2. CONTENTS
• Introduction
• Components of cooling tower
• Significance of cooling tower
• Types of Cooling tower
• Cooling tower selection criteria
3. Introduction
• Cooling tower :-
HEAT REJECTION DEVICE
(COOLING TOWER)
COLD WATER
HOT WATER
DRY AIR IN
MOIST, WARM AIR OUT
A heat rejection device, which extracts waste heat to the
atmosphere through the cooling of a water stream to a
lower temperature.
4. Cooling tower
• The principal means of heat transfer involved in cooling towers is evaporative
cooling.
• Evaporation of a small portion of the water being sprayed or percolated in the air of
the tower removes sensible heat from the remaining water.
• The increasing heat content of the air is of no consequence since the air is
exhausted to the atmosphere on the surface or to the upcast shaft underground.
• Depending on the relative temperatures of air and water, sensible cooling of the
water and latent heating plus sensible heating or cooling of the air occurs.
5. • Cooling towers are used to cool the heated condenser water for reuse in a cyclic
system. In underground mines, cooling towers have to be properly located and
designed depending on the amount of heat to be extracted, and the temperature,
humidity and flow rate of air available for cooling.
• Spray chambers/towers are used instead of cooling towers in some u/g plants.
Most spray towers are located in parts of shafts or winzes where the condenser
water is sprayed at the top and works its way down through sets of screens, with
the cooling air flowing upwards under the ventilating pressure of the mine.
7. Components of cooling tower
• Fan or Blower: Draws air through the tower for cooling.
• Heat Exchange Media: Enhances heat transfer between air and water.
• Water Distribution System: Sprays water evenly over the media.
• Water Reservoir or Basin: Collects and recirculates water.
• Pump System: Circulates water from reservoir to the tower.
• Drift Eliminators: Prevent water loss and contamination.
• Ventilation System: Regulates airflow for air quality control.
• Monitoring and Control Systems: Manage tower operation parameters.
• Safety Features: Guardrails, access doors, and emergency shut-offs ensure
safety.
8. Significance of cooling tower
Equipment Cooling: Preventing overheating and damage to machinery.
Worker Safety: Maintaining comfortable working conditions underground.
Air Quality Control: Removing dust and contaminants for healthier air.
Preventing Equipment Failures: Extending machinery lifespan and reducing
downtime.
Environmental Protection: Minimizing thermal pollution and conserving
water.
Regulatory Compliance: Meeting standards for workplace safety and
environmental impact.
9. Types of cooling tower
Cooling tower
Mechanical Draft
Natural Draft
Design of cooling tower is such
that cold air of the bottom of
tower push the warmer air out
from top.
Forced Draft
Air is pushed in
the tower with a
fan from the
side.
Induced Draft
Air is pulled from cooling
tower by a fan at the top.
Counter flow Cross flow
10. Natural fan draft
Natural Draft Cooling Towers utilize the natural buoyancy of air for heat
dissipation.
• Distinctive Shape: These towers are known for their tall, hyperbolic shape,
which enhances the natural draft effect.
• Buoyancy-Driven Airflow: Warm air rises inside the tower due to heat from
circulating water, creating a draft that draws in cooler air from the
surroundings. This continuous airflow cools the water.
Key Features:
• No Mechanical Fans: Natural draft towers rely solely on buoyancy. This design
reduces energy consumption and operational costs.
• Energy Efficiency: The absence of fans makes them energy-efficient.
• Large Heat Rejection Capacity:Their tall structure allows for substantial
contact between ascending warm air and descending cool air, maximizing heat
transfer.
12. Mechanical draft cooling tower
Air Circulation: Fans induce or force air through the tower, enhancing the
natural convection process for heat transfer.
Types: There are two main types of mechanical draft towers:
• Forced Draft: Fans at the air inlet push air into the tower.
• Induced Draft: Fans at the exhaust pull air through the tower.
Temperature Control: They offer precise control over the cooling process,
suitable for maintaining specific temperature levels.
Adaptability: The ability to control fan speed or use multiple fans makes them
suitable for variable heat loads.
13. Cont….
Components: These towers include mechanical fans, motors, water distribution
systems, fill media, drift eliminators, and structural supports.
Energy Consumption: They consume electrical energy to operate the fans.
16. Cooling tower selection criteria
Temperature Design Criteria:
• Determining the required cooling capacity based on mine-specific conditions.
• Consider the heat load profile and required cooling efficiency.
Mine Working Depth :
• Deeper mines experience higher temperatures due to the geothermal gradient.
• Cooling tower selection should account for depth-related heat challenges.
Heat Load:
• Assess the overall heat generated by mining activities, equipment, and rock
movement.
• Optimize cooling tower capacity based on the mine’s specific heat load.
17. Cont……
Water Availability and Recirculation:
• Consider water availability for cooling tower operation.
• Choose designs that efficiently recirculate water to minimize consumption.
Cost-Effectiveness:
• Balance initial capital costs with long-term energy savings.
• Evaluate the economic impact of cooling tower selection.
Maintenance Accessibility:
• UG mines may pose challenges for tower maintenance due to depth.
• Ensure ease of access for inspections and repairs.