Manufacturing process of an improved sk static mixer

Abstract

This invention discloses an improved manufacturing process for an SK static mixer, comprising the following steps: S1: raw material processing; S2: die stamping; S3: workpiece clamping; S4: rotary twisting; S5: finished product inspection. This invention relates to the field of static mixer manufacturing technology. This manufacturing process abandons the traditional assembly method of welding section by section, and forms the entire unit in one piece through rotary twisting, eliminating welding joints between mixing units, avoiding material residue and cross-contamination, and reducing the risk of corrosive media erosion of the structure, effectively extending the service life of the equipment. Simultaneously, this process avoids the problem of localized high-temperature thermal deformation caused by section-by-section welding, and can accurately maintain the preset torsion angle of each mixing unit, further improving the stability of the mixing effect. Furthermore, this process reduces the large number of welding and inspection steps required for multi-section welding, simplifies the production process, reduces labor and time costs, improves production efficiency, and reduces manufacturing costs.

Description

Technical Field

[0001] This invention relates to the field of static mixer manufacturing technology, specifically to an improved manufacturing process for an SK static mixer. Background Technology

[0002] The SK-type static mixer, also known as the SK-type single-spiral static mixer, is a static mixing device installed inside a pipeline with no moving parts. It consists of multiple spiral plate units twisted 180° or 270°, with adjacent units rotating in opposite directions (left and right) and arranged alternately within the pipeline. When the fluid passes through the mixer under pressure, it is continuously cut and split by the spiral plates. Through the combined action of rotation and reverse vortices, radial mixing and repeated recombination are achieved, ultimately reaching a homogeneous state at the outlet. The SK-type static mixer is widely used in chemical, petroleum, pharmaceutical, food, and environmental protection industries, and is particularly suitable for low to medium flow rates, high viscosity, and conditions containing impurities.

[0003] Currently, the SK-type static mixers widely used in the existing technology field are mostly manufactured by producing twisted units section by section, and then connecting and assembling these individual sections by welding to construct a complete overall mixer structure. However, this traditional segmented welding manufacturing method has several significant drawbacks. First, because the surface of the SK-type static mixer has multiple welding joints, these welds are prone to retaining processing media during actual use, making it difficult to completely remove residues when switching between different materials. This not only causes cross-contamination between different batches or types of materials, affecting product purity and quality, but may also lead to the long-term accumulation of certain corrosive media that erodes the weld area, thereby weakening structural integrity and shortening the overall service life of the static mixer.

[0004] Secondly, the multi-section welding assembly method places high demands on assembly precision, which is often difficult to achieve in actual production. Slight misalignment or misfitting can easily occur at the docking points between adjacent mixing units. This geometric deviation can interfere with the preset flow path of the fluid in the mixer, change its original trajectory, thereby reducing mixing efficiency and uniformity, and affecting the final mixing effect.

[0005] In addition, the local high temperature generated during the welding process can easily cause thermal deformation, which leads to deviation of the predetermined torsion angle of the mixing unit, further weakening the uniformity and stability of the mixture.

[0006] Meanwhile, this multi-step welding process increases the complexity of the production process, requiring more manual intervention and quality inspection, thus driving up manufacturing costs and time investment. Therefore, existing manufacturing methods have certain limitations in terms of performance reliability, ease of cleaning and maintenance, and long-term durability. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an improved manufacturing process for an SK static mixer. This process solves the problems of existing SK static mixer manufacturing processes, which involve producing each section independently, twisting, and then welding. These processes often result in the welding points being prone to retaining processing media during actual use, making it difficult to control assembly accuracy. Furthermore, the localized high temperatures generated during the welding process can easily cause thermal deformation, and the production process is highly complex.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a manufacturing process for an improved SK static mixer, comprising the following steps: S1: Raw material processing -- Pre-treatment of the metal sheets required for manufacturing the SK static mixer to remove surface oxide scale and oil.

[0009] S2: Die stamping -- The pre-treated metal sheet is placed in a forming die and formed in one step through a stamping process to form a hybrid unit blank with a predetermined torsion angle and spiral structure.

[0010] S3: Workpiece clamping -- Arrange the multiple formed hybrid unit blanks in a predetermined order, and clamp and fix the multiple hybrid unit blanks in the tubular shell by a clamp, so that the torsion directions of two adjacent hybrid unit blanks are opposite and staggered by a predetermined angle.

