CN108114671B - Flanging type impact-reducing flow-equalizing disc - Google Patents

Abstract

The invention discloses a flanging type impact-reducing flow-equalizing disc. The edge-folded impact-reducing flow-equalizing disc comprises a tower tray and a plurality of chimney-type distributors vertically arranged on the tower tray; the chimney type distributor comprises a downcomer and a wing plate arranged at the top of the downcomer; the downcomer is a structure with two open ends, the wing plates have certain included angle, side length and height, and the wing plates are parallel to the axis of the downcomer or form a certain included angle with the axis of the downcomer. The edge-folded impact-reducing flow-equalizing disc is arranged in the idle space of the upper end socket of the reactor or at the upper end of the barrel of the reactor, can reduce the strong impact force formed by the 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 the reactor to a liquid layer of the distribution disc. The edge-folded impact-reducing flow-equalizing disc is suitable for all hydrogenation reactors, and is particularly suitable for hydrogenation reactors with large liquid-gas ratio and large scale.

Description

Flanging type impact-reducing flow-equalizing disc

Technical Field

The invention relates to a flanging type impact-reducing flow-equalizing disc, and belongs to the field of chemical equipment. The edge-folding impact-reducing flow-equalizing disc is a newly added internal component of the reactor. The edge-folded impact-reducing flow-equalizing disc is suitable for various hydrogenation reactors, and is particularly suitable for hydrogenation reactors with large liquid-gas ratio and large scale.

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. Typically, installation errors will cause the distributor plate surface to be horizontally inclined at 1/8-1/2 degrees with the maximum inclination being 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 flanging type impact-reducing flow-equalizing disc. The edge-folding type impact-reducing flow-equalizing disc is a newly added reactor inner component 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 device can be used for reducing the strong impact force formed by the residual kinetic energy when the fluid enters the reactor; the 'wave pushing' phenomenon of the inclined flow line formed when the central point enters the distribution tray liquid layer is eliminated, and the impact force converted from the potential energy of the liquid falling from the inlet of the reactor to the top distribution tray is eliminated; 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. The edge-folded impact-reducing flow-equalizing disc has a good distribution effect, fully utilizes the idle space of the reactor end socket, and has the characteristics of small volume, simple structure, convenience in installation, high operation elasticity and the like.

The technical scheme of the invention is as follows:

a flanging type impact-reducing flow-equalizing disc comprises a tower tray and a chimney type distributor vertically arranged on the tower tray; the chimney type distributor comprises a downcomer and a wing plate arranged at the top of the downcomer; the downcomer is of a structure with openings at two ends, and the wing plates have a certain included angle, side length and height; the wing plates are parallel to the axis of the downcomer, or the central lines of the wing plates form a certain included angle with the axis of the reactor.

In the impact reducing flow equalizing disc, the included angle of the wing plates is far away from the center or circle center of a tower tray. Furthermore, the central line of the included angle of the wing plate is superposed with the ray of the reactor cylinder, and the included angle of the wing plate faces the wall of the cylinder closest to the reactor.

Furthermore, the wing plates have certain included angle, side length and height. The number of the wing plates and the number of the down-flow pipes are the same, and the wing plates and the down-flow pipes are arranged up and down. The bottom edge of the wing plate is connected with the upper edge of the downcomer in an overlapping or non-overlapping manner; when the downcomer is overlapped, the ratio of the overlap height to the height of the downcomer is 5% to 30%, preferably 10% to 25%.

Furthermore, the wing plates incline towards the wall of the reactor closest to the wall of the reactor, and the angle between the central line of the included angle of the wing plates and the axis of the reactor is 15-80 degrees.

Further, the chimney distributors are vertically arranged on the tray. The lower end opening of the downcomer in the chimney distributor is directly opened on the tray or penetrates through the opening of the tray.

Furthermore, the tray also comprises a supporting beam and a tray connecting piece which are arranged below the tray and used for supporting.

