Ammonia smoke mixing device with adaptive flue gas flow rate

Abstract

The present invention relates to the technical field of flue gas mixing equipment, and in particular to an ammonia-smoke mixing device based on flue gas flow rate self-adaptation, comprising a flue gas mixing duct, a mixing flow module arranged in the flue gas mixing duct, an air inlet arranged at the bottom of the flue gas mixing duct, a rectifying grid installed at the top, the mixing flow module comprising a static fan and a dynamic fan coaxially distributed, the dynamic fan rotates and changes the distance between the static fan and the dynamic fan after longitudinally moving along a positioning axis, the position of the dynamic blades can be changed by the rotation of the dynamic fan, and then the size of the channel can be changed, thereby interfering with the flow rate of the mixed gas of flue gas and ammonia, and a plurality of groups of mixing flow modules are installed in a flue gas mixing duct along its length direction, which can balance the flow rate of the flue gas, and avoid the flow rate of the mixed gas of flue gas and ammonia being too large or too small at a certain position, thereby affecting its subsequent destocking operation.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas mixing equipment, and in particular to an ammonia-smoke mixing device with self-adaptive flue gas flow rate. Background Art

[0002] In the denitrification system, due to the uneven distribution of flue gas velocity, the unevenness of the flue gas temperature field is aggravated, and some areas deviate from the working conditions required by the denitrification process; flue gas with large velocity differences will mix with smoke dust and cause the catalyst to be unevenly washed. In local areas where the flow rate is too high, the wear rate of the catalyst will be significantly accelerated. For the catalyst in the denitrification system, excessive wear will cause its active components to fall off and the specific surface area to decrease, thereby reducing the activity and service life of the catalyst. For example, in the high-velocity area, the pore wall of the honeycomb catalyst may be washed away by the high-speed flue gas, resulting in the destruction of the channel structure of the catalyst and the inability to play a normal catalytic role. In addition, uneven flue gas velocity is one of the main reasons for many problems such as poor ammonia smoke mixing effect, low denitrification efficiency, and excessive ammonia escape.

[0003] At present, in order to solve the above-mentioned problem of uneven flue gas flow rate, the commonly used method is to add a series of devices such as guide and rectifying grids in the flue of the denitrification system. However, the method of adding guide and rectifying devices can only adjust the flue gas flow rate under a certain working condition. When the actual operating conditions change, the adjustment effect of the original guide and rectifying devices will be greatly reduced, or even counterproductive. At this stage, frequent unit load adjustment has become the norm, and the working conditions of the denitrification system will also change with the unit load adjustment. Therefore, the above adjustment method can no longer meet the requirements of the on-site denitrification process. Summary of the invention

[0004] This patent provides an ammonia-smoke mixing device based on flue gas velocity adaptation, which is mainly designed to solve the problems of temperature fluctuation and poor ammonia-smoke mixing effect caused by flue gas velocity changes when the denitrification system operating conditions change frequently. The device creatively uses the local pressure changes in the flue caused by flue gas velocity changes to automatically adjust the adjustment blades of the mixing device in real time, making the overall resistance in the flue more uniform, thereby achieving uniform flue gas velocity, ensuring ammonia-smoke mixing effect, and improving overall denitrification efficiency.

[0005] In order to achieve the above-mentioned purpose, the embodiment of the present invention specifically adopts the following technical scheme: an ammonia smoke mixing device based on flue gas flow rate adaptation, comprising a flue gas mixing duct, a mixing flow module is arranged in the flue gas mixing duct, an air inlet is arranged at the lower part of the flue gas mixing duct, and a rectifying grid is arranged at the upper part, the mixing flow module comprises a coaxially distributed static fan and a dynamic fan, a positioning shaft is arranged in the middle part of the dynamic fan, and cross braces connected to the inner side wall of the flue gas mixing duct are arranged at both ends of the positioning shaft, and an adjustment device is arranged on the positioning shaft for driving the dynamic fan to rotate and changing the distance between the static fan and the dynamic fan.

[0006] As a further improvement of the above technical solution:

[0007] The adjusting device comprises a movable sleeve arranged outside the positioning shaft, a bushing is arranged inside the movable sleeve, a guide groove is arranged on the side wall of the bushing, and a positioning block used in conjunction with the guide groove is arranged on the side wall of the positioning shaft.

[0008] The guide groove is arc-shaped, and the vertical distance between the upper and lower end points of the guide groove is 100-200 mm, and the rotation angle is 20-50°.

[0009] The number of the guide grooves and the positioning blocks are both two and they are symmetrically distributed with the center line of the positioning axis as the axis.

