Evaporator for ethylene carbonate rectification

Abstract

The utility model discloses a kind of evaporators for ethylene carbonate rectification, it is related to the technical field of ethylene carbonate rectification.The utility model includes tower body, tower body includes rectification section and distillation section, and fixed pedestal is connected with inside of rectification section and distillation section by bolt, and fixed pedestal inside is connected with tower plate main body by torsion spring, and tower plate bottom is equipped with boss, fixed pedestal side is equipped with liquid fall mouth, and fixed pedestal bottom side is connected with drain tank.The utility model is through the cooperation structure of the tower plate main body and torsion spring, drain tank of being set up can be turned over, can adapt to fluid flow variation, when flow is greater than torsion spring bearing value, tower plate main body turns over and introduces excess liquid into drain tank, and then through liquid level sensor trigger circulation pump and return liquid to corresponding pipeline, avoid liquid flooding phenomenon to occur, guarantee rectification process continuous stability.

Description

Technical Field

[0001] This utility model relates to the field of ethylene carbonate distillation technology, specifically to an evaporator for ethylene carbonate distillation. Background Technology

[0002] Ethylene carbonate (EC) is a core solvent in the electrolyte of new energy lithium-ion batteries. Its purity directly affects the cycle life and safety performance of the battery and it is widely used in new energy, chemical and other fields. Distillation purification is the core process to ensure the purity of ethylene carbonate in the production process. The evaporator is a key piece of equipment in the distillation system, which undertakes the core functions of gas-liquid mass transfer and heat transfer. Its operational stability directly determines the distillation efficiency and product quality.

[0003] Traditional evaporators for ethylene carbonate distillation use a fixed tray structure. When the feed flow rate fluctuates or the operating parameters are adjusted, the fluid flow rate inside the column can easily exceed the tray's load-bearing limit, leading to flooding. Liquid inside the column cannot be discharged through the downcomer in time and accumulates on the tray to form a liquid layer, disrupting the gas-liquid mass transfer balance. This not only reduces distillation efficiency but also causes fluctuations in product purity and may even require shutdown for cleaning, seriously affecting production continuity. Summary of the Invention

[0004] Therefore, the purpose of this utility model is to provide an evaporator for the distillation of ethylene carbonate, so as to solve the technical problems in the background art mentioned above.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an evaporator for ethylene carbonate distillation, comprising a column body, the column body including a rectification section and a stripping section, both the rectification section and the stripping section being connected to a fixed base by bolts, the fixed base being connected to a main body of a column plate by a torsion spring, the bottom of the column plate being provided with a boss, a downcomer being provided on one side of the fixed base, and a drain tank being connected to one side of the bottom of the fixed base.

[0006] Furthermore, a gas delivery pipe is connected to the top of the tower body, a reflux pipe is connected to one side of the upper part of the tower body, a feed pipe is connected to the middle part of the tower body, a gas phase pipe is connected to one side of the lower part of the tower body, and a bottom liquid pipe is connected to one side of the bottom of the tower body.

[0007] By adopting the above technical solution, the gas supply pipe is used to discharge the gaseous products generated by distillation, the reflux pipe realizes the return of part of the gaseous condensate to the distillation section to maintain the gas-liquid balance of the distillation section; the feed pipe is used to transport the ethylene carbonate feed liquid to be distilled, the gas phase pipe introduces the heating gas phase required by the stripping section, and the bottom liquid pipe discharges the bottom liquid of heavy components after distillation. All pipelines work together to realize the material circulation of the distillation system.

[0008] Furthermore, the main body of the tray is a sieve tray, and the main body of the tray is rotatably connected to the fixed base.

[0009] By adopting the above technical solutions, sieve trays can achieve full gas-liquid contact and ensure mass and heat transfer efficiency; the rotating connection design allows the main body of the tray to adaptively rotate under fluid impact, adjust the liquid flow path in time, and cope with flow fluctuations.

[0010] Furthermore, the bottom of the boss is inclined, and the boss is integrally formed with the main body of the tower plate.

[0011] By adopting the above technical solution, the inclined boss can guide the liquid to flow quickly into the drain tank when the main body of the tray is flipped, avoiding the accumulation of liquid at the bottom of the tray. At the same time, the boss and the drain tank work together to limit the angle of the main body of the tray, preventing the main body of the tray from over-flipping (the flipping angle is 0-15 degrees). The one-piece molding structure improves the structural strength and corrosion resistance of the main body of the tray and extends its service life.

[0012] Furthermore, the drain tank is provided with two baffles on one side, and the two baffles are symmetrically distributed at the inlet of the drain tank.

