CN108426458A - A kind of glass furnace fume bypass system for desulfuration and denitration - Google Patents

Abstract

This application relates to a glass kiln flue gas bypass desulfurization and denitrification system, which includes a glass kiln, a waste heat boiler, and a chimney. The flue is connected with a side door flue, and the side flue is connected with the first flue gas cooler, the denitrification reactor, and the second flue gas cooler in sequence, and the flue after being cooled by the second flue gas cooler is connected to the inlet The smoke outlets are connected, the heat exchange air inlets of the first flue gas desuperheater and the second flue gas desuperheater are respectively connected with the first blower and the second blower, and the heat exchange air outlets are connected to the chimney through pipes. During the temporary maintenance of the glass kiln, the pollution index of the exhausted flue gas can be effectively reduced to meet the emission standard and the cost is low. The first flue gas cooler can effectively reduce the temperature of the flue gas to about 340°C and enter the denitrification reactor. The second The flue gas cooler can reduce the flue gas temperature after denitrification to 220°C.

Description

A glass kiln flue gas bypass desulfurization and denitrification system

technical field

The invention relates to a glass furnace, in particular to a glass furnace flue gas bypass desulfurization and denitrification system.

Background technique

It is known that the glass kiln waste heat boiler improves the utilization efficiency of the flue gas, but the nitrogen oxides in the flue gas will have an adverse impact on the environment, so the SCR method is currently used to denitrify the flue gas, and the flue gas required for denitrification The gas temperature is generally 330-380°C, and the flue gas temperature at the inlet of the glass kiln waste heat boiler is between 400-600°C. In order to meet the flue gas temperature required for out-of-stock, the newly designed waste heat boiler is led out after the first-stage evaporator. The flue gas that goes out of stock will return to the secondary evaporator. The higher the temperature of the flue gas that goes out of stock, the greater the loss to the waste heat boiler; during the operation of the glass furnace, when a waste heat boiler fails and needs temporary maintenance , The furnace flue gas needs to be discharged after flue gas treatment. If the flue gas is not treated, it will cause serious pollution to the environment. The traditional glass kiln flue gas bypass system uses a spare waste heat boiler, and the investment of the spare waste heat boiler The cost is high, and the operation of the standby waste heat boiler is not stable. If it takes a long time, it may cause another shutdown; another commonly used flue gas bypass system for glass furnaces uses traditional tube heat exchangers. The device has a large investment, a large area, a large weight, and inconvenient transportation and movement. The carbon steel pipe used has a small heat transfer coefficient, is easy to scale and corrode, is inconvenient to clean and maintain, and has a short service life. There are problems in the structure of traditional low-temperature smoke coolers: 1. Corrosion: the temperature of the smoke drops below 90°C, which is lower than the acid dew point; 2. Ash accumulation: after acid condensation, dust is absorbed and the blockage is serious; 3. Pressure drop: the capacity of the fan is limited, Resistance affects operation; 4. Installation space: bulky and difficult to implement. Cost-effectiveness of investment: large investment.

Contents of the invention

The object of the present invention is to provide a glass kiln flue gas bypass desulfurization and denitrification system in order to solve the deficiencies in the background technology.

In order to achieve the above object, the present invention adopts the following technical scheme: a glass kiln flue gas bypass desulfurization and denitrification system, including a glass kiln, a waste heat boiler, and a chimney, and a waste heat boiler, The desulfurization tower, dust collector and induced draft fan are connected to the side flue on the main flue, and the side flue is connected to the first flue gas cooler, denitrification reactor, and second flue gas cooler in turn, and the second flue gas is cooled The flue after being cooled by the desulfurization tower is connected to the flue inlet of the desulfurization tower. The heat exchange air inlet ports of the first flue gas cooler and the second flue gas cooler are respectively connected with the first blower and the second blower. The air outlet ends are respectively communicated and connected with the chimney through pipes.

For an optimization of the present invention, a smoke extraction pipe and a smoke return pipe are respectively provided on the flue of the waste heat boiler, and the smoke extraction pipe and the smoke return pipe are connected to a denitrification reactor.

