Structure for heating raw gas of blast furnace and method for treating raw gas of blast furnace

Abstract

The invention relates to a structure for heating raw gas of a blast furnace and a method for treating the raw gas of the blast furnace, the structure for heating the raw gas of the blast furnace comprises a communicating pipeline, one end of the communicating pipeline is connected with a hot air main pipe, and the other end of the communicating pipeline is communicated with a raw gas pipe network of the blast furnace; the communicating pipeline is used for guiding the hot-blast stove hot air in the hot-blast main pipe to a raw gas pipe network of the blast furnace so as to heat blast furnace raw gas in the raw gas pipe network by using the hot-blast stove hot air generated by the hot-blast stove. Hot-blast stove hot air in the hot-blast main pipe can be guided to a raw gas pipe network of the blast furnace through the communicating pipeline, so that blast furnace raw gas can be heated by the hot-blast stove hot air; the method successfully solves the problems of blockage of a semi-clean gas pipe, bag condensation, bag pasting, hardening and the like under the low top temperature operation condition of the blast furnace.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical raw gas treatment, and in particular relates to a structure for heating blast furnace raw gas and a method for treating blast furnace raw gas. Background Art

[0002] Blast furnace gas is a by-product of blast furnace ironmaking. The gas contains a large amount of dust. Blast furnace gas needs to be further dusted and purified before it can be used normally. At present, there are two main dust removal and purification processes for blast furnace gas: wet dust removal and dry dust removal. The wet dust removal process is relatively mature, but its defects are also obvious, such as water and electricity consumption in the treatment process, low gas calorific value, low TRT power generation, and sewage sludge treatment that easily causes secondary pollution. Compared with wet dust removal, dry dust removal has the process characteristics of water saving, electricity saving, and pollution reduction, and has obvious economic, social and environmental benefits. It is currently widely used in steel mills at home and abroad.

[0003] In traditional blast furnace operation, in order to reduce fuel consumption and production costs, it is recommended that the top temperature should be as low as possible, which is conducive to improving gas utilization and reducing energy loss. At the same time, in order to achieve efficient smelting and increase production, oxygen enrichment must be increased, which will also cause the top gas temperature to decrease. However, the temperature of blast furnace gas is the main factor affecting the life of the bag in the subsequent dust removal and purification process. If the gas temperature is lower than the dew point, it will cause the bag to stick and the backblowing effect to be poor, and finally the bag will be compressed, deformed, and damaged, affecting the dust removal effect. Summary of the invention

[0004] In order to solve all or part of the above problems, the present invention aims to provide a structure for heating blast furnace raw gas and a method for treating blast furnace raw gas. The present invention can guide the hot air from the hot blast furnace in the hot blast main pipe to the blast furnace raw gas network through a connecting pipe, so that the hot air from the hot blast furnace can be used to heat the blast furnace raw gas. The present invention successfully solves the problems of blockage of semi-clean gas pipe, condensation of cloth bags, sticking of bags and compaction under the low top temperature operation conditions of the blast furnace.

[0005] According to one aspect of the present invention, a structure for heating blast furnace raw gas is provided, comprising a connecting pipe, one end of which is connected to a hot blast main pipe, and the other end of which is connected to a raw gas pipeline network of the blast furnace, wherein the connecting pipe is used to guide hot blast furnace hot air in the hot blast main pipe to the raw gas pipeline network of the blast furnace, so as to heat the blast furnace raw gas in the raw gas pipeline network with the hot blast furnace hot air generated by the hot blast furnace.

[0006] Furthermore, a flow regulating valve is provided on the connecting pipe, and the flow regulating valve is used to regulate the amount of hot air entering the blast furnace raw gas pipeline network through the connecting pipe.

[0007] Furthermore, a shut-off valve is provided on the connecting pipeline, and the shut-off valve is a normally open valve, so that the hot air from the hot blast furnace can be guided to the blast furnace raw gas pipeline network through the shut-off valve, and the shut-off valve can be switched to a cut-off state during maintenance.

[0008] Furthermore, an axial corrugated compensator and a large tie rod compensator are provided on the connecting pipe, and the corrugated compensator and the large tie rod compensator are used to compensate for the deformation of the connecting pipe along its axial direction.

[0009] Furthermore, the working lining of the connecting pipeline is built with andalusite-mullite composite refractory bricks with a creep resistance temperature of 1400°C, and the thickness of the working lining is 180 mm.

