CN108114669B - Baffle type impact-reducing flow-equalizing disc - Google Patents

Abstract

the invention discloses a baffle type impact reducing and flow equalizing disc. The baffle type impact reduction and flow equalization plate comprises a tray and a plurality of downcomer distributors arranged on the tray; the downcomer distributor comprises a downcomer and a surge-reducing disc fixed at the upper end of the downcomer, and the surge-reducing disc comprises a bottom plate and a plurality of baffles which are fixed on the upper surface of the bottom plate and are arranged in parallel; the upper part of the downcomer is an oblique line-shaped notch, and the lower end of the downcomer is open; the baffles are parallel to the axis of the reactor or on the same plane with the axis of the reactor. The impact reduction flow equalizing disc is a newly added internal component of the hydrogenation reactor, is arranged in an idle space of an upper end socket of the reactor or at the upper end of a cylinder body of the reactor, can reduce the strong impact force formed by residual kinetic energy when fluid enters the reactor, and eliminates the phenomenon of 'wave pushing' of an inclined flow line formed when a central point enters a liquid layer of the distribution disc. The flow reducing and equalizing disc is suitable for all hydrogenation reactors, is particularly suitable for large-scale hydrogenation reactors, and can realize the initial distribution of materials.

Description

Baffle type impact-reducing flow-equalizing disc

Technical Field

The invention relates to a baffle type impact reducing and flow equalizing disc, and belongs to the field of chemical equipment.

Background

In recent years, with the rapid development of national economy and the enhancement of environmental awareness, the requirements on the quality and the environmental protection of petrochemical products are higher and higher. In order to meet the requirements of processing sulfur-containing crude oil, meet the increasing demands of chemical raw materials and improve the quality of products, the importance and the role of hydrogenation technology in the oil refining industry are increasing. 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 the internal components of the hydrogenation reactor at home and abroad always pay attention to and continuously update the internal components of the reactor so as to obtain better effect.

The hydrogenation reactor internals include inlet diffuser, gas-liquid distribution disc, scale depositing basket, catalyst bed support, cold hydrogen tank, outlet collector, inert ceramic ball, etc. the most important internals directly concerning the catalyst utilization efficiency are gas-liquid distribution disc and cold hydrogen tank.

In the processes of gas-liquid-solid three-phase hydrocracking and hydrodesulfurization reactions, a fixed bed hydrogenation reactor is widely used, and a gas-liquid distributor is one of the most key internal components of the fixed bed hydrogenation reactor. The gas-liquid distributor has the function of distributing, mixing and uniformly spraying gas-liquid two-phase raw materials on the surface of the catalyst bed layer, and improving the flowing state of a liquid phase in the catalyst bed layer.

The gas-liquid distributor has macroscopic uniformity and microscopic uniformity for the distribution of the reaction materials. A plurality of gas-liquid distributors are mounted on the tray in an array to form a distribution tray. The amount of liquid phase flowing through each distributor is the same as the volume of gas, ensuring "uniform" coverage of the catalyst bed by the material, defined as the macroscopic uniformity of the gas-liquid distributor. Achieving a high macroscopic uniformity of liquid distribution is difficult because the distribution trays are assembled in blocks due to the increasing diameter of the hydrogenation reactor at present, and the level of the distribution plates cannot be accurately guaranteed. Generally, the installation error can cause the distribution plate surface to incline by 1/8-1/2 degrees along the horizontal direction, and the maximum inclination can reach 3/2 degrees. Even if the distribution tray is highly level at the beginning of installation, the distribution tray face loses its levelness due to the combined action of thermal expansion and material impact load during operation. Therefore, the distributor structure is required to realize the homogeneity of liquid phase macroscopic distribution.

The liquid is distributed over the bed catalyst by a distributor. The catalyst bed layer has no blank area which is not covered by liquid, so that the complete coverage of the catalyst bed layer by the material is ensured, and the microscopic uniformity of the gas-liquid distributor is realized. It is characterized by that it can reflect the liquid distribution effect of local zone of reactor bed layer.

The fixed bed hydrogenation reactor is a trickle bed reactor. The reactants flow downwardly in parallel in a gas-liquid two-phase fashion through a fixed catalyst bed. The liquid phase flows downward in a stream as the dispersed phase, while the gas phase, which is the continuous phase, flows downward co-currently with the liquid phase. The liquid phase wets the catalyst particles as it flows over the surface of the catalyst particles and the reaction takes place on the wetted catalyst particles, so that the effective wetting rate of the catalyst has a very important influence on the overall reaction rate. When the liquid-phase material enters the catalyst bed layer, the uneven distribution of the liquid-phase material forms channeling or bias flow on the catalyst bed layer, so that part of the catalyst cannot be wetted or the wetting effect is poor, the performance of the part of the catalyst cannot be exerted, and the product quality is influenced.

