Gas-solid separation device for outlet of tail gas dry desulfurization and denitrification riser reactor

Abstract

The application discloses a gas-solid separation device for the outlet of a tail gas dry desulfurization and denitrification riser reactor and relates to the technical field of flue gas treatment. The application comprises a riser, a cyclone passage, a separator exhaust pipe and a separator settling pipe. The separator exhaust pipe is vertically arranged. The riser is located below the separator exhaust pipe and vertically extends into the separator exhaust pipe. The separator settling pipe comprises a separator outer cylinder and a separator outer cone which are arranged outside the separator exhaust pipe and are connected in an up-down mode. The top of the separator outer cylinder is sealingly connected with the side wall of the separator exhaust pipe. The inlet of the cyclone passage is connected with the top end of the riser, and the outlet of the cyclone passage extends between the separator exhaust pipe and the separator outer cylinder. The application designs a high-efficiency separation device which can realize the separation of flue gas and adsorbent at the outlet of the riser. Moreover, the application can effectively reduce the occupied space of the separation system, and the pressure drop and energy loss of the separation system are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas treatment, and in particular to a gas-solid separation device at the outlet of a riser reactor for dry desulfurization and denitration of tail gas. Background Art

[0002] Dry desulfurization and denitrification is a method for simultaneous desulfurization and denitrification of flue gas with no water or a small amount of water. Compared with wet desulfurization and denitrification, dry desulfurization and denitrification has the advantages of simple equipment, small footprint, low investment and operating costs, easy operation, low energy consumption, easy disposal of products and no sewage treatment system.

[0003] In the dry desulfurization and denitrification process, the separation of flue gas from the catalyst and adsorbent at the outlet of the dry desulfurization and denitrification reactor has an important impact on the effectiveness and economy of the method; among them, the separation of flue gas from the adsorbent at the outlet of the dry desulfurization and denitrification riser reactor is the key to the successful implementation of the method.

[0004] At present, riser reactors are mainly used in the field of petroleum refining. Various devices have been developed at home and abroad for separating the catalyst and oil and gas at the outlet of catalytic cracking riser reactors, such as inertial separation devices such as semi-circular cap and T-shaped components, and cyclone separators that rely on centrifugal force separation.

[0005] Among them, inertial separation devices such as semicircular hat-shaped and T-shaped components mainly rely on changing the flow direction of the gas-solid two-phase to achieve phase separation. They have a small pressure drop and a simple structure, but the separation effect is very limited. Compared with the above-mentioned inertial separation devices, cyclone separators have better separation performance, but cyclone separators occupy a larger space and waste site space.

[0006] In order to reduce the residence time of oil and gas in the cyclone separator, the United States has also developed the VDS system (Vortex Desphalting System) and the VSS system (Vortex Separation System), and China has also developed the FSC system (Flare Slow Closure System), VQS system (Vortex Quick Separation System), CSC system (Cyclone Separation System) and SVQS system (Swirl Vortex Quick Separation System). Although these technologies have their own advantages, they also have some shortcomings: for example, the SVQS system is too complicated, and a second-stage cyclone separator is required at the outlet of the riser reactor, resulting in a large system pressure drop.

[0007] The above analysis shows that the current separation technology for dry desulfurization and denitrification riser reactors is very limited, and the existing separation equipment for catalytic cracking riser outlets has at least the following problems: low gas and catalyst separation efficiency, large system space occupation, and large system energy loss. As a result, the existing separation devices for petroleum catalytic cracking risers cannot be used in dry desulfurization and denitrification riser reactors.

[0008] Therefore, how to solve the problem that the separation technology for dry desulfurization and denitrification riser reactors is very limited, and the gas-solid separation equipment of existing petroleum refining riser reactors has low separation efficiency, large system space occupation, and large pressure drop is a technical problem that technicians in this field urgently need to solve.

[0009] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0010] In response to the above technical problems, an embodiment of the present invention provides a gas-solid separation device at the outlet of a riser reactor for dry desulfurization and denitrification of tail gas to solve the problems raised in the above background technology.

