Solid particle distributor system of countercurrent reactor of circulating fluidized bed

Abstract

The invention provides a solid particle distributor system of a countercurrent reactor of a circulating fluidized bed, which solves the problem that solid particles are concentrated on one side when entering the reactor and realizes uniform distribution of the solid particles, and comprises a reactor, a conveying pipe, a solid particle distributor and a rectifying gas distributor, the conveying pipe comprises an inclined conveying pipe, a transverse conveying pipe and a vertical conveying pipe, the inclined conveying pipe is connected with the transverse conveying pipe, the middle of the transverse conveying pipe is connected with the vertical conveying pipe, the solid particle distributor is located below the vertical conveying pipe, and the vertical conveying pipe is inserted into the solid particle distributor; the solid particle distributor comprises an overflow barrel, a bottom distributor and an annular distributor, the top of the overflow barrel is open, the bottom of the overflow barrel is connected with the bottom distributor, and the annular distributor is arranged around the overflow barrel; the rectifying gas distributor is arranged between the bottom distributor and the conveying vertical pipe; and uniform distribution of solid particles is realized through mutual cooperation of the conveying pipe, the solid particle distributor and the rectifying gas distributor.

Description

Technical Field

[0001] The present invention belongs to the field of chemical engineering, and particularly relates to a solid particle distributor system for a circulating fluidized bed countercurrent reactor. Background Art

[0002] The circulating fluidized bed reactor is an efficient reaction device designed based on the principle of gas-solid two-phase flow, and is a core device in many application fields such as petroleum processing, energy conversion, nanoparticle synthesis, waste plastic recycling, etc. There are two operating modes for the gas-solid two-phase in the circulating fluidized bed reactor. One is the co-current flow mode in which the gas-solid two-phase flow in the same direction, and the other is the countercurrent flow mode in which the gas-solid two-phase flow in the opposite direction. In the countercurrent flow mode, the gas phase flow in the circulating fluidized bed reactor runs from bottom to top, and the solid particles fall from top to bottom. The two contact reversely in the reactor, with intense mass transfer, heat transfer, and chemical reactions occurring. During the flow of the gas phase flow, due to the characteristic that the gas fills the entire space, it will spontaneously distribute evenly on the same cross-section. However, during the downward movement of the solid particles, mainly affected by the gravity, drag force, and buoyancy of the gas of the solid particles, the distribution to the surrounding is very limited and cannot achieve a uniform distribution effect. Therefore, whether the solid particles are evenly distributed determines the mass transfer and heat transfer efficiency in the reactor, and mass transfer and heat transfer are the basis for the reaction to proceed, so it also determines the reaction effect.

[0003] In the existing circulating fluidization form, for the process of solid particles entering the reactor through the conveying pipe, please refer to Figure 1 , Figure 1 discloses the structure and conveying process of a conveying pipe in the prior art, including: 1 - solid particle conveying pipe, 2 - reactor, and 3 - solid particles. The solid particles are conveyed to the reactor along the conveying pipeline, first entering the horizontal pipeline through the inclined pipe. When entering the vertical pipeline from the horizontal pipeline, due to inertia, the solid particles will concentrate on one side and fall into the reactor along one side of the vertical pipeline. The defect of this structure is that: when the solid particles enter the reactor from the conveying pipeline, they are already biased towards one side, and they will still be biased towards one side after being distributed by the distributor, and the uniform distribution of the solid particles in the reactor cannot be achieved.

[0004] Figure 2 discloses an improved structure and conveying process of a conveying pipe in the prior art, including 4 - solid particle conveying pipe, 5 - horizontal pipe blind plug, 6 - reactor, and 7 - solid particles, Figure 2 The structure disclosed in Figure 1 Compared with Figure 2The middle part of the horizontal pipeline is connected to the vertical pipeline. The advantages of this structure are as follows: Solid particles are transported to the reactor along the transportation pipeline. First, they enter the horizontal pipeline through the inclined pipe. When entering the vertical pipeline from the horizontal pipeline, some solid particles will enter the blind plug of the horizontal pipe and then return to the vertical pipeline. This structure can, to a certain extent, weaken the situation where solid particles concentrate on one side due to inertia. After being distributed by the distributor, the solid particles in the reactor are still uneven.

