CN117065661A - Ultra-large hydrogenation reactor and pre-distribution assembly thereof - Google Patents

Abstract

The invention discloses a pre-distribution assembly, which comprises: an inlet diffuser, comprising: the bottom end of the inner cylinder is higher than the bottom end of the outer cylinder, and a liquid holding area is arranged between the inner cylinder and the outer cylinder; the annular bottom plate is coaxially connected to the bottom end of the outer cylinder, and a liquid phase channel is formed between the annular bottom plate and the inner cylinder; the top cover is arranged above the inner cylinder, and a gas phase channel is formed between the top cover and the inner cylinder; the rotating shaft is coaxially arranged in the inner cylinder in a penetrating way, and the lower end of the rotating shaft penetrates through the annular bottom plate; at least one layer of helical blades which are arranged in the inner cylinder and drive the rotating shaft to rotate; the splash plate is in a cone-shaped structure with a downward opening and is connected to the lower end of the rotating shaft in a linkage manner; and a stepped distribution disk coaxially disposed below the inlet diffuser. The invention also discloses an ultra-large hydrogenation reactor. The invention can realize the uniform distribution of gas-liquid phase materials in the ultra-large hydrogenation reactor by matching the rotary inlet diffuser of the pre-distribution component with the stepped distribution plate.

Description

Ultra-large hydrogenation reactor and pre-distribution assembly thereof

Technical Field

The invention relates to the technical field of hydrogenation reaction equipment, in particular to hydrogenation reaction equipment with larger reactor scale, and particularly relates to an ultra-large hydrogenation reactor and a pre-distribution component thereof.

Background

In recent years, with the rapid development of economy and the enhancement of environmental awareness, the requirements on quality and environmental protection of petrochemical products are higher and higher. As one of the technical means for producing clean fuels, the importance and the roles of hydrogenation technology in the oil refining industry are increasing. In a hydrogenation device, the hydrogenation catalyst technology and the hydrogenation process technology are the same, the internal component technology of the hydrogenation reactor is also an important component part of a reaction system, and the three components form three factors of the performance of the reactor.

The hydrogenation process is exothermic reaction, uneven material distribution can lead to severe reaction degree at the position with good catalyst wetting effect, and the faster the reaction rate, the more heat generated, thereby affecting the radial temperature difference of the reactor. When the radial temperature difference is large, the local temperature of the catalyst rises to form hot spots, so that the performance of the catalyst is deactivated prematurely, the performance of the catalyst is damaged, even coking and hardening of the catalyst in a partial area can be caused, and materials can not normally flow. Because the fixed bed hydrogenation reactor is in a trickle bed state, the catalyst below the hardening area cannot continue to play a role, the service life of the catalyst and the operating period of the device can be greatly reduced, the local hardening phenomenon can also cause the pressure drop of the catalyst bed to be increased, the operating pressure of the reactor is passively increased, on one hand, the energy consumption is increased, and on the other hand, hidden danger is brought to the stable operation of the device. When the pressure drop is excessively fast increased to reach the design value of the reactor, abnormal shutdown is required, skimming treatment is carried out, inspection and maintenance cost is additionally paid, and meanwhile, catalyst loss and waste are caused by screening of the catalyst.

In a hydrogenation device, a hydrogenation reactor serving as key equipment is used for refining, cracking and other reactions of raw oil mixed with hydrogen according to a certain proportion under the action of a hydrogenation catalyst. Whether the hydrogenation reaction in the hydrogenation reactor can be stably operated, whether the hydrogenation catalyst can fully play the role of the hydrogenation reaction, whether the product quality can reach high quality or not depends on the uniformity of the distribution of the gas phase and the liquid phase in the catalyst bed layer to a great extent. Whether the distribution of the gas phase and the liquid phase in the catalyst bed is uniform or not has close relation with the design of the internal components of the hydrogenation reactor. It can be said that the performance of the inner member directly affects the service life of the catalyst, the quality of the product and the running period of the device, and the inner member of the hydrogenation reactor with excellent performance is not inferior to the replacement of a hydrogenation catalyst with higher activity. Therefore, research and engineering development of the hydrogenation reactor and the internal components thereof are always very important at home and abroad, and the internal components of the reactor are continuously updated to obtain better effects.

The hydrogenation reactor is usually fed from the center of the top of the reactor, and an inlet diffuser is used as a medium and enters the first part of the reactor, so that the gas-liquid two phases are uniformly mixed by disturbance on one hand, and the gas-liquid two phases are diffused to the whole section on the other hand, the vertical impact of the gas-liquid two phases on the top distribution plate is eliminated, and stable working conditions are created for the distribution plate. Patent document CN106268524a discloses a diffuser and a fixed bed reactor, the diffuser is arranged at the inlet of the reactor body, and comprises a cylinder body and a cyclone plate arranged in the cylinder body, wherein the top of the cylinder body is provided with a gas-liquid material inlet, the side surface of the bottom of the cylinder body is provided with a gas-liquid material diffusion port, and the cyclone plate is a curved plate extending to the gas-liquid material diffusion port along the axial direction of the cylinder body. Patent document CN205495530U discloses a cyclone inlet diffuser, which comprises a barrel, a buffer plate, a cover plate and a crushing plate which are coaxially connected, wherein a flange is welded at the top end of the barrel, a bottom plate with a circular outlet arranged at the center is arranged at the bottom end of the barrel, a plurality of guide plates which are spirally arranged are fixed on the bottom plate, and a cylindrical mixing cavity is enclosed as a channel of gas-liquid medium. The method has the advantages of strong buffer effect, sufficient gas-liquid mixing, large liquid phase spraying area and the like, can reduce the peak value of liquid phase distributed along the radial direction, uniformly diffuses the gas-liquid medium onto the section of the whole reactor, and creates conditions for the stable performance of the catalytic hydrogenation reaction.

As the hydrogenation device gradually enters the stage of the development of the large-scale hydrogenation device, the prior art has a remarkable problem in coping with the large-scale equipment, firstly, the inlet of the hydrogenation reactor needs to be connected with a pipeline, so that the diameter of the hydrogenation reactor has a certain upper limit, the diameter of the hydrogenation reactor cannot be arbitrarily increased along with the expansion of the diameter of the reactor, and the maximum ratio of the diameter of the reactor to the diameter of the inlet is more than 10 times at present. The conventional inlet diffuser adopts a mode of gas phase to entrain liquid phase to realize the distribution of the medium so as to enlarge the spraying area of the liquid phase material on the whole section of the reactor, but the accumulated speed of the gas phase is rapidly reduced due to the huge difference between the diameter of the reactor and the diameter of an inlet pipeline after the gas phase enters the reactor from the inlet diffuser through the analysis of the process of fluid movement. And after the liquid phase loses the continuous promotion of gaseous phase, also can fall fast under the action of gravity, even set up the splash plate structure of different forms, still can't satisfy the demand of large-scale hydrogenation reactor to material distribution area.

Secondly, the conventional inlet distributor adopts a fixed structure, and lacks the adaptability to the fluctuation of the material flow, namely, after the structural parameters are determined, the actual spraying area of the liquid phase is only influenced by the flow rate of the liquid phase, namely, the liquid phase quantity is completely determined. In practical working conditions, the liquid-phase feeding amount is in a continuously fluctuating state, and the upper limit of the flow velocity in the pipe is not usually reached, so that the inlet diffuser cannot realize long-period full-load stable operation. When the liquid phase amount is reduced, the flow speed is correspondingly reduced, the phenomenon of polycondensation to the central area of the hydrogenation reactor is generated in the spraying range, the service area is reduced, and stable working conditions cannot be created for the top distribution plate.

A layer of gas-liquid pre-distribution plate is added above the top distribution plate of the traditional hydrogenation reactor to improve the inlet condition of the work of the top distribution plate. Patent document CN109985573a discloses a hydrogenation reactor for improving liquid phase uniformity, in the idle space of the upper end enclosure of the reactor or at the upper end of the reactor cylinder body, a flanging type flow reducing and equalizing disc is arranged, materials are distributed to a top distribution disc through a chimney type distributor vertically arranged on the tray, a stable and uniform inlet working condition is provided for the top distribution disc, the material distribution of a top bed layer is optimized, and a primary distribution function is realized. Patent document CN204058374U discloses a fluid pre-distributor and a fluid pre-distributor tray, which are arranged above a gas-liquid distributor tray in a fixed bed hydrogenation reactor to pre-distribute hydrogenation raw materials, reduce the impact of the gas-liquid two-phase lower gas-liquid distributor tray, and keep the liquid level stable to form a more uniform and good distribution effect.

The prior art does not fundamentally solve the problem of distribution of gas-liquid two phases in the whole section, and firstly, a gas-liquid pre-distribution plate is additionally arranged, so that the problem that the top distribution plate is directly influenced is avoided, but as the liquid phase material passes through an inlet diffuser, the residual kinetic energy of the liquid phase material can generate strong inertia force, the liquid phase material is caused to fall on the top distribution plate and then is gathered along the periphery of a reactor, incremental distribution is usually formed on the pre-distribution plate, namely, the liquid layer has a tendency of gradually rising from a central position to an edge position. Along with the increasing treatment scale of the hydrogenation device, the diameter of the hydrogenation reactor is gradually increased, and the height of the material liquid layer on the distribution plate at the top of the reactor, namely in the central position, is relatively smaller, and the height of the material liquid layer on the side wall is relatively larger, as can be obviously observed from engineering implementation.

The distributor on the pre-distributing disc with distributing function usually needs to reach a certain liquid layer height to enter the working state, which results in that when the distributor on the side wall of the reactor is started, the distributor in the central position area of the pre-distributing disc is still in the standby state due to insufficient liquid layer height, and the liquid layer on the top distributing disc forms incremental distribution again. Even the best performance distributor can not realize even distribution of materials under the condition of different liquid layer heights, the working effect of the top distributor is seriously affected, and the expansion of radial temperature difference is unavoidable.

Secondly, the gas phase is influenced by the pressure distribution in the space of the reactor head, and the gas phase can be gathered to the central area of the reactor after passing through the inlet diffuser, so that a distribution rule which is completely opposite to the liquid phase is formed. When the distributor in the central position area of the pre-distributing disc can not be normally started, the gas phase can directly pass through the pre-distributing disc without being mixed with the liquid phase, and seriously and even directly pass through the top distributing disc to enter the catalyst bed layer, so that the gas-liquid phase material distribution generates great deviation along with the increasing diameter of the hydrogenation reactor.

Thirdly, in order to ensure that the liquid phase amount flowing through each distributor is the same, the uniform coverage of materials to the catalyst bed layer is realized, the requirement of a pre-distribution plate on levelness is extremely high, but as the diameter of the current hydrogenation reactor is larger and larger, the tray is installed in a block combination mode, and the integral levelness of a distribution plate surface cannot be accurately ensured. The distribution plate surface is inclined by 1/8-1/2 degrees along the horizontal direction due to common installation errors, and the maximum inclination can reach 3/2 degrees, so that even if the levelness at the beginning of installation is higher, the levelness can be lost due to the combined action of thermal expansion and material impact load in the operation process, and the using effect of the distributor is further affected.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art.

Disclosure of Invention

One of the purposes of the invention is to provide an oversized hydrogenation reactor and a pre-distribution component thereof, so as to solve the problem of insufficient spraying area of liquid phase materials in the oversized hydrogenation reactor.

Another object of the present invention is to provide a very large hydrogenation reactor and a pre-distribution assembly thereof, thereby improving the problem of serious deviation of the distribution of gas-liquid phase materials on the top distribution plate of the hydrogenation reactor.

Another object of the present invention is to provide an oversized hydrogenation reactor and a pre-distribution assembly thereof, so as to solve the problems of high installation accuracy requirement of the pre-distribution plate in the existing hydrogenation reactor, easy deformation in the operation process, etc.

To achieve the above object, according to a first aspect of the present invention, there is provided a pre-dispensing assembly comprising: an inlet diffuser, comprising: the sleeve consists of an inner cylinder and an outer cylinder which are coaxially arranged, the bottom end of the inner cylinder is higher than the bottom end of the outer cylinder, and a liquid holding area is arranged between the inner cylinder and the outer cylinder; the annular bottom plate is coaxially connected to the bottom end of the outer cylinder, and a liquid phase channel is formed between the annular bottom plate and the inner cylinder; the top cover is arranged above the inner cylinder, and a gas phase channel is formed between the top cover and the inner cylinder; the rotating shaft is coaxially arranged in the inner cylinder in a penetrating way, and the lower end of the rotating shaft penetrates through the annular bottom plate; at least one layer of helical blades which are arranged in the inner cylinder and drive the rotating shaft to rotate; the splash plate is in a cone-shaped structure with a downward opening and is connected to the lower end of the rotating shaft in a linkage manner; and a stepped distribution plate coaxially disposed below the inlet diffuser, the stepped distribution plate having a stepped shape with a low middle and a high periphery.

Furthermore, in the technical scheme, the cone angle of each layer of splash plate is 90-180 degrees.

Furthermore, in the technical scheme, each layer of splash plate is formed by a plurality of fan-shaped pieces in an interval distribution mode, and the number of the fan-shaped pieces of each layer of splash plate is 3-8.

Further, in the above technical scheme, the outer end of the sector piece is provided with saw teeth.

Further, in the above technical scheme, when two layers of splash plates are provided, the fan-shaped pieces of the upper layer splash plate and the fan-shaped pieces of the lower layer splash plate are staggered.

Further, in the above technical scheme, when two layers of splash plates are provided, the cone angle of the upper layer splash plate is larger than that of the lower layer splash plate.

Further, in the above technical solution, the number of the spiral blades in each layer is 3-5; the windward side of the helical blade is in the axial direction, and the blade angle is 50-78 degrees.

In the technical scheme, the inner diameter of the annular bottom plate is 0.6-1.0 times of the diameter of the inner cylinder.

Further, in the above technical solution, the top cover is in a conical, spherical or flat structure.

Further, in the above technical solution, the step distribution plate includes: the plurality of trays comprise a circular tray and a plurality of annular trays, the inner diameter and the outer diameter of the plurality of trays are sequentially matched and are distributed in a multi-layer stepped mode by taking the circular tray as a center, the circular tray is the lowest layer, the annular tray with the largest outer diameter is the highest layer, and the plurality of trays are all provided with a plurality of sieve holes; and a connecting member connecting the adjacent two trays and sealing the inter-layer gap of the adjacent two trays.

Furthermore, in the technical scheme, each annular tray is formed by splicing a plurality of tray plates.

According to a second aspect of the present invention there is provided an oversized hydrogenation reactor comprising: the body is of a cylindrical structure, and a feed inlet is arranged in the center of the upper end of the body; the pre-dispensing assembly of any one of the above technical solutions, the inlet diffuser being disposed at the feed inlet; and a top distribution tray disposed below the stepped distribution tray.

Further, in the above technical scheme, a circle of boss is arranged on the inner wall of the body, and the periphery of the stepped distribution disc is arranged in the body through the boss.

Further, in the above technical scheme, the boss is welded in the upper seal head of the body.

Further, in the above technical solution, the diameter of the body is greater than or equal to 6.5m.

Compared with the prior art, the invention has one or more of the following beneficial effects:

1. the pre-distribution component is matched with the stepped distribution plate through the inlet diffuser, so that the uniform distribution of gas-liquid phase materials in the ultra-large hydrogenation reactor can be realized.

2. The rotary inlet diffuser is a movable inner member, and realizes the distribution of liquid phase in an oversized hydrogenation reactor after being sprayed out through a small-diameter pipeline. The gas phase positively blows the helical blades through the channel of the inner cylinder to drive the main shaft to rotate, the kinetic energy of the gas phase during the flow in the pipe is fully utilized, the splash plate below the main shaft is further driven to rotate, and then a stable centrifugal force field is formed, so that the horizontal initial speed is provided for the liquid phase. The liquid phase flows out from the center of the annular bottom plate, different horizontal initial speeds are obtained in the process of entering the reactor through different positions of the splash plate saw teeth or gaps of adjacent fan-shaped sheets, the spray area can be covered on the section of the whole reactor, and the requirement of device maximization on the liquid phase coverage area can be met.

3. The rotary inlet diffuser is suitable for the material flow with larger air content, and can realize long-period stable operation under the condition of ensuring the stable flow of gas-phase materials. When the flow rate of the liquid phase is reduced, namely the liquid phase feeding amount is in the fluctuation valley, the spraying range can still be kept in a stable state, the condensation polymerization to the central area of the reactor is avoided, stable working conditions can be created for the top distribution plate, and the adaptability to the fluctuation of the liquid phase material flow is higher.

4. The spiral blade of the rotary inlet diffuser is positioned in the inner cylinder, and the power during working is mainly from a large amount of kinetic energy during gas phase flow, so that the kinetic energy is converted into mechanical energy for rotating the rotating shaft, and then the kinetic energy of the gas phase is transmitted to the liquid phase through collision of the splash plate and the liquid phase. The problem that the accumulated energy is rapidly attenuated after the gas phase enters the reactor due to the large difference between the diameter of the reactor and the diameter of an inlet pipeline of the traditional inlet diffuser, and the liquid phase cannot be continuously pushed by the gas phase is avoided.

5. The stepped distribution plate disclosed by the invention is formed by the circular tray and the plurality of annular trays to be distributed in a multi-layer stepped manner, so that the arrangement mode of the traditional pre-distribution plate is changed, and the liquid layers on all trays are not in the same horizontal plane through faults manufactured between the adjacent trays, so that the blocking effect of the liquid in the same direction in the flowing process is reduced, and the liquid phase is prevented from accumulating around the reactor; the liquid layers on the adjacent trays are not in direct contact, and single continuous liquid level which is distributed over the section of the whole reactor is not present, so that the bridge approach effect generated by mutual support between liquid phases is fundamentally broken, and the incremental distribution phenomenon of the liquid layers from the central position to the edge position is eliminated.

6. The step distribution plate is not provided with a conventional gas-liquid distributor, liquid phase flows down through the sieve holes on each layer of tray, the liquid phase quantity passing through each sieve hole is basically the same, the gas partial pressure of each part of the section of the whole reactor is ensured to be approximately the same, the uniform distribution of gas phase is realized, the generation of great deviation of gas-liquid phase materials is avoided, and good preconditions are provided for the stable operation of a hydrogenation device.

7. The trays in the stepped distribution tray are positioned at different horizontal positions, so that the accumulated error in the radial direction is effectively reduced, the levelness of the trays in the same layer is only required to be ensured in the installation process, the integral levelness of the stepped distribution tray is not required to be accurately ensured, and the installation difficulty is reduced.

8. Each tray can be divided into a plurality of tray plates according to the manhole size, the number of the tray plates and the number of the tray layers are correspondingly increased along with the increase of the diameter of the hydrogenation reactor, and the resistance to thermal expansion and material impact load in the running process of the device is improved.

The foregoing description is only an overview of the present invention, and it is to be understood that it is intended to provide a more clear understanding of the technical means of the present invention and to enable the technical means to be carried out in accordance with the contents of the specification, while at the same time providing a more complete understanding of the above and other objects, features and advantages of the present invention, and one or more preferred embodiments thereof are set forth below, together with the detailed description given below, along with the accompanying drawings.

Drawings

FIG. 1 is a schematic partial structure of an oversized hydrogenation reactor according to an embodiment of the present invention.

Fig. 2 is a schematic structural view of an inlet diffuser according to an embodiment of the present invention.

Fig. 3 is a schematic top view of a sputtering plate according to an embodiment of the present invention.

Fig. 4 is a schematic bottom view of a stepped distribution tray according to an embodiment of the present invention.

The main reference numerals illustrate:

100-ultra-large hydrogenation reactor, 110-body, 111-feed inlet, 112-boss, 120-inlet diffuser, 121-inner barrel, 1211-lower leg, 1212-upper leg, 1213-bearing bracket, 122-outer barrel, 123-annular bottom plate, 124-top cover, 125-spindle, 126-spiral vane, 127-splash plate, 1270-fan-shaped piece, 130-step distribution tray, 131-circular tray, 132-annular tray, 133-I-beam, 134-support beam.

Detailed Description

The following detailed description of embodiments of the invention is, therefore, to be taken in conjunction with the accompanying drawings, and it is to be understood that the scope of the invention is not limited to the specific embodiments.

Throughout the specification and claims, unless explicitly stated otherwise, the term "comprise" or variations thereof such as "comprises" or "comprising", etc. will be understood to include the stated element or component without excluding other elements or other components.

Spatially relative terms, such as "below," "beneath," "lower," "above," "upper," and the like, may be used herein for ease of description to describe one element's or feature's relationship to another element's or feature's in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the article in use or operation in addition to the orientation depicted in the figures. For example, if the article in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the elements or features. Thus, the exemplary term "below" may encompass both a direction of below and a direction of above. The article may have other orientations (rotated 90 degrees or other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terms "first," "second," and the like herein are used for distinguishing between two different elements or regions and are not intended to limit a particular position or relative relationship. In other words, in some embodiments, the terms "first," "second," etc. may also be interchanged with one another.

As shown in fig. 1, the oversized hydrogenation reactor 100 according to the embodiment of the present invention has a cylindrical body 110, and a feed inlet 111 is provided at the center of the upper end of the body 110. An inlet diffuser 120 is provided at the feed inlet 111, and a stepped distribution plate 130, a top distribution plate and a catalyst bed (not shown) are provided below the inlet diffuser 120 in this order from top to bottom.

Further, in one or more exemplary embodiments of the present invention, a circle of bosses 112 are provided on an inner wall of the body 110, and an outer circumference of the stepped distribution disc 130 is installed in the body 110 through the bosses 112. Further, in one or more exemplary embodiments of the invention, the boss 112 is welded within the upper head of the body 110. It should be appreciated that boss 112 may not be disposed within the upper head.

As shown in connection with fig. 1-4, a pre-dispensing assembly according to an embodiment of the present invention includes an inlet diffuser 120 and a stepped dispensing disk 130. The inlet diffuser 120 comprises a sleeve formed by an inner cylinder 121 and an outer cylinder 122 which are coaxially arranged, wherein the bottom end of the inner cylinder 121 is higher than the bottom end of the outer cylinder 122, and a liquid holding area is arranged between the inner cylinder 121 and the outer cylinder 122. The bottom end of the outer cylinder 122 is coaxially connected with an annular bottom plate 123, and a liquid phase channel is formed between the annular bottom plate 123 and the inner cylinder 121. Illustratively, the outer circumference of the annular base 123 may be welded to the bottom end of the outer tub 122. A top cover 124 is arranged above the inner cylinder 121, and a gas phase passage is formed between the top cover 124 and the inner cylinder 121. The inner cylinder 121 is coaxially penetrated with a rotating shaft 125, and the lower end of the rotating shaft 125 penetrates through the annular bottom plate 123. At least one layer of spiral blades 126 is arranged on the rotating shaft 125, and the spiral blades 126 are arranged in the inner cylinder 121 and drive the rotating shaft 125 to rotate. At least one layer of splash plate 127 is connected to the lower end of the rotating shaft 125 in a linkage manner, and the splash plate 127 has a cone-shaped structure with a downward opening. The stepped distribution plate 130 is coaxially disposed below the inlet diffuser 120, and the stepped distribution plate 130 has a stepped shape with a low middle and a high circumference.

Further, in one or more exemplary embodiments of the invention, the cap 124 may be tapered, spherical, or a flat plate structure. Illustratively, as shown in FIG. 1, the top cover 124 is a flat plate structure with edges turned up and toothed slots.

Further, in one or more exemplary embodiments of the present invention, the lower end of the inner cylinder 121 may be connected to the annular bottom plate 123 through the lower leg 1211, with a gap therebetween being a liquid phase channel. The upper end of the inner barrel 121 may be connected to the canopy 124 by upper legs 1212, with a gap therebetween being a gas phase passage.

Further, in one or more exemplary embodiments of the invention, the inner wall of the inner barrel 121 is provided with bearing brackets 1213, including upwardly opening bearing blocks and legs. The rotary shaft 125 is provided with a bearing which is correspondingly arranged in the bearing seat, and the outer ring is used as a fixed ring to be fixed on the inner wall of the inner cylinder 121.

Further, in one or more exemplary embodiments of the present invention, the taper angle of each layer of splash plates 127 may be 90-180 °. Further, in one or more exemplary embodiments of the present invention, each layer of the splash plate 127 may be formed of a plurality of fan-shaped pieces 1270 spaced apart, with the number of fan-shaped pieces of each layer of the splash plate 127 ranging from 3 to 8. Further, in one or more exemplary embodiments of the invention, the outer ends of the segments 1270 are provided with serrations. Further, in one or more exemplary embodiments of the present invention, two layers of splash plates are provided, with the fan-shaped pieces 1270 of the upper layer splash plate staggered with the fan-shaped pieces 1270 of the lower layer splash plate. Further, in one or more exemplary embodiments of the present invention, a two-layer splash plate is provided, and the cone angle of the upper layer splash plate is greater than the cone angle of the lower layer splash plate.

Further, in one or more exemplary embodiments of the invention, the number of helical blades 126 per layer may be 3-5.

Further, in one or more exemplary embodiments of the invention, the annular base 123 has an inner diameter that is 0.6 to 1.0 times, preferably 0.7 to 0.9 times, the diameter of the inner barrel 121.

Further, in one or more exemplary embodiments of the present invention, the stepped distribution tray 130 includes a plurality of trays, one of the plurality of trays is a circular tray 131, the other is an annular tray 132, the inner and outer diameters of the plurality of trays are sequentially matched and are in multi-layered stepped distribution centering on the circular tray 131, wherein the circular tray 131 is the lowest layer, and the annular tray 132 having the largest outer diameter is the highest layer. The circular tray 131 and the plurality of annular trays 132 are each provided with a plurality of mesh openings (not shown). Adjacent two layers of trays are connected by a connecting piece, and the connecting piece seals the interlayer gap of the adjacent two layers of trays.

Further, in one or more exemplary embodiments of the present invention, adjacent two trays are connected by an i-beam 133, and in the adjacent two trays, an inner edge of an upper tray is overlapped on an upper surface of an upper wing plate of the i-beam 133, an outer edge of a lower tray is overlapped on an upper surface of a lower wing plate of the i-beam 133, and a web of the i-beam 133 seals an inter-layer gap of the adjacent two trays. Illustratively, the i-beams 133 are ring beams, and two adjacent layers of i-beams 133 (ring beams) are connected by a plurality of radially disposed support beams 134 to form a unitary mounting bracket. The distribution of the support beams 134 and the ring beams can be shown in fig. 4, but the invention is not limited thereto. Further, in one or more exemplary embodiments of the present invention, the height difference between adjacent two layers of trays is about 200 to 400mm, i.e., the height of an I-beam.

Referring to fig. 1, in one or more exemplary embodiments of the present invention, the pre-distribution assembly operates as follows, in which the gas-liquid mixture falls from the feed port 111 of the oversized hydrogenation reactor 100 onto the top cover 124 above the inner cylinder 121 of the inlet diffuser 120, and most of the liquid phase is buffered by the folds, and enters the liquid holding area between the outer cylinder 122 and the inner cylinder 121 along the tooth slots in the circumferential direction. The liquid phase material passes through the liquid phase channel between the lower end of the inner cylinder 121 and the annular bottom plate 123, and falls onto the upper layer splash plate 127 and the lower layer splash plate 127 in sequence under the action of gravity, and forms a certain liquid layer on the annular bottom plate 123 at the same time, so that the gas phase material is prevented from entering the ultra-large hydrogenation reactor 100 along the same path.

Since the inner diameter of the annular bottom plate 123 is 0.7-0.9 times of the diameter of the inner cylinder 121, a liquid seal is formed when the liquid phase flows through the liquid phase channel, and the gas phase material is affected by the liquid seal and can only flow downwards along the center of the inner cylinder 121 through the gas phase channel between the upper end of the inner cylinder 121 and the top cover 124, and meanwhile, the spiral blades 126 are blown forward to drive the rotating shaft 125 to rotate, so that the two layers of splash plates 127 at the lower end of the rotating shaft 125 are driven to rotate. After passing through the inlet diffuser 120, the time for the material to fall onto the lower distribution tray is mainly affected by gravity, while the distribution in the cross section of the reactor is affected by the horizontal initial velocity, that is, the larger the initial velocity in the horizontal direction of the liquid phase, the larger the spray area that it can cover. According to the circular motion formula, when the rotation angular velocity of the splash plate is determined, the linear velocity of the edge is only related to the diameter, and the inlet diffuser 120 ensures that the material leaves the splash plate at different positions through multi-stage flow division of the liquid phase, and the distribution along the whole reactor section is formed by utilizing the difference of the initial velocities of the material.

The splash plate 127 may be formed by a plurality of fan-shaped pieces 1270 distributed at intervals, and the blank areas of two adjacent splash plates 127 are distributed alternately, so that the liquid phase falls onto the upper splash plate 127 to generate a split flow, part of the material falls onto the lower splash plate 127 along the blank area of the upper splash plate 127, the other part of the material falls onto the blank area of the lower splash plate 127 along the upper splash plate 127, and the other part of the material directly falls into the reactor through the gap between the two splash plates 127. The liquid phase sliding down the splash plate 127, due to the centrifugal force field created by the spinning action, has a certain initial horizontal velocity, the magnitude of which is related to the position from the axis of rotation 125. The outer edges of the two layers of splash plates 127 are provided with saw teeth, so that liquid phase separated from the edges of the splash plates 127 can generate speed demarcations, the flow dividing effect of the liquid phase is further enhanced, the whole coverage of the cross section of the whole reactor can be formed, and the development trend of the large-scale hydrogenation device is met.

The helical blades 126 are located inside the inner cylinder 121 at a position where the gas phase has a large kinetic energy, so that after a stable liquid level is established, they enter a normal working state, and can fully convert the accumulated energy into the mechanical energy of the splash plate 127. After the splash plate 127 collides with the liquid phase, part of the mechanical energy is converted into kinetic energy of the liquid phase moving in the horizontal direction, and the continuous energy transfer process is completed, wherein in the process, the vertical kinetic energy of the gas phase is converted into the horizontal kinetic energy of the liquid phase through the rotating shaft, and although partial loss can be generated, the method has positive significance in the aspect of reasonable utilization of energy.

After the majority of the liquid phase material falls to the stepped distribution tray 130, it first gathers along the inner wall of the body 110, the liquid layer tends to flow toward a central position under the action of gravity, part of the liquid phase will fall to the top distribution tray through the mesh openings on the annular tray 132, and the rest of the liquid phase flows through the annular tray 132. Because the adjacent trays are arranged in a stepped manner along the axial direction, the liquid phases on each layer of trays are not in the same horizontal plane, the liquid layers are not in direct contact, and the rest liquid phases are blocked by the inner wall of the body 110 or the web of the I-beam 133, and can only flow inwards through the artificially-made faults and then flow to the lower layer of trays.

Further, in one or more exemplary embodiments of the invention, each annular tray 132 may be formed from a plurality of tray decks that are spliced together. The tray deck may be divided according to the size of the manhole.

Further, in one or more exemplary embodiments of the present invention, the diameter of the body 110 is greater than or equal to 6.5m.

The present invention will be described in more detail by way of specific examples, and it should be understood that the present invention is not limited thereto.

Example 1

In this embodiment, referring to FIGS. 1-4, a very large hydrogenation reactor 100 is provided with the pre-distribution elements of the present invention, namely an inlet diffuser 120 and a stepped distribution plate 130. The oversized hydrogenation reactor 100 has a diameter of 6.8m. The inlet diffuser 120 is provided with two layers of spiral blades 126 and two layers of conical splash plates 127, wherein the number of each layer of spiral blade is 3, each layer of splash plate consists of 3 fan-shaped sheets, and the fan-shaped sheets of the upper layer of splash plate and the lower layer of splash plate are arranged in a staggered manner; the cone angle of the upper layer splash plate is 150 degrees, and the cone angle of the lower layer splash plate is 120 degrees. The stepped distribution tray 130 is constructed as described above, wherein the annular tray 132 is divided into a plurality of tray decks according to manhole dimensions. The connecting piece is an I-beam 133, the I-beam 133 is a ring beam, and two adjacent layers of ring beams are connected through a supporting beam 134. A circle of bosses 112 are provided in the body 110 of the hydrogenation reactor 100 of this embodiment.

When in installation, the installation frame formed by the I-beam 133 (ring beam) and the support beam 134 is fixed in the body 110 of the hydrogenation reactor 100, and a plurality of tray plates of each layer of annular tray 132 and the circular tray 131 are respectively connected with the ring beam for installation. The height difference between two adjacent trays is about 220mm.

