almost too simple....Now I'm suspicious.
Hi George,
The distance between the blower and the firebox was also about a foot, there was nothing magical about that number other than it seemed like the combination of distance and baffling would do a nice job of eliminating any transmission of heat from the burner to the blower. In an actual powerplant I'd make it all much more compact and use other means to achieve the same but for these tests simple, quick and dirty seemed the route to go. Next time I try this, I'd opt for a standard off the shelf automotive carb. The output would be better than the snowmobile and the response would be much more linear over a wide throttle range. It's funny how peoples backgrounds affect perceptions. When I mentioned the idea of the fan drawing air from the carb, many SACA guys thought it dangerous, whereas no GM guy batted an eyelash. I suspect that the difference was that the SACA guys were familiar with Doble carbs and burners and the GM guys never heard of them, but were well acquainted with super and turbochargers. After pointing out turbos and superchargers to the SACA guys, they instantly got it, they are all smart; I just found it fascinating how a difference in initial knowledge affects first impressions. My conclusion was that it probably pays to bounce ideas off people who have no specialist knowledge as well as those who do; the former won't be unduly prejudiced by precedent while the latter won't overlook the obvious.
Hi Keith, I like the corrugator. Now just need a small gear motor to generate really stupid amounts of metal per hour! (OK, OK, maybe I am production driven....) Seriously, though, anything that leads to consistent results and minimum workload can only yield superior results...something often lacking in steam projects, too many of which seem to rely on components that are totally dependant on fine hand tuning in order to function.
Regards,
Ken
Edited 1 time(s). Last edit at 04/17/2011 11:41AM by frustrated.
I should have been a bit more concise, what I need is a Pyrex window in the burner housing to observe the back side of the flameholder to see what is happening to the air/fuel mix during operation. OK, you weren't trying to push me into it, but you got me thinking (a dangerous pastime, I know) and I think I just figured out how to run the larger output capacity burner and still obtain turndown ratios in the 100:1 range. Just need to redefine the parameters....as usual when trying to push the envelope.
The flashback occurs when you throttle the blower back and the air speed through the orifices drops below the flame propagation speed...and the air speed is proportional to the blower output pressure. If you could instead leave the blower output at a high enough constant pressure, you'd never get the backflash. The other variable in the equation is the surface area of the orifice(s). If you could make the stupid holes smaller, you'd be all set....
OK, after the laughing died down, turns out that isn't difficult. If you have two pieces of identical perforated stock (say 0.063 inch holes) and lay them one on top of the other so that the holes matched, you'd have a flameholder with 0.063 orifices. If you move one perforated sheet 0.063 inches you have essentially no orifices. Any fraction between 0.063 and 0 inches movement will vary the hole sizes accordingly. That is a stunningly small mechanical input to achieve that kind of change in power output.
Now, if one wanted to get really weird, attach a cylinder to one of these sheets with a massive spring loading on it, say 1,000 psi, and have the cylinder opened by steam system pressure. Below 1,000 psi the burner would be full open. Once the pressure starts to lift the spring, the burner will ramp down rapidly. To prevent total flameout a few holes on the upper sheet can be reamed out a bit so that they never reach shutoff, we can think of these as pilots.... Anyhow, this should yield an infinitely adjustable, blowback proof burner with very high output designed to maintain system pressure. With a carburetor your fuel/air ratios should be well taken care of, automatically, without the complexity of developing your own fuel injection systems (although by swiping a stock automotive MFAS that shouldn't be real hard). Hmmm...... Almost too simple....Now I'm suspicious.
Hi George,
The distance between the blower and the firebox was also about a foot, there was nothing magical about that number other than it seemed like the combination of distance and baffling would do a nice job of eliminating any transmission of heat from the burner to the blower. In an actual powerplant I'd make it all much more compact and use other means to achieve the same but for these tests simple, quick and dirty seemed the route to go. Next time I try this, I'd opt for a standard off the shelf automotive carb. The output would be better than the snowmobile and the response would be much more linear over a wide throttle range. It's funny how peoples backgrounds affect perceptions. When I mentioned the idea of the fan drawing air from the carb, many SACA guys thought it dangerous, whereas no GM guy batted an eyelash. I suspect that the difference was that the SACA guys were familiar with Doble carbs and burners and the GM guys never heard of them, but were well acquainted with super and turbochargers. After pointing out turbos and superchargers to the SACA guys, they instantly got it, they are all smart; I just found it fascinating how a difference in initial knowledge affects first impressions. My conclusion was that it probably pays to bounce ideas off people who have no specialist knowledge as well as those who do; the former won't be unduly prejudiced by precedent while the latter won't overlook the obvious.
Hi Keith, I like the corrugator. Now just need a small gear motor to generate really stupid amounts of metal per hour! (OK, OK, maybe I am production driven....) Seriously, though, anything that leads to consistent results and minimum workload can only yield superior results...something often lacking in steam projects, too many of which seem to rely on components that are totally dependant on fine hand tuning in order to function.
Regards,
Ken
Edited 1 time(s). Last edit at 04/17/2011 11:41AM by frustrated.
|
Re: Stanley and White Burner Howl April 17, 2011 11:57AM |
Registered: 16 years ago Posts: 152 |
Ken, I had almost the exact idea and was talking it over with my brother just yesterday. I hadn't thought of the feedback control run directly by steam pressure, but the idea of having the holes closed seems good to me. Also you might be able to have the rotating plate go from larger to smaller holes in certain places to give an even larger variation of output. I have a question for you and anyone else with experience. How well does something like this do going from diesel to gas or a combination of both? I always like the multifuel idea. Keep working on this idea, I'd love to see something like this in operation!
Steve
Steve
|
Re: Stanley and White Burner Howl April 17, 2011 02:47PM |
Admin Registered: 18 years ago Posts: 2,107 |
Hi Steve,
I thought of the rotating flameholder first, it is easier to implement. For simplicity sake I'd use commercial perforated metal, the price isn't that high and the die stamped holes are pretty accurately spaced. The problem, if you want to view it as such, is that by using such stock the holes are all identically spaced and the outer holes in a rotary burner would be closed while the inner holes would be mostly opened. This limits potential turndown levels and the possibility of uneven heating in various sections of the tube nest. Different sized holes might work, but the overall burner size will be limited. If the outer holes are around .063", the inner ones may be pretty small. Overall burner size is then limited by the difference in smallest versus largest practical hole sizes. Since you'd probably want about even heat distribution across the burner, you'd also have to change the hole spacing as you changed the hole diameters. With a CNC machine this would all be trivial, but on a Bridgeport there is just way more diddling around than I'm willing to fool with.
The problem with any multifuel burner is that one simple delivery system won't work at optimum efficiency, without some sort of adjustment, unless all the fuels use exactly the same fuel/air ratio. In modern flex fuel vehicles, the electronic fuel injection system can tell what percentage ethanol and gasoline are in the tank and jiggle the fuel delivery to match. With a stock carburetor, this means fiddling with the needle valves every time you toss something different in the tank. If running entirely separate fuels, then you could add more than one carb and switch them out (much as in some natural gas conversion vehicles so as to permit gasoline operation when natural gas isn't readily available). Like anything else, this isn't an insurmountable problem, but all depends on how much effort you're willing to put into it.
Personally, if I were running a wide variety of liquid fuels, I'd go with automotive fuel injectors and toss in a stock automotive Mass Flow Air Sensor (MFAS) and an O2 sensor, and control the fuel injector with an intervalometer to vary the duty cycle. I'd set up a mixer with inputs from the MFAS and the O2 sensor, the mixer output would control the intervalometer. The MFAS output would set the mixer output level proportional to the air flow and the O2 sensor would move that up or down a to reach a setpoint figure. None of this is really high end electronics, it could all be done with a 555 timer and an op-amp chip or two.
