Guide for construction of the brick kiln

IS 4805 - 1978 (Reaffirmed 2002): Scope Key Points

• Chimney Shape & Attachments (Clause 4.10)

  • Must follow the shape shown in Fig. 3.
  • Two chimneys are required for the installation.

• Flue Construction & Size (Clause 4.8)

  • Flues constructed as per Fig. 2.
  • Flue dimensions: 1.20 m × 0.90 m.

• Material Specifications (Clause 2.5)

  • Mild Steel (MS) sheet thickness: 3 to 25 mm.
  • Base plate thickness: 25 mm or two plates of 12 mm welded.
  • Brass bush tread: 50 mm diameter.
  • Brass washer: 100 mm diameter, 12.5 mm thick.
  • Pin: 25 mm diameter, 225 mm long.

Summary Table of Key Dimensions

If needed, refer to Fig. 2 and Fig. 3 of IS 4805 for detailed geometry and assembly.

IS 4805: Necessary Information for Top-Fed Coal Fired Continuous Brick Kilns

Key Information to be Furnished (Clause 2.1)

For efficient design and construction, provide:

• Sub-soil water level at the kiln site
• Ground slope and natural drainage pattern
• Soil type, especially noting black cotton soil (expansive soil)
• Climatic conditions (temperature, humidity, wind)
• Proximity to inhabited areas and communication facilities

Specifications for Chimney Base Plate (Clause 2.5)

All dimensions in centimeters unless specified.

Notes:

• Soil and drainage data help in foundation design.
• Climatic data influence kiln thermal performance.
• Close proximity to habitation requires emission control.

flowchart TD
    A[Site Investigation] --> B[Sub-soil Water Level]
    A --> C[Ground Slope & Drainage]
    A --> D[Soil Type]
    A --> E[Climatic Conditions]
    A --> F[Vicinity to Habitation]
    B & C & D & E & F --> G[Design & Construction Inputs]

This ensures the kiln foundation and chimney are designed for durability and operational efficiency.

IS 4805: Site Selection and Ground Conditions for Brick Kilns

Key Specifications from IS 4805:

• Sub-soil Water Level:

  • Floor level of trenches must be ≥ 3 m above the water table during rainy season (Clause 3.2).
  • Floor level should not be more than 1 m below ground level.

• Ground Slope & Drainage:

  • Natural slope and drainage must be assessed to avoid water accumulation (Clause 2.1b).

• Soil Type:

  • Special attention to black cotton soil due to its expansive nature (Clause 2.1c).

• Floor & Trench Dimensions:

  • Trench height: 2.25 m (Clause 4.2).
  • Side walls with flues for chimneys; two flues per chamber (Clause 4.3).

Checklist for Site Selection:

• Sub-soil water level and seasonal variation
• Ground slope and natural drainage
• Soil type and bearing capacity
• Climatic conditions (temperature, rainfall)
• Proximity to inhabited areas and communication

Recommended Floor Level Criteria:

Conceptual Diagram of Site Conditions:

flowchart LR
    A[Ground Level] --> B[Trench Floor Level]
    B -->|≥ 3 m above| C[Water Table (Rainy Season)]
    A -->|≤ 1 m below| B
    D[Soil Type] --> E{Black Cotton Soil?}
    E -->|Yes| F[Special Foundation Considerations]
    E -->|No| G[Standard Foundation]

Summary:
Ensure trench floors are well above the water table, assess soil type (especially black cotton soil), and verify natural drainage and slope for stable kiln construction.

IS 4805: Guide for Construction of Brick Kiln – Key Points

Construction Specifications:

• Flue Size:
  • Dimensions: 1.20 m x 0.90 m (Clause 4.8)
  • Flues should be constructed as per Fig. 2 (not provided here).

Important Considerations for Construction (Clause 2.1):

• Sub-soil water level at site
• Ground slope and natural drainage
• Soil type, especially black cotton soil
• Climatic conditions
• Proximity to inhabited areas and communication facilities

General Notes:

• The kiln is top-fed, coal-fired, and operates on natural draught.
• Proper site evaluation is critical for structural stability and operational efficiency.

