Structure:

The main functional components of this equipment include: an input roller conveyor, a preheating chamber, a shot-blasting cleaning chamber, a transition roller conveyor, a painting booth, a drying oven, an output roller conveyor, a dust-collection system, and an electrical control system, among others.

Process flow:

Material feeding, preheating, shot blasting, cleaning, painting, drying, and unloading.

Working principle:

This equipment is a high-efficiency, continuous-operation steel pretreatment production line with continuous material feeding. Steel is conveyed via a roller table, preheated, and then fed into the shot-blasting cleaning chamber. Multiple high-efficiency shot blasters positioned at various spatial orientations deliver powerful, dense impacts and friction using abrasive shots, rapidly removing scale, rust spots, and surface contaminants to clean and strengthen the steel surface. During the blasting process, the fallen shot–dust mixture is collected by chamber-floor hoppers and longitudinal and transverse screw conveyors, routed to the lower section of the elevator, and then lifted to the upper part of the machine for separation in a separator. The separated shots fall into the separator hopper and are conveyed via a shot-delivery pipeline back to the individual blast wheels for recirculation. Dust generated during operation is extracted through exhaust ducts and directed to a dust-collection system; after purification, the cleaned air is discharged into the atmosphere, while particulate dust is captured and collected by the dust collector.

After shot blasting, the steel workpieces are conveyed into a cleaning chamber, where rotary brush rollers remove any residual shot media from the surface. Subsequently, high-power blowers perform omnidirectional back-blowing to ensure the workpiece surface is thoroughly cleaned and meets the cleanliness standards required for painting. The cleaned workpieces are then transferred to a painting booth, which is equipped with two paint-spraying units—one positioned above and one below—to apply the coating. During the painting process, the coating thickness can be precisely controlled by adjusting the conveyor speed, nozzle size, and operating mode. Following surface painting, the steel workpieces are sent to a drying chamber for curing. The drying chamber can be heated either by combustion or electric heating. After drying, the workpieces proceed to the discharge-end conveyor, thereby completing the entire pre-treatment process for the steel.