A waste gas recycling system for rock wool production

Abstract

The utility model relates to the technical field of rock wool production equipment, concretely refers to a kind of waste gas recycling system for rock wool production, it includes: furnace body, the inside fixed setting of furnace body is provided with cylinder;Air intake component, air intake component includes: fixedly set in the waste gas air inlet pipe of furnace body bottom and with the inside communication of furnace body, fixedly set in the annular frame of furnace body inside and located the uppermost of cylinder, multiple circumferential uniform annular array distribution's cyclone nozzle, and fixedly set in the oxygen gas inlet pipe of furnace body side wall and one end with the inside communication of annular frame;The inside of cylinder is provided with spiral flow channel for guiding waste gas spiral ascending, and the end of waste gas air inlet pipe into furnace body inside integrally formed has oblique air outlet.The utility model improves the waste gas air intake mode of incineration tower, extends the axial length of incinerator, extends the time of waste gas in incineration cavity, improves the mixing efficiency of waste gas and oxygen, and then improves combustion efficiency.

Description

Technical Field

[0001] This utility model relates to the technical field of rock wool production equipment, specifically to a waste gas recovery and utilization system for rock wool production. Background Technology

[0002] Rock wool, a commonly used thermal insulation material, relies on cupola furnaces to melt raw materials during its production, which typically use coke as fuel. Because coke is prone to incomplete combustion, it produces large amounts of industrial waste gas, primarily composed of carbon monoxide (CO). To meet environmental emission requirements and achieve energy recovery, the industry's standard treatment process involves: first, pre-treating the waste gas using a cyclone dust collector and a bag filter to remove dust and impurities; then, passing the CO-containing waste gas into an incinerator for oxidation and combustion (converting CO into harmless CO2). Simultaneously, the high-temperature flue gas generated during combustion is used for heat recovery to reduce production energy consumption.

[0003] Currently, existing rock wool waste gas recovery systems, such as the Chinese patent with announcement number CN207230575U, have achieved the basic functions of dust removal, incineration, and heat exchange, but in practical applications, they still have the following key technical defects, making it difficult to balance system efficiency and environmental protection effects.

[0004] Existing incinerators mostly employ a straight-line air intake design, where exhaust gas flows directly upwards from the bottom, and oxygen is supplied from a single direction. The contact between the two is either co-current or simple cross-flow, resulting in low mixing efficiency. Furthermore, the incinerators have a short axial length and lack internal flow guiding structures, meaning the exhaust gas only resides in the combustion chamber for 1-2 seconds. CO is discharged before being fully oxidized, leading to energy waste and excessive residual CO concentration in the exhaust gas, increasing the burden on subsequent purification. Existing heat exchangers mostly use straight-tube heat exchange structures with limited heat exchange area and lack staged heat exchange based on the flue gas temperature gradient. The heat exchange between high-temperature flue gas (800-1000℃) and ambient-temperature combustion air is insufficient, resulting in the combustion air preheating temperature only reaching 200-300℃, failing to effectively reduce cupola coke consumption. Simultaneously, the heat from medium-temperature flue gas (400-600℃) is not specifically recovered and is directly emitted, causing energy waste. The existing system lacks a precise fluid control structure, and the flow rates of exhaust gas and oxygen cannot be dynamically adjusted according to combustion conditions, easily leading to problems of excessive or insufficient oxygen. Furthermore, the upper part of the combustion chamber lacks an airflow stabilization structure, causing the high-temperature flue gas to rise too quickly, easily resulting in turbulent airflow in the heat exchange area and affecting heat exchange efficiency. During combustion, a small amount of incompletely burned coke particles or dust may be generated. The existing system lacks a pretreatment structure at the exhaust end, and these impurities enter subsequent desulfurization and denitrification equipment with the flue gas, easily causing equipment blockage or catalyst poisoning, increasing maintenance costs. Utility Model Content

[0005] The purpose of this invention is to provide a waste gas recovery and utilization system for rock wool production that achieves complete combustion of waste gas, efficient heat recovery, and stable and reliable operation.

