Roller kiln tail gas treatment device

Abstract

The utility model discloses a roller kiln tail gas treatment device which comprises a primary tail gas purification unit, a secondary tail gas purification unit, a tail gas purification unit and a tail gas purification unit, wherein a gas inlet of the primary tail gas purification unit is communicated with a roller kiln tail gas exhaust pipe; a gas inlet of the ammonia gas absorption unit is communicated with a gas outlet pipeline of the tail gas preliminary purification unit, and a purified gas exhaust port is formed in the ammonia gas absorption unit; the absorption liquid circulating unit comprises an absorption liquid storage tank, and the absorption liquid storage tank is respectively communicated with the liquid inlet and the liquid outlet of the ammonia gas absorption unit through pipelines; the solid-liquid separation and recovery unit comprises a cooling crystallization separation part and a mother liquor tank which are communicated through a pipeline, the cooling crystallization separation part is communicated with the absorption liquid storage tank through a pipeline, and the mother liquor tank is communicated with the absorption liquid storage tank through a pipeline. The waste of resources is avoided, the recycling of ammonia gas is realized, the energy consumption is reduced, and the production cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of tail gas recovery and utilization, in particular to a roller kiln tail gas treatment device. Background Art

[0002] The chemical industry has been in a state of rapid development in the past few decades. In recent years, the chemical industry has been advocating green, energy-saving and sustainable production.

[0003] In the process of using traditional roller kilns to calcine ammonium metavanadate to produce vanadium pentoxide, a large amount of ammonia, water vapor and other waste gases are generated. Previously, these tail gases were generally discharged directly as tail gas or treated as waste after preliminary purification. This not only polluted the environment to a certain extent, but also wasted a large amount of recyclable ammonia resources.

[0004] At present, the ammonia in the production tail gas is generally directly absorbed by sulfuric acid solution. After the absorption reaches saturation, the mixed liquid is evaporated and dried to obtain the final product ammonium sulfate crystals. This method has the following problems: incomplete absorption of ammonia, resulting in a waste of some resources; high energy consumption, for example, a large amount of heat energy is consumed during evaporation and drying; high sulfuric acid consumption; high cost. Utility Model Content

[0005] In order to solve the above technical problems, the embodiment of the utility model proposes a roller kiln tail gas treatment device, which can solve at least one of the technical problems of incomplete ammonia absorption resulting in waste of resources, high energy consumption and high cost in the existing technology of using sulfuric acid solution to absorb ammonia in roller kiln tail gas to obtain ammonium sulfate product.

[0006] The utility model discloses a roller kiln tail gas treatment device, which comprises:

[0007] An exhaust gas preliminary purification unit, wherein the air inlet of the exhaust gas preliminary purification unit is connected to the roller kiln exhaust pipe;

[0008] an ammonia absorption unit, wherein the air inlet of the ammonia absorption unit is connected to the air outlet pipeline of the tail gas preliminary purification unit, and the ammonia absorption unit is provided with a purified gas discharge port;

[0009] An absorption liquid circulation unit, the absorption liquid circulation unit comprising an absorption liquid storage tank, the absorption liquid storage tank being respectively connected to the liquid inlet and liquid outlet pipelines of the ammonia absorption unit;

[0010] A solid-liquid separation and recovery unit, the solid-liquid separation and recovery unit comprises a cooling crystallization separation part and a mother liquor tank connected by a pipeline, the cooling crystallization separation part is connected to the absorption liquid storage tank pipeline, and the mother liquor tank is connected to the absorption liquid storage tank pipeline.

[0011] According to one embodiment of the utility model, the exhaust gas preliminary purification unit includes an S-shaped centrifugal air duct, a spray dust removal tower and a circulating water clarification tank. The inlet of the S-shaped centrifugal air duct is connected to the roller kiln exhaust pipe, the outlet of the S-shaped centrifugal air duct is connected to the lower air inlet pipe of the spray dust removal tower, the upper air outlet of the spray dust removal tower is connected to the air inlet pipe of the ammonia absorption unit, and the upper liquid inlet and bottom liquid outlet of the spray dust removal tower are respectively connected to the circulating water clarification tank pipe.

