A propylene oxide reactor

Abstract

The invention belongs to the technical field of propylene oxide processing, in particular to an propylene oxide reactor; the invention comprises a saponification tower, a waste discharge pipe, a feed pipe, a discharge pipe and an impurity removal unit, wherein the saponification tower comprises a tower body, a tower cover, a tower plate, a steam coil and a condenser, wherein the tower cover is arranged on the top of the tower body, and the tower plate is evenly fixedly connected to the inner wall of the tower body; the invention drives the impurity removal shaft to rotate by a motor, so that a scraper acts on lime milk accumulated above the sieve plate, and the lime milk is effectively removed under the combined action of the scraping action of the scraper and the corrosive action of the pickling liquid, and the rotating scraper accelerates the flow of the pickling liquid while cleaning the lime milk, so that the pickling liquid accelerates the outflow of the dissolved lime milk, thereby reducing the corrosion of the pickling liquid to various components inside the tower body.

Description

Technical Field

[0001] The invention belongs to the technical field of propylene oxide processing, in particular to a propylene oxide reactor. Background Art

[0002] Propylene oxide, also known as propylene oxide and methyl ethylene oxide, is a very important raw material for organic compounds. It is the third largest propylene derivative after polypropylene and acrylonitrile. Propylene oxide is a colorless ether-smelling liquid with a low boiling point and is flammable. It is chiral, and industrial products are generally racemic mixtures of two enantiomers. It is partially miscible with water and miscible with ethanol and ether. It forms a binary azeotropic mixture with pentane, pentene, cyclopentane, cyclopentene, and dichloromethane. It is toxic and irritating to mucous membranes and skin, can damage the cornea and conjunctiva, cause respiratory pain, skin burns and swelling, and even tissue necrosis. For this reason, the preparation process needs to be carried out in a closed environment, and the stirring in the reactants is not thorough. When the stirring stops, the reactants tend to sink to the bottom of the liquid again, making the reactants react unevenly and reducing the mass of the produced propylene oxide.

[0003] There is also a patent in the prior art regarding a technical solution for a new type of saponification tower device. For example, a Chinese patent with application number CN2009202501659 discloses a new type of saponification tower device, specifically a saponification tower device for producing propylene oxide, including a tower body, a tower plate, a flushing water pipe, and a steam coil. The tower plate is fixed to the tower body, an arc-shaped flushing water pipe is provided on the tower plate, and a steam coil is provided at the lower part of the tower body. The tower plate is a double overflow tower plate and is provided with an overflow weir, and a downcomer is provided near the tower wall. The utility model has large production capacity, small pressure drop on the tower plate, high efficiency, and strong anti-clogging and scaling ability; however, the above patent still has defects. During the saponification reaction, because the high-pressure steam at the bottom rises and passes through the sieve holes on the tower plate, the sieve holes can be effectively prevented from being blocked by the lime milk waste remaining in the reaction. After the reaction is completed, the steam coil stops working. At this time, the flowing lime milk may enter the sieve holes and scale in the sieve holes, causing the sieve holes to be blocked; and during the flushing process, the flushing liquid can only act on the lime milk blocked on the top of the sieve holes, and continuous action is required to enable the lime milk in the sieve holes to be more thoroughly removed, the consumption of the flushing liquid is large, and the flushing efficiency is low, which limits the technical solution.

[0004] In view of this, the present invention solves the above technical problems by proposing a propylene oxide reactor. Summary of the invention

[0005] In order to make up for the deficiencies of the prior art and solve the problems that the existing saponification tower equipment for propylene oxide processing consumes a large amount of cleaning liquid during the cleaning process, has a low cleaning efficiency, and the sieve holes of the tower plate are easily blocked, which affects the production efficiency of propylene oxide; the present invention proposes a propylene oxide reactor.

[0006] The technical solution adopted by the present invention to solve its technical problems is as follows: the propylene oxide reactor described in the present invention comprises a saponification tower, a waste discharge pipe, a feed pipe, a discharge pipe and an impurity removal unit, the saponification tower comprises a tower body, a tower cover, a tower plate, a steam coil and a condenser, the tower cover is installed on the top of the tower body, the inner wall of the tower body is evenly fixedly connected with the tower plate, the tower plate is evenly provided with circular sieve holes, the upper surface of the tower plate near the edge is symmetrically fixedly connected with an overflow weir, the portion between the overflow weir and the inner wall of the tower body is fixedly connected with a downcomer, and the downcomers on adjacent tower plates are staggered; the inner part of the tower body near the bottom is installed with a steam coil, the tower cover is installed with a discharge pipe, and the discharge pipe is fixedly connected with a condenser below the end of the discharge pipe located inside the tower body condenser; the feed pipe passes through the side wall of the tower body near the top, and the end of the feed pipe located inside the tower body is opposite to the part between the overflow weirs on the tower plate; the waste discharge pipe is fixedly connected to the bottom of the tower body and communicates with the outside; the impurity removal unit includes a pickling pipe, an impurity removal shaft and a scraper, the end of the pickling pipe extends into the interior of the tower body and points to the upper surface of the tower plate at the highest height; a impurity removal shaft is provided near the middle of the interior of the tower body, the bottom of the impurity removal shaft is connected to the motor installed on the outer surface of the bottom of the tower body, and the impurity removal shaft passes through the tower plate and is rotatably connected to the tower plate; a plurality of scrapers are evenly installed on the outer surface of the impurity removal shaft near the upper surface of the tower plate, the scrapers are inclined, the scrapers are elastic plates, and the lower surface of the scrapers is close to the upper surface of the tower plate.

