Cooling drum evaporation

[ronmar]

It could, and would work well I think. You can also get basic float valves at most farm and feed stores that are designed to clamp to the side of a tank and connect to a garden hose to automatically keep horse and livestock tanks full.

Ron

[mike90045]

Just invert a 5ga water bottle over the open tank, level drops enough, and glug glug.... 2 quarts come out, tops off tank.
  Just like the office water cooler.

[ronmar]

Just invert a 5ga water bottle over the open tank, level drops enough, and glug glug.... 2 quarts come out, tops off tank.
  Just like the office water cooler.

Now why didn't I think of that?  Our animals water dish in the house is like that.  The dish is always full and we only have to refill that bottle every 2 weeks or so...

Ron

[rbodell]

It could, and would work well I think. You can also get basic float valves at most farm and feed stores that are designed to clamp to the side of a tank and connect to a garden hose to automatically keep horse and livestock tanks full.

Ron

I was originally concerned about the antifreeze evaporating which it appears is not a problem. As for keeping the tank full, that is not a problem either as I check it at the begining of each run. In my case anyhow, Not enough is lost for evaporation even in the summer, make an auto fill system necessary. Although the auto fill would take care of any accidental overlooking of the water level in the drum, I think the auto fill would tend to make us lazy and not check it. Then if the valve should stick, you could eventually loose water.

When I worked on a tug boat, I walked my engine room every 20 minutes and that avirted a lot of potential problems before they got to be a real problem. I don't think every 20 minutes is really necessary here but still a regular visual check is foolproof. I do check my temperature about every 20 minutes via camera hooked to the video/sound input of the TV. The audio lets me listen to the engine at the same time.

I think nothing beats a habitual walkthrough of the engine room.

[rbodell]

Having sufficient radiation of any type is essential in any heating  or engine cooling system but the advantage of (passively) recapturing water results in less corrosion as the water frees itself of contaminants and dissolved air.

A farm of heat pipes on top would I believe passively accomplish this and cut evap water losses to basically nothing.  Each 2" X 50" pipe would add 318 SQ/IN to the radiation surface.  A 55 gallon drum top has about 380 SQ/IN of surface.  So adding twenty 2X50 pipes would be like adding 16 drum lids of additional surface area to which the hottest vapor would rise into and transfer it's heat to... 
Ron 

I was just thinking, Would those pipes be more efficient if they were placed in the side of the drum instead of the top where they would have water behind them instead of air?

[mike90045]

I think the auto fill would tend to make us lazy and not check it. Then if the valve should stick, you could eventually loose water.

Valve will stick in ON position, and flood your engine room, drain your well, and steal your women.

[ronmar]

Having sufficient radiation of any type is essential in any heating  or engine cooling system but the advantage of (passively) recapturing water results in less corrosion as the water frees itself of contaminants and dissolved air.

A farm of heat pipes on top would I believe passively accomplish this and cut evap water losses to basically nothing.  Each 2" X 50" pipe would add 318 SQ/IN to the radiation surface.  A 55 gallon drum top has about 380 SQ/IN of surface.  So adding twenty 2X50 pipes would be like adding 16 drum lids of additional surface area to which the hottest vapor would rise into and transfer it's heat to... 
Ron 

     
I was just thinking, Would those pipes be more efficient if they were placed in the side of the drum instead of the top where they would have water behind them instead of air?

Water behind them is only good if there is hot water circulated tru them with enough turbulence to break up any laminar flow.  That is what puts a large drum on the lower end of the efficiency scale.  It is passive, but it is not especially efficient as the central water mass in the tank stores a lot of energy.  The only way we get away with it is due to the self regulating nature of evap.  The hotter it gets, the more heat flows away as vapor.  Putting the tubes around the sides would shield/insulate the existing sides and so cancell out some of the current surface area.  Putting them on top grows more surface area which is what is needed for a closed system whith these dissipatin characteristics.