[0011] S4: Rotary Twisting -- Drive the clamp or tubular shell to rotate, and perform an overall rotational twisting operation on the multiple mixing unit blanks after clamping and fixing, so that the multiple mixing unit blanks form a continuous and uninterrupted spiral mixing pattern in the tubular shell of the SK static mixer.

[0012] S5: Finished product inspection - Check the straightness of the sk static mixer 1 after it has been rotated and twisted to ensure that it can be smoothly inserted into the matching workpiece and meet the production requirements.

[0013] In some embodiments, the pretreatment in step S1 includes pickling to remove rust, alkaline washing to remove oil, high-pressure water rinsing and drying, with the drying temperature at 80-120°C and the drying time at 10-30 minutes.

[0014] In some embodiments, the forming mold in step S2 is a combined precision stamping mold with a stamping pressure of 25-200 tons.

[0015] In some embodiments, the predetermined torsion angle of the spiral plate blank in step S2 is 180° or 270°, and the wall thickness of the spiral plate blank is 0.5-3.2 mm.

[0016] In some embodiments, the torsion directions of adjacent mixed unit blanks in step S3 are opposite and offset by 90°, and the clamp is a mechanical, hydraulic or pneumatic clamping device with a clamping force of 2-10MPa.

[0017] In some embodiments, the rotating twisting operation in step S4 is performed by alternating between leftward and rightward twisting of 180°±5°, with a rotation speed of 5-10 rpm, and the rotating twisting operation is repeated 2-4 times.

[0018] In some embodiments, during the rotational twisting operation in step S4, a protective gas is introduced into the tubular housing to prevent oxidation of the mixing unit blank. The protective gas is an inert gas.

[0019] In some embodiments, after step S4 is completed, the end face of the tubular shell after rotation and twisting is cut to make the end face meet the flatness requirements.

[0020] In some embodiments, the heat treatment in step S5 is to hold at 400-600°C for 1-2 hours and then cool with the furnace, and the surface treatment is sandblasting or pickling passivation.

[0021] In some embodiments, after step S5 is completed, the entire sk static mixer is subjected to a pressure test and a mixing uniformity test, with the pressure for the pressure test being 1.0-5.0 MPa.

[0022] This invention provides an improved manufacturing process for an SK static mixer, which has the following advantages: This manufacturing process abandons the traditional segment-by-segment welding assembly method. It achieves a one-time forming process through integral rotation and twisting, eliminating welding joints between mixing units, avoiding material residue and cross-contamination, and reducing the risk of corrosive media erosion, effectively extending the equipment's service life. The method of integral clamping and fixing followed by integral twisting ensures better relative positional accuracy between mixing units, preventing misalignment between adjacent units, ensuring the fluid flow path conforms to the preset design, and stably guaranteeing mixing efficiency and uniformity. Simultaneously, this process avoids the localized high-temperature thermal deformation problems caused by segment-by-segment welding, precisely maintaining the preset torsion angle of each mixing unit, further improving the stability of the mixing effect. Furthermore, this process reduces the numerous welding and inspection steps required for multi-segment welding, simplifying the production process, reducing labor and time costs, improving production efficiency, lowering manufacturing costs, and enhancing the structural stability of the finished product. It also facilitates cleaning and maintenance, demonstrating significant advantages in performance reliability and long-term durability. Attached Figure Description

[0023] Figure 1 This is a flowchart of the manufacturing process of the present invention.

[0024] Figure 2 This is a finished product diagram of the sk static mixer 1 of the present invention.

[0025] In the diagram: 1. sk static mixer. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1 Please see Figure 1 This invention provides a technical solution: a manufacturing process for an improved SK static mixer, comprising the following steps: S1: Raw material processing -- Pre-treatment of the metal sheets required for manufacturing the SK static mixer to remove surface oxide scale and oil.

[0028] S2: Die stamping -- The pre-treated metal sheet is placed in a forming die and formed in one step through a stamping process to form a hybrid unit blank with a predetermined torsion angle and spiral structure.

[0029] S3: Workpiece clamping -- Arrange multiple mixed unit blanks after forming in a predetermined order, and clamp and fix the multiple mixed unit blanks in the tubular shell by a fixture, so that the torsion directions of two adjacent mixed unit blanks are opposite and staggered by a predetermined angle.

