JP2007046113A - Facility for cleaning blast furnace gas and method for cleaning blast furnace gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a facility for cleaning a blast furnace gas, which effectively collects thermal energy from a blast furnace gas to increase electric energy to be generated, and prevents dew from forming in a dry type dust collector, and to provide a method for cleaning the blast furnace gas. <P>SOLUTION: The facility has a heat exchanger 5 for collecting heat from the blast furnace gas by using a heat medium before passing the dry type dust collector 3, and a heat exchanger 6 for returning the heat to the blast furnace gas after dust has been collected, so as to avoid temperature-fall/restriction of the dry type dust collector 3, which largely affects the recovery efficiency of an electric power in TRT 8. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a blast furnace top gas cleaning equipment and a blast furnace top gas cleaning method.

  In the blast furnace, a furnace top pressure generator (TRT) is installed to recover the temperature and pressure energy of the blast furnace top gas as electric power, and dust collection equipment that removes dust in the blast furnace top gas. Is installed. There are two types of conventional dust collectors: dry dust collectors and wet dust collectors.

  FIG. 6 shows an example of a wet dust collector, in which blast furnace top gas from the blast furnace 1 is removed by the first stage gravity settling dust remover 2, dust is collected by the second stage wet dust collector 4, and power is generated by the TRT 8. 10 is a septum valve.

In the wet dust collector, the blast furnace top gas temperature on the TRT entry side is lowered by watering for dust collection in the blast furnace top gas, and the power generation amount of the TRT is reduced. Therefore, in order to suppress the decrease in the blast furnace top gas temperature on the TRT entry side and increase the amount of TRT power generation, as shown in FIG. It has been proposed to install a wet dust collector 4 and a dry dust collector 3 in parallel therewith to remove dust from the blast furnace top gas with the dry dust collector 3 when the blast furnace operation is stable (Patent Document 1).
Japanese Patent Laid-Open No. 2002-249808

  The dry dust collector is a system designed to increase the power recovery efficiency.However, if the blast furnace top gas temperature exceeds the heat resistance temperature of the filter cloth body of the dry dust collector due to blast furnace blowout, etc. The gas temperature is forcibly lowered by watering. As a result, the blast furnace top gas temperature on the TRT entry side is lowered, causing a loss in the power generation capability of the TRT.

  In addition, when the gas temperature at the time of off-air is low, moisture in the blast furnace top gas is condensed on the filter cloth, and dust adheres and solidifies and the dry dust collector cannot be operated. Since it is installed, there is a problem that the system becomes complicated and the cost cannot be reduced.

  Therefore, the present invention effectively recovers temperature energy that has not been recovered in the current TRT facility, increases the amount of power generation, and prevents dew condensation in a dry dust collector, and A blast furnace top gas cleaning method is proposed.

  The present invention pays attention to the fact that the recovered power can be increased by increasing the TRT inlet temperature of the blast furnace top gas, and avoids the temperature drop / restriction of the dust collection facility that greatly affects the power recovery efficiency of the TRT facility. Therefore, it is characterized in that heat is recovered from the blast furnace top gas with a heat medium in front of the dust collection facility, and recuperated after dust collection.

  In the present invention, a heat exchanger is provided on each of the gas inlet side and the gas outlet side of the dry dust collector, a heat storage body is provided between the heat exchangers, and the blast furnace top gas is supplied by the heat exchanger before the dry dust collector. By recovering the heat energy and storing it in the heat storage body, the gas temperature at the top of the blast furnace furnace is kept below the heat resistance temperature of the filter body of the dry dust collector, and the heat energy stored in the heat storage body is used again in the heat exchanger after the dry dust collector. Heat the gas.

  When the blast furnace top gas temperature is low when the blast furnace is closed, the dry dust collector has a problem that the moisture in the blast furnace top gas causes condensation on the filter cloth of the dry dust collector, causing dust to adhere and solidify. However, dew condensation can be prevented by preheating the blast furnace top gas with the heat exchanger in front of the dry dust collector with the heat stored in the heat accumulator before the break.

  Further, by providing a cooling device for cooling the heat medium in the circulation path of the heat medium, the heat medium can be cooled so as not to exceed the boiling point when the blast furnace top gas temperature rises abnormally when blown through.

  The present invention can increase the TRT power generation amount by increasing the TRT inlet temperature of the blast furnace top gas by installing a heat storage body between the heat exchanger and the heat exchanger before and after the dry dust collector.

  In addition, when the blast furnace top gas is hot due to blow-off of the blast furnace top gas, etc., the blast furnace top gas is cooled by a heat exchanger and stored in a heat storage body with a heated heat medium. Sometimes, by circulating the heat medium heated by the heat accumulator to the heat exchanger on the gas inlet side, moisture in the low temperature blast furnace top gas is condensed on the tube of the heat exchanger and the filter cloth of the dry dust collector. It becomes possible to prevent.

