CN214913483U - Rectifying device for separating acrolein - Google Patents

Abstract

The utility model relates to a chemical industry equipment field discloses a rectification device of separation acrolein, and the device uses the feed inlet to divide into rectification section and stripping section as the boundary, and the high-efficient direction column plate is adopted on the upper portion of rectification section, and the lower part adopts the direction three-dimensional injection column plate, and the stripping section adopts the compound three-dimensional injection column plate of direction. The rectifying device adopting various tower plates utilizes the good performance of each tower internal part, improves the separation efficiency of the rectifying device, and reduces the polymerization tendency of a separation system, thereby prolonging the operation period of the rectifying device and reducing the loss of raw material acrolein. The device has the advantages of reduced pressure, high mass transfer efficiency, and the acrolein content in the separated material is less than 0.5% (mass fraction), and can meet the requirement of the subsequent hydrogenation reaction.

Description

Rectifying device for separating acrolein

Technical Field

The utility model relates to a chemical industry equipment field especially relates to a separation acrolein's rectifier unit.

Background

The preparation of 3-hydroxy-propionaldehyde by acrolein hydration is the first step reaction in the process of preparing 1, 3-propylene glycol from acrolein, and the reaction is to generate the 3-hydroxy-propionaldehyde under the action of an acidic resin catalyst. In order to improve the selectivity of the product, the conversion rate of the acrolein is maintained at 40-70%, the content of the acrolein in the generated hydrated liquid is high, so that not only is the waste of the raw material acrolein caused, but also the catalyst of the subsequent hydrogenation reaction is affected, the by-products in the product are increased, and the difficulty in refining the product is increased. And because the acrolein is unsaturated aldehyde and has active chemical property, the self-polymerization reaction can be carried out at the temperature of more than 60 ℃, and the 3-hydroxypropionaldehyde and the acrolein can carry out aldol condensation reaction, thereby reducing the product yield and influencing the purity of the product. It is therefore necessary to separate acrolein from the hydration liquid before the hydrogenation reaction.

The traditional process adopts a rectification mode to separate and recover acrolein from a hydration liquid, a rectification device mostly adopts bulk packing or large-aperture sieve tray, but the internal parts are easy to block and have low mass transfer efficiency, the packing is replaced after the blockage, the device can be stopped, the productivity of the device is influenced, the pressure drop of the whole tower is increased after the tray is blocked, the temperature of the whole tower is increased, and the polymerization reaction of the acrolein and the 3-hydroxypropionaldehyde is accelerated. Patents US3518310, US5093537, US6140543 propose to use a thin film evaporator to reduce the contact time of the hydration liquid with the heat source and reduce the polymerization reaction of acrolein and 3-hydroxypropionaldehyde, but the equipment investment of the falling film evaporator is large and the operation is difficult; patent CN1398843A proposes that inert gas is introduced into the bottom of a rectifying tower to reduce the temperature of a tower kettle, but the condensing efficiency at the top of the tower is reduced, and the load of tail gas treatment is increased; patent CN101033180A proposes to adopt the mode of setting up different kinds of tower internals in segmentation, and the rectification section upper portion adopts novel vertical sieve board promptly, and the rectification section upper segment adopts the parallel flow injection packing column plate, and the stripping section adopts regular packing. The novel vertical sieve plate adopted by the combined internal part plays respective advantages, an arch area and more liquid phase dead areas exist on a plate of a parallel flow injection packed tower, so that the liquid phase is promoted to polymerize on the plate, and the packing arranged in a stripping section promotes the polymerization of the 3-hydroxypropionaldehyde.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the utility model provides a rectifier unit of separation acrolein. The utility model discloses the device uses the feed inlet to divide into rectifying section and stripping section from top to bottom as the limit, and rectifying section upper portion adopts high-efficient direction column plate, and the rectifying section lower part adopts the three-dimensional injection column plate of direction, and the stripping section adopts the compound three-dimensional injection column plate of direction. By selecting different internal parts in the rectifying device, the problem of polymerization of acrolein and 3-hydroxypropionaldehyde in the separation process is solved, and the operation period of the rectifying device is prolonged.