[0012] According to an embodiment of the utility model, it further comprises: a filter, wherein the filter is connected to the drainage pump pipeline of the circulating water clarification tank, and the bottom of the filter is connected to the circulating water tank pipeline.

[0013] According to one embodiment of the utility model, the liquid outlet at the bottom end of the spray dust removal tower is connected to the circulating water clarification tank through a first pipe, the liquid inlet at the top of the spray dust removal tower is connected to the water outlet pump of the circulating water clarification tank through a second pipe, a first regulating valve is arranged on the second pipe, a first flow meter is arranged on the pipeline connecting the air inlet of the spray dust removal tower and the outlet of the S-shaped centrifugal air duct, the roller kiln exhaust gas treatment device also includes a controller, and the first flow meter, the first regulating valve and the water outlet pump of the circulating water clarification tank are all communicatively connected to the controller.

[0014] According to one embodiment of the utility model, the ammonia absorption unit includes an ammonia absorption tower, the lower air inlet of the ammonia absorption tower is connected to the air outlet pipeline of the spray dust removal tower, the bottom of the ammonia absorption tower is provided with a liquid outlet, the upper part of the ammonia absorption tower is provided with a liquid inlet, and the top of the ammonia absorption tower is provided with the purified gas discharge outlet.

[0015] According to one embodiment of the utility model, the absorption liquid storage tank is connected to the bottom liquid outlet of the ammonia absorption tower through a third pipeline, the liquid outlet pump of the absorption liquid storage tank is connected to the upper liquid inlet of the ammonia absorption tower through a fourth pipeline, and a second regulating valve and a second flow meter are arranged on the fourth pipeline, and the second regulating valve is located between the liquid outlet pump of the absorption liquid storage tank and the second flow meter, and the roller kiln tail gas treatment device also includes a controller, and the second flow meter, the second regulating valve, and the liquid outlet pump of the absorption liquid storage tank are all communicatively connected to the controller.

[0016] According to one embodiment of the utility model, it also includes: a sulfuric acid supply tank, the feeding pump of the sulfuric acid supply tank is connected to the absorption liquid storage tank through a fifth pipeline, a third regulating valve and a third flow meter are arranged on the fifth pipeline, the third regulating valve is located between the feeding pump of the sulfuric acid supply tank and the third flow meter, the roller kiln tail gas treatment device also includes a controller, and the third flow meter, the third regulating valve, and the feeding pump of the sulfuric acid supply tank are all communicatively connected to the controller.

[0017] According to one embodiment of the utility model, the cooling crystallization separation part includes a crystallizer and a centrifuge connected by a pipeline, the crystallizer is connected to the liquid outlet pump pipeline of the absorption liquid storage tank, a switching valve is arranged on the pipeline connecting the liquid outlet pump of the absorption liquid storage tank and the crystallizer, and the centrifuge is respectively connected to the crystallizer and the mother liquid tank pipeline.

[0018] According to one embodiment of the utility model, the crystallizer is equipped with a cooling circulation component, and the cooling circulation component includes a cooling water jacket, a circulating cooling water tank and a cooling tower. The cooling water jacket is arranged outside the crystallizer, the inlet pipe of the cooling water jacket is connected to the outlet pump of the circulating cooling water tank, the outlet pipe of the cooling water jacket is connected to the cooling tower, and the outlet pipe of the cooling tower is connected to the circulating cooling water tank.

[0019] According to one embodiment of the utility model, a safety valve is provided on the top of the spray dust removal tower and / or the ammonia absorption tower.

