Air nozzle assembly of fuming furnace

Abstract

The tuyere assembly of the fuming furnace comprises a tuyere valve, an extension section, a mixing section, a transition section and a tuyere section which are sequentially connected end to end; the tuyere valve is internally provided with a tuyere ball and an inclined slideway cavity thereof, and the horizontal axes of the secondary air pipe and the secondary air pipe tuyere assembly form an acute angle; the outlet end of the secondary air pipe is connected with the extension section; the mixing section is a three-way sleeve and is provided with a primary air pipe and a mixing cavity; the outlet end of the mixing section is connected with the transition section; the tuyere section is inserted into a molten pool from a fuming furnace copper water jacket; the intersection point P of the outermost side bus a-a of the secondary air pipe and the lowest edge bus b-b of the extension section is located within the length range of the extension section, and the intersection point P does not exceed the inlet end face A-A of the mixing section. The fluid dynamic state of secondary air conveying is improved, the pulverized coal conveying path is optimized, pulverized coal is linearly and evenly conveyed along the pipe wall of the air nozzle assembly, abrasion of the air nozzle assembly is extremely small, the service life is greatly prolonged, potential safety hazards of a copper water jacket are basically eliminated, and operation of the fuming furnace is safer and more controllable.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous pyrometallurgical technology, and in particular to a tuyeres assembly for a fumigation furnace. Background Technology

[0002] Currently, fuming furnaces are generally composed of copper and steel water jackets. The copper water jacket is located at the bottom, forming the high-temperature molten pool, while the steel water jacket sits on top of the copper water jacket. Some copper water jackets have tuyeres, and the tuyeres are inserted into the molten pool through these tuyeres. For example, a fuming furnace with a bed area of ​​13 square meters typically has 48 sets of tuyeres. The furnace uses these tuyeres to blow a mixture of air and pulverized coal into the liquid molten pool to provide fuel and initiate a chemical reaction, causing certain valuable metals in the molten pool to volatilize in the form of metals, oxides, or sulfides.

[0003] The existing technology for fuming furnace tuyeres suffers from uneven secondary air delivery, leading to poor pulverized coal transport. This causes the pulverized coal to undergo refractive movement within the tuyeres' internal tube walls, resulting in wear and tear at these refractive points, creating pits or even penetration. To increase smelting intensity, increased pulverized coal and secondary air volumes are required, further exacerbating wear and severely limiting the furnace's capacity. Existing tuyeres generally have short service lives, high spare parts consumption, and require significant labor intensity for replacement. In particular, wear and tear at the tuyeres' end section directly threatens the safety of the copper water jacket, forcing the furnace to be shut down for maintenance. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this invention designs a nozzle assembly for a fuming furnace, which improves the hydrodynamic state of secondary air conveying, enabling pulverized coal to be conveyed in a straight and uniform manner along the tube wall of the nozzle assembly. The nozzle assembly experiences minimal wear, has a significantly extended service life, is safe and controllable, and greatly improves production capacity, achieving good economic benefits.

[0005] The present invention adopts the following technical solution: A tuyer assembly for a fuming furnace, used for air-coal mixed blowing, is characterized by comprising a tuyer valve, an extension section, a mixing section, a transition section, and a tuyer section connected end-to-end; the tuyer valve contains a tuyer ball and its inclined slide cavity, as well as a secondary air duct, the secondary air duct being an inclined straight pipe forming an acute angle with the horizontal axis of the tuyer assembly; the outlet end of the secondary air duct is connected to the extension section; the outlet end of the extension section is connected to the mixing section; the mixing section is a three-way sleeve, containing a primary air duct for the primary air and pulverized coal mixture to enter, and a mixing cavity; the outlet end of the mixing section is connected to the transition section; the tuyer section is inserted from the copper water jacket of the fuming furnace into the molten pool; The extension section has a certain length, such that the intersection point P of the outermost busbar aa of the secondary air duct and the lowermost busbar bb of the extension section is located within the length range of the extension section, and the intersection point P does not exceed the inlet end face AA of the mixing section.

[0006] The further beneficial effect of adopting the above is that the angled secondary airflow is first forced to change direction within the extension section, and finally enters the mixing section in a horizontal direction, which is conducive to promoting the uniform forward transport of pulverized coal along the component axis. In principle, when the airflow entering the secondary air duct obliquely impacts the pipe wall of the extension section, the pipe wall exerts a reaction force perpendicular to the wall surface on the airflow. After this force is decomposed, the vertical component perpendicular to the pipe wall is completely canceled out by the pipe wall, forcing the airflow to be unable to maintain its directional motion component, while the horizontal component propels the airflow along the axial direction of the pipe.