[0005] Therefore, it is necessary to provide a technical solution to solve the above problems. Summary of the Invention

[0006] To solve the above problems, the present invention provides a distributor system to solve the problem that solid particles concentrate on one side when entering the reactor and achieve uniform distribution of solid particles.

[0007] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0008] A solid particle distributor system for a circulating fluidized bed countercurrent reactor, comprising: a reactor, a conveying pipe, a solid particle distributor, and a rectifying gas distributor; the conveying pipe includes a conveying inclined pipe, a conveying horizontal pipe, and a conveying vertical pipe. The conveying inclined pipe is connected to the conveying horizontal pipe, and the middle part of the conveying horizontal pipe is connected to the conveying vertical pipe. The solid particle distributor is located below the conveying vertical pipe, and the conveying vertical pipe is inserted into the solid particle distributor; the outlet of the conveying vertical pipe is processed into a frustum-shaped contraction, and the ratio of the cross-sectional area after the frustum-shaped contraction of the outlet of the conveying vertical pipe to the cross-sectional area before contraction is 0.1 - 1; the solid particle distributor includes an overflow bucket, a bottom distributor, and an annular distributor. The top of the overflow bucket is open, the bottom of the overflow bucket is connected to the bottom distributor, the annular distributor is arranged around the overflow bucket, the bottom distributor has openings, and the annular distributor has openings; the rectifying gas distributor is arranged between the bottom distributor and the conveying vertical pipe.

[0009] In the technical solution provided by the present invention, the conveying inclined pipe penetrates into the reactor through the surface of the reactor, and one end of the conveying inclined pipe inside the reactor is connected to the conveying horizontal pipe; one end of the conveying horizontal pipe is connected to the conveying inclined pipe, and the other end is a blind plug; the middle part of the conveying horizontal pipe is connected to the conveying vertical pipe, and the conveying horizontal pipe and the conveying vertical pipe are of a T-shaped structure.

[0010] In the technical solution provided by the present invention, the ratio of the cross-sectional area after the frustum-shaped contraction of the outlet of the conveying vertical pipe to the cross-sectional area before contraction is preferably 0.45 - 0.65.

[0011] In the technical solution provided by the present invention, the opening ratio of the bottom distributor is 3% to 70%, preferably 40% to 65%; preferably, the opening mode of the bottom distributor is as follows: the opening ratio of the middle 20% part of the bottom distributor is 1% to 40%, and the opening ratio of the surrounding 80% part is 3% to 85%; preferably, the bottom distributor is one of a cone, a butterfly shape, and a sphere.

[0012] In the technical solution provided by the present invention, the opening ratio of the annular distributor is 0% to 90%; when the included angle between the annular distributor and the overflow bucket is greater than 90°, the opening ratio is 0% to 75%; when the included angle between the annular distributor and the overflow bucket is less than or equal to 90°, the opening ratio is 20% to 90%.

[0013] The ratio of the diameter of the solid particle distributor to the diameter of the reactor is 0.1 to 0.95, preferably 0.5 to 0.8.

[0014] The rectifying gas distributor is one annular pipe or multiple annular pipes; the opening ratio of the rectifying gas distributor is 10% to 50%, preferably 20% to 35%.

[0015] The rectifying gas of the rectifying gas distributor includes but is not limited to one or more of air, nitrogen, dry gas, liquefied gas, and water vapor.

[0016] The beneficial effects that can be obtained by the present invention:

[0017] When the distributor provided by the present invention is in use, the solid particles do not directly enter the reactor through the conveying inclined pipe, the conveying horizontal pipe, and the conveying vertical pipe. Instead, they first enter the container composed of the overflow bucket and the bottom distributor, and a certain height of the material level is formed in the overflow bucket. The static pressure difference formed by the solid particles in the overflow bucket will also cause a certain height of the material level to be formed in the conveying vertical pipe. The solid particles on one side of the conveying vertical pipe do not directly enter the distributor, but gather into a cylindrical material in the conveying vertical pipe and enter the container composed of the overflow bucket and the bottom distributor in the form of dense-phase conveying, which can solve the problem that the solid particles concentrate on one side when entering the reactor.

