Energy-saving xylene distillation system
By employing a multi-stage separation and heat recovery design in the xylene distillation system, the problems of difficult moisture removal and low heat utilization rate are solved, resulting in high-purity xylene products and energy-saving effects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- YUNNAN DAWEI HENGYUAN CHEM CO LTD
- Filing Date
- 2025-09-06
- Publication Date
- 2026-07-21
AI Technical Summary
In existing xylene distillation systems, moisture is difficult to remove effectively, affecting product purity and chemical reactivity. Furthermore, the distillation process is energy-intensive and has low heat utilization.
The system design includes a steam generator, a steam heater, and a distillation tank. It combines ring plate separation, lime block layer filtration, and density separation, and utilizes the differences in boiling point and density for multiple separations. Combined with a heat accumulator to recover heat, it achieves efficient utilization of moisture and heat.
It achieves complete removal of moisture, improves the purity and chemical reactivity of xylene products, reduces energy consumption, improves heat utilization, and achieves the goal of energy saving.
Smart Images
Figure CN224523987U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of xylene distillation equipment, specifically to an energy-saving xylene distillation system. Background Technology
[0002] Xylene is a colorless and transparent liquid, a product of benzene rings in which two hydrogen atoms are replaced by methyl groups. It exists in three isomers: ortho, meta, and para. Industrially, xylene refers to a mixture of these isomers. It is widely used as a solvent in industries such as coatings, resins, dyes, and inks, and as a synthetic monomer or solvent in industries such as pharmaceuticals, explosives, and pesticides. It can also be used as a component of high-octane gasoline. It is an important raw material in organic chemicals. In the production process, a xylene distillation system is generally required to separate and purify the raw materials to obtain qualified xylene.
[0003] Existing xylene distillation systems suffer from the following problems: First, the raw materials contain a certain amount of moisture, which is often not effectively removed during distillation, resulting in a high water content in the xylene product. This affects the purity and chemical reactivity of the xylene product, leading to substandard quality. Second, the raw materials require heating during distillation, consuming significant energy, and the generated steam is directly discharged, wasting heat and reducing heat utilization efficiency. Therefore, developing an energy-efficient xylene distillation system that effectively removes moisture, produces high-quality products, and has high heat utilization efficiency is objectively necessary. Utility Model Content
[0004] The purpose of this invention is to provide an energy-saving xylene distillation system that removes water cleanly, produces high-quality products, and has high heat utilization efficiency.
[0005] The purpose of this utility model is achieved as follows: it includes a steam generator, a steam heater, and a distillation tank connected in sequence. The distillation tank is divided into a distillation chamber and a steam chamber by a ring plate. A liquid-holding cylinder with a sealed bottom is provided on the ring plate. The top of the distillation chamber is provided with a feed inlet and a steam outlet. The upper part of the steam chamber is provided with a steam inlet, and the bottom of the steam chamber is provided with a steam outlet. The upper part of the distillation chamber is connected in sequence to a filter, a water cooler, and a sedimentation tank via pipelines. Multiple lime block layers are arranged at intervals along the material flow direction in the filter. A heat accumulator is provided on one side of the sedimentation tank. The bottom outlet of the sedimentation tank, the hot water outlet of the water cooler, the steam outlet of the steam chamber, and the steam outlet of the distillation chamber are respectively connected to the inlet of the heat accumulator via pipelines. The outlet of the heat accumulator is connected to the inlet of the steam generator via a pipeline.
[0006] Furthermore, a preheater is installed on the pipeline between the outlet of the accumulator and the steam generator. The inlet of the preheater is connected to the raw material tank, and the outlet is connected to the inlet of the distillation chamber.
[0007] Furthermore, the liquid-containing cylinder is equipped with a hollow cylinder with its upper end sealed. The lower end of the hollow cylinder is connected to the steam chamber, and the upper part of the hollow cylinder is connected to the outlet of the steam heater.
[0008] Furthermore, a filter screen is installed inside the filter, and the filter screen is located near the filter outlet.
[0009] Furthermore, a material exchange port is provided at the top of the filter above each lime block layer, and a material discharge port is provided at the bottom of the filter below each lime block layer. Screw conveyors are connected to the upper end of the material exchange port and the lower end of the material discharge port, respectively.
