An experimental apparatus for liquid phase oxidation of cyclohexane

Abstract

The utility model relates to a kind of cyclohexane liquid phase oxidation experimental device, including premixing tank, the premixing tank is by tank body and flange connection in the tank cover on the top of tank body, at least two feed ports with feed valve are equipped on the tank cover, the bottom center of the tank body is equipped with the discharge port with discharge valve, stirring device is equipped in the tank body, the stirring device includes stirring shaft, the top end of the stirring shaft is rotatably connected with tank cover and this end penetrates tank cover and is drivingly connected with the drive mechanism arranged on the top of tank cover outside, detachable protective sleeve is equipped on the middle part of the stirring shaft, the bottom end of the stirring shaft is fixedly connected with several L-shaped stirring rods, the stirring rod is circumferentially spaced distribution in the side of stirring shaft and the outside of horizontal part and the inside and outside of vertical part are all fixed with several stirring branch rods.The utility model can effectively enhance the stirring effect and service life of stirrer, more practical.

Description

Technical Field

[0001] This invention belongs to the field of experimental technology of cyclohexane oxidation, and specifically relates to an experimental apparatus for the liquid-phase oxidation of cyclohexane. Background Technology

[0002] The liquid-phase oxidation of cyclohexane is an experimental process that converts cyclohexane into products such as cyclohexanone or adipic acid through liquid-phase oxidation or catalytic-free oxidation. The process mainly includes raw material preparation, premixing, reaction condition control, catalytic oxidation, and product separation. The experimental apparatus used mainly includes: premixing equipment (premixing tank); reaction equipment (oxidation reactor, circulating pump); separation equipment (flash tank, separator, extraction and washing tower); condensation and control equipment (straight condenser, temperature control equipment); and other auxiliary equipment (gas spray pipe, point vents, quick connectors, etc.). Different combinations of equipment are selected depending on the experimental scale and process requirements. For example, small-scale laboratory tests typically use basic equipment such as straight condenser and magnetic stirrer, while industrial-scale tests require high-efficiency separation equipment such as flash tanks and separators.

[0003] The premixing tank serves to premix cyclohexane and the catalyst. Premixing ensures a stable suspension of the catalyst in cyclohexane, avoiding localized reaction rate differences caused by uneven catalyst distribution. For example, in the liquid-phase catalytic oxidation process to produce cyclohexanone, premixing significantly improves the yield of cyclohexanone. Premixing is typically carried out at room temperature or low temperature through stirring or mechanical mixing. The premixed mixture is then pumped into the oxidation reactor for catalytic oxidation. However, the conventional stirrers used in existing premixing tanks have limited stirring effect, often failing to adequately mix the material at the bottom of the tank, resulting in poor overall premixing quality, which is detrimental to subsequent oxidation reactions. Furthermore, because the stirring shaft needs to be connected to the drive mechanism on the top of the tank cover, the stirring shaft is usually quite long. Longer stirring shafts suffer severe wear and corrosion due to impact from the material during use, leading to cracking and breakage, reducing the lifespan of the stirrer and the efficiency of premixing. These issues need to be addressed. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a cyclohexane liquid phase oxidation experimental device that can effectively enhance the stirring effect and service life of the stirrer, so as to solve the above problems.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a cyclohexane liquid-phase oxidation experimental apparatus, comprising a premixing tank, the premixing tank consisting of a tank body and a tank cover connected to the top of the tank body by a flange, the tank cover having at least two feed ports with feed valves, the bottom center of the tank body having a discharge port with a discharge valve, a stirrer being provided in the tank body, the stirrer including a stirring shaft, the top end of the stirring shaft being rotatably connected to the tank cover and passing through the tank cover and being driven by a drive mechanism located on the top of the tank cover, a protective sleeve being detachably fitted on the middle part of the stirring shaft, and several L-shaped stirring rods being fixedly connected to the bottom end of the stirring shaft, the stirring rods being circumferentially spaced around the stirring shaft, and several stirring support rods being fixedly provided on the outer side of the horizontal part and the inner and outer sides of the vertical part.

