Device and method for dust removal and purification of tail gas from glass melting furnace

Abstract

The present invention relates to a method for dust removal and purification of tail gas from a glass melting furnace, comprising: introducing flue gas at 450-560°C into a negative pressure main pipe (1) for cooling; the flue gas at 120-400°C after cooling enters a spray cooling tower (3), where the flue gas temperature at its outlet (3d) is reduced to 75-80°C; then enters a mixer (4) and a mixing pipe (5), where it reacts with calcium hydroxide from a negative pressure branch pipe (7), absorbs acidic pollutants and excess water in the flue gas, and reduces the flue gas temperature to below 65°C; then enters a bag filter (6), where unreacted calcium hydroxide continues to react with acidic gases in the flue gas for a secondary reaction, and finally is filtered by the bag filter (6) and introduced into a chimney (16) via a variable frequency fan (14) for discharge. The advantages of the present invention are that the tail gas is filtered, reacted, and dusted layer by layer, so that the tail gas meets the discharge standard, improves the deacidification efficiency, recycles materials, and reduces operating costs and system pressure fluctuations.

Description

Technical Field

[0001] The present invention relates to the technical field of dust removal of tail gas from a glass melting furnace, and in particular to a device and method for dust removal and purification of tail gas from a glass melting furnace. Background Art

[0002] The glass industry is a major energy consumer and polluter in the building materials industry. Glass kilns generate large amounts of smoke, dust, and SO2 during operation. Dust production primarily occurs during the processing and transportation of raw materials and the smelting process in glass furnaces, with glass furnaces being the primary source of pollution.

[0003] Glass melting furnace flue gas contains SO2, which is highly corrosive. When it is discharged into the atmosphere, it will combine with rainwater to form acid rain. Therefore, if these major pollutants are not purified and treated in a timely and effective manner and are directly discharged into the atmosphere, it will pose a huge threat to the earth's atmospheric environment, the earth's soil and even human life safety. Summary of the Invention

[0004] The purpose of the present invention is to solve the above-mentioned problems existing in the dust removal of the existing glass melting furnace exhaust gas, and to provide a device for dust removal and purification of the glass melting furnace exhaust gas, which filters, reacts and removes dust layer by layer, so that the purified exhaust gas meets the discharge standards, improves the deacidification efficiency, and reduces operating costs and system pressure fluctuations.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A device for dust removal and purification of tail gas from a glass melting furnace comprises a negative pressure main pipe connected to a flue gas interface, a group of electric air supply valves being provided on the negative pressure main pipe, the negative pressure main pipe being connected to the top inlet of a spray cooling tower, a group of spray guns connected to industrial water being provided at the top of the spray cooling tower, a recovery port being provided in the middle, and an air outlet being provided at the bottom, the air outlet being connected to a mixer via a pipeline and having a baffle provided therein, the outlet of the mixer being connected to a bag dust collector via a mixing pipe, the mixing pipe being connected to a negative pressure branch pipe, and the negative pressure branch pipe being connected to a calcium hydroxide silo;

[0007] The ash hopper below the bag dust collector is connected to a recovery pipe, one end of which is connected to a recovery fan and a manual regulating valve. The recovery pipe is connected to the recovery port in the middle of the spray cooling tower to recover calcium hydroxide in the dust collector.

[0008] The outlet of the bag dust collector is connected to a group of parallel variable frequency fans through a pipe, and each variable frequency fan is connected to an electric butterfly valve. The variable frequency fan is connected to a chimney through a pipe to discharge the flue gas after dust removal.

[0009] Furthermore, the spray gun is a dual-fluid spray gun.

[0010] Furthermore, a bag-type dust collector is provided on the top of the calcium hydroxide silo to handle a large amount of dust generated during the addition of materials.

[0011] Furthermore, all pipelines are negative pressure pipelines, and sensors are installed on the pipelines to monitor the pressure, temperature, flow and dew point of the gas.

[0012] The devices of the present invention are all uniformly operated by an external electronic control system, which automatically processes the operating conditions of each device, and timely feeds back the data monitored by the sensors and responds.