[0013] By adopting the above technical solution, the baffle fits snugly against the edge of the main body of the tray, and can block the edge when the main body of the tray is flipped to prevent liquid from flowing out from the edge; at the same time, it forms a closed flow channel with the main body of the tray to ensure that the liquid flows accurately into the drain tank.

[0014] Furthermore, a drain pipe is connected to one side of the drain tank, and the drain pipe extends through the tower body to the outside.

[0015] By adopting the above technical solution, the drain pipe, as a channel for liquid circulation, can quickly export the excess liquid collected in the drain tank and send it back to the corresponding pipeline through an external circulation pump, thereby realizing the recycling of liquid and avoiding material waste.

[0016] Furthermore, a liquid level sensor is installed inside the drain tank, and the liquid level sensor is a capacitive liquid level sensor.

[0017] By adopting the above technical solution, the capacitive liquid level sensor has the characteristics of high detection accuracy and strong corrosion resistance. It can monitor the liquid level in the drain tank in real time. When the liquid level reaches the preset threshold, it will trigger the circulation pump to start in time, so as to realize the automatic liquid return without manual intervention.

[0018] Furthermore, the fixed base is provided in several groups, and the several groups of fixed bases are equidistant and staggered.

[0019] By adopting the above technical solution, the equidistantly staggered fixed bases can make the gas-liquid contact in the tower more uniform and improve the mass and heat transfer effect; at the same time, multiple sets of tower plates work together to comprehensively cope with flow fluctuations in different areas and avoid local flooding.

[0020] Furthermore, the torsion spring is made of Hastelloy C-276.

[0021] By adopting the above technical solution, Hastelloy C-276 has excellent corrosion resistance and elastic stability, and can adapt to the high temperature and corrosive environment under the distillation conditions of ethylene carbonate, ensuring the long-term stable operation of the torsion spring and accurately controlling the triggering force of the tray flipping.

[0022] Furthermore, the baffle is made of 316 stainless steel, and the contact surface between the baffle and the main body of the tower plate is coated with polytetrafluoroethylene.

[0023] By adopting the above technical solutions, 316 stainless steel ensures the corrosion resistance and structural strength of the baffle, while the polytetrafluoroethylene coating can reduce the coefficient of friction between the baffle and the main body of the tray, reduce wear when the tray is turned over, and at the same time improve the sealing performance and prevent gas phase leakage.

[0024] In summary, the present invention has the following main advantages: 1. This utility model, by setting a rotating tower plate body in conjunction with a torsion spring and a drain tank, can adapt to changes in fluid flow rate. When the flow rate is greater than the torsion spring's withstand value, the tower plate body rotates to guide the excess liquid into the drain tank. Then, the liquid level sensor triggers a circulation pump to return the liquid to the corresponding pipeline, thus avoiding flooding and ensuring a continuous and stable distillation process. 2. This utility model achieves dynamic response and adaptive adjustment of the tray through the design of torsion spring and boss, without the need for external intervention, reducing energy consumption and operational complexity; the polytetrafluoroethylene coating can reduce the friction coefficient between the baffle and the tray body, reduce wear when the tray is turned over, and at the same time improve sealing performance to prevent gas phase leakage. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the cross-sectional structure of the tower body of this utility model; Figure 3 This is a schematic diagram of the bottom structure of the main body of the tower plate of this utility model; Figure 4 This is a schematic cross-sectional view of the fixed base structure of this utility model.

[0026] In the diagram: 1. Tower body; 101. Stripping section; 102. Rectifying section; 103. Gas delivery pipe; 104. Reflux pipe; 105. Feed pipe; 106. Vapor phase pipe; 107. Bottom liquid pipe; 2. Fixed base; 3. Tower plate body; 4. Boss; 5. Torsion spring; 6. Downcomer; 7. Drain tank; 8. Drain pipe; 9. Baffle; 10. Liquid level sensor. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0028] The embodiments of this utility model will be described below based on its overall structure.

[0029] Example 1: An evaporator for the distillation of ethylene carbonate, such as... Figures 1-4 As shown, the column includes a column body 1, which comprises a rectification section 102 and a stripping section 101. Both the rectification section 102 and the stripping section 101 are internally connected to fixed bases 2 via bolts. Inside the fixed bases 2, a column tray body 3 is connected via a torsion spring 5. A boss 4 is provided at the bottom of the column tray. A downcomer 6 is provided on one side of the fixed base 2. A drain tank 7 is connected to one side of the bottom of the fixed base 2. A gas delivery pipe 103 is connected to the top of the column body 1. A reflux pipe 104 is connected to one side of the upper part of the column body 1. A feed pipe 105 is connected to the middle of the column body 1. A vapor phase pipe 106 is connected to one side of the bottom of the column body 1, and a bottom liquid pipe 107 is connected to one side of the bottom of the column body 1. A gas delivery pipe 103 is used to discharge the vapor phase products generated by distillation. A reflux pipe 104 allows part of the vapor phase condensate to be returned to the rectification section 102 to maintain the gas-liquid balance of the rectification section 102. A feed pipe 105 is used to transport the ethylene carbonate feed liquid to be distilled. A vapor phase pipe 106 introduces the heating vapor phase required by the stripping section 101. A bottom liquid pipe 107 discharges the bottom liquid of the heavy components after distillation. All the pipes work together to realize the material circulation of the distillation system.