[0011] The present invention provides the following technical solutions:

[0012] A gas-solid separation device at the outlet of a riser reactor for dry desulfurization and denitration of tail gas, comprising: a riser, a cyclone channel, a separator exhaust pipe, and a separator settling pipe;

[0013] The separator exhaust pipe is arranged vertically;

[0014] The riser is located below the separator exhaust pipe and extends vertically into the separator exhaust pipe;

[0015] The separator settling pipe includes a separator outer cylinder and a separator outer cone which are sleeved on the outside of the separator exhaust pipe and connected up and down; the top of the separator outer cylinder is sealed with the side wall of the separator exhaust pipe;

[0016] The inlet of the swirl channel is connected to the top of the riser, and the outlet extends between the separator exhaust pipe and the separator outer cylinder; wherein,

[0017] The inner channel of the swirl channel forms a first separation space for gas and solid phases;

[0018] The space between the separator outer cylinder and the separator exhaust pipe forms a second separation space for gas and solid phases;

[0019] The space between the outer cone of the separator and the riser forms the third separation space for gas and solid phases.

[0020] Preferably, the gas-solid phases are separated according to the following steps:

[0021] The gas and solid phases enter the riser from the outlet of the desulfurization and denitrification riser reactor and rise to the top of the riser;

[0022] The gas and solid phases enter the first separation space in the cyclone channel from the top of the riser for separation;

[0023] After the gas and solid phases are separated in the first separation space, they enter the second separation space between the separator outer cylinder and the separator exhaust pipe for further separation;

[0024] The gas and solid phases descend from the second separation space into the third separation space between the outer cone of the separator and the riser for further separation;

[0025] The separated solid phase falls into the sedimentation area of ​​the desulfurization and denitrification riser reactor from the outlet between the outer cone of the separator and the riser 1 under the action of gravity;

[0026] The purified gas phase flows through the channel between the separator exhaust pipe and the riser and is discharged from the outlet of the separator exhaust pipe.

[0027] Preferably, the diameter of the separator exhaust pipe is 1.2-1.8 times the diameter of the riser pipe, so as to ensure that there is a sufficient gas rising channel between the separator exhaust pipe and the riser pipe.

[0028] Preferably, the height of the separator exhaust pipe inserted into the separator outer cylinder is 1-3 times the diameter of the riser; and the diameter of the separator outer cylinder is 1.8-2.4 times the diameter of the riser.

[0029] Preferably, the height of the separator outer cylinder is 1.5-3 times the height of the separator exhaust pipe; the bottom diameter of the separator outer cone is 1.5-2.5 times the diameter of the riser; and the height of the separator outer cone is 1.5-2.5 times the height of the separator exhaust pipe.

[0030] Preferably, the outer wall surface of the swirl channel is tangent to the riser, and the upper wall surface of the swirl channel is aligned with the top end cover of the riser.

[0031] Preferably, the number of the swirl channels is 3-6, and the 3-6 swirl channels are symmetrically distributed about the central axis of the riser; the axis of the swirl channel is a quadratic curve and is in a horizontal plane.

[0032] Preferably, the cross section of the swirl channel is rectangular, circular or elliptical.

[0033] Preferably, when the cross-section of the swirl channel is rectangular, the area of ​​its rectangular cross-section is 20-40% of the cross-sectional area of ​​the riser; when the cross-section of the swirl channel is circular, the diameter of its circular cross-section is 20-40% of the diameter of the riser; when the cross-section of the swirl channel is elliptical, the major axis and minor axis of its elliptical cross-section are 20-40% and 10-20% of the diameter of the riser, respectively.

[0034] Preferably, the axial distance between the separator exhaust pipe outlet and the top end of the riser is 1-2 times the diameter of the riser.