[0006] Preferably, positioning blocks are fixed on both the left and right sides of the middle part of the stirring shaft, and a fixing cylinder is sleeved on the middle part of the stirring shaft. The top of the fixing cylinder is closed and can rotate and slide up and down on the stirring shaft, the bottom is open, and the inner side wall is provided with internal threads. The protective sleeve is formed by joining two semi-circular sleeves. A positioning groove is opened on the inner side of the sleeve corresponding to the positioning block, and a flange is fixed on the upper part of the outer side of the sleeve. An external thread is provided on the outer side of the sleeve above the flange. The external threads on the two sleeves after joining are continuous and adapted to the internal threads. The fixing cylinder is threaded onto the upper part of the protective sleeve and its bottom end abuts against the flange.

[0007] Preferably, the sleeve is made of 316L stainless steel and has a foamed aluminum coating on the inner side and a wear-resistant ceramic coating on the outer side.

[0008] Preferably, a sealing gasket is fixed on the mating surface of one sleeve and the other sleeve.

[0009] Preferably, a plurality of rotating handles are fixed on the outer periphery of the fixed cylinder.

[0010] Preferably, it also includes a feed pump, wherein the feed inlet of the feed pump is connected to the discharge outlet.

[0011] The beneficial effects of this invention are as follows: During premixing, cyclohexane and the corresponding catalyst can be fed into the tank through two inlets, and then the agitator is rotated by the drive mechanism for mixing. During the process, the L-shaped stirring rod and its multiple stirring supports achieve efficient and high-quality mixing of the materials. In particular, the stirring supports on the outer side of the horizontal part of the stirring rod ensure effective mixing of the materials at the bottom of the tank, reducing dead zones and significantly improving overall premixing efficiency and quality, which is more conducive to subsequent oxidation reactions. Simultaneously, the protective sleeve on the stirring shaft provides effective protection, reducing direct impact and erosion from the materials, lowering the risk of wear, cracking, or even breakage, thus extending the service life of the entire agitator without affecting the premixing process and ensuring higher premixing efficiency. Furthermore, the detachable flange connection between the tank cover and the tank body, and the detachable connection between the protective sleeve and the stirring shaft, allow for convenient disassembly and replacement of the protective sleeve when it is damaged or fails, ensuring effective protection of the stirring shaft and making it more practical. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the main structure of this utility model; Figure 2 This is a schematic diagram of the main structure of the premix tank of this utility model; Figure 3 This is a schematic diagram of the main structure of the stirrer of this utility model; Figure 4 yes Figure 3 Enlarged structural diagram at point A; Figure 5 This is a schematic diagram of the main structure of the stirring shaft of this utility model; Figure 6 This is a top view of the stirring shaft of this utility model; Figure 7 This is a schematic diagram of the main structure of the protective sleeve of this utility model; Figure 8 This is a top view of the protective sleeve of this utility model.

