Refining device of dioctyl terephthalate

Abstract

The utility model belongs to the technical field of separation devices, and particularly relates to a dioctyl terephthalate refining device which comprises a gas stripping kettle, a plurality of preheaters sequentially connected to the side part of the gas stripping kettle, stirrers horizontally arranged in the preheaters, a gas inlet pipeline connected to the bottom of the gas stripping kettle, and a gas distributor vertically arranged in the gas stripping kettle, the gas inlet pipeline is connected with a gas distributor, an arc-shaped liquid distributor is arranged in the gas stripping kettle, the bottom of the gas stripping kettle is connected with an adsorption tank, a plurality of activated carbon pipes are vertically arranged in the adsorption tank, a reseparator is arranged at the top of the adsorption tank, the bottom of the adsorption tank is connected with a product storage tank, and the top of the gas stripping kettle is connected with a condenser. According to the device disclosed by the utility model, impurities in a dioctyl terephthalate crude product obtained after esterification reaction are removed through gas stripping, so that the purity of dioctyl terephthalate can be improved, and the recovered impurities can be reused.

Description

Technical Field

[0001] This invention belongs to the field of carbocyclic compound technology, specifically relating to a purification apparatus for dioctyl terephthalate. Background Technology

[0002] Dioctyl terephthalate (DOTP) is a high-performance plasticizer. It is a product obtained by the esterification reaction of terephthalic acid and 2-ethylhexanol. It possesses excellent heat resistance, cold resistance, low migration, water resistance, oil resistance, and superior electrical properties. Due to its excellent overall performance, DOTP is widely used in high-performance applications such as wire and cable materials, automotive interiors, high-temperature resistant materials, children's toys, and medical products.

[0003] The refining process of dioctyl terephthalate is a crucial step in its production, directly determining key quality indicators such as the purity, color, acid value, and thermal stability of the final product.

[0004] The purpose of refining is to remove unreacted raw materials, reaction byproducts, catalyst residues, and colored impurities from the esterification products to obtain pure dioctyl terephthalate. Therefore, the refining process requires removing various impurities at the lowest possible temperature and within the shortest possible time using high vacuum and efficient separation methods, while simultaneously preventing oxidation and thermal degradation of the dioctyl terephthalate material throughout the process. Current dioctyl terephthalate refining processes involve complex pretreatment and a heavy burden on subsequent refining processes. Utility Model Content

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is to provide a purification device for dioctyl terephthalate, so as to realize the purification of dioctyl terephthalate and improve the purification efficiency of dioctyl terephthalate.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] The purification apparatus for dioctyl terephthalate of this invention includes a stripping kettle, with several preheaters connected sequentially to the side of the stripping kettle. A stirrer is horizontally arranged inside the preheater. An air inlet pipe is connected to the bottom of the stripping kettle. A gas distributor is vertically arranged inside the stripping kettle, and the air inlet pipe is connected to the gas distributor. An arc-shaped liquid distributor is arranged inside the stripping kettle. An adsorption tank is connected to the bottom of the stripping kettle. Several activated carbon tubes are vertically arranged inside the adsorption tank. A re-distributor is arranged inside the adsorption tank. A product storage tank is connected to the bottom of the adsorption tank. A condenser is connected to the top of the stripping kettle.

[0008] in:

[0009] The gas distributor includes an inlet pipe and several gas nozzles inclinedly arranged on the inlet pipe.

[0010] The height of the gas nozzle at the end furthest from the inlet pipe is lower than the height at the end closest to the inlet pipe.

[0011] The preheater is connected to the liquid distributor.

[0012] The liquid distributor has a higher height in the middle than at the end, and a liquid outlet is provided at the top of the liquid distributor.

[0013] A vacuum pump is installed between the stripping vessel and the condenser.

[0014] The aforementioned preheaters are connected end to end in sequence, and a heating jacket is provided on the outside of each preheater. Each preheater is connected to an exhaust pipe at the top.

