Improved structure of mixing machine for PVA production

Abstract

This invention discloses an improved structure for a mixer used in PVA production, relating to the field of chemical equipment technology. It solves the technical problem of uneven mixing in the upper left mixer of a hydrolysis machine, which affects PVA yield and quality. The invention includes a casing and a mixing unit. The mixing unit is used to mix the materials within the casing and includes a drive motor, a rotating shaft, an inner distribution disc, an outer distribution disc, a stirring element, and a multi-segment collecting cone. The inner and outer distribution discs are installed inside the casing, near the top, with the outer distribution disc covering the inner distribution disc. The drive motor is installed at the center of the top of the casing. This invention utilizes counter-clockwise centrifugal force to achieve dynamic balance of the originally eccentric rotating shaft during high-speed rotation. Simultaneously, the angle of the mixer blades is adjusted to ensure uniform mixing of materials before entering the hydrolysis machine, thereby improving equipment utilization. The improved mixer achieves an operating rate of 96% per day.

Description

Technical Field

[0001] This invention relates to the field of chemical equipment technology, and specifically to an improved structure of a mixer for PVA production. Background Technology

[0002] The mixer is one of the key pieces of equipment for controlling the alcoholysis reaction in the PVA production process. Through the outer and inner distribution discs at the top of the mixer, the resin and liquid alkali are dispersed and flow downwards between the three-stage impeller and the collecting cone fixed on the casing. They are homogenized and mixed evenly between the high-speed rotating three-stage impeller and the collecting cone fixed on the casing, and then enter the double-helix alcoholysis machine.

[0003] To improve production efficiency and equipment utilization, mixer A and mixer B are currently symmetrically installed above the alcoholysis machine. Figure 1 As shown, the two mixers are used alternately. When one mixer needs maintenance or cleaning, the other mixer can continue to be used for production, thus ensuring uninterrupted production and improving efficiency. Mixers A and B are used for 3-4 hours each time, and both mixers A and B rotate clockwise. The blades of the three-section impellers in mixers A and B are angled at a 45-degree angle from right to left, perpendicular to the centerline. Figure 2 (As shown).

[0004] Because the feeding section between mixer B and the alcoholysis machine is tilted to the lower right, and the three-section paddles inside mixer B push the material closer to the lower left position during clockwise rotation, and because the rotating shaft inside the mixer is long, it is prone to eccentricity under the centrifugal force of high-speed rotation, resulting in uneven mixing of the material inside mixer B. This affects the subsequent alcoholysis reaction effect, the operating rate and utilization rate of the mixer, and consequently the output and quality of PVA. Summary of the Invention

[0005] The purpose of this invention is to provide an improved structure for a mixer used in PVA production, which solves the problem of uneven mixing in the upper left mixer of the alcoholysis machine, which affects the yield and quality of PVA.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] An improved structure for a PVA production mixer includes a housing and a mixing unit. The mixing unit is used to mix materials inside the housing. The mixing unit includes a drive motor, a rotating shaft, an inner distribution disc, an outer distribution disc, a stirring element, and multiple collecting cones. The inner and outer distribution discs are installed inside the housing near the top of the housing. The outer distribution disc covers the inner distribution disc. The drive motor is installed at the center of the top of the housing. The output end of the drive motor is connected to the top of the rotating shaft via a coupling. The drive motor is used to drive the rotating shaft to rotate counterclockwise. The multiple collecting cones are installed at equal intervals from top to bottom on the inner wall of the housing. The stirring element is fixedly installed on the rotating shaft.

[0008] The mixing component includes a delivery paddle and multiple mixing paddles. The delivery paddle and the mixing paddle have the same structure. The delivery paddle is fixedly installed at the bottom end of the rotating shaft, and the multiple mixing paddles are fixedly installed on the shaft wall of the rotating shaft from top to bottom.

[0009] The mixing paddle includes a bushing and multiple blades. The bushing is fixedly mounted on a rotating shaft, and the multiple blades are evenly welded to the outside of the bushing. The rotation angle of the blades from left to right is perpendicular to the center line of the bushing.

[0010] As a further aspect of the present invention: the number of blades on the outer side of the bushing is four, and the blades are 81mm long, 33mm wide, and 5mm thick.

