Flue gas desulfurization and denitrification device for hot-blast stove

Abstract

The invention discloses a hot-blast stove flue gas desulfurization and denitrification device which comprises a hot-blast stove, a gas outlet of the hot-blast stove is connected with a gas inlet of a preheater through a preheating pipeline, a gas outlet of the preheater is connected with a chimney through a gas outlet pipeline I, an isolating valve is arranged on the gas outlet pipeline between the preheater and the chimney, and a bypass flue is arranged on the preheating pipeline. The bypass pipeline is communicated with one end of the bypass flue, a bypass valve is arranged on the bypass pipeline, the other end of the bypass flue is connected with an inlet of a desulfurization and denitrification tower, an outlet of the desulfurization and denitrification tower is connected with an inlet of an induced draft fan through a discharge pipeline, and an outlet of the induced draft fan is connected with a gas outlet pipeline I through a gas outlet pipeline II; a branch pipeline is arranged on the gas outlet pipeline I, one end of the branch pipeline is communicated with the gas outlet pipeline I, and the other end of the branch pipeline is connected with the bypass flue; the desulfurization and denitrification integrated device is simple in structure and small in occupied area, and desulfurization and denitrification integration is achieved.

Description

Technical Field

[0001] The invention relates to a hot blast furnace flue gas desulfurization and denitration device, belonging to the technical field of desulfurization and denitration of flue gas generated by blast furnace gas combustion. Background Art

[0002] The steel industry has many types of pollutants in flue gas and a large amount of emissions. It is one of the industries with the highest proportion of conventional pollutants in the non-power industry, except for the power industry. As the power industry has completed ultra-low emission transformation, China's focus on air pollution control has shifted from the power industry to the non-power industry. Promoting ultra-low emission control of flue gas in China's steel industry is the only way to promote deep reduction of pollutants. It is urgent for all processes in the steel industry to complete ultra-low emission transformation.

[0003] In this regard, in order to achieve ultra-low emissions in each process of the steel industry, a lot of research has been conducted in this field on the desulfurization and denitrification of flue gas from blast furnaces and hot blast stoves in the steel industry.

[0004] At present, the fixed bed desulfurization technology for hot blast furnace flue gas is mature, but for the removal of nitrogen oxides in the flue gas, an independent denitrification unit is required. It is impossible to implement the integration of desulfurization and denitrification, which increases the floor space and investment cost. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a blast furnace hot blast stove flue gas desulfurization and denitrification device, which realizes the integration of desulfurization and denitrification.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a hot blast furnace flue gas desulfurization and denitrification device, including a hot blast furnace, the air outlet of the hot blast furnace is connected to the air inlet of a preheater through a preheating pipe, the air outlet of the preheater is connected to the chimney through an outlet pipe one, a shut-off valve is arranged on the outlet pipe between the preheater and the chimney, a bypass flue is arranged on the preheating pipe and connected to one end thereof, a bypass valve is arranged on the bypass pipe, the other end of the bypass flue is connected to the inlet of a desulfurization and denitrification tower, the outlet of the desulfurization and denitrification tower is connected to the inlet of an induced draft fan through a discharge pipe, the outlet of the induced draft fan is connected to the outlet pipe one through an outlet pipe two; a branch pipe is arranged on the outlet pipe one, one end of the branch pipe is connected to the outlet pipe one, and the other end is connected to the bypass flue.

[0007] The present invention further defines the technical solution: Preferably, the preheating pipe is provided with a SO2 content detection meter and a NOx content detection meter, both of which are arranged at the front end of the connection between the bypass flue and the preheating pipe.

[0008] Preferably, an air intake valve is provided on the branch pipe, and a connection between the branch pipe and the air outlet pipe is located in front of the inlet end of the isolation valve, and a connection between the branch pipe and the bypass flue is located behind the outlet end of the isolation valve.

[0009] Preferably, a thermometer and a denitrification agent spraying device are installed on the bypass flue between the air intake valve and the desulfurization and denitrification tower. Preferably, the desulfurization and denitrification tower comprises a desulfurization bin and a denitrification bin which are interconnected, and a desulfurization agent layer and a denitrification catalyst layer are respectively arranged inside the desulfurization bin and the denitrification bin, and the desulfurization agent layer and the denitrification catalyst layer are fixed in the corresponding bin through a grid plate.

[0010] Preferably, the denitrification agent spraying device is composed of a plurality of nozzles, and the plurality of nozzles are arranged in the bypass flue and connected in parallel to the denitrification pipeline, and are connected to the denitrification agent generator through the denitrification pipeline. Beneficial Effects

[0011] The present invention has a simple structure, and integrates the flue gas desulfurization and denitrification device of the hot blast furnace into a desulfurization and denitrification tower, thereby realizing the integration of desulfurization and denitrification, reducing the occupied area, and saving investment. The SO2 content and NOx content in the flue gas can be detected on the preheating pipeline SO2 content detection meter and the NOx content detection meter. The denitrification agent injection device is connected to the denitrification agent generator and can spray the denitrification agent into the flue gas, so that the flue gas is mixed with the denitrification agent, which is convenient for subsequent flue gas denitrification. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a schematic diagram of the structure of the desulfurization and denitrification tower of the present invention; Figure 3 It is a structural schematic diagram of the denitrification agent injection device of the present invention. DETAILED DESCRIPTION

[0013] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0014] See also Figure 1-3The present embodiment provides a hot blast furnace flue gas desulfurization and denitrification device, comprising a hot blast furnace 1, the air outlet of the hot blast furnace 1 is connected to the air inlet of the preheater 2 through a preheating pipe 5, the air outlet of the preheater 2 is connected to the chimney 3 through an air outlet pipe 16, a cut-off valve 4 is arranged on the air outlet pipe 16 between the preheater 2 and the chimney 3, a bypass flue 7 is arranged on the preheating pipe 5, and is connected to one end thereof, a SO2 content detection meter 13 and a NOx content detection meter 14 are arranged on the preheating pipe, both of which are arranged at the front end of the connection between the bypass flue and the preheating pipe, a bypass valve 18 is arranged on the bypass pipe 7, and the other end of the bypass flue 7 is connected to the inlet of the desulfurization and denitrification tower 8, The desulfurization and denitration tower comprises a desulfurization chamber 8-1 and a denitration chamber 8-2 which are interconnected, wherein a desulfurization agent layer 8-3 and a denitration catalyst layer 8-4 are respectively arranged inside the desulfurization chamber and the denitration chamber, and the desulfurization agent layer and the denitration catalyst layer are fixed in the corresponding chamber through a grid plate 8-5; the outlet of the denitration chamber in the desulfurization and denitration tower is connected to the inlet of the induced draft fan 10 through a discharge pipe 9, and the outlet of the induced draft fan is connected to the outlet pipe 16 through an outlet pipe 2 11; a branch pipe 12 is arranged on the outlet pipe 6, and one end of the branch pipe 12 is connected to the outlet pipe 1, and the other end is connected to the outlet pipe 16. The end is connected to the bypass flue 7, an air intake valve 15 is arranged on the branch pipe 12, and a connection between the branch pipe and the outlet pipe is located in front of the inlet end of the isolation valve, and the connection between the branch pipe and the bypass flue is located behind the outlet end of the isolation valve. A thermometer 16 and a denitrification agent blowing device 17 are installed on the bypass flue between the air intake valve 15 and the desulfurization and denitrification tower 8. The denitrification agent blowing device 17 is composed of a plurality of nozzles 18, and the plurality of nozzles are arranged in the bypass flue 7 and are connected in parallel to the denitrification pipe 20, and are connected to the denitrification agent generator 19 through the denitrification pipe.

[0015] The flue gas desulfurization and denitrification process of this embodiment is as follows: after the flue gas from the hot blast furnace 1 enters the preheater 2, it enters the desulfurization and denitrification tower 8 through the air intake valve 15. Before the flue gas enters the sulfur denitrification tower 8, the denitrification agent is sprayed by the denitrification agent spraying device 17. The flue gas mixed with the denitrification agent first enters the desulfurization agent layer 8-3 for desulfurization, and then enters the denitrification catalyst layer 8-4 for denitrification. After passing through the desulfurization and denitrification tower 8, the sulfur dioxide and nitrogen oxides in the flue gas are removed, and the clean flue gas is sent to the induced draft fan 10 for pressurization and then discharged through the chimney 3. It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent to such process, method, article, or apparatus.

[0016] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hot blast furnace flue gas desulfurization and denitrification device, comprising a hot blast furnace, characterized in that: The air outlet of the hot blast furnace is connected to the air inlet of the preheater through a preheating pipe, and the air outlet of the preheater is connected to the chimney through an air outlet pipe 1. A shut-off valve is arranged on the air outlet pipe between the preheater and the chimney, and a bypass flue is arranged on the preheating pipe and connected with one end thereof, and a bypass valve is arranged on the bypass pipe, and the other end of the bypass flue is connected to the inlet of a desulfurization and denitrification tower, and the outlet of the desulfurization and denitrification tower is connected to the inlet of an induced draft fan through a discharge pipe, and the outlet of the induced draft fan is connected to the air outlet pipe 1 through an air outlet pipe 2; a branch pipe is arranged on the air outlet pipe 1, and one end of the branch pipe is connected with the air outlet pipe 1, and the other end is connected with the bypass flue.

2. A hot blast stove flue gas desulfurization and denitrification device according to claim 1, characterized in that: The preheating pipeline is provided with a SO2 content detection meter and a NOx content detection meter, both of which are arranged at the front end of the connection between the bypass flue and the preheating pipeline.

3. A hot blast stove flue gas desulfurization and denitrification device according to claim 1, characterized in that: An air intake valve is provided on the branch pipeline, and a connection between the branch pipeline and the air outlet pipeline is located in front of the inlet end of the isolation valve, and a connection between the branch pipeline and the bypass flue is located behind the outlet end of the isolation valve.

4. A hot blast stove flue gas desulfurization and denitrification device according to claim 1, characterized in that: A thermometer and a denitrification agent spraying device are installed on the bypass flue between the air intake valve and the desulfurization and denitrification tower.

5. The hot blast stove flue gas desulfurization and denitrification device according to claim 1, characterized in that: The desulfurization and denitration tower comprises a desulfurization bin and a denitration bin which are interconnected. A desulfurization agent layer and a denitration catalyst layer are respectively arranged inside the desulfurization bin and the denitration bin. The desulfurization agent layer and the denitration catalyst layer are both fixed in the corresponding bins through grid plates.

6. A hot blast stove flue gas desulfurization and denitrification device according to claim 4, characterized in that: The denitrification agent spraying device is composed of a plurality of nozzles, which are arranged in the bypass flue and connected in parallel with the denitrification pipeline, and are connected to the denitrification agent generator through the denitrification pipeline.

Images