Heating system for raw gas of blast furnace

Abstract

The utility model relates to a blast furnace raw gas heating system which comprises a blast furnace raw gas pipeline, a dust remover, a bag-type dust remover, a high-pressure clean gas pipeline, a residual pressure turbine power generation device and a gas pipe network, and is characterized by further comprising a blast furnace raw gas heat compensation system, the blast furnace raw gas heat compensation system comprises a plate heat exchanger, a flue gas generator, a high-pressure clean gas conveying pipeline, a low-pressure clean gas conveying pipeline, a mixed flue gas pipeline, a hot gas conveying pipeline and a hot blast stove waste heat flue gas conveying pipeline. The utility model has the advantages that the plate heat exchanger is adopted to exchange heat between low-temperature high-pressure clean gas and low-pressure clean gas of the blast furnace and high-temperature flue gas of the flue gas combustion furnace, so that after the clean gas is heated to 550 DEG C, the temperature of the heated and mixed raw coke oven gas is more than or equal to 130 DEG C under the action of the gas pressurizing machine; therefore, the unfavorable problem caused by low gas at the top of the blast furnace is solved, and meanwhile, the flue gas of the hot blast stove is reused.

Description

Technical Field

[0001] The utility model belongs to the technical field of blast furnace gas bag dust removal, in particular to a heating system for blast furnace raw gas. Background Art

[0002] In recent years, in order to improve production efficiency and reduce operating costs, blast furnaces have continuously increased smelting intensity, continuously optimized the fuel ratio of blast furnaces, and adopted economical furnace materials to increase wind temperature and oxygen enrichment rate. After improving the raw ore ratio and other operations, the blast furnace top gas temperature has gradually decreased. The blast furnace top gas temperature is an important indicator for blast furnace operation monitoring. Once the temperature is too low, the blast furnace operation will reduce the smelting intensity, which will have a great adverse effect on blast furnace production.

[0003] The raw gas from the blast furnace top enters the dust collector for coarse dust removal, and then enters the bag dust collector for fine dust removal. The clean gas then enters the pipeline network for use by downstream users.

[0004] The blast furnace gas bag filter has requirements for the temperature of the blast furnace raw gas. When the temperature is too high, the bag will burn out and eventually fail to work; when the top gas temperature is less than 120°, the gas temperature will continue to drop during transportation, which will cause condensation of moisture contained in the gas, leading to a series of problems such as blockage of the raw gas pipeline, shortened service life of the bag, and difficulty in dust removal of the dust collector. Generally, the raw gas temperature is required to be controlled between 120° and 250°. Utility Model Content

[0005] In order to solve the above technical problems, the purpose of the utility model is to provide a blast furnace raw gas heating system, which can effectively heat the blast furnace raw gas and make it reach the operating temperature requirement of the bag dust collector, and has a simple structure and is easy to operate.

[0006] The purpose of the utility model is achieved in this way. A blast furnace raw gas heating system of the utility model includes a blast furnace raw gas pipeline, a dust collector, a bag dust collector, a high-pressure clean gas pipeline, a residual pressure turbine power generation device and a gas pipeline network, characterized in that it also includes a blast furnace raw gas heating system.

[0007] The blast furnace raw gas heating system includes a plate heat exchanger, a flue gas generator, a high-pressure clean gas transmission pipeline, a low-pressure clean gas transmission pipeline, a mixed flue gas pipeline, a hot gas transmission pipeline and a hot blast furnace waste heat flue gas transmission pipeline.

[0008] The plate heat exchanger is connected in parallel to the pipelines on both sides of the dust collector and the bag dust collector. The plate heat exchanger is provided with a clean gas inlet, a mixed flue gas inlet, a hot gas outlet and a plate heat exchanger flue gas outlet. One end of the hot gas delivery pipeline is connected to the hot gas outlet of the plate heat exchanger, and the other end is connected to the dust collector inlet. One end of the high-pressure clean gas delivery pipeline is connected to the clean gas inlet of the plate heat exchanger, and the other end is connected to the high-pressure clean gas pipeline at the bag dust collector outlet. A shut-off valve A and a flow meter regulating valve B are provided on the high-pressure clean gas delivery pipeline. The flue gas outlet of the plate heat exchanger is delivered to the chimney of the hot blast furnace through a pipeline.

