Dry powder injection deacidification device and method for blast furnace gas

Abstract

The invention discloses a blast furnace gas dry powder spraying deacidification device and a blast furnace gas dry powder spraying deacidification method. The device comprises a blast furnace, primary dust removal equipment, a deacidification reaction tower, deacidification injection equipment and secondary dust removal equipment, wherein the primary dust removal equipment is connected with the blast furnace, and is used for receiving blast furnace gas and carrying out coarse dust removal on the blast furnace gas to form primary treatment coarse dust removal blast furnace gas; the deacidification reaction tower is connected with the first-stage dust removal equipment and is used for removing acidic materials in the first-stage treated coarse dust removal coal gas through deacidification agent dry powder to form second-stage treated coal gas; the deacidification injection equipment is connected with the deacidification reaction tower and is arranged to inject dry powder of a deacidification agent into the deacidification reaction tower; the second-stage dust removal equipment is connected with the deacidification reaction tower and is used for performing fine dust removal on the second-stage treated coal gas to form dust-removed coal gas. The device can solve the problem of insufficient reaction of a deacidification agent and coal gas, and improves the removal rate of acidic substances in the coal gas.

Description

Technical Field

[0001] The invention relates to a blast furnace gas dry powder spraying deacidification device and method. Background Art

[0002] In the prior art, the most common methods for removing and purifying acid gases in blast furnace gas are wet technology, semi-dry technology and dry technology.

[0003] Since HCl acid gas is highly soluble in water, wet technology can remove acid gas by spraying water or alkaline solution in the scrubbing tower. However, wet acid removal has defects such as insufficient acid removal and high water consumption, and is accompanied by a gas cooling process. At the same time, the gaseous saturated water content in the gas is relatively high, and the water carried has a certain impact on the process flow.

[0004] Semi-dry technology uses a spray absorption reactor, where the slurry is atomized, and the droplets come into contact with the flue gas to produce mass transfer and chemical reactions to remove the acidic gas. This method has high purification efficiency and no wastewater is discharged during the acid removal process, but its main disadvantages are that the nozzle is easy to wear and clog and has high atomization requirements.

[0005] The dry process technology removes acidic gases such as HCl contained in the gas through alkaline adsorbents. The dry adsorption equipment has a simple structure, low construction cost, simple operation, good purification effect without sewage generation, and is the most widely used. There are corresponding engineering implementation cases in the fields of petrochemicals and coal gasification. At present, the dry dust removal process widely used in domestic blast furnaces cannot effectively remove acidic gases such as HCl contained in blast furnace gas, resulting in corrosion and failure of subsequent gas pipes and ancillary equipment, and there is a risk of gas leakage. In addition, acidic gases entering the subsequent desulfurization process of blast furnace gas will cause the hydrolyzing agent to be poisoned and fail, reduce the service life of the catalyst, and increase the operating costs of steel enterprises.

[0006] CN114606026A discloses a method for simultaneously desulfurizing and dechlorinating blast furnace gas, wherein a dechlorination spraying device comprises a dechlorinating agent silo, a dechlorinating storage tank, a dechlorinating spraying tank, a dechlorinating pipeline component and a dechlorinating feeding component. The dechlorinating spraying device is directly connected to the inlet of a gravity dust collector and is located at the bottom of the gravity dust collector. This method makes it difficult for the raw material to fully contact the flue gas. In addition, it is also impossible to monitor and regulate the carrier gas flow rate online in real time and control the powder spraying amount, which easily causes a large solid waste output problem. Summary of the invention

[0007] In view of this, the present invention provides a blast furnace gas dry powder spray deacidification device that can solve the problem of insufficient reaction between the deacidification agent and the coal gas and improve the removal rate of acidic substances in the coal gas. On the other hand, the present invention provides a method for blast furnace gas dry powder spray deacidification using the above device. The present invention achieves the above technical purpose through the following technical solutions.

