Online ethylene cooling device for ethylene oligomerization reaction and polymerization reaction

Abstract

The utility model relates to the technical field of ethylene reaction devices, in particular to an on-line ethylene cooling device for ethylene oligomerization reaction and polymerization reaction, which comprises an ethylene cooling mechanism, a jacket reaction kettle and an ethylene flowmeter, a spiral heat exchange pipe is fixedly installed in the cooling shell, and a cold water circulation system is arranged on the outer side of the cooling shell. According to the utility model, a modular design is adopted, the ethylene flow meter, the ethylene cooling mechanism and the jacket reaction kettle are connected in series through the pipeline assembly to form a closed cycle, a cold water system consisting of the small water pump and the ice water storage tank can realize refrigerant circulation only by maintaining low-power operation, and ethylene does not need to be compressed into a liquid state for feeding by using a compressor; the integrated design simplifies the reaction process, reduces the occupied area of equipment, avoids invalid loss of ethylene through accurate cooling, and is suitable for continuous industrial production.

Description

Technical Field

[0001] This utility model relates to the technical field of ethylene reaction equipment, and in particular to an online ethylene cooling device for ethylene oligomerization and polymerization reactions. Background Technology

[0002] The oligomerization and polymerization of ethylene release a large amount of heat of reaction. If this heat of reaction is not removed in time, it will cause problems such as the generation of by-products, catalyst deactivation, and runaway reaction. For example, the patent document with announcement number CN110639459A discloses an apparatus and method for the continuous selective oligomerization of ethylene to prepare 1-octene. It adopts a process of series connection of a batch reactor and a tubular reactor: ethylene is transported to the batch reactor at low temperature and heated and vaporized in the reactor. Part of the ethylene gas is injected into the reaction system through a distributor to participate in the reaction, and another part of the ethylene is vaporized as a heat transfer medium to absorb the heat of reaction and is recycled. However, ethylene must be compressed and cooled to a low temperature to become liquid. But liquefying ethylene is a high-energy-consuming process, which will lead to energy waste. Extremely cold ethylene will also reduce the reaction activity and even change the selectivity of the catalyst.

[0003] In addition, patent document CN101113184A discloses a gas external circulation heat removal method, in which gaseous ethylene, hydrogen and hexane vapors escaping from the polymerization reactor are passed into a condenser, where hexane is condensed by heat exchange, and then separated into gas and liquid phases by a condensate tank. The liquid hexane is pumped back to the polymerization reactor through a condensate pump, achieving the purpose of hexane evaporation and circulation heat removal, thereby avoiding the possibility of local overheating and powder agglomeration. However, the drawback is that the diameter of the polymerization reactor must be set very large, which has a very adverse effect on the manufacturing of the polymerization reactor, the design of the agitator and the polymerization reaction process. Moreover, hexane liquefaction is also a relatively energy-intensive process, which will greatly increase the production cost. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this utility model provides an online ethylene cooling device for ethylene oligomerization and polymerization reactions, which solves the technical problems of large size and energy consumption of external chillers and compressors in existing technologies, and has the advantages of effectively reducing floor space and energy consumption.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution: an online ethylene cooling device for ethylene oligomerization and polymerization reactions, including an ethylene cooling mechanism, a jacketed reactor, and an ethylene flow meter. The ethylene cooling mechanism includes a cooling shell, on which a feed pipe and a discharge pipe are provided. A spiral heat exchange tube is fixedly installed inside the cooling shell. A cold water circulation system is provided on the outside of the cooling shell. A cooling vertical pipe is coaxially arranged inside the cooling shell. The cold water circulation system continuously circulates and delivers ice water into the cooling vertical pipe. During the flow of ethylene in the spiral heat exchange tube, heat exchange occurs between ethylene and the ice water inside the cooling vertical pipe, thereby achieving the cooling of ethylene.

[0006] Preferably, the feed pipe is connected to the lower end of the spiral heat exchanger tube, and the discharge pipe is connected to the upper end of the spiral heat exchanger tube, so that ethylene flows slowly from bottom to top inside the spiral heat exchanger tube.

[0007] Preferably, the spiral heat exchange tube is wound around the outside of the cooling vertical tube. When ethylene flows inside the spiral heat exchange tube, it exchanges heat with the refrigerant circulating inside the cooling vertical tube.

