Rectification multistage column

Abstract

The application discloses a rectification multistage tower, which comprises a tower body and a preheater, wherein the tower body comprises a first-stage tower, a second-stage tower, a third-stage tower, a fourth-stage tower and a fifth-stage tower; the first-stage tower, the second-stage tower, the third-stage tower, the fourth-stage tower and the fifth-stage tower are communicated with the preheater through pipelines respectively; the first-stage tower is communicated with the second-stage tower through a pipeline; the second-stage tower is communicated with the third-stage tower through a pipeline; the third-stage tower is communicated with the fourth-stage tower through a pipeline; the fourth-stage tower is communicated with the fifth-stage tower through a pipeline; a first-stage pump is arranged at the lower end of the first-stage tower; a second-stage pump is arranged at the lower end of the second-stage tower; a third-stage pump is arranged at the lower end of the third-stage tower; a fourth-stage pump is arranged at the lower end of the fourth-stage tower; and a fifth-stage pump is arranged at the lower end of the fifth-stage tower. The first-stage tower, the second-stage tower, the third-stage tower, the fourth-stage tower and fifth-stage tower are all square structures and are arranged side by side. The above technical scheme has the advantages of reasonable structure design, compact structure, low height, high heat and mass exchange efficiency, easy maintenance and good practicability.

Description

Technical Field

[0001] This invention relates to the field of distillation column technology, and more specifically to a multi-stage distillation column. Background Technology

[0002] Existing distillation equipment generally uses traditional distillation columns. A search reveals that, for example, Chinese invention patent CN202421311861.7 discloses "a distillation device for hydrogen cyanide, including a column body, a tray structure disposed within the column body, and a spray structure disposed at the top of the column, and also includes a liquid separation structure disposed at the bottom of the column body, wherein the liquid separation structure includes a connecting ring platform fixed to the inner wall of the column body and several first dividing plates fixed within the connecting ring platform, the bottom surface of the first dividing plates not contacting the bottom surface of the column body." Such distillation columns are generally over 20 meters long and have a dispersed layout, requiring high-level construction. Furthermore, existing distillation columns use steam as a heat source and cooling circulating water as a cold source, resulting in high energy consumption costs. Traditional distillation columns, due to their considerable height, are highly susceptible to problems even with slight tilting. This can lead to uneven liquid distribution, wall flow, and reduced heat and mass exchange efficiency. Furthermore, equipment maintenance is difficult, time-consuming, and costly, often requiring the deployment of lifting equipment for repairs.

[0003] Traditional distillation columns require a long time to heat up and undergo total reflux before operation, which wastes both steam and time. In addition, the large heat dissipation area of ​​the traditional distillation column body results in unnecessary steam waste. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a multi-stage distillation column with reasonable structural design, compact structure, low height, high heat and mass exchange efficiency, easy maintenance and good practicality.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a multi-stage distillation column, comprising a column body and a preheater, wherein the column body comprises a primary column, a secondary column, a tertiary column, a quaternary column, and a quinary column, wherein the primary column, secondary column, tertiary column, quaternary column, and quinary column are respectively connected to the preheater via pipelines, the primary column and the secondary column are connected via pipelines, the secondary column and the tertiary column are connected via pipelines, the tertiary column and the quaternary column are connected via pipelines, and the quaternary column and the quinary column are connected via pipelines, wherein a primary pump is installed at the lower end of the primary column, a secondary pump is installed at the lower end of the secondary column, a tertiary pump is installed at the lower end of the tertiary column, a quaternary pump is installed at the lower end of the quaternary column, and a quinary pump is installed at the lower end of the quinary pump, wherein the primary column, secondary column, tertiary column, quaternary column, and quinary column are all square structures and are arranged side by side.

[0006] The present invention is further configured such that: a reboiler is provided on one side of the primary tower, the primary tower and the reboiler are connected by a pipeline, and a wastewater discharge pump is provided at the bottom of the reboiler.

