What is an Atomiser?
- An atomiser is a device that converts liquid into a spray or mist, enabling uniform distribution.
- A spray is a collection of droplets dispersed in gas.
- Key spray characteristics include:
- Drop size
- Spray pattern
- Angle of application
- Drop size metrics:
- Average surface area or volume
- Relative Span Factor (RSF) – measures drop size uniformity.
- Laser-based scattering is used to measure drop size accurately.
Relevance : GS 3(Science and Technology)
How Do Atomisers Work?
- Basic mechanism: Liquid is forced through a narrow channel, creating a pressure drop that breaks it into droplets.
- Types of flow outputs:
- Flat fan spray – used in paint sprayers.
- Sheeted spray hitting a ramp – useful for uniform coatings like pesticides.
- Pressure-swirl atomiser:
- Liquid swirls along chamber walls.
- Air passes through center, forming a conical spray.
- Aerosol atomisers:
- Produce droplets <10 micrometres.
- Can stay suspended in air for hours.
- Created using high shear force, ultrasound, or air-assisted methods.
Applications of Atomisers
Industrial Uses
- Power plants: Coolants sprayed on turbine blades.
- Lubrication: On moving mechanical parts to reduce heat.
- Spray drying: Used in making milk powder.
Automobile & Aerospace
- Fuel injectors: Pressurised fuel sprayed into combustion chambers.
Firefighting
- Foam sprays: Used to suppress flammable solid fires.
Agriculture
- Spraying fertilizers/pesticides.
- Spray irrigation in poorly percolating soils.
Medical Uses
- Nasal sprays for lungs.
- Topical sprays for pain relief and antiseptics.
- Disinfectants for air and surfaces in hospitals.
Scientific Research
- COVID-19 aerosol modelling: Helped understand airborne spread.
- Climate science: Studying aerosol cooling effects in atmosphere.
Household Uses
- Spraying cooking oil, mirror cleaners, perfumes, hair sprays.
- Deodorants – the most familiar and widespread use.
Conclusion:
- Atomisers combine engineering precision with everyday practicality.
- They are ubiquitous, essential in fields from medicine to climate science, and help improve efficiency, safety, and comfort in modern life.