[0011] As a further aspect of the present invention: the mixing paddle, the delivery paddle, and the collecting cone are all made of stainless steel, and the mixing paddle is specifically composed of three sections.

[0012] As a further aspect of the present invention: a first feed pipe and a second feed pipe are respectively installed on the side wall near the top of the housing, and a left feed valve and a right feed valve are respectively installed on the first feed pipe and the second feed pipe.

[0013] As a further aspect of the present invention: the left feed valve is used to add liquid alkali into the machine housing in proportion and distribute it through the inner distribution plate; the right feed valve is used to add resin into the machine housing in proportion and distribute it through the outer distribution plate.

[0014] As a further aspect of the present invention: a feeding section is installed at the discharge port at the bottom of the casing, the feeding section being used to introduce the mixed material into the alcoholysis machine for alcoholysis reaction.

[0015] As a further aspect of the present invention: the collecting cone is specifically composed of four segments, each consisting of two inclined semicircular rings, with an inner diameter of φ105mm and an outer diameter of φ340mm. The distance between two adjacent collecting cones is 65mm, and the distance between the mixing paddle located below the collecting cone and the collecting cone is 20mm.

[0016] As a further aspect of the present invention: the operating speed of the drive motor, the rotating shaft and the stirring component is 1400 m / min, and the driving motor runs for 5 to 6 hours each time.

[0017] The beneficial effects of this invention are:

[0018] 1. In this invention, the rotating shaft inside the housing is driven to rotate counterclockwise by a drive motor. At the same time, the angle of the blades on the mixer's discharge paddle and the multi-stage mixing paddle is adjusted. The original 45-degree angle from right to left, which is perpendicular to the center line, is changed to a 45-degree angle from left to right, which is perpendicular to the center line. This allows the originally eccentric rotating shaft to reach a dynamic balance state during rotation, which facilitates the uniform mixing of materials into the alcoholysis machine, effectively increasing the material throughput and thus improving the yield and quality of PVA.

[0019] 2. In this invention, by extending the usage time of the mixer from 3-4 hours before the technical upgrade to 5-6 hours after the technical upgrade, the frequency of mixer switching during PVA production is reduced, and the utilization rate and operating rate of the mixer are improved, so that the operating rate of the mixer reaches 96% / day. Attached Figure Description

[0020] The invention will now be further described with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the connection between the alcoholysis machine and mixers A and B in the prior art;

[0022] Figure 2 This is a schematic diagram of the structure of a three-section impeller in a mixer in the prior art;

[0023] Figure 3 This is a schematic diagram of an improved structure of a mixer for PVA production according to the present invention;

[0024] Figure 4 This is a schematic diagram of the connection between the blade and the bushing in an improved structure of a mixer for PVA production according to the present invention.

[0025] Figure 5 This is a perspective view of the mixing paddle in an improved structure of a PVA production mixer according to the present invention.

[0026] In the diagram: 1. Casing; 2. Drive motor; 3. Rotating shaft; 4. Inner distribution disc; 5. Outer distribution disc; 6. Agitator; 61. Feeding paddle; 62. Mixing paddle; 621. Bushing; 622. Paddle blade; 7. Collecting cone; 8. Left feed valve; 9. Right feed valve; 10. Discharge section. Detailed Implementation

[0027] 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.

[0028] Please see Figure 1-5 As shown, the present invention is an improved structure of a mixer for PVA production, including a housing 1 and a mixing unit. The mixing unit is used to mix the materials inside the housing 1. The mixing unit includes a drive motor 2, a rotating shaft 3, an inner distribution plate 4, an outer distribution plate 5, a stirring element 6, and a multi-stage collecting cone 7. The inner distribution plate 4 and the outer distribution plate 5 are installed inside the housing 1 and near the top of the housing 1. The outer distribution plate 5 covers the inner distribution plate 4. A first feed pipe and a second feed pipe are respectively installed on the side wall of the housing 1 near the top. A left feed valve 8 and a right feed valve 9 are respectively installed on the first feed pipe and the second feed pipe. The left feed valve 8 is used to add liquid alkali into the housing 1 in proportion and distribute it through the inner distribution plate 4. The right feed valve 9 is used to add resin into the housing 1 in proportion and distribute it through the outer distribution plate 5.

