Tail gas treatment system of glass melting furnace

Abstract

The utility model discloses a tail gas treatment system of a glass melting furnace, and belongs to the technical field of float glass production. Comprising a waste heat boiler, an electric precipitation device, an SCR denitration device, a boiler fan, a semi-dry desulfurization device, a high-temperature cooler and a low-temperature cooler, a flue gas outlet of a glass melting furnace is connected with a high-temperature flue gas inlet of the waste heat boiler, and the high-temperature flue gas outlet of the waste heat boiler, the electric precipitation device, the SCR denitration device and a low-temperature flue gas inlet of the waste heat boiler are sequentially connected. A low-temperature flue gas outlet of the waste heat boiler, the boiler fan and the semi-dry desulfurization device are connected in sequence; the flue gas outlet of the glass melting furnace is further connected with a hot air inlet of the high-temperature cooler, a cold air outlet of the high-temperature cooler is connected with an inlet of the electric dust removal device, an outlet of the SCR denitration device is further connected with a hot air inlet of the low-temperature cooler, and a cold air outlet of the low-temperature cooler is connected with an inlet of the boiler fan; the high-temperature cooler and the low-temperature cooler are air-cooling heat exchangers and are vertically arranged, and ash hoppers are arranged at the bottoms of the high-temperature cooler and the low-temperature cooler.

Description

Technical Field

[0001] The utility model belongs to the technical field of float glass production, and particularly relates to an exhaust gas treatment system of a glass melting furnace. Background Art

[0002] The production of float glass requires the following processes: raw material preparation - high temperature melting into glass liquid in a melting furnace - drawing and shaping in a float glass forming tin bath - annealing in an annealing furnace - cooling, cutting, packaging, and storage. The melting furnace will produce a large amount of high-temperature flue gas. The flue gas contains not only dust, but also SO 2 , NOx and other harmful substances.

[0003] The prior art discloses a method for simultaneously removing dust and SO from flue gas. 2 Since denitrification can achieve a higher removal rate under high temperature conditions, and the smelting flue gas itself has a high temperature, the existing technology usually uses the heat of the smelting flue gas itself to first denitrify, and then recover the heat before removing SO in the tail gas. 2 Removal of acidic pollutants such as spodumene. For example, the patent with application number CN201610534118.1 discloses a method for treating the flue gas at the tail of a spodumene roasting rotary kiln, which adopts the process of "rotary roasting kiln-high temperature membrane filtration-SCR denitrification-air cooler-desulfurization". For example, the patent with application number CN202321232789.4 discloses a system for treating the flue gas at the tail of a lithium smelting rotary roasting kiln, which adopts "solid denitrification-dust removal-waste heat recovery-semi-dry desulfurization-low temperature liquid phase desulfurization".

[0004] For the treatment of glass melting furnaces, the prior art provides an exhaust gas treatment system, including a waste heat boiler, an electrostatic precipitator, an SCR denitrification device, a boiler fan and a semi-dry desulfurization device, etc. The flue gas outlet of the glass melting furnace is connected to the high-temperature flue gas inlet of the waste heat boiler through a flue gas pipeline, the high-temperature flue gas outlet of the waste heat boiler, the electrostatic precipitator, the SCR denitrification device and the low-temperature flue gas inlet of the waste heat boiler are connected in sequence through the flue gas pipeline, and the low-temperature flue gas outlet of the waste heat boiler, the boiler fan and the semi-dry desulfurization device are connected in sequence through the flue gas pipeline.

