A double flue system for preventing carbon black tail gas boiler from being blocked

Abstract

The utility model discloses a double flue system for carbon black tail gas boiler anti -blocking dust, including hearth, hearth side is equipped with low nitrogen combustor, one side of hearth is connected with main flue, is equipped with a plurality of superheater, senior coal economizer, SCR reaction area in proper order in main flue, the tail portion intercommunication of main flue is equipped with tail flue no.

Description

Technical Field

[0001] This utility model relates to the field of boiler exhaust gas treatment equipment, and in particular to a dual flue system for preventing ash blockage in carbon black exhaust gas boilers. Background Technology

[0002] Carbon black tail gas boilers use tail gas generated during the carbon black process as fuel. This fuel contains a high amount of sulfur, and combustion of the fuel also produces a certain amount of NO. x (Nitrogen oxides). To meet the final emission requirements of boilers, this type of boiler is often equipped with SCR denitrification, using ammonia water as a reducing agent. Unreacted ammonia and SO2 in the flue gas condense together with H2O at the hot surface of the boiler tail to form an acidic liquid (mainly ammonium bisulfate). The ammonium bisulfate liquid is viscous and will stick to the hot surface at the tail, combining with ash in the flue gas to form hot surface ash blockage, affecting the normal operation and service life of the boiler. However, existing single-channel boilers need to be shut down and cleaned with water after each ash blockage. Shutting down the boiler will cause the entire boiler system to shut down, reducing the company's revenue. Alternatively, cleaning with water will produce acidic liquid, which will corrode the flue wall. At the same time, wastewater purification treatment is required, causing environmental pollution and increasing operating costs. Utility Model Content

[0003] The purpose of this invention is to provide a dual flue system for preventing ash blockage in carbon black tail gas boilers, in order to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a dual-flue system for preventing ash blockage in a carbon black tail gas boiler, comprising a furnace, a low-NOx burner on the side of the furnace, a main flue connected to one side of the furnace, a plurality of superheaters, an upper economizer, and an SCR reaction zone arranged sequentially in the main flue, a tail flue I and a tail flue II respectively connected to the tail flue I and the tail flue II respectively, a lower economizer, an upper air preheater, a lower air preheater and a chimney arranged sequentially in the tail flue I and the tail flue II, an air supply assembly connected to the low-NOx burner in the upper air preheater and a water supply assembly connected to the lower economizer in the upper economizer.

[0005] Preferably, the multiple superheaters arranged in sequence are a screen-type superheater, a high-temperature superheater, and a low-temperature superheater.

[0006] Preferably, the tail flue 1 is connected to the tail flue 2 and is provided with a cleaning hot smoke bypass, and one end of the cleaning hot smoke bypass is provided with an electric cleaning hot smoke bypass baffle door.

[0007] Preferably, both the first and second tail flues are equipped with electric flue valves at one end of the main flue.

[0008] Preferably, both ends of the tail flue one and the tail flue two are equipped with pressure measuring devices, and the flue gas outlets on both sides are connected to a chimney.

[0009] Preferably, the air supply assembly includes a blower, and the blower is connected to both lower-level air preheaters with cold air ducts. The lower-level air preheaters are connected to the upper-level air preheaters on the same side through pipes, and both upper-level air preheaters are connected to the low-NOx burner through hot air ducts.

[0010] Preferably, a cold air duct valve is provided in the middle of the cold air duct, and a hot air duct valve is provided in the middle of the hot air duct.

[0011] Preferably, the water supply assembly includes a water pump, which is connected to the lower economizers on both sides via a water pipe one, and the lower economizers on both sides are connected to the upper economizer via a water pipe two, with a boiler drum connected to the upper economizer.

[0012] Preferably, the middle section of the first water pipe is connected to an inlet shut-off valve, and the middle section of the second water pipe is connected to an outlet shut-off valve.

[0013] The beneficial effects of this utility model are:

[0014] 1. By opening the hot flue bypass for cleaning the ash removal without shutting down the boiler, the cleaning operation of the tail flue 1 or tail flue 2 can be carried out, which can ensure the continuous operation of the boiler and reduce the operating losses caused by traditional shutdown cleaning.

[0015] 2. The tail flue 1 and tail flue 2 are connected to the main flue. The dual flue system can clean the acidic deposits on the tail flue hot surface in time, reduce acid corrosion of the pipes, and extend the service life of the tail hot surface.