[0009] The flue gas generating furnace is arranged at the lower part of the plate heat exchanger, and is provided with a hot blast furnace waste heat flue gas inlet, a clean coal gas inlet, a combustion air inlet and a mixed flue gas outlet. One end of the low-pressure clean coal gas delivery pipeline is connected to the gas pipeline network, and the other end is connected to the clean coal gas inlet of the flue gas generating furnace. One end of the hot blast furnace waste heat flue gas delivery pipeline is connected to the hot blast furnace exhaust pipe, and the other end is connected to the hot blast furnace waste heat flue gas inlet of the flue gas generating furnace. A flue gas induced draft fan and a shut-off valve are provided on the hot blast furnace waste heat flue gas delivery pipeline. One end of the mixed flue gas pipeline is connected to the mixed flue gas outlet of the flue gas generating furnace, and the other end is connected to the mixed flue gas inlet of the plate heat exchanger.

[0010] Preferably, a gas pressurizing blower and a shut-off valve B are also provided on the hot gas delivery pipeline.

[0011] Preferably, a flue gas induced draft fan and a shut-off valve C are also provided on the hot blast stove waste heat flue gas conveying pipeline.

[0012] The utility model has the advantages that a plate heat exchanger is used to exchange heat between the low-temperature and high-pressure clean coal gas and the low-pressure clean coal gas of the blast furnace and the high-temperature flue gas of the flue gas combustion furnace, so that after the clean coal gas is heated to 550°, under the action of a gas compressor, the temperature of the heated and mixed raw coal gas is made ≥130°, thereby solving the disadvantageous problem caused by low coal gas at the top of the blast furnace and also allowing the hot blast furnace flue gas to be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the heating system of the blast furnace raw gas of the utility model. DETAILED DESCRIPTION

[0014] The implementation of the present invention will be described in detail below in conjunction with the accompanying drawings, but they do not constitute a limitation of the present invention and are only used as examples. At the same time, the advantages of the present invention will become clearer and easier to understand through the description.

[0015] like Figure 1As shown, a blast furnace raw gas heating system of the utility model comprises a blast furnace raw gas pipeline 1, a dust collector 2, a bag dust collector 3, a high-pressure clean gas pipeline 4, a residual pressure turbine power generation device 5, a pressure regulating valve group 6 and a gas pipeline network 7, characterized in that it also includes a supplementary heat system,

[0016] The heat supplement system includes a plate heat exchanger 8, a flue gas generator 11, a high-pressure clean gas delivery pipeline 10, a low-pressure clean gas delivery pipeline 12, a mixed flue gas pipeline 15, a hot gas delivery pipeline 9 and a hot blast furnace waste heat flue gas delivery pipeline 13.

[0017] The plate heat exchanger 8 is connected in parallel to the pipelines on both sides of the dust collector 2 and the bag dust collector 3. A clean gas inlet 83, a mixed flue gas inlet 84, a hot gas outlet 81 and a plate heat exchanger flue gas outlet 82 are provided on the plate heat exchanger 8. One end of the hot gas delivery pipeline 9 is connected to the hot gas outlet 81 of the plate heat exchanger, and the other end is connected to the dust collector inlet. One end of the high-pressure clean gas delivery pipeline 10 is connected to the clean gas inlet 83 of the plate heat exchanger, and the other end is connected to the high-pressure clean gas pipeline 4 at the bag dust collector outlet. A shut-off valve A102 and a flow meter regulating valve A101 are provided on the high-pressure clean gas delivery pipeline 10. The plate heat exchanger flue gas outlet 82 is delivered to the hot blast furnace chimney through the pipeline; a gas pressurizing fan 91 and a shut-off valve B92 are also provided on the hot gas delivery pipeline 9.

[0018] The flue gas generator 11 is arranged at the lower part of the plate heat exchanger 8, and is provided with a hot blast furnace waste heat flue gas inlet 114, a clean coal gas inlet 112, a combustion air inlet 113 and a mixed flue gas outlet 111. One end of the low-pressure clean coal gas delivery pipeline 12 is connected to the gas network 7, and the other end is connected to the clean coal gas inlet 112 of the flue gas generator. A shut-off valve C121 and a flow regulating valve B122 are also provided on the low-pressure clean coal gas delivery pipeline 12. One end of the hot blast furnace waste heat flue gas conveying pipeline 13 is connected to the hot blast furnace exhaust pipe 14, and the other end is connected to the hot blast furnace waste heat flue gas inlet 114 of the flue gas generator. A flue gas induced draft fan 131 and a shut-off valve C132 are provided on the hot blast furnace waste heat flue gas conveying pipeline 13. One end of the mixed flue gas pipeline 15 is connected to the mixed flue gas outlet 111 of the flue gas generator, and the other end is connected to the mixed flue gas inlet 84 of the plate heat exchanger.