The liquid phase is sprayed onto the edge of the hydrogenation reactor 100 through the inlet diffuser 120 to achieve full coverage of the material along the entire reactor cross-section. Reducing the distribution bias of the gas-liquid phase by the stepped distribution plate 130 provides a friendly, smooth, uniform inlet condition for the top distribution plate. After the pre-distribution component of the embodiment is adopted, compared with a conventional inlet diffuser and a pre-distribution disc, the problems of local flying and abnormal pressure drop rise in the operation of the device are solved, and the maximum radial temperature difference of the catalyst bed can be reduced from 14.2 ℃ to 1.2 ℃ and the pressure drop is reduced from 220kPa to 65kPa by comparing temperature measuring points arranged at the same height.

The foregoing descriptions of specific exemplary embodiments of the present invention are presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application to thereby enable one skilled in the art to make and utilize the invention in various exemplary embodiments and with various modifications as are suited to the particular use contemplated. Any simple modifications, equivalent variations and modifications of the above-described exemplary embodiments should fall within the scope of the present invention.

Claims (15)

1. A pre-dispensing assembly, comprising:

an inlet diffuser, comprising:

the sleeve consists of an inner cylinder and an outer cylinder which are coaxially arranged, the bottom end of the inner cylinder is higher than the bottom end of the outer cylinder, and a liquid holding area is arranged between the inner cylinder and the outer cylinder;

the annular bottom plate is coaxially connected to the bottom end of the outer cylinder, and a liquid phase channel is formed between the annular bottom plate and the inner cylinder;

the top cover is arranged above the inner cylinder, and a gas phase channel is formed between the top cover and the inner cylinder;

the rotating shaft is coaxially arranged in the inner cylinder in a penetrating way, and the lower end of the rotating shaft penetrates through the annular bottom plate;

at least one layer of helical blades which are arranged in the inner cylinder and drive the rotating shaft to rotate; and

at least one layer of splash plate is in a cone-shaped structure with a downward opening, and the splash plate is connected to the lower end of the rotating shaft in a linkage manner; and

and the stepped distribution plate is coaxially arranged below the inlet diffuser and is in a stepped shape with a lower middle and a higher periphery.

2. The pre-dispensing assembly of claim 1, wherein the cone angle of each layer of splash plates is 90-180 °.

3. The pre-distribution assembly of claim 1, wherein each layer of splash plates is comprised of a plurality of fan-shaped pieces spaced apart, and the number of fan-shaped pieces of each layer of splash plates is 3-8.

4. A pre-dispensing assembly in accordance with claim 3 in which said segments are provided with serrations at their outer ends.

5. A pre-distribution assembly according to claim 3, wherein when two layers of splash plates are provided, the scallops of the upper layer splash plate are staggered with the scallops of the lower layer splash plate.

6. The pre-distribution assembly of claim 5, wherein when two layers of splash plates are provided, the cone angle of the upper layer splash plate is greater than the cone angle of the lower layer splash plate.

7. The pre-dispensing assembly of claim 1, wherein the number of spiral blades per layer is 3-5; the windward side of the helical blade is in the axial direction, and the blade angle is 50-78 degrees.

8. The pre-dispensing assembly of claim 1, wherein the annular base plate has an inner diameter of 0.7 to 0.9 times the diameter of the inner barrel.

9. The pre-dispensing assembly of claim 1, wherein the top cap is a cone, sphere, or flat plate structure.

10. The pre-dispensing assembly of claim 1, wherein the stepped dispensing disc comprises:

the plurality of trays comprise a circular tray and a plurality of annular trays, the inner diameter and the outer diameter of the trays are sequentially matched and are in multi-layer stepped distribution taking the circular tray as a center, the circular tray is the lowest layer, the annular tray with the largest outer diameter is the highest layer, and the trays are all provided with a plurality of sieve holes; and

and the connecting piece is used for connecting the adjacent two layers of trays and sealing the interlayer gaps of the adjacent two layers of trays.

11. The pre-distribution assembly of claim 10, wherein each of said annular trays is formed from a plurality of tray decks that are spliced together.

12. An oversized hydrogenation reactor, comprising:

the device comprises a body, a feeding hole and a sealing device, wherein the body is of a cylindrical structure, and the center of the upper end of the body is provided with the feeding hole;

the pre-dispensing assembly of any one of claims 1 to 11, said inlet diffuser being disposed at said feed inlet; and

a top distribution tray disposed below the stepped distribution tray.

13. The oversized hydrogenation reactor of claim 12 wherein the inner wall of the body is provided with a ring of bosses by which the periphery of the stepped distribution disk is mounted within the body.

14. The oversized hydrogenation reactor of claim 13 wherein the boss is welded within the upper head of the body.

15. The oversized hydrogenation reactor of claim 12 wherein the body has a diameter greater than or equal to 6.5m.