[0008] On the one hand, the present invention provides a blast furnace gas dry powder spraying deacidification device, comprising a blast furnace, a primary dust removal device, a deacidification reaction tower, a deacidification spraying device and a secondary dust removal device; wherein,

[0009] The primary dust removal equipment is connected to the blast furnace and is configured to receive blast furnace gas and perform rough dust removal on the blast furnace gas to form a primary treated rough dust-removed blast furnace gas;

[0010] The deacidification reaction tower is connected to the primary dust removal equipment and is configured to remove acidic substances in the primary treated rough dust removal coal gas through a deacidification agent dry powder to form a secondary treated coal gas;

[0011] The deacidification spraying device is connected to the deacidification reaction tower and is configured to spray the deacidification agent dry powder into the deacidification reaction tower;

[0012] The secondary dust removal equipment is connected to the deacidification reaction tower and is configured to perform fine dust removal on the secondary treated coal gas to form dust-removed coal gas.

[0013] According to the blast furnace gas dry powder spray deacidification device of the present invention, preferably, the deacidification reaction tower is provided with a first inlet, a second inlet and an outlet; the first inlet is connected to the outlet of the first-level dust removal equipment, for receiving the first-level treated coarse dust-removed blast furnace gas; the second inlet is located above the first inlet; the second inlet is connected to the deacidification spraying equipment, for receiving the deacidification agent dry powder sprayed from the deacidification spraying equipment; the outlet is connected to the second-level dust removal equipment.

[0014] According to the blast furnace gas dry powder spray deacidification device of the present invention, preferably, a gas distributor is provided in the deacidification reaction tower; the gas distributor is arranged at the lower part of the deacidification reaction tower, and the gas distributor is configured to make the primary treated coarse dust-removed blast furnace gas evenly distributed in the deacidification reaction tower.

[0015] According to the blast furnace gas dry powder spray deacidification device of the present invention, preferably, a spray gun is also provided in the deacidification reaction tower; the spray gun is arranged above the first inlet, and the vertical distance between the two is 2 to 6 m; the nozzle of the spray gun forms an angle of 30° to 90° with the flue gas flow direction.

[0016] According to the blast furnace gas dry powder spraying deacidification device of the present invention, preferably, the deacidification spraying equipment comprises a feeding unit, a pulverizer, an injector and a carrier gas controller; the deacidification spraying equipment is located above the primary dust removal equipment;

[0017] The unloading unit is used to store the deacidifying agent;

[0018] One end of the pulverizer is connected to the feeding unit, and the other end is connected to the ejector. The pulverizer is used to grind the deacidifying agent into ultrafine powder particles to form deacidifying agent dry powder;

[0019] The injector is also connected to the deacidification reaction tower and the carrier gas controller respectively, and is used to spray the deacidification agent dry powder into the deacidification reaction tower.

[0020] According to the blast furnace gas dry powder spraying deacidification device of the present invention, preferably, the unloading unit includes a raw material bin, a material level sensor, a unloading pipe, a unloading valve and a balance pipe; the raw material bin is connected to the top of the grinder through the unloading pipe, and the material level sensor is located in the raw material bin for detecting the material level; the unloading valve is located on the unloading pipe; one end of the balance pipe is connected to the upper part of the raw material bin, and the other end is connected to the grinder.

[0021] According to the blast furnace gas dry powder spray deacidification device of the present invention, preferably, the injector is correspondingly provided with an injection regulating valve and a gas detection sensor; the injection regulating valve is configured to adjust the opening of the carrier gas inlet valve, and the gas detection sensor is configured to detect the concentration of acidic substances in the gas in the deacidification reaction tower in real time, and transmit the concentration value to the carrier gas controller.

