Preparation process of suspension insulator blank

Abstract

The invention discloses a preparation process of a suspension insulator blank. The preparation process comprises the following steps: preparing mixed slurry; squeezing mud, and dehydrating the mixed mud at constant pressure until mud cakes are formed; rough refining: transporting the mud cake to a mud cutting machine for cutting; aging, namely aging the green body; performing vacuum pugging, namely performing vacuum pugging on the green body to enable the green body to be in a round roller shape; the method comprises the following steps: carrying out constant-pressure dehydration treatment on the slurry through a filter press so as to enable the difference between the surface humidity and the internal humidity of the green body to be + / -0.2%, pressing the slurry for 8 hours by the filter press under the pressure of 8-10N, and arranging a conveying belt below the filter press. According to the preparation process of the suspension insulator green body, each step is tightly matched from mud squeezing to rough refining to aging, so that the subsequent glazing and firing quality of the green body is guaranteed, the performance and stability of the suspension insulator are favorably improved, and meanwhile, the production efficiency and the yield are also favorably improved.

Description

Technical Field

[0001] The invention relates to the technical field of insulators, in particular to a preparation process of a suspension insulator blank. Background Art

[0002] Composite insulators are key components in the field of modern power transmission. They mainly include core rods, umbrella sleeves and end fittings. The core rod is the core load-bearing part, which is often made of glass fiber reinforced resin. It has excellent strength and rigidity and can effectively bear various mechanical forces such as conductor weight and wind load. The umbrella sleeve is mostly made of high-insulation polymer materials such as silicone rubber, which tightly wraps the core rod. On the one hand, it provides reliable external insulation performance for the composite insulator, and on the other hand, it protects the core rod from erosion by the external environment. At the same time, the creepage distance is increased through a specific shape design to meet the requirements of different voltage levels. The end fittings are generally made of metal and are responsible for firmly connecting the composite insulator to the tower and the conductor to ensure the stable operation of the entire transmission line.

[0003] According to a processing technology of a suspension insulator blank disclosed in Patent Application No. 2023114095843, it relates to the field of insulator production technology, including S1: ball milling mixing, quantitatively proportioning the raw materials according to a predetermined ingredient list, adding pre-made proportions of materials, balls and water into a ball mill, and then adding a water reducer corresponding to the quantitative ingredients into the ball mill; S2: ball milling control, ball milling each ingredient in the ball mill, controlling the ball milling fineness and passing through a 180-mesh sieve, and then placing it in a magnetic separation barrel for magnetic separation and iron removal to obtain a prepared mud; S3: aging treatment, placing the prepared mud in a slurry extraction and mud squeezing device to squeeze it into a mud cake and seal it for aging; S4: bar making, using a mud kneading machine to extrude the aged mud cake into a test bar of a predetermined shape and size, and then drying the test bar in the shade until it turns white and then placing it in an oven to dry it to a moisture content of less than 1.5% to obtain a blank. The finished product fired by the processing technology of the present invention has a smooth glaze surface without glaze defect, glaze accumulation, glaze sticking, crystallization and uneven color.

[0004] In the processing process of the above-mentioned suspension insulator blank, the blank in a mud cake state is placed in an aging chamber for aging, and the surface of the blank is sealed. The blank in such a state cannot reduce the moisture content of the mud cake in the aging chamber, and the uniformity of the mud cake and moisture cannot be guaranteed, which will lead to a decrease in the yield and delay the delivery time. Summary of the invention

[0005] The object of the present invention is to provide a process for preparing a suspension insulator blank to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a preparation process of a suspension insulator blank, comprising the following steps:

[0007] S1: preparing mixed mud;

[0008] S2: Squeezing mud, dehydrating the mixed mud at a constant pressure until a mud cake is formed;

[0009] S3: rough smelting, transporting the mud cake to a mud cutter for cutting;

[0010] S4: aging, aging treatment of the blank;

[0011] S5: vacuum kneading, vacuum kneading the clay to make the green body into a round roll shape;

[0012] S6: Perform subsequent operations on the blank until glazing and firing.

