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Design Criteria

The pressurisation of a rubber bladder alters the angles within the parallelogram modules, thereby providing precise and uniform blade pressure to the belt surface. The system automatically compensates for blade wear. The constant blade to belt angle and even blade to belt pressure over the full belt width are unique features of the design.

  • The cleaner blades are designed to bring about minimal belt wear to the belt top cover
  • The innovative parallelogram design maintains the optimal belt blade angle irrespective of blade wear
  • The air bladder system sustains even blade-to-belt pressure over the full cleaner width
  • The blade design is compatible with the majority of mechanical belt fasteners
  • The unit requires no mechanical adjustment in-between blade changes
  • There is a visual indication of belt-to-blade pressure at all times
  • The belt-to-blade pressure can be adjusted from a suitable remote location

Air System

Each blade on a DirtWhacker belt cleaner is 150 mm wide. It has its own parallelogram and hence each blade acts independently of any other blade in the scraper, all the time riding on a cushion of air. The single air bladder runs through all the parallelograms which has a fixed end cap on one side and an air inlet port (like a car tyre) with a pressure gauge at the other side.

The result is a scraper blade that is constantly being forced upwards towards the belt via the air pressure in the bladder, against an opposing downwards force being created by the belt due to its close proximity to the head drum position. The result is that the rubber belt is squeezed between the blade and the head drum. The conveyor belt carry back is therefore forced from the belt just prior to the blade. due to the squeezing effect. The outcome is then a cleaned belt going over a blunt blade, resulting in significantly less carry back, belt wear and roller wear compared to any other scraper.

Blades

The DirtWhacker blades have been developed to provide the industry with a durable and cost-effective scraping solution. These blades provide an excellent balance for the customer when it comes to durability and belt compatibility. The DirtWhacker secondary blade system meets the following design criteria:

  • The cleaning blade exhibits excellent belt friendliness
  • Carryback is eliminated by the blades
  • The blades have an outstanding ability to accommodate thermal shock
  • Compatible with the majority of mechanical belt fasteners
  • Blades are replaced by removing a single bolt, no complicated systems

The DirtWhacker uses blunt blades. The blunt blades are applied to the top cover at an effective pressure and as such eliminating the abrasive media (carryback) between the belt and the blade. The blade only wears due to the polishing of the hard metal by the softer rubber material of the conveyor belt.

Parallelogram

The parallelogram ensures that the scraper blades maintain the optimal belt to blade angle irrespective of blade wear. Each 150mm blade section is mounted independently on its own parallelogram. This ensures that the belt and blade wear are optimally accommodated for, while a single air bladder supports all parallelograms on a given cleaner unit so that every blade will have equal belt-to-blade pressure irrespective of wear.