{"id":39339,"date":"2025-09-23T09:53:27","date_gmt":"2025-09-23T01:53:27","guid":{"rendered":"https:\/\/stark-water.com\/?p=39339"},"modified":"2025-09-23T09:53:29","modified_gmt":"2025-09-23T01:53:29","slug":"edi-vs-mixed-bed-di","status":"publish","type":"post","link":"https:\/\/stark-water.com\/es\/blog\/edi-vs-mixed-bed-di\/","title":{"rendered":"EDI frente a DI de lecho mixto: selecci\u00f3n industrial, dimensionamiento y OPEX"},"content":{"rendered":"

This practical guide compares\u00a0edi vs mixed bed<\/strong>\u00a0polishing in an industrial\u00a0sistema di water<\/em>. You\u2019ll get a decision matrix, field-tested sizing rules, typical OPEX differences, feed-water windows, polishing steps, and a concise BOM you can send to procurement. Focus: commercial\/industrial users \u2014 electronics, laboratories, food & beverage, hotels, plating, and light pharma (note: DI is not WFI).<\/p>\n\n\n\n

\"After
After RO, choose EDI for continuous operation without bulk chemicals, or mixed bed for tolerance and simple retrofits.\n<\/figcaption><\/figure>\n\n\n\n

1) Basics: What They Do<\/h2>\n\n\n\n

In most industrial trains, RO<\/strong> removes bulk salts first. A polisher then drives ionic content to the final target: EDI<\/strong> (electrodeionization) uses ion-exchange resins and membranes under an electric field for continuous<\/em> polishing without bulk acid\/caustic handling; a cama mixta<\/strong> uses separate cation\/anion resins in one vessel that you regenerate<\/em> with acid and caustic between runs.<\/p>\n\n\n\n

Quality is specified as resistividad (M\u03a9-cm)<\/strong> o conductividad (\u03bcS\/cm)<\/strong>. Quick conversion: conductividad (\u03bcS\/cm) = 1 \/ resistividad (M\u03a9-cm)<\/code>. Many plants target 1\u201310 M\u03a9\u00b7cm<\/strong>; Type I lab water requires ~18 M\u03a9\u00b7cm<\/strong> with a polished loop.<\/p>\n\n\n\n

\"Selection
Selection flow: feed stability, chemical policy, uptime and staffing often decide edi vs mixed bed.\n<\/figcaption><\/figure>\n\n\n\n

2) EDI vs Mixed Bed \u2014 Decision Matrix<\/h2>\n\n\n\n
Criterios<\/th>Pulido EDI<\/th>Mixed bed DI<\/th><\/tr><\/thead>
Modo de funcionamiento<\/td>Continuous, automated; no bulk chemicals<\/td>Batch; periodic acid\/caustic regeneration and neutralization<\/td><\/tr>
Feed-water window<\/td>Best with stable RO permeate; low hardness\/CO2<\/sub>\/silica; low TOC<\/td>More tolerant to swings; handles intermittent operation well<\/td><\/tr>
Quality stability<\/td>Very stable resistivity at constant load<\/td>High resistivity achievable; may drift as resin exhausts<\/td><\/tr>
Uptime & staffing<\/td>High uptime; commissioning requires expertise<\/td>Simpler hardware; regeneration skills and safety training needed<\/td><\/tr>
OPEX<\/td>Electrical power; occasional CIP<\/td>Acid\/caustic, rinse water, neutralization, PPE & handling<\/td><\/tr>
Huella<\/td>Compact skid; power supply & controls<\/td>Vessels + chemical storage + neutralization system<\/td><\/tr>
When to prefer<\/td>Continuous production, limited chemical handling, tight specs<\/td>Retrofits, frequent stops\/starts, wide feed variability, lower capex<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Regla de oro:<\/strong> if your site restricts bulk chemicals or aims for continuous lights-out operation, pick EDI. If you need tolerance to irregular feeds, stop\u2013start shifts, or want the lowest upfront cost, start with a mixed bed.<\/p>\n\n\n\n

3) Sizing Rules & Quick Formulas<\/h2>\n\n\n\n

3.1 EDI Sizing<\/h3>\n\n\n\n