Much the same could probably be accomplished by an O2 sensor and a method of controlling the carb jets to adjust the mixture on the fly. The fuel injection system is probably more user friendly for this sort of thing, but I have seen flex fuel carburetor systems on display back in the mid 70s at an SAE booth. I'm really not sure what issues there would be with something like diesel fuel dropping out of suspension at the flameholder. I did have the problem, and the simple solution was a small recirculation line from the bottom of the flameholder back to the base of the carburetor. If fuel did gather, it was drawn back by the fan and reinserted into the air flow, I'd imagine it wouldn't be out of the question to heat it a bit on the return route so as to improve the mixture vaporization. This should be naturally self correcting, the more fuel that drops out, the more that is heated by passage near the burner and recycled to the fan...raising overall temperature and increasing the vaporization rate. At some point equilibrium should be achieved...if no fuel is recycled then a bit of air/fuel mix is recycled and this will absorb far less energy from the burner and overall temperature rise should fall.
Regards,
Ken
Edited 1 time(s). Last edit at 04/17/2011 02:53PM by frustrated.
I thought of the rotating flameholder first, it is easier to implement. For simplicity sake I'd use commercial perforated metal, the price isn't that high and the die stamped holes are pretty accurately spaced. The problem, if you want to view it as such, is that by using such stock the holes are all identically spaced and the outer holes in a rotary burner would be closed while the inner holes would be mostly opened. This limits potential turndown levels and the possibility of uneven heating in various sections of the tube nest. Different sized holes might work, but the overall burner size will be limited. If the outer holes are around .063", the inner ones may be pretty small. Overall burner size is then limited by the difference in smallest versus largest practical hole sizes. Since you'd probably want about even heat distribution across the burner, you'd also have to change the hole spacing as you changed the hole diameters. With a CNC machine this would all be trivial, but on a Bridgeport there is just way more diddling around than I'm willing to fool with.
The problem with any multifuel burner is that one simple delivery system won't work at optimum efficiency, without some sort of adjustment, unless all the fuels use exactly the same fuel/air ratio. In modern flex fuel vehicles, the electronic fuel injection system can tell what percentage ethanol and gasoline are in the tank and jiggle the fuel delivery to match. With a stock carburetor, this means fiddling with the needle valves every time you toss something different in the tank. If running entirely separate fuels, then you could add more than one carb and switch them out (much as in some natural gas conversion vehicles so as to permit gasoline operation when natural gas isn't readily available). Like anything else, this isn't an insurmountable problem, but all depends on how much effort you're willing to put into it.
Personally, if I were running a wide variety of liquid fuels, I'd go with automotive fuel injectors and toss in a stock automotive Mass Flow Air Sensor (MFAS) and an O2 sensor, and control the fuel injector with an intervalometer to vary the duty cycle. I'd set up a mixer with inputs from the MFAS and the O2 sensor, the mixer output would control the intervalometer. The MFAS output would set the mixer output level proportional to the air flow and the O2 sensor would move that up or down a to reach a setpoint figure. None of this is really high end electronics, it could all be done with a 555 timer and an op-amp chip or two.
Much the same could probably be accomplished by an O2 sensor and a method of controlling the carb jets to adjust the mixture on the fly. The fuel injection system is probably more user friendly for this sort of thing, but I have seen flex fuel carburetor systems on display back in the mid 70s at an SAE booth. I'm really not sure what issues there would be with something like diesel fuel dropping out of suspension at the flameholder. I did have the problem, and the simple solution was a small recirculation line from the bottom of the flameholder back to the base of the carburetor. If fuel did gather, it was drawn back by the fan and reinserted into the air flow, I'd imagine it wouldn't be out of the question to heat it a bit on the return route so as to improve the mixture vaporization. This should be naturally self correcting, the more fuel that drops out, the more that is heated by passage near the burner and recycled to the fan...raising overall temperature and increasing the vaporization rate. At some point equilibrium should be achieved...if no fuel is recycled then a bit of air/fuel mix is recycled and this will absorb far less energy from the burner and overall temperature rise should fall.
Regards,
Ken
Edited 1 time(s). Last edit at 04/17/2011 02:53PM by frustrated.
|
Re: Stanley and White Burner Howl April 17, 2011 03:01PM |
Registered: 19 years ago Posts: 1,771 |
As the plates rotate the holes toward the outer edge would close off long before the center ones got two small. Making the burner smaller in diameter as the pressure got up to the dwell point.
The problem. What happens with the fuel you’re spraying in, nice flooded burner? Makes for a Long fire or a big bang with a backfire. You need to control the fuel as with a steam pressure automatic. Not the hole size. There are a lot’s of drilled and slotted burners that work just fine with minimal noise.
But it’s all-mute. Stanley’s use a pressure regulator on the fuel already. You can make the valve on the steam automatic tapered to the point it will varies the pressure over a longer dwell. Not needed with a good burner and pilot. On and off works just fine.
Some of the early car used no pilot and worked with a steam automatic that never closed off completely. Relied on the operator.
Some burners with larger holes or slots are subject to backfires when hot if the automatic does not shut quick enough.
More, smaller holes work better then fewer larger holes. Hole diameter to plate thickness makes a difference as slot width to plate thickness. Also space between rows.
I have never seen a well-built burner not keep up with the fastest speed the car can go safely. As long as the burner cycles on and off while maintaining roar speed.
Well maybe on a long steep hill, but not often.
More often then not there maintaining two high of a water level and not getting superheat to start with.
Big learning curve to running a steam car.
The problem. What happens with the fuel you’re spraying in, nice flooded burner? Makes for a Long fire or a big bang with a backfire. You need to control the fuel as with a steam pressure automatic. Not the hole size. There are a lot’s of drilled and slotted burners that work just fine with minimal noise.
But it’s all-mute. Stanley’s use a pressure regulator on the fuel already. You can make the valve on the steam automatic tapered to the point it will varies the pressure over a longer dwell. Not needed with a good burner and pilot. On and off works just fine.
Some of the early car used no pilot and worked with a steam automatic that never closed off completely. Relied on the operator.
Some burners with larger holes or slots are subject to backfires when hot if the automatic does not shut quick enough.
More, smaller holes work better then fewer larger holes. Hole diameter to plate thickness makes a difference as slot width to plate thickness. Also space between rows.
I have never seen a well-built burner not keep up with the fastest speed the car can go safely. As long as the burner cycles on and off while maintaining roar speed.
Well maybe on a long steep hill, but not often.
More often then not there maintaining two high of a water level and not getting superheat to start with.
Big learning curve to running a steam car.
|
Re: Stanley and White Burner Howl April 17, 2011 06:57PM |
Registered: 19 years ago Posts: 1,453 |
Good points, Rolly. Seems to be about a 50 psi boiler pressure range between full-fire and full-off in the Stanley steam automatic; in between the fire should vary. So, at 25 psi below "set-point", the burner would be about half-fire, "and etc". Then approaching shutoff a bit of pressure overshoot keeps the valve closing, to a positive shutoff, before backfire occurs. While accelerating, delay in steam generation (takes time for heat to get thru tubes into water) keeps boiler pressure dropping and valve moving to a positive opening. Thanks to hysteresis, the "Steam Automatic" fuel valve moves relatively quickly through the "possible backfire" ultra-low-firing-rate range during both opening and closing. The cooler the grate runs, the slower the initial-opening and final-closing of the fuel automatic can be, without backfiring. Stored energy in boiler allows driving at very low power levels with burner cycling thru a variable-output range between full-on and off. Meanwhile hysteresis/thermal-inertia in the boiler/engine steam path keeps superheat in a good range. No need for extreme burner turndown.