[0022] On the other hand, the present invention provides a method for dry powder spraying deacidification of blast furnace gas using the above-mentioned blast furnace gas dry powder spraying deacidification device, comprising the following steps:

[0023] (1) passing the coal gas to be treated from the blast furnace into the primary dust removal equipment, and undergoing rough dust removal to form primary treated rough dust-removed blast furnace gas;

[0024] (2) A deacidifying agent is stored in the raw material bin, and the deacidifying agent is fed into the pulverizer through the feeding unit. The pulverizer grinds the deacidifying agent into a deacidifying agent dry powder with a particle size of 300 to 800 mesh ultrafine powder; a carrier gas enters the ejector and carries the deacidifying agent dry powder entering the ejector into the deacidifying reaction tower, and the acidic substances in the primary treated coarse dust removal blast furnace gas contact and react with the deacidifying agent dry powder in the deacidifying reaction tower to form a secondary treated gas;

[0025] (3) The secondary treated coal gas enters the secondary dust removal equipment, undergoes fine dust removal, and forms dust-removed coal gas; the powder captured during the fine dust removal process is discharged from the ash discharge port of the secondary dust removal equipment.

[0026] According to the method of the present invention, preferably, the carrier gas volume is 40 to 90 m 3 / h.

[0027] According to the method of the present invention, preferably, the deacidifying agent is selected from one or more of alkaline oxides, alkaline hydroxides, carbonates or bicarbonates.

[0028] The blast furnace gas dry powder spraying deacidification device of the present invention can increase the contact area between the deacidifying agent and the coal gas reaction, improve the removal rate of acidic substances in the coal gas, and can regulate the carrier gas flow rate in real time online, control the powder spraying amount, and effectively reduce the overspray of powder, thereby reducing the solid waste discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of a blast furnace gas dry powder spraying deacidification device of the present invention.

[0030] Figure 2 It is a schematic diagram of the installation of the nozzle of the present invention.

[0031] The following are the descriptions of the reference numerals:

[0032] 1-blast furnace; 2-primary dust removal equipment; 3-deacidification reaction tower; 4-deacidification injection equipment; 411-raw material warehouse; 413-feeding pipe; 414-balance pipe; 42-pulverizer; 43-injector; 44-carrier gas controller; 45-powder injection pipeline; 5-secondary dust removal equipment. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0034] <Blast furnace gas dry powder spraying deacidification device>

[0035] The blast furnace gas dry powder spraying deacidification device of the present invention comprises a blast furnace, a primary dust removal device, a deacidification reaction tower, a deacidification spraying device and a secondary dust removal device, which are described in detail below.

[0036] Primary dust removal equipment

[0037] The primary dust removal equipment of the present invention is used for roughly removing dust from blast furnace gas to form a primary treated roughly dust-removed blast furnace gas.

[0038] The primary dust removal device of the present invention may be a gravity dust collector. The gravity dust collector is provided with at least one ash hopper, preferably at least three ash hoppers, and the ash hopper is provided with an ash discharge valve.

[0039] Deacidification reaction tower

[0040] The deacidification reaction tower of the present invention is used to remove acidic substances in the coarse dust-removed coal gas to form secondary treated coal gas.

[0041] The deacidification reaction tower is provided with a first inlet, a second inlet and an outlet, wherein the first inlet is connected to the outlet of the primary dust removal device for receiving the coarse dust removal gas of the primary dust removal device. The second inlet is connected to the deacidification spraying device for receiving the deacidification agent dry powder sprayed from the deacidification spraying device.

[0042] A gas distributor and a spray gun may also be provided in the deacidification reaction tower. The gas distributor is provided at the lower part of the deacidification reaction tower, and the gas distributor is provided to evenly distribute the primary treated coarse dust removal blast furnace gas in the deacidification reaction tower. The spray gun may be provided above the first inlet, and the vertical distance between the two may be 2 to 6 m, preferably 3 to 5 m. The nozzle of the spray gun forms an angle of 30° to 90° with the direction of the flue gas, preferably an angle of 30° to 60°, and more preferably an angle of 30° to 50°. Such an installation angle is more conducive to the powder particles suspended in the gas to fully contact with the acidic substances in the gas, improve the mixing degree of the powder and the gas, and improve the deacidification efficiency of the dry powder spraying method.

