Introduction to the Single-Layer Recirculating Tunnel Dryer

The recirculating single-layer tunnel dryer has a similar structure, but instead of moving straight through, the kiln cars circulate back and forth inside the tunnel.

I. Structural Features:
1. Enclosed drying tunnel with return tracks.
2. Kiln cars are driven by transmission systems to move in cycles according to preset paths.
3. Hot air is recirculated in different sections, ensuring high heat efficiency.

II. Process Features:
1. Flexible drying time due to back-and-forth movement, adaptable to various brick types.
2. Multiple hot air recirculation improves energy efficiency.
3. Ensures more uniform drying, especially for bricks with higher moisture content or thicker green bodies.

III. Applications:
1. Suitable for larger-scale plants with diverse product types.
2. Requires higher investment and more advanced control systems than the through-type dryer.

Introduction to the Single-Layer Through-Type Tunnel Dryer

The single-layer through-type tunnel dryer is a widely used drying system for clay sintered brick green bodies. Its defining feature is that the kiln cars enter from one end, pass straight through the tunnel, and exit from the other end, hence the name “through-type.”

I. Structural Features:
1. Tunnel-shaped channel with a single-layer track.
2. Hot air supplied by waste heat from the kiln or a hot-air furnace, distributed evenly by fans along the tunnel.
3. The bricks move forward at a constant speed, sequentially passing through preheating, constant drying, and cooling zones.

II. Process Features:
1.  One-way, stable drying process that is easy to control.
2. Suitable for standardized bricks with uniform sizes in mass production.
3. Simple operation, relatively low investment, and easy maintenance.

III. Applications:
1. Ideal for small to medium-scale brick plants.
2. Especially suitable for regions with poor natural drying conditions, where mechanical drying is necessary.

Comparison of the Two Systems

1. The through-type single-layer tunnel dryer offers lower equipment cost, simple operation, and is well-suited for small to medium-sized brick plants with stable production needs.
2. The recirculating single-layer tunnel dryer requires higher investment but delivers superior drying performance and energy efficiency, making it suitable for large-scale plants with diverse production requirements.