[0010] Furthermore, the thermal insulation lining of the connecting pipe is constructed with 114 mm thick lightweight high-alumina bricks and 114 mm thick lightweight clay bricks.

[0011] Furthermore, the inner wall of the connecting pipe is provided with a 60 mm thick fire-resistant layer.

[0012] Furthermore, expansion joints are provided between the refractory bricks of the communicating pipes, and the expansion joints are filled with fiber felt.

[0013] Furthermore, the refractory bricks at the expansion joint are bonded with oil paper, and the oil paper is used to prevent the fiber felt in the expansion joint from falling off.

[0014] The embodiment of the present invention further provides a method for treating blast furnace raw gas, the method adopts the structure for heating blast furnace raw gas as described above, and the method comprises the following steps:

[0015] The hot air from the hot blast furnace in the hot blast main pipe is guided to the raw gas pipe network of the blast furnace by using the connecting pipe, so as to heat the raw gas in the raw gas pipe network by using the hot air from the hot blast furnace;

[0016] The heated blast furnace raw gas is subjected to dust removal and purification treatment using a gravity dust collector and / or a bag dust collector.

[0017] It can be seen from the above technical scheme that the structure for heating blast furnace raw gas and the method for treating blast furnace raw gas provided by the present invention have the following beneficial effects:

[0018] The present invention can guide the hot air of the hot blast furnace in the hot blast main pipe to the blast furnace crude gas pipeline network through a connecting pipeline, has the advantages of simple structure and low production and maintenance costs, and can bring huge economic value to the steel plant.

[0019] The present invention utilizes hot air from a hot blast stove to heat the raw blast furnace gas, thereby successfully solving the problems of blockage of a semi-clean gas pipe, condensation on bags, sticking of bags, and hardening of bags under low top temperature operation conditions of the blast furnace.

[0020] The present invention utilizes hot air from a hot blast furnace to heat the raw gas from the blast furnace. Therefore, there is no need to control the temperature of the raw gas from the blast furnace, and low top temperature operation of the blast furnace can be achieved, thereby improving gas utilization, reducing energy loss, reducing fuel consumption and thus reducing blast furnace production costs. It can also increase oxygen enrichment to achieve efficient smelting and increase blast furnace iron production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of a structure for heating blast furnace raw gas according to an embodiment of the present invention;

[0022] The reference numerals in the figure are: hot air main pipe 1, connecting pipe 2, shut-off valve 3, flow regulating valve 4, crude gas pipe network 5, gravity dust collector 6, semi-clean gas pipe 7, bag dust collector 8, blast furnace 9, hot air stove 10. DETAILED DESCRIPTION

[0023] In order to better understand the purpose, structure and function of the present invention, the structure for heating blast furnace raw gas and the method for treating blast furnace raw gas of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0024] like Figure 1 As shown, it shows a structure for heating blast furnace raw gas in an embodiment of the present invention, including a connecting pipe 2, one end of the connecting pipe 2 is connected to the hot air main pipe 1, and the other end of the connecting pipe 2 is connected to the raw gas pipeline network 5 of the blast furnace 9. The connecting pipe 2 is used to guide the hot air of the hot blast furnace in the hot air main pipe 1 to the raw gas pipeline network 5 of the blast furnace 9, so as to use the hot air generated by the hot blast furnace 10 to heat the blast furnace raw gas in the raw gas pipeline network 5.

[0025] In this embodiment, the hot air from the hot blast furnace in the hot blast main pipe 1 is guided to the blast furnace crude gas pipe network 5 through the connecting pipe 2, thereby achieving the purpose of heating the blast furnace crude gas with the hot air from the hot blast furnace 10, and the crude gas can be kept within a reasonable temperature range by controlling the amount of hot air blown into the crude gas pipe network 5, thereby avoiding the problem of dry bag condensation affecting the normal production of the blast furnace 9. The heated blast furnace crude gas first passes through the gravity dust collector 6 for coarse dust removal, and the semi-clean gas obtained enters the dry bag dust collector 8 through the semi-clean gas pipe 7 for fine dust removal.

[0026] This embodiment utilizes hot air from a hot blast stove to heat the raw blast furnace gas, thereby successfully solving the problems of blockage of the semi-clean gas pipe 7 and bag sticking and hardening due to condensation under the low top temperature operation condition of the blast furnace 9.