[0007] During operation, the chloropropanol aqueous solution with a concentration of 4%-5% from the chlorohydrinization process is preheated to a suitable temperature in a chlorobenzene alcohol preheater, and the preheated chloropropanol aqueous solution is mixed with lime milk to form a mixed solution, which is passed through the inside of the tower body through a feed pipe. The mixed solution accumulates on the tower plate and flows horizontally along the upper surface of the tower plate, flows along the downcomer to the tower plate below, and flows horizontally again into the downcomer; under the action of the overflow weir, the mixed solution forms a liquid layer of a certain thickness on the upper surface of each layer of the tower plate, and saponification reaction occurs between the chloropropanol and lime milk in the mixed solution during the flow process, and the chloropropanol is converted into propylene oxide under the saponification reaction; and while pouring the mixed solution, high-pressure high-pressure steam is filled into the steam coil. After the warm steam flows out from the micropores evenly distributed on the steam coil, the high-temperature steam rises under the impetus of the pressure difference. A part of the high-temperature steam rises from the downcomer and acts on the mixed solution in the downcomer, and another part of the mixed solution flows out from the sieve holes on each layer of the tower plate under the impetus of the pressure difference, and is dispersed into fine streams under the action of the sieve holes, and bubbles out from the liquid layer on the tower plate. The gas and liquid are in close contact and mass transfer is carried out. The propylene oxide mixed in the contacting mixed solution is heated and stripped out under the action of the high-temperature steam. Part of the stripped gas is condensed and refluxed by the condenser during the rising process and returns to the inside of the tower body. Most of the gas flows out from the discharge pipe after preliminary condensation to form crude propylene oxide. , and is sent to the next refining process, while the remaining lime milk waste in the reaction gradually flows and accumulates at the bottom of the tower body and flows out along the waste discharge pipe; during the long-term operation, a large amount of lime milk may accumulate on the upper surface of the tower plate and is difficult to flow and be cleaned, causing blockage on the top of the sieve hole and affecting the normal saponification reaction inside the tower body; therefore, after the saponification tower has been working for a long time, on the one hand, chloromethanol is injected into the tower body through the pickling pipe as a pickling liquid, and the hydrochloric acid in the chloromethanol is used to pickle the inside of the tower body, so that the accumulated and agglomerated lime milk is quickly dissolved under the action of hydrochloric acid, thereby accelerating the discharge of lime milk; on the other hand, the motor is started, and the motor drives the impurity removal shaft to rotate, so that the scraper connected to the impurity removal shaft acts on the top of the sieve plate The accumulated lime milk is effectively removed by the scraping action of the scraper and the corrosive action of the pickling solution. The rotating scraper accelerates the flow of the pickling solution while cleaning the lime milk, so that the pickling solution accelerates the outflow of the dissolved lime milk, thereby reducing the corrosion of the pickling solution to the internal parts of the tower body. Due to the effect of the overflow weir, when the scraper contacts the side of the overflow weir, the elastic scraper is compressed and deformed, and the side of the overflow weir is subjected to increased pressure as the deformation degree of the scraper increases, and is further scraped and cleaned. When the scraper continues to rotate and passes through the overflow weir, the deformation of the scraper is restored. During the deformation and recovery process of the scraper, the vibration of the scraper effectively removes the lime milk impurities attached to the scraper surface during the cleaning process.

[0008] Preferably, sawtooth blocks are evenly arranged on the lower surface of the scraper, and the ends of the sawtooth blocks are in contact with the upper surface of the tower tray.

[0009] During operation, as the scraper rotates, the sharp ends of the sawtooth blocks on the lower surface of the scraper scrape against the upper surface of the tower plate, causing the lime milk accumulated on the upper surface of the tower plate to be subjected to concentrated stress, so that the lime milk tightly attached to the upper surface of the tower plate is separated from the tower plate under the action of concentrated stress, so that the surface of the tower plate is cleaned more thoroughly; in addition, because the cross-section of the sawtooth block end is small, the sawtooth block can be embedded in the sieve hole during rotation and effectively remove the lime milk accumulated in the sieve hole, thereby ensuring the permeability of the sieve hole and further ensuring the normal progress of the saponification reaction inside the saponification tower.