[0013] In order to further achieve the purpose of the present invention, a method for dust removal and purification of tail gas from a glass melting furnace is also provided. The device used includes a spray cooling tower, a mixer, a calcium hydroxide silo and a bag dust collector. The specific steps are as follows, including:

[0014] (1) The flue gas in the glass kiln is mixed with cold air and its temperature drops to 450~560℃. After merging, it enters the negative pressure main pipe. At the same time, the electric air supply valve controls the temperature of the flue gas in the negative pressure main pipe.

[0015] (2) The flue gas with a temperature of 120~400℃ after treatment enters the spray cooling tower. Since the smoke pipe on the top of the furnace is relatively high, the spray cooling tower adopts the top-in and bottom-out forward spraying type. The atomized soft water in the tower cools the flue gas. The flue gas has a flow time of at least 15s in the environment of less than 80℃ in the tower. The flue gas temperature at the outlet of the spray cooling tower is reduced to 75~80℃, so as to facilitate the crystallization and granulation of arsenic oxide and boron oxide in the tail gas.

[0016] (3) After cooling, the flue gas containing water vapor enters the mixer. A baffle is set in the air mixer, and the water-containing calcium hydroxide, boron oxide, and arsenic oxide crystals coming out of the spray cooling tower are settled here;

[0017] (4) The flue gas then enters the mixing pipe and reacts with the calcium hydroxide from the negative pressure branch pipe. The calcium hydroxide fully absorbs the hydrogen chloride and excess water contained in the flue gas and reduces the flue gas temperature to below 65°C, so that the boron oxide can be completely crystallized, effectively preventing the dust collector bag from sticking;

[0018] (5) The mixed and cooled flue gas enters the bag dust collector, is filtered by the bag dust collector, and is introduced into the chimney through the variable frequency fan and discharged into the atmosphere.

[0019] Furthermore, in steps (4) to (5), the calcium hydroxide collected by the ash hopper in the bag filter is recovered through a recovery pipe and introduced into the spray cooling tower through a recovery port for reuse.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] (1) Controlling the wind speed and temperature in the negative pressure main pipe can effectively prevent dust accumulation and scaling in the pipe, and also prevent the precipitation of boron oxides from causing pipe blockage;

[0022] (2) The characteristics of arsenic oxide and boron oxide are fully considered, and the temperature of the flue gas in each pipeline is reasonably set according to their characteristics to make arsenic oxide and boron oxide recrystallize, thereby meeting the flue gas emission standards;

[0023] (3) When the system has only one or two kilns in production, the amount of water sprayed can be reduced, and the flue gas temperature entering the dust collector can be lowered to an appropriate temperature by adding cold air. Adding a mixer can effectively avoid the filter bag sticking caused by excessive water spraying;

[0024] (4) The calcium hydroxide collected by the dust collector is added to the spray cooling tower to achieve better deacidification effect, reduce the amount of calcium hydroxide used, reduce operating costs, and reduce the water content of the flue gas leaving the tower to avoid bag sticking;

[0025] (5) The entire system control process is simple and reliable, and the system operating pressure fluctuation is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a process flow chart of a method for dust removal and purification of tail gas from a glass melting furnace according to the present invention;

[0027] Figure 2 It is a structural schematic diagram of the spray cooling tower of the present invention. DETAILED DESCRIPTION

[0028] To make the present invention more clear, the following further describes an apparatus and method for dust removal and purification of tail gas from a glass melting furnace in accordance with the present invention in conjunction with the accompanying drawings. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] See also Figure 1 A device for dust removal and purification of tail gas from a glass melting furnace comprises a negative pressure main pipe 1 connected to a flue gas interface, characterized in that:

[0030] See also Figure 1 and Figure 2, three electric air supply valves 2 are provided on the negative pressure main pipe 1, and the negative pressure main pipe 1 is connected to the top inlet 3a of a spray cooling tower 3. The upper part of the spray cooling tower 3 is provided with a group of spray guns 3b connected to industrial water, the middle part is provided with a recovery port 3c, and the lower part is provided with an air outlet 3d. The air outlet 3d is connected to a mixer 4 through a pipeline, and a baffle 4a is provided therein. The outlet of the mixer 4 is connected to a bag dust collector 6 through a mixing pipe 5. The mixing pipe 5 is connected to a negative pressure branch pipe 7, and the negative pressure branch pipe 7 is connected to a calcium hydroxide silo 8. The bottom of the calcium hydroxide silo 8 is provided with a star-shaped discharge valve 10, and the top is provided with a silo top bag dust collector 9 to handle a large amount of dust generated during feeding;

[0031] The ash hopper below the bag filter 6 is connected to a recovery pipe 11, one end of which is connected to a recovery fan 12, and a manual regulating valve 13 is provided on the recovery pipe 11. The recovery pipe 11 is connected to the recovery port 3c in the middle of the spray cooling tower 3 to recover the calcium hydroxide in the dust collector;

[0032] The outlet of the bag filter 6 is connected to a set of parallel variable frequency fans 14 through a pipe, and each variable frequency fan 14 is connected to an electric butterfly valve 15. The variable frequency fans 14 are connected to a chimney 16 through a pipe to discharge the dust-removed flue gas;

[0033] The spray gun 3b is a dual-fluid spray gun, all pipelines are negative pressure pipelines, and sensors 17 are provided on the pipelines to monitor the pressure, temperature, flow rate and dew point of the gas.

[0034] The devices of the present invention are all uniformly operated by an external electronic control system, which automatically processes the operating conditions of each device, and timely feeds back the data monitored by the sensors and responds.

[0035] The method for using the above device to remove dust from tail gas of a glass melting furnace has the following specific steps, which are characterized by comprising:

[0036] (1) The flue gas in the glass kiln is mixed with cold air and its temperature drops to 450~560℃. After merging, it enters the negative pressure main pipe 1 with a length of 26 meters. At the same time, the electric air supply valve 2 controls the temperature of the flue gas in the negative pressure main pipe 1.

[0037] (2) The flue gas with a temperature of 120~400℃ after treatment enters the spray cooling tower 3. Since the smoke pipe on the top of the furnace is relatively high, the spray cooling tower 3 adopts the top-in and bottom-out sequential spraying type. The atomized soft water in the tower cools the flue gas. The design of the spray cooling tower 3 must ensure that the flue gas has a flow time of at least 15s in an environment with a temperature of less than 80℃ in the tower, and the outlet flue gas temperature is controlled at 75~80℃, which is convenient for the crystallization of arsenic oxide and boron oxide in the tail gas.

[0038] (3) After cooling, the flue gas containing water vapor enters the mixer 4. A baffle 4a is provided in the mixer 4, and the water-containing calcium hydroxide, boron oxide, and arsenic oxide crystals coming out of the spray cooling tower 3 are settled here;

[0039] (4) The flue gas then enters the mixing pipe 5 and reacts with the calcium hydroxide from the branch pipe 7. The calcium hydroxide bin 8 is arranged on one side of the pipeline and is directly added to the negative pressure branch pipe 7 through the star-shaped discharge valve 10. The negative pressure branch pipe 7 is connected to the mixing pipe 5 at a high speed of about 30m / s to ensure that it is completely mixed with the flue gas in the air mixer and no additional power is required;

[0040] (5) Calcium hydroxide fully absorbs the hydrogen chloride and excess water contained in the flue gas and reduces the flue gas temperature to below 65°C, so that the boron oxide can be completely crystallized, effectively preventing the dust collector from sticking;

[0041] (6) The mixed and cooled flue gas enters the bag filter 6, is filtered by the bag filter 6, and is introduced into the 60-meter-high chimney 16 through the variable frequency fan 14 and discharged into the atmosphere;

[0042] (7) The calcium hydroxide collected by the ash hopper in the bag filter 6 is recovered through the recovery pipe 11 and introduced into the spray cooling tower 3 through the recovery port 3c for reuse, so as to increase the deacidification capacity and reduce the consumption of calcium hydroxide.