[0013] Preferably, the step S1 is to perform constant pressure dehydration treatment on the slurry by a filter press so that the difference between the surface humidity and the internal humidity of the green body is plus or minus 0.2%.

[0014] Preferably, the filter press presses the slurry for at least eight hours at a pressure of 8-10N.

[0015] Preferably, a conveyor belt is provided below the filter press for delivering the green body after constant pressing to the mud cutter for rough cutting.

[0016] Preferably, the step S2 is to press the mud cake-shaped blank into a long strip.

[0017] Preferably, the rough-refined green bodies are stacked by a stacking robot located on one side of the mud cutter.

[0018] Preferably, the blanks are stacked on a support frame, and air holes are provided on the support frame to prevent the bottom blank from being in close contact with the support frame, resulting in inconsistent moisture content of the blanks.

[0019] Preferably, the blanks are stacked vertically and horizontally, and there are gaps between the blanks on the same plane to reduce the contact area between the blanks.

[0020] Preferably, the blanks are stacked on a support frame, and air holes are provided on the support frame to prevent the bottom blank from being in close contact with the support frame, resulting in inconsistent moisture content of the blanks.

[0021] Preferably, the aging in step S3 requires placing the stacked blanks in an aging chamber for 72 hours to make the moisture in the blanks uniform.

[0022] Preferably, before vacuum mud kneading in step S4, the moisture content of the green body is ensured to be 19%-21%.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The preparation process of the suspension insulator blank uses a specific mud squeezing step and a filter press to treat the mud at a constant pressure. This can accurately control the humidity of the blank and ensure consistent humidity inside and outside, laying a good foundation for subsequent processes.

[0025] In the preparation process of the suspension insulator blank, in the roughing stage, the mud cutter cuts the mud cake after constant pressure into long strips, and then stacks them with the help of a stacking robot to reduce the contact area, which is conducive to the stable placement and subsequent processing of the blank. At the same time, such stacking enters the aging room, and the stacking of the mud segments entering the aging room must fully consider the loss of surface moisture during the aging process of the mud. Although there are process regulations for the temperature and humidity of the aging room, for the same mud material, if it is stacked, the moisture loss of the outer surface of the pallet mud segment is faster and the penetration is slower, while the moisture loss of the internal mud segment is slower and the penetration is faster. The stacking method of the blank with a gap in a section can avoid the above situation.

[0026] In the preparation process of the suspension insulator blank, the aging step places the stacked blanks in an aging chamber for 72 hours to make the moisture uniform, thereby improving the blank quality.

[0027] The preparation process of the suspension insulator blank, from mud squeezing to rough smelting to aging, each step is closely coordinated to ensure the quality of the subsequent glazing and firing of the blank, which helps to improve the performance and stability of the suspension insulator. At the same time, this process is also conducive to improving production efficiency and yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the process flow of the present invention;

[0029] Figure 2 It is a schematic diagram of the structure of the mud roughing production line of the present invention.

[0030] In the picture: 1. Filter press; 2. Conveyor belt; 3. Mud cutter; 4. Palletizing robot. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1-2 The present invention provides a technical solution: a preparation process of a suspension insulator blank, including ball milling, iron removal by screening and slurry mixing, and further comprising the following steps:

[0033] S1: Mud squeezing. After the mud has completed the meticulous mixing process, it enters the mud squeezing stage. The constant pressure method used in this stage has significant advantages over traditional pressurization and other existing mud squeezing methods. It can carry out comprehensive and in-depth drainage operations on the mud cake, and can accurately ensure that the moisture content of every position of the mud cake from the surface to the core is completely consistent, effectively avoiding quality risks such as the water content of the mud cake being too low due to excessive drainage, but the water content of the inside being too high due to blocked drainage. Through this precise constant pressure operation, the excess water in the mud cake can be properly and efficiently discharged, creating excellent conditions for subsequent processes.

