Transcript Achieving Efficiency in Abrasive Blasting William P. Nelson Schmidt Engineered Abrasive Systems Sponsored by: What is the Definition of “Efficiency”?  Abrasive blasting is defined as a controlled.

Achieving Efficiency
in Abrasive Blasting
William P. Nelson
Schmidt Engineered
Abrasive Systems
Sponsored by:
What is the Definition of
“Efficiency”?
 Abrasive blasting is defined as a
controlled erosion process whereas your
productivity is measured by how much
area is blasted, in what time frame and
by using how much abrasive
What is Abrasive Blasting?
 “To combine the energy of compressed
air with a granular abrasive, which is
propelled to impact a surface in a
controlled, repeatable and predictable
surface preparation method.”
Enemies of any Air Blast
System
 Insufficient air supply
 Moisture
 Pressure drop
Enemy #1
Insufficient Air Supply
 You lose 1.5% of productivity for every 1 psi
reduction in blast nozzle pressure
(As stated in research by NACE)
Enemy #1
Insufficient Air Supply
NOZZLE
No. 4 No. 5 No. 6 No. 7 No. 8
Orifice Size
1/4”
5/16”
3/8”
7/16”
1/2”
CFM @ 100 psi
90
150
200
270
350
(All figures are approximate)
Enemy #2
Moisture
 Increased operating costs
 Increased material costs
 Decreased operating efficiencies
 Reduced productivity
Enemy #2
Moisture
How does water get into the compressed air?
 All air contains moisture
 As the air is compressed, any moisture in it will
also be compressed
 As you compress the air/moisture, it heats up
 Hot air retains moisture remaining a vapor
So…How do you remove moisture?
Enemy #2
Moisture
Convert moisture from a vapor to a solid (water droplets)
HOW?
By cooling the air you can then remove the moisture:
► By expansion (Moisture Trap)
► Use of radiator (ACS)
Once the air is cooled, you have to separate it:
► Demister Pad
► Centrifugal
► Absorption / Adsorption
Enemy #2
Aftercooler
System
Moisture
3” Air Inlet
1) 3” Outlet 2) 2”
Outlet
4) 1”
Outlet
Enemy #2
Moisture
Water Volume in Air
1500 CFM
200°
90°
Air Compressor
270
gal./day
90 Gal/day
180 Gal/day
75° Ambient Air
75% RH
Enemy #3
Pressure Drop
 Nozzles
 Hoses; Blast & Air
 Restrictive Piping
Enemy #3
Pressure Drop
Nozzle Wear
Hoses & Set-Up
Enemy #3
Pressure Drop
Auto
Air
Valve
Enemy #3
Pressure Drop
High-Flow
Auto
Air
Valve
Proper Set-Up
Difference of Control
System Types
PRESSURE HOLD
NON-PRESSURE HOLD
Non-Pressure Hold System
Pressure Hold System
Fine Tuning an Abrasive
Blast System
Adjustments can be made to the following for
enhanced productivity:
 Abrasive metering
 Minimizing pressure drop & increasing air flow
 Hose length, hose size, couplings
 Nozzle size
 Moisture in air
Achieving Efficiency
in Abrasive Blasting
THANK
YOU
Sponsored by: