Anti-condensation corrosion semi-dry desulfurization device

Abstract

The utility model discloses a semi-dry desulfurization device capable of preventing condensation corrosion. The device comprises an inlet flue, a backflow flue, a smoke box, a Venturi tube, a lower-layer atomizing spray gun, an upper-layer atomizing spray gun, a tower body, a desulfurizing tower outlet smoke temperature measuring device, a desulfurizing tower outlet smoke absolute pressure measuring device, a desulfurizing tower outlet smoke humidity measuring device, a bag-type dust collector and a dust collector outlet smoke temperature measuring device. The device comprises a dust remover outlet flue gas absolute pressure measuring device, a dust remover outlet flue gas humidity measuring device, an outlet flue and a material returning chute. According to the device, an upper-layer atomizing spray gun and a lower-layer atomizing spray gun are adjusted in real time according to the dew-point allowance of an outlet of a desulfurizing tower and the dew-point allowance of an outlet of a dust remover, and the minimum value of the dew-point allowance is controlled within the set range of the dew-point safety allowance. The anti-condensation device can effectively prevent and control condensation corrosion of the semi-dry desulfurization device.

Description

TECHNICAL FIELD

[0001] The utility model belongs to flue gas purification technical field relates to a kind of semi-dry desulfurization devices of anti-condensation corrosion. BACKGROUND

[0002] Circulating fluidized bed semi-dry desulfurization is widely used in the field of flue gas purification in steel and garbage incineration industry due to its simple system, low corrosion and other advantages. However, corrosion problems occur in the actual application process, and the main reason is that the dew point corrosion occurs due to too low flue gas temperature control at the outlet of the desulfurization tower. The flue gas temperature at the outlet of the desulfurization tower is usually designed to be higher than the water dew point by 10℃ to avoid bag blinding and equipment corrosion during operation. In actual operation, the composition of flue gas fluctuates and deviates from the design value, especially the water vapor content in flue gas and the flue gas temperature, which causes the water dew point of flue gas at the outlet of the desulfurization tower to deviate seriously from the design, so that the water dew point control parameters of flue gas at the outlet of the desulfurization tower cannot be accurately evaluated in real time.

[0003] The semi-dry desulfurization tower usually has one layer of atomizing lances in the main reaction zone and the secondary reaction zone for atomizing water into droplets to fully absorb SO2 in flue gas. When flue gas load and flue gas parameters change, the outlet temperature of the desulfurization tower is usually controlled by adjusting the working load of the atomizing lances. However, the concentration of circulating materials changes at each cross section in the tower during load change, and in this case, the fixed single-layer atomizing lance scheme has poor load adaptability.

[0004] Based on the above status, the utility model provides a kind of semi-dry desulfurization device of anti-condensation corrosion, and the device has the advantages of variable condition control and anti-condensation corrosion. UTILITY MODEL CONTENTS

[0005] The utility model discloses a kind of semi-dry desulfurization devices of anti-condensation corrosion, and its component equipment includes inlet flue (1), backflow flue (2), smoke tank (3), venturi (4), lower layer atomizing lance (5), upper layer atomizing lance (6), tower body (7), desulfurization tower outlet flue gas temperature measuring device (8), desulfurization tower outlet flue gas absolute pressure measuring device (9), desulfurization tower outlet flue gas humidity measuring device (10), bag filter (11), dust collector outlet flue gas temperature measuring device (12), dust collector outlet flue gas absolute pressure measuring device (13), dust collector outlet flue gas humidity measuring device (14), outlet flue (15), return material chute (16).

[0006] The desulfurization tower is a CFB desulfurization tower, consisting of a tower body and a bottom smoke box. The bottom smoke box is connected to the inlet flue and the return flue. A venturi tube connects the smoke box and the tower body. There is one layer of lower atomizing spray guns and three layers of upper atomizing spray guns. Both the lower and upper atomizing spray guns are evenly distributed in a ring on the side wall of the tower body. The desulfurization tower outlet flue gas temperature measuring device, the desulfurization tower outlet flue gas absolute pressure measuring device, and the desulfurization tower outlet flue gas humidity measuring device are all arranged on the flue between the tower body and the bag filter. The dust collector outlet flue gas temperature measuring device, the dust collector outlet flue gas absolute pressure measuring device, and the dust collector outlet flue gas humidity measuring device are arranged on the outlet flue of the bag filter. The return chute is located at the bottom of the bag filter.