[0018] The solid particles entering the overflow bucket are divided into two paths. The first path falls into the reactor through the openings of the bottom distributor, and the second path flows upward through the annular gap between the overflow bucket and the conveying vertical pipe. When the material is higher than the overflow bucket, it falls along the outer surface of the overflow bucket and falls into the reactor through the annular distributor arranged around the overflow bucket. By setting reasonable opening ratios of the bottom distributor, the height of the overflow bucket, the size of the annular gap between the overflow bucket and the conveying vertical pipe, and the size and opening ratio of the annular distributor, the problem of uniform distribution of solid particles in the reactor can be solved.

[0019] The rectifying gas distributor disposed between the conveying vertical pipe and the bottom distributor has two functions. One is to rectify the solid particle flow flowing out of the conveying vertical pipe through fluidization, so that the solid particles entering the overflow bucket are in a uniform fluidized state, preventing the solid particles from flowing unevenly in the overflow bucket and also preventing the solid particles from accumulating in the overflow bucket. The other is the distribution function. The size and direction of the gas flow of the rectifying distributor can control the ratio of the solid particles flowing through the bottom distributor and the annular gap between the overflow bucket and the conveying vertical pipe. Brief Description of the Drawings

[0020] Appendix Figure 1 It is a schematic diagram of the situation where solid particles are biased to one side in the background art.

[0021] Appendix Figure 2 It is a schematic diagram of the situation where solid particles are biased to one side in the background art.

[0022] Appendix Figure 3 It is a front view of the solid particle distributor of the present invention.

[0023] Appendix Figure 4 It is a top view of the bottom distributor of the present invention.

[0024] Appendix Figure 5 It is a top view of the rectifying gas distributor of the present invention.

[0025] Appendix Figure 6 It is a side expanded view of the annular distributor of the present invention.

[0026] The descriptions of the numbers in the drawings are as follows: 1 - solid particle conveying pipe, 2 - reactor, 3 - solid particles, 4 - solid particle conveying pipe, 5 - horizontal pipe blind plug, 6 - reactor, 7 - solid particles, 8 - conveying inclined pipe, 9 - conveying horizontal pipe, 10 - conveying vertical pipe, 11 - overflow bucket, 12 - rectifying gas, 13 - bottom distributor, 14 - rectifying gas distributor, 15 - annular distributor, 16 - reactor, 17 - bottom distributor opening, 18 - annular distributor opening, 19 - rectifying gas distributor opening, 8, 9 and 10 form the conveying pipe, and 10, 13 and 15 form the solid particle distributor. Detailed Embodiment

[0027] The drawings are only for illustrative purposes, and the prior art or common general knowledge is omitted. The following will be further described in conjunction with the drawings of the present invention.

[0028] As Figure 3As shown in the figure, a solid particle distributor for a circulating fluidized bed countercurrent reactor includes: a reactor 16, a conveying pipe 8-10, a solid particle distributor, and a rectifying gas distributor 14; the conveying pipe includes a conveying inclined pipe 8, a conveying horizontal pipe 9, and a conveying vertical pipe 10. The conveying inclined pipe 8 is connected to the conveying horizontal pipe 9, and the middle of the conveying horizontal pipe 9 is connected to the conveying vertical pipe 10. The solid particle distributor is located below the conveying vertical pipe 10, and the conveying vertical pipe 10 is inserted into the solid particle distributor; the outlet of the conveying vertical pipe 10 is processed into a frustum shape, and the ratio of the cross-sectional area after the frustum-shaped contraction of the outlet of the conveying vertical pipe 10 to the cross-sectional area before contraction is 0.6; the solid particle distributor includes an overflow bucket 11, a bottom distributor 13, and an annular distributor 15. The top of the overflow bucket 11 is open, the bottom of the overflow bucket 11 is connected to the bottom distributor 13, and the annular distributor 15 is arranged around the overflow bucket 11. The bottom distributor 13 has openings, and the annular distributor 15 has openings; the rectifying gas distributor 14 is arranged at the middle position between the bottom distributor 13 and the conveying vertical pipe 10.