[0015] The agitator is arranged in a spiral shape and is fitted into the inner wall of the preheater.

[0016] A material pump is installed between the stripping vessel and the adsorption tank, and a material pump is installed between the stripping vessel and the preheater.

[0017] The resor is located above several activated carbon tubes.

[0018] The beneficial effects of this utility model are:

[0019] This invention removes impurities from crude dioctyl terephthalate (DTP) obtained after esterification by gas stripping, which not only improves the purity of DTP but also allows for the recovery and reuse of impurities. A preheater preheats the esterification reaction solution, and a stirrer improves the mixing degree of the preheated solution during this process. Simultaneously, the solution is transported to the other end of the preheater, enhancing the preheating effect and rate. A liquid distributor evenly sprays the solution upwards, slowing its descent and creating an umbrella-shaped descent path to increase the contact area with the heating gas. The heating gas is dispersed into the stripping vessel via a gas distributor. A vacuum pump ensures rapid discharge of the heating gas after sufficient contact with the solution. The stripped DTP is then adsorbed and guided through an activated carbon tube to obtain DTP. This invention achieves higher purification efficiency and better purification results. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2 This is a schematic diagram of the gas distributor structure of this utility model;

[0022] Figure 3 This is a schematic diagram of the activated carbon tube structure of this utility model;

[0023] In the diagram: 1. Stripping vessel; 2. Adsorption tank; 3. Product storage tank; 4. Preheater; 5. Inlet pipe; 6. Liquid distributor; 7. Agitator; 8. Gas distributor; 9. Condenser; 10. Heating jacket; 11. Redistributor; 12. Activated carbon tube; 13. Vacuum pump; 14. Exhaust pipe; 801. Gas nozzle; 802. Lead pipe. Detailed Implementation

[0024] The embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0025] Example 1

[0026] like Figure 1-3 As shown, the purification apparatus for dioctyl terephthalate of this invention includes a stripping vessel 1, with several preheaters 4 connected sequentially to the side of the stripping vessel 1. A stirrer 7 is horizontally arranged inside the preheater 4. An air inlet pipe 5 is connected to the bottom of the stripping vessel 1. A gas distributor 8 is vertically arranged inside the stripping vessel 1. The air inlet pipe 5 is connected to the gas distributor 8. An arc-shaped liquid distributor 6 is arranged inside the stripping vessel 1. An adsorption tank 2 is connected to the bottom of the stripping vessel 1. Several activated carbon tubes 12 are vertically arranged inside the adsorption tank 2. A re-distributor 11 is arranged inside the adsorption tank 2. A product storage tank 3 is connected to the bottom of the adsorption tank 2. A condenser 9 is connected to the top of the stripping vessel 1.

[0027] The gas distributor 8 includes a lead pipe 802 and a plurality of gas nozzles 801 inclinedly disposed on the lead pipe 802.

[0028] The height of the end of the gas nozzle 801 furthest from the inlet pipe 802 is lower than the height of the end closest to the inlet pipe 802.

[0029] The preheater 4 is connected to the liquid distributor 6.

[0030] The height of the middle part of the liquid distributor 6 is higher than the height of the end part, and the liquid distributor 6 is provided with a liquid outlet at the top.

[0031] A vacuum pump 13 is installed between the stripping vessel 1 and the condenser 9.

[0032] If the preheaters 4 are connected end to end in sequence, a heating jacket 10 is provided on the outside of the preheater 4, and an exhaust pipe 14 is connected to the top of each preheater 4.

[0033] The agitator 7 is arranged in a spiral shape and is fitted to the inner wall of the preheater 4.

[0034] A material pump is installed between the stripping vessel 1 and the adsorption tank 2, and a material pump is installed between the stripping vessel 1 and the preheater 4.

[0035] The resor 11 is located above several activated carbon tubes 12.

