Customer's Requirement ISO 9001 Certified Industrial Dust Collection Centrifugal Radial Fan With Explosion Proof Design

Radial Fan Industrial Dust Collection Centrifugal Radial Fan Induced Draft Fan With And Explosion Proof Design For Industrial

Analysis of the Definition, Characteristics, and Impeller Manufacturing Process of Radial Centrifugal Fans

I. Definition of Radial Centrifugal Fans
A radial centrifugal fan is a typical type of centrifugal fan. Its core working principle is that through the high - speed rotation of the impeller, gas obtains centrifugal force along the radial direction of the impeller (perpendicular to the main shaft direction), thus realizing gas pressurization and transportation. Specifically, gas is axially sucked in from the center of the impeller, rotates with the impeller under the drive of the blades, is thrown to the outer periphery of the impeller by centrifugal force, and is collected by the volute and then discharged radially. During this whole process, mechanical energy is converted into the pressure energy and kinetic energy of the gas.

II. Characteristics of Radial Centrifugal Fans
1. Structural and Airflow Characteristics
- Clear airflow direction: The gas intake and exhaust directions are perpendicular (axial intake and radial exhaust). The impeller blades are arranged radially or nearly radially, and the movement trajectory of the airflow in the impeller is mainly radial.
- Pressure and flow characteristics: Compared with axial - flow fans, radial centrifugal fans have a higher head and are suitable for scenarios that need to overcome greater resistance (such as long pipelines and high - resistance equipment). However, the flow rate is relatively small, making them suitable for medium - to - low - flow, medium - to - high - pressure working conditions.
2. Adaptability to Application Scenarios
- Industrial scenarios: They are commonly used for boiler induced - draft, workshop ventilation, dust collection (such as in the mining and cement industries), and gas compression (such as in small pneumatic conveying systems). They are especially suitable for scenarios that need to overcome system resistance or pressurize the gas.
- Civil and commercial use: They are also common in air - conditioning systems, kitchen exhaust, and small ventilation equipment. Due to their compact structure and stable pressure, they can meet the resistance requirements of indoor and outdoor ventilation.
3. Performance Advantages and Limitations
- Advantages: The efficiency curve is gentle, and the efficiency is relatively high when operating near the rated working condition; the structure is relatively simple and easy to maintain; by adjusting parameters such as the impeller rotation speed and blade angle, they can be flexibly adapted to different working conditions.
- Limitations: They are large in size and have high energy consumption under large - flow working conditions; the noise is relatively obvious when the impeller rotates at high speed, and sound - insulation measures are required.

