Denitration two-way adjusting device for cement kiln

Abstract

The utility model belongs to the technical field of cement production denitration, and discloses a denitration bidirectional adjusting device for a cement kiln, which comprises a reduction component communicated with a smoke outlet of a cement production component, an outlet of the reduction component is communicated with a preheating and predecomposition component, and the preheating and predecomposition component is communicated with an SCR (Selective Catalytic Reduction) component; the reduction assembly comprises a reduction pipeline, and the reduction pipeline is arranged between the cement production assembly and the preheating and predecomposition assembly; the SCR assembly comprises a simple SCR device communicated with the preheating and predecomposition assembly, an inlet of the simple SCR device is provided with a gas detection device, and the gas detection device is in signal connection with the preheating and predecomposition assembly. The device is simple in structure and convenient to use, can realize efficient treatment of nitrogen oxides, reduces the use amount of ammonia water and ammonia escape, and has good environmental protection performance and economic benefits.

Description

Technical Field

[0001] The utility model belongs to the technical field of denitration in cement production, and in particular relates to a denitration bidirectional regulating device for a cement kiln. Background Art

[0002] Nitrogen oxides (NOx) are one of the causes of pollution phenomena such as haze and acid rain, and have become the focus of air pollution control. NOx emissions from the cement industry account for about 10% to 12% of the total national NOx emissions, making it the third largest source of pollution after thermal power and motor vehicles. With the increasing awareness of environmental protection and increasingly stringent regulations, the flue gas emissions of cement kilns have been under increasing scrutiny.

[0003] In the cement production process, the cement industry currently uses two main denitrification technologies, namely SCR (selective catalytic reduction) and SNCR (selective non-catalytic reduction). However, although the denitrification methods in traditional cement production have achieved certain results, they still have problems such as low denitrification efficiency, large amount of ammonia water consumption, and high operating costs.

[0004] Therefore, in order to solve the above problems, the utility model proposes a denitrification device for a cement kiln. Utility Model Content

[0005] In order to solve the above technical problems, the utility model proposes a denitration bidirectional regulating device for a cement kiln, which is used to design and develop an efficient and economical denitration device for the cement industry.

[0006] To achieve the above-mentioned purpose, the utility model provides a denitrification bidirectional regulating device for a cement kiln, comprising a reduction component connected to the smoke outlet of a cement production component, the outlet of the reduction component is connected to a preheating and predecomposition component, and the preheating and predecomposition component is connected to an SCR component;

[0007] The reduction assembly includes a reduction pipeline, and the reduction pipeline is arranged between the cement production assembly and the preheating and predecomposition assembly;

[0008] The SCR component comprises a simple SCR device connected to the preheating and predecomposition component. The inlet of the simple SCR device is provided with a gas detection device, and the gas detection device is connected to the preheating and predecomposition component by signal.

[0009] Preferably, a high-temperature fan is provided between the outlet of the preheating and pre-decomposition component and the simple SCR device, and the high-temperature fan discharges air toward the simple SCR device.

[0010] Preferably, the preheating and predecomposition component comprises a preheating and predecomposition unit connected to the reduction pipeline, and the preheating and predecomposition unit is provided with an ammonia injection device.

[0011] Preferably, the preheating and predecomposition unit includes a plurality of cyclones connected in sequence, the outlet of the topmost cyclone is connected to the inlet of the high-temperature blower, and the ammonia injection device is connected to the inner cavity of the bottommost cyclone.

[0012] Preferably, two of the uppermost cyclone tubes are arranged in parallel, and the outlets of the two uppermost cyclone tubes arranged in parallel are merged and connected to the inlet of the high-temperature fan.

[0013] Preferably, the cement production assembly comprises a rotary kiln for producing cement, the rotary kiln is provided with a smoke chamber, and the outlet of the smoke chamber is connected to the reduction pipe.

[0014] Preferably, a first catalyst installation space and a second catalyst installation space are provided in the simple SCR device, and catalysts are installed in the first catalyst installation space and the second catalyst installation space, respectively.

[0015] Preferably, the ammonia spraying device is signal-connected to the gas detection device.

[0016] Compared with the prior art, the utility model has the following advantages and technical effects: the utility model discloses a denitrification bidirectional regulating device for a cement kiln, wherein the reduction component is used to completely treat the nitrogen oxides generated by the cement production component, thereby reducing the denitrification load of the subsequent SCR component, improving the denitrification efficiency, reducing the amount of ammonia water used, and reducing the treatment cost; the gas detection device imported by the simple SCR device of the SCR component is used to detect the gas composition after the treatment of the front-end process in real time, and control the amount of ammonia water used in the preheating and pre-decomposition components, thereby realizing precise control of nitrogen oxides and ammonia.

[0017] The utility model has a simple structure and is easy to use, can realize the efficient treatment of nitrogen oxides, reduces the amount of ammonia water used, reduces ammonia escape, and has good environmental protection performance and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0019] Figure 1 This is a schematic diagram of the structure of the denitration bidirectional regulating device for cement kiln of the utility model;

[0020] In the figure: 1. Rotary kiln; 2. Smoke chamber; 3. Decomposition furnace; 4. Reduction pipeline; 5. Cyclone; 6. Ammonia injection device; 7. High-temperature fan; 8. Gas detection device; 9. Simple SCR device. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0023] Reference Figure 1 As shown, this embodiment provides a denitration bidirectional regulating device for a cement kiln, comprising a reduction component connected to a smoke outlet of a cement production component, the outlet of the reduction component is connected to a preheating and predecomposition component, and the preheating and predecomposition component is connected to an SCR component;

[0024] The reduction component includes a reduction pipeline 4, which is arranged between the cement production component and the preheating and predecomposition component;

[0025] The SCR component includes a simple SCR device 9 connected to the preheating and predecomposition component. The inlet of the simple SCR device 9 is provided with a gas detection device 8, and the gas detection device 8 is connected to the preheating and predecomposition component signal.

[0026] The utility model discloses a denitration bidirectional regulating device for a cement kiln, wherein a reduction component is used to completely process the nitrogen oxides generated by a cement production component, thereby reducing the denitration load of a subsequent SCR component, improving the denitration efficiency, reducing the amount of ammonia water used, and reducing the processing cost; a gas detection device 8 imported by a simple SCR device 9 of the SCR component is used to detect in real time the composition of the gas after being processed by a front-end process entering the device, and to control the amount of ammonia water used by a preheating and pre-decomposition component, thereby realizing precise control of nitrogen oxides and ammonia gas; the utility model has a simple structure and is easy to use, can realize efficient processing of nitrogen oxides, reduce the amount of ammonia water used, reduce ammonia escape, and has good environmental protection performance and economic benefits.

[0027] Furthermore, the preheating and predecomposition components are mainly used for preheating (heating) of materials, heating the material temperature from dozens of degrees at room temperature to about 900 degrees, and predecomposition refers to the decomposition of CaCO3 into CaO and CO2 at high temperature, leaving CaO.

[0028] Further optimizing the scheme, a high temperature fan 7 is provided between the outlet of the preheating and pre-decomposition component and the simple SCR device 9, and the high temperature fan 7 discharges air toward the simple SCR device 9. The high temperature fan 7 is used to accelerate the air discharged from the preheating and pre-decomposition component, and is essentially a conventional induced draft fan, which can act on the high temperature medium and facilitates entering the simple SCR device 9 for treatment.

[0029] Further optimization scheme, the preheating and predecomposition assembly includes a preheating and predecomposition unit connected to the reduction pipeline 4, and an ammonia spraying device 6 is provided on the preheating and predecomposition unit; the preheating and predecomposition unit includes a plurality of cyclones 5 connected in sequence, the outlet of the topmost cyclone 5 is connected to the inlet of the high-temperature blower 7, and the ammonia spraying device 6 is connected to the inner cavity of the lowest cyclone 5. The preheating and predecomposition unit is composed of a plurality of cyclones 5 in sequence, wherein the lowest cyclone 5 is connected to the ammonia spraying device 6, and the ammonia spraying device 6 is arranged below the volute of the lowest cyclone 5, and is used to introduce ammonia water into the gas reduced by the reduction pipeline 4, so that the flue gas reacts in the preheating and predecomposition assembly.

[0030] Furthermore, the preheating and pre-decomposition component of this embodiment also includes a decomposition furnace 3, which is connected to the outlet of the reduction pipe 4. The gas in the rotary kiln 1 enters the reduction pipe 4, and the reduced gas enters the cyclone 5 behind from the decomposition furnace 3.

[0031] For further information, see Appendix Figure 1 The cyclone 5 of this embodiment is divided into five layers, which are marked as C1, C2, C3, C4, and C5.

[0032] Furthermore, the cyclone 5 is an important component of the rotary kiln 1, and its main functions include the following aspects:

[0033] Storage and transportation: The cyclone 5 can be used as a transfer device for storing and transporting materials. It has low requirements for the viscosity and fluidity of the transported materials and is particularly suitable for powder and granular materials. Screening and grading: The cyclone 5 can classify materials into different grades according to the particle size. It is widely used in the classification and screening of fly ash, steel slag, cement and other materials in the fields of mining, metallurgy, and building materials. Separation and filtration: The cyclone 5 can filter and remove tiny particles in the air through centrifugal separation, and is used for air purification in the field of environmental protection. At the same time, it can also filter and separate harmful substances, dust, etc. in the air, and is one of the industrial waste gas treatment equipment. Drying and drying: The cyclone 5 can contact with hot air and flue gas in the drying system to increase the heat of the material and evaporate the water, thereby achieving the purpose of drying. It is used for drying products in the fields of metallurgy and chemical industry.

[0034] Further, the working principle of the cyclone 5 can be summarized into the following steps:

[0035] Airflow enters cyclone 5: Through the air inlet, the airflow is guided into cyclone 5. The air inlet is usually located at the top of cyclone 5; Airflow rotation: Once the airflow enters cyclone 5, it starts to rotate. The design inside cyclone 5 guides the airflow to form a rotating cylinder; Gravity separation: As the rotation occurs, the material particles are subjected to centrifugal force due to their mass and inertia. The heavier particles move down along the outer wall of cyclone 5, while the lighter particles remain in the cavity at the center of the airflow; Material collection: After gravity separation, the heavier particles fall into the collection chamber of cyclone 5. This collection chamber is usually located at the bottom of cyclone 5, and the material can be collected by opening the door of the collection chamber; Airflow discharge: After gravity separation, the lighter particles are discharged with the airflow through the top of cyclone 5. Sometimes, in order to further purify the airflow, a filter can be set at the top of cyclone 5 to capture fine particles.

[0036] Further optimizing the scheme, the cement production assembly includes a rotary kiln 1 for producing cement, and a smoke chamber 2 is provided on the rotary kiln 1, and the outlet of the smoke chamber 2 is connected to the reduction pipe 4. The rotary kiln 1 is a common equipment for cement production, which is mainly composed of a long and inclined rotating cylinder. The material enters from one end of the kiln and gradually moves to the other end through the rotating movement. In the process, the material is affected by high temperature and other processing conditions, and chemical and physical changes occur. Its working principle mainly includes the steps of heating and sintering, reaction and conversion, cooling and processing; specifically, fuel and air are provided inside the rotary kiln 1 to form a high-temperature environment, and the material is gradually heated at high temperature, and the moisture and volatile substances therein are evaporated and discharged, and the ore is sintered and solidified at the same time. At high temperature, the chemical components in the material react and transform, such as limestone and clay in cement production. The material is gradually cooled in the rotary kiln 1 to stabilize and solidify the product; the kiln cylinder of the rotary kiln 1 is rolled and welded by steel plates and is tiltedly installed on several pairs of supporting wheels. The lower end of the kiln body is equipped with a kiln mouth guard plate that is resistant to high temperature and wear and forms a sleeve space. A special fan is provided to cool the kiln mouth. Several rectangular belts are sleeved along the length of the kiln body to bear the weight of all rotating parts such as the kiln body, kiln lining, and materials, and transfer their weight to the supporting device; the smoke chamber 2 is mainly used to connect the rotary kiln 1 with the kiln tail process system. Its design usually takes into account the symmetry with the kiln axis and the axis of the decomposition furnace 3 to ensure the uniformity of the airflow and reduce the generation of bias flow and local vortex.

[0037] Further optimization scheme, the first catalyst installation space and the second catalyst installation space are set in the simple SCR device 9. The simple SCR device 9 is the last process device for denitration treatment and is arranged after the high-temperature blower 7. The simple SCR device 9 adopts the medium-temperature SCR form. The first layer of catalyst space is in normal use state, and the second catalyst space is a spare space, which is used only when the pollutants are too high and is generally not used, so that the concentrations of nitrogen oxides and ammonia in the flue gas after emission meet the requirements for atmospheric pollutant emissions.

[0038] To further optimize the solution, the ammonia spraying device 6 is connected to the gas detection device 8 by signal. The gas detection device 8 is installed at the inlet of the simple SCR device 9 to detect the gas composition in real time and transmit the detected information to the ammonia spraying device 6 to guide the adjustment of the amount of ammonia water entering the SCR device, thereby achieving dual control of nitrogen oxides and ammonia escape.

[0039] Working process:

[0040] The gas generated by the operation of the rotary kiln 1 enters the reduction pipe 4 from the smoke chamber 2. The high-concentration CO generated by the fuel and the high-nitrogen oxide flue gas generated in the rotary kiln 1 react in the reducing atmosphere to reduce the nitrogen oxides to harmless nitrogen, which then passes through the decomposition furnace 3 and enters the lowest cyclone 5. At the same time, the wind from the tertiary air duct also flows into the decomposition furnace 3 and enters the rear cyclone 5 together.

[0041] At the same time, the gas detection device 8 transmits the detected gas signal to the ammonia spraying device 6, spraying ammonia water into the lowest cyclone 5, and the ammonia water reduces part of the nitrogen oxides produced in the decomposition furnace 3. Due to the low reaction efficiency, a large amount of ammonia and unreduced nitrogen oxides are mixed in the gas;

[0042] After the multi-stage mixed flue gas passes through the induced draft of the high-temperature fan 7, it enters the simple SCR device 9, and the gas detection device 8 is used to detect the composition of the gas entering the simple SCR device 9, which can adjust the working state of the catalyst in the simple SCR device 9, and at the same time, it can control the ammonia injection amount of the ammonia injection device 6 through the detected data, so that the amount of ammonia water is more accurate, ensuring the dual control of nitrogen oxides and ammonia escape, while reducing the processing cost.

[0043] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] The embodiments described above are only descriptions of the preferred methods of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims

1. A denitration bidirectional regulating device for a cement kiln, characterized in that: It includes a reduction component connected to the smoke outlet of the cement production component, the outlet of the reduction component is connected to a preheating and predecomposition component, and the preheating and predecomposition component is connected to the SCR component; The reduction component comprises a reduction pipeline (4), and the reduction pipeline (4) is arranged between the cement production component and the preheating and predecomposition component; The SCR component comprises a simple SCR device (9) connected to the preheating and predecomposition component. The inlet of the simple SCR device (9) is provided with a gas detection device (8). The gas detection device (8) is signal-connected to the preheating and predecomposition component.

2. The denitration bidirectional regulating device for cement kiln according to claim 1, characterized in that: A high-temperature fan (7) is provided between the outlet of the preheating and pre-decomposition component and the simple SCR device (9), and the high-temperature fan (7) blows air toward the simple SCR device (9).

3. The denitration bidirectional regulating device for cement kiln according to claim 2, characterized in that: The preheating and predecomposition component comprises a preheating and predecomposition unit connected to the reduction pipeline (4), and an ammonia injection device (6) is arranged on the preheating and predecomposition unit.

4. The denitration bidirectional regulating device for cement kiln according to claim 3 is characterized in that: The preheating and predecomposition unit comprises a plurality of cyclone barrels (5) connected in sequence, the outlet of the topmost cyclone barrel (5) being connected to the inlet of the high-temperature blower (7), and the ammonia injection device (6) being connected to the inner cavity of the bottommost cyclone barrel (5).

5. The denitration bidirectional regulating device for cement kiln according to claim 4 is characterized in that: Two of the uppermost cyclone barrels (5) are arranged in parallel, and the outlets of the two uppermost cyclone barrels (5) arranged in parallel are connected and then connected to the inlet of the high-temperature fan (7).

6. The denitration bidirectional regulating device for cement kiln according to claim 1, characterized in that: The cement production assembly comprises a rotary kiln (1) for producing cement, wherein the rotary kiln (1) is provided with a smoke chamber (2), and the outlet of the smoke chamber (2) is connected to the reduction pipe (4).

7. The denitration bidirectional regulating device for cement kiln according to claim 1, characterized in that: The simple SCR device (9) is provided with a first catalyst installation space and a second catalyst installation space.

8. The denitration bidirectional regulating device for cement kiln according to claim 3, characterized in that: The ammonia spraying device (6) is signal-connected to the gas detection device (8).

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