Posted: 1/25/2009 7:10:04 PM EDT
| Does anyone have a link for how to set up a water distillery? Not alcohol, but a simple way to distill water for drinking? |
|
Actually, there's not much difference if you are making one yourself. The only difference is how much heat you apply.
Distillation is a principle of heating a liquid to its boiling point then condensing it again in order to separate its products. Keep in mind, liquids with a lower boiling point in your mix will boil off first. For example, if you were distilling water that had oil mixed in, the first product out of the still would be the oil products not the water. Its why in distilling about anything manually, the first product is discarded to get rid the lighter boiling point products. There are distillation devices you can buy outright and not make them. Most, unfortunately, are electric and most of the balance are stove top which is not going to have a good output. They'd have to be ran most of the day to provide the drinking water for say a family. The larger booze type stills, you could do the same in a matter of a couple hours. I guess it depends on where you want to go with it. Its that size to get quantiy issue and power (heat) requirement that leans more people to filtering and/or treatment. The most frequent approach to emergency drinking water is filter which there are once again many types. A straight pore size filer will not remove dissolved solids (salt etc.) and are only designed to remove suspended solids. To remove disolved solids one must add activated charcoal. The exception to this is the RO unit which a different principle. Its a high pressure membrane principle which will remove 90% plus of suspended solids and depending on what typically 80% of dissolved solids. The best water treatment is always in knowing the best you can your initial starting water quality and treating for that specific application much as your city water plants do. That can be as simple like in a clear mountain stream as a pore size filter or as complex as a Clarifier (basically a holding tank to allow solids to settle), RO units, and activated charcoal. None of the filtering methods other than a small hand held filter called First Need actually are rated to remove virus, but then virus doesn't live long in cold water either. Almost all of the commercially made back packing filters will remove most large cell bacteria (the most concern in water). Sometimes a secondary treatment is needed to remove this biological hazards. That's why cities add chlorine. There's a number of ways to do this as well. The most common is simply boiling the water. The other most common is adding a chemical such as iodine, chlorine (bleach with no additives) or various commercially available treatment chemicals which are typically lower in taste. Hope that helps. Tj |
|
What if one were traveling on the ocean/by the ocean alot??
I live minutes away from the Gulf of Mexico, and anything NOT saltwater is far, far away. If I get stranded, bottle water will only last me so long in 95+ degree heat. Is there any simple (cheap) way to get your DV of H20 without getting too extravagant?? |
|
Solar stills work pretty good if primed with water. Not so well if gettign the water from the soil. Making a prebuilt unit (shallow black pan of raw water, connected to shaded high surface are condensing area) should work even better.
A fuel operated unit is allways going to burn quite abit of fuel to boil the water off. The condenser can heat the raw water to near boiling, but you will allways loose the hear required for boiling. Commerical packaged units condense the vapor under pressure, so almost all of the heat can be returned to the raw water. In fact when running, such a system only requires waste heat from the prime mover to operate. There are RO systems for turning salt water into fresh. The only hand powered units were made by recovery engineering, which was bought by PUR, and then I think by Katadyn. The larger hand power unit will also run on 12V. Lots of companies make 12V or AC power units. I helped rebuild one off shore that had a 7.5hp 3 phase motor. |
|
Quoted:
What if one were traveling on the ocean/by the ocean alot?? I live minutes away from the Gulf of Mexico, and anything NOT saltwater is far, far away. If I get stranded, bottle water will only last me so long in 95+ degree heat. Is there any simple (cheap) way to get your DV of H20 without getting too extravagant?? Salt water I'm afraid is never easy because of the massive amount of salt. The solar as well as the little life boat type RO hand pump units have very low outputs but are an option for short-term a couple days to supplement what water you have. Long-term, about the only option is distillation but keep in mind that salt caking so when you build your still you can open it up to clean the salt out. Also keep in mind as you distill salt water it will foam so the main heating tank needs to be tall to maximize output. Years back I got to work on a giant still for a chemical plan in Saudi for salt water. Man, that thing was neat. It used the coolant lines from diesel engines being ran anyway to pump and a series of tanks, about four piped together in series. This was a neat concept with output measured in GPH. TJ |
|
Quoted:
What if one were traveling on the ocean/by the ocean alot?? I live minutes away from the Gulf of Mexico, and anything NOT saltwater is far, far away. If I get stranded, bottle water will only last me so long in 95+ degree heat. Is there any simple (cheap) way to get your DV of H20 without getting too extravagant?? You could build a solarstill with some plastic sheeting. |
|
I've been working [mentaly] on a water still that uses heat recovery and is portable
but as mentioned mineral buildup can be a big problem. a not so portable unit can be made with a presto pressure cooker, which would allow you clean it. you will need to drill another hole in the top. Unscrew the nipple and install a water feed fitting so that a level float valve can be installed to keep the liquid at 1/4-1/2" and drill a hole in the top for a steam escape line then solder about three feet each of 1/4" copper in parrallel so that the feed water will cool the steam as it flows into the pot and the steam preheats the feed water. this will supply alot more water for far less fuel. the safty valve remains and you could convert it back to a presure cooker by plugging the hole you drilled with a bolt/teflon washer. language is a clumsy way to express ideas. |
|
Lady McBeth-
Water has a specific heat of 4.18 J/g. This means heating water from 25 deg C (room temperature) to 100 degC (boiling) takes about 300J/g (or 1200 watts for 4 minutes per quart.) Boiling the water (latent heat of evaporation) is 2270 J/g (2270 watts for 15 minutes per quart.) So even with a good heat exchanger, you can only save about 15% of the energy. Thats why you have to do vapor compression to really improve the efficiency. |
|
Lady McBeth-
Water has a specific heat of 4.18 J/g. This means heating water from 25 deg C (room temperature) to 100 degC (boiling) takes about 300J/g (or 1200 watts for 4 minutes per quart.) Boiling the water (latent heat of evaporation) is 2270 J/g (2270 watts for 15 minutes per quart.) So even with a good heat exchanger, you can only save about 15% of the energy. Thats why you have to do vapor compression to really improve the efficiency. A cross flow heat exchanger is very effecient even a cheap one like I mentioned will do better than 85%, by making it even longer and insulating it you can even get closer to parity. All of the energy required to turn the water into steam is conserved and returned to somewhere, the trick is to put it back into the input stream, with a feed water and the steam moving in oposite directions the high quality heat is preserved and the steam {water}leaving the exchanger will be with in a few degrees of the input water,likewise on the hot end, the input water will be very near boiling hot. most of the energy required to boil the water is returned. The system still requires alot of energy but much less than the classic pot and coil method. |
|
Quoted:
Quoted:
Why would you want to distill water when you can use a ____ ____ filter so much easier.  Will those 1mil filters remove salt? Can you make salt water potable with those filers? Actually yes, there's a couple very nice RO hand pump units on the market for use in life boats and not too expensive around the $400 mark. They do a fair job but their volume is very limited not near as fast or easy as even a back packing fresh water filter. You are right though, salt water would take a activated charcoal principle filter out, max the charcoal capacity, very fast. Tj |
|
Quoted:
Lady McBeth-
Water has a specific heat of 4.18 J/g. This means heating water from 25 deg C (room temperature) to 100 degC (boiling) takes about 300J/g (or 1200 watts for 4 minutes per quart.) Boiling the water (latent heat of evaporation) is 2270 J/g (2270 watts for 15 minutes per quart.) So even with a good heat exchanger, you can only save about 15% of the energy. Thats why you have to do vapor compression to really improve the efficiency. A cross flow heat exchanger is very effecient even a cheap one like I mentioned will do better than 85%, by making it even longer and insulating it you can even get closer to parity. All of the energy required to turn the water into steam is conserved and returned to somewhere, the trick is to put it back into the input stream, with a feed water and the steam moving in oposite directions the high quality heat is preserved and the steam {water}leaving the exchanger will be with in a few degrees of the input water,likewise on the hot end, the input water will be very near boiling hot. most of the energy required to boil the water is returned. The system still requires alot of energy but much less than the classic pot and coil method. The massive skid mounted system I was involved with was a vapor recovery pressure system that actually didn't boil the water but like the coolant lines from the turbines was awfully close to the boiling point. The system was a series of pressure tanks one after the other in series that the water increased its purity through each tank. This was intended of offshore oil platforms and (I'm just going off memory now) output somewhere around 300 gph. Man, that's a hefty fresh water system. Just as a side bar, my boat hot water tank (something I special ordered hooked up) uses the same principle of utilizing engine waste heat to make hot water. Man, that's something I have been thankful I spent the bucks on for eight years now. Its like taking a shower at home despite not being hooked up to 110 ac. The entire concept is simply neat since any time you can do something with waste heat you are generating anyway, its btu cost is zero. You just have upfront capital cost. Tj |