Typical Flue Section Dimensions (for reference):

flowchart LR
    A[Site Selection] --> B[Soil & Water Table Analysis]
    B --> C[Ground Slope & Drainage]
    C --> D[Climate Considerations]
    D --> E[Kiln Construction]
    E --> F[Flue Construction (1.20 x 0.90 m)]

This ensures efficient airflow and combustion in the kiln.

Kiln Size and Capacity as per IS 4805

• Kiln Shape: Refer to Fig. 1 (Bull's Trench Kiln shape with earth embankment and enlarged section).

• Trench Height:

  • Fixed at 2.25 m (Clause 4.2).

• Large Capacity Kiln (Clause 4.1.1):

  • Number of chambers = 30
  • Length per chamber = 5.0 m
  • Width of trench = 9.0 m
  • Capacity per chamber = 28,000 standard bricks

• Small Capacity Kiln (Clause 4.1.2):

  • Number of chambers = 30
  • Length per chamber = 5.0 m
  • Width of trench = 4.5 m
  • Capacity per chamber = 14,000 standard bricks

• Flues (Clause 4.3):

  • Each chamber: 2 flues (inner & outer walls) for large capacity
  • Small capacity: 1 flue on outer wall per chamber

Summary Table

flowchart LR
    A[Trench Height = 2.25 m]
    B[Large Capacity Kiln]
    C[Small Capacity Kiln]
    A --> B
    A --> C
    B -->|30 Chambers| D[Each 5m length]
    B -->|Width 9m| E[Capacity 28000 bricks/chamber]
    B -->|2 flues per chamber| F[Inner & Outer walls]
    C -->|30 Chambers| G[Each 5m length]
    C -->|Width

Key Specifications for Trench Height (IS 4805)

• Trench Height:
  As per Clause 4.2, the trench height should be 2.25 m for both small and large capacity kilns.

• Floor Level (Clause 3.2):

  • Minimum 3 m above the water table during rainy season.
  • Not more than 1 m below ground level.

• Trench Floor:

  • Should be paved with burnt bricks on edge (Clause 4.5).

• Access:

  • Provide an adequate number of wickets for easy access (Clause 4.4).

Summary Table

flowchart TD
    A[Ground Level] -->|Max 1 m| B[Trench Floor Level]
    B -->|Min 3 m above water table| C[Water Table]
    A --> D[Trench Height = 2.25 m]
    D --> E[Side Walls with Flues]
    B --> F[Burnt Brick Paving]
    D --> G[Wickets for Access]

This ensures structural stability, water protection, and operational convenience.

IS 4805: Side Walls and Flues - Key Specifications

• Side Walls:

  • Thickness: 60 cm (Clause 4.6)
  • Material: Ordinary burnt bricks recommended for durability and maintenance.
  • Construction: Two flues per chamber, one on inner and one on outer wall. For small kilns, only one flue on the outer wall per chamber is needed (Clause 4.3).

• Flues:

  • Size: 1.20 m x 0.90 m (Clause 4.8)
  • Construction details as per Fig. 2 (not shown here) (Clause 4.8).
  • Flues support chimneys placed on side walls (Clause 4.3).

• Height:

  • Trenches height: 2.25 m (Clause 4.2)

• Chimneys:

  • Two chimneys required per kiln (Clause 4.10).
  • Shape and attachments as shown in Fig. 3 (not shown here).

Summary Table

flowchart TB
    A[Side Wall (60 cm thick)] --> B[Flue (1.20 x 0.90 m)]
    B --> C[Chimney (2 per kiln)]
    A --> D[Inner Flue]
    A --> E[Outer Flue]

IS 4805: Access Wickets Key Points

• Clause 4.4: Provide an adequate number of access wickets for easy entry to different trench parts.