The utility model discloses a concrete technical scheme does: the utility model provides a rectifier unit of separation acrolein, includes the tower body, the top, lateral part and the bottom of tower body are equipped with top of the tower gas phase export, feed inlet and the liquid phase export at the bottom of the tower respectively. The tower body is divided into a rectifying section positioned at the upper section and a stripping section positioned at the lower section by taking the feed inlet as a boundary; a plurality of guide three-dimensional jet tower plates and a plurality of efficient guide tower plates are arranged in the rectifying section from bottom to top; a plurality of guide composite three-dimensional jet tower plates are arranged in the stripping section; the high-efficiency guide tower plates, the guide three-dimensional spray tower plates and the guide composite three-dimensional spray tower plates are respectively arranged in a staggered mode to form a baffling channel.

The utility model discloses the device uses the feed inlet to divide into rectifying section and stripping section from top to bottom as the limit, and rectifying section upper portion adopts high-efficient direction column plate, and the rectifying section lower part adopts the three-dimensional injection column plate of direction, and the stripping section adopts the compound three-dimensional injection column plate of direction.

The working principle of the device is as follows: the separated material liquid (the hydration liquid solution containing acrolein and 3-hydroxy propionaldehyde) enters the tower from the feed inlet, the mixed liquid and the gas phase rising from the tower bottom carry out mass transfer on the tower plate of the stripping section, and part of the uncondensed gas phase enters the reflux liquid on the tower plate of the rectifying section to continuously carry out gas-liquid mass transfer. The light component acrolein is obtained at the tower top and the water solution of the heavy component 3-hydroxypropionaldehyde is obtained at the tower bottom through the gas-liquid mass transfer process on the tower plates of the rectifying section and the stripping section.

The invention can solve the problem of polymerization of acrolein and 3-hydroxypropionaldehyde in the separation process by selecting different internal parts in the rectifying device, thereby increasing the operation period of the rectifying device.

Preferably, the efficient guide column plate is provided with guide holes, the edges of the guide holes are provided with guide plates protruding upwards, and the opening of a slot formed by the guide holes and the guide plates is consistent with the flowing direction of the liquid phase on the efficient guide column plate where the guide holes and the guide plates are located.

In the above structure, the guide hole and the guide plate are combined to form a slit, and the opening of the slit coincides with the flow direction of the liquid phase. During operation, the gas phase rising from the lower tray enters the liquid phase on the tray through the guide holes and the slits, and in the process, the direction of the gas phase ejected from the slits and the direction of the liquid flow are at an angle, and the gas phase can be divided into a horizontal direction and a vertical direction by a velocity decomposition method (see FIG. 4). The gas phase in the vertical direction vertically rises and passes through the liquid layer on the tower plate to form bubbling for mass transfer, and the horizontal direction is the same as the flowing direction of the liquid phase on the tower plate, so that the flowing of the liquid phase on the tower plate can be promoted, the reduction of the liquid phase gradient is promoted, the occurrence of back mixing is reduced, and the formation of a dead zone on the tower plate is prevented.

Preferably, the distribution density of the guide holes on the high-efficiency guide tower plate at the position close to the side wall of the tower body is greater than that of the center of the high-efficiency guide tower plate.

The reason for the above design is: the part close to the tower wall is a liquid phase flow slow zone on the tower plate, and a mass transfer dead zone is easily formed at the position. The arrangement number of the guide holes is increased, so that the liquid phase on the pushing plate can be pushed to flow, and mass transfer dead zones can be prevented.

Preferably, the guided solid spray tray comprises a tray and a cap; the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole and a guide hole; each large hole upper cover is provided with the cap cover, the side wall of the cap cover is provided with sieve holes, and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit and a lower end slit respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.