[0005] SCR denitrification requires the flue gas to be maintained at a certain high temperature (such as between 330-400°C) to meet the catalytic temperature requirements of the catalyst, while desulfurization needs to be carried out at a lower temperature. Once the waste heat boiler is damaged or abnormal, the flue gas cannot reach the appropriate denitrification and desulfurization temperature, which will cause SO in the discharged flue gas. 2 If the NOx exceeds the standard, the company will face penalties from the environmental protection department and will need to suspend production (the glass melting furnace cannot be shut down because the solidified glass is difficult to handle). Utility Model Content

[0006] In order to solve the above problems, the embodiment of the utility model provides an exhaust gas treatment system for a glass melting furnace, which can use a high-temperature cooler and a low-temperature cooler for emergency response when the waste heat boiler is damaged or abnormal, so that the exhaust gas always meets the emission standards without stopping. The technical solution is as follows:

[0007] The utility model embodiment provides an exhaust gas treatment system for a glass melting furnace, the system comprising a waste heat boiler, an electrostatic precipitator 3, an SCR denitrification device 4, a boiler fan, a semi-dry desulfurization device 6, a high-temperature cooler 2 and a low-temperature cooler 5, the flue gas outlet of the glass melting furnace 1 is connected to the high-temperature flue gas inlet of the waste heat boiler through a flue gas pipeline, the high-temperature flue gas outlet of the waste heat boiler, the electrostatic precipitator 3, the SCR denitrification device 4 and the low-temperature flue gas inlet of the waste heat boiler are connected in sequence through the flue gas pipeline, the low-temperature flue gas outlet of the waste heat boiler, the boiler fan and the semi-dry desulfurization device 6 are connected in sequence through the flue gas pipeline; the flue gas outlet of the glass melting furnace 1 is also connected to the hot air inlet of the high-temperature cooler 2 through the flue gas pipeline, the cold air outlet of the high-temperature cooler 2 is connected to the inlet of the electrostatic precipitator 3 through the flue gas pipeline, the outlet of the SCR denitrification device 4 is also connected to the hot air inlet of the low-temperature cooler 5 through the flue gas pipeline, and the cold air outlet of the low-temperature cooler 5 It is connected to the inlet of the boiler fan through the flue gas pipeline; the high-temperature cooler 2 and the low-temperature cooler 5 are both air-cooled heat exchangers, and a cooling fan is provided on the cold air inlet or hot air outlet thereof, which is vertically arranged and has an ash hopper 7 at the bottom; the hot air inlet and cold air outlet of the high-temperature cooler 2 are respectively provided with a first valve and a second valve, the hot air inlet and cold air outlet of the low-temperature cooler 5 are respectively provided with a third valve and a fourth valve, and the low-temperature flue gas outlet of the waste heat boiler is provided with a fifth valve; the heat exchange area of ​​the low-temperature cooler 5 is 4-6 times the heat exchange area of ​​the high-temperature cooler 2; when the waste heat boiler is working normally, the fifth valve is opened, the first valve, the second valve, the third valve and the fourth valve are closed, and the flue gas is cooled through the waste heat boiler; when the waste heat boiler is abnormal, the fifth valve is closed, the first valve, the second valve, the third valve and the fourth valve are opened, and the flue gas is cooled through the high-temperature cooler 2 and the low-temperature cooler 5.

[0008] Among them, the high-temperature cooler 2 and the low-temperature cooler 5 in the embodiment of the utility model are both shell-and-tube heat exchangers, the heat exchange tubes of the shell-and-tube heat exchanger are arranged horizontally, the heat exchange tubes are filled with cold air, and the heat exchange tubes are filled with flue gas; for the high-temperature cooler 2, its hot air inlet is arranged at the bottom, and its cold air outlet is arranged at the top; for the low-temperature cooler 5, its hot air inlet is arranged at the top, and its cold air outlet is arranged at the bottom.

[0009] Specifically, the heat exchange area of ​​the high temperature cooler 2 in the embodiment of the utility model is 450-550m 2The air volume of the cold air inlet is 70,000-100,000 Nm3 / h; the heat exchange area of ​​the low temperature cooler 5 is 2300-2500m 2 The air intake volume of the cold air inlet is 400,000-450,000 Nm3 / h.

