Cement kiln SCR (Selective Catalytic Reduction) reactor
By setting a flow guiding component and a gradient porosity design at the air inlet of the SCR reactor in a cement kiln, the problems of catalyst wear and ash accumulation were solved, and the denitrification efficiency and the sufficiency of the catalytic reaction were improved.
Patent Information
- Application Number
- CN202423274075.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2034-12-27
AI Technical Summary
Existing SCR reactors in cement kilns are prone to catalyst wear and blockage under high temperature and high dust conditions, resulting in low denitrification efficiency.
A flow guiding assembly, including a flow guide plate, a flow guide grid, and a perforated plate, is installed at the inlet end of the reactor. Through gradient porosity design and flow straightening grid, the flue gas velocity and flow direction are controlled, the impact force of dust particles on the catalyst is reduced, and the contact time between the flue gas and the catalyst is increased.
It effectively reduces catalyst wear, prevents reactor ash accumulation, and improves denitrification efficiency and the completeness of catalytic reaction.
Smart Images
Figure CN223716827U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to cement industry SCR reactor flue gas denitration technical field especially, a kind of cement kiln SCR reactor. BACKGROUND
[0002] Cement kiln SCR (selective catalytic reduction) reactor is a kind of equipment for reducing cement kiln nitrogen oxide (NOx) emissions. In the process of cement production, a large amount of NOx will be produced in kiln, which is a major atmospheric pollutant. The working principle of SCR reactor is that, under the action of catalyst, reducing agent (such as ammonia) is sprayed, so that NOx reacts with reducing agent, and is converted into nitrogen and water, thereby reducing the emission of NOx.
[0003] At present, the arrangement of cement kiln SCR reactor in China mainly has four forms, which are high-temperature high-dust, high-temperature medium-dust, medium-temperature medium-dust and low-temperature low-dust. High-temperature high-dust and medium-temperature medium-dust arrangement are most widely used, and the flue gas temperature of high-temperature high-dust is 280-400℃, and the flue gas dust content is extremely high, which is easy to cause problems such as catalyst wear and blockage. UTILITY MODEL CONTENT
[0004] The purpose of the utility model is to provide a kind of cement kiln SCR reactor, by the flow guide assembly of uniform flow field being arranged at the air inlet end of reactor body, in particular, the structure that the multi-hole plate is set to high porosity in the middle and low porosity around, the flow velocity is relatively moderate when middle flue gas passes, the impact force of dust particles in flue gas on catalyst is reduced, so as to reduce the wear of catalyst;At the same time, the porosity of the four corners of the multi-hole plate is higher, the flow velocity of the periphery of the airflow is faster, and the overall airflow presents a kind of tendency of outward diffusion, and the contact with the catalyst is more sufficient, in addition, it can also avoid the dust accumulation around the reactor.
[0005] To achieve the above purpose, the utility model provides the following technical scheme:
[0006] The utility model discloses a kind of cement kiln SCR reactor, including reactor body, be located in the air inlet pipe of the upper end of the reactor body, be located in the exhaust pipe of the lower end of reactor body, the connecting place of the air inlet pipe and the reactor body is equipped with gradually expanding section, gradually expanding section is equipped with baffle, flow guide grating and multi-hole plate in turn from top to bottom;The porosity of the multi-hole plate is arranged in gradient from the center to the periphery.
[0007] Further scheme: the number of the baffle is at least one, when the number is greater than one, it is parallelly arranged;The top of the baffle is inclinedly arranged to the direction of air inlet pipe.
[0008] Further scheme: the flow guide grating includes parallel strip grating and cross grating arranged in upper and lower;The louver of the parallel strip grating is inclinedly arranged along the direction of airflow.
[0009] Further scheme: the expansion angle of the gradually expanding section is 50-70°.
[0010] Further scheme: a flow regulation grid is arranged below the porous plate.
[0011] Further scheme: a dust hopper is arranged below the reactor body, and the exhaust duct is arranged at one side of the dust hopper.
[0012] Further scheme: a high-temperature fan is arranged at the end of the exhaust duct.