[0010] Furthermore, a vacuum device and a humidity sensor are installed on the exhaust port.
[0011] This invention is used for the distillation of xylene. During operation, the xylene feedstock is introduced into the distillation chamber through the feed inlet. The steam generator is started, and the steam is introduced into the steam heater for heating. The steam is then introduced into the steam chamber, where it heats the feedstock in the liquid container. The heating temperature is controlled between 110℃ and 120℃. This temperature ensures that the water in the feedstock is fully vaporized, while other components, whose boiling points are higher than this temperature, remain liquid. Once no more steam is emitted, the exhaust port at the top of the distillation chamber is closed. The steam heater is then used to raise the steam temperature, further vaporizing the feedstock. The vaporized feedstock is then passed through a filter and sequentially... The process involves passing through layers of lime blocks, utilizing the principle that lime blocks absorb water but not xylene. The remaining xylene vapor is then fed into a water cooler, where cooling water condenses the xylene vapor, causing it to liquefy. The liquefied xylene is then fed into a sedimentation tank, where the density difference between xylene and water causes them to separate into layers. The discharged water yields high-purity xylene. The water discharged from the sedimentation tank, the hot water discharged from the water cooler, the steam discharged from the steam chamber, and the steam discharged from the distillation chamber are all fed into a heat accumulator, which in turn feeds into a steam generator to produce steam, thus achieving the reuse of water resources and heat. In this invention, firstly, the difference in boiling points is used to evaporate the water from the xylene raw material; secondly, the principle that lime absorbs water but not xylene is used to separate the water from the xylene raw material; and thirdly, the difference in density between water and xylene is used to separate the xylene and water into layers. These three separation methods are performed sequentially and in combination, resulting in a relatively clean and thorough separation of water from xylene, improving the purity and chemical reactivity of the xylene product, and thus improving its quality. Secondly, regarding heat utilization, the water discharged from the centralized sedimentation tank, the hot water discharged from the water cooler, the steam discharged from the steam chamber, and the steam discharged from the distillation chamber form a steam-water mixture with a certain temperature. This mixture is then fed into a steam generator, allowing for the full recovery and utilization of the heat from the hot water and steam, reducing heat loss, improving the utilization rate of heat and water resources, and thus reducing the energy consumed by the steam generator to produce steam, achieving energy saving and consumption reduction. In summary, this invention has the advantages of clean water removal, high product quality, high heat utilization rate, and energy saving. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model; In the diagram: 1-Steam generator, 2-Steam heater, 3-Distillation tank, 4-Distillation chamber, 5-Steam chamber, 6-Liquid container, 7-Filter, 8-Water cooler, 9-Sedimentation tank, 10-Lime block layer, 11-Heat accumulator, 12-Preheater, 13-Raw material tank, 14-Hollow cylinder, 15-Filter screen, 16-Screw conveyor, 17-Vacuum device, 18-Humidity sensor. Detailed Implementation
[0013] The present invention will be further described below with reference to the accompanying drawings, but this description is not intended to limit the present invention in any way. Any changes or improvements made based on the present invention shall fall within the protection scope of the present invention.
[0014] like Figure 1 As shown, this utility model includes a steam generator 1, a steam heater 2, and a distillation tank 3 connected in sequence. The steam generator 1 is used to produce saturated steam, the steam heater 2 is used to increase the temperature of the steam to meet the needs of subsequent distillation, and the distillation tank 3 is used for distilling xylene feedstock. First, the water in the xylene feedstock is vaporized, and then the xylene feedstock is vaporized to remove any high-boiling-point heavy component impurities that may be present. The distillation tank 3 is divided into a distillation chamber 4 and a steam chamber 5 by a ring plate. A bottom-sealed liquid container 6 is provided on the ring plate. The liquid container 6 can be made of a material with good thermal conductivity to facilitate the heating of the xylene feedstock. The top of the distillation chamber 4 is provided with a feed inlet and a steam inlet. The steam chamber 5 has an inlet at the top and an outlet at the bottom. The upper part of the distillation chamber 4 is connected to a filter 7, a water cooler 8, and a sedimentation tank 9 via pipelines. The water cooler 8 is an existing heat exchanger structure that uses cooling water to condense and liquefy xylene vapor. Multiple lime block layers 10 are spaced along the material flow direction inside the filter 7. A heat accumulator 11 is installed on one side of the sedimentation tank 9. The bottom outlet of the sedimentation tank 9, the hot water outlet of the water cooler 8, the steam outlet of the steam chamber 5, and the exhaust port of the distillation chamber 4 are connected to the inlet of the heat accumulator 11 via pipelines. The outlet of the heat accumulator 11 is connected to the inlet of the steam generator 1 via a pipeline.