[0006] This utility model is achieved through the following technical solution: a waste gas recovery and utilization system for rock wool production, comprising: The furnace body has a cylinder fixedly installed inside it to guide the flow of exhaust gas. The air intake assembly includes: an exhaust gas intake pipe fixedly installed at the bottom of the furnace body and communicating with the interior of the furnace body; an annular frame fixedly installed inside the furnace body and located directly above the cylinder; a plurality of swirling nozzles evenly distributed in an annular array along the circumference of the annular frame; and an oxygen intake pipe fixedly installed on the side wall of the furnace body and communicating with the interior of the annular frame at one end. The interior of the cylinder is provided with a spiral guide channel for guiding the exhaust gas to rise in a spiral. One end of the exhaust gas inlet pipe that extends into the furnace body is integrally formed with an oblique exhaust port. The jet direction of the oblique exhaust port is consistent with the spiral direction of the spiral guide channel. The jet direction of the swirling nozzle is obliquely downward and points towards the top area of ​​the cylinder.

[0007] The working principle of this technical solution is as follows: the spiral guide channel inside the cylinder, combined with the oblique outlet of the exhaust gas inlet pipe, ensures that the exhaust gas flows in the same direction as the spiral, forcing the exhaust gas to rise along the spiral path. This increases the flow path by a factor of two compared to traditional straight-line intake. Simultaneously, the spiral motion breaks the laminar boundary layer of the gas, creating a strong turbulent flow field, which facilitates subsequent mixing with oxygen. The circumferentially distributed swirling nozzles on the annular frame spray air obliquely downwards, pointing towards the top outlet of the cylinder. This allows oxygen to be injected obliquely from above, forming a mixing pattern of vertical crossflow and circumferential swirling with the spiraling exhaust gas flowing out of the cylinder outlet. This improves mixing efficiency and ensures sufficient contact between CO and O2.

[0008] To better realize this utility model, a first control valve for adjusting the exhaust gas intake flow rate is further provided in series on the exhaust gas intake pipe.

[0009] To better realize this utility model, a second control valve for adjusting the oxygen intake flow rate is further provided in series on the oxygen intake pipe.

[0010] To better realize this utility model, a plurality of burners are fixedly installed on the side wall of the furnace body and symmetrically distributed along the circumference of the furnace body. The burners are located directly below the annular frame and correspond to the top outlet area of ​​the cylinder.

[0011] To better realize this utility model, the furnace body is further provided with a plurality of flow-blocking walls that are spaced apart along the axial direction of the furnace body and are inclined. The flow-blocking walls are located directly above the annular frame, and the inclination directions of adjacent flow-blocking walls are opposite.

[0012] To better realize this utility model, the furnace body is further provided with a first heat exchange rack and a second heat exchange rack fixedly installed inside. The first heat exchange rack is located directly above the flow-blocking wall, and the second heat exchange rack is located directly above the first heat exchange rack. Heat exchange tubes are fixedly installed on both the first and second heat exchange racks. One end of each heat exchange tube is connected to an air inlet pipe, and the other end of each heat exchange tube is connected to an air outlet pipe. Both the air inlet pipe and the air outlet pipe extend to the outside of the furnace body.

[0013] To better realize this utility model, the heat exchange tube is further formed by a continuous U-shaped bend or a serpentine bend, and multiple heat dissipation fins are integrally formed on the outer wall of the heat exchange tube.

[0014] To better realize this utility model, the top center of the furnace body is provided with an exhaust port for discharging the combustion gases, and a metal filter screen for filtering impurities is detachably connected to the exhaust port.