[0030] S4: Rotary Twisting – The driving fixture or tubular shell rotates to perform an overall rotary twisting operation on multiple clamped and fixed mixing unit blanks, causing the multiple mixing unit blanks to form a continuous, uninterrupted spiral mixing pattern within the tubular shell. (e.g., SK static mixer 1) Figure 2 (The sk static mixer shown).

[0031] S5: Finished product inspection - Check the straightness of the sk static mixer 1 after it has been rotated and twisted to ensure that it can be smoothly inserted into the matching workpiece and meet the production requirements.

[0032] The raw material processing in step S1 involves selecting metal plates that meet the manufacturing requirements of the SK static mixer. The metal plates are made of 304 or 316L stainless steel. First, the metal plates are immersed in an acid pickling tank for rust removal. The pickling solution is a mixed solution containing 10-15% nitric acid and 3-5% hydrofluoric acid. The pickling temperature is 30-50℃, and the pickling time is 10-20 minutes. After pickling, the surface acid residue is removed by high-pressure water rinsing. Then, the plates are immersed in an alkaline washing tank for degreasing. The alkaline washing solution is a solution containing 5-8% sodium hydroxide and 2-3% surfactant. The alkaline washing temperature is 60-80℃, and the alkaline washing time is 5-15 minutes. After alkaline washing, the plates are rinsed again by high-pressure water and then sent to a drying oven for drying. The drying temperature is 80-120℃, and the drying time is 10-30 minutes. Finally, the straightness of the entire finished SK static mixer 1, formed after rotation and twisting, is checked to ensure it can be smoothly inserted into the matching workpiece and meets production requirements. The above pretreatment process makes the surface of the metal sheet smooth, oil-free and rust-free, providing good surface quality for subsequent stamping and forming.

[0033] Step S2, die stamping, involves placing the pre-treated metal sheet into a combined precision stamping die. The die includes an upper die and a lower die, with the forming surfaces of both dies having concave and convex profiles matching the spiral structure of the SK mixing unit. The stamping equipment is started, and the stamping pressure is controlled between 50 and 200 tons. Through a single stamping process, the metal sheet is directly pressed into a mixing unit blank with a predetermined torsion angle and spiral structure. In this embodiment, the wall thickness of the mixing unit blank is 0.5-3.2 mm, and the torsion angle of the spiral plate can be 180° or 270°, selected specifically according to the design requirements of the mixer. This single-stamping process results in a dense, weld-free, and internally defect-free mixing unit blank, completely avoiding the heat-affected zone and weld stress concentration problems caused by welding in traditional welding processes.

[0034] Step S3, workpiece clamping, involves arranging the multiple stamped mixing unit blanks from step S2 in a predetermined order to form a complete SK mixer core. The spiral directions of adjacent mixing unit blanks are opposite; one is left-handed, and the adjacent one is right-handed, with the spiral starting angles of adjacent mixing unit blanks offset by 90°. The arranged mixing unit blanks are then sequentially placed into a cylindrical tubular shell. The clamping device is activated. In this embodiment, a hydraulic clamping device is used, where multiple hydraulic jaws synchronously and uniformly apply clamping force from the radial direction to firmly clamp and fix the mixing unit blanks in a predetermined position within the tubular shell cavity. The clamping force of the hydraulic clamping device is controlled between 2-10 MPa to ensure that the mixing unit blanks do not undergo relative displacement during subsequent rotational twisting.

[0035] The rotational knurling in step S4 is as follows: After the workpiece is fixed, start the rotational drive device to drive the fixture or the entire tubular housing to rotate, and perform an overall rotational knurling operation on the clamped and fixed hybrid unit blanks. During the rotational knurling process, the rotational drive device alternately performs a left twist of 180° ± 5° and a right twist of 180° ± 5° according to a predetermined program. The rotational speed for each twist is controlled between 5 - 10 rpm, and the left and right twists are alternately repeated 2 - 4 times. While performing the rotational knurling operation, continuously and steadily introduce an inert gas (such as nitrogen, argon, etc.) into the tubular housing as a protective gas to isolate the air, effectively preventing the surface oxidation of the hybrid unit blanks under the action of high temperature (if any) and torsional force. After the rotational knurling is completed, continuous and unbroken spiral mixing channels are formed in the tubular housing for each hybrid unit blank, and the connection between adjacent hybrid unit blanks is tightly seamless without any welding process. After the rotational knurling is completed, perform end face cutting on the two end faces of the tubular housing to remove the excess material at both ends, so that both end faces meet the predetermined flatness requirement, and the end face flatness is not greater than 0.1 mm.

