Ionpure Electrodeionization (EDI) Module Cleaning, Flushing and Replacement
According to the current Ionpure LX (0426) and VNX (0526) manuals, an electrodeionization (EDI) module may need cleaning when product differential pressure rises by 25 %, reject differential pressure rises by 50 %, product quality declines at constant temperature, flow and feed conductivity, or electrical resistance rises by 50 % (normalized for feed temperature). If cleaning does not restore flow or quality, the feed-water chlorine level and the sanitization procedure are checked and Ionpure technical support is contacted before a replacement module is ordered.
In Turkey, Mikron Proses, an Ionpure OEM partner, supplies spare LX, MX, and VNX modules and supports cleaning-procedure reviews for industrial electrodeionization systems.
Cleaning prompts and decision matrix
The Ionpure LX and VNX manuals (section 6.3, "Cleaning and Sanitization Prompts") list four prompts. Each one is read against the previous baseline, with temperature and flow unchanged.
| Observation | What it may indicate | Action in the manual |
|---|---|---|
| Product differential pressure +25 % | Fouling or scaling | Plan a cleaning; contact the local service provider to confirm |
| Reject differential pressure +50 % | Fouling or scaling | Plan a cleaning; contact the local service provider to confirm |
| Product quality declines at unchanged temperature, flow and feed conductivity | Fouling or scaling | Plan a cleaning; contact the local service provider to confirm |
| Electrical resistance +50 % (normalized for feed temperature) | Fouling or scaling | Plan a cleaning |
| Scale or organic fouling cannot be told apart | Mixed fouling | Brine flush, then NaCl/NaOH, brine, then HCl |
| Cleaning does not restore flow or quality | Resin oxidized or permanently fouled | Check feed Cl₂ and the sanitization procedure; contact Ionpure technical support; evaluate module replacement |
All cleaning work follows the manufacturer's current manual revision and plant safety procedures.
Cleaning solutions named in the manuals
The LX and VNX manuals list approved solutions by purpose (section 6.2):
- Hydrochloric acid, 2 %: removes scale and metal oxides. Acid is added as needed to hold pH at 0.5-1.0 during recirculation.
- Sodium chloride 5 % / sodium hydroxide 1 % (brine/caustic): removes organic foulants and biofilm. A brine flush precedes it so that hardness is displaced before the high-pH step.
- Sodium percarbonate, 1.5 %: removes organic foulants, reduces pressure drop and sanitizes. It follows a salt flush and a water rinse.
- Sodium hydroxide, 2 %: sanitization and biofilm removal, after a salt flush and water rinse (LX manual).
- Peracetic acid, 0.04 %: routine disinfection and bacteria control; the LX manual notes it is not very effective for biofilm removal.
- Aggressive multi-agent cleaning (VNX manual): a sequence of caustic, percarbonate, brine and acid for heavily biofouled systems.
Low-pH and high-pH solutions are separated by a brine flush and a water rinse.
Typical cleaning flow in the manuals
The manuals describe a clean-in-place (CIP) circuit with a tank, circulating pump, cartridge filter, valves and hoses. In outline:
- Turn off the DC power supply. A cleaning solution is never run through the module while DC power is on.
- Drain most of the water from the CEDI system, then connect the CIP pump discharge and the product and reject return lines to the cleaning tank.
- Prepare the solution from the recipe tables in section 6.7 and circulate it through the module. The preferred flows are nominal product flow and a reject flow of 0.5 × nominal product flow (see Table 6-1 for each module size). The CIP pump must provide at least 30 psig (2 bar) and not more than 100 psig.
- Recirculate for 30-60 minutes; the manuals note that a longer contact time may be useful in some cases.
- Check the pH of the used solution, neutralize if needed, and drain the CIP tank. An optional brine circulation helps remove chemicals and may speed up the rinse.
- Flush with RO product water to drain for five minutes, then apply DC power and flush to drain until the target product quality is reached.
The LX and VNX modules are never opened in the field; the manuals state that opening the module voids the warranty and causes irreversible damage.
Feed-water limits that protect a replacement module
Cleaning only helps when the cause of fouling is removed. The manuals give these feed limits for the RO permeate: feed conductivity equivalent (FCE) ≤ 40 µS/cm, total hardness ≤ 1.0 ppm, total chlorine ≤ 0.02 ppm (LX-Z: ≤ 0.05 ppm), silica ≤ 1.0 ppm (VNX-Ultra and VNX-EX: ≤ 0.5 ppm; VNX55-E: ≤ 0.2 ppm), iron, manganese and sulfide ≤ 0.01 ppm, TOC ≤ 0.5 ppm. Some VNX models use model-specific hardness and silica limits (VNX manual Table 2-4).
