Powder combustion improver adding pipe group of petroleum coke reaction circulating air inlet system in calcining furnace

Abstract

The utility model discloses a powder combustion improver adding pipe group of a petroleum coke reaction circulating air inlet system in a calcining furnace, and mainly relates to carbon production. Comprising a jet device assembly and a connecting pipeline connected with the jet device assembly. The jet device assembly comprises a jet device pipeline and a combustion improver adding port communicated with the outer wall of the jet device pipeline; the connecting pipeline is located in the furnace body, and a flow dividing guide piece is arranged in the connecting pipeline and used for dividing flow of fluid in the connecting pipeline. The powder combustion improver adding device has the beneficial effects that the powder combustion improver is added into the calcining furnace body, and can be uniformly and dispersedly added into the calcining furnace body, so that the temperature change in the calcining furnace body is kept stable, and the waste caused by insufficient combination of the combustion improver in the calcining furnace body is avoided. And in addition, air is used as a power source, so that the powder combustion improver is added to a deeper position in the furnace body.

Description

Technical Field

[0001] The utility model relates to the field of carbon production, in particular to a powder combustion-supporting agent adding pipe group of a petroleum coke reaction circulation air intake system in a calcining furnace. Background Art

[0002] The statements in this section merely provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] In the electrolytic aluminum industry, carbon blocks are usually used as anodes. Anode carbon blocks are made of petroleum coke as aggregate and coal tar as binder, and are used as anode materials for pre-baked aluminum electrolytic cells. In the process of producing anode carbon blocks, the raw petroleum coke is first calcined. Calcination is a pretreatment process for carbon production. During the calcination process, petroleum coke will undergo a series of significant changes from elemental composition to organizational structure. Because petroleum coke contains volatiles, it needs to be calcined to remove moisture and volatiles from the raw materials, so that the volume of the carbon raw materials can be fully shrunk and its thermal stability and physical and chemical properties can be improved. During calcination, the molecular structure changes continuously with the discharge of volatiles, and the volume of the raw materials themselves gradually shrinks, thereby increasing the density and mechanical strength of the raw materials and reducing the resistivity of the calcined petroleum coke. If the volatiles of the raw materials are too high, the petroleum coke will shrink too much during the subsequent roasting process, resulting in structural deformation, and ultimately making the anode carbon blocks very easy to break after forming, so it is necessary to discharge the volatiles in the raw materials. During calcination, the calcination temperature affects the conductivity of the calcined petroleum coke product. Calcination causes the molecular structure of the petroleum coke to change continuously, and the volatile matter to escape continuously, making the resistivity of the petroleum coke the lowest. As the calcination temperature increases, the impurities contained in the carbon raw materials are gradually eliminated, reducing the chemical activity of the raw materials, thereby improving the conductivity of the raw materials.

[0004] The existing calcined petroleum coke production method generally calcines petroleum coke in a calcining furnace. Most of the existing calcining furnaces control the calcination temperature in the furnace by the oxygen intake at the air inlet. When heating, the air inlet gates on the outside of the calcining furnace body need to be manually opened, and air enters the calcining furnace through the air inlet, so that the oxygen intake in the calcining furnace is rapidly increased. However, in this method, during the heating stage of calcining petroleum coke, all the air inlet gates need to be opened, and the oxygen content in the furnace body is increased by natural wind, which makes the heating of the furnace body slow. Therefore, the oxygen content in the furnace body can only be increased by multiple air inlets on each furnace body to achieve the effect of combustion-supporting. However, when calcining petroleum coke, dozens of furnace bodies are generally used for calcination at the same time, and each furnace body has three air inlets. When heating, the air inlet gates on each furnace body need to be fully opened. Manual control is labor-intensive and the temperature increase effect is slow. When the furnace body is heated, since the air inlet is natural wind, there is a large temperature difference between the natural wind and the inside and outside of the furnace body. The large temperature difference between the inside and outside of the furnace body will cause frequent thermal expansion and contraction of the calcining furnace body wall, and eventually cause the outer wall of the calcining furnace to crack, which directly shortens the life of the furnace body and increases the cost investment of the factory.