[0010] A positioning hole is arranged on the side wall of the bushing, and a positioning pin corresponding to the position of the positioning hole is arranged on the side wall of the movable sleeve.

[0011] Both ends of the movable sleeve are provided with connecting flanges, the positioning shaft is provided with a clamping flange connected to the connecting flange, and a sealing gasket is provided between the connecting flange and the clamping flange.

[0012] The dynamic fan is located below the static fan, and the dynamic fan includes a plurality of dynamic blades arranged on the outer side wall of the movable sleeve.

[0013] Each of the dynamic blades forms an angle of 45° with the flow direction of the flue gas.

[0014] The static fan comprises a vertical rod, and static blades are arranged on the outer side wall of the vertical rod.

[0015] The number of the static blades is multiple and evenly distributed along the circumferential direction of the vertical rod. Each static blade forms an angle of 135° with the flow direction of the smoke. A channel for smoke circulation is formed between the static blades and the dynamic blades.

[0016] The beneficial effects of the embodiments of the present invention are as follows: the ammonia-smoke mixing device based on flue gas flow rate self-adaptation comprises a flue gas mixing duct, a mixing flow module is arranged in the flue gas mixing duct, an air inlet is arranged at the lower part of the flue gas mixing duct, a rectifying grid is installed at the upper part, the mixing flow module comprises a static fan and a dynamic fan which are coaxially distributed, a positioning shaft is arranged in the middle part of the dynamic fan, and cross braces which are connected to the inner wall of the flue gas mixing duct are arranged at both ends of the positioning shaft, and an adjusting device is arranged on the positioning shaft, which is used to drive the dynamic fan to rotate and change the distance between the static fan and the dynamic fan after longitudinally moving along the positioning shaft, and the position of the dynamic blades can be changed by the rotation of the dynamic fan, thereby changing the size of the channel, thereby interfering with the flow velocity of the mixed gas of flue gas and ammonia, and installing multiple groups of mixing flow modules in a flue gas mixing duct along its length direction can balance the flow velocity of the flue gas, thereby avoiding that the flow velocity of the mixed gas of flue gas and ammonia is too large or too small at a certain position, thereby affecting its subsequent destocking operation;

[0017] The dynamic blades are at an angle of 45° to the flow direction of the flue gas, and each static blade is at an angle of 135° to the flow direction of the flue gas. A channel for flue gas circulation is formed between the static blades and the dynamic blades. When the mixed gas of flue gas and ammonia first passes through the dynamic blades, it can rotate counterclockwise along the axis direction of a single group of adjustment blades, and then when it passes through the static blades, it can rotate clockwise along the axis direction of a single group of adjustment blades. This allows the ammonia and flue gas to be fully stirred and mixed, thereby improving the uniformity of the mixing of the flue gas and ammonia. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 It is a structural schematic diagram of the rectifying grid in the present invention;

[0020] Figure 3 It is a structural schematic diagram of the flow mixing module in the present invention;

[0021] Figure 4 It is a schematic diagram of the installation structure of the static fan and the dynamic fan in the present invention;

[0022] Figure 5 It is a structural schematic diagram of the dynamic fan in the present invention;

[0023] Figure 6 is a cross-sectional view of the dynamic fan of the present invention;

[0024] Figure 7 It is a schematic diagram of the installation structure of the dynamic blade and the movable sleeve in the present invention;

[0025] Figure 8 It is a schematic diagram of the installation structure of the bushing in the present invention;

[0026] Fig. 9 It is a structural schematic diagram of the bushing in the present invention;

[0027] Fig.10 It is a schematic diagram of the changing state of the channel in the present invention;

[0028] Fig.11 Schematic diagram of the structure of different types of rectifier grids in the present invention.

[0029] In the figure: 1. flue gas mixing duct; 2. air inlet; 3. rectifier grille; 4. static fan; 5. dynamic fan; 6. positioning shaft; 7. movable sleeve; 8. bushing; 9. guide groove; 10. positioning block; 11. positioning hole; 12. positioning pin; 13. connecting flange; 14. clamping flange; 15. sealing gasket; 16. vertical rod; 17. static blade; 18. dynamic blade; 19. channel; 20. cross brace. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0031] like Figure 1-11 As shown, the ammonia-smoke mixing device based on flue gas flow rate self-adaptation of the present embodiment comprises a flue gas mixing duct 1, a mixing flow module is arranged in the flue gas mixing duct 1, an air inlet 2 is arranged at the lower part of the flue gas mixing duct 1, a rectifying grid 3 is installed at the upper part, the mixing flow module comprises a static fan 4 and a dynamic fan 5 which are coaxially distributed, a positioning shaft 6 is arranged in the middle part of the dynamic fan 5, and cross braces 20 connected to the inner wall of the flue gas mixing duct 1 are arranged at both ends of the positioning shaft 6, and an adjusting device is arranged on the positioning shaft 6 for driving the dynamic fan 5 to rotate and change the distance between the static fan 4 and the dynamic fan 5 after longitudinally moving along the positioning shaft 6, the position of the dynamic blade 18 can be changed by the rotation of the dynamic fan 5, and then the size of the channel 19 can be changed, so as to interfere with the flow velocity of the mixed gas of flue gas and ammonia, and a plurality of groups of mixing flow modules are installed in a flue gas mixing duct 1 along its length direction, so as to balance the flow velocity of the flue gas, and avoid the flow velocity of the mixed gas of flue gas and ammonia being too large or too small at a certain position, thereby affecting its subsequent destocking operation.

[0032] The regulating device comprises a movable sleeve 7 sleeved on the outside of the positioning shaft 6, a bushing 8 is installed on the inner side of the movable sleeve 7, a guide groove 9 is arranged on the side wall of the bushing 8, the guide groove 9 is arc-shaped, and the vertical distance between the upper and lower end points of the guide groove 9 is 100-200mm, the rotation angle is 20-50°, preferably 150mm, at this time, the maximum rotation angle of the dynamic blade 18 is 30°, and a positioning block 10 used in conjunction with the guide groove 9 is arranged on the side wall of the positioning shaft 6. The initial position of the dynamic fan 5 is located at the bottom of the positioning shaft 6 under the action of its own gravity. At this time, the projections of the dynamic blade 18 and the static blade 17 completely overlap, and at this time the channel 19 is at the maximum value, and the flue gas and ammonia The flow rate of the mixed gas is at its maximum value. As the mixed gas enters, it will apply an upward thrust to the dynamic blades 18 when passing through the dynamic fan 5. At this time, the movable sleeve 7 moves upward. At the same time, under the action of the guide groove 9 and the positioning block 10, the dynamic blades 18 rotate counterclockwise. During the rotation, the channel 19 gradually becomes smaller. When the positioning block 10 contacts the top of the guide groove 9, the dynamic blades 18 rotate 30° counterclockwise, and the flow rate of the channel 19 reaches the minimum value. At this time, under the action of gravity, the dynamic fan 5 starts to reset, and changes the flow rate of the mixed gas at this location through this reciprocating motion to ensure that the flow rate at various locations in the flue gas mixing duct 1 is relatively uniform.

[0033] There are two guide grooves 9 and two positioning blocks 10 , which are symmetrically distributed around the center line of the positioning axis 6 .

[0034] A positioning hole 11 is provided on the side wall of the bushing 8, and a positioning pin 12 corresponding to the position of the positioning hole 11 is provided on the side wall of the movable sleeve 7. There are two groups of positioning holes 11, each group includes three positioning holes 11 distributed in sequence from top to bottom along the height direction of the bushing 8, wherein the upper and lower positioning holes 11 are U-shaped and connected to the upper and lower edges of the bushing, and are used to add graphite particles or other solid lubricants into the bushing 8.

[0035] Both ends of the movable sleeve 7 are provided with connecting flanges 13, and the positioning shaft 6 is provided with a clamping flange 14 connected to the connecting flange 13. A sealing gasket 15 is provided between the connecting flange 13 and the clamping flange 14. The function of the sealing gasket 15 is to seal the added graphite particles or solid curing agent, and at the same time prevent smoke from entering the dynamic fan 5 during operation, causing damage to the equipment.

[0036] The dynamic fan 5 is located below the static fan 4 , and includes a plurality of dynamic blades 18 mounted on the outer side wall of the movable sleeve 7 , and each dynamic blade 18 forms an angle of 45° with the flow direction of the smoke.

[0037] The static fan 4 includes a vertical rod 16, and static blades 17 are arranged on the outer wall of the vertical rod 16. There are multiple static blades 17 and they are evenly distributed along the circumferential direction of the vertical rod 16. Each static blade 17 forms an angle of 135° with the flow direction of the flue gas. A channel 19 for flue gas circulation is formed between the static blades 17 and the dynamic blades 18. When the mixed gas of flue gas and ammonia first passes through the dynamic blades 18, it can rotate counterclockwise along the axial direction of a single group of adjustment blades, and then when passing through the static blades 17, it can rotate clockwise along the axial direction of a single group of adjustment blades, so that the ammonia and flue gas are fully stirred and mixed, thereby improving the uniformity of the mixing.

[0038] It should be noted that the rectifying grid 3 is selected from one of an equidistant grid, a dense grid or a sparse grid, and the specific selection method needs to be selected in combination with the flow rate of the mixed gas and the distribution in the flue gas mixing duct 1.

[0039] Equally spaced grids: The spacing between grids in a single rectifier grid module is equal;

[0040] Differential variable spacing dense grid: The spacing between the grids of a single rectifier grid module gradually decreases from the periphery to the middle at a certain range coefficient d, and the air resistance of the module from the periphery to the middle tends to increase. Compared with the equally spaced grid, the setting of this module increases the air resistance in the area and appropriately reduces the flue gas flow rate.

[0041] Differential variable spacing sparse grid: The spacing between the grids of a single rectifier grid module gradually increases from the periphery to the middle at a certain range coefficient d, and the air resistance of the module from the periphery to the middle tends to decrease. Compared with the equally spaced grid, the module is set to reduce the air resistance in the area and appropriately increase the flue gas flow rate.

[0042] It should be noted that in the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0043] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] The term "comprise" or any other similar term is intended to cover a non-exclusive inclusion, such that a process, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, article, or apparatus / device.

[0045] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. An ammonia-smoke mixing device based on flue gas velocity self-adaptation, comprising a flue gas mixing pipeline (1), characterized in that: A mixing flow module is arranged in the flue gas mixing pipe (1); an air inlet (2) is arranged at the bottom of the flue gas mixing pipe (1), and a rectifying grid (3) is arranged at the top; The mixed flow module comprises a coaxially distributed static fan (4) and a dynamic fan (5), a positioning shaft (6) is arranged in the middle of the dynamic fan (5), and both ends of the positioning shaft (6) are provided with cross braces (20) connected to the inner wall of the smoke mixing duct (1), and an adjustment device is arranged on the positioning shaft (6) for driving the dynamic fan (5) to rotate and changing the distance between the static fan (4) and the dynamic fan (5).

2. The ammonia-smoke mixing device based on flue gas velocity self-adaptation according to claim 1 is characterized in that: The adjustment device comprises a movable sleeve (7) arranged outside the positioning shaft (6), a bushing (8) is arranged inside the movable sleeve (7), a guide groove (9) is arranged on the side wall of the bushing (8), and a positioning block (10) used in conjunction with the guide groove (9) is arranged on the side wall of the positioning shaft (6).

3. The ammonia-smoke mixing device based on flue gas velocity self-adaptation according to claim 2 is characterized in that: The guide groove (9) is arc-shaped, and the vertical distance between the upper and lower end points of the guide groove (9) is 100-200 mm, and the rotation angle is 20-50°.

4. The ammonia-smoke mixing device based on flue gas velocity self-adaptation according to claim 3 is characterized in that: The number of the guide grooves (9) and the positioning blocks (10) are both two and they are symmetrically distributed around the center line of the positioning axis (6).

5. The ammonia-smoke mixing device based on flue gas velocity self-adaptation according to claim 2 is characterized in that: A positioning hole (11) is provided on the side wall of the bushing (8), and a positioning pin (12) corresponding to the position of the positioning hole (11) is provided on the side wall of the movable sleeve (7).

6. The ammonia-smoke mixing device based on flue gas velocity self-adaptation according to claim 5, characterized in that: Both ends of the movable sleeve (7) are provided with connecting flanges (13), the positioning shaft (6) is provided with a clamping flange (14) connected to the connecting flange (13), and a sealing gasket (15) is provided between the connecting flange (13) and the clamping flange (14).

7. The ammonia-smoke mixing device based on flue gas velocity self-adaptation according to claim 2 is characterized in that: The dynamic fan (5) is located below the static fan (4), and the dynamic fan (5) comprises a plurality of dynamic blades (18) arranged on the outer side wall of the movable sleeve (7).

8. The ammonia-smoke mixing device based on flue gas velocity self-adaptation according to claim 7, characterized in that: Each of the dynamic blades (18) forms an angle of 45° with the flow direction of the flue gas.

9. The ammonia-smoke mixing device based on flue gas velocity self-adaptation according to claim 8, characterized in that: The static fan (4) comprises a vertical rod (16), and static blades (17) are arranged on the outer side wall of the vertical rod (16).

10. The ammonia-smoke mixing device based on flue gas velocity self-adaptation according to claim 9, characterized in that: The number of the static blades (17) is multiple and evenly distributed along the circumferential direction of the vertical rod (16), each static blade (17) forms an angle of 135° with the flow direction of the smoke, and a channel (19) for smoke circulation is formed between the static blades (17) and the dynamic blades (18).

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