In the structure, the tower plate is provided with a large hole (such as a round or rectangular hole), the hole is provided with a cap cover with a corresponding shape, the side surface of the upper end of the cap cover is provided with a sieve hole, the top and the bottom of the cap cover are provided with a slit, and the slit is arranged between the bottom of the cap cover and the tower plate. A number of guide holes are arranged close to the tower side wall. In the operation process, the gas phase of the lower tower plate enters the tower plate through the guide holes and the large holes on the plate respectively. The gas phase entering the guide holes and the slits promotes the reduction of the liquid phase gradient and reduces the occurrence of back-mixing, preventing the formation of dead zones on the tray. The gas phase entering the large holes on the plate lifts the liquid phase on the column plate from the slit at the lower end of the bottom of the cap cover, the liquid phase starts to be broken in the lifting process to form small liquid drops and is fully contacted and mixed with the gas phase, one part of the rising gas-liquid mixed phase is sprayed out of the cap cover through the sieve holes on the cap cover, and the other part of the rising gas-liquid mixed phase is sprayed out of the slit at the upper end of the top of the cap cover.

Preferably, the guide composite three-dimensional jet tower plate comprises a tower plate, a cap and a filler; the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole and a guide hole; each large hole upper cover is provided with the cap cover, the filler is filled at the top of the cap cover, sieve holes are distributed on the side wall of the cap cover, and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit and a lower end slit respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.

The difference between the guiding composite stereo jet tower plate and the guiding stereo jet tower plate is that a packing layer is additionally arranged at the upper end of a cap cover, a part of liquid phase entering the cap cover from a slit at the lower end of the bottom of the cap cover is sprayed out of the cap cover from a sieve hole after being crushed into small liquid drops, and the other part of liquid phase enters the packing layer at the upper end of the cap cover to complete mass transfer of gas phase and liquid phase.

Preferably, the cross section of the guide plate is an arc shape with an inner arc surface facing the guide hole.

The arc-shaped arrangement can effectively change the ascending gas phase direction into the direction of nearly 45 degrees obliquely upwards.

Preferably, the filler is a metal open-cell plate corrugated filler or a metal open-cell wire mesh filler.

Preferably, the number of the high-efficiency guide tower plates accounts for 10-40%, preferably 15-30% of the total number of the tower plates; the number of the guide three-dimensional jet tower plates accounts for 5-35%, preferably 15-30% of the total number of the tower plates; the number of the guide composite three-dimensional jet tower plates accounts for 15-70%, preferably 30-60% of the total number of the tower plates.

The reason for the above allocation is: the high-efficiency guide sieve plate has good anti-blocking performance, but has poor mass transfer efficiency and high pressure drop, and is used in an area with higher acrolein concentration at the upper part of the rectification section; the anti-blocking performance of the guide three-dimensional injection tower is weaker than that of the guide three-dimensional injection tower, but the mass transfer efficiency is higher and the pressure drop is low, and the guide three-dimensional injection tower is used for the lower part of the rectifying section; the guide composite stereo jet tower plate has high mass transfer efficiency, great pressure drop and poor blocking resistance, and is used in the stripping section area.

Preferably, the aperture ratio of the high-efficiency guide column plate is 5-15%; the aperture ratio of the guide three-dimensional jet tower plate is 5-20%, and the aperture of the upper aperture of the cap cover is 3-15 mm; the aperture ratio of the guide composite three-dimensional jet column plate is 5-20%, the aperture of the upper aperture of the cap cover is 3-15 mm, and the thickness of the filler accounts for 20-40% of the height of the cap cover.

The aperture ratio is reasonable, the pressure drop of the tower plate can be increased if the aperture ratio is small, the temperature of the tower kettle is not favorably reduced, abnormal operations such as liquid leakage and the like are easily generated on the tower plate with large aperture ratio, the mass transfer efficiency of the tower plate is reduced, and the number of theoretical plates of the whole tower is reduced. Similarly, too small an aperture will increase the pressure drop of the column plate, and too large an aperture will be unfavorable for the contact of gas-liquid two-phase, reducing the mass transfer efficiency of the column plate.

Preferably, the upper side and the lower side of the notch edge of the high-efficiency guide tower plate, the guide three-dimensional spray tower plate and the guide composite three-dimensional spray tower plate are respectively provided with an overflow weir and a down-flow guide plate; wherein: the height of an overflow weir on the high-efficiency guide column plate is 5-45 mm, the height of an overflow weir on the guide three-dimensional spray column plate is 10-50 mm, and the height of an overflow weir on the guide composite three-dimensional spray column plate is 10-50 mm; the radial cross section of falling liquid deflector is the arc parallel with the tower body lateral wall, falls the liquid deflector and is cascaded downwardly extending and be close to the tower body lateral wall and arc length shortens.

