JPS60255910A - Method of controlling pressurization of hot stove - Google Patents

Abstract

PURPOSE:To prevent the deterioration of refractories due to thermal shocks and the variation of blast temps. by refuxing the hot air in a hot air main pipe through a hot air pipeline to pressurize a hot stove before the blasting is started. CONSTITUTION:When a combustion stage is switched to a blasting stage in a hot air stove 11, a pressurizing valve 38 is opened immediately before the blasting is started. Consequently, a part of hot air in a hot air main pipe 36 is refluxed through a hot air pipeline 33, and sent into a regenerator (b) which is pressurized. The hot air pipeline 33 is preheated by the pressurization with hot air. Consequently, when the stage is switched to the blasting stage by opening a cold air valve 32 and a hot air valve 34, thermal shocks to refractories in the hot air pipeline 33, a decrease in the temps. of the hot air due to heat absorption by the hot air pipeline 33 and a disorder in temp. control due to the time lag in a temp. sensor can be reduced, and the operation can be carried out smoothly.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is applicable to blast furnace hot blast furnace equipment in which a plurality of hot blast furnaces intermittently sequentially blow air to a combustion T culm (7I-culm). This article concerns the method for filling one heating furnace.

(Conventional technology) Hot blast furnace equipment for blast furnaces consists of three or four hot blast furnaces/)+
By operating each hot-blast furnace by intermittently switching between the combustion process and the blowing process, high-temperature hot air is continuously sent to the blast furnace as a whole. In such a hot blast furnace installation, when transitioning from the combustion process to the blowing process, there is a difference in the pressure inside the hot blast stove in both processes, so in order to take advantage of this pressure difference, the hot blast Air is pumped into the furnace, which is called charging. In the past, this charging pressure was applied to the feed J! This was done using cold air from the Ill side.

Once the charging is completed, the process moves on to the blowing process, but at that point the hot air pipe route (hot air pipe, mixed cooling pipe,
It consists of hot air valves, refractories, etc. ) gradually cools down as time passes from the end of the previous air blowing.
The temperature is relatively low. Therefore, when the air blast starts, high-temperature, high-pressure hot air flows through the hot-air tube path that is in a low-temperature state, causing deterioration of the refractory due to thermal shock and malfunctions in humidity control due to the time delay of the humidity sensor.
Furthermore, the heat absorption in the hot air pipe route at the beginning of the air flow causes the air to flow I! Problems such as a decrease in I temperature occurred.

(Problems to be Solved by the Invention) This invention aims to solve the above-mentioned problems in the conventional technology and realize smooth operation by preventing deterioration of refractories due to thermal shock and fluctuations in air temperature. It is something special.

[Means for solving problems]

In this invention, the charging pressure lll1lIII, which was conventionally performed by sending cold air from the sending Flilfi side, is changed so that the hot air from the hot air main pipe is sent back to the hot air pipe path.

(Function) According to the solution of the present invention, the hot air pipe path is preheated by the charging control using hot air, so when the air blowing is started, the refractory material is not subjected to thermal shock, and the air blowing temperature is This eliminates fluctuations in the flow rate and allows smooth operation.

(Example) An example of the present invention is shown in FIG. In Figure 1, 1
Nos. 1 to 14 are No. 1 to No. 4 hot air stoves, each of which is configured with a combustion chamber a and a heat storage chamber.

The combustion chamber a includes a combustion gas cutoff valve 16 and a combustion air cutoff valve 1.
8 are connected. The combustion exhaust gas is exhausted from the heat storage chamber through a flue valve 20 and a flue 22. The release valve 24 releases high-pressure gas during blowing into the atmosphere to prepare for the combustion process.

The high-pressure cold air sent from the blower Ju1 is guided from the air pipe 26 through the control valve 28 and the cold air valve 32 to the heat storage chamber, and after being made into high-temperature hot air, it is passed through the heat III pipe path 33 in which the hot air valve 34 is interposed. The hot air reaches the wood pipe 36 and is blown into the furnace.

