Rock wool electric furnace waste gas treatment and recovery system and working method

Abstract

The invention provides a rock wool electric furnace waste gas treatment and recovery system and a working method. The rock wool electric furnace waste gas treatment and recovery system comprises a rock wool electric furnace, a rotary dryer, a thermolator, a high-temperature bag dust collector, an induced draft fan and a wet desulfurization dust collector which are sequentially connected; two supporting structures are arranged between a feeding port and a discharging port of the rotary dryer, a middle rotary barrel and a driving structure are arranged between the two supporting structures, and the middle rotary barrel is driven by the driving structure; a front-end pipeline temperature sensor is arranged at the feeding port, a rear-end pipeline temperature sensor is arranged at the discharging port, the front-end pipeline temperature sensor and the rear-end pipeline temperature sensor are connected with a controller, and the controller is further connected with the feeding port and the driving structure and used for adjusting the feeding amount and the operation frequency of the driving structure. The problems that in the prior art, waste gas needs to be cooled and discharged, and dual-energy waste is caused by energy consumption of rock wool drying are solved.

Description

Technical Field

[0001] This invention belongs to the field of waste heat recovery technology in rock wool production, specifically relating to a rock wool electric furnace waste gas treatment and recovery system and its working method. Background Technology

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

[0003] In the rock wool production process, the electric furnace is a core piece of equipment, and the efficiency and stability of its waste gas treatment system directly affect the overall production's energy consumption, cost, and environmental compliance. Traditional rock wool electric furnaces typically employ a hot-top furnace process, which generates a large amount of high-temperature flue gas during production, with temperatures usually ranging from 500 to 600°C. This high-temperature flue gas not only carries a significant amount of heat energy but also poses a severe challenge to subsequent processing equipment due to its high-temperature characteristics.

[0004] Currently, the high-temperature flue gas in traditional rock wool electric furnace exhaust gas treatment systems results in a significant waste of heat energy, with 10-20% of the total heat loss. This not only increases energy consumption but also reduces overall energy efficiency. Due to the lack of effective heat recovery methods, this heat is typically directly released into the atmosphere, causing significant economic losses and environmental thermal pollution. The air preheater in the thermostat meets dust removal requirements through alternating heating and cooling. However, rock wool production has strict requirements for raw material moisture content, typically needing to be controlled between 2-4%. To achieve this standard, production enterprises often need to use natural gas for heating and drying, further leading to energy waste. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a rock wool electric furnace exhaust gas treatment and recovery system and its operating method, which solves the dual energy waste problems caused by the need for cooling and emission of exhaust gas in existing technologies and the energy consumption of rock wool drying.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a rock wool electric furnace exhaust gas treatment and recovery system, comprising: a rock wool electric furnace, a rotary dryer, a thermostat, a high-temperature bag dust collector, an induced draft fan, and a wet desulfurization and dust removal device connected in sequence. The rotary dryer has two support structures between its inlet and outlet, and an intermediate rotating cylinder and a drive structure between the two support structures. The intermediate rotating cylinder is driven by the drive structure. A front-end pipe temperature sensor is installed at the inlet, and a rear-end pipe temperature sensor is installed at the outlet. The front-end and rear-end pipe temperature sensors are connected to a controller, which is also connected to the inlet and the drive structure to adjust the feed rate and the operating frequency of the drive structure.

[0007] As a further implementation, the temperature controller is provided with a chimney at the upper end and a temperature regulating fan at the lower end; the temperature controller is connected to the feed inlet through a first pipe and is provided with a first solenoid valve; the temperature controller is connected to the high-temperature bag dust collector through a second pipe and is provided with a second solenoid valve.

[0008] As a further implementation, the temperature controller is connected to the high-temperature bag filter via a third pipe and is equipped with a third solenoid valve; the high-temperature bag filter is equipped with a dust collector inlet temperature sensor.

[0009] As a further implementation, the first pipe is connected in series with the second pipe via a thermostat, and after being connected in series, it is arranged in parallel with the third pipe.

[0010] As a further implementation, a double-layer double-plate airlock unloading valve and an electric segmented wheel unloader are installed at the upper end of the feed inlet and the lower end of the discharge outlet.

[0011] As a further implementation, the intermediate rotating cylinder is provided with a first guide plate, a second guide plate, a single-bend guide plate, and a double-bend guide plate. The first guide plate is arranged near the inlet, and the second guide plate is arranged near the outlet. Both the first and second guide plates are spiral-shaped, and the pitch of the first guide plate is greater than that of the second guide plate. This allows the first guide plate to advance and disperse quickly, the second guide plate to ensure smooth discharge, and the single-bend and double-bend guide plates to fully lift the material and extend the residence time of the material in the intermediate rotating cylinder.