[0043] Deacidification injection equipment

[0044] The deacidification spraying equipment of the present invention is used for spraying the deacidification agent dry powder into the deacidification reaction tower.

[0045] The deacidification spraying equipment of the present invention may include a feed unit, a pulverizer, an ejector and a carrier gas controller.

[0046] The unloading unit preferably includes a raw material bin, a material level sensor, a unloading pipe, an unloading valve and a balance pipe. The raw material bin is used to store raw materials (powder deacidification agent), which is connected to the top of the pulverizer through the unloading pipe. The material level sensor is located in the raw material bin for detecting the material level. The unloading valve is located on the unloading pipe, which can control the opening and closing of the unloading pipe so as to enable unloading and refilling. One end of the balance pipe is connected to the upper part of the raw material bin, and the other end is connected to the pulverizer, which is used to balance the pressure between the raw material bin and the pulverizer to ensure smooth unloading of materials.

[0047] The other end of the pulverizer is connected to an injector, which is used to grind the powder material into ultrafine powder particles to form a deacidification agent dry powder. One end of the injector is connected to a carrier gas controller, and the other end is connected to a deacidification reactor through a powder spraying pipeline. The injector can also be provided with an injection regulating valve and a gas detection sensor, the injection regulating valve is configured to adjust the opening of the carrier gas inlet valve, and the gas detection sensor is configured to detect the concentration of acidic substances in the gas in the deacidification reaction tower in real time, and transmit the concentration value to the carrier gas controller, the carrier gas controller controls the carrier gas flow rate, and further controls the powder spraying amount by the size of the carrier gas flow rate.

[0048] The pulverizer of the present invention can be selected from one of a gas flow pulverizing classifier, a mechanical pulverizer or a multi-stage tandem classifier, preferably a gas flow pulverizing classifier or a multi-stage tandem classifier.

[0049] Secondary dust removal equipment

[0050] The secondary dust removal equipment of the present invention is used for fine dust removal of deacidified coal gas to form dust-removed coal gas.

[0051] The secondary dust removal is connected to the outlet of the deacidification reaction tower. According to one embodiment of the present invention, the secondary dust removal equipment is a bag filter.

[0052] <Blast furnace gas dry powder spray deacidification method>

[0053] The blast furnace gas dry powder spraying deacidification method of the present invention comprises the following steps: (1) a primary dust removal step; (2) a deacidification step; and (3) a secondary dust removal step. The deacidification efficiency of the method of the present invention is relatively high, at least greater than 91%. It is described in detail below.

[0054] Primary dust removal step

[0055] The coal gas to be treated is introduced from the outlet of the blast furnace into the primary dust removal equipment for rough dust removal to form the primary treated rough dust-removed blast furnace coal gas.

[0056] Deacidification step

[0057] Powdered deacidifier is stored in the raw material bin. The material level is detected by the material level sensor, and the electric discharge valve is opened to discharge the material. At the same time, the balance pipe balances the pressure between the raw material bin and the grinder to ensure smooth material discharge. The powdered deacidifier is ground into ultrafine powder particles (deacidifier dry powder) with a particle size of 300 to 800 meshes by the grinder, and then the deacidifier dry powder passes through the discharge valve to the injector. The carrier gas enters the injector and carries the deacidifier dry powder entering the injector into the spray gun pipeline in the deacidification reaction tower. According to the gas sensor to detect the concentration of gaseous acidic substances in the deacidification reaction tower, the carrier gas flow rate is adjusted by the carrier gas controller to control the spray gun powder spraying amount. The deacidifying agent dry powder is sprayed into the deacidifying tower under appropriate temperature, pressure and carrier gas flow rate. The specific surface area of ​​the powder increases rapidly, and the deacidifying powder particles are quickly activated. Under the installation angle of the nozzle, the powder particles suspended in the gas can fully contact with the acidic substances in the coal gas to react chemically. After the acidic substances such as HCl, H2S, HCN, SO2, SO3 in the blast furnace gas are absorbed, very small amounts of powder fall to the bottom of the reaction tower.