Compared with the prior art, the beneficial effects of the utility model are that:

the utility model discloses a choose the column plate of different grade type for use, rectification section upper portion adopts the high-efficient column plate that leads, and the three-dimensional injection column plate that leads is adopted to rectification section lower part, and the stripping section has adopted the compound three-dimensional injection column plate of direction, and this rectifier unit has utilized high-efficient anti stifled performance of direction column plate to be good, and the characteristics that the pressure drop is low are good with the three-dimensional column plate mass transfer performance that leads, the characteristics that the processing load is big. Compared with the rectifying device adopting the large-pore sieve plate in the prior art, the utility model has the advantages that the tower plate efficiency is improved by 100 percent, the operation elasticity is improved by more than 50 percent, and the processing load is improved by 100 percent. Compare with patent CN101033180A column plate compound mode, the anti stifled performance of device is better, and the guiding hole on the column plate promotes the evenly distributed of liquid layer on the board, reduces the formation in liquid phase dead zone, and the rectifying column top adopts high-efficient direction sieve mesh column plate to change the washing moreover.

The rectification device has higher acrolein concentration at the upper part and higher possibility of polymerization, so that the upper part of the rectification section selects the high-efficiency guide sieve tray, the lower part of the rectification section selects the guide three-dimensional injection tray, and the tray has higher flux and higher mass transfer efficiency, and has stronger anti-blocking performance and is easy to clean. The concentration of acrolein in the stripping section is reduced, but the concentration of the hydration product 3-hydroxypropionaldehyde is increased, the operation temperature is higher, and the possibility of polymerization is higher, so that the guide composite three-dimensional injection column plate is selected, the mass transfer efficiency of the column plate is improved, and the column plate also has higher anti-blocking performance. The total tower pressure of the rectifying device adopting the combination is reduced to 4-15 kPa, the tower bottom temperature is reduced to 50-65 ℃, and the polymerization reaction of acrolein and 3-hydroxypropionaldehyde in the tower is effectively prevented.

Drawings

FIG. 1 is a schematic diagram of the structure inside a rectifying apparatus of the present invention;

FIG. 2 is a schematic structural view of a guided three-dimensional jet tray according to the present invention;

FIG. 3 is a schematic structural view of a guiding composite three-dimensional jet tray in the present invention;

fig. 4 is a schematic structural view of a guide hole and a guide plate in the present invention;

fig. 5 is a schematic view of the perforated area of a guiding three-dimensional jet tray and a guiding composite three-dimensional jet tray in the present invention.

The reference signs are: the tower body 100, a gas phase outlet 101 at the top of the tower, a feed inlet 102, a liquid phase outlet 103 at the bottom of the tower, a guide three-dimensional spray tray 104, a high-efficiency guide tray 105, a guide composite three-dimensional spray tray 106, a guide hole 107, a guide plate 108, a tray 109, a cap 110, a large hole 111, a sieve hole 112, an upper end slit 113, a lower end slit 114, a filler 115, an overflow weir 116 and a downcomer guide plate 117.

Detailed Description

The present invention will be further described with reference to the following examples. The devices, connections, and methods referred to in this disclosure are those known in the art, unless otherwise indicated.

General examples

As shown in fig. 1, a rectification apparatus for separating acrolein comprises a column body 100, wherein a top gas phase outlet 101, a feed inlet 102 and a bottom liquid phase outlet 103 are respectively arranged at the top, the side and the bottom of the column body. The tower body is divided into a rectifying section positioned at the upper section and a stripping section positioned at the lower section by taking the feed inlet as a boundary; a plurality of guide three-dimensional jet tower plates 104 and a plurality of efficient guide tower plates 105 are arranged in the rectifying section from bottom to top; a plurality of guide composite three-dimensional jet tower plates 106 are arranged in the stripping section; the high-efficiency guide tower plates, the guide three-dimensional spray tower plates and the guide composite three-dimensional spray tower plates are respectively arranged in a staggered mode to form a baffling channel.

