Centrifugal Blast Cleaning Flashcards
What are some general basic centrifugal blast setups
- Tumbling mill
- Multi Table
- Plain Table
- Swing Table
- Custom designed systems
What types of applications are automated wheel blast system available for?
- Hot-rolled bar stock
- Wire-rod castings
- Hot-rolled steel strip
- Plate
- Structural members
Conveyor systems are commonly used for the cleaning of?
- Plate
- Rolled structural shapes
- Large trusses
- Girders
- Large structural parts
Permit on-site wheel blasting cleaning during new construction and maintenance include?
- Ship decks, hull sides, and bottoms
- Storage tanks
- Concrete floors
- Highways & bridge decks
What are the components of the Blast System?
- Centrifugal abrasive throwing wheel
- Blast cabinet (or enclosure)
- Material handling system (in fixed systems)
- Abrasive recycling system
- Dust collector & vent-pipe system
- Abrasives
The rate speed important in regard to a centrifugal blast system. True or false?
True
What is the ‘heart of the system’ that throws the abrasive in a controlled pattern against the surface to be cleaned?
The blast wheel
The efficiency of the blast wheel(s) depends on what factors?
- Abrasive operating mix
- Size of the abrasive
- Velocity of the abrasive coming off of the wheel
- Quantity and direction of the thrown abrasive
- Condition of the feed parts
What is the concentrated area of blast in centrifugal blast cleaning called?
Hot spot
Centrifugal Blast Cleaning
The quantity of the abrasive being thrown by the wheel is determined by what?
With an ammeter
Centrifugal Blast Cleaning
Low amperage readings could signify what?
- An abrsaive-starved wheel
- A flooded or choked wheel
Centrifugal Blast Cleaning
What are the functions of the separator?
- Control sizing of the abrasive mix (used)
- Remove sand, spent abrasives (fines), rust, dirt, and any other contaminants from the abrasive stream
- Control abrasive consumption
Abrasive blast machines clean best with a range of abrasives.
True or false?
True
Centrifugal Blast Cleaning
List benefits of a well-balanced operating mix (working mix) of abrasive sizes.
- Provide consistency of the finish
- Ensure uniform abrasive coverage
- Ensure conditioning of the abrasive for optimum cleaning
- Minimize lowest abrasive and machine part-wear
- Reduce downtime for maintenance
What abrasives are used most commonly in preparing steel and concrete for coating?
- Steel shot (round)
- Steel Grit (angled)
What is steel shot abrasive best used for?
Blast cleaning, peening, or de-scaling abrasive available
What is steel grit abrasive best used for?
Etching, i.e. creating surface profile prior to painting or plating
Centrifugal Blast Cleaning
What does abrasive wear do?
Creates a finer particle size than the desired operating mix
What should be monitored during inspection of centrifugal blast cleaning?
- Dust collector
- Amperage of the wheel motors/low amperage
- Handling and loading of the conveyor line for contaminates/possible discontinuities in the steel
- Speed of the line
- Inspect steel as it leaves the production line
In a centrifugal blast operation, the degree of cleanliness is determined primarily by __________?
A. Sized of abrasive
B. Speed of travel
C. Grade of steel
D. Size of the hot spot
B. Speed of travel
Which of the following are advantages of portable centrifugal blast cleaning? (Select all that apply)
A. Can be used for multiple substrates
B. Dust can be collected for disposal
C. Removes non-visible contaminates
D. Abrasives can be recycled
A. Can be used for multiple substrates
B. Dust can be collected for disposal
D. Abrasives can be recycled
Which of the following are abrasives that can be used in centrifugal blast units? (Select all that apply)
A. Steel shot/grit
B. Glass beads
C. Garnet
D. Walnut shells
A. Steel shot/grit
B. Glass beads
C. Garnet
D. Walnut shells
What is an abrasive?
A solid substance that, because of its hardness, toughness, size, shape, consistency, and other properties is suitable for cutting, roughening, polishing, or cleaning a surface by friction or high-velocity impact
What is an ammeter?
A device used to measure the electrical current in a circuit
What is a blank test?
A test that does not use metallic abrasives and allows the solvent to reduce in volume before pouring onto the mirror
What is centrifugal blast cleaning?
An enclosed blast cleaning process that throws abrasive at the surface being cleaned
What are multi-table machines?
A series of independent revolving work tables mounted on a rotating platform or “spider” in centrifugal blast cleaning
What are swing tables?
Work tables used in centrifugal blast cleaning that rotate under that blast or one or more abrasive throwing wheels. The table swings out with the cabinet door when the door opens. It offers a high degree or work handling flexibility and can accommodate very large and heavy work up to 10 tons.
What are tumbling mills?
Mills generally used to abrasive clean batch loads and parts/ The wheel units are usually mounted on the roof of the cabinet to blast clean parts as they tumble in the mill