[0007] The invention is further configured such that: automatic valves are respectively installed on the pipelines between the first-stage, second-stage, third-stage, fourth-stage, and fifth-stage towers and the preheater. After the liquid phase material is heated, the automatic valves control the material to enter one of the first-stage, second-stage, third-stage, or fourth-stage towers according to different concentrations. The liquid in the first-stage tower and the liquid in the reboiler are combined and then enter the reboiler through a first-stage pump, where heat exchange occurs through the tubes and refrigerant, generating rising steam. The liquid in the second-stage tower enters the first-stage tower through a second-stage pump and exchanges heat and mass with the rising hot steam in the first-stage tower within the packing. The liquid in the third-stage tower enters the second-stage tower through a third-stage pump and exchanges heat and mass with the rising hot steam in the second-stage tower within the packing. The liquid in the fourth-stage tower enters the third-stage tower through a fourth-stage pump and exchanges heat and mass with the rising hot steam in the third-stage tower within the packing. The liquid in the fifth-stage tower enters the fourth-stage tower through a fifth-stage pump and exchanges heat and mass with the rising hot steam in the fourth-stage tower within the packing. The steam from the top of the fifth-stage tower is introduced into the preheater for heat exchange with the raw material.

[0008] The present invention is further configured such that: a main condenser, a heat balance condenser, a vacuum system, a buffer tank, a finished product cooler, and a qualified product storage tank are provided on one side of the preheater; the main condenser is connected to the preheater via a pipeline; the main condenser is connected to the heat balance condenser via a pipeline; the heat balance condenser is connected to the vacuum system via a pipeline; the heat balance condenser is connected to the buffer tank via a pipeline; the buffer tank is connected to the finished product cooler via a pipeline; the finished product cooler is connected to the qualified product storage tank via a pipeline; the main condenser is connected to the buffer tank via a pipeline; the buffer tank is connected to the five-stage tower via a pipeline; and the five-stage tower is connected to the preheater via a pipeline.

[0009] The present invention is further configured such that: steam and a small amount of liquid phase material are introduced into the main condenser through a preheater via a pipeline; the main condenser introduces a small amount of steam into the heat balance condenser through a ventilation pipeline; the heat balance condenser allows the liquid phase material to flow by gravity into the buffer tank through a pipeline; the liquid in the buffer tank flows back to the finished product cooler through a pipeline; and the qualified liquid phase product at room temperature is introduced into the qualified product storage tank through a pipeline.

[0010] The present invention is further configured such that: each of the first-stage, second-stage, third-stage, fourth-stage, and fifth-stage towers is equipped with a distribution plate and packing. The distribution plate is located at the top of each stage of the tower. The reflux liquid enters the distribution plate from the top of each stage of the tower and is evenly distributed before entering the packing. The liquid phase material that falls after heat and mass exchange at the bottom of each stage of the tower is pumped to the previous stage of the tower as reflux liquid for redistribution, thereby forming components of different concentrations in each stage of the tower, with the lowest concentration in the first stage of the tower.

[0011] The beneficial effects of this invention are as follows: Compared with the prior art, this invention has a reasonable structural design. Each tower section presents a regular matrix, allowing for side-by-side arrangement. Each tower section has a certain volume at its bottom, which is pumped to the top of the next stage tower. A distribution plate is installed at the top of the tower to ensure uniform distribution of the liquid within the packing. This change not only fully realizes all the functions of previous single-stage high-rise towers but also avoids the various drawbacks that occurred during the design, manufacture, and installation of single-stage high-rise towers. It features a compact structure, low height, high heat and mass exchange efficiency, easy maintenance, and good practicality, as specifically demonstrated below: (1) The total height of the equipment of the present invention is within 6m, which can meet the requirements of indoor installation without crossing floors, and can also be installed outdoors without steel frame or building support. The installation cost is greatly reduced. Only cable laying and small steam pipe and circulating water are needed, which can greatly reduce the construction cost of public system.

[0012] (2) This invention can be made into a skid-mounted structure, which is compact and reasonable, with high space utilization, and has passed the commissioning and operation test before leaving the factory. Compared with traditional distillation columns, it can significantly shorten the on-site installation and commissioning time.

[0013] (3) Each tower section of the present invention is independently positioned, which can effectively ensure the verticality of each tower section. Each tower section has a distribution plate for liquid collection and redistribution, thereby improving the packing efficiency.

[0014] (4) Each tower section of the present invention can be repaired independently without the need for lifting equipment.

[0015] (5) Each tower section of the present invention has an independent liquid storage function. When the machine is stopped, the concentration difference of each tower section is still maintained, saving energy consumption costs in the next cycle, while reducing the hot tower and total reflux time when the machine is started.

[0016] (6) Each tower section of the present invention is compact, reducing the external heat dissipation area and reducing energy waste.