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 local temperature of the catalyst is higher, the reaction rate is higher, the effect superposition of the two effects can form hot spots, the performance of the catalyst is inactivated prematurely, the performance of the catalyst is damaged, even coking and hardening of a part of regions of the catalyst can be caused, the material can not flow normally, and the catalyst below the hardening region can not play a role because the fixed bed hydrogenation reactor is in a trickle bed flow state, so that the service life of the catalyst and the start-up period of the device are greatly reduced. The local hardening also causes the pressure drop of a catalyst bed layer to rise, the operation pressure of the reactor has to be increased for the continuous operation, and the energy consumption is increased; when the pressure drop is increased too fast to reach the designed value of the reactor, the reactor has to be shut down abnormally, the head skimming treatment is carried out, the maintenance cost is paid, and meanwhile, the catalyst is lost and wasted due to the sieving. Therefore, in a fixed bed hydrogenation reactor, the uniformity of liquid phase material distribution is very important.

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 state characteristic of central position feeding is that the streamline of material formation in reactor head space is the slope, and the liquid phase that has kinetic energy produces "pushing away unrestrained" phenomenon to the liquid layer on the top distributor tray, brings unfavorable entry condition for the distributor that relies on the tray levelness, even the best distributor of performance, under the liquid layer condition of the different degree of depth, also can't realize evenly distributed material, and radial difference in temperature enlarges inevitable.

The gas-liquid distribution plate is composed of a gas-liquid distributor arranged on a distribution plate, and has the main function of uniformly distributing liquid-phase reactants on a catalyst bed layer so as to ensure that all catalysts in the reactor can obtain uniform wetting degree, so that all the catalysts have similar catalytic efficiency, and the integral production efficiency of the reactor is effectively improved. In addition, the liquid phase reactant is uniformly distributed on the section of the whole catalyst bed layer, and the generation of 'hot spots' in the catalyst bed layer can be reduced, namely, the excessive radial temperature difference in the reactor is avoided, so that the coking and the inactivation of the catalyst are effectively inhibited, and the service life of the catalyst and the operation period of the reactor are prolonged. However, the gas-liquid distributor widely applied in the domestic hydrogenation field still has the defects of weak tower plate inclination resistance and poor liquid dispersion performance.

The study on the distribution uniformity of liquid in a fixed bed reactor at home and abroad has been for more than 50 years, and many researchers find that the initial distribution of the liquid on a catalyst bed layer is an important factor influencing the overall distribution uniformity of the catalyst bed layer, because single-strand liquid usually needs 4-5 times of the diameter of the reactor to realize uniform distribution on the whole bed layer.

The gas-liquid distributor is an important internal member in the fixed bed oxygen adding reactor, and the main function of the gas-liquid distributor is to provide a mixing and interaction place for gas-liquid two-phase fluid, so that the liquid is broken into liquid drops which are dispersed into gas flow and fall onto the filler along with the gas flow to form initial distribution of the liquid on the filler bed layer. The uniformity of initial liquid distribution directly influences the wetting degree and the use efficiency of downstream catalysts, if the gas-liquid distributor is unreasonable in design, the distribution effect of reaction raw materials is poor, the non-uniformity of hydrogenation reaction in a catalyst bed layer can be caused, the radial temperature difference is overlarge, the utilization rate and the service life of the catalysts are reduced, and even the quality of products cannot meet the requirements.

Along with the improvement of environmental awareness of people in recent years, the worldwide demand for clean fuels is more and more urgent, and new and higher requirements are put forward on the product quality of a hydrogenation reactor. The uniformity of the distribution of the reaction raw materials on the catalyst bed layer determines whether the hydrogenation reactor can realize stable operation or not to a great extent and the quality of the product can reach high quality, so the requirements on the performance of the gas-liquid distributor are higher and higher.

The gas-liquid distributor plays a very important role in the stable operation of the fixed bed oxygen adding reactor and the quality of the hydrogenation products, so the research on the structure and the performance of the gas-liquid distributor arouses the interests of a plurality of experts and scholars, and is also valued by main petroleum refining companies and scientific research institutions at home and abroad. Domestic units such as China petrochemical engineering construction company, Fushun petrochemical research institute and Luoyang petrochemical engineering company, and foreign units such as British Petroleum company (BP), Union Oil company (Union Oil), Texaco (Texaco), Oil products around the globe company (UOP), Chevrong Company (CHEVRON), Shell company (SHELL) have been devoting great attention to the development and application of gas-liquid distributors, and various gas-liquid distributors with different styles have been developed. Different gas-liquid distributors have different methods for achieving macroscopic distribution uniformity and microscopic distribution uniformity. The main classification according to its action mechanism is three: overflow type, suction type, and a mixed type of the two. Their structures and working mechanisms are different from each other, and their micro-distribution uniformity is also very different.