[0036] The finished product inspection in step S5 is: Inspect the straightness of the overall finished product of the sk static mixer 1 formed after rotational knurling, and detect that it can smoothly pass through the matching workpiece to meet the production requirements.

[0037] At the same time, according to different materials, a finished product treatment can also be added before step S5: Send the entire sk static mixer 1 after rotational knurling and end face cutting into a heat treatment furnace for stress relief annealing. The annealing temperature is 400 - 600 °C, the holding time is 1 - 2 h, and then it is cooled to room temperature with the furnace. After the annealing treatment, perform sandblasting on the inner and outer surfaces of the mixer to remove the tiny burrs and processing marks on the surface, and reduce the surface roughness Ra to within the range of 0.4 - 0.8 μm. After the sandblasting treatment, perform pickling and passivation on all the inner and outer surfaces of the sk static mixer 1 to further improve its corrosion resistance. After the finished product treatment, perform a pressure test on the entire sk static mixer 1. The pressure of the pressure test is 1.0 - 5.0 MPa, and the pressure stabilization time is 15 - 30 min. No leakage during the test is considered qualified; at the same time, perform a mixing uniformity test. Using the unevenness coefficient σX of the liquid-liquid and liquid-solid phases of the detection index ≤ 5% is judged as qualified. Through the above two pressure test and mixing uniformity test, if it is judged as a qualified product, the final cleaning, drying, and packaging processes can be carried out.

[0038] This embodiment is further set that the pretreatment in step S1 includes pickling and rust removal, caustic washing and degreasing, high-pressure water rinsing, and drying. The drying temperature is 80 - 120 °C, and the drying time is 10 - 30 min.

[0039] This manufacturing process abandons the traditional segment-by-segment welding assembly method. It achieves a one-time forming process through integral rotation and twisting, eliminating welding joints between mixing units, avoiding material residue and cross-contamination, and reducing the risk of corrosive media erosion, effectively extending the equipment's service life. The method of integral clamping and fixing followed by integral twisting ensures better relative positional accuracy between mixing units, preventing misalignment between adjacent units, ensuring the fluid flow path conforms to the preset design, and stably guaranteeing mixing efficiency and uniformity. Simultaneously, this process avoids the localized high-temperature thermal deformation problems caused by segment-by-segment welding, precisely maintaining the preset torsion angle of each mixing unit, further improving the stability of the mixing effect. Furthermore, this process reduces the numerous welding and inspection steps required for multi-segment welding, simplifying the production process, reducing labor and time costs, improving production efficiency, lowering manufacturing costs, and enhancing the structural stability of the finished product. It also facilitates cleaning and maintenance, demonstrating significant advantages in performance reliability and long-term durability.

[0040] In this embodiment, the forming mold in step S2 is a combined precision stamping mold with a stamping pressure of 25-200 tons.

[0041] The modular mold consists of two mating mold bases. The inner side of each mold base has a positioning groove that matches the outer contour of the mixing unit. This groove allows multiple mixing unit mandrels to be sequentially inserted into the positioning groove for pre-fixation, preventing movement of the mandrels during stamping and twisting, and ensuring accurate forming position. During stamping, pressure is applied steadily to the entire mixer blank. Combined with the overall rotational twisting process, the overall structure can be formed in one step, eliminating the need for segment-by-segment adjustments.

[0042] Table 1 compares the effects of different stamping pressures on the performance of hybrid unit blanks and finished products.

[0043] Table 1 The preferred value is 112 tons. Under this pressure, the metal sheet undergoes full and uniform plastic flow, ensuring both high-precision replication of the spiral structure and internal density, while avoiding excessive residual stress and surface damage. The finished product achieves an optimal balance in two core indicators: mixing uniformity (σX as low as 1.8%-2.5%) and pressure bearing capacity (100% pass rate across the entire pressure range). It also exhibits strong adaptability to raw materials and economical mold life.

