Description:TECHNICAL FIELD OF THE INVENTION
[001] The embodiments of the present disclosure generally relate to industrial fan systems. In particular, the present disclosure relates to a carbon fiber reinforced plastic (CFRP) blades for enhanced airflow in industrial axial fans.
BACKGROUND OF THE DISCLOSURE
[002] The following description of related art is intended to provide background information pertaining to the field of the disclosure. This section may include certain aspects of the art that may be related to various features of the present disclosure. However, it should be appreciated that this section be used only to enhance the understanding of the reader with respect to the present disclosure, and not as admissions of prior art.
[003] Industrial axial fans are essential components in refineries, playing a critical role in processes such as cooling. The efficiency and performance of these fans directly impact the overall operational effectiveness and safety of refinery operations. The design and construction of fan blades significantly influence the fan's capability to handle the demanding requirements of refinery environments.
[004] In refinery applications, industrial axial fans often operate in harsh conditions, including exposure to corrosive chemicals, high temperatures, and particulate-laden air. Conventional fan blades, typically constructed from materials such as aluminum or steel, face substantial challenges in these environments. While these materials offer durability, the resulting blades are often heavy, requiring more energy to operate and failing to achieve optimal airflow efficiency. This inefficiency leads to increased energy consumption and higher operational costs for refineries.
[005] The design of traditional blades in refinery fans frequently fails to optimize the aerodynamic properties necessary for enhanced air movement. This suboptimal design results in reduced cooling efficiency, inadequate fume extraction, and overall decreased performance of refinery processes. The inability to maintain consistent performance under varying refinery conditions further compounds these issues.
[006] Refinery operations require fans with specific airflow characteristics to meet diverse process needs. However, current blade designs lack the flexibility to adapt to these requirements. This inflexibility often results in compromised performance across different refinery applications, leading to inefficiencies in critical processes.
[007] The harsh refinery environment poses significant challenges to the durability and longevity of fan blades. Exposure to corrosive chemicals and high temperatures accelerates wear and degradation of conventional blade materials. This degradation necessitates frequent maintenance or replacement, resulting in increased downtime and reduced productivity in refinery operations.
[008] Energy efficiency remains a critical concern in refinery operations. With stringent environmental regulations and the need for cost-effective operations, refineries require fan blades that deliver higher airflow rates while consuming less power. Current blade designs often fall short in this aspect, contributing to excessive energy consumption and increased operational costs.
[009] Noise generation by industrial axial fans presents another challenge in refinery settings. Excessive noise from fans can create hazardous working conditions and may violate occupational safety standards. Conventional blade designs often produce high noise levels due to turbulence and vibration, necessitating additional noise mitigation measures.
[0010] Conventional systems and methods face difficulty in achieving an optimal balance between airflow efficiency, energy consumption, durability, and adaptability in industrial axial fan blades used in refinery applications. There is, therefore, a need in the art to provide a system that can overcome the shortcomings of the existing prior arts in refinery environments.
[0011] It is therefore an objective of the present invention to provide an enhanced airflow industrial axial fan system with improved aerodynamic efficiency, durability, and adaptability. The present invention aims to address the aforementioned challenges by introducing a Carbon Fibre Reinforced Plastic (CFRP) blade design, thereby overcoming the above-mentioned disadvantages in the field of industrial axial fans.

SUMMARY OF THE DISCLOSURE
[0012] This summary may be provided to introduce concepts related to a carbon fiber reinforced plastic (CFRP) blades for enhanced airflow in industrial axial fans, the concepts are further described below in the detailed description. This summary may be not intended to identify essential features of the claimed subject matter nor maybe it intended for use in determining or limiting the scope of the claimed subject matter.
[0013] In an exemplary embodiment, a system for an enhanced airflow industrial axial fan is described. The system comprises at least two Carbon Fibre Reinforced Plastic (CFRP) blades. Each of the at least two CFRP blades is configured to form a single structure having a varying chord length in a longitudinal direction with a camber in a transverse direction thereof. Each of the at least two CFRP blades comprises a leading edge with a defined leading-edge radius, an extended curved trailing edge, a shoulder side, a tip side, an upper surface with curvature, and a lower surface. The upper surface and the lower surface form an aerofoil profile. The shoulder side is configured with a straight profile. Each of the at least two CFRP blades is hollow. The at least two CFRP blades are symmetrically arranged with respect to each other on the industrial axial fan. Each of the at least two CFRP blades is configured to generate a pressure differential between the upper surface and the lower surface when powered, resulting in enhanced airflow directed parallel to a hub axis.
[0014] In some embodiments, each of the at least two CFRP blades is further configured such that a point of maximum thickness of the aerofoil profile is located closer to the leading edge than the extended curved trailing edge. The maximum thickness and the varying chord length at the shoulder side gradually decrease towards the tip side of each of the at least two CFRP blades.
[0015] In some embodiments, each of the at least two CFRP blades is further configured such that a blade thickness at the shoulder side is greater than at other parts of each of the at least two CFRP blades. The shoulder side may have a maximum thickness in a range of 3 to 7 percent of the blade length. A maximum thickness at the tip side of each of the at least two CFRP blades is in a range of 1 to 2 percent of the blade length.
[0016] In some embodiments, each of the at least two CFRP blades is further configured with a pitch angle of 2-15 degrees with respect to a plane perpendicular to the hub axis. (The pitch angle is usually measured using an angle finder placed on the upper surface of the blade at its tip end). Each of the at least two CFRP blades might also configured with a twist angle of not more than 5 degrees along a blade length.
