Surface treatment processes are essential across the entire steel production and manufacturing sector. All semi-finished or finished products must undergo rust, scale, or impurity
Surface treatment processes are essential across the entire steel production and manufacturing sector. All semi-finished or finished products must undergo rust, scale, or impurity removal before proceeding to the next stage of operations. Mechanical descaling via shot blasting offers a clean, rapid, and safe processing method. Various stages in the production of hot-rolled steel strip (including carbon, silicon, and stainless steel) are integrated into a single processing line. Combining mechanical descaling with chemical pickling reduces the consumption of chemical agents. Chunjiu offers shot-blasting descaling solutions for narrow, medium, and wide steel strips. Our adjustable shot-blasting systems accommodate a wide range of strip specifications, quality grades, and other product requirements.
Stable, reliable, and cost-effective operation, ensuring an extremely high level of surface cleanliness.
Shot blasting and surface quality can reach Sa 2 to Sa 2.5.
High overall efficiency and reliability, with low space requirements.
Easily adaptable to steel strip widths
Features
The layout and design concept of the blast wheels ensure maximum utilization of blasting energy and intensity while preventing interference between blast streams.
Highly efficient abrasive feed, optimal abrasive cleaning and recovery performance, and effective dust extraction.
Wear-resistant operation of components subject to wear.
Continuous R&D ensures the application of the latest technologies; high level of sustainability.
Applications
Steel strips (stainless steel, silicon steel, low-carbon steel, titanium) are integrated into highly complex continuous production lines, delivering highly efficient mechanical descaling performance.
Available in a range of models accommodating strip widths of 600 mm, 1650 mm, and 2100 mm.
Modular design meets specific production requirements.
Superior Quality Through Detailed Design
Mechanical pre-treatment and final chemical surface treatment for hot-rolled stainless steel strips (including Cr-Ni alloys and titanium-alloyed steel) and silicon steel strips can largely be carried out on production lines that integrate annealing, cooling, and mechanical descaling processes. Chunjiu’s GD steel strip shot blasting system enjoys a prestigious reputation in this field, delivering significant benefits to customers.
Descaling of narrow, medium, and wide steel strips
The equipment is suitable for continuous pickling lines and push-pull pickling lines.
KEEJOO shot blasting systems can be adjusted to meet specific specifications at various processing stages. These adjustments are achieved by modifying the abrasive flow rate, the abrasive projection speed, or the blast pattern width. This approach maximizes power utilization and ensures energy efficiency.
Specific surface finishing requirements can also be met through the sequential operation of multiple machine modules. Cold-rolled steel strips can pass through the system without undergoing shot blasting.
Machine Design and Operating Mode
The machine is composed of independent modules and can be installed with or without a foundation pit.
Structural Features and Components:
Hardened manganese steel shot-blasting chamber: Each module is equipped with four blast wheels—two for the top side of the steel strip and two for the bottom side. Rubber rollers are installed at the inlet and outlet of the chamber to support the steel strip. Abrasive removal unit: A compressed air blower is located behind each shot-blasting chamber to remove residual abrasive from the top of the steel strip and return it to the circulation system for reuse. Abrasive return and recovery system with air separator: An air separator is used to clean the circulating abrasive. Fresh abrasive can be added based on consumption rates, ensuring consistent system operation and blasting efficiency. Dust extraction system: The shot-blasting and abrasive removal chambers, circulation system, and separator are all connected to a dust collection system.
Depending on the module arrangement and the subsequent pickling process, the steel strip can exit the unit along a straight path or be diverted diagonally upwards.
Shot Blasting System for Medium-to-Wide Steel Strip (Horizontal Configuration)
This system is designed for transverse shot blasting. The modules operate in sequence; by controlling the blasting pattern and ensuring continuous maximum-intensity impact, the settings of the blast wheels can be adjusted to achieve full coverage across the width of the steel strip. The blast wheels are arranged in a staggered pattern to prevent interference between the blast streams. The blasting power remains constant, independent of the strip width; only the strip travel speed requires adjustment based on the width.
Horizontal Shot Blasting System for Narrow Steel Strips
This system is designed specifically for longitudinal shot blasting and features four blast wheels, each with a maximum projection speed of 78 m/s. The blast wheels are angled relative to the steel strip surface to prevent interference between the blast streams. By adjusting the projection angles, the installed power can be fully utilized for descaling. To accommodate varying steel strip configurations, all blast wheels feature rapid, automatic adjustment capabilities to ensure optimal utilization of the blast stream.