Generally speaking, according to the liquid dispersion mechanism, in the overflow type, suction type and mixed type three-type gas-liquid distribution discs with overflow and suction functions, the suction type gas-liquid distributor can disperse liquid into liquid drops with smaller particle size due to better liquid crushing performance, and under the action of the suction type gas-liquid distributor, the distribution uniformity of the liquid on a catalyst bed layer is better than that of the other two types, such as the combined oil type gas-liquid distributor widely applied in the domestic oxygenation field at present. However, since the combined oil type gas-liquid distributor adopts the same gas-liquid inlet, the area of the gas inlet will change along with the fluctuation of the liquid level, so as to cause the change of the gas velocity and the liquid suction capacity, when the gas-liquid distribution disk has a certain inclination, the gas-liquid distributors at different horizontal heights will have different gas inlet areas and liquid suction capacities, so that the liquid distribution of the gas-liquid distribution disk is not uniform enough, that is, the anti-column plate inclination capacity of the combined oil type gas-liquid distributor is not strong. In addition, some recent research reports show that the combined oil type gas-liquid distributor has a relatively serious central confluence phenomenon, and the distribution uniformity of the liquid is not ideal enough.

In recent years, with the increasing demand of domestic markets for high-quality distillate oil, together with the increasingly strict environmental regulations around the world and the global popularization and application of clean fuels, the traditional oil refining technology needs to be upgraded and upgraded for technical improvement. The technical level of the hydrogenation process mainly depends on the advancement of the catalyst performance, and the exertion of the catalyst performance greatly depends on the advancement and reasonableness of the internal structure of the reactor. One of the key technologies is that the reactor must have good initial distribution of liquid and gas and bed-to-bed redistribution to achieve the maximum utilization rate of the catalyst, otherwise, the production of ultra-low sulfur diesel oil is impossible. In order to realize the economic scale and the improvement of the manufacturing capacity of hydrogenation equipment, the size of a hydrogenation reactor is being increased, the diameter of the reactor is continuously increased, and the requirement on the reactant flow distribution effect of the components in the reactor is higher and higher.

At present, the heterogeneous condition of distribution exists to different degrees in present hydrogenation ware gas-liquid distributor home and abroad, and if domestic wide use be bubble cap type distributor, or improved generation bubble cap distributor, there is obvious inhomogeneous condition in gas-liquid distribution performance, and this distributor is based on the suction principle: the liquid phase is entrained during gas phase baffling, and liquid phase distribution is realized.

Bubble cap type dispensers rely primarily on the suction of the gas phase against the liquid phase on the dispensing tray to overcome the dispensing plate mounting tilt and maintain the uniformity of the liquid macro-distribution. However, the overflow port of the bubble cap type distributor is a straight slit, and the macroscopic uniformity of the bubble cap type distributor is not as good as that of the overflow type distributor. And the bubble cap distributor has larger size and larger installation distance, and occupies more space of the reactor. Moreover, due to the large flow in the central region of the bubble cap distributor, the microscopic distribution of the liquid phase is not uniform; and because the flow state of the bubble cap distributor is plug flow, the impact force is larger. For the reasons, the bubble cap distributor has to be filled with an inert ceramic ball layer with enough thickness when in use to reduce the impact force and assist in uniformly dispersing the liquid phase, and the liquid phase can be uniformly dispersed only after flowing through a certain section of bed layer depth, thereby wasting precious reactor space.

The wide range of fractions from crude gasoline to residual oil can be used as the raw material of a hydrogenation device, the flow state working condition of the crude gasoline can be divided into full gas phase and gas liquid phase flow, even if the gas phase and the liquid phase working condition exist, the hydrogen-oil ratio of the crude gasoline is greatly different, and the liquid phase density and the viscosity of the crude gasoline are greatly different, so that the bubble cap distributor based on the suction principle cannot be suitable for all the working conditions.

In addition, along with the fact that the raw oil deterioration is getting worse, the processing process flow is longer and longer, and the degree of continuity is higher and higher, rust scale generated by corrosion of equipment and process pipelines caused by acid in the raw oil, an auxiliary agent carried by instability of an upstream process, dissolved oxygen in the storage and transportation process and the like can generate scale after entering a hydrogenation reactor, and a top distribution disc is covered. The bubble cap distributor based on the suction principle is easily covered or partially covered, so that the material distribution is not uniform, and when the inlet liquid is not uniformly distributed, the effect of the distributor at the top of the hydrogenation reactor can be seriously influenced.

Aiming at the technical problems that the traditional gas-liquid distributor is weaker in tower plate inclination resistance and large in influence of uneven liquid layer depth on a distribution plate, a novel inner member technology with the functions of reducing impact and flow equalization, small in size, good in distribution effect and low in installation precision must be developed for reducing the strong impact force formed by the residual kinetic energy of fluid entering a reactor, eliminating the 'wave pushing' phenomenon of the fluid in an inclined flow state on the liquid layer on the distribution plate and realizing the uniform distribution of the fluid.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a baffle type impact reducing flow equalizing disc. The flow reducing and equalizing disc is a newly added internal component of the reactor and is arranged in an idle reactor upper end socket or arranged at the upper end of a reactor cylinder body and above a top distribution disc.

