Flue gas zero emission method for circular cooler

Abstract

The invention relates to a flue gas zero emission method for a circular cooler, and belongs to the technical field of sintering machine design methods in the metallurgical industry. According to the technical scheme, the circular cooler is divided into six sections, and cooling fans are arranged on the six sections respectively; the first annular cooler section and the second annular cooler section are connected with the waste heat boiler. The front end part of cooling waste flue gas of the third section of the annular cooler is merged into the first section of the annular cooler and the second section of the annular cooler to be introduced into the waste heat boiler, the middle part is introduced to a flue gas circulating system, and the tail end part is introduced to a sintering igniter; one part of cooling waste flue gas of the fourth circular cooler section and the fifth circular cooler section is returned to an inlet of a cooling fan of the third circular cooler section, and the other part of the cooling waste flue gas is led to a sintering flue gas circulating system; and cooling waste flue gas of the sixth section of the circular cooler is returned to an inlet of a cooling fan of the fifth section of the circular cooler. The method has the beneficial effects that the circular cooler is segmented, the cooling waste smoke of each segment is utilized, all the cooling waste smoke of the circular cooler is recycled and recycled and is not discharged to the atmosphere, zero emission of the waste gas of the circular cooler is achieved, and the energy recycling rate is increased.

Description

Technical Field

[0001] The invention relates to a zero-emission method for flue gas from an annular cooler, and belongs to the technical field of sintering machine design methods in the metallurgical industry. Background Art

[0002] The steel industry is a high-energy-consuming and high-polluting industry. In order to achieve sustainable development, the country has increasingly stringent environmental protection requirements for the steel industry. In recent years, the industry has vigorously carried out ultra-low emission transformation, environmental performance A-level enterprise assessment and other work, striving to achieve sustainable and coordinated development of economic benefits and the environment. The sintering industry is also a major energy consumer and polluter in steel enterprises. Reducing the energy consumption and pollution of the sintering process is the key to reducing energy consumption and pollution in the steel industry.

[0003] The conventional process design of annular coolers is as follows: the hot exhaust gas from the first and second stages is used to generate steam or generate electricity after generating steam, and the exhaust gas from the third and fourth stages is directly discharged. This design wastes a large part of the waste heat and also causes great pollution to the environment. Summary of the invention

[0004] The purpose of the present invention is to provide a method for zero emission of flue gas from a ring cooler. By dividing the ring cooler into sections and utilizing the cooling waste flue gas from each section separately, all the cooling waste gas from the ring cooler is recovered and recycled without being discharged into the atmosphere, thereby achieving zero emission of waste gas from the ring cooler, improving the energy recovery rate, greatly improving the environmental protection effect, having excellent promotion value in the industry, and effectively solving the above-mentioned problems existing in the background technology.

[0005] The technical solution of the present invention is: a method for zero emission of flue gas from an annular cooler, comprising the following steps: (1) The ring cooler is divided into six sections, each equipped with a cooling fan; (2) The first and second stages of the ring cooler are connected to the waste heat boiler, and the high-temperature cooled waste flue gas is used to generate steam or generate electricity after steam is generated; (3) The cooling waste flue gas of the three-stage annular cooler is divided into three parts. The front part is merged into the first stage of the annular cooler and the second stage of the annular cooler and introduced into the waste heat boiler. The middle part is led to the flue gas circulation system to participate in the flue gas circulation. The end part is led to the sintering igniter as the combustion air of the combustion-supporting fan. (4) The cooling waste gas from the fourth stage of the ring cooler is divided into two parts, one part is returned to the inlet of the cooling fan of the third stage of the ring cooler for recycling, and the other part is led to the sintering flue gas circulation system for utilization; (5) The cooling waste gas from the fifth stage of the ring cooler is divided into two parts, one part is returned to the inlet of the cooling fan of the third stage of the ring cooler for recycling, and the other part is led to the sintering flue gas circulation system for utilization; (6) The cooling waste gas from the sixth stage of the ring cooler is returned to the inlet of the cooling fan of the fifth stage of the ring cooler for recycling.

[0006] The number of sections of the annular cooler matches the configuration; the distribution form and number of cooling fans match the configuration. When small cooling fans are selected for arrangement, their number matches the arrangement of the inner and outer rings of the annular cooler.

