Optimized Design 

The fan adopts advanced technology. The design of backward curved centrifugal wheel is optimized by means of CFD hydro-field simulating. The design is more accordant with the aerodynamic characteristics, high efficiency, and stable airflow. 

Advanced Process

All steel laser cut blades are welded and positioned accurately. The overall strength of the blades are designed and welded to withstand long hours high speed operation..  

High Balance Level

Each wheel has been dynamically balanced up to G4.0 standard (Just G6.3 for general products domestically and internationally).Durability, stability and quietness are guaranteed.

High Performance Curve

The wheel has a stable, smooth air performance curve which can efficiently avoid performance drop caused by the deviation of the working point. 

Surge Protection

The fan shaft power will not exceed the motor rated power regardless the operation point of the stable working range. Customers can use it without any worries.

High Reliability

· Our products adopt advanced FEA-aided design for both fan main unit and integral jet plume stack system, optimizing structural strength, wind load resistance and anti-vibration performance to fully enhance the overall structural reliability of the complete exhaust system.

· The hub, impeller, fan housing and integral jet stack adopt all-steel continuous welding process, realizing strengthened structure and leak-proof performance, while significantly improving safety and stability during high-pressure, high-speed long-term operation.

· Pre-engineered integral jet exhaust system realizes single-source full responsibility, eliminating component misapplication, fit-up issues and reliability risks caused by field-fabricated or sourced components, ensuring full consistency between design, production and on-site application.

· The upgraded shaft and coupling technology ensures high assembly accuracy of the fan transmission system, while the factory pre-assembled complete system minimizes on-site assembly errors, maintaining high reliability under full working conditions.
· Maximum load design surpasses 35% of the limit speed, providing sufficient safety margin to guarantee the safety of long-term continuous operation under variable working conditions.

· The integral jet stack system is designed and factory-tested to withstand a wind load of 34 PSF (equivalent to 115 mph / 185 km/h), no guy wires required, ensuring structural safety and stability in harsh outdoor wind environments.

· The bearing assembly is equipped with a lubricable seal structure, with a standard service life of more than L10: 80,000 hours, and optional L10: 200,000 hours heavy-duty bearings for harsh working conditions, fully ensuring operation reliability and long-term durability.

· All steel components of the complete system (including fan main unit and jet stack) adopt electrostatic powder coating with corrosion-resistant Permatector™ or Hi-Pro Polyester, which resists a wide spectrum of acids, alkalis and solvents, ensuring long-term anti-corrosion performance in harsh industrial environments.

· Optional spark-resistant construction (Spark B/Spark C grade) are available, which strictly comply with global mainstream explosion-proof standards, ensuring safe and reliable operation in flammable and explosive exhaust scenarios.
· The drive unit is equipped with a protective shield in eye-catching warning color, which fully guarantees personal safety during daily operation and maintenance.
· All complete machines (including the integral jet stack system) undergo strict factory vibration test, full performance calibration and balance verification before delivery, ensuring reliable and durable on-site operation, and avoiding unexpected performance deviation during field commissioning.

High Efficiency

·The precision-matched venturi inlet and impeller front disc effectively avoid turbulent flow and air leakage, ensuring smoother air flow and greatly improving the aerodynamic performance of the fan.

·Repeated optimized design through CFD flow field simulation for the complete system including impeller, housing, jet stack and discharge nozzle, ensuring that the aerodynamic performance of the whole system fully conforms to the flow field characteristics, eliminating additional local resistance loss.

·Factory performance calibration has fully included the resistance loss of all system components including integral jet stack, inlet boxes, dampers and supporting accessories, completely eliminating extra energy consumption caused by system effects from field-built systems, ensuring on-site operating efficiency is fully consistent with the design value.

·The fan main unit has excellent aerodynamic performance, with the maximum static efficiency up to 81%; the optimized jet nozzle design achieves higher plume rise for safe fume dilution without additional pressure drop or negative impact on fan aerodynamic performance, realizing both safe high-altitude emission and high-efficiency energy-saving operation.
·Optional factory-programmed variable frequency drive (VFD) supports constant air volume, constant pressure and air quality linkage control, which can dynamically adjust operating conditions according to actual exhaust demand, further reducing operating energy consumption while ensuring emission safety.

Fan Type

The fan shall be Fume Jet Centrifugal Fan, a pre-engineered integral exhaust system consisting of a single inlet steel backward curved centrifugal wheel and factory-integrated jet exhaust stack. The drive type includes direct drive, coupling drive and belt drive. The equipment structure allows convenient withdrawal of the impeller for daily maintenance and cleaning. The system safely discharges exhaust fumes to a safe height above the roof through the integral jet stack, effectively preventing re-entrainment of contaminated air into the building.

Quality Standards

The complete Fume Jet Centrifugal Fan shall be subject to strict factory performance testing before delivery. The factory performance rating includes all system losses from the integral jet stack and supporting accessories to avoid unexpected performance deviation during field commissioning. The manufacturer must have passed ISO 9001 Quality Management System, ISO 14001 Environmental Management System and ISO 45001 Occupational Health and Safety Management System certification.

