Has anyone made

[nimbusgb]

Don't know what other comments will come up but a CAT 277 pump runs to around US $1100 and you need to mount and drive it properly from the engine. An off the shelf TDS controller will set you back around £250. Figure 3 hundred ( ?) for filters, fittings and a primary ( intake ) pump.

Next big items will be the RO membranes and pressure chambers. Still looking for a UK price on those. I get around US$350 for a 4 * 40 membrane and US$220 for a 4inch diameter S/S housing. ( FRP twice the price! )

So all in all around £1300 to £1500 for a 20gal / hour system - about 1/2 the going rate.

 

[dougg]

What is meant by TDS controler.? Total disolved solids? Or the pressure regulator and gauge

 

[prv]

What is meant by TDS controler.? Total disolved solids?

I believe so - to indicate how much salt is in the product water.

Pete

 

[nimbusgb]

Total Dissolved Solids

A controller could just control a valve to direct the water product to the tank or overboard if the salinity is too high.

Hanna does a neat 12v version for £125, the matching probe costs £36, simple relay output, contact closed when TDS over setpoint.

 

[nimbusgb]

Got a quote from a UK supplier for a 4*21 inch membrane and matching pressure chamber for £221.44 each and £340.31 respectively so 1$ = 1£ - fancy that!

 

[dougg]

Nimbusgb

It looks like your going down the route of diy watermaker.
What pump are you going to use?

Which type of material is best for the pump to be made of? I see it as low carbon 316 stainless steel or nickel aluminum bronze.
I think the NAB ones are slightly cheaper.

Has anyone done any reasearch into 12dc motors to drive the pump yet?

 

[nimbusgb]

Got a quote on a 4 inch *21 inch 1000psi working press housing from the Netherlands ( same manufacturer ) for €250 so getting better all the time.

I was looking at a CAT 241. 316 Stainless. Driven off the main engine via a magnetic clutch pulley.

A 4021 membrane will deliver 150 litres per hour or product so an hours engine run ( daily occurence in the Ionianan ) to make up for all the showers you could wish for.

That's one approach and not sure I need that much water! The other is to downsize considerably ( 2.5 inch by 14 inch membrane) and only make say 30l per hour. The trouble is the costs don't scale proportionally. Pressure vessel about 30% reduction but barely any pump saving and a regulator valve and all the piping stays the same price.