RRR
500 LPH RO Plant — FRP Skid | CRI Pump | TFC Membranes
High-selling 500 LPH RO package for Tamil Nadu: compact, low-maintenance, drinking & commercial grade permeate. Turnkey supply, installation & commissioning by RRR ENVIRO SYSTEMS.
Quick Snapshot
Capacity: 500 LPH (12 m³/day). Design feed TDS: 1500 mg/L. Recovery: 70% (typical). Vessel: FRP. High-pressure pump: CRI. Permeate intended for Drinking + Commercial with post-RO polishing (UV + remineralization) where required.
Why 500 LPH is popular in TN
- Perfect size for small hotels, hostels, factories, offices, and communities — not too big, not too small.
- Low running cost with CRI pumps & FRP skid; easy serviceability in Tamil Nadu towns.
- Produces reliable drinking-grade water after polishing — highest repeat sales due to strong service network.
Technical Specification (Indicative)
| Item | Specification |
|---|---|
| Permeate capacity | 500 LPH (0.5 m³/hr; 12 m³/day) |
| Design feed TDS | Up to 1500 mg/L (brackish) |
| Recovery | ~70% (site dependent) |
| Feed pump | CRI high-pressure pump with VFD option |
| Pressure vessel | FRP pressure vessel, 1–2 element / vessel arrangement |
| Membranes | Thin-film composite (TFC) RO elements (e.g., 4040 style modules) |
| Pre-treatment | Sand Filter → Carbon Filter → Anti-scalant dosing → Cartridge Filter (5 µm) |
| Post-treatment | UV disinfection, remineralization / pH correction as required |
| Control | PLC panel with skid-mounted gauges, flow meter, conductivity meter, auto flush |
Design Calculations — step by step (transparent)
Goal: produce 500 LPH permeate with ~70% recovery.
1) Determine feed flow (Qf):
Permeate Qp = 500 LPH.
Recovery r = 0.70 → Qf = Qp ÷ r = 500 ÷ 0.70 = 714.29 LPH.
Convert to m³/hr: 714.29 ÷ 1000 = 0.71429 m³/hr.
Convert to m³/s (for pump power calc): 0.71429 ÷ 3600 = 0.00019841 m³/s.
2) Select operating pressure (approx.):
For feed TDS 1500 mg/L, RO pressure typically ≈ 15–20 bar. We design with 20 bar (safe).
20 bar = 2,000,000 Pa. 3) Compute head (H):
H (m) = Pressure / (ρ × g) = 2,000,000 ÷ (1000 × 9.81) = 2,000,000 ÷ 9,810 ≈ 203.87 m. 4) Hydraulic power (Phyd):
Phyd = ρ × g × Q × H.
ρ × g = 1000 × 9.81 = 9,810.
Q (m³/s) = 0.00019841.
9,810 × 0.00019841 = 1.947 (approx) (units: N/s which is watts per meter head factor).
Multiply by H = 203.87 → Phyd ≈ 1.947 × 203.87 = 396.9 W (hydraulic power). 5) Pump & motor sizing (allowing efficiency)
Assume pump+motor combined efficiency η ≈ 60% (0.60).
Required shaft/motor power = Phyd ÷ η = 396.9 ÷ 0.60 ≈ 661.5 W.
Choose a standard motor rating → round up to 1.0 kW motor (common market size). We often select 1.0–1.5 kW with VFD for reliability.
1) Determine feed flow (Qf):
Permeate Qp = 500 LPH.
Recovery r = 0.70 → Qf = Qp ÷ r = 500 ÷ 0.70 = 714.29 LPH.
Convert to m³/hr: 714.29 ÷ 1000 = 0.71429 m³/hr.
Convert to m³/s (for pump power calc): 0.71429 ÷ 3600 = 0.00019841 m³/s.
2) Select operating pressure (approx.):
For feed TDS 1500 mg/L, RO pressure typically ≈ 15–20 bar. We design with 20 bar (safe).
20 bar = 2,000,000 Pa. 3) Compute head (H):
H (m) = Pressure / (ρ × g) = 2,000,000 ÷ (1000 × 9.81) = 2,000,000 ÷ 9,810 ≈ 203.87 m. 4) Hydraulic power (Phyd):
Phyd = ρ × g × Q × H.