[0007] During operation, the absolute pressure and humidity measuring devices for the flue gas at the desulfurization tower outlet, the flue gas at the desulfurization tower outlet, the flue gas at the dust collector outlet, and the flue gas at the dust collector outlet are measured online in real time, and the dew point temperature at the desulfurization tower outlet and the dust collector outlet are calculated accordingly. The formula for calculating the dew point temperature is as follows:

[0008]

[0009] In the formula, T is the water dew point temperature, M is the flue gas humidity, and P is the flue gas absolute pressure.

[0010] The flue gas temperature measuring devices at the outlets of the desulfurization tower and the dust collector measure their respective temperatures in real time. The differences between the flue gas temperature at the desulfurization tower outlet and the dew point temperature at the desulfurization tower outlet, and between the flue gas temperature at the dust collector outlet and the dew point temperature at the dust collector outlet, are calculated online in real time; these are the dew point margins at the desulfurization tower outlet and the dust collector outlet. The minimum values ​​of these dew point margins are calculated and denoted as the minimum dew point margin. A minimum dew point safety margin and a maximum dew point safety margin are set. When the flue gas load is stable but the flue gas parameters fluctuate, if the minimum dew point margin is lower than the minimum dew point temperature safety margin or higher than the maximum dew point temperature safety margin, the water flow rate of all atomizing spray guns should be reduced or increased simultaneously until the minimum dew point margin is within the range of the minimum and maximum dew point safety margins. When the flue gas composition is stable but the flue gas load fluctuates, if the minimum dew point margin is lower than the minimum dew point temperature safety margin or higher than the maximum dew point temperature safety margin, the upper atomizing spray guns should be closed or opened layer by layer. If the minimum dew point margin is higher than the minimum dew point temperature safety margin, the upper atomizing spray guns should be opened layer by layer until the minimum dew point margin is within the range of the minimum and maximum dew point safety margins.

[0011] The semi-dry desulfurization device for preventing condensation corrosion proposed in this invention is suitable for semi-dry desulfurization with flue gas parameter fluctuations and can effectively prevent condensation corrosion. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 The utility model discloses a half dry method desulfurization device anti-condensation corrosion facade schematic view.

[0013] In the drawing: 1. Inlet flue, 2. Backflow flue, 3. Smoke box, 4. Venturi tube, 5. Lower layer atomization spray gun, 6. Upper layer atomization spray gun, 7. Tower body, 8. Desulfurization tower outlet flue gas temperature measuring device, 9. Desulfurization tower outlet flue gas absolute pressure measuring device, 10. Desulfurization tower outlet flue gas humidity measuring device, 11. Bag-type dust collector, 12. Dust collector outlet flue gas temperature measuring device, 13. Dust collector outlet flue gas absolute pressure measuring device, 14. Dust collector outlet flue gas humidity measuring device, 15. Outlet flue, 16. Return material chute DETAILED DESCRIPTION

[0014] Reference Figure 1 .

[0015] The utility model provides a half dry method desulfurization device anti-condensation corrosion for flue gas purification, and its component equipment includes inlet flue (1), backflow flue (2), smoke box (3), venturi tube (4), lower layer atomization spray gun (5), upper layer atomization spray gun (6), tower body (7), desulfurization tower outlet flue gas temperature measuring device (8), desulfurization tower outlet flue gas absolute pressure measuring device (9), desulfurization tower outlet flue gas humidity measuring device (10), bag-type dust collector (11), dust collector outlet flue gas temperature measuring device (12), dust collector outlet flue gas absolute pressure measuring device (13), dust collector outlet flue gas humidity measuring device (14), outlet flue (15), return material chute (16).

[0016] The desulfurization tower is a CFB desulfurization tower, which is composed of a tower body (7) and a bottom smoke box (3). The bottom smoke box (3) is respectively communicated with an inlet flue (1) and a backflow flue (2). The Venturi tube (4) is connected with the bottom smoke box (3) and the tower body (7). The lower layer atomizing spray gun (5) is provided with one layer, and the upper layer atomizing spray gun (6) is provided with three layers. The lower layer atomizing spray gun (5) is provided with one layer, and the upper layer atomizing spray gun (6) is provided with three layers. The lower layer atomizing spray gun (5) and the upper layer atomizing spray gun (6) are evenly distributed in the lower part of the side wall of the tower body (7) in a ring shape. The return chute (16) is arranged at the bottom of the bag-type dust collector (11) and is used for recycling the removed material of the bag-type dust collector. The desulfurization tower outlet flue gas temperature measuring device (8), the desulfurization tower outlet flue gas absolute pressure measuring device (9) and the desulfurization tower outlet flue gas humidity measuring device (10) are all arranged on the flue between the tower body (7) and the bag-type dust collector (11). The dust collector outlet flue gas temperature measuring device (12), the dust collector outlet flue gas absolute pressure measuring device (13) and the dust collector outlet flue gas humidity measuring device (14) are arranged on the bag-type dust collector outlet flue. The return chute (16) is arranged at the bottom of the bag-type dust collector (11).