Safe Operation and Easy Maintenance
The shot blasting system is designed to ensure the steel strip surface remains undamaged during transport. Thorough abrasive removal and dust extraction keep the machine and the processed steel strip clean and tidy. Simple yet highly effective sealing components prevent stray abrasive from interfering with machine operation.
Large safety doors and a specialized structural design facilitate inspection and maintenance. Routine checks of the blast wheels and the replacement of wear parts can be performed with ease. Minimal component tolerance variations ensure that spare parts can be removed and installed quickly.
To ensure optimal system performance, we recommend using KEEJOO materials along with genuine spare and wear parts, combined with Chunjiu’s superior manufacturing technology. The system operates autonomously, requiring no constant operator supervision—only periodic inspections.
Production Cost Savings
The system integrates seamlessly into existing production lines without requiring major modifications. By fully utilizing its blasting capabilities, the system achieves full-width coverage of the steel strip, delivering a high level of surface cleanliness and significantly reducing pickling costs.
Technical Specifications
Medium/Wide Steel Strip Shot Blasting System
GD-4/1600
GD-4/2100
Steel strip width (mm)
600-1600
1550-2100
Through-feed speed (m/min*)
20
15
Number of blast wheels
4
4
Power per shot blasting unit (kW)
90
90
Abrasive Flow Rate / Shot Blasting Wheel (kg/min)
1200
1200
* Steel strip travel speeds tailored to specific materials, bandwidths, rust types, and surface cleaning requirements can be provided upon request.
Shot blasting cleaning system for narrow steel strips
GD-4/600
Steel strip width (mm)
400-600
Number of blast wheels
2-4
Power per shot blasting unit (kW)
22-45
Abrasive Flow Rate / Shot Blasting Wheel (kg/min)
400-550
This machine is equipped with the HAI Ocean Surge® direct-coupled high-efficiency blast wheel (German design with independent patents, Patent No.: ZL 2015 2 0702933.5).
The blast wheel is the heart of a shot blasting machine, and its design determines the performance of the entire system. The HAI Pengpai® blast wheel comes as standard equipment, delivering superior blasting performance. Available in a variety of sizes and materials, the H-series blast wheel ensures flexibility across diverse manufacturing processes. Its key advantages include enhanced blasting performance, reduced abrasive consumption, significantly extended equipment uptime, and effective noise reduction.The casing is lined with curved, multi-layer labyrinth-style sealing plates; the hot zone features a thickness of 70mm, ensuring excellent sealing performance and a uniform distribution of the projected abrasive media over an expanded coverage area. The internal design allows for the adjustment of abrasive trajectories, thereby enhancing blasting efficiency and minimizing self-wear. Additionally, a specialized dynamic design boosts efficiency by 30% compared to standard blast wheels.
Selected Cases of KEEJOO Roller Conveyor Steel Shot Blasting Machine
245 sets of section steel shot blasting machines manufactured for Hangxiao Steel Structure Company
16 sets of section steel shot blasting machines manufactured for Hangzhou Southeast Grid
9 sets of section steel shot blasting machines manufactured for China Construction Steel Structure Tianjin Company
8 sets of through-type shot blasting machines manufactured for Shanghai Baoye Steel Structure
So far, the performance of more than 600 set-type steel pass-through shot blasting machines at home and abroad is far ahead.
......
A large listed domestic agricultural equipment group phased out its outdated shot blasting machines in the past two years and fully adopted hook-type shot blasting machines independently developed and manufactured by Qingdao KEEJOO Group. Up to now, the group has purchased a total of 58 units.........
The various shot blasting machines manufactured by Qingdao KEEJOO Group for European clients are highly acclaimed and well-received.!
Introduction to the Components of the Shot Blasting Machine
1Blast wheel
1. The blast wheel and motor adopt Germany-joint developed high-efficiency HP technology. Compared with conventional old-style blast wheels, this design eliminates multiple friction loss links, lifting motor efficiency by 20%, cutting down fault points and slashing maintenance costs by 50%.
2. features a more compact footprint than traditional blast wheels, supports arbitrary installation angle arrangement, and enables far easier inspection and maintenance.
3.Constant blasting performance is maintained throughout operation, free from inconsistent and fluctuating cleaning quality seen on conventional units.
4. Blades and all wear-resistant consumables are manufactured in Taiwan via high-chromium investment precision casting, delivering outstanding abrasion resistance. Their service life ranges from 1,200 to 4,000 hours, 3–4 times longer than ordinary casting materials.
