Recycling heating device for denitration flue gas after wet desulphurization

Abstract

The utility model discloses a recirculating heating device for denitration flue gas after wet desulphurization, which comprises a high-temperature circulating fan, an inlet and an outlet of the high-temperature circulating fan are respectively connected with a high-temperature circulating fan inlet flue and a high-temperature circulating fan outlet flue, and the high-temperature circulating fan inlet flue is connected with a denitration outlet flue. A high-temperature circulating fan outlet flue is connected with a flue header, a plurality of flue branch pipes are connected to the flue header in the length direction of the flue header, the other ends of the flue branch pipes are all located in a GGH heat exchanger cold end inlet flue, a plurality of flue branch pipe nozzles are formed in the flue branch pipes, and the flue branch pipe nozzles are located in the GGH heat exchanger cold end inlet flue. High-temperature flue gas is mixed with saturated wet flue gas at the cold end inlet of the GGH heat exchanger through the flue header and the multiple flue branch pipe nozzles, the high-temperature flue gas and the saturated wet flue gas are evenly mixed, the heat exchange efficiency is improved, the saturated wet flue gas entering the cold end of the GGH heat exchanger is heated to become overheated flue gas, and corrosion of the flue gas to the GGH heat exchanger is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of metallurgy and environmental protection, and in particular to a recirculation heating device for denitrified flue gas after wet desulfurization. Background Art

[0002] In the production of the steel industry, the flue gas produced contains a large amount of pollutants such as nitrogen oxides and sulfur dioxide. As the environmental protection requirements of the steel industry gradually increase, the requirements for environmental protection equipment are also getting higher and higher. With the development of environmental protection technology, the denitrification process after wet desulfurization is widely used in the treatment of sintering machine tail gas. Since the denitrification reactor requires an inlet temperature higher than 200°C, it is necessary to add a GGH heat exchanger in front of the denitrification reactor to increase the flue gas temperature from the original 55°C to above 200°C to meet the inlet temperature requirements of the denitrification reactor.

[0003] However, since the flue gas entering the GGH heat exchanger is in a wet saturated state with high humidity and high salt content in the water vapor, the heating surface of the GGH heat exchanger will be severely corroded and blocked after running for a period of time, and the denitrification equipment cannot be put into operation normally. Therefore, the conventional wet desulfurization and denitrification process needs to replace the heat exchange surface of the GGH heat exchanger after running for a period of time, which increases the production cost of the steel industry and causes great economic losses. Utility Model Content

[0004] The purpose of the utility model is to provide a recirculation heating device for flue gas denitrified after wet desulfurization to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a recirculation heating device for denitrification flue gas after wet desulfurization, which includes a high-temperature circulation fan, the inlet and outlet of the high-temperature circulation fan are respectively connected to the high-temperature circulation fan inlet flue and the high-temperature circulation fan outlet flue, the high-temperature circulation fan inlet flue is connected to the denitrification outlet flue, the high-temperature circulation fan outlet flue is connected to a flue header, a plurality of flue branches are connected to the flue header along the length direction of the flue header, the other ends of the flue branches are all located in the cold end inlet flue of a GGH heat exchanger, a plurality of flue branch nozzles are provided on the flue branch, and the flue branch nozzles are located inside the cold end inlet flue of the GGH heat exchanger.

[0006] Preferably, an expansion joint is installed on one end of the flue branch pipe close to the flue manifold.

[0007] Preferably, the flue header is arranged vertically to the high-temperature circulation fan outlet flue.

[0008] Beneficial effects: Compared with the prior art, the beneficial effects of the utility model are as follows: the high-temperature flue gas is mixed with the saturated wet flue gas at the cold end inlet of the GGH heat exchanger through the flue header and multiple flue branch pipe nozzles, the high-temperature flue gas and the saturated wet flue gas are mixed evenly, the heat exchange efficiency is increased, and the saturated wet flue gas entering the cold end of the GGH heat exchanger is heated up to become superheated flue gas, reducing the corrosion of the GGH heat exchanger by the flue gas; during the heating process, the water vapor changes from a saturated state to a superheated state, so that the salt in the water vapor is precipitated in the flue in advance, and no scaling is formed on the heating surface, which significantly reduces the blockage of the heating surface of the GGH heat exchanger; and the service life of the GGH heat exchanger is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a front view of a flue gas recirculation heating device for denitrification after wet desulfurization proposed by the utility model.

[0010] Figure 2 for Figure 1 Side view of.