[0029] The conveying inclined pipe 8 penetrates into the reactor through the reactor surface, and one end of the conveying inclined pipe 8 inside the reactor is communicated with the conveying horizontal pipe 9; one end of the conveying horizontal pipe 9 is communicated with the conveying inclined pipe 8, and the other end is a blind plug; the middle of the conveying horizontal pipe 9 is communicated with the conveying vertical pipe 10. The conveying horizontal pipe 9 and the conveying vertical pipe 10 are of a T-shaped structure, and the insertion depth of the conveying vertical pipe 10 is 80% of the height of the overflow bucket 11.

[0030] As Figure 4 shown, the bottom distributor 13 is provided with circular holes 17, and the hole-opening method is: the hole-opening rate of the middle 20% part of the bottom distributor 13 is 10%, and the hole-opening rate of the surrounding 80% part is 20%; the bottom distributor 13 is conical.

[0031] As Figure 6 shown, the included angle between the annular distributor 15 and the overflow bucket 11 is 45°, and the surface is provided with circular holes 18, and the hole-opening rate is 50%.

[0032] The ratio of the diameter of the solid particle distributor to the diameter of the reactor is 0.75, and the ratio of the diameter of the overflow bucket 11 to the diameter of the solid particle distributor is 0.5.

[0033] As Figure 5 shown, the rectifying gas distributor 14 is a single annular pipe, with circular holes 19 opened in the upper, inner, and outer directions. The ratio of the opening areas in the upper, inner, and outer directions is 1:3:9, and the total hole-opening rate is 30%. The rectifying gas 12 passes through the overflow bucket 11 and enters the rectifying gas distributor 14.

[0034] Example 1.

[0035] This embodiment includes 1 group of experimental groups and 1 group of control groups. Both groups are tested in a cold-state countercurrent reactor, and the test conditions are as follows: The cold-state countercurrent reactor used in this embodiment is made of acrylic material, and the situation inside the reactor can be directly observed; the experimental group uses Figure 3 the conveying structure shown, and the control group uses Figure 2 the conveying structure shown; the solid particles used are spherical catalyst particles with an average particle size of 80 microns; the gas-phase medium is nitrogen in both cases; the inner diameter of the reactor is 45 cm and the height is 235 cm. The gas velocity inside the reactor is 0.3 m / s, and the catalyst circulation velocity is 60 kg / (m 2 ·s); 16 uniformly distributed measuring holes with a diameter of 8 mm are opened on the same cross-section in the middle of the reactor. The measuring hole located below the conveying inclined pipe is marked as the 0° measuring hole. When observing from top to bottom, they are respectively recorded as the 45°, 90°, 135°, 180°, 225°, 270°, and 315° measuring holes in the clockwise direction; an insertion-type solid particle concentration measuring instrument is used to detect the distribution of the catalyst inside the reactor. 11 points are measured outward from the center position of the reactor for each measuring hole, and the distances from the center position of the reactor to the measuring points are 0 cm, 2 cm, 4 cm, 6 cm, 8 cm, 10 cm, 12 cm, 14 cm, 16 cm, 18 cm, and 20 cm from the inside to the outside respectively.

[0036] During the 2-group test process of this embodiment, the catalyst circulation route is as follows: The catalyst of the experimental group enters the solid particle distributor from the regenerator through the conveying pipe, and after being distributed by the solid particle distributor, it enters the reactor. After the catalyst enters the reactor, it moves downward and forms a dense phase region at the bottom of the reactor. The catalyst in the dense phase region enters the regenerator through the catalyst conveying pipeline. The gas-phase medium is divided into two paths. One path enters the bottom of the reactor, and the other path enters the middle and lower part of the reactor (above the catalyst dense phase region). Both paths of the gas-phase medium move upward and leave the device through the filter at the top of the reactor; the catalyst circulation route of the control group does not pass through the solid particle distributor, and the others are the same as those of the experimental group.

[0037] According to the above test conditions, the catalyst flow rates at each measurement point are detected.

[0038] The results of the experimental group are shown in Table 1.

[0039] Table 1 Data table of catalyst flow rates at different distances from the reactor center at each measurement port of the experimental group

[0040]

[0041] The results of the control group are shown in Table 2.