[0008] Preferably, the cold water circulation system consists of a small water pump and an ice water storage tank. During the heat exchange and cooling process, the small water pump automatically circulates and delivers ice water into the interior of the cooling vertical pipe.

[0009] Preferably, pipeline assemblies are provided between the feed pipe and the ethylene flow meter, and between the discharge pipe and the jacketed reactor. Ethylene passes through the pipeline assemblies in sequence through the ethylene flow meter and the ethylene cooling mechanism before entering the interior of the jacketed reactor.

[0010] Preferably, both the cooling vertical pipe and the spiral heat exchange pipe are made of 316 stainless steel, which has excellent thermal conductivity and can ensure cooling efficiency.

[0011] By employing the above technical solution, this utility model provides an online ethylene cooling device for ethylene oligomerization and polymerization reactions, which has at least the following beneficial effects:

[0012] 1. By setting up an ethylene cooling mechanism, this utility model can pre-cool the ethylene during the feeding process, and then combine it with the jacket temperature control of the jacketed reactor to remove heat from the ethylene oligomerization and polymerization reaction. This can control the temperature within a stable range, thereby eliminating the problems of large amounts of polymers and catalyst deactivation caused by local hot spots during the ethylene oligomerization or polymerization reaction.

[0013] 2. This utility model adopts a modular design, which connects the ethylene flow meter, ethylene cooling mechanism and jacketed reactor in series through pipeline components to form a closed loop. The cold water system composed of a small water pump and an ice water storage tank only needs to maintain low power operation to achieve refrigerant circulation. This integrated design simplifies the reaction process, reduces the equipment footprint, and avoids the ineffective loss of ethylene through precise cooling. It does not require an external compressor to press ethylene into a liquid state, which reduces production costs and is suitable for continuous industrial production. Attached Figure Description

[0014] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0016] Figure 2 This is a schematic diagram of the ethylene cooling mechanism in this utility model.

[0017] In the diagram: 1. Ethylene cooling mechanism; 2. Jacketed reactor; 3. Ethylene flow meter; 4. Piping assembly; 101. Cooling shell; 102. Feed pipe; 103. Discharge pipe; 104. Spiral heat exchange tube; 105. Cooling riser; 106. Cold water circulation system. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] Example 1

[0020] The oligomerization and polymerization of ethylene release a large amount of heat. If this heat is not removed in time, it can cause problems such as byproduct generation, catalyst deactivation, and runaway reaction. To address this technical deficiency in existing technologies, such as... Figure 1 and Figure 2As shown, this embodiment proposes an online ethylene cooling device for ethylene oligomerization and polymerization reactions. It can pre-cool ethylene during the feeding process, controlling the temperature within a stable range. The device includes an ethylene cooling mechanism 1, a jacketed reactor 2, and an ethylene flow meter 3. The ethylene cooling mechanism 1 includes a cooling shell 101, with a feed pipe 102 and a discharge pipe 103. A spiral heat exchange tube 104 is fixedly installed inside the cooling shell 101. The feed pipe 102 is connected to the lower end of the spiral heat exchange tube 104, and the discharge pipe 103 is connected to the upper end of the spiral heat exchange tube 104, allowing ethylene to flow slowly from bottom to top inside the spiral heat exchange tube 104. A cold water circulation system 106 is provided on the outside of the cooling shell 101. The cold water circulation system 106 consists of a small water pump and an ice water storage tank. During the heat exchange and cooling process, the small water pump automatically circulates ice water to the cooling vertical pipe 104. Inside the cooling shell 101, a cooling vertical pipe 105 is coaxially arranged. The cold water circulation system 106 continuously circulates and supplies ice water into the cooling vertical pipe 105. During the flow of ethylene in the spiral heat exchange tube 104, it exchanges heat with the ice water inside the cooling vertical pipe 105, thereby cooling the ethylene. The spiral heat exchange tube 104 is arranged around the outside of the cooling vertical pipe 105. When the ethylene flows inside the spiral heat exchange tube 104, it exchanges heat with the refrigerant circulating inside the cooling vertical pipe 105. Pipeline assemblies 4 are provided between the feed pipe 102 and the ethylene flow meter 3, and between the discharge pipe 103 and the jacketed reactor 2. The ethylene passes through the pipeline assembly 4, sequentially through the ethylene flow meter 3 and the ethylene cooling mechanism 1, and then enters the interior of the jacketed reactor 2. Both the cooling vertical pipe 105 and the spiral heat exchange tube 104 are made of 316 stainless steel, which has excellent thermal conductivity and can ensure cooling efficiency.

