Identify the waste incinerator(s) commonly categorized according to combustion chamber:
A. Rotary kiln
B. Moving grate
C. Fixed-hearth
D. Fluidized-bed
Choose the correct answer from the options given below:

Correct option is D

Introduction

• Waste incineration is a thermal waste treatment process that involves the combustion of organic substances in waste materials at high temperatures (850-1100°C).
• Incinerators are primarily classified based on their combustion chamber design, which determines how waste is fed, burned, and processed.
• Understanding these classifications is crucial for environmental management and waste-to-energy operations.

Information Booster

• A. Rotary Kiln Incinerator
  
• Features a cylindrical, rotating combustion chamber inclined at a slight angle
• Rotation ensures thorough mixing and complete combustion
  
• Ideal for hazardous and industrial waste, including solids and liquids
  
• Operates at 850-1200°C
  
• B. Moving Grate Incinerator
  
• Most common type for municipal solid waste (MSW)
  
• Waste moves through the chamber on a series of mechanical grates
  
• Allows continuous feeding and ash removal
  
• Provides controlled combustion with good air distribution
  
• C. Fixed-Hearth Incinerator
  
• Stationary combustion chamber with a non-moving hearth
  
• Suitable for batch-type operations and smaller capacities
  
• Often used for medical and pathological waste
  
• Simpler design but requires manual ash removal
  
• D. Fluidized-Bed Incinerator
  
• Uses a bed of inert material (sand/limestone) suspended by upward air flow
  
• Creates turbulent mixing for efficient combustion
  
• Excellent for sewage sludge and industrial waste
  
• Operates at lower temperatures (750-900°C) with better emission control
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