Thermal insulation system of hot blast stove

Abstract

The utility model provides a hot-blast stove heat preservation system which comprises a hot-blast stove and a combustion fan, an inlet of the combustion fan is a cold air inlet, an air outlet of the combustion fan is connected with a combustion-supporting air pipe header pipe, the other end of the combustion-supporting air pipe header pipe is connected with two combustion-supporting air pipe branch pipes, and one combustion-supporting air pipe branch pipe is directly communicated with the upper portion of the hot-blast stove. The other combustion-supporting air pipe branch pipe is communicated with a reverse air supply pipeline, the reverse air supply pipeline is communicated with the lower portion of the hot blast stove, a first air valve is arranged on one combustion-supporting air pipe branch pipe, and a second air valve is arranged on the reverse air supply pipeline. When the blast furnace stops production, the heat preservation system of the hot blast stove adjusts the temperature of the upper portion and the temperature of the lower portion of the hot blast stove through switching between two different cold air paths, the temperature control over the upper portion and the lower portion of the hot blast stove is more accurate, and efficiency is higher; and moreover, the combustion fan is low in power and power-saving, so that the energy consumption cost is favorably controlled.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of belt conveyor, especially to a hot blast stove heat preservation system. BACKGROUND

[0002] With the depression of real estate industry, most of the steel enterprises in the country turn from winning to loss, and the number of blast furnace maintenance and shutdown increases. After the blast furnace is shut down, the hot blast stove needs to be insulated. If not, the checker bricks, lightweight bricks, clay bricks and silica bricks in the hot blast stove will crack after a long time, affecting the service life of the hot blast stove. When the hot blast stove is insulated, in order to avoid cracking of the checker bricks, lightweight bricks, clay bricks and silica bricks in the hot blast stove, the temperature of the hot blast stove dome cannot be lower than 900 DEG C, and the dome temperature below 900 DEG C needs to be burned; at the same time, the lower part of the hot blast stove is made of cast iron, and the temperature cannot exceed 400 DEG C. If the temperature of the hot blast stove grate exceeds the limit, the hot blast stove will collapse, so the working temperature inside the hot blast stove is high at the top and low at the bottom, and the temperature difference is large.

[0003] When the hot blast stove is burned each time, the flue gas will inevitably increase the temperature of the upper part of the hot blast stove, and the temperature of the lower part will also increase. Even if the hot blast stove is in a state of stop using, the heat of the upper part will gradually transfer to the lower part, so that the temperature of the upper part becomes lower and lower, and the temperature of the lower part becomes higher and higher, which is contrary to the above-mentioned temperature requirement of high temperature at the top and low temperature at the bottom. Therefore, how to control the temperature of the upper and lower parts to meet their respective requirements is a difficult problem.

[0004] By installing a cold air pipe at the manhole of the side of the hot blast stove bottom, the grate is cooled by blowing cold air through the cold air pipe, which is a way to cool the grate currently used, for example: Chinese patent with authorization publication number CN112342332B. However, in this way of cooling the grate, the combustion-supporting air required for burning the hot blast stove comes entirely from the warm air formed after the reverse blowing of cold air and the heat exchange with the grate. When the temperature of the lower part of the hot blast stove is high, the demand of the grate for cold air is large, but the demand of the upper part of the hot blast stove for combustion-supporting air is small; when the temperature of the lower part of the hot blast stove decreases to meet the requirement, the demand of the grate for cold air becomes small, but the demand of the upper part of the hot blast stove for combustion-supporting air becomes large, therefore, the demand of the upper and lower parts of the hot blast stove for cold air and combustion-supporting air does not match, and the temperature control is still very difficult. CONTENT OF THE UTILITY MODEL

[0005] The utility model aims at providing a hot blast stove heat preservation system.

[0006] The heat preservation system of hot blast stove comprises a hot blast stove and a combustion air fan, the inlet of the combustion air fan is a cold air inlet, the outlet of the combustion air fan is connected with a combustion air pipe main pipe, the other end of the combustion air pipe main pipe is branched into two combustion air pipe branch pipes, one of the combustion air pipe branch pipes is directly communicated with the upper part of the hot blast stove, the other combustion air pipe branch pipe is communicated with a reverse air pipe line, the reverse air pipe line is further communicated with the lower part of the hot blast stove, the first air valve is arranged on the one of the combustion air pipe branch pipes, and the second air valve is arranged on the reverse air pipe line.

