Special flue system for glass melting furnace and transformation method thereof

Abstract

The invention belongs to the technical field of flue gas treatment, and relates to a special flue system for a glass melting furnace and a transformation method thereof, the transformation method comprises the following steps: (1) integrating a melting furnace flue in a branching manner, introducing flue gas into a corresponding integrated treatment system in groups, and stopping the original system; (2) optimizing the flue, dismantling redundant pipelines and elbows, replacing a straight-section flue, and blocking a connection interface of the flue and a shutdown system; (3) additionally arranging a booster fan; (4) transforming a shutdown system fan into a boiler induced draft fan standby system; (5) the upgrading pressure monitoring device is connected to a DCS control system; (6) an additional heat exchanger is communicated with the original heat exchanger; (7) constructing a temperature and pressure reduction system for an external project; and (8) opening holes, introducing external waste gas, and adjusting the positions of the on-line monitoring device and the denitration agent spray gun. The flue system for the glass melting furnace is structurally modified, so that the operation efficiency of the system is improved, the stability of furnace pressure and the reliability of equipment are ensured, the environment-friendly requirement is considered, and the production cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of flue gas treatment technology, and relates to a special flue gas system for glass melting furnaces, and more particularly to a special flue gas system for glass melting furnaces and its modification method. Background Technology

[0002] Currently, the flue systems used in glass melting furnaces generally suffer from complex layouts, redundant pipelines, and numerous bends, which significantly increases system resistance. Furthermore, the abundance of air leaks can lead to insufficient fan suction when flue gas enters the integrated sulfur, dust, and nitrate treatment system.

[0003] Excessive resistance in the flue system can lead to a series of adverse effects: on the one hand, it can cause unstable kiln pressure, which can seriously affect the stable production and safety of the melting furnace; on the other hand, it can cause a surge in the power consumption of the blower, the integrated treatment system to be in a high pressure differential condition for a long time, the ceramic filter cartridge to have a high breakage rate, and the simultaneous operation of new and old environmental protection facilities can result in high environmental protection operating costs.

[0004] In addition, traditional flue systems are complex and interconnected. When the furnace is switched on, the pressure fluctuations will affect each other. Furthermore, the lack of pressure measuring points at key points in the flue makes it difficult for staff to accurately determine the source of the pressure fluctuations, which is not conducive to timely problem solving.

[0005] Furthermore, due to the numerous air leaks in the old equipment in the series flue system, the flue gas is prone to instability when entering the integrated treatment system, causing unstable pressure in the melting kiln and frequent pressure build-up, which seriously affects the normal production of the main line. Moreover, the boiler does not have a backup induced draft fan during operation. Once the fan fails, the boiler needs to be shut down, which not only affects production but also prevents the environmental protection facilities from operating normally and stably.

[0006] Therefore, how to structurally modify the flue system used in glass melting furnaces to improve system operating efficiency, ensure furnace pressure stability and equipment reliability, while also taking into account environmental protection requirements and reducing production costs, has become an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a dedicated flue system for glass melting furnaces and its modification method. By structurally modifying the flue system used in glass melting furnaces, the system's operating efficiency is improved, ensuring furnace pressure stability and equipment reliability, while also taking into account environmental protection requirements and reducing production costs.

[0008] To achieve this objective, the present invention employs the following technical solution:

[0009] In a first aspect, the present invention provides a method for modifying a dedicated flue system for glass melting furnaces, comprising the following steps:

[0010] (1) The original flue gas ducts of the furnace are integrated and the flue gas is introduced into the corresponding integrated sulfur, dust and nitrate treatment system according to the preset grouping, and the original desulfurization, denitrification and electrostatic precipitator systems are shut down.

[0011] (2) Optimize and renovate the flue after the branch line integration, remove redundant pipes and bends and replace them with straight flue sections, and seal the connection interface between the original flue and the shutdown system;

[0012] (3) A booster fan is added after the interface where the waste heat boiler and heat exchanger meet, and on the main pipe of the direct exhaust chimney of the integrated treatment system.