[0019] The working principle of the utility model is described in detail below with reference to the accompanying drawings:

[0020] As shown by the arrows in the figure:

[0021] A factory's waste gas flow rate is 380000Nm 3 / h, raw gas temperature 90°~120°, high pressure clean gas flow to plate heat exchanger 90000Nm 3 / h, the high-pressure clean gas temperature is 90°, the waste heat flue gas temperature of the hot blast furnace leading to the flue gas generator is 150°, and the low-pressure clean gas flow rate is 15000Nm 3 / h, clean gas temperature is 60°, and the flue gas flow provided by the flue gas induced draft fan is 40000Nm 3 / h, the temperature of the mixed flue gas provided by the flue gas generator to the plate heat exchanger is 550°, the temperature of the hot gas outlet 81 of the plate heat exchanger is 300°, the high-temperature clean gas provided to the raw gas pipeline by the gas pressure fan, the temperature of the flue gas discharged from the flue gas outlet of the plate heat exchanger is 150°, and the raw gas after heating and mixing is 145°; the utility model utilizes the waste heat of the high-pressure clean gas and low-pressure clean gas of the blast furnace after dust removal and the waste heat of the hot blast furnace, realizes the recycling of waste heat and saves energy. At the same time, by introducing high-temperature clean gas to raise the temperature of the blast furnace raw gas to above 130°, it effectively solves the adverse effects of the low temperature of the furnace top gas on production operation and forward operation.

Claims

1. A blast furnace raw gas heating system, comprising a blast furnace raw gas pipeline, a dust collector, a bag dust collector, and a high-pressure clean gas pipeline 、 A residual pressure turbine power generation device and a gas pipeline network, characterized in that: It also includes a blast furnace waste gas heating system. The blast furnace raw gas heating system includes a plate heat exchanger, a flue gas generator, a high-pressure clean gas transmission pipeline, a low-pressure clean gas transmission pipeline, a mixed flue gas pipeline, a hot gas transmission pipeline and a hot blast furnace waste heat flue gas transmission pipeline. The plate heat exchanger is connected in parallel to the pipelines on both sides of the dust collector and the bag dust collector. The plate heat exchanger is provided with a clean gas inlet, a mixed flue gas inlet, a hot gas outlet and a flue gas outlet. One end of the hot gas delivery pipeline is connected to the hot gas outlet of the plate heat exchanger, and the other end is connected to the dust collector inlet. One end of the high-pressure clean gas delivery pipeline is connected to the clean gas inlet of the plate heat exchanger, and the other end is connected to the high-pressure clean gas pipeline at the bag dust collector outlet. A shut-off valve A and a flow meter regulating valve B are provided on the high-pressure clean gas delivery pipeline. The flue gas outlet of the plate heat exchanger is delivered to the chimney of the hot blast furnace through a pipeline. The flue gas generator is arranged at the lower part of the plate heat exchanger, and is provided with a hot blast stove waste heat flue gas inlet, a clean coal gas inlet, a combustion air inlet and a mixed flue gas outlet. Gas pipe The other end is connected to the The hot blast furnace waste heat flue gas conveying pipeline is connected to the clean coal gas inlet of the flue gas generator, and a shut-off valve C and a flow regulating valve B are provided on the low-pressure clean coal gas delivery pipeline. One end of the hot blast furnace waste heat flue gas delivery pipeline is connected to the hot blast furnace exhaust pipe, and the other end is connected to the hot blast furnace waste heat flue gas inlet of the flue gas generator. A flue gas induced draft fan and a shut-off valve are provided on the hot blast furnace waste heat flue gas delivery pipeline. One end of the mixed flue gas pipeline is connected to the mixed flue gas outlet of the flue gas generator, and the other end is connected to the mixed flue gas inlet of the plate heat exchanger.

2. The blast furnace raw gas heating system according to claim 1, characterized in that: A gas pressurizing blower and a shut-off valve B are also provided on the hot gas delivery pipeline.

3. The blast furnace raw gas heating system according to claim 1, characterized in that: A flue gas induced draft fan and a shut-off valve C are also provided on the hot blast furnace waste heat flue gas conveying pipeline.

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