[0013] In the diagram, the following numbers are used to indicate different components: 1 is the premix tank, 2 is the tank body, 3 is the tank cover, 4 is the feed valve, 5 is the feed port, 6 is the discharge valve, 7 is the discharge port, 8 is the agitator, 9 is the agitator shaft, 10 is the drive mechanism, 11 is the protective sleeve, 12 is the agitator rod, 13 is the agitator support rod, 14 is the positioning block, 15 is the fixing cylinder, 16 is the internal thread, 17 is the sleeve, 18 is the positioning groove, 19 is the flange, 20 is the external thread, 21 is the sealing gasket, 22 is the handle, and 23 is the feed pump. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: like Figures 1 to 8 As shown, a cyclohexane liquid-phase oxidation experimental apparatus includes a premixing tank 1, which consists of a tank body 2 and a tank cover 3 connected to the top of the tank body 2 by a flange. The tank cover 3 is provided with at least two feed ports 5 with feed valves 4, and the bottom center of the tank body 2 is provided with a discharge port 7 with a discharge valve 6. A stirrer 8 is provided in the tank body 2, which includes a stirring shaft 9. The top end of the stirring shaft 9 is rotatably connected to the tank cover 3 and passes through the tank cover 3 and is connected to a drive mechanism 10 located on the top of the tank cover 3. A protective sleeve 11 is detachably fitted on the middle part of the stirring shaft 9, and several L-shaped stirring rods 12 are fixedly connected to the bottom end of the stirring shaft 9. The stirring rods 12 are circumferentially distributed around the stirring shaft 9, and several stirring support rods 13 are fixedly provided on the outer side of the horizontal part and the inner and outer sides of the vertical part. During premixing, cyclohexane and the corresponding catalyst can be fed into the tank 2 through the two feed ports 5, and then the agitator 8 can be rotated by the drive mechanism 10 to mix them. During the process, the L-shaped stirring rod 12 and its multiple stirring support rods 13 can achieve efficient and high-quality mixing of the corresponding materials. In particular, the stirring support rods 13 on the outer side of the horizontal part of the stirring rod 12 can ensure the stirring effect on the materials at the bottom of the tank 2, reduce the stirring dead zone, and thus greatly improve the overall premixing efficiency and premixing quality, which is more conducive to the subsequent oxidation reaction. At the same time, the protective sleeve 11 on the stirring shaft 9 can effectively protect the stirring shaft 9, effectively reduce the direct impact and erosion of the stirring shaft 9 by the materials, reduce the risk of wear, cracking or even breakage of the stirring shaft 9, and thus further improve the service life of the entire agitator 8, without affecting the premixing process, and thus better ensure the premixing efficiency. Furthermore, the detachable flange connection between the tank cover 3 and the tank body 2, and the detachable connection between the protective sleeve 11 and the stirring shaft 9, allow for convenient disassembly and replacement of the protective sleeve 11 when it is damaged or fails, ensuring effective protection for the stirring shaft 9 and making it more practical. The drive mechanism 10 can utilize existing conventional drive motors and other equipment.

[0015] In this embodiment, positioning blocks 14 are fixed on both the left and right sides of the middle of the stirring shaft 9. A fixing cylinder 15 is sleeved on the middle of the stirring shaft 14. The top of the fixing cylinder 15 is closed and can rotate and slide up and down on the stirring shaft 9, the bottom is open, and the inner side wall is provided with internal threads 16. The protective sleeve 11 is formed by joining two semi-circular sleeves 17. The inner side of the sleeve 17 is provided with a positioning groove 18 corresponding to the positioning block 14, and a flange 19 is fixed on the upper part of the outer side of the sleeve 17. An external thread 20 is provided on the outer side of the sleeve 17 above the flange 19. The external threads 20 on the two sleeves 17 after joining are continuous and are adapted to the internal threads 16. The fixing cylinder 15 is threaded onto the upper part of the protective sleeve 11 and its bottom end abuts against the flange 19. When the protective sleeve 11 needs to be replaced, the tank cover 3 can be detached from the tank body 2 using the flange connection while the machine is stopped. Then, rotate the fixing cylinder 15 to unscrew it from the external thread 20 of the protective sleeve 11, thus releasing the threaded connection lock of the protective sleeve 11. Next, remove the two sleeves 17 of the protective sleeve 11 from the stirring shaft 9 to complete the disassembly of the original protective sleeve 11. Then, take the new protective sleeve 11, align the two sleeves 17 with the corresponding positioning blocks 14, and then move the fixing cylinder 15 to the external thread 20 and rotate it until the bottom end of the fixing cylinder 15 abuts against the flange 19, thus completing the installation of the new protective sleeve 11. After that, the tank cover 3 can be installed and the machine can continue to be used. During the premixing process, the locking of the positioning blocks 14 and the threaded connection limit of the fixing cylinder 15 ensure the stable installation of the protective sleeve 11, allowing it to rotate synchronously with the stirring shaft 9 and providing appropriate protection for the stirring shaft 9.