[0013] (4) Modify the standby fan of the shutdown system to adapt it to the parameters of the boiler induced draft fan, and form a standby system by adding a flue valve to connect with the boiler ash hopper;

[0014] (5) Upgrade the pressure monitoring device and add pressure measuring points on the flue boundary line and the fan outlet main pipe of the integrated treatment system, and connect them to the DCS control system.

[0015] (6) Add independent heat exchangers to some boilers and connect them with the original heat exchangers, and configure axial flow fans to cool the heat exchangers;

[0016] (7) Construct a desuperheating and pressure reduction system, take steam from a preset steam source, process it and supply it to external projects, and take desuperheating water from the boiler feed water pump outlet header;

[0017] (8) Open the flue gas inlet of the integrated treatment system to connect to external exhaust gas, and adjust the position of the online monitoring device and the denitrification agent spray gun.

[0018] This invention integrates existing flue gas ducts and shuts down outdated environmental protection systems, avoiding flue gas mixing interference, reducing pipeline redundancy, lowering system resistance and energy consumption, and improving environmental treatment efficiency. Optimizing and transforming the flue gas duct into a straight section and sealing connection interfaces further reduces resistance and air leakage, ensuring stable flue gas flow, preventing kiln pressure fluctuations, and improving furnace safety. Adding a booster fan compensates for flue gas transport power, ensuring stable kiln pressure and reducing the load and energy consumption of the main fan. Modifying the standby fan to form a backup system for the boiler induced draft fan avoids furnace shutdowns due to fan failures, ensuring smooth production and compliance with flue gas emission standards. Upgrading the pressure monitoring device and integrating it into the DCS control system further enhances its effectiveness. The system can provide real-time feedback on differential pressure and dynamically adjust the fan output, precisely controlling kiln pressure and flow rate to improve system stability. An independent heat exchanger is added and connected to the existing heat exchanger, equipped with an axial flow fan for cooling, enabling smooth switching of flue gas when the boiler is shut down, ensuring continuous operation of the melting furnace and environmental treatment. A desuperheating and pressure reduction system is constructed, providing stable steam supply to external projects and ensuring continuous steam supply through desuperheating water backup, expanding functionality and improving energy efficiency. An opening is made in the inlet flue of the integrated treatment system to connect to external waste gas, and the positions of the monitoring devices and denitrification agent spray guns are adjusted to ensure compliant waste gas treatment while ensuring accurate monitoring data and denitrification efficiency, preventing waste gas from interfering with the environmental treatment effect.

[0019] Therefore, it can be seen that by structurally modifying the flue system used in glass melting furnaces, the present invention significantly improves the system operating efficiency, ensures the stability of furnace pressure and equipment reliability, while taking into account environmental protection requirements and reducing production costs, which is conducive to large-scale promotion and application.

[0020] Preferably, the preset grouping method in step (1) includes: introducing the flue gas generated by the first half of the kiln body into the first integrated sulfur, dust and nitrate treatment system, and introducing the flue gas generated by the second half of the kiln body into the second integrated sulfur, dust and nitrate treatment system, and the two integrated treatment systems operate independently.

[0021] Preferably, the standby fan of the modified shutdown system in step (4) further includes: configuring a frequency converter for the standby fan, and connecting the operation control signal and feedback signal of the standby fan to the original DCS control system to realize the automatic switching between the standby fan and the main induced draft fan.

[0022] Preferably, the medium flow direction of the independent heat exchanger added in step (6) adopts a low-inlet and high-outlet design, and the outlet of the independent heat exchanger is connected to the flue gas header of the boiler to the integrated treatment system, so as to ensure that it forms a complementary path for flue gas transportation with the original heat exchanger.

[0023] Preferably, the outlet pipe of the desuperheating and depressurization system in step (7) is equipped with two drain valves and two electric regulating valves to control the flow rates of the steam side and the desuperheating water side, respectively.

[0024] Preferably, the pipeline used to access the external exhaust gas in step (8) is equipped with an electric butterfly valve and a carbon steel blind flange.

[0025] Preferably, the adjustment method of the position of the online monitoring device and the denitrification agent spray gun in step (8) includes: moving the online monitoring device to the front of the exhaust gas interface, moving the denitrification agent spray gun back from its original position, and repairing the corroded flue area near the spray gun.