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0018] Figure 1 This is a structural illustration of an embodiment of the present invention. Figure 1 ; Figure 2 This is a structural illustration of an embodiment of the present invention. Figure 2 ; Figure 3 This is a top view schematic diagram of an embodiment of the present invention; Figure 4 This is a front view schematic diagram of an embodiment of the present invention; Figure 5 This is a schematic diagram illustrating the principle of an embodiment of the present invention. Detailed Implementation

[0019] In the description of this embodiment, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] See Figures 1 to 5 This invention discloses a multi-stage distillation column, comprising a column body and a preheater 8. The column body includes a primary column 13, a secondary column 14, a tertiary column 15, a quaternary column 16, and a quinary column 17. The primary column 13, secondary column 14, tertiary column 15, quaternary column 16, and quinary column 17 are connected to the preheater 8 via pipes. The primary column 13 is connected to the secondary column 15 via a pipe; the secondary column 14 is connected to the tertiary column 15 via a pipe; the tertiary column 15 is connected to the quaternary column 16 via a pipe; and the quaternary column 16 is connected to the quinary column 17 via a pipe. The towers are connected by pipelines. A primary pump 131 is installed at the lower end of the primary tower 13, a secondary pump 141 is installed at the lower end of the secondary tower 14, a tertiary pump 151 is installed at the lower end of the tertiary tower 15, a quaternary pump 161 is installed at the lower end of the quaternary tower 16, and a quintuplet pump 171 is installed at the lower end of the quintuplet pump 17. All the towers 13, 14, 15, 16, and 17 are square structures and are arranged side by side.

[0021] Preferably, the first-stage tower 13, second-stage tower 14, third-stage tower 15, fourth-stage tower 16, and fifth-stage tower 17 are assembled side-by-side into one unit; the first-stage pump 131, second-stage pump 141, third-stage pump 151, fourth-stage pump 161, and fifth-stage pump 171 are all water pumps. The vacuum system 11 includes a vacuum pump and a water tank.

[0022] Each of the first-stage tower 13, second-stage tower 14, third-stage tower 15, fourth-stage tower 16, and fifth-stage tower 17 is equipped with an independent liquid storage structure. Due to the independent liquid storage function, the concentration difference between each tower section is maintained when the machine is shut down, saving energy consumption costs for the next cycle, while reducing the hot tower and total reflux time during startup.

[0023] To make the structural design of the present invention more reasonable, as a preferred embodiment, a reboiler 5 is provided on one side of the primary tower 13, the primary tower 13 and the reboiler 5 are connected by a pipeline, and a wastewater discharge pump is provided at the bottom of the reboiler 5.

[0024] Automatic valves are installed on the pipelines between the primary tower 13, secondary tower 14, tertiary tower 15, quaternary tower 16, and quinary tower 17 and the preheater 8. After the liquid material is heated, the automatic valves control the flow of the material into one of the primary tower 13, secondary tower 14, tertiary tower 15, or quaternary tower 16 according to different concentrations. The liquid in the primary tower 13 and the liquid in the reboiler 5 are combined and then enter the reboiler 5 through the primary pump 131. Heat exchange is conducted through the tubes and refrigerant to generate rising steam. The liquid in the secondary tower 14 enters the primary tower 13 through the secondary pump 141 and combines with the liquid in the primary tower 13. The rising hot steam in the first stage undergoes heat and mass exchange within the packing. The liquid in the third-stage tower 15 enters the second-stage tower 14 through the third-stage pump 151, and exchanges heat and mass with the rising hot steam in the second-stage tower 14 within the packing. The liquid in the fourth-stage tower 16 enters the third-stage tower 15 through the fourth-stage pump 161, and exchanges heat and mass with the rising hot steam in the third-stage tower 15 within the packing. The liquid in the fifth-stage tower 17 enters the fourth-stage tower 16 through the fifth-stage pump 171, and exchanges heat and mass with the rising hot steam in the fourth-stage tower 16 within the packing. The steam from the top of the fifth-stage tower 17 is introduced into the preheater 8 for heat exchange with the raw material.