[0030] See Figure 2 , Figure 3 and Figure 4 In the above embodiments, the main body 3 of the tray is a sieve tray, and the main body 3 of the tray is rotatably connected to the fixed base 2. The sieve tray can achieve full gas-liquid contact and ensure mass and heat transfer efficiency. The rotatable connection design allows the main body 3 of the tray to adaptively rotate under fluid impact, adjust the liquid flow path in time, and cope with flow fluctuations.

[0031] See Figure 3 and Figure 4 In the above embodiment, the bottom of the boss 4 is inclined, and the boss 4 is integrally formed with the tray body 3. The inclined boss 4 can guide the liquid to flow quickly into the drain tank 7 when the tray body 3 is flipped, avoiding the accumulation of liquid at the bottom of the tray. At the same time, the boss 4 and the drain tank 7 cooperate to limit the angle of the tray body 3, preventing the tray body 3 from over-flipping (the flipping angle is 0-15 degrees). The integrally formed structure improves the structural strength and corrosion resistance of the tray body 3 and extends its service life.

[0032] See Figure 2 , Figure 3 and Figure 4In the above embodiment, two baffles 9 are provided on one side of the drain tank 7, and the two baffles 9 are symmetrically distributed at the inlet of the drain tank 7. The baffles 9 are adapted to fit the edge of the main body 3 of the tower plate. When the main body 3 of the tower plate is flipped, it can block its edge to prevent liquid from flowing out from the edge. At the same time, it forms a closed flow channel with the main body 3 of the tower plate to ensure that the liquid flows accurately into the drain tank 7.

[0033] See Figures 1-4 In the above embodiment, a drain pipe 8 is connected to one side of the drain tank 7. The drain pipe 8 extends through the tower body 1 to the outside. As a channel for liquid circulation, the drain pipe 8 can quickly discharge the excess liquid collected in the drain tank 7 and send it back to the corresponding pipeline through an external circulation pump, so as to realize the recycling of liquid and avoid material waste.

[0034] See Figure 4 In the above embodiment, a liquid level sensor 10 is installed inside the drain tank 7. The liquid level sensor 10 is a capacitive liquid level sensor. The capacitive liquid level sensor has the characteristics of high detection accuracy and strong corrosion resistance. It can monitor the liquid level in the drain tank 7 in real time. When the liquid level reaches the preset threshold, it will trigger the circulation pump to start in time to realize automatic liquid return without manual intervention.

[0035] See Figure 1 In the above embodiments, the fixed base 2 is provided in several groups, and the several groups of fixed base 2 are equidistant and staggered. The equidistant and staggered fixed base 2 can make the gas-liquid contact in the tower more uniform and improve the mass transfer and heat transfer effect. At the same time, multiple groups of tower plates work together to comprehensively cope with the flow fluctuations in different areas and avoid local flooding.

[0036] See Figure 4 In the above embodiments, the torsion spring 5 is made of Hastelloy C-276, which has excellent corrosion resistance and elastic stability. It can adapt to the high temperature and corrosive environment under the distillation conditions of ethylene carbonate, ensuring that the torsion spring 5 works stably for a long time and accurately controlling the triggering force of the tray flipping.

[0037] Example 2: To improve sealing performance and prevent gas phase leakage, Example 2 is an improvement on Example 1. (See attached document for details.) Figure 2 , Figure 3 and Figure 4 The baffle 9 is made of 316 stainless steel, and the contact surface between the baffle 9 and the main body of the tower plate 3 is coated with polytetrafluoroethylene. The 316 stainless steel ensures the corrosion resistance and structural strength of the baffle 9, while the polytetrafluoroethylene coating can reduce the coefficient of friction between the baffle 9 and the main body of the tower plate 3, reduce wear when the tower plate is turned over, and at the same time improve the sealing performance and prevent gas phase leakage.

