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#1
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better RO water system for cruisers
Most RO systems work by pressurizing water against a membrane that
only passes fresh water. Pressurizing and the pumping is done either electrically or mechanically from the engine. This involves running the engine. I imagine you could do it by having the prop turn your alternator as you sail or use a towed generator behind the boat but the efficiency of turning motion into electricity and then into motion to produce pressure may be low. I propose to use a variation on the old hydraulic ram pumps to directly produce pressure from the boats motion. HYdraulic ram pumps use the momentum of falling water to force a small part of the falling water to a higher level than the water falls. In other words, if your water falls 20', you can pump a very small portion of it to say 50' higher without any electricity or engine. Used on a sailboat, the momentum is not produced by falling, but simply by the boats motion produced by the wind. This directly produces pressure in a small portion of the water against the RO membrane. Of course this produces drag but with proper design the drag can be varied thus enabling the user to produce more fresh water in a lot of wind. Havent done th ecalculations yet but it may be reasonable. |
#2
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#3
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On Thu, 28 Oct 2004 00:41:55 -0400, rhys wrote:
The pilot house will be the saloon. The saloon will be the work bench/test bed/micro-foundry. All socializing will be on deck as you...Captain Frankenstein...build the perfect labour-saving gadgets for budget-conscious cruising. The V-berth will hold 500 lbs of tools. And you and the missus can sleep in the back. ====================================== Don't laugh, I once saw a 60 footer that was rigged out just about like that. The welder was in the pilot house and all construction material too large for the V berths was under a tarp on the foredeck. Not pretty but very functional. |
#4
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On Thu, 28 Oct 2004 06:33:48 -0400, Wayne.B
wrote: Don't laugh, I once saw a 60 footer that was rigged out just about like that. The welder was in the pilot house and all construction material too large for the V berths was under a tarp on the foredeck. Not pretty but very functional. Except for the raised CG, I would imagine. Actually, that layout has some appeal. November's Cruising World has an 83 foot pilothouse cruiser that just sleeps four, because the owner is realistic about how many crew he's ever going to have and because he's rich enough to have a skipper and mate as permanent employees. The workshop is to drool over, I swear. Although I would likely design something in the 40-45 foot range for myself (if I won a lottery, say), I find the idea of a larger work/cargo space and a more compact saloon appealing. "Cozy" is safer, too. R. |
#5
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rhys wrote in message . ..
On 27 Oct 2004 20:43:14 -0700, (Parallax) wrote: in a lot of wind. Havent done th ecalculations yet but it may be reasonable. Tell me again why you are hesitant to go long-term cruising again... With all the clever if untested notions you come up with I would suggest a 45 footer pilot house. The pilot house will be the saloon. The saloon will be the work bench/test bed/micro-foundry. All socializing will be on deck as you...Captain Frankenstein...build the perfect labour-saving gadgets for budget-conscious cruising. The V-berth will hold 500 lbs of tools. And you and the missus can sleep in the back. Now, you can't tell me that's not an attractive plan. R. That actually crossed my mind a while back. I have a Prazi jewelers lathe/mill that I considered putting in a Gulfstar 42 and cruising and just making weird things. However, then I realized that I am really terrible at making "pretty" things. Everything I make has lots of duct tape, hose clamps and gouge marks all over. In real life, I have realized that it pays to pay people who do that sort of thing so i have two very good machinist/instrument makers. They look at me like I am crazy when I explain what I want, but I think they like the challenges. My designer walks away shaking his head but returns a few days later with a way to do things. My engineer and physicist joke that they will lock up the electron microscopes for fear I turn em into "Frankenscopes". It would be tough to have this sort of great relationship with these people long distance and working with them is a real joy. |
#6
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#8
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You *might* get 1 or two PSI from the ram action. You need about 3000!
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#9
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Actually you only need 800 PSI which is still way past what a ram pump can
produce. There is a tow behind RO watermaker called the Waterlog that uses a small mechanical pump powered by a propellor. Though JAX claims them to be mythical I met two cruisers in the BVI who used them all the way from Gibralter and were very happy with their performance. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com "joe_sailor" wrote in message ... You *might* get 1 or two PSI from the ram action. You need about 3000! |
#10
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On Thu, 28 Oct 2004 22:00:46 -0400, "Glenn Ashmore"
wrote: There is a tow behind RO watermaker called the Waterlog that uses a small mechanical pump powered by a propellor. Though JAX claims them to be mythical I met two cruisers in the BVI who used them all the way from Gibralter and were very happy with their performance. ============================ 72 gpd: http://www.watermakers.ws/ |
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