Cayman Brac
Partnering for Performance Reduces Energy Costs by 28%
|
Site Location: |
Cayman Islands |
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Date: |
July 1, 2011 |
|
Scale: |
556 m3/d (146,880 USGPD) |
|
Product: |
Qfx SW 365 ES |
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Offering: |
Membrane Performance Contract |
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Client: |
Water Authority Cayman |
Overview
Cayman Brac is a single train 2-pass SWRO plant with inland feed wells and cartridge filtration. It provides potable water to the Cayman Brac distribution system. The plant was expanded and upgraded in 2003 featuring ERI, new vessels and elements, and additional pre-filtration. The plant nameplate is 556 m
3/d (146,880 USGPD). It uses five PX25 ERI’s, a Wheatley HP125 PD Pump, a Grundfos Booster pump, 36 (6x6) Filmtec™ SW30HR elements and 36 (6x6) FilmTec 4-inch BW30-4040 BWRO elements. The second pass is a 2-stage 4-into-2 design. There are three spare 8-inch 6-element vessels. Second pass pressure is 14.1 BAR (205 PSIG) and second pass feed is 6.6 m
3/h (29 USGPM). Overall plant permeate quality is 50 TDS. First pass overall permeate quality is approximately 120 TDS.
The flow and feed streams are given in Table 1. Conversion is estimated at 37%.
Table 1: Plant operating parameters PRIOR to installation of QuantumFlux elements.
|
Stream |
BAR (PSIG) |
m3/h (USGPM) |
TDS |
|
Overall HP Feed |
70.6 (1024) |
59.3 (261) |
34380 |
|
1st Pass Permeate |
0.69 (10) |
15.2 (67) |
120 |
|
Specific Energy |
3.47 kWh/m3 (13.14 kWh/1000 USG) |
|
1st Pass Recovery |
37 % |
|
|
Note: Temperature range is between 25° to 29°C
Table 2: Plant operating parameters AFTER installation of QuantumFlux elements.
|
Stream |
BAR (PSIG) |
m3/h (USGPM) |
TDS |
|
Overall HP Feed |
44.8 (650) |
57.7 (254) |
31445 |
|
1st Pass Permeate |
0.69 (10) |
16.1 (71) |
263 |
|
Specific Energy |
2.49 kWh/m3 (9.44 kWh/1000 USG) |
|
1st Pass Recover |
40% |
|
|
Note: Temperature range is between 25° to 29°C
Performance Results:
NanoH
2O installed Qfx SW 365 ES elements and consequently saved Water Authority Cayman 0.98 kWh/m
3 (3.7 kWh/1,000 USG), or 28%, by lowering the pressure from 70.6 BAR (1,024 PSIG) to 44.8 BAR (650 PSIG) while exceeding their required permeate quality. In addition, NanoH
2O offered the client an opportunity to partner with NanoH
2O through the company’s unique Membrane Performance Contracts offering.
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