For an optimization of the present invention, both the first flue gas desuperheater and the second flue gas desuperheater include heat exchange devices, and the heat exchange devices are all thin-walled stainless steel wide-channel plate heat exchangers.

Compared with the background technology, the present invention has reasonable structure and convenient manufacture; when the glass kiln is temporarily overhauled, the flue gas is discharged after being treated by the side door flue, which is small in size, light in weight, fast and effective in operation, low in cost and long in service life Longer, the flue gas desuperheater is easy to clean and maintain, and greatly improves the heat transfer coefficient; effectively reduces the emission pollution index of the flue gas to meet the emission standard and has low cost. The first flue gas desuperheater can effectively reduce the flue gas temperature It enters the denitrification reactor at about 340°C, and the second flue gas cooler can reduce the temperature of the flue gas after denitrification to 220°C again. Its operation is simple, fast and effective, and the combined use of wide channel plate heat exchangers has a longer life.

Description of drawings

Figure 1 is a schematic diagram of the principle of a glass kiln flue gas bypass desulfurization and denitrification system.

Figure 2 is a schematic diagram of the principle of the glass kiln flue gas bypass desulfurization and denitrification system.

Detailed ways

Embodiment 1: With reference to Fig. 1 and 2. A glass kiln flue gas bypass desulfurization and denitrification system, including a glass kiln 1, a waste heat boiler 2, and a chimney 3. The main flue 11 of the glass kiln 1 and the chimney 3 are connected to a waste heat boiler 2, a desulfurization tower 4, and a dust removal system. device 5 and induced draft fan 6, the main flue 11 is connected with a side door flue 12, and the side door flue 12 is connected with a first flue gas cooler 7, a denitrification reactor 8, and a second flue gas cooler 9 in sequence, The flue cooled by the second flue gas desuperheater 9 is connected to the flue inlet of the desulfurization tower 4, and the heat exchange air inlet ports of the first flue gas desuperheater 7 and the second flue gas desuperheater 9 are respectively connected with the second flue gas desuperheater 9. The first air blower 71 and the second air blower 91 are respectively communicated with the chimney 3 through pipes at their heat exchange air outlet ends. The flue of the waste heat boiler 2 is provided with a smoke extraction pipe 21 and a smoke return pipe 22 respectively, and the smoke extraction pipe 21 and the smoke return pipe 22 are connected to the denitrification reactor 8 .

By connecting the side door flue 12 on the main flue 11 coming out of the glass kiln, when the furnace is shut down, the flue gas passes through the first flue gas cooler 7, the denitrification reactor 8, the second flue gas cooler 9, Desulfurization tower 4, dust collector 5, induced draft fan 6 to chimney 3, first air blower 71, second air blower 91 supply air to first flue gas cooler 7, second flue gas cooler 9, and pass through first flue gas cooler 7. The second flue gas desuperheater 9 is combined and led to the chimney 3. In order to make the flue gas reach the temperature of denitrification and desulfurization, a first flue gas cooler 7 is installed in front of the denitrification reactor 8, and a second flue gas cooler 9 is arranged in front of the desulfurization tower 4.

Both the first flue gas desuperheater 7 and the second flue gas desuperheater 9 include heat exchange devices, and the heat exchange devices are thin-walled stainless steel wide-channel plate heat exchangers. Stainless steel has the advantages of strong corrosion resistance, good surface non-stick property, wide temperature range and anti-oxidation, so the flue gas desuperheater with wide channel plate heat exchanger has the following characteristics:

a) Good corrosion resistance, because the stainless steel material contains chromium content (22%), molybdenum (3%) and nitrogen content (0.18%), which improves the corrosion resistance of the material relative to other carbon steel materials, stainless steel The dual-phase microstructure helps to improve the stress corrosion cracking resistance of stainless steel, and the high strength and corrosion resistance of stainless steel make it have a high corrosion fatigue resistance;