[0058] In the present invention, the deacidification agent can be selected from one or more of alkaline oxides, alkaline hydroxides, carbonates or bicarbonates, etc.; preferably selected from alkaline hydroxides or carbonates; wherein the alkaline oxide can be one or more of potassium oxide, sodium oxide or calcium oxide, preferably sodium oxide or calcium oxide. The carbonate can be one of potassium carbonate, sodium carbonate or calcium carbonate; preferably potassium carbonate or sodium carbonate. The bicarbonate can be one of potassium bicarbonate, sodium bicarbonate or calcium bicarbonate; preferably potassium bicarbonate or sodium bicarbonate.

[0059] In the present invention, the mass ratio of the deacidifying agent to the acidic component may be 1.5 to 6:1, preferably 2.5 to 4.5:1, and more preferably 3 to 4:1. This can improve the deacidification efficiency.

[0060] In the present invention, the particle size of the deacidifying agent powder is 300 to 800 meshes, preferably 500 to 800 meshes, and more preferably 650 to 750 meshes.

[0061] In the present invention, the carrier gas flow rate can be 40 to 90 m 3 / h, preferably 50 to 80 m 3 / h. The powder spraying amount can be 0.75~1.2g / Nm 3 , preferably 0.8 to 1.0 g / Nm 3 Appropriate carrier gas volume and powder spraying volume can improve the full reaction between powder and gas. Too high or too low carrier gas volume is not conducive to full reaction.

[0062] The temperature of the raw dust-removed coal gas at the outlet of the primary dust removal device of the present invention can be 100-220°C, preferably 100-200°C, more preferably 150-180°C; the HCl concentration can be 50-200 mg / Nm 3 , preferably 80 to 180 mg / Nm 3 , more preferably 100 to 150 mg / Nm 3 The dust content can be 5-10g / m 3 , preferably 6 to 10 g / m 3 , more preferably 7 to 9 g / m 3 ; The water content can be 30-55g / Nm 3 , preferably 35 to 50 g / Nm 3 , more preferably 40 to 45 g / Nm 3 .

[0063] Secondary dust removal steps

[0064] After the acidic substances are absorbed, most of the powder enters the secondary dust removal equipment with the gas, and the blast furnace gas dust and the deacidifying agent powder after the reaction are captured together and discharged from the ash discharge port of the secondary dust removal equipment. After purification, the blast furnace gas enters the TRT power generation system or other gas purification equipment system for subsequent treatment or application.

[0065] According to a specific embodiment of the present invention, the secondary dust removal equipment is configured as a bag dust collector.

[0066] The deacidification efficiency of the following examples is calculated as follows:

[0067]

[0068] Where, γ represents the removal efficiency of HCl, %; C in Indicates the concentration of acid gas at the outlet of primary treatment rough dust removal blast furnace gas, mg / Nm 3 ; C out Indicates the concentration of acidic gas in the fine dust removal outlet gas treated by the secondary dust removal equipment, mg / Nm 3 .

[0069] Example 1

[0070] Figure 1 It is a schematic diagram of a blast furnace gas dry powder spraying deacidification device of the present invention. Figure 2 It is a schematic diagram of the installation of the nozzle of the present invention.

[0071] like Figure 1 As shown, the blast furnace gas dry powder spraying deacidification device of this embodiment includes a blast furnace 1, a primary dust removal device 2, a deacidification reaction tower 3, a deacidification spraying device 4 and a secondary dust removal device 5.

[0072] The inlet of the primary dust removal device 2 is connected to the outlet of the blast furnace 1, and is used to receive the coal gas from the blast furnace 1, and roughly remove the blast furnace gas to form a primary treated roughly dusted blast furnace gas (hereinafter referred to as roughly dusted coal gas). In this embodiment, the primary dust removal device 2 is a gravity dust collector, and the gravity dust collector is provided with three ash hoppers.