[0026] Preferably, the denitrification agent includes ammonia.

[0027] Preferably, the modification method further includes replacing the inlet and outlet components of the boiler induced draft fan.

[0028] Preferably, the inlet / outlet components include an expansion joint and a flue valve.

[0029] Secondly, the present invention provides a glass melting furnace dedicated flue system obtained by the modification method described in the first aspect. The glass melting furnace dedicated flue system includes a branch flue module, an induced draft fan module, a heat exchanger module, an integrated treatment module, a de-temperature and pressure reduction module, a waste gas introduction module, and a pressure monitoring module.

[0030] Preferably, the branch flue module includes multiple sets of straight flue sections, which are connected to the melting furnace and the corresponding integrated processing module according to a preset group, and the branch flue module blocks the connection interfaces of the original desulfurization system, denitrification system and electrostatic precipitator system.

[0031] Preferably, the induced draft fan module includes a booster fan, an integrated standby induced draft fan, and a boiler standby induced draft fan. The booster fan is respectively installed at the junction of the waste heat boiler and the heat exchanger and on the main exhaust chimney pipe of the integrated processing module. The integrated standby induced draft fan and the main induced draft fan of the integrated processing module form a dual-use and one-standby architecture. The boiler standby induced draft fan is connected to the boiler ash hopper by adding a flue valve to form a standby system.

[0032] Preferably, the heat exchanger module includes an existing heat exchanger and an additional independent heat exchanger, wherein the additional independent heat exchanger is connected to the existing heat exchanger, and the heat exchanger module is equipped with an axial flow fan for cooling the heat exchanger.

[0033] Preferably, the integrated treatment module includes at least two sets of integrated sulfur, dust and nitrate treatment systems, each set of integrated treatment systems corresponding to the pre-defined group of furnace flue gas, and old environmental protection facilities that run parallel to the integrated treatment system are shut down.

[0034] Preferably, the desuperheating and pressure reducing module includes a desuperheating and pressure reducing device, a steam pipe, and a desuperheating water pipe. The steam pipe is connected to the desuperheating and pressure reducing device from a preset steam source, and the desuperheating water pipe is connected to the desuperheating and pressure reducing device from the boiler feedwater pump outlet header. The outlet pipe of the desuperheating and pressure reducing module is connected to an external steam-using project.

[0035] Preferably, the exhaust gas inlet module includes an exhaust gas inlet pipe, an electric butterfly valve, and a carbon steel blind flange, wherein the exhaust gas inlet pipe is located on the inlet flue of the integrated treatment module.

[0036] Preferably, the pressure monitoring module includes multiple pressure measuring points and a pressure transmitter. The pressure measuring points are set on the dividing line of the branch flue module and the fan outlet main pipe of the integrated processing module. The pressure transmitter transmits the monitoring signal to the DCS control system.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] This invention significantly improves system operating efficiency, ensures kiln pressure stability and equipment reliability by structurally modifying the flue system used in glass melting furnaces, while also taking into account environmental protection requirements and reducing production costs, which is conducive to large-scale promotion and application. Attached Figure Description

[0039] Figure 1 This is a circuit diagram of the modified glass melting furnace dedicated flue system provided in Example 1.

[0040] Among them: 1-Chimney; 2-NID fan; 3-Boiler induced draft fan; 4-Booster fan; 5-Integrated fan. Detailed Implementation

[0041] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0042] Example 1

[0043] This embodiment provides a dedicated flue system for glass melting furnaces and its modification method, such as... Figure 1 As shown, the specific solution is as follows:

[0044] A. Exhaust fan system

[0045] Two additional booster fans (4 units) will be added to lines 1 and 2. The inlet pipes will be led out from the T-junction of the high-temperature section and heat exchanger outlet of boiler 1, and the outlet will be connected to the original integrated φ3300 flue gas inlet. Booster fan 4 of line 2 will supply the direct exhaust gas from the heat exchangers of boilers 1 and 2 under operating conditions. All power distribution and control will be moved to the original desulfurization power distribution room of line 2.

