JP3341072B2 - Blast furnace bottom cooling piping and blast furnace bottom cooling method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling pipe for a blast furnace bottom and a method for cooling the same.

[0002]

2. Description of the Related Art In a blast furnace, a cooling pipe is installed at a lower portion of a bottom brick to prevent erosion of a bottom refractory, and cooling is performed by flowing a cooling medium such as water or air. . The conventional cooling piping method is generally a method of flowing a cooling medium through pipes arranged in parallel.In this method, when there is a heat load distribution at the bottom of the furnace, the cooling capacity is controlled according to the magnitude of the heat load. Can not do. In recent years, large-scale blast furnaces often have an annular flow around the bottom of the furnace, increasing the heat load.
In many cases, it is desirable to cool the periphery of the furnace bottom more strongly than the center of the furnace bottom in order to prevent selective erosion of this part. In order to solve this problem, Japanese Patent Application Laid-Open No. 58-55509 and Japanese Patent Application Laid-Open No. 63-105913 disclose cooling pipes capable of changing the cooling capacity by separately controlling the cooling of the central part and the peripheral part of the furnace bottom. A method has been proposed in which a heat transfer resistor is provided in a part of a cooling pipe to form regions having different cooling capacities.

[0003]

However, in the method disclosed in Japanese Patent Application Laid-Open No. 58-55509, a plurality of cooling ducts are provided around the furnace bottom, which complicates the structure and increases the difficulty in facility construction. Also, JP-A-63-105913
The method disclosed in Japanese Patent Application Laid-Open No. H11-157873 has a disadvantage that it is difficult to provide a heat transfer resistor in a cooling pipe, and equipment and construction costs are increased. The present invention provides a blast furnace bottom cooling pipe and a furnace bottom cooling method capable of controlling the cooling capacity in the furnace bottom radial direction according to the temperature distribution of the furnace bottom without using a special structure other than a particularly complicated structure or piping. The purpose is to:

[0004]

According to the present invention, the cooling pipe at the bottom of the blast furnace is formed in a spiral shape, and the flow direction and the flow rate of the cooling medium are controlled in accordance with the heat load. It is characterized in that it is possible to change the cooling capacity of the central part and the peripheral part of the furnace bottom without using a structure. That is,
The gist of the present invention is (1). The cooling pipe on the bottom of the blast furnace is formed spirally from the peripheral part to the central part, and the inlet or outlet of the cooling medium is provided at the peripheral part and the central part of the cooling pipe.
The cooling pipes are provided at one location and at two locations in the middle ,
-A middle part, a middle part- a blast furnace bottom cooling pipe, comprising two systems of a central part , (2). In the cooling method using the blast furnace bottom cooling pipe described in (1),
When the temperature of the intermediate portion and the outer peripheral portion is central portion> intermediate portion> outer peripheral portion, two blast furnace bottom cooling pipes are connected in series, and the cooling medium reaches the outer peripheral portion from the central portion via the intermediate portion. When the center portion <intermediate portion <peripheral portion, the two blast furnace bottom cooling pipes are connected in series so that the cooling medium flows from the outer peripheral portion to the central portion via the intermediate portion, and also to the intermediate portion. in the direction in which the temperature of the reaches the central portion and the outer peripheral portion from the intermediate portion to connect the highest when the two systems the high furnace hearth cooling piping in parallel, the high furnace hearth cooling of two systems when the temperature of the middle portion is the lowest In the direction from the central part and the outer peripheral part to the intermediate part by connecting the pipes in parallel, the temperature difference between the central part, the intermediate part, and the peripheral part is small,
When the temperature is slightly higher from the center to the periphery 2
The blast furnace bottom cooling pipes of the system are connected in parallel and
In the direction from the middle and the middle to the center, the center,
The temperature difference between the center and the periphery is small, but from the center to the periphery
In a direction leading to the intermediate portion from the peripheral portion and the central portion from between in the high furnace hearth cooling pipes of two systems when the temperature is slightly lower then connected in parallel portion toward the part, the cooling water of the region to be strongly respectively cooling The temperature distribution such that the temperature is lowered,
A blast furnace bottom cooling method characterized by selecting from among,,, and, and connecting a cooling pipe and flowing a cooling medium in a cooling direction so that the temperature distribution is obtained.

[0005]

In the bottom of the blast furnace, there is a coke filling region called a furnace core, and hot metal and slag produced by the reduction and melting of ore are accumulated in the voids. Refractories containing carbon as the main component are used in the furnace bottom, but cooling is performed by installing cooling pipes under the refractory to prevent erosion of the refractory due to the flow of hot metal and heat load . The flow of hot metal differs depending on the erosion profile of the furnace, the shape of the lower end of the mandrel, and the liquid permeability in the mandrel. When there is a narrow gap between the furnace bottom and the furnace bottom, a lot of hot metal flows through this space, and when the center part of the furnace core floats around the furnace bottom and there is a gap, through this gap An annular flow toward the taphole is created. The temperature of the hearth refractory corresponding to the portion where the hot metal flows a lot increases and receives much heat load.