[0043] In order to ensure the amount of calcium hydroxide added, the star-shaped discharge valve adopts frequency conversion control. Calcium hydroxide is added to the silo by a tank truck or is lifted to the top of the silo by electric means at regular intervals and added manually. Since a large amount of dust will be generated during the addition, a silo-top bag dust collector is arranged on the top of the calcium hydroxide silo.

[0044] The entire dust removal system consists of a pipeline system, a spray cooling system, a bag dust collector and an ash unloading system, an alkali adding system, etc. The control process is simple and reliable, and the system operating pressure fluctuates little. It can not only avoid dust accumulation and scaling in the pipeline and filter bag sticking of the dust collector, but also recycle materials and reduce operating costs. The exhaust gas is filtered, reacted and dust-removed layer by layer, so that the purified exhaust gas meets the discharge standards and improves the deacidification efficiency.

[0045] In addition to the above embodiments, the present invention may also have other implementations. Any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection required by the present invention.

Claims

1. A method for dust removal and purification of tail gas from a glass melting furnace, characterized in that: include: Step 1: The flue gas in the glass furnace is mixed with cold air and its temperature is reduced to 450-560°C. After being combined, the flue gas enters the negative pressure main pipe (1). At the same time, the electric air supply valve (2) controls the temperature of the flue gas in the negative pressure main pipe (1); Step 2: The treated flue gas with a temperature of 120-400° C. enters the spray cooling tower (3) for cooling, and the flue gas temperature at the outlet (3d) of the spray cooling tower (3) is reduced to 75-80° C.; Step 3: After cooling, the flue gas containing water vapor enters the mixer (4), and the water-containing calcium hydroxide, boron oxide, and arsenic oxide crystals coming out of the spray cooling tower (3) are precipitated here; Step 4: The flue gas enters the mixing tube (5) and reacts with the calcium hydroxide from the negative pressure branch pipe (7), fully absorbing the hydrogen chloride and excess water in the flue gas and reducing the flue gas temperature to below 65°C; Step 5: The mixed and cooled flue gas enters the bag filter (6). The unreacted calcium hydroxide adheres to the windward side of the bag and continues to react with the acid gas in the flue gas. After being filtered by the bag filter (6), it is introduced into the chimney (16) through the variable frequency fan (14) and discharged into the atmosphere.

2. The method for dust removal and purification of tail gas from a glass melting furnace according to claim 1, characterized in that: In steps 4 and 5, the calcium hydroxide collected in the ash hopper of the bag filter (6) is introduced into the spray cooling tower (3) through the recovery pipe (11) and the recovery port (3c) for reuse.

3. The method for dust removal and purification of tail gas from a glass melting furnace according to claim 1, characterized in that: The device used includes a negative pressure main pipe (1) connected to the flue gas interface, a group of electric air supply valves (2) are provided on the negative pressure main pipe (1), the negative pressure main pipe (1) is connected to the top inlet (3a) of a spray cooling tower (3), the upper part of the spray cooling tower (3) is provided with a group of spray guns (3b), the middle part is provided with a recovery port (3c), and the lower part is provided with an air outlet (3d), the spray gun (3b) is a double-fluid spray gun, the air outlet (3d) is connected to a mixer (4) through a pipeline, and a baffle (4a) is provided in the mixer (4), the outlet of the mixer (4) is connected to a bag dust collector (6) through a mixing pipe (5), and the mixing pipe (5) is connected to a negative pressure branch pipe (7), and the negative pressure branch pipe (7) is connected to the bag dust collector (6). ) is connected to a calcium hydroxide silo (8), and a silo-top bag dust collector (9) is provided on the top of the calcium hydroxide silo (8); the bottom of the bag dust collector (6) is connected to a recovery pipe (11), one end of the recovery pipe (11) is connected to a recovery fan (12), and a manual regulating valve (13) is provided on the recovery pipe (11), and the recovery pipe (11) is connected to the recovery port (3c) in the middle of the spray cooling tower (3); the outlet of the bag dust collector (6) is connected to a group of parallel variable frequency fans (14) through a pipeline, and the variable frequency fans (14) are connected to a chimney (16) through a pipeline. All pipelines are negative pressure pipelines, and sensors (17) are provided on the pipelines.

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