Ammonia-containing tail gas treatment device for urea fluidized bed granulation

Abstract

A urea fluidized bed granulation ammonia-containing tail gas treatment device aims to solve the problems that in the prior art, a dry method and a wet method are used for urea fluidized bed granulation tail gas treatment, so that ammonia resources are wasted, a cloth bag is prone to being affected with damp to form hardening, the cloth bag replacement period is short, the consumable cost is high, the washing efficiency is low, dust and ammonia emission is not up to standard, the demisting effect is poor, and the like. The device comprises a wall plate, a top plate, a bottom plate and a device body, the interior of the device body is vertically divided into an upper layer, a middle layer and a lower layer, segmented partition plates are arranged in the upper layer and the middle layer respectively, and each layer of the upper layer and the middle layer is transversely divided into a coarse washing section, a fine washing section and an ammonia recovery section through the segmented partition plates. According to the utility model, the filling height of the filler and the wire mesh is reduced, spray liquid at the lower parts of the folded plate and the wire mesh is prevented from coalescing into a water curtain, meanwhile, tail gas bias flow caused by damage of the filler and the wire mesh in the use process is prevented, secondary entrainment can be prevented, the water consumption is small, the resistance is low, and the demisting effect is good.

Description

Technical Field

[0001] The utility model relates to the field of chemical production, in particular to a device for treating ammonia-containing tail gas from urea fluidized bed granulation. Background Art

[0002] Urea fluidized bed granulation tail gas treatment is mainly divided into two forms: dry method and wet method. Dry method treatment technology can effectively recover solid dust in tail gas, but it cannot remove free ammonia in tail gas, resulting in waste of ammonia resources after tail gas is discharged. At the same time, the bag is easily affected by moisture and forms compaction, the bag replacement cycle is short, and the cost of consumables is high. Wet method treatment technology adopts reverse spray washing + folding plate demisting structure mode, with low washing efficiency, dust and ammonia emissions that do not meet the standards, poor demisting effect, and serious tailing phenomenon of tail gas. Therefore, seeking a technology that can reduce the dust content in granulation tail gas emissions and reduce the waste of ammonia resources is increasingly receiving attention. Utility Model Content

[0003] In order to solve the problems that the existing technology uses both dry and wet methods to treat the exhaust gas from urea fluidized bed granulation, ammonia resources cannot effectively remove free ammonia in the exhaust gas, emptying causes a waste of ammonia resources, the bags are easily affected by moisture and become compacted, the bag replacement cycle is short, the cost of consumables is high, the washing efficiency is low, the external dust and ammonia emissions do not meet the standards, the demisting effect is poor, and the exhaust tailing phenomenon is serious.

[0004] The technical means of the utility model is: a urea fluidized bed granulation ammonia tail gas treatment device, including an equipment body, the equipment body includes a wall plate, a top plate, and a bottom plate, forming a square working area, two partition plates are arranged in the equipment body, the two partition plates vertically divide the interior of the equipment body into three layers of upper, middle and lower layers, the upper and middle layers are respectively provided with segmented partition plates, and the segmented partition plates respectively divide each of the upper and middle layers into a rough washing section, a fine washing section and an ammonia recovery section in the horizontal direction;

[0005] The rough washing section is provided with a wire mesh assembly, a spray washing assembly is provided in front of the wire mesh assembly and a segmented partition is provided in the rear;

[0006] The fine washing section is provided with a packing assembly, a folding plate assembly is provided behind the packing assembly, a screen assembly is provided behind the folding plate assembly, a spray washing assembly is provided in front of the packing assembly, a spray washing assembly is provided between the folding plate assembly and the screen assembly, and a segmented partition is provided behind the screen assembly;

[0007] The ammonia recovery section is provided with a packing assembly, a folding plate assembly is provided behind the packing assembly, a wire mesh assembly is provided behind the folding plate assembly, a spray washing assembly is provided in front of the packing assembly, a spray washing assembly is provided between the folding plate assembly and the wire mesh assembly, and a segmented partition is provided behind the wire mesh assembly;

[0008] The lower layer is provided with a partition plate, which divides the lower layer horizontally into a high-concentration washing liquid tank, a clear liquid tank, and an ammonium sulfate solution collection tank;

[0009] A downcomer is also provided, the rough washing section is connected to the high-concentration washing liquid tank through the downcomer, the fine washing section is connected to the clear liquid tank through the downcomer; the ammonia recovery section is connected to the ammonium sulfate solution collection tank through the downcomer; and an exhaust gas outlet is provided at the rear end of the equipment body.

[0010] The tail gas outlet is in a square cone shape.

[0011] The packing components of the fine washing section and the ammonia recovery section are inclined by about 5 to 10 degrees.

[0012] The wire mesh assembly comprises a stainless steel wire mesh and supporting fixings thereof.

[0013] The spray washing component comprises a pipe and a spray head, and is in a tree-like shape.

[0014] The packing assembly includes stainless steel packing and a packing frame.

[0015] The folding plate assembly comprises a stainless steel double-bag folding plate and a folding plate box.

[0016] An inspection port with a viewing mirror is arranged on the equipment body.

[0017] The advantages of the fluidized bed granulation tail gas scrubber of the utility model are:

[0018] 1. Tail gas washing adopts segmented washing and absorption. Dirty water washes dirty gas, clean water washes clean gas, and finally dilute sulfuric acid recovers free ammonia and demisters it for discharge.

[0019] 2. The washing and absorption sections of the effective working area of ​​the equipment body are divided into two layers, which reduces the filling height of the filler and the wire mesh, avoids the spray liquid under the folding plate and the wire mesh from agglomerating into a water curtain, and prevents the damage of the filler and the wire mesh during use from causing tail gas deviation.

[0020] 3. The spray washing component is installed in front of the wire mesh and filler to prevent secondary mist entrainment.

[0021] 4. When the filler is tilted at a certain angle, it can ensure that the wetting liquid sprayed above the filler can still play a wetting role under the action of exhaust gas, forming a liquid film, with low water consumption and low resistance.

[0022] 5. The cross-sectional area of ​​the exhaust gas outlet is as large as possible, and the outlet is designed to be a square cone to avoid sudden changes in shape and cause air flow turbulence. At the same time, it ensures that the gas flowing through the filler, folding plate and wire mesh flows evenly to prevent the re-atomization of droplets on the folding plate surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of the utility model:

[0024] Description of reference numerals: 1. scrubber inlet; 2. spray scrubbing assembly; 3. screen assembly; 4. packing assembly; 5. folding plate assembly; 6. partition plate; 7. inspection port with sight glass; 8. partition plate; 9. segmented plate; 10. downcomer; 11. tail gas outlet; 12. high concentration washing liquid tank; 13. clear liquid tank; 14. ammonium sulfate solution collecting tank; DETAILED DESCRIPTION

[0025] like Figure 1 As shown: the utility model equipment mainly includes: a urea fluidized bed granulation ammonia tail gas treatment device, including an equipment body 1, the equipment body 1 includes a wall plate, a top plate, and a bottom plate, forming a square working area, two partition plates 6 are arranged in the equipment body 1, and the two partition plates 6 vertically divide the interior of the equipment body 1 into three layers of upper, middle and lower layers, and the upper and middle layers are respectively provided with segmented partition plates 9, and the segmented partition plates 9 respectively divide each of the upper and middle layers into a rough washing section, a fine washing section and an ammonia recovery section in a horizontal direction;

[0026] The rough washing section is provided with a screen assembly 3, a spray washing assembly 2 is provided in front of the screen assembly 3 and a segmented partition 9 is provided in the rear;

[0027] The fine washing section is provided with a packing assembly 4, a folding plate assembly 5 is provided behind the packing assembly 4, a screen assembly 3 is provided behind the folding plate assembly 5, a spray washing assembly 2 is provided in front of the packing assembly 4, a spray washing assembly 2 is provided between the folding plate assembly 5 and the screen assembly 3, and a segmented partition 9 is provided behind the screen assembly 3;

[0028] The ammonia recovery section is provided with a packing assembly 4, a folding plate assembly 5 is provided behind the packing assembly 4, a wire mesh assembly 3 is provided behind the folding plate assembly 5, a spray washing assembly 2 is provided in front of the packing assembly 4, a spray washing assembly 2 is provided between the folding plate assembly 5 and the wire mesh assembly 3, and a segmented partition 9 is provided behind the wire mesh assembly 3;

[0029] The lower layer is provided with a partition plate 8, and the partition plate 8 divides the lower layer horizontally into a high-concentration washing liquid tank 12, a clear liquid tank 13, and an ammonium sulfate solution collection tank 14;

[0030] A downcomer 10 is also provided, the rough washing section is connected to the high-concentration washing liquid tank 12 through the downcomer 10, the fine washing section is connected to the clear liquid tank 13 through the downcomer 10; the ammonia recovery section is connected to the ammonium sulfate solution collecting tank 14 through the downcomer 10; and an exhaust gas outlet 11 is provided at the rear end of the equipment body 1.

[0031] The exhaust gas outlet 11 is in a square cone shape.

[0032] The packing components 4 of the fine washing section and the ammonia recovery section are inclined at about 5 to 10 degrees.

[0033] The wire mesh assembly 3 includes a stainless steel wire mesh and supporting fixings thereof.

[0034] The spray washing assembly 2 includes pipes and spray heads, and is in a tree-like shape.

[0035] The packing assembly 4 includes a stainless steel packing and a packing frame.

[0036] The folding plate assembly 5 includes a stainless steel double-bag folding plate and a folding plate box.

[0037] The equipment body 1 is provided with an inspection port 7 with a viewing mirror.

[0038] During installation and use: the scrubber inlet 1 is located at the upper left of the main body. The exhaust gas enters the equipment from the inlet 1, and passes through the upper two layers of channels divided by the partition plate 6 welded to the equipment body. It passes through the wire mesh assembly 3, the filler assembly 4, and the folding plate assembly 5 fixed on the equipment body and the partition plate 6 in turn, meets the emission requirements, and flows out of the equipment through the exhaust gas outlet 11.

[0039] The spray washing component 2 is in the shape of a tree branch and is installed in front of the inlet pipe or the wire mesh component 3 and the filler component 4. It is connected to the equipment body or fixed to the inlet pipe. The nozzles are arranged equidistantly and the spray coverage area is required to be ≥150%.

[0040] The inspection port 7 with a sight glass is welded to the side plate of the equipment body and is used for observation during normal operation and installation and removal of components such as fillers and screens during shutdown and maintenance.

[0041] The partition plate 8 is located in the equipment body, and the bottom plate, the side plate and the partition plate 6 are welded to divide the lower layer of the equipment into a high-concentration washing liquid tank 12; a clear liquid tank 13; and an ammonium sulfate solution collection tank 14; three independent liquid storage spaces.

[0042] The segmented partition 9 is located in the upper and middle layers of the equipment body, welded with the side plates and the partition 6, with a height of 100-150mm, mainly to prevent the mixing of high-concentration washing liquid, clear liquid and ammonium sulfate solution.

[0043] Utility Model Effect

[0044] 1. The tail gas is washed and absorbed in sections. The tail gas flows into the high-concentration washing liquid tank 12, the clear liquid tank 13, and the ammonium sulfate solution collection tank 14 through the downcomer to avoid mixing of different washing liquids.

[0045] 2. The washing and absorption sections of the effective working area of ​​the equipment body 1 are divided into two layers to reduce the filling height of the filler and the wire mesh, avoid the spray liquid under the folding plate and the wire mesh from agglomerating into a water curtain, and prevent the filler and the wire mesh from being damaged during use and causing tail gas deviation.

[0046] 3. The spray washing component is installed in front of the wire mesh and filler to prevent secondary mist entrainment.

[0047] 4. When the filler is tilted at a certain angle, it can ensure that the wetting liquid sprayed from the top of the filler can still play a wetting role under the action of the exhaust gas, with less water consumption and low resistance.

[0048] 5. The cross-sectional area of ​​the tail gas outlet 11 is as large as possible, and the outlet is designed to be square cone to avoid sudden changes in shape and cause air flow turbulence. At the same time, it ensures that the gas flowing through the filler, folding plate and wire mesh flows evenly to prevent the re-atomization of droplets on the folding plate surface.

Claims

1. A urea fluidized bed granulation ammonia tail gas treatment device, comprising an equipment body (1), wherein the equipment body (1) comprises a wall plate, a top plate, and a bottom plate, forming a square working area, characterized in that: Two partition plates (6) are arranged in the equipment body (1), and the two partition plates (6) vertically divide the interior of the equipment body (1) into three layers, namely, an upper, middle and lower layer. The upper and middle layers are respectively provided with segmented partition plates (9), and the segmented partition plates (9) respectively divide each of the upper and middle layers into a rough washing section, a fine washing section and an ammonia recovery section in the horizontal direction; The rough washing section is provided with a wire mesh assembly (3), a spray washing assembly (2) is provided in front of the wire mesh assembly (3) and a segmented partition plate (9) is provided in the rear; The fine washing section is provided with a packing assembly (4), a folding plate assembly (5) is provided behind the packing assembly (4), a screen assembly (3) is provided behind the folding plate assembly (5), a spray washing assembly (2) is provided in front of the packing assembly (4), a spray washing assembly (2) is provided between the folding plate assembly (5) and the screen assembly (3), and a segmented partition (9) is provided behind the screen assembly (3); The ammonia recovery section is provided with a packing assembly (4), a folding plate assembly (5) is provided behind the packing assembly (4), a wire mesh assembly (3) is provided behind the folding plate assembly (5), a spray washing assembly (2) is provided in front of the packing assembly (4), a spray washing assembly (2) is provided between the folding plate assembly (5) and the wire mesh assembly (3), and a segmented partition (9) is provided behind the wire mesh assembly (3); The lower layer is provided with a partitioning partition (8), and the partitioning partition (8) divides the lower layer into a high-concentration washing liquid tank (12), a clear liquid tank (13), and an ammonium sulfate solution collecting tank (14) in the horizontal direction; a downcomer (10) is also provided, and the rough washing section is connected to the high-concentration washing liquid tank (12) through the downcomer (10), and the fine washing section is connected to the clear liquid tank (13) through the downcomer (10); the ammonia recovery section is connected to the ammonium sulfate solution collecting tank (14) through the downcomer (10); and an exhaust gas outlet (11) is provided at the rear end of the equipment body (1).

2. A urea fluidized bed granulation ammonia-containing tail gas treatment device as claimed in claim 1, characterized in that: The tail gas outlet (11) is in the shape of a square cone.

3. A urea fluidized bed granulation ammonia-containing tail gas treatment device as claimed in claim 1, characterized in that: The packing components (4) of the fine washing section and the ammonia recovery section are inclined at about 5 to 10 degrees.

4. A urea fluidized bed granulation ammonia-containing tail gas treatment device as claimed in claim 1, characterized in that: The wire mesh assembly (3) comprises a stainless steel wire mesh and supporting fixings thereof.

5. The device for treating ammonia-containing tail gas from urea fluidized bed granulation as claimed in claim 1, characterized in that: The spray washing component (2) comprises a pipe and a spray head, and is in a tree-like shape.

6. The device for treating ammonia-containing tail gas from urea fluidized bed granulation as claimed in claim 1, characterized in that: The packing assembly (4) comprises a stainless steel packing and a packing frame.

7. A urea fluidized bed granulation ammonia-containing tail gas treatment device as claimed in claim 1, characterized in that: The folding plate assembly (5) comprises a stainless steel double-bag folding plate and a folding plate box.

8. The device for treating ammonia-containing tail gas from urea fluidized bed granulation as claimed in claim 1, characterized in that: The equipment body (1) is provided with an inspection port (7) with a viewing mirror.

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