[0007] When the hot blast stove is stopped, the heat preservation system of hot blast stove can control the first air valve to open the one of the combustion air pipe branch pipes when the temperature of the upper part of the hot blast stove is too low, and the combustion air fan blows air to the upper part of the hot blast stove, and the upper part of the hot blast stove is ignited to burn the furnace (the cold air path is: combustion air fan→the one of the combustion air pipe branch pipes→the upper part of the hot blast stove). When the temperature of the upper part of the hot blast stove is too high, the first air valve is controlled to close the one of the combustion air pipe branch pipes, and the second air valve is controlled to open the reverse air pipe line, at this time, the combustion air fan blows cold air to the lower part of the hot blast stove through the other combustion air pipe branch pipe and the reverse air pipe line, and the grate of the lower part of the hot blast stove is cooled, so that the temperature of the grate is not higher than 400 DEG C (the cold air path is: combustion air fan→the other combustion air pipe branch pipe→reverse air pipe line→the lower part of the hot blast stove). The heat preservation system of hot blast stove can switch between the two cold air paths, and the temperature of the upper part and the lower part of the hot blast stove is adjusted respectively, so that the temperature control of the upper part and the lower part of the hot blast stove is more accurate, and the efficiency is higher.

[0008] Further, the upper part of the hot blast stove is communicated with the blast furnace through a hot air pipe, and the third air valve is arranged on the hot air pipe, so that the blast furnace is preserved by the residual heat of the hot blast stove, the excess water vapor in the blast furnace is dried, and the drying time and the iron hole spatter when the blast furnace is started are reduced.

[0009] Furthermore, a mixed air pipeline is also connected to the connection position of the other combustion-supporting air duct branch and the reverse air supply pipeline. The other combustion-supporting air duct branch, the reverse air supply pipeline, and the mixed air pipeline are connected through a three-way joint. The mixed air pipeline is then connected to the hot air pipeline. The third air valve is located on the hot blast furnace side of the mixed air pipeline. A fifth air valve is provided on the mixed air pipeline. When the fifth air valve is opened, part of the cold air sent out from the other combustion-supporting air duct branch enters the hot blast furnace through the reverse air supply channel, and the other part enters the blast furnace after merging with the hot air from the hot air pipeline through the mixed air pipeline. At the beginning of the reverse air supply, the hot air temperature in the hot air pipeline is the highest; as the reverse air supply time becomes longer and longer, the hot air temperature in the hot air pipeline will become lower and lower. The utility model can adjust the cold air intake in the fifth air valve to gradually decrease as the hot air temperature gradually decreases, thereby ensuring that the air temperature sent to the blast furnace can be stable.

[0010] Furthermore, a fourth air valve is provided on the other combustion-supporting air duct branch. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a simplified structural diagram of the hot blast furnace insulation system of the present invention. DETAILED DESCRIPTION

[0012] The preferred embodiment of the hot blast furnace insulation system of the present invention will be described in detail below with reference to the accompanying drawings.

[0013] like Figure 1 As shown, a hot blast furnace insulation system includes a hot blast furnace 10 and a combustion-supporting fan 20, the inlet of the combustion-supporting fan 20 is a cold air inlet, and the air outlet of the combustion-supporting fan 20 is connected to a combustion-supporting air duct main pipe 30, and the other end of the combustion-supporting air duct main pipe 30 is connected to two combustion-supporting air duct branches (31, 32), one of the combustion-supporting air duct branches 31 is directly connected to the upper part of the hot blast furnace 10, and the other combustion-supporting air duct branch 32 is connected to the reverse air supply pipeline 40, and the reverse air supply pipeline 40 is further connected to the lower part of the hot blast furnace 10, one of the combustion-supporting air duct branches 31 is provided with a first air valve 310, and the reverse air supply pipeline 40 is provided with a second air valve 400.

[0014] When the blast furnace 60 is shut down, the temperature at the upper portion of the hot blast furnace 10 (i.e. the dome temperature) drops to about 900 DEG C, the first air valve 310 is controlled to open the one combustion air pipe branch 31, the combustion air blower 20 sends air to the upper portion of the hot blast furnace 10, and the upper portion of the hot blast furnace 10 is ignited to start the furnace (the corresponding cold air path is: the combustion air blower 20 - the one combustion air pipe branch 31 - the upper portion of the hot blast furnace 10); when the temperature at the upper portion of the hot blast furnace 10 reaches about 1200 DEG C, the first air valve 310 is controlled to close the one combustion air pipe branch 31, and the second air valve 400 is controlled to open the reverse air pipe 40; at this time, the combustion air blower 20 sends cold air to the lower portion of the hot blast furnace 10 through the other combustion air pipe branch 32 and the reverse air pipe 40, and cools the grate located at the lower portion of the hot blast furnace 10, so that the temperature of the grate does not exceed 400 DEG C (the corresponding cold air path is: the combustion air blower 20 - the other combustion air pipe branch 32 - the reverse air pipe 40 - the lower portion of the hot blast furnace 10); the hot blast furnace heat preservation system of the utility model switches between the two cold air paths, adjusts the temperature at the upper portion and the lower portion of the hot blast furnace 10 respectively, the temperature control at the upper portion and the lower portion of the hot blast furnace 10 is more accurate, and the efficiency is higher.

