Gas combustion improver adding pipe group of petroleum coke reaction circulating gas inlet system in calcining furnace

Abstract

The utility model discloses a gas combustion improver adding pipe group of a petroleum coke reaction circulating gas 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, the tail end of the connecting pipeline is in an arc shape, and a spray head is arranged at the tail end of the connecting pipeline and used for guiding flow of the combustion improver sprayed out of the connecting pipeline. The gas combustion improver adding device has the advantages that the gas combustion improver is added into the calcining furnace body, the angle of a connecting pipeline can be designed according to the purposes of products calcined by the calcining furnace, combination between the combustion improver and fuel is more reasonable, the energy utilization rate is higher, and energy is saved. And the fuel can be combusted more sufficiently and can reach a specific temperature at the same time.

Description

Technical Field

[0001] The utility model relates to the field of carbon production, in particular to a gas 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 combustion aids into the furnace body. For gaseous combustion aids, the addition of gaseous combustion aids has the least impact on the internal temperature of the furnace body and the fastest combustion effect. However, it is inconvenient to add and it is also inconvenient to control the amount of addition. Utility Model Content

[0006] The utility model aims to provide a gas combustion aid adding pipe group of a petroleum coke reaction circulation air intake system in a calcining furnace, which is used to add a gas combustion aid into the interior of the calcining furnace body, and can design the angle of the connecting pipeline according to the purpose of the product calcined in the calcining furnace, and makes the combination between the combustion aid and the fuel more reasonable, the energy utilization rate is better, and the fuel combustion is more complete while reaching a specific temperature.

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

[0008] The gas combustion-aiding agent 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-aiding agent adding port connected to the outer wall of the ejector pipe; the connecting pipe is located in the furnace body, the end of the connecting pipe is arc-shaped, and a nozzle is provided at the end of the connecting pipe, and the nozzle is used to guide the combustion-aiding agent sprayed out of the connecting pipe.

[0009] The nozzle at the end of the connecting pipeline faces the bottom of the furnace body.

[0010] 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.

[0011] The angle between the bent portion of the connecting pipeline and the horizontal portion of the connecting pipeline is 60°-110°.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] It is used to add gaseous combustion aid into the calcining furnace body, and can design the angle of the connecting pipeline according to the purpose of the product calcined in the calcining furnace, so that the combination between the combustion aid and the fuel is more reasonable, the energy utilization rate is better, and the fuel combustion is more complete while reaching a specific temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Attached Figure 1 This is an internal view of the calcining workshop of the utility model.

[0015] Attached Figure 2 This is a pipeline connection view of the calcining workshop in the utility model.

[0016] Attached Figure 3 It is an internal sectional view of the ejector assembly in the utility model.

[0017] Attached Figure 4 This is the internal view of the ejector assembly in the utility model

[0018] Attached Figure 5 It is an overall view of the device in the utility model.

[0019] Attached Figure 6 It is an internal sectional view of the device in the utility model.

[0020] Numbers shown in the accompanying drawings:

[0021] 1. Connecting pipeline; 2. Ejector pipeline; 3. Combustion-supporting agent adding port; 4. Furnace body; 5. Nozzle; 6. Nozzle; 7. Suction chamber; 8. Gradually contracting section; 9. Diffuser section; 10. Air inlet pipeline. DETAILED DESCRIPTION

[0022] 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.

[0023] The utility model discloses a gas combustion-supporting agent adding pipe group of a petroleum coke reaction circulation air intake system in a calcining furnace. Before describing the above, a workshop for calcining petroleum coke is briefly described. Since the ventilation openings of the furnace body 4 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 crushing and calcining the 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 4 described in the background technology, because the reduction of the air inlet on the furnace body 4 will lead to a reduction in the amount of oxygen entering the furnace body 4, and the air inlet on the furnace body 4 is all natural wind, which will cause the temperature in the furnace body 4 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 10 of the circulating air intake system. The air inlet pipeline 10 is provided with a plurality of ejector assemblies and a connecting pipeline 1. One end of the connecting pipeline 1 of the ejector assembly is connected to the air inlet pipeline 10, and the other end is connected to the connecting pipeline 1.