[0012] Secondly, the present invention also provides a method for operating a rock wool electric furnace exhaust gas treatment and recovery system, comprising the following steps: Step 1: Introduce the 500-600℃ flue gas generated by the rock wool electric furnace into the rotary dryer through the centrifugal action of the induced draft fan; Step 2: In the rotary dryer, the flue gas flows in the opposite direction to the material entering from the feed inlet. The material is turned over by the guide plate inside the rotating cylinder, so that the flue gas and the material can come into full contact, thereby achieving material preheating and drying. Step 3: By activating the double-layer double-plate airlock discharge valve and the electric segmented wheel discharger at the feed inlet, the raw material is fed into the intermediate rotating cylinder; Step 4: Monitor the temperature of the flue gas in the front-end pipe of the rotary dryer, and automatically adjust the feed rate at the inlet and the operating speed of the drive structure through the controller; discharge the raw material by activating the double-layer double-plate airlock discharge valve and the electric segmented wheel unloader at the outlet and wait for further use; Step 5: If the flue gas temperature in the front-end duct is within the normal range, the third solenoid valve opens, and the flue gas enters the high-temperature bag filter through the third duct; if the flue gas temperature in the front-end duct is within the set alarm temperature range, the controller automatically opens the first and second solenoid valves, starts the temperature regulating fan, and makes the flue gas exchange heat with the air in reverse through the temperature regulator. The air is finally discharged through the chimney, and the flue gas temperature is controlled to drop to the set range. Step 6: The treated flue gas enters the high-temperature bag filter, and is then introduced into the wet desulfurization and dust removal unit by the induced draft fan for further treatment before being discharged in compliance with standards.

[0013] As a further implementation, the rotary dryer processes materials with a particle size of 3-50mm, including basalt, dolomite, slag, waste cotton, and other smelting waste.

[0014] As a further implementation, the thermostat is an air preheater structure, in which flue gas flows inside the heating tube of the thermostat and air flows in the opposite direction outside the heating tube of the thermostat to achieve the maximum cooling range.

[0015] As a further implementation, the flue gas is connected in parallel with a third pipe equipped with a third solenoid valve and a series pipe formed by the first solenoid valve, thermostat, second solenoid valve, first pipe and second pipe, serving as backups for each other and allowing for mutual adjustment of air volume.

[0016] Compared with the prior art, the advantages and positive effects of this invention are: This invention uses front-end and rear-end pipe temperature sensors to monitor the temperature of the exhaust gas entering and leaving the rotary dryer in real time, and dynamically adjusts the rotation speed of the intermediate rotating cylinder to ensure that the heat in the exhaust gas is absorbed by the material to the maximum extent, avoiding heat waste and ensuring that the drying degree of the material is consistent. The exhaust gas is sent into the rotary dryer through a rock wool electric furnace to recover the heat source in the high-temperature exhaust gas. After heat exchange in the rotary dryer, the thermostat controls the temperature of the exhaust gas, adjusting it to the optimal temperature for dust removal. This ensures that the temperature of the exhaust gas entering the dust collector is within the safe range allowed by the filter bags. At the appropriate temperature, the physical properties of the dust, such as resistivity, are more conducive to being captured by the filter bags, resulting in higher dust removal efficiency. The high-temperature bag filter first removes most of the solid particles, and then the wet desulfurization and dust removal device removes sulfur dioxide and captures escaped fine dust and mist droplets generated during the wet process, achieving near-zero emissions of pollutants. In the original technology, the heat source of the exhaust gas was not addressed, requiring the thermostat to cool it down, which led to energy waste. Furthermore, in the air preheater, dew point deposition easily caused dust condensation due to temperature differences, making it difficult to clean. In this invention, the heat source of the exhaust gas is consumed at the front end, avoiding the operation of the thermostat to cool the exhaust gas and preventing dust condensation caused by dew point deposition in the thermostat.

[0017] The first pipe of this invention is connected in series with the second pipe via a thermostat, and then arranged in parallel with the third pipe. By adjusting the valve openings of the two passages, stepless and precise adjustment between direct exhaust gas flow and exhaust gas temperature regulation can be achieved. A closed-loop control is formed based on feedback from the dust collector inlet temperature sensor. When the sensor detects that the temperature is close to a dangerous value, the flow rate of the temperature regulation path is automatically increased, and the temperature of the mixed gas is reduced, thereby most effectively protecting the filter bags of the high-temperature bag filter and preventing them from burning out due to overheating. When the exhaust gas temperature is within a suitable range, most or all of the flow can take the direct path, avoiding unnecessary energy consumption of the temperature regulation fan and achieving energy-saving operation. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0019] Figure 1 This is a schematic diagram of the rock wool electric furnace exhaust gas treatment and recovery system of the present invention; Figure 2 This is a schematic diagram of the intermediate rotating cylinder structure of the present invention.