The baffle plate type impact reduction flow equalizing disc is a newly-added reactor inner member and is used for reducing strong impact force formed by residual kinetic energy when fluid enters a reactor; the device is used for eliminating the 'wave pushing' phenomenon of the distribution disc liquid layer caused by the inclined flow line formed when the central point enters. The functions of fine adjustment of fluid flow state and initial distribution of materials are realized, or the distribution function of a top distribution plate is replaced; good access conditions can be provided for the top dispensing tray. Compared with the prior art, the baffle plate has good impact-reducing and flow-equalizing distribution effect, fully utilizes the idle space of the reactor end socket, and has the characteristics of small volume, simple structure, convenient installation, large operation elasticity and the like.

The technical scheme of the invention is as follows:

A baffle type impact reduction and flow equalization plate comprises a tower tray and a plurality of downcomer distributors vertically arranged on the tower tray; the downcomer distributor comprises a downcomer and a surge-reducing disc fixed at the upper end of the downcomer, and the surge-reducing disc comprises a bottom plate and a plurality of baffles which are fixed on the upper surface of the bottom plate and are arranged in parallel; the upper end of the downcomer is an oblique line-shaped notch, and the lower end of the downcomer is open; the baffles are parallel to the axis of the reactor, are on the same plane with the axis of the reactor, or form a certain included angle with the axis of the reactor.

Furthermore, the baffle (upper end) inclines towards the nearest reactor wall, and the included angle formed by the plane of the baffle and the axis of the reactor is 15-80 degrees, preferably 10-45 degrees.

Furthermore, the cut of the downcomer is inclined from high to low in the sequence from the center of a circle to the inside and the outside of the tray. The angle between the cut of the downcomer and the axis of the reactor is between 10 and 75 deg., preferably between 15 and 60 deg..

Further, the tray also comprises a supporting beam for supporting and a tray connecting piece for fixing.

Furthermore, the baffles are fixed on the upper surface of the bottom plate in parallel, and a certain distance is reserved between every two adjacent baffles. The bottom edges of the plurality of baffles have certain gaps or no gaps with the upper surface of the bottom plate, when no gap exists, overflow holes with certain specifications are formed along the bottom edges, and the center lines of the overflow holes have certain distances from the upper surface of the bottom plate. The height from the central line of the overflow hole arranged on the bottom edge of the baffle to the upper surface of the bottom plate is not more than 30% of the height of the baffle. The shape of the overflow hole can be round, long strip, triangle and polygon, preferably round. When the bottom edges of the baffles are provided with circular, triangular and semicircular channels, the overflow hole channels arranged on two adjacent baffles are suitable to be arranged in a staggered manner.

In the present invention, the downcomer distributor may be made of any suitable material known in the art, preferably steel. The downcomer is usually made of metal pipe, and has a certain specification, and its upper end is made into oblique line-shaped notch to form elliptical cross-section to form gas phase flow channel, and the oblique line formed by its upper end notch and horizontal line have a certain included angle.

Furthermore, a certain number of overflow holes are arranged in the downcomer in the horizontal direction. The overflow holes have a certain specification and are at a certain distance from the surface of the tray. The total cross-sectional area of the overflow apertures is typically 10% to 100%, preferably 30% to 50% of the cross-sectional area of the downcomer (horizontal).

In the baffle type impact reduction flow equalizing disc, the impact reduction discs and the downcomers are the same in number. The impact reducing disc is fixed at the upper end of the downcomer. The central line of the impact reduction disc is coincident or not coincident with the axis of the downcomer.

In the baffle type impact reduction flow equalizing disc, a plurality of downcomer distributors are arranged on a tray in a certain regular arrangement, such as a triangular arrangement, a quadrangular arrangement and a rhombic arrangement.

In the baffle type impact reduction flow equalizing disc, the tray can be divided into a plurality of blocks and can be spliced into a circular plate. The edge of the outermost edge of the tray is provided with a folding edge which is turned upwards at a certain height.

In the invention, the baffle type impact reduction and flow equalization disc is suitable for a fixed bed reactor which is fed upwards and has a gas-liquid parallel flow form, and is preferably suitable for a fixed bed trickle bed reactor. The baffled flow reduction and equalization plate is suitable for all hydrogenation reactors, and is particularly suitable for hydrogenation reactors with large scale (such as the diameter of the reactor is more than 4 meters).

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.

Compared with the prior art, the baffle type impact reduction and flow equalization disc has the following advantages:

1. The baffle type impact-reducing flow-equalizing disc reduces the installation size of the distributor through special structural design, is convenient to be installed at an idle upper end socket of a reactor or arranged at the upper end of a reactor barrel and above the top distribution disc, achieves the aim of saving the space of the reactor, improves the space utilization rate of a hydrogenation reactor, is convenient to load more catalysts or reduces the scale of the reactor.

