Fired Wall Material Production: Optimize Brick Making Line Weak Points

Manufacturing fired brick and fired wall materials is a systematic engineering project. Each production process connects closely with others. Every production unit acts as one plank of a water bucket. The bucket’s capacity depends not on the longest plank, but the shortest one. This well-known bucket effect applies fully to brick plants. The weakest production stage determines your overall factory output and profit margin.

Many brick project investors focus only on headline daily output numbers such as 500,000 or 800,000 pieces of fired brick. However, they ignore the total material circulation volume across the whole plant. The actual daily turnover of raw materials and green bricks can reach 5 million to 8 million pieces, far beyond the target finished brick output. We analyze common weak points in the full brick production workflow step by step.

Raw Material Stock and Raw Material Processing

If you cannot use local shale or coal gangue, you need multiple raw material storage areas. The raw material processing capacity must exceed the designed daily brick output, and working hours are limited to 8–10 hours. Engineers need to select crushers, roller screens, belt conveyors and magnetic separators based on raw material hardness and moisture level. Maintainability is critical. Even heavy-duty crushers become a bottleneck if hammer replacement takes a full day. Many plants lack overhead lifting equipment, relying on manual handling for heavy screen plates, causing frequent turnover of maintenance workers.

Aging Silo and Fine Material Storage

Aging silos are essential for stabilizing raw material plasticity. The recommended aging capacity is 2–3 times daily production with 72-hour aging time. This buffer keeps continuous supply when crushing equipment stops for maintenance. For sandy and hard raw materials, anti-seepage design avoids uneven moisture distribution. Installing soil kneaders after mixing improves raw material homogeneity.

Vacuum Extrusion and Brick Stacking System

The vacuum extruder, cutting system and brick stacking machine form the core extrusion & forming section. Equipment performance varies greatly under different raw materials and climate conditions. A real case in Lanzhou: factories copied production parameters from central China and obtained good green bricks, but encountered slow drying, high cracking rate and low firing yield, forming a severe process short board.

Drying Chamber Design

Tunnel kilns have multiple drying-firing combinations: direct drying direct firing, one drying plus one firing, two drying plus one firing and other layouts. Direct drying direct firing works well for solid bricks made from high-plasticity shale or coal gangue. Raw materials with high drying sensitivity cannot adopt this layout, as it will create irreversible defects.

Extreme dry climate brings green body cracking. In Kuitun, Xinjiang, operators reduce the height of workshops and green brick shelters, use curtains to increase air humidity and adopt 1.5 times brick stacking layout. Correspondingly, kiln car and track quantity need to increase.

Drying heat sources include flue gas drying, waste heat drying and combined drying. High sulfur raw materials are not suitable for flue gas drying due to secondary pollution. Combined flue gas and waste heat drying achieves better energy efficiency for low-sulfur raw materials.

For moisture exhaust design, pure centralized exhaust has high power consumption. The optimal solution combines decentralized and centralized exhaust with positive pressure as primary and negative pressure as auxiliary. Many rotary tunnel kiln projects have unreasonable drying designs, and exhaust fans consume excessive power.

Kiln Firing Technology & Kiln Type Selection

Firing quality and fuel consumption are determined in kiln design and construction. Kiln types include masonry tunnel kilns, combined tunnel kilns and rotary tunnel kilns. Rotary tunnel kilns solve cross-section temperature difference, while traditional tunnel kilns feature higher brick loading density. However, traditional tunnel kilns suffer from structural drawbacks: bricks move while kiln body remains static, which may cause kiln car burning. Breaking through this bottleneck requires technical innovation.

A qualified kiln operator is not merely a flame watcher. He needs to master kiln airflow, heat distribution, brick stacking scheme, kiln car insulation and drying parameters. The industry principle states: 70% of brick quality comes from brick stacking, 30% from firing. Operators must never feed coal or open fire holes at kiln car joints in high-temperature zones, which will damage kiln cars.

Auxiliary System Design: Loading Lane, Finished Yard

Auxiliary systems are easy to neglect. One 3.7m wide kiln with 4-drying-3-firing configuration only has one loading lane. No space for expansion, so the kiln can never run full capacity. The number of loading stations, packing stations must be calculated according to designed output.

Finished product storage yard is another common bottleneck. Limited yard space leads to forced production reduction during rainy seasons. Hollow brick projects require larger storage space, so insufficient yard becomes a big short board.

Raw Material Inspection & Environmental Facilities

Raw material chemical testing must be completed before plant construction. Raw materials with high sulfur, calcium, potassium or magnesium will cause emission problems, deliquescence or brick efflorescence. Many desulfurization towers fail because suppliers lack kiln and fluid mechanics knowledge. Poorly designed desulfurization equipment increases fan load and reduces production. Horizontal + vertical combined flue design delivers better desulfurization effect.

Natural gas fired kilns achieve cleaner production. Project designers need to assess whether existing kilns can be modified for natural gas combustion.

Conclusion

To achieve the designed daily output of a tunnel kiln brick plant, all links must meet the following capacity matching rules:

1. Raw material stock: multiple times daily output
2. Raw material processing ≥1.5× daily output
3. Aging capacity: 2–3× daily output
4. Extrusion system completes 1× daily output within 8–12h
5. Green brick storage:1.5–2× daily output
6. Empty kiln car ≥0.5× daily output
7. Drying capacity:1× daily output
8. Firing capacity:1× daily output
9. Finished transport lane ≥0.75× daily output
10. Loading station ≥0.3× daily output
11. Finished yard: multiple times daily output

The total turnover of materials and green bricks can reach dozens of times finished brick daily output. A plant targeting 500,000 bricks/day may need total turnover of 5 million pieces.

Fired wall material manufacturing is a full-chain system. The profit level of your brick factory is limited by the weakest production link.

FAQ

Q1: What are the most common short boards in brick making line construction?

A: Common weak links include insufficient aging silo capacity, defective drying chamber design, inadequate loading lanes, shortage of finished yard, untested raw materials and mismatched desulfurization equipment.

Q2: How to select moisture exhaust method for fired brick drying chamber?

A: Decentralized exhaust plus centralized exhaust, positive pressure as main and negative pressure as auxiliary is the preferred design. It avoids green brick collapse, reduces temperature and cuts power consumption.

Q3: What is the core rule for matching capacity of each brick production process?

 A: Each stage must reserve reasonable capacity buffer. Raw material processing, aging and green brick storage need extra surplus capacity, to ensure the whole line runs smoothly even when individual equipment is under maintenance.