[0010] Preferably, an anti-clogging device is nested on the sieve hole, and the anti-clogging device includes a plug cap, a scraper and a connecting rope. The plug cap is located above the sieve hole, and the upper surface of the plug cap is a smooth arc. A plurality of scrapers are annularly fixed to the lower surface of the plug cap. The end of the scraper is in contact with the inner wall of the sieve hole, and the bottom of the scraper extends out of the sieve hole and is fixed to the lower surface of the tower plate through a connecting rope, and the connecting rope is made of elastic steel rope.

[0011] During operation, because the plug cap is embedded in the sieve hole, the gap of the sieve hole is small, and the lime milk mixed in the mixed solution on the upper surface of the tower plate is difficult to enter the sieve hole due to the obstruction of the plug cap, which effectively reduces the blockage of the sieve hole; when the high-pressure steam flows upward inside the tower body, the high-pressure steam flows in from the bottom of the sieve hole, and is obstructed by the plug cap when flowing out. On the one hand, the plug cap is pressed upward, so that the gap of the sieve hole is increased, which is conducive to the outflow of high-pressure steam and accelerates the stripping effect on the propylene oxide product in the mixed solution; on the other hand, the high-pressure steam flowing out of the sieve hole is obstructed by the plug cap, and flows out horizontally from the gap between the plug cap and the sieve hole to fully contact with the mixed solution in the adjacent area, thereby improving the utilization rate of the high-pressure steam and reducing the proportion of high-pressure steam that is not fully utilized due to the inability to contact with the mixed solution due to vertical outflow; and when the plug cap is pressed upward, and moves downward under the squeezing action of the sawtooth block at the lower end of the rotating scraper after the reaction is completed, the scraper on the plug cap effectively cleans the inner wall surface of the sieve hole in the process of moving up and down with the plug cap, thereby ensuring the smooth flow of the sieve hole.

[0012] Preferably, a guide rod is fixedly connected to the upper surface of the plug cap, the guide rod has a circular cross-section and a smooth outer surface, and the guide rod is located at a position on the upper surface of the plug cap close to the impurity removal shaft.

[0013] During operation, in the process of clearing the accumulated lime milk after the reaction is completed, the end of the sawtooth block at the lower end of the rotating scraper comes into contact with the guide rod on the plug cap when it contacts the plug cap. Because the guide rod is a round shaft structure and the outer surface of the guide rod is smooth, the plug cap is driven to rotate after the guide rod is compressed, and the guide rod slides along the side of the sawtooth block and moves out from the gap between adjacent sawtooth blocks. At this time, the connecting rope connected to the plug cap pulls the plug cap to reset; on the one hand, the guide rod clears the lime milk attached to the gap between the sawtooth blocks in the process of moving out from the gap between the adjacent sawtooth blocks; on the other hand, in the process of rotating and resetting the plug cap, the scraper on the plug cap further clears the lime milk attached to the inner wall of the sieve hole, thereby ensuring the smooth flow of the sieve hole.

[0014] Preferably, a connecting groove is provided on the top of the impurity removal shaft, the end of the pickling pipe is directly opposite to the connecting groove, a drainage channel is provided at the position of the outer surface of the impurity removal shaft corresponding to the scraper, and a No. 1 drainage groove is provided on the surface of the scraper, and the No. 1 drainage groove is communicated with the drainage channel.

[0015] During operation, in the process of injecting the pickling liquid, because the end of the pickling pipe points to the receiving tank, the incoming pickling liquid flows into the receiving tank and then flows into the No. 1 drainage tank on the scraper under the action of the drainage channel, and accumulates in the No. 1 drainage tank and overflows the scraper surface. Therefore, the pickling liquid is in full contact with the scraper. On the one hand, the lime milk impurities accumulated on the scraper are effectively removed. On the other hand, the pickling liquid is sprinkled from the scraper and evenly distributed on the tower plate as the scraper rotates, so that the lime milk accumulated on the tower plate is evenly affected by the pickling liquid, thereby improving the utilization rate of the pickling liquid and making the lime milk on the tower plate be removed more thoroughly.

[0016] Preferably, the cross-sections of the No. 1 drainage groove and the drainage channel are both trapezoidal, and a No. 2 drainage groove is provided at a portion of the side wall of the No. 1 drainage groove corresponding to the gap between the sawtooth blocks, and the No. 2 drainage groove is used to introduce the pickling liquid inside the No. 1 drainage groove into the gap between the sawtooth blocks.