Wherein:

the efficient guide tower plate is provided with guide holes 107 (the opening rate is 5-15%), as shown in fig. 4, the edges of the guide holes are provided with guide plates 108 protruding upwards, and the opening of a hole seam formed by the guide holes and the guide plates is consistent with the flowing direction of a liquid phase on the efficient guide tower plate where the guide holes and the guide plates are located. The distribution density of the guide holes on the efficient guide tower plate close to the side wall of the tower body is greater than that of the center of the efficient guide tower plate.

As shown in FIG. 2, the guided solid jet tray comprises a tray 109 and a cap 110; as shown in fig. 5, the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole 111 and a guide hole, and the opening rate is 5-20%; each large-hole upper cover is provided with the cap cover, the side wall of each cap cover is provided with a sieve pore 112 (the pore diameter is 3-15 mm), and the top and the bottom of the side wall of each cap cover are circumferentially provided with an upper end slit 113 and a lower end slit 114 respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.

As shown in FIG. 3, the guided composite three-dimensional spray tray comprises a tray, a cap and packing 115 (metal open-plate corrugated packing or metal open-wire mesh packing); the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole and a guide hole, and the opening rate is 5-20%; each large hole upper cover is provided with the cap cover, the top of the cap cover is filled with the filler (the thickness accounts for 20-40% of the height of the cap cover), the side wall of the cap cover is provided with sieve pores (the pore diameter is 3-15 mm), and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit and a lower end slit respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.

In the above structure, the cross section of the guide plate is an arc shape in which the intrados faces the guide hole. The number of the efficient guide tower plates accounts for 10-40%, preferably 15-30% of the total number of the tower plates; the number of the guide three-dimensional jet tower plates accounts for 5-35%, preferably 15-30% of the total tower plates; the number of the guide composite three-dimensional jet tower plates accounts for 15-70%, preferably 30-60% of the total number of the tower plates.

The upper side and the lower side of the notch edge of the high-efficiency guide tower plate, the guide three-dimensional spray tower plate and the guide composite three-dimensional spray tower plate are respectively provided with an overflow weir 116 and a down-flow guide plate 117; wherein: the height of an overflow weir on the high-efficiency guide column plate is 5-45 mm, the height of an overflow weir on the guide three-dimensional spray column plate is 10-50 mm, and the height of an overflow weir on the guide composite three-dimensional spray column plate is 10-50 mm; the radial cross section of falling liquid deflector is the arc parallel with the tower body lateral wall, falls the liquid deflector and is cascaded downwardly extending and be close to the tower body lateral wall and arc length shortens.

Example 1

As shown in figure 1, a rectification device for separating acrolein comprises a tower body 100 (tower height 8000 mm, tower diameter 500 mm), wherein the top, side and bottom of the tower body are respectively provided with a tower top gas phase outlet 101, a feed inlet 102 and a tower bottom liquid phase outlet 103. The tower body is divided into a rectifying section positioned at the upper section and a stripping section positioned at the lower section by taking the feed inlet as a boundary; 8 guide three-dimensional jet trays 104 and 2 high-efficiency guide trays 105 are arranged in the rectifying section from bottom to top; the stripping section is internally provided with 4 guide composite three-dimensional jet trays 106; the high-efficiency guide tower plates, the guide three-dimensional spray tower plates and the guide composite three-dimensional spray tower plates are respectively arranged in a staggered mode to form a baffling channel.

Wherein:

the efficient guide column plate is provided with guide holes 107 (the aperture is 10 × 20mm rectangular open holes, the aperture ratio of the guide holes is 2%), as shown in fig. 4, the edge of each guide hole is provided with a guide plate 108 protruding upwards, the height of each protrusion is 3mm, and the opening of a hole seam formed by the guide holes and the guide plates is consistent with the flow direction of the liquid phase on the efficient guide column plate where the guide holes and the guide plates are located. The distribution density of the guide holes on the efficient guide tower plate close to the side wall of the tower body is greater than that of the center of the efficient guide tower plate.

As shown in FIG. 2, the guided solid jet tray comprises a tray 109 and a cap 110; as shown in fig. 5, the central area of the tray and the position close to the side wall of the tower body are respectively provided with large holes 111 (rectangular holes with the aperture size of 60 × 180 mm) and guide holes 1 (rectangular holes with the aperture size of 10 × 20 mm), and the total aperture ratio is 15%; each large hole upper cover is provided with the cap cover, the side wall of the cap cover is provided with sieve holes 112 (the aperture is 6 mm), and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit 113 and a lower end slit 114 respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.