[0016] 3. Compared with the method of cleaning with water, the present invention avoids the generation of acidic liquid that corrodes the flue wall, and also eliminates the need for wastewater purification treatment, thus avoiding environmental pollution and reducing operating costs. Attached Figure Description

[0017] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model.

[0018] In the diagram: 1. Furnace; 2. Low-NOx burner; 3. Main flue; 4. Upper economizer; 5. SCR reaction zone; 6. Tail flue 1; 7. Tail flue 2; 8. Lower economizer; 9. Upper air preheater; 10. Lower air preheater; 11. Flue gas outlet; 12. Gas supply assembly; 121. Blower; 122. Cold air duct; 123. Pipeline; 124. Hot air duct; 13. Water supply assembly; 131. Water pump; 13 2. Water pipe 1; 133. Water pipe 2; 134. Boiler drum; 14. Screen-type superheater; 15. High-temperature superheater; 16. Low-temperature superheater; 17. Ash removal hot flue bypass; 18. Electric ash removal hot flue bypass damper; 19. Electric flue gas valve; 20. Pressure measuring equipment; 21. Cold air duct valve; 22. Hot air duct valve; 23. Inlet shut-off valve; 24. Outlet shut-off valve; 25. Carbon black tail gas inlet; 26. Chimney. Detailed Implementation

[0019] The detailed embodiments of this utility model will be described clearly and completely below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0020] Please see Figure 1 This utility model provides a dual flue system for preventing ash blockage in a carbon black tail gas boiler, including a furnace 1. A low-NOx burner 2 is provided on the side of the furnace 1. A main flue 3 is connected to one side of the furnace 1. Multiple superheaters, an upper economizer 4, and an SCR reaction zone 5 are arranged sequentially in the main flue 3. The tail end of the main flue 3 is connected to a tail flue 6 and a tail flue 7. The tail flue 6 and the tail flue 7 are respectively provided with a lower economizer 8, an upper air preheater 9, a lower air preheater 10, and a flue gas outlet 11. The upper air preheater 9 and the lower air preheater 10 are connected to the low-NOx burner 2 and are provided with a gas supply assembly 12. The lower economizer 8 is connected to the upper economizer 4 and is provided with a water supply assembly 13.

[0021] Specifically, during normal boiler operation, the electric flue gas valve 19 on the side of tail flue 6 is opened, along with the cold air duct 122, cold air duct valve 21, upper / lower air preheater 10, hot air duct 124, hot air duct valve 22, lower economizer 8, inlet shut-off valve, and outlet shut-off valve on the same side. The electric flue gas valve 19 on the side of tail flue 7 is closed, and the devices in the flue on that side are also closed. The water in the lower economizer 8 is drained by opening the drain valve in the lower economizer 8 in tail flue 7. Depending on the ash blockage, the electric cleaning hot flue bypass damper 18 is opened, and the pressure measuring devices 20 installed at the inlet and outlet of the lower economizer 8 are observed. When the flue gas resistance drop reaches the expected value, the electric cleaning hot flue bypass damper 18 is closed. If ash blockage occurs on the hot surface of tail flue 6, the above process is repeated to complete the system cleaning; otherwise, tail flue 7 is cleaned.

[0022] Specifically, along the flue gas flow path, this system consists of, in sequence, a low-NOx burner, furnace 1, multi-stage superheater area, upper economizer 4, SCR reaction zone 5, two flue ducts, namely tail flue duct one 6 or tail flue duct two 7, electric flue gas valve 19, lower economizer 8, upper air preheater 9, lower air preheater 10, and chimney 26.

[0023] This system has two sets of upper and lower air preheaters 10 installed in the tail of the main flue 3 to heat the cold air into hot air and send it into the furnace 1 to assist in the combustion of carbon black tail gas, thereby improving the efficiency of the entire system. The system passes through the blower 121, cold air duct 122, cold air duct valve 21, lower air preheater 10, upper air preheater 9, hot air duct 124, hot air duct valve 22, and low-NOx burner in sequence along the air flow path.

