I. Why is high-salinity wastewater prone to clogging and scaling?

High-salinity wastewater contains large amounts of Ca²⁺, Mg²⁺, SO₄²⁻, SiO₂, and HCO₃⁻. When heated, the following occurs:

Crystallization and precipitation → pipe and nozzle clogging

Adhesion to heat exchange surfaces → sharp drop in thermal efficiency

Formation of hard scale → tube burnout and equipment failure

Low-temperature evaporation must prevent scaling through four aspects: structure, process, control, and material.

II. Core technical measures for anti-clogging and anti-scaling of equipment (proven effective in practice)

1. Structural design: fundamentally prevent scaling

① Adopt forced circulation evaporators (essential for high-salinity wastewater)

Wastewater flows at high speed (≥2.5 m/s) inside heat exchange tubes

No static retention, no wall adhesion, no local overheating

Prevents crystal adhesion at the source

② Avoid nozzles and falling film designs (easily clogged structures)

Spray systems are never used for high-salinity wastewater; only the following are selected:

Tube-side forced circulation

Scraped film evaporation

Eliminates nozzle clogging.

2. Process anti-scaling: eliminate scaling factors in advance

① Front-end softening / pretreatment

Chemical softening → removal of calcium and magnesium ions

Filtration / security filtration → removal of suspended solids (SS)

Addition of scale inhibitors → inhibition of crystal adhesion

② Control of concentration ratio

Do not evaporate to saturation; maintain below critical concentration

Automatic concentrated discharge to prevent salt overload

3. Automatic control: intelligent anti-scaling

① Online concentration monitoring

Real-time monitoring of conductivity / density

Automatic concentrated discharge upon reaching threshold

Prevents salt crystallization

② Stable control of temperature / vacuum

Stable low temperature of 40–60°C

No fluctuations, no local overheating

Reduces scale precipitation

4. Online cleaning: scale removal without shutdown

① CIP online automatic cleaning system

Automatic switching between acid cleaning (citric acid), alkaline cleaning, and water washing

Supports timed, manual, and one-key cleaning

Keeps heat exchange surfaces clean long-term

② Quick-cleaning structure for shutdowns

Quick-opening manholes, easily detachable pipelines

Simple maintenance, inspection completed in 10 minutes

5. Material selection for corrosion and scale resistance

316L stainless steel for high-salinity wastewater

Duplex steel 2205 for high-chloride environments

Titanium for highly corrosive conditions

Corrosion resistance → no formation of corrosive scale layers