[0020] By adopting the above technical solution, the utility model has at least the following beneficial effects:

[0021] The roller kiln tail gas treatment device provided by the utility model passes the mixed gas after preliminary purification into an ammonia absorption unit, in the ammonia absorption unit, ammonia in the mixed gas is absorbed by the sulfuric acid solution entering the ammonia absorption unit and reacts to generate ammonium sulfate, and then the absorption liquid that has absorbed ammonia flows out of the ammonia absorption unit and enters the absorption liquid storage tank again, and then the absorption liquid circulates into the ammonia absorption unit again to further absorb ammonia in the mixed gas, thereby realizing that the sulfuric acid solution in the absorption liquid storage tank continuously circulates into the ammonia absorption unit and continuously absorbs ammonia, and the circulation of the absorption liquid can be stopped when it is detected that the concentration of ammonium sulfate in the absorption liquid storage tank reaches a predetermined value; then the absorption liquid in the absorption liquid storage tank enters the solid-liquid separation and recovery unit for cooling, crystallization and separation, and the mother liquor after separation is a balanced electrolyte solution of sulfuric acid-ammonium sulfate, and the mother liquor can further enter the absorption liquid storage tank and be used for absorbing ammonia in the tail gas again.

[0022] The roller kiln tail gas treatment device provided by the utility model realizes the purification treatment of the roller kiln tail gas and ensures the full absorption of ammonia in the roller kiln tail gas, greatly avoids the waste of resources and realizes the recycling of ammonia; the mother liquor after the absorption liquid crystallizes can be further used for the absorption of ammonia, reduces the amount of sulfuric acid used and saves energy consumption; the ammonium sulfate product and the mother liquor are obtained by cooling crystallization separation, greatly reduces energy consumption and further reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 The present invention is a schematic diagram of the pipeline instrumentation flow structure of a roller kiln tail gas treatment device disclosed in one embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0026] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are for distinguishing two non-identical entities with the same name or non-identical parameters. It can be seen that "first" and "second" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. The subsequent embodiments will not explain this one by one.

[0027] In the following description, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the utility model.

[0028] like Figure 1 As shown, an embodiment of the utility model discloses a roller kiln tail gas treatment device, which includes:

[0029] A tail gas preliminary purification unit 10, wherein the air inlet of the tail gas preliminary purification unit 10 is connected to the roller kiln tail gas exhaust pipe;

[0030] An ammonia absorption unit 20, wherein the air inlet of the ammonia absorption unit 20 is connected to the air outlet pipeline of the tail gas preliminary purification unit 10, and a purified gas outlet 25 is provided on the ammonia absorption unit;

[0031] The absorption liquid circulation unit 30 includes an absorption liquid storage tank 31, and the absorption liquid storage tank 31 is connected to the liquid inlet and liquid outlet pipelines of the ammonia absorption unit 20 respectively;

[0032] The solid-liquid separation and recovery unit 40 includes a cooling crystallization separation section 41 and a mother liquid tank 44 connected by a pipeline. The cooling crystallization separation section 41 is connected to the absorption liquid storage tank 31 by a pipeline, and the mother liquid tank 44 is connected to the absorption liquid storage tank 31 by a pipeline.

[0033] The roller kiln tail gas treatment device disclosed in the embodiment of the utility model realizes the purification treatment of the roller kiln tail gas by circulating the absorption liquid for absorbing ammonia in the tail gas, and finally cools, crystallizes and separates, and further uses the separated mother liquor for absorbing ammonia, thereby ensuring the full absorption of ammonia in the roller kiln tail gas, greatly avoiding the waste of resources, and realizing the recycling of ammonia; the mother liquor after the absorption liquid is crystallized can be further used for absorbing ammonia, reducing the amount of sulfuric acid used and saving energy consumption; in addition, the ammonium sulfate product and the mother liquor are obtained through cooling, crystallization and separation, realizing waste utilization, greatly reducing energy consumption and reducing production costs.

[0034] In some embodiments, the size and material of the mother liquid tank 42 are: volume V=10m³, ø2500mm×H2500mm, wall thickness 6mm, material 316L.

[0035] In some embodiments, the exhaust gas preliminary purification unit 10 includes an S-shaped centrifugal air duct 11 and a spray dust removal tower 12, the inlet of the S-shaped centrifugal air duct 11 is connected to the roller kiln exhaust gas exhaust pipe L, the outlet of the S-shaped centrifugal air duct 11 is connected to the lower air inlet 13 pipeline of the spray dust removal tower 12, the upper air outlet 14 of the spray dust removal tower 12 is connected to the air inlet pipeline of the ammonia absorption unit 20, and the upper liquid inlet 16 and the bottom liquid outlet 15 of the spray dust removal tower 12 are respectively connected to the circulating water clarification tank 17 pipeline.

[0036] In the above embodiment, the tail gas of the roller kiln passes through the S-shaped centrifugal duct 11. Since the dust particles (containing ammonium metavanadate) in the tail gas are coated by droplets, the mass and volume will increase several times, the inertia will increase, and the movement trajectory of the dust particles in the air flow will also become smooth and regular; after the tail gas of the roller kiln enters the S-shaped centrifugal duct, the flow rate will suddenly drop, and the gas will continue to flow forward under the action of the centrifugal fan, while the dust particles will enter the bottom of the box body along the bend due to inertia and centrifugal force, and finally settle in the mud bucket. In this process, most of the dust particles will be processed and gas-liquid separation will be achieved. The mixed gas enters the spray dust removal tower 12 and achieves the purpose of further water washing and dust removal through the water flowing from top to bottom, thereby obtaining a relatively pure mixed gas, which is conducive to reducing other impurities in the tail gas, such as ammonium metavanadate, from entering the absorption liquid and affecting the quality of the ammonium sulfate product obtained by the reaction of ammonia and sulfuric acid.

[0037] In some embodiments, the size and material of the spray dust removal tower 12 are: tower diameter: DN700H15000mm (including skirt); internal parts form: high-efficiency filler; filler height: 3m; material: tower body is FRP, internal parts are 316L.

[0038] In some embodiments, the roller kiln tail gas treatment device further includes: a filter 18, the filter 18 is connected to the drainage pump P5 pipeline of the circulating water clarification tank 17, and the bottom of the filter 18 is connected to the pipeline of the circulating water clarification tank 17. In this embodiment, the filter 18 can remove solid impurities in the circulating water, ensure the cleanliness of the circulating water entering the spray dust removal tower, and avoid the circulating water in the circulating water clarification tank 17 from increasing turbidity due to long-term water washing and dust removal of the tail gas, thereby affecting the effect of water washing and dust removal and affecting the transportation capacity of the pipeline.

[0039] In some embodiments, the liquid outlet 15 at the bottom end of the spray dust removal tower 12 is connected to the circulating water clarification tank 17 through a first pipe 51, and the liquid inlet 16 at the top of the spray dust removal tower 12 is connected to the water outlet pump P1 of the circulating water clarification tank 17 through a second pipe 52. A first regulating valve 53 is arranged on the second pipe 52, and a first flow meter 54 is arranged on the pipeline connecting the air inlet 13 of the spray dust removal tower 12 and the outlet of the S-shaped centrifugal air duct 11. The roller kiln exhaust gas treatment device also includes a controller, and the first flow meter 54, the first regulating valve 53 and the water outlet pump P1 of the circulating water clarification tank 17 are all communicatively connected to the controller.

[0040] In the above embodiment, the flow rate of the mixed gas is detected by setting a first flow meter, and the first flow meter is communicated with the controller. The first flow meter feeds back information of the detected flow rate of the mixed gas to the controller, and the controller controls the degree of opening of the first regulating valve according to the feedback information to adjust the spraying amount of circulating water entering the spray dust removal tower; at the same time, the controller will also control the outlet pump of the circulating water clarification tank according to the feedback information to appropriately adjust the speed of the impeller to ensure the outflow of circulating water.

[0041] In some embodiments, the ammonia absorption unit 20 includes an ammonia absorption tower 21, the lower air inlet 22 of the ammonia absorption tower 21 is connected to the air outlet 16 of the spray dust removal tower 12 by a pipeline, the bottom of the ammonia absorption tower 21 is provided with a liquid outlet 24, the upper part of the ammonia absorption tower 21 is provided with a liquid inlet 23, and the top of the ammonia absorption tower 21 is provided with a purified gas outlet 25. In this embodiment, by providing the ammonia absorption tower 21 and allowing the mixed gas to enter from the lower air inlet 22 of the ammonia absorption tower 21, the mixed gas moves from bottom to top in the ammonia absorption tower 21, and the absorption liquid enters from the upper liquid inlet 23 of the ammonia absorption tower 21 and flows downward, which ensures that the mixed gas fully contacts and reacts with the absorption liquid entering the ammonia absorption tower 21, which is conducive to achieving full absorption of ammonia in the roller kiln tail gas and effectively avoiding waste of resources.

[0042] In some embodiments, the size and material of the ammonia absorption tower 21 are: tower diameter: DN800 / 600 H18000mm (including skirt); internal parts form: high-efficiency packing; packing height: 9m; material: tower body and internal parts are 316L.

[0043] In some embodiments, the absorption liquid storage tank 31 is connected to the bottom liquid outlet 24 of the ammonia absorption tower 21 through a third pipe 32, and the liquid outlet pump P2 of the absorption liquid storage tank 31 is connected to the upper liquid inlet 23 of the ammonia absorption tower 21 through a fourth pipe 33. A second regulating valve 35 and a second flow meter 34 are provided on the fourth pipe 33. The second regulating valve 35 is located between the liquid outlet pump P2 of the absorption liquid storage tank 31 and the second flow meter 34. The roller kiln tail gas treatment device also includes a controller, and the second flow meter 34, the second regulating valve 35, and the liquid outlet pump P2 of the absorption liquid storage tank 31 are all communicatively connected to the controller.

[0044] In the above embodiment, a second regulating valve 35 and a second flow meter 34 are arranged on the pipeline between the absorption liquid storage tank 31 and the ammonia absorption tower 21, and the flow rate of the absorption liquid entering the ammonia absorption tower 21 is detected by the second flow meter 34, and then the second flow meter 34 feeds back information to the controller, and the controller controls the degree of opening of the second regulating valve 35 according to the feedback information; at the same time, the controller also controls the liquid outlet pump P2 of the absorption liquid storage tank 31 according to the feedback information to adjust the rotation speed of the liquid outlet pump P2, so as to ensure the outflow amount of the absorption liquid.

[0045] In the embodiment of the utility model, sampling can be carried out from the absorption liquid storage tank 31 for chemical experimental analysis to determine the concentration of ammonium sulfate in the absorption liquid storage tank 31, and the flow rate of the absorption liquid entering the ammonia absorption tower 21 and the number of circulations of the absorption liquid can be controlled according to the concentration of ammonium sulfate in the absorption liquid storage tank 31.

[0046] In some embodiments, the roller kiln tail gas treatment device also includes: a sulfuric acid supply tank 60, a feeding pump (not shown in the drawings) of the sulfuric acid supply tank 60 is connected to the absorption liquid storage tank 31 through a fifth pipeline 61, and a third regulating valve 62 and a third flow meter 63 are arranged on the fifth pipeline 61, and the third regulating valve 62 is located between the feeding pump of the sulfuric acid supply tank 60 and the third flow meter 62. The roller kiln tail gas treatment device also includes a controller, and the third flow meter 62, the third regulating valve 63, and the feeding pump of the sulfuric acid supply tank 60 are all communicatively connected to the controller.