[0013] Compared with the prior art, the beneficial effects of the utility model are:
[0014] The utility model discloses a reactor body, the reactor body is provided with the gradually expanding section, the gradually expanding section is provided with the inclined flow guide plate, the flow guide grid and the porous plate, the gradually expanding section is provided with the exhaust duct, the exhaust duct is provided with the high-temperature fan, the dust hopper is arranged below the reactor body, and the exhaust duct is arranged at one side of the dust hopper.
[0015] The porous plate is arranged as the structure that the middle porosity is high and the periphery porosity is low, the flow velocity is relatively moderate when the middle smoke passes, the impact force of the dust particle in the smoke to the catalyst is reduced, thereby the abrasion condition of the catalyst is alleviated, simultaneously, the periphery porosity of the porous plate is higher, and the flow velocity of the airflow periphery is faster, and the airflow whole presents a kind of outward diffusion tendency, and the contact with the catalyst is more sufficient, in addition, the dust accumulation around the reactor can be avoided. BRIEF DESCRIPTION OF DRAWINGS
[0016] Fig. 1 It is the structural schematic diagram of the utility model;
[0017] Fig. 2 It is the internal structure perspective view of the utility model;
[0018] In the drawing: 1-reactor body, 2-inlet duct, 3-exhaust duct, 4-gradually expanding section, 5-flow guide plate, 6-flow guide grid, 61-parallel strip grid, 62-crossed grid, 7-porous plate, 8-dust hopper. DETAILED DESCRIPTION
[0019] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model, and obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor belong to the range of protection of the utility model.
[0020] In the description of the utility model, it needs to explain, the terms "upper", "lower", "left", "right", "internal", "external" and so on indicate the position relation or location relation is based on the position relation or location relation shown in the drawing, or is the position or location relation of the utility model product when using, only is for the convenience of describing the utility model and simplifying the description, and is not indicate or imply that the indicated device or element must have a particular orientation, construct and operate in a particular orientation, therefore cannot be understood as a limitation on the utility model.
[0021] Please refer to Figs. 1-2 In the embodiment, a cement kiln SCR reactor includes a reactor body 1, an air inlet pipe 2 arranged at the upper end of the reactor body 1, and an air outlet pipe 3 arranged at the lower end of the reactor body 1. The connection between the air inlet pipe 2 and the reactor body 1 is provided with a gradually expanding section 4. The gradually expanding section 4 is sequentially provided with a flow guide plate 5, a flow guide grid 6, and a porous plate 7 from top to bottom. The porosity of the porous plate 7 is arranged in a gradient decreasing manner from the center to the periphery. The catalyst is fixed in the middle of the reactor body 1. The flue gas passes through the flow guide plate 5, the flow guide grid 6, changes the airflow direction, and then passes through the porous plate 7 after uniform fluid distribution. Due to the higher porosity in the middle of the porous plate 7 and the lower porosity around, the flow speed of the flue gas in the middle is slow, and the flow speed of the flue gas around is fast. The flow speed of the middle flue gas through the catalyst layer is relatively slow, the impact force of the dust particles in the flue gas on the catalyst is reduced, and the catalyst wear is reduced. The flue gas as a whole presents an outward diffusion trend, and the contact with the catalyst layer is more sufficient, thereby improving the catalytic efficiency.
[0022] Further, the number of the flow guide plate 5 is at least one, and when the number is greater than one, the flow guide plates are arranged in parallel with each other. The top of the flow guide plate 5 is arranged in an inclined manner toward the air inlet pipe 2. In the embodiment, the number of the flow guide plate 5 is one, which plays a role in roughly adjusting the flow direction of the flue gas, so that the flue gas can more smoothly enter the subsequent flow guide grid 6 for fine guidance.
[0023] Further, the flow guide grid 6 includes parallel strip grids 61 and cross grids 62 arranged in an upper and lower manner. The strips of the parallel strip grids 61 are arranged in an inclined manner along the airflow direction, and the inclination direction is substantially the same as the inclination direction of the flow guide plate 5. The parallel strip grids 61 preliminarily guide the flue gas to form a relatively regular flow direction, and the cross grids 62 can perform secondary guidance and redistribution on the flue gas, so that the flue gas flows along a more complex and accurate path and diffuses downward more uniformly. This combination of the parallel strip grids 61 and the cross grids 62 can enhance the stability of the flow guidance. The parallel strip grids 61 preliminarily order the flow of the fluid, reduce the disorder, and the cross grids 62 further regularize on this basis. The cooperation of the two can reduce the pulsation and fluctuation of the fluid and reduce the vibration caused by the impact of the fluid.