[0027] This embodiment utilizes hot air from a hot blast furnace to heat the raw blast furnace gas. Therefore, there is no need to control the temperature of the raw blast furnace gas. Low top temperature operation of the blast furnace 9 can be achieved, thereby improving gas utilization, reducing energy loss, and reducing fuel consumption, thereby reducing the production cost of the blast furnace 9. It can also increase oxygen enrichment to achieve efficient smelting and increase the iron output of the blast furnace 9.

[0028] This embodiment can guide the hot air from the hot blast furnace in the hot blast main pipe 1 to the raw gas pipe network 5 of the blast furnace through the connecting pipe 2, which has the advantages of simple structure and low production and maintenance costs, and can bring huge economic value to the steel plant.

[0029] The connecting pipe 2 is provided with a flow regulating valve 4 , and the flow regulating valve 4 is used to regulate the amount of hot air entering the blast furnace raw gas pipeline network 5 through the connecting pipe 2 .

[0030] The flow regulating valve 4 is provided to regulate the amount of hot air entering the raw gas pipe network 5 of the blast furnace through the connecting pipe 2, so as to avoid the situation where excessive hot air causes carbon monoxide in the raw gas of the blast furnace to mix with oxygen in the hot air and cause explosion.

[0031] Thirdly, the mixture ratio of gas and air needs to be within the explosion limit to cause explosion. The flow rate of raw gas in raw gas pipeline 5 is set to 83.333 Nm 3 / s, the initial temperature of the raw gas is 120℃, the initial temperature of the hot air is 1200℃, and the temperature of the mixed gas is controlled to be 140℃ after the raw gas and hot air are mixed. The hot air flow rate can be calculated by thermodynamics to be 1.212Nm 3 / s, at this time, the ratio of coal gas to air is 69:1, and the oxygen content in the mixed gas is 0.3%, so there will be no explosion. That is, after calculation, the flow rate of hot air that will not cause explosion can be obtained, and the flow rate of hot air can be adjusted by the flow regulating valve 4.

[0032] Finally, because a smaller amount of hot air is needed to achieve the purpose of heating the coal gas, the diameter of the connecting pipe 2 is relatively small; and the hot air pressure must be higher than the raw coal gas pressure.

[0033] Among them, a shut-off valve 3 is provided on the connecting pipe 2, and the shut-off valve 3 is a normally open valve, so that the hot air of the hot blast furnace can be guided to the raw gas pipeline 5 of the blast furnace through the shut-off valve 3, and the shut-off valve 3 can be switched to the cut-off state during maintenance.

[0034] The shut-off valve 3 of the present embodiment is a normally open valve, that is, the shut-off valve 3 is in an open state under normal circumstances, and the hot air in the connecting pipe 2 can be smoothly guided to the raw gas pipeline 5 of the blast furnace through the shut-off valve 3; the shut-off valve 3 of the present embodiment can be adjusted to a shut-off state as needed, so that the hot air stops being guided to the raw gas pipeline 5 of the blast furnace; the shut-off valve 3 can be switched to a shut-off state during maintenance.

[0035] Among them, an axial corrugated compensator and a large tie rod compensator are arranged on the connecting pipe 2, and the corrugated compensator and the large tie rod compensator are used to compensate for the deformation of the connecting pipe 2 along its axial direction.

[0036] The medium in the connecting pipe 2 is the hot air in the hot air main pipe 1. Therefore, based on the principle of thermal expansion and contraction, the connecting pipe 2 will experience thermal expansion and deformation. The axial corrugated compensator and the large pull rod compensator of this embodiment are both used to compensate for the thermal deformation of the connecting pipe 2.

[0037] The working lining of the connecting pipe 2 is built with andalusite-mullite composite refractory bricks with a creep resistance temperature of 1400°C, and the thickness of the working lining is 180mm.

[0038] Since the medium in the connecting pipe 2 is the hot air in the hot air pipe 1, the hot air temperature is relatively high, so the connecting pipe 2 needs to be subjected to high temperature resistance treatment. In this embodiment, the working lining of the connecting pipe 2 is built with andalusite mullite composite refractory bricks, and the creep resistance temperature of andalusite mullite composite refractory bricks is 1400°C, which can meet the application requirements of high temperature environments. Thirdly, the brick joints of the refractory bricks should also be staggered.

[0039] Among them, the thermal insulation lining of the connecting pipe 2 is built with 114mm thick lightweight high-alumina bricks and 114mm thick lightweight clay bricks.

[0040] The thermal insulation lining of this embodiment is provided to reduce the heat spillover of hot air.

[0041] Among them, the inner wall of the connecting pipe 2 is provided with a 60mm thick fire-resistant layer.