[0021] As can be seen from the above, during the process of ethylene oligomerization or ethylene polymerization using the jacketed reactor 2, ethylene will first enter the interior of the ethylene flow meter 3 through the pipeline assembly 4, and then enter the interior of the ethylene cooling mechanism 1.

[0022] like Figure 2 As shown, after ethylene enters the ethylene cooling mechanism 1, it enters from the lower end of the spiral heat exchange tube 104 through the feed pipe 102, and then flows out from the upper end of the spiral heat exchange tube 104. After the ethylene flows out, it enters the interior of the jacketed reactor 2 through the discharge pipe 103.

[0023] During this process, the cold water circulation system 106 continuously circulates ice water into the interior of the cooling vertical pipe 105, so that the surface of the cooling vertical pipe 105 is always at a low temperature. Therefore, as the ethylene flows upward through the spiral heat exchange pipe 104, it will exchange heat with the cooling vertical pipe 105, thereby cooling the ethylene.

[0024] This embodiment, by setting up an ethylene cooling mechanism 1, can pre-cool the ethylene during the feeding process. Then, combined with the jacket temperature control of the jacketed reactor 2, it can remove heat from the ethylene oligomerization and polymerization reactions, thus controlling the temperature within a stable range. This eliminates the problem of a large amount of polymer produced due to local hot spots during the ethylene oligomerization or polymerization reaction. Moreover, this embodiment adopts a modular design, connecting the ethylene flow meter 3, the ethylene cooling mechanism 1, and the jacketed reactor 2 in series through the pipeline assembly 4 to form a closed loop. Only a small water pump and an ice water storage tank are needed to maintain low-power operation to achieve refrigerant circulation, without the need for an external compressor to pressurize and liquefy the ethylene. This integrated design simplifies the reaction process, reduces the equipment footprint, and avoids ineffective ethylene loss through precise cooling, making it suitable for continuous industrial production.

[0025] The control method of this utility model is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the field. Since this utility model is mainly used to protect mechanical devices, the control method and circuit connection will not be explained in detail.

[0026] It should be noted that, in this document, relational terms such as "first" and "second" are used only 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 process, method, article, or apparatus.

[0027] Although embodiments of the present 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 present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An online ethylene cooling device for ethylene oligomerization and polymerization reactions, comprising an ethylene cooling mechanism (1), a jacketed reactor (2), and an ethylene flow meter (3), characterized in that: The ethylene cooling mechanism (1) includes a cooling shell (101), a feed pipe (102) and a discharge pipe (103) are provided on the cooling shell (101), a spiral heat exchange tube (104) is fixedly installed inside the cooling shell (101), a cold water circulation system (106) is provided on the outside of the cooling shell (101), and a cooling vertical pipe (105) is coaxially provided inside the cooling shell (101).

2. The online ethylene cooling device for ethylene oligomerization and polymerization reactions according to claim 1, characterized in that: The feed pipe (102) is connected to the lower end of the spiral heat exchanger (104), and the discharge pipe (103) is connected to the upper end of the spiral heat exchanger (104).

3. The online ethylene cooling device for ethylene oligomerization and polymerization reactions according to claim 1, characterized in that: The spiral heat exchange tube (104) is wound around the outside of the cooling vertical tube (105).

4. The online ethylene cooling device for ethylene oligomerization and polymerization reactions according to claim 1, characterized in that: The cold water circulation system (106) consists of a small water pump and an ice water storage tank.

5. The online ethylene cooling device for ethylene oligomerization and polymerization reactions according to claim 1, characterized in that: Pipeline assemblies (4) are provided between the feed pipe (102) and the ethylene flow meter (3), and between the discharge pipe (103) and the jacketed reactor (2).

6. The online ethylene cooling device for ethylene oligomerization and polymerization reactions according to claim 1, characterized in that: Both the cooling riser (105) and the spiral heat exchanger (104) are made of 316 stainless steel.

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