[0017] In some embodiments, each of the at least two CFRP blades may further configured such that an angle made by the extended curved trailing edge with a chord line not more than 49 degrees.
[0018] In some embodiments, each of the at least two CFRP blades is further configured to have a chord length that exhibits a progressive reduction along the span of the blade, optimizing aerodynamic performance and structural integrity.
[0019] In some embodiments, the system is further configured for manufacturing each of the at least two CFRP blades using carbon and glass fibre reinforcement with a pressure bag moulding technique.
[0020] In some embodiments, each of the at least two CFRP blades also has a curved trailing edge extending along the entire blade length.

BRIEF DESCRIPTION OF DRAWINGS
[0021] The accompanying drawings, which are incorporated herein, and constitute a part of this disclosure, illustrate exemplary embodiments of the disclosed methods and systems in which like reference numerals refer to the same parts throughout the different drawings. Components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Some drawings may indicate the components using block diagrams and may not represent the internal circuitry of each component. It will be appreciated by those skilled in the art that disclosure of such drawings includes the disclosure of electrical components, electronic components or circuitry commonly used to implement such components.
[0022] FIG. 1 illustrates an exemplary system for enhanced airflow in industrial axial fans, in accordance with embodiments of the present disclosure.
[0023] FIG. 2 illustrates an exemplary perspective view of a carbon fiber reinforced plastic (CFRP) blades for enhanced airflow in industrial axial fans, in accordance with embodiments of the present disclosure.
[0024] FIG. 3 illustrates an exemplary view of aerofoil profile of a carbon fiber reinforced plastic (CFRP) blades for enhanced airflow in industrial axial fans, in accordance with embodiments of the present disclosure.
[0025] FIG. 4 illustrates an exemplary cross sections of a carbon fiber reinforced plastic (CFRP) blades for enhanced airflow in industrial axial fans, in accordance with embodiments of the present disclosure.
[0026] The foregoing shall be more apparent from the following more detailed description of the disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE
[0027] In the following description, for the purposes of explanation, various specific details are set forth in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent, however, that embodiments of the present disclosure may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. An individual feature may not address all of the problems discussed above or might address only some of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein.
[0028] The ensuing description provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the disclosure as set forth.
[0029] Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, networks, processes, and other components may be shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.
[0030] The word “exemplary” and/or “demonstrative” is used herein to mean serving as an example, instance, or illustration. For the avoidance of doubt, the subject matter disclosed herein is not limited by such examples. In addition, any aspect or design described herein as “exemplary” and/or “demonstrative” is not necessarily to be construed as preferred or advantageous over other aspects or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art. Furthermore, to the extent that the terms “includes,” “has,” “contains,” and other similar words are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term “comprising” as an open transition word without precluding any additional or other elements.

[0031] Reference throughout this specification to “one embodiment” or “an embodiment” or “an instance” or “one instance” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0032] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0033] The aspects of the present disclosure are directed to a system for an enhanced airflow industrial axial fan utilizing Carbon Fibre Reinforced Plastic (CFRP) blades. The system aims to improve aerodynamic efficiency and durability in demanding environments such as refineries by employing hollow CFRP blades with a unique aerofoil profile. These blades feature a varying chord length, an extended curved trailing edge, and a specifically designed camber, collectively contributing to enhanced airflow directed parallel to the hub axis while maintaining structural integrity under harsh operational conditions.
[0034] The various embodiments throughout the disclosure will be explained in more detail with reference to FIGS. 1-4.
[0035] FIG. 1 illustrates an exemplary system for enhanced airflow in industrial axial fans, in accordance with embodiments of the present disclosure. FIG. 1 illustrates an exemplary system for enhanced airflow in industrial axial fans, in accordance with embodiments of the present disclosure. The system (100) may comprise at least two Carbon Fibre Reinforced Plastic (CFRP) blades (102), Hub assembly (103) and a motor (104). CFRP, as used herein, refers to a composite material consisting of carbon fibers embedded in a polymer matrix, which may provide high strength-to-weight ratio and excellent fatigue resistance.
[0036] The at least two CFRP blades (102) may be symmetrically arranged around a central hub, which may be connected to the motor (104). In this context, symmetrical arrangement refers to the uniform distribution of the blades around the hub, for example, in a system with four blades, each blade may be positioned 90 degrees apart from adjacent blades.
[0037] Each of the CFRP blades (102) may be configured to form a single structure with a specific aerofoil profile designed for enhanced airflow. An aerofoil profile, in this instance, refers to the cross-sectional shape of the blade that determines its aerodynamic properties. For example, the profile may include a curved upper surface and a relatively flat lower surface to create lift and reduce drag.
[0038] The motor (104) may be operatively connected to the central hub to drive the rotation of the CFRP blades (102). This motor may be, for example, an electric motor, depending on the specific application requirements.
[0039] The system (100) may be designed for use in demanding industrial environments, such as refineries, where the CFRP blades (102) may provide improved aerodynamic efficiency and durability. In a refinery setting, for instance, the fan might be exposed to corrosive chemicals, high temperatures, and particulate matter, conditions under which traditional metal blades might degrade rapidly.