[0015] This invention is used for the distillation of xylene. During operation, the xylene feedstock is introduced into the distillation chamber 4 through the feed inlet. The steam generator 1 is started, and the steam heater 2 is introduced for heating. Then, the steam is introduced into the steam chamber 4. The steam in the steam chamber 4 heats the feedstock in the liquid container 6, controlling the heating temperature at 110℃~120℃. This temperature ensures that the water in the feedstock is fully vaporized, while other components in the feedstock remain liquid because their boiling points are higher than this temperature. When no more steam is discharged, the exhaust port at the top of the distillation chamber 4 is closed. The steam heater 2 is used to increase the steam temperature, thereby continuously vaporizing the feedstock, which is then passed through the filter 7. Each lime block layer 10 utilizes the principle that lime blocks absorb water but not xylene. The remaining xylene vapor is passed into a water cooler 8, where cooling water condenses the xylene vapor, causing it to liquefy. The liquefied xylene is then passed into a sedimentation tank 9, where the density difference between xylene and water causes them to separate into layers. The discharged water yields xylene with higher purity. The water discharged from the sedimentation tank 9, the hot water discharged from the water cooler 8, the steam discharged from the steam chamber 5, and the steam discharged from the distillation chamber 4 are all passed into a heat storage tank 11, and then into a steam generator 1 to produce steam, thus completing the reuse of water resources and heat.
[0016] In this invention, firstly, the principle of different boiling points is used to evaporate the water in the xylene raw material; secondly, the principle that lime absorbs water but not xylene is used to separate the water in the xylene raw material; and thirdly, the principle of different densities of water and xylene is used to separate xylene and water into layers. These three separation methods are performed sequentially and combined to remove water from xylene more cleanly and thoroughly, improving the purity and chemical reactivity of the xylene product, thereby improving the quality of the xylene product. Secondly, regarding heat utilization, the water discharged from the centralized sedimentation tank 9, the hot water discharged from the water cooler 8, the steam discharged from the steam chamber 5, and the steam discharged from the distillation chamber 4 form a steam-water mixture with a certain temperature. This mixture is then fed into the steam generator 1, which can fully recover and utilize the heat in the hot water and steam, reduce heat loss, improve the utilization rate of heat and water resources, and thus reduce the energy consumed by the steam generator 1 to generate steam, achieving the purpose of energy saving and consumption reduction.
[0017] A preheater 12 is installed on the pipeline between the outlet of the accumulator 11 and the steam generator 1. The inlet of the preheater 12 is connected to the raw material tank 13, and the outlet is connected to the inlet of the distillation chamber 4. The preheater 12 can be a shell-and-tube heat exchanger. It uses the heat contained in the water-steam mixture to preheat the xylene raw material and improve the distillation efficiency of the subsequent xylene raw material.
[0018] The liquid container 6 is equipped with a hollow cylinder 14 with the upper end sealed. The lower end of the hollow cylinder 14 is connected to the steam chamber 5, and the upper part of the hollow cylinder 14 is connected to the outlet of the steam heater 2. During operation, steam is introduced into the hollow cylinder 14. At this time, the xylene raw material in the liquid container 6 is heated from the inside and the outside at the same time, thereby improving the heating efficiency of the xylene raw material.
[0019] The filter 7 is equipped with a filter screen 15, which is located near the outlet of the filter 7. Considering that there may be some debris in the lime block, which will be carried away by xylene vapor and thus reduce the purity of xylene, the filter screen 15 is set up to filter out the debris and impurities in the xylene vapor and improve the purity of xylene.