Wheel

The wheel shall be fully welded steel backward curved centrifugal structure, and shall be statically and dynamically balanced to grade G4.0. When operating at the maximum allowable speed, the wheel shall deliver stable air volume with low noise, and shall be designed to avoid performance degradation caused by working point slip. The wheel material shall be matched to operating temperature: Q235 for temperature below 60℃, Q345 for 61℃-250℃, 304SS for 251℃-450℃, to ensure the structural strength of the wheel without creep deformation under high temperature and high speed working conditions.

Integral Jet Exhaust Stack System

1.Integral Pre-engineered Design: The jet stack is factory-integrated with the fan housing as a complete system, eliminating component misapplication, fit-up issues and on-site fabrication risks, with unified responsibility for the complete system.

2.Discharge Height Options: Standard effective discharge height is 2.1m, with optional extended heights of 3m and 4.6m to meet different plume rise requirements for safe fume dilution. 

3.Discharge Nozzle Configurations: Multiple nozzle options are available to meet application requirements:

• Straight Stack: Standard uniform straight discharge design, the most economical option;
• Fixed Nozzle: Tapered nozzle design to increase outlet velocity for higher plume rise, with no negative impact on fan performance;
• Adjustable Nozzle: Allows on-site adjustment of discharge area according to installed conditions;
• No Loss Rainproof Stack: Low resistance design with zero pressure drop, integrated rain water shedding structure to divert rain away from the fan housing.

4.Structural Design: The stack and fan assembly adopts optimized mechanical structure design, with excellent outdoor wind load resistance, no guy wires required for conventional installation. 
5.Material & Structure: The stack is constructed with the same grade steel as the fan housing, with material grade matched to operating temperature (304SS for temperature over 250℃). The stack adopts continuous welding with the fan housing for reliable leak-proof performance, with accessible design for inspection and maintenance.

Fan Housing

The fan housing shall be steel, with thickness and strength adequate to support the maximum running weight of the complete fan and jet stack assembly. The volute shall be continuously welded and equipped with an access door for inspection, cleaning and removing foreign objects in the scroll.

Fan Inlet

Fan inlet shall be strictly designed in accordance with aerodynamic performance, constructed of glass fiber reinforced plastics. The surface shall be smooth and streamline with excellent rectification effect, effectively reducing turbulence to improve fan efficiency and reduce operating noise. For explosion-proof models, a copper rub ring shall be installed at the inlet.

Surface Coating

Fan surface shall be polished and cleaned up to remove particulates, welding slag, burrs, sharp edge, iron, oil, then epoxy coating or high temperature coating for high temperature environments use, fan surface shall be free of sags, wrinkle, blisters, exposed metal or peeling after coating. It shall be no corrosion and rust at least 10 years in allowable working condition.

Transmission Device (Only for belt drive type)

Fan shaft shall be heat treated through soaking furnace to match the required hardness, with maximum load design 35% higher than the maximum RPM, and the shaft shall be furnished with a protective cover. The material of the shaft shall be 40Cr when the working temperature is under 250℃, and 35CrMo when the working temperature is between 251℃ and 450℃. The support structure shall be integral drum-type bearing box. The bearings shall be selected for a minimum L10 life in excess of 80,000 hours at maximum cataloged operating speed. The bearing lubrication shall adopt thin oil between N32 and N46, with oil volume complying with the oil level mark requirements. For working temperature between 61℃ and 250℃, the bearing box shall be equipped with optional water cooling device; for working temperature above 250℃, the bearing box shall be equipped with water cooling pipeline, with water consumption ranging from 0.3~1m³/h according to temperature. The pulley shall be made of cast iron, sized for a minimum of 130% of driving power. The pulley and belt shall be furnished with a protective cover. The coupling shall be elastic coupling with a protective cover, with power and torque transmission safety meeting design requirements.

Motor

Motor shall be closely matched to the full-system load of the Fume Jet Centrifugal Fan, with IP54 protection and insulation class F. Motor and drives shall be located outside of the airflow to avoid erosion by corrosive gas and extend service life. Optional factory-programmed Variable Frequency Drive (VFD) is available to meet different control requirements. For explosion-proof models, explosion-proof motor with corresponding protection grade shall be provided.

Explosion-proof Structure (Only for explosion-proof type)

The fan shall adopt Spark C explosion-proof structure. The inlet shall be equipped with copper rub ring, and the motor shall be explosion-proof type. The complete fan system shall have CNEX certification, with optional IECEx and ATEX certification for international projects.

Nameplate

Permanently fixed aluminum nameplate shall be fixed on fan body clearly display fan mark, product model and serial number (i.e.: unique ID for each fan), so that the customer can use this number to find out the parts used.

Acceptable Manufacturers

 Qualified suppliers shall have an AAA credit rating. Providing INFINAIR or similar products, with their design based on YFBCSL/R-FJ models of INFINAIR.