As shown in FIG. 3, the guided composite three-dimensional jet tray comprises a tray, a cap and packing 115 (metal apertured plate corrugated packing); the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole and a guide hole, and the opening rate is 15%; each large hole upper cover is provided with the cap cover, the top of the cap cover is filled with the filler (the thickness accounts for 30% of the total height of the cap cover), the side wall of the cap cover is provided with sieve pores (the pore diameter is 6 mm), and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit and a lower end slit respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.

The upper side and the lower side of the notch edge of the high-efficiency guide tower plate, the guide three-dimensional spray tower plate and the guide composite three-dimensional spray tower plate are respectively provided with an overflow weir 116 and a down-flow guide plate 117; wherein: the height of an overflow weir on the high-efficiency guide tower plate is 15mm, the height of an overflow weir on the guide three-dimensional jet tower plate is 15mm, and the height of an overflow weir on the guide composite three-dimensional jet tower plate is 15 mm; the radial cross section of the down-flow guide plate is an arc parallel to the side wall of the tower body, and the down-flow guide plate extends downwards in a stepped mode and has an increasing arc diameter.

The device comprises a feed inlet, a rectification device and a rectifying tower, wherein a hydration liquid containing 4 mass percent of acrolein continuously enters the rectification device from the feed inlet, the height of the tower of the device is 8000 mm, the diameter of the tower is 500 mm, 8 guide composite three-dimensional jet tower plates are installed on a stripping section, 2 high-efficiency guide tower plates are installed on the upper part of the rectification section, 4 guide three-dimensional jet tower plates are installed on the lower part of the rectification section, the heights of overflow weirs are 15mm, the pressure drop of the whole tower is 11 kPa, the operating temperature of the tower bottom is 62 ℃, the content of the acrolein at the tower bottom is controlled to be less than 0.5 mass percent, and the requirement of subsequent hydrogenation reaction is met. After the rectifying device continuously operates for 300 hours, the operating temperature of the tower bottom rises to 64 ℃, the number of theoretical plates of a rectifying section is 4, the number of theoretical plates of a stripping section is 5, and the number of theoretical plates of the whole tower is 9. The polymeric material on the tray of the rectification apparatus is significantly reduced compared to comparative example 1.

Comparative example 1

The difference from example 1 is that: the method comprises the following steps of continuously feeding a hydration liquid containing 4 mass percent of acrolein into an acrolein rectifying device from a feeding hole, wherein the height of a tower of the device is 8000 mm, the diameter of the tower is 500 mm, 8 guide composite three-dimensional jet tower plates are installed on a stripping section, 6 guide three-dimensional jet tower plates are installed on a rectifying section, the height of an overflow weir is 15mm, the pressure drop of the whole tower is 10 kPa, the operating temperature of the bottom of the tower is 60 ℃, the content of the acrolein at the bottom of the tower is controlled to be less than 0.5 mass percent, and the requirement of the subsequent hydrogenation reaction is met. After the rectifying device continuously operates for 300 hours, the operating temperature of the bottom of the tower rises to 65 ℃, the number of the rectifying section theoretical plates is 4, the number of the stripping section theoretical plates is 5, and the number of the whole tower theoretical plates is 9. The upper part of the rectifying section of the device is guided to the mesh part of the cap cover of the three-dimensional jet tower plate to generate a small amount of polymeric substances.

Comparative example 2

The difference from example 1 is that: the method comprises the following steps of continuously feeding a hydration liquid containing 4 mass percent of acrolein into an acrolein rectifying device from a feeding hole, wherein the height of a tower of the device is 8000 mm, the diameter of the tower is 500 mm, 8 guide composite three-dimensional jet tower plates are installed on a stripping section, 6 efficient guide tower plates are installed on a rectifying section, the height of an overflow weir is 15mm, the pressure drop of the whole tower is 13 kPa, the operating temperature of the bottom of the tower is 65 ℃, the content of the acrolein at the bottom of the tower is controlled to be less than 0.5 mass percent, and the requirement of the subsequent hydrogenation reaction is met. After the rectifying device continuously operates for 300 hours, the operating temperature of the tower bottom rises to 68 ℃, the number of theoretical plates of a rectifying section is 3, the number of theoretical plates of a stripping section is 5, and the number of theoretical plates of the whole tower is 8. The pressure drop of the whole rectifying tower is increased, and the number of theoretical plates is reduced.