  Also, by cooling the blast furnace top gas with a heat exchanger, it becomes possible to collect dust from the blast furnace top gas using only a dry dust collector, so the wet dust collector itself becomes unnecessary, reducing the equipment cost and shortening the construction work. It becomes possible.

  In addition, a cooling device for the heat medium is provided in the circulation path of the heat medium, and when the temperature of the heat medium rises abnormally due to the high temperature blast furnace top gas, the heat medium does not exceed the boiling point by cooling the heat medium with the cooling device. Can be.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a view showing an embodiment of the blast furnace top gas cleaning equipment of the present invention.

  In FIG. 1, the blast furnace top gas discharged from the blast furnace 1 is introduced into a gravity settling dust remover 2. A temperature measuring device (not shown) for measuring the temperature of the blast furnace top gas is arranged on the outlet side of the dust remover 2, and the opening and closing of the valve of the heat medium circuit and the control of the flow rate are controlled by the temperature of the blast furnace top gas. Do. The blast furnace top gas discharged from the dust remover 2 is sent to the dry dust collector 3 for dust collection, and then sent to the TRT 8 for power generation. 10 is a septum valve.

  In the blast furnace top gas cleaning equipment of the present invention, the heat exchangers 5 and 6 are arranged on the gas inlet side and the gas outlet side of the dry dust collector 3, respectively. It is circulated by. Bypass piping 11 and 12 are disposed on the heat medium inlet side and the heat medium outlet side of the heat exchangers 5 and 6.

  A heat accumulator 7 is disposed in the circulation path of the heat medium between the heat exchangers 5 and 6. The heat storage body 7 forms a plurality of heat medium passages in the casting block so as to communicate with each other, and stores the heat in the casting block by passing the heat medium through the heat medium passage. The heat storage body 7 is provided with a bypass pipe having a bypass valve.

  The heat exchanger 5 on the gas inlet side of the dry dust collector 3 recovers the heat of the blast furnace top gas, stores the heat in the heat storage body 7 installed between the heat exchangers 5 and 6, and when the blast furnace top gas temperature decreases, The heat medium heated by the heat stored in the heat accumulator 7 is circulated so that the heat is reheated to the blast furnace top gas by the heat exchanger 6 on the gas outlet side.

  Next, the blast furnace top gas cleaning method of the present invention will be described.

  FIG. 2 is a diagram showing a circulation path of the heat medium when the blast furnace top gas temperature is equal to or higher than the heat resistance temperature of the filter cloth of the dry dust collector.

  The blast furnace top gas is in the range above the heat resistance temperature of the filter cloth of the dry dust collector (about 180 ° C) and below the top water sprinkling start temperature (set to 350 ° C) for protecting each equipment of the blast furnace top charging equipment. In this case, since the blast furnace top gas temperature exceeds the heat resistance temperature of the filter cloth of the dry dust collector 3, it needs to be cooled. Therefore, the blast furnace top gas is cooled through the heat exchanger 5 on the gas inlet side of the dry dust collector 3 to lower the heat resistance temperature (180 ° C.) of the cloth of the dry dust collector 3. The heat medium heated by the heat exchanger 5 stores heat through the heat storage body 7.

  Since the temperature of the blast furnace top gas exiting the dry dust collector 3 is decreasing, the heat medium heated by the heat storage of the heat storage body 7 is supplied to the heat exchanger 6 on the gas outlet side of the dry dust collector 3 in order to increase the amount of power generation. The blast furnace top gas is heated so as not to exceed the TRT heat resistance temperature (set to about 240 ° C.), the temperature is raised to about 225 ° C., and introduced into the TRT for power generation.

  FIG. 3 is a graph showing the amount of power generated when the present invention with a heat exchanger and the heat exchanger are not provided. It can be seen that this embodiment of the high temperature operation increases the amount of power generation. In addition, when no heat exchanger is provided, the top water sprinkling of the blast furnace top gas starts at about 160 ° C. However, in the present invention, when the blast furnace top gas is 180 ° C. to 350 ° C., the top water sprinkling is unnecessary. Become.

  FIG. 4 is a diagram showing a circulation path of the heat medium when the blast furnace is closed.

  Since the blast furnace top gas is low temperature when the blast furnace is closed, the heat exchanger 5 is circulated through the heat medium heated by the heat stored in the heat accumulator 7 on the gas inlet side of the dry dust collector 3. Let

  By heating the heat exchanger 5 on the gas inlet side of the dry dust collector 3 with a heat medium, it is possible to prevent dust from adhering to the tube of the heat exchanger 5 or the filter cloth of the dry dust collector 3 due to condensation. .

