1 Steam Cars : Phorum
General Steam Car topics
Fuel and water consumption
Posted by: Per Nielsen (IP Logged)
Date: May 17, 2006 07:40PM
<HTML>What would be the water and fuel consumption/h for a Locomobile (1903) going full speed on level road?
Regards, Per</HTML>
Regards, Per</HTML>
Re: Fuel and water consumption
Posted by: Ben (IP Logged)
Date: May 17, 2006 11:40PM
<HTML>Hi,,,What burner is in it?,,,Does it have superheat?? Cheers Ben</HTML>
Re: Fuel and water consumption
Posted by: Per Nielsen (IP Logged)
Date: May 18, 2006 05:35PM
<HTML>Hi Ben,
It is a 1903 locomobile. The fuel system is not complete and I think the vaportube over the boiler is too short. And the fuel line does'nt go though the boiler tubes. When steam leaves the boiler it travels though a spiral shaped tube before it reaches the regulating steam valve. So it must be overheating.
I need the figures for fuel- and water consumption to estimate safetyvalve capacity.
regards, Per</HTML>
It is a 1903 locomobile. The fuel system is not complete and I think the vaportube over the boiler is too short. And the fuel line does'nt go though the boiler tubes. When steam leaves the boiler it travels though a spiral shaped tube before it reaches the regulating steam valve. So it must be overheating.
I need the figures for fuel- and water consumption to estimate safetyvalve capacity.
regards, Per</HTML>
Re: Fuel and water consumption
Posted by: SSsssteamer (IP Logged)
Date: May 20, 2006 02:14AM
<HTML>How one drives the steam car also greatly affects it's water and fuel mileage. Last month at the "Bakersfield swap meet and car tour", the new owner of Dick Vennerbeck's Curved Dash Olds/Locomobile steamer type stopped 7 times to fill his water tank on the way to the 24 mile point lunch stop. On the return 24 mile trip he only had to stop two times. It was all flat land and only his driving technique had changed. On the way out, he kept his throttle wide open, never getting over 60 psi on his steam pressure gauge. After giving him some advice, on his return trip, he openned his throttle only enough to keep his burner from cycling off. Saturated steam verses super heated steam makes a big difference in water consumption. On my Stanleys I find that speed will also eat up my water suppley a lot more quickly. At 35 mph with our 10 hp Stanley, it can get up to 1 1/2 miles to the gallon of water. At 55 mph, it is sure to drop down to 1 mile to the gallon of water. Vern Wellburn said that he is getting two miles to the gallon of water on his 1899 Locomobile.</HTML>
Re: Fuel and water consumption
Posted by: Rolly (IP Logged)
Date: May 20, 2006 10:37PM
<HTML>If I understand your question correctly you are only interested in sizing your safety valve.
First calculate your heating surface. Per the SAME code, on a fire tube boiler one HP = 10 square foot of heating
One HP is also defined as evaporating 34.5 Lb of water per hour.
So you should be able to calculate your total water rate the boiler is capable of. It has nothing to do with how efficient your engine is or your burner.
You need to pass enough water & pressure through your safety valve so that your pressure will not increase more then 7% under full fire.
The size hole you will need is listed in the catalog of safety valves based on your total water rate.
Off coarse I would think you should check the rules in England.
Rolly</HTML>
Rolly
First calculate your heating surface. Per the SAME code, on a fire tube boiler one HP = 10 square foot of heating
One HP is also defined as evaporating 34.5 Lb of water per hour.
So you should be able to calculate your total water rate the boiler is capable of. It has nothing to do with how efficient your engine is or your burner.
You need to pass enough water & pressure through your safety valve so that your pressure will not increase more then 7% under full fire.
The size hole you will need is listed in the catalog of safety valves based on your total water rate.
Off coarse I would think you should check the rules in England.
Rolly</HTML>
Rolly
Re: Fuel and water consumption
Posted by: Rolly (IP Logged)
Date: May 20, 2006 10:52PM
<HTML>I hope you also understand your expected to test your newly selected safety valve by wedging it open and firing the boiler at full fire and not raising the pressure beyond the 7%. You can then adjust the hole size accordingly.</HTML>
Rolly
Rolly
Re: Fuel and water consumption
Posted by: Ben (IP Logged)
Date: May 21, 2006 12:39AM
<HTML>Hi Rolly,,,,Is there a time spec the test should be run,,,to normalize ? Cheers Ben</HTML>
Re: Fuel and water consumption
Posted by: Rolly (IP Logged)
Date: May 21, 2006 01:33AM
<HTML>Hi Ben
One of the problems with testing a safety on small boilers is you can blow the water out before you can get enough back in. You just have to watch very carefully to see that the pressure is not increasing.