[0036] Working principle and process:

[0037] The esterification reaction liquid prepared by the esterification reaction is transported to several preheaters 4 for preheating. The stirrers 7 inside the preheaters 4 can improve the mixing degree of the esterification reaction liquid and improve the preheating efficiency. At the same time, some of the gas carried in the esterification reaction liquid can be discharged from the exhaust pipe 14 to prevent the internal gas pressure from increasing. Then, the preheated esterification reaction liquid is transported to the gas stripping vessel 1 and distributed into uniformly dispersed droplets by the liquid distributor 6. At the same time, heating gas is transported into the gas stripping vessel 1 through the gas inlet pipe 5. The heating gas is dispersed into the gas stripping vessel 1 through the gas distributor 8 and several gas nozzles 80. The inclined setting promotes the blowing of heating gas in all directions and its contact with the droplets, thereby achieving efficient gas carrying. The vacuum pump 13 at the top of the gas stripping vessel 1 can transport the vaporized substances and gases in the gas stripping vessel 1 to the condenser 9 for condensation. The condensed substances can be recycled. The esterification reaction liquid after gas stripping is transported to the adsorption tank 2 and uniformly dispersed by the redistributor 11. Several activated carbon tubes 12 in the adsorption tank 2 can further absorb impurities in the esterification reaction liquid, improving the purification effect of dioctyl terephthalate. Finally, dioctyl terephthalate is transported to the product storage tank 3 for storage.

Claims

1. A purification apparatus for dioctyl terephthalate, comprising a stripping vessel (1), characterized in that, The gas stripping vessel (1) is connected to several preheaters (4) in sequence on the side. A stirrer (7) is horizontally installed inside the preheater (4). An air inlet pipe (5) is connected to the bottom of the gas stripping vessel (1). A gas distributor (8) is vertically installed inside the gas stripping vessel (1). The air inlet pipe (5) is connected to the gas distributor (8). An arc-shaped liquid distributor (6) is installed inside the gas stripping vessel (1). An adsorption tank (2) is connected to the bottom of the gas stripping vessel (1). Several activated carbon tubes (12) are vertically installed inside the adsorption tank (2). A re-distributor (11) is installed inside the adsorption tank (2). A product storage tank (3) is connected to the bottom of the adsorption tank (2). A condenser (9) is connected to the top of the gas stripping vessel (1).

2. The refining apparatus for dioctyl terephthalate according to claim 1, characterized in that, The gas distributor (8) includes a lead pipe (802) and several gas nozzles (801) inclinedly disposed on the lead pipe (802).

3. The refining apparatus for dioctyl terephthalate according to claim 2, characterized in that, The height of the end of the gas nozzle (801) away from the inlet pipe (802) is lower than the height of the end near the inlet pipe (802).

4. The refining apparatus for dioctyl terephthalate according to claim 1, characterized in that, The preheater (4) is connected to the liquid distributor (6).

5. The refining apparatus for dioctyl terephthalate according to claim 1, characterized in that, The height of the middle part of the liquid distributor (6) is higher than the height of the end part, and the liquid distributor (6) has an outlet at the top.

6. The refining apparatus for dioctyl terephthalate according to claim 1, characterized in that, A vacuum pump (13) is installed between the gas stripping vessel (1) and the condenser (9).

7. The refining apparatus for dioctyl terephthalate according to claim 1, characterized in that, If the preheaters (4) are connected end to end in sequence, a heating jacket (10) is provided on the outside of the preheater (4), and an exhaust pipe (14) is connected to the top of each preheater (4).

8. The refining apparatus for dioctyl terephthalate according to claim 1, characterized in that, The agitator (7) is arranged in a spiral shape and is fitted to the inner wall of the preheater (4).

9. The refining apparatus for dioctyl terephthalate according to claim 1, characterized in that, A material pump is installed between the stripping vessel (1) and the adsorption tank (2), and a material pump is installed between the stripping vessel (1) and the preheater (4).

10. The refining apparatus for dioctyl terephthalate according to claim 1, characterized in that, The resor (11) is located above several activated carbon tubes (12).

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