  FIG. 5 is a diagram showing a circulation path of the heat medium when the temperature of the heat medium is abnormally increased by the high temperature blast furnace top gas.

  When the temperature of the heating medium rises abnormally due to the high temperature blast furnace top gas when the blast furnace is blown through, the heating medium is cooled by the cooling device 13 so that the heating medium does not exceed the boiling point (about 340 ° C.). Cooling by the heat exchanger 5 and heating by the heat exchanger 6 are performed by circulating a heat medium as in the second embodiment.

It is a figure which shows one Example of the blast furnace top gas cleaning equipment of this invention. It is a figure which shows the circulation path of a heating medium in case a blast furnace top gas temperature is more than the heat-resistant temperature of the filter cloth of a dry dust collector. It is a graph which shows the electric power generation amount at the time of not providing this invention with the heat exchanger and the heat exchanger. It is a figure which shows the circulation path | route of the heat medium at the time of blast furnace rest wind rise. It is a figure which shows the circulation path | route of a heat medium when a heat medium temperature raises abnormally with high temperature blast furnace top gas. It is the schematic at the time of installing only the conventional wet dust collector. It is the schematic at the time of installing the conventional dry dust collector and the wet dust collector in parallel.

Explanation of symbols

1: Blast furnace 2: Dust collector 3: Dry dust collector 4: Wet dust collector 5: Heat exchanger on the gas inlet side 6: Heat exchanger on the gas outlet side 7: Heat storage body 8: TRT
9: Pump
10: Septum valve 11: Bypass piping 12: Bypass piping 13: Cooling device

Claims (9)

In the furnace top gas cleaning equipment that cleans the blast furnace top gas through a dust remover and a dry dust collector and then introduces it into the furnace top pressure generator,
A blast furnace top gas cleaning facility, wherein a heat exchanger for exchanging heat between a blast furnace top gas and a heat medium is disposed on a gas inlet side and a gas outlet side of the dry dust collector.   The heat medium outlet side pipe of the gas inlet side heat exchanger is connected to the heat medium supply side of the gas outlet side heat exchanger, and the heat medium outlet side pipe of the gas outlet side heat exchanger is connected to the gas inlet side. The blast furnace top gas cleaning equipment according to claim 1, wherein the equipment is connected to a heat medium supply side of the heat exchanger.   The heat storage body is provided in the heat medium outlet side pipe of the heat exchanger on the gas inlet side, and the circulation pump is provided in the heat medium outlet side pipe of the heat exchanger on the gas outlet side. Or the blast furnace top gas cleaning equipment of 2.  The blast furnace gas cleaning equipment according to any one of claims 1 to 3, wherein a thermometer for measuring a temperature of the blast furnace gas is disposed on a gas outlet side of the dust remover.   5. A bypass pipe is provided in the middle of each of the heat medium inlet side pipe and the heat medium outlet side pipe of each of the gas inlet side heat exchanger and the gas outlet side heat exchanger. The blast furnace top gas cleaning equipment according to claim 1.   6. A heat medium cooling device is provided in a pipe connecting the heat medium outlet side of the gas outlet side heat exchanger and the heat medium supply side of the gas inlet side heat exchanger. The blast furnace top gas cleaning equipment according to any one of the above. In the blast furnace top gas cleaning method of introducing the blast furnace top gas through a dust remover and a dry dust collector and then introducing it into the furnace top pressure generator,
A heat exchanger is provided on each of the gas inlet side and the gas outlet side of the dry dust collector, and when the temperature of the blast furnace gas is higher than a predetermined temperature and lower than the start water spray temperature, A method of cleaning a blast furnace top gas, wherein the top gas is cooled and the blast furnace top gas is heated by a heat exchanger on a gas outlet side. In the blast furnace top gas cleaning method of introducing the blast furnace top gas through a dust remover and a dry dust collector and then introducing it into the furnace top pressure generator,
A heat exchanger is provided on each of the gas inlet side and the gas outlet side of the dry dust collector, and when the temperature of the blast furnace top gas is equal to or lower than a predetermined temperature, the heat exchanger on the gas outlet side is switched to a bypass pipe. Blast furnace top gas cleaning method. In the blast furnace top gas cleaning method of introducing the blast furnace top gas through a dust remover and a dry dust collector and then introducing it into the furnace gas turbine,
Heat exchangers are installed on the gas inlet side and gas outlet side of the dry dust collector, respectively, and when the temperature of the blast furnace gas exceeds the furnace sprinkling start temperature, the blast furnace furnace top gas is cooled by the gas inlet side heat exchanger. Then, the gas outlet side heat exchanger is switched to a bypass pipe, cooled by a cooling device, and circulated after being cooled.

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