Industrial furnace dry desulfurization device and desulfurization method

Abstract

The present invention provides an industrial furnace dry desulfurization device and a desulfurization method. The industrial furnace dry desulfurization device comprises a dry desulfurization tower, an inlet flue and an outlet flue. The dry desulfurization tower is divided into a left desulfurization chamber and a right desulfurization chamber by a vertically arranged partition. The left desulfurization chamber and the right desulfurization chamber are connected at the bottom. A first ash hopper is arranged at the bottom of the dry desulfurization tower, a compressed air interface is arranged at the lower part of the first ash hopper, and a star-shaped discharge valve is arranged at the ash discharge port at the bottom of the first ash hopper; the top of the right desulfurization chamber is connected to the inlet flue through a venturi, a slaked lime interface is arranged at the throat of the venturi, a steam interface is arranged on the inlet flue, and the top of the left desulfurization chamber is connected to the outlet flue. The industrial furnace dry desulfurization device of the present invention has the advantages of compact structure, low investment, easy operation and high desulfurization efficiency.

Description

Technical Field

[0001] The invention relates to flue gas desulfurization technology, and in particular to an industrial furnace dry desulfurization device and a desulfurization method. Background Art

[0002] After nearly 30 years of development, flue gas desulfurization has become a mature and stable technology. Various types of flue gas desulfurization devices have been widely used in industrial furnaces and coal-fired power plants in various countries around the world. Flue gas desulfurization technology is an important means to control sulfur dioxide and acid rain. According to the state of the absorbent and the desulfurization product, it is divided into three types: wet desulfurization, semi-dry desulfurization and dry desulfurization. Compared with wet desulfurization, the advantages of dry desulfurization technology are simple process, no sewage and dirty acid treatment problems, low energy consumption, especially the purified flue gas does not require secondary heating and is less corrosive; its disadvantages are low desulfurization efficiency, not as good as wet desulfurization, and large equipment, large investment, large floor space, and high operating technology requirements. Summary of the invention

[0003] The purpose of the present invention is to propose an industrial furnace dry desulfurization device, which has the advantages of compact structure, low investment, easy operation and high desulfurization efficiency, in view of the problems that the current dry desulfurization equipment is large in size, requires large investment, occupies a large area, has high operating technical requirements and low desulfurization efficiency.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a dry desulfurization device for an industrial furnace, comprising a dry desulfurization tower, an inlet flue and an outlet flue, the dry desulfurization tower is divided into a left desulfurization chamber and a right desulfurization chamber by a vertically arranged partition, the left desulfurization chamber and the right desulfurization chamber are connected at the bottom, a first ash hopper is arranged at the bottom of the dry desulfurization tower, a compressed air interface is arranged at the lower part of the first ash hopper, and a star-shaped unloading valve is arranged at the ash discharge port at the bottom of the first ash hopper; the inlet flue is connected with the top of the right desulfurization chamber through a venturi, a slaked lime interface is arranged at the throat of the venturi, a steam interface is arranged on the inlet flue, and the top of the left desulfurization chamber is connected with the outlet flue.

[0005] Furthermore, the Venturi is a Venturi contraction tube, which is located at the flue gas inlet section of the dry desulfurization tower. A slaked lime interface is arranged at the throat of the Venturi. The flue gas that needs to be desulfurized by the industrial furnace is introduced into the Venturi through the inlet flue. Through the scaling effect of the Venturi, the slaked lime and the flue gas are fully mixed, so that the acidic sulfur dioxide gas in the flue gas is fully neutralized with the alkaline slaked lime powder to achieve the purpose of primary desulfurization.

[0006] Furthermore, an inertial louver mixer is provided in the upper middle part of the right desulfurization chamber. The inertial louver mixer is welded to the front and rear walls of the right desulfurization chamber by angle steels, 3-4 rows in the longitudinal direction (along the flue gas flow direction), and two adjacent rows in the transverse direction (vertical to the flue gas flow direction) in a staggered arrangement. The setting of the inertial louver mixer increases the mixing and travel of the flue gas in the dry desulfurization tower, increases the reaction time of the flue gas and slaked lime in the dry desulfurization tower, and makes the acidic sulfur dioxide gas in the flue gas fully react with the alkaline slaked lime powder to achieve the purpose of secondary desulfurization.

[0007] Furthermore, the bottom of the left desulfurization chamber is connected to the right desulfurization chamber through the first ash hopper, which is a conical structure (narrowed form), and two star-shaped discharge valves are arranged in series at the ash discharge port at the bottom of the first ash hopper. The staggered operation of the two star-shaped discharge valves can ensure the airtightness of the dry desulfurization tower. The sulfate generated by the reaction can be discharged from the dry desulfurization tower regularly through the star-shaped discharge valve. When the flue gas passes through the first ash hopper, the direction of the flue gas changes 180° and enters the left desulfurization chamber, where it continues to react with sulfur dioxide in the flue gas.