[0046] Since the integration of No. 1 only applies to lines 1 and 2, the flue in the area of ​​the original two fans will be modified and optimized to reduce air leakage; a new 1600KW standby high-pressure fan and related frequency converters, flues, inlet and outlet valves, expansion joints and related electrical accessories will be added.

[0047] The original two NID desulfurization fans were converted into backup fans for boiler induced draft fan 3. A valve was installed at the ash hopper inlet of boiler #1, connecting it to the NID inlet pipe. The original NID inlet flue near the boiler induced draft fan 3 outlet pipe was sealed. The square-to-round shape of the NID inlet flues for lines #1 and #2 at the desulfurization tower inlet was removed, and the NID inlet flues for lines #1 and #2 were connected. The modified NID inlet header for line #1 was connected to the horizontal header for NID fan 2, and the horizontal headers for NID fans #1 and #2 were sealed with intermediate isolation. A flue valve was added to the inlet of the original boiler induced draft fan 3. A new pressure measuring point was installed on the outlet flue gas header for integrated fan 5 to control the output distribution between NID fan 2 and integrated fan 5. A pressure transmitter, cables, conduits, and other accessories were added and connected to the integrated DCS system.

[0048] After the valve is installed at the ash hopper outlet of boiler #2, it is connected to the NID inlet pipe. The original NID inlet flue near the blower outlet pipe is blocked. The NID inlet pipe of #2 is connected to the inlet vertical air pipe of NID blower #2. Flue valves are added to the inlets of the original induced draft fans #3 of boilers #1 and #2, and to the inlet of the original induced draft fan #3 of boiler #2.

[0049] The original CFB blower of boiler #3 was used as a backup induced draft fan for boiler #3. After removing the desulfurization tower of boiler #3, a valve was installed at the flue gas inlet of boiler #3's ash hopper and connected to the NID inlet flue. The original NID inlet and outlet flues were connected to the original desulfurization tower location via the flue. The operation control and feedback signals of the original CFB blower, CFB inlet gate valve, and flue valve were introduced into the existing DCS system, and new cabling was carried out (not shown in the figure).

[0050] B. Heat exchanger system

[0051] The No. 1 heat exchanger and its accessories all utilize the original heat exchanger with low inlet and high outlet, and the outlet is connected to the integrated flue header of the boiler; considering the limited space on site, the heat exchanger is cooled by an axial flow fan.

[0052] C. Flue system modification

[0053] To reduce air leakage, the connection interface between the No. 1 integrated system and the old SCR and electrostatic precipitator systems was sealed. In order to optimize and improve the flue gas flow and reduce system resistance, the No. 2 electrostatic precipitator was removed and the flue gas flow in that area was optimized. At the same time, part of the flue gas flow of the No. 1 line was optimized, renovated and replaced. After the renovation, the old desulfurization and denitrification systems of the No. 1 and No. 2 lines can be isolated and shut down.

[0054] The flue gas interface of boiler #3 connected to the integrated system was changed to be connected from the direction of line #4 and connected to the original integrated inlet and outlet flue; the original flue of line #3 was cut off, blocked and removed to the integrated interfaces of #1 and #2; a tee was opened from the integrated return flue of line #2, a valve was added and connected to the exhaust pipe at the base of chimney #1 through the flue (not shown in the figure).

[0055] D. Temperature and pressure reduction system

[0056] A new desuperheating and pressure reducing system is added for the TCO project, providing saturated steam with a flow rate of 2t / h and a pressure reduced from 2.35MPa to 1.25MPa. Steam is taken from the existing SCR steam soot blowing pipe interface of Line 2, and a desuperheating and pressure reducing device is installed. After desuperheating and pressure reducing, the pipe diameter is DN80, and two drain valves are installed on the outlet pipe. Two electric regulating valves (steam side and desuperheating water side) are configured according to the pipe diameter. The desuperheating water is connected from the outlet header of the boiler feedwater pumps of Lines 1 and 2 to achieve mutual switching and standby. Double valves are installed at the intake.

[0057] E. TCO exhaust gas is connected to the integrated inlet flue.