[0020] In the diagram: 1. Rock wool electric furnace; 2. Rotary dryer; 201. Feed inlet; 202. Discharge outlet; 203. Support structure; 204. Drive structure; 205. Rear pipeline temperature sensor; 206. Front pipeline temperature sensor; 207. Controller; 208. Intermediate rotating cylinder; 209. First guide plate; 210. Single-bend guide plate; 211. Double-bend guide plate; 212. Second guide plate; 3. Temperature controller; 301. Temperature regulating fan; 302. Chimney; 303. Third solenoid valve; 304. First solenoid valve; 305. Second solenoid valve; 306. Dust collector inlet temperature sensor; 4. High-temperature bag filter; 5. Exhaust fan; 6. Wet desulfurization dust collector. Detailed Implementation

[0021] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. Example 1 This embodiment provides a rock wool electric furnace exhaust gas treatment and recovery system, such as Figure 1As shown, the system includes: a rock wool electric furnace 1, a rotary dryer 2, a thermostat 3, a high-temperature bag dust collector 4, an induced draft fan 5, and a wet desulfurization and dust removal device 6, connected in sequence. Two support structures 203 are provided between the inlet 201 and outlet 202 of the rotary dryer 2. An intermediate rotating cylinder and a drive structure 204 are provided between the two support structures 203. Each support structure 203 consists of a tire on the intermediate rotating cylinder and a set of lower rollers. The drive structure 204 consists of two sets of large and small transmission gears and a reduction mechanism, providing rotational power. The intermediate rotating cylinder is driven by the drive structure 204. A front-end pipe temperature sensor 206 is provided at the inlet 201, and a... A rear-end pipe temperature sensor 205 is installed. The front-end pipe temperature sensor 206 and the rear-end pipe temperature sensor 205 are connected to a controller 207. The controller 207 is also connected to the feed inlet 201 and the drive structure 204. It is used to adjust the feed rate and the operating frequency of the drive structure 204. The front-end pipe temperature sensor 206 and the rear-end pipe temperature sensor 205 monitor the temperature of the exhaust gas entering and leaving the rotary dryer 2 in real time, and dynamically adjust the rotation speed of the intermediate rotating cylinder to ensure that the heat in the exhaust gas is absorbed by the material to the maximum extent, avoid heat waste, and ensure that the drying degree of the material is consistent. The exhaust gas is sent into the rotary dryer 2 through the rock wool electric furnace 1 to recover the heat source in the high-temperature exhaust gas. After heat exchange in the rotary dryer 2, the temperature controller 3 controls the temperature of the exhaust gas to adjust it to the most suitable temperature for dust removal. This ensures that the temperature of the exhaust gas entering the dust collector is within the safe range allowed by the filter bags. At the appropriate temperature, the physical properties of the dust, such as resistivity, are more conducive to being captured by the filter bags, resulting in higher dust removal efficiency. The high-temperature bag dust collector 4 first removes most of the solid particles, and then the wet desulfurization dust collector 6 removes sulfur dioxide and captures the escaped fine dust and mist droplets generated during the wet process, achieving near-zero emissions of pollutants.

[0023] As a further implementation, the thermostat 3 has a chimney 302 at its upper end and a temperature-regulating fan 301 at its lower end; the thermostat 3 is connected to the feed inlet 201 via a first pipe and is equipped with a first solenoid valve 304; the thermostat 3 is connected to the high-temperature bag filter 4 via a second pipe and is equipped with a second solenoid valve 305. The thermostat 3 is connected to the high-temperature bag filter 4 via a third pipe and is equipped with a third solenoid valve 303; the high-temperature bag filter 4 is equipped with a dust collector inlet temperature sensor 306. The first pipe is connected in series with the second pipe via the thermostat 3, and after series connection, it is arranged in parallel with the third pipe. By adjusting the valve opening of the two passages, stepless and precise adjustment between direct exhaust gas flow and exhaust gas temperature regulation can be achieved; a closed-loop control is formed based on the feedback from the dust collector inlet temperature sensor 306. When the inlet temperature sensor 306 detects that the temperature is approaching a dangerous value, it automatically increases the flow rate of the temperature-regulating path to reduce the temperature of the mixed gas, thereby most effectively protecting the filter bags of the high-temperature bag filter 4 and preventing them from burning out due to overheating. When the exhaust gas temperature is within a suitable range, most or all of the flow can be through a straight path, avoiding unnecessary energy consumption by the temperature-regulating fan 301 and achieving energy-saving operation.