[0047] In the above embodiment, by setting the sulfuric acid supply tank 60 and the third regulating valve 63 and the third flowmeter 62 arranged on the fifth pipeline 61, the third flowmeter 62 feeds back information to the controller according to the detected sulfuric acid flow rate, and according to the control of the controller, adjusts the opening and closing degree of the third regulating valve 63 and the speed of the impeller of the feeding pump of the sulfuric acid supply tank 60, thereby facilitating the control of the amount of sulfuric acid added to the absorption liquid storage tank 31, and is beneficial to adjust and control the amount of sulfuric acid added according to the ammonia content in the roller kiln tail gas, thereby facilitating the rational use of sulfuric acid and avoiding waste of resources.

[0048] In some embodiments, the cooling crystallization separation section 41 includes a crystallizer 42 and a centrifuge 43 connected by a pipeline, the crystallizer 42 is connected to the outlet pump P2 of the absorption liquid storage tank 31 by a pipeline, a switching valve 45 is arranged on the pipeline connecting the outlet pump P2 of the absorption liquid storage tank 31 and the crystallizer 42, and the centrifuge 43 is connected to the crystallizer 42 and the mother liquor tank 44 by pipelines. In this embodiment, the crystallizer 42 is conducive to the full precipitation of ammonium sulfate crystals in the absorption liquid, thereby improving the yield of the obtained ammonium sulfate product; the absorption liquid after the crystals are precipitated is then fully separated by the centrifuge 43 to obtain sulfuric acid-ammonium sulfate mother liquor and ammonium sulfate product respectively, and the sulfuric acid-ammonium sulfate mother liquor can further enter the absorption liquid storage tank 31 and be used again for the absorption of ammonia in the tail gas, which is conducive to greatly reducing energy consumption and production costs.

[0049] In some embodiments, the crystallizer 42 is equipped with a cooling circulation assembly, which includes a cooling water jacket, a circulating cooling water tank 71 and a cooling tower 72. The cooling water jacket is arranged outside the crystallizer 42, and the inflow pipe 73 of the cooling water jacket is connected to the outlet pump P3 of the circulating cooling water tank 71, and the outflow pipe 74 of the cooling water jacket is connected to the cooling tower 72, and the outlet pipe of the cooling tower 72 is connected to the circulating cooling water tank 71. Cooling the crystallizer 42 by cooling the circulating water further ensures that the ammonium sulfate crystals in the absorption liquid are fully separated, which is conducive to improving the yield of ammonium sulfate.

[0050] In some embodiments, a safety valve 50 is provided at the top of the spray dust removal tower 12 and / or the ammonia absorption tower 21. In this embodiment, the safety valve 50 is provided at the top of the spray dust removal tower 12 and the ammonia absorption tower 21, so that once the pressure in the spray dust removal tower 12 and the ammonia absorption tower 21 exceeds the critical threshold and the degassing valve is not opened, the safety valve 50 can be opened for emergency pressure relief, effectively preventing the pressure in the spray dust removal tower 12 and the ammonia absorption tower 21 from exceeding the standard.

[0051] The working principle of the roller kiln tail gas treatment device disclosed in one embodiment of the utility model is as follows:

[0052] The tail gas of the roller kiln is introduced into the S-shaped centrifugal air duct 11, and the dust particles and droplets in the tail gas are first removed, and then the mixed gas enters the spray dust removal tower 12. The water in the circulating water clarification tank 16 enters the spray dust removal tower 12 and flows from top to bottom to contact the mixed gas to further wash and remove dust from the mixed gas; the mixed gas after preliminary purification enters the ammonia absorption tower 21, and in the ammonia absorption tower 21, the ammonia in the mixed gas is absorbed by the sulfuric acid solution entering the ammonia absorption tower 21 and reacts to generate ammonium sulfate. The absorption liquid that absorbs the ammonia flows out and enters the absorption liquid storage tank 31 again, and is circulated into the ammonia absorption tower 21 again under the action of the liquid outlet pump P2 of the absorption liquid storage tank 31 to further absorb the mixed gas. The ammonia in the combined gas is circulated several times in this way until the concentration of ammonium sulfate in the absorption liquid storage tank 31 is detected to reach about 85% of the ammonia content in the initial tail gas discharged from the roller kiln tail gas exhaust pipe L, and the circulation of the absorption liquid is stopped; then the second regulating valve 35 is closed and the switching valve 45 is opened to discharge the absorption liquid in the absorption liquid storage tank 31 into the crystallizer 42 for cooling and crystallization, and then discharged into the centrifuge 43 for solid-liquid separation after crystallization, and ammonium sulfate product and sulfuric acid-ammonium sulfate mother liquor are obtained after centrifugation; the ammonium sulfate product after centrifugation enters the dryer 46 for drying treatment to finally obtain the ammonium sulfate product, and the sulfuric acid-ammonium sulfate mother liquor enters the mother liquor tank 44 and the absorption liquid storage tank 31 respectively for the recovery of ammonia in the tail gas.