5. Blast wheel impeller: Treated with carburizing wear-resistant alloy. The impeller hub is one-time finished by high-precision CNC machining centers for ultra-high dimensional accuracy, ensuring perfect dynamic balance during high-speed rotation, low vibration, low noise and extended service life.
6. Equipped with SKF bearings imported from Sweden.
7. Fitted with genuine Siemens motors.
8. German Schenck dynamic balancing tester is applied to guarantee precise high-speed dynamic balance of impeller hubs.
2Flow control valve
1. Semi-automatic flow control system for regulating the flow of abrasive media into the blast wheel, featuring manual adjustment of the steel shot flow rate.
2. Fully sealed structural design, featuring a lockable inspection opening and equipped with two bearings.
3. A manual shut-off valve is installed above each flow valve; this can be closed to stop the flow of media from the hopper, thereby facilitating maintenance of the flow valve.
3Blasting chamber
1.The shot blasting chamber is constructed from welded manganese steel.
2. Manganese steel protective plates are installed in the "hot zone" of the chamber—specifically covering three-quarters of the area directly exposed to the blast stream—to prevent steel shot from striking the chamber's outer walls; these plates are suspended for easy installation, removal, and replacement.
3. A three-layer sealing structure is installed at the top to prevent steel shot from leaking out during the blasting process.
4Variable-frequency automatic speed-regulating conveyor system (comprising an infeed roller conveyor, a shot-blasting zone roller conveyor, and an outfeed roller conveyor with automatic speed regulation)
Roller conveyor pass-through type:
1. The workpiece conveying system for the entire production line utilizes stepless variable-frequency speed control and consists of an input roller conveyor, a shot-blasting chamber roller conveyor, and an output roller conveyor.
2. The rollers for both the input and output roller tables are manufactured by welding heat-treated shaft ends to high-quality carbon steel seamless pipes, followed by integral machining on a lathe. Machining is performed after welding to ensure both a load-bearing capacity of 0.5 t/m and precise coaxiality.
3. The rollers within the shot blasting chamber that are subjected to the impact of the shot are all fitted with easily replaceable, wear-resistant sleeves made of special high-chromium-molybdenum iron.
4. The roller pitch is 600–800 mm, and the entire line utilizes variable-frequency speed control, enabling both high-speed and low-speed workpiece transport.
Wire mesh-belt conveyor type:
1. The system comprises dozens of transmission components, including carbon steel rollers, sprockets and chains, mesh belts, and bearings. The roller conveyor is divided into three sections: the infeed section, the shot-blasting section, and the discharge section. The rollers are constructed by precision-welding quenched-and-tempered end caps to high-quality seamless carbon steel pipes; their profiles and mounting dimensions are machined after welding to ensure compliance with load-bearing and coaxiality requirements.
2. The roller conveyors inside the blast chamber are equipped with easily replaceable wear-resistant medium-chromium cast iron sleeves. Labyrinth seals made of wear-resistant manganese steel are used at both ends of the roller shafts, completely preventing abrasive media from wearing down the bearings.
3. Utilizes imported HD wear-resistant manganese steel that has undergone solution and tempering treatments to eliminate internal residual stresses, moderately reduce the hardness of the manganese steel wire, and enhance its toughness and ductility.
4. A geared drive motor is installed on the right side of the conveyor belt and directly coupled to the drive roller, propelling both the belt and the workpieces; variable frequency speed control is employed, providing a conveying speed of 0.5–4 m/min.
5. A roller is installed under the driving shaft to serve as a guide and tensioner. When the steel mesh belt is loose, it can be tightened through this mechanism.
5Light curtain sensing system, automatic loading system/automatic unloading system
1. Two sets of light curtain sensing units are installed at the infeed and outfeed openings, respectively; the light curtain resolution can be selected based on workpiece size, and the units are used in pairs.
2. When a workpiece enters the shot blasting chamber, a light curtain at the inlet detects its presence, triggering a delayed start of the blast wheels. A light curtain sensor is also installed at the outlet; when the inlet and outlet sensors detect that no workpieces are passing through, the flow valve closes automatically and immediately to prevent "air blasting" (blasting without a workpiece present).
6Sorting system
1. A mesh screen separator is connected to the elevator and positioned above the magnetic separator; fine material passes through the screen into the magnetic separator, while coarse material and impurities are conveyed by a spiral mechanism along the screen to the discharge port at the rear.
2. It is designed to finely separate usable shot, broken shot, and dust, ensuring the uniformity of the shot media.
3.Featuring a welded structure, the interior contains multiple carefully designed compartments for airflow guidance. An access door on the front allows for routine inspection and maintenance; this door is equipped with an air inlet to provide the necessary airflow for dust separation.