[0024] As a further implementation, both the upper end of the feed inlet 201 and the lower end of the discharge outlet 202 are equipped with double-layer, double-plate airlock discharge valves and electric dividing wheel dischargers. This prevents flue gas leakage when materials enter and exit the rotary dryer 2, ensuring normal pressure inside the rock wool electric furnace 1.

[0025] As a further implementation, the intermediate rotating cylinder 208 is provided with a first guide plate 209, a second guide plate 212, a single-bend guide plate 210, and a double-bend guide plate 211. The first guide plate 209 is arranged near the feed inlet, and the second guide plate 212 is arranged near the discharge outlet. Both the first guide plate 209 and the second guide plate 212 are spiral-shaped, and the pitch of the first guide plate 209 is greater than the pitch of the second guide plate 212. This allows the first guide plate 209 to achieve rapid advancement and dispersion, the second guide plate 212 to ensure smooth discharge, and the single-bend guide plate 210 and the double-bend guide plate 211 to fully lift the material, extending the residence time of the material in the intermediate rotating cylinder 208 and allowing the exhaust gas to fully contact the material.

[0026] Example 2 This embodiment provides a working method for a rock wool electric furnace exhaust gas treatment and recovery system, including the following steps: Step 1: The flue gas generated by the rock wool electric furnace 1 at 500-600℃ is introduced into the rotary dryer 2 by the centrifugal action of the induced draft fan 5; Step 2: In the rotary dryer 2, the flue gas flows in the opposite direction to the material entering from the feed inlet 201. The material is turned over by the guide plate in the middle rotating cylinder, so that the flue gas and the material can be fully contacted to achieve material preheating and drying. Step 3: By activating the double-layer double-plate airlock discharge valve and electric segmented wheel discharger at the feed inlet 201, the raw material is fed into the intermediate rotating cylinder; Step 4: Monitor the temperature of the flue gas in the front pipe of the rotary dryer 2, and automatically adjust the feed rate of the feed inlet 201 and the operating speed of the drive structure 204 through the controller 207; discharge the raw material and wait for further use by activating the double-layer double-plate airlock discharge valve and electric dividing wheel discharger at the discharge port 202. Step 5: If the flue gas temperature in the front-end pipeline is within the normal range, the third solenoid valve 303 opens, and the flue gas enters the high-temperature bag filter through the third pipeline; if the flue gas temperature in the front-end pipeline is within the set alarm temperature range, the controller 207 automatically opens the first solenoid valve 304 and the second solenoid valve 305, starts the temperature regulating fan 301, so that the flue gas exchanges heat with the air in reverse through the temperature regulator 3, and the air is finally discharged through the chimney 302, controlling the flue gas temperature to drop to the set range. Step 6: The treated flue gas enters the high-temperature bag filter, and is then introduced into the wet desulfurization and dust removal device 6 by the induced draft fan 5 for treatment before being discharged in compliance with standards.

[0027] As a further implementation, the rotary dryer 2 processes materials with a particle size of 3-50mm, including basalt, dolomite, slag, waste cotton and other smelting waste.

[0028] As a further implementation, the thermostat 3 is an air preheater structure, in which flue gas flows inside the heating tube of the thermostat 3, and air flows in the opposite direction outside the heating tube of the thermostat 3, so as to achieve the maximum cooling range.

[0029] As a further implementation, the flue gas is connected in parallel with a third pipe equipped with a third solenoid valve 303 and a series pipe formed by a first solenoid valve 304, a thermostat 3, a second solenoid valve 305, the first pipe, and the second pipe. These pipes serve as backups for each other and allow for mutual adjustment of airflow. While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A rock wool electric furnace exhaust gas treatment and recovery system, characterized by, The application relates to a rock wool electric furnace, a rotary dryer, a temperature regulator, a high-temperature bag dust collector, an induced draft fan and a wet desulfurization dust collector which are sequentially connected. Two support structures are arranged between the feeding port and the discharging port of the rotary dryer, an intermediate rotary cylinder and a driving structure are arranged between the two support structures, the intermediate rotary cylinder is driven by the driving structure, a front-end pipeline temperature sensor is arranged at the feeding port, a rear-end pipeline temperature sensor is arranged at the discharging port, the front-end pipeline temperature sensor and the rear-end pipeline temperature sensor are connected with a controller, and the controller is also connected with the feeding port and the driving structure and used for adjusting the feeding amount and the operating frequency of the driving structure. A chimney is arranged at the upper end of the temperature regulator, and a temperature regulating fan is arranged at the lower end; the temperature regulator is connected with the feeding port through a first pipeline and is provided with a first electromagnetic valve; the temperature regulator is connected with the high-temperature bag dust collector through a second pipeline and is provided with a second electromagnetic valve.