• Material Specs (Clause 2.5):

  • Wickets made from 3-25 mm thick MS sheet.
  • Base plate of chimney: 25 mm thick or two plates of 12 mm thick welded.
  • Brass bush tread: 50 mm diameter.
  • Brass washer: 100 mm diameter, 12.5 mm thick.
  • Pin: 25 mm diameter, 225 mm long.
  • Base plate with wheels (3B type) for mobility.

• Dimensions:

  • All dimensions in cm unless otherwise stated.
  • Flue size (Clause 4.8): 1.20 m x 0.90 m.

Typical Access Wicket Construction Summary

Conceptual Diagram of Access Wicket Components

graph LR
    A[MS Sheet Wicket Door] --> B[Base Plate (25 mm thick)]
    B --> C[Brass Bush Tread (50 mm)]
    C --> D[Brass Washer (100 mm x 12.5 mm)]
    D --> E[Pin (25 mm x 225 mm)]
    B --> F[Wheels (3B Base Plate)]

Summary: Ensure wickets are robust, sized for easy access, and constructed per the specified thickness and materials for durability and functionality in coal-fired brick kiln trenches.

IS 4805: Trench Floor Paving - Key Specifications

• Floor Paving (Clause 4.5):
  The trench floor must be paved with burnt bricks laid on edge to provide a durable, heat-resistant surface.

• Floor Level (Clause 3.2):

  • Minimum 3 m above the water table (measured during rainy season).
  • Maximum 1 m below ground level to avoid water seepage.

• Trench Dimensions (Clause 4.2 & 4.1.1):

  • Height: 2.25 m
  • Width: 9.0 m
  • Length per chamber: 5.0 m
  • Number of chambers (large capacity): 30
  • Capacity per chamber: 28,000 standard bricks

Typical Trench Floor Paving Detail

flowchart TB
    A[Subsoil Water Table] -->|≥3 m above| B[Trench Floor (Burnt bricks on edge)]
    B --> C[Trench Walls with Flues]
    C --> D[Chimney Placement]

This ensures durability, prevents water ingress, and supports kiln operation per IS 4805.

IS 4805 Key Specifications for Side Wall Thickness and Materials

• Side Wall Thickness:

  • Minimum 60 cm thick (Clause 4.6).

• Materials:

  • Constructed with ordinary burnt bricks (recommended for durability and maintenance).
  • Un-burnt bricks are permissible but less efficient.
  • Side walls plastered with mud-mortar (Clause 4.7).

• Optional Insulation:

  • Side walls may have a 25 cm cavity filled loosely with fine ash for better insulation (Clause 4.7 Note).

• Additional Notes:

  • Trenches height: 2.25 m (Clause 4.2).
  • Flues provided on inner and outer walls for chimney placement (Clause 4.3).

Summary Table

flowchart TD
    A[Side Wall] --> B[Thickness: 60 cm]
    A --> C[Material: Burnt Bricks]
    A --> D[Plaster: Mud Mortar]
    A --> E{Optional Cavity}
    E --> F[25 cm cavity]
    F --> G[Filled with fine ash for insulation]

This ensures structural strength, thermal efficiency, and durability of kiln side walls per IS 4805.

IS 4805: Wall Plastering & Insulation Key Points

• Wall Thickness:

  • Side walls should be 60 cm thick using ordinary burnt bricks (clause 4.6).
  • Un-burnt bricks allowed but burnt bricks recommended for durability and efficiency.

• Plastering:

  • Side walls must be plastered with mud-mortar (clause 4.7).

• Insulation:

  • For better insulation, construct walls with a 25 cm cavity.
  • The cavity may be loosely filled with fine ash to improve thermal resistance.

Summary Table

Notes:

• The cavity with fine ash reduces heat transfer, improving kiln efficiency.
• Mud plastering provides a breathable surface, aiding moisture control.

flowchart TD
    A[Side Wall Construction] --> B[60 cm Thick Burnt Brick Wall]
    B --> C[Plastered with Mud Mortar]
    B --> D[Cavity of 25 cm (Optional)]
    D --> E[Loose Fine Ash Filling]
    E --> F[Improved Thermal Insulation]

This approach ensures structural stability, durability, and thermal efficiency as per IS 4805 guidelines.