[0040] The arrangement of the CFRP blades (102) in relation to the motor (104) may be optimized to generate a pressure differential, resulting in enhanced airflow directed parallel to the hub axis when the system (100) is in operation. This pressure differential is created by the specific design of the blade's aerofoil profile, which may include features such as an extended curved trailing edge or a varying chord length along the blade's span.
[0041] For example, the CFRP blades (102) may have a pitch angle of 2-15 degrees with respect to a plane perpendicular to the hub axis, and a twist angle of not more than 5 degrees along the blade length. These angles may be optimized to maximize airflow efficiency for specific operational conditions.
[0042] The enhanced airflow generated by this system may be quantified in terms of increased air volume moved per unit of energy consumed, compared to conventional fan systems. For instance, the system might achieve a 15-20% increase in airflow rate while maintaining the same power consumption as a traditional fan of similar size.
[0043] Now referring to FIG. 2, FIG. 3 and FIG. 4, FIG. 2 illustrates an exemplary perspective view of a carbon fiber reinforced plastic (CFRP) blades for enhanced airflow in industrial axial fans, in accordance with embodiments of the present disclosure. FIG. 3 illustrates an exemplary view of aerofoil profile of a carbon fiber reinforced plastic (CFRP) blades for enhanced airflow in industrial axial fans, in accordance with embodiments of the present disclosure. FIG. 4 illustrates an exemplary cross sections of a carbon fiber reinforced plastic (CFRP) blades for enhanced airflow in industrial axial fans, in accordance with embodiments of the present disclosure.
[0044] The present disclosure may relate to a system (100) for an enhanced airflow industrial axial fan. Industrial axial fans, used in various industrial settings, such as refineries, power plants, or manufacturing facilities. These fans may be characterized by their ability to move large volumes of air in a direction parallel to the fan's rotational axis.
[0045] The system (100) may comprise at least two Carbon Fibre Reinforced Plastic (CFRP) blades (102). The term "at least two" may indicate that the system can accommodate multiple blades, typically ranging from two to eight, depending on the specific application requirements. For example, a smaller fan used for localized cooling might employ two or three blades, while a larger fan designed for cooling entire industrial processes might utilize six or eight blades.
[0046] Carbon Fibre Reinforced Plastic, as used herein, may refer to a composite material that combines carbon fibers with a polymer matrix, typically a thermosetting resin like epoxy or polyester.
[0047] This CFRP material may provide a high strength-to-weight ratio, often surpassing that of traditional materials used in fan blades such as aluminum or steel. For instance, CFRP may have high strength-to-weight ratio, leading to three to seven times higher than steel and half that of aluminum. This high strength-to-weight ratio may allow for the design of larger, more efficient fan blades that can operate at higher speeds without succumbing to the increased centrifugal forces.
[0048] The CFRP material may also offer excellent fatigue resistance, which refers to the ability of a material to withstand repeated loading and unloading cycles without failure. In the context of fan blades, fatigue resistance is crucial as the blades undergo constant cyclic stresses during operation. CFRP may typically exhibit a fatigue limit of about 60-70% of its ultimate tensile strength, compared to about 30-40% for most metals.
[0049] These properties of CFRP may be particularly beneficial in demanding industrial environments such as refineries. Refineries present a challenging operating environment for fan systems due to several factors. The presence of corrosive atmospheres, including sulfur compounds and hydrocarbons, may rapidly degrade many traditional materials. CFRP, being chemically inert to many of these substances, may offer superior corrosion resistance. Some areas in refineries may experience temperatures exceeding 200°C (392°F). CFRP, depending on the specific resin system used, may maintain its structural integrity at these elevated temperatures.
[0050] Refinery processes often run continuously, requiring fan systems that can operate 24/7 with minimal maintenance. The fatigue resistance of CFRP may contribute to extended operational life and reduced maintenance frequency. Many areas in refineries are classified as hazardous due to the presence of potentially explosive gases. The use of CFRP, being non-sparking and non-conductive, may reduce the risk of ignition in such environments. Refinery processes often require the movement of large volumes of air for cooling. The high strength-to-weight ratio of CFRP may allow for the design of larger, more efficient fan blades capable of moving greater volumes of air.
[0051] By utilizing CFRP in the construction of the fan blades (102), the system (100) may be able to meet the demanding requirements of these industrial environments while potentially offering improved performance and longevity compared to traditional fan blade materials. The specific design and configuration of these CFRP blades (102), which will be detailed in subsequent paragraphs, may further enhance the system's ability to provide enhanced airflow in these challenging industrial settings.
[0052] Each of the at least two CFRP blades (102) may be configured to form a single structure. This single structure configuration may refer to the blade being manufactured as one continuous piece, rather than assembled from multiple components. The single structure design may offer several potential benefits, including improved structural integrity, reduced likelihood of component separation during operation, and potentially simpler maintenance procedures.
[0053] This single structure may have a varying chord length in a longitudinal direction. The chord length, in this context, may refer to the distance between the leading edge and trailing edge of the blade at any given point along its length. For instance, in a typical industrial fan blade, the chord length at the blade root is typically 1 to 2 times that of the chord length at the blade tip. This variation in chord length is a crucial aspect of blade design that can significantly influence the fan's performance characteristics.
[0054] The varying chord length may allow for optimized aerodynamic performance along the entire span of the CFRP blade (102). This optimization may be achieved through a process known as chord distribution, where the chord length is carefully tailored at each radial position along the blade. For example, a longer chord near the blade root may provide the structural strength needed to withstand the high stresses in this region, while a shorter chord near the tip may reduce drag and noise at the blade's fastest-moving section.
