Dholera Industrial Chimney Height Calculations: DSIRDA Stack Norms

1. GPCB Stack Height Calculation Formulas

The minimum physical height of an industrial chimney in Dholera is calculated based on the type of fuel burned and the expected emission load of gaseous pollutants:

Formula A: Based on Sulphur Dioxide ($\text{SO}_2$) Emissions

For manufacturing processes emitting $\text{SO}_2$ (such as coal, heavy oil, or chemical processing plants):

$$\Large H = 14 \cdot (Q)^{0.3}$$

Where: * $H$ = Minimum Stack Height (Meters): The calculated vertical chimney height measured from ground level. * $Q$ = $\text{SO}_2$ Emission Rate ($\text{kg/hr}$): The maximum estimated mass rate of sulphur dioxide discharged per hour. * Absolute Minimum Floor Cap: In all cases, no industrial chimney emitting $\text{SO}_2$ can be less than 30 meters in height, regardless of how low $Q$ is calculated.

Formula B: Based on Boiler Thermal Capacity

For small-to-medium industrial boilers burning gaseous fuels (such as PNG or LPG):

$$\Large H = 14 \cdot (Q_t)^{0.3} \quad \text{or} \quad H = 30\text{m (whichever is greater)}$$

For small boilers where thermal rating is expressed in tonnes per hour ($\text{TPH}$): * Boiler Capacity $< 2\text{ TPH}$: Minimum chimney height = 15 meters. * Boiler Capacity $2\text{ to }5\text{ TPH}$: Minimum chimney height = 18 meters. * Boiler Capacity $5\text{ to }10\text{ TPH}$: Minimum chimney height = 24 meters. * Boiler Capacity $> 10\text{ TPH}$: Minimum chimney height = 30 meters or calculated via $\text{SO}_2$ formula.

The table below outlines industrial chimney height specifications in Dholera SIR:

2. Aviation Hazard Lighting & Structural Safety

Because Dholera SIR is served by the Dholera International Airport, tall industrial structures must conform to Directorate General of Civil Aviation (DGCA) obstacle safety codes:

• Aviation Obstacle Lights: Any industrial chimney exceeding 30 meters in height must be fitted with medium-intensity aviation obstacle lights (flashing red lights during night, white flashing lights during day) installed at the stack top and at 30-meter vertical intervals along the shaft.
• Color Band Marking: The top 15 meters of industrial chimneys must be painted with alternating orange and white aviation warning bands (each 1.5m to 3m wide) using heat-resistant epoxy paint.
• Wind & Seismic Stability: Stack foundations must be engineered for basic wind speeds of 47 m/s and Seismic Zone V dynamic loads in Dholera’s marine clay foundation layers.

3. Continuous Emission Monitoring Systems (CEMS)

To ensure compliance with GPCB emission thresholds:

• Sampling Ports & Ladders: Stacks must feature an insulated sampling platform and port (minimum diameter 100mm) located at a distance of at least 8 stack diameters downstream and 2 stack diameters upstream from any flow disturbance (bends, fans).
• CEMS Telemetry: High-capacity chemical plants and boilers must install real-time CEMS probes measuring Particulate Matter (PM10/PM2.5), $\text{SO}_2$, $\text{NO}_x$, and Carbon Monoxide ($\text{CO}$), streaming data 24/7 to DICDL and GPCB central servers.

Frequently Asked Questions (FAQ)

#### What is the mathematical formula for calculating industrial chimney height in Dholera?

Under GPCB and DSIRDA GDCR Section 11.2, stack height is calculated using $H = 14 (Q)^{0.3}$, where $H$ is stack height in meters and $Q$ is the $\text{SO}_2$ emission rate in kg/hr.

#### What is the absolute minimum chimney height allowed for a industrial factory in Dholera?

For any manufacturing plant emitting gaseous pollutants, the absolute minimum stack height cap is 30 meters, regardless of lower calculated values.

#### Are aviation obstacle lights required on industrial chimneys in Dholera SIR?

Yes. Due to proximity to Dholera International Airport, any stack exceeding 30 meters in height must feature DGCA-compliant aviation hazard lights and orange/white warning bands.