Most ASME safety do not reset till the pressure drops below 7% of the setting. A safety set at 750 PSI might not reset till it gets down to below 700. You really never want to let your boiler get to the point of blowing the safety.
On good well-made ASME safety there is a backing ring that can be adjusted to reduce the 7% to 2 to 3 % but it has to be done on a live steam manifold with constant pressure. I had this done on both my code boilers in my boats.</HTML>
Rolly
One of the problems with testing a safety on small boilers is you can blow the water out before you can get enough back in. You just have to watch very carefully to see that the pressure is not increasing.
Most ASME safety do not reset till the pressure drops below 7% of the setting. A safety set at 750 PSI might not reset till it gets down to below 700. You really never want to let your boiler get to the point of blowing the safety.
On good well-made ASME safety there is a backing ring that can be adjusted to reduce the 7% to 2 to 3 % but it has to be done on a live steam manifold with constant pressure. I had this done on both my code boilers in my boats.</HTML>
Rolly
Re: Fuel and water consumption
Posted by: Mike Clark (IP Logged)
Date: May 21, 2006 11:43AM
<HTML>Rolly,
My experience with Stanley safety valves is that they do not close again until the pressure has dropped right down - I only had mine go off once when I tapped it to discourage a minor sizzle - pressure dropped from 400 to about 200psi before it shut, the burner was off at the time.
I suspect the test is much more relevant to a locomotive where the fire cannot be put out to stop steam being made - the Stanley's fuel automatic is a safety feature in its own right which lcomotives just don't have. Rightly or wrongly the rules for boiler safety don't take this into account.
It would be nice to know if anyone has ever actually measured the required safety valve hole size in the way you describe. I believe Per is in Norway not in the UK.
Mike</HTML>
My experience with Stanley safety valves is that they do not close again until the pressure has dropped right down - I only had mine go off once when I tapped it to discourage a minor sizzle - pressure dropped from 400 to about 200psi before it shut, the burner was off at the time.
I suspect the test is much more relevant to a locomotive where the fire cannot be put out to stop steam being made - the Stanley's fuel automatic is a safety feature in its own right which lcomotives just don't have. Rightly or wrongly the rules for boiler safety don't take this into account.
It would be nice to know if anyone has ever actually measured the required safety valve hole size in the way you describe. I believe Per is in Norway not in the UK.
Mike</HTML>
Re: Fuel and water consumption
Posted by: Rolly (IP Logged)
Date: May 21, 2006 12:47PM
<HTML>Yes Mike you are correct in that there are many other forms of safety equipment. My big boat Tryall has automatic emergence feed water, automatic burner control, as does my Stanley. All this has nothing to do with sizing the safety valve.
A Stanley safety valve as designed, sucks. It is a piss pure excuse for a safety valve and would not qualify under the ASME rules. Today that type of design is used on air compressors under that section of the code. The valve should be designed to reduce pressure not blow all the water out of the boiler. And yes any one that builds to the ASME code checks and uses the correct valve. When I designed my ASME boiler for my small boat, that is one of item you have to submit the cut sheets on as well as the calculations you used to size the hole. There are other ways to be more precise in your calculations, but I’m not about to look up all the data. The test is more relevant to a boiler with limited water capacity in my experience but is a requirement after installing a new safety valve per the ASME code.
There is still a right way to do things.
Per Nielsen in on the right track.</HTML>
Rolly
A Stanley safety valve as designed, sucks. It is a piss pure excuse for a safety valve and would not qualify under the ASME rules. Today that type of design is used on air compressors under that section of the code. The valve should be designed to reduce pressure not blow all the water out of the boiler. And yes any one that builds to the ASME code checks and uses the correct valve. When I designed my ASME boiler for my small boat, that is one of item you have to submit the cut sheets on as well as the calculations you used to size the hole. There are other ways to be more precise in your calculations, but I’m not about to look up all the data. The test is more relevant to a boiler with limited water capacity in my experience but is a requirement after installing a new safety valve per the ASME code.