[0055] Additionally, each of the at least two CFRP blades (102) may have a camber in a transverse direction. The camber, as used herein, may refer to the asymmetry between the upper and lower surfaces of the aerofoil. More specifically, camber may be defined as the maximum distance between the mean camber line and the chord line, expressed as a percentage of the chord length. The mean camber line is an imaginary line drawn halfway between the upper and lower surfaces of the aerofoil.
[0056] The degree of camber can significantly influence the blade's lift characteristics. A highly cambered aerofoil may generate more lift at a given angle of attack compared to a symmetrical aerofoil. However, it may also produce more drag. For example, a fan designed for high-pressure applications might use blades with more pronounced camber to generate the required lift, while a fan designed for quieter operation might use blades with less camber to reduce drag and associated noise.
[0057] In industrial axial fans, the camber may not be constant along the blade length. Instead, it may vary in the transverse direction, which means the degree of camber may change from the blade root to the blade tip. This variation in camber may allow for further optimization of the blade's performance characteristics along its entire length.
[0058] For instance, the camber might be more pronounced near the blade root, where the relative air velocity is lower, to generate more lift in this region. Conversely, the camber might be reduced near the blade tip, where the relative air velocity is higher, to prevent excessive drag and maintain efficiency. In an industrial fan blade have a maximum camber of less than 8% of the chord length near the shoulder, gradually decreasing near the tip.
[0059] The combination of varying chord length and camber in the CFRP blades (102) may allow for a high degree of design flexibility. This flexibility may enable the creation of fan blades that can be precisely tailored to meet the specific performance requirements of different industrial applications, potentially offering improvements in efficiency, noise reduction, and overall performance compared to more traditional blade designs.
[0060] The CFRP blades (102) may comprise several key components that contribute to their enhanced performance. Each of these components plays a crucial role in the overall functionality and efficiency of the blade, and by extension, the entire fan system.
[0061] Each of the at least two CFRP blades (102) may include a leading edge (202) with a defined leading-edge radius. The leading edge (202) may be the front edge of the blade that first contacts the air. In aerodynamic terms, the leading edge is the foremost point of the blade profile and is critical in determining how the airflow separates as it moves over and under the blade surface. The defined leading-edge radius may refer to the curvature of this front edge, which can significantly impact the blade's performance.
[0062] The leading-edge radius is carefully designed to optimize airflow over the blade surface, potentially reducing drag and improving efficiency. A well-designed leading edge can help maintain attached flow over the blade surface, reducing the formation of turbulent eddies that can decrease efficiency. In an industrial fan applications, a leading-edge radius is not more than 5% of the chord length be used.
[0063] The importance of the leading-edge design becomes particularly evident when considering the Reynolds number, a dimensionless quantity used to predict flow patterns in different fluid flow situations. In industrial fans, which often operate at high Reynolds numbers, the leading-edge design can significantly influence the transition point from laminar to turbulent flow along the blade surface.
[0064] Another crucial component of each CFRP blade (102) may be an extended curved trailing edge (204). The trailing edge (204) may be the rear edge of the blade where the airflow exits. In aerodynamic theory, the trailing edge is where the airflow over the upper and lower surfaces of the blade reunites. The design of the trailing edge can have a substantial impact on the blade's performance, particularly in terms of noise generation and efficiency.
[0065] The extended curved design of the trailing edge (204) may help in controlling the airflow separation, potentially reducing turbulence and enhancing overall fan efficiency. The curvature of the trailing edge can influence the pressure recovery at the rear of the blade, which in turn affects the overall lift and drag characteristics. For instance, a gradually curved trailing edge might be used to promote a smooth reuniting of the airflows from the upper and lower surfaces, reducing the formation of vortex streets that can lead to increased drag and noise.
[0066] Each of the at least two CFRP blades (102) may also include a shoulder side (208) and a tip side (206). These components represent the radial extremes of the blade and play crucial roles in the overall blade design and performance.
[0067] The shoulder side (208) may refer to the part of the blade closest to the hub. This region of the blade typically experiences the highest stresses during operation due to the bending moments induced by centrifugal forces. As such, the design of the shoulder side is critical for the structural integrity of the blade. In industrial fan designs, the shoulder region of the blade may have a thickness up to four times greater than that of the blade tip to provide the necessary structural strength.
[0068] The shoulder side also plays a significant role in the aerodynamic performance of the blade. The airflow in this region is often complex due to the interaction with the hub and the relatively low linear velocity. Careful design of the shoulder side profile, including features such as fillets or fairings where the blade meets the hub, can help manage this complex flow and improve overall fan efficiency.
[0069] The tip side (206) may refer to the outermost part of the blade. This region of the blade experiences the highest linear velocities during operation and is often a critical area for noise generation and efficiency losses. The design of the tip side can significantly influence the formation and strength of tip vortices, which are a major source of energy loss and noise in axial fans.
[0070] The tip side design also influences the effective diameter of the fan, which is a key factor in determining the fan's flow rate and pressure characteristics. In industrial fan designs, the tip is designed with a thickness of not more than one-fourth of the blade shoulder thickness to optimize blade weight and aerodynamic characteristics.
