I. Introduction:
The method of stacking bricks inside tunnel kilns directly affects internal airflow organization, thermal uniformity, and product quality. It is one of the core control points in the brick manufacturing process. In recent years, misunderstandings regarding proper stacking, especially concerning the role of lateral airflow channels, have been common. This article systematically explains the principles and design considerations for scientific stacking based on kiln type, fuel source, and product characteristics.

II. Function and Common Misunderstandings of Lateral Airflow Channels Lateral airflow channels refer to the space between kiln cars, which serves to:
1. Ensure smooth delivery of hot air into brick stacks during drying and firing phases;
2. Distribute airflow evenly across the kiln's cross-section;
3. Avoid bottlenecks or airflow short circuits that compromise process stability.
Common mistakes include:
(1) Overstacking bricks into lateral airflow channels to increase quantity, disrupting airflow balance;
(2) Poor kiln car dimension control, causing misalignment between airflow channels and kiln ports;
(3) Kiln car frame deformation from thermal expansion, leading to cumulative misalignments;

III. Stacking Variations Across Kiln Types:
1. Hoffmann Kilns:
(1) Utilize "gap stacking" at burner ports to connect brick stacks with airflow channels;
(2) Widespread use of diagonal stacking for stability and improved ventilation;
2. Tunnel Kilns:
(1) Kiln cars introduce movement, increasing risk of stack instability;
(2) Horizontal stacking predominates, which limits ventilation in specific regions;
(3) Large-section kilns require wider, well-aligned lateral airflow channels;
3. Rotary Kilns:
(1) No kiln car movement, theoretically allowing more flexible stacking;
(2) Commonly adopt grid-style and horizontal stacking depending on equipment configuration;

IV. Factors Influencing Stacking Methods
1. Product Dimensions:
(1) Large-format panels require layered stacking to ensure even drying and natural shrinkage;
(2) Standard bricks, perforated bricks, and hollow blocks need flexible airflow consideration;
2. Fuel Structure:
(1) Internal combustion products differ from externally fired products in stacking needs;
(2) Top-firing, side-firing, or under-firing systems impact stack density and airflow design;
3. Kiln Design:
(1) Large-section kilns demand wider airflow channels to avoid lateral concentration;
(2) Small-section kilns, such as those for decorative paving bricks, often rely on side-firing with tighter spacing;

V. Scientific Stacking Management Recommendations
1. Maintain appropriate lateral airflow channel dimensions, avoid overstacking;
2. Standardize kiln car dimensions to minimize cumulative alignment errors;
3. Optimize stacking machine settings to balance side gaps and airflow channel integrity;
4. Develop differentiated stacking strategies based on kiln type, product form, and fuel structure;
5. Regularly inspect airflow alignment to ensure system efficiency;

VI. Conclusion
Scientific stacking design and management require a systematic approach that considers kiln structure, airflow layout, product types, and combustion methods. Avoid prioritizing production quantity at the expense of process balance. Standardized and well-planned stacking is fundamental to ensuring product quality, energy efficiency, and stable operations.