|
Quoted:
A cross flow heat exchanger is very effecient even a cheap one like I mentioned will do better than 85%, by making it even longer and insulating it you can even get closer to parity. All of the energy required to turn the water into steam is conserved and returned to somewhere, the trick is to put it back into the input stream, with a feed water and the steam moving in oposite directions the high quality heat is preserved and the steam {water}leaving the exchanger will be with in a few degrees of the input water,likewise on the hot end, the input water will be very near boiling hot. most of the energy required to boil the water is returned. The system still requires alot of energy but much less than the classic pot and coil method. The problem (with ut going into a lot of thermodynamics) is you heat exchager will work fine. The steam will give up the almost 300 J/g required to raise the water to boiling. But you can't use 100 deg wet steam to boil water at 100 deg. There is no temperature difference to make heat flow The "hot" side of you heat exchanger will be spewing out 15% boiling water and 85% steam, while the water in the pressure cooker will still need another 2270 J to turn it in to steam. You say the heat must go somewhere, and it will- either into the latent heat of the released steam, or more realistically, you will have to hook up an condensing coil to return the heat to the air and produce liquid water. So out of 2570 J, you can only recover 300 from the heat exchanger. Do the math and it's about 85-90%. If you were melting snow, you might improve the efficiency, but it still going to take the same BTU input. The only way to go better is to use vapor compression where the steam is pressurized to condense it above the boiling point of the water in the boiler. For example, if we compress the steam to 15 psi, it will condense at 120 degrees C. it's fairly easy to use the 120 degree steam to boil the water, and then use the condensed steam to heat the raw water. The only heat needed (once the system is started) can be supplied by waste heat from the prime mover. The prime mover is required to compress the steam which has a volume almost 2000 time higher then the the raw water And if you think about it, this is the main problem with the steam engine- or even low pressure turbines, unless you are a factory and want the steam anyway. |
|
Quoted:
Quoted:
What if one were traveling on the ocean/by the ocean alot?? I live minutes away from the Gulf of Mexico, and anything NOT saltwater is far, far away. If I get stranded, bottle water will only last me so long in 95+ degree heat. Is there any simple (cheap) way to get your DV of H20 without getting too extravagant?? Salt water I'm afraid is never easy because of the massive amount of salt. The solar as well as the little life boat type RO hand pump units have very low outputs but are an option for short-term a couple days to supplement what water you have. Long-term, about the only option is distillation but keep in mind that salt caking so when you build your still you can open it up to clean the salt out. Also keep in mind as you distill salt water it will foam so the main heating tank needs to be tall to maximize output. Years back I got to work on a giant still for a chemical plan in Saudi for salt water. Man, that thing was neat. It used the coolant lines from diesel engines being ran anyway to pump and a series of tanks, about four piped together in series. This was a neat concept with output measured in GPH. TJ i thought all stills opened up. otherwise how would you clean the old sour mash out of it? 
|
|
Quoted:
So you say If I put the nipple and weight on the end of the heat exchanger it will up the efficency, sounds good, the cooker is rated to 15 psi anyway and the tubeing is over rated at much more. Nope Sounds good, but this makes it worse. With the fifteen psi weight, the water must reach 120 deg C to boil, while it will still condenses at 100 deg C. You have to have the condenser at a higher pressure then the boiler, and they only way to do that is compress the vapor after it is boiled. And to do this with efficiency, you really need and engine, and you might as well use a water cooled one to eleminate the need for a seperate heater. BTW, the energy used by the compresser increases the energy of the vapor, which pretty much means it adds heat to the system as well. That is why all small water maker systems are RO (they range above 1000 gpd). I've seen one that supplied all the potable (drinking, washing, cooking) water for about 30-40 people. Toilets used raw rain water from cisterns. |
|
Quoted:
Quoted:
So you say If I put the nipple and weight on the end of the heat exchanger it will up the efficency, sounds good, the cooker is rated to 15 psi anyway and the tubeing is over rated at much more. That is why all small water maker systems are RO (they range above 1000 gpd). I've seen one that supplied all the potable (drinking, washing, cooking) water for about 30-40 people. Toilets used raw rain water from cisterns. Well, I'll be darned. 
All of mine with the standard RO cartridge will do many 1000's of gallons [with a sedimentation and carbon block in front and a samll carbon block in output]. In a package not much bigger than a gym bag. With no pumping. Let's see that should take care of, say. 2 peoples' consumption needs for at least 4 years. Also, spares are cheap and plentyful, -right now... |