2. The invention relates to a baffle plate type impact-reducing flow-equalizing disc, which is provided with a downcomer with an impact-reducing disc, wherein a baffle plate at the upper part of the baffle plate blocks fluid which is sprayed to the periphery at the center of a reactor and is in an inclined flow state, so that the impact force of the fluid is reduced; the fluid losing kinetic energy is blocked and then converted into vertical flow state from the original inclined line flow state under the action of the earth gravitation, natural falling is realized, a liquid layer with consistent depth is formed on the tray, the 'wave pushing' phenomenon formed by the impact force of the inclined line on the liquid layer on the tray is eliminated, uniform inlet conditions are created for the downcomer, the material is distributed on the top part distribution plate through the downcomer, the primary distribution function is realized, and friendly, stable and uniform inlet conditions of the liquid layer are provided for the distributor. The arrangement of the downcomers with the impact reducing discs and the impact reducing and flow equalizing functions is suitable, so that the existing top distribution discs can be replaced, and the uniform distribution of materials is realized. The baffle type impact reduction and flow equalization plate improves the inlet working condition of the first bed layer distribution plate, improves the distribution effect of the distribution plate, optimizes the material distribution of the top bed layer and improves the utilization rate of the first bed layer catalyst.

3. Compared with a general bubble cap distributor adopting a suction principle, the baffle type impact reduction flow equalizing disc realizes liquid phase distribution by the baffle and the downcomer, and compared with a bubble cap distributor adopting the suction principle, the scattering power of liquid phase distribution is changed from gas phase suction to potential energy to form splashing, so that the pressure drop is reduced.

4. The baffle type impact reduction flow equalizing disc of the invention is provided with the position and the shape of an overflow hole on the pipe wall of a downcomer, thus forming reasonable liquid storage depth of a tray and reducing the macro-distribution unevenness caused by levelness deviation and liquid level fluctuation of the tray.

5. The baffle type impact reduction flow equalizing disc disclosed by the invention adopts a unique design principle and fluid mechanics characteristics to realize uniform distribution of materials, so that the radial temperature difference of a catalyst bed layer is reduced, the radial temperature difference of the catalyst bed layer is less than or equal to 3 ℃, and the radial temperature difference reflects the distribution effect of fluid, so that the baffle type impact reduction flow equalizing disc disclosed by the invention has a good effect on distribution of reaction feed material flow and gas-liquid mixing, and has a certain auxiliary effect on a hydrogenation catalytic reaction process and catalyst coking control.

6. The baffle plate type impact-reducing flow-equalizing disc is a newly added internal member of the hydrogenation reactor, has the advantages of simple structure, convenient installation and large operation elasticity, can improve the space utilization rate of the hydrogenation reactor, improve the inlet condition of top-divided materials of the reactor, improve the radial distribution effect of feeding materials of the reactor, effectively eliminate the radial temperature difference of the reactor, eliminate the hot spot of a catalyst bed layer caused by uneven material distribution, provide excellent inlet condition for the effective use of the catalyst in the hydrogenation reactor, reduce the times of catalyst skimming or agent changing, prolong the start-up period of the device, improve the hydrogenation process effect and have good economic benefit.

Drawings

FIG. 1 is a schematic structural diagram of a baffle type impact reduction flow equalizing disc of the invention.

Wherein, 1 is a downcomer distributor, 2 is a tray, 3 is a tray supporting beam, 4 is a tray connecting piece and 5-overflow holes.

FIG. 2 is a schematic view of the configuration of a downcomer distributor of the present invention.

Wherein 11 is a downcomer and 12 is a damping disc.

Fig. 3 is a schematic view of the baffle structure of the impact reduction disk of the present invention.

Wherein 121 is a baffle, 122 is a bottom plate, and 123 is an overflow hole.

FIG. 4 is a schematic top view of the baffle distribution of the present invention impact reduction disk.

FIG. 5 is a schematic view of the flow field of the baffle type flow reducing and equalizing plate of the present invention.

FIG. 6 is a schematic view of the positions of different temperature measuring points on the same bed section in the embodiment of the invention.

Detailed Description

As shown in fig. 1-2, the baffle type impact-reducing flow-equalizing tray of the present invention comprises a tray 4 and a number of downcomer distributors 1 (vertically) arranged on the tray. The downcomer distributor 1 comprises a downcomer 11 and a baffle plate 12 secured to the upper end of the downcomer. The damping disk 12 includes a base plate 121 and a plurality of parallel arranged baffles 122 secured to an upper surface of the base plate. The upper end of the downcomer 11 is cut in the form of an oblique line. The baffles 122 are parallel to the axis of the reactor, are on the same plane with the axis of the reactor, or form a certain included angle with the axis of the reactor. A number of downcomer distributors 1 are fixed to tray support beams 3 by tray connectors 2.

In the impact reduction disk 12, the bottom plate 121 may have a circular, triangular, rectangular, or polygonal shape, and is preferably circular.