[0016] In this embodiment, the sleeve 17 is made of 316L stainless steel, which has excellent corrosion resistance, ensuring corrosion protection for the stirring shaft 9. The inner side of the sleeve 17 is coated with a foamed aluminum coating, and the outer side is coated with a wear-resistant ceramic coating (not shown in the figure). Both coatings are existing materials. The foamed aluminum coating has excellent damping, shock absorption, and corrosion resistance properties. In addition to further enhancing the corrosion protection of the stirring shaft 9, it also provides a certain degree of buffering and shock absorption protection for the stirring shaft 9, which is more conducive to improving the working stability of the stirring shaft 9, and thus better ensuring the efficiency and quality of premixing. The wear-resistant ceramic coating can ensure impact and wear protection for the stirring shaft 9, thereby improving the service life of the entire stirrer 8.

[0017] In this embodiment, a sealing gasket 21 is fixed on the mating surface of one set of bodies 17 and the other set of bodies 17 to ensure the sealing of the mating when the two sets of bodies 17 are mated to form the whole protective sleeve 11, thus ensuring the protective effect.

[0018] In this embodiment, a plurality of rotating handles 22 are fixed on the outer periphery of the fixed cylinder 15 to facilitate control of the rotation of the fixed cylinder 15.

[0019] In this embodiment, a feed pump 23 is also included. The feed inlet of the feed pump 23 is connected to the discharge outlet 7, and the discharge outlet of the feed pump 23 is connected to the feed inlet of the subsequent oxidation reactor, so that after the premixing is completed, the mixture can be sent to the subsequent oxidation reactor for oxidation reaction through the feed pump 23.

[0020] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A cyclohexane liquid-phase oxidation experimental apparatus, comprising a premixing tank, characterized in that, The premixing tank consists of a tank body and a tank cover connected to the top of the tank body by a flange. The tank cover has at least two feed ports with feed valves. The bottom center of the tank body has a discharge port with a discharge valve. The tank body contains a stirrer, which includes a stirring shaft. The top end of the stirring shaft is rotatably connected to the tank cover and passes through the tank cover, and is driven by a drive mechanism located on the top of the tank cover. A protective sleeve is detachably fitted on the middle part of the stirring shaft. Several L-shaped stirring rods are fixedly connected to the bottom end of the stirring shaft. The stirring rods are circumferentially spaced around the stirring shaft, and several stirring support rods are fixed on the outer side of the horizontal part and the inner and outer sides of the vertical part.

2. The experimental apparatus for the liquid-phase oxidation of cyclohexane according to claim 1, characterized in that, Positioning blocks are fixed on both sides of the middle of the stirring shaft. A fixing cylinder is fitted on the middle of the stirring shaft. The top of the fixing cylinder is closed and can rotate and slide up and down on the stirring shaft. The bottom is open and the inner wall is provided with internal threads. The protective sleeve is formed by joining two semi-circular sleeves. A positioning groove is opened on the inner side of the sleeve corresponding to the positioning block, which is inserted into the corresponding positioning block. A flange is fixed on the upper part of the outer side of the sleeve. An external thread is provided on the outer side of the sleeve above the flange. The external threads on the two sleeves after joining are continuous and adapted to the internal threads. The fixing cylinder is threaded onto the upper part of the protective sleeve and its bottom end abuts against the flange.

3. The experimental apparatus for the liquid-phase oxidation of cyclohexane according to claim 2, characterized in that, The sleeve is made of 316L stainless steel and has a foamed aluminum coating on the inside and a wear-resistant ceramic coating on the outside.

4. The experimental apparatus for the liquid-phase oxidation of cyclohexane according to claim 2, characterized in that, A sealing gasket is fixed on the mating surface between one sleeve and the other sleeve.

5. The experimental apparatus for the liquid-phase oxidation of cyclohexane according to claim 2, characterized in that, Several rotating handles are fixed on the outer periphery of the fixed cylinder.

6. The experimental apparatus for the liquid-phase oxidation of cyclohexane according to claim 1, characterized in that, It also includes a feed pump, the feed inlet of which is connected to the discharge outlet.

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