Actually, it looks like this anti-backfire "hysteresis switch action" would become more positive with less stored energy (water/steam in evaporator zone/section) for a given burner output -- up to a point.
Yet another problem already solved over a century ago?
Ken, definitely a linear-sliding rather than rotating variable-opening grate. One thing to look out for is whether the grate/flameholder layer closer to the fire will run hotter than the inner layer. Heat transfer between the 2 separate layers does not look ideal; "fuel side" layer might run cooler than "fire side" layer. Depends on temperature difference and width/length of flameholder, but differential thermal expansion between the 2 layers might misalign the holes from one side of flameholder to the other -- in every direction; outer holes more misaligned than inner holes.
Reducing grate size to minimize the distance factor might increase flame density and temperature/expansion differential to compensate! Increasing grate size to reduce the flame density and temperature differential might also give the same hole-offset problem, due to the reduced differential expansion occurring over a correspondingly greater distance.
If that is no problem, or a solveable one [ITC coating on fire side?], then with a carburetor burner, some means of continuously varying the air flow, carefully synchronized with the "shutter grate", might work. This setup might have some potential for an ultra-lightweight steam generator with minimal "stored energy". But simply adding some extra stored energy might still be a tempting alternative.
Peter
Actually, it looks like this anti-backfire "hysteresis switch action" would become more positive with less stored energy (water/steam in evaporator zone/section) for a given burner output -- up to a point.
Yet another problem already solved over a century ago?
Ken, definitely a linear-sliding rather than rotating variable-opening grate. One thing to look out for is whether the grate/flameholder layer closer to the fire will run hotter than the inner layer. Heat transfer between the 2 separate layers does not look ideal; "fuel side" layer might run cooler than "fire side" layer. Depends on temperature difference and width/length of flameholder, but differential thermal expansion between the 2 layers might misalign the holes from one side of flameholder to the other -- in every direction; outer holes more misaligned than inner holes.
Reducing grate size to minimize the distance factor might increase flame density and temperature/expansion differential to compensate! Increasing grate size to reduce the flame density and temperature differential might also give the same hole-offset problem, due to the reduced differential expansion occurring over a correspondingly greater distance.
If that is no problem, or a solveable one [ITC coating on fire side?], then with a carburetor burner, some means of continuously varying the air flow, carefully synchronized with the "shutter grate", might work. This setup might have some potential for an ultra-lightweight steam generator with minimal "stored energy". But simply adding some extra stored energy might still be a tempting alternative.
Peter
|
Re: Stanley and White Burner Howl April 17, 2011 09:32PM |
Admin Registered: 18 years ago Posts: 2,107 |
Hi Rolly,
A steam automatic connected to the very specific system I was describing above, which is derived from the photos posted on the previous page and in response to Peter's question about the 'Driveway Buster', would seem to be a contraindicated.
To swiftly recap, this burner employs a multistage centrifugal blower for relatively high pressure delivery. The air is drawn through the carburetor and into the blower, and thence to the flameholder.
Two facts to note:
* Centrifugal fans are, by nature, non-positive displacement; if the flame holder is closed down, there will be no flow through the blower.
* Carburetors are venturi devices and since the flow of air is the driving force, the fuel delivery is dependant on, and proportional to, air flow.
As the flameholder is closed off, the flow of air drops apace until the air flow comes to a screeching halt. If the blower is sized to provide enough pressure to ensure that the flow speed through the flameholder is higher than the propagation speed when the flameholder is fully open, then the pressure will be high enough to do likewise at any lesser state. Since the flow through the flameholder drops to a screeching halt, so does the flow through the carburetor. Since it IS a carburetor, the fuel delivery is proportionate to the airflow. If the flameholder is closed, the air that is no longer passing through the carb is no longer pulling fuel from the jet via the venturi. Fuel is never just being squirted in, so there should be no flooding and no problems. This isn't theory, I have restricted the flameholder on my carb burner out of curiosity and the mixture never changed appreciably, I was never able to generate a backflash, all that happened was that the fan noise just changed pitch as the flow dropped off.
The carbureted, centrifugal fan driven, flameholder burner is basically a bastard cross between a Doble and the SES burners: neither of which had the steam automatic and yet ran OK. The air flow can be choked off almost anywhere in the system, as the flow rate will drop everywhere and the fuel flow will follow. By choking the air flow right at the flameholder it becomes possible to reduce the airflow through the system without reducing the centrifugal blower outlet pressure, thus permitting dramatic degrees of turndown without the risk of backflash that would occur if the airflow were decreased by reducing fan speed. Adjusting the choking effect by using the steam pressure to adjust the flameholder directly looks like the simplest solution, it's mechanically simple and should provide infinite adjustment. Really seems to be no reason why it won't work.
Hi Peter,
The thermal expansion isn't really much of an issue in practical terms so long as the flameholders aren't huge, and given the firing rates both Chuk and I have seen, I can't imagine wanting to make one of these things anywhere near the size of a Stanley or White burner....I couldn't afford that much fuel in any case. If the two perforated sheets are in direct metal to metal contact, then there will be a tendency for temperatures to equalize and the problem diminishes. If there is a tendency to lose a bit of capacity due to misalignment caused by thermal expansion, it would be a simple matter to increase the overall grate size just enough to make up for that loss, we're talking a matter of percent in any case. Likewise, opening up the holes a bit on the 'bottom' sheet would allow for some misalignment and a bit extra motion might be programmed into the control cylinder.
Another way to achieve the same end would be two perforated sheets spaced apart from one another, with the holes totally out of alignment and the gap between them kept small and adjustable to regulate overall flow. Not my favorite option, however as it is really twitchy.
As far as stored energy goes, that is one reason I was looking in the other direction. THAT design has tons of thermal inertia and very good turndown ratio as there is zero opportunity for backflash. The MFAS and O2 controlled fuel injection definitely looked like the way to go although a mechanical fuel pump directly driven by an adjustable stroke eccentric on the blower shaft could do a pretty decent job for minimum complexity.
Ken
A steam automatic connected to the very specific system I was describing above, which is derived from the photos posted on the previous page and in response to Peter's question about the 'Driveway Buster', would seem to be a contraindicated.
To swiftly recap, this burner employs a multistage centrifugal blower for relatively high pressure delivery. The air is drawn through the carburetor and into the blower, and thence to the flameholder.
Two facts to note:
* Centrifugal fans are, by nature, non-positive displacement; if the flame holder is closed down, there will be no flow through the blower.
* Carburetors are venturi devices and since the flow of air is the driving force, the fuel delivery is dependant on, and proportional to, air flow.
As the flameholder is closed off, the flow of air drops apace until the air flow comes to a screeching halt. If the blower is sized to provide enough pressure to ensure that the flow speed through the flameholder is higher than the propagation speed when the flameholder is fully open, then the pressure will be high enough to do likewise at any lesser state. Since the flow through the flameholder drops to a screeching halt, so does the flow through the carburetor. Since it IS a carburetor, the fuel delivery is proportionate to the airflow. If the flameholder is closed, the air that is no longer passing through the carb is no longer pulling fuel from the jet via the venturi. Fuel is never just being squirted in, so there should be no flooding and no problems. This isn't theory, I have restricted the flameholder on my carb burner out of curiosity and the mixture never changed appreciably, I was never able to generate a backflash, all that happened was that the fan noise just changed pitch as the flow dropped off.
The carbureted, centrifugal fan driven, flameholder burner is basically a bastard cross between a Doble and the SES burners: neither of which had the steam automatic and yet ran OK. The air flow can be choked off almost anywhere in the system, as the flow rate will drop everywhere and the fuel flow will follow. By choking the air flow right at the flameholder it becomes possible to reduce the airflow through the system without reducing the centrifugal blower outlet pressure, thus permitting dramatic degrees of turndown without the risk of backflash that would occur if the airflow were decreased by reducing fan speed. Adjusting the choking effect by using the steam pressure to adjust the flameholder directly looks like the simplest solution, it's mechanically simple and should provide infinite adjustment. Really seems to be no reason why it won't work.