[0015] Compared with the prior art, this utility model has the following advantages and beneficial effects: (1) In this utility model, after the exhaust gas enters the cylinder through the inclined outlet, it moves upward in a spiral flow channel. The path length is 3-5 times longer than that of the straight inlet, and a strong turbulent flow field is formed, breaking the gas laminar boundary layer. Oxygen is sprayed out from the oblique bottom through the swirl nozzle of the ring frame, forming a cross swirling flow with the spirally rising exhaust gas. The mixing efficiency is greatly improved compared with the existing co-current mixing, ensuring that CO and O2 are fully in contact. The flow barrier forms a labyrinth-like airflow channel, further slowing down the rising speed of the flue gas, so that the residence time of the exhaust gas in the combustion chamber is extended to 4-6 seconds, the CO oxidation rate is improved, the CO residual concentration in the tail gas is low, and the environmental protection pressure is greatly reduced. (2) This utility model realizes a staged heat exchange system in which high-temperature flue gas is used to preheat the combustion air and medium-temperature flue gas is used to heat the curing furnace. The first heat exchange rack contacts the high-temperature flue gas at 800-1000℃. By bending the heat exchange tubes and heat dissipation fins, the normal-temperature combustion air is preheated to 500-600℃. After being introduced into the cupola furnace, the amount of coke consumed can be reduced. The second heat exchange rack contacts the medium-temperature flue gas at 400-600℃. The medium-temperature gas after heat exchange is transported to the rock wool product curing furnace, completely replacing the traditional natural gas heating. A single rock wool production line can reduce natural gas consumption and save costs. The bending structure and fin design of the heat exchange tubes improve the overall heat recovery efficiency and significantly improve the energy utilization rate. (3) The first control valve and the second control valve of this utility model can dynamically adjust the flow rate of exhaust gas and oxygen according to the temperature of the combustion chamber to ensure stable combustion conditions. For example, if the temperature is too high, the oxygen supply will be reduced, and if the temperature is too low, the oxygen supply will be increased to avoid over-burning or under-burning and extend the service life of the furnace body. The metal filter screen at the exhaust port can filter the solid impurities remaining in the flue gas, such as unburned coke particles and dust, effectively preventing the packing of the subsequent desulfurization tower and denitrification tower from being blocked or the catalyst from being poisoned, extending the equipment maintenance cycle and reducing maintenance costs. (4) The spiral guide channel, swirling nozzle, and bent heat exchange tube in this utility model can all be realized through conventional machining. The manufacturing cost is basically the same as that of the existing system, with no additional process cost. The furnace diameter and the number of heat exchange racks can be flexibly adjusted according to the exhaust gas emission of the rock wool production line. It is suitable for rock wool production equipment of different scales, has strong versatility, and is easy to promote and apply in the industry. Attached Figure Description

[0016] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 This is a schematic diagram of the internal structure of the middle cylinder of this utility model; Figure 4 This is a three-dimensional structural diagram of the heat exchange tube in this utility model.

[0017] Wherein: 1—furnace body, 2—exhaust gas inlet pipe, 3—first control valve, 4—slanted outlet, 5—cylinder, 6—spiral guide channel, 7—annular frame, 8—swirling nozzle, 9—oxygen inlet pipe, 10—second control valve, 11—burner, 12—flow barrier, 13—first heat exchange frame, 14—heat exchange tube, 15—air inlet pipe, 16—air outlet pipe, 17—second heat exchange frame, 18—exhaust port. Detailed Implementation

[0018] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0019] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly including one or more of the feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Example 1:

[0021] The main structure of this embodiment is as follows: Figures 1-3 As shown, it includes: Furnace body 1, wherein a cylinder 5 for guiding the flow of exhaust gas is fixedly installed inside the furnace body 1; The air intake assembly includes: an exhaust gas intake pipe 2 fixedly installed at the bottom of the furnace body 1 and communicating with the interior of the furnace body 1; an annular frame 7 fixedly installed inside the furnace body 1 and located directly above the cylinder 5; a plurality of swirling nozzles 8 evenly distributed in an annular array along the circumference of the annular frame 7; and an oxygen intake pipe 9 fixedly installed on the side wall of the furnace body 1 and communicating with the interior of the annular frame 7 at one end. The interior of the cylinder 5 is provided with a spiral guide channel 6 for guiding the exhaust gas to rise in a spiral. The end of the exhaust gas inlet pipe 2 that extends into the furnace body 1 is integrally formed with an oblique outlet 4. The jet direction of the oblique outlet 4 is consistent with the spiral direction of the spiral guide channel 6. The jet direction of the swirling nozzle 8 is obliquely downward and points towards the top area of ​​the cylinder 5.