Furthermore, a plurality of overflow holes are arranged on the pipe wall of the downcomer, so that liquid can conveniently pass through the overflow holes, enter the downcomer and flow downwards along the downcomer. The center line of the overflow hole and the surface of the tray plate should keep a certain distance. The number of the overflow holes is generally 1-6, preferably 1-2. The total cross-sectional area of the overflow holes is 10-100%, preferably 30-50% of the cross-sectional area of the downcomer (horizontal). When only 1 overflow hole is arranged on the downcomer, the position of the overflow hole is opposite to the connection point of the downcomer and the wing plate; when the number of the overflow holes is 2, the overflow holes are arranged on two sides of the connection point of the downcomer and the wing plate. The shape of the overflow hole can be round, long strip, triangle and polygon, preferably round.

Further, the chimney distributor may be made of any suitable material, such as ceramic, metal, etc., preferably steel. The wing plate and the downcomer can be integrally manufactured, and for example, the wing plate and the downcomer can be integrally processed; or, vertical and horizontal cutting is carried out at a certain height of the upper part of the downcomer with certain height, incomplete cutting of wall thickness is reserved, then the downcomer is unfolded for a certain angle to form a wing plate, or the upper edge of the downcomer is fixedly connected with a wing plate with a certain included angle. The fixed connection can adopt various suitable modes such as welding, bolt connection, screw connection, buckle connection and the like.

In the flow reducing and equalizing disc of the present invention, the tray is usually divided into several pieces and can be spliced into a circular plate. And a folded edge is arranged on the edge of the outermost edge of the tray and is folded upwards. The upper edge of the said flange should generally be higher than the lower edge of the overflow aperture provided in the downcomer. The arrangement of the folded edge can maintain a certain liquid level on the tray, so that the influence on liquid phase distribution caused by the insufficient level of the tray in the prior art can be eliminated to a certain extent.

In the baffle plate type impact reduction flow equalizing disc, a plurality of chimney type distributors are usually arranged according to a certain rule, for example, the chimney type distributors can be arranged on a tower tray in a triangular, quadrangular or rhombic shape.

In the invention, the downcomer is used for liquid to pass through and is also used as a flow channel for gas feeding in feeding.

In the invention, the reactor suitable for the baffling type impact reduction and flow equalization disc is a fixed bed reactor which is fed upwards and has a gas-liquid parallel flow mode, and is particularly suitable for a fixed bed trickle bed reactor; more preferably various fixed bed hydrogenation reactors, particularly hydrogenation reactors with large liquid-gas ratio and large scale.

Compared with the prior art, the edge-folding impact-reducing flow-equalizing disc has the following advantages:

1. the edge-folded 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 flanging type impact reducing flow equalizing disc, which is provided with wing plates, and is used for blocking fluid which is injected in a diagonal flow state due to center entering, reducing the impact force of the fluid, converting the original inclined line flow state into a vertical flow state under the action of gravity after the fluid losing kinetic energy is blocked, realizing natural falling, forming a liquid layer with consistent depth on a tray, eliminating the phenomenon of 'pushing waves' formed by the inclined line impact force on the liquid layer on the tray, creating uniform inlet conditions for a chimney distributor, distributing materials on a top part distribution disc through the chimney distributor, realizing a primary distribution function, and providing friendly, stable liquid layer and uniform inlet conditions for the distributor. The chimney type distributors with proper quantity and flow equalizing function are arranged, and even the existing top distribution plate can be replaced, so that the uniform distribution of materials is realized. The edge-folded impact-reducing flow-equalizing disc improves the inlet working condition of the first bed layer distribution disc, improves the distribution effect of the distribution disc, optimizes the material distribution of the top bed layer and improves the utilization rate of the first bed layer catalyst.

3. Compared with a bubble cap distributor adopting a general suction principle, the edge-folding type impact-reducing flow-equalizing disc realizes liquid phase distribution by the arranged wing plate and the chimney distributor, and the dispersed power of the liquid phase distribution is changed from gas phase suction to potential energy to form splashing, so that the pressure drop is reduced.

4. According to the edge-folding type impact-reducing flow-equalizing disc, the positions and the shapes of the overflow holes in the pipe wall of the chimney distributor are arranged, so that reasonable liquid storage depth of a tower tray is formed, and macroscopic distribution unevenness caused by levelness deviation and liquid level fluctuation of the tower tray is reduced.

5. The edge-folded impact-reducing 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 edge-folded impact-reducing 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 edge-folded 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 reactor feeding, 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 view of a flanged impact-reducing flow-equalizing disc structure according to the present invention.

