PROJECT OVERVIEW

This case study presents a heat recovery system implemented in a steel and metallurgy production facility with high-temperature, dust-heavy, and corrosive flue gas conditions.

The primary objective was to recover waste heat from furnace exhaust while ensuring long-term stable operation under severe industrial environments.

PROJECT CHALLENGE

Harsh Metallurgical Operating Conditions

The facility presented multiple simultaneous challenges:

● Flue gas temperature: 180°C – 420°C

● High dust and particulate concentration

● Sulfur-containing corrosive gases

● Frequent acid dew-point condensation risk

● Continuous 24/7 operation

● High abrasion from solid particles

These conditions resulted in rapid degradation of conventional heat exchangers.

ENGINEERING OBJECTIVE

The system was required to achieve:

● efficient waste heat recovery from furnace exhaust

● stable operation under high dust load conditions

● resistance to acid and corrosion attack

● reduced maintenance frequency

● long-term operational reliability

SYSTEM SOLUTION

Fluoroplastic-Steel Composite Heat Recovery System

To address the harsh conditions, a fluoroplastic-steel composite heat recovery system was implemented.

Structural Design

● Outer Layer: Fluoroplastic corrosion-resistant coating

● Inner Core: Steel structural support tube

This combination provided both chemical resistance and mechanical strength.

KEY ENGINEERING FEATURES

1. Corrosion Protection

The fluoroplastic outer layer prevents direct contact between acidic flue gas condensate and metal surfaces.

2. Anti-Fouling Performance

The smooth, low-surface-energy coating reduces dust adhesion and scaling formation.

3. Mechanical Strength

The steel core ensures high structural stability under pressure and thermal stress.

4. Low Pressure Drop Design

Optimized flow paths reduce resistance in high-volume furnace exhaust systems.

5. Thermal Stability

System operates reliably under fluctuating furnace load conditions.

PERFORMANCE OUTCOME

After implementation, the system achieved:

● Stable heat recovery under continuous operation

● Reduced fouling compared to conventional steel exchangers

● Improved resistance to acid condensation corrosion

● Lower maintenance frequency

● Extended equipment service life

KEY ENGINEERING INSIGHT

Dust + Corrosion Must Be Solved Together

In steel and metallurgy applications, performance failure is typically caused by:

● combined dust fouling

● acid dew-point corrosion

● thermal stress cycling

Addressing only one factor is insufficient for long-term reliability.

SYSTEM VALUE

The implemented solution enabled:

● recovery of waste heat from high-temperature exhaust streams

● improved overall plant energy efficiency

● reduction in fuel consumption for auxiliary systems

● enhanced system stability in continuous operation

CONCLUSION

Steel and metallurgy environments represent some of the most demanding conditions for heat recovery systems.

By combining corrosion-resistant materials with structural engineering design, it is possible to achieve:

● reliable long-term operation

● stable energy recovery performance

● reduced maintenance requirements

● improved lifecycle economics