[0022] The specific implementation process is as follows: the rock wool production waste gas containing CO and a small amount of dust, which has been pretreated by the cyclone dust collector and the bag dust collector, is transported through the waste gas inlet pipe 2 at the bottom of the furnace body 1; the waste gas is sprayed out from the inclined outlet 4 inside the furnace body 1 through the waste gas inlet pipe 2. Since the inclined outlet 4 is aligned with the spiral direction of the spiral guide channel 6 inside the cylinder 5, the waste gas moves steadily upward along the spiral guide channel 6 and gradually moves towards the top outlet of the cylinder 5.

[0023] The oxygen supply device is started simultaneously. Oxygen enters the annular frame 7 through the oxygen inlet pipe 9 on the side wall of the furnace body 1. The annular frame 7 is fixed directly above the cylinder 5 and is coaxial with the cylinder 5. The oxygen passes through the swirl nozzles 8 on the annular frame 7. The swirl nozzles 8 are evenly distributed around the circumference, usually 6-8, and are sprayed out at a downward angle of 30° to 5°. The nozzle outlets are precisely pointed to the top outlet area of ​​the cylinder 5, so that the oxygen directly merges with the spiral exhaust gas flowing out of the cylinder 5, forming a cross swirling flow, and completing the full mixing of exhaust gas and oxygen.

[0024] The mixed exhaust gas and oxygen flow enter the combustion zone of the furnace body 1, located below the annular frame 7 and around the top of the cylinder 5. With the assistance of the ambient temperature and the subsequent burners, CO and O2 undergo an oxidation reaction to generate CO2, thus initially achieving exhaust gas purification. Example 2:

[0025] This embodiment, based on the above embodiment, further adds a first control valve 3, such as... Figure 1 , Figure 2 As shown, a first control valve 3 for adjusting the exhaust gas intake flow rate is connected in series on the exhaust gas intake pipe 2. By controlling the exhaust gas flow rate, the exhaust gas to oxygen ratio required for subsequent combustion is matched, avoiding incomplete combustion due to insufficient oxygen caused by excessive exhaust gas flow rate, or energy waste due to insufficient flow rate, thus ensuring stable combustion conditions.

[0026] The specific implementation process is as follows: a first control valve 3 is installed on the exhaust gas inlet pipe 2. The first control valve 3 is usually an electric butterfly valve, which can be linked with a temperature sensor and calibrate the correspondence between the control valve opening degree and the flow rate.

[0027] After the waste gas recovery and utilization system is started, the waste gas flow rate is first adjusted to the initial value through the first control valve 3, so that the waste gas rises along the spiral guide channel 6 along the set path and mixes with oxygen.

[0028] Temperature is monitored by a temperature sensor in the combustion zone of furnace body 1. If the temperature is below 800℃, the minimum temperature required for CO oxidation, it indicates that the exhaust gas flow is too large and the oxygen is relatively insufficient. In this case, the opening of the first control valve 3 is reduced to decrease the amount of exhaust gas entering and increase the oxygen ratio. If the temperature is above 1000℃, it indicates that the exhaust gas flow is too small and heat is wasted. In this case, the opening of the first control valve 3 is increased to increase the amount of exhaust gas entering and make full use of the heat. Once the temperature stabilizes between 800-1000℃, the efficient CO oxidation range, the current opening of the first control valve 3 is maintained to keep the exhaust gas flow stable. The other parts of this embodiment are the same as those in the above embodiment and will not be repeated. Example 3:

[0029] This embodiment, based on the above embodiment, further adds a second control valve 10, such as... Figure 1 , Figure 2 As shown, a second control valve 10 for adjusting the oxygen intake flow rate is connected in series on the oxygen intake pipe 9. Based on the exhaust gas flow rate and combustion temperature, the oxygen quantity is adjusted to 1.05~1.1 times the theoretical air quantity, which is the optimal oxygen excess coefficient for complete CO oxidation. This avoids excessive oxygen increasing fan energy consumption or insufficient oxygen causing incomplete combustion, further optimizing combustion efficiency.

[0030] The specific implementation process is as follows: a second control valve 10 is installed on the oxygen inlet pipe 9. The second control valve 10 is the same as the first control valve, and a matching relationship between the exhaust gas flow rate and the oxygen flow rate is established.

[0031] After the oxygen supply device is started, the opening of the second control valve 10 is adjusted to the matching value according to the current opening of the first control valve 3. Oxygen enters the annular frame 7 through the oxygen inlet pipe 9 and is sprayed out from the swirl nozzle 8.

[0032] Adjustments are made based on data from both the temperature sensor and the online CO monitor. If the residual CO concentration exceeds 50 mg / m³... 3 Incomplete combustion, coupled with a normal temperature of 800℃~1000℃, indicates insufficient oxygen. Increase the opening of the second control valve by 10 degrees to increase oxygen supply. If the residual CO concentration is less than 10mg / m³... 3 However, if the temperature exceeds 1000℃, it indicates an excess of oxygen. The opening of the second control valve 10 should be reduced to decrease the amount of oxygen entering the system. If both the first control valve 3 and the second control valve 10 are activated simultaneously, the ratio of exhaust gas flow rate to oxygen flow rate must be kept stable to avoid conflict in their regulation. Other parts of this embodiment are the same as those in the previous embodiment and will not be repeated here. Example 4:

[0033] This embodiment further defines the structure of the furnace body 1 based on the above embodiments, such as... Figures 1-3As shown, multiple burners 11 are fixedly installed on the side wall of the furnace body 1, symmetrically distributed around the circumference of the furnace body 1. The burners 11 are located directly below the annular frame 7 and correspond to the top outlet area of ​​the cylinder 5. This solves the problem of difficult ignition of mixed gas under low-temperature conditions, ensuring that CO burns in the highly efficient oxidation range of 800℃~1000℃. At the same time, the symmetrically distributed burners 11 can avoid uneven local temperature and prevent local overheating of the furnace body 1.

[0034] The specific implementation process is as follows: 4-6 burners 11 are installed on the side wall of the furnace body 1, ensuring that the burners 11 are symmetrically distributed around the furnace body 1, and that the flame jet direction is directed towards the center of the furnace body 1, that is, the top outlet area of ​​the cylinder 5, which is consistent with the flow direction of the mixed gas.

[0035] Before the exhaust gas and oxygen enter during the initial startup of the system, the burner 11 is turned on to preheat the combustion zone below the annular frame 7 of the furnace body 1 to 600℃~700℃ to prevent the mixed gas from failing to ignite after entering.

[0036] After the temperature reaches the preheating value, the first control valve 3 of the exhaust gas inlet pipe 2 and the second control valve 10 of the oxygen inlet pipe 9 are opened according to the steps of the above embodiment, allowing the mixed gas to enter the combustion zone; the burner 11 adjusts the flame size according to the temperature sensor data. When the temperature is below 800℃, the burner 11 flame is increased to supplement heat; when the temperature is above 1000℃, the burner 11 flame is decreased, or some burners 11 are paused. Once the mixed gas can maintain a temperature of 800℃~1000℃ through combustion, the burner 11 can be switched to heat preservation mode, supplementing heat only when the temperature fluctuates. The other parts of this embodiment are the same as those in the above embodiment and will not be repeated. Example 5:

[0037] This embodiment further defines the structure of the furnace body 1 based on the above embodiments, such as... Figures 1-3 As shown, the furnace body 1 is internally equipped with multiple inclined baffle walls 12 spaced apart along the axial direction of the furnace body 1. The baffle walls 12 are located directly above the annular frame 7, and adjacent baffle walls 12 are inclined in opposite directions. By increasing the resistance to the flow of exhaust gas and slowing down the upward velocity, the residence time of exhaust gas in the furnace body 1 is extended, ensuring that CO has sufficient time to be completely oxidized; at the same time, the inverted baffle walls 12 can prevent airflow deviation and ensure uniform temperature.