The heat pipes on top would not have air behind them, they would have heat saturated water vapor that is rising off the water surface in the drum.  This vapor naturally rises away from the surface as it does in normal open tank evap and carries a lot of heat with it.  In the tubes it finds abundent cooler surface area to condense back into liquid and drip back into the main tank as cool water.  Similar to thermosiphon, but with a couple of changes in state...

Ron

[rbodell]

    
I was just thinking, Would those pipes be more efficient if they were placed in the side of the drum instead of the top where they would have water behind them instead of air?

Water behind them is only good if there is hot water circulated tru them with enough turbulence to break up any laminar flow.  That is what puts a large drum on the lower end of the efficiency scale.  It is passive, but it is not especially efficient as the central water mass in the tank stores a lot of energy.  The only way we get away with it is due to the self regulating nature of evap.  The hotter it gets, the more heat flows away as vapor.  Putting the tubes around the sides would shield/insulate the existing sides and so cancell out some of the current surface area.  Putting them on top grows more surface area which is what is needed for a closed system whith these dissipatin characteristics.

The heat pipes on top would not have air behind them, they would have heat saturated water vapor that is rising off the water surface in the drum.  This vapor naturally rises away from the surface as it does in normal open tank evap and carries a lot of heat with it.  In the tubes it finds abundent cooler surface area to condense back into liquid and drip back into the main tank as cool water.  Similar to thermosiphon, but with a couple of changes in state...

Ron

Ok that makes sense now. Hot air rises, cold water falls.

[rbodell]

I think the auto fill would tend to make us lazy and not check it. Then if the valve should stick, you could eventually loose water.

Valve will stick in ON position, and flood your engine room, drain your well, and steal your women.

I thought they would be most likely to stick in the off position. That is what I get for thinking i guess.

Wish I had known that while the x wife was around.

[lev-l-lok]

Perhaps the system used sucessfully in the 30's for condensers on flywheel motors would prove useable. Get some heavy bronze mesh, roll into a slight cone shape, approx. 21" OD at the big end X 18" OD at the small end X about 20" long. Put a ring at the big end to hold the dia., then flatten the other end closed to form sort of a flattened teepee. If you go to old engine shows you will see several versions of this type of condenser. Another version of this I have seen is U shaped copper (flashing ?) ribs, about 3/16 between the legs and spaced about the same in an A frame shape, the open side of the U faces inward, this will also provide ample surface area for condensing the evaporated water, and letting it drip back into the barrel. It will add that true, old engine look to your rig.

Paul

[rleonard]

One trick to retard evaporation is placing a layer or two of hollow plastic balls to float on the surface.  They act as little condensors and let the vapor drip back into the fluid. 

This trick is used in heat treat, metal processing and acid bath processes.  Check US Plastics and other sources for them.

Bob

[lev-l-lok]

Bob, the spheres you are talking about are used to prevent evaporation, like using oil, but the balls allow the material being processed to pass into the tank without being contaminated. Afriend of mine that owns an industrial plating shop uses them for that purpose.

Paul

[Grael]

One trick to retard evaporation is placing a layer or two of hollow plastic balls to float on the surface.  They act as little condensors and let the vapor drip back into the fluid. 

This trick is used in heat treat, metal processing and acid bath processes.  Check US Plastics and other sources for them.

Bob

I'm thinking ping pong balls for some reason...

[mike90045]

I think the auto fill would tend to make us lazy and not check it. Then if the valve should stick, you could eventually loose water.

Valve will stick in ON position, and flood your engine room, drain your well, and steal your women.

I thought they would be most likely to stick in the off position. That is what I get for thinking i guess.

Wish I had known that while the x wife was around.

The valve will nearly always stick opposite the position you plan for.
 Sort of like the "Law of Selective Gravitation" where the amount of law applied is proportional to the amount of jelly on the toast, and the value of the carpet underneath.