[0071] By carefully optimizing each of these key components - the leading edge (202), the extended curved trailing edge (204), the shoulder side (208), and the tip side (206) - the CFRP blades (102) may achieve enhanced aerodynamic performance, structural integrity, and overall efficiency in industrial axial fan applications.
[0072] The CFRP blades (102) may further comprise an upper surface (302) with curvature and a lower surface (304). The upper surface (302) and the lower surface (304) may together form an aerofoil profile. The specific shape of this aerofoil profile is crucial to the blade's performance and is often the result of computational fluid dynamics (CFD) analysis and physical testing.
[0073] This aerofoil profile may be a key factor in generating the pressure differential that drives airflow. The principle behind this is based on Bernoulli's equation, which states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. In the context of fan blades, this means that the aerofoil shape is designed to create a difference in air velocity between the upper and lower surfaces of the blade.
[0074] The curvature of the upper surface (302) may be designed to create a low-pressure area above the blade. This is achieved by shaping the upper surface so that air traveling over it must move faster to reach the trailing edge at the same time as air moving under the blade. According to Bernoulli's principle, this increased velocity results in lower pressure. The lower surface (304) may create a higher-pressure area below the blade, often by having less curvature.
[0075] A notable feature of the system (100) may be that the shoulder side (208) is configured with a straight profile. In this context, a straight profile refers to a linear, non-curved shape when viewed from the side. This straight profile may help in minimizing dead areas and optimizing airflow near the hub of the fan.
[0076] The straight profile of the shoulder side (208) may also contribute to the structural integrity of the CFRP blade (102). A straight profile can provide a more direct load path for the forces experienced by the blade during operation.
[0077] Another significant aspect of the system (100) may be that each of the at least two CFRP blades (102) is hollow. The hollow nature of the CFRP blades (102) may contribute to weight reduction without compromising structural integrity. This is possible due to the high strength-to-weight ratio of CFRP material and the principle of structural efficiency in hollow sections.
[0078] The hollow CFRP blade may have a mass of not more than the 15-20 kg per meter of length. This weight reduction can be crucial in large industrial fans, where the total weight of all blades can significantly impact the load on the fan's bearings and support structure.
[0079] The hollow design may allow for larger blade designs, potentially increasing airflow capacity while maintaining manageable inertial loads. Inertial loads, in this context, refer to the forces generated by the mass of the blades as they rotate. These forces increase with the square of the rotational speed and linearly with the mass of the blades. By reducing the mass through a hollow design, larger blades can be used without excessive inertial loads.
[0080] The at least two CFRP blades (102) may be symmetrically arranged with respect to each other on the industrial axial fan. Symmetrical arrangement in this context means that the blades are positioned at equal angular intervals around the fan's central axis. For instance, in a four-bladed fan, each blade would be positioned 90 degrees apart from its neighbouring blades.
[0081] A key functional aspect of the system (100) may be that each of the at least two CFRP blades (102) is configured to generate a pressure differential between the upper surface (302) and the lower surface (304) when powered. This pressure differential is the driving force behind the fan's ability to move air.
[0082] This pressure differential may result in enhanced airflow directed parallel to a hub axis. The direction of airflow parallel to the hub axis may be crucial for efficient operation in many industrial applications, such as in refineries where directional airflow is often required for cooling process.
[0083] In some embodiments of the system (100), each of the at least two CFRP blades (102) may be further configured with specific design features that enhance their performance. These features are the result of careful aerodynamic analysis and optimization, often involving computational fluid dynamics (CFD) simulations and wind tunnel testing.
[0084] A key design feature is the location of the point of maximum camber (308) of the aerofoil profile. This point may be located above the 50 % of chord length to the trailing edge (204).
[0085] This design feature may help in maintaining laminar flow over a larger portion of the blade surface, potentially reducing drag and improving efficiency.
[0086] Furthermore, the maximum thickness and the varying chord length at the shoulder side (208) may gradually decrease towards the tip side (206) of each of the at least two CFRP blades (102). This design feature is often referred to as blade tapering.
[0087] This gradual decrease may help in optimizing the blade's performance along its entire length, potentially providing a balance between structural strength and aerodynamic efficiency. The thicker section at the shoulder provides the necessary strength to withstand the high stresses in this region, while the thinner section at the tip reduces weight and drag where the blade moves at the highest linear velocity.
[0088] The system (100) may also incorporate specific dimensional configurations to optimize performance. For example, the blade thickness at the shoulder side (208) may be greater than at other parts of each of the at least two CFRP blades (102). This design approach is based on the principle of structural efficiency, where material is placed where it's most needed to resist loads.
[0089] More specifically, the shoulder side (208) may have a maximum thickness. This thickness may provide the necessary strength to withstand the operational stresses near the hub. The high thickness in this region is crucial because this is where the blade experiences the highest bending moments due to the aerodynamic and centrifugal forces during operation. As the blades are hollow in nature, and the maximum contraction and expansion takes place in the blade neck and shoulder region. In order to strengthen this region, blades are developed by increasing the number of composite layers and the thickness at that region, hence the strength will be more.
[0090] In contrast, a maximum thickness at the tip side (206) of each of the at least two CFRP blades (102) is gradually reduced. This reduced thickness at the tip may help in minimizing the blade's weight while maintaining its aerodynamic properties. The thinner tip also helps in reducing tip vortex strength, which can be a significant source of energy loss and noise in axial fans.
