Hydrogenation reactor for improving liquid phase uniformity
Technical Field
The invention relates to a hydrogenation reactor, and belongs to the field of chemical equipment. The hydrogenation reactor is suitable for all hydrogenation reaction processes, in particular to the hydrofining or hydrocracking process with large reactor scale.
Background
In recent years, with the rapid development of economy and the enhancement of environmental awareness, the quality and environmental protection requirements of petrochemicals are higher and higher. As a technical means for producing clean fuels, hydrogenation technology plays an increasingly important role in the oil refining industry. In the hydrogenation device, as with the hydrogenation catalyst technology and the hydrogenation process technology, the hydrogenation reactor technology is an important component of the reactor system, and the three components form three factors of the performance of the reactor. In a hydrogenation device, raw oil which is used as a key device of a hydrogenation reactor is mixed with hydrogen according to a certain proportion, and the reactions such as refining, cracking and the like are completed under the action of a hydrogenation catalyst. Whether the hydrogenation reaction in the hydrogenation reactor can be stably operated or not, whether the hydrogenation catalyst can fully exert the function or not, whether the product quality can reach high quality or not, and the method depends on the uniformity of the distribution of gas and liquid in a catalyst bed layer to a great extent. Whether the gas and liquid are uniformly distributed in the catalyst bed layer or not is closely related to the design of the internal components of the hydrogenation reactor. In other words, the performance of the internals directly affects the catalyst life, product quality and the operation period of the apparatus, i.e. the effect obtained by using a set of excellent-performance internals in the hydrogenation process is in no way inferior to that obtained by using a more active catalyst. Therefore, the research and engineering development of hydrogenation reactors and internal components thereof at home and abroad are always very important, and the internal components of the reactors are continuously updated to obtain better effect.
The industrial device production practice shows that two factors are mainly used for restricting the stable operation of the hydrogenation process device, one is larger radial temperature difference of the reactor caused by uneven material distribution, and the other is too fast pressure drop of the catalyst bed layer of the reactor.
The hydrogenation reactor feeds materials at the center of the top of the reactor, and although an inlet diffuser is arranged, the residual kinetic energy of material conveying can generate strong impact force; another flow regime characteristic of central point position feeding is that the streamline of material in the formation of reactor head space is the tilt line, the kinetic energy of material and the flow regime that is the tilt line, with the liquid layer on top distributor tray to the reactor rush to send all around, form the "push away unrestrained" phenomenon of material on top distributor tray, promptly, reactor distributor tray is from the central point to the liquid layer height of border position and is incremental type distribution: the material liquid layer in the central area is small and even has no liquid layer, and the height of the material liquid layer on the side wall of the reactor is the largest, so that unfavorable inlet conditions are brought to a distributor depending on the levelness of a tray, and even the distributor with the best performance can not realize uniform distribution of materials under the conditions of the liquid layers with different heights. Along with the increasing scale of the hydrogenation reactor, the 'push wave' phenomenon generated by the impact force formed by the conversion of residual kinetic energy and potential energy of the material after entering the reactor is more and more serious, so that the material distribution has serious deviation.
The hydrogenation process is an exothermic reaction, and uneven material distribution can cause severe reaction at the part with good catalyst wetting effect and generate more heat; i.e. the radial temperature difference affecting the reactor. When the radial temperature difference is large, the higher the local temperature of the catalyst is, the faster the reaction rate is, hot spots are formed, the performance of the catalyst is inactivated too early, the performance of the catalyst is damaged, even coking and hardening of a part of regions of the catalyst can be caused, materials can not flow normally, and the catalyst below the hardening region can not play a role due to the fact that the fixed bed hydrogenation reactor is in a trickle bed flow state, so that the service life of the catalyst is greatly prolonged, and the start-up period of the device is greatly shortened. Localized sheeting also causes an increase in the pressure drop across the catalyst bed, which increases the operating pressure of the reactor to continue operation, resulting in increased energy consumption.
The injection disc is arranged between the cold hydrogen disc and the redistribution disc (gas-liquid distribution disc). Quenching hydrogen is pumped into the cold hydrogen box, in order to neutralize the reaction heat released by the hydrogenation reaction, the temperature of reactants is controlled not to exceed a specified value, and the hydrogen flow sprayed out of the cold hydrogen pipe is primarily mixed with the reactants from the upper bed layer and then enters the cold hydrogen box, and is uniformly mixed. The fluid which is uniformly mixed passes through the spraying disc and then is sprayed onto the redistribution disc (gas-liquid distribution disc) on the lower layer, and the redistribution disc has the same structure as the top distribution disc, thereby playing the role of uniformly distributing the cross section of the lower bed layer.
Due to the limitation of the position height, the fluid mixed by the cold hydrogen disc is in an approximate horizontal streamline flow state when flowing out of the cold hydrogen disc, so that the liquid phase has a serious wave pushing phenomenon, namely the radial liquid distribution of the reactor is uneven, and the central position on the distribution disc even has no liquid phase. The spraying tray generally adopts a liquid spraying tray with uniform holes, namely a flat tower sieve hole tray structure, when fluid mixed by a cold hydrogen tray passes through sieve holes, the fluid can only be converted from a horizontal flow state to a vertical flow state, flow equalization can not be realized, the wave pushing phenomenon on the tray can not be changed, namely, uniform inlet conditions can not be provided for the redistributing tray, unfavorable inlet conditions are brought for the distributor depending on the levelness of the tray, even if the distributor has the best performance, even under the liquid layer conditions of different depths, uniform distribution of materials can not be realized, the effect of the redistributor is seriously influenced, and the radial temperature difference expansion can not be avoided.