[0044] 25 tons (lower limit): Insufficient pressure leads to "incomplete molding", and the product basically does not meet the requirements for qualified products.

[0045] 200 tons (upper limit): Excessive pressure leads to "overstress" problems. Although the macroscopic performance is qualified, the microscopic residual stress and long-term reliability are inferior to the 112-ton scheme.

[0046] In this embodiment, the predetermined torsion angle of the spiral plate blank in step S2 is 180° or 270°, and the wall thickness of the spiral plate blank is 2.5-3.2mm.

[0047] This thickness range ensures the structural strength of the spiral plate and meets the deformation resistance requirements under mixing conditions, while avoiding excessive wall thickness that would lead to waste of raw materials. It also prevents excessive wall thickness from encroaching on the effective flow space for fluid mixing, ensuring that the mixer's processing efficiency meets design requirements. Combined with the preset torsion angle, it allows the fluid to form a stable turbulent cutting effect when passing through the mixing unit, ensuring that the uniformity of static mixing meets the standards.

[0048] Table 2 shows the effect of different predetermined torsion angles on mixing performance.

[0049] Table 2 For this patented manufacturing process, 270° is the optimal torsion angle, providing the highest mixing efficiency while ensuring molding reliability. 180° is suitable for applications sensitive to pressure drop.

[0050] In this embodiment, the torsion directions of adjacent mixing unit blanks in step S3 are opposite and offset by 90°, and the clamp is a hydraulic or pneumatic clamping device with a clamping force of 2-10MPa.

[0051] This arrangement allows the fluid, after being divided and split by the previous mixing unit, to be further divided and remixed by the next mixing unit, thereby enhancing the turbulent mixing effect, avoiding mixing dead zones, and improving mixing uniformity. The use of hydraulic or pneumatic clamping devices provides a stable and controllable clamping force for the mixing unit mandrel. This pressure range prevents insufficient clamping force from causing displacement of the mixing unit blank during processing, affecting the final assembly accuracy, while also preventing excessive clamping force from deforming the mandrel, ensuring that the processed dimensions meet tolerance requirements.

[0052] Table 3 shows the effect of different clamping forces on the rotational twisting process and the accuracy of the finished product.

[0053] Table 3 6 MPa is the optimal clamping force, balancing fixation reliability and housing geometric accuracy. 2 MPa provides poor positioning, while 10 MPa requires a reinforced housing design.

[0054] In this embodiment, the twisting operation in step S4 is performed by alternating between leftward twisting of 180°±5° and rightward twisting of 180°±5°, with a rotation speed of 5-10 rpm, and the twisting operation is repeated 2-4 times.

[0055] This range of torsion angle and rotation speed allows the spiral torsion surface after the mixing unit is formed to be smoother and more regular, avoiding wrinkles or cracks on the surface of the blank caused by excessive rotation speed. Repeated twisting operation can stabilize the spiral shape and prevent elastic deformation from causing the torsion angle to rebound, ensuring that the torsion accuracy of each mixing unit meets the design requirements and stably achieves the expected fluid turbulence mixing effect.

[0056] Table 4 shows the effect of different rotation speeds on the twisting quality and internal stress of the blank.

[0057] Table 4 7.5 rpm is the optimal rotational speed. 5 rpm provides the best quality but is less efficient; 10 rpm is highly efficient but requires enhanced process monitoring and heat treatment.

[0058] Table 5 shows the effect of different rotational twisting repetitions on the connection strength and continuity of the hybrid unit.

[0059] Table 5 Three rotations are the optimal number of repetitions for the twisting process, achieving seamless connection between the mixed units without additional damage. Two repetitions are insufficient, and four repetitions offer limited benefits and introduce additional stress.

[0060] In this embodiment, it is further configured that during the rotation and twisting operation in step S4, a protective gas is introduced into the tubular shell to prevent oxidation of the mixing unit blank, and the protective gas is an inert gas.

[0061] Inert gases are chemically stable and will not react with the blank material during the heating process. They can form an oxygen-isolated protective layer on the blank surface during the rotary twisting operation, preventing the blank surface from being oxidized and developing defects such as discoloration and pitting at high temperatures. This ensures that the surface quality and structural strength of the mixed unit after molding meet the requirements.