[0058] The TCO (Total CO) emissions from the float glass production line 2 are connected to an integrated inlet flue. A φ300mm stainless steel 316L pipe is drilled into the existing integrated inlet flue and inserted. This pipe requires a 300mm diameter stainless steel 316L electric butterfly valve and a carbon steel blind flange. Since the TCO emissions connection affects the inlet CEMS (Conductivity, Maintenance, and Storage) monitoring, the entire CEMS online monitoring system was moved to before the TCO emissions interface. To improve the uniformity of ammonia mixing with the flue gas at the ammonia spray nozzle outlet, the ammonia spray nozzle was moved approximately 2 meters from its previous position, increasing the length of the straight pipe section for mixing the flue gas and ammonia. The corroded flue near the ammonia spray nozzle was also repaired.

[0059] The wiring diagram of the modified glass melting furnace flue system obtained in this embodiment is shown below. Figure 1 .

[0060] In actual operation, after the flue gas duct of Unit 1 was modified, the number of bends in the flue gas duct was reduced compared to the original system. The original redundant flue gas duct was eliminated and replaced with a straight flue gas duct, resulting in smoother flue gas flow and reduced flue gas resistance. The negative pressure at the inlet of the desulfurization tower of Unit 1 decreased slightly. After the addition of two booster fans, the operation of the booster fan of Unit 1 avoided the problem of flue gas flow obstructing the flow of flue gas into Unit 1 due to the proximity of the flue gas from Unit 2 to Unit 1 when only one boiler induced draft fan 3 was used under heat exchanger operation. A new heat exchanger was added to Unit 2. After the modification of the booster fan 4 of Unit 2, the flue gas exiting Unit 1 was directly discharged into chimney 1 under heat exchanger operation. The booster fan 4 of Unit 2 assisted the two high-pressure induced draft fans of Unit 1 to make the direct discharge into chimney 1 even smoother. A new 1600KW integrated high-pressure induced draft fan was added, bringing the total number of high-pressure induced draft fans to two in operation and one on standby. The two operating fans operate at frequencies of 40Hz and 41.5Hz respectively, resolving the issue of having no backup fan compared to the previous system where both fans were running simultaneously. A new heat exchanger was added to Boiler #2. Previously, Boilers #1 and #2 shared a single heat exchanger. With the addition of this new exchanger, the flue gas resistance of Boiler #2 will be lower during shutdowns, and the frequency of Boiler #2 induced draft fan 3 will be reduced compared to the previous system. The replacement of the inlet and outlet expansion joints and flue valves for Boiler #1 and #2 induced draft fans 3 has reduced air leakage in the boiler flue system and valve jamming, which could lead to unstable flue gas flow and kiln pressure fluctuations. By using NID fan 2 as a backup induced draft fan, the boiler induced draft fan 3 system achieves a one-in-one-out system, making the boiler system operation more stable and reliable. The steam heating required for the TCO project has already been supplied by desuperheaters and pressure reducers installed next to boilers #1 and #2. The steam supply pipeline has been connected to the maintenance platform next to the newly added 316L flue valve in the integrated inlet flue. A flue valve has been installed at the integrated inlet flue. The subsequent work will be completed by the TCO project team.

[0061] After the flue gas duct of Boiler #3 was modified, the flue gas now enters the integrated boiler #2 directly from the east side of Boiler #3, bypassing the complex and redundant bends, and is connected to the integrated inlet header, significantly reducing system resistance. Previously, the two high-pressure induced draft fans in the integrated boiler #2 could not provide traction alone; both fans had to operate simultaneously at frequencies of 39Hz and 38Hz respectively, making it impossible to have one in operation and one on standby. If a fan malfunctioned, a shutdown for emergency repairs was necessary. After the flue gas duct modification of Boiler #3, one high-pressure induced draft fan at a frequency of 43.5Hz can now drive the flue gas from both Boilers #3 and #4 back to the boiler, reducing power consumption. Furthermore, the conversion of the CFB induced draft fan to a backup fan for the boiler ensures that the outlet induced draft fan of Boiler #3 has one in operation and one on standby, making the system more stable (not shown in the diagram).

[0062] Therefore, it can be seen that by structurally modifying the flue system used in glass melting furnaces, the present invention significantly improves the system operating efficiency, ensures the stability of furnace pressure and equipment reliability, while taking into account environmental protection requirements and reducing production costs, which is conducive to large-scale promotion and application.