[0073] The deacidification reaction tower 3 is configured to remove acidic substances from the coarse dust-removed coal gas to form a secondary treated coal gas. The deacidification reaction tower 3 is provided with a first inlet, a second inlet and an outlet, wherein the first inlet is connected to the outlet of the primary dust removal equipment 2 for receiving the coarse dust-removed coal gas from the primary dust removal equipment 2. The second inlet is arranged above the first inlet, and both are located on the same side of the deacidification reaction tower 3. The second inlet is connected to the deacidification spraying equipment 4 for receiving the deacidification agent dry powder sprayed from the deacidification spraying equipment. The outlet is arranged on the other side of the deacidification reaction tower 3 near the top. A gas distributor and a spray gun (not shown) are arranged in the deacidification reaction tower 3; the gas distributor is arranged at the lower part of the deacidification reaction tower 3, and the gas distributor is arranged to evenly distribute the primary treated coarse dust-removed blast furnace gas in the deacidification reaction tower 3. As Figure 2 As shown, the spray gun is arranged above the first inlet, the vertical distance between the two is 2 to 6 m, and the nozzle of the spray gun is aligned with the direction of the smoke (such as Figure 2 As shown, the smoke flows upward) to form an angle α, and in this embodiment, α is 30°.

[0074] The deacidification spraying device 4 includes a feeding unit, a pulverizer 42 , an injector 43 and a carrier gas controller 44 .

[0075] The unloading unit includes a raw material bin 411, a material level sensor, a unloading pipe 413, an unloading valve and a balance pipe 414. The raw material bin 411 is connected to the top of the grinding mill 42 through the unloading pipe 413. The material level sensor is located in the raw material bin 411 and is used to detect the material level. The unloading valve is located on the unloading pipe 413, which can control the opening and closing of the unloading pipe 413 so as to unload and replenish the material. One end of the balance pipe 414 is connected to the upper part of the raw material bin 411, and the other end is connected to the grinding mill 42, which is used to balance the pressure between the raw material bin 411 and the grinding mill 42 to ensure smooth unloading of materials.

[0076] The lower end of the pulverizer 42 is connected to the top of the injector 43, and the pulverizer 42 is used to grind the powder material into ultrafine powder particles. The ultrafine powder particles can flow into the injector 43. One end of the injector 43 is connected to the carrier gas controller 44, and the other end is connected to the deacidification reactor 3 through the powder injection pipeline 45. The injector 43 is correspondingly provided with an injection regulating valve and a gas detection sensor (not shown); the injection regulating valve is configured to adjust the opening of the carrier gas inlet valve, and the gas detection sensor is configured to detect the concentration of acidic substances in the gas in the deacidification reaction tower 3 in real time, and transmit the concentration value to the carrier gas controller 44, and the carrier gas controller 44 controls the carrier gas flow rate according to the concentration of the acidic substance, and controls the powder injection amount by the carrier gas flow rate.

[0077] The secondary dust removal device 5 is connected to the outlet of the deacidification reaction tower 3, and is used to receive the deacidified coal gas from the deacidification reaction tower 3, and perform fine dust removal on the deacidified coal gas to form dust-removed coal gas. In this embodiment, the secondary dust removal device 5 is a bag dust collector.

[0078] Example 2

[0079] The method for dry powder spraying deacidification of blast furnace gas using the blast furnace gas dry powder spraying deacidification device of Example 1, the specific steps are as follows:

[0080] The gas to be treated (i.e., blast furnace gas) is introduced from the top outlet of blast furnace 1 into primary dust removal equipment 2 for rough dust removal to form primary treated rough dust-removed blast furnace gas. The concentration of HCl in the primary treated rough dust-removed blast furnace gas is 80 mg / m 3 .

[0081] The raw material bin 411 stores a powder deacidifying agent. In this embodiment, the powder deacidifying agent is sodium bicarbonate, and the mass ratio of sodium bicarbonate to the acidic component is 3:1. The material level is detected by the material level sensor, and the electric discharge valve is opened to discharge the material. At the same time, the balance pipe 414 balances the pressure between the raw material bin 411 and the grinder 42, which can ensure that the material is smoothly discharged into the grinder 42. The powder deacidifying agent is ground into ultrafine powder particles (deacidifying agent dry powder) with a particle size of 300 to 800 mesh by the grinder 42, and then the ultrafine powder particles pass through the discharge valve (the discharge valve is arranged between the grinder 42 and the injector 43) to the injector 43. The carrier gas is passed into the injector 43, and then the powder is driven into the spray gun pipeline 45 according to the flow rate of the carrier gas. The concentration of the gaseous acidic substance in the deacidification reaction tower 3 is detected by the gas detection sensor, and the carrier gas flow rate is adjusted to 50 to 80m through the carrier gas controller 44. 3 / h, thereby controlling the spray gun powder spraying amount. The sprayed powder deacidifying agent is sprayed into the deacidification reaction tower 3 under appropriate temperature, pressure and carrier gas flow rate, and the specific surface area of ​​the powder increases rapidly, and the deacidification powder particles are quickly activated. At the installation angle of the nozzle, the powder particles suspended in the gas can fully contact with the acidic substances in the coal gas to react chemically. After the acidic substances such as HCl, H2S, HCN, SO2, SO3 in the blast furnace gas are absorbed, a very small part of the powder falls to the bottom of the deacidification reaction tower 3, and most of the powder enters the secondary dust removal equipment 5 with the gas. The powder deacidifying agent is deposited on the secondary dust removal equipment 5 to form a layer of powder cake, and the coal gas further undergoes deacidification reaction through the surface powder cake layer. The powder deacidifying agent is fully utilized, and the deacidification efficiency is further improved. The blast furnace gas dust and the deacidifying agent powder after the reaction are captured together and discharged from the ash discharge port of the secondary dust removal equipment 5.

[0082] Example 3

[0083] Except for the following settings, the rest is the same as Example 2:

[0084] The concentration of HCl in the primary treatment of rough dust removal blast furnace gas is 100 mg / m 3; The design direction of the nozzle installation is to form an angle of 45° with the direction of the smoke.

[0085] Example 4

[0086] Except for the following settings, the rest is the same as Example 2:

[0087] The concentration of HCl in primary treatment of crude dust removal blast furnace gas is 150 mg / m 3 ; The design installation direction of the nozzle is to form an angle of 90° with the direction of the smoke.

[0088] The concentrations in the blast furnace gas after being treated by the methods of Examples 2 to 4 are shown in Table 1.

[0089] Table 1

[0090]

[0091] The present invention is not limited to the above-mentioned embodiments. Without departing from the essential content of the present invention, any deformation, improvement and substitution that can be conceived by those skilled in the art shall fall within the scope of the present invention.

Claims

1. A blast furnace gas dry powder spraying deacidification device, characterized in that: It includes blast furnace, primary dust removal equipment, deacidification reaction tower, deacidification injection equipment and secondary dust removal equipment; among which, The primary dust removal equipment is connected to the blast furnace and is configured to receive blast furnace gas and perform rough dust removal on the blast furnace gas to form a primary treated rough dust-removed blast furnace gas; The deacidification reaction tower is connected to the primary dust removal equipment and is configured to remove acidic substances in the primary treated rough dust removal coal gas through a deacidification agent dry powder to form a secondary treated coal gas; The deacidification spraying device is connected to the deacidification reaction tower and is configured to spray the deacidification agent dry powder into the deacidification reaction tower; The secondary dust removal equipment is connected to the deacidification reaction tower and is configured to perform fine dust removal on the secondary treated coal gas to form dust-removed coal gas.