[0035] The gas-solid separation device at the outlet of the riser reactor for dry desulfurization and denitration of tail gas provided by the embodiment of the present invention has the following beneficial effects:

[0036] 1. The separation system is organically combined with the riser and arranged around the axis of the riser. This avoids the problem of a large axial height and large space occupied by the separation system caused by the axial dimension of a conventional cyclone separator being 5-10 times the diameter of its cylinder when the separation unit is used. This can reduce the infrastructure cost and equipment investment cost of the entire high-temperature flue gas purification system.

[0037] 2. Achieve efficient gas-solid cyclone separation at the riser outlet. Compared with inertial separation devices such as semi-circular cap-shaped and T-shaped components, the separation system provided by the present invention has higher separation efficiency;

[0038] 3. The present invention adopts a single separation system to replace the prior art's requirement for installing a multi-stage separation device in the reactor, which includes two-stage cyclone separators connected in series or an inertial separator and a cyclone separator connected in series. Experimental data show that in a riser system with a diameter of 200 mm, the pressure drop of the device of the present invention is 384.0 Pa, while the pressure drop of the prior art's two-stage cyclone separators connected in series is 1100 Pa. The device of the present invention has a small fluid pressure drop and low energy loss, which can ensure the normal operation of the high-temperature flue gas purification system. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of the present invention;

[0040] Figure 2 For the present invention Figure 1 Schematic diagram of the cross-sectional structure in the AA direction;

[0041] Figure 3 For the present invention Figure 1 Schematic diagram of the cross-sectional structure in the middle BB direction;

[0042] Figure 4 is a specific particle size distribution diagram;

[0043] Figure 5 is the classification efficiency diagram of Example 1;

[0044] Figure 6 is the classification efficiency diagram of Example 2;

[0045] Figure 7 This is the classification efficiency diagram of Example 3. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0047] 1. Reference Figure 1-Figure 7 The embodiment of the present invention provides a gas-solid separation device at the outlet of a riser reactor for dry desulfurization and denitrification of tail gas to solve the above technical problems. The technical solution is as follows:

[0048] A gas-solid separation device at the outlet of a tail gas dry desulfurization and denitration riser reactor, connected to the outlet of the desulfurization and denitration riser reactor;

[0049] It includes: a riser 1, a swirl channel 2, a separator exhaust pipe 3 and a separator settling pipe;

[0050] The separator exhaust pipe 3 is arranged vertically;

[0051] The riser 1 is located below the separator exhaust pipe 3 and extends vertically into the separator exhaust pipe 3;

[0052] The separator settling pipe includes a separator outer cylinder 5 and a separator outer cone 6 which are sleeved outside the separator exhaust pipe 3 and connected up and down; the top of the separator outer cylinder 5 is sealed with the side wall of the separator exhaust pipe 3;

[0053] The inlet 7 of the swirl channel 2 is connected to the top of the riser 1, and the outlet 8 thereof extends between the separator exhaust pipe 3 and the separator outer cylinder 5;

[0054] The inner channel of the swirl channel 2 forms a first separation space for gas and solid phases;

[0055] The space between the separator outer cylinder 5 and the separator exhaust pipe 3 forms a second separation space for gas and solid phases;

[0056] The space between the separator outer cone 6 and the riser 1 forms a third separation space for gas-solid two-phases.

[0057] In this embodiment, the gas-solid phases are separated according to the following steps:

[0058] Flue gas and adsorbent enter the riser 1 from the outlet of the desulfurization and denitrification riser reactor and rise to the top of the riser 1;

[0059] The flue gas and adsorbent enter the first separation space in the cyclone channel 2 from the top of the riser 1 for separation;

[0060] After being separated in the first separation space, the flue gas and the adsorbent enter the second separation space between the separator outer cylinder 5 and the separator exhaust pipe 3 for further separation;

[0061] The flue gas and adsorbent descend from the second separation space into the third separation space between the separator outer cone 6 and the riser 1 for further separation;

[0062] The separated adsorbent falls into the settling area of ​​the desulfurization and denitration riser reactor from the outlet between the separator outer cone 6 and the riser 1 under the action of gravity; and then returns to the denitration reactor for recycling or enters the regeneration system;

[0063] The purified gas phase flows through the channel between the separator exhaust pipe 3 and the riser 1 and is discharged from the outlet 4 of the separator exhaust pipe 3.