In normal blast furnace operation, a change in temperature of the refractory is monitored by a thermometer buried in the refractory at the bottom of the furnace, and a countermeasure is taken when the temperature rises. The furnace bottom cooling capacity can be controlled as follows. An example in which water is used as a cooling medium using an iron cooling pipe will be described with reference to the drawings. That is, (1). 1A and 1B show a furnace bottom cooling pipe, wherein FIG. 1A is a front view and FIG. 1B is a plan view. As shown in the figure, the cooling pipe 3 on the bottom of the blast furnace is formed in a spiral shape,
In addition to the inlet and outlet of the peripheral part and the central part , two other parts are provided at the intermediate part in addition to the peripheral part and the central part , and the cooling water is serially or in parallel to the two systems of the peripheral part-the intermediate part and the intermediate part-the central part, and If a furnace bottom cooling pipe that can flow in any direction is used, depending on the flow of cooling water, if connected in series, from the periphery to the center, depending on the direction of cooling water flow As shown in FIG. 2, the temperature of the cooling water is distributed in the direction of the diameter of the furnace bottom when flowing, and as shown in FIG. 3, the temperature of the cooling water is distributed in the direction of the diameter of the furnace bottom when flowing from the center to the periphery. Distribution. When connected in parallel, depending on the direction of cooling water flow,
Periphery → Middle, Middle → Center, Peripheral → Middle, Center → Middle,
In the case of middle → periphery, middle → center, middle → periphery, center → middle, the cooling water temperature distribution as shown in FIG. 4, FIG. 5, FIG. 6, and FIG. Also, increasing the cooling water flow rate can reduce the radial temperature gradient, and reducing the cooling water flow rate can increase the radial temperature gradient. Therefore, the temperature distribution of the thermometer buried in the furnace bottom refractory is high, that is, the temperature distribution in which the cooling water temperature of the part where the cooling is desired to be increased is selected from FIGS. If the connection of the cooling pipe and the control of the cooling direction are performed so that the temperature distribution is obtained, the erosion of the furnace bottom refractory can be effectively suppressed.

(Example 1) As shown in FIG. 1, an iron cooling pipe 3 on the bottom of a blast furnace is formed in a spiral shape with 15 turns, and an inlet or an outlet of a cooling medium is provided at each of a peripheral portion and a central portion , and between them. It provided two positions from the outer snare Chi to parts in the position of the Volume 7, peripheral → intermediate, intermediate → center 2
Furnace bottom cooling water piping was installed so that cooling water could flow in either direction in series or in parallel to the system.
In the two blast furnaces, while observing the indicated value of the thermometer 4 buried in the refractory at the bottom of the furnace, if the difference and the fluctuation of the indicated value in the peripheral part and the central part are small, the pipes are connected in series and the direction of the cooling water flow alternately However, at a certain point in time, among the indicated values of the thermometer, the indicated values near the center of the furnace bottom and the middle of the outer periphery increased by about 30 ° C. It is presumed that the erosion of the refractory in this portion has progressed, and the cooling water flow is switched in parallel, and the cooling method of changing the direction from middle to peripheral, middle to center, and increasing the cooling water flow by 10% is continued for a while. The temperature at the intermediate portion showed a tendency to decrease. When the temperature decreased by 20 ° C., the cooling method was returned to the original one. As a result, it was possible to suppress a rise in the temperature of the middle part of the furnace bottom and suppress further erosion of the furnace bottom refractory.

[0008]

According to the present invention, the following effects can be obtained. Without using a particularly complex equipment at the bottom of the high <br/> furnace furnace bottom, 2
Connection method of cooling pipe divided into systems, direction of water flow and water
By controlling the amount, fine cooling in the radial direction of the furnace bottom
Pattern can be formed.
Corrosion of the furnace bottom refractory can be suppressed while cooling is more effectively performed according to the radial distribution of the flow .

[Brief description of the drawings]

FIG. 1 is a furnace bottom cooling piping diagram of the present invention (Example 1).

FIG. 2 Radial temperature distribution of furnace bottom cooling water

FIG. 3 Radial temperature distribution of furnace bottom cooling water

FIG. 4 Radial temperature distribution of hearth cooling water

FIG. 5 Radial temperature distribution of furnace bottom cooling water

FIG. 6: Radial temperature distribution of hearth cooling water

FIG. 7: Radial temperature distribution of furnace bottom cooling water

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 Blast furnace body 2 Furnace bottom refractory 3 Furnace bottom cooling pipe 4 Buried thermometer

Claims (2)

(57) [Claims] 1. A cooling pipe on the bