Dual-Chamber Regenerative Shaft Kiln for Lime Calcination-Lime Kiln Manufacturer

Dual-Chamber Regenerative Shaft Kiln for Lime Calcination-Lime Kiln Manufacturer

The kiln employs two interconnected chambers (Chamber A and Chamber B) for lime calcination. The calcination zones at the bottom of both chambers are connected, allowing materials to descend through both chambers simultaneously.

Operational Cycle

1. Calcination in Chamber A:
   • Combustion air and fuel flow co-currently with the material in Chamber A.
   • The highest-temperature flames contact cooler, heat-absorbing raw materials, while relatively lower-temperature combustion gases interact with partially calcined materials, ensuring uniform heating and high thermal efficiency.
   • Combustion byproducts and CO₂ released from decomposition travel through the connecting channel into Chamber B.
2. Regeneration in Chamber B:
   • Chamber B acts as the regenerative chamber, where limestone absorbs heat from exhaust gases, cooling the gases to lower temperatures.
   • The stored heat in the material is later used to preheat combustion air in the next cycle.
3. Cycle Reversal:
   • Roles alternate periodically: Chamber A becomes the regenerative chamber, while Chamber B becomes the combustion chamber.
   • This cyclic operation enables continuous calcination with minimal heat loss.

Key Features
a. Co-current flow of combustion gases and limestone in the calcination zone.
b. Regenerative heat recovery from all combustion gases during preheating.

Advantages of Dual-Chamber Design

• Ideal for high-activity lime production: Optimized for lightweight calcined lime, high-activity lime, and dolomitic lime.
• Lowest heat loss: Superior to all existing lime kiln types due to regenerative heat exchange.
• Uniform product quality: Eliminates under-burning and over-burning.

Comparative Analysis of Calcination Modes
Refer to Figures 1 & 2 for temperature profiles (Green: Material/Product; Red: Combustion Air & Exhaust; Blue: Cooling Air).

1. Counter-current Calcination (Fig. 1):
   • Separation of gas and material temperature curves.
   • Shortened calcination reaction time, inefficient heat utilization.
   • Results in low activity, uneven quality (under/over-burned products).
2. Co-current Calcination (Fig. 2):
   • Gas and material flow in the same direction, ensuring uniform gas distribution.
   • Prolonged exposure to high-temperature gases extends the calcination zone.
   • Delivers high-activity lime (≥370ml) with consistent quality and no defects.