[0064] The above process changes the gas-solid flow along the axial direction of the riser 1 into a tangential swirl mode, making the gas-solid flow mode similar to the gas-solid flow mode in a cyclone separator. The riser 1 also has the function of stabilizing the vortex core, which can achieve efficient separation of flue gas and adsorbent.

[0065] In this embodiment, the diameter of the separator exhaust pipe 3 is 1.2-1.8 times the diameter of the riser 1 , so as to ensure that there is a sufficient gas rising channel between the separator exhaust pipe 3 and the riser 1 .

[0066] In this embodiment, the height of the separator exhaust pipe 3 inserted into the separator outer cylinder 5 is 1-3 times the diameter of the riser 1 ; the diameter of the separator outer cylinder 5 is 1.8-2.4 times the diameter of the riser 1 .

[0067] In this embodiment, the height of the separator outer cylinder 5 is 1.5-3 times the height of the separator exhaust pipe 3; the diameter and height of the separator outer cylinder 5 together determine the size of the second separation space.

[0068] In this embodiment, the bottom diameter of the separator outer cone 6 is 1.5-2.5 times the diameter of the riser 1, forming a particle sedimentation channel; the height of the separator outer cone 6 is 1.5-2.5 times the height of the separator exhaust pipe 3, determining the size of the third separation space for gas-solid separation.

[0069] In this embodiment, the outer wall surface of the swirl channel 2 is tangent to the riser 1 , and the upper wall surface of the swirl channel 2 is aligned with the top end cover of the riser 1 .

[0070] In this embodiment, the number of the swirl channels 2 is 3-6, and the 3-6 swirl channels 2 are symmetrically distributed about the central axis of the riser 1; the axis of the swirl channel 2 is a quadratic curve and is in the horizontal plane.

[0071] In this embodiment, the cross section of the swirl channel 2 is rectangular, circular or elliptical.

[0072] In this embodiment, when the cross-section of the swirl channel 2 is rectangular, the area of ​​its rectangular cross-section is 20-40% of the cross-sectional area of ​​the riser 1; when the cross-section of the swirl channel 2 is circular, the diameter of its circular cross-section is 20-40% of the diameter of the riser 1; when the cross-section of the swirl channel 2 is elliptical, the major axis and minor axis of its elliptical cross-section are 20-40% and 10-20% of the diameter of the riser 1, respectively; the size of the swirl channel determines the speed of gas-solid flow in the swirl channel.

[0073] In this embodiment, the axial distance between the outlet of the separator exhaust pipe 3 and the top of the riser 1 is 1-2 times the diameter of the riser 1, which determines the axial height of the separation device.

[0074] Second, the design principles of the present invention are as follows:

[0075] 1. By establishing a cyclone channel between the riser, the separator outer cylinder, and the separator exhaust pipe, the gas-solid two-phase flow rises from the riser and enters the cyclone channel to construct a gas-solid cyclone flow pattern, thereby achieving centrifugal separation of gas and solid;

[0076] 2. The riser itself also acts as a swirl stabilizing device, which can make the center of the rotating airflow vortex core more stable, avoiding the scavenging effect of the unstable movement of the vortex core on the separated particles, and further improving the separation efficiency of the system;

[0077] 3. On the other hand, when a conventional cyclone separator is used as the separation unit for gas-solid separation at the riser outlet, the conventional cyclone separator is usually installed above the riser outlet. The conventional cyclone separator is mainly composed of a cylinder and a cone connected in sequence in the axial direction. The sum of the cylinder height and the cone height is usually 5-10 times the cylinder diameter. This leads to the problem of large space occupation and large energy loss of the separation system.

[0078] 4. The separation system provided by the present invention constructs three separation spaces: the first separation space, the second separation space, and the third separation space, thereby ensuring the gas-solid separation efficiency of the separation system. The third separation space does not require the long cone portion of a conventional separator.