[0029] The drive motor 2 is installed at the top center of the casing 1. The output end of the drive motor 2 is connected to the top of the rotating shaft 3 through a coupling. The drive motor 2 is used to drive the rotating shaft 3 to rotate counterclockwise. The stirring component 6 is fixedly installed on the rotating shaft 3. The operating speed of the drive motor 2, the rotating shaft 3 and the stirring component 6 is 1400 m / min. The counterclockwise rotation makes it easy for the originally eccentric rotating shaft 3 to reach a dynamic balance state during rotation, which facilitates the uniform mixing of materials into the alcoholysis machine. The drive motor 2 runs for 5 to 6 hours each time, extending the usage time of the mixer from 3 to 4 hours before the technical improvement to 5 to 6 hours after the technical improvement. This reduces the frequency of mixer switching during PVA production, improves the utilization rate and operating rate of the mixer, and makes the mixer operating rate reach 96% / day.

[0030] The mixing component 6 includes a delivery paddle 61 and a multi-section mixing paddle 62. The delivery paddle 61 and the mixing paddle 62 have the same structure. The delivery paddle 61 is fixedly installed at the bottom end of the rotating shaft 3. The multi-section mixing paddle 62 is fixedly installed on the shaft wall of the rotating shaft 3 from top to bottom. The mixing paddle 62 is specifically divided into three sections. The rotating mixing paddle 62 and the delivery paddle 61 facilitate the mixing of materials in the casing 1. At the same time, the rotating delivery paddle 61 facilitates the discharge of the mixed materials.

[0031] The mixing paddle 62 includes a bushing 621 and multiple blades 622. The bushing 621 is fixedly mounted on the rotating shaft 3. The multiple blades 622 are evenly welded to the outside of the bushing 621. There are four blades 622 on the outside of the bushing 621. The blades 622 are 81mm long, 33mm wide, and 5mm thick. The blades 622 rotate 45 degrees from left to right and are perpendicular to the center line of the bushing 621. Together with the counterclockwise rotating shaft 3, this facilitates the uniform mixing of materials into the alcoholysis machine. A discharge section 10 is installed at the discharge port at the bottom of the casing 1. The discharge section 10 is used to guide the mixed materials into the alcoholysis machine for alcoholysis reaction. In addition, by optimizing the alkali molar ratio, adjusting the alcoholysis machine speed (increasing the reduction ratio of the alcoholysis machine reducer from 1:35 to 1:23), and the alcoholysis reaction temperature, the equipment operating rate and material throughput can be effectively improved without increasing equipment investment, thereby increasing PVA production.

[0032] The multi-segment collecting cones 7 are installed equidistantly from top to bottom on the inner wall of the housing 1. The collecting cones 7 are specifically four segments, which are located below the inner distribution plate 4. The four collecting cones 7 are respectively distributed above the three mixing paddles 62 and the delivery paddle 61. The mixing paddle 62 located below the collecting cones 7 is 20mm away from them to facilitate thorough mixing of the materials. The collecting cones 7 are composed of two semi-circular rings inclined at 60 degrees. The inner diameter of the collecting cones 7 is φ105mm and the outer diameter is φ340mm. The distance between two adjacent collecting cones 7 is 65mm. The mixing paddle 62, the delivery paddle 61 and the collecting cones 7 are all made of 304 stainless steel to improve their corrosion resistance and wear resistance.

[0033] The working principle of this invention is as follows: Liquid alkali is added to the casing 1 through the left feeding valve 8 in a specific ratio and distributed diffusely by the inner distribution plate 4. Resin is added to the casing 1 through the right feeding valve 9 in a specific ratio and distributed diffusely by the outer distribution plate 5. The liquid alkali and resin flow downwards between the stirring element 6 and the multi-segment collecting cone 7 fixed on the casing 1. The drive motor 2 is started to drive the rotating shaft 3 and the stirring element 6 to rotate counterclockwise at high speed, so that the liquid alkali and resin added to the casing are homogeneously mixed between the high-speed rotating stirring element 6 and the collecting cone 7 fixed on the casing. The material processed by the mixer is fed into the alcoholysis machine through the feeding section 10 for alcoholysis reaction to generate PVA for the next process. To avoid the high-speed rotation of the rotating shaft 3 and the stirring element 6 causing deviation... The centrifugal force of the mixer affects the dynamic balance of the rotating shaft 3. The angle of the blades 622 on the mixing component 6 of the mixer is adjusted from a 45-degree angle from right to left perpendicular to the center line to a 45-degree angle from left to right perpendicular to the center line. The blades are also controlled to rotate counterclockwise. This allows the eccentric rotating shaft 3 to reach a dynamic balance under the centrifugal force of high-speed rotation. This facilitates the uniform mixing of materials in the casing 1 into the alcoholysis machine, effectively increasing the material throughput and thus increasing PVA production. In addition, the usage time of the drive motor 2 is extended from 3-4 hours before the technical improvement to 5-6 hours after the technical improvement, reducing the frequency of mixer switching during PVA production and improving the mixer utilization and operating rate, so that the mixer operating rate reaches 96% / day.