[0010] Furthermore, the high-temperature cooler 2 and the low-temperature cooler 5 in the embodiment of the utility model are both arranged on corresponding brackets and suspended in the air, and a shock wave soot blower is provided in the upper inner part and above the heat exchange tube; the ash hopper 7 is a conical hopper with a larger upper part and a smaller lower part, and a manual plug valve is provided at the bottom.

[0011] Specifically, for the high-temperature cooler 2, its hot air inlet is arranged on the ash hopper 7, and the flue gas pipeline is obliquely upward along the conveying direction of the flue gas to the hot air inlet; for the low-temperature cooler 5, its cold air outlet is arranged on the ash hopper 7, and the flue gas pipeline is obliquely downward along the conveying direction of the flue gas to be output from the cold air outlet.

[0012] Among them, the first valve, the second valve and the fourth valve in the embodiment of the utility model are all gate doors, and the third valve and the fifth valve are both baffle doors.

[0013] Furthermore, the hot air inlet and cold air outlet of the high-temperature cooler 2 in the embodiment of the utility model are both provided with temperature sensors and air pressure sensors, and the hot air inlet and cold air outlet of the low-temperature cooler 5 are both provided with temperature sensors and air pressure sensors.

[0014] Furthermore, a heat-insulating jacket is provided on the flue gas pipeline in the embodiment of the utility model.

[0015] The beneficial effects of the technical solution provided by the embodiment of the utility model are as follows: the embodiment of the utility model provides an exhaust gas treatment system for a glass melting furnace, which can use a high-temperature cooler and a low-temperature cooler for emergency response when the waste heat boiler is damaged or abnormal, so that the exhaust gas always meets the emission standards without shutting down, thereby ensuring production. In addition, when the waste heat boiler is partially abnormal (the possibility is relatively low), only the corresponding cooler can be turned on, and of course the waste heat boiler can be directly unused. If the high-temperature flue gas part of the waste heat boiler is abnormal, the low-temperature flue gas part of the waste heat boiler is still used, the high-temperature cooler is used, and the low-temperature cooler is not used. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a principle block diagram of the tail gas treatment system of the existing glass melting furnace;

[0017] Figure 2 is a principle block diagram of the tail gas treatment system of the glass melting furnace in this embodiment;

[0018] Figure 3 is a partial structural schematic diagram of the tail gas treatment system of the glass melting furnace in this embodiment;

[0019] Figure 4 It is a structural schematic diagram of a high temperature cooler and its hot air inlet combination;

[0020] Figure 5 It is a structural schematic diagram of a high temperature cooler and its cold air outlet combination;

[0021] Figure 6 It is a structural schematic diagram of a low temperature cooler and its hot air inlet combination;

[0022] Figure 7 It is a structural schematic diagram of a low-temperature cooler and its cold air outlet combination.

[0023] In the figure: 1 glass melting furnace, 2 high temperature cooler, 3 electrostatic precipitator, 4 SCR denitrification device, 5 low temperature cooler, 6 semi-dry desulfurization device, 7 ash hopper. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail below with reference to the accompanying drawings.

[0025] Example 1

[0026] See also Figure 2-7 , Embodiment 1 provides an exhaust gas treatment system for a glass melting furnace, the system includes a waste heat boiler, an electrostatic precipitator 3, an SCR denitrification device 4, a boiler fan, a semi-dry desulfurization device 6, a high temperature cooler 2 and a low temperature cooler 5, etc. The flue gas outlet of the glass melting furnace 1 is divided into two outputs and can be selected, one (conducted when the waste heat boiler works normally) is connected to the high temperature flue gas inlet of the waste heat boiler through the flue gas pipeline, and the other (conducted when the waste heat boiler is abnormal) is connected to the hot air inlet of the high temperature cooler 2 through the flue gas pipeline. The high temperature flue gas outlet of the waste heat boiler and the cold air outlet of the high temperature cooler 2 are both connected to the inlet of the electrostatic precipitator 3 through the flue gas pipeline for dust removal. The outlet of the electrostatic precipitator 3 is connected to the inlet of the SCR denitrification device 4 through the flue gas pipeline for denitrification. The SCR denitrification device 4 has two outputs, one of which (conducted when the waste heat boiler is working normally) is connected to the low-temperature flue gas inlet of the waste heat boiler through the flue gas pipeline, and the other (conducted when the waste heat boiler is abnormal) is connected to the hot air inlet of the low-temperature cooler 5 through the flue gas pipeline. The low-temperature flue gas outlet of the waste heat boiler and the cold air outlet of the low-temperature cooler 5 are both connected to the inlet of the boiler fan through the flue gas pipeline, and the outlet of the boiler fan is connected to the inlet of the semi-dry desulfurization device 6 through the flue gas pipeline for desulfurization.