[0017] During operation, since the cross-sections of the No. 1 drainage trough and the drainage channel are both trapezoidal, and the cross-sections of the ends of the No. 1 drainage trough and the drainage channel close to the outside are smaller, the pickling liquid is well preserved after entering the No. 1 drainage trough and the drainage channel, effectively reducing the overflow of the pickling liquid from the outlet during the flow in the No. 1 drainage trough and the drainage channel, and reducing the loss of the pickling liquid during the flow; and after entering the No. 1 drainage trough, the pickling liquid flows into the gap of the sawtooth block under the action of the No. 2 drainage trough, and flows down along the surface of the sawtooth block, so that the lime milk mixed in the gap of the sawtooth block is effectively removed, and as the sawtooth block acts on the accumulated lime milk, the pickling liquid falls from the sawtooth block into the contact part with the tower plate, dissolves the agglomerated lime milk, and reduces the obstruction encountered by the sawtooth block in removing the lime milk.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. The propylene oxide reactor described in the present invention drives the impurity removal shaft to rotate by a motor, so that the scraper connected to the impurity removal shaft acts on the lime milk accumulated above the sieve plate, and the lime milk is effectively removed under the combined action of the scraping action of the scraper and the corrosive action of the pickling solution. The rotating scraper accelerates the flow of the pickling solution while cleaning the lime milk, so that the pickling solution accelerates the outflow of the dissolved lime milk, thereby reducing the corrosion of the pickling solution to the internal components of the tower body; and because the elastic scraper is compressed and deformed when the scraper contacts the side of the overflow weir, and the deformation of the scraper is restored after the scraper continues to rotate and passes through the overflow weir, during the deformation and restoration of the scraper, the scraper vibrates, so that the lime milk impurities attached to the scraper surface during the cleaning process are effectively removed.

[0020] 2. The propylene oxide reactor described in the present invention scrapes the upper surface of the tower plate with the ends of the sawtooth blocks evenly arranged on the lower surface of the scraper, so that the lime milk accumulated on the upper surface of the tower plate is subjected to concentrated stress, so that the lime milk tightly attached to the upper surface of the tower plate is separated from the tower plate under the action of the concentrated stress, so that the surface of the tower plate is cleared more thoroughly; in addition, because the cross-section of the end of the sawtooth block is small, the sawtooth block can be embedded in the sieve hole during the rotation process and the lime milk accumulated in the sieve hole can be effectively cleared, further ensuring the permeability of the sieve hole, so that the saponification reaction inside the saponification tower proceeds normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the accompanying drawings.

[0022] Figure 1 is a cross-sectional view of the present invention;

[0023] Figure 2 It is a top view of the present invention after removing the tower cover;

[0024] Figure 3 yes Figure 1 A partial enlarged view of the middle A;

[0025] Figure 4 yes Figure 2 A partial enlarged view of point B in the middle;

[0026] Figure 5 is a cross-sectional view of the scraper in the present invention;

[0027] In the figure: saponification tower 1, tower body 11, tower cover 12, tower plate 13, sieve hole 131, overflow weir 132, downcomer 133, steam coil 14, condenser 15, waste pipe 2, feed pipe 3, discharge pipe 4, impurity removal unit 5, pickling pipe 51, impurity removal shaft 52, receiving trough 521, drainage channel 522, No. 1 drainage trough 523, No. 2 drainage trough 524, scraper 53, sawtooth block 531, anti-blocking 54, plug cap 541, scraper 542, connecting rope 543, guide rod 544. DETAILED DESCRIPTION

[0028] 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.

[0029] like Figures 1 to 5 As shown, a propylene oxide reactor described in the present invention comprises a saponification tower 1, a waste pipe 2, a feed pipe 3, a discharge pipe 4 and an impurity removal unit 5, wherein the saponification tower 1 comprises a tower body 11, a tower cover 12, a tower plate 13, a steam coil 14 and a condenser 15, wherein the tower cover 12 is installed on the top of the tower body 11, the tower plate 13 is evenly fixedly connected to the inner wall of the tower body 11, and circular sieve holes 131 are evenly opened on the tower plate 13, and overflow weirs 132 are symmetrically fixedly connected to the portion near the edge of the upper surface of the tower plate 13, and a downcomer 133 is fixedly connected to the portion between the overflow weir 132 and the inner wall of the tower body 11, and the downcomers 133 on adjacent tower plates 13 are staggered; a steam coil 14 is installed near the bottom of the tower body 11, a discharge pipe 4 is installed on the tower cover 12, and a condenser 15 is fixedly connected to the lower end of the discharge pipe 4 located inside the tower body 11; the feed The pipe 3 passes through the side wall of the tower body 11 near the top, and the end of the feed pipe 3 located inside the tower body 11 faces the part between the overflow weirs 132 on the tower plate 13; the waste discharge pipe 2 is fixedly connected to the bottom of the tower body 11 and communicates with the outside; the impurity removal unit 5 includes a pickling pipe 51, an impurity removal shaft 52 and a scraper 53, the end of the pickling pipe 51 extends into the tower body 11 and points to the upper surface of the tower plate 13 at the highest height; the impurity removal shaft 52 is provided near the middle of the tower body 11, the bottom of the impurity removal shaft 52 is connected to the motor installed on the outer surface of the bottom of the tower body 11, and the impurity removal shaft 52 passes through the tower plate 13 and is rotatably connected to the tower plate 13; a plurality of scrapers 53 are evenly installed on the outer surface of the impurity removal shaft 52 near the upper surface of the tower plate 13, the scrapers 53 are inclined, the scrapers 53 are elastic plates, and the lower surface of the scrapers 53 is close to the upper surface of the tower plate 13.