[0007] The heat-resistant temperature of the cooling fan matches the cooling requirements of sintered ore in different stages.

[0008] Bypass valves are arranged on the cooling fan cascade pipelines after the first stage of the annular cooler and the second stage of the annular cooler.

[0009] The butterfly valve at the cooling fan outlet is a wear-resistant dust-gas butterfly valve.

[0010] The beneficial effects of the present invention are as follows: by dividing the ring cooler into sections and utilizing the cooling waste gas from each section separately, all the cooling waste gas from the ring cooler is recovered and recycled without being discharged into the atmosphere, thus achieving zero emission of waste gas from the ring cooler, improving the energy recovery rate, greatly improving the environmental protection effect, and having excellent promotion value in the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of a cooling method of the background technology; Figure 2 It is a schematic diagram of the cooling method of the present invention; Figure 3 is a system layout diagram of the present invention; In the figure: annular cooler 1, annular cooler section 11, annular cooler section 2 12, annular cooler section 3 13, annular cooler section 4 14, annular cooler section 5 15, annular cooler section 6 16, NO.1 cooling fan 2, NO.2 cooling fan 3, NO.3 cooling fan 4, NO.4 cooling fan 5, NO.5 cooling fan 6, NO.6 cooling fan 7, waste heat boiler 8, sintering igniter 9, flue gas circulation system 10. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical solutions and advantages of the invention implementation cases clearer, the technical solutions in the implementation cases of the present invention will be clearly and completely described below in conjunction with the drawings in the implementation cases. Obviously, the implementation cases described are only a small part of the implementation cases of the present invention, rather than all the implementation cases. Based on the implementation cases in the present invention, all other implementation cases obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0013] A method for zero emission of flue gas from an annular cooler, comprising the following steps: (1) The ring cooler is divided into six sections, each equipped with a cooling fan; (2) The first and second stages of the ring cooler are connected to the waste heat boiler, and the high-temperature cooled waste flue gas is used to generate steam or generate electricity after steam is generated; (3) The cooling waste flue gas of the three-stage annular cooler is divided into three parts. The front part is merged into the first stage of the annular cooler and the second stage of the annular cooler and introduced into the waste heat boiler. The middle part is led to the flue gas circulation system to participate in the flue gas circulation. The end part is led to the sintering igniter as the combustion air of the combustion-supporting fan. (4) The cooling waste gas from the fourth stage of the ring cooler is divided into two parts, one part is returned to the inlet of the cooling fan of the third stage of the ring cooler for recycling, and the other part is led to the sintering flue gas circulation system for utilization; (5) The cooling waste gas from the fifth stage of the ring cooler is divided into two parts, one part is returned to the inlet of the cooling fan of the third stage of the ring cooler for recycling, and the other part is led to the sintering flue gas circulation system for utilization; (6) The cooling waste gas from the sixth stage of the ring cooler is returned to the inlet of the cooling fan of the fifth stage of the ring cooler for recycling.

[0014] The number of sections of the annular cooler matches the configuration; the distribution form and number of cooling fans match the configuration. When small cooling fans are selected for arrangement, their number matches the arrangement of the inner and outer rings of the annular cooler.

[0015] The heat-resistant temperature of the cooling fan matches the cooling requirements of sintered ore in different stages.

[0016] Bypass valves are arranged on the cooling fan cascade pipelines after the first stage of the annular cooler and the second stage of the annular cooler.

[0017] The butterfly valve at the cooling fan outlet is a wear-resistant dust-gas butterfly valve.

[0018] In actual application, the ring cooler 1 is divided into six sections. The number of cooling sections of the ring cooler can be increased or decreased according to the configuration. Six cooling fans are set, namely NO.1 cooling fan 2, NO.2 cooling fan 3, NO.3 cooling fan 4, NO.4 cooling fan 5, NO.5 cooling fan 6 and NO.6 cooling fan 7. The number of cooling fans can be increased or decreased according to the configuration.

[0019] The high-temperature cooled waste flue gas from the first and second stages of the ring cooler is introduced into the waste heat boiler 8 to generate steam or generate electricity after generating steam.