[0024] First, the ejector assembly is described: the ejector is based on the Venturi effect, and low pressure is generated near the high-speed flowing fluid, thereby generating an adsorption effect. The ejector assembly includes an ejector pipe 2, a nozzle 6 connected to the air inlet pipeline 10, an air inlet provided at one end of the ejector pipe 2, and an oxidant addition port 3 connected to the outer wall of the ejector pipe 2;

[0025] A nozzle 6 is provided at the air inlet, a suction chamber 7 is provided between the nozzle 6 and the combustion-supporting agent addition port 3, a tapered section 8 is provided between the suction chamber 7 and the connecting pipeline 1; the connecting pipeline 1 and the nozzle 6 are both located in the furnace body 4, a diffuser section 9 is provided in the connecting pipeline 1, and the cross section of the diffuser section 9 is larger than that of the tapered section 8. Figure 2 and Figure 3As shown, air is taken in through a nozzle 6 with a small cross-sectional area, so that the flow rate of the gas is accelerated, thereby reducing the pressure in the suction chamber 7 to be lower than the external atmospheric pressure, so that the combustion aid at the combustion aid adding port 3 enters the suction chamber 7 through the atmospheric pressure and mixes with the gas entering from the air inlet pipe 10. After the combustion aid and the gas are mixed, they pass through the tapered section 8 and enter the expansion section 9 in the connecting pipe 1, and then directly enter the furnace body 4 from the expansion section 9. For the ejector assembly, a flow rate control device can be set at the nozzle 6, and the flow rate at the air inlet is determined by changing and controlling the cross-sectional size at the nozzle 6.

[0026] It should be noted that: the waste gas such as dust discharged from the pulse dust removal equipment enters the air inlet pipe 10, then enters the connecting pipe 1 from the air inlet pipe 10, and then enters the furnace body 4 from the connecting pipe 1. After the waste gas such as dust enters the furnace body 4, it will form tar when it encounters heat. The tar will adhere to the inner wall of the connecting pipe 1, but the tar will be burned after entering the furnace body 4. After the tar adheres to the inner wall of the connecting pipe 1, the addition of the combustion aid into the furnace body 4 will be greatly affected, which is described in detail below:

[0027] When the added combustion aid is gas, please note that the gas that can help combustion may not be able to burn itself, so the gas combustion aid does not only refer to air and oxygen, but also ozone, chlorine, etc. However, considering the comprehensive cost and ease of use, the gas combustion aid here refers to air, because the gas supply through the booster fan and the induced draft fan alone is insufficient. According to the reaction temperature of the purpose, for example: the calcination temperature of the anode for aluminum smelting is 1150℃; the calcination temperature of ordinary graphite electrodes is 1250℃-1350℃; the calcination temperature of high-power and ultra-high-power electrodes is 1400℃ or higher. According to the reaction temperature of the heating stage: in the initial stage of heating, heat to 700℃-1000℃ and keep warm for one hour at the corresponding temperature, and then continue to heat to the heating temperature required by the respective products and keep warm for one hour. For example, the anode for aluminum smelting needs to be heated to 700℃ and kept warm for one hour, and then continue to heat to 1150℃ and keep warm for one hour. Therefore, it is necessary to further add gaseous combustion aid into the furnace body 4. In the following description, air is used, so an electromagnetic gate valve (not shown in the figure) is used at the combustion aid addition port 3. The electromagnetic gate valve is connected to the air. When the furnace body 4 is in the first calcination stage, air is supplied through the booster fan and the induced draft fan. When the furnace body 4 is in the second calcination stage, the electromagnetic gate valve is opened to connect with the outside air, which greatly increases the air intake volume, increases the oxygen content in the furnace body 4, and thus increases the calcination temperature.

[0028] However, tar and dust adhere to the inner wall of the connecting pipe 1 for a long time. If they are not cleaned, the flow rate of the gas combustion aid will be affected, thereby reducing the gas flow of the combustion aid, which greatly reduces the effect of the gas combustion aid on oxygenation in the furnace body 4. In the long run, it is very likely to cause blockage of the inner wall of the connecting pipe 1. Therefore, the connecting pipe 1 is improved:

[0029] As shown in the attached figure of the instruction manual Figure 5 and Figure 6 As shown, the connecting pipeline 1 is located in the furnace body 4, the end of the connecting pipeline 1 is arc-shaped, the material used for the connecting pipeline 1 is a high-temperature resistant alloy, and a nozzle 5 is provided at the end of the connecting pipeline 1. The nozzle 5 at the end of the connecting pipeline 1 faces the bottom of the furnace body 4, and the nozzle 5 is used to guide the combustion-supporting agent sprayed from the connecting pipeline 1. For the tar generated by the inner wall of the connecting pipeline 1 when it is heated, for the change of the internal diameter of the pipeline, the connecting part of the connecting pipeline 1 and the ejector pipeline are both the same diameter of the tapered section 8, where the flow rate is fast and it is difficult to form tar accumulation. For the expansion section 9 of the connecting pipeline 1, due to the expansion of the diameter, it is easy to form tar accumulation on the inner wall of the tapered section 8, so the connecting pipeline 1 is set to be arc-shaped, and the connecting pipeline 1 and the nozzle 5 are both facing the bottom of the furnace body 4, so that the tar generated by the heat can be blown from the inside of the connecting pipeline 1 to the inside of the furnace body 4 by gas under the action of gravity along the direction of the connecting pipeline 1 to burn inside the furnace body 4.

[0030] When the gas combustion aid is added to the furnace body 4 through the ejector assembly and the connecting pipe 1, the gas directly acts on the fuel inside the furnace body 4, and avoids the flame directly blowing into the furnace body 4, which causes uneven heating inside the furnace body 4. Directly acting on the fuel can make the fuel burn more fully and reach a specific temperature. However, for the angle between the bent portion of the connecting pipe 1 and the horizontal portion of the connecting pipe 1, different effects will be achieved inside the furnace body 4. With 90° perpendicular to the bottom of the furnace body 4 as the dividing line, under the condition that the tar can be ensured to enter the furnace body 4 by the gas under the action of gravity, the angle between the bent portion of the connecting pipe 1 and the horizontal portion of the connecting pipe 1 is 60°-90°, and the nozzle 6 at the end of the connecting pipe 1 is facing the side wall of the furnace body 4, rather than directly acting on the fuel, which is suitable for the calcination of the anode for aluminum smelting described above. The calcination temperature of the anode for aluminum smelting is relatively low and the heat preservation time is long during calcination, which is convenient for temperature control. For the angle between the bent portion of the connecting pipeline 1 and the horizontal portion of the connecting pipeline 1 being 90°-110°, the nozzle 6 under the above angle range is more inclined toward the center of the fuel in the furnace body 4, which is suitable for high-power and ultra-high-power electrode calcination under high-temperature conditions. This angle has a good effect and can directly act on the center of the fuel in the furnace body 4, making the temperature rise faster during the calcination stage.

[0031] Because the above is only described using air as an example, the combustion aid addition port 3 is connected to the outside, and will generate negative pressure inside the suction chamber 7, thereby allowing the outside air to enter the furnace body 4. For other types of combustion aids, it is necessary to ensure that the internal pressure of the container containing the combustion aid is able to meet the requirements of the ejector assembly to deliver the gas into the furnace body 4, the gas pressure balance needs to be met, and the control assembly is also required to control the connection between the container containing the combustion aid and the ejector assembly.

[0032] In summary, this device is used to add gaseous combustion aid to the inside of the calcining furnace body 4, and can design the angle of the connecting pipeline 1 according to the purpose of the product calcined in the calcining furnace, and make the combination between the combustion aid and the fuel more reasonable, the energy utilization rate is better, and the fuel burns more fully while reaching a specific temperature.

Claims

1. A gas combustion-supporting agent adding pipe 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 (4); the end of the connecting pipeline (1) is arc-shaped; a nozzle (5) is provided at the end of the connecting pipeline (1); the nozzle (5) is used to guide the combustion-supporting agent sprayed out of the connecting pipeline (1).

2. The gas 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 nozzle (5) at the end of the connecting pipeline (1) faces the bottom of the furnace body (4).

3. The gas 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 ejector assembly further comprises an air inlet arranged at one end of the ejector pipe (2), a nozzle (6) arranged at the air inlet, an intake chamber (7) arranged between the nozzle (6) and the combustion-supporting agent addition port (3), and a tapered section (8) arranged between the intake chamber (7) and the connecting pipeline (1); The connecting pipeline (1) and the nozzle (6) are both located in the furnace body (4); a diffuser section (9) is provided in the connecting pipeline (1); and the cross section of the diffuser section (9) is larger than that of the tapered section (8).

4. The gas combustion-supporting agent adding pipe group of the petroleum coke reaction cycle air intake system in the calcining furnace according to claim 2, characterized in that: The angle between the bent portion of the connecting pipeline (1) and the horizontal portion of the connecting pipeline (1) is 60°-110°.

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