[0053] In summary, the roller kiln tail gas treatment device disclosed in the embodiment of the utility model realizes the purification treatment of the roller kiln tail gas by circulating the absorption liquid to absorb ammonia in the tail gas, and finally cools, crystallizes, separates, and further uses the separated mother liquor for absorbing ammonia, thereby ensuring the full absorption of ammonia in the roller kiln tail gas, greatly avoiding the waste of resources, and realizing the recycling of ammonia; the mother liquor after the absorption liquid is crystallized can be further used for the absorption of ammonia, reducing the amount of sulfuric acid used and saving energy consumption; in addition, the ammonium sulfate product and the mother liquor are obtained by cooling, crystallizing and separating, which greatly reduces energy consumption and further reduces production costs.

[0054] It should be pointed out in particular that the various components or steps in the above-mentioned embodiments can be cross-linked, replaced, added, or deleted with each other. Therefore, the combinations formed by these reasonable arrangements and combinations should also fall within the scope of protection of the present utility model, and the scope of protection of the present utility model should not be limited to the embodiments.

[0055] The above are exemplary embodiments disclosed by the present utility model. The order in which the above embodiments are disclosed is for description only and does not represent the advantages and disadvantages of the embodiments. However, it should be noted that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope disclosed by the embodiments of the present utility model (including the claims) is limited to these examples. Various changes and modifications may be made without departing from the scope defined by the claims. In addition, although the elements disclosed in the embodiments of the present utility model may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0056] Those skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present utility model (including the claims) is limited to these examples; under the idea of ​​the embodiments of the present utility model, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present utility model as described above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present utility model should be included in the protection scope of the embodiments of the present utility model.

Claims

1. A roller kiln tail gas treatment device, characterized in that: include: An exhaust gas preliminary purification unit, wherein the air inlet of the exhaust gas preliminary purification unit is connected to the roller kiln exhaust pipe; an ammonia absorption unit, wherein the air inlet of the ammonia absorption unit is connected to the air outlet pipeline of the tail gas preliminary purification unit, and the ammonia absorption unit is provided with a purified gas discharge port; An absorption liquid circulation unit, the absorption liquid circulation unit comprising an absorption liquid storage tank, the absorption liquid storage tank being respectively connected to the liquid inlet and liquid outlet pipelines of the ammonia absorption unit; A solid-liquid separation and recovery unit, the solid-liquid separation and recovery unit comprises a cooling crystallization separation part and a mother liquor tank connected by a pipeline, the cooling crystallization separation part is connected to the absorption liquid storage tank pipeline, and the mother liquor tank is connected to the absorption liquid storage tank pipeline.

2. The roller kiln tail gas treatment device according to claim 1, characterized in that: The exhaust gas preliminary purification unit includes an S-shaped centrifugal air duct, a spray dust removal tower and a circulating water clarification tank. The inlet of the S-shaped centrifugal air duct is connected to the roller kiln exhaust pipe of the exhaust gas, the outlet of the S-shaped centrifugal air duct is connected to the lower air inlet pipeline of the spray dust removal tower, the upper air outlet of the spray dust removal tower is connected to the air inlet pipeline of the ammonia absorption unit, and the upper liquid inlet and bottom liquid outlet of the spray dust removal tower are respectively connected to the circulating water clarification tank pipeline.

