Fatty nitrile rectification apparatus

Abstract

The utility model relates to the technical field of fatty nitrile production, concretely is fatty nitrile rectification device, fatty nitrile rectification device, including raw material storage tank, raw material storage tank is connected with reactor through preheating jar, and reactor is connected with buffer tank through primary reverse filter, and buffer tank is connected with primary rectification tower through backflush filter, and the inside of primary reverse filter is equipped with filter plate, and the below of filter plate is equipped with rotary scraper, the preheating jar coil pipe in the preheating jar of the device is connected with secondary collecting tank through connecting pipeline, and the raw material in preheating jar is preheated using the high temperature condensate of secondary rectification tower discharge, realizes the cyclic utilization of heat.

Description

Technical Field

[0001] This utility model relates to the field of fatty nitrile production technology, specifically to a fatty nitrile distillation apparatus. Background Technology

[0002] Fatty nitriles are an important class of organic chemical intermediates, widely used in surfactants, textile auxiliaries, oilfield chemicals, and other fields. Their distillation process is a crucial step in achieving the separation and purification of fatty nitriles, directly affecting product quality and production efficiency.

[0003] In the existing equipment, before distillation, the reaction products often contain solid impurities such as catalyst particles and polymer residues. The ordinary filtration methods used in the existing equipment are difficult to completely remove fine impurities, causing them to accumulate in the distillation column, block the trays and pipes, increase the system pressure drop, reduce the distillation efficiency, and affect the purity of the product.

[0004] Furthermore, the existing equipment does not preheat the liquid raw materials during feeding. When the outdoor temperature is low (especially in winter), the raw material temperature is low, the feeding rate is slow, and the temperature difference between the raw material and the reactor is large, which will cause severe thermal shock, resulting in temperature fluctuations in the reactor, affecting the reaction rate and product quality stability, and thus reducing the overall production efficiency. Utility Model Content

[0005] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a fatty nitrile distillation device, in which the preheating tank coil inside the preheating tank is connected to the secondary collection tank through a connecting pipe, and the high-temperature condensate discharged from the secondary distillation column is used to preheat the raw material in the preheating tank, thereby realizing the recycling of heat.

[0006] This utility model is achieved using the following technical solution:

[0007] The fatty nitrile distillation apparatus includes a raw material storage tank, which is connected to a reactor via a preheating tank. The reactor is connected to a buffer tank via a primary reverse filter, and the buffer tank is connected to a primary distillation column via a backwash filter. The primary reverse filter has a filter plate inside, and a rotating scraper is located below the filter plate.

[0008] The raw material storage tank is made of stainless steel with a smooth inner wall and is equipped with a level gauge and a stirring device. This prevents the raw material from corroding the tank and ensures the stability of the raw material storage. The stirring device can prevent the raw material from settling and stratifying (in the case of easily settling materials) and ensure uniform feeding. The preheating tank has a jacketed or coiled structure. The preheating tank coil uses spiral stainless steel pipes and is directly connected to the secondary collection tank. The spiral coil increases the heat exchange area and improves the preheating efficiency; it utilizes the waste heat from distillation to preheat the raw material, reducing energy consumption.

[0009] The reactor is connected to a catalyst storage tank, and a magnetic conveying pump is installed between the reactor and the primary reverse filter. The connection between the magnetic conveying pump and the primary reverse filter is located below the filter plate.

[0010] The connection between the buffer tank and the primary backwash filter is located above the filter plate, with the upper edge of the rotating scraper tangent to the lower edge of the filter plate. The backwash filter is equipped with a backwash pipe. The backwash filter can be repeatedly cleaned and reused, reducing filtration costs; the backwash function ensures long-term stable filtration accuracy and maintains the quality of the clear liquid.

[0011] The primary distillation column is connected to the secondary distillation column via a magnetic discharge pump, and the top of the secondary distillation column is connected to the tail gas treatment column via a vacuum pump.

[0012] The first-stage distillation column is connected to a first-stage liquid collection tank, and the second-stage distillation column is connected to a second-stage liquid collection tank.

[0013] The preheating tank is equipped with a preheating tank coil inside, and the secondary liquid collection tank is connected to the preheating tank coil through a connecting pipe.

[0014] Magnetic drive pumps are leak-free pumps driven by magnetic force, avoiding the leakage risks of traditional mechanical seal pumps. They are suitable for conveying flammable, explosive, or toxic fatty nitrile materials, improving production safety.

[0015] The working principle of this utility model is as follows:

[0016] Raw material pretreatment and preheating: Fatty nitrile raw materials are transported from the raw material storage tank to the preheating tank via pipeline. The high-temperature condensate in the secondary collection tank enters the preheating tank coil through the connecting pipeline to indirectly heat the raw materials in the preheating tank, raising the raw material temperature to 30-50℃ to reduce the heat load of subsequent reactions.