ρ × g = 1000 × 9.81 = 9,810.
Q (m³/s) = 0.00019841.
9,810 × 0.00019841 = 1.947 (approx) (units: N/s which is watts per meter head factor).
Multiply by H = 203.87 → Phyd ≈ 1.947 × 203.87 = 396.9 W (hydraulic power). 5) Pump & motor sizing (allowing efficiency)
Assume pump+motor combined efficiency η ≈ 60% (0.60).
Required shaft/motor power = Phyd ÷ η = 396.9 ÷ 0.60 ≈ 661.5 W.
Choose a standard motor rating → round up to 1.0 kW motor (common market size). We often select 1.0–1.5 kW with VFD for reliability.
Qp = 500 LPH
r = 0.70
Qf = 500 ÷ 0.70 = 714.29 LPH = 0.71429 m³/hr = 0.00019841 m³/s
Pressure = 20 bar = 2,000,000 Pa
H = 2,000,000 ÷ (1000×9.81) = 203.87 m
P_hyd = 1000×9.81×0.00019841×203.87 ≈ 396.9 W
Motor ≈ 396.9 ÷ 0.60 ≈ 661.5 W → select 1.0 kW motor
Notes: final pump selection considers friction losses, membrane feed booster needs, and safety margin — vendor will provide exact model (we recommend CRI 1.0 kW with VFD option).
Membrane & Vessel Recommendation
- Use standard 4040 TFC elements. For small 500 LPH plants we recommend using a 1–2 vessel arrangement (each vessel 1–3 elements depending on design). Example: 2 vessels × 2 elements in series for pressure balancing.
- Permeate quality expected: TDS < 100 mg/L (depends on feed and recovery). Final polishing (UV + remineralizer) recommended for drinking water.
- Antiscalant dosing recommended to protect membranes at 70% recovery for 1500 ppm feed.
Recommended Pre-treatment & Chemicals
- Sand filter — remove suspended solids & turbidity.
- Activated carbon filter — remove free chlorine & organics (protect membranes).
- Antiscalant dosing — protects against scaling (especially for TDS ~1500 ppm).
- pH adjustment / acid dosing — if hardness & alkalinity high.
- 5 µm cartridge filter — final particulate removal before RO.
- NaOCl — for periodic sanitization/chemical cleaning (as per schedule).
Operation & Maintenance (O&M)
- Daily: Check feed/ permeate flow, pressures, conductivity, and record RO rejection.
- Weekly: Backwash sand filter, check carbon headloss, check antiscalant feed.
- Monthly: Clean cartridge filters, inspect membranes for fouling; check dosing tanks & pumps.
- Periodic (3–6 months): Chemical Clean-In-Place (CIP) with acid/alkali as per membrane vendor.
Troubleshooting & Tips
- Low permeate: Check membrane fouling, antiscalant dosing, and feed pressure.
- High conductivity: Membrane breach or high feed TDS; check rejection % and perform integrity checks.
- High pressure drop: Replace cartridge filters, check sand/carbon headloss.
- Always keep a spare membrane element and spare cartridge filters on site.
FAQ
Q: What final TDS can I expect?
A: For feed 1500 ppm and TFC membranes, expect permeate typically <100 mg/L depending on recovery and membrane condition; final polishing (UV + pH correction) recommended for drinking.
Q: How often do membranes need cleaning?
A: Routine chemical cleaning every 3–6 months (depending on feed), and periodic sanitization with NaOCl; frequency depends on fouling rate.
Q: Do you provide AMC?
A: Yes — we offer AMC packages (monthly/quarterly) with spare parts & periodic CIP included (customized).
A: For feed 1500 ppm and TFC membranes, expect permeate typically <100 mg/L depending on recovery and membrane condition; final polishing (UV + pH correction) recommended for drinking.
Q: How often do membranes need cleaning?
A: Routine chemical cleaning every 3–6 months (depending on feed), and periodic sanitization with NaOCl; frequency depends on fouling rate.
Q: Do you provide AMC?
A: Yes — we offer AMC packages (monthly/quarterly) with spare parts & periodic CIP included (customized).