Main components of pretreatment line
Lateral conveyor
Inlet roller conveyor
Preheating furnace
Roller conveyor shot blasting machine
Shot blasting dust collector
Spray booth
Paint delivery system
VOC system filter
VOC system (paint booth exhaust gas treatment system)
Drying room
Plate conveyor
Export roller conveyor
Lateral conveyor

Process flow
The workpiece moves along the entrance of the roller conveyor to the preheater. Dry and heat them before starting work in the shot blasting machine. After shot blasting, the coating is applied in the spraying chamber, and then the finished workpiece is moved to the drying chamber. The slat conveyor conveys the parts towards the exit of the roller table. They are removed there, or sent to the downstream logistics system via a cross conveyor.

Roller conveyor entrance
The first part is the entrance roller conveyor. The steel plates and profiles are delivered here and then sent to the processing process. The entrance roller conveyor can be equipped with a cross conveyor to optimize efficiency or connect it to a logistics system.

Preheater
Used to remove residual moisture. It is usually located upstream of the shot blasting machine to ensure that the workpiece is dry before entering the shot blasting chamber. The product will also be heated to reach the necessary temperature to ensure that the primer dries quickly.

The preheater is located in front of the shot blasting machine, which means that it takes longer for the plate or profile to reach the entrance of the spray booth.

This balances the inevitable temperature peaks and avoids damage to the primer.

Advantage
To maximize the transfer of heat to the material while consuming the least amount of gas: the long tube burner (directly through the preheater's combustion rod with hundreds of individual flames) directly impacts the workpiece, combined with the high-speed synchronous high-speed fan Hot air circulation (about 250°C)
The variable number of controllable long tube burners makes it easy to adjust the heating performance and thus avoid the preheater being too long
Shot blasting machine
Roller conveyor shot blasting machine is the key equipment in the pretreatment line. The workpiece (plate, profile or pipe) is passed through the shot blasting machine to remove rust and scale. All equipment is equipped with a high-efficiency HAOPIN shot blaster that is easy to maintain. According to specific requirements, the shot blaster and its position can be changed, and the workpiece can be completely cleaned in a safe process to ensure that the surface finish meets the internationally recognized ISO 8501-1 preparation level.

For advanced corrosion protection, shot blast cleaning is usually required to prepare Sa 2.5. In some cases, Sa 3 may be required, which requires a significant reduction in working speed (about 50%).

Round steel shots are usually used to obtain a surface roughness of about Rz40-80μm.