[0007] Preferably, the inner wall of the transition section is provided with at least one conical cavity that gradually narrows to a cylindrical cavity.

[0008] The further beneficial effects of adopting the above are: the inlet aperture of the transition section gradually becomes smaller and the airflow velocity increases, which helps to overcome the resistance of the molten pool and enter the interior of the melt.

[0009] Preferably, the outlet end of the transition section and the inlet end of the nozzle section are connected by a nested countersunk joint. The outlet end of the transition section is provided with a countersunk platform, and the inlet end of the nozzle section is provided with a boss, and the countersunk joint is connected by the boss and the countersunk platform.

[0010] The further beneficial effect of adopting the above is that the countersunk connection can play a better guiding and sealing role, preventing pulverized coal from leaking from the connection surface between the transition section and the tuyer section.

[0011] Preferably, the distance L from the intersection point P to the inlet end face AA of the mixing section is greater than 60 mm. This ensures that the secondary wind has sufficient distance to be redirected.

[0012] Preferably, a contraction section is provided in the middle of the inner cavity of the extension section. This can accelerate the airflow, increase the proportion of horizontal momentum, reduce the influence of the initial angle, and allow the secondary wind to change direction more quickly, ultimately entering the mixing section in a horizontal direction.

[0013] Preferably, the air outlet valve, extension section, mixing section, transition section and air nozzle section are connected end to end by means of threaded connection or flange connection.

[0014] The beneficial effects of this invention are as follows: The fuming furnace tuyeres assembly of this invention improves the fluid dynamics of secondary air conveying, optimizes the pulverized coal conveying path, and ensures that the pulverized coal is conveyed in a straight and uniform manner along the tube wall of the tuyeres assembly. The wear of the tuyeres assembly is minimal, and its service life is greatly extended. It also basically eliminates the safety hazards of the copper water jacket, making the operation of the fuming furnace safer and more controllable, significantly improving the production capacity and operating rate, and achieving good economic benefits. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention.

[0016] Figure 2 This is a schematic diagram of the structure of the air outlet valve, extension section, and mixing section in this invention.

[0017] Figure 3 This is a schematic diagram of the actual structure in use of the present invention with the extension section removed.

[0018] In the diagram: 1. Air outlet valve; 1.1. Air outlet ball; 1.2. Inclined slide cavity; 1.3. Secondary air duct; 2. Extension section; 2.1. Contraction section; 3. Mixing section; 3.1. Primary air duct; 3.2. Mixing chamber; 4. Transition section; 4.1. Conical cavity; 4.2. Cylindrical cavity; 4.3. Recessed platform; 5. Air nozzle section; 5.1. Boss; 6. Copper water jacket; 7. Drill rod; 8. Recess. Detailed Implementation

[0019] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings: Example: Figure 1 As shown, a tuyer assembly for a fuming furnace, used for air-coal mixing, includes a tuyer valve 1, an extension section 2, a mixing section 3, a transition section 4, and a tuyer section 5, connected end to end. The tuyer valve 1 contains a tuyer ball 1.1 and its inclined slide cavity 1.2, as well as a secondary air duct 1.3. The secondary air duct 1.3 is an inclined straight pipe, forming an acute angle with the horizontal axis of the tuyer assembly. The outlet end of the secondary air duct 1.3 is connected to the extension section 2. The outlet end of the extension section 2 is connected to the mixing section 3. The mixing section 3 is a three-way sleeve, with a primary air duct 3.1 for the primary air and pulverized coal mixture to enter and a mixing cavity 3.2. The outlet end of the mixing section is connected to the transition section 4. The tuyer section is inserted from the copper water jacket 6 of the fuming furnace into the molten pool.

[0020] The outlet end of the secondary air duct 1.3 is connected to an extension section 2 of a certain length, such that the intersection (P) of the outermost generatrix aa of the secondary air duct and the lowermost generatrix bb of the extension section 2 is located between the extension sections 2, and the intersection P does not exceed the inlet end face AA of the mixing section 3.

[0021] When the drill rod 7 is inserted into the inlet of the tuyere valve 1 to ventilate the air nozzle, the tuyere ball 1.1 is squeezed into the upper end of the inclined slide cavity 1.2. When the drill rod is pulled out, the tuyere ball 1.1 slides freely and blocks the inlet of the tuyere valve, which plays a role in sealing the melt or gas. Compressed air is introduced from the secondary air duct 1.3, and pulverized coal is simultaneously sent from the primary air duct 3.1. Under the action of the secondary air, the pulverized coal is transported to the transition section 4 and the tuyere section 5 respectively, and finally sent into the melting pool of the fuming furnace.