Spare EDI module selection
When cleaning cannot restore performance, Mikron Proses supplies spare Ionpure replacement modules matched to the system duty.
| Series | Model codes | Flow per module | Product quality |
|---|---|---|---|
| LX-X / LX-EU | LXM4X, LXM10X, LXM18X, LXM24X, LXM30X, LXM45X | 0.22 - 7.67 m³/h (1 - 33.8 gpm) | > 15 MΩ·cm at nominal flow; > 17 MΩ·cm at minimum flow |
| LX-Z | LX-Z 55 | 0.22 - 10 m³/h (1 - 44 gpm) | Typical 17 MΩ·cm |
| LX-HI (hot-water sanitizable) | LXM4HI-3, LXM10HI-3, LXM18HI-3, LXM24HI-3, LXM30HI-3, LXM45HI-3 | 0.22 - 7.67 m³/h (1 - 33.8 gpm) | < 0.1 µS/cm product conductivity; sanitization at 85 ± 5 °C |
| MX | MXM030, MXM060, MXM125, MXM250, MXM500 | 30 - 500 L/h nominal | > 16 MΩ·cm |
| VNX | VNX-Mini, VNX-Max, VNX28-EP, VNX55-EP, VNX55-E, VNX55-EX, VNX55-HH, VNX23-Ultra, VNX55-Ultra, VNX15-CDIT, VNX30-CDIT | VNX-Max up to 22.7 m³/h; VNX-Mini up to 17.9 m³/h | VNX-Max and VNX-Mini: > 17 MΩ·cm (RO feed), > 18 MΩ·cm (DI feed) |
New modules are sized with reference to the full EDI systems range. Feed pretreatment, including softening and silica measurement, is checked to avoid rapid re-fouling. System layout guidance is available under EDI system selection and purified water systems. For an overview of the technology, see what is electrodeionization.
How Mikron Proses helps
Send the module model, DC voltage/current and differential pressure readings, and Mikron Proses reviews them against the Ionpure manuals to decide between cleaning and replacement. The company supplies spare LX, MX and VNX modules and DC power supplies. For PW/WFI loop sanitization practices, see the related PW/WFI loop sanitization guide.
For a spare-module quote or cleaning procedure review, contact Mikron Proses through the contact page.
Frequently Asked Questions
Technical answers from Mikron Proses.
When should an Ionpure EDI module be chemically cleaned?
The current Ionpure LX (0426) and VNX (0526) manuals list four prompts: product differential pressure up 25 %, reject differential pressure up 50 %, product quality declining without a change in temperature, flow or feed conductivity, and electrical resistance up 50 % (normalized for feed temperature). These changes may indicate fouling or scaling. The manuals advise contacting the local service provider to decide whether the module needs cleaning.
Which cleaning solution is used for scale and which for organic fouling?
According to the manuals, 2 % hydrochloric acid removes scale and metal oxides, while 5 % NaCl with 1 % NaOH removes organic foulants and biofilm. Sodium percarbonate removes organic foulants, reduces pressure drop and sanitizes. If it is unclear whether the module is scaled or organically fouled, the manuals recommend a brine flush, then NaCl/NaOH, then brine, then hydrochloric acid.
Why is a brine flush used between low-pH and high-pH cleaning?
The LX manual notes that a high-pH cleaning should be preceded by a brine flush to displace hardness, and that brine flush and water rinse are used between low-pH and high-pH steps. This keeps caustic from meeting hardness held in the module.
Can an EDI module be opened and repaired on site?
No. Both manuals state that the module is not opened; opening it voids the warranty and causes irreversible damage. Replacement is made with a new module of the matching series.
When does cleaning fail and a spare module become necessary?
The troubleshooting flow chart in the LX manual asks whether cleaning restored flow and quality; if it did not, it points to checking feed-water Cl₂ and the sanitization procedure and contacting Ionpure technical support. The chart lists oxidized resin as a cause that affects flow and quality. If cleaning does not restore them, the module is evaluated for replacement together with Ionpure, and Mikron Proses supplies a spare module matched to the original duty; the root cause in pretreatment is corrected to protect the replacement.
Which EDI spare modules are available in Turkey?
Mikron Proses supplies Ionpure LX (LXM4X through LXM45X, LX-Z and LX-HI), MX (MXM030 through MXM500), and VNX (VNX-Mini, VNX-Max, VNX28-EP through VNX30-CDIT) spare modules. Flow ranges cover 30 L/h to 22.7 m³/h, with product quality from > 16 MΩ·cm up to > 18 MΩ·cm depending on the series and feed type. The LX-HI series is the hot-water sanitizable range, with sanitization at 85 ± 5 °C.
Planning a project? Send us your flow rate, feed water source and target water quality to [email protected] — our engineers will reply with a technical proposal.