Wind Tower Blasting

Bronco has partnered with Turnkey Anticorrosion to design and build blast machines for the surface preparation of steel wind tower sections up to 90’ long and 18’ in diameter, saving tower manufacturers time and money.

TRADITIONAL METHOD

The traditional method of surface preparation for coating steel is hand blasting with air nozzles and metallic steel abrasive.  It is an inefficient and costly process.

• A typical nozzle has a small effective blast pattern, usually less than 2" in diameter.
• One ½" nozzle requires 338 CFM and 75 HP of compressor power, yet cleans less than 200 square feet per hour.
• An 80-90’ tower section requires 7-10 hours of hand blasting in preparation for coating

AUTOMATED PROCESS

The automated blasting process pioneered with Turnkey Anticorrosion utilizes Bronco airless shot blast technology to clean each tower section.

• Our Bronco direct drive blast wheel creates an effective blast pattern 3-4" wide x 40" long.
• Each direct drive wheel throws 1,100 pounds of steel grit per minute at up to 325 feet per second velocity for an effective cleaning rate of 45 square feet per minute.
• The ID and OD of an 80-90’ tower section can be cleaned in less than 1-½ hours.

DESIGNS

Two basic systems are available: one to blast the inside diameter and a second to blast the outside diameter.  From fixed units, to traveling, multi-wheel units that clean the ID and OD simultaneously, there is a design to meet your needs, based on space restrictions and capacity requirements.

These systems are proven and currently in use at several major tower manufacturers in the United States.  The equipment is built and serviced out of Houston, TX, LaGrange, IN and Waukesha, WI.

Additional photos, videos and quotations are available upon request.

PROCESS DESCRIPTION

INTERNAL

The blast boom assembly for the ID blaster is hard mounted to the floor, supporting the gleaning and recovery equipment.  Each tower section is rotated while driven in and out on the customer-supplied rotation carts and drive system.  Steel abrasive is loaded into the main hopper where the bucket elevator carries the abrasive into the auger and rotary screen, filtering the abrasive and removing any foreign material from the abrasive stream.

All remaining abrasive flows through the rotary screen and is collected in the preliminary holding hopper.  From the preliminary holding hopper, it flows at a metered rate to the airless centrifugal blast wheel.  Approximately 40% of the abrasive thrown will rebound back to the return belt located on the bottom of the blast boom.  This belt dumps the abrasive back into the elevator, completing the abrasive cycle.  The remaining 60% of the abrasive falls to the bottom of the tower section where a vacuum hose pulls the abrasive off the bottom of the tower section and through a cyclone separation system, located beside the elevator.

EXTERNAL

The OD blaster is mounted on a moving platform that rolls forward to make contact with the outer surface of the tower section.  Each tower section is rotated while the OD blaster travels along the length of the tower section.  Steel abrasive is loaded into the main hopper where the bucket elevator carries the abrasive into the auger and rotary screen, filtering the abrasive and removing any foreign material from the abrasive stream.

All remaining abrasive flows through a screen and is collected in the preliminary holding hopper.  From the preliminary holding hopper, it flows at a metered rate to the airless centrifugal blast wheel that throws it at an accelerated rate onto the outside wall of the wind tower section.  The abrasive is captured inside the blast cabinet and returned to the bottom of the elevator, completing the abrasive cycle.

The OD blasters have several axis capabilities to compensate for different section diameters and tapers as it travels.

Click here to view the video of an OD blast machine in operation