[0027] Among them, both the high-temperature cooler 2 and the low-temperature cooler 5 are air-cooled heat exchangers (specifically, shell-and-tube heat exchangers), and a cooling fan (specifically, a centrifugal fan) is provided on the cold air inlet or hot air outlet (with a bell mouth provided thereon), which is arranged vertically, and an ash hopper 7 is provided at the bottom thereof for collecting deposited ash (discharged regularly to avoid secondary dusting and affecting the cooler resistance). The hot air inlet (or its input flue gas pipeline) and the cold air outlet (or its output flue gas pipeline) of the high-temperature cooler 2 are respectively provided with a first valve and a second valve, the hot air inlet (or its input flue gas pipeline) and the cold air outlet (or its output flue gas pipeline) of the low-temperature cooler 5 are respectively provided with a third valve and a fourth valve, and the low-temperature flue gas outlet of the waste heat boiler is provided with a fifth valve (or its output flue gas pipeline, which is the original structure).

[0028] The heat exchange area of ​​the low temperature cooler 5 is 4-6 times that of the high temperature cooler 2. Specifically, for a glass melting furnace 1 with a flue gas volume of about 140,000 Nm3 / h, the heat exchange area of ​​the high temperature cooler 2 is 450-550m 2 The air volume of the cold air inlet is 70,000-100,000 Nm3 / h. The heat exchange area of ​​the low temperature cooler 5 is 2300-2500m 2 The air intake volume of the cold air inlet is 400,000-450,000 Nm3 / h.

[0029] When the waste heat boiler is working normally, the fifth valve is opened, the first valve, the second valve, the third valve and the fourth valve are closed, and the flue gas is cooled by the waste heat boiler, which is consistent with the prior art. When the waste heat boiler is abnormal, the fifth valve is closed, the first valve, the second valve, the third valve and the fourth valve are opened, and the flue gas is cooled by the high-temperature cooler 2 (reducing the flue gas from about 500°C to about 440°C, so that the denitration temperature of the SCR denitration device 4 is about 350°C) and the low-temperature cooler 5 (reducing the flue gas from about 380°C to about 180°C).

[0030] Among them, the heat exchange tubes of the shell and tube heat exchanger in the embodiment of the utility model are arranged horizontally, the heat exchange tubes are filled with cold air, and the outside of the heat exchange tubes (inside the shell of the heat exchanger) is flue gas; that is, the tube side is cold air, and the shell side is flue gas. For the high-temperature cooler 2, its hot air inlet is arranged at the bottom, and its cold air outlet is arranged at the top. That is, for the high-temperature cooler 2, the flue gas is cooled by the bottom-in-top-out method. For the low-temperature cooler 5, its hot air inlet is arranged at the top, and its cold air outlet is arranged at the bottom. That is, for the low-temperature cooler 5, the flue gas is cooled by the top-in-bottom-out method. Further, the high-temperature cooler 2 and the low-temperature cooler 5 are both arranged on the corresponding brackets and suspended in the air, and a shock wave soot blower (multiple purge ports are arranged horizontally and evenly distributed around the vertical axis of the shell and tube heat exchanger) is arranged in the upper part thereof and above the heat exchange tube to extend the continuous use time of the cooler. The ash hopper 7 is a cone hopper with a large top and a small bottom, and a manual plug valve is arranged at its bottom. Specifically, for the high-temperature cooler 2, its hot air inlet is arranged on the ash hopper 7, and the smoke pipeline is obliquely upward along the conveying direction of the smoke to the hot air inlet. For the low-temperature cooler 5, its cold air outlet is arranged on the ash hopper 7, and the smoke pipeline is obliquely downward along the conveying direction of the smoke to be output from the cold air outlet.