[0017] Catalytic reaction: The preheated raw material flows into the reactor, and at the same time, the catalyst is quantitatively added into the reactor from the catalyst storage tank. The catalytic reaction is carried out under stirring conditions. The reaction temperature is controlled at 80-120℃, the pressure is atmospheric pressure to 0.3MPa, and the reaction time is adjusted according to the reaction progress, usually 2-4 hours, so that the raw material is fully converted.

[0018] Multi-stage filtration and impurity removal: After the reaction, the material is pressurized by a magnetic conveying pump and fed into a primary reverse filter from below the filter plate. The material passes through the filter plate from bottom to top, and solid impurities are trapped below the filter plate. A rotating scraper rotates continuously at a speed of 5-10 r / min, scraping off the impurities on the surface of the filter plate and collecting them at the bottom of the filter. The filtered material flows into a buffer tank from above the filter plate. The material in the buffer tank undergoes secondary filtration through a backwash filter with a filtration accuracy of 5-10 μm to further remove fine impurities. The filtered clear liquid enters the primary distillation column.

[0019] Multi-stage distillation separation: The material undergoes preliminary separation in the first-stage distillation column, with the top temperature controlled at 90-130℃ and the bottom temperature at 150-180℃, and the operating pressure at 0.05-0.1MPa. Light components are distilled off from the top, extracted by a vacuum pump, and then sent to the tail gas treatment column for purification. Heavy components are conveyed from the bottom of the column to the second-stage distillation column via a magnetic discharge pump. The second-stage distillation column is a vacuum distillation column, operating at a pressure of -0.08 to -0.05MPa, with the top temperature controlled at 60-90℃ and the bottom temperature at 120-150℃, for further separation and purification of fatty nitriles. High-purity fatty nitriles flow from the bottom of the column into the second-stage collecting tank, while trace amounts of light components distilled off from the top are extracted by a vacuum pump to the tail gas treatment column for further processing. The high-temperature fatty nitriles (100-130℃) in the second-stage collecting tank enter the preheating tank coil through connecting pipes, where they exchange heat with the raw material in the preheating tank, achieving heat recovery and reducing the energy consumption of the entire system.

[0020] Compared with the prior art, the beneficial effects of this utility model are:

[0021] (1) By setting a combination structure of filter plate and rotating scraper in the primary back filter, the filter plate can trap solid impurities, and the rotating scraper can remove impurities attached to the surface of the filter plate in time through mechanical scraping, avoiding filter plate blockage, ensuring stable filtration efficiency, significantly reducing the impurity content of the material entering the distillation system, reducing the risk of blockage in the distillation column, and improving distillation efficiency and product purity. The setting of the backwash filter further enhances the impurity filtration effect. The filter can be cleaned regularly through the backwash pipeline to maintain filtration accuracy and ensure the smooth operation of the subsequent distillation process.

[0022] (2) The preheating tank coil inside the preheating tank is connected to the secondary collection tank via a connecting pipe. The high-temperature condensate discharged from the secondary distillation column is used to preheat the raw materials in the preheating tank, realizing the recycling of heat. This design allows the raw materials to be preheated to a suitable temperature before entering the reactor. Even in low-temperature environments (such as winter), it can significantly increase the feed rate, reduce the temperature difference between the raw materials and the reactor, reduce thermal shock, stabilize the temperature environment inside the reactor, improve the reaction rate and product quality stability, thereby improving the overall production efficiency. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the fatty nitrile distillation apparatus of this utility model;

[0024] In the diagram: 1. Raw material storage tank; 2. Preheating tank; 3. Reactor; 4. Primary reverse filter; 5. Buffer tank; 6. Backwash filter; 7. Primary distillation column; 8. Secondary distillation column; 9. Tail gas treatment column; 10. Catalyst storage tank; 11. Preheating tank coil; 12. Magnetic conveying pump; 13. Magnetic discharge pump; 14. Filter plate; 15. Rotary scraper; 16. Vacuum pump; 17. Primary collection tank; 18. Secondary collection tank; 19. Connecting pipeline. Detailed Implementation

[0025] To make the objectives and technical solutions of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0026] Example 1

