CDL Hobby 200 Flow Rates

[BradWilson]

Afternoon,

Just trying to get an idea of what folks are getting for flow rates. We have a CDL 200 Horizontal. I've done all the rinsing prior to using. Made sure the membranes were in "right" and U-cup were in the right positions. I haven't done the calculations yet because I'm still "sugaring" the membranes. Here's what I've done.

300-500 gallons of sap

First Pass sap = 2% at 40-45 degrees (some early days were 35+ degrees)
Pressure was just above 200psi
Second Pass sap = 4% +/- at 45-50 degrees
Pressure was still just above 200psi
End up with 8% or slightly less concentrate

Rinse for 10 minutes with permeate - 0% sugar

Wash with 5 gallons of 80 degree water with a PH of 12 - approximately 2 hours with solution recirculating in the pail

Rinse with remaining permeate - 180-220 gallons

The directions state to keep the Concentrate and Permeate flows equal

The best concentrate flow I've gotten so far on first past is 1 gpm and it drops off while concentrating (somewhat expect that)

CDL came and adjusted the pump pressure closer to 250psi

First Pass sap = 2% at 40-45 degrees (some early days were 35+ degrees)
Pressure was just above 200psi
Second Pass sap = 4% +/- at 45-50 degrees
Pressure was still just above 200psi
End up with 8% or slightly less concentrate

Rinse for 10 minutes with permeate - 0% sugar

Wash with 5 gallons of 80 degree water with a PH of 12 - approximately 2 hours with solution recirculating in the pail

Rinse with remaining permeate - 180-220 gallons

The directions state to keep the Concentrate and Permeate flows equal

Now the best flow rate I can get is 1.5 to 1.75gpm and drops significantly during processing. Usually my second pass (no rinse) drops below 1gpm

Next step is an acid wash. Is this normal or am I expecting too much from this thing?

[SeanD]

I don't know your machine, but that flow rate sounds too low, especially if you are only removing 50% in your first pass. Is that C and P combined? That's only around 90-105 gph. I'm guessing it's called a 200 bc that's it's flow rate in ideal conditions. Flow rates do drop off on a second pass. That's typical, but again, I don't know your machine's peak/target.

[SeanD]

I should also mention that if you have 450 taps on vac, that RO is undersized for your operation.