[0038] The specific implementation process is as follows: 3-4 layers of flow-blocking walls 12 are installed inside the furnace body 1 and directly above the annular frame 7. These walls can be constructed using fireproof bricks and have an inclination angle of 30°~45°. The inclination directions of adjacent flow-blocking walls 12 are opposite, such as the first layer tilting to the left and the second layer tilting to the right, with a spacing of 50cm~80cm between layers, forming a maze-like passage.

[0039] The high-temperature flue gas after combustion contains CO2 and a small amount of incompletely burned CO, which flows upward and first comes into contact with the first layer of baffle wall 12. Due to the obstruction of the baffle wall 12, the flue gas cannot rise directly and needs to go around along the inclined surface. For example, the baffle wall tilted to the left forces the flue gas to flow to the lower left and then upward from the edge. When it goes around to the second layer of baffle wall 12, which is tilted in the opposite direction, it changes its flow direction again and goes around to the lower right. This process is repeated through multiple layers of baffle walls 12, which further extends the flow path and prolongs the residence time.

[0040] During the delay process, the small amount of unburned CO can further react with the residual oxygen in the flue gas, increasing the CO oxidation rate and ensuring that the exhaust gas meets the standards. The other parts of this embodiment are the same as those in the above embodiments and will not be repeated here. Example 6:

[0041] This embodiment further defines the structure of the furnace body 1 based on the above embodiments, such as... Figures 1-3 As shown, a first heat exchange rack 13 and a second heat exchange rack 17 are fixedly installed inside the furnace body 1. The first heat exchange rack 13 is located directly above the flow-blocking wall 12, and the second heat exchange rack 17 is located directly above the first heat exchange rack 13. Heat exchange tubes 14 are fixedly installed on both the first heat exchange rack 13 and the second heat exchange rack 17. One end of the heat exchange tubes 14 is connected to an air inlet pipe 15, and the other end of the heat exchange tubes 14 is connected to an air outlet pipe 16. Both the air inlet pipe 15 and the air outlet pipe 16 extend to the outside of the furnace body 1. The first heat exchange rack 13 is located above the baffle wall 12, in contact with high-temperature flue gas of 800℃~1000℃, preheating the ambient temperature combustion air to 500℃~600℃ for use in the cupola furnace, reducing coke consumption; the second heat exchange rack 17 is located above the first heat exchange rack 13, in contact with medium-temperature flue gas of 400℃~600℃, heating the air to 300℃~400℃ for use in the rock wool curing furnace, replacing natural gas; through high-temperature high-use and medium-temperature medium-use, heat is utilized in a cascade manner, improving the energy recovery rate.

[0042] The specific implementation process is as follows: a first heat exchanger 13 is installed inside the furnace body 1, adjacent to the top of the flow-blocking wall 12 and a second heat exchanger 17. Heat exchanger tubes 14 are fixedly installed on both heat exchanger frames. The air inlet pipe 15 is divided into two branches, which are respectively connected to the inlets of the heat exchanger tubes 14 of the first and second heat exchanger frames. The air outlet pipe 16 is also divided into two branches, which are respectively connected to the outlets of the heat exchanger tubes 14. Both the air inlet pipe 15 and the air outlet pipe 16 extend to the outside of the furnace body 1. The air inlet pipe is connected to a blower, and the air outlet pipe is respectively connected to the cupola oven and the curing oven.

[0043] High-temperature heat exchange first heat exchange frame: The 800℃~1000℃ high-temperature flue gas flows upward through the baffle wall 12 and passes through the heat exchange tube 14 of the first heat exchange frame 13. The heat is transferred through the tube wall to the ambient temperature combustion air that enters from the branch of the air inlet pipe 15 inside the heat exchange tube 14. After the combustion air is preheated to 500℃~600℃, it is delivered from the branch of the air outlet pipe 16 to the cupola furnace for rock wool production, replacing part of the cold air and reducing coke consumption.