[0034] In this embodiment, the constant pressure drainage process is achieved by an advanced reinforced polypropylene filter press. As the core equipment of the mud squeezing process, the filter press 1 uses the hydraulic principle to implement constant pressure squeezing and drainage of the green body. A special hydraulic station is provided on one side of the filter press. The hydraulic station has an oil pump power of 4KW and a working oil pressure of 25. It provides continuous, stable and strong energy for the filter press 1, ensuring that the filter press 1 stably and accurately applies constant pressure to the green body and ensures that the surface and internal humidity of the green body are consistent. The filter press 1 performs constant pressure treatment on the mud for eight hours at a pressure range of 8-10N. The surface can more efficiently and thoroughly discharge the moisture of the mud cake, leaving no corner where water may accumulate to ensure that the humidity of the mud cake meets the standard. On the other hand, the drainage will not destroy the internal moisture balance of the green body, nor will the moisture distribution of the green body deviate, thereby ensuring the quality and stability of the green body. Moreover, the conveyor belt 2 arranged on the filter press 1 is evenly and reasonably distributed. Its main function is to steadily receive the squeezed mud cake discharged by the filter press 1, and then transport the mud cake to the roughing machine, so as to make full preparations for the subsequent smooth delivery of the green body after constant pressure to the mud cutter 3 for roughing and cutting, thereby ensuring the continuity and stability of the production process.

[0035] S2: Rough sieving. The mud cake after constant pressure treatment is transported to the mud cutter 3, where the rough sieving process is started. Its purpose is to cut the mud cake after constant pressure dehydration by the filter press 1. The mud cake is cut into long strips. The reason for choosing this long strip shape is that it has significant advantages. This shape is convenient for the subsequent palletizing robot 4 to perform palletizing operations. When the mud cake is in the shape of long strips, the palletizing robot 4 can grab it more conveniently. Moreover, the long strips of blanks can be arranged into 3×3 stacking piles during the palletizing process. The blanks after rough sieving are palletized by the palletizing robot 4 located on one side of the mud cutter 3. When the stacked blanks are sent to the aging chamber, it is necessary to fully consider the loss of surface moisture during the aging process. Although the temperature and humidity of the aging room have corresponding process regulations, for the same clay material, if it is densely stacked, the moisture loss rate of the clay segment on the outside of the pallet will be faster, but the moisture penetration rate inside is slower, while the moisture loss rate of the clay segment inside is slower, but the penetration rate is faster. In order to ensure that the moisture of the clay material can have better consistency, a 3×3 stacking method with a certain gap in the middle is selected. When stacking the blanks, the method of horizontal and vertical cross-over should be adopted, and gaps should be ensured between the blanks in the same plane to reduce the contact area between the blanks, so that a certain amount of moisture can be lost during aging, thereby better meeting the process requirements.

[0036] S3: Aging. The stacked blanks are transported to the aging room for aging. Compared with the original aging process, there is no need to seal the blanks. The advantages of this are that, first, the sealing steps of the blanks can be reduced, thereby improving the processing efficiency. Second, it is convenient for the blanks to lose water in the aging room. Compared with the original process, the necessary process is removed, and the workload and difficulty of the upper and lower processes of molding are not increased. Instead, the work efficiency of the next process is improved. Because the moisture content of the clay is lower and more uniform than that of the traditional process, the drying time is shortened and the drying efficiency is improved. XP-120 / 255x320 is shortened from 36h to 24h, XP-210 / 330x550 is shortened from 48h to 36h, etc. The drying cycle is shortened by 1 / 3-1 / 4 of the original. It can mainly allow manufacturers that can achieve automated production to improve production efficiency and reduce energy consumption. Manufacturers that cannot achieve automated production can fully realize automated production of the molding process through the above improvements, because the problem of high cost of automated shade drying equipment has been solved. The improvement of product quality is reflected in the improvement of process qualification rate. Because the moisture content of the mud is uniform, the automated molding repair is basically completed within the same moisture range, and there is no difference in moisture content inside and outside the blank due to multiple handling and the lack of multiple handling. Therefore, the size of the blank is stable and consistent, and the deformation is small. The maximum deviation between products with a diameter within 300mm is ≤1.5mm, and the maximum deviation between products with a diameter within 300-450mm is S3mm. The inspection pass rate of blanks has been increased to over 99.6% (originally 90%), the inspection pass rate of porcelain parts has been increased to over 99.6% (originally 89%), and the electrical inspection pass rate of finished products has reached over 99.3% (originally 98.5%). For aging, the blanks after stacking should be placed in the aging room for 72 hours to make the moisture in the blanks uniform. At the same time, it can also promote the oxidation, hydrolysis and decomposition of residual organic matter in the blanks, produce humic acid, and naturally eliminate bubbles and stress in the blanks, make the moisture uniform, enhance plasticity, and improve molding quality.