[0022] Preferably, the distance L from the intersection point P to the AA section is greater than 60mm, so that the secondary wind has enough distance to be fully redirected.

[0023] Preferred, such as Figure 2As shown, the inner cavity of the extension section adopts a tapering design and has a contraction section 2.1, which can accelerate the airflow, enhance the proportion of horizontal momentum, reduce the influence of the initial angle, and make the secondary wind change direction more quickly, eventually entering the mixing section in a horizontal direction.

[0024] However, as Figure 3 As shown, without extension section 2, or with an excessively short extension section, part of the airflow (approximately 50 kPa pressure) from the secondary air duct 1.3 will directly enter the mixing chamber 3.2 at a certain angle. At this point, the intersection point P of the outermost generatrix aa of the secondary air duct and the lowermost generatrix bb of extension section 2 is located inside the mixing chamber 3, extending beyond the inlet end face AA of the mixing section 3. Meanwhile, the mixture of primary air and pulverized coal (approximately 45 kPa pressure) enters the mixing chamber 3.2 vertically downwards from the primary air duct 3.1 or at a certain angle. Thus, under the combined force of the secondary and primary air, the pulverized coal accelerates towards the bottom of the mixing chamber 3.2, impacting and refracting. Practice shows that pits 8 are easily formed at the bottom of the mixing chamber 3.2, and the pulverized coal undergoes refracted forward movement within the internal pipe wall of the nozzle assembly. The pulverized coal impacts and rubs against each refraction point, rapidly forming other pits 8, which penetrate the pipe wall in a short time. In particular, the pits near the copper water jacket 6 directly threaten the safety of the copper water jacket, posing a significant safety hazard.

[0025] Preferably, after the pulverized coal fed from the primary air duct 3.1 enters the mixing chamber 3.2, the volume of the space increases instantaneously, the flow velocity decreases rapidly, and the pulverized coal is easily pushed forward by the horizontal airflow entering from the secondary air duct, thus entering the transition section 4.

[0026] Preferably, the transition section 4 adopts a gradually shrinking structure, with at least one conical cavity 4.1 that gradually shrinks into a cylindrical cavity 4.2.

[0027] Preferably, the outlet end of the transition section 4 is provided with a countersunk platform 4.3, while the inlet end of the nozzle section 5 is provided with a boss 5.1, forming a nested countersunk connection.

[0028] Preferably, the air outlet valve 1, extension section 2, mixing section 3, transition section 4 and air nozzle section 5 are connected end to end by means of threaded connection or flange connection, etc.

[0029] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A tuyeres assembly for a fuming furnace, used for mixed air and coal blowing, characterized in that, It includes an air outlet valve, an extension section, a mixing section, a transition section, and an air nozzle section, connected end to end. The air outlet valve contains an air outlet ball and its inclined slide cavity, as well as a secondary air duct. The secondary air duct is an inclined straight pipe, forming an acute angle with the horizontal axis of the air nozzle assembly. The outlet end of the secondary air duct is connected to the extension section. The outlet end of the extension section is connected to the mixing section. The mixing section is a three-way sleeve, with a primary air duct for the primary air and pulverized coal mixture to enter and a mixing cavity. The outlet end of the mixing section is connected to the transition section. The air nozzle section is inserted from the copper water jacket of the fuming furnace into the molten pool. The intersection point P of the outermost busbar aa of the secondary air duct and the lowermost busbar bb of the extension section is located within the length range of the extension section, and the intersection point P does not exceed the inlet end face AA of the mixing section.

2. The nozzle assembly for a fumigation furnace according to claim 1, characterized in that, The inner wall of the transition section is provided with at least one conical cavity that gradually narrows to a cylindrical cavity.

3. The duct assembly for a fumigation furnace according to claim 1, characterized in that, The outlet end of the transition section and the inlet end of the nozzle section are connected by a nested countersunk joint.

4. The duct assembly for a fumigation furnace according to claim 3, characterized in that, The outlet end of the transition section is provided with a countersunk platform, and the inlet end of the nozzle section is provided with a boss. The boss and the countersunk platform are connected by nesting countersunk heads.

5. The duct assembly for a fumigation furnace according to claim 1, characterized in that, The distance L from the intersection point P to the inlet end face AA of the mixing section is greater than 60 mm.

6. The tuyeres assembly for a fumigation furnace according to claim 1, characterized in that, A contraction section is provided in the middle of the inner cavity of the extension section.

7. The duct assembly for a fumigation furnace according to claim 1, characterized in that, The air outlet valve, extension section, mixing section, transition section, and air nozzle section are connected end to end by threaded connection or flange connection.

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