Centrifugal Blast Cleaning

Question 1

What are some general basic centrifugal blast setups

Answer 1

• Tumbling mill
• Multi Table
• Plain Table
• Swing Table
• Custom designed systems

Question 2

What types of applications are automated wheel blast system available for?

Answer 2

• Hot-rolled bar stock
• Wire-rod castings
• Hot-rolled steel strip
• Plate
• Structural members

Question 3

Conveyor systems are commonly used for the cleaning of?

Answer 3

• Plate
• Rolled structural shapes
• Large trusses
• Girders
• Large structural parts

Question 4

Permit on-site wheel blasting cleaning during new construction and maintenance include?

Answer 4

• Ship decks, hull sides, and bottoms
• Storage tanks
• Concrete floors
• Highways & bridge decks

Question 5

What are the components of the Blast System?

Answer 5

• Centrifugal abrasive throwing wheel
• Blast cabinet (or enclosure)
• Material handling system (in fixed systems)
• Abrasive recycling system
• Dust collector & vent-pipe system
• Abrasives

Question 6

The rate speed important in regard to a centrifugal blast system. True or false?

Answer 6

True

Question 7

What is the ‘heart of the system’ that throws the abrasive in a controlled pattern against the surface to be cleaned?

Answer 7

The blast wheel

Question 8

The efficiency of the blast wheel(s) depends on what factors?

Answer 8

• 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

Question 9

What is the concentrated area of blast in centrifugal blast cleaning called?

Answer 9

Hot spot

Question 10

Centrifugal Blast Cleaning

The quantity of the abrasive being thrown by the wheel is determined by what?

Answer 10

With an ammeter

Question 11

Centrifugal Blast Cleaning

Low amperage readings could signify what?

Answer 11

• An abrsaive-starved wheel
• A flooded or choked wheel

Question 12

Centrifugal Blast Cleaning

What are the functions of the separator?

Answer 12

• 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

Question 13

Abrasive blast machines clean best with a range of abrasives.
True or false?

Answer 13

True

Question 14

Centrifugal Blast Cleaning

List benefits of a well-balanced operating mix (working mix) of abrasive sizes.

Answer 14

• 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

Question 15

What abrasives are used most commonly in preparing steel and concrete for coating?

Answer 15

• Steel shot (round)
• Steel Grit (angled)

Question 16

What is steel shot abrasive best used for?

Answer 16

Blast cleaning, peening, or de-scaling abrasive available

Question 17

What is steel grit abrasive best used for?

Answer 17

Etching, i.e. creating surface profile prior to painting or plating

Question 18

Centrifugal Blast Cleaning

What does abrasive wear do?

Answer 18

Creates a finer particle size than the desired operating mix

Question 19

What should be monitored during inspection of centrifugal blast cleaning?

Answer 19

• 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

Question 20

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

Answer 20

B. Speed of travel

Question 21

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

Answer 21

A. Can be used for multiple substrates
B. Dust can be collected for disposal
D. Abrasives can be recycled

Question 22

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

Answer 22

A. Steel shot/grit
B. Glass beads
C. Garnet
D. Walnut shells

Question 23

What is an abrasive?

Answer 23

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

Question 24

What is an ammeter?

Answer 24

A device used to measure the electrical current in a circuit

Question 25

What is a blank test?

Answer 25

A test that does not use metallic abrasives and allows the solvent to reduce in volume before pouring onto the mirror

Question 26

What is centrifugal blast cleaning?

Answer 26

An enclosed blast cleaning process that throws abrasive at the surface being cleaned

Question 27

What are multi-table machines?

Answer 27

A series of independent revolving work tables mounted on a rotating platform or “spider” in centrifugal blast cleaning

Question 28

What are swing tables?

Answer 28

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.

Question 29

What are tumbling mills?

Answer 29

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