[0044] Medium-temperature heat exchanger second heat exchanger: After being cooled by the first heat exchanger 13, the medium-temperature flue gas at 400℃~600℃ continues to flow upward through the heat exchange tube 14 of the second heat exchanger 17, transferring heat to the ambient temperature air entering from another branch of the air inlet duct 15; after the air is heated to 300℃~400℃, it is transported from another branch of the air outlet duct 16 to the rock wool product curing oven, replacing traditional natural gas heating and reducing natural gas consumption.

[0045] The flow rate of the medium is regulated by a fan in the air inlet duct 15 to ensure stable heat exchange efficiency. The other parts of this embodiment are the same as those in the above embodiments and will not be repeated here. Example 7:

[0046] This embodiment further defines the structure of the heat exchange tube 14 based on the above embodiments, such as... Figure 4 As shown, the heat exchange tube 14 has a curved structure formed by continuous U-shaped bends or serpentine bends, and multiple heat dissipation fins are integrally formed on the outer wall of the heat exchange tube 14. The bending structure increases the length of the heat exchange tube 14 within the same furnace space by 2-3 times, extending the contact time between the medium and the flue gas; the heat dissipation fins on the outer wall with a spacing of 10mm~15mm further expand the heat exchange area, improve the heat exchange efficiency, and increase the heat recovery rate.

[0047] The specific implementation process is as follows: heat exchange tube processing and installation: heat exchange tube 14 is processed into a continuous U-shape suitable for small spaces or a serpentine shape suitable for large spaces, and heat dissipation fins are integrally formed on the tube wall. The heat dissipation fins are made of metal and have a thickness of 1-2mm. The processed heat exchange tube 14 is fixed on the first heat exchange frame 13 and the second heat exchange frame 17 to ensure that there is no blockage at the bend and no deformation of the fins.

[0048] After the combustion air enters the U-shaped heat exchange tube 14 of the first heat exchange rack 13, the flow speed slows down due to the bend in the pipe path, the contact time with the high-temperature flue gas is extended, the heat absorption is more complete, and the preheating temperature is increased from 500℃ to 600℃. After the ambient temperature air enters the serpentine heat exchange tube 14 of the second heat exchange rack 17, the heating temperature is also increased from 300℃ to 400℃ due to the bend in the path and the effect of the fins, and the temperature distribution is more uniform.

[0049] Every three months, the system is shut down and compressed air is used to blow back through the air inlet duct 15 to remove accumulated dust from the fins, preventing dust from affecting heat exchange efficiency and ensuring the long-term stable operation of the heat exchange tube 14. Other parts of this embodiment are the same as those in the above embodiments and will not be repeated. Example 8:

[0050] This embodiment further refines the structure of the furnace body 1 based on the above embodiment, such as... Figures 1-3 As shown, an exhaust port 18 for discharging combustion gases is provided at the top center of the furnace body 1. A metal filter screen for filtering impurities is detachably connected to the exhaust port 18. The exhaust port 18 is located at the top center of the furnace body 1 to ensure uniform discharge of flue gas and avoid local stagnation. The metal filter screen with a pore size of 50μm~100μm can filter residual solid impurities in the flue gas, such as incompletely burned coke particles and dust, preventing them from entering subsequent desulfurization and denitrification equipment and avoiding equipment blockage or catalyst poisoning.

[0051] The specific implementation process is as follows: an exhaust port 18 is opened at the center of the top of the furnace body 1. The diameter of the exhaust port 18 is 1:3 with the diameter of the furnace body 1 to ensure smooth exhaust. A metal filter screen is detachably connected to the inside of the exhaust port 18 by bolts. The metal filter screen is made of stainless steel and is easy to clean.

[0052] After heat exchange, the low-temperature flue gas, with a temperature of 150℃~200℃, has a CO residue of ≤50mg / m³. 3 The flue gas flows upward and is discharged from the exhaust port 18 at the top of the furnace body 1. During the process, solid impurities in the flue gas with a particle size greater than 50μm are intercepted by the metal filter screen and remain inside the filter screen. The filtered clean flue gas enters the subsequent desulfurization tower and denitrification tower to further remove SO2 and NOx, and finally meets the emission standards.

