System for preparing isopropyl ether through isopropyl ether etherification reaction rectification

Abstract

The invention belongs to the technical field of separation and rectification, and particularly relates to a system for preparing isopropyl ether through isopropyl etherification reaction rectification, the system comprises a dehydration tower, a reaction rectification tower, a product tower and a dehydration system which are connected with one another, and the dehydration tower, the reaction rectification tower and the product tower are provided with corresponding auxiliary equipment; the reactive distillation tower comprises a tower body, a tower plate is mounted in the tower body, a downcomer and an overflow weir are arranged on the tower plate, a contact plate is mounted on the tower plate, and the contact plate is immersed in a liquid layer on the tower plate; the contact plate comprises an upper plate and a lower plate, through holes are formed in the upper plate and the lower plate, and a catalyst is filled between the upper plate and the lower plate; according to the invention, the catalyst filler is in full contact with the gas-liquid two phases, the contact time of the catalyst filler and the gas-liquid two phases is prolonged, the reaction effect, the reaction rate and the rectification effect are improved, liquid drops condensed at the top in the tower body are cleaned, and the liquid drops are prevented from adhering to influence the rectification efficiency and reduce the product quality.

Description

Technical Field

[0001] The invention belongs to the technical field of separation and rectification, in particular to a system for preparing isopropyl ether by rectification through etherification reaction of isopropyl alcohol. Background Art

[0002] Isopropyl ether, also known as diisopropyl ether, is abbreviated as DIPE. It is a colorless transparent liquid with a special odor of ethers. It is an important chemical product and raw material. Isopropyl ether has a high octane number and good antifreeze properties. It can be used as a gasoline additive. Its mixture with other alcohols and ethers can dissolve nitrocellulose, so it is widely used as a solvent in the chemical fiber industry. It can also be used to treat wastewater from gas plants to reduce water pollution.

[0003] Traditional methods for preparing isopropyl ether can be roughly divided into two categories, namely separation method and synthesis method. The separation method is to obtain a by-product containing isopropyl ether in the process of producing isopropyl alcohol using propylene and water as raw materials and liquid or solid acid as catalyst. The by-product can be refined through processes such as distillation and pickling to obtain the isopropyl ether product, but this method has the following shortcomings: since the composition of the isopropyl alcohol by-product is not constant, the product and quality of the isopropyl ether are limited; the isopropyl alcohol by-product also contains many other impurities (such as isopropyl oil, etc.), which makes the refining of isopropyl ether very difficult, and it is not easy to obtain a high-quality product; in addition, there are environmental problems in the refining process. The synthesis methods so far mainly include alcohol-olefin synthesis, isopropanol dehydration, propylene hydration, etc. The process technology of alcohol-olefin synthesis is relatively mature, and the obtained isopropyl ether has a higher purity, but this process is relatively complicated: the isopropyl alcohol dehydration method mostly uses concentrated sulfuric acid and concentrated phosphoric acid as catalysts, which will corrode equipment and cause environmental pollution. The propylene hydration method has the disadvantages of low purity of the obtained isopropyl ether and high requirements for catalysts, so this method is rarely used now.

[0004] In the process of preparing isopropyl ether, a catalyst as a filler is filled in a reaction distillation tower, and the gas and liquid are countercurrently passed through the gaps between the packing layers continuously, and the gas-liquid two-phase is in close contact on the packing surface for mass transfer, which will make the liquid tend to gradually concentrate on the tower wall when flowing down the packing layer, so that the liquid flow rate near the tower wall gradually increases, thereby causing the gas-liquid two-phase to be unevenly distributed in the packing layer, reducing the mass transfer efficiency between the gas and the liquid, and the liquid load of the liquid phase after being sprayed by the liquid distributor is small, which may be difficult to effectively wet the surface of the packing, and the mass transfer efficiency will also be reduced, affecting the distillation effect; at the same time, after the reaction, when the steam carrying the product is transmitted from bottom to top, before the steam is discharged from the exhaust port at the top of the distillation tower, it is easy for the steam to condense into water droplets when it encounters cold on its inner wall surface, and the water droplets adhere to the inner wall surface of the top of the distillation tower and are not easy to be collected. In addition, the dripping droplets will cause the liquid layer on the tower plate to fluctuate, affecting the distillation efficiency and distillation effect. Summary of the invention

[0005] In order to make up for the shortcomings of the prior art, the catalyst filler is fully in contact with the gas-liquid two phases, the contact time between the catalyst filler and the gas-liquid two phases is prolonged, the reaction effect, reaction rate and distillation effect are improved, and the droplets condensed on the top of the tower body are cleaned to avoid droplet adhesion, which affects the distillation efficiency and reduces the product quality. The present invention proposes a system for preparing isopropyl ether by isopropyl alcohol etherification reaction distillation.

[0006] The technical solution adopted by the present invention to solve the technical problem is as follows: the system for preparing isopropyl ether by isopropyl alcohol etherification reaction distillation of the present invention comprises a dehydration tower, a reaction distillation tower, a product tower and a dehydration system connected to each other, wherein the dehydration tower, the reaction distillation tower and the product tower are all equipped with corresponding reboilers, condensers and reflux tanks; The top product of the dehydration tower is input into a reaction distillation tower, the top product of the reaction distillation tower is input into a product tower, the bottom product of the reaction distillation tower is input into a dehydration tower, the bottom product of the product tower is input into a reaction distillation tower, the top product of the product tower is input into a dehydration system, and the dehydration system dehydrates the product to obtain a high-purity isopropyl ether product; The reactive distillation tower comprises a tower body, a tower plate is installed in the tower body, a downcomer and an overflow weir are arranged on the tower plate, a contact plate is installed on the tower plate, and the contact plate is immersed in the liquid layer on the tower plate; The contact plate comprises an upper plate and a lower plate, through holes are provided on the upper plate and the lower plate, and a catalyst is filled and installed between the upper plate and the lower plate.

[0007] Preferably, the diameter and number of the through holes on the upper plate are smaller than the diameter and number of the through holes on the lower plate.

[0008] Preferably, the middle position of the contact plate is recessed downwards, and the contact plate is in an arc shape as a whole.

[0009] Preferably, the contact plate is fixedly mounted on the tower plate via a rotating shaft, and a protrusion is arranged above the lower surface of the contact plate, and the protrusion is arranged in an arc shape.

[0010] Preferably, the rotating shaft is installed at an angle, and the height between the side of the contact plate close to the overflow weir and the tower plate is lower than that of the other opposite side.

[0011] Preferably, a cleaner is installed on the inner wall of the tower body, and the cleaner is located at one end of the tower body close to the tower top; The cleaner comprises a fixed rail, a floating ring is installed below the fixed rail through a spring, and the floating ring is in contact with the inner wall of the tower body; The upper surfaces of the floating ring and the fixed rail are arranged as inclined surfaces, and a blade is installed in the middle of the floating ring.

[0012] Preferably, a sliding rail is rotatably mounted below the fixed rail, the floating ring is mounted on the sliding rail via a spring, and the blade is a fan blade with a driving rotation effect; A lower scraper rod is installed below the floating ring, and an upper scraper rod is installed on the sliding rail. The upper scraper rod and the lower scraper rod contact the inner wall of the tower body.

[0013] Preferably, the upper scraper rod and the lower scraper rod are elastic, and guide grooves are provided on the surfaces of the upper scraper rod and the lower scraper rod.

[0014] The beneficial effects of the present invention are as follows: 1. The system for preparing isopropyl ether by reactive distillation of isopropyl alcohol etherification of the present invention, by providing a contact plate, a rotating shaft and a catalyst, enables the reactive distillation tower in the system to fully contact the gas-liquid two phases, improve the mass transfer effect of the gas-liquid two phases, improve the uniform contact and uniform distribution of the gas-liquid two phases with the catalyst filler, thereby improving the distillation effect and product quality.

[0015] 2. The system for preparing isopropyl ether by reaction and distillation of isopropyl alcohol described in the present invention cleans the inner wall of the tower top in the tower body by arranging fixed rails, sliding rails, springs, floating rings, upper scraper rods, lower scraper rods and guide grooves to avoid the generation of droplets on the inner wall after gas phase condensation, which affects the distillation effect and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below in conjunction with the accompanying drawings.

[0017] Figure 1 is a schematic diagram of the system of the present invention; Figure 2 is a front view of a reactive distillation tower used in the system of the present invention; Figure 3 is a cross-sectional view of a reactive distillation tower used in the system of the present invention; Figure 4 is a front view of the trays and contact plates in the reactive distillation tower used in the system of the present invention; Figure 5 It is a schematic diagram of the structure of the contact plate in the reaction distillation tower used in the system of the present invention; Figure 6 It is a schematic diagram of the structure of the cleaner in the reaction distillation tower used in the system of the present invention; Figure 7 yes Figure 3 A partial enlarged view of the middle part; In the figure: dehydration tower 1, reaction distillation tower 11, product tower 12, dehydration system 13, tower body 2, tower plate 3, cleaner 4, fixed rail 41, sliding rail 42, upper scraper 421, floating ring 43, spring 431, blade 432, lower scraper 44, contact plate 5, rotating shaft 51, protrusion 52, upper plate 53, lower plate 54, catalyst 55. DETAILED DESCRIPTION

[0018] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0019] like Figures 1 to 7 As shown, the system for preparing isopropyl ether by reaction and distillation of isopropyl alcohol according to the present invention comprises a dehydration tower 1, a reaction and distillation tower 11, a product tower 12 and a dehydration system 13 which are interconnected, wherein the dehydration tower 1, the reaction and distillation tower 11 and the product tower 12 are all equipped with corresponding reboilers, condensers and reflux tanks; The top product of the dehydration tower 1 is input into the reaction distillation tower 11, the top product of the reaction distillation tower 11 is input into the product tower 12, the bottom product of the reaction distillation tower 11 is input into the dehydration tower 1, the bottom product of the product tower 12 is input into the reaction distillation tower 11, and the top product of the product tower 12 is input into the dehydration system 13, and the dehydration system 13 dehydrates the product to obtain a high-purity isopropyl ether product; The reactive distillation tower 11 comprises a tower body 2, a tower plate 3 is installed in the tower body 2, a downcomer and an overflow weir are arranged on the tower plate 3, a contact plate 5 is installed on the tower plate 3, and the contact plate 5 is immersed in the liquid layer on the tower plate 3; The contact plate 5 includes an upper plate 53 and a lower plate 54. Through holes are provided on the upper plate 53 and the lower plate 54. A catalyst 55 is filled and installed between the upper plate 53 and the lower plate 54. During operation, in the reaction distillation tower 11, the liquid-phase raw material and the gas-phase raw material meet at the tower plate 3 and exchange heat. At this time, the isopropyl alcohol contacts the catalyst 55 on the tower plate 3, and reacts to generate isopropyl ether under the action of the catalyst 55. At the same time, the generated isopropyl ether is separated and enters the gas phase. As the gas phase leaves the reaction distillation tower 11 and enters the product tower 12, the gas phase components entering the product tower 12 are further distilled, and a large amount of mixed isopropyl ether and a small amount of isopropyl alcohol are separated, so that the separated water-containing isopropyl ether leaves the top of the product tower 12 and enters the dehydration system 13, completing the separation of water in the isopropyl ether product, and obtaining a high-purity isopropyl ether product; In the reaction distillation tower 11, due to the presence of the overflow weir on the tower plate 3, there is a liquid layer with a thickness equal to the height of the overflow weir above the tower plate 3, so that the contact plate 5 installed on the tower plate 3 is immersed in the liquid layer. At the same time, after the gas phase passes through the tower plate 3 from bottom to top, the gas phase will contact with the liquid layer on the tower plate 3, and mass transfer will occur between the gas and the liquid. At this time, due to the effect of the through holes or float valves opened on the tower plate 3, the gas phase will appear in the liquid layer as a bubble state. At the same time, since the contact plate 5 is located above the tower plate 3, the contact plate 5 will The gas phase passing through the tower plate 3 is hindered, that is, the gas phase in the bubble state cannot leave the liquid layer upward along the shortest route in the vertical direction. The gas phase in the bubble state needs to move horizontally in the liquid layer along the surface of the contact plate 5. After the gas phase in the bubble state leaves the area covered by the contact plate 5, the gas phase in the bubble state can leave the liquid layer on the tower plate 3 upward along the shortest path in the vertical direction, thereby effectively increasing the contact time and contact area between the gas phase and the liquid phase, improving the mass transfer effect between the gas and liquid phases, and improving the reaction effect and distillation effect; At the same time, since the catalyst 55 is filled in the contact plate 5, the liquid layer on the tower plate 3 can fully contact with the catalyst 55 in the contact plate 5, and since the contact plate 5 is provided with a through hole, there is a situation where the gas phase moving upward passes through the contact plate 5 and the catalyst 55 from the through hole, so that the gas-liquid two phases are evenly distributed in the packing layer, increasing the contact area and contact time between the gas-liquid two phases and the catalyst 55 packing, thereby improving the catalytic reaction effect and the distillation effect; At the same time, the catalyst 55 filler is placed in the contact plate 5 so that the catalyst 55 is relatively dispersed in the reaction distillation tower 11, the contact area between the catalyst 55 and the raw material is increased, and the amount of catalyst 55 used is reduced. At the same time, it can also avoid setting up a catalytic reaction section. The filler loaded with the catalyst 55 affects the uniform distribution and contact of the liquid phase and the gas phase in the tower body 2, resulting in poor gas-liquid mass transfer effect, affecting the reaction effect of the raw material in the reaction distillation tower 11 and the distillation effect of the product.

[0020] As an embodiment of the present invention, the diameter and number of the through holes on the upper plate 53 are smaller than the diameter and number of the through holes on the lower plate 54; Since the contact plate 5 is used to guide the movement of the gas phase passing through the tower plate 3, the number and diameter of the through holes on the upper plate 53 and the lower plate 54 are respectively set, so that most of the gas phase passing through the tower plate 3 moves laterally along the surface of the contact plate 5, and a small part of the gas phase passing through the tower plate 3 passes through the contact plate 5 and the catalyst 55 filler from the through holes, so as to ensure that the contact time and contact area between the gas phase and the liquid phase are increased, and the gas-liquid mass transfer effect and the distillation effect are improved. At the same time, the gas phase passing through the contact plate 5 from the through holes drives the liquid phase in the contact plate 5 to move, thereby replacing and circulating the liquid phase in the contact plate 5, so that the catalyst The filler of the catalytic agent 55 is fully infiltrated to avoid stagnation and non-flow of the liquid phase in the contact plate 5, which results in the catalyst 55 failing to fully contact other isopropanol raw materials in time after the catalytic reaction of the isopropanol raw material is completed, affecting the reaction effect, reaction rate and distillation effect. At the same time, due to the through holes opened on the lower plate 54, when the gas phase moves laterally along the surface of the contact plate 5, the moving gas phase will also drive the liquid phase near it to move, thereby making the catalyst 55 in the contact plate 5 constantly contact the new liquid phase, catalyzing the reaction of the isopropanol raw material in the liquid phase, thereby improving the reaction effect and distillation effect.

[0021] As an embodiment of the present invention, the middle position of the contact plate 5 is concave downward, and the contact plate 5 is in an arc shape as a whole; Since the contact plate 5 is in an arc shape, after the gas phase part passing through the tower plate 3 contacts the lower surface of the contact plate 5, it will be guided by the arc portion of the contact plate 5 surface, so that the gas phase part moves laterally and leaves the area covered by the contact plate 5, thereby preventing the gas phase part from smoothly moving laterally after the gas phase moving upward contacts the flat contact plate 5, so that the gas phase part is easily accumulated under the flat contact plate 5, affecting the mass transfer between gas and liquid and affecting the flow of the gas phase in the liquid layer on the tower plate 3, which is easy to cause liquid flooding, tower flooding, and tower flushing, affecting the normal operation of the reaction distillation tower 11; At the same time, the arc shape of the contact plate 5 is used to guide the gas phase passing through the tower plate 3 to prevent the gas phase from accumulating under the contact plate 5, resulting in excessive pressure above the tower plate 3 and below the contact plate 5, and then causing most of the gas phase to pass through the contact plate 5 and the catalyst 55 from the through hole, affecting the guiding effect of the gas phase flow path in the liquid layer, and affecting the subsequent process of the gas phase passing through the tower plate 3 from bottom to top.

[0022] As an embodiment of the present invention, the contact plate 5 is fixedly mounted on the tower plate 3 via a rotating shaft 51, and a protrusion 52 is provided above the lower surface of the contact plate 5, and the protrusion 52 is arranged in an arc shape; After the gas phase passing through the tower plate 3 contacts the protrusion 52 on the contact plate 5, the gas phase will produce a pushing effect on the protrusion 52 and the contact plate 5, causing the contact plate 5 to rotate. Afterwards, the liquid layer on the tower plate 3 is moved and driven by the rotation of the contact plate 5, so that the liquid layer path above the tower plate 3 becomes a curve, rather than a straight line pointing from the liquid receiving area on the tower plate 3 to the direction of the downcomer, thereby extending the flow path of the liquid layer on the tower plate 3, further increasing the gas-liquid contact time and contact area, improving the mass transfer effect, and making the gas-liquid two phases fully contact with the contact plate 5 and the catalyst 55 filler, thereby improving the reaction effect and distillation effect.

[0023] As an embodiment of the present invention, the rotating shaft 51 is installed obliquely, and the height between the side of the contact plate 5 close to the overflow weir and the tower plate 3 is lower than the other side; Since the rotating shaft 51 is installed obliquely, the end of the contact plate 5 facing the liquid receiving area is higher than the end of the contact plate 5 facing the overflow weir. When the liquid layer on the tower plate 3 flows toward the overflow weir, the liquid layer will impact the contact plate 5, thereby promoting and pushing the contact plate 5 to rotate, thereby avoiding that only the gas phase contacts the contact plate 5, and the gas phase has a poor pushing effect on the rotation of the contact plate 5. At the same time, due to the inclination angle of the contact plate 5, after the gas phase passes through the tower plate 3, the gas phase will be further guided by the surface of the contact plate 5, so that the gas phase as a whole tends to flow along the surface of the contact plate 5 toward the liquid receiving area, thereby reducing the speed at which the gas phase leaves the liquid layer, increasing the contact time between the gas phase and the liquid phase, improving the gas-liquid mass transfer effect and the contact effect between the gas-liquid two phases and the catalyst 55 filler, so that the reaction effect and distillation effect are good.

[0024] As an embodiment of the present invention, a cleaner 4 is installed on the inner wall of the tower body 2, and the cleaner 4 is located at one end of the tower body 2 close to the tower top; The cleaner 4 includes a fixed rail 41, a floating ring 43 is installed below the fixed rail 41 through a spring 431, and the floating ring 43 is in contact with the inner wall of the tower body 2; The upper surfaces of the floating ring 43 and the fixed rail 41 are arranged as inclined surfaces, and a blade 432 is installed in the middle of the floating ring 43; When the gas phase moves upward to the top of the tower, it will contact the blade 432, exerting a force on the blade 432, so that under the action of the spring 431, the blade 432 drives the floating ring 43 to move up and down, so that the floating ring 43 cleans the droplets condensed on the inner wall of the tower body 2 near the top of the tower, so that the droplets fall back to the tower plate 3 below to participate in the reaction and distillation, thereby avoiding poor distillation effect.

[0025] As an embodiment of the present invention, a sliding rail 42 is rotatably mounted below the fixed rail 41, the floating ring 43 is mounted on the sliding rail 42 via a spring 431, and the blade 432 is a fan blade with a pushing rotation effect; A lower scraper rod 44 is installed below the floating ring 43, and an upper scraper rod 421 is installed on the sliding rail 42. The upper scraper rod 421 and the lower scraper rod 44 contact the inner wall of the tower body 2. Since the blade 432 is a fan blade, after the upward gas phase contacts the blade 432, it will drive the blade 432 to rotate, and due to the action of the spring 431, it will also drive the blade 432 to move up and down, that is, the floating ring 43 moves up and down and rotates, and the sliding rail 42 rotates, so that the droplets condensed on the inner wall of the upper end of the tower body 2 are cleaned up by the lower scraper rod 44 and the upper scraper rod 421 rotating along the inner wall. At the same time, by providing the lower scraper rod 44, the volume and mass of the floating ring 43 are relatively reduced, which makes it easier for the blade 432 to drive the floating ring 43 to rotate under the impact of the gas phase, and avoids the mass of the floating ring 43 being too large, which affects its rotation and the cleaning of the inner wall. At the same time, since the top of the reaction distillation tower 11 is arc-shaped, the inner wall above the fixed rail 41 is cleaned by rotating the upper scraper 421 installed on the sliding rail 42, thereby ensuring that the interior of the tower top is fully and completely cleaned to avoid the presence of residual parts.

[0026] As an embodiment of the present invention, the upper scraper rod 421 and the lower scraper rod 44 are elastic, and guide grooves are provided on the surfaces of the upper scraper rod 421 and the lower scraper rod 44; Due to the elasticity of the upper scraper rod 421 and the lower scraper rod 44, the upper scraper rod 421 and the lower scraper rod 44 can be tightly attached to the inner wall of the tower body 2, ensuring that the condensed droplets on the inner wall are cleaned and the droplets fall onto the tower plate 3 below to react and distill again. At the same time, by providing guide grooves on the upper scraper rod 421 and the lower scraper rod 44, the cleaned droplets can flow along the guide grooves, and then the droplets can slide smoothly from the area close to the inner wall of the tower body 2 to the tower plate 3 below, avoiding the cleaned droplets from directly falling down into the liquid layer on the tower plate 3, so as to avoid impacting the liquid layer on the tower plate 3, resulting in fluctuation and instability of the liquid layer, affecting the distillation effect and product quality.

[0027] The specific workflow is as follows: During operation, in the reaction distillation tower 11, the liquid-phase raw material and the gas-phase raw material meet at the tower plate 3 and exchange heat. At this time, the isopropyl alcohol contacts the catalyst 55 on the tower plate 3, and reacts to generate isopropyl ether under the action of the catalyst 55. At the same time, the generated isopropyl ether is separated and enters the gas phase. As the gas phase leaves the reaction distillation tower 11 and enters the product tower 12, the gas phase components entering the product tower 12 are further distilled, and a large amount of mixed isopropyl ether and a small amount of isopropyl alcohol are separated, so that the separated water-containing isopropyl ether leaves the top of the product tower 12 and enters the dehydration system 13, completing the separation of water in the isopropyl ether product, and obtaining a high-purity isopropyl ether product; In the reaction distillation tower 11, the contact plate 5 installed on the tower plate 3 is immersed in the liquid layer. At the same time, after the gas phase passes through the tower plate 3 from bottom to top, the gas phase will contact with the liquid layer on the tower plate 3. The contact plate 5 hinders the gas phase passing through the tower plate 3, that is, the gas phase in the bubble state cannot leave the liquid layer upward along the shortest path in the vertical direction. The gas phase in the bubble state needs to move horizontally in the liquid layer along the surface of the contact plate 5. After the gas phase in the bubble state leaves the area covered by the contact plate 5, the gas phase in the bubble state can leave the liquid layer on the tower plate 3 upward along the shortest path in the vertical direction. At the same time, since the catalyst 55 is filled in the contact plate 5, the liquid layer on the tower plate 3 can fully contact with the catalyst 55 in the contact plate 5, and since the contact plate 5 is provided with through holes, there is a situation where the gas phase moving upward passes through the contact plate 5 and the catalyst 55 from the through holes, so that the gas and liquid phases are evenly distributed in the packing layer; At the same time, the catalyst 55 filler is placed in the contact plate 5, so that the catalyst 55 is relatively dispersed in the reaction distillation tower 11, the contact area between the catalyst 55 and the raw material is increased, and the amount of catalyst 55 used is reduced. At the same time, it can also avoid setting a catalytic reaction section, and the filler loaded with the catalyst 55 affects the uniform distribution and contact of the liquid phase and the gas phase in the tower body 2; By respectively setting the number and diameter of the through holes on the upper plate 53 and the lower plate 54, most of the gas phase that passes through the tower plate 3 moves laterally along the surface of the contact plate 5, and a small part of the gas phase that passes through the tower plate 3 passes through the contact plate 5 and the catalyst 55 filler from the through holes. At the same time, the gas phase that passes through the contact plate 5 from the through holes drives the liquid phase in the contact plate 5 to move, and replaces and circulates the liquid phase in the contact plate 5. At the same time, due to the through holes opened on the lower plate 54, when the gas phase moves laterally along the surface of the contact plate 5, the moving gas phase will also drive the liquid phase nearby to move, so that the catalyst 55 in the contact plate 5 is constantly in contact with new liquid phases. Since the contact plate 5 is in an arc shape, after the gas phase part passing through the tower plate 3 contacts the lower surface of the contact plate 5, it will be guided by the arc portion of the surface of the contact plate 5, so that the gas phase part moves horizontally and leaves the area covered by the contact plate 5, so as to avoid the gas phase part moving upward from contacting the flat contact plate 5, which will cause the gas phase part to easily accumulate under the flat contact plate 5, resulting in excessive pressure above the tower plate 3 and below the contact plate 5, and then most of the gas phase part will pass through the contact plate 5 and the catalyst 55 from the through hole; After the gas phase passing through the tower plate 3 contacts the protrusion 52 on the contact plate 5, the gas phase will produce a pushing effect on the protrusion 52 and the contact plate 5, causing the contact plate 5 to rotate. Afterwards, the liquid layer on the tower plate 3 is moved and driven by the rotation of the contact plate 5, so that the path of the liquid layer above the tower plate 3 becomes a curve, instead of a straight line from the liquid receiving area on the tower plate 3 to the downcomer direction, thereby extending the flow path of the liquid layer on the tower plate 3; Since the rotating shaft 51 is installed obliquely, the end of the contact plate 5 facing the liquid receiving area is higher than the end of the contact plate 5 facing the overflow weir. When the liquid layer on the tower plate 3 flows toward the overflow weir, the liquid layer will impact the contact plate 5, thereby promoting and pushing the contact plate 5 to rotate. At the same time, due to the inclination angle of the contact plate 5, after the gas phase passes through the tower plate 3, the gas phase will be further guided by the surface of the contact plate 5, so that the gas phase as a whole tends to flow along the surface of the contact plate 5 toward the liquid receiving area, thereby reducing the speed at which the gas phase leaves the liquid layer; When the gas phase moves upward to the top of the tower, the gas phase will contact the blade 432, generating a force on the blade 432, so that under the action of the spring 431, the blade 432 drives the floating ring 43 to move up and down, so that the floating ring 43 cleans the droplets condensed on the inner wall of the tower body 2 near the top of the tower; Since the blade 432 is a fan blade, after the upward gas phase contacts the blade 432, it will drive the blade 432 to rotate, and due to the action of the spring 431, it will also drive the blade 432 to move up and down, that is, the floating ring 43 moves up and down and rotates, and the sliding rail 42 rotates, so that the droplets condensed on the inner wall of the upper end of the tower body 2 are cleaned up by the lower scraper rod 44 and the upper scraper rod 421 rotating along the inner wall; Due to the elasticity of the upper scraper rod 421 and the lower scraper rod 44, the upper scraper rod 421 and the lower scraper rod 44 can be tightly attached to the inner wall of the tower body 2. At the same time, by providing guide grooves on the upper scraper rod 421 and the lower scraper rod 44, the cleaned droplets can flow along the guide grooves, thereby allowing the droplets to smoothly slide from the area close to the inner wall of the tower body 2 to the tower plate 3 below.

[0028] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A system for preparing isopropyl ether by isopropyl alcohol etherification reaction distillation, comprising a dehydration tower (1), a reaction distillation tower (11), a product tower (12) and a dehydration system (13) which are connected to each other, wherein the dehydration tower (1), the reaction distillation tower (11) and the product tower (12) are all equipped with corresponding reboilers, condensers and reflux tanks; The top product of the dehydration tower (1) is input into a reaction distillation tower (11), the top product of the reaction distillation tower (11) is input into a product tower (12), the bottom product of the reaction distillation tower (11) is input into the dehydration tower (1), the bottom product of the product tower (12) is input into the reaction distillation tower (11), the top product of the product tower (12) is input into a dehydration system (13), and the dehydration system (13) dehydrates the product to obtain a high-purity isopropyl ether product; Features: The reactive distillation tower (11) comprises a tower body (2), a tower plate (3) is installed in the tower body (2), a downcomer and an overflow weir are arranged on the tower plate (3), a contact plate (5) is installed on the tower plate (3), and the contact plate (5) is immersed in the liquid layer on the tower plate (3); The contact plate (5) comprises an upper plate (53) and a lower plate (54), through holes are provided on the upper plate (53) and the lower plate (54), and a catalyst (55) is filled and installed between the upper plate (53) and the lower plate (54).

2. According to claim 1, a system for preparing isopropyl ether by isopropyl alcohol etherification reaction and rectification, characterized in that: The diameter and number of the through holes on the upper plate (53) are smaller than the diameter and number of the through holes on the lower plate (54).

3. The system for preparing isopropyl ether by isopropyl alcohol etherification reaction and rectification according to claim 1, characterized in that: The middle position of the contact plate (5) is recessed downwards, and the contact plate (5) is in an arc shape as a whole.

4. A system for preparing isopropyl ether by isopropyl alcohol etherification reaction and distillation according to claim 3, characterized in that: The contact plate (5) is fixedly mounted on the tower plate (3) via a rotating shaft (51), and a protrusion (52) is arranged above the lower surface of the contact plate (5), and the protrusion (52) is arranged in an arc shape.

5. A system for preparing isopropyl ether by isopropyl alcohol etherification reaction and distillation according to claim 4, characterized in that: The rotating shaft (51) is installed tilted, and the height between the side of the contact plate (5) close to the overflow weir and the tower plate (3) is lower than that of the other side.

6. The system for preparing isopropyl ether by isopropyl alcohol etherification reaction and distillation according to claim 1, characterized in that: A cleaner (4) is installed on the inner wall of the tower body (2), and the cleaner (4) is located at one end of the tower body (2) close to the tower top; The cleaner (4) comprises a fixed rail (41), a floating ring (43) is installed below the fixed rail (41) via a spring (431), and the floating ring (43) is in contact with the inner wall of the tower body (2); The upper surfaces of the floating ring (43) and the fixed rail (41) are arranged as inclined surfaces, and a blade (432) is installed in the middle of the floating ring (43).

7. A system for preparing isopropyl ether by isopropyl alcohol etherification reaction and rectification according to claim 6, characterized in that: A sliding rail (42) is rotatably mounted below the fixed rail (41); the floating ring (43) is mounted on the sliding rail (42) via a spring (431); and the blade (432) is a fan blade having a driving rotation effect; A lower scraper rod (44) is installed below the floating ring (43), and an upper scraper rod (421) is installed on the sliding rail (42). The upper scraper rod (421) and the lower scraper rod (44) contact the inner wall of the tower body (2).

8. A system for preparing isopropyl ether by isopropyl alcohol etherification reaction and distillation according to claim 7, characterized in that: The upper scraper rod (421) and the lower scraper rod (44) are elastic, and guide grooves are provided on the surfaces of the upper scraper rod (421) and the lower scraper rod (44).

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