[0079] 5. The most important thing is that the three separation spaces of the present invention coincide with the axial direction of the riser, and do not occupy axial space, thus solving the problem of large space occupation and large energy loss of the separation system in conventional cyclone separators.

[0080] 3. The effects of the present invention are verified by combining specific examples below.

[0081] Example 1

[0082] like Figure 2 As shown, the flue gas and adsorbent coming up from the riser 1 enter the second separation space between the separator outer cylinder 5 and the separator exhaust pipe 3 through the cyclone channel 2 for centrifugal separation. The adsorbent separated from the flue gas rotates and flows downward along the wall of the separator outer cylinder 5 and the separator outer cone 6, and finally enters the sedimentation area of ​​the desulfurization and denitrification reactor through the outlet between the separator outer cone 6 and the riser 1, and then returns to the denitrification reactor for recycling or enters the adsorbent regeneration system.

[0083] The clean flue gas after separation is discharged from the desulfurization and denitrification riser reactor through the opening 10 at the bottom of the separator exhaust pipe 3 and the channel between the separator exhaust pipe 3 and the riser 1, and then through the outlet 4 of the separator exhaust pipe 3. This not only achieves efficient separation of flue gas and adsorbent, but also reduces the space occupied by the separation device, and reduces the system pressure drop and energy loss.

[0084] The above process was experimentally studied. The main characteristic dimensions of the separation device used in the experiment are: riser diameter 100mm, riser height 500mm, 3 swirl channels, swirl channel cross-section is rectangular (36×18mm), cone outlet outer diameter 150mm, cone height 180mm, separator outer cylinder diameter 244mm, separator outer cylinder height 240mm, exhaust pipe diameter 100mm. The particle size of the granular material used in the experiment is between 5-140μm, with a median particle size of 68μm (such as Figure 4 As shown). The gas velocity in the riser is 8.0 m / s, and the fractional efficiency of the separator obtained in the experiment is as follows Figure 5 As shown, the results show that the separation efficiency of particles with a particle size of 15μm reaches 100%, and the pressure drop is 340Pa, which can meet the requirements of the dry desulfurization and denitrification system.

[0085] Example 2

[0086] The process flow of Example 2 is similar to that of Example 1. The main difference between Example 2 and Example 1 is that a circular cross-section swirl channel is used in Example 2 instead of the rectangular cross-section channel in Example 1. The cross-sectional diameter of the swirl channel is 25 mm. The numerical calculation and analysis of the above process are performed to obtain the classification efficiency of the separator as shown in FIG. Figure 6 As shown, the results show that the separation efficiency of particles with a particle size of 18 μm reaches 100%, and the pressure drop is 360 Pa, which can meet the requirements of the dry desulfurization and denitrification system.

[0087] Example 3

[0088] The process flow of Example 3 is similar to that of Example 1. The main difference between Example 3 and Example 1 is that an elliptical cross-section swirl channel is used in Example 3 instead of the rectangular cross-section channel in Example 1. The long and short circumferences of the elliptical cross-section of the swirl channel are 38 and 16 mm respectively. The above process is numerically analyzed to obtain the classification efficiency of the separator as shown in the figure. Figure 7 As shown, the results show that the separation efficiency of particles with a particle size of 14 μm reaches 100%, and the pressure drop is 355 Pa, which can meet the requirements of the dry desulfurization and denitrification system.