[0037] S4: Vacuum clay training. The aged green body is transported to the vacuum clay training machine for vacuum clay training to make it into a round roll shape. First of all, the moisture content of the clay entering the vacuum clay training machine should be controlled to be low, and the moisture control range of the clay should be narrow. It should be suitable for both the moisture content of the clay used for molding and the moisture content of the clay used for repairing. The moisture content of the traditional process is generally 19% to 21%. The moisture content of the clay used in this scheme is *±0.2%, and this moisture content is consistent with both the inside and outside of the clay. The moisture content of the clay after shade drying is low on the outside and high on the inside. Therefore, in terms of moisture consistency alone, its uniformity is better than that of the shade drying process.

[0038] S5: The round roll-shaped body is then subjected to subsequent operations until it is glazed and fired.

[0039] In the preparation process of the suspension insulator blank, the first step is the mud squeezing step. This step uses an advanced reinforced polypropylene filter press, which squeezes and drains the mud blank in a constant pressure manner. This process is based on the hydraulic principle. This constant pressure method has significant advantages over traditional pressurization methods and other existing mud squeezing methods. As the core equipment, the filter press 1 is equipped with a special hydraulic station on one side. The hydraulic station has an oil pump power of 4KW and a working oil pressure of 25, which continuously and stably supplies energy to the filter press 1. The filter press 1 treats the mud at a constant pressure of 8-10N for eight hours. It can perform comprehensive and in-depth drainage operations on the mud cake. Whether it is the surface or the core of the mud cake, it can ensure that its moisture content is completely consistent, thereby effectively avoiding many quality problems, such as the mud cake surface has too low water content due to excessive drainage, while the interior has too high water content due to poor drainage. Through this precise constant pressure operation, not only can the excess water in the mud cake be properly and efficiently discharged, but also extremely good conditions can be created for subsequent process flows. The conveyor belt 2 arranged on the filter press 1 is evenly and reasonably distributed, and its main function is to steadily receive the squeezed mud cake discharged from the filter press 1, and then transport the mud cake to the roughing machine to ensure the continuity and stability of the production process.

[0040] Next is the roughing stage, in which the mud cutter 3 is used to cut the mud cake after the constant pressure treatment of the filter press 1 into strips. The long strips are chosen because this shape is very convenient for the subsequent operation of the stacking robot 4. In the stacking stage, it is necessary to fully consider the loss of moisture on the surface of the blank during the aging process. To address this problem, a specific stacking method is adopted, which can ensure that the moisture of the mud material remains consistent during the aging process, thereby improving the quality of the blank.

