Ch. 6 Centrifugal Blast Cleaning

Question 1

In general, basic centrifugal blast setups include:

Answer 1

Tumbling mills

Multi-table machines

Plain table machines

Swing tables

Custom designed systems for continuous high volume production

Question 2

Centrifugal blast conveyor systems are commonly used for the cleaning of :

Answer 2

Steel plate

Fabricated beams

Rolled shapes

Rods

Piping

Question 3

Portable centrifugal blasting systems can be used on

Answer 3

Ship decks, hull sides, and bottoms

Storage tanks

Concrete floors

Highways and bridge decks

Question 4

Generally, centrifugal blast systems are composed of the following elements

Answer 4

Screw Conveyor
Rotary screen
Abrasive separator
Abrasive storage hopper
Abrasive control valve
Blast wheel
Screw conveyor
Work conveyor
Blast cabinet
Elevator

Question 5

The efficiency of the centrifugal blast wheels depends on several factors

Answer 5

Abrasive operating mix
Size of the abrasive
Velocity of the abrasive coming off the wheel
Quantity and direction of the thrown abrasive
Condition of the feed parts including feed spout, impeller, impeller case, and vanes

Question 6

Low amperage readings on a centrifugal blasting machine could signify

Answer 6

A blast wheel is either starved or choked

Question 7

The functions of the centrifugal blasting machine separator include

Answer 7

To control the size of the abrasive mix, which influences cleaning efficiency

To remove sand, fines, rust, dirt, and any other contaminants from the abrasive stream so only good clean abrasive is fed to the blast machine

To control abrasive consumption, which is measure by the size of abrasive pellets removed from the machine

Question 8

Some of inspection concerns during centrifugal blasting include

Answer 8

Constantly monitor the dust collector and make sure the vacuum is removing all the dust debris from the substrate

Monitor the amperage of the wheel motors and slook for indications of low amperage

Monitor the handling and loadoing of hte conveyor line for contaminates and discontinuities in the steel

Monitor the speed of the line

Most important, inspect the steel as it leave the production line to ensure all surfaces comply with the project specification