There is still a right way to do things.
Per Nielsen in on the right track.</HTML>
Rolly
Re: Fuel and water consumption
Posted by: Mike Clark (IP Logged)
Date: May 21, 2006 10:56PM
<HTML>Rolly
I don't doubt that correctly sizing the safety valve outlet is the right thing to do - it's just that every Stanley I have seen still runs with the original design of safety valve - bad though it is.
Is there an alternative design which has been used and proven on a Stanley? It would be nice to have one which would :-
1. Shut off again (reset) not too far below working pressure. Locomotive safety valves can run blowing off continuously at working pressure yet still close properly.
2. Not need to be dismantled and reground each time it goes off!
3. If it succeeded in meeting points 1 and 2 then it could be set closer to the working pressure so that with a slight tweak of the steam auto the safety could be tested and cleaned through under steam. This would be useful as they do get horribly crudded up if even the smallest leak is passing through.
I suspect the main reason why nobody has come up with something better is a fear of legislation - if you make something different to the original and it goes wrong all hell will let loose. At least with an original you can say "well they've been made like that for 100 years".
Mike</HTML>
I don't doubt that correctly sizing the safety valve outlet is the right thing to do - it's just that every Stanley I have seen still runs with the original design of safety valve - bad though it is.
Is there an alternative design which has been used and proven on a Stanley? It would be nice to have one which would :-
1. Shut off again (reset) not too far below working pressure. Locomotive safety valves can run blowing off continuously at working pressure yet still close properly.
2. Not need to be dismantled and reground each time it goes off!
3. If it succeeded in meeting points 1 and 2 then it could be set closer to the working pressure so that with a slight tweak of the steam auto the safety could be tested and cleaned through under steam. This would be useful as they do get horribly crudded up if even the smallest leak is passing through.
I suspect the main reason why nobody has come up with something better is a fear of legislation - if you make something different to the original and it goes wrong all hell will let loose. At least with an original you can say "well they've been made like that for 100 years".
Mike</HTML>
Re: Fuel and water consumption
Posted by: Rolly (IP Logged)
Date: May 22, 2006 12:27AM
<HTML>Hi Mike
I don’t know of any ASME rated valve currently on the market that would be small enough and rated at the needed pressure for a steam car.
I still use a Stanley safety valve on my car, but my boiler is a Derr and can take a hydro for 3000 Lb. and I run all electric burner and controllers. My boats are only 300 PSI and safety are available.
I have no problem with using one if you don’t walk away and leave the boiler main fire on. The most you will do is blow all the water out and cook your boiler and it’s your money.
I think if you look through some of the old model-engineering book you will find articles on how to build pop safety valves so they will limit the amount of water that is passed. I seem to remember some English books in the sixty.
Per asked the question and I just tried to give him an honest answer, as I know it.</HTML>
Rolly
I don’t know of any ASME rated valve currently on the market that would be small enough and rated at the needed pressure for a steam car.
I still use a Stanley safety valve on my car, but my boiler is a Derr and can take a hydro for 3000 Lb. and I run all electric burner and controllers. My boats are only 300 PSI and safety are available.
I have no problem with using one if you don’t walk away and leave the boiler main fire on. The most you will do is blow all the water out and cook your boiler and it’s your money.
I think if you look through some of the old model-engineering book you will find articles on how to build pop safety valves so they will limit the amount of water that is passed. I seem to remember some English books in the sixty.
Per asked the question and I just tried to give him an honest answer, as I know it.</HTML>
Rolly
Re: Fuel and water consumption
Posted by: Per Nielsen (IP Logged)
Date: May 23, 2006 09:57PM
<HTML>Thanks for all your comments. I think I can do an estimate for the inspector. And then test if it works.
I did this on the 23" boiler for my 735. When testing it live I had to take it above the saftyvalve release pressure with burner going full flame. The pressure was infact dropping.
Regards Per (Denmark)</HTML>
I did this on the 23" boiler for my 735. When testing it live I had to take it above the saftyvalve release pressure with burner going full flame. The pressure was infact dropping.
Regards Per (Denmark)</HTML>
Sorry, only registered users may post in this forum.