[0020] The cooling waste flue gas of the three stages of the ring cooler is divided into three parts. The front end part is merged into the first stage of the ring cooler and the second stage of the ring cooler and introduced into the waste heat boiler 8 for generating steam or generating electricity after generating steam; the middle part is led to the flue gas circulation system 10 for utilization and participates in the flue gas circulation; the end part is led to the sintering igniter 9 as the combustion-supporting air of the combustion-supporting fan.

[0021] The cooling waste flue gas of the fourth stage of the ring cooler is divided into two parts, one part is returned to the inlet of the cooling fan of the third stage of the ring cooler for recycling, and the other part is led to the sintering flue gas circulation system 10 for utilization.

[0022] The cooling waste flue gas of the fifth stage of the ring cooler is divided into two parts, one part is returned to the inlet of the fourth stage cooling fan for recycling, and the other part is led to the sintering flue gas circulation system 10 for utilization.

[0023] The cooling waste flue gas from the sixth stage of the ring cooler is returned to the inlet of the cooling fan of the fifth stage of the ring cooler for recycling.

[0024] The segmentation of the annular cooler can be flexibly adjusted, and the distribution of the corresponding cooling fans can also be adjusted according to the situation. The number of cooling fans can be increased or decreased. If multiple small cooling fans are selected for arrangement, they can be flexibly adjusted according to the arrangement of the inner and outer rings of the annular cooler.

[0025] The cooling fan is selected with fans of different heat-resistant temperatures according to the cooling requirements of sintered ore in different sections, so that the cooling fan can operate under the best working conditions and effectively improve the efficiency of the fan.

[0026] Bypass valves are installed on the cooling fan cascade pipelines after the first and second stages of the ring cooler. When the cooling effect of the sintered ore is not good, the flue gas path can be adjusted at any time to avoid affecting the sintering production. The operation is simple and convenient.

[0027] A wear-resistant dust butterfly valve is used at the cooling fan outlet so that when the cooling fan is ready to exit, it can effectively block the overflow of cooling smoke and dust, thereby achieving the purpose of energy saving and consumption reduction.

[0028] In the present invention, all the cooling waste gas of the ring cooler is recovered and recycled without being discharged into the atmosphere, thus achieving zero emission of waste gas from the ring cooler, improving the energy recovery rate, greatly improving the environmental protection effect, and having excellent promotion value in the industry.

Claims

1. A method for zero emission of flue gas from an annular cooler, characterized in that The following steps are involved: (1) The ring cooler is divided into six sections, each equipped with a cooling fan; (2) The first and second stages of the ring cooler are connected to the waste heat boiler, and the high-temperature cooled waste flue gas is used to generate steam or generate electricity after steam is generated; (3) The cooling waste flue gas of the three-stage annular cooler is divided into three parts. The front part is merged into the first stage of the annular cooler and the second stage of the annular cooler and introduced into the waste heat boiler. The middle part is led to the flue gas circulation system to participate in the flue gas circulation. The end part is led to the sintering igniter as the combustion air of the combustion-supporting fan. (4) The cooling waste gas from the fourth stage of the ring cooler is divided into two parts, one part is returned to the inlet of the cooling fan of the third stage of the ring cooler for recycling, and the other part is led to the sintering flue gas circulation system for utilization; (5) The cooling waste gas from the fifth stage of the ring cooler is divided into two parts, one part is returned to the inlet of the cooling fan of the third stage of the ring cooler for recycling, and the other part is led to the sintering flue gas circulation system for utilization; (6) The cooling waste gas from the sixth stage of the ring cooler is returned to the inlet of the cooling fan of the fifth stage of the ring cooler for recycling.

2. A method for zero emission of flue gas from an annular cooler according to claim 1, characterized in that: The number of sections of the annular cooler matches the configuration; the distribution form and number of cooling fans match the configuration. When small cooling fans are selected for arrangement, their number matches the arrangement of the inner and outer rings of the annular cooler.

3. The method for zero emission of flue gas from an annular cooler according to claim 1, characterized in that: The heat-resistant temperature of the cooling fan matches the cooling requirements of sintered ore in different stages.

4. The method for zero emission of flue gas from an annular cooler according to claim 1, characterized in that: Bypass valves are arranged on the cooling fan cascade pipelines after the first stage of the annular cooler and the second stage of the annular cooler.

5. The method for zero emission of flue gas from an annular cooler according to claim 1, characterized in that: The butterfly valve at the cooling fan outlet is a wear-resistant dust-gas butterfly valve.

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