Roller Support on a Reciprocating Grate: Why It Stays Clean

The moving frame of a reciprocating grate travels back and forth thousands of times a day, in a hot and dusty place under the grate. Two arrangements are common for carrying it: sliding contact and roller support. Roller support is the second, and by turning sliding into rolling it also deals with ash build-up and lubrication.

Friction plate above, rollers below

In a roller support the friction plate is mounted above and the rollers below, so the weight of the moving frame presses downward onto the rollers. The load path is fixed: the rollers carry the vertical load of the frame only, and neither the depth of the fuel bed nor its variation changes the stress on the rolling surface.

That matters most on a long grate. Over a long span a small deflection in the moving frame is enough to jam a sliding surface locally, while rolling tolerates more misalignment and jams far less often.

Ash cannot reach the raceway

The area under the grate is where ash and fall-through collect. With the rollers underneath, ash travels downward and does not pile up in the raceway, so routine cleaning is lighter than with sliding supports.

On biomass with a high ash load this counts for more than the saving on a few parts: a shutdown caused by ash jamming the moving frame is usually worse than the wear itself.

Lubrication: self-lubricating parts instead of regular greasing

Inside the rollers are high-temperature bearings. At this position the partner factory uses self-lubricating parts in place of bearings that need regular grease, so no greasing is required in service.

One greasing point fewer means one maintenance stop fewer, and one less risk of burning a bearing through a missed grease round. On a biomass boiler running continuously, that difference shows up in annual operating hours.

Modular, so shipping and installation are simpler

Roller support can be built in modules, and both transport and on-site lifting work module by module, which cuts installation effort. When an older grate is upgraded, modular support units also fit into the existing space more easily.

The arrangement also leaves the drive free: both gearbox drive and hydraulic drive can be fitted. If the drive changes later, the support structure does not have to change with it.

What to send when ordering rollers

Rollers and friction plates are supplied against the grate drawing. For a quotation, give the grate model, the number of moving frames, the number and spacing of roller rows, or simply the measured dimensions of the old parts.

We supply rollers, friction plates and other structural parts for reciprocating grates, dispatched from a partner factory, and we can check row count and dimensions against your grate model.