Wherein, a plurality of baffles 122 arranged on the impact reduction disc are fixed on the upper surface of the bottom plate 121 in parallel. The height of the baffle is 5-200 mm, preferably 30-80 mm; the distance between adjacent baffles is 5-100 mm, preferably 20-80 mm. In FIG. 1, the baffle 122 is parallel to the reactor axis, and a perpendicular line from the center point of the baffle in the length direction is perpendicular to and horizontal with the reactor centerline and intersects therewith.

The bottom edge of the baffle plates is not in clearance with the upper surface of the bottom plate; or a gap exists; or a plurality of overflow holes are arranged along the bottom edge. When a gap exists between the bottom edge of the baffle and the upper surface of the bottom plate, the height of the gap is not more than 50mm, preferably 5-20 mm. The height of the baffle from the central line of the overflow hole arranged on the bottom edge to the upper surface of the bottom plate is not more than 30 percent of the height of the baffle. The shape of the overflow hole can be round, long strip, triangle and polygon, preferably round. When the shape of the overflow holes can be round, triangular or semicircular, the overflow hole channels arranged on two adjacent baffles are arranged in a staggered way.

In the baffle type impact-reducing flow-equalizing tray of the present invention, the downcomer distributors are usually made of metal tubes. The diameter of the downcomer is generally 10-120 mm, and preferably 20-60 mm; the height of the downcomer is 50-200 mm, preferably 80-120 mm. The upper end of the downcomer is provided with an oblique line-shaped notch to form an oval cross section to form a gas phase flow channel; the inclined line formed by the upper end notch forms an included angle of 5-70 degrees, preferably 20-45 degrees with the horizontal line. The part of the downcomer on the tray is provided with 1-6 overflow holes in the horizontal direction, preferably 1-2 overflow holes. The total cross-sectional area of the overflow holes is 10-100%, preferably 30-50% of the cross-sectional area of the downcomer. The shape of the overflow hole on the downcomer can be round, long strip, triangle and polygon, preferably round. The distance between the center line of the overflow hole and the surface of the tray is 5-100 mm, and preferably 30-50 mm.

In the baffle type impact reducing and flow equalizing disc, the impact reducing discs and the downcomers are the same in number; the impact reducing disc is fixed at the upper end of the downcomer. The central line of the impact reduction disc is coincident or not coincident with the axis of the downcomer.

the plurality of downcomer distributors are arranged on the tray in a triangular, quadrangular or rhombic shape. The downcomer distributor is typically inserted onto the tray through the lower end of the downcomer and may be secured by welding, threading, snap-fit connection, or the like.

In the baffle type impact reduction flow equalizing disc, a tower tray is divided into a plurality of blocks which can be spliced into circular plates; and the edge of the outermost edge of the tray is provided with a folding edge, and the folding edge is folded upwards. The height of the folded edge is generally 5-80 mm, preferably 30-50 mm.

With reference to fig. 1-5, the baffle type impact reduction and flow equalization plate of the present invention has the following working processes:

When the device works, fluid which is injected to the periphery from the center of the reactor and has oblique line flow state and larger impact force collides with the baffle plate, the fluid which is injected in the oblique line flow state can be effectively blocked, the impact force is reduced, the baffle plate is utilized to block the action, the gas phase entrained liquid drops are forced to be dispersed to the periphery, 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 liquid phase potential energy is converted into the kinetic energy of a free falling body and falls onto a tray plate of a baffling tray type impact reduction flow equalizing tray, and as a downcomer material channel is horizontally arranged and has a certain height difference from the tray plate, the material can form a liquid layer with a certain depth on the upper surface of the tray plate, and even if the tray plate has deviation in levelness, the liquid phase of each distributor can still be ensured to. Because the number of the distributors is large, any point on the surface of the catalyst bed layer is provided with a certain number of distributors for working, so that the uniformity of the distributors is guaranteed. The material flows into the distribution pipe from an overflow hole channel arranged on the pipe wall of the downcomer to realize the initial distribution of the liquid. Because the materials after passing through the baffle plate type impact reducing and flow equalizing 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 tray plate of the top distribution disc has no thrust any more, the phenomenon of 'pushing waves' of the materials on the liquid layer on the distribution disc is eliminated, friendly, stable and uniform inlet conditions are provided for the top distributor, and the materials are uniformly distributed on the catalyst bed layer together with the top distribution disc.

When the liquid phase material amount is less, or the upper part of the catalyst bed layer is filled with a tooth-ball-shaped protective agent or a hollow ball-shaped protective agent, the baffle plate type impact reduction and flow equalization disc can replace a top distribution disc to realize the integration of impact reduction, flow equalization and distribution, thereby greatly simplifying the internal structure of the reactor and reducing the investment.