[0041] Then comes the aging process, which is different from the original aging process. It does not require the green body to be sealed. There are two major advantages to this. First, it reduces the sealing steps of the green body, thereby improving the efficiency of the entire processing process; second, it facilitates the process of water loss in the green body in the aging chamber, and does not increase the workload and difficulty of the upper and lower processes, but can improve the work efficiency of the subsequent processes. Moreover, since the moisture content of the mud is lower and more uniform than that of the traditional process, the drying time can be shortened, and the drying efficiency has also been significantly improved. For example, the drying time of the XP-120 / 255x320 type product is shortened from the original 36h to 24h, and the XP-210 / 330x550 type product is shortened from the original 48h to 36h, and the drying cycle is shortened by 1 / 3-1 / 4 of the original. For manufacturers who realize automated production, this can improve production efficiency and reduce energy consumption. For manufacturers that originally could not realize automated production, after these improvements, it is possible to realize automated production of the molding process because the problem of high cost of automated shade drying equipment has been solved. In addition, this improvement also improves product quality, which is reflected in the improvement of process qualification rate, more stable and consistent blank size, and reduced deformation. The blank inspection qualification rate has increased from the original 90% to more than 99.6%, the porcelain inspection qualification rate has increased from the original 89% to more than 99.6%, and the finished product electrical inspection qualification rate has increased from the original 98.5% to more than 99.3%. Aging requires the blanks to be placed in the aging room for 72 hours after palletizing to make the moisture in the blanks uniform. At the same time, it can also promote the oxidation, hydrolysis and decomposition of residual organic matter in the blanks, produce humic acid enhancement, naturally eliminate bubbles and stress in the blanks, make the moisture uniform, enhance plasticity, and improve molding quality.

[0042] The last step is vacuum mud kneading, where the aged green body is transported to the vacuum mud kneading machine for processing to make it into a round roll. In this process, the moisture control of the mud entering the vacuum mud kneading machine is strictly required, the moisture should be low and the control range should be narrow. The moisture of the traditional process is generally 19% to 21%, while the moisture of the mud to achieve this solution is 18% ± 0.2% (the data here is only an example and can be adjusted according to actual conditions), and this moisture is consistent with both the inside and outside of the mud, while the moisture of the mud after shade drying is low outside and high inside, so in terms of moisture consistency alone, its uniformity is better than that of the shade drying process.

[0043] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for preparing a suspension insulator blank, characterized in that: The following steps are involved: S1: preparing mixed mud; S2: Squeezing mud, dehydrating the mixed mud at a constant pressure until a mud cake is formed; S3: rough slicing, transporting the mud cake to a mud cutter (3) for cutting; S4: aging, aging treatment of the blank; S5: vacuum kneading, vacuum kneading the clay to make the green body into a round roll shape; S6: Perform subsequent operations on the blank until glazing and firing.

2. The process for preparing a suspension insulator blank according to claim 1, characterized in that: The step S1 is to perform a constant pressure dehydration treatment on the slurry by means of a filter press (1) so that the difference between the surface humidity and the internal humidity of the green body is plus or minus 0.2%.

3. The process for preparing a suspension insulator blank according to claim 2, characterized in that: The filter press (1) presses the slurry for at least eight hours at a pressure of 8-10N.

4. The process for preparing a suspension insulator blank according to claim 2, characterized in that: A conveyor belt (2) is provided below the filter press (1) for conveying the green body after constant pressing to the mud cutter (3) for rough cutting.

5. The process for preparing a suspension insulator blank according to claim 1 or 3, characterized in that: The step S2 is to press the cake-shaped green body into a long strip.

6. The process for preparing a suspension insulator blank according to claim 5, characterized in that: The rough-refined green bodies are stacked by a stacking robot (4) arranged on one side of the mud cutter (3).

7. The process for preparing a suspension insulator blank according to claim 6, characterized in that: The blanks should be stacked crosswise up and down, horizontally and vertically, and there should be gaps between the blanks on the same plane to reduce the contact area between the blanks.

8. The process for preparing a suspension insulator blank according to claim 7, characterized in that: The blanks are stacked on a support frame, and air holes are provided on the support frame to prevent the bottom blank from being in contact with the support frame, resulting in inconsistent moisture content of the blanks.

9. The process for preparing a suspension insulator blank according to claim 1 or 7, characterized in that: The aging in step S3 requires placing the stacked blanks in an aging chamber for 72 hours to make the moisture in the blanks uniform.

10. The process for preparing a suspension insulator blank according to claim 1, characterized in that: Before the vacuum mud kneading in step S4, the moisture content of the green body is ensured to be 19%-21%.

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