4. An adjustable multi-vane baffle structure is used to regulate the uniformity of the falling abrasive curtain.
5. Stationary magnets installed at both the top and bottom enable the fine separation of usable shot from broken steel shot, ensuring the consistency of the blast media.
6. A storage hopper is connected at the bottom; after separation, the usable shot flows into the hopper for storage and subsequent reuse.
7Electrical control cabinet
1. Siemens PLC and touch screen
2.Siemens variable frequency drive (VFD) for speed control
3.Schneider low-voltage electrical components
4.Shot blasting time controller
5. AirTAC pneumatic components
6. Ammeter for flow monitoring
7.1 lighting fixture
8.Dedicated constant-temperature air conditioning unit (optional)
8Dust collector
Pulse-jet cleaning system
Precision filter cartridge filtration system
High-efficiency three-stage dust removal
Optimized and upgraded Donaldson (USA) dust removal technology system
Standard configuration：
1
Electrical cabinet: This model comes standard with a cooling fan; air conditioning is available as an option.
2
Programmable Logic Controller (PLC): Siemens (other brands available as options upon customer request)
3
Touchscreen: Siemens (other brands available as options upon customer request)
4
Variable Frequency Drive (VFD): Inovance (China) — (Specific brands can be designated upon customer request; we recommend our domestic brand, as its quality is on par with or superior to Siemens.)
5
Power supply voltage: AC 380V, three-phase five-wire system
6
Low-voltage electrical components: Schneider (other brands available upon customer request)
7
Pneumatic components: ARITAC series (other brands available upon customer request)
8
Wires and cables
9
Qingdao KEEJOO Group can also customize various non-standard shot blasting machines according to your requirements.
Specifications (Hangzhou Southeast Space Frame Steel Structure Project)
Qingdao KEEJOO Group Roller Conveyor Shot Blasting Machine: Specifications and Configuration List
No.
Name
Roller conveyor type shot blasting machine
1
Model
KJ-2230P15-16
KJ-2028P11-14
2
Sorting configuration
Air separation
3
Application
Shot blasting and derusting of large workpieces, profiles, and welded steel structures.
4
Blast wheel type
German-style High-Performance HAI Shot Blasting Unit
American-style Pan-bagnat
5
No. of blast wheel
16 sets
6
Blast wheel motor power
11KW
7
Roller spacing
φ280*1000
8
Load-bearing capacity (excluding fixtures)
≤5吨
9
Dimensions of a single workpiece (width × height × length)
≤2200*3000*14600mm
10
Max entrance dimensions (width x height) in mm
2400*3000mm
11
Semi-automatic flow valve
16 Sets
12
Fully automatic flow valve
Optional
13
Dry dust collector
QL-48 Filter Element (37 kW)
14
Wet dust collector
Optional
15
Airflow (m³/h)
≤38000
Qingdao KEEJOO Group comprises three subsidiaries and an international business division, standing as a leading Asian manufacturer of high-end shot blasting and peening machinery, as well as environmental protection equipment. The company has introduced and developed over 100 types of shot blasting and peening machines for cleaning and surface strengthening; more than 20 of these products have filled gaps in the domestic market. Its products are utilized by renowned enterprises such as ThyssenKrupp, Siemens, FAW-Volkswagen, Cummins Engine, Dongfeng Motor, Weichai Power, Sinotruk (Jinan), China High-Speed Rail, Bombardier, Chery Automobile, North Benz, Hitachi Nuclear, Sany Heavy Industry, Fuji Heavy Industries, Tangshan Gear, Aisin (Japan), Alstom (France), Doosan (South Korea), and Caterpillar (USA). With exports reaching 49 countries—including Spain, France, the USA, South Korea, Japan, Singapore, Australia, and Russia—the company enjoys an excellent global and domestic reputation.
In recent years, by introducing and assimilating advanced technologies from companies such as Germany's AGTOS, KEEJOO has achieved a world-class level in product design. The company's high-efficiency, direct-drive shot blasting wheel—representing the best of Asian technology in this field—has garnered praise and recommendations from customers in Europe and the Americas.
The company was among the first in China's casting machinery industry to obtain ISO 9001, German TÜV, EU CE, French BV, and North American FCC certifications, as well as import-export rights. By introducing and further optimizing technologies from Germany, the United States, and other regions, the company has enhanced product performance and accelerated the phase-out of outdated technologies, earning recognition from new and existing customers worldwide.
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Spare Parts and Consumables
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High-end shot blasting unit manufacturing workshop
Equipment Upgrade
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