The following examples are given to illustrate the reaction effect of the present invention, but do not limit the scope of the present invention.

comparative example 1

The diameter of a certain hydrogenation reactor is 4.6m, the upper end enclosure is idle before modification, only the inlet of the first bed layer comprises a top distribution disc, an ERI type bubble cap type gas-liquid distributor which is conventional in the field is used in the top distribution disc, the hydrogenation raw material is diesel oil, and the density of the diesel oil is 860kg/m³The sulfur content is 1.7wt%, the catalyst is RS-2000 type hydrofining catalyst, and the process conditions are as follows: hydrogen partial pressure of 6.8MPa (G) and volume space velocity of 1.9h^-1The volume ratio of hydrogen to oil is 400:1, and the inlet temperature of the reactor is 365 ℃. Before reforming, the bed radial temperature and temperature difference are shown in Table 1.

Example 1

After transformation, the baffle type impact reduction and flow equalization disc is additionally arranged in the upper end socket, and the baffle type impact reduction and flow equalization disc shown in figure 1 is combined with a common ERI type bubble cap type gas-liquid distributor for use. Wherein, the main parameters of the baffle type impact reduction flow equalizing disc are as follows: the baffle plates are fixed on the upper surface of the bottom plate in parallel, and the height of the baffle plates is 50 mm; the distance between the adjacent baffles is 80 mm; a gap exists between the bottom edge of the baffle and the upper surface of the bottom plate, and the height of the gap is 20 mm. The down-flow spout with the impact reducing disc is made of metal tubes, and the diameter of the down-flow spout is 50 mm; the height of the downcomer is 100 mm; the upper end of the downcomer is provided with an oblique line-shaped notch to form an oval cross section to form a gas phase flow channel; the included angle between the oblique line formed by the upper end notch and the horizontal line is 45 degrees; the downcomer is provided with a surge reducing disc, and 2 overflow holes are arranged in the horizontal direction. The total cross-sectional area of the overflow holes is 30 percent of the cross-sectional area of the downcomer; the shape of the overflow hole is round; the center line of the spill orifice was 30mm from the tray surface. In the baffle plate type impact reduction flow equalizing plate, downcomer distributors are arranged on a tower tray in a triangular mode. The tray can be divided into 9 blocks and can be spliced into circular plates, each cutting plate is provided with 3 downcomer distributors, the edge of the outermost edge of the tray is provided with an upward folded edge, and the height of the folded edge is 50 mm.

The hydrogenation feedstock and process conditions were the same as in comparative example 1. The radial temperature distribution and temperature difference at the inlet of the first catalyst bed after the restart are shown in Table 1.

Example 2

After transformation, the baffle type impact reduction flow-equalizing disc is added in the upper end socket, and an ERI type gas-liquid distributor in the prior art in the original reactor is eliminated, wherein the main parameters of the baffle type impact reduction flow-equalizing disc are as follows: the baffle plates are fixed on the upper surface of the bottom plate in parallel, and the height of the baffle plates is 50 mm; the distance between the adjacent baffles is 80 mm; a gap exists between the bottom edge of the baffle and the upper surface of the bottom plate, and the height of the gap is 20 mm. The down-flow spout with the impact reducing disc is made of metal tubes, and the diameter of the down-flow spout is 50 mm; the height of the downcomer is 100 mm; the upper end of the downcomer is provided with an oblique line-shaped notch to form an oval cross section to form a gas phase flow channel; the included angle between the oblique line formed by the upper end notch and the horizontal line is 45 degrees; 2 downcomers with an attached impact reduction plate are arranged in the horizontal direction. The total cross-sectional area of the overflow holes is 30 percent of the cross-sectional area of the downcomer; the shape of the arranged overflow hole is round; the center line of the overflow hole is 30mm from the surface of the tray. In the baffle plate disk impact reduction flow equalizing disk, downcomer distributors are arranged on a tower tray in a triangular mode. The tray can be divided into 9 blocks and can be spliced into circular plates, each cutting plate is provided with 3 downcomer distributors, the edge of the outermost edge of the tray is provided with an upward folded edge, and the height of the folded edge is generally 50 mm.

The hydrogenation feedstock and process conditions were the same as in comparative example 1. The inlet radial temperature and temperature differential of the first catalyst bed after restart are shown in table 1.

TABLE 1 results of application

	Comparative example 1	Example 1	Example 2
				Temperature a, C	370.5	366.8	365.9
Temperature b, C	367.3	365.5	365.7
				Temperature c, C DEG C	363.6	365.8	366.8
Temperature d, DEG C	361.0	365.7	366.6
				Temperature e,. degree.C	369.8	366.4	365.1
Maximum radial bed temperature difference, deg.C	9.5	1.3	1.7

Claims (27)

1. A baffle type impact reduction and flow equalization disc is suitable for a fixed bed reactor which is fed upwards and gas-liquid is in a parallel flow form, and is arranged in an idle upper head of the reactor or arranged at the upper end of a cylinder body of the reactor and above a distribution disc at the top of the cylinder body of the reactor; the baffle type impact reduction and flow equalization disc comprises a tray and a plurality of downcomer distributors vertically arranged on the tray; the downcomer distributor comprises a downcomer and a surge-reducing disc fixed at the upper end of the downcomer, and the surge-reducing disc comprises a bottom plate and a plurality of baffles which are fixed on the upper surface of the bottom plate and are arranged in parallel; the upper part of the downcomer is an oblique line-shaped notch, and the lower end of the downcomer is open; the baffles are parallel to the axis of the reactor or on the same plane with the axis of the reactor, or form a certain included angle with the axis of the reactor.