[0011] In the attached figure: 1-high temperature circulation fan, 2-high temperature circulation fan inlet flue, 3-high temperature circulation fan outlet flue, 4-flue header, 5-flue branch pipe, 6-flue branch pipe nozzle, 7-GGH heat exchanger cold end inlet flue, 8-expansion joint. DETAILED DESCRIPTION

[0012] In order to more clearly understand the above-mentioned purpose, features and advantages of the utility model, the utility model is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0013] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein. Therefore, the present invention is not limited to the specific embodiments of the following disclosure.

[0014] Example

[0015] Please refer to the drawings of the specification. In the embodiment of the utility model, a recirculation heating device for denitrification flue gas after wet desulfurization comprises a high-temperature circulation fan 1. The inlet and outlet of the high-temperature circulation fan 1 are respectively connected to a high-temperature circulation fan inlet flue 2 and a high-temperature circulation fan outlet flue 3. The high-temperature circulation fan inlet flue 2 is connected to the denitrification outlet flue. The high-temperature circulation fan outlet flue 3 is connected to a flue header 4. The flue header 4 is arranged vertically to the high-temperature circulation fan outlet flue 3. A plurality of flue branches 5 are connected to the flue header 4 along the length direction of the flue header 4. The other ends of the flue branches 5 are all located in a GGH heat exchanger cold end inlet flue 7. A plurality of flue branch nozzles 6 are provided on the flue branch 5. The flue branch nozzles 6 are located inside the GGH heat exchanger cold end inlet flue 7. An expansion joint 8 is installed on one end of the flue branch 5 close to the flue header 4.

[0016] The high-temperature flue gas first enters the flue header from the high-temperature circulation fan outlet, then enters the flue branch pipe, and finally enters the flue at the cold end of the GGH heat exchanger; the header and the high-temperature fan outlet flue are arranged vertically to buffer the pressure pulsation and airflow fluctuation of the flue gas at the high-temperature circulation fan outlet, so that the flue gas flows smoothly and evenly when it flows out; each flue branch pipe has multiple nozzles opened in the direction of the flue gas flow, so that the flue gas flows evenly into the flue at the cold end of the GGH heat exchanger when it flows out, so that the high-temperature flue gas and the saturated wet flue gas are evenly mixed, thereby increasing the heat exchange effect between the flue gases.

[0017] In the utility model, high-temperature flue gas is mixed with saturated wet flue gas at the cold end inlet of the GGH heat exchanger through a flue header and a plurality of flue branch pipe nozzles. The high-temperature flue gas and the saturated wet flue gas are evenly mixed, thereby increasing the heat exchange efficiency, and causing the saturated wet flue gas entering the cold end of the GGH heat exchanger to be heated up to become superheated flue gas, thereby reducing the corrosion of the GGH heat exchanger by the flue gas. During the heating process, water vapor changes from a saturated state to an overheated state, thereby causing the salt in the water vapor to precipitate in the flue in advance and not to scale on the heating surface, thereby significantly reducing the blockage of the heating surface of the GGH heat exchanger. The service life of the GGH heat exchanger is significantly improved. The application has a simple structure, strong practicability, and is simple to operate, and is worthy of promotion.

[0018] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0019] In the description of the present invention, it is necessary to understand that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0020] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, which is only for the convenience of describing the utility model and simplifying the description, and does 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 cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

Claims

1. A recirculation heating device for flue gas denitrification after wet desulfurization, characterized in that: The invention comprises a high-temperature circulation fan (1), wherein the inlet and outlet of the high-temperature circulation fan (1) are respectively connected to a high-temperature circulation fan inlet flue (2) and a high-temperature circulation fan outlet flue (3), wherein the high-temperature circulation fan inlet flue (2) is connected to a denitration outlet flue, and the high-temperature circulation fan outlet flue (3) is connected to a flue header (4), and a plurality of flue branch pipes (5) are connected to the flue header (4) along the length direction of the flue header (4), and the other ends of the flue branch pipes (5) are all located in a GGH heat exchanger cold end inlet flue (7), and the flue branch pipes (5) are provided with a plurality of flue branch pipe nozzles (6), and the flue branch pipe nozzles (6) are located inside the GGH heat exchanger cold end inlet flue (7).

2. The device for recirculating and heating the flue gas after wet desulfurization and denitrification according to claim 1, characterized in that: An expansion joint (8) is installed on one end of the flue branch pipe (5) close to the flue header (4).

3. The device for recirculating and heating flue gas after wet desulfurization and denitrification according to claim 1 is characterized in that: The flue header (4) is arranged vertically to the high-temperature circulation fan outlet flue (3).

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