A Complete Guide to LCX-H Series High-Temperature EDI Membrane Stacks Technical Specifications for Inlet Water Quality and Operating Parameters
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In scenarios with strict requirements for both water quality and temperature—such as pharmaceuticals, food processing, and high-temperature industrial cleaning—the LCX-H series high-temperature EDI membrane stacks (China EDI stacks) stand out as core equipment for ultrapure water production, thanks to their stable operation at 5-60℃ and high-temperature disinfection capability at 85℃. The long-term efficient operation of the equipment hinges on two critical factors: whether the inlet water quality meets standards and whether the operating parameters are properly set. From a technical perspective, this article details the inlet water quality requirements and operating parameter standards for this series of high-temperature EDI membrane stacks, providing users with practical, actionable guidance.
As high-temperature-specific China EDI stacks, the LCX-H series must use reverse osmosis (RO) product water as inlet water. This is because RO product water has most impurities removed, preventing issues like impurity deposition and membrane fouling under high-temperature conditions—problems that directly impact equipment lifespan and water production quality. Specific water quality indicators must strictly adhere to the following standards:
| Water Quality Indicator | Required Standard | Core Impacts & Precautions |
|---|
| Inlet Water Conductivity (including CO₂, Si) | ≤10μS/cm (preferably ≤5μS/cm) | Excessively high conductivity increases membrane stack load, leading to higher energy consumption and reduced product water purity. Lower conductivity is required when silicon is present to prevent silicon precipitation and scaling at high temperatures. |
| Inlet Water Temperature | 5-60℃ (≤85℃ during disinfection) | Temperatures below 5℃ reduce ion activity and deionization efficiency; temperatures exceeding 60℃ accelerate membrane material aging and shorten membrane stack lifespan. |
| Inlet Water Pressure | 0.1-0.3MPa | Insufficient pressure causes uneven water distribution and incomplete ion removal in the freshwater chamber; excessive pressure easily damages membrane sheets and sealing structures. |
| Total Chlorine Content (Cl₂) | ＜0.02ppm | Chlorine is a strong oxidant that oxidizes and damages ion exchange resins and membrane components, requiring complete removal through pretreatment. |
| Heavy Metal Content (Fe/Mn/S⁻) | All ＜0.01ppm | At high temperatures, heavy metals easily react with substances in water to form precipitates, clogging membrane pores, contaminating resins, and affecting water production stability. |
| pH Value | 7-8 (neutral range) | Excessively high or low pH corrodes metal components of the equipment and impairs the ion exchange capacity of resins, causing fluctuations in product water quality. |
| Total Hardness (as CaCO₃) | ＜0.5ppm | Excess hardness leads to scaling (calcium carbonate, magnesium carbonate) at high temperatures, which adheres to membrane surfaces and directly reduces deionization efficiency and membrane lifespan. |
| Total Organic Carbon (TOC) | ＜0.5ppm (calculated as C) | High temperatures accelerate organic matter decomposition; the resulting small-molecule substances may contaminate resins and even affect subsequent water use processes (e.g., pharmaceutical injections). |
| Silicon Content (as SiO₂) | ＜0.5ppm | Silicon easily forms silica precipitates at high temperatures, especially when pH deviates from neutrality, making it a major cause of membrane stack scaling. |
| Oxidizing Substances/Oil/Fat | Not detected | Oxidizing substances oxidize resins; oil/fat forms an oil film on membrane surfaces, blocking ion migration channels and causing equipment failure. |
Key Reminder: It is recommended to install online monitoring instruments (conductivity meters, hardness detectors, etc.) at the inlet of the LCX-H series membrane stacks to monitor water quality indicators in real time. If any indicator exceeds the standard, immediately shut down the equipment to inspect the pretreatment system (e.g., whether the RO membrane is faulty, whether the security filter is clogged), and restart the equipment only after water quality meets the standards.
