Stoker Classification

Coal stokers classified on basis of coal burning capacities according to ASHRAE standards. Determines stoker class based on coal burning capacity in lbs/hour.

Stoker ClassCoal Burning Capacity (lbs/hour)Coal Burning Capacity (kg/hour)Typical Use
Class 1 Stokers10 to 1004.5 to 45Small residential/light commercial
Class 2 Stokers100 to 30045 to 135Medium commercial applications
Class 3 Stokers300 to 1200135 to 540Large commercial/industrial
Class 4 StokersMore than 1200More than 540Heavy industrial applications

Optimal Operating Conditions

Bituminous Coal Specifications:

  • Ash fusion temperature: 2200°F to 2600°F (ideal range)

Coal Size Requirements:

  • Recommended size range: 3/4-inch to 1 1/4-inch
  • Size varies depending on stoker construction

Coal Treatment:

  • Oil treatment is common to reduce dust problems
  • Oil treatment extends lifetime of mechanical conveyors and feed screws
  • Helps reduce wear on mechanical components