[0053] The machine should be shut down every month. Remove the bolts at exhaust port 18, take out the metal filter screen, rinse the surface of the filter screen with a high-pressure water gun to remove impurities, let it dry, and then reinstall it to ensure filtration effectiveness. If the filter screen is damaged, replace it with a new one promptly. The other parts of this embodiment are the same as those in the above embodiment and will not be repeated.

[0054] It is understood that the working principle and process of the waste gas recovery and utilization system structure according to one embodiment of the present utility model, such as the control valve and burner 11, are existing technologies and are well known to those skilled in the art, and will not be described in detail here.

[0055] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A waste gas recovery and utilization system for rock wool production, characterized in that, include: Furnace body (1), and a cylinder (5) for guiding the flow of exhaust gas is fixedly installed inside the furnace body (1); The air intake assembly includes: an exhaust gas inlet pipe (2) fixedly installed at the bottom of the furnace body (1) and communicating with the interior of the furnace body (1); an annular frame (7) fixedly installed inside the furnace body (1) and located directly above the cylinder (5); a plurality of swirling nozzles (8) evenly distributed in an annular array along the circumference of the annular frame (7); and an oxygen inlet pipe (9) fixedly installed on the side wall of the furnace body (1) and communicating with the interior of the annular frame (7) at one end. The interior of the cylinder (5) is provided with a spiral guide channel (6) for guiding the exhaust gas to spiral upward. The exhaust gas inlet pipe (2) extends into the furnace body (1) and has an integrally formed oblique outlet (4). The jet direction of the oblique outlet (4) is consistent with the spiral direction of the spiral guide channel (6). The jet direction of the swirling nozzle (8) is obliquely downward and points to the top area of ​​the cylinder (5).

2. The waste gas recovery and utilization system for rock wool production according to claim 1, characterized in that, A first control valve (3) for adjusting the exhaust gas intake flow rate is connected in series on the exhaust gas intake pipe (2).

3. A waste gas recovery and utilization system for rock wool production according to claim 1 or 2, characterized in that, A second control valve (10) for adjusting the oxygen intake flow rate is connected in series on the oxygen intake pipe (9).

4. A waste gas recovery and utilization system for rock wool production according to claim 1 or 2, characterized in that, Multiple burners (11) are fixedly installed on the side wall of the furnace body (1) and are symmetrically distributed around the circumference of the furnace body (1). The burners (11) are located directly below the annular frame (7) and correspond to the top outlet area of ​​the cylinder (5).

5. A waste gas recovery and utilization system for rock wool production according to claim 1 or 2, characterized in that, The furnace body (1) is fixedly provided with a plurality of flow-blocking walls (12) that are spaced apart along the axial direction of the furnace body (1) and are inclined. The flow-blocking walls (12) are located directly above the annular frame (7), and the inclination directions of adjacent flow-blocking walls (12) are opposite.

6. A waste gas recovery and utilization system for rock wool production according to claim 1 or 2, characterized in that, The furnace body (1) is fixedly provided with a first heat exchange rack (13) and a second heat exchange rack (17). The first heat exchange rack (13) is located directly above the flow barrier wall (12), and the second heat exchange rack (17) is located directly above the first heat exchange rack (13). Heat exchange tubes (14) are fixedly installed on both the first heat exchange rack (13) and the second heat exchange rack (17). One end of the heat exchange tubes (14) is connected to an air inlet pipe (15), and the other end of the heat exchange tubes (14) is connected to an air outlet pipe (16). Both the air inlet pipe (15) and the air outlet pipe (16) extend to the outside of the furnace body (1).

7. A waste gas recovery and utilization system for rock wool production according to claim 6, characterized in that, The heat exchange tube (14) has a curved structure formed by continuous U-shaped bends or serpentine bends, and multiple heat dissipation fins are integrally formed on the outer wall of the heat exchange tube (14).

8. A waste gas recovery and utilization system for rock wool production according to claim 1 or 2, characterized in that, The furnace body (1) has an exhaust port (18) at the top center for discharging the combustion gases. A metal filter screen for filtering impurities is detachably connected to the exhaust port (18).

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