Clean Air with the Cottrell Precipitator
In the first photo, gray smoke inside a capped tube with wires spiraling along the sides of the tube. A black lead is connected to an electrode on top of the tube, and a red lead is connected to an electrode on the right side of the tube. In the second photo, less gray smoke reveals an electrode inside the tube with a black lead connected to an electrode on top of the tube and a red lead connected to an electrode on the inner surface of the tube.
Description: When cigarette smoke is passed through a chamber in which a high electrical potential exists between two electrodes, the smoke precipitates on the electrodes.
Source: Shakhashiri, B.Z. Chemical Demonstrations: A Handbook for Teachers of Chemistry
Year: 1989 Vol: 3 Page: 341
Keywords: Cottrell Precipitator, Smoke reduction, Pollution, Air pollution, Electrostatic attraction
Rating: 
Hazard: Some
- Electrocution hazard
Effectiveness: Average
- Somewhat connected conceptually to course material
- Results are observable with guidance
- Time to results is medium
- Moderate failure rate
Difficulty: Medium
- Some careful manipulations required
- Some intermediate steps to results
- Demos at non-standard conditions
Safety Precautions:
- Eye protection required
- Gloves recommended
- UL approved three-prong plug and outlet required
Class: Physical Properties, Electronic Structure, Properties of Substances
Division: General
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