2. The blast furnace gas dry powder spraying deacidification device according to claim 1, characterized in that: The deacidification reaction tower is provided with a first inlet, a second inlet and an outlet; the first inlet is connected to the outlet of the first-level dust removal equipment, for receiving the first-level treated coarse dust-removed blast furnace gas; the second inlet is located above the first inlet; the second inlet is connected to the deacidification spraying equipment, for receiving the deacidification agent dry powder sprayed from the deacidification spraying equipment; the outlet is connected to the second-level dust removal equipment.

3. The blast furnace gas dry powder spraying deacidification device according to claim 2, characterized in that: A gas distributor is arranged in the deacidification reaction tower; the gas distributor is arranged in the lower part of the deacidification reaction tower, and the gas distributor is configured to make the primary treated coarse dust-removed blast furnace gas evenly distributed in the deacidification reaction tower.

4. The blast furnace gas dry powder spraying deacidification device according to claim 3, characterized in that: A spray gun is also arranged in the deacidification reaction tower; the spray gun is arranged above the first inlet, and the vertical distance between the two is 2 to 6 meters; the nozzle of the spray gun forms an angle of 30° to 90° with the flow direction of the flue gas.

5. The blast furnace gas dry powder spraying deacidification device according to claim 1, characterized in that: The deacidification spraying equipment includes a feeding unit, a pulverizer, an ejector and a carrier gas controller; the deacidification spraying equipment is located above the primary dust removal equipment; The unloading unit is used to store the deacidifying agent; One end of the pulverizer is connected to the feeding unit, and the other end is connected to the ejector. The pulverizer is used to grind the deacidifying agent into ultrafine powder particles to form deacidifying agent dry powder; The injector is also connected to the deacidification reaction tower and the carrier gas controller respectively, and is used to spray the deacidification agent dry powder into the deacidification reaction tower.

6. The blast furnace gas dry powder spraying deacidification device according to claim 5, characterized in that: The unloading unit includes a raw material bin, a material level sensor, a unloading pipe, a unloading valve and a balance pipe; the raw material bin is connected to the top of the grinding mill through the unloading pipe, and the material level sensor is located in the raw material bin for detecting the material level; the unloading valve is located on the unloading pipe; one end of the balance pipe is connected to the upper part of the raw material bin, and the other end is connected to the grinding mill.

7. The blast furnace gas dry powder spraying deacidification device according to claim 5 or 6, characterized in that: The injector is correspondingly provided with an injection regulating valve and a gas detection sensor; the injection regulating valve is configured to adjust the opening of the carrier gas inlet valve, and the gas detection sensor is configured to detect the concentration of acidic substances in the gas in the deacidification reaction tower in real time and transmit the concentration value to the carrier gas controller.

8. A method for dry powder spraying deacidification of blast furnace gas using the blast furnace gas dry powder spraying deacidification device according to any one of claims 5 to 7, characterized in that: The steps include: (1) passing the coal gas to be treated from the blast furnace into the primary dust removal equipment, and undergoing rough dust removal to form primary treated rough dust-removed blast furnace gas; (2) A deacidifying agent is stored in the raw material bin, and the deacidifying agent is fed into the pulverizer through the feeding unit. The pulverizer grinds the deacidifying agent into a deacidifying agent dry powder with a particle size of 300 to 800 mesh ultrafine powder; a carrier gas enters the ejector and carries the deacidifying agent dry powder entering the ejector into the deacidifying reaction tower, and the acidic substances in the primary treated coarse dust removal blast furnace gas contact and react with the deacidifying agent dry powder in the deacidifying reaction tower to form a secondary treated gas; (3) The secondary treated coal gas enters the secondary dust removal equipment, undergoes fine dust removal, and forms dust-removed coal gas; the powder captured during the fine dust removal process is discharged from the ash discharge port of the secondary dust removal equipment.

9. The method according to claim 8, characterized in that The flow rate of carrier gas is 40~90m 3 / h.

10. The method according to claim 9, characterized in that The deacidifying agent is selected from one or more of alkaline oxides, alkaline hydroxides, carbonates or bicarbonates.

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