Demole DNF1/DNF2 4040 and 8040 Spiral-Wound Nanof | RFQ Sourcing Details

The Demole DNF1 and DNF2 series consists of spiral-wound aromatic polyamide nanofiltration membrane elements developed for industrial material concentration and separation. Available model formats are DNF1-4040, DNF1-8040, DNF2-4040, and DNF2-8040.

The 8040 elements have a stated active membrane area of 37 m², while the 4040 elements have 7.6 m². All listed models use a 34 mil feed spacer. DNF1 is positioned for high total organic carbon removal with medium inorganic-salt rejection.

Under the stated standard test conditions, DNF1 has MgSO₄ rejection of at least 98% and Na. Cl rejection of 30% ±10%. Its stated permeate flow is 40 m³/day (10,500 GPD) for the 8040 model and 8 m³/day (2,100 GPD) for the 4040 model.

DNF2 is designed for high rejection of multivalent ions and lower rejection of monovalent ions. Under the stated standard test conditions, it has MgSO₄ rejection of at least 98% and Na. Cl rejection of 60% ±10%. Stated permeate flow is 38 m³/day (10,000 GPD) for DNF2-8040 and 7.6 m³/day (2,000 GPD) for DNF2-4040.

Performance testing uses solutions containing 2,000 mg/L MgSO₄ and 500 mg/L Na. Cl at 25°C, 15% recovery, and pH 6.5–7. The stated operating pressure is 0.5 MPa for DNF1 and 0.75 MPa for DNF2. Parameters are measured after 30 minutes of stable system operation, and water-yield deviation is stated as ±15%.

Published application limits include a maximum operating pressure of 4.1 MPa, a feed-temperature range of 5–45°C, feed pH of 3–10, cleaning pH of 2–11, maximum feed turbidity of 1.0 NTU, maximum feed SDI15 of 5, and a maximum pressure drop of 15 psi per element.

Maximum feed flow is listed as 17 m³/h (75 GPM) for 8040 elements and 3.6 m³/h (16 GPM) for 4040 elements. Residual chlorine must be controlled below the stated limit of 0.1;buyers should confirm the applicable unit and monitoring method before operation.

Listed application fields include salt-mine recycling, high-salinity zero-discharge processes, material separation and concentration, food concentration, pharmaceutical purification, water purification, reclaimed-water reuse, cooling-water treatment, and boiler-water treatment.

Suitability for a particular process depends on feed composition, pretreatment, target separation, operating recovery, cleaning regime, and system design.

Procurement questions to confirm: request model-specific data sheets and current acceptance criteria;verify required permeate flow and rejection using the buyer’s actual feed analysis;confirm element dimensions, vessel fit, seal configuration, and connection details;clarify chlorine-limit units and required dechlorination controls;define pretreatment requirements for turbidity and SDI;confirm cleaning chemicals, exposure limits, and cleaning procedures;and agree on inspection, packaging, quantity, customization scope, delivery schedule, and warranty terms before ordering.