[0030] During operation, the chloropropanol aqueous solution with a concentration of 4%-5% from the chlorohydrinization process is preheated to a suitable temperature in the chlorobenzene alcohol preheater, and the preheated chloropropanol aqueous solution is mixed with lime milk to form a mixed solution, and then passes through the inside of the tower body 11 through the feed pipe 3. The mixed solution accumulates on the tower tray 13 and flows horizontally along the upper surface of the tower tray 13, flows along the downcomer 133 to the tower tray 13 below, and flows horizontally again into the downcomer 133; under the action of the overflow weir 132, the mixed solution forms a liquid layer of a certain thickness on the upper surface of each layer of the tower tray 13, and saponification reaction occurs between the chloropropanol and lime milk in the mixed solution during the flow process, and the chloropropanol is converted into propylene oxide under the saponification reaction; and while pouring the mixed solution When the steam coil 14 is filled with high-temperature steam under high pressure, the high-temperature steam flows out from the micropores evenly distributed on the steam coil 14, and then rises under the driving force of the pressure difference. A part of the high-temperature steam rises from the downcomer 133 and acts on the mixed solution in the downcomer 133, and another part of the mixed solution flows out from the sieve holes 131 on each layer of the tower plate 13 under the driving force of the pressure difference, and is dispersed into fine streams under the action of the sieve holes 131, and bubbles out from the liquid layer on the tower plate 13. The gas and liquid are in close contact and mass transfer is carried out. The propylene oxide mixed in the contacted mixed solution is heated and stripped out under the action of the high-temperature steam, and a part of the stripped gas is condensed and refluxed by the condenser 15 during the rising process, and returns to the tower plate 13. Inside the tower body 11, most of the gas flows out from the discharge pipe 4 to form crude propylene oxide after preliminary condensation, and is sent to the next refining process, while the remaining lime milk waste in the reaction gradually flows and accumulates at the bottom of the tower body 11 and flows out along the waste discharge pipe 2; during the long-term operation, a large amount of lime milk may accumulate on the upper surface of the tower plate 13 and is difficult to flow and be cleaned, causing blockage at the top of the sieve hole 131 and affecting the normal saponification reaction inside the tower body 11; therefore, after the saponification tower 1 has been working for a long time, on the one hand, chloromethane is injected into the tower body 11 through the pickling pipe 51 as a pickling liquid, and the hydrochloric acid in the chloromethane is used to pickle the inside of the tower body 11, so that the accumulated agglomerated lime milk is quickly dissolved under the action of hydrochloric acid, accelerating On the other hand, the motor is started, and the motor drives the impurity removal shaft 52 to rotate, so that the scraper 53 connected to the impurity removal shaft 52 acts on the lime milk accumulated above the screen plate, and the lime milk is effectively removed under the combined action of the scraping action of the scraper 53 and the corrosive action of the pickling solution, and the rotating scraper 53 accelerates the flow of the pickling solution while cleaning the lime milk, so that the pickling solution accelerates the outflow of the dissolved lime milk, thereby reducing the corrosion of the pickling solution to the internal components of the tower body 11; and because of the action of the overflow weir 132, when the scraper 53 contacts the side of the overflow weir 132, the elastic scraper 53 is compressed and deformed, and the side of the overflow weir 132 is subjected to increased pressure as the deformation degree of the scraper 53 increases, and is further subjected to the scraping and cleaning action;When the scraper 53 continues to rotate and passes through the overflow weir 132, the deformation of the scraper 53 is restored. During the deformation and restoration process of the scraper 53, the scraper 53 vibrates so that the lime milk impurities attached to the surface of the scraper 53 during the cleaning process are effectively removed. ;

[0031] As a specific embodiment of the present invention, sawtooth blocks 531 are evenly arranged on the lower surface of the scraper 53 , and the ends of the sawtooth blocks 531 are in contact with the upper surface of the tower tray 13 .

[0032] During operation, as the scraper 53 rotates, the end of the sawtooth block 531 on the lower surface of the scraper 53 scrapes against the upper surface of the tower plate 13. The sharp end causes the lime milk accumulated on the upper surface of the tower plate 13 to be subjected to concentrated stress, so that the lime milk tightly attached to the upper surface of the tower plate 13 is separated from the tower plate 13 under the action of concentrated stress, so that the surface of the tower plate 13 is cleared more thoroughly; in addition, because the cross-section of the end of the sawtooth block 531 is small, the sawtooth block 531 can be embedded in the sieve hole 131 during the rotation process and the lime milk accumulated in the sieve hole 131 can be effectively cleared, thereby ensuring the permeability of the sieve hole 131, and further ensuring the normal progress of the saponification reaction inside the saponification tower 1.