[0025] The preheater 8 is equipped with a main condenser 1, a heat balance condenser 9, a vacuum system 11, a buffer tank 10, a finished product cooler 12, and a qualified product storage tank on one side. The main condenser 1 is connected to the preheater 8 via a pipeline. The main condenser 1 is connected to the heat balance condenser 9 via a pipeline. The heat balance condenser 9 is connected to the vacuum system 11 via a pipeline. The heat balance condenser 9 is connected to the buffer tank 10 via a pipeline. The buffer tank 10 is connected to the finished product cooler 12 via a pipeline. The finished product cooler 12 is connected to the qualified product storage tank via a pipeline. The main condenser 1 is connected to the buffer tank 10 via a pipeline. The buffer tank 10 is connected to the five-stage tower 17 via a pipeline. The five-stage tower 17 is connected to the preheater 8 via a pipeline. Steam and a small amount of liquid material are introduced into the main condenser 1 through the preheater 8 via pipeline. The main condenser 1 introduces a small amount of steam into the heat balance condenser 9 through the ventilation pipeline. The heat balance condenser 9 allows the liquid material to flow by gravity into the buffer tank 10 through pipeline. The liquid in the buffer tank 10 flows back to the finished product cooler 12 through pipeline. The qualified liquid product at room temperature is introduced into the qualified product storage tank through pipeline.

[0026] Each of the first-stage tower 13, second-stage tower 14, third-stage tower 15, fourth-stage tower 16, and fifth-stage tower 17 is equipped with a distribution plate and packing. The distribution plate is located at the top of each stage of the tower. The reflux liquid enters the distribution plate from the top of each stage of the tower and is evenly distributed before entering the packing. The liquid phase material that falls after heat and mass exchange at the bottom of each stage of the tower is pumped to the previous stage of the tower as reflux liquid for redistribution, thereby forming components of different concentrations in each stage of the tower, with the lowest concentration in the first stage of the tower.

[0027] The two ends of each of the above-mentioned pipes are fixed by flange connection, welding, or threaded connection.

[0028] This invention presents each tower section in a regular matrix, allowing for side-by-side arrangement. Each section has a specific volume at its bottom, from which liquid is pumped to the top of the next stage. A distribution plate at the top ensures uniform liquid distribution within the packing. This modification not only fully realizes all the functions of previous single-stage high-rise towers but also avoids the various drawbacks of designing, manufacturing, and installing single-stage high-rise towers. The structure is rationally designed, compact, low in height, highly efficient in heat and mass exchange, easy to maintain, and highly practical.

[0029] The specific beneficial effects are as follows: (1) The total height of the equipment of the present invention is within 6m, which can meet the requirements of indoor installation without crossing floors, and can also be installed outdoors without steel frame or building support. The installation cost is greatly reduced. Only cable laying and small steam pipe and circulating water are needed, which can greatly reduce the construction cost of public system.

[0030] (2) This invention can be made into a skid-mounted structure, which is compact and reasonable, with high space utilization, and has passed the commissioning and operation test before leaving the factory. Compared with traditional distillation columns, it can significantly shorten the on-site installation and commissioning time.

[0031] (3) Each tower section of the present invention is independently positioned, which can effectively ensure the verticality of each tower section. Each tower section has a distribution plate for liquid collection and redistribution, thereby improving the packing efficiency.

[0032] (4) Each tower section of the present invention can be repaired independently without the need for lifting equipment.

[0033] (5) Each tower section of the present invention has an independent liquid storage function. When the machine is stopped, the concentration difference of each tower section is still maintained, saving energy consumption costs in the next cycle, while reducing the hot tower and total reflux time when the machine is started.

[0034] (6) Each tower section of the present invention is compact, reducing the external heat dissipation area and reducing energy waste.

[0035] In addition, improvements can be made to the technical solution of this embodiment: for example, the structures of the first-level tower 13, the second-level tower 14, the third-level tower 15, the fourth-level tower 16 and the fifth-level tower 17 can all be set as cylindrical.

[0036] The above description of the specific embodiments of the present invention is only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above description shall fall within the scope of protection of the present invention.

Claims

1. A multi-stage distillation column, comprising a column body and a preheater (8), characterized in that: The tower body includes a primary tower (13), a secondary tower (14), a tertiary tower (15), a quaternary tower (16), and a quinary tower (17). The primary tower (13), secondary tower (14), tertiary tower (15), quaternary tower (16), and quinary tower (17) are connected to the preheater (8) via pipes. The primary tower (13) is connected to the secondary tower (15) via a pipe, the secondary tower (14) is connected to the tertiary tower (15) via a pipe, the tertiary tower (15) is connected to the quaternary tower (16) via a pipe, and the quaternary tower (16) is connected to the quinary tower (17) via a pipe. The primary tower (13), secondary tower (14), tertiary tower (15), quaternary tower (16), and quinary tower (17) are connected to the preheater (8) via pipes. 3) A primary pump (131) is installed at the lower end of the secondary tower (14), a secondary pump (141) is installed at the lower end of the secondary tower (14), a tertiary pump (151) is installed at the lower end of the tertiary tower (15), a quaternary pump (161) is installed at the lower end of the quaternary tower (16), and a quintuplet pump (171) is installed at the lower end of the quintuplet pump (17). The primary tower (13), secondary tower (14), tertiary tower (15), quaternary tower (16), and quintuplet (17) are all square structures, and the primary tower (13), secondary tower (14), tertiary tower (15), quaternary tower (16), and quintuplet (17) are arranged side by side.