[0091] The thickness-to-chord ratio (often denoted as t/c in aerodynamics) might vary at the shoulder to the tip. This variation allows the blade to maintain structural integrity while optimizing aerodynamic performance along its length.
[0092] The system (100) may further incorporate specific angular configurations to optimize airflow. Each of the at least two CFRP blades (102) may be configured with a pitch angle (θ1) of 2-15 degrees with respect to a plane perpendicular to the hub axis.
[0093] This pitch angle may be crucial in determining the amount of air moved by the fan and the pressure developed. The specific range of 2-15 degrees may provide an optimal balance between airflow volume and pressure for many industrial applications.
[0094] The relationship between pitch angle and fan performance is often represented by fan laws, which describe how changes in fan speed, diameter, and pitch angle affect flow rate, pressure, and power consumption. For example, increasing the pitch angle while keeping the fan speed constant will generally increase both the flow rate and the pressure, but at the cost of higher power consumption.
[0095] In addition to the pitch angle, each of the at least two CFRP blades (102) may also have a twist angle (θ2) of not more than 5 degrees along a blade length. The twist angle, also known as the blade twist or aerodynamic twist, refers to the gradual change in the blade's angle of attack from shoulder to tip.
[0096] The twist angle may help in maintaining optimal angle of attack along the entire length of the blade, potentially improving efficiency across different radial sections of the fan. This is necessary because the relative velocity of the air changes along the blade's length due to the different linear velocities at different radii.
[0097] Another angular configuration that may be incorporated in the system (100) is the angle made by the extended curved trailing edge (204) with a chord line (310). This angle is not more than 49 degrees. In aerodynamic terminology, this angle is related to the concept of blade camber. A highly cambered aerofoil (with a larger angle between the trailing edge and chord line) can produce more lift. The specific angle of the trailing edge may influence the airflow separation point and the overall aerodynamic performance of the blade.
[0098] For instance, a trailing edge angle might provide an optimal balance between lift generation and drag reduction for the specific operating conditions of the fan. This angle might be the result of extensive CFD analysis and wind tunnel testing, optimized for the fan's intended operating range in terms of airflow and pressure requirements.
[0099] These specific design features, working in concert, contribute to the overall performance and efficiency of the CFRP blade system. By carefully balancing structural requirements with aerodynamic optimization, the system aims to provide superior performance in demanding industrial applications.
[00100] The system (100) may incorporate varying thicknesses at different chord-wise sections of each CFRP blade (102). This design feature, known as thickness distribution, is crucial for optimizing the blade's structural and aerodynamic performance.
[00101] This varying thickness profile may allow for optimal distribution of material, potentially providing the necessary strength where it's most needed while minimizing weight where possible. The thicker sections near the blade root (sections AA and BB) provide the structural strength needed to withstand the high bending moments experienced in this region. The gradual reduction in thickness towards the blade tip (sections CC, DD, and EE) helps to minimize the blade's overall weight and reduce the centrifugal forces acting on the blade during operation.
[00102] The system (100) may be further configured for manufacturing each of the at least two CFRP blades (102) using carbon and glass fibre reinforcement with a pressure bag moulding technique. This manufacturing technique, also known as bladder moulding or inflatable bladder moulding, is a specialized process well-suited for producing hollow composite structures with complex geometries.
[00103] The pressure bag moulding technique may involve several key steps:
a. Laying up: The carbon and glass fibre reinforcement materials are carefully positioned in the mould. These materials typically come in the form of pre-impregnated (prepreg) sheets or dry fabrics that are later infused with resin.
b. Bladder insertion: An inflatable bag or bladder, usually made of silicone or nylon, is inserted into the layup.
c. Mould closing: The mould is closed, encapsulating the fibre layup and the bladder.
d. Pressurization and curing: The bladder is inflated, typically to pressures ranging from 5 to 15 psi, depending on the specific requirements of the part. This pressure forces the fibre reinforcement against the mould walls, ensuring good consolidation and minimizing voids.
e. Demoulding: After curing, the pressure is released, and the finished blade is removed from the mould.
[00104] This technique may result in a high-quality, consistent blade structure with minimal voids or defects. For example, a well-executed pressure bag moulding process might achieve a void content of less than 1%, compared to 2-5% that might be typical with hand layup processes. This low void content contributes to the structural integrity and fatigue resistance of the blade.
[00105] Additionally, each of the at least two CFRP blades (102) may have a leading edge extending along an entire blade length. The curvature of the leading edge is often defined by its radius of curvature, which is 2-3% of the chord length.
[00106] Similarly, each blade may have a curved trailing edge extending along the entire blade length. The curvature of the trailing edge is often characterized by its departure angle from the chord line. In this system, as mentioned earlier, the angle made by the extended curved trailing edge (204) with a chord line (310) is not more than 49 degrees. The curved trailing edge may assist in controlling the airflow as it leaves the blade, potentially reducing turbulence.
[00107] Lastly, each of the at least two CFRP blades (102) may exhibit camber in the transverse direction along its length. Camber, in aerofoil design, refers to the asymmetry between the top and bottom surfaces of the aerofoil. It is typically quantified as the maximum distance between the mean camber line and the chord line, expressed as a percentage of the chord length.
[00108] This consistent camber along the blade length may help in maintaining optimal lift characteristics across the entire span of the blade. For example, the blade might have a maximum camber of less than 8% of the chord length, with the point of maximum camber located at above 50% of the chord length from the leading edge. This camber profile could potentially increase the lift coefficient compared to a symmetric aerofoil, contributing to improved overall performance of the fan system.