[0042] Among them, expansion joints are arranged between the refractory bricks of the connecting pipe 2, and fiber felt is filled in the expansion joints. The refractory bricks at the expansion joints are bonded with oil paper, and the oil paper is used to prevent the fiber felt in the expansion joints from falling off.

[0043] The expansion joint of this embodiment is used to allow the refractory bricks to expand after being heated, and the fiber felt in the expansion joint is used to reduce the heat spillover of the hot air.

[0044] Again, an embodiment of the present invention further provides a method for treating blast furnace raw gas, the method adopts the structure for heating blast furnace raw gas of any one of the above embodiments, and the method comprises the following steps:

[0045] Step S01: using the connecting pipe 2 to guide the hot air of the hot blast furnace in the hot blast main pipe 1 to the raw gas pipe network 5 of the blast furnace, so as to heat the raw gas in the raw gas pipe network with the hot air of the hot blast furnace 10;

[0046] The heated blast furnace raw gas is subjected to dust removal and purification treatment using a gravity dust collector 6 and / or a bag dust collector 8.

[0047] In step S01, the hot air from the hot blast furnace in the hot blast main pipe 1 is guided to the raw gas network 5 of the blast furnace by the connecting pipe 2, so that the raw gas in the raw gas network is heated by the hot air from the hot blast furnace 10. In this process, the opening of the flow regulating valve 4 is adjusted as needed to adjust the air volume of the hot air.

[0048] Step S02 uses the gravity dust collector 6 and / or the bag dust collector 8 to perform dust removal and purification on the heated blast furnace raw gas, which specifically includes:

[0049] The heated raw gas is roughly dedusted by a gravity dust collector 6 to obtain semi-clean gas; and the obtained semi-clean gas is again sent to a dry bag dust collector 8 through a semi-clean gas pipe 7 to perform fine dust removal on the semi-clean gas.

[0050] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A structure for heating blast furnace raw gas, characterized in that: The invention comprises a connecting pipe, one end of which is connected to the hot blast main pipe, and the other end of which is connected to the raw gas pipeline network of the blast furnace. The connecting pipe is used to guide the hot blast furnace hot air in the hot blast main pipe to the raw gas pipeline network of the blast furnace, so as to heat the raw gas of the blast furnace in the raw gas pipeline network by using the hot blast furnace hot air generated by the hot blast furnace.

2. The structure according to claim 1, characterized in that: The communicating pipe is provided with a flow regulating valve, and the flow regulating valve is used to regulate the amount of hot air entering the blast furnace raw gas pipeline network through the communicating pipe.

3. The structure according to claim 1, characterized in that: The connecting pipeline is provided with a shut-off valve, which is a normally open valve, so that the hot air from the hot blast furnace can be guided to the blast furnace raw gas network through the shut-off valve, and the shut-off valve can be switched to a cut-off state during maintenance.

4. The structure according to claim 1, characterized in that The communicating pipe is provided with an axial corrugated compensator and a large tie rod compensator, and the corrugated compensator and the large tie rod compensator are used to compensate for the deformation of the communicating pipe along the axial direction thereof.

5. The structure according to claim 1, characterized in that: The working lining of the connecting pipeline is built with andalusite-mullite composite refractory bricks with a creep resistance temperature of 1400°C, and the thickness of the working lining is 180mm.

6. The structure according to claim 5, characterized in that The heat insulation lining of the connecting pipe is built with 114 mm thick lightweight high-alumina bricks and 114 mm thick lightweight clay bricks.

7. The structure according to claim 6, characterized in that The inner wall of the connecting pipe is provided with a 60 mm thick fire-resistant layer.

8. The structure according to claim 7, characterized in that Expansion joints are arranged between the refractory bricks of the communicating pipe, and the expansion joints are filled with fiber felt.

9. The structure according to claim 8, characterized in that The refractory bricks at the expansion joint are bonded with oil paper, and the oil paper is used to prevent the fiber felt in the expansion joint from falling off.

10. A method for treating blast furnace raw gas, characterized in that: The method adopts the structure for heating blast furnace raw gas according to any one of claims 1 to 9, and the method comprises the following steps: The hot air from the hot blast furnace in the hot blast main pipe is guided to the raw gas pipe network of the blast furnace by using the connecting pipe, so as to heat the raw gas in the raw gas pipe network by using the hot air from the hot blast furnace; The heated blast furnace raw gas is subjected to dust removal and purification treatment using a gravity dust collector and / or a bag dust collector.

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