Что такое дробемётная очистка?

Several methods are used to prepare and clean steel surfaces. Different types of abrasive blasting are often used to remove coatings, mill scale, paint and other contamination. Most of them work in the same way: abrasive is carried by compressed air and propelled at high velocity against the surface, so the contamination separates from the object. Sandblasting is the best-known example, but blasting with other abrasives such as glass beads or plastic media, and wet methods such as vapor blasting, are also used. Wheel blasting is a different form of blasting. This article explains how it works, its advantages and disadvantages, and what to use where it does not fit.

How does wheel blasting work?

Wheel blasting is similar to other forms of abrasive blasting in many ways, but it has one clear difference: it does not use compressed air to propel the abrasive. Instead, abrasive is fed into the center of a rotating, bladed wheel and thrown outward onto the steel by centrifugal force. The diameter and speed of the wheel determine the velocity of the abrasive.

Wheel blast machines are enclosed. Parts pass through the blast chamber on a roller conveyor, hang from a monorail or tumble in a drum, while one or more wheels aim abrasive at them. Spent abrasive falls to the bottom of the cabinet and is carried back to the wheels, passing through a separator that removes dust, fines and removed scale so that clean abrasive can be reused.

Wheel blast equipment generally uses a metallic abrasive such as steel shot or steel grit. Shot leaves a rounded, peened texture; grit leaves an angular anchor profile that suits protective coatings. Operators often run a mix of shot and grit to balance cleaning speed and profile.

Where is wheel blasting used?

• Steel plate and sections in service centers and fabrication shops, often in automated lines that blast and then apply a shop primer.
• Castings and forgings, to remove sand, scale and residue.
• Mass-produced parts in tumble or spinner-hanger machines.
• Floors and decks, using portable wheel blasters that ride over large, flat horizontal surfaces such as concrete floors or ship decks.

What are the benefits of wheel blasting?

Wheel blasting has several advantages over other forms of abrasive blasting:

• Efficiency. A mechanical wheel converts drive power into abrasive velocity far more efficiently than compressed air, so throughput per unit of energy is high.
• Abrasive recycling. Abrasive thrown by the wheel is collected, cleaned and reused many times during the process. This reduces abrasive consumption and means less waste remains at the end.
• Adjustable intensity. Wheel speed, abrasive mix and line speed can be adjusted, so abrasive is used economically and a greater intensity can be chosen for heavier contamination or a deeper profile.
• Speed and consistency. In an automated line, wheel blasting prepares steel surfaces quickly and uniformly, with no operator at the nozzle and enclosed dust control.

What are the disadvantages of wheel blasting?

• Geometry. Wheel blast machines work best on relatively flat or simple shapes. Deep recesses, internal corners and shadowed areas that the abrasive stream cannot see are cleaned poorly and may need touch-up by hand.
• Fixed installation. Except for portable floor and deck machines, the work has to come to the machine. Assembled structures, installed pipework and in-service assets cannot be wheel blasted.
• Not for every surface. The high abrasive velocity can damage thin or fragile parts. For more delicate surfaces, low-pressure methods such as vapor blasting are often preferred.
• Maintenance. Wheel blast machines contain many mechanical parts, including blades, liners, control cages and conveyors, that wear quickly because they are constantly hit by abrasive. Wear-part replacement and downtime make wheel blasting a capital- and maintenance-intensive method of surface preparation, economical mainly at high volume.

Wheel blasting vs. air abrasive blasting

More methods are compared in the 10 types of abrasive blasting.

What to use when wheel blasting is not possible

Wheel blasting prepares new steel well in the shop. Once the steel has been fabricated, erected or put into service, the surfaces that need preparation are usually the ones a wheel blast machine cannot reach: weld seams and heat-affected zones made after shop priming, damaged areas, field joints and corroded spots on live plant. Air blasting can be used where containment, a compressor and waste handling are practical; for in-service preparation and small areas they often are not.

The Bristle Blaster® is a handheld, grit-free alternative for these areas. Hardened wire tips, released by an accelerator bar, strike the steel and rebound, removing rust, mill scale and coating and leaving an anchor profile in one pass. Documented tests on standard steel show cleanliness comparable to Sa 2½ / SSPC-SP 10 and a 65–85 µm Rz profile; results vary with steel grade, rust grade, belt and technique. There is no abrasive to recover, although the removed rust and coating still become dust that needs extraction and respiratory protection. For removing scale on smaller areas, see how to remove mill scale from steel.

Frequently asked questions

What is the difference between wheel blasting and sandblasting?

Sandblasting, and air abrasive blasting generally, uses compressed air to carry abrasive through a hose and nozzle. Wheel blasting uses a rotating bladed wheel to throw the abrasive mechanically. Wheel blasting is more energy-efficient and suited to automated lines, while air blasting is more flexible for complex shapes and field work.

What abrasive is used in wheel blasting?

Generally a metallic abrasive such as steel shot or steel grit. Shot gives a rounded, peened texture; grit gives an angular profile that suits protective coatings. Because the abrasive is recovered, cleaned and reused many times, durable metallic media are preferred over the lighter, more friable non-metallic abrasives used in air blasting.

Can wheel blasting remove mill scale?

Yes. Wheel blasting is widely used in steel service centers and fabrication shops to remove mill scale from plate and sections before priming. Shop lines typically blast to a cleanliness such as Sa 2½ and apply a shop primer straight afterwards, so the steel arrives on site already prepared.

What do you use when wheel blasting is not possible?

For assembled structures, weld seams after fabrication, repairs and in-service assets, use a portable method. Air abrasive blasting is one option where containment is practical; grit-free bristle blasting is another, giving cleanliness comparable to Sa 2½ / SSPC-SP 10 and a 65–85 µm Rz profile on standard steel in documented tests.