The shutoff valve 38 is a pressure filling valve for filling the pressure difference in the furnace between the combustion culm and the blowing process, and is connected between the heat storage chamber and the heat and air main pipe 36 by bypassing the hot air valve 34. . Conventionally, this pressure filling valve 38, as indicated by the reference numeral 38',
Bypassing the control valve 28 and the cold air valve 32, the air pipe 26
It was connected between the heat storage chamber and the heat storage chamber. The pressure charging valve 38 has a smaller diameter than the hot air valve 34.

The charging valve 38 is opened immediately before transitioning from the combustion process to the blowing process, and directs a portion of the hot air from the hot air main pipe 36 to the hot air pipe path 33.
It is made to flow backwards and sent into the heat storage chamber to perform charging. The hot air pipe path 33 is preheated by charging with this hot air.

Therefore, even if the cold air valve 32 and the hot air valve 34 are opened to proceed to the air blowing process, there will be a thermal shock of the refractories in the hot air pipe path 33, a decrease in the hot air temperature due to heat absorption in the hot air pipe path 33, and a time delay in the temperature sensor. Temperature control malfunctions due to this are reduced. By the way, in the past, the charging valve 38'
As the cold air from the blower side was sent into the heat storage chamber to fill the heat storage chamber, the heat ffl@ route 33 became cooled as time passed after the previous blowing ended, and the blowing
As the culm begins, it heats up rapidly, causing normal shocks in the refractory and fluctuations in hot air temperature.

FIG. 2 shows a time sequence of the operation of the joint venture when switching the air blowing from the first base 11 to the third base 13.

When the combustion process is completed, the third base 13 closes the flue valve 20 and prepares for the blowing process.

When the blowing of air to No. 1 base 11 approaches the end, the pressure charging valve 38 is opened. As a result, a portion of the hot air from the hot air main pipe 36 flows back from the pressure filling valve 38 to the heat storage chamber of the third base 13 via the heat ffl pipe path 33, and the third base 13 is filled with pressure. At this time, the heat 8a pipe light path 33 of the third base 13 is preheated.

When a predetermined time t has elapsed since the start of filling the third base 13, the hot air valve 34 is opened, and then the cold air valve 32 is opened to start blowing air to the third base 13.

A little while after the ventilation of No. 3 base 13 started, the charging valve 3
8 is closed.

At No. 1 base 11G, the hot air valve 34 and the cold air valve 32 are then closed to complete the air blowing process. Send J! When the II culm is finished, the release valve 24 is opened, the high pressure gas during the blowing process is released, and the combustion process begins.

(Example of modification) In the above embodiment, the pressure charging valve 38 was provided separately from the hot air valve 34 to perform charging, but it is also possible to use a parent-child valve that integrates both valves, or to change the shape of the hot air valve 34. The lift difference of the valve is J, and the small flow (for charging) and the large flow (for air blowing) are 1.
It is also possible to adopt a configuration in which control is performed using one valve.

〔effect〕

As explained above, according to the present invention, hot air from the hot air main is supplied to the hot air stove before the air blowing starts. Since the hot air pipe path was filled with pressure by sending the hot air back into the pipe route, the hot air pipe route was preheated before the start of air blowing, which caused thermal shock in the refractories and a time delay in the temperature sensor when air blowing started. It is possible to reduce malfunctions in temperature control due to detection errors and temperature drops due to heat absorption in the hot air pipe path, making it difficult to operate smoothly.

[Brief explanation of drawings]

FIG. 1 is a route diagram of hot air stove equipment showing one embodiment of the present invention. Figure 2 shows the air blowing unit No. 1 in the hot blast furnace equipment shown in Figure 1.
This is a time sequence showing the operation of the joint venture when switching from No. 1 to No. 3 No. 13. 11... Hot air stove No. 1, 12... Hot air stove No. 2, 1
3... Hot air stove No. 3 unit, 14... Hot air or No. 4 bullet, 16
...Combustion gas cutoff valve, 18...Combustion air cutoff valve, 2
0... Flue valve, 22... Flue, 24... Opening valve,
26... Air pipe, 28... g9 node valve, 32... Cold air valve, 33... Hot air pipe route, 34... Hot air valve, 36
. . . Hot air main pipe, 38 . . . Pressure charging valve, 38' .

Claims (1)

[Claims] Charging of a hot-blast stove: [Control method.