Difficulty: Easy
Correct Answer: 30 to 70 kV DC
Explanation:
Introduction / Context:
Electrostatic precipitators remove fine particles by charging them in a high-voltage field and collecting them on oppositely charged plates. The selection of voltage magnitude and polarity is vital for corona formation and charging efficiency.
Given Data / Assumptions:
Concept / Approach:
Stable corona discharge for particle charging is achieved using high-voltage direct current in the tens of kilovolts range. Typical setpoints are 30–70 kV DC depending on gas properties and spacing. AC would not maintain a steady unidirectional field for effective charging and collection, and household-level voltages are far too low to sustain corona in industrial gaps.
Step-by-Step Solution:
Identify the need for a steady electric field and corona: favors DC.Recall typical industrial ranges: tens of kilovolts.Select 30–70 kV DC as the appropriate magnitude and type.
Verification / Alternative check:
Manufacturer datasheets and commissioning records list transformer–rectifier outputs in this DC range.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
30 to 70 kV DC
Discussion & Comments