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

FIG. 2 is a schematic view of the chimney distributor with impact-reducing plate according to the present invention. Wherein 11 is a wing plate, and 12 is a downcomer.

FIG. 3 is a top view of the chimney distributor structure of the present invention.

FIG. 4 is a schematic view of the liquid flow regime of the chimney distributor of the present invention.

FIG. 5 is a top view of the liquid flow regime of the chimney distributor 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. 1-3, the edge-folding impact-reducing flow-equalizing tray of the present invention comprises a tray 2 and a plurality of chimney distributors 1 vertically arranged on the tray. The chimney distributor 1 comprises a downcomer 1-2 and a wing plate 11 arranged at the top of the downcomer 1-2. The downcomer 12 is open at both ends. The wings 11 and the downcomer 12 are arranged up and down. The wing panels 11 have a certain included angle, side length and height and are generally made of folded steel plates. The vanes 11 are parallel to the axis of the downcomer 12.

As shown in fig. 2, in the chimney distributors, the number of the wings is the same as that of the chimney distributors, and the wings and the chimney distributors are in one-to-one correspondence. The included angle of the wing plates is generally 15-180 degrees, preferably 90-120 degrees; the side length of the wing plate is generally 20 mm-200 mm, preferably 60 mm-120 mm; the height of the wing plate is generally 30mm to 200mm, preferably 60mm to 120 mm. The bottom edge of the wing plate is connected with the upper edge of the downcomer and can also be arranged in an overlapping way with the downcomer. When the bottom edge of the wing plate is coincided with the upper edge of the downcomer, the height of the downcomer can be 10-100%, and the preferred height is 5-20%. When the central line of the included angle of the wing plate is superposed with the ray of the reactor cylinder, the included angle faces the nearest cylinder wall of the reactor.

In the edge-folding impact-reducing flow-equalizing disc, the down-flow pipe is generally made of metal pipes. The height of the downcomer is generally 20 to 300mm, preferably 50 to 120 mm. 1-6 overflow holes are arranged on the downcomer in the horizontal direction, and 1-2 overflow holes are preferably selected; the total cross section area of the overflow holes is 10-100%, preferably 30-50% of the cross section area of the downcomer. When 1 overflow hole is arranged on the downcomer, the position of the overflow hole is opposite to the connection point of the downcomer and the impact reduction plate; when the number of the overflow holes is 2, the overflow holes are arranged on two sides of the connection point of the downcomer and the impact reduction plate. The shape of the overflow hole can be round, long strip, triangle and polygon, preferably round. The distance between the center line of the overflow hole and the surface of the tray is 5-100 mm, and preferably 30-50 mm.

In the edge-folding type impact-reducing flow-equalizing disc, a plurality of chimney type distributors are arranged on one layer of the edge-folding type impact-reducing flow-equalizing disc. The plurality of chimney type distributors are arranged on the tower tray in a triangular, quadrangular or rhombic shape. The chimney distributor is usually inserted on the tray through the lower end of the downcomer and can be fixedly connected by welding, screwing, buckling connection and the like.

In the impact-reducing flow-equalizing disc of the present invention, the tray is usually divided into several pieces and can be spliced into circular plates. And the edge of the outermost edge of the tray is provided with an upward folded edge. The height of the folded edge is generally 5-80 mm, preferably 30-50 mm.

With reference to fig. 1-5, the working method of the edge-folding impact-reducing flow-equalizing disc of the invention comprises the following steps:

when in work, the fluid which is injected to the periphery from the center of the reactor, presents a diagonal flow state and has larger impact force impacts the wing plates, and the wing plates are arranged at a certain included angle, the liquid sprayed in oblique line flow state can be effectively blocked, the impact force is cut off, the gas phase entrained liquid drops are forced to be dispersed to the periphery by utilizing the blocking effect of the wing plate, the larger diffusion angle of the material is realized, the liquid 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 the impact reduction flow equalizing tray, because distributor material passageway is horizontal arrangement and has certain difference in height apart from the tray board, therefore the material can form the liquid layer of certain degree of depth on the tray board upper surface of hem formula reduction and rush current-sharing dish, even there is the deviation in tray levelness, still can ensure that every distributor all has the liquid phase to exist. 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 materials flow into the distribution pipe from an overflow hole channel arranged on the pipe wall of the chimney type distributor, so that the primary distribution of the liquid is realized. Because the materials after passing through the edge-folding type flow reducing and 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 a catalyst bed layer is filled with a tooth-ball-shaped protective agent or a hollow ball-shaped protective agent, the edge-folding type impact reduction flow equalizing disc can replace a top distribution disc, so that impact reduction, flow equalization and distribution integration can be realized. 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 1.7 percent, the catalyst is an RS-2000 type hydrofining catalyst,the process conditions are as follows: hydrogen partial pressure 6.8MPa (G), volume space velocity 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 edge-folding type impact-reducing flow-equalizing disc is added in the upper end enclosure, and the edge-folding type impact-reducing flow-equalizing disc shown in figure 1 is combined with a common ERI type bubble cap type gas-liquid distributor for use. The main parameters of the edge-folding impact-reducing flow-equalizing disc are as follows: the included angle of the wing plates is 120 degrees; the side length of the wing plate is 120 mm; the height of the wing plate is 60 mm. The wings of which are parallel to the axis of the chimney distributor. The bottom edge of the wing plate is superposed with the upper edge of the chimney distributor, and the superposition point is 20% of the height of the distributor. The height of the chimney distributor is 120 mm; 2 overflow ports are arranged on the pipe wall of the chimney distributor in the horizontal direction. The total cross-sectional area of the overflow holes is 30% of the cross-sectional area of the chimney distributor pipe; the pipe wall of the chimney distributor is provided with an overflow hole which is round; the center line of an overflow hole arranged on the pipe wall of the chimney distributor is 50mm away from the upper surface of the tower tray; in the edge-folding impact-reducing flow-equalizing disc, the chimney type distributor is arranged on the tray in a triangular shape. The tray can be divided into 9 blocks and can be spliced into round plates, each cutting plate is provided with 3 chimney type distributors, and the edge of the outermost edge of the tray is provided with a folding edge, wherein the height of the folding edge is 50 mm.

The hydrogenation feedstock and process conditions were the same as in comparative example 1.

After restarting, the bed radial temperature difference is shown in Table 1.

Example 2

After transformation, the flanging plate type impact reduction flow equalizing disc is added in the upper end enclosure, and an ERI type gas-liquid distributor in the prior art in the original reactor is cancelled, wherein the flanging plate type impact reduction flow equalizing disc has the main parameters: the included angle of the wing plates is 120 degrees; the side length of the wing plate is 120 mm; the height of the wing plate is 60 mm. The wings of which are parallel to the axis of the chimney distributor. The bottom edge of the wing plate is superposed with the upper edge of the chimney distributor, and the superposition point is 20% of the height of the distributor. The height of the chimney distributor is 120 mm; 2 overflow ports are arranged on the pipe wall of the chimney distributor in the horizontal direction. The total cross-sectional area of the overflow holes is 30% of the cross-sectional area of the chimney distributor pipe; the pipe wall of the chimney distributor is provided with an overflow hole which is round; the center line of an overflow hole arranged on the pipe wall of the chimney distributor is 50mm away from the upper surface of the tower tray; in the edge-folding impact-reducing flow-equalizing disc, the chimney type distributor is arranged on the tray in a triangular shape. The tray can be divided into 9 blocks and can be spliced into round plates, each cutting plate is provided with 3 chimney type distributors, and the edge of the outermost edge of the tray is provided with a folding edge, wherein the height of the folding 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.

TABLE 1 results of application

Claims (24)

1. A hem formula subtracts towards flow equalizing dish, the said hem formula subtracts towards flow equalizing dish is suitable for the fixed bed reactor of upper feeding and gas-liquid for the form of cocurrent flow, and set up in the idle reactor upper end socket, or set up in the upper end of the reactor barrel, top distribution plate; the edge-folding type impact-reducing flow-equalizing disc comprises a tower tray and a plurality of chimney type distributors vertically arranged on the tower tray; the chimney type distributor comprises a downcomer and a wing plate arranged at the top of the downcomer; the downcomer is of a structure with two open ends, and the wing plates have a certain included angle, side length and height; the wing plates are parallel to the axis of the downcomer, or the wing plates form a certain included angle with the axis of the reactor.