3. The roller kiln tail gas treatment device according to claim 2, characterized in that: Also includes: A filter is connected to the drainage pump pipeline of the circulating water clarification tank, and the bottom of the filter is connected to the circulating water tank pipeline.

4. The roller kiln tail gas treatment device according to claim 2, characterized in that: The liquid outlet at the bottom end of the spray dust removal tower is connected to the circulating water clarification tank through a first pipe, the liquid inlet at the top of the spray dust removal tower is connected to the water outlet pump of the circulating water clarification tank through a second pipe, a first regulating valve is arranged on the second pipe, a first flow meter is arranged on the pipeline connecting the air inlet of the spray dust removal tower and the outlet of the S-shaped centrifugal air duct, the roller kiln tail gas treatment device also includes a controller, and the first flow meter, the first regulating valve and the water outlet pump of the circulating water clarification tank are all communicatively connected to the controller.

5. The roller kiln tail gas treatment device according to claim 2, characterized in that: The ammonia absorption unit comprises an ammonia absorption tower, the lower air inlet of the ammonia absorption tower is connected to the air outlet pipeline of the spray dust removal tower, the bottom of the ammonia absorption tower is provided with a liquid outlet, the upper part of the ammonia absorption tower is provided with a liquid inlet, and the top of the ammonia absorption tower is provided with the purified gas discharge outlet.

6. The roller kiln tail gas treatment device according to claim 5, characterized in that: The absorption liquid storage tank is connected to the bottom liquid outlet of the ammonia absorption tower through a third pipeline, and the liquid outlet pump of the absorption liquid storage tank is connected to the upper liquid inlet of the ammonia absorption tower through a fourth pipeline. A second regulating valve and a second flow meter are arranged on the fourth pipeline, and the second regulating valve is located between the liquid outlet pump of the absorption liquid storage tank and the second flow meter. The roller kiln tail gas treatment device also includes a controller, and the second flow meter, the second regulating valve, and the liquid outlet pump of the absorption liquid storage tank are all communicatively connected to the controller.

7. The roller kiln tail gas treatment device according to claim 1, characterized in that: Also includes: A sulfuric acid supply tank, a feeding pump of the sulfuric acid supply tank is connected to the absorption liquid storage tank through a fifth pipeline, a third regulating valve and a third flow meter are arranged on the fifth pipeline, the third regulating valve is located between the feeding pump of the sulfuric acid supply tank and the third flow meter, the roller kiln tail gas treatment device also includes a controller, and the third flow meter, the third regulating valve, and the feeding pump of the sulfuric acid supply tank are all connected to the controller for communication.

8. The roller kiln tail gas treatment device according to claim 1, characterized in that: The cooling crystallization separation section includes a crystallizer and a centrifuge connected by a pipeline. The crystallizer is connected to the outlet pump pipeline of the absorption liquid storage tank. A switching valve is provided on the pipeline connecting the outlet pump of the absorption liquid storage tank and the crystallizer. The centrifuge is respectively connected to the crystallizer and the mother liquid tank pipeline.

9. The roller kiln tail gas treatment device according to claim 8, characterized in that: The crystallizer is equipped with a cooling circulation component, which includes a cooling water jacket, a circulating cooling water tank and a cooling tower. The cooling water jacket is arranged outside the crystallizer, the inlet pipe of the cooling water jacket is connected to the outlet pump of the circulating cooling water tank, the outlet pipe of the cooling water jacket is connected to the cooling tower, and the outlet pipe of the cooling tower is connected to the circulating cooling water tank.

10. The roller kiln tail gas treatment device according to claim 6, characterized in that: A safety valve is provided on the top of the spray dust removal tower and / or the ammonia absorption tower.

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