Coal Crusher

About Coal Crusher

A coal crusher reduces run-of-mine or received coal to the size the boiler is designed to burn. Grate-fired boilers need coal broken to a consistent lump size so that it burns evenly across the grate; fluidized bed boilers need it crushed much finer and to a controlled size range, because the bed only fluidizes and burns properly when the particles are within it.

The crushing method is chosen against the coal and the size wanted. Hammer crushers break coal with swinging hammers on a fast rotor and suit most medium-hardness coals. Ring granulators use rings instead of hammers and produce a more uniform product with fewer fines, which is why they are common in coal handling for boilers. Double roll crushers squeeze coal between two rolls for a closely controlled size with little fines generation.

What reaches the crusher matters as much as the crusher. A magnetic separator ahead of it removes tramp iron that would damage the rotor; a screen ahead of it bypasses coal that is already in size; and wet, sticky coal needs a crusher and chutes designed not to choke. Dust has to be contained at the crusher, which is the dustiest point in a coal handling system.

We supply coal crushers as part of complete coal handling systems, selected for the coal's hardness, moisture and the size the boiler needs, together with the screens, magnetic separators and conveyors around them.

Selection starts with three numbers: the largest lump the crusher will be asked to accept, the product size the boiler needs, and the tonnes per hour. The ratio between the first two decides whether one stage of crushing will do or whether a primary and a secondary stage are needed, since asking a single machine for a very large reduction produces heat, wear and a great deal of fines. Coal hardness — reported as the Hardgrove Grindability Index — tells us how hard the coal resists that reduction, and it is worth asking the supplier for it.

Moisture is the other half of the problem. Wet, clayey coal packs into the crushing chamber and the chutes around it, and a crusher that chokes stops the entire fuel path behind it. That is designed around with generous chute angles, liners that material does not key to, a larger discharge setting where the boiler can tolerate it, and access to clear a blockage quickly and safely rather than with a bar through an inspection door.

A crusher is also a machine with a heavy rotor turning fast, so the mechanical installation matters as much as the crushing. The rotor is balanced, and wear parts are renewed in matched sets so it stays balanced; the machine sits on a foundation designed to take the vibration rather than pass it into the building; and the drive is arranged so that hammers or rings can be changed without dismantling the surrounding plant. The crusher house is the dustiest point in coal handling, so it is enclosed and extracted rather than simply roofed.

Typical duty is sizing received coal for grate-fired boilers and crushing to the finer, controlled size an AFBC bed needs, along with lignite, petcoke and limestone for in-bed sulfur capture. We supply crushers within complete coal handling systems and as replacements in existing crusher houses, with the screens, magnetic separators and conveyors around them, plus erection, commissioning, wear parts and an AMC where the plant wants one.

Coal Crusher Key Features

• Hammer, ring granulator and double roll crushers
• Output size matched to grate or fluidized bed firing
• Screen ahead of the crusher to bypass in-size coal
• Magnetic separator provision to remove tramp iron
• Adjustable product size
• Wear-resistant hammers, rings and liners
• Chutes designed for wet, sticky coal
• Dust enclosure at the crusher house
• Feed and product size, tonnage and coal hardness taken as the selection basis
• Single or two-stage crushing according to the reduction required
• Generous chute angles and non-keying liners for wet, clayey coal
• Balanced rotor with wear parts renewed in matched sets
• Foundation and mounting designed to contain vibration
• Maintenance access for changing hammers, rings and liners
• Dust extraction at the crusher house, not merely a roof

Coal Crusher Specification

Materials Handled

Crushing Technology

Coal Crusher Applications

Industries Served

Advantages of a Coal Crusher

Optional Accessories