[0015] Further, as shown in Figure 1 the upper portion of the hot blast furnace 10 is communicated with the blast furnace 60 through the hot blast pipe 50, the third air valve 500 is arranged on the hot blast pipe 50, and the remaining heat of the hot blast furnace 10 is used to preserve the temperature of the blast furnace 60 through the hot blast pipe 50.

[0016] Further, as shown in Figure 1 the other combustion air pipe branch 32 is connected with the reverse air pipe 40, and the other combustion air pipe branch 32, the reverse air pipe 40 and the air mixing pipe 70 are communicated through a three-way joint, the air mixing pipe 70 is communicated with the hot blast pipe 50, the third air valve 500 is located on the side of the hot blast furnace 10 of the air mixing pipe 70, and the fifth air valve 700 is arranged on the air mixing pipe 70; when the fifth air valve 700 is opened, the cold air sent by the other combustion air pipe branch 32 enters the hot blast furnace 10 through the reverse air pipe 40, and enters the blast furnace 60 after being mixed with the hot air of the hot blast pipe 50 through the air mixing pipe 70. When the reverse air blowing just starts, the temperature of the hot air in the hot blast pipe 50 is high; but as the reverse air blowing time becomes longer and longer, the temperature of the hot air in the hot blast pipe 50 becomes lower and lower. The utility model can gradually reduce the cold air intake of the fifth air valve 700 in the process that the temperature of the hot air gradually decreases, so that the temperature of the air sent into the blast furnace is always kept stable, and the temperature of the blast furnace is preserved at about 150 DEG C. Of course, the air mixing pipe 70 and the fifth air valve 700 can not be arranged.

[0017] The power of the combustion-supporting fan 20 is 630kW, the power of the blast furnace 60 matched fan is 23500kW, the blast furnace 60 needs 24h from normal temperature to 150 DEG C and constant temperature at 150 DEG C, the power consumption of the reverse air supply of the combustion-supporting fan 20 is about 11.9*10*1.723*0.8*24=3936.7kW·h, if the blast furnace matched fan is used, the power consumption is about 400*10*1.723*0.8*24=132326.4kW·h, and the power consumption is 128389.7kW·h more, therefore, the new reverse air supply blast furnace energy-saving oven device can save cost about 73 million yuan.

[0018] The heat preservation system of the hot blast furnace can not only guarantee the temperature requirements of the upper and lower parts of the hot blast furnace 10, but also can fully utilize the excess heat, greatly reducing the consumption of energy medium.

[0019] Further, as shown in Figure 1 Of course, the utility model can also not set up the fourth air valve 320.

[0020] The above-mentioned is only the embodiment of the utility model, and does not limit the patent range of the utility model, and the equivalent process transformation of the utility model specification content or direct or indirect application in other related technical fields are all included in the patent protection range of the utility model.

Claims

1. A hot blast stove insulation system, characterized by: The hot blast stove and combustion air fan are provided, the inlet of the combustion air fan is cold air inlet, the outlet of the combustion air fan is connected with combustion air pipe main pipe, the other end of the combustion air pipe main pipe is connected with two combustion air pipe branch pipes, one of the combustion air pipe branch pipes is directly communicated with the upper part of the hot blast stove, the other combustion air pipe branch pipe is communicated with the reverse air blowing pipeline, the reverse air blowing pipeline is communicated with the lower part of the hot blast stove, the first air valve is arranged on the one of the combustion air pipe branch pipes, and the second air valve is arranged on the reverse air blowing pipeline.

2. The hot blast stove insulation system as claimed in claim 1, wherein: The upper part of the hot blast stove is communicated with the blast furnace through the hot blast pipeline, and the third air valve is arranged on the hot blast pipeline.

3. The hot blast stove insulation system as claimed in claim 2, wherein: The other combustion air pipe branch pipe is connected with the reverse air blowing pipeline, and the mixing air pipeline is branched from the connection position of the other combustion air pipe branch pipe and the reverse air blowing pipeline, the other combustion air pipe branch pipe, the reverse air blowing pipeline and the mixing air pipeline are communicated through the tee joint, the mixing air pipeline is communicated with the hot blast pipeline, the third air valve is located on the hot blast stove side of the mixing air pipeline, and the fifth air valve is arranged on the mixing air pipeline.

4. The hot blast stove insulation system according to claim 3, characterized in that: The fourth air valve is arranged on the other combustion air pipe branch pipe.

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