2. A rock wool electric furnace exhaust gas treatment and recovery system according to claim 1, characterized in that, The temperature regulator is connected with the high-temperature bag dust collector through a third pipeline and is provided with a third electromagnetic valve; a dust collector inlet temperature sensor is arranged on the high-temperature bag dust collector.

3. A rock wool electric furnace exhaust gas treatment and recovery system according to claim 2, characterized in that, The first pipeline is connected with the second pipeline in series through the temperature regulator, and the first pipeline, the second pipeline and the third pipeline are arranged in parallel after being connected in series.

4. A rock wool electric furnace exhaust gas treatment and recovery system according to claim 3, characterized in that, The upper end of the feeding port and the lower end of the discharging port are both provided with a double-layer double-plate air-locking discharging valve and an electric grating wheel discharger.

5. A rock wool electric furnace exhaust gas treatment and recovery system according to claim 4, characterized in that, The intermediate rotary cylinder is provided with a first guide plate, a second guide plate, a single-bend guide plate and a double-bend guide plate; the first guide plate is arranged close to the feeding port, the second guide plate is arranged close to the discharging port, and the first guide plate and the second guide plate are both in a spiral shape, and the pitch of the first guide plate is larger than that of the second guide plate.

6. A rock wool electric furnace exhaust gas treatment and recovery system according to claim 1, characterized in that, The application further discloses a rock wool production method.

7. A method of operating a rock wool electric furnace exhaust gas treatment and recovery system as defined in claim 1, characterized by, Step one: 500-600 DEG C flue gas generated by the rock wool electric furnace is introduced into the rotary dryer through the centrifugal action of the induced draft fan; Step two: in the rotary dryer, the flue gas and the materials entering from the feeding port flow in opposite directions, the materials are turned over through the guide plates in the intermediate rotary cylinder, so that the flue gas and the materials are fully contacted, and the materials are preheated and dried; Step three: the double-layer double-plate air-locking discharging valve and the electric grating wheel discharger of the feeding port are started, and the raw materials are sent into the intermediate rotary cylinder; Step four: the temperature of the flue gas in the front-end pipeline of the rotary dryer is monitored, the feeding amount of the feeding port and the operating speed of the driving structure are automatically adjusted through the controller, the double-layer double-plate air-locking discharging valve and the electric grating wheel discharger of the discharging port are started, and the raw materials are discharged and used further; Step five: if the flue gas temperature in the front-end pipeline is within the normal range, the third electromagnetic valve is opened, the flue gas enters the high-temperature bag dust collector through the third pipeline; if the flue gas temperature in the front-end pipeline is within the set alarm temperature range, the first electromagnetic valve and the second electromagnetic valve are automatically opened through the controller, the temperature regulating fan is started, the flue gas is reversely heat-exchanged with air through the temperature regulator, and the air is finally discharged through the chimney, so that the flue gas temperature is reduced to the set range; Step six: the treated flue gas enters the high-temperature bag dust collector, is introduced into the wet desulfurization dust collector through the induced draft fan, and is discharged after treatment. ​ 8. A method of operating a rock wool electric furnace exhaust gas treatment and recovery system as claimed in claim 7, characterized in that, The material particle size processed by the rotary dryer is 3-50mm, including basalt, dolomite, slag, waste cotton and other smelting waste slag.

9. A method of operating a rock wool electric furnace exhaust gas treatment and recovery system as claimed in claim 7, characterized in that, The temperature adjuster is an air preheater structure, flue gas flows in the heating pipe of the temperature adjuster, and air flows reversely outside the heating pipe of the temperature adjuster to realize maximum temperature drop range.

10. The method of operating a rock wool electric furnace exhaust gas treatment and recovery system of claim 7, wherein, The flue gas passes through the third pipeline provided with the third electromagnetic valve and is in parallel relationship with the series pipeline formed by the first electromagnetic valve, the temperature adjuster, the second electromagnetic valve, the first pipeline and the second pipeline, and the two pipelines are mutual standby and can adjust air volume mutually.

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