Steel Abrasives - #3 How to reduce your shot blasting costs
Tip #3

"My blast cycle time has increased!"

"My machine doesn't clean the steel thoroughly anymore."

These are comments we hear regularly from our shot blasting & shot peening customers. These are important issues to those in the industry as everyone strives to improve their productivity. There are a number of reasons these issues arise. Lets go over them...

Possible reasons
  1. Your machine is out of abrasive or the storage hopper level is low.
  2. The impellor is badly worn and needs replacing.
  3. The blades are worn and need replacing.
  4. The control cage is out of alignment.
  5. The control cage is worn and the opening is enlarged.
  6. The blast wheel motor has been changed and the rotation is incorrect.
  7. Your fines separator isn't pulling out enough 'fines' from the steel shot & the Steel Shot working mix is too fine
  8. There is a blockage in your abrasive recycling system - elevator, shot pipe, abrasive control valve - which is starving the blast wheel of steel shot. The ammeter showing less than full load amps, is an indication of this.
  9. My shotblast parts are wearing out too fast due to fines & dust in the steel abrasive shot mix
The solutions
  1. No abrasive or low abrasive levels mean that insufficient abrasive is reaching the blast wheels to clean the product. It is imperative to maintain a consistent level of shot in the storage hopper to maintain the blast quality and performance of the machine.
  2. The impellor leads and regulates the flow of abrasive so that when the abrasive passes through the gap it will flow onto the blades with minimum bounce. A worn impellor will cause premature blade or wheel assembly wear. It can also cause the wheel to become imbalanced and vibrate, causing further significant issues. The impellor should be changed with every blade change.
     impellor NEW  impellor WORN
  3. Worn blades cause the shot to be thrown in an ineffective and inefficient manner. The blasting 'hot spot' will also be affected meaning the product is not being blasted effectively. Inspect regularly and replace when required.

    blades NEW2  blades WORN2   blades WORN3
  4. The control cage is one of the most important components in the wheel. This governs the direction of the blast out of the wheel and onto the work to be cleaned. As little as 10% mis-alignment of the hot spot can reduce blasting efficiency by up to 25%!
  5. The opening on the control cage determines the hot spot position. If the control cage is worn and the opening enlarged, the wheel will no longer throw the shot at the target location. The control cage needs to be inspected regularly and changed with the impellor at every blade change.

     control-cage NEW2 control-cage WORN2 
  6. The direction of the blast wheel is important in determining the location of the hot spot. Whilst some wheel styles can work in both directions, they may not be turning in the correct direction. Ensure all wheels are turning in the correct rotation to suit your blasting needs.