Circulating fluidized bed desulfurization conveying chute fluidization air system

Abstract

The utility model discloses a fluidizing air system for a desulfurization conveying chute of a circulating fluidized bed, relates to the technical field of flue gas desulfurization, and can solve the problems that the temperature of fluidizing air heated by steam is low, steam consumption is reduced, and material hardening caused by damage of a coil pipe of a steam heat exchanger is avoided. The device comprises a high-temperature air pipe, a high-temperature air pipe adjusting valve, a low-temperature air pipe, a low-temperature air pipe adjusting valve, a mixed air pipe, a multi-stage centrifugal fan unit, a fan outlet pipeline, a conveying chute and the like. One end of the high-temperature air pipe is connected with the clean flue gas inlet side of the rotary heat exchanger; one end of the low-temperature air pipe is connected with the outlet side of the booster fan; one end of the mixed air pipe is connected with the high-low temperature air pipe; the centrifugal fan is communicated with the circulating fluidized bed desulfurization conveying chute through an outlet pipeline, and a temperature measuring element is arranged on the outlet pipeline. The fluidized bed is simple in structure, and materials in the chute are fluidized by utilizing waste heat of desulfurized and denitrified flue gas.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of flue gas desulfurization and denitrification, and particularly relates to a circulating fluidized bed desulfurization conveying chute fluidization air system. BACKGROUND

[0002] The main process route of the ultra-clean emission desulfurization and denitrification of the steel sintering flue gas emission is the circulating fluidized bed desulfurization + selective catalytic reduction (SCR) denitrification mode. The circulating fluidized bed desulfurization desulfurizer is continuously circulated between the desulfurization tower and the dust collector by means of the fluidization air blowing chute fluidization distribution. In order to avoid the cold air fluidization causing the desulfurizer to be hardened, the current commonly used heating mode of the fluidization air in China is steam heating, and the medium of the fluidization air is air. The above heating mode has the risk that the steam coil is easily broken, and the leaked steam is blown into the chute along with the fluidization air to cause the desulfurizer to be humidified and hardened. At the same time, the air temperature of the steam heating needs to be heated from the ambient temperature to above 100 DEG C, and there are problems of large steam consumption and difficulty in reaching the standard temperature, especially in the northern winter, the steam heater drainage also easily causes a large amount of water vapor to be difficult to diffuse, affects the visibility of the factory area, and has a safety hidden danger. Therefore, it is urgent to improve the above traditional fluidization air heating mode. SUMMARY

[0003] The utility model aims at providing a circulating fluidized bed desulfurization conveying chute fluidization air system to solve the problems of large steam consumption and difficulty in reaching the standard temperature.

[0004] In order to achieve the above-mentioned purpose, the utility model provides the following technical scheme: a circulating fluidized bed desulfurization conveying chute fluidization air system, the utility model discloses a high temperature air pipe, high temperature air pipe regulating valve, low temperature air pipe, low temperature air pipe regulating valve, mixed air pipe, multistage centrifugal fan, fan outlet pipeline, conveying chute, one end of high temperature air pipe connects rotary heat exchanger clean flue gas inlet side, one end connects mixed air pipe, one end of low temperature air pipe connects booster fan outlet side, one end connects mixed air pipe, one end of mixed air pipe connects high and low temperature air pipe, one end connects multistage centrifugal fan group, and the centrifugal fan is connected with the circulating fluidized bed desulfurization conveying chute through the outlet pipeline, and the temperature measuring element is arranged on the outlet pipeline.

[0005] Preferably, the fluidization air medium is high and low temperature mixed flue gas after desulfurization and denitrification.

[0006] Preferably, the fluidization air temperature can be controlled through the adjustment of the high temperature air pipe regulating valve and the low temperature air pipe regulating valve, wherein the fluidization air is mainly low temperature air.

[0007] Preferably, the high temperature air pipe gas taking point is the rotary heat exchanger clean flue gas inlet side of the denitrification system, and the low temperature air pipe gas taking point is between the booster fan and the chimney.

[0008] Preferably, the fan selection flow rate of the ash hopper multi-stage centrifugal fan unit and the chute multi-stage centrifugal fan unit is based on the required fluidization area multiplied by (2-2.5) m 3 / min for calculation.

[0009] Preferably, the outlet pipe and the circulating fluidized bed desulfurization conveying chute are evenly distributed to each small chute through a redistribution branch pipe.

[0010] Preferably, the wind pressure is selected such that the ash hopper multi-stage centrifugal fan unit is not less than 35 kPa, and the chute multi-stage centrifugal fan unit is not less than 10 kPa. A spare fan is provided in each of the two fan units.

[0011] Preferably, in actual use, the ratio of high-temperature air is adjusted according to actual conditions to control the temperature on the outlet pipe, and the temperature is not lower than 110°C.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] The circulating fluidized bed desulfurization conveying chute fluidizing air system has a simple structure. It changes the original fluidizing air medium from air to sintering flue gas, does not require steam heating, saves heating equipment, and avoids the risk of steam coil rupture and steam leakage accompanied by fluidizing air blowing into the chute, causing moisture and compaction in the desulfurizer.