III. Manufacturing Process of the Impeller (Detailed Analysis)
The manufacturing process of the impeller of a radial centrifugal fan directly affects its performance, wear resistance, and service life. The common processes are as follows:
1. Core Structural Composition of the Impeller
The impeller is mainly composed of three parts: blades, a front disc, and a rear disc (hub). According to different structures, it can be divided into open (without front and rear discs), semi - open (only with a rear disc), and closed (with front and rear discs) impellers. Among them, the closed impeller has the highest efficiency and is the most widely used.
2. Manufacturing Process Steps and Technical Details
(1) Material Selection
- Common carbon steel (such as Q235, Q345): It has a low cost and is suitable for normal - temperature, clean gas (such as ventilation).
- Stainless steel (304, 316L): It has strong corrosion resistance and is used in the chemical and food industries or scenarios with corrosive gases.
- Wear - resistant alloys (high - chromium cast iron, tungsten carbide alloy): They are used in high - dust, high - wear environments (such as mine fans) and need to be combined with wear - resistant layer processes (such as surfacing and spraying).
- Engineering plastics/fiberglass: They are light in weight and resistant to acids and alkalis and are suitable for low - pressure scenarios with high anti - corrosion requirements (such as waste gas treatment).
(2) Blade Processing Technology
- Stamping and forming:
- It is suitable for the mass production of small - and medium - sized impellers. The steel plate is stamped into the preset shape of the blade (such as forward - curved, backward - curved, and radial blades) through a mold, with high precision and efficiency.
- The key is that the blade profile needs to be designed according to aerodynamics to ensure smooth airflow and reduce eddy - current losses; after stamping, deburring and shape correction treatments are required to avoid stress concentration.
- Forging processing:
- For high - strength, large - size blades (such as those of large industrial fans), the density of the metal material is increased and the strength is enhanced through forging, which is suitable for high - speed, heavy - load working conditions.
- Heat treatment (such as quenching and tempering) is required later to improve toughness and prevent blade breakage during operation.
- Casting process:
- For blades with complex profiles (such as twisted blades), sand - casting or precision - casting is used to cast molten metal into the mold for forming.
- It is often used for wear - resistant alloy impellers, and wear - resistant materials (such as high - chromium cast - iron inserts) can be directly embedded in the blade surface during casting to improve wear - resistance.
(3) Impeller Assembly Process
- Welding assembly:
- The blades, front disc, and rear disc are welded and fixed through processes such as argon arc welding and carbon dioxide shielded welding.
- The key is that the welding sequence needs to be carried out symmetrically to reduce thermal deformation; stress - relief annealing is required after welding to avoid vibration of the impeller during operation due to internal stress.
- Bolt connection:
- For some large impellers or scenarios that require frequent disassembly, high - strength bolts are used to fix the blades to the hub for easy maintenance and replacement.
- Attention should be paid to the anti - loosening treatment of the bolts (such as using anti - loosening nuts and applying thread glue) to prevent loosening during high - speed rotation.
(4) Surface Treatment and Wear - Resistance Enhancement
- Wear - resistant layer process:
- Surfacing: High - chromium alloys, tungsten carbide and other materials are surfaced on the easily - worn parts of the blade (such as the leading edge and working surface) to improve wear - resistance (suitable for dust environments).
- Spraying: A dense wear - resistant layer is formed by spraying ceramic (such as alumina) or cermet coatings through plasma spraying, which has both high - temperature resistance and anti - scouring ability (such as in power plant induced - draft fans).
- Anti - corrosion treatment:
- Electroplating (such as galvanizing), spraying anti - rust paint or epoxy resin coatings are used in humid or corrosive gas environments to extend the service life of the impeller.
(5) Dynamic Balance and Precision Calibration
- After the impeller is assembled, a dynamic balance test is required. By adding or removing weights on the impeller (such as milling), the unbalance amount is controlled below G2.5 level (according to the speed requirements) to avoid damage to the main shaft and bearings due to vibration during operation.
- For high - precision impellers, the coaxiality (the deviation between the main shaft and the impeller center ≤0.05mm) and the consistency of the blade angle (error ≤1°) need to be calibrated to ensure uniform airflow and reduce efficiency losses.
3. Special Processes and Innovative Technologies
- 3D printing (additive manufacturing): It is used for the small - batch production of customized impellers with complex profiles. Twisted blades or porous lightweight structures can be directly printed to improve efficiency and reduce weight.
- Composite forming process: For example, the combination of "stamping + welding + spraying". First, the blades are stamped and formed, then welded and assembled, and finally sprayed with a wear - resistant coating, taking into account both cost and performance.

IV. Summary
Radial centrifugal fans have unique advantages in medium - to - high - pressure, medium - to - low - flow scenarios through the design of "radial airflow + centrifugal force". The manufacturing process of the impeller focuses on the three core requirements of "aerodynamic efficiency, wear - resistance and anti - corrosion, and structural strength", forming a complete technical chain from material selection to dynamic balance calibration to ensure the stable operation of the fan under different working conditions."

Do you think 3D printing will become the mainstream impeller manufacturing technology in the future?

Key Features 

• Impeller diameter: 70~3500 mm 
• Speed of mainshaft: 560~2900 rpm
• Pressure range: 1000~25425 Pa
• Flow range: 3297~733050 m3/h
• Air Temperature: 20~1000 Celsius degree

• Material: Cast Iron, Carbon Steel, Stainless Steel.

• Efficiency: 70%-90%