[0005] In order to reduce the impact of multiple air inlets on the furnace body on the life of the furnace body, the following improvements are made: the multiple air inlets on each furnace body are reduced to a single one. After the air inlet on the furnace body is improved to a single one, in order to meet the temperature requirements of different calcination stages of petroleum coke, it is necessary to add a combustion aid into the furnace body. The powder (granular) combustion aid has strong oxidizing properties and can be added to the furnace body to generate oxygen or promote the combustion of the dye when heated. However, for the powder combustion aid, it is not convenient to add it into the furnace body. Secondly, when adding the powder combustion aid into the furnace body, it needs to enter the furnace body evenly and dispersedly, so that the powder combustion aid can burn more fully and energy utilization is sufficient to avoid waste. Utility Model Content

[0006] The purpose of the utility model is to provide a powder combustion aid adding pipe group of a petroleum coke reaction cycle air intake system in a calcining furnace, which is used to add powder combustion aid to the inside of the calcining furnace body, and can be added to the inside of the furnace body evenly and dispersedly when adding powder combustion aid, so that the temperature change inside the furnace body remains stable, thereby avoiding the combustion aid from being insufficiently combined inside the furnace body and causing waste. In terms of the adding method, air is used as a power source, so that the powder combustion aid is added to a deeper position inside the furnace body.

[0007] In order to achieve the above purpose, the utility model is implemented through the following technical solutions:

[0008] The powder combustion-aid adding pipe group of the petroleum coke reaction circulation air intake system in the calcining furnace includes an ejector assembly and a connecting pipeline connected to the ejector assembly; the ejector assembly includes an ejector pipe and a combustion-aid adding port connected to the outer wall of the ejector pipe; the connecting pipe is located in the furnace body, and a diverter guide is provided in the connecting pipe, and the diverter guide is used to divert the fluid in the connecting pipe.

[0009] The ejector assembly also includes an air inlet arranged at one end of the ejector pipe, a nozzle arranged at the air inlet, an intake chamber arranged between the nozzle and the combustion-aiding agent addition port, and a tapered section arranged between the intake chamber and the connecting pipeline; the connecting pipeline and the nozzle are both located in the furnace body, and a pressure expansion section is arranged in the connecting pipeline, and the cross-section of the pressure expansion section is larger than that of the tapered section.

[0010] A pressure diffuser section is provided in the connecting pipeline, and the cross section of the pressure diffuser section is larger than that of the tapered section.

[0011] The diverter guide comprises a diverter ball, a fixed shaft connected to the diverter ball, a diverter pipe opening arranged outside the connecting pipeline, and a diverter plate arranged at the diverter pipe opening. The fixed shaft cooperates with the diverter plate, and an adjustment ring is provided at the end of the fixed shaft.

[0012] The length of the connecting pipeline is 400-800 mm, and the cross-sectional diameter of the tapered section of the connecting pipeline is 40-100 mm.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] Powdered combustion aid is added to the calcining furnace body, and it can be added evenly and dispersedly to the furnace body, so that the temperature change inside the furnace body remains stable, thereby avoiding the waste caused by insufficient combination of the combustion aid inside the furnace body. In terms of the adding method, air is used as the power source, so that the powdered combustion aid can be added to a deeper position inside the furnace body. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Attached Figure 1 This is an interior view of the calcining workshop of the utility model.

[0016] Attached Figure 2 This is a view of the pipeline connection in the calcining workshop of the utility model.

[0017] Attached Figure 3 It is an internal view of the ejector assembly in the utility model.

[0018] Attached Figure 4 It is an internal view of the ejector assembly in the utility model.

[0019] Attached Figure 5 It is an overall view of the device in the utility model.

[0020] Attached Figure 6 It is a sectional view of the overall view of the device in the utility model.

[0021] Numbers shown in the accompanying drawings:

[0022] 1. Connecting pipeline; 2. Ejector pipeline; 3. Combustion-supporting agent adding port; 4. Air inlet; 5. Nozzle; 6. Suction chamber; 7. Gradually contracting section; 8. Diffuser section; 9. Diverter ball; 10. Fixed shaft; 11. Diverter pipe opening; 12. Diverter plate; 13. Adjustment ring; 14. Nozzle; 15. Furnace body; 16. Spraying seam; 17. Flow rate control device; 18. Air inlet pipeline. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the present application.

[0024] The utility model discloses a powder combustion-supporting agent adding pipe group of the petroleum coke reaction circulation air intake system in the calcining furnace. Before the description, a brief description is given of the workshop for calcining petroleum coke. Since the ventilation openings of the furnace body 15 are reduced and the air intake volume needs to be further increased, a pulse bag dust removal device is arranged in the calcining workshop to filter the waste gas such as dust generated by the crushed and calcined petroleum coke. The dust-containing gas enters the dust collector under the gravitational effect of the induced draft fan, and the large particles of dust in the gas are filtered under the action of gravity. The fine dust adheres to the outer surface of the bag under the filtering effect of the bag. After filtering, the bag is cleaned of dust by a pressurized pulse air cannon, so that the dust in the filter hole of the bag falls off, and the purified gas passes through the bag and is directly discharged into the atmosphere through the ventilation duct. This dust removal method has disadvantages. The bags of the pulse bag dust removal equipment need to be replaced regularly. Once the bags are broken or the filtering effect deteriorates, if the smoke is not discovered in time, it will be directly discharged into the atmosphere, affecting the environment in the atmosphere and causing an increase in PM2.5 in the environment. Because the gas passing through the pulse dust removal equipment is continuously transported by the induced draft fan, it is finally discharged into the atmosphere after dust removal. Combined with the content of the improvement of the furnace body 15 described in the background technology, because the reduction of the air inlet 4 on the furnace body 15 will lead to a decrease in the amount of oxygen entering the furnace body 15, and the air inlet 4 on the furnace body 15 is all natural wind, which will cause the temperature in the furnace body 15 to rise slowly and fail to reach a specific temperature. Therefore, the gas discharged from the ventilation duct of the pulse bag dust removal equipment is combined with the air inlet pipeline of the circulating air intake system. A plurality of ejector assemblies and connecting pipelines 1 are provided on the air inlet pipeline. One end of the connecting pipeline 1 of the ejector assembly is connected to the air inlet pipeline, and the other end is connected to the connecting pipeline 1.

[0025] First, the ejector assembly is described: the ejector is based on the Venturi effect, where a high-speed flowing fluid will generate low pressure near it, thereby generating an adsorption effect. The ejector assembly includes an ejector pipe 2, a nozzle 5 connected to the air inlet pipeline, an air inlet 4 arranged at one end of the ejector pipe 2, and an oxidant addition port 3 connected to the outer wall of the ejector pipe 2;

[0026] A nozzle 5 is provided at the air inlet 4, a suction chamber 6 is provided between the nozzle 5 and the combustion-supporting agent addition port 3, a tapered section 7 is provided between the suction chamber 6 and the connecting pipeline 1; the connecting pipeline 1 and the nozzle 5 are both located in the furnace body 15, a diffuser section 8 is provided in the connecting pipeline 1, and the cross section of the diffuser section 8 is larger than that of the tapered section 7. Figure 3 and Figure 4 As shown, air is taken in through a nozzle 5 with a small cross-sectional area, so that the flow rate of the gas is accelerated, thereby reducing the pressure in the suction chamber 6 to be lower than the external atmospheric pressure, so that the combustion aid at the combustion aid adding port 3 is allowed to enter the suction chamber 6 through the atmospheric pressure and mix with the gas entering from the air inlet pipeline. After the combustion aid and the gas are mixed, they pass through the tapered section 7 and enter the expansion section 8 in the connecting pipeline 1, and then directly enter the furnace body 15 from the expansion section 8. For the ejector assembly, a flow rate control device 17 can be provided at the nozzle 5, and the flow rate at the air inlet 4 is determined by changing and controlling the cross-sectional size at the nozzle 5.

