float material that can survive 200+ F degrees indefinitely

[pybyr]

I just had an idea that may hold promise- enough so that I don't want to give it away in detail yet, in case I may actually want to take it somewhere commercially.

But I need suggestions on what material or combination of materials may be able to survive as a "float" - with significant buoyancy- on top of 200+ F water in a heat storage tank.

Ideas/ suggestions are much appreciated.

Thanks

 

[chuck172]

Any metal that can hold air, how about a piece of copper with sweat caps soldered on.

 

[steam man]

Your looking for something to stop evaporation I presume. I use something like this in a pollution control system. Try this:

http://cicball.thomasnet.com/viewitems/hollow-plastic-balls/polypropylene-hollow-balls

Mike

 

[pybyr]

Your looking for something to stop evaporation I presume. I use something like this in a pollution control system. Try this:

http://cicball.thomasnet.com/viewitems/hollow-plastic-balls/polypropylene-hollow-balls

Mike

Thanks Mike- not quite- but I appreciate the suggestion. What I am thinking is that what better way to achieve and maintain stratification (in an unpressurized tank) than if an appropriate inlet/ outlet could actually float at/ just below the upper surface of the water (which will vary in height as the water level goes up and down with expansion and contraction of temperature changes). So the float balls might work if I could somehow "entrain them" and support something from them, but something flat, wide, and impermeable (that the "port" could be attached to the bottom of) would be the cat's meow.

Thanks for any further ideas, folks

 

[MaineMike100]

A floating strainer of sorts? One can be simply manufactured using metal tubes for floatation as already suggested, welded to a perforated strainer. We use a similar device on fire departments all the time to float on the water and pump water from the pond.

 

[stokes79]

you could use a blown glass ball in a wire mesh net, japanese fisherman have been using them for centuries and it they are thick enough they are pretty hardy

 

[Der Fuirmeister]

....What I am thinking is that what better way to achieve and maintain stratification (in an unpressurized tank) than if an appropriate inlet/ outlet could actually float at/ just below the upper surface of the water (which will vary in height as the water level goes up and down with expansion and contraction of temperature changes). So the float balls might work if I could somehow "entrain them" and support something from them, but something flat, wide, and impermeable (that the "port" could be attached to the bottom of) would be the cat's meow.

Thanks for any further ideas, folks

You are on the same line of thinking that I was. My thought was to not attach, but leave it float. A SS 2"X16" float would be buoyant enough for what I had in mind. A hose(s) from there to the side wall / piping. The same float could handle suction and discharge and not flip over. Initially I thought of foam, but that would breakdown. I've tried welding an enclosed tank before and the heated air makes it difficult. A guy could just go to the store and buy two 9"X13" SS sheet pans with the wide lip sides. Them mate them top to top and epoxy the seams together. Much the same way small engine gas tanks were made before they started using plastic.


Do I get to share in the patent ???

 

[pybyr]

Well, Der Fiur Meister, while we're on the topic of great minds thinking alike... (and yeah, I was initially thinking of foam for a float, too, but like you, realized it would not hold up)

what were you thinking for the hose or other flexible tubing to get from the tank wall to the "floating port" in the middle of the tank? I am temporarily stumped on materials that are large diameter, flexible, heat resistant, and do not cost like something from/ for NASA.

patent- who knows if this could pass muster for one, or if it has already been patented?

 

[Der Fuirmeister]

Heater hose typically used in a car. The more flexibility required, the longer I would make it. If there's a concern over material life, I'd go with the silicone type.

 

[coolidge]

Polystyrene will melt at 130 i believe, How about a piece of foam board with foil face, some good silicone from Sherwin Williams that you can paint on the board?

 

[Der Fuirmeister]

Polystyrene will melt at 130 i believe, How about a piece of foam board with foil face, some good silicone from Sherwin Williams that you can paint on the board?

I'm not sure the foam would take the abuse over time. Also not sure how you would attach the piping / tubing so it wouldn't come off under flow......

