The workings of an atomiser and its myriad applications, Pg11

• Atomiser: A device that converts liquid into fine mist or spray using pressure or airflow.

  • Used in spray bottles, deodorants, fuel injectors, crop sprayers, and medical nebulisers.

  • Factors influencing atomisation include drop size, spray angle, and spray pattern.

  Detailed Insights:

  • What is an Atomiser?

    A mechanical or electronic device that breaks a liquid into fine droplets and propels it as a spray using:

    • Compressed air

      • Hydraulic pressure

      • Sonic waves

      • Centrifugal force

    • Working Principle:

    • When a liquid is pushed through a narrow nozzle under pressure, it shears into tiny droplets due to velocity change and surface tension forces.

      • Atomisers are tailored to control:

        • Drop size (smaller for finer coating or mist)

          • Spray angle and range

          • Spray pattern uniformity

      • Types and Applications:

    • Spray pumps and nozzles – found in perfume and pesticide sprays.

      • Pressure-swirl atomisers – used in fuel injection, coating industries.

      • Ultrasound atomisers – used in humidifiers and medical nebulisers.

      • Spray drying atomisers – used in dairy and pharma industries for powdered product generation.

      • Fire safety – Atomisers in fire extinguishers help cover wide areas with extinguishing chemicals.

      • Irrigation – Precision agriculture uses atomisers to deliver controlled water to crops.

  Key Concepts:

  • RSF (Relative Span Factor): Measures uniformity of droplet size – lower RSF = uniform spray.

  • Spray pattern: Spatial distribution of drops.

  • Spray drying: Converting liquid to dry powder by spraying into hot gas – e.g., milk powder.

  Significance:

  • Atomisers improve efficiency and precision in sectors like healthcare, agriculture, manufacturing, and consumer goods.

  • They exemplify how scientific principles are embedded in everyday life.

  • Understanding atomisers offers insights into fluid mechanics, thermodynamics, and aerosol physics.

Mains Mock Question:

“Explain the principle of atomisation and its role in industries such as agriculture, pharmaceuticals, and fire safety. Illustrate with examples.”