[0089] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0090] In the present invention, unless otherwise clearly stipulated and limited, the terms "install", "set", "connect", "fix", "screw" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0091] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solutions and concepts of the present invention, and all these changes or substitutions should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A gas-solid separation device at the outlet of a riser reactor for dry desulfurization and denitrification of tail gas, characterized in that: include: Riser, swirl channel, separator exhaust pipe and separator settling pipe; The separator exhaust pipe is arranged vertically; The riser is located below the separator exhaust pipe and extends vertically into the separator exhaust pipe; The separator settling pipe includes a separator outer cylinder and a separator outer cone which are sleeved on the outside of the separator exhaust pipe and connected up and down; the top of the separator outer cylinder is sealed with the side wall of the separator exhaust pipe; The inlet of the swirl channel is connected to the top of the riser, and the outlet extends between the separator exhaust pipe and the separator outer cylinder; wherein, The inner channel of the swirl channel forms a first separation space for gas and solid phases; The space between the separator outer cylinder and the separator exhaust pipe forms a second separation space for gas and solid phases; The space between the outer cone of the separator and the riser forms the third separation space for gas and solid phases; The gas-solid phases are separated according to the following steps: The gas and solid phases enter the riser from the outlet of the desulfurization and denitrification riser reactor and rise to the top of the riser; The gas and solid phases enter the first separation space in the cyclone channel from the top of the riser for separation; After the gas and solid phases are separated in the first separation space, they enter the second separation space between the separator outer cylinder and the separator exhaust pipe for further separation; The gas and solid phases descend from the second separation space into the third separation space between the outer cone of the separator and the riser for further separation; The separated solid phase falls into the settling area of ​​the desulfurization and denitrification riser reactor from the outlet between the outer cone of the separator and the riser under the action of gravity; The purified gas phase flows through the channel between the separator exhaust pipe and the riser and is discharged from the outlet of the separator exhaust pipe.

2. The gas-solid separation device at the outlet of the riser reactor for dry desulfurization and denitration of tail gas according to claim 1, characterized in that: The diameter of the separator exhaust pipe is 1.2-1.8 times the diameter of the riser pipe, so as to ensure that there is a sufficient gas rising channel between the separator exhaust pipe and the riser pipe.

3. The gas-solid separation device at the outlet of the riser reactor for dry desulfurization and denitrification of tail gas according to claim 1, characterized in that: The height of the separator exhaust pipe inserted into the separator outer cylinder is 1-3 times the diameter of the riser; the diameter of the separator outer cylinder is 1.8-2.4 times the diameter of the riser.

4. The gas-solid separation device at the outlet of the riser reactor for dry desulfurization and denitration of tail gas according to claim 1, characterized in that: The height of the separator outer cylinder is 1.5-3 times the height of the separator exhaust pipe; the bottom diameter of the separator outer cone is 1.5-2.5 times the diameter of the riser; the height of the separator outer cone is 1.5-2.5 times the height of the separator exhaust pipe.

5. The gas-solid separation device at the outlet of the riser reactor for dry desulfurization and denitration of tail gas according to claim 1, characterized in that: The outer wall surface of the swirl channel is tangent to the riser, and the upper wall surface of the swirl channel is aligned with the top end cover of the riser.

6. The gas-solid separation device at the outlet of the riser reactor for dry desulfurization and denitration of tail gas according to claim 1, characterized in that: The number of the swirl channels is 3-6, and the 3-6 swirl channels are symmetrically distributed about the central axis of the lifting tube; the axis of the swirl channel is a quadratic curve and is in a horizontal plane.

7. The gas-solid separation device at the outlet of the riser reactor for dry desulfurization and denitration of tail gas according to claim 1, characterized in that: The cross section of the swirl channel is rectangular, circular or elliptical.

8. The gas-solid separation device at the outlet of the riser reactor for dry desulfurization and denitrification of tail gas according to claim 1, characterized in that: When the cross-section of the swirl channel is rectangular, the area of ​​the rectangular cross-section is 20-40% of the cross-section area of ​​the riser; when the cross-section of the swirl channel is circular, the diameter of the circular cross-section is 20-40% of the diameter of the riser; when the cross-section of the swirl channel is elliptical, the major axis and minor axis of the elliptical cross-section are 20-40% and 10-20% of the diameter of the riser, respectively.

9. The gas-solid separation device at the outlet of the riser reactor for dry desulfurization and denitrification of tail gas according to claim 1, characterized in that: The axial distance between the separator exhaust pipe outlet and the top end of the riser is 1-2 times the diameter of the riser.

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