Optimizing Skirtboard Design for Enhanced Conveyor Performance and Safety
The strength and stability of the skirtboard are crucial for its effectiveness. Often, conveyor skirtboards rely on cantilever brackets that may not be sufficiently rigid to endure material impact or equipment vibration. This poses a risk of structural failure, jeopardizing both the belt and the transfer point.
The thickness of the skirtboard must adequately withstand side pressures that can occur when the chute becomes blocked or the belt reverses. Positioned close to the belt, any movement of the skirtboard must be prevented to minimize the risk of damage. For mild steel used in skirtboard construction, a minimum thickness of 6 millimeters (0.25 in.) is recommended, except for very light applications. For belts moving faster than 3.7 meters per second (750 ft/min) or wider than 1300 millimeters (54 in.), the minimum thickness should be 10 millimeters (3/8 in.). For higher speeds (over 5 meters per second or 1000 ft/min) or wider belts (1800 millimeters or 72 in.), a minimum thickness of 12 millimeters (0.5 in.) is advised.
Skirtboards should be installed on structural steel supports spaced approximately 1.2 meters (48 in.) apart to avoid interfering with belt support cradles and idlers. A common support design is the angle iron "A-frame," installed at intervals similar to carrying idlers. These frames should be robust, well-gusseted, and positioned sufficiently above the belt to allow easy access for skirtboard seal adjustment or replacement.
Each skirtboard should have at least one "A-frame" at the start and another at the end. Closer spacing is recommended in the conveyor's impact zone, potentially doubling the support structure.
Specific sizes of angle iron are necessary for constructing these "A-frames," tailored to handle low-density, free-flowing materials. For belt feeders or dense materials like ore, heavier steel and closer support spacing are required.
Proper clearance between the bottom of the skirtboard supports and the belt is crucial to accommodate the installation and maintenance of the skirtboard seal and clamp system. The minimum clearance at the skirtboard wall should be 230 millimeters (9 in.) horizontally from the belt.
If there is dynamic vibration in the system from belt movement or operational machinery such as breakers, crushers, or screens, the skirtboard may need isolation.
These guidelines are suitable for standard conveyor installations with normal duty ratings, where the belt is approximately waist-high and idlers are standard width. For applications requiring "double height" skirtboards or in severe conditions, additional support structures may be necessary. Consultation with a conveyor or structural engineer is advised for advice on skirtboard thicknesses and required support structures.