[0063] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for modifying a dedicated flue gas system for glass melting furnaces, characterized in that, The modification method includes the following steps: (1) The original flue gas ducts of the furnace are integrated and the flue gas is introduced into the corresponding sulfur, dust and nitrate integrated treatment system according to the preset grouping, and the original desulfurization system, denitrification system and electrostatic precipitator system are shut down. (2) Optimize and renovate the flue after the branch line integration, remove redundant pipes and bends and replace them with straight flue sections, and seal the connection interface between the original flue and the shutdown system; (3) A booster fan is added after the junction of the waste heat boiler and the heat exchanger and on the main pipe of the direct exhaust chimney of the integrated treatment system; (4) Modify the standby fan of the shutdown system to adapt it to the parameters of the boiler induced draft fan, and form a standby system by adding a flue valve to connect with the boiler ash hopper; (5) Upgrade the pressure monitoring device and add pressure measuring points on the flue boundary line and the fan outlet main pipe of the integrated treatment system, and connect them to the DCS control system. (6) Add independent heat exchangers to some boilers and connect them with the original heat exchangers, and configure axial flow fans to cool the heat exchangers; (7) Construct a desuperheating and pressure reduction system, take steam from a preset steam source, process it and supply it to external projects, and take desuperheating water from the boiler feed water pump outlet header; (8) Open the flue gas inlet of the integrated treatment system to connect to external exhaust gas, and adjust the position of the online monitoring device and the denitrification agent spray gun.

2. The method for modifying the dedicated flue system for glass melting furnaces according to claim 1, characterized in that, The preset grouping method in step (1) includes: introducing the flue gas generated by the first half of the kiln body into the first integrated sulfur, dust and nitrate treatment system, and introducing the flue gas generated by the second half of the kiln body into the second integrated sulfur, dust and nitrate treatment system, and the two integrated treatment systems operate independently.

3. The method for modifying the dedicated flue system for glass melting furnaces according to claim 1, characterized in that, The backup fan in step (4) of the modified shutdown system also includes: configuring a frequency converter for the backup fan, and connecting the operation control signal and feedback signal of the backup fan to the original DCS control system to realize the automatic switching between the backup fan and the main induced draft fan.

4. The method for modifying the dedicated flue system for glass melting furnaces according to claim 1, characterized in that, In step (6), the medium flow direction of the added independent heat exchanger adopts a low-inlet, high-outlet design, and the outlet of the added independent heat exchanger is connected to the flue gas header of the boiler to the integrated treatment system, so as to ensure that it forms a complementary path for flue gas transportation with the original heat exchanger.

5. The method for modifying the dedicated flue system for glass melting furnaces according to claim 1, characterized in that, In step (7), the outlet pipe of the desuperheating and pressure reducing system is equipped with two steam traps and two electric regulating valves to control the flow rates of the steam side and the desuperheating water side, respectively.

6. The method for modifying the dedicated flue system for glass melting furnaces according to claim 1, characterized in that, The pipeline used for connecting to external exhaust gas in step (8) is equipped with an electric butterfly valve and a carbon steel blind flange.

7. The method for modifying the dedicated flue system for glass melting furnaces according to claim 6, characterized in that, The adjustment method for the position of the online monitoring device and the denitrification agent spray gun in step (8) includes: moving the online monitoring device to the front of the exhaust gas interface, moving the denitrification agent spray gun back from its original position, and repairing the corroded flue area near the spray gun.

8. The method for modifying the dedicated flue system for glass melting furnaces according to claim 1, characterized in that, The modification method also includes replacing the inlet and outlet components of the boiler induced draft fan.

9. The method for modifying the dedicated flue system for glass melting furnaces according to claim 8, characterized in that, The inlet and outlet components include expansion joints and flue valves.

10. A dedicated flue system for glass melting furnaces obtained by the modification method described in any one of claims 1-9, characterized in that, The dedicated flue system for glass melting furnaces includes a branch flue module, an induced draft fan module, a heat exchanger module, an integrated treatment module, a de-temperature and pressure reduction module, a waste gas introduction module, and a pressure monitoring module.

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