IS 4805: Flue Construction Details for Top-Fed Coal Fired Brick Kilns

Key Specifications:

• Flue Size: 120 cm (length) × 90 cm (width) (Clause 4.8)
• Distance Between Flues: 5.0 m (centre-to-centre) (Clause 4.9)
• Number of Chimneys: Two chimneys required (Clause 4.10)
• Shape & Attachments: As per Fig. 3 (not provided here), typically rectangular with proper draft provisions.

Construction Guidelines:

• Flues must be constructed as per Fig. 2 (rectangular cross-section)
• Use fire-resistant bricks and mortar
• Ensure smooth internal surfaces to minimize resistance to gas flow

Additional Notes:

• Flue dimensions ensure adequate natural draught for combustion
• Centre-to-centre spacing avoids thermal interference between flues

Summary Table:

flowchart LR
    A[Flue 1] ---|5 m| B[Flue 2]
    A & B --> C[Chimneys]
    C --> D[Natural Draught]

This ensures efficient combustion and heat flow in brick kiln operation as per IS 4805.

IS 4805 Key Specifications for Flue Spacing and Construction

• Flue Size (Clause 4.8):

  • 1.20 m x 0.90 m (120 cm x 90 cm)

• Flue Spacing (Clause 4.9):

  • 5.0 m centre-to-centre distance between flues

• Chimney Details (Clause 4.10):

  • Two chimneys required
  • Shape and attachments as per Fig. 3 (not shown here)

• Materials (Clause 2.5):

  • Flue sheet thickness: 3 to 25 mm MS sheet
  • Base plate: 25 mm thick or two 12 mm thick welded plates
  • Brass bush tread: 50 mm diameter
  • Brass washer: 12.5 mm thick, 100 mm diameter
  • Pin: 25 mm diameter, 225 mm long

Summary Table

flowchart LR
    A[Flue Size: 1.20 x 0.90 m] --> B[Spacing: 5.0 m C-C]
    B --> C[Two Chimneys Required]
    C --> D[Base Plate: 25 mm thick or 2x12 mm welded]
    D --> E[Brass Bush: 50 mm dia]
    E --> F[Brass Washer: 12.5 mm thick, 100 mm dia]
    F --> G[Pin: 25 mm dia, 225 mm long]

This ensures proper structural integrity and spacing for flue and chimney assemblies as per IS 4805.

IS 4805: Chimney Shape and Attachments - Key Points

Chimney Shape (Clause 4.10 & Fig. 3)

• Chimneys must follow the shape shown in Fig. 3 of the code.
• Two chimneys are required for each chamber.
• Chimney attachments include base plates, brass bushes, washers, and pins as detailed below.

Dimensions & Specifications

• Flue size: 1.20 m x 0.90 m (Clause 4.8, Fig. 2)
• Height of trenches: 2.25 m (Clause 4.2)
• Base plate thickness: 25 mm or two plates of 12 mm each (Clause 2.5)
• MS sheet thickness: 3–25 mm (Clause 2.5)
• Brass bush tread: 50 mm
• Brass washer thickness: 12.5 mm, diameter 100 mm
• Pin: 25 mm diameter, 225 mm long

Attachments Summary (Clause 2.5)

Flue & Chimney Arrangement (Clause 4.3)

• Two flues per chamber: one inner wall, one outer wall.
• Small kilns: only one outer wall flue per chamber.

flowchart TD
    A[Chimney] --> B[Base Plate (25 mm thick)]
    B --> C[Brass Bush (50 mm tread)]
    C --> D[Brass Washer (100 mm dia, 12.5 mm thick)]
    D --> E[Pin (25 mm dia, 225 mm long)]
    A --> F[Flue (1.20 m x 0.90 m)]
    F --> G[Inner Wall Flue]
    F --> H[Outer Wall Flue]

This ensures chimney stability and proper flue gas flow as per IS 4805.