[0027] like Figure 1 As shown, the fatty nitrile distillation unit includes a raw material storage tank 1, which is connected to a reactor 3 via a preheating tank 2. The reactor 3 is connected to a buffer tank 5 via a primary reverse filter 4, and the buffer tank 5 is connected to a primary distillation column 7 via a backwash filter 6. The primary reverse filter 4 has a filter plate 14 inside, and a rotating scraper 15 is located below the filter plate 14. The preheating tank 2 has a coiled structure, and the coil 11 of the preheating tank uses a spiral stainless steel pipe, which is directly connected to a secondary collection tank 18. The spiral coil increases the heat exchange area and improves the preheating efficiency; it utilizes the waste heat from distillation to preheat the raw material, reducing energy consumption. A catalyst storage tank 10 is connected to the reactor 3. A magnetic transfer pump 12 is installed between the reactor 3 and the primary reverse filter 4, and the connection point of the magnetic transfer pump 12 and the primary reverse filter 4 is located below the filter plate 14. The connection point of the buffer tank 5 and the primary reverse filter 4 is located above the filter plate 14, and the upper edge of the rotating scraper 15 is tangent to the lower edge of the filter plate 14. The backwash filter 6 is equipped with a backwash pipe. The primary distillation column 7 is connected to the secondary distillation column 8 via a magnetic discharge pump 13. The top of the secondary distillation column 8 is connected to the tail gas treatment column 9 via a vacuum pump 16. A primary collection tank 17 is connected to the primary distillation column 7, and a secondary collection tank 18 is connected to the secondary distillation column 8. The primary distillation column 7 is an atmospheric pressure column, and the secondary distillation column 8 is a vacuum pressure column. Both columns are equipped with condensers and reflux devices at their tops. The preheating tank 2 has a preheating tank coil 11 inside, and the secondary collection tank 18 is connected to the preheating tank coil 11 via a connecting pipe 19.

[0028] The above-mentioned fatty nitrile distillation apparatus, when in operation, includes the following steps:

[0029] (1) The fatty nitrile raw material enters the preheating tank 2 from the raw material storage tank 1 through the pipeline. The high-temperature condensate flows into the preheating tank coil 11 through the secondary collection tank 18 and the connecting pipeline 19. After the raw material is preheated to 30-50℃, it flows into the reactor 3. At the same time, the catalyst storage tank 10 adds a quantitative amount of catalyst to the reactor. The reaction is stirred at 80-120℃ and atmospheric pressure to 0.3MPa for 2-4 hours. (2) After the reaction, the material is sent from below the filter plate 14 to the primary reverse filter 4 through the magnetic conveying pump 12. The rotating scraper scrapes off the filter plate at a speed of 5-10r / min. 14. Impurities, after filtration, the material flows into the buffer tank 5, and then enters the first-stage distillation column 7 after secondary filtration by the backwash filter 6 with a filtration accuracy of 5-10μm; the operating pressure of the first-stage distillation column 7 is 0.05-0.1MPa, the top temperature is 90-130℃ and the bottom temperature is 150-180℃, and the heavy components are sent to the second-stage distillation column 8 by the magnetic discharge pump 13; (3) The operating pressure of the second-stage distillation column 8 is -0.08 to -0.05MPa, the top temperature is 60-90℃ and the bottom temperature is 120-150℃, and the high-purity fatty nitriles flow into the second-stage collection tank 18.

Claims

1. A fatty nitrile distillation apparatus, characterized in that, It includes a raw material storage tank (1), which is connected to the reactor (3) via a preheating tank (2). The reactor (3) is connected to the buffer tank (5) via a primary reverse filter (4). The buffer tank (5) is connected to the primary distillation column (7) via a backwash filter (6). The primary reverse filter (4) is equipped with a filter plate (14) inside, and a rotating scraper (15) is provided below the filter plate (14).

2. The fatty nitrile distillation apparatus according to claim 1, characterized in that, The reactor (3) is connected to a catalyst storage tank (10), and a magnetic transfer pump (12) is provided between the reactor (3) and the primary reverse filter (4). The connection between the magnetic transfer pump (12) and the primary reverse filter (4) is located below the filter plate (14).

3. The fatty nitrile distillation apparatus according to claim 1, characterized in that, The connection between the buffer tank (5) and the primary backwash filter (4) is located above the filter plate (14), the upper edge of the rotating scraper (15) is tangent to the lower edge of the filter plate (14), and the backwash filter (6) is provided with a backwash pipe.

4. The fatty nitrile distillation apparatus according to claim 1, characterized in that, The primary distillation column (7) is connected to the secondary distillation column (8) via a magnetic discharge pump (13), and the top of the secondary distillation column (8) is connected to the tail gas treatment column (9) via a vacuum pump (16).

5. The fatty nitrile distillation apparatus according to claim 4, characterized in that, The first-stage distillation column (7) is connected to a first-stage liquid collection tank (17), and the second-stage distillation column (8) is connected to a second-stage liquid collection tank (18).

6. The fatty nitrile distillation apparatus according to claim 5, characterized in that, The preheating tank (2) is equipped with a preheating tank coil (11) inside, and the secondary liquid collection tank (18) is connected to the preheating tank coil (11) through a connecting pipe (19).

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