b) Excellent dust cleaning function, because the plate tube is formed by hydraulic expansion, the outer surface of the plate is smooth, there is no dead angle, and it has self-cleaning ability. In addition, under the mechanical and thermal shock of the medium, the plate surface will produce slight deformation, which can make the The dirt layer is brittle and peeled off. Since the surface and inner wall of the heat exchange plate tube are very smooth and there is enough space between each other, the dust outside the plate tube is not easy to stick and accumulate, and the medium inside the plate tube has static turbulence, which is difficult to Scaling can greatly reduce the maintenance and cleaning times of equipment, and ensure its long-term safe operation under a relatively stable heat transfer coefficient;

c) Excellent wear resistance and good heat exchange performance. The plate and tube heat exchange element itself has excellent wear resistance, and the design of the plate and tube flue gas waste heat recovery heat exchanger is designed with low wear and low resistance flue gas. Air flow rate, thereby reducing wear and tear on heat exchanger elements. The plate-and-tube heat exchanger adopts thin-walled plates that are spot-welded with low stress and then bulged under high pressure. The wall thickness is ~1mm, so it overcomes the shortcomings of low thermal conductivity of stainless steel materials and has good heat transfer performance;

d) Excellent oxidation resistance, stainless steel has high flexible fatigue strength, does not contain photosensitive genes, has excellent atmospheric aging resistance, and the aging period is more than ten years, so the plate and pipe processed by it are durable and have a long service life . Under the condition that the connection strength of low-stress laser welding is guaranteed, the plate-tube heat exchange tube will not undergo stress cracking during operation, there is no risk of leakage, and it can basically be maintenance-free;

e) Good temperature and pressure resistance and low resistance. The service temperature of stainless steel is 760°C, and the plate and tube processed by it can work well under various working conditions with a flue gas temperature below 700°C. The surface of the plate tube heat exchange element itself is smooth, the friction coefficient is small, and the resistance to the flue gas is small; the design of the flue gas waste heat recovery heat exchanger also fully considers the resistance of the heat exchanger itself to the flue gas itself, and the middle of the plate tube is made hollow. , There is a corresponding distance between multiple sets of heat exchangers to reduce the resistance to the flue gas itself, and there is no obvious impact on the upstream and downstream equipment;

f) Excellent transportation and installation convenience. Due to the use of thin-walled plates, the heat exchanger under the same working condition is much lighter than the traditional tube heat exchanger, which is conducive to transportation and on-site installation.

It should be understood that: although the present embodiment has described the present invention in more detail, these descriptions are only simple descriptions of the present invention, rather than limitations of the present invention, and any inventions that do not exceed the essence of the present invention are all fall within the protection scope of the present invention.

Claims (3)

1. A glass kiln flue gas bypass desulfurization and denitrification system, characterized in that it comprises a glass kiln (1), a waste heat boiler (2), a chimney (3), a main flue (11) and a chimney of the glass kiln (1) (3) are connected with waste heat boiler (2), desulfurization tower (4), dust collector (5) and induced draft fan (6), and the main flue (11) is connected with side door flue (12), side door The flue (12) is sequentially connected with a first flue gas cooler (7), a denitrification reactor (8), and a second flue gas cooler (9). After being cooled by the second flue gas cooler (9), The flue is connected to the smoke inlet of the desulfurization tower (4), and the heat exchange air inlets of the first flue gas cooler (7) and the second flue gas cooler (9) are respectively connected with a first air blower (71) , The second air blower (91), the heat exchange air outlet end of which is communicated with the chimney (3) through pipes respectively. 2. The glass kiln flue gas bypass desulfurization and denitrification system according to claim 1, characterized in that: the flue of the waste heat boiler (2) is respectively provided with a smoke extraction pipe (21) and a smoke return pipe (22). The smoke pipe (21) and the smoke return pipe (22) are communicated with the denitrification reactor (8). 3. The glass kiln flue gas bypass desulfurization and denitrification system according to claim 1, characterized in that: the first flue gas cooler (7) and the second flue gas cooler (9) both include heat exchange devices, so The above heat exchange devices all adopt thin-walled stainless steel wide channel plate heat exchangers.