CNOOC — Limited Steel Plate Pretreatment Line

Qingdao Jinwo Machinery Manufacturing Co., Ltd., a professional manufacturer of shot blasting equipment, has successfully completed the full-set installation project of the steel plate pretreatment line equipment for CNOOC Limited. This line is capable of pretreating steel plates and profiles within 5.3 meters. The entire line includes one steel plate shot blasting machine, one painting booth, and one set of drying room. The equipment has been installed, debugged, and delivered to the user, who has spoken highly of our company's equipment.

The steel plate pretreatment line is a key production line for steel plate surface treatment in industries such as steel processing, machinery manufacturing, shipbuilding, and bridge construction. Its main function is to perform pretreatment operations such as derusting, descaling, and priming on steel plates, so as to improve the corrosion resistance of steel plates, enhance the adhesion of subsequent painting or processing, and lay a solid foundation for subsequent production links.

Main Components of the Steel Plate Pretreatment Line

Feeding Device

It is responsible for conveying the steel plates to be treated to the pretreatment line. Common forms include roller conveying, chain conveying, or forklift-assisted feeding. The appropriate feeding method can be selected according to the specifications (thickness, length, width) and weight of the steel plates to ensure that the steel plates enter the production line smoothly.

Preheating Device

Some pretreatment lines are equipped with a preheating link, which heats the steel plates to a certain temperature by means of hot air or electric heating. The purpose is to remove moisture and oil stains on the surface of the steel plates and improve the effect of subsequent derusting and painting.

Shot Blasting and Derusting System

This is the core part of the pretreatment line. Through high-speed rotating shot blasters, steel shots (or other abrasives) are sprayed onto the surface of the steel plates at a high speed. The impact force of the steel shots is used to remove impurities such as scale, rust, and old coatings on the surface of the steel plates.

The number and layout of shot blasters are designed according to the width of the steel plates to ensure uniform coverage of the steel plate surface. The derusting grade can reach Sa2.5 or even Sa3 (international derusting standards).

Dust Removal System

It is matched with the shot blasting system and used to collect dust, steel shot debris, etc. generated during the shot blasting process, so as to avoid environmental pollution and recover reusable steel shots. Usually, bag filters or pulse dust collectors are adopted, which have high dust removal efficiency and meet environmental protection requirements.

Painting System

After the derusted steel plates are cleaned (to remove residual steel shots and dust on the surface), they enter the painting link. Common painting methods include roller coating and spray painting. Primers (such as epoxy primers) can be applied as needed. The primer can form a protective film on the surface of the steel plates to prevent secondary rusting.

Drying System

It is used for drying the painted steel plates. Through hot air circulation or infrared heating, the primer is quickly cured to ensure that the adhesion of the paint film meets the standard. The drying temperature and time are adjusted according to the type of primer and the thickness of the steel plates.

Unloading Device

It conveys the pretreated steel plates from the production line to the storage area. Usually, it is matched with the feeding device and adopts roller or chain conveying. Some production lines are also equipped with an automatic stacking function to improve stacking efficiency.

Working Process of the Steel Plate Pretreatment Line

Steel plates enter the production line through the feeding device and are conveyed to the preheating device (if preheating is required) via the conveying rollers. The preheated steel plates enter the shot blasting and derusting chamber, where shot blasters spray steel shots to remove surface impurities, and the dust removal system works simultaneously. The derusted steel plates are cleaned by cleaning devices (such as brushes and purging) to remove residual abrasives and dust on the surface. The cleaned steel plates enter the painting system to be evenly coated with primer. The painted steel plates enter the drying room to cure the primer. Finally, the treated steel plates are conveyed to the designated area for stacking through the unloading device.

Advantages of the Steel Plate Pretreatment Line

Improving Efficiency: With a high degree of automation, it can realize continuous production, greatly improving the efficiency of steel plate surface treatment and reducing manual intervention.

Good Treatment Effect: The shot blasting and derusting are uniform and thorough, and the painting quality is stable, which can meet the strict requirements of different industries on the surface quality of steel plates (such as the high standards for corrosion resistance in the shipbuilding industry).

Prolonging Steel Plate Service Life: Through derusting and priming, it can effectively prevent steel plates from rusting and prolong their service life in subsequent products (such as ships, bridges, and pressure vessels).

Meeting Environmental Standards: Equipped with an efficient dust removal system, it reduces dust emissions, complies with environmental protection regulations, and improves the working environment.

Application Fields

It is widely used in industries such as shipbuilding, marine engineering, bridge construction, engineering machinery, pressure vessels, and steel structure workshops. It is an indispensable pretreatment equipment for steel plates before entering subsequent processes such as welding and painting.

Pretreatment lines from different manufacturers will be custom-designed according to user needs (such as maximum steel plate specifications, processing speed, and automation level) to adapt to different production scenarios.