[0024] This system has two sets of lower economizers 8 installed in the tail of the main flue 3 double flue for heating boiler feedwater. The water-side flow of this system passes through feedwater pump 131, water pipe 132, inlet shut-off valve 23, lower economizer 8, water pipe 23, outlet shut-off valve 24, upper economizer 4, and boiler drum 134 in sequence.

[0025] Specifically, the multiple superheaters arranged in sequence are a screen-type superheater 14, a high-temperature superheater 15, and a low-temperature superheater 16. Through the multiple heaters arranged in sequence, heat in the flue gas is absorbed in stages, realizing the cascade utilization of flue gas heat and improving the overall thermal efficiency of the boiler.

[0026] Specifically, the tail flue 1 6 is connected to the tail flue 2 7 and is equipped with a cleaning hot flue bypass 17. One end of the cleaning hot flue bypass 17 is equipped with an electric cleaning hot flue bypass damper 18. The pressure measuring device 20 installed at the inlet of the lower economizer 8 and the outlet of the lower air preheater 10 is observed. When the flue gas resistance exceeds the limit value, the electric cleaning hot flue bypass damper 18 in the cleaning hot flue bypass 17 is opened. When the flue gas resistance drops to the expected value, the damper of the cleaning hot flue bypass 17 is closed.

[0027] Specifically, both the tail flue 1 6 and the tail flue 2 7 are equipped with electric flue gas valves 19 at one end of the main flue 3. By controlling the opening and closing of the electric flue gas valves 19 on both sides, the flue gas from the main flue 3 can be discharged into the tail flue 1 6 or the tail flue 2 7 respectively for further treatment of the flue gas.

[0028] Specifically, pressure measuring devices 20 are installed at both ends of the tail flue 6 and the tail flue 7. The flue gas outlets 11 on both sides are connected to a chimney 26. The pressure measuring devices 20 detect the gas pressure in the tail flue 6 and / or the tail flue 7. When the flue gas resistance exceeds the expected value, the cleaning hot flue bypass 17 will be opened to clean the tail flue 6 or the tail flue 7 on that side, so as to ensure the continuous operation of the boiler and reduce the operating losses caused by traditional shutdown cleaning.

[0029] Specifically, the pressure measuring device 20 is an existing flue pressure detection device, so it will not be described in detail.

[0030] Specifically, the electric dust removal hot smoke bypass damper 18, electric flue gas valve 19, cold air duct valve 21, hot air duct valve 22, water inlet shut-off valve 23, and water outlet shut-off valve 24 are all existing valve equipment, so they will not be described in detail.

[0031] Specifically, the air supply assembly 12 includes a blower 121. The blower 121 is connected to the lower-level air preheaters 10 on both sides, each of which is equipped with a cold air duct 122. The lower-level air preheaters 10 are connected to the upper-level air preheaters 9 on the same side through pipes 123. The upper-level air preheaters 9 on both sides are connected to the low-NOx burner 2 through hot air ducts 124. This system has two sets of upper and lower-level air preheaters 10 in the double flue at the tail end of the flue, which are used to heat the cold air into hot air and send it into the furnace 1 to assist in the combustion of carbon black tail gas, thereby improving the efficiency of the entire system.

[0032] Specifically, the cold air duct 122 is provided with a cold air duct valve 21 in the middle, and the hot air duct 124 is provided with a hot air duct valve 22 in the middle. By controlling the opening and closing of the cold air duct valve 21 and / or the hot air duct valve 22 respectively, the opening and closing of the cold air duct 122 and / or the hot air duct 124 can be realized, which facilitates the airflow delivery.

[0033] Specifically, the water supply component 13 includes a water pump 131, which is connected to the lower economizers 8 on both sides via a water pipe 132. The lower economizers 8 on both sides are connected to the upper economizer 4 via a water pipe 2 133. The upper economizer 4 is connected to a boiler drum 134. This system has two sets of lower economizers 8 in the double flue at the tail of the flue for heating boiler feedwater.

[0034] Specifically, the middle section of the first water pipe 132 is connected to an inlet shut-off valve 23, and the middle section of the second water pipe 133 is connected to an outlet shut-off valve 24. By controlling the opening and closing of the inlet shut-off valve 23 and / or the outlet shut-off valve 24 respectively, the opening and closing of the first water pipe 132 and / or the second water pipe 133 can be realized, which facilitates the transportation of water.

[0035] The working principle of this utility model is as follows: During use, the boiler operates normally. The electric flue gas valve 19 on the side of the tail flue 6 is opened, and the cold air duct 122, cold air duct valve 21, upper / lower air preheater 10, hot air duct 124, hot air duct valve 22, lower economizer 8, inlet shut-off valve, and outlet shut-off valve on the same side are opened. The electric flue gas valve 19 on the side of the tail flue 7 is closed, and the device in the flue on that side is closed. The water in the lower economizer 8 is drained by opening the drain valve in the lower economizer 8 in the tail flue 7. Depending on the ash blockage, the electric cleaning hot flue bypass damper 18 is opened. The pressure measuring device 20 installed at the inlet and outlet of the lower economizer 8 is observed. When the flue gas resistance drop reaches the expected value, the electric cleaning hot flue bypass damper 18 is closed. If ash blockage occurs on the hot surface of the tail flue 6, the above process is repeated to complete the system cleaning. Otherwise, the tail flue 7 is cleaned.

[0036] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A dual-flue system for preventing ash blockage in a carbon black tail gas boiler, comprising a furnace (1), characterized in that, The furnace (1) is provided with a low-NOx burner (2) on the side. The furnace (1) is connected to a main flue (3) on one side. The main flue (3) is provided with multiple superheaters, an upper economizer (4), and an SCR reaction zone (5) in sequence. The tail of the main flue (3) is connected to a tail flue one (6) and a tail flue two (7). The tail flue one (6) and the tail flue two (7) are provided with a lower economizer (8), an upper air preheater (9), a lower air preheater (10), and a flue gas outlet (11) in sequence. The upper air preheater (9) and the lower air preheater (10) are connected to the low-NOx burner (2) and are provided with a gas supply assembly (12). The lower economizer (8) is connected to the upper economizer (4) and is provided with a water supply assembly (13).

2. A dual-flue system for preventing ash blockage in a carbon black tail gas boiler according to claim 1, characterized in that, The multiple superheaters arranged in sequence are a screen-type superheater (14), a high-temperature superheater (15), and a low-temperature superheater (16).

3. A dual-flue system for preventing ash blockage in a carbon black tail gas boiler according to claim 1, characterized in that, The tail flue 1 (6) is connected to the tail flue 2 (7) and is provided with a cleaning hot smoke bypass (17). One end of the cleaning hot smoke bypass (17) is provided with an electric cleaning hot smoke bypass baffle door (18).

4. A dual-flue system for preventing ash blockage in a carbon black tail gas boiler according to claim 1, characterized in that, Both the tail flue 1 (6) and the tail flue 2 (7) are equipped with electric flue gas valves (19) at one end of the main flue (3).

5. A dual-flue system for preventing ash blockage in a carbon black tail gas boiler according to claim 1, characterized in that, Both the tail flue duct 1 (6) and the tail flue duct 2 (7) are equipped with pressure measuring devices (20) at one end of the flue gas outlet (11), and the flue gas outlets (11) on both sides are connected to a chimney (26).

6. A dual-flue system for preventing ash blockage in a carbon black tail gas boiler according to claim 1, characterized in that, The gas supply assembly (12) includes a blower (121), which is connected to the lower air preheaters (10) on both sides and is provided with a cold air duct (122). The lower air preheaters (10) are connected to the upper air preheaters (9) on the same side through a pipe (123). The upper air preheaters (9) on both sides are connected to the low-NOx burner (2) through a hot air duct (124).

7. A dual-flue system for preventing ash blockage in a carbon black tail gas boiler according to claim 6, characterized in that, The cold air duct (122) is provided with a cold air duct valve (21) in the middle, and the hot air duct (124) is provided with a hot air duct valve (22) in the middle.

8. A dual-flue system for preventing ash blockage in a carbon black tail gas boiler according to claim 1, characterized in that, The water supply component (13) includes a water pump (131), which is connected to the lower economizers (8) on both sides through a water pipe (132). The lower economizers (8) on both sides are connected to the upper economizer (4) through a water pipe (133). The upper economizer (4) is connected to a boiler drum (134).

9. A dual-flue system for preventing ash blockage in a carbon black tail gas boiler according to claim 8, characterized in that, The middle section of the first water pipe (132) is connected to an inlet shut-off valve (23), and the middle section of the second water pipe (133) is connected to an outlet shut-off valve (24).

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