What Sets EcoQuip 2 Apart from the Competition
Fluidized Abrasive Blasting with EcoQuip 2
As an alternative to dry blasting, wet abrasive blasting has been developed in recent years to address health, safety, and environmental issues. By mixing water with an abrasive spray, wet blasting can be used to restore concrete, steel, and other surfaces while generating significantly less fugitive dust than dry blasting.
Three main types of wet blasting are now available: nozzle-based wet blasting, slurry blasting, and fluidized abrasive blasting. As a brief overview, nozzle-based blasting adds water to the abrasive stream in or around the nozzle of blasting equipment. Slurry blasting combines water and abrasive in a pot under air pressure, and draws the mixture into the airflow using the Venturi effect. Fluidized abrasive blasting combines water and abrasive in a pot under pressure, then injects the mixture into the airflow.
Recent testing and analysis has shown Graco’s fluidized abrasive blasting equipment provides significant benefits over other wet blasting techniques. The Graco EcoQuip 2 Vapor Abrasive blasting equipment, shown in two configurations in Figure 1, can provide superior performance through higher pot pressures, improved pot design, and more precise control of abrasive materials. In this article, we will explore four areas that differentiate EcoQuip from all other wet abrasive technologies.
Vapor abrasive blasting units are available in both portable and fixed-skid configurations. Above: EcoQuip EQp (left) and EcoQuip 2 EQs (right).
The EcoQuip 2 pot is rated to handle pressures up to 200 psi. Most competing equipment is rated at 150 psi or less. The additional pressure enables the EcoQuip 2 to achieve a higher pressure differential between pot and blast pressure, which helps deliver abrasive material more efficiently, smoothly, and at higher pressures for more production.
The EcoQuip 2 models are also automatically pressurized to a pre-set pressure. With competing models, operators need to set the pressure manually, adjusting the pot pressure relief valve to vent air as the pot is being pressurized. The need to vent air from the pot can add 2 to 5 minutes to the setup process.
A comparison of various properties of the EcoQuip 2 EQs with competing equipment is shown in Figure 2. The higher pot pressure, along with the fixed pot pressure setting and abrasive consumption display, set the EcoQuip 2 apart from competing models that have similar run times.
|EcoQuip 2 EQs||Greener Blast GBT 760||Dustless Blasting DB3000||CLEARBLAST 650MAX|
|Run Time (approx)||4 or more hours||N/A||4 or more hours||4 or more hours|
|Weight (dry)||1,070 lbs||1,030 lbs||1,200 lbs||775 lbs|
|Dimensions||60"L x 46"W x 56"H||78"L x 31"W x 55"H||46"L x 48"W x 98"H||54.5"L x 54.5"W x 40.5"H|
|Pot Coating||A-coat / Powder||Galvanized / Powder||N/A||Powder|
|Pot Capacity||6.5 cu. ft.||7.6 cu. ft.||30 cu. ft.||N/A|
|Air Requirements||185 CFM||375 CFM||375 CFM||185 CFM|
|Max Blast Pressure||175 psi||120 psi||150 psi||130 psi|
|Pressure Pot Rating||200 psi||150 psi||150 psi||150 psi|
|Fixed Pot Pressure Setting||Yes||No||N/A||No|
|Abrasive Consumption Display||Yes||No||No||No|
Above: Comparison of EcoQuip 2 EQs along side competitive equipment with similar run times.
Most wet blasting equipment uses a conventional dry pot similar to that used in sandblasting equipment. The dish-shaped top, shown on the left of Figure 3, can allow air to be trapped between the dish and the upper bulkhead welding of the pot. Because air is compressible, trapped air can create an uneven flow of material and sputtering. In blasting operations, this can create an irregular profile on the substrate, thus requiring additional passes to ensure a consistent finish. The EcoQuip 2 uses a proprietary dome design, as shown on the right of Figure 3, which prevents trapping of air. The EcoQuip 2 design results in more consistent blast pattern, flow, and production.
Conventional pots (left) have a dish-shaped top which can trap air. The EcoQuip 2 pot (right) uses a dome design that prevents trapping of air.
Abrasive Control and Monitoring
Control of the abrasive-water mixture and flow is critical for creating a consistent blast pattern. The EcoQuip 2 includes a built-in metering system that enables precise control of abrasive media. The metering valve has a lockable set-point so production rates can be set once and automatically controlled by the system. Competing equipment requires ongoing visual monitoring of production rates and adjustment of valves as needed. This creates challenges in tracking what settings work best for certain types of media and substrates. Precise control of the flow rate allows a faster startup, as the settings are known, rather than visually adjusted by working with the nozzle person to communicate a desired result.
Ease of Maintenance
Maintenance of the EcoQuip 2 is aided by a hinged, easily opened cover panel, as shown in Figure 4. Loosening a single screw provides access to key components. Competing equipment often requires removal of multiple screws and total removal of the cover panel. In addition, Graco has color-coded and simplified everything within the cabinet, making it easy for Graco’s technical service team and distributors to diagnose and fix a machine while operators are in the field, helping them get back up and running quickly.
The EcoQuip 2 provides ready access to key components via removal of a single screw on the cover panel.
Health, Safety & Environmental Benefits
The EcoQuip 2 has also demonstrated benefits related to health, safety, and environmental concerns. In recent testing conducted by a third party, three different types of blasting -- dry blasting, nozzle-based wet blasting, and fluidized abrasive blasting -- were used on 4-foot-by-4-foot concrete slabs to compare respirable levels of dust and silica. As shown in Figures 5 and 6, Graco’s fluidized abrasive blasting produced significantly lower levels of dust and silica than both water-injection blasting and dry blasting. This occurred for two reasons: 1) fluidized blasting uses less abrasive media than other types of blasting; and 2) fluidized blasting encapsulates each particle in water, so when it shatters, the small shards of media are saturated, and the extra weight of the water allows particles to drop in a small radius around the operator.
Respirable dust quantities for various abrasive blasting methods
Respirable dust generated by fluidized abrasive blasting was significantly lower than water-injection and dry blasting.
Respirable Silica quantities for various abrasive blasting methods
Respirable silica generated by fluidized abrasive blasting was significantly lower than water-injection and dry blasting.
Permissible Exposure Limits (PEL) Test Parameters
Media: Medium recycled crushed glass
Blast Hose: 50 ft x 1.25 in ID
Nozzle: #8 High Performance
Compressor: Doosan 425 CFM
Substrate: 4 ft x 4 ft concrete slab
Blasting Time per Test: 25 - 28 minutes
Considering performance, maintenance, and environmental factors, the EcoQuip 2 series of equipment offers numerous benefits over competing products. Available in a wide range of portable and skid-mounted models, the EcoQuip 2 has proven effective in treating a variety of surfaces, ranging from removal of paints and coatings on bridges and highways to restoration of steel sculptures and various building surfaces. By leveraging Graco’s fluidized abrasive blasting technology, end users can maximize quality of surface restoration projects, while minimizing use of water and abrasive media, and reducing dust generation by up to 92 percent when compared with dry blasting.