[0033] As a specific embodiment of the present invention, an anti-clogging 54 is nested on the sieve hole 131, and the anti-clogging 54 includes a plug cap 541, a scraper 542 and a connecting rope 543. The plug cap 541 is located above the sieve hole 131, and the upper surface of the plug cap 541 is a smooth arc. A plurality of scrapers 542 are annularly fixed to the lower surface of the plug cap 541. The ends of the scrapers 542 are in contact with the inner wall of the sieve hole 131, and the bottoms of the scrapers 542 extend out of the sieve hole 131 and are fixedly connected to the lower surface of the tower plate 13 through the connecting rope 543, and the connecting rope 543 is made of elastic steel rope.

[0034] During operation, since the plug cap 541 is embedded in the sieve hole 131, the gap of the sieve hole 131 is small, and the lime milk mixed in the mixed solution on the upper surface of the tower plate 13 is difficult to enter the sieve hole 131 due to the obstruction of the plug cap 541, which effectively reduces the blockage of the sieve hole 131; when the high-pressure steam flows upward inside the tower body 11, the high-pressure steam flows in from the bottom of the sieve hole 131, and is obstructed by the plug cap 541 when flowing out. On the one hand, the plug cap 541 is pressed upward, so that the gap of the sieve hole 131 is increased, which is conducive to the outflow of high-pressure steam and accelerates the stripping effect on the propylene oxide product in the mixed solution; on the other hand, The high-pressure steam flowing out of the sieve hole 131 is blocked by the plug cap 541, and flows out horizontally from the gap between the plug cap 541 and the sieve hole 131 to fully contact the mixed solution in the adjacent area, thereby improving the utilization rate of the high-pressure steam and reducing the proportion of high-pressure steam that is not fully utilized due to the inability to contact the mixed solution due to vertical outflow; and when the plug cap 541 moves upward under pressure and moves downward under the squeezing action of the sawtooth block 531 at the lower end of the rotating scraper 53 after the reaction is completed, the scraper 542 on the plug cap 541 effectively cleans the inner wall surface of the sieve hole 131 in the process of moving up and down with the plug cap 541, thereby ensuring the smooth flow of the sieve hole 131.

[0035] As a specific embodiment of the present invention, a guide rod 544 is fixedly connected to the upper surface of the plug cap 541 . The guide rod 544 has a circular cross-section and a smooth outer surface. The guide rod 544 is located on the upper surface of the plug cap 541 near the impurity removal shaft 52 .

[0036] During operation, in the process of removing the accumulated lime milk after the reaction is completed, the end of the sawtooth block 531 at the lower end of the rotating scraper 53 contacts the plug cap 541 and the guide rod 544 on the plug cap 541. Because the guide rod 544 is a round shaft structure and the outer surface of the guide rod 544 is smooth, the plug cap 541 is driven to rotate after the guide rod 544 is pressed, and the guide rod 544 slides along the side of the sawtooth block 531 and moves out from the gap between adjacent sawtooth blocks 531. At this time, the connecting rope 543 connected to the plug cap 541 pulls the plug cap 541 to reset; on the one hand, the guide rod 544 plays a role in removing the lime milk attached to the gap between the sawtooth blocks 531 in the process of moving out from the gap between the adjacent sawtooth blocks 531; on the other hand, in the process of rotating and resetting the plug cap 541, the scraper 542 on the plug cap 541 plays a further role in removing the lime milk attached to the inner wall of the sieve hole 131, thereby ensuring the smooth flow of the sieve hole 131.

[0037] As a specific embodiment of the present invention, a connecting groove 521 is provided on the top of the impurity removal shaft 52, and the end of the pickling pipe 51 is directly opposite to the connecting groove 521. A drainage channel 522 is provided on the outer surface of the impurity removal shaft 52 corresponding to the scraper 53, and a No. 1 drainage groove 523 is provided on the surface of the scraper 53, and the No. 1 drainage groove 523 is communicated with the drainage channel 522.

[0038] During operation, in the process of injecting the pickling liquid, because the end of the pickling pipe 51 points to the receiving groove 521, the incoming pickling liquid flows into the receiving groove 521 and then flows into the No. 1 drainage groove 523 on the scraper 53 under the action of the drainage channel 522, and accumulates in the No. 1 drainage groove 523 and overflows the scraper surface. Therefore, the pickling liquid is in full contact with the scraper 53. On the one hand, the lime milk impurities accumulated on the scraper 53 are effectively removed. On the other hand, the pickling liquid is sprinkled from the scraper 53 and evenly distributed on the tower plate 13 as the scraper 53 rotates, so that the lime milk accumulated on the tower plate 13 is evenly affected by the pickling liquid, thereby improving the utilization rate of the pickling liquid and making the lime milk on the tower plate 13 removed more thoroughly.