[0027] It should be noted that: the waste gas such as dust discharged from the pulse dust removal equipment enters the air inlet pipeline, then enters the connecting pipeline 1 from the air inlet pipeline, and then enters the furnace body 15 from the connecting pipeline 1. After the waste gas such as dust enters the furnace body 15, it will form tar when it encounters heat. The tar will adhere to the inner wall of the connecting pipeline 1, but the tar will be burned after entering the furnace body 15. After the tar adheres to the inner wall of the connecting pipeline 1, the addition of the combustion aid into the furnace body 15 will be greatly affected, which is described in detail below:

[0028] When the combustion aid is powder or granules, such as potassium permanganate, the tar attached to the connecting pipe 1 has little effect on the gaseous combustion aid. The difference between powder and gas is that the powdered combustion aid will adhere to the tar, which will not only lead to waste of the combustion aid, but also cause the powdered combustion aid to mix with the tar and block the connecting pipe 1. Therefore, the above problem is solved by the following structure:

[0029] As shown in the attached figure of the instruction manual Figure 5As shown, because the tar produced after preheating adheres to the inner wall of the pipeline, the length of the connecting pipeline 1 is reduced as much as possible, so that the length of the connecting pipeline 1 is 400-800mm. After reducing the length of the connecting pipeline 1, in order not to affect the spraying distance of the powdered combustion aid, it is necessary to further improve the diameter of the cross section of the tapered section 7 to increase the flow rate of the combustion aid powder and the air. Therefore, the cross-sectional diameter of the tapered section 7 of the connecting pipeline 1 is 40-100mm. By increasing the flow rate of the combustion aid powder and the air, the tar and the combustion aid powder attached to the pipe wall of the diffusion section of the connecting pipeline 1 are blown out by the air. After the test, it is concluded that: since the tar is attached to the pipe wall, when the gas is blown to the tar first, the tar cannot be blown off directly, resulting in the combustion aid powder agglomerating after contacting the tar and spraying into the furnace body 15, resulting in insufficient use of the combustion aid, and it may block the pipeline, so it needs further improvement:

[0030] As shown in the attached figure of the instruction manual Figure 6 As shown, a diverter guide is provided in the connecting pipeline 1, including a diverter ball 9, a fixed shaft 10 connected to the diverter ball 9, a diverter pipe port 11 arranged on the outside of the connecting pipeline 1, and a diverter plate 12 arranged at the diverter pipe port 11. The fixed shaft 10 cooperates with the diverter plate 12, and an adjustment ring 13 is provided at the end of the fixed shaft 10. The diversion pipe mouth 11 is arranged on the outside of the connecting pipeline 1, and the fixed shaft 10 and the connecting pipeline 1 are matched through a fixed hole. A block is provided at the other end of the fixed shaft 10 and the inner side of the diversion plate 12 for limiting, so as to prevent the fixed shaft 10 from being displaced under the action of gravity, so that the diversion ball 9 can be maintained at the center of the connecting pipeline 1. When tar is attached to the inner wall of the connecting pipeline 1, the gas is diverted by the diversion ball 9 when passing through the diffusion section of the connecting pipeline 1, so that the gas is blown out from both sides of the inner wall of the pipeline instead of from the center of the pipeline. The diverted gas can directly act on the tar attached to the inner wall of the pipeline, and the agglomeration of the combustion-aiding agent powder and the tar can be reduced after being blown out. However, if tar is stuck on the diverter ball 9, the combustion-aiding agent powder will also adhere to the diverter ball 9. Therefore, an adjustment ring 13 is provided at the end of the fixed shaft 10. The angle of the adjustment ring 13 is manually rotated regularly. After the angle is changed, the gas will blow off the powder and tar on the diverter ball 9 to avoid the effect of the combustion-aiding agent being affected by the tar stuck on the diverter ball 9.

[0031] Because the powdered combustion aid needs to be evenly sprayed inside the furnace body 15, if the powdered combustion aid is concentratedly sprayed at a specific angle, the powdered combustion aid will not have time to play a role and will be covered by the newly added powdered combustion aid, resulting in insufficient volatilization of the combustion aid. Therefore, the nozzle 14 shape needs to be changed at the nozzle mouth of the connecting pipeline 1. The nozzle 14 is a duckbill type (flat), and a spraying seam 16 is provided in the middle of the nozzle 14. The powdered combustion aid enters the nozzle 14 from the connecting pipeline 1, and the powdered combustion aid is sprayed out from the nozzle 14 in a fan shape, so that the spraying area of ​​the powdered combustion aid is larger, and the powdered combustion aid is dispersed after being sprayed out from the nozzle 14, rather than being concentrated and single.