[0024] Further, the expansion angle of the gradually expanding section 4 is 50-70°. Preferably, the expansion angle is set to 60°, which is conducive to the diffusion of the flue gas.
[0025] Further, the reactor body 1 is also provided with a flow regulation grid. The flow regulation grid is arranged below the porous plate 7 and above the catalyst layer, reduces the flue gas flow rate, prolongs the residence time of the flue gas in the reactor body 1, so that the pollutants in the flue gas have more time to contact the catalyst, thereby improving the efficiency of the denitration reaction.
[0026] Further, the reactor body 1 is also provided with a flow regulation grid. The flow regulation grid is arranged below the porous plate 7 and above the catalyst layer, reduces the flue gas flow rate, prolongs the residence time of the flue gas in the reactor body 1, so that the pollutants in the flue gas have more time to contact the catalyst, thereby improving the efficiency of the denitration reaction.
[0027] Further, the reactor body 1 is also provided with a flow regulation grid. The flow regulation grid is arranged below the porous plate 7 and above the catalyst layer, reduces the flue gas flow rate, prolongs the residence time of the flue gas in the reactor body 1, so that the pollutants in the flue gas have more time to contact the catalyst, thereby improving the efficiency of the denitration reaction.
[0028] The utility model discloses in operation, flue gas enters the reactor by air inlet pipe 2, and the flue gas angle is further adjusted to parallel strip grid 61 and cross grid 62 ordered flow guide after the flow guide plate 5 is roughly adjusted, then further evenly distributed airflow through the porous plate 7, the flue gas middle part flow rate is reduced, forms the tendency of outward diffusion, finally reaches the catalyst layer after further reducing the flue gas flow rate through the flow regulation grid, and fully reacts with the catalyst. The treated gas flows out from the exhaust pipe 3, enters the next process, and the solid impurities in the flue gas fall into the ash bucket 8 and are collected.
[0029] Although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be combined appropriately to form other embodiments that those skilled in the art can understand.
[0030] Therefore, the above-mentioned is only the preferred embodiment of the present application, and is not used to limit the scope of the present application; that is, various equivalent transformations made within the scope of the claims of the present application are within the protection scope of the claims of the present application.
Claims
1. A cement kiln SCR reactor comprising a reactor body (1), an inlet duct (2) arranged at the upper end of the reactor body (1), an outlet duct (3) arranged at the lower end of the reactor body (1), characterized in that, The connection part of the air inlet pipeline (2) and the reactor body (1) is provided with a gradually expanding section (4), the gradually expanding section (4) is sequentially provided with a flow guide plate (5), a flow guide grid (6) and a porous plate (7) from top to bottom; the porosity of the porous plate (7) is arranged in a gradient decreasing manner from the center to the periphery.
2. The cement kiln SCR reactor of claim 1, wherein, The number of the flow guide plate (5) is at least one, and when the number is more than one, the flow guide plates are arranged in parallel with each other; the top of the flow guide plate (5) is arranged in an inclined manner towards the air inlet pipeline (2).
3. The cement kiln SCR reactor of claim 1, wherein, The flow guide grid (6) comprises upper and lower parallel strip grids (61) and cross grids (62); the strips of the parallel strip grids (61) are arranged in an inclined manner along the air flow direction.
4. The cement kiln SCR reactor of claim 1, wherein, The expansion angle of the gradually expanding section (4) is 50-70°.
5. The cement kiln SCR reactor of claim 1, wherein, The lower part of the porous plate (7) is provided with a flow regulation grid.
6. The cement kiln SCR reactor of claim 1, wherein, The lower part of the reactor body (1) is provided with an ash hopper (8), and the air outlet pipeline (3) is arranged on one side of the ash hopper (8).
7. The cement kiln SCR reactor of claim 1, wherein, The end of the air outlet pipeline (3) is provided with a high-temperature fan.