1 Steam Cars : Phorum
General Steam Car topics
Placing condensor inside of feed water tank?
Posted by: Caleb Ramsby (IP Logged)
Date: October 17, 2002 05:44PM
<HTML>Reading the discussion of boiler and condensor unit ratios has lead me to disclose an idea that I have kept to my self for a while. I have just recently realized that to produce a viable steam car there must be a conglomeration of ideas and knowledge. Otherwise the inventors and the engineers shall not acomplish their full potential or most likely anything at all.
I know that it has been a practice to preheat the feed water with a small portion of the condensor just before admiting the water to the boiler. To the best of my knowledge this has been acomplished with a small secondary condensor only heating a small portion of the feed water.
A while ago I was thinking about how much energy is lost when the steam is condensed from a gas to a liquid. Almost all of this energy is going into the atmosphere. I believe that if one were to place the whole of the condensor into the feed water tank, then not only would all of the condensing energy be placed back into the system. But, the cooling medium(water) would have a much greater conductivity thus effeciency than the prior medium (air).
This is where the people in the know come in, because I am forseeing a few difficulties. Please enlighten me on these points.
1. What is the greatest pheasible heat that the feed water could achieve without imparting difficulties to the feed water pump?
2. There will be a massive amount of energy expelled into the feed water tank when the steam is being condensed. What amount of water would be needed to inhibit the water from begining to boil?
3. If the feed water was allowed to boil. Could the feed pump take the water from the bottem of the tank, or would the gaseas action of the water create problems?
A fix I just thought of would be to have a preasurized feed water tank. Make the tank with a height to diameter ratio of 4 to 1. Have a small secondary tank about 1/10 the capacity of the feed water tank. Place the secondary tank with it's top at the same height of the main tank. Connect the secondary tank to the primary tank with a tube that comes from the side at the bottem of the primary tank going to the bottem of the secondary tank. Have the secondary tank cooled with fins or such.
Theoreticly I am visualizing the primary tank using it's low pressure to push the boiling water in the bottem of it up the tube into the secondary tank. The secondary tank being cooled until the temperature is sufficient to be utilized by the pump and the preasure form the main tank assisting the pumping action of the feed water pump.
There would be a few penalties using this preasurized tank system. The main being a second boiler as it would be. This would increase cost and make for a much more complicated system.
Thanks for allowing the access to such a great group of fertile and experienced minds! This site is a God send!
Caleb Ramsby</HTML>
I know that it has been a practice to preheat the feed water with a small portion of the condensor just before admiting the water to the boiler. To the best of my knowledge this has been acomplished with a small secondary condensor only heating a small portion of the feed water.
A while ago I was thinking about how much energy is lost when the steam is condensed from a gas to a liquid. Almost all of this energy is going into the atmosphere. I believe that if one were to place the whole of the condensor into the feed water tank, then not only would all of the condensing energy be placed back into the system. But, the cooling medium(water) would have a much greater conductivity thus effeciency than the prior medium (air).
This is where the people in the know come in, because I am forseeing a few difficulties. Please enlighten me on these points.
1. What is the greatest pheasible heat that the feed water could achieve without imparting difficulties to the feed water pump?
2. There will be a massive amount of energy expelled into the feed water tank when the steam is being condensed. What amount of water would be needed to inhibit the water from begining to boil?
3. If the feed water was allowed to boil. Could the feed pump take the water from the bottem of the tank, or would the gaseas action of the water create problems?
A fix I just thought of would be to have a preasurized feed water tank. Make the tank with a height to diameter ratio of 4 to 1. Have a small secondary tank about 1/10 the capacity of the feed water tank. Place the secondary tank with it's top at the same height of the main tank. Connect the secondary tank to the primary tank with a tube that comes from the side at the bottem of the primary tank going to the bottem of the secondary tank. Have the secondary tank cooled with fins or such.
Theoreticly I am visualizing the primary tank using it's low pressure to push the boiling water in the bottem of it up the tube into the secondary tank. The secondary tank being cooled until the temperature is sufficient to be utilized by the pump and the preasure form the main tank assisting the pumping action of the feed water pump.
There would be a few penalties using this preasurized tank system. The main being a second boiler as it would be. This would increase cost and make for a much more complicated system.
Thanks for allowing the access to such a great group of fertile and experienced minds! This site is a God send!
Caleb Ramsby</HTML>
Re: Placing condensor inside of feed water tank?
