Explanatory notes
… generally fitted with a refractory lining or a water-cooled double wall enclosing a grate (either of fixed, … many kinds of solid fuel (e.g., coal, coke, charcoal, wood, vegetable or other waste). For certain uses, … (comprising perforated cones, coke beds, scrubbers, etc.), coolers, dryers, reheaters, etc. Such purifiers and other …