Comparative example 3

The difference from example 1 is that: the method comprises the following steps of continuously feeding a hydration liquid containing 4 mass percent of acrolein into a rectifying device from a feeding hole, wherein the height of a tower of the rectifying device is 8000 mm, the diameter of the tower is 500 mm, 8 composite three-dimensional jet tower plates are installed on a stripping section, 2 common sieve tray plates (without guide plates) are installed on the upper section of the rectifying section, 4 three-dimensional jet tower plates are installed on the lower section of the rectifying section, the height of an overflow weir is 15mm, the pressure drop of the whole tower is 10 kPa, the operating temperature of the tower bottom is 60 ℃, and the content of the acrolein at the tower bottom is controlled to be less than 0.5 mass percent so as to meet the requirement of subsequent hydrogenation reaction. After the rectifying device continuously operates for 300 hours, the operating temperature of the tower bottom rises to 68 ℃, the number of theoretical plates of a rectifying section is 4, the number of theoretical plates of a stripping section is 5, and the number of theoretical plates of the whole tower is 9. The bow-shaped area of the tower plate of the rectifying device without the guide holes and other dead areas have a large amount of polymeric substances, so that the efficiency of the tower plate is reduced, and the pressure drop of the whole tower is increased.

Comparative example 4

The difference from example 1 is that: the method comprises the following steps of continuously feeding a hydration liquid containing 4 mass percent of acrolein into an acrolein rectifying device from a 6-material inlet, wherein the height of a tower of the device is 8000 mm, the diameter of the tower is 500 mm, 2m of metal structured packing is installed on a stripping section, 2 high-efficiency guide tower plates are installed on the upper part of a rectifying section, 4 guide three-dimensional injection tower plates are installed on the lower part of the rectifying section, the heights of overflow weirs are 15mm, the pressure drop of the whole tower is 6 kPa, the operating temperature of the tower bottom is 55 ℃, the content of the acrolein at the tower bottom is controlled to be less than 0.5 mass percent, and the requirement of subsequent hydrogenation reaction is met. After the rectifying device continuously operates for 300 hours, the operating temperature of the bottom of the tower rises to 65 ℃, the number of the rectifying section theoretical plates is 4, the number of the stripping section theoretical plates is 5, and the number of the whole tower theoretical plates is 9. The stripping section packing of the rectifying device contains a large amount of polymerization products, the pressure drop of the whole tower is increased, and the tower plate efficiency is reduced.

Comparative example 5

The difference from example 1 is that: the hydration liquid containing 4% (mass) acrolein continuously enters an acrolein rectifying device from a 6-material inlet, the height of a tower of the device is 8000 mm, the diameter of the tower is 500 mm, 8 large-hole sieve plates are installed on a stripping section, 6 large-hole sieve plates are installed on a rectifying section, the hole diameter is 12mm, the aperture ratio is 13%, the height of an overflow weir is 15mm, the pressure drop of the whole tower is 12 kPa, the operating temperature of the tower bottom is 60 ℃, the content of the acrolein at the tower bottom is controlled to be less than 0.5% (mass), and the requirement of subsequent hydrogenation reaction is met. After the rectifying device continuously operates for 300 hours, the operating temperature of the tower bottom rises to 68 ℃, the number of theoretical plates of a rectifying section is 3, the number of theoretical plates of a stripping section is 4, and the number of theoretical plates of the whole tower is 7. The tray efficiency is low and the liquid phase dead zone on the tray generates more polymeric substances.

The above, only be the utility model discloses a preferred embodiment, it is not right the utility model discloses do any restriction, all according to the utility model discloses the technical entity all still belongs to any simple modification, change and equivalent structure transform of doing to above embodiment the utility model discloses technical scheme's protection scope.