Hi Peter,
The thermal expansion isn't really much of an issue in practical terms so long as the flameholders aren't huge, and given the firing rates both Chuk and I have seen, I can't imagine wanting to make one of these things anywhere near the size of a Stanley or White burner....I couldn't afford that much fuel in any case. If the two perforated sheets are in direct metal to metal contact, then there will be a tendency for temperatures to equalize and the problem diminishes. If there is a tendency to lose a bit of capacity due to misalignment caused by thermal expansion, it would be a simple matter to increase the overall grate size just enough to make up for that loss, we're talking a matter of percent in any case. Likewise, opening up the holes a bit on the 'bottom' sheet would allow for some misalignment and a bit extra motion might be programmed into the control cylinder.
Another way to achieve the same end would be two perforated sheets spaced apart from one another, with the holes totally out of alignment and the gap between them kept small and adjustable to regulate overall flow. Not my favorite option, however as it is really twitchy.
As far as stored energy goes, that is one reason I was looking in the other direction. THAT design has tons of thermal inertia and very good turndown ratio as there is zero opportunity for backflash. The MFAS and O2 controlled fuel injection definitely looked like the way to go although a mechanical fuel pump directly driven by an adjustable stroke eccentric on the blower shaft could do a pretty decent job for minimum complexity.
Ken
|
Re: Stanley and White Burner Howl April 17, 2011 09:53PM |
Registered: 19 years ago Posts: 657 |
Ken,
Just a heads up about the centrifugal blowers, they tend to prefer having the inlet closed off over having the outlet closed off.
If the inlet is left open and the outlet is stopped up then it will still be throwing around some air and using a good bit of power while fluttering around. I don't really understand how it is ingesting air seeing as there isn't an outlet for it, but something is going on that makes a racket and uses up power. I suspect that they dead head against the pressure and produce a lot of turbulance inside the fan housing, maybe not as much with your multistage blower?
Virtually all of the steady speed centrifugal fans used by blacksmiths have the air flow adjusted by a sliding sheet of metal that closes off the inlet port.
This may not jive with your idea of using the grate as an outlet valve, but it may be something to keep in mind while going forward. Maybe a combination of a butterfly throttle on the inlet end and the grate hole varience would work?
Caleb Ramsby
Just a heads up about the centrifugal blowers, they tend to prefer having the inlet closed off over having the outlet closed off.
If the inlet is left open and the outlet is stopped up then it will still be throwing around some air and using a good bit of power while fluttering around. I don't really understand how it is ingesting air seeing as there isn't an outlet for it, but something is going on that makes a racket and uses up power. I suspect that they dead head against the pressure and produce a lot of turbulance inside the fan housing, maybe not as much with your multistage blower?
Virtually all of the steady speed centrifugal fans used by blacksmiths have the air flow adjusted by a sliding sheet of metal that closes off the inlet port.
This may not jive with your idea of using the grate as an outlet valve, but it may be something to keep in mind while going forward. Maybe a combination of a butterfly throttle on the inlet end and the grate hole varience would work?
Caleb Ramsby
|
Re: Stanley and White Burner Howl April 17, 2011 11:21PM |
Registered: 19 years ago Posts: 1,453 |
Well, give it a shot; see how it works. Might be great!
I was just thinking about Chuk's flameholder burner, which turns down and down and down then just goes out without backfiring. It also has a tremendous firing rate in a very compact space. Another interesting thing is the famous "miner's lamp", which has fire inside surrounded with a very fine-mesh wire screen. This could be taken into a mine filled with an explosive mix of methane and air, and not set off an explosion. The flame would not pass through the screen, despite the near-zero outward flow through the screen.
The Delling steam car's vaporizing burner had no "grate", per se, just a fine-mesh flameholder screen, which was claimed to be backfire-proof "like a miner's lamp". In a similar vein, D.A. Warriner had a fine Monel wire screen beneath his corrugated flameholder, which he claimed prevented backfires. Weirdly, he also said that it glowed -green- while firing!
I cannot remember where or when, but I seem to recall reading about a Stanley(?) burner, in an open-air test, which was gradually turned all the way down, slowly, and simply went out at some point rather than backfiring. As I recall, the operator was testing the burner, after repairing something which had caused backfires. I reviewed the burner threads on the Forums recently, and did not see the reference. Then again, I wasn't looking for it. Might have been in one of the old steam magazines.
Maybe some flameholders or grates re-radiate more heat than they absorb at very low firing rates, thus remaining cool enough to quench any flames which try to sneak through the openings and cause a backfire when fuel/air flow becomes slower than flame front speed? Or perhaps the "chimney effect" is at work in some of them?... both cooling the grate and accelerating fuel/air mix up through it... I never had a backfire with a gas stove burner, or with my Coleman Dual-Fuel (gasoline vaporizing burner) campstove... in fact, I can't recall backfires in any grate-type gas or vapor burner which I have operated, even when they were turned down to virtually zero firing rate...
Anyway, my point is that proper design of one-piece fixed-opening grates looks like another way to prevent "flash-backs"...
Peter
I was just thinking about Chuk's flameholder burner, which turns down and down and down then just goes out without backfiring. It also has a tremendous firing rate in a very compact space. Another interesting thing is the famous "miner's lamp", which has fire inside surrounded with a very fine-mesh wire screen. This could be taken into a mine filled with an explosive mix of methane and air, and not set off an explosion. The flame would not pass through the screen, despite the near-zero outward flow through the screen.
The Delling steam car's vaporizing burner had no "grate", per se, just a fine-mesh flameholder screen, which was claimed to be backfire-proof "like a miner's lamp". In a similar vein, D.A. Warriner had a fine Monel wire screen beneath his corrugated flameholder, which he claimed prevented backfires. Weirdly, he also said that it glowed -green- while firing!
I cannot remember where or when, but I seem to recall reading about a Stanley(?) burner, in an open-air test, which was gradually turned all the way down, slowly, and simply went out at some point rather than backfiring. As I recall, the operator was testing the burner, after repairing something which had caused backfires. I reviewed the burner threads on the Forums recently, and did not see the reference. Then again, I wasn't looking for it. Might have been in one of the old steam magazines.
Maybe some flameholders or grates re-radiate more heat than they absorb at very low firing rates, thus remaining cool enough to quench any flames which try to sneak through the openings and cause a backfire when fuel/air flow becomes slower than flame front speed? Or perhaps the "chimney effect" is at work in some of them?... both cooling the grate and accelerating fuel/air mix up through it... I never had a backfire with a gas stove burner, or with my Coleman Dual-Fuel (gasoline vaporizing burner) campstove... in fact, I can't recall backfires in any grate-type gas or vapor burner which I have operated, even when they were turned down to virtually zero firing rate...
Anyway, my point is that proper design of one-piece fixed-opening grates looks like another way to prevent "flash-backs"...
Peter
|
Re: Stanley and White Burner Howl April 17, 2011 11:37PM |
Registered: 13 years ago Posts: 95 |
Caleb is talking about centrifugal blower (or compressor) surge. This is an aerodynamic effect similar to stall of an aircraft wing. If the discharge pressure is too high or the flow rate is too low or the rotor speed is too low the rotor blades will stop "flying." The airflow will reverse through the wheel(s). The rotor will bounce violently in its bearings. The discharge pressure will fall and the cycle begins again. Large machines can be quickly destroyed by surging.