[0062] Table 6 shows the inhibitory effect of different types of protective gas on the oxidation of blanks during the rotary twisting process.

[0063] Table 6 Argon is the optimal protective gas, completely eliminating high-temperature oxidation. Nitrogen is an economical alternative, suitable for general chemical applications. Unprotected operation is strictly prohibited.

[0064] In this embodiment, after step S4 is completed, the end face of the tubular shell after rotation and twisting is cut to make the end face meet the flatness requirements.

[0065] After cutting, ensure that the two end faces of the tubular shell are parallel to each other and perpendicular to the axis of the tubular shell. This facilitates the precise connection and installation of the mixing unit with the flanges at the inlet and outlet ends of the equipment after subsequent processing, avoiding fluid leakage at the connection point due to uneven end faces. At the same time, it ensures that the coaxiality of the mixer after overall installation meets the assembly accuracy requirements, ensuring that the fluid flows stably in the pipe along the preset path.

[0066] In this embodiment, the heat treatment in step S5 is to keep the temperature at 400-600℃ for 1-2 hours and then cool it with the furnace, and the surface treatment is to sandblast or pickling passivation.

[0067] Insulation at 400-600℃ eliminates residual internal stress in the tubular shell and mixing unit blank after rotary twisting, preventing deformation due to stress release during subsequent use. Furnace cooling further evenly releases stress, reducing residual stress levels and improving the overall structural stability of the mixing unit. Sandblasting or pickling passivation removes scale, oil, and processing residue from the outer surface of the tubular shell and the core of the mixing unit, improving surface cleanliness, stress distribution, corrosion resistance, and extending the lifespan of the static mixer.

[0068] Table 7 shows the effects of different heat treatment temperatures and holding times on stress relief and mechanical properties.

[0069] Table 7 A heat treatment regime of 500℃ for 1.5 hours is the optimal choice, which completely eliminates residual stress while avoiding material sensitization. 400℃ is insufficient, and 600℃ is only suitable for low-carbon grades (such as 304L and 316L; 600℃ / 2 hours is not recommended for 304, but is acceptable for 316L).

[0070] In this embodiment, before step S5 is completed, a pressure test and a mixing uniformity test are performed on the entire SK static mixer. The pressure for the pressure test is 1.0-5.0 MPa.

[0071] Pressure testing is primarily used to inspect the weld connection quality and overall pressure resistance of the mixer, identifying welding defects and inadequate sealing, thus preventing leaks and structural cracks during actual pressure operations and ensuring it meets pressure requirements under various working conditions. Mixing uniformity testing, on the other hand, involves introducing multiple fluid media to be mixed and detecting the degree of mixing at the outlet. This verifies whether the static mixer achieves the designed mixing effect. If the test results do not meet performance requirements, the mixing unit can be adjusted and reworked to ensure that every static mixer leaving the factory meets performance standards.

[0072] Table 8 shows the differentiation of finished product quality assessment based on different pressure test pressure levels.

[0073] Table 8 For the seamless, monolithic static mixer manufactured under this patent, 3.0 MPa is the most reasonable standard factory pressure test, as it reliably verifies structural integrity without causing excessive testing. 5.0 MPa is suitable for more stringent testing in special high-pressure applications.

[0074] The following describes a specific embodiment of this application with reference to the accompanying drawings: Through the complete manufacturing process of "raw material processing - mold stamping - workpiece clamping - rotary twisting - finished product processing" described above, the SK static mixer 1 finally manufactured in this embodiment has no welding joints or weld dead corners. Its internal mixing channel is a continuous, smooth, and complete structure. It completely eliminates a series of technical problems caused by traditional welding processes, such as material retention in welds, difficulty in cleaning, welding heat deformation, and assembly misalignment. This significantly improves the service life, mixing uniformity, cleaning convenience, and pressure resistance of the SK static mixer 1. It is especially suitable for industries with high hygiene requirements, such as food and pharmaceutical, as well as precision chemical production scenarios with high requirements for media purity and containing fine impurities and easily clogged materials.