[0017] The operation method of the anti-condensation corrosion semi-dry desulfurization device is as follows:

[0018] 1. The desulfurization tower outlet flue gas temperature measuring device (8), the absolute pressure measuring device (9), the humidity measuring device (10), the dust collector outlet flue gas temperature measuring device (12), the absolute pressure measuring device (13) and the humidity measuring device (14) are respectively used for measuring the temperature, the absolute pressure and the humidity of the desulfurization tower outlet and the dust collector outlet in real time.

[0019] 2. According to the absolute pressure and the humidity of the desulfurization tower outlet and the dust collector outlet measured in step (1), the dew point temperature of the desulfurization tower outlet and the dew point temperature of the dust collector outlet are respectively calculated, and the calculation formula is as follows:

[0020]

[0021] In the formula, T is the water dew point temperature, M is the flue gas humidity, and P is the flue gas absolute pressure.

[0022] 3. The difference between the desulfurization tower outlet flue gas temperature and the desulfurization tower outlet dew point temperature and the difference between the dust collector outlet flue gas temperature and the dust collector outlet dew point temperature, that is, the desulfurization tower outlet dew point margin and the dust collector outlet dew point margin, are calculated in real time.

[0023] The desulfurization tower outlet dew point temperature is recorded as T M1 , and the dust collector outlet dew point temperature is recorded as T M2 .

[0024] 4. Calculate the minimum value of the desulfurization tower outlet dew point margin and the dust remover outlet dew point margin, and record it as the dew point margin minimum value.

[0025] 5. On-line real-time adjustment of the lower layer atomizing spray gun (5) and the upper layer atomizing spray gun (6), the specific method is:

[0026] When the minimum value of the dew point margin is lower than the minimum value of the dew point temperature safety margin and greater than the maximum value of the dew point temperature safety margin under the condition of stable flue gas load and flue gas parameter fluctuation, the water flow of the lower layer atomizing spray gun (5) and the upper layer atomizing spray gun (6) is simultaneously reduced or increased until the minimum value of the dew point margin is within the range of the minimum value and the maximum value of the dew point safety margin; under the condition of stable flue gas composition and flue gas load fluctuation, when the minimum value of the dew point margin is lower than the minimum value of the dew point temperature safety margin or greater than the maximum value of the dew point temperature safety margin, the upper layer atomizing spray gun (6) is closed or opened layer by layer, and when the minimum value of the dew point margin is greater than the minimum value of the dew point temperature safety margin, the upper layer atomizing spray gun (6) is opened layer by layer until the minimum value of the dew point margin is within the range of the minimum value and the maximum value of the dew point safety margin.

Claims

1. A semi-dry desulfurization device for preventing condensation corrosion, comprising an inlet flue, a return flue, a flue box, a venturi tube, a lower atomizing spray gun, an upper atomizing spray gun, a tower body, a desulfurization tower outlet flue gas temperature measuring device, a desulfurization tower outlet flue gas absolute pressure measuring device, a desulfurization tower outlet flue gas humidity measuring device, a bag filter, a bag filter outlet flue gas temperature measuring device, a bag filter outlet flue gas absolute pressure measuring device, a bag filter outlet flue gas humidity measuring device, an outlet flue, and a return chute, characterized in that... The desulfurization tower outlet flue gas temperature measuring device, the desulfurization tower outlet flue gas absolute pressure measuring device, and the desulfurization tower outlet flue gas humidity measuring device are arranged on the flue between the tower body and the bag filter. The dust collector outlet flue gas temperature measuring device, the dust collector outlet flue gas absolute pressure measuring device, and the dust collector outlet flue gas humidity measuring device are arranged on the bag filter outlet flue.

2. The semi-dry desulfurization device for preventing condensation corrosion according to claim 1, characterized in that: The upper atomizing spray gun has three layers, and each layer of atomizing spray gun is evenly distributed in a ring on the side wall of the tower.

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