A methanol rectification column
By designing a methanol distillation tower with multiple descending trays and anti-entrainment devices, the problems of small throughput, easy clogging, and gas-liquid entrainment in existing technologies have been solved, realizing a highly efficient methanol distillation process and improving product quality and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- TIANJIN CHUANGJU TECHNOLGOY
- Filing Date
- 2025-06-11
- Publication Date
- 2026-07-07
AI Technical Summary
Existing methanol distillation columns suffer from problems such as low throughput, easy clogging, easily damaged float valves, and severe gas-liquid entrainment, resulting in low production efficiency and high maintenance costs.
A methanol distillation column was designed, which adopts a multi-drop tray structure, combined with a cover, top plate and anti-entrainment device, to achieve full contact and dispersion of gas and liquid, enhance mass transfer efficiency, and isolate the mass-transferred and non-mass-transferred liquids through the liquid guide tank to prevent gas-liquid back mixing.
It significantly improved the processing capacity and product quality of the methanol distillation tower, reduced the unit pressure drop and construction cost, extended the maintenance cycle, and improved production efficiency and product purity.
Smart Images
Figure CN224462280U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a high-efficiency methanol distillation device in the chemical industry, specifically a methanol distillation tower. Background Technology
[0002] Methanol is an important chemical raw material with wide applications in various fields. During its synthesis, methanol generates a large number of impurities, making efficient methanol distillation technology crucial. The quality of refined methanol not only affects the end market and user satisfaction but also directly relates to a company's investment costs and operating profits. As a high-energy-consuming piece of equipment in chemical production, the energy consumption, product quality, and overall quality of methanol distillation units have become key indicators of a company's core competitiveness.
[0003] Green methanol is produced using renewable energy or low-carbon technologies, resulting in lower carbon emissions and aligning with sustainable development requirements. Highly efficient and energy-saving methanol distillation units not only reduce production costs and enhance product competitiveness but also contribute to green methanol production and drive the green transformation of the chemical industry.
[0004] The methanol distillation column is a key piece of equipment in methanol synthesis, consisting of the column body and internal components. Currently, its internal components mainly include the feed distributor, trays, demister, and their auxiliary parts. Trays are divided into two types: bubbling and jetting. Bubbling trays are mainly valve trays, but they have disadvantages such as low throughput, high pressure drop, susceptibility to clogging, and easy damage to the valves, resulting in unsatisfactory performance. Jetting trays, such as vertical sieve trays, although simple in structure, suffer from severe gas-liquid entrainment and poor shock resistance, especially during methanol system fluctuations, leading to higher maintenance costs in the later stages. Utility Model Content
[0005] To address the shortcomings of existing technologies, this utility model provides a methanol distillation column.
[0006] The technical solution of this utility model to solve the aforementioned technical problem is to provide a methanol distillation column, characterized in that the methanol distillation column includes a column body, a feed distributor, a tray section, a reflux distributor, a gas outlet, an inlet gas distributor, a liquid outlet, a reboiler outlet, and a reboiler return outlet; the feed distributor is located in the middle of the column body, the reflux distributor is located in the upper part of the column body, the inlet gas distributor and the reboiler return outlet are located in the lower part of the column body, the gas outlet is located at the top of the column body, and the liquid outlet and the reboiler outlet are located at the bottom of the column body;
[0007] The tray section is composed of several trays arranged in layers. Each tray is composed of an upper tray and a lower tray. Each tray layer includes a tray plate, a downcomer, a receiving tray, a cover, a support plate, a top plate, plate holes, a liquid guide channel, a downcomer hole, and an anti-entrapment device.
[0008] The tray is fixed to the inner wall of the tower body. It is a multi-fallout tray with several drip-type fallout channels and receiving channels. The fallout channels and receiving channels are spaced apart, with the receiving channels on both sides of the fallout channels and the fallout channels on both sides of the receiving channels. In adjacent tray layers, the fallout channels of the upper tray correspond to the receiving channels of the lower tray, and vice versa.
[0009] The tray has multiple perforations, evenly distributed in the area between adjacent downcomers and receiving tanks. Each perforation is fitted with a cover, fixed to the tray with a gap between the bottom of the cover and the tray. A top plate is fixed to the top of each cover via a support plate, also with a gap between the top plate and the top of the cover. A liquid guide channel is fixed to the outer wall of all covers in the same area, with an opening at one end facing the downcomer. An anti-entrapment device is installed in the area above the top plate.