Posted by: Peter Heid (IP Logged)
Date: October 17, 2002 07:15PM
<HTML>Caleb,
Most feed water is kept below 180 degrees F. as the pump cavation can become a great trouble. Special pumps have been designed to pump higher temperatures but require carefull design and they are normally at least a few feet below the water level. After the pump has the water under pressure, then you can add great amounts of heat.
To determine the amount of water to keep the tank from boiling depends on how fast the tank cooling fins can remove the heat, how much steam is entering the tank and at what temperature as well as the initial temperature of the water it is entering.
I would not be suprised to find your idea has been used to one extent or another. The guys on the forum with all the knowledge can tell you more.
Peter Heid</HTML>
Most feed water is kept below 180 degrees F. as the pump cavation can become a great trouble. Special pumps have been designed to pump higher temperatures but require carefull design and they are normally at least a few feet below the water level. After the pump has the water under pressure, then you can add great amounts of heat.
To determine the amount of water to keep the tank from boiling depends on how fast the tank cooling fins can remove the heat, how much steam is entering the tank and at what temperature as well as the initial temperature of the water it is entering.
I would not be suprised to find your idea has been used to one extent or another. The guys on the forum with all the knowledge can tell you more.
Peter Heid</HTML>
Re: Placing condensor inside of feed water tank?
Posted by: Mike Bennett (IP Logged)
Date: October 17, 2002 07:30PM
<HTML>Caleb,
what you just described is very similar to a standard industrial boiler installation. The pressure tank with the addition of a gas vent, internal feedwater spray bars and an oxygen scavaging chemical would become a D.A. (deairator). Yes, the pumps will cavitate if you get them outside of thier curve (often solvable by increasing the D.A. pressure.
Regars,
Mike</HTML>
what you just described is very similar to a standard industrial boiler installation. The pressure tank with the addition of a gas vent, internal feedwater spray bars and an oxygen scavaging chemical would become a D.A. (deairator). Yes, the pumps will cavitate if you get them outside of thier curve (often solvable by increasing the D.A. pressure.
Regars,
Mike</HTML>
Re: Placing condensor inside of feed water tank?
Posted by: David K Nergaard (IP Logged)
Date: October 18, 2002 10:30AM
<HTML>The exhaust steam has almost ten times as much heat as needed to heat the feed water to the temperature of the steam. The remainder must be dumped to the atmaoshere.
Steam car feed water heaters heat all the feed water and are fitted on the output, high presseure, side of the pumps so cavitation problems are minimized. Most car condensors cannot handle all the steam, eapecially on hills. The usual result is steam entering the feed tank with the condensate, heating the tank. That usually means the feed water pumps have cavitation problems, evidenced by pounding noises, as the car reaches the top of a hill. This is definately bad as this is just the time when efficient pumps are needed most!</HTML>
Steam car feed water heaters heat all the feed water and are fitted on the output, high presseure, side of the pumps so cavitation problems are minimized. Most car condensors cannot handle all the steam, eapecially on hills. The usual result is steam entering the feed tank with the condensate, heating the tank. That usually means the feed water pumps have cavitation problems, evidenced by pounding noises, as the car reaches the top of a hill. This is definately bad as this is just the time when efficient pumps are needed most!</HTML>
Re: Placing condensor inside of feed water tank?
Posted by: Caleb Ramsby (IP Logged)
Date: October 19, 2002 03:13PM
<HTML>Thanks for the thorough responses!
After considering this information it occurs to me that heating the whole feed water tank is realy a waste of time and a waste of "waste" energy. Chuckle. . . Chuckle. At least in an automotive aplication. I am just trying to figure out a way to recapture the energy lost when condensing occurs.
The often mentioned "condense inside the engine" idea, is in my opinion a very inefective one. Slowing down the engines cycles and creating great seal problems.
Another problem with using the feed water tank to condense the steam is that the final temperature of the condensed water would be just below boiling. Acording to some other discussions the fully condensed water creates the greatest vacuum when at 72 deg. F. So this would be another considerable penelty!
Thanks again for the enlightment.
Caleb Ramsby</HTML>
After considering this information it occurs to me that heating the whole feed water tank is realy a waste of time and a waste of "waste" energy. Chuckle. . . Chuckle. At least in an automotive aplication. I am just trying to figure out a way to recapture the energy lost when condensing occurs.
The often mentioned "condense inside the engine" idea, is in my opinion a very inefective one. Slowing down the engines cycles and creating great seal problems.
Another problem with using the feed water tank to condense the steam is that the final temperature of the condensed water would be just below boiling. Acording to some other discussions the fully condensed water creates the greatest vacuum when at 72 deg. F. So this would be another considerable penelty!
Thanks again for the enlightment.
Caleb Ramsby</HTML>
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