2. A flanged flow-reducing flow-equalizing disc according to claim 1, wherein the included angle of the vanes is remote from the center or circle center of the tray.

3. A flanged flow-reducing isopipe according to claim 1 or claim 2, wherein the central axis of the included angle of the vanes is coincident with the reactor barrel ray, and the included angle of the vanes faces the nearest barrel wall of the reactor.

4. The flanged impact-reducing flow-equalizing disc of claim 1, wherein the number of said wings and downcomers is the same, and the wings and downcomers are arranged in an up-down arrangement.

5. A flanged impact-reducing flow-equalizing disc according to claim 4, wherein the bottom edges of the vanes are connected with the upper edge of the downcomer in an overlapping or non-overlapping manner.

6. A flanged impact-reducing flow-equalizing disc according to claim 5, wherein the bottom edges of the wings are partially overlapped with the upper edge of the downcomer, and the overlapping height is 5-30% of the height of the downcomer.

7. The flanged flow reduction and equalization plate of claim 4, wherein the flanged flow reduction and equalization plate is suitable for use in a fixed bed trickle bed reactor.

8. The flanged flow reduction and equalization tray of claim 1, wherein the lower end opening of the downcomer opens directly into the tray or through the tray opening.

9. The gusseted flow reducing and averaging plate of claim 1, wherein said tray further comprises support beams and tray connectors thereunder for support.

10. A flanged impact-reducing flow-equalizing disc according to claim 1, wherein a plurality of overflow holes are provided on the wall of the downcomer, and the total cross-sectional area of the overflow holes is 10% to 100% of the cross-sectional area of the downcomer.

11. A gusseted flow reducing isopipe in accordance with claim 10 wherein the centerline of said spill orifices is spaced from the tray deck surface.

12. The edge-folding impact-reducing flow-equalizing disc of claim 10, wherein the number of the overflow holes is 1-6.

13. A flanged flow-reducing and flow-equalizing disc as claimed in claim 12, wherein only 1 overflow aperture is provided in the downcomer, oriented opposite the junction of the downcomer and the vanes.

14. A flanged impact-reducing flow-equalizing disc according to claim 12, wherein the downcomer is provided with 2 overflow apertures oriented on both sides of the junction of the downcomer and the vanes.

15. The edge-folded impact-reducing flow-equalizing disc of claim 10, wherein said overflow apertures are in the shape of circles, strips, triangles, and polygons.

16. The flanged impact-reducing flow-equalizing disc of claim 1, wherein said flaps and said downcomer are integrally formed and are integrally machined from the downcomer and the flaps.

17. A flanged flow-reducing and flow-equalizing tray as claimed in claim 16, wherein the integral process is to cut the upper part of the downcomer vertically and horizontally with a certain height, leave an incomplete cut of the wall thickness, and then spread it at an angle to form a wing.

18. A flanged impact-reducing flow-equalizing disc as claimed in claim 1, wherein the said wing plates and downcomer are assembled together by fixedly connecting a wing plate with a certain included angle to the upper edge of the downcomer.

19. A hemmed impact reducing and flow equalizing disc as in claim 18, wherein said securing connection is at least one of a welded, bolted, screwed, or snap-fit connection.

20. A flanged flow-reducing isopipe according to claim 1, wherein the tray is divided into several pieces and can be spliced into a circular plate.

21. A flanged impact-reducing flow-equalizing tray according to claim 1, wherein an upwardly turned flange is provided at the edge of the outermost edge of the tray, and the upper edge of the flange is higher than the upper edge of the overflow hole provided in the downcomer.

22. A flanged flow-reducing and flow-equalizing disc as defined in claim 21, wherein said chimney distributors are arranged in a triangular, quadrilateral, or rhombus pattern on the tray.

23. A flanged impact-reducing flow-equalizing disc according to claim 21, wherein the height of the flange is 5 to 80 mm.

24. A flanged flow-reducing flow-equalizing disk as claimed in claim 1, wherein the vanes are inclined towards the nearest reactor wall and the angle between the centre line of the included angle of the vanes and the axis of the reactor is in the range of 15 ° to 80 °.

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