2. A multi-stage distillation column according to claim 1, characterized in that: A reboiler (5) is provided on one side of the primary tower (131). The primary tower (13) and the reboiler (5) are connected by a pipeline. A wastewater discharge pump is provided at the bottom of the reboiler (5).

3. A multi-stage distillation column according to claim 2, characterized in that: Automatic valves are installed on the pipelines between the first-stage tower (13), second-stage tower (14), third-stage tower (15), fourth-stage tower (16), and fifth-stage tower (17) and the preheater (8). After the liquid material is heated, the automatic valves control the flow of the material into one of the first-stage tower (13), second-stage tower (14), third-stage tower (15), or fourth-stage tower (16) according to the different concentrations. The liquid in the first-stage tower (13) and the liquid in the reboiler (5) are combined and then enter the reboiler (5) through the first-stage pump (131). Through heat exchange with the refrigerant in the tubes, rising steam is generated. The liquid in the second-stage tower (14) enters the first-stage tower (13) through the second-stage pump (141) and merges with the liquid in the first-stage tower. The rising hot steam in (13) undergoes heat and mass exchange within the packing; the liquid in the third-stage tower (15) enters the second-stage tower (14) through the third-stage pump (151) and undergoes heat and mass exchange with the rising hot steam in the second-stage tower (14) within the packing; the liquid in the fourth-stage tower (16) enters the third-stage tower (15) through the fourth-stage pump (161) and undergoes heat and mass exchange with the rising hot steam in the third-stage tower (15) within the packing; the liquid in the fifth-stage tower (17) enters the fourth-stage tower (16) through the fifth-stage pump (171) and undergoes heat and mass exchange with the rising hot steam in the fourth-stage tower (16) within the packing; the steam from the top of the fifth-stage tower (17) is introduced into the preheater (8) for heat exchange with the raw material.

4. A multi-stage distillation column according to claim 3, characterized in that: The preheater (8) is equipped with a main condenser (1), a heat balance condenser (9), a vacuum system (11), a buffer tank (10), a finished product cooler (12), and a qualified product storage tank on one side. The main condenser (1) is connected to the preheater (8) through a pipeline. The main condenser (1) is connected to the heat balance condenser (9) through a pipeline. The heat balance condenser (9) is connected to the vacuum system (11) through a pipeline. The heat balance condenser (9) is connected to the buffer tank (10) through a pipeline. The buffer tank (10) is connected to the finished product cooler (12) through a pipeline. The finished product cooler (12) is connected to the qualified product storage tank through a pipeline. The main condenser (1) is connected to the buffer tank (10) through a pipeline. The buffer tank (10) is connected to the five-stage tower (17) through a pipeline. The five-stage tower (17) is connected to the preheater (8) through a pipeline.

5. A multi-stage distillation column according to claim 4, characterized in that: Steam and a small amount of liquid material are introduced into the main condenser (1) through the preheater (8) via a pipeline. The main condenser (1) introduces a small amount of steam into the heat balance condenser (9) through a ventilation pipeline. The heat balance condenser (9) allows the liquid material to flow by gravity into the buffer tank (10) through a pipeline. The liquid in the buffer tank (10) flows back to the finished product cooler (12) through a pipeline. The qualified liquid product at room temperature is introduced into the qualified product storage tank through a pipeline.

6. A multi-stage distillation column according to claim 5, characterized in that: Each of the first-stage tower (13), second-stage tower (14), third-stage tower (15), fourth-stage tower (16), and fifth-stage tower (17) is equipped with a distribution plate and packing. The distribution plate is located at the top of each stage of the tower. The reflux liquid enters the distribution plate from the top of each stage of the tower and is evenly distributed before entering the packing. The liquid phase material that falls after heat and mass exchange at the bottom of each stage of the tower is pumped to the previous stage of the tower as reflux liquid for redistribution, so that each stage of the tower forms components of different concentrations, with the lowest concentration in the first stage of the tower.

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