[0042] Table 2 Data table of catalyst flow rates at different distances from the reactor center at each measurement port of the control group

[0043]

[0044] Table 1 shows the results of the experimental group. The catalyst flow rate is basically uniform everywhere in the reactor, and the flow rate is 57-62 kg / (m 2 ·s); Table 2 shows the results of the control group. The catalyst flow rate at the 0° measurement hole is the lowest, and the catalyst flow rate at the 180° measurement hole is the highest. That is, the catalyst flow rate is low on the side close to the conveying inclined pipe and high on the side far from the conveying inclined pipe. More catalysts are distributed on the side far from the conveying inclined pipe due to the action of inertia.

Claims

1. A solid particle distributor system for a circulating fluidized bed countercurrent reactor, characterized in that, Comprising: A reactor, a conveying pipe, a solid particle distributor, and a rectifying gas distributor; The conveying pipe includes a conveying inclined pipe, a conveying horizontal pipe, and a conveying vertical pipe. The conveying inclined pipe is connected to the conveying horizontal pipe, and the middle of the conveying horizontal pipe is connected to the conveying vertical pipe. The solid particle distributor is located below the conveying vertical pipe, and the conveying vertical pipe is inserted into the solid particle distributor; The outlet of the conveying vertical pipe is processed with a frustum-shaped contraction, and the ratio of the cross-sectional area after the frustum-shaped contraction of the outlet of the conveying vertical pipe to the cross-sectional area before contraction is 0.1 to 1; The solid particle distributor includes an overflow bucket, a bottom distributor, and an annular distributor. The top of the overflow bucket is open, the bottom of the overflow bucket is connected to the bottom distributor, the annular distributor is arranged around the overflow bucket, the bottom distributor has openings, and the annular distributor has openings; The rectifying gas distributor is arranged between the bottom distributor and the conveying vertical pipe.

2. The solid particle distributor system of a circulating fluidized bed countercurrent reactor according to claim 1, characterized in that: The conveying inclined pipe penetrates into the reactor through the surface of the reactor, and one end of the conveying inclined pipe inside the reactor is communicated with the conveying horizontal pipe; One end of the conveying horizontal pipe is communicated with the conveying inclined pipe, and the other end is a blind plug; The middle of the conveying horizontal pipe is communicated with the conveying vertical pipe, and the conveying horizontal pipe and the conveying vertical pipe are of a T-shaped structure.

3. The solid particle distributor system of a circulating fluidized bed countercurrent reactor according to claim 1, characterized in that: Preferably, the ratio of the cross-sectional area after the frustum-shaped contraction of the outlet of the conveying vertical pipe to the cross-sectional area before contraction is 0.45 to 0.

65.

4. The solid particle distributor system of a circulating fluidized bed countercurrent reactor according to claim 1, characterized in that: The opening ratio of the bottom distributor is 3% to 70%; Preferably, the opening ratio of the bottom distributor is 40% to 65%; Preferably, the opening mode of the bottom distributor is: the opening ratio of the middle 20% part of the bottom distributor is 1% to 40%, and the opening ratio of the surrounding 80% part is 3% to 85%; Preferably, the bottom distributor is one of a cone, a butterfly shape, and a sphere.

5. The solid particle distributor system of a circulating fluidized bed countercurrent reactor according to claim 1, characterized in that: The opening ratio of the annular distributor is 0% to 90%.

6. The annular distributor according to claim 5, wherein: When the included angle between the annular distributor and the overflow bucket is greater than 90°, the opening ratio is 0% to 75%; when the included angle between the annular distributor and the overflow bucket is less than or equal to 90°, the opening ratio is 20% to 90%.

7. The solid particle distributor system of a circulating fluidized bed countercurrent reactor according to claim 1, characterized in that: The ratio of the diameter of the solid particle distributor system to the diameter of the reactor is 0.1 to 0.95; Preferably, the ratio of the diameter of the solid particle distributor system to the diameter of the reactor is 0.5 to 0.

8.

8. The solid particle distributor system of a circulating fluidized bed countercurrent reactor according to claim 1, characterized in that: The rectifying gas distributor is one annular pipe or multiple annular pipes.

9. The rectifying gas distributor according to claim 8, wherein: The opening ratio of the rectifying gas distributor is 10% to 50%; Preferably, the opening ratio of the rectifying gas distributor is 20% to 35%.

10. The rectifying gas distributor according to claim 8, wherein: The rectifying gas of the rectifying gas distributor includes, but is not limited to, one or more of air, nitrogen, dry gas, liquefied gas, and water vapor.

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