[0032] It should be noted that the bag dust collector will only discharge unfiltered dust and other waste gases into the pipeline when the filter bag is working abnormally, which is normal air emission. However, in order to avoid the filter bag of the bag dust collector being damaged and not being discovered in time, the petroleum coke dust enters the connecting pipeline 1 and affects the connecting pipeline 1. Therefore, it is not that the bag dust collector discharges petroleum coke dust into the air inlet pipeline for a long time, but in order to avoid special circumstances, it is necessary to solve the impact on the connecting pipeline 1.

[0033] In the specific implementation process, the device is not only suitable for adding combustion aids, because during the calcination process, it may be necessary to add catalysts, desulfurizers, sulfur-fixing agents, etc., which can also be added through the device.

[0034] Because the present application only describes the tube group of powdered combustion aid, how to add powdered combustion aid at the adding port and the structure of adding combustion aid are not within the scope of consideration of the present application. However, a silo can be connected to the combustion aid adding port 3, and the combustion aid inside the silo can be connected to the suction chamber 6 through a control valve. What needs to be noted is the change in air pressure, and a one-way valve connected to the external atmospheric pressure should be provided on the silo.

[0035] In summary, the device is used to add powdered combustion aid to the calcining furnace body 15. When adding the powdered combustion aid, it can be added to the furnace body 15 evenly and dispersedly, so that the temperature change inside the furnace body 15 remains stable, thereby avoiding the waste caused by insufficient combination of the combustion aid inside the furnace body 15. In terms of the adding method, air is used as the power source, so that the powdered combustion aid is added to a deeper position inside the furnace body 15.

Claims

1. A powder combustion-supporting agent adding tube group for the petroleum coke reaction cycle air intake system in a calcining furnace, characterized in that: It comprises an ejector assembly and a connecting pipeline (1) connected to the ejector assembly; The ejector assembly comprises an ejector pipe (2) and an oxidant addition port (3) connected to the outer wall of the ejector pipe (2); The connecting pipeline (1) is located in the furnace body (15), and a flow diversion guide is provided in the connecting pipeline (1), and the flow diversion guide is used to divert the fluid in the connecting pipeline (1).

2. The powder combustion-supporting agent adding pipe group of the petroleum coke reaction cycle air intake system in the calcining furnace according to claim 1, characterized in that: The ejector assembly further comprises an air inlet (4) arranged at one end of the ejector pipe (2), a nozzle (5) arranged at the air inlet (4), an intake chamber (6) arranged between the nozzle (5) and the combustion-supporting agent addition port (3), and a tapered section (7) arranged between the intake chamber (6) and the connecting pipe (1); The connecting pipeline (1) and the nozzle (5) are both located in the furnace body (15); a diffuser section (8) is provided in the connecting pipeline (1); and the cross section of the diffuser section (8) is larger than that of the tapered section (7).

3. The powder combustion-supporting agent adding pipe group of the petroleum coke reaction cycle air intake system in the calcining furnace according to claim 1 or 2, characterized in that: The flow dividing guide comprises a flow dividing ball (9), a fixed shaft (10) connected to the flow dividing ball (9), a flow dividing pipe opening (11) arranged outside the connecting pipeline (1), and a flow dividing plate (12) arranged at the flow dividing pipe opening (11); the fixed shaft (10) cooperates with the flow dividing plate (12), and an adjusting ring (13) is provided at the end of the fixed shaft (10).

4. The powder combustion-supporting agent adding pipe group of the petroleum coke reaction cycle air intake system in the calcining furnace according to claim 3, characterized in that: The length of the connecting pipeline (1) is 400-800 mm, and the cross-sectional diameter of the tapered section (7) of the connecting pipeline (1) is 40-100 mm.

5. The powder combustion-supporting agent adding pipe group of the petroleum coke reaction cycle air intake system in the calcining furnace according to claim 4, characterized in that: The connecting pipeline (1) is provided with a nozzle (14), and the nozzle (14) is fan-shaped, and the nozzle (14) is used to guide the combustion-supporting agent sprayed out of the connecting pipeline (1).

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