[0020] Each lime block layer 10 has a material replacement port at the top of the filter 7, and each lime block layer 10 has a discharge port at the bottom of the filter 7. The upper end of the material replacement port and the lower end of the discharge port are connected to screw conveyors 16. The lime block layer 10 is used to absorb moisture from xylene vapor. In actual use, after a period of operation, the lime block layer 10 may become saturated with moisture and need to be replaced. To improve replacement efficiency, screw conveyors 16 are installed. During replacement, the old lime blocks are conveyed out of the lime block layer 10 via screw conveyors 16, while new lime blocks are simultaneously conveyed to the various material replacement ports via screw conveyors 16. This process of replacing lime blocks does not affect the absorption of moisture in xylene, enabling online replacement of lime blocks without manual operation and demonstrating good working efficiency.
[0021] A vacuum device 17 and a humidity sensor 18 are installed on the exhaust port. The vacuum device 17 and humidity sensor 18 are existing technologies. The vacuum device 17 is used to evacuate the distillation chamber 4, so that the distillation chamber 4 has a certain negative pressure, thereby reducing the evaporation temperature of water, so that water can evaporate before reaching 100°C, thereby reducing the heating temperature, reducing energy consumption, and improving distillation efficiency. The humidity sensor 18 detects the discharged water vapor. When there is still water evaporating in the xylene raw material, the humidity sensor 18 will detect a higher humidity. Conversely, when the water in the xylene raw material has evaporated, the humidity sensor 18 will not detect water vapor, indicating that the distillation is complete, and the xylene raw material can be heated again, vaporized, and then passed into the subsequent process for further processing.
Claims
1. An energy-saving xylene distillation system, comprising a steam generator (1), a steam heater (2), and a distillation tank (3) connected in sequence, characterized in that: The distillation tank (3) is divided into a distillation chamber (4) and a steam chamber (5) by a ring plate. A liquid container (6) with a bottom seal is provided on the ring plate. The top of the distillation chamber (4) is provided with a feed inlet and a steam outlet. The upper part of the steam chamber (5) is provided with a steam inlet and the bottom of the steam chamber (5) is provided with a steam outlet. The upper part of the distillation chamber (4) is connected to a filter (7), a water cooler (8) and a sedimentation tank (9) in sequence by pipelines. Multiple lime block layers (10) are arranged at intervals along the material flow direction in the filter (7). A heat accumulator (11) is provided on one side of the sedimentation tank (9). The bottom outlet of the sedimentation tank (9), the hot water outlet of the water cooler (8), the steam outlet of the steam chamber (5) and the steam outlet of the distillation chamber (4) are respectively connected to the inlet of the heat accumulator (11) by pipelines. The outlet of the heat accumulator (11) is connected to the inlet of the steam generator (1) by pipelines.
2. The energy-saving xylene distillation system according to claim 1, characterized in that: A preheater (12) is installed on the pipeline between the outlet of the accumulator (11) and the steam generator (1). The inlet of the preheater (12) is connected to the raw material tank (13), and the outlet is connected to the inlet of the distillation chamber (4).
3. The energy-saving xylene distillation system according to claim 1, characterized in that: The liquid container (6) is provided with a hollow cylinder (14) with the upper end sealed. The lower end of the hollow cylinder (14) is connected to the steam chamber (5), and the upper part of the hollow cylinder (14) is connected to the outlet of the steam heater (2).
4. The energy-saving xylene distillation system according to claim 1, characterized in that: The filter (7) is provided with a filter screen (15), which is located near the outlet of the filter (7).
5. The energy-saving xylene distillation system according to claim 1, characterized in that: Each lime block layer (10) has a material exchange port at the top of the filter (7) and a discharge port at the bottom of the filter (7) below the lime block layer (10). The upper end of the material exchange port and the lower end of the discharge port are respectively connected to a screw conveyor (16).
6. The energy-saving xylene distillation system according to claim 1, characterized in that: The exhaust port is equipped with a vacuum device (17) and a humidity sensor (18).