When inlet water quality meets standards, proper setting of operating parameters is essential to keep the LCX-H series China EDI stacks in optimal working condition—ensuring product water quality while reducing energy consumption and equipment wear. Below are the standard operating parameters and regulation recommendations:
| Operating Parameter | Standard Range | Regulation Principles & Practical Recommendations |
|---|
| Water Recovery Rate | 85-95% | Prioritize control at around 90%: Low recovery wastes water resources, while excessively high recovery increases concentrated water ion concentration and scaling risk. Concentrated water can be recycled to the RO inlet water tank for reuse. |
| Maximum Inlet Water Pressure | ≤0.5MPa | Maintain 0.2-0.3MPa during daily operation (matching the inlet water pressure requirement). Activate the pressure relief valve when pressure exceeds 0.4MPa to prevent membrane sheet damage from excessive pressure. |
| Pressure Drop at Normal Flow | 0.1-0.3MPa | Excessively high pressure drop may indicate pipeline blockage or internal membrane stack contamination, requiring shutdown for inspection; excessively low pressure drop may indicate insufficient flow, requiring adjustment of the inlet valve. |
| Maximum Inlet Water Temperature | ≤60℃ (continuous operation) | For short-term temperature increases (e.g., 55-60℃) required by the process, reduce inlet flow by 10-15% to minimize high-temperature impact on membranes. Continuous operation above 60℃ is strictly prohibited. |
| Disinfection Temperature/Frequency | 85℃ (single disinfection), ≥150 times | During disinfection, close the product water outlet and maintain concentrated water circulation. After disinfection, slowly cool to below 60℃ before resuming water production to avoid membrane sheet deformation from excessive temperature difference. Disinfect 1-2 times per month and record the number of disinfections. |
| Maximum Inlet Conductivity | ≤5μS/cm (during operation) | If inlet conductivity exceeds 5μS/cm during operation, the equipment will automatically alarm and shut down (thresholds must be set in the control system in advance). Prioritize troubleshooting the RO system instead of forcing startup. |
| Product Water Quality | ≥10MΩ·CM | Monitor product water quality with an online resistance meter daily. If quality drops below 10MΩ·CM, check if inlet water quality meets standards and if operating current is stable to rule out resin contamination or membrane damage. |
| Operating Current/Voltage | Current: 2.5A (adjustable 0-6A); Voltage: 0-550VDC (model-dependent) | Voltage ranges vary by model (e.g., LCX-05H, LCX-45H) (refer to the product manual). Maintain stable current at 2.5A during operation to avoid resin polarization from excessive current fluctuations. |
Practical Case: A pharmaceutical factory used the LCX-20H membrane stack to produce high-temperature injection water, setting operating parameters as follows: inlet water temperature 50℃, inlet water pressure 0.25MPa, recovery rate 90%, and disinfection temperature 85℃ (twice a month). After over a year of operation, product water quality remained stable at 12-14MΩ·CM, with no scaling or membrane damage. Equipment energy consumption was 8% lower than expected.
Daily Monitoring: Record operating parameters (temperature, pressure, flow rate, product water resistance) three times a day to generate parameter curves. If a parameter shows a trending change (e.g., gradually increasing pressure, gradually decreasing product water resistance), proactively identify potential issues to avoid sudden failures.
Regular Maintenance: Dismantle the electrode junction boxes at both ends of the membrane stack every 3 months to check for electrode corrosion (common at high temperatures); test ion exchange resin activity every 6 months and replace resins promptly if activity decreases by more than 30%.
Disinfection Standards: Ensure the membrane stack is fully filled with water (to avoid dry heating) during high-temperature disinfection (85℃). Control disinfection time to 30-60 minutes, and rinse with RO product water for 10-15 minutes after disinfection to remove residual impurities.
The LCX-H series high-temperature EDI membrane stacks include models such as LCX-05H, LCX-10H, LCX-20H, LCX-30H, LCX-38H, and LCX-45H, with a flow range of 0.4-5.3m³/h, suitable for high-temperature ultrapure water needs of different scales. For detailed model parameters or customized solutions, visit our product details page:
LCX-H Series High-Temperature EDI Membrane Stacks Product Link
For technical support (e.g., water quality anomaly troubleshooting, operating parameter adjustment), contact our technical team. We will provide you with professional solutions to ensure long-term stable operation of your equipment.