[0039] As a specific embodiment of the present invention, the cross-sections of the No. 1 drainage groove 523 and the drainage channel 522 are both trapezoidal, and a No. 2 drainage groove 524 is provided at a position corresponding to the gap between the side wall of the No. 1 drainage groove 523 and the sawtooth block 531, and the No. 2 drainage groove 524 is used to introduce the pickling liquid inside the No. 1 drainage groove 523 into the gap between the sawtooth blocks 531.

[0040] During operation, since the cross-sections of the No. 1 drainage groove 523 and the drainage channel 522 are both trapezoidal, and the cross-sections of the ends of the No. 1 drainage groove 523 and the drainage channel 522 close to the outside are smaller, the pickling liquid is well preserved after entering the No. 1 drainage groove 523 and the drainage channel 522, effectively reducing the overflow of the pickling liquid from the outlet during the flow in the No. 1 drainage groove 523 and the drainage channel 522, and reducing the loss of the pickling liquid during the flow; and after entering the No. 1 drainage groove 523, the pickling liquid flows into the gap of the sawtooth block 531 under the action of the No. 2 drainage groove 524, and flows down along the surface of the sawtooth block 531, so that the lime milk mixed in the gap of the sawtooth block 531 is effectively removed, and as the sawtooth block 531 acts on the accumulated lime milk, the pickling liquid falls from the sawtooth block 531 into the contact area with the tower plate 13, dissolves the agglomerated lime milk, and reduces the obstruction encountered by the sawtooth block 531 when removing the lime milk.

[0041] The specific workflow is as follows:

[0042] During operation, the chloropropanol aqueous solution with a concentration of 4%-5% from the chlorohydrinization process is preheated to a suitable temperature in the chlorobenzene alcohol preheater, and the preheated chloropropanol aqueous solution is mixed with lime milk to form a mixed solution, and then passes through the inside of the tower body 11 through the feed pipe 3. The mixed solution accumulates on the tower tray 13 and flows horizontally along the upper surface of the tower tray 13, flows along the downcomer 133 to the tower tray 13 below, and flows horizontally again into the downcomer 133; under the action of the overflow weir 132, the mixed solution forms a liquid layer of a certain thickness on the upper surface of each layer of the tower tray 13, and saponification reaction occurs between the chloropropanol in the mixed solution and the lime milk during the flow process, and the chloropropanol is converted into propylene oxide under the saponification reaction. and at the same time as the mixed solution is poured in, high-pressure high-temperature steam is filled into the steam coil 14. After the high-temperature steam flows out from the micropores evenly distributed on the steam coil 14, the high-temperature steam rises under the driving action of the pressure difference. A part of the high-temperature steam rises from the downcomer 133 and acts on the mixed solution in the downcomer 133. Another part of the mixed solution flows out from the sieve holes 131 on each layer of the tower plate 13 under the driving action of the pressure difference, and is dispersed into fine streams under the action of the sieve holes 131, and bubbles out from the liquid layer on the tower plate 13. The gas and liquid are in close contact and mass transfer is carried out. The propylene oxide mixed in the contacted mixed solution is heated and stripped out under the action of the high-temperature steam, and part of the stripped propylene oxide is heated and stripped out. During the rising process, the gas is condensed and refluxed by the condenser 15 and returns to the inside of the tower body 11. Most of the gas flows out from the discharge pipe 4 to form crude propylene oxide after preliminary condensation and is sent to the next refining process, while the remaining lime milk waste in the reaction gradually flows and accumulates at the bottom of the tower body 11 and flows out along the waste discharge pipe 2; after the saponification tower 1 has been working for a long time, on the one hand, chloromethanol is injected into the tower body 11 through the pickling pipe 51 as a pickling liquid, and the hydrochloric acid in the chloromethanol is used to pickle the inside of the tower body 11; on the other hand, the motor is started, and the motor drives the impurity removal shaft 52 to rotate, so that the scraper 53 connected to the impurity removal shaft 52 acts on the lime milk accumulated above the sieve plate; when the high-pressure steam is in the tower body 11, the impurity removal shaft 52 is driven by the motor ... When the high-pressure steam flows upward, it flows in from the bottom of the sieve hole 131 and is hindered by the plug cap 541 when flowing out. On the one hand, the plug cap 541 is pressed upward, so that the gap leaking from the sieve hole 131 is increased, which is conducive to the outflow of high-pressure steam; on the other hand, the high-pressure steam flowing out of the sieve hole 131 is hindered by the plug cap 541, and flows out laterally from the gap between the plug cap 541 and the sieve hole 131 to fully contact the mixed solution in the adjacent area; and when the plug cap 541 is pressed upward and moves downward under the squeezing action of the sawtooth block 531 at the lower end of the rotating scraper 53 after the reaction is completed, the scraper 542 on the plug cap 541 cleans the inner wall surface of the sieve hole 131 in the process of moving up and down with the plug cap 541.