 

[Fred61]

How-'bout bending up a sheet of copper flashing and soldering it lile the float in a carburator. I've got a port-o-bender out in the shop that ain't too busy now.

 

[pybyr]

Thanks, all- now I am starting to look at some of these (Fred- thanks for your suggestion/ offer- only thing with the copper is that I wonder how it'd do in contact with air in a tank open to the atmosphere (with dissimilar metals elsewhere in the tank):

http://www.mcmaster.com/#valve-floats/=ei9q3

anyone remember any of the ways that one can figure the approximate "amount of flotation" one gets from an object of a specific size and volume?

 

[DaveBP]

figure the approximate “amount of flotation” one gets from an object of a specific size and volume?

Measure the volume of your object; H X W X D or L X circular area or whatever you have. Calculate the weight of the same volume of water (about 63 lbs./ 1728 cu. in.).

Weigh your object and subtract its weight from the calculated weight of water. The difference is the bouyancy.

 

[Der Fuirmeister]

I was thinking of using something wide and relatively flat so that it would be stable when subjected to the thrust of the water flowing through the fittings. The size would be more for stability than buoyancy. Round or cylindrical floats would roll and twist around.

The copper float that Fred mentioned should be OK if you are using copper coils for the hx. Otherwise SS would work. I would avoid aluminum with copper coils.

 

[heaterman]

Flatten out a copper toilet tank float.

 

[brad068]

Hummm.... I wonder if a guy could go the other way. Keep the supply support fixed and regulate the water level with a displacement object. Set up a float control to maintain the water level by submerging or removing an object in accordance with the temp of the water. Kind of like a carburetor float only the float is controlled by heat not flow. Then float oil on top of the water to control evaporation?? Remove with a skimmer??

 

[gorsuchmill]

Depending how heavy the item is you're attaching, what about a piece of plywood?

 

[mtnmizer]

Pumice, it floats on water, 200 degree
water would not bother it in any way.
Not sure if it waterlogs..

I comes in many different forms.. Blocks?

http://www.alibaba.com/product-tp/100265954/Pumice_Blocks.html

Dan

 

[pybyr]

Hmm- now I am wondering- perhaps a sheet of polypropylene 0.5 inch thick, and 2 ft by 2 ft, floating on top of the water level in the tank, with a second smaller plate with a hole in the center, and then a flange bolted to its center underside, with spacers, so that the water could enter and exit in all directions across the underside of the polypro sheet.

The goal here is to always be adding or taking the hottest water from the very top of the tank, at the center, and in a low-velocity flow that is roughly the same in all horizontal directions.

Anyone hazard any educated guesses as to whether the surface area of a 2x2 ft polypropylene sheet in contact with the water, and the surface tension of the water, would be enough to keep the circulator (which will be at a vertically lower level, down nearer the bottom of the tank, outside the tank- to try to maximize head and minimize cavitation, at the circulator itself) from pulling in pockets of air from the edges? Circulator will be a Wilo Star 21 3-speed, which has characteristics that are pretty nearly identical to the Grundfos 15-58:
(broken link removed to http://www.patriot-supply.com/products/showitem.cfm/177257)

With the semi- buoyancy of the polypro sheeting, I may not even need too much extra boost in flotation to keep it at or just below water level. The polypro sheeting looks surprisingly modest in cost, so maybe I'll get some chunks and see how it behaves in the "small research tank" at the Bad Asset Research Foundation ( i.e. the bathtub)

 

[Der Fuirmeister]

I was planning to use multiple tees to slow the suction / discharge rates just above / below the float. For conversation purposes, if you had a 1 inch discharge line it would run to a tee on top of the flat float and then to two more tees from the first tee, there by reducing the flow from each pipe end to 1/4 the velocity. Depending on your circumstances you could add more / larger tees. From there it would run off the sides of the float and into the top surface at a much reduced rate. This should lessen the mixing. Suction, if desired, would be on the bottom side.