[0031] Among them, the first valve, the second valve and the fourth valve in the embodiment of the utility model are all gate doors, and the third valve and the fifth valve are all baffle doors.

[0032] Furthermore, in the embodiment of the utility model, the hot air inlet and the cold air outlet of the high temperature cooler 2 are both provided with temperature sensors and air pressure sensors, and the hot air inlet and the cold air outlet of the low temperature cooler 5 are both provided with temperature sensors and air pressure sensors. The temperature sensor and the air pressure sensor are used to monitor the flue gas movement and the change of the cooler resistance respectively.

[0033] Furthermore, the newly added flue gas pipeline in the embodiment of the utility model has the same specifications as the original flue gas pipeline. An insulation jacket is provided on the flue gas pipeline. Both the high-temperature cooler 2 and the low-temperature cooler 5 adopt internal insulation. Specifically, the flue insulation thickness from the glass melting furnace 1 to the high-temperature cooler 2 is 200mm. The flue insulation thickness at the cold air outlet of the high-temperature cooler 2 is 200mm, the cooler is internally insulated, and the bottom ash hopper 7 needs to be insulated with a thickness of 200mm. The flue insulation thickness at the hot air inlet of the low-temperature cooler 5 is 200mm, and the flue insulation thickness at the cold air outlet is 150mm. The cooler is internally insulated, and the bottom ash hopper 7 needs to be insulated with a thickness of 200mm.

[0034] Example 2

[0035] Example 2 provides an exhaust gas treatment system for a glass melting furnace, and its structure is basically the same as that of Example 1, except that: the production capacity of the glass melting furnace in this example is 600t / d, the flue gas volume is 140,000 Nm3 / h, and the flue gas temperature is about 500°C. The specifications of the high temperature cooler 2 are shown in Table 1:

[0036] Table 1

[0037] .

[0038] The specifications of the cryocooler 5 are shown in Table 2:

[0039] Table 2

[0040] .

[0041] The specifications of the valve are shown in Table 3:

[0042] Table 3

[0043] .

[0044] The specifications of the corresponding structures are shown in Table 4:

[0045] Table 4

[0046]