[0038] The implementation principle of this utility model is as follows: During the distillation of ethylene carbonate, the raw material liquid to be purified enters the middle of the column body 1 through the feed pipe 105, and gas-liquid mass transfer and heat transfer occur in the rectification section 102 and the stripping section 101. In the stripping section 101, heated gas phase is introduced through the gas phase pipe 106, causing the heavy components in the liquid to move downwards and be discharged through the bottom liquid pipe 107. In the rectification section 102, the gas phase rises, and after condensation at the top of the column, part of it is refluxed through the reflux pipe 104 to maintain the gas-liquid balance in the column. The purified gas phase product is discharged through the gas delivery pipe 103. When the feed flow rate fluctuates or the operating parameters are adjusted, causing the fluid flow rate in the column to be too large, the impact force of the fluid on the main body 3 of the column plate exceeds the bearing capacity of the torsion spring 5, and the column... The tray body 3 rotates and flips around the fixed base 2 (angle 0-15 degrees). At this time, the baffle 9, which is attached to the edge of the tray body 3, blocks its edge to prevent liquid from flowing out. At the same time, it forms a flow channel with the tray body 3. Under the guidance of the inclined boss 4, excess liquid flows precisely into the drain tank 7. When the liquid in the drain tank 7 reaches the preset height, the liquid level sensor 10 detects the liquid level signal and transmits it to the external control system, triggering the external circulation pump to start. The liquid in the drain tank 7 is discharged through the drain pipe 8. The drain pipe 8 of the rectification section 102 sends the liquid back to the reflux pipe 104, and the drain pipe 8 of the stripping section 101 sends the liquid back to the feed pipe 105, realizing liquid recycling. When the fluid flow rate in the column returns to the normal range, the elastic force of the torsion spring 5 drives the tray body 3 to reset. The liquid flows normally through the downcomer 6 on one side of the fixed base 2, continuing gas-liquid mass transfer, effectively avoiding flooding and ensuring a stable and efficient rectification process.

[0039] Although embodiments of the present invention have been shown and described, these specific embodiments are merely explanations of the present invention and are not intended to limit the invention. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions, and variations to the embodiments as needed without departing from the principles and spirit of the present invention, provided that such modifications, substitutions, and variations are within the scope of the claims of the present invention and are protected by patent law.

Claims

1. An evaporator for ethylene carbonate distillation, comprising a column body (1), characterized in that: The tower body (1) includes a rectification section (102) and a stripping section (101). The rectification section (102) and the stripping section (101) are both connected to a fixed base (2) by bolts. The fixed base (2) is connected to the main body of the tower plate (3) by a torsion spring (5). The bottom of the tower plate is provided with a boss (4). The fixed base (2) is provided with a downcomer (6) on one side. The bottom side of the fixed base (2) is connected to a drain tank (7).

2. The evaporator for ethylene carbonate distillation according to claim 1, characterized in that: The top of the tower body (1) is connected to a gas delivery pipe (103), the upper side of the tower body (1) is connected to a return pipe (104), the middle part of the tower body (1) is connected to a feed pipe (105), the lower side of the tower body (1) is connected to a gas phase pipe (106), and the bottom side of the tower body (1) is connected to a bottom liquid pipe (107).

3. The evaporator for ethylene carbonate distillation according to claim 1, characterized in that: The main body of the tower plate (3) is a sieve-type tower plate, and the main body of the tower plate (3) is rotatably connected to the fixed base (2).

4. The evaporator for ethylene carbonate distillation according to claim 1, characterized in that: The bottom of the boss (4) is inclined, and the boss (4) is integrally formed with the tower plate body (3).

5. An evaporator for ethylene carbonate distillation according to claim 1, characterized in that: The drain tank (7) is provided with two baffles (9) on one side, and the two baffles (9) are symmetrically distributed at the inlet of the drain tank (7).

6. An evaporator for ethylene carbonate distillation according to claim 1, characterized in that: The drain tank (7) is connected to a drain pipe (8) on one side, and the drain pipe (8) extends through the tower body (1) to the outside.

7. An evaporator for ethylene carbonate distillation according to claim 1, characterized in that: The drain tank (7) is equipped with a liquid level sensor (10), and the liquid level sensor (10) is a capacitive liquid level sensor.

8. An evaporator for ethylene carbonate distillation according to claim 1, characterized in that: The fixed base (2) is provided in several groups, and the several groups of fixed bases (2) are equidistant and staggered.

9. An evaporator for ethylene carbonate distillation according to claim 1, characterized in that: The torsion spring (5) is made of Hastelloy C-276.

10. An evaporator for ethylene carbonate distillation according to claim 5, characterized in that: The baffle (9) is made of 316 stainless steel, and the contact surface between the baffle (9) and the main body of the tower plate (3) is coated with polytetrafluoroethylene.

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