[00109] The system (100) as described may provide several potential benefits in industrial axial fan applications. The use of CFRP material may result in lighter blades, potentially reducing the overall weight of the fan system compared to equivalent metal blades. This weight reduction may lead to lower inertial loads, potentially allowing for larger blade designs or higher rotational speeds without excessive stress on the system components.
[00110] The weight reduction allow the fan to operate at higher rotational speeds without increasing the stress on the hub and bearing systems, potentially increasing airflow capacity without requiring a larger fan diameter.
[00111] The hollow design of the CFRP blades (102) may further contribute to weight reduction while maintaining structural integrity. This design may allow for improved performance without compromising durability, a crucial factor in demanding industrial environments such as refineries.
[00112] In conclusion, the combination of advanced materials, optimized geometry, and specialized manufacturing techniques in this CFRP blade system offers the potential for significant improvements in performance, efficiency, and durability in industrial axial fan applications. These improvements could translate into tangible benefits such as reduced energy consumption, lower maintenance requirements, and increased operational flexibility in demanding industrial environments.
[00113] The specific aerofoil profile created by the upper surface (302) and lower surface (304), combined with the extended curved trailing edge (204), may result in enhanced airflow characteristics. In aerodynamics, an aerofoil profile is defined by several key parameters, including the mean camber line, thickness distribution, leading edge radius, and trailing edge angle. The unique combination of these parameters in the CFRP blades (102) may create a highly efficient aerofoil.
[00114] The system (100) may potentially move larger volumes of air more efficiently than conventional fan designs, leading to improved cooling in industrial settings.
[00115] The varying chord length and thickness along the blade, from the shoulder side (208) to the tip side (206), may allow for optimized performance along the entire blade length. This design feature, known as blade tapering, is crucial for aerodynamic efficiency. The chord length variation may have from proportion of 1 to 2 along the blade length, while the thickness may gradually decrease from proportion of 1 to 5 along the blade length.
[00116] This optimization may result in improved efficiency and reduced energy consumption compared to conventional blade designs. The tapered design might allow the blade to maintain a consistent angle of attack along its length, even as the relative air velocity increases from root to tip. This could potentially increase the overall fan efficiency, translating to significant energy savings in large industrial applications.
[00117] The pressure bag moulding technique used in manufacturing the CFRP blades (102) may allow for precise control over the blade geometry and material distribution. This manufacturing method involves placing dry or pre-impregnated carbon fiber layers into a mold, inserting an inflatable bladder, and applying pressure to cure the resin and compact the layers.
[00118] The precision of this technique can be quantified in terms of dimensional tolerances and fiber volume fraction. The pressure bag moulding might achieve dimensional tolerances of ±0.5 mm per meter blade length.
[00119] This manufacturing precision may result in blades with consistent performance characteristics, potentially improving the overall reliability of the fan system. The consistency might be measured in terms of blade-to-blade variation in key performance metrics. For example, the variation in lift coefficient between blades at the same angle of attack might be kept within ±1%, ensuring that all blades contribute equally to the fan's overall performance.
[00120] The system (100) may include additional features that, while not explicitly claimed, may contribute to the overall design and functionality of the CFRP blades (102). A point of maximum camber (308) may be present on each blade, representing the location where the curvature of the aerofoil profile reaches its peak. This point may play a role in determining the blade's lift characteristics. The neck (210) may refer to a transitional region between the blade's main body and the attachment point at the hub, potentially providing structural reinforcement. The collar (212) may be a feature at the base of each blade, possibly serving as an interface between the blade and the hub or contributing to the blade's mounting mechanism. These elements, while not central to the claimed invention, may be part of the comprehensive blade design that supports the claimed features and overall system performance.
[00121] In conclusion, the system (100) for an enhanced airflow industrial axial fan, comprising at least two Carbon Fibre Reinforced Plastic (CFRP) blades (102), may offer a combination of advanced materials, optimized blade geometry, and precision manufacturing. The use of CFRP, a composite material consisting of carbon fibers embedded in a polymer matrix, allows for high strength-to-weight ratios.
[00122] The optimized blade geometry, including features such as the extended curved trailing edge, varying chord length, and thickness distribution, works to maximize aerodynamic efficiency. This optimization might be quantified in terms of the fan's specific speed, a dimensionless parameter that relates flow rate, pressure rise, and rotational speed. A fan with this optimized CFRP blade design might achieve an airflow higher than conventional designs, indicating superior aerodynamic performance.
[00123] These features may work in concert to potentially provide improved performance, efficiency, and durability in demanding industrial applications such as refineries. In such environments, where fans might operate continuously for years, the benefits of the CFRP blade system could be substantial. For example, the system might achieve a 10-15% increase in airflow capacity, a 15-20% reduction in energy consumption, and a 30-40% extension in maintenance intervals compared to conventional fan systems.
[00124] The system (100) may represent a significant advancement in industrial axial fan technology, potentially offering benefits in terms of energy efficiency, operational performance, and long-term reliability. These advancements could translate into tangible benefits for industrial operators. For instance, in a large refinery using more no. of these fans, the cumulative energy savings could amount to hundreds of thousands of kilowatt-hours per year, while the extended maintenance intervals could reduce downtime and associated costs by 20-30% over the system's lifetime.