[0034] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. An improved structure of a mixer for PVA production, comprising a housing (1) and a mixing unit, wherein the mixing unit is used to mix materials within the housing (1), characterized in that, The mixing unit includes a drive motor (2), a rotating shaft (3), an inner distribution disk (4), an outer distribution disk (5), a stirring component (6), and a multi-segment collecting cone (7). The inner distribution disk (4) and the outer distribution disk (5) are installed inside the housing (1) and near the top of the housing (1). The outer distribution disk (5) covers the inner distribution disk (4). The drive motor (2) is installed at the center of the top of the housing (1). The output end of the drive motor (2) is connected to the top of the rotating shaft (3) through a coupling. The drive motor (2) is used to drive the rotating shaft (3) to rotate counterclockwise. The multi-segment collecting cone (7) is installed at equal intervals from top to bottom on the inner wall of the housing (1). The stirring component (6) is fixedly installed on the rotating shaft (3). The stirring component (6) includes a delivery paddle (61) and a multi-section mixing paddle (62). The delivery paddle (61) and the mixing paddle (62) have the same structure. The delivery paddle (61) is fixedly installed at the bottom end of the rotating shaft (3). The multi-section mixing paddle (62) is fixedly installed on the shaft wall of the rotating shaft (3) from top to bottom. The mixing paddle (62) includes a bushing (621) and multiple blades (622). The bushing (621) is fixedly mounted on the rotating shaft (3). The multiple blades (622) are evenly welded to the outside of the bushing (621). The blades (622) rotate 45 degrees from left to right and are perpendicular to the center line of the bushing (621).

2. The improved structure of a PVA production mixer according to claim 1, characterized in that, The number of blades (622) on the outside of the bushing (621) is four, and the blades (622) are 81mm long, 33mm wide and 5mm thick.

3. The improved structure of a PVA production mixer according to claim 1, characterized in that, The mixing paddle (62), the delivery paddle (61) and the collecting cone (7) are all made of 304 stainless steel, and the mixing paddle (62) is specifically composed of three sections.

4. The improved structure of a PVA production mixer according to claim 1, characterized in that, The first feed pipe and the second feed pipe are respectively installed on the side wall near the top of the housing (1), and the left feed valve (8) and the right feed valve (9) are respectively installed on the first feed pipe and the second feed pipe.

5. An improved structure of a PVA production mixer according to claim 4, characterized in that, The left feed valve (8) is used to add liquid alkali into the housing (1) in proportion and distribute it through the inner distribution plate (4). The right feed valve (9) is used to add resin into the housing (1) in proportion and distribute it through the outer distribution plate (5).

6. The improved structure of a PVA production mixer according to claim 1, characterized in that, A feeding section (10) is installed at the discharge port at the bottom of the casing (1). The feeding section (10) is used to introduce the mixed material into the alcoholysis machine for alcoholysis reaction.

7. The improved structure of a PVA production mixer according to claim 1, characterized in that, The collecting cone (7) is specifically composed of four segments. The collecting cone (7) is composed of two semi-circular rings inclined at 60 degrees. The inner diameter of the collecting cone (7) is φ105mm and the outer diameter is φ340mm. The distance between two adjacent collecting cones (7) is 65mm. The distance between the mixing paddle (62) located below the collecting cone (7) and the collecting cone (7) is 20mm.

8. An improved structure of a PVA production mixer according to claim 1, characterized in that, The operating speed of the drive motor (2), the rotating shaft (3) and the stirring component (6) is 1400 m / min, and the driving motor (2) runs for 5 to 6 hours each time.

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