Aiming at the problems existing in the traditional spraying plate, namely the structure of the sieve tray of the flat tower, the spraying plate structure which can provide uniform liquid phase inlet conditions for the redistribution plate must be developed, the initial distribution of materials is realized, the wave pushing phenomenon of the liquid layer on the redistribution plate by the fluid in the inclined flow state of the cold hydrogen plate is eliminated, and the uniform distribution of the fluid is realized.
With the increasing enlargement of the scale of hydrogenation reactors, the product precision requirement is increased, and the uniform distribution of materials on a catalyst bed layer is very important. Because the hydrogenation process is an exothermic reaction, raw oil is unevenly distributed on the radial section of a catalyst bed, so that radial temperature difference is generated due to different reaction degrees, even local overheating occurs, and the performance of the catalyst is damaged, thereby greatly reducing the service cycle of the catalyst. Therefore, it is necessary to select a hydrogenation reactor with reasonable design.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a hydrogenation reactor for improving the uniformity of a liquid phase.
The invention relates to a hydrogenation reactor for improving liquid phase uniformity, which comprises a material inlet pipe, an inlet diffuser, a reactor upper end enclosure, a folded edge type impact reduction flow equalizing disc, a catalyst bed layer, a catalyst support grid, a reactor barrel, a reactor lower end enclosure, an outlet collector, a material outlet pipe and an agent unloading pipe, wherein the material inlet pipe is connected with the inlet diffuser; the edge-folding type impact-reducing and flow-equalizing disc is arranged in the idle space of the upper end socket of the reactor or at the upper end of the reactor barrel; the edge-folding type impact-reducing flow-equalizing disc comprises a tray and a chimney distributor vertically arranged on the tray, wherein the chimney distributor comprises a downcomer and a wing plate arranged on the upper part of the downcomer.
In certain embodiments, the hydrogenation reactor of the present invention further comprises a bed unloading agent tube, a cold hydrogen tray, an injection tray, and an interbed distribution tray. That is, the hydrogenation reactor of the present invention comprises more than two hydrogenation catalyst beds.
In a further preferred embodiment, the hydrogenation reactor of the present invention further comprises a top distribution tray located below the hemmed flow-reducing equalization-tray and above the uppermost catalyst bed.
In the hydrogenation reactor, the edge-folded impact-reducing flow-equalizing disc is a newly added reactor inner groove piece. The downcomer is of a cylindrical structure with openings at two ends, and the wing plates have a certain included angle, side length and height. The wing plates are parallel to the axis of the downcomer, or the central lines of the wing plates form a certain included angle with the axis of the reactor.
Furthermore, the included angle of the wing plates in the edge-folding type impact reduction and flow equalization plate is far away from the center or circle center of the tray, or the included angle of the wing plates faces the wall of the cylinder body closest to the reactor. Furthermore, the central line of the included angle of the wing plate is superposed with the ray of the reactor cylinder.
Furthermore, the wing plates incline towards the wall of the reactor closest to the wall of the reactor, and the angle between the central line of the included angle of the wing plates and the axis of the reactor is 15-80 degrees.
Furthermore, the wing plates have certain included angle, side length and height. The number of the wing plates and the number of the downcomers are the same, and the wing plates and the downcomers are arranged up and down. The bottom edge (lower part) of the wing plate is connected with the upper edge (upper part) of the downcomer in an overlapping or non-overlapping way; when the downcomer is overlapped, the height of the overlapped portion is 5 to 30%, preferably 10 to 25% of the height of the downcomer.
Further, the chimney distributors are vertically arranged on the tray. The lower end opening of the downcomer in the chimney distributor is directly opened on the tray or penetrates through the opening of the tray.
Furthermore, the tray also comprises a supporting beam and a tray connecting piece which are arranged below the tray and used for supporting.
Furthermore, a plurality of overflow holes are arranged on the pipe wall of the downcomer, so that liquid can conveniently pass through the overflow holes, enter the downcomer and flow downwards along the downcomer. The center line of the overflow hole and the surface of the tray plate should keep a certain distance. The number of the overflow holes is generally 1-6, preferably 1-2. The total cross-sectional area of the overflow holes is 10-100%, preferably 30-50% of the cross-sectional area of the downcomer (horizontal). When only 1 overflow hole is arranged on the downcomer, the position of the overflow hole is opposite to the connection point of the downcomer and the wing plate; when the number of the overflow holes is 2, the overflow holes are arranged on two sides of the connection point of the downcomer and the wing plate. The shape of the overflow hole can be round, long strip, triangle and polygon, preferably round.
The chimney distributor may be made of any suitable material, such as ceramic, metal, etc., preferably steel. The wing plate and the downcomer can be integrally manufactured, and for example, the wing plate and the downcomer can be integrally processed; or, vertical and horizontal cutting is carried out at a certain height of the upper part of the downcomer with certain height, incomplete cutting of wall thickness is reserved, then the downcomer is unfolded for a certain angle to form a wing plate, or the upper edge of the downcomer is fixedly connected with a wing plate with a certain included angle. The fixed connection can adopt various suitable modes such as welding, bolt connection, screw connection, buckle connection and the like.
In the invention, the tray of the edge-folding impact-reducing flow-equalizing disc is generally divided into a plurality of blocks and can be spliced into a circular plate. And a folded edge is arranged on the edge of the outermost edge of the tray and is folded upwards. The upper edge of the said flange should be generally higher than the lower edge of the overflow orifice provided in the downcomer wall. The upward folded edge can maintain a certain liquid level on the tray, thereby eliminating the influence on liquid phase distribution caused by the insufficient level of the tray in the prior art to a certain extent.
In the invention, a plurality of chimney distributors on the edge-folding type impact-reducing and flow-equalizing disc are generally arranged according to a certain rule, such as being arranged on the tray in a triangular, quadrangular or rhombic shape.
In the invention, the downcomer is used for liquid to pass through and is also used as a flow channel for gas feeding in feeding.
Further, the hydrogenation reactor of the present invention comprises more than two catalyst beds, and therefore the reactor further comprises a bed unloading agent pipe, a cold hydrogen tray, an injection tray and an inter-bed distribution tray. The edge-folding type jet disc is preferably adopted by the jet disc, and the structure of the edge-folding type jet disc is the same as that of the edge-folding type impact reducing flow equalizing disc. The edge-folded injection disc is arranged between a cold hydrogen disc of the hydrogenation reactor and the inter-bed distribution disc. The edge-folded jet disc comprises a jet tray and a chimney type distributor vertically arranged on the jet tray; the chimney type distributor comprises a downcomer and a wing plate arranged at the upper part of the downcomer.
Furthermore, the down-flow pipe of the edge-folding type jet disc is of a cylindrical structure with two open ends. The upper edge of the wing plate is flush with or slightly higher than the upper edge of the downcomer, the wing plate has a certain included angle, side length and height, and the lower edge of the wing plate is attached to the upper surface of the tray plate or has a gap with a certain height with the upper surface of the tray plate.
Furthermore, the included angle of the wing plates of the edge-folded injection tray is far away from the center or circle center of the tower tray. Furthermore, the central line of the included angle of the wing plate is superposed with the ray of the reactor cylinder, and the included angle of the wing plate faces the wall of the cylinder closest to the reactor. In the invention, the wing plates are parallel to the axis of the downcomer. The wing plate is a folded plate with a certain included angle, side length and height. The number of the wing plates and the downcomers is the same and the wing plates and the downcomers are in one-to-one correspondence. The middle lower part of the wing plate and the middle upper part of the downcomer can be partially overlapped; when arranged in an overlapping manner, the height of the overlapping part accounts for 50 to 90 percent of the total height of the downcomer, and preferably 60 to 80 percent.
In the edge-folding type spraying tray, a plurality of chimney type distributors are vertically arranged on the spraying tray. Chimney distributors are typically inserted onto the jet tray through the lower end of the downcomer and may be fixedly attached by welding, screwing, snapping, etc. The lower end opening of the downcomer is directly opened on the jet tray or is opened through the jet tray. The jet tray also comprises a supporting beam and a tray connecting piece which are arranged below the jet tray and used for supporting.
Furthermore, a plurality of overflow holes are arranged on the pipe wall of the downcomer in the edge-folding type spraying disc, so that liquid can conveniently pass through the overflow holes to enter the downcomer and flow downwards along the downcomer. A certain distance should be kept between the center line of the overflow hole and the surface of the tray plate. The number of the overflow holes is generally 1 to 6, preferably 1 to 2. The total cross-sectional area of the overflow holes is 10-100%, preferably 30-50% of the cross-sectional area of the downcomer (horizontal). When only 1 overflow hole is arranged on the downcomer, the position of the overflow hole is opposite to the connection point of the downcomer and the wing plate; when the number of the overflow holes is 2, the positions of the overflow holes are arranged on two sides of the symmetry axis of the wing plate. The shape of the overflow hole can be round, long strip, triangle and polygon, preferably round.
In the flanged spray tray, the chimney distributor may be made of any suitable material, such as ceramic, metal, etc., preferably steel. The wing plate and the downcomer can be integrally formed and manufactured; or the wing plate and the downcomer are assembled, for example, the wing plate with a certain included angle can be fixedly connected to the middle upper part of the downcomer. The fixed connection can adopt various suitable modes such as welding, bolt connection, screw connection, buckle connection and the like. In particular, the downcomer can be made of steel pipes, and the wing plates are preferably made of steel plates through folding.
In the present invention, the jet tray is generally divided into several pieces and may be spliced into a circular plate. And an upward folded edge is arranged on the edge of the outermost edge of the jet tray. The upper edge of the folded edge should be higher than the upper edge of the overflow hole arranged on the pipe wall of the downcomer. The arrangement of the folded edge can maintain a certain liquid level on the jet tray, so that the influence on liquid phase distribution caused by the insufficient level of the jet tray in the prior art can be eliminated to a certain extent.
In the folded edge type spray tray, a plurality of chimney distributors are generally arranged according to a certain rule, for example, the plurality of chimney distributors can be arranged on the spray tray in a triangular, quadrangular or rhombic shape.
Compared with the prior art, the hydrogenation reactor has the following advantages:
1. the edge-folded flow equalizing disc of the hydrogenation reactor is designed by a special structure, reduces the installation size of the distributor, is convenient to install at an idle upper end socket of the reactor or is arranged at the upper end of a cylinder body of the reactor and above the top distribution disc, achieves the aim of saving the space of the reactor, improves the space utilization rate of the hydrogenation reactor, is convenient to load more catalysts or reduces the scale of the reactor.
2. According to the hydrogenation reactor, the edge-folded impact reduction flow equalizing disc and the edge-folded injection disc are both provided with wing plates, so that fluid injected in an oblique line flow state due to center entering can be blocked, and the impact force of the fluid can be reduced; the fluid losing kinetic energy is blocked and then converted into a vertical flow state from the original inclined line flow state under the action of gravity, natural falling is realized, a liquid layer with consistent depth is formed on the tray, the phenomenon that the impact force of the inclined line gives the liquid layer on the tray and forms 'pushing waves' is eliminated, uniform inlet conditions are created for the chimney distributor, the material is distributed on the catalyst bed layer or the top distribution plate through the chimney distributor, the primary distribution function is realized, and friendly, stable liquid layer and uniform inlet conditions are provided for the catalyst bed layer or the distributor. The edge-folded impact-reducing flow-equalizing disc improves the inlet working condition of the first bed layer distribution disc, improves the distribution effect of the top distribution disc, optimizes the material distribution of the top bed layer and improves the utilization rate of the first bed layer catalyst. The edge-folded jet disc improves the material distribution condition in the middle of the bed layer and improves the distribution effect of the distribution disc between the bed layers.
3. Compared with a common bubble cap distributor adopting a suction principle, the edge-folded impact reduction flow equalizing disc and the edge-folded injection disc realize liquid phase distribution, and the dispersed power of liquid phase distribution is changed from gas phase suction to potential energy to form splashing so as to reduce pressure drop.
4. According to the hydrogenation reactor, the edge-folded impact-reducing flow-equalizing disc and the edge-folded injection disc are provided with the positions and the shapes of overflow holes in the pipe wall of the chimney distributor, so that reasonable liquid storage depth of the tower tray is formed, and macroscopic distribution unevenness caused by levelness deviation and liquid level fluctuation of the tower tray is reduced.
5. The hydrogenation reactor, the edge-folded impact-reducing flow-equalizing disc and the edge-folded injection disc adopt unique design principles and fluid mechanics characteristics to realize uniform distribution of materials, so that the radial temperature difference of a catalyst bed is reduced, the radial temperature difference of the catalyst bed is less than or equal to 3 ℃, and the radial temperature difference reflects the distribution effect of fluid, thereby fully showing that the edge-folded impact-reducing flow-equalizing disc has good distribution effect on reaction feed material flow and gas-liquid mixing effect, and has certain auxiliary effect on the hydrogenation catalytic reaction process and the catalyst coking control.
6. Compared with the prior art, the hydrogenation reactor has the advantages that the edge-folded flow equalizing disc and the edge-folded injection disc are newly added internal components of the hydrogenation reactor, the structure is simple, the installation is convenient, the operation elasticity is high, the space utilization rate of the hydrogenation reactor can be improved, the material distribution condition in the reactor can be improved, the radial temperature difference of the reactor can be effectively eliminated, the hot spot caused by uneven material distribution of a catalyst bed layer can be eliminated, excellent inlet conditions are provided for the effective use of a catalyst in the hydrogenation reactor, the times of catalyst head skimming or agent changing are reduced, the start-up period of the device is prolonged, the hydrogenation process effect is improved, and good economic benefits are achieved.
Drawings
FIG. 1 is a schematic diagram of a hydrogenation reactor for improving the uniformity of a liquid phase according to the present invention.
Fig. 2 is a schematic view of the edge-folded impact-reducing flow-equalizing disc of the present invention.
FIG. 3 is a schematic structural diagram of a chimney distributor 4-1 in the edge-folded impact-reducing flow-equalizing disc of the present invention.
FIG. 4 is a top view of the structure of the chimney distributor 4-1 in the edge-folded impact-reducing flow-equalizing tray of the present invention.
FIG. 5 is a schematic view of the flow direction of the liquid when the edge-folded flow-reducing and equalizing disc of the present invention is in operation.
FIG. 6 is a schematic view of a distributor for a flanged spray disk of the present invention.
FIG. 7 is a schematic of the distributor of the chimney distributor 10-1 in the flanged jet disk of the present invention.
FIG. 8 is a top view of the distributor structure of the chimney distributor 10-1 in the flanged jet disk of the present invention.
FIG. 9 is a schematic view of the flow of liquid during operation of the present invention folded jet disk.
FIG. 10 is a schematic view showing the positions of different temperature measuring points on the same bed section in the example of the present invention and the comparative example.
Detailed Description
The embodiments of the present invention will be described in further detail with reference to the drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
In the description of the present invention, it is to be noted that, unless otherwise specified, "a plurality" means one or more than one, and "a plurality" means two or more than two; the terms "upper", "lower", "inner", "outer", "top", "bottom", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing and simplifying the description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present invention can be understood as appropriate to those of ordinary skill in the art.
As shown in fig. 1 to 4, the invention discloses a hydrogenation reactor, which comprises a material inlet pipe 1, an inlet diffuser 2, a reactor upper end enclosure 3, a folded edge type flow reduction and equalization disc 4, a catalyst bed layer 5, a catalyst support grid 6, a reactor barrel 12, a reactor lower end enclosure 13, an outlet collector 14, a material outlet pipe 15 and an agent discharge pipe 16. In certain embodiments, the hydrogenation reactor further comprises a bed unloading agent pipe 7, a cold hydrogen pipe 8, a cold hydrogen tray 9, a hem-folded spray tray 10, an inter-bed distribution tray 11. In a further preferred embodiment, the hydrogenation reactor further comprises a top distribution tray 17, the top distribution tray 17 being located below the hemmed flow reducing and equalizing tray 4, above the uppermost catalyst bed.
The edge-folded impact-reducing flow-equalizing disc comprises a tray 4-2 and a plurality of chimney type distributors 4-1 vertically arranged on the tray. The chimney type distributor 4-1 comprises a downcomer 4-1-2 and a wing plate 4-1-1 arranged at the top of the downcomer 4-1-2. The downcomer 4-1-2 is a structure with two open ends. The wing plates 4-1-1 and the downcomer 4-1-2 are arranged up and down. The wing plate 4-1-1 has a certain included angle, side length and height, and is generally made of a steel plate through folding. The wings 4-1-1 are parallel to the axis of the downcomer 4-1-2.
Wherein, the number of the wing plates 4-1-1 is the same as that of the down-flow pipes 4-1-2, and the wing plates correspond to the down-flow pipes one by one. The included angle of the wing plate 4-1-1 is generally 15-180 degrees, preferably 90-120 degrees; the side length of the wing plate 4-1-1 is generally 20 mm-200 mm, preferably 60 mm-120 mm; the height of the wing plate 4-1-1 is generally 30mm to 200mm, preferably 60mm to 120 mm. The bottom edge of the wing plate 4-1-1 is connected with the upper edge of the downcomer 4-1-2, and can also be partially overlapped with the downcomer 4-1-2. When the bottom edge of the wing plate 4-1-1 and the upper edge of the downcomer 4-1-2 are arranged in an overlapping manner, the height of the overlapping portion can be 10% -100%, preferably 5% -20% of the height of the downcomer 4-1-2. The central line of the included angle of the wing plate 4-1-1 coincides with the ray of the reactor cylinder 12, and the included angle faces the wall of the cylinder closest to the reactor.
In the hydrogenation reactor of the present invention, the downcomer 4-1-2 is generally made of a metal tube. The height of the downcomer 4-1-2 is generally 20 to 300mm, preferably 50 to 120 mm. 1-6 overflow holes 4-1-3, preferably 1-2, are arranged on the downcomer 4-1-2 in the horizontal direction; the total cross section area of the overflow holes is 10-100%, preferably 30-50% of the cross section area of the downcomer. When 1 overflow hole is arranged on the downcomer, the position of the overflow hole is opposite to the connection point of the downcomer 4-1-2 and the wing plate 4-1-1; when the number of the overflow holes 4-1-3 is 2, the direction is arranged at two sides of the connection point of the downcomer 4-1-2 and the wing plate 4-1-1. The shape of the overflow hole can be round, long strip, triangle and polygon, preferably round. The distance between the center line of the overflow hole and the upper surface of the tower tray is 5-100 mm, and preferably 30-50 mm.
In the hydrogenation reactor, one layer of the edge-folded impact-reducing and flow-equalizing disc comprises a plurality of chimney type distributors 4-1. The plurality of chimney distributors 4-1 are arranged on the tower tray in a triangular, quadrangular or rhombic shape. The chimney distributor 4-1 is usually inserted on the tray through the lower end of the downcomer 4-1-2 and can be fixedly connected by welding, screwing, buckling connection and the like.
In the hydrogenation reactor of the present invention, the tray 4-2 is generally divided into a plurality of pieces and can be spliced into a circular plate. The edge of the outermost edge of the tray 4-2 is provided with an upward folded edge, and the height of the folded edge is generally 5-80 mm, preferably 30-50 mm.
As shown in fig. 1, fig. 6, fig. 7 and fig. 8, the hydrogenation reactor of the present invention comprises a material inlet pipe 1, an inlet diffuser 2, a reactor upper head 3, a flanged flow reduction and equalization tray 4, a top distribution tray 17, a catalyst bed 5, a catalyst support grid 6, a bed agent discharge pipe 7, a cold hydrogen pipe 8, a cold hydrogen tray 9, a flanged spray tray 10, an inter-bed distribution tray 11, a reactor cylinder 12, a reactor lower head 13, an outlet collector 14, a material outlet pipe 15 and an agent discharge pipe 16. Wherein, the edge-folding type jet disc 10 is arranged between the cold hydrogen disc 9 of the hydrogenation reactor and the inter-bed distribution disc 11. The edge-folded spraying disc 10 comprises a tray plate 10-2 and a chimney type distributor 10-1 vertically arranged on the tray plate; the chimney type distributor 10-1 comprises a downcomer 10-1-2 and a wing plate 10-1-1 arranged at the upper part of the downcomer.
The downcomer 10-1-2 is of a cylindrical structure with two open ends, and the upper edge of the wing plate 10-1-1 is flush with the upper edge of the downcomer 10-1-2 or slightly higher than the upper edge of the downcomer 10-1-2. The wing plates 10-1-1 have certain included angles, side lengths and heights, and the lower edges of the wing plates 10-1-1 are attached to the upper surface of the tray plate 10-2 or have gaps with certain heights with the upper surface of the tray plate 10-2. The included angle of the wings 10-1-1 is away from the center or circle center of the tray 10-2. Furthermore, the central line of the included angle of the wing plate 10-1-1 is coincident with the ray of the cylinder 12 of the reactor, and the included angle of the wing plate 10-1-1 faces the wall of the cylinder closest to the reactor. The wing plates 10-1-1 are parallel to the axis of the downcomer 10-1-2. The wing plates 10-1-1 have certain included angles, side lengths and heights. The wing plate 10-1-1 is a folded plate with a certain included angle, side length and height. The number of the wing plates 10-1-1 and the number of the down-flow pipes 10-1-2 are the same and are in one-to-one correspondence. The middle lower part of the wing plate 10-1-1 and the middle upper part of the downcomer 10-1-2 can be partially overlapped and connected; when overlapped, the overlapping height accounts for 50 to 90 percent of the total height of the downcomer 10-1-2, and the preferred overlapping height accounts for 60 to 80 percent.
The chimney distributors 10-1 should be vertically arranged on the tray plate 10-2. The chimney distributor 10-1 is usually inserted into the tray plate 10-2 through the lower end of the downcomer 10-1-2, and may be fixedly connected by welding, screwing, or fastening. The lower end opening of the downcomer 10-1-2 is directly opened on the tray plate 10-2 or penetrates through the tray plate 10-2 to be opened. The tray also comprises a supporting beam 10-4 and a tray connecting piece 10-3 which are arranged below the tray and used for supporting.
The pipe wall of the downcomer is provided with a plurality of overflow holes 10-1-3, so that liquid can conveniently pass through the overflow holes 10-1-3 to enter the downcomer 10-1-2 and flow downwards along the downcomer 10-1-2. A certain distance is kept between the central line of the overflow hole 10-1-3 and the surface of the tray plate 10-2. The number of the overflow holes 10-1-3 is generally 1-6, preferably 1-2. The total cross-sectional area of the overflow holes 10-1-3 is 10-100%, preferably 30-50% of the horizontal cross-sectional area of the downcomer 10-1-2. When only 1 overflow hole 10-1-3 is arranged on the downcomer 10-1-2, the position is arranged opposite to the connection point of the downcomer 10-1-2 and the wing plate 10-1-1; when the number of the overflow holes 10-1-3 is 2, the positions are arranged on two sides of the symmetry axis of the wing plate 10-1-1. The shape of the overflow holes 10-1-3 can be round, long strip, triangle and polygon, preferably round.
The chimney distributor 10-1 may be made of any suitable material, such as ceramic, metal, etc., preferably steel. The wing plates 10-1-1 and the downcomer 10-1-2 can be integrally formed and manufactured; or the wing plate 10-1-1 and the downcomer 10-1-2 are assembled, for example, the middle upper part of the downcomer 10-1-2 can be fixedly connected with the wing plate 10-1-1 with a certain included angle. The fixed connection can adopt various suitable modes such as welding, bolt connection, screw connection, buckle connection and the like. In specific application, the downcomer 10-1-2 can be made of steel pipes, and the wing plates 10-1-1 are preferably made of steel plates through folding.
The tray 10-2 of the flanged jet disk is typically divided into several pieces and may be spliced into a circular plate. The edge of the outermost edge of the tray 10-2 is provided with a folding edge 10-5, and the folding edge 10-5 is folded upwards. The upper edge of the hem 10-5 should generally be higher than the upper edge of the overflow aperture 10-1-3 provided in the downcomer 10-1-2. The arrangement of the folding edge 10-5 can maintain a certain liquid level on the tray 10-2, thereby eliminating the influence of the insufficient level of the tray in the prior art on liquid phase distribution to a certain extent.
In the flanged spray tray, a plurality of chimney distributors 10-1 are generally arranged according to a certain rule, such as being arranged on a tray plate 10-2 in a triangular, quadrangular or rhombic shape.
The working process of the edge-folding type impact-reducing flow-equalizing disc in the hydrogenation reactor of the invention is further explained by combining with the figure 5: when the edge-folding type impact-reducing flow-equalizing disc works, materials enter the reactor from the inlet diffuser of the reactor, and fluid has residual kinetic energy due to the conveying of a pump, so that the materials have strong impact force. Because the material is fed from the center of the reactor, the material is still sprayed to the periphery in an oblique line flow state although the existing reactors are all provided with inlet diffusers. After the edge-folding type impact-reducing flow-equalizing disc provided by the invention is arranged in the reactor, fluid firstly impacts the wing plates 4-1-1 of the chimney distributor 4-1, the wing plates 4-1-1 can effectively block material fluid sprayed in a diagonal flow state, the impact force of the material fluid is eliminated, the flow state of the material is changed by arranging the wing plates 4-1-1, and the fluid is changed from the diagonal flow state to a vertical flow state and falls onto the tray 4-2 under the action of gravity after being blocked and losing kinetic energy. Because the down-flow pipe 4-1-2 is provided with the overflow holes 4-1-3, namely the material channel is horizontally arranged, and the overflow holes 4-1-3 have a certain height difference from the tray 4-2, the material can form a liquid layer with a certain depth on the tray 4-2, and even if the levelness of the tray 4-2 has deviation, each chimney distributor 4-1 can still ensure that the liquid phase exists. Due to the fact that the number of the chimney distributors 4-1 is large, a certain number of the chimney distributors 4-1 can work at any point on the surface of a catalyst bed layer in the reactor, and uniformity of the chimney distributors 4-1 is guaranteed. Fluid flows into the topmost distribution plate in the reactor from overflow holes 4-1-3 formed in the pipe wall of the downcomer 4-1-2, so that the primary distribution of materials is realized. Because the materials after passing through the edge-folding type impact reduction flow disc are converted into a vertical flow state when being distributed on the top distribution disc, and the kinetic energy disappears, the liquid layer on the surface of the top distribution disc tray has no thrust any more, the 'wave pushing' action of the materials on the liquid layer on the distribution disc is eliminated, friendly, stable and uniform inlet conditions are provided for the top distribution disc, and the materials are uniformly distributed on the catalyst bed layer together with the top distribution disc.
The operation of the flanged jet disc in the hydrogenation reactor according to the present invention is further illustrated with reference to fig. 9: when the device works, the fluid which is mixed by the cold hydrogen disc 9 and has an inclined flow state similar to a horizontal flow line impacts the wing plate 10-1-1, and the wing plate 10-1-1 is arranged at a certain included angle, so that the fluid which is sprayed in an oblique flow state can be effectively blocked, and the impact force of the fluid is reduced; the liquid drops carried by the gas phase are forced to be dispersed to the periphery by utilizing the blocking effect of the wing plates 10-1-1, a larger diffusion angle of the material is realized, the fluid naturally drops under the action of gravity after the kinetic energy is exhausted to form a vertical descending flow state, the potential energy of the liquid phase is converted into the kinetic energy of a free falling body and falls onto the tray plate 10-2 of the jet tray, and the material can form a liquid layer with a certain depth on the tray plate 10-2 of the jet tray because the material channel arranged on the downcomer 10-1-2 is horizontally arranged and has a certain height difference from the tray plate 10-2, so that the liquid layer of each downcomer 10-1-2 can be ensured to exist even if the levelness of the tray plate 10-2 has deviation. Because the materials after passing through the edge-folded type jet disc are converted into a vertical flow state when being distributed on the jet disc 10-2 and kinetic energy disappears, thrust is not provided for a liquid layer on the surface of the tray plate 10-2 of the jet disc any more, the phenomenon of 'pushing wave' of the materials to the liquid layer on the distribution disc is eliminated, friendly, stable and uniform inlet conditions for the redistributor are provided, and the materials are uniformly distributed on a catalyst bed layer together with the redistribution disc.
The edge-folding type injection tray can replace a redistribution tray, realizes the integration of impact reduction, flow equalization and distribution, greatly simplifies the internal structure of the reactor and reduces the investment.
The effect of the flanged flow reduction equalizing disc and the flanged jet disc of the present invention is described below by way of specific embodiments.
Comparative example 1
The diameter of a certain hydrogenation reactor is 4.6m, the upper end enclosure is idle, a top distribution disc is arranged at the inlet of the uppermost catalyst bed layer, an ERI type bubble cap type gas-liquid distributor which is conventional in the field is used in the top distribution disc, and the process conditions of the reactor are as follows: hydrogen partial pressure of 2.0MPa and volume space velocity of 2.0h-1The volume ratio of hydrogen to oil is 300:1, and the inlet of the reactor isThe temperature was 280 ℃, and the reactor comprised three catalyst beds. The existing spray tray with uniform holes, namely a flat tower sieve tray structure, is adopted between the cold hydrogen box and the redistribution tray between the first catalyst bed layer and the second catalyst bed layer; and a flat tower sieve tray structure is also adopted between the hydrogen cooling box and the redistribution tray between the second catalyst bed layer and the third catalyst bed layer, the tower tray is provided with uniformly distributed round holes with the diameter of 3mm, and the opening rate of the tower tray is 8%. The hydrogenation raw material is wax oil (the sulfur content is 2.0 wt%), the catalyst is 3936 hydrogenation catalyst, and the process conditions are as follows: the hydrogen partial pressure is 9.0MPa (G), the volume space velocity is 1.5h-1The volume ratio of hydrogen to oil is 700:1, and the inlet temperature of the reactor is 260 ℃. Before modification, the radial temperature and temperature difference of the inlets of the second bed layer and the third bed layer are shown in the table 1.
Example 1
Compared with the embodiment 1, the edge-folded impact-reducing flow-equalizing disc replaces a bubble cap type gas-liquid distributor, and the edge-folded injection disc replaces a flat tower sieve disc hole structure. The main parameters of the edge-folding impact-reducing flow-equalizing disc are as follows: the included angle of the wing plates is 120 degrees; the side length of the wing plate is 120 mm; the height of the wing plate is 60 mm. The wings of which are parallel to the axis of the chimney distributor. The bottom edge of the wing plate is superposed with the upper edge of the chimney distributor, and the superposition point is 20% of the height of the distributor. The height of the chimney distributor is 120 mm; 2 overflow ports are arranged on the pipe wall of the chimney distributor in the horizontal direction. The total cross-sectional area of the overflow holes is 30% of the cross-sectional area of the chimney distributor pipe; the pipe wall of the chimney distributor is provided with an overflow hole which is round; the center line of an overflow hole arranged on the pipe wall of the chimney distributor is 50mm away from the upper surface of the tower tray; in the edge-folding impact-reducing flow-equalizing disc, the chimney type distributor is arranged on the tray in a triangular shape. The tray is divided into 9 blocks which can be spliced into round plates, each cutting plate is provided with 3 chimney type distributors, and the edge of the outermost edge of the tray is provided with a folding edge, and the height of the folding edge is 50 mm.
The main parameters of the flanged jet disk are: the number of the wing plates and the number of the downcomers are the same, the wing plates are formed by folding steel plates, the included angles of the wing plates are 90 degrees, and the side lengths of the wing plates are 60 mm. The height of the wing plate is equal to that of the downcomer, the central line of the included angle of the wing plate 1-1 is superposed with the ray of the reactor cylinder, and the included angle faces the wall of the cylinder with the closest distance from the wall of the reactor. The height of the downcomer is 60 mm. The pipe wall of the downcomer is provided with 2 circular overflow holes which are arranged in the horizontal direction. The total cross section area of the overflow holes arranged on the pipe wall of the downcomer is 30 percent of the cross section area of the downcomer. The center line of the overflow hole arranged on the downcomer is 20mm from the surface of the tray. In the edge-folding type jet tray, a tray is divided into 9 small trays which can be spliced into a circular plate, chimney distributors are arranged on the edge-folding type jet tray in a triangular mode, and each small tray is provided with 3 chimney distributors. And the edge of the tray on the outermost edge is provided with an upward folded edge, and the height of the folded edge is 50 mm.
After the modification, the radial temperature distribution and temperature difference of the inlet of the first catalyst bed layer, the inlet of the second catalyst bed layer and the inlet of the third catalyst bed layer are shown in table 1.
Example 2
Compared with the embodiment 1, the edge-folded impact-reducing flow-equalizing disc is arranged above the bubble cap type gas-liquid distributor in the upper end socket of the hydrogenation reactor, and the edge-folded injection disc replaces a sieve disc hole structure of a flat tower. The main parameters of the edge-folding impact-reducing flow-equalizing disc are as follows: the included angle of the wing plates is 120 degrees; the side length of the wing plate is 120 mm; the height of the wing plate is 60 mm. The wings of which are parallel to the axis of the chimney distributor. The bottom edge of the wing plate is superposed with the upper edge of the chimney distributor, and the superposition point is 20% of the height of the distributor. The height of the chimney distributor is 120 mm; 2 overflow ports are arranged on the pipe wall of the chimney distributor in the horizontal direction. The total cross-sectional area of the overflow holes is 30% of the cross-sectional area of the chimney distributor pipe; the pipe wall of the chimney distributor is provided with an overflow hole which is round; the center line of an overflow hole arranged on the pipe wall of the chimney distributor is 50mm away from the upper surface of the tower tray; in the edge-folding impact-reducing flow-equalizing disc, the chimney type distributor is arranged on the tray in a triangular shape. The tray is divided into 9 blocks which can be spliced into round plates, each cutting plate is provided with 3 chimney type distributors, and the edge of the outermost edge of the tray is provided with a folding edge, and the height of the folding edge is 50 mm.
The main parameters of the flanged jet disk are: the number of the wing plates and the number of the downcomers are the same, the wing plates are formed by folding steel plates, the included angles of the wing plates are 90 degrees, and the side lengths of the wing plates are 60 mm. The height of the wing plate is equal to that of the downcomer, the central line of the included angle of the wing plate 1-1 is superposed with the ray of the reactor cylinder, and the included angle faces the wall of the cylinder with the closest distance from the wall of the reactor. The height of the downcomer is 60 mm. The pipe wall of the downcomer is provided with 2 circular overflow holes which are arranged in the horizontal direction. The total cross section area of the overflow holes arranged on the pipe wall of the downcomer is 30 percent of the cross section area of the downcomer. The center line of the overflow hole arranged on the downcomer is 20mm from the surface of the tray. In the edge-folding type jet tray, a tray is divided into 9 small trays which can be spliced into a circular plate, chimney distributors are arranged on the edge-folding type jet tray in a triangular mode, and each small tray is provided with 3 chimney distributors. And the edge of the tray on the outermost edge is provided with an upward folded edge, and the height of the folded edge is 50 mm.
After the modification, the radial temperature distribution and temperature difference of the inlet of the first catalyst bed layer, the inlet of the second catalyst bed layer and the inlet of the third catalyst bed layer are shown in table 1.
TABLE 1 results of application
|
Comparative example 1
|
Example 1
|
Example 2
|
First catalyst bed inlet
|
|
|
|
Radial temperature a
|
266.6
|
265.2
|
265.1
|
Radial temperature difference b
|
265.5
|
264.5
|
265.5
|
Radial temperature c
|
270.3
|
264.9
|
265.9
|
Radial temperature d
|
276.0
|
265.0
|
265.0
|
Radial temperature difference e
|
278.4
|
265.8
|
265.8
|
Maximum bed radial temperature difference
|
12.9
|
1.3
|
0.9
|
Second catalyst bed inlet
|
|
|
|
Radial temperature a
|
276.6
|
275.2
|
275.1
|
Radial temperature difference b
|
279.5
|
274.5
|
274.5
|
Radial temperature c
|
280.3
|
274.9
|
274.8
|
Radial temperature d
|
286.0
|
275.0
|
275.2
|
Radial temperature difference e
|
288.4
|
275.8
|
275.6
|
Maximum radial bed temperature difference, deg.C
|
11.8
|
1.3
|
1.1
|
Third catalyst bed inlet
|
|
|
|
Radial temperature a
|
281.3
|
282.9
|
282.9
|
Radial temperature difference b
|
283.6
|
283.5
|
283.4
|
Radial temperature c
|
292.5
|
284.5
|
284.3
|
Radial temperature d
|
286.7
|
284.3
|
284.5
|
Radial temperature difference e
|
289.6
|
283.7
|
283.9
|
Maximum radial bed temperature difference, deg.C
|
11.2
|
1.6
|
1.4 |