Deconstructing Spectra's Clark Pump

[4kMike]

Originally Posted by 4kMike

Hi Tellie! I sended a pm to you.

No fesponse or did I miss smtng?

Mike

[SVI]

Hi, I came across a dead Spectra WM cheap.
I want to use its pump to enhance my 3*2540 230V watermaker (to get more efficiency).

Can anybody help me to identify its model?

[Franziska]

Hi, while I can not help with the identification, you might find this very useful :

https://youtu.be/v2Gt5EQ57Gs

Good luck!

Originally Posted by SVI

Hi, I came across a dead Spectra WM cheap.
I want to use its pump to enhance my 3*2540 230V watermaker (to get more efficiency).

Can anybody help me to identify its model?

[SVI]

Actually, the model is Newport 400 24V with Procon pump. I have only 12V or 230V aboard.

How do I convert it to 12V or 230V?

[Frode]

The Newport 400 uses a 10% Clark pump. In larger systems, such as the Newport 700 and Newport 1000, the 20% pump is used. Hence, the possibility of simply expanding your system from one to three membranes, and get the output of a Newport 1000, is slim. You'd have to see if you can purchase a 20% pump from someone (perhaps Tellie's got some in stock).

The Newport 400 requires a feed flow of about 150 GPH, at around 100 PSI. Many of Procon's vane pumps are capable of reaching that level. The Newport 1000 requires a feed flow of about 215 GPH, at a pressure of about 200 PSI. Hence, you have to upgrade the feed pump to one of the 240 GPH models, ensuring either that it has no over-pressure bypass valve, or one that is suitable for the expected pressures.

Finally, the pump's drive motor needs to be replaced. The energy requirements for running a 240 GPH at 200 PSI would indicate at least a 3/4HP motor, but it would be safer to go with a 1 HP, for greater longevity and lessened need for heat removal. At that level, a three-phase, 230/240 VAC motor is the only thing that makes sense, as the amperage required for a 12V motor would be exceedingly difficult to work with.

With a three-phase motor, a Lenze variable frequency drive (VFD) would allow you soft starting and shutdown, and a precise tuning of motor speed. For manual (non computer-controlled) operation, you just need to keep in mind that you regulate the flow pressure, and the flow rate follows (and is used to verify correct operation).

For information, I changed my feed pump to a 190 GPH direct-drive pump, coupled to a sealed Leeson 1/2 HP motor, controlled with a Lenze VFD. I run this without a cooling fan, and since it's fed by 240 VAC, the cables are 14 AWG (could have been smaller).

[SVI]

Thanks for your comments.
What happens if I use 10% pump with 240gph 80psi pump and 3*2540 in series?

[Frode]

While I have studied the Clark device fairly deeply, it would be speculation to state what might happen if used in the proposed scenario. However, perhaps a deeper understanding may help you figure out if it's worth trying.

The Procon pump's GPH rating is a nominal value. The flow rate is almost linearly tied to the rotational speed. The nominal rate is given for a rotational speed of 1725 RPM, at 100 PSI. With the same speed, but with back pressure increasing, the flow rate will decrease.

The Series 5 pump most likely used in the Newport 400 system you have, achieves various flow rates presumably through variations in vane configuration and/or pump chamber volume. The models may, according to feedback from Procon, not be modified for a different flow rate.

The Clark device you have will divert 10% of its total flow through the membrane. It does this regardless of pressure. If you increase membrane surface area, through adding additional membranes, or going with a larger diameter membrane, at a given flow rate, the back pressure produced will decrease. In order to retain desired product quality (salinity level), flow rate, hence, pressure, needs to be adjusted to compensate.

The 10% Clark device amplifies the incoming pressure roughly ten-fold, whereas the 20% device gives just under a five-fold increase. Could the 10% pump handle the 215 GPH flow rate at about 200 PSI? Could it even handle the 200 PSI? Given Spectra's years of experience, and reputation for dependable products, one would expect there to be a good reason for using a device with twice the piston rod cross area on the larger models than the Newport 400.

As you're contemplating this upgrade, through adding pressure vessels, high pressure plumbing, a new Procon pump, a new drive motor, a motor speed controller, but leaving the Clark as is, you indicate you're quite comfortable with performing such an intricate upgrade yourself. You should also be comfortable with the idea that while it might work, you could have a system that is less reliable, with a significantly greater chance of failure, than if the Clark device is also updated.

My recommendation is to engage Tellie, to see if he's willing to sell you the Spectra parts you need, and to work with you on the design, to get your current system upgraded to what you desire.

[SVI]

I opened a separate thread on my Newport 400 project:
https://www.cruisersforum.com/forums...on-246268.html