2. The baffle type flow reducing and equalizing disk of claim 1, wherein said plurality of baffle plates are substantially perpendicular to and substantially horizontal with the reactor axis from a perpendicular to the longitudinal center point of the baffle plates and intersect the reactor axis.

3. The baffle type impact reducing and flow equalizing disk of claim 1, wherein the outermost edges of said trays are provided with upturned folds.

4. A baffle-type flow-reducing and flow-equalizing tray according to any one of claims 1 to 3, wherein overflow holes are provided in the lower tube wall of said downcomer.

5. The baffle type flow reduction and equalization plate of claim 1, further comprising support beams for supporting said trays and tray connectors for securing said trays to each other.

6. The baffle type flow reducing and equalizing disk of claim 1, wherein adjacent baffle plates are spaced apart.

7. The baffle type flow reducing and equalizing disk of claim 1, wherein the bottom edge of said baffle plate has a gap with the upper surface of said bottom plate.

8. The baffle type impact reducing and flow equalizing disk of claim 1, wherein the bottom edge of said baffle is seamless with the upper surface of the bottom plate.

9. The baffle type impact reducing and flow equalizing tray of claim 1, wherein the baffle plate has a plurality of overflow holes along a bottom edge, and a centerline of the overflow holes is spaced from an upper surface of the bottom plate.

10. The baffle type impact reducing and flow equalizing disk of claim 9, wherein said overflow apertures are in the shape of circles, semicircles, elongated shapes, triangles, and polygons.

11. The baffle type impact-reducing flow-equalizing disc of claim 10, wherein the overflow holes are circular, triangular or semicircular, and the overflow hole channels of two adjacent baffles are arranged in a staggered manner.

12. The baffle type flow reducing and equalizing disk of claim 9, wherein the centerline of said spill ports is no more than 30% of the height of the baffle from the upper surface of the base plate.

13. The baffle type impact reducing flow equalizing tray according to claim 1, wherein the oblique line-shaped slits at the upper end of said downcomer are formed in an elliptical cross section to form a gas phase flow passage, and the oblique line formed by the slits at the upper end thereof is formed at an angle to the horizontal.

14. The baffle type flow reduction and equalization plate of claim 4, wherein said spill orifices are spaced from the tray surface.

15. The baffle type impact reducing flow equalizing tray of claim 14, wherein said overflow apertures have a total cross-sectional area of 10% to 100% of the cross-sectional area of the downcomer.

16. The baffle type surge-reducing flow-equalizing tray of claim 1, wherein the number of said surge-reducing trays and downcomers is the same.

17. The baffle type surge-reducing flow-equalizing tray of claim 1, wherein the centerline of the surge-reducing tray coincides or does not coincide with the downcomer axis.

18. The baffle type flow reducing and equalizing disk of claim 7, wherein the height of the gap between the bottom edge of said baffle plate strip and the upper surface of said bottom plate is not greater than 50 mm.

19. The baffle type impact reducing and flow equalizing disk of claim 6, wherein the spacing between adjacent baffle plates is 5 to 100 mm.

20. The baffle plate type impact reducing and flow equalizing plate of claim 1, wherein the diameter of the downcomer is 10-120 mm, and the height of the downcomer is 10-120 mm.

21. The baffle type flow reducing and equalizing tray of claim 13, wherein said upper end slit forms an oblique line having an angle of 5 ° to 70 ° with the horizontal.

22. The baffle type impact reducing and flow equalizing disc of claim 4, wherein the number of overflow holes arranged on the downcomer is 1-6 overflow ports.

23. The baffle type impact reducing and flow equalizing disk of claim 4, wherein said overflow apertures are in the shape of circles, stripes, triangles, and polygons.

24. The baffle type impact reducing and flow equalizing disc of claim 14, wherein the center line of said spill orifice is 5 to 100mm from the tray surface.

25. The baffle type impact reducing and flow equalizing tray of claim 1, wherein said downcomer distributors are triangular, quadrilateral, diamond-shaped on the tray.

26. The baffle type impact reducing and flow equalizing disk of claim 3, wherein the height of the outermost edge of the tray flange is 5 to 80 mm.

27. The baffle type flow reducing and equalizing disk of claim 1, wherein said baffles are inclined toward the nearest reactor wall and the plane in which the baffles lie is at an angle of from 15 ° to 80 ° to the axis of the reactor.