[0010] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0011] (1) The tray used in the methanol distillation column of this utility model has the advantages of large raw material processing capacity, easy clogging and long maintenance cycle. Its unique cover structure can realize gas-liquid constriction jet, so that the gas-liquid contact is more sufficient and the gas-liquid has good uniformity and dispersion. In addition, compared with the floating valve tray, the tray has a larger opening ratio, which significantly improves the liquid lifting capacity and enhances the processing capacity. The large gap between the top plate and the cover not only increases the gas-liquid mass transfer space, making the mass transfer process more sufficient, but also allows the gas and liquid to scatter outward from the upper gap after hitting the top plate, effectively reducing the force on the top plate and the cover, avoiding the risk of the tray being blown away by gas impact, and thus extending the service life of the tray. At the same time, the tray plate has large holes and no moving parts, and with the large upper gap between the top plate and the cover, the tray is not easy to be clogged by dirty or sticky materials.
[0012] (2) The methanol distillation tower of this utility model adopts a drop-down type multi-downsink tank. The bottom of the downsink tank has several downsink holes, which can not only play the role of holding liquid and reducing foam, but also increase the residence time of liquid in the downsink tube, effectively eliminate the bubbles on the upper tray, prevent them from entering the lower tray and causing gas back mixing, increase the operational flexibility of the downsink tank, and thus ensure the high mass transfer efficiency of each tray.
[0013] (3) The methanol distillation tower of this utility model adopts a drop-down type multi-drop tank, which also functions as a support beam. Each component can be disassembled and installed through the manhole. The tower plate adopts a bent structure, which does not require direct welding of the main beam to the tower body. This design is simple, scientific and reasonable, which can reduce the amount of materials used and facilitate installation and maintenance.
[0014] (4) The methanol distillation column of this utility model is equipped with a liquid guide tank structure on the tray to isolate the liquid that has been transferred and the liquid that has not been transferred. The liquid that has been transferred can be directly introduced into the downcomer through the liquid guide tank and enter the next tray, avoiding back mixing with the liquid that has not been transferred, so as to maximize the concentration difference between the liquid and gas components, thereby significantly improving the mass transfer driving force and the tray efficiency.
[0015] (5) The methanol distillation column of this utility model is equipped with an anti-entrainment device on the tray, which can effectively intercept small droplets entrained in the lower gas phase, prevent them from mixing into the upper tray, reduce the mist entrainment phenomenon, and thus improve the overall operating efficiency of the column.
[0016] (6) This utility model, through innovative design of the internal mass transfer unit and tray structure, makes the methanol distillation system more adaptable to parameter fluctuations and more flexible in operation, meeting production needs and significantly improving product quality and production efficiency. It has been widely used in production. Tests have shown that, under the same operating conditions, the ethanol content in the product produced by this methanol distillation tower is reduced from 200±40ppm to 30-55ppm, effectively improving product quality. The new tray structure reduces the pressure drop per unit theoretical plate to 0.25kPa. With the same number of trays, its processing capacity is superior to the original technology, and the designed tower diameter can be reduced by about 10-20%, thereby reducing construction costs. In addition, the maintenance cycle of this methanol distillation tower is more than twice that of the original technology. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the overall structure of the methanol distillation column of this utility model;
[0018] Figure 2 This is a schematic diagram of the main tray of the methanol distillation column of this utility model;
[0019] Figure 3 This is a cross-sectional view (AA) of the methanol distillation column tray of this utility model.
[0020] In the diagram: 1. Tower body; 2. Feed distributor; 3. Tray section; 4. Reflux distributor; 5. Gas outlet; 6. Inlet gas distributor; 7. Liquid outlet; 8. To reboiler port; 9. Reboiler return port.
[0021] 31. Tray plate, 32. Liquid receiving tank, 33. Cover, 34. Support plate, 35. Top plate, 36. Plate hole, 37. Liquid guiding channel, 38. Liquid receiving hole, 39. Anti-entrapment device, 310. Detailed Implementation
[0022] The present invention will be further described below with reference to the embodiments and accompanying drawings. The specific embodiments are only used to further illustrate the present invention and do not limit the scope of protection of the claims of this application.
[0023] This utility model provides a methanol distillation column, characterized in that the methanol distillation column includes a column body 1, a feed distributor 2, a tray section 3, a reflux distributor 4, a gas outlet 5, an inlet distributor 6, a liquid outlet 7, a reboiler outlet 8, and a reboiler return outlet 9; the feed distributor 2 is located in the middle of the column body 1; the reflux distributor 4 is located in the upper part of the column body 1; the inlet distributor 6 is located in the lower part of the column body 1; the gas outlet 5 is located at the top of the column body 1; the liquid outlet 7 and the reboiler outlet 8 are located at the bottom of the column body 1; the reboiler return outlet 9 is located in the lower part of the column body 1; the tray section 3 has at least two trays arranged alternately inside the column body 1, and there is a tray spacing between adjacent trays in the tray section 3.
[0024] The tray section 3 is composed of several upper and lower trays; each tray includes a tray plate 31, a downcomer 32, a receiving tank 33, a cover 34, a support plate 35, a top plate 36, a plate hole 37, a liquid guide channel 38, a downcomer hole 39, and an anti-entrapment device 310.
[0025] The tray 31 is fixed to the inner wall of the tower body 1; several downcomer troughs 32 and receiving troughs 33 are provided on the tray 31; the downcomer troughs 32 and receiving troughs 33 are spaced apart, with the receiving troughs 33 on both sides of the downcomer troughs 32 and the downcomer troughs 32 on both sides of the receiving troughs 33. In two adjacent trays 31, the downcomer troughs 32 of the upper tray 31 correspond to the receiving troughs 33 of the lower tray 31, and the receiving troughs 33 of the upper tray 31 correspond to the downcomer troughs 32 of the lower tray 31; several downcomer holes 39 are opened at the bottom of the downcomer troughs 32.
[0026] The tray 31 has multiple perforations 37 located in the area between adjacent downcomer 32 and receiving tank 33. Each perforation 37 is equipped with a cover 34, which is fixed to the tray 31 with a gap between the bottom of the cover 34 and the tray 31. A top plate 36 is fixed to the top of each cover 34 by a support plate 35, with a gap between the top plate 36 and the top of the cover 34. A liquid guide channel 38 is fixed to the outer wall of all covers 34 in the same area, with one end of the liquid guide channel 38 open and facing the downcomer 32. An anti-entrapment device 310 is provided in the area above the top plate 36.
[0027] Preferably, the cover 34, the top plate 36, and the plate hole 37 are coaxial, the diameter of the bottom circle of the cover 34 is larger than the diameter of the plate hole 37, and the diameter of the top plate 36 is larger than the diameter of the top circle of the cover 34.
[0028] Preferably, the cover 34 is a hollow cylindrical or hollow conical structure, the plate hole 37 is a circular hole, and the top plate 36 is a circular plate.
[0029] Preferably, the length of the descending channel 32 depends on the diameter or chord length of its location;
[0030] Preferably, the length of the receiving tank 33 depends on the diameter or chord length of its location;
[0031] Preferably, the depth of the descending tank 32 is 200~500mm (preferably 300mm), and the width is 50~400mm.
[0032] Preferably, the width of the liquid guide groove 38 is greater than the width occupied by all the covers 34 in the area on the tray plate 31.
[0033] Preferably, the size and number of the downcomer holes 39 are adjusted to ensure that the liquid level in the downcomer tank 32 is maintained at 60~70mm.
[0034] Preferably, the anti-entrapment device 310 is located above the top plate 36, at a distance of 50~200mm. The anti-entrapment device 310 is made of wire mesh or structured packing. The anti-entrapment device 310 needs to fill the remaining cross-section of the tower body 1 except for the descending tank 32 (e.g., Figure 2 ).
[0035] The working principle and workflow of this utility model are as follows:
[0036] Liquid enters the tower body 1 through the feed distributor 2 and falls into the receiving tank 33. It then flows from the receiving tank 33 through the cover 34 to the downcomer 32. As the liquid flows through the cover 34, it enters the cover 34 through the gap between the cover 34 and the tray 31. Gas rising from below the tray 31 enters the cover 34 through the orifice 37 of the tray 31, constricting and accelerating. The gas lifts the liquid entering the cover 34, forming an annular film that impacts the top plate 36. The liquid then scatters outward in a circular pattern from the gap between the cover 34 and the top plate 36, forming numerous small droplets. These droplets fall into the guide tank 38, which separates the mass-transferred and non-mass-transferred liquids, allowing the liquid undergoing gas-liquid mass transfer to directly flow from the guide tank 38 through the downcomer 32. The gas flows from tank 32 to the next tray. During the gas rise, small droplets that rise with the gas are intercepted by the anti-entrainment device 310 and do not rise to the upper tray. After the liquid flows from top to bottom through several trays and reaches the bottom of the tower body 1, part of it is discharged through liquid outlet 7 and part of it enters the external reboiler for heating through reboiler outlet 8. It then enters the gas distributor 6 inside the tower body 1 through reboiler return outlet 9 for distribution. It passes through several trays from bottom to top, and after mass transfer with the liquid inside the tower body 1, it is discharged through gas outlet 5. The gas at the top exits the tower through gas outlet 5 and enters the external condenser, where it is condensed into liquid. It then enters the tower through reflux distributor 4 and enters the liquid receiving tank of tray 3, and then flows through the tray for mass transfer.
[0037] Any aspects not covered in this utility model are applicable to the prior art.
Claims
1. A methanol distillation column, characterized in that, The methanol distillation column includes a column body, a feed distributor, a tray section, a reflux distributor, a gas outlet, an inlet gas distributor, a liquid outlet, a reboiler outlet, and a reboiler return outlet. The feed distributor is located in the middle of the column body, the reflux distributor is located in the upper part of the column body, the inlet gas distributor and the reboiler return outlet are located in the lower part of the column body, the gas outlet is located at the top of the column body, and the liquid outlet and the reboiler outlet are located at the bottom of the column body. The tray section is composed of several trays arranged in layers. Each tray is composed of an upper tray and a lower tray. Each tray layer includes a tray plate, a downcomer, a receiving tray, a cover, a support plate, a top plate, plate holes, a liquid guide channel, a downcomer hole, and an anti-entrapment device. The tray is fixed to the inner wall of the tower body; the tray is a multi-drop liquid structure tray, with several drop-down liquid channels and receiving channels on the tray; the drop-down liquid channels and receiving channels are arranged alternately, with receiving channels on both sides of the drop-down liquid channels and drop-down liquid channels on both sides of the receiving channels; in two adjacent tray layers, the drop-down liquid channels of the upper tray layer correspond to the receiving channels of the lower tray layer, and the receiving channels of the upper tray layer correspond to the drop-down liquid channels of the lower tray layer. The tray plate has multiple perforations, which are evenly distributed in the area between adjacent downcomers and receiving tanks. Each perforation is equipped with a cover, which is fixed to the tray plate with a gap between the bottom of the cover and the tray plate. The top of each cover is fixed with a top plate by a support plate, with a gap between the top plate and the top of the cover. A liquid guide channel is fixed to the outer wall of all covers in the same area. One end of the liquid guide channel is open and faces the downcomer. An anti-clamping device is installed in the area above the top plate.
2. The methanol distillation column according to claim 1, characterized in that, The cover, top plate, and plate hole are coaxial. The diameter of the bottom circle of the cover is larger than the diameter of the plate hole, and the diameter of the top plate is larger than the diameter of the top circle of the cover.
3. The methanol distillation column according to claim 1, characterized in that, The cover is a hollow cylindrical or hollow conical structure with circular holes in the plates and a circular plate on top.
4. The methanol distillation column according to claim 1, characterized in that, The lengths of the descending and receiving tanks depend on the diameter or chord length of their location.
5. The methanol distillation column according to claim 1, characterized in that, The width of the liquid guide channel is greater than the width occupied by all the covers in the area on the tray.
6. The methanol distillation column according to claim 1, characterized in that, The liquid level in the downcomer can be maintained at 60-70 mm by adjusting the size and number of downcomer holes.
7. The methanol distillation column according to claim 1, characterized in that, The anti-entrapment device is located on the top plate. The anti-entrapment device is made of wire mesh or structured packing. The anti-entrapment device needs to fill the remaining cross-section of the tower body except for the downcomer.