[0047] Among them, the "first", "second", "third", "fourth" and "fifth" in this embodiment are only used for distinction and have no other special meanings.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An exhaust gas treatment system for a glass melting furnace, comprising a waste heat boiler, an electrostatic precipitator (3), an SCR denitrification device (4), a boiler fan and a semi-dry desulfurization device (6), wherein a flue gas outlet of the glass melting furnace (1) is connected to a high-temperature flue gas inlet of the waste heat boiler via a flue gas pipeline, wherein the high-temperature flue gas outlet of the waste heat boiler, the electrostatic precipitator (3), the SCR denitrification device (4) and a low-temperature flue gas inlet of the waste heat boiler are connected in sequence via the flue gas pipeline, and the low-temperature flue gas outlet of the waste heat boiler, the boiler fan and the semi-dry desulfurization device (6) are connected in sequence via the flue gas pipeline; characterized in that: The system further comprises a high-temperature cooler (2) and a low-temperature cooler (5); the flue gas outlet of the glass melting furnace (1) is also connected to the hot air inlet of the high-temperature cooler (2) through a flue gas pipeline; the cold air outlet of the high-temperature cooler (2) is connected to the inlet of the electrostatic precipitator (3) through a flue gas pipeline; the outlet of the SCR denitrification device (4) is also connected to the hot air inlet of the low-temperature cooler (5) through a flue gas pipeline; and the cold air outlet of the low-temperature cooler (5) is connected to the inlet of the boiler fan through a flue gas pipeline; The high-temperature cooler (2) and the low-temperature cooler (5) are both air-cooled heat exchangers, and a cooling fan is provided at the cold air inlet or hot air outlet thereof, which is arranged vertically and has an ash hopper (7) at the bottom thereof; the hot air inlet and the cold air outlet of the high-temperature cooler (2) are respectively provided with a first valve and a second valve, the hot air inlet and the cold air outlet of the low-temperature cooler (5) are respectively provided with a third valve and a fourth valve, and the low-temperature flue gas outlet of the waste heat boiler is provided with a fifth valve; the heat exchange area of ​​the low-temperature cooler (5) is 4-6 times the heat exchange area of ​​the high-temperature cooler (2); When the waste heat boiler is operating normally, the fifth valve is opened, the first valve, the second valve, the third valve and the fourth valve are closed, and the flue gas passes through the waste heat boiler to be cooled; When the waste heat boiler is abnormal, the fifth valve is closed, the first valve, the second valve, the third valve and the fourth valve are opened, and the flue gas is cooled by passing through the high-temperature cooler (2) and the low-temperature cooler (5).

2. The tail gas treatment system of the glass melting furnace according to claim 1, characterized in that: The high-temperature cooler (2) and the low-temperature cooler (5) are both shell-and-tube heat exchangers, the heat exchange tubes of the shell-and-tube heat exchangers are arranged horizontally, the heat exchange tubes are filled with cold air, and the heat exchange tubes are filled with flue gas; for the high-temperature cooler (2), its hot air inlet is arranged at the bottom, and its cold air outlet is arranged at the top; for the low-temperature cooler (5), its hot air inlet is arranged at the top, and its cold air outlet is arranged at the bottom.

3. The tail gas treatment system of the glass melting furnace according to claim 2, characterized in that: The heat exchange area of ​​the high temperature cooler (2) is 450-550m 2 The air volume of the cold air inlet is 70,000-100,000 Nm3 / h; the heat exchange area of ​​the low temperature cooler (5) is 2300-2500m 2 The air intake volume of the cold air inlet is 400,000-450,000 Nm3 / h.

4. The tail gas treatment system of the glass melting furnace according to claim 2, characterized in that: The high-temperature cooler (2) and the low-temperature cooler (5) are both arranged on corresponding brackets and suspended in the air, and a shock wave soot blower is arranged in the upper inner part thereof and above the heat exchange tube; the ash hopper (7) is a conical hopper with a larger upper portion and a smaller lower portion, and a manual gate valve is arranged at the bottom thereof.

5. The tail gas treatment system of the glass melting furnace according to claim 4, characterized in that: For the high-temperature cooler (2), its hot air inlet is arranged on the ash hopper (7), and the smoke pipeline is obliquely upward along the conveying direction of the smoke to the hot air inlet; for the low-temperature cooler (5), its cold air outlet is arranged on the ash hopper (7), and the smoke pipeline is obliquely downward along the conveying direction of the smoke to be discharged from the cold air outlet.

6. The tail gas treatment system of the glass melting furnace according to claim 1, characterized in that: The first valve, the second valve and the fourth valve are all gate valves, and the third valve and the fifth valve are all baffle valves.

7. The tail gas treatment system of the glass melting furnace according to claim 1, characterized in that: The hot air inlet and the cold air outlet of the high-temperature cooler (2) are both provided with a temperature sensor and an air pressure sensor, and the hot air inlet and the cold air outlet of the low-temperature cooler (5) are both provided with a temperature sensor and an air pressure sensor.

8. The tail gas treatment system of the glass melting furnace according to claim 1, characterized in that: The flue gas pipeline is provided with a heat-insulating jacket.

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