[0075] Example 2 Unlike Embodiment 1, in this embodiment, the forming mold in step S2 is an adjustable combination mold. By changing the mold cavity of different specifications, mixed unit blanks of different specifications (different pipe diameters, different helix angles, and different wall thicknesses) can be produced quickly to meet the personalized needs of different customers and different working conditions. The hydraulic clamping device in step S3 is equipped with an automatic centering mechanism, which can automatically align the central axis of all mixed unit blanks with the central axis of the tubular shell during the clamping process.

[0076] The remaining structure and working principle of this embodiment are the same as those of Embodiment 1, and will not be repeated here.

[0077] Example 3 Unlike Embodiment 1, in this embodiment, step S4, the rotational twisting operation, is carried out in an inert gas protection chamber. Argon gas is introduced into the protection chamber to remove air. After the rotational twisting is completed, the overall structure is subjected to online ultrasonic testing to check for internal defects such as cracks and pores. Step S5, the pressure test and mixing uniformity test, are recorded and permanently stored in the product database or production management system for easy product quality traceability.

[0078] The remaining structure and working principle of this embodiment are the same as those of Embodiment 1, and will not be repeated here.

[0079] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0080] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A manufacturing process for an improved SK static mixer, characterized in that, Includes the following steps: S1: Raw material processing -- Pre-treatment of the metal sheets required for manufacturing the SK static mixer to remove surface oxide scale and oil stains; S2: Die stamping -- The pre-treated metal sheet is placed in a forming die and formed in one step through a stamping process to form a hybrid unit blank with a predetermined torsion angle and spiral structure; S3: Workpiece clamping -- Arrange the multiple mixed unit blanks after forming in a predetermined order, and clamp and fix the multiple mixed unit blanks in the tubular shell by a clamp, so that the torsion directions of two adjacent mixed unit blanks are opposite and staggered by a predetermined angle; S4: Rotary twisting -- drive the clamp or tubular shell to rotate, and perform an overall rotary twisting operation on the multiple mixing unit blanks after clamping and fixing, so that the multiple mixing unit blanks form a continuous and uninterrupted spiral mixing pattern in the tubular shell sk static mixer 1; S5: Finished product inspection - Check the straightness of the sk static mixer 1 after it has been rotated and twisted to ensure that it can be smoothly inserted into the matching workpiece and meet the production requirements.

2. The manufacturing process of the improved SK static mixer according to claim 1, characterized in that, The pretreatment described in step S1 includes pickling to remove rust, alkaline washing to remove oil, high-pressure water rinsing and drying. The drying temperature is 80-120℃ and the drying time is 10-30 minutes.

3. The manufacturing process of the improved SK static mixer according to claim 1, characterized in that, The forming mold mentioned in step S2 is a combined precision stamping mold with a stamping pressure of 25-200 tons.

4. The manufacturing process of the improved SK static mixer according to claim 1, characterized in that, The predetermined torsion angle of the spiral plate blank in step S2 is 180° or 270°, and the wall thickness of the spiral plate blank is 0.5-3.2 mm.

5. The manufacturing process of an improved SK static mixer according to claim 1, characterized in that, In step S3, the torsion directions of adjacent mixed unit blanks are opposite and offset by 90°. The clamp is a mechanical, hydraulic or pneumatic clamping device with a clamping force of 2-10MPa.

6. The manufacturing process of an improved SK static mixer according to claim 1, characterized in that, The twisting operation described in step S4 involves alternating between leftward and rightward twists of 180°±5°, with a rotation speed of 5-10 rpm. The twisting operation is repeated 2-4 times.

7. The manufacturing process of an improved SK static mixer according to claim 1, characterized in that, During the rotational twisting operation described in step S4, a protective gas is introduced into the tubular shell to prevent oxidation of the mixing unit blank. The protective gas is an inert gas.

8. The manufacturing process of an improved SK static mixer according to claim 1, characterized in that, After step S4 is completed, the end face of the tubular shell after rotation and twisting is cut to make the end face meet the flatness requirements.

9. The manufacturing process of an improved SK static mixer according to claim 1, characterized in that, The heat treatment in step S5 is to hold at 400-600℃ for 1-2 hours and then cool it with the furnace. The surface treatment is sandblasting or pickling passivation.

10. The manufacturing process of an improved SK static mixer according to claim 1, characterized in that, After step S5 is completed, a pressure test and a mixing uniformity test are performed on the entire sk static mixer 1. The pressure for the pressure test is 1.0-5.0 MPa.

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