Double Hook Shot Blasting Machine: An Overview
The double hook shot blasting machine is a highly efficient surface
treatment system designed for the descaling, derusting, and surface
preparation of heavy and bulky workpieces. It is particularly
suited for components that require all-around blasting, such as
large castings, forgings, welded structures, and heat-treated
parts. The machine employs two independent lifting hooks that
rotate and traverse within a sealed blast cabinet, ensuring uniform
exposure of the workpiece to high-velocity abrasive media.
Working Principle
The system operates by suspending workpieces on two separate hooks,
each capable of independent rotation and vertical movement. Once
loaded, the hooks enter the blast chamber, where a set of
centrifugal turbines (typically 4 to 8 units) project steel shots
or grit at high speed (70–120 m/s) onto the workpiece surfaces. The
simultaneous rotation of the hooks and the workpiece allows
complete coverage, eliminating shadow zones. The abrasive is
recovered via a screw or pneumatic conveyor, cleaned of fines and
dust in an integrated separator, and recirculated to the turbines.
Dust-laden air is extracted through a cartridge or baghouse filter,
maintaining environmental compliance.
Key Structural Features
Double Hook Configuration: Enables independent or synchronized
operation, increasing throughput by allowing loading/unloading on
one hook while the other is being blasted.
Robust Blast Turbines: High-efficiency, wear-resistant blades
(often made of chromium cast iron) ensure consistent abrasive
velocity and distribution.
Spiral or Belt Conveyor Floor: Prevents abrasive accumulation and
facilitates automatic recycling.
Full-Lined Chamber: Interior walls are protected with manganese
steel or rubber liners to withstand continuous impact.
Automated Control System: PLC-based controls regulate hook
movement, turbine activation, and cycle time, with options for
remote monitoring.
Applications
Commonly used in foundries, automotive plants, railway workshops,
and heavy machinery factories. Typical parts include engine blocks,
cylinder heads, gearboxes, suspension arms, large springs, and
structural steel beams. The machine excels at removing sand, scale,
rust, and old coatings, while simultaneously improving fatigue
resistance through compressive stress generation.
Advantages
High productivity: Two workpieces processed simultaneously or
consecutively.
Consistent quality: Programmable rotation ensures 360° coverage.
Reduced manual handling: Fully enclosed automation lowers labor
intensity.
Low maintenance: Modular turbine design and wear-part access doors
simplify servicing.
Conclusion
The double hook shot blasting machine offers a robust, scalable
solution for heavy-duty surface preparation. Its dual-hook design
balances throughput with thorough cleaning, making it indispensable
in industries where large component finishing is critical. Proper
selection of abrasive type, turbine configuration, and cycle
parameters ensures optimal results for any given application.