[0008] Furthermore, the lower edge of the partition in the dry desulfurization tower extends into the first ash hopper at 1 / 2-1 / 3, and the built-in partition of the dry desulfurization tower forms another large Venturi type of the entire dry desulfurization tower, ensuring that the acidic sulfur dioxide gas in the flue gas is fully neutralized with the alkaline slaked lime powder to achieve the purpose of three-stage desulfurization. At the same time, the built-in partition of the dry desulfurization tower forms a U-shaped structure of the entire dry desulfurization tower, which increases the residence time of the flue gas in the dry desulfurization tower, effectively reducing the volume of the dry desulfurization tower, and providing sufficient neutralization reaction time for dry desulfurization.

[0009] Furthermore, a second ash hopper is provided at the bottom of the outlet flue, a star-shaped discharge valve is provided at the ash discharge port of the second ash hopper, and a smoke outlet is provided on the lower side of the outlet flue.

[0010] Furthermore, the steam interface is a low-pressure steam interface. The low-pressure steam sprayed into the inlet flue from the low-pressure steam interface mixes with the flue gas to increase the moisture content of the flue gas. Since SO2 gas easily forms H2SO3 with H2O gas, and the oxygen content in dry flue gas is generally not less than 6%, the oxygen in the flue gas further oxidizes H2SO3 into H2SO4 to form a strong acid, which provides conditions for the subsequent acid-base neutralization reaction and is beneficial to improving the desulfurization efficiency.

[0011] Furthermore, the slaked lime interface and the steam interface are arranged separately, and the steam interface is located on the flue before the slaked lime interface. The reason why the steam and slaked lime are not sprayed into the flue together is to prevent the slaked lime powder that has just entered the flue from being agglomerated before being dispersed due to the high humidity of the steam, which affects the full contact between the slaked lime and the flue gas, and reduces the desulfurization efficiency.

[0012] Another object of the present invention is to provide a dry desulfurization method for an industrial furnace, comprising the following steps: the flue gas is mixed with steam to reach a certain moisture content (when the relative humidity is 40%-50%, the activity of slaked lime is enhanced and it can absorb SO2 very effectively), and then further mixed with slaked lime in a venturi to accelerate the flue gas into the right desulfurization chamber of the desulfurization tower, and the flue gas runs from top to bottom; the flue gas enters the left desulfurization chamber from the right desulfurization chamber through the bottom ash hopper, and the flue gas runs from bottom to top. After the flue gas undergoes a desulfurization reaction in the desulfurization tower, it is discharged and enters subsequent processes (such as a bag filter).

[0013] The industrial furnace dry desulfurization device of the present invention has a simple and compact structure, and the industrial furnace dry desulfurization method is scientific and reasonable. Compared with the prior art, it has the following advantages:

[0014] 1) The present invention is provided with a low-pressure steam interface at the inlet flue. The low-pressure steam injected from the low-pressure steam interface is mixed with the flue gas to increase the moisture content of the flue gas and greatly improve the efficiency of dry desulfurization. The present invention uses steam instead of water spraying, on the one hand to prevent the flue gas from being greatly cooled due to water spraying, resulting in dust sticking to the bag after the flue gas enters the bag filter, and on the other hand to prevent the temperature from being greatly reduced, thereby increasing the heating cost during flue gas denitration.

[0015] 2) The flue gas inlet of the desulfurization tower of the present invention adopts a Venturi, and a slaked lime injection interface is arranged at the throat of the Venturi. The flue gas that needs to be desulfurized by the industrial furnace is introduced into the Venturi through the inlet flue. Through the scaling effect of the Venturi, the slaked lime and the flue gas are fully mixed, so that the acidic sulfur dioxide gas in the flue gas is fully neutralized with the alkaline slaked lime powder to achieve the purpose of primary desulfurization.

[0016] 3) The dry desulfurization tower of the present invention is divided into two chambers, the left and right chambers. The flue gas to be treated enters the right desulfurization chamber of the dry desulfurization tower. The inertial shutter mixer arranged in the upper part of the right desulfurization chamber can strengthen the mixing of flue gas and slaked lime, prolong the reaction time of flue gas and slaked lime in the desulfurization tower, and improve the desulfurization efficiency;

[0017] 4) The bottoms of the left and right desulfurization chambers of the dry desulfurization tower of the present invention are conical ash hopper structures, and the bottom connection is in a conical form. The flue gas is accelerated when passing through the bottom, so that the unreacted slaked lime and the like are carried into the left chamber by the flue gas and continue to react with the sulfur dioxide in the flue gas.