Assuming that you are working with a constant rotor speed, things are fairly simple. The safe discharge pressure versus flow curve will be a more or less straight line over the machine's useful working range. You can plot this curve for yourself by monitoring discharge pressure and flow rate or motor current consumption as you slowly choke the discharge of the blower. You will see the pressure, flow and power consumption start to flutter as you approach surge. The racket Caleb talks about is a sure sign that you are on the wrong side of the line.
Once you know the surge line of your particular machine and set up, you can predict the surge and get out in front of it by opening a bypass valve from discharge to suction (or atmosphere, assuming that you are not compressing a fuel air mixture).
Note that centrifugal pumps do not work this way. Centrifugal pumps cavitate if the suction pressure is too low or the flow rate is too high. You unload a centrifugal pump by choking the discharge.
Kerry
Assuming that you are working with a constant rotor speed, things are fairly simple. The safe discharge pressure versus flow curve will be a more or less straight line over the machine's useful working range. You can plot this curve for yourself by monitoring discharge pressure and flow rate or motor current consumption as you slowly choke the discharge of the blower. You will see the pressure, flow and power consumption start to flutter as you approach surge. The racket Caleb talks about is a sure sign that you are on the wrong side of the line.
Once you know the surge line of your particular machine and set up, you can predict the surge and get out in front of it by opening a bypass valve from discharge to suction (or atmosphere, assuming that you are not compressing a fuel air mixture).
Note that centrifugal pumps do not work this way. Centrifugal pumps cavitate if the suction pressure is too low or the flow rate is too high. You unload a centrifugal pump by choking the discharge.
Kerry
|
Re: Stanley and White Burner Howl April 18, 2011 12:52AM |
Registered: 19 years ago Posts: 1,453 |
Another option, Ken, is to vary the blower speed. 12vDC blower motor with some kind of zero-to-max variable-speed controller? Rheostat for the old-school approach; or there are solid-state "chopper" and similar motor controllers. These blowers can probably "vweeeeeee" up to speed in under a second...
Of course personally I prefer to just open a fuel valve, and let trillions of moving parts (fuel vapor molecules) quietly induct the combustion air...
=====================
One gild-the-lily thing which occurred to me recently: instead of jumping up or down several thousandths jet ID per step with number-size drill bits while tuning a vaporizing burner, how about varying the _length_ of the bore in the jet? That would change the fuel flow in a very precisely-adjustable fashion. Longer jet bore for less fuel flow, shorter bore for more fuel. To shorten bore, just file or Dremel the end of the jet, in tiny steps, & of course deburr the hole edge. For accurate replacement jets, jet/bore length could be measured later, after successful tuning. IE, #60 too big, #61 too small, how about a longer-bore #60, then file a bit at a time to "dial in" the length? Is there a standard length for Stanley burner jet bores -- or good records of what lengths they used in different years and burner sizes?
I wonder how many burner problems have arisen from people using Stanley-recommended or other-guy-proven jet bore diameters, but (unsuspectedly) different jet bore lengths... same for White and other vaporizing burners...
Ottaway took a step toward standardization by using standard Holley carburetor jets...
Peter
Of course personally I prefer to just open a fuel valve, and let trillions of moving parts (fuel vapor molecules) quietly induct the combustion air...
=====================
One gild-the-lily thing which occurred to me recently: instead of jumping up or down several thousandths jet ID per step with number-size drill bits while tuning a vaporizing burner, how about varying the _length_ of the bore in the jet? That would change the fuel flow in a very precisely-adjustable fashion. Longer jet bore for less fuel flow, shorter bore for more fuel. To shorten bore, just file or Dremel the end of the jet, in tiny steps, & of course deburr the hole edge. For accurate replacement jets, jet/bore length could be measured later, after successful tuning. IE, #60 too big, #61 too small, how about a longer-bore #60, then file a bit at a time to "dial in" the length? Is there a standard length for Stanley burner jet bores -- or good records of what lengths they used in different years and burner sizes?
I wonder how many burner problems have arisen from people using Stanley-recommended or other-guy-proven jet bore diameters, but (unsuspectedly) different jet bore lengths... same for White and other vaporizing burners...
Ottaway took a step toward standardization by using standard Holley carburetor jets...
Peter
|
Re: Stanley and White Burner Howl April 18, 2011 02:19AM |
Registered: 19 years ago Posts: 1,771 |
|
Re: Stanley and White Burner Howl April 18, 2011 05:54AM |
Admin Registered: 18 years ago Posts: 2,107 |
Hi Guys (it's early and easier than adressing everyone individually, slugabed that I am),
I basically identified 3 different methods for controlling a carburetor burner when it is being pushed to stall out:
* Slow down the motor
* Close down the carburetor throttle (choke off the intake)
* Open a recirculation pathway from discharge to opening
I've worked with both centrifugal blowers and pumps that used all three methods. With a flameholder, I feel you'd need some way of sensing discharge pressure so as to keep air velocity through the flameholder above flashback velocity. Minimizing the blower workload too much will make for that nasty "BAMPF" sound.
Truthfully, I don't believe it is the flameholder preventing flashback on Chuk's burner. I tested units with similar hole sizes, they throttled down to lower output than the 'driveway buster' but also had less overall capacity; I still couldn't prevent flashback. Not that I doubt what Chuk says in the slightest. I suspect the difference may be the fuel/air ratios at very low firing rates. In my testing, if I throttled down just above the flashback velocity and then leaned out (or enriched) the mix, the burner would simply go out. If I spun the blower back up and relit, the mix was now out of whack and the flame wasn't good. This is just a wild guess, but maybe at very low flow rates the fuel/air mixture in Chuk's burner was enough different to allow the flame to quench but above that level the two units fuel delivery were fairly similar. This would be a small difference at an extreme end of the operating spectrum, so might be hard to detect and immaterial most of the time. <shrug> Beats me, the engineers definition of hell is a place where all the parts are right but the machine still won't work; purgatory might be the place where two machines look the same but work differently....
Regards,
Ken
I basically identified 3 different methods for controlling a carburetor burner when it is being pushed to stall out:
* Slow down the motor
* Close down the carburetor throttle (choke off the intake)
* Open a recirculation pathway from discharge to opening
I've worked with both centrifugal blowers and pumps that used all three methods. With a flameholder, I feel you'd need some way of sensing discharge pressure so as to keep air velocity through the flameholder above flashback velocity. Minimizing the blower workload too much will make for that nasty "BAMPF" sound.
Truthfully, I don't believe it is the flameholder preventing flashback on Chuk's burner. I tested units with similar hole sizes, they throttled down to lower output than the 'driveway buster' but also had less overall capacity; I still couldn't prevent flashback. Not that I doubt what Chuk says in the slightest. I suspect the difference may be the fuel/air ratios at very low firing rates. In my testing, if I throttled down just above the flashback velocity and then leaned out (or enriched) the mix, the burner would simply go out. If I spun the blower back up and relit, the mix was now out of whack and the flame wasn't good. This is just a wild guess, but maybe at very low flow rates the fuel/air mixture in Chuk's burner was enough different to allow the flame to quench but above that level the two units fuel delivery were fairly similar. This would be a small difference at an extreme end of the operating spectrum, so might be hard to detect and immaterial most of the time. <shrug> Beats me, the engineers definition of hell is a place where all the parts are right but the machine still won't work; purgatory might be the place where two machines look the same but work differently....
Regards,
Ken
|
Re: Stanley and White Burner Howl April 18, 2011 07:41AM |
Registered: 19 years ago Posts: 338 |
Caleb-
The Dragster burner DOES put out one helluva fire!! I have a very good pre-mix set-up....the vaporized fuel is injected into the airstream just before the second blower, which is a hi-pressure axial-type. The boiler generates 1200 lbs/hr at 800psi/800F, and is set up for on-off operation. I planned to continue development of the burner, but the USLSR Project has since gotten all my attention!! When things get back to normal, I plan to get back into the development of the burner/generator for use in a road vehicle.