Claims (12)

1. The utility model provides a rectifier unit of separation acrolein, includes tower body (100), the top, lateral part and the bottom of tower body are equipped with top of the tower gas phase export (101), feed inlet (102) and bottom of the tower liquid phase export (103) respectively, its characterized in that: the tower body is divided into a rectifying section positioned at the upper section and a stripping section positioned at the lower section by taking the feed inlet as a boundary; a plurality of guide three-dimensional jet tower plates (104) and a plurality of efficient guide tower plates (105) are arranged in the rectifying section from bottom to top; a plurality of guide composite three-dimensional jet tower plates (106) are arranged in the stripping section; the high-efficiency guide tower plates, the guide three-dimensional spray tower plates and the guide composite three-dimensional spray tower plates are respectively arranged in a staggered mode to form a baffling channel.

2. The rectification apparatus as claimed in claim 1, characterized in that the high-efficiency guide tray is provided with guide holes (107), the edges of the guide holes are provided with guide plates (108) protruding upwards, and the slit openings formed by the guide holes and the guide plates are consistent with the flowing direction of the liquid phase on the high-efficiency guide tray.

3. The rectification apparatus as claimed in claim 2, wherein the distribution density of the guide holes on the high efficiency guide trays at a position close to the side wall of the column body is greater than that of the center of the high efficiency guide trays.

4. Rectification unit according to claim 1, characterized in that the guided solid jet tray comprises a tray (109) and a cap (110); the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole (111) and a guide hole; each large hole upper cover is provided with the cap cover, the side wall of the cap cover is provided with a sieve mesh (112), and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit (113) and a lower end slit (114) respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.

5. The rectification apparatus according to claim 1, characterized in that the guided multiple jet solid trays comprise trays, caps and packing (115); the central area of the tower plate and the position close to the side wall of the tower body are respectively provided with a large hole and a guide hole; each large hole upper cover is provided with the cap cover, the filler is filled at the top of the cap cover, sieve holes are distributed on the side wall of the cap cover, and the top and the bottom of the side wall of the cap cover are circumferentially provided with an upper end slit and a lower end slit respectively; the edge of the guide hole is provided with a guide plate protruding upwards, and a hole seam opening formed by the guide hole and the guide plate is consistent with the flowing direction of the liquid phase on the tower plate where the guide hole and the guide plate are located.

6. Rectification unit according to one of claims 2 to 5, characterized in that the cross section of the guide plate is curved with the intrados facing the guide bore.

7. The rectification apparatus according to claim 5, wherein said packing is a metal open-plate corrugated packing or a metal open-wire mesh packing.

8. The rectification apparatus of claim 1, wherein:

the number of the efficient guide tower plates accounts for 10-40% of the total number of the tower plates;

the number of the guide three-dimensional jet tower plates accounts for 5-35% of the total tower plates;

the number of the guide composite three-dimensional jet tower plates accounts for 15-70% of the total tower plates.

9. The rectification apparatus of claim 2, wherein: the aperture ratio of the efficient guide column plate is 5-15%.

10. The rectification apparatus of claim 4, wherein: the aperture ratio of the guide three-dimensional jet tower plate is 5-20%, and the aperture of the upper aperture of the cap cover is 3-15 mm.

11. The rectification apparatus of claim 5, wherein: the aperture ratio of the guide composite three-dimensional jet column plate is 5-20%, the aperture of the upper aperture of the cap cover is 3-15 mm, and the thickness of the filler accounts for 20-40% of the height of the cap cover.

12. The rectification apparatus according to claim 1, characterized in that the upper and lower sides of the gap edge of the high-efficiency guide tray, the guide three-dimensional spray tray and the guide composite three-dimensional spray tray are respectively provided with an overflow weir (116) and a down-flow guide plate (117); wherein: the height of an overflow weir on the high-efficiency guide column plate is 5-45 mm, the height of an overflow weir on the guide three-dimensional spray column plate is 10-50 mm, and the height of an overflow weir on the guide composite three-dimensional spray column plate is 10-50 mm; the radial cross section of falling liquid deflector is the arc parallel with the tower body lateral wall, falls the liquid deflector and is cascaded downwardly extending and be close to the tower body lateral wall and arc length shortens.

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