[0014] This circulating fluidized bed desulfurization conveying chute fluidized air system utilizes the flue gas from the denitrification booster fan outlet as the fluidized air source, eliminating the need for a steam heat exchanger and avoiding the problems of high steam consumption and difficulty in achieving temperature standards. Compared with previous steam-heated fluidized air processes, it offers advantages in energy conservation and economic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the utility model;

[0016] In the figure: 1. Desulfurization system; 2. Denitrification system; 3. High-temperature air duct; 4. Low-temperature air duct; 5. High-temperature air duct regulating valve; 6. Low-temperature air duct regulating valve; 7. Mixing air duct; 8. Ash hopper multi-stage centrifugal fan unit; 9. Chute multi-stage centrifugal fan unit; 10. Outlet air duct; 11. Conveying chute unit; 12. Booster fan; 13. External exhaust chimney. DETAILED DESCRIPTION

[0017] like Figure 1The figure shows a circulating fluidized bed desulfurization (CFB) conveying chute fluidized air system, comprising a high-temperature air duct 3, a high-temperature air duct regulating valve 5, a low-temperature air duct 4, a low-temperature air duct regulating valve 6, a mixing air duct 7, a multi-stage centrifugal fan unit 8 for the ash hopper, a multi-stage centrifugal fan unit 9 for the chute, a fan outlet mixing duct 10, and a conveying chute unit 11. One end of the high-temperature air duct 3 is connected to the clean flue gas inlet side of the denitrification system 2's heat exchanger and the other end is connected to the mixing air duct 7; one end of the low-temperature air duct is connected to the outlet side of the booster fan 12 and the other end is connected to the mixing air duct 7. Centrifugal fan units 8 and 9 are connected to the circulating fluidized bed desulfurization conveying chute unit 11 via the outlet mixing air duct 7, and a temperature measuring element is provided on the mixing air duct 7.

[0018] During normal fluidization, the low-temperature air duct regulating valve 6 is fully open. The desulfurized and denitrified sintering flue gas at the outlet of the booster fan 12 is delivered to the conveying chute assembly 11 by the suction force of the multi-stage centrifugal fan unit. The fluidizing air temperature is controlled by the temperature measuring element on the outlet mixing air duct 7. If the air temperature falls below 110°C, the high-temperature air duct regulating valve 5 is opened to mix in high-temperature flue gas for supplemental temperature.

[0019] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection defined by the claims.

[0020] Anything not described in detail in the present invention is well known to those skilled in the art.

[0021] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A circulating fluidized bed desulfurization conveying chute fluidizing air system, comprising a high-temperature air duct (3), a high-temperature air duct regulating valve (5), a low-temperature air duct (4), a low-temperature air duct regulating valve (6), a mixing air duct (7), an ash hopper multi-stage centrifugal fan unit (8), and a chute multi-stage centrifugal fan unit (9), characterized in that: One end of the high-temperature air duct (3) is connected to the clean flue gas inlet side of the heat exchanger of the denitrification system (2), and the other end is connected to the mixing air duct (7); one end of the low-temperature air duct (4) is connected to the outlet side of the booster fan (12), and the other end is connected to the mixing air duct (7); the outlets of the ash hopper multi-stage centrifugal fan unit (8) and the chute multi-stage centrifugal fan unit (9) are connected to the conveying chute group (11) of the circulating fluidized bed desulfurization through the outlet air duct (10), and a temperature measuring element is provided on the outlet air duct (10).

2. The circulating fluidized bed desulfurization conveying chute fluidized air system according to claim 1, characterized in that: The fluidized air used in the circulating fluidized bed desulfurization conveying chute fluidized air system has a medium of high and low temperature mixed flue gas after desulfurization and denitrification.

3. The circulating fluidized bed desulfurization conveying chute fluidized air system according to claim 2, characterized in that: The temperature of the fluidizing air can be controlled by adjusting the high-temperature air duct regulating valve and the low-temperature air duct regulating valve, wherein the fluidizing air is mainly low-temperature air.

4. The circulating fluidized bed desulfurization conveying chute fluidized air system according to claim 1, characterized in that: The high-temperature air duct (3) has an air intake point at the clean flue gas inlet side of the heat exchanger of the denitrification system (2); the low-temperature air duct (4) has an air intake point between the booster fan (12) and the exhaust chimney (13).

5. The circulating fluidized bed desulfurization conveying chute fluidized air system according to claim 1, characterized in that: The fan selection flow of the ash hopper multi-stage centrifugal fan unit (8) and the chute multi-stage centrifugal fan unit (9) is based on the required fluidization area multiplied by (2-2.5) m 3 / min for calculation.

6. The circulating fluidized bed desulfurization conveying chute fluidized air system according to claim 1, characterized in that: The outlet air duct (10) and the conveying chute group (11) of the circulating fluidized bed desulfurization are evenly distributed to each small chute through a redistribution branch pipe.

7. The circulating fluidized bed desulfurization conveying chute fluidized air system according to claim 3, characterized in that: In actual use, adjust the ratio of high-temperature air according to actual conditions to control the temperature on the outlet pipe, and the temperature should not be lower than 110℃.

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