Cheers--Chuk
The Dragster burner DOES put out one helluva fire!! I have a very good pre-mix set-up....the vaporized fuel is injected into the airstream just before the second blower, which is a hi-pressure axial-type. The boiler generates 1200 lbs/hr at 800psi/800F, and is set up for on-off operation. I planned to continue development of the burner, but the USLSR Project has since gotten all my attention!! When things get back to normal, I plan to get back into the development of the burner/generator for use in a road vehicle.
Cheers--Chuk
|
Re: Stanley and White Burner Howl April 18, 2011 08:05AM |
Admin Registered: 18 years ago Posts: 2,107 |
|
Re: Stanley and White Burner Howl April 18, 2011 09:44AM |
Registered: 19 years ago Posts: 1,771 |
Yes Ken
My error.
When you started talking about drilled plates I thought you were back talking vaporizing Stanley burners again. Sorry to interrupt you’re off topic discussion. As long as where off topic how’s that engine you were casting up. I haven’t seen any machined parts yet.
Rolly
My error.
When you started talking about drilled plates I thought you were back talking vaporizing Stanley burners again. Sorry to interrupt you’re off topic discussion. As long as where off topic how’s that engine you were casting up. I haven’t seen any machined parts yet.
Rolly
|
Re: Stanley and White Burner Howl April 18, 2011 12:26PM |
Registered: 19 years ago Posts: 657 |
Hey Chuk,
Sounds wicked! I've got to mention that I love the furnace fire showing through the front of your boiler on your Ford frame conversion!
Any idea yet as to what engine you will be using in your new road car?
Ken,
You may be on to something there!
This is just a theory, but seeing as how Chuk's burner mixes vaporized fuel with the air through a fan and yours mixed "atmoized" fuel through a fan there could very well have been pockets of very rich mixtures of fuel and air around droplets of fuel in your burner at low outputs. This could explain why yours flashed back with the same sized grate holes when Chuk's didn't. Something to consider at least.
Peter,
I have only encountered one gas burner that flashes back on a consistent basis and that is the "turkey frying" burner that my brother has and we use to brew beer with. It only has a mixing chamber with a hole in the tapered hole in the top with a corrugated disk that is bolted down and produces slots about 1/4" to 3/8" wide by 1" long for the air and fuel to pass through. I will measure them next time I am over there. That thing makes a furious and LOUD roaring fire when cranked up, but no matter how the air shutter is set it always flashes back when turned down. I discovered however that if it is burning inside the mixing chamber after flashing back at a low output, I can crank it up and the fire will leap out of the mixing chamber and above the grate. It is a wild fire but serves its purpose well!
Caleb Ramsby
Sounds wicked! I've got to mention that I love the furnace fire showing through the front of your boiler on your Ford frame conversion!
Any idea yet as to what engine you will be using in your new road car?
Ken,
You may be on to something there!
This is just a theory, but seeing as how Chuk's burner mixes vaporized fuel with the air through a fan and yours mixed "atmoized" fuel through a fan there could very well have been pockets of very rich mixtures of fuel and air around droplets of fuel in your burner at low outputs. This could explain why yours flashed back with the same sized grate holes when Chuk's didn't. Something to consider at least.
Peter,
I have only encountered one gas burner that flashes back on a consistent basis and that is the "turkey frying" burner that my brother has and we use to brew beer with. It only has a mixing chamber with a hole in the tapered hole in the top with a corrugated disk that is bolted down and produces slots about 1/4" to 3/8" wide by 1" long for the air and fuel to pass through. I will measure them next time I am over there. That thing makes a furious and LOUD roaring fire when cranked up, but no matter how the air shutter is set it always flashes back when turned down. I discovered however that if it is burning inside the mixing chamber after flashing back at a low output, I can crank it up and the fire will leap out of the mixing chamber and above the grate. It is a wild fire but serves its purpose well!
Caleb Ramsby
|
Re: Stanley and White Burner Howl April 18, 2011 02:18PM |
Registered: 14 years ago Posts: 63 |
Hi all,
very intertesting topic, I have a 1904 Turner Miesse, it has a kerosene vapourising burner, with a single jet of around 1/16" diameter, this is directed down the midle of a mixing tube, where it entrains oxygen (air) the mixture of air/fuel enters the firebox through 1200 holes, these holes are in the sides of 7 tubes at 45degrees so that the jets hit on each other, there is no burner howl.
very intertesting topic, I have a 1904 Turner Miesse, it has a kerosene vapourising burner, with a single jet of around 1/16" diameter, this is directed down the midle of a mixing tube, where it entrains oxygen (air) the mixture of air/fuel enters the firebox through 1200 holes, these holes are in the sides of 7 tubes at 45degrees so that the jets hit on each other, there is no burner howl.
|
Re: Stanley and White Burner Howl April 19, 2011 07:46PM |
Registered: 19 years ago Posts: 257 |
Has anyone ever checked the frequency of the burners? It would be interesting to check several cars and correlate as much information as you can. If you know the frequency, you can check to see if it is a harmonic related to vapor tube lengths or such. Has anyone pointed a video camera at the flame and broken the action down frame by frame.
No one has really mentioned temperature much either, fluctuations in temperature will cause fluctuations in the fuel vapor/air mixture. The air and fuel temps may make a difference, and how evenly the air is heated is important for maintaining a homologous mixture. If the flame surges a little it can cause draft surges that can pulse the inlet air and which will usually result in uneven air temperatures entering the fire chamber. Actual air inlet pulsing may cause flame pulsations and be a product of the chamber resonation. The air pulsations may not produce much noise alone, but may induce flame pulsation noise.
Flame speeds are known, what is the speed of the vapors exiting the orifice ? This should be easily calculated to a reasonably accurate figure. Just measure the air volume entering over time, and take into account temp changes and fuel vapors. Divide the flow by the orifices and you can determine the velocity exiting the orifice. It should be reasonably close to flame speed. I believe one manual indicated the flame speed should match the vapor speed at a point 1/8 to 1/4 inch from the orifice. This is how burners are engineered to be quiet.
Peter Brow,
"Some Stanley burners run silently under all conditions, and with no backfire at shutdown. How?"
Good question !
No flame is silent, it is either to low in intensity for human hearing or out of the frequency range. The appearance of silence on a Stanley is probably just normal flame noise without extraneous events such as continuous flame pulsations or harmonic amplifications.
Peter Heid
No one has really mentioned temperature much either, fluctuations in temperature will cause fluctuations in the fuel vapor/air mixture. The air and fuel temps may make a difference, and how evenly the air is heated is important for maintaining a homologous mixture. If the flame surges a little it can cause draft surges that can pulse the inlet air and which will usually result in uneven air temperatures entering the fire chamber. Actual air inlet pulsing may cause flame pulsations and be a product of the chamber resonation. The air pulsations may not produce much noise alone, but may induce flame pulsation noise.
Flame speeds are known, what is the speed of the vapors exiting the orifice ? This should be easily calculated to a reasonably accurate figure. Just measure the air volume entering over time, and take into account temp changes and fuel vapors. Divide the flow by the orifices and you can determine the velocity exiting the orifice. It should be reasonably close to flame speed. I believe one manual indicated the flame speed should match the vapor speed at a point 1/8 to 1/4 inch from the orifice. This is how burners are engineered to be quiet.
Peter Brow,
"Some Stanley burners run silently under all conditions, and with no backfire at shutdown. How?"
Good question !
No flame is silent, it is either to low in intensity for human hearing or out of the frequency range. The appearance of silence on a Stanley is probably just normal flame noise without extraneous events such as continuous flame pulsations or harmonic amplifications.