[0043] The above-mentioned front, back, left, right, top and bottom are all based on the figures in the specification. Figure 1As a benchmark, according to the person's observation perspective, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0044] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0045] 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 propylene oxide reactor, characterized in that: The invention comprises a saponification tower (1), a waste discharge pipe (2), a feed pipe (3), a discharge pipe (4) and an impurity removal unit (5). The saponification tower (1) comprises a tower body (11), a tower cover (12), a tower plate (13), a steam coil (14) and a condenser (15). The tower cover (12) is installed on the top of the tower body (11). The tower plate (13) is evenly fixed to the inner wall of the tower body (11). The tower plate (13) is evenly provided with circular sieve holes (131). The upper surface of the tower plate (13) is close to the edge. An overflow weir (132) is symmetrically fixedly connected to the position of the tower body (11); a downcomer (133) is fixedly connected to the position between the overflow weir (132) and the inner wall of the tower body (11); and the downcomers (133) on adjacent tower plates (13) are arranged in a staggered manner; a steam coil (14) is installed at a position near the bottom of the tower body (11); a discharge pipe (4) is installed on the tower cover (12); and a condenser (15) is fixedly connected to the lower end of the discharge pipe (4) located inside the tower body (11); the feed pipe (3) passes through the tower body (11); The tower body (11) is provided with a side wall near the top thereof, and the end of the feed pipe (3) located inside the tower body (11) faces the part between the overflow weirs (132) on the tower plate (13); the waste discharge pipe (2) is fixedly connected to the bottom of the tower body (11) and communicates with the outside; the impurity removal unit (5) comprises an acid cleaning pipe (51), an impurity removal shaft (52) and a scraper (53); the end of the acid cleaning pipe (51) extends into the interior of the tower body (11) and points to the upper surface of the tower plate (13) with the highest height; the tower body (11) is provided with a side wall near the top of the tower body (11), and the end of the feed pipe (3) located inside the tower body (11) faces the part between the overflow weirs (132) on the tower plate (13); the waste discharge pipe (2) is fixedly connected to the bottom of the tower body (11) and communicates with the outside; the impurity removal unit (5) comprises an acid cleaning pipe (51), an impurity removal shaft (52) and a scraper (53); the end of the acid cleaning pipe (51) extends into the interior of the tower body (11) and points to the upper surface of the tower plate (13) with the highest height; 1) A cleaning shaft (52) is provided at a position near the middle of the interior, the bottom of the cleaning shaft (52) is connected to a motor installed on the outer surface of the bottom of the tower body (11), and the cleaning shaft (52) passes through the tower plate (13) and is rotatably connected to the tower plate (13); a plurality of scrapers (53) are evenly installed at a position near the upper surface of the tower plate (13) on the outer surface of the cleaning shaft (52), the scrapers (53) are inclined, the scrapers (53) are elastic plates, and the lower surface of the scrapers (53) is close to the upper surface of the tower plate (13); The lower surface of the scraper (53) is evenly provided with sawtooth blocks (531), and the ends of the sawtooth blocks (531) are in contact with the upper surface of the tower tray (13); An anti-clogging device (54) is nested on the sieve hole (131), and the anti-clogging device (54) comprises a plug cap (541), a scraper (542) and a connecting rope (543). The plug cap (541) is located above the sieve hole (131), and the upper surface of the plug cap (541) is in a smooth arc shape. A plurality of scrapers (542) are annularly fixedly connected to the lower surface of the plug cap (541). The ends of the scrapers (542) are in contact with the inner wall of the sieve hole (131), and the bottoms of the scrapers (542) extend out of the sieve hole (131) and are fixedly connected to the lower surface of the tower plate (13) via the connecting rope (543), and the connecting rope (543) is made of elastic steel rope. A guide rod (544) is fixedly connected to the upper surface of the plug cap (541); the guide rod (544) has a circular cross section and a smooth outer surface; the guide rod (544) is located at a position on the upper surface of the plug cap (541) close to the impurity removal shaft (52).

2. A propylene oxide reactor according to claim 1, characterized in that: The top of the impurity removal shaft (52) is provided with a connection groove (521), the end of the pickling pipe (51) is directly aligned with the connection groove (521), a drainage channel (522) is provided at a portion of the outer surface of the impurity removal shaft (52) corresponding to the scraper (53), a first drainage groove (523) is provided on the surface of the scraper (53), and the first drainage groove (523) is communicated with the drainage channel (522).

3. A propylene oxide reactor according to claim 2, characterized in that: The cross-sections of the No. 1 drainage groove (523) and the drainage channel (522) are both trapezoidal, and a No. 2 drainage groove (524) is provided at a position corresponding to the gap between the side wall of the No. 1 drainage groove (523) and the sawtooth block (531), and the No. 2 drainage groove (524) is used to guide the pickling liquid inside the No. 1 drainage groove (523) into the gap between the sawtooth blocks (531).

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