[00125] In essence, this CFRP blade system represents a holistic approach to fan design, where material science, aerodynamics, and advanced manufacturing techniques converge to create a product that pushes the boundaries of what's possible in industrial air movement technology.
[00126] While considerable emphasis has been placed herein on the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter to be implemented merely as illustrative of the disclosure and not as limitation.

ADVANTAGES OF THE PRESENT DISCLOSURE
[00127] The present disclosure provides a Carbon Fibre Reinforced Plastic (CFRP) blade system for industrial axial fans with the following technical advantages:
[00128] The present disclosure offers enhanced aerodynamic efficiency through an optimized aerofoil profile with a specific combination of upper surface curvature, lower surface shape, and extended curved trailing edge, potentially increasing the lift-to-drag ratio by 15-20% compared to conventional designs.
[00129] The present disclosure enables improved air-moving capacity, potentially allowing a fan to move 10 -12% more cubic meters of air per hour, while consuming 15-20% less power than traditional bladed fans of the same size.
[00130] The present disclosure incorporates a varying chord length and thickness distribution along the blade, optimizing performance across the entire blade span and potentially increasing overall fan efficiency by 5-8 percentage points.
[00131] The present disclosure utilizes a pressure bag moulding technique for blade manufacturing, allowing for precise control of blade geometry with dimensional tolerances of ±0.5 mm per meter blade length.
[00132] The present disclosure employs CFRP material with a specific tensile strength of approximately 361 N·m/kg, compared to 166 N·m/kg for aluminium, enabling significant weight reduction and improved performance.
[00133] The present disclosure allows for larger blade designs or higher rotational speeds due to reduced weight, potentially increasing airflow capacity by 10-15% without increasing stress on hub and bearing systems.
[00134] The present disclosure features a hollow blade design that may reduce blade weight by an additional 20-25% compared to conventional blades.
[00135] The present disclosure offers potential energy savings amounting to hundreds of thousands of kilowatt-hours per year in large industrial applications like refineries, where multiple fans are employed.
[00136] The present disclosure may extend maintenance intervals by 30-40% compared to conventional fan systems, potentially reducing downtime and associated costs by 20-30% over the system's lifetime.
[00137] The present disclosure provides a comprehensive solution for industrial air movement, combining advancements in material science, aerodynamics, and manufacturing techniques to significantly improve performance, efficiency, and durability in demanding industrial applications.
, Claims:CLAIMS
We claim:
1. A system (100) for an enhanced airflow industrial axial fan, the system (100) comprising: at least two Carbon Fibre Reinforced Plastic (CFRP) blades (102), wherein each of the at least two CFRP blades (102) is configured to form a single structure having a varying chord length in a longitudinal direction with a camber in a transverse direction thereof;
wherein each of the at least two CFRP blades (102) comprises:
(i) a leading edge (202) with a defined leading-edge radius;
(ii) an extended curved trailing edge (204);
(iii) a shoulder side (208);
(iv) a tip side (206);
(v) an upper surface (302) with curvature; and
(vi) a lower surface (304);
wherein the upper surface (302) and the lower surface (304) form an aerofoil profile;
wherein the shoulder side (208) is configured with a straight profile;
wherein each of the at least two CFRP blades (102) is hollow;
wherein the at least two CFRP blades (102) are symmetrically arranged with respect to each other on the industrial axial fan;
wherein each of the at least two CFRP blades (102) is configured to generate a pressure differential between the upper surface (202) and the lower surface (204) when powered, resulting in enhanced airflow directed parallel to a hub axis.

2. The system (100) as claimed in claim 1, wherein each of the at least two CFRP blades (102) is further configured such that:
a point of maximum camber (308) of the aerofoil profile is located above 50 % of chord length (310) from the leading edge (202);
the maximum thickness and the varying chord length at the shoulder side (208) gradually decrease towards the tip side (206) of each of the at least two CFRP blades (102).

3. The system (100) as claimed in claim 1, wherein each of the at least two CFRP blades (102) is further configured such that:
a blade thickness at the shoulder side (208) is greater than at other parts of each of the at least two CFRP blades (102);
the shoulder side (208) has a maximum thickness in a range of 3 to 7 percent of the blade length; and
a maximum thickness at the tip side (206) of each of the at least two CFRP blades (100) is in a range of 1 to 2 percent of the blade length.

4. The system (100) as claimed in claim 1, wherein each of the at least two CFRP blades (102) is further configured with:
a pitch angle (θ1) of 2-15 degrees with respect to a plane perpendicular to the hub axis; and
a twist angle (θ2) of not more than 5 degrees along a blade length.

5. The system (100) as claimed in claim 1, wherein each of the at least two CFRP blades (102) is further configured such that an angle made by the extended curved trailing edge (204) with a chord line (310) is not more than 49 degrees.

6. The system (100) as claimed in claim 1 is further configured for manufacturing each of the at least two CFRP blades (102) using carbon and glass fibre reinforcement with a pressure bag moulding technique.

7. The system (100) as claimed in claim 1, wherein each of the at least two CFRP blades (102) is further configured to have:
(a) a varying chord length along the entire blade length, wherein the varying chord length is designed to maintain aerodynamic characteristics of each of the at least two CFRP blades (102);
(b) a leading edge extending along an entire blade length; and
(c) a curved trailing edge extending along the entire blade length.