[0018] 5) The bottom of the dry desulfurization tower of the present invention is a conical ash hopper structure, and the sodium sulfate salt generated by the reaction is discharged through a star-shaped discharge valve. A large amount of sulfate is generated here and needs to be discharged continuously, so two star-shaped discharge valves are arranged to ensure the airtightness of the tower.

[0019] 6) The conical structure at the bottom of the dry desulfurization tower of the present invention, when the ash hopper is unloading ash, if the flow is blocked, open the compressed air interface to allow compressed air to enter the ash hopper to loosen the accumulated materials at the bottom, so that the sulfate can be discharged smoothly from the desulfurization device.

[0020] 7) The dry desulfurization of the present invention comprehensively utilizes the flues before and after the desulfurization tower to participate in the reaction of removing sulfur dioxide, the design of the inlet venturi, the design of the inertial louver mixer in the desulfurization tower, the design of the left and right desulfurization chambers in the desulfurization tower, and the design of the flue gas accelerated return at the first ash hopper at the bottom. Although the dry desulfurization tower is compact and not bulky, the reaction time is long enough and the desulfurization effect is good.

[0021] In summary, the present invention adopts dry desulfurization with slaked lime to remove acidic gas (sulfur dioxide) in flue gas. No waste water or waste acid liquid is discharged during the treatment process, thereby reducing secondary pollution. At the same time, the present invention has carried out a series of transformation designs on the dry desulfurization device of the industrial furnace, so that the device has a compact structure, low investment, easy operation, and significantly improved desulfurization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of the industrial furnace dry desulfurization device of the present invention.

[0023] Among them: 1. Steam interface, 2. Inlet flue, 3. Slaked lime interface, 4. Venturi, 5. Inertial shutter mixer, 6. Dry desulfurization tower, 7. Star-shaped unloading valve, 8. Compressed air interface, 9. Star-shaped unloading valve, 10. First ash hopper, 11. Second ash hopper 11. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with embodiments:

[0025] Example 1

[0026] This embodiment discloses an industrial furnace dry desulfurization device, the structure of which is as follows: Figure 1As shown, it includes an industrial furnace dry desulfurization device, including a dry desulfurization tower 6, an inlet flue 2 and an outlet flue 9. The dry desulfurization tower 6 is divided into a left desulfurization chamber and a right desulfurization chamber by a vertically arranged partition. The lower edge of the partition in the dry desulfurization tower 6 extends into the first ash hopper 1 / 2-1 / 3. The bottoms of the left desulfurization chamber and the right desulfurization chamber are connected. The bottom of the desulfurization tower 6 is provided with a first ash hopper 10, and the lower part of the first ash hopper 10 is provided with a compressed air interface 8. A star-shaped discharge valve 7 is provided in series at the ash discharge port at the bottom of the first ash hopper. The setting of the two star-shaped discharge valves can ensure the airtightness of the flue gas in the tower. The sodium sulfate salt generated by the reaction can be discharged in time through the star-shaped discharge valve. The bottom of the left desulfurization chamber is connected to the right desulfurization chamber through the first ash hopper. The ash hopper is a conical structure (narrowed form). The flue gas is accelerated when passing through the first ash hopper, so that the unreacted slaked lime, etc. are carried by the flue gas and turned 180°C before entering the left desulfurization chamber to continue reacting with sulfur dioxide in the flue gas.

[0027] The inlet flue 2 is connected to the top of the right desulfurization chamber through the venturi 4. The throat of the venturi 4 is provided with a slaked lime interface 3. The venturi is a venturi contraction tube, which is located at the inlet flue of the dry desulfurization tower. The flue gas that needs to be desulfurized by the industrial furnace is introduced into the venturi through the inlet flue. Through the scaling effect of the venturi, the slaked lime and the flue gas are fully mixed, so that the acidic sulfur dioxide gas in the flue gas is fully neutralized with the alkaline slaked lime powder to achieve the purpose of primary desulfurization. The inlet flue 2 is provided with a steam interface 1, which is a low-pressure steam interface. The low-pressure steam sprayed from the low-pressure steam interface 1 and the flue gas can be mixed to increase the moisture content of the flue gas. The top of the left desulfurization chamber is connected to the outlet flue 9. The bottom of the outlet flue 9 is provided with a second ash hopper 11, and the ash outlet of the second ash hopper 11 is provided with a star-shaped discharge valve 7. The lower side of the outlet flue 9 is provided with a flue gas outlet, and the lower part of the second ash hopper 11 is also provided with a compressed air interface 8.

[0028] An inertial louver mixer 5 is arranged in the upper middle part of the right desulfurization chamber. The arrangement of the inertial louver mixer 5 strengthens the mixing of flue gas and slaked lime, prolongs the reaction time of flue gas and slaked lime in the desulfurization tower, and further improves the desulfurization efficiency.

[0029] The method for desulfurizing flue gas using the dry desulfurization device for industrial furnaces of this embodiment comprises the following steps: after the flue gas is mixed with low-pressure steam in the inlet flue 2, it is further mixed with slaked lime in a venturi to accelerate the flue gas into the right desulfurization chamber of the desulfurization tower 6, and further mixed with the flue gas and slaked lime in the inertial shutter mixer 5, and the flue gas runs from top to bottom; the flue gas enters the left desulfurization chamber from the right desulfurization chamber through the bottom ash hopper, and the flue gas runs from bottom to top. After the flue gas undergoes a desulfurization reaction in the dry desulfurization tower 6, the flue gas is discharged from the bottom side of the outlet flue 9 and enters a subsequent process (such as the next flue gas treatment equipment - bag filter).

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An industrial furnace dry desulfurization method, characterized in that: The following steps are involved: After the flue gas is mixed with steam and reaches a relative humidity of 40%-50%, it is further mixed with slaked lime in the venturi to accelerate into the right desulfurization chamber of the desulfurization tower, and the flue gas flows from top to bottom; the flue gas enters the left desulfurization chamber from the right desulfurization chamber through the first ash hopper at the bottom, and the flue gas flows from bottom to top. After the desulfurization reaction occurs in the desulfurization tower, the flue gas is discharged and enters the subsequent process; The flue gas that needs to be desulfurized in industrial furnaces is introduced into the Venturi through the inlet flue. Through the scaling effect of the Venturi, the slaked lime and the flue gas are fully mixed, so that the acidic sulfur dioxide gas in the flue gas is fully neutralized with the alkaline slaked lime powder to achieve the purpose of primary desulfurization; The setting of the inertial shutter mixer increases the mixing and travel of the flue gas in the dry desulfurization tower, increases the reaction time of the flue gas and slaked lime in the dry desulfurization tower, and makes the acidic sulfur dioxide gas in the flue gas fully react with the alkaline slaked lime powder to achieve the purpose of secondary desulfurization; The built-in partition of the dry desulfurization tower forms another large Venturi type, ensuring that the acidic sulfur dioxide gas in the flue gas is fully neutralized with the alkaline slaked lime powder to achieve the purpose of tertiary desulfurization; The industrial furnace dry desulfurization device adopted in the industrial furnace dry desulfurization method comprises a dry desulfurization tower (6), an inlet flue (2) and an outlet flue (9); the dry desulfurization tower (6) is divided into a left desulfurization chamber and a right desulfurization chamber by a vertically arranged partition; the left desulfurization chamber and the right desulfurization chamber are connected at the bottom; a first ash hopper (10) is arranged at the bottom of the dry desulfurization tower (6); a compressed air interface (8) is arranged at the lower part of the first ash hopper; a star-shaped discharge valve (7) is arranged at the ash discharge port at the bottom of the first ash hopper; the inlet flue (2) is connected to the top of the right desulfurization chamber through a venturi (4); a slaked lime interface (3) is arranged at the throat of the venturi (4); a steam interface (1) is arranged on the inlet flue (2); and the top of the left desulfurization chamber is connected to the outlet flue (9); The Venturi is a Venturi contraction tube, which is located at the flue gas inlet section of the dry desulfurization tower, and a slaked lime interface is arranged at the throat of the Venturi; An inertial shutter type mixer (5) is arranged in the middle and upper part of the right desulfurization chamber; the inertial shutter type mixer is welded to the front and rear walls of the right desulfurization chamber by angle steels, and arranged in 3-4 rows in the longitudinal direction and two adjacent rows in the transverse direction in a staggered arrangement; The lower edge of the inner partition of the dry desulfurization tower (6) extends into the first ash hopper (10) by 1 / 2 to 1 / 3; The steam interface (1) is a low-pressure steam interface; The slaked lime interface (3) is arranged separately from the steam interface (1), and the steam interface (1) is arranged on the flue in front of the slaked lime interface (3). The flue gas in the flue is first mixed with the steam to humidify the flue gas.

2. The industrial furnace dry desulfurization method according to claim 1, characterized in that: Two star-shaped discharge valves (7) are arranged in series at the ash discharge port at the bottom of the first ash hopper (10).

3. The industrial furnace dry desulfurization method according to claim 1, characterized in that: A second ash hopper (11) is provided at the bottom of the outlet flue (9), and a star-shaped discharge valve is provided at the outlet of the second ash hopper (11).

4. The industrial furnace dry desulfurization method according to claim 1 or 3, characterized in that: A smoke outlet is provided on the lower side of the outlet flue (9).

Images