Peter Heid
|
Re: Stanley and White Burner Howl April 19, 2011 08:48PM |
Registered: 19 years ago Posts: 338 |
Caleb-
You asked about the engine for the "road car"......I've got a good friend who's building a nice little 125 HP V4, and I mentioned-back when it was just an idea-that "if he built it"-I'd "build a car around it"....so it looks like he's gonna hold me to my promise!!
So, while working on the LSR Streamliner, I've been giving a bit of thought to the next one.....we'll see how it goes!
Chuk
You asked about the engine for the "road car"......I've got a good friend who's building a nice little 125 HP V4, and I mentioned-back when it was just an idea-that "if he built it"-I'd "build a car around it"....so it looks like he's gonna hold me to my promise!!
So, while working on the LSR Streamliner, I've been giving a bit of thought to the next one.....we'll see how it goes!
Chuk
|
Re: Stanley and White Burner Howl April 20, 2011 01:36AM |
Registered: 19 years ago Posts: 657 |
Hey Chris,
Very interesting burner that you have there! Is it an atmospheric type, that is, does it have an open bottom for air to pass up around the burner and complete the combustion.
I believe that the Lane had an atmospheric burner too, I wonder if it howled.
Peter Heid,
The more I look into this the more I believe that some Stanley burners are just flat out magic and some are the devil incarnate!
Chuk,
That sounds like a really healthy engine that you will be working with! Good luck with both of your projects!
Caleb Ramsby
Very interesting burner that you have there! Is it an atmospheric type, that is, does it have an open bottom for air to pass up around the burner and complete the combustion.
I believe that the Lane had an atmospheric burner too, I wonder if it howled.
Peter Heid,
The more I look into this the more I believe that some Stanley burners are just flat out magic and some are the devil incarnate!
Chuk,
That sounds like a really healthy engine that you will be working with! Good luck with both of your projects!
Caleb Ramsby
|
Re: Stanley and White Burner Howl April 20, 2011 04:11AM |
Registered: 19 years ago Posts: 1,771 |
Caleb
I believe that the Lane had an atmospheric burner too, I wonder if it howled.
Yes the Lane has an open burner and no it does not howl
Tig Eldredge SACA-NE has a Lane.
[www.steamautomobile.com]
I believe that the Lane had an atmospheric burner too, I wonder if it howled.
Yes the Lane has an open burner and no it does not howl
Tig Eldredge SACA-NE has a Lane.
[www.steamautomobile.com]
|
Re: Stanley and White Burner Howl April 20, 2011 10:05AM |
Registered: 19 years ago Posts: 1,453 |
>The appearance of silence on a Stanley is
>probably just normal flame noise without
>extraneous events such as continuous flame
>pulsations or harmonic amplifications.
That is good. I am not interested in some scientifically-defined "perfect silence"; "imperceptible" noise is more than good enough. Better by far than the quite obvious noise of IC engines... on which billions of dollars have been spent in an [ever-unsuccessful] effort to mask, muffle, or filter out...
Peter
>probably just normal flame noise without
>extraneous events such as continuous flame
>pulsations or harmonic amplifications.
That is good. I am not interested in some scientifically-defined "perfect silence"; "imperceptible" noise is more than good enough. Better by far than the quite obvious noise of IC engines... on which billions of dollars have been spent in an [ever-unsuccessful] effort to mask, muffle, or filter out...
Peter
|
Re: Stanley and White Burner Howl April 20, 2011 12:22PM |
Registered: 16 years ago Posts: 358 |
I don't recall burner flame noise in Stanley,cars,,,mostly the hiss of the jet at the nozzle,,from outside the car,,
From inside the car the buzz buzz buzz ,,of the early pumps
And the whump,,bump whump,,bump slowly of the long stroke pumps,,
The pump noise changes just a bit when pumping or bypassing,,so you can tell what its doing,,happy sound,,
I just add this for those not familiar with these cars,,
On the Lane,,,I think there are just 2 cars left,,early,,Tig's car,,and an 07 that went overseas a year or so ago,, just think,,,,,the Grout outnumber the Lane !!! Cheers,,Ben
From inside the car the buzz buzz buzz ,,of the early pumps
And the whump,,bump whump,,bump slowly of the long stroke pumps,,
The pump noise changes just a bit when pumping or bypassing,,so you can tell what its doing,,happy sound,,
I just add this for those not familiar with these cars,,
On the Lane,,,I think there are just 2 cars left,,early,,Tig's car,,and an 07 that went overseas a year or so ago,, just think,,,,,the Grout outnumber the Lane !!! Cheers,,Ben
|
Re: Stanley and White Burner Howl April 20, 2011 05:47PM |
Registered: 14 years ago Posts: 63 |
Hi again.
the answer is no, all the air needed for combustion is entrained up the mixing tube, there is a flat plate closing the bottom of the combustion chamber, if this plate is not sealed, back fires occour regularly when traveling into a head wind, my theory is that if the flame only has one way out, an incomming gust cannot turn it around or even push in back into the box, also if the air is force to enter via the mixing tube the velocity of the mixture comming through the jets is going to be greater than if only some of the air is comming out of the jets and some of the air is gathered from the atmosphere.I believe that having the combustion chamber sealed is the total answer with this burner, the speed of the jet up the mixing tube increases masivly as the mixture is lit, I think that the air pressure in the boiler case is lower because the oxygen has/is being burnt, and also the combusion is rising because of its heat, the combination of these two draws the necassary air through the tube and produces a mat of blue flame, rather than individual jets.
the answer is no, all the air needed for combustion is entrained up the mixing tube, there is a flat plate closing the bottom of the combustion chamber, if this plate is not sealed, back fires occour regularly when traveling into a head wind, my theory is that if the flame only has one way out, an incomming gust cannot turn it around or even push in back into the box, also if the air is force to enter via the mixing tube the velocity of the mixture comming through the jets is going to be greater than if only some of the air is comming out of the jets and some of the air is gathered from the atmosphere.I believe that having the combustion chamber sealed is the total answer with this burner, the speed of the jet up the mixing tube increases masivly as the mixture is lit, I think that the air pressure in the boiler case is lower because the oxygen has/is being burnt, and also the combusion is rising because of its heat, the combination of these two draws the necassary air through the tube and produces a mat of blue flame, rather than individual jets.
|
Re: Stanley and White Burner Howl April 20, 2011 06:14PM |
Registered: 19 years ago Posts: 657 |
Chris,
That is very interesting! So the tube assembly for the burner basically sits in a sealed chamber bellow the boiler tubing?
The lack of howl may very well have something to do with the impinging effect that the arrangement of the holes have. I have read of other early steam cars which used impinging flames set at 45 degrees to eachother which didn't even have the usual flame roar when being fired and no mention of any howling.
It could be that the flame impingement destroys any tendency of the flames to modulate in a frequency.
It is getting deeper!
Caleb Ramsby
That is very interesting! So the tube assembly for the burner basically sits in a sealed chamber bellow the boiler tubing?
The lack of howl may very well have something to do with the impinging effect that the arrangement of the holes have. I have read of other early steam cars which used impinging flames set at 45 degrees to eachother which didn't even have the usual flame roar when being fired and no mention of any howling.
It could be that the flame impingement destroys any tendency of the flames to modulate in a frequency.
It is getting deeper!
Caleb Ramsby
|
Re: Stanley and White Burner Howl April 20, 2011 07:27PM |
Registered: 19 years ago Posts: 1,453 |
Hi Ben,
I am definitely not familiar with Stanleys. I rode in one condensing car and 2 non-condensing cars, and in those cars I heard no mechanical or pump noise, despite listening for it. However, years of Stanley experience may allow "tuning in" even the quietest pump sounds. After lots of years I can tell a lot about Old VW engines -- valve adjustment, ignition timing, etc -- just from the sound, where somebody less familiar with these cars only hears a jumble of meaningless noise.
Some of the Stanley videos on YouTube, on the other hand, have lots of pump noise; no familiarity needed to hear the pumps on those cars. Even video cameras hear it. I plan to try some pump ideas which will hopefully avoid that kind of noise.
Jeff Theobald's 1919 Stanley got up to good speed and hard pulling on a grade, in one of my videos linked to above. No pump noise detected by me or the camera, with the camera microphone and my ears about 3 feet away from the pumps. Then again, Jeff's Stanley-tuned ear may have been listening to the pumps cycling on and off!
I did hear that faint burner hiss in 2 of the Stanleys I rode in. As you said, not from inside the car, but standing outside, near the boiler. And those cars had some howl under some conditions.
======
To be fair to IC cars, money spent on mufflers is not wasted. I've heard IC engines with no mufflers, and with bad mufflers. Whew. And realistically, I don't think that IC carmakers "try to eliminate" the noise, they just minimize it as much as possible with all the other factors which have to be balanced together. They do pretty well. But condensing steam cars can be much quieter.
If, that is, if burner "howl" can be avoided.
Peter
I am definitely not familiar with Stanleys. I rode in one condensing car and 2 non-condensing cars, and in those cars I heard no mechanical or pump noise, despite listening for it. However, years of Stanley experience may allow "tuning in" even the quietest pump sounds. After lots of years I can tell a lot about Old VW engines -- valve adjustment, ignition timing, etc -- just from the sound, where somebody less familiar with these cars only hears a jumble of meaningless noise.
Some of the Stanley videos on YouTube, on the other hand, have lots of pump noise; no familiarity needed to hear the pumps on those cars. Even video cameras hear it. I plan to try some pump ideas which will hopefully avoid that kind of noise.
Jeff Theobald's 1919 Stanley got up to good speed and hard pulling on a grade, in one of my videos linked to above. No pump noise detected by me or the camera, with the camera microphone and my ears about 3 feet away from the pumps. Then again, Jeff's Stanley-tuned ear may have been listening to the pumps cycling on and off!
I did hear that faint burner hiss in 2 of the Stanleys I rode in. As you said, not from inside the car, but standing outside, near the boiler. And those cars had some howl under some conditions.
======
To be fair to IC cars, money spent on mufflers is not wasted. I've heard IC engines with no mufflers, and with bad mufflers. Whew. And realistically, I don't think that IC carmakers "try to eliminate" the noise, they just minimize it as much as possible with all the other factors which have to be balanced together. They do pretty well. But condensing steam cars can be much quieter.
If, that is, if burner "howl" can be avoided.
Peter
|
Re: Stanley and White Burner Howl April 20, 2011 07:49PM |
Registered: 16 years ago Posts: 358 |
Hi Peter,,,,Condensr cars can be quieter????Gee I'm missing??something
My 735 was quieter than my 1925 Packard,,Quieter than a Silver Ghost even,,
Hiss from burner,,barely audible pump noise,,zero exhaust noise,,Barely audible rear gears,,,quieter than the Packard [which was spiral bevel,,not hypoy] you could ALMOST hear the spedometer gear,,
The non condensers pump noise is much like a T Ford coil buzzers,, Limiting the ball lift affects the ball clatter ,, OOOps got on wrong noise, its not burner,,but still noise,,Hope this helps,,Ben
My 735 was quieter than my 1925 Packard,,Quieter than a Silver Ghost even,,
Hiss from burner,,barely audible pump noise,,zero exhaust noise,,Barely audible rear gears,,,quieter than the Packard [which was spiral bevel,,not hypoy] you could ALMOST hear the spedometer gear,,
The non condensers pump noise is much like a T Ford coil buzzers,, Limiting the ball lift affects the ball clatter ,, OOOps got on wrong noise, its not burner,,but still noise,,Hope this helps,,Ben
|
Re: Stanley and White Burner Howl April 20, 2011 08:37PM |
Admin Registered: 18 years ago Posts: 2,107 |
Eh...
Yesterday a Chevy Volt came up on me from behind and I nearly jumped out of my skin, didn't begin to hear it coming, nothing is any quieter than that. I would be less than surprised to see legislation requiring a minimum amount of vehicle noise so as to protect the blind, children and guys distracted by pretty girls. We may see a trend to prohibit 'too quiet'.
Ken
Yesterday a Chevy Volt came up on me from behind and I nearly jumped out of my skin, didn't begin to hear it coming, nothing is any quieter than that. I would be less than surprised to see legislation requiring a minimum amount of vehicle noise so as to protect the blind, children and guys distracted by pretty girls. We may see a trend to prohibit 'too quiet'.
Ken
|
Re: Stanley and White Burner Howl April 21, 2011 04:35AM |
Registered: 19 years ago Posts: 1,453 |
Hi Ken,
I almost mentioned the engine-off hybrids & electrics which I have seen recently. Close-up, and at low speed, every bit as eerily quiet as the 2 condensing Stanleys which I've seen running (one in '05 UK, one in early-'80s CA). Yep, there has already been talk about yet more of that wonderful government red tape, and at least one Japanese automaker is experimenting with add-on noisemakers for their hybrids. Might depend on what percentage of the cars on the road get that quiet. Voluntary noisemakers might derail new regs. Or the "noise pollution" lobby might push regs in the opposite direction. "Ever in motion, the future is."
Hi Ben,
It does help; brings back pleasant memories of nice quiet steam car rides. And how to duplicate them. Quieter than a good Packard or Rolls, that's saying something. Years ago I read an article in The Steam Automobile about nylon balls for Stanley pump checks, to help keep the pumps quiet; also easier on the check valve seats. I might try it.
Peter
I almost mentioned the engine-off hybrids & electrics which I have seen recently. Close-up, and at low speed, every bit as eerily quiet as the 2 condensing Stanleys which I've seen running (one in '05 UK, one in early-'80s CA). Yep, there has already been talk about yet more of that wonderful government red tape, and at least one Japanese automaker is experimenting with add-on noisemakers for their hybrids. Might depend on what percentage of the cars on the road get that quiet. Voluntary noisemakers might derail new regs. Or the "noise pollution" lobby might push regs in the opposite direction. "Ever in motion, the future is."
Hi Ben,
It does help; brings back pleasant memories of nice quiet steam car rides.
And how to duplicate them. Quieter than a good Packard or Rolls, that's saying something. Years ago I read an article in The Steam Automobile about nylon balls for Stanley pump checks, to help keep the pumps quiet; also easier on the check valve seats. I might try it.Peter
|
Re: Stanley and White Burner Howl April 21, 2011 12:47PM |
Registered: 19 years ago Posts: 1,771 |
Years ago I read an article in The Steam Automobile about nylon balls for Stanley pump checks, to help keep the pumps quiet; also easier on the check valve seats. I might try it.
Peter
Peter
I’ve gone that route once on my big steamboat at 300 PSI. Typically the seat of the check is sharp edged, the ball I used in less then a season got smaller and smaller till they passed through the check and caused trouble. You need a hard ball like Torlon, and a V type seat. That aside if the height the ball can lift is correct for the ball diameter you can hardly hear it anyway. As Ben stated it’s nice to know the pumps are working when you close the bypass or the water gets low and the automatic lets you know your pumping.
Rolly
Peter
Peter
I’ve gone that route once on my big steamboat at 300 PSI. Typically the seat of the check is sharp edged, the ball I used in less then a season got smaller and smaller till they passed through the check and caused trouble. You need a hard ball like Torlon, and a V type seat. That aside if the height the ball can lift is correct for the ball diameter you can hardly hear it anyway. As Ben stated it’s nice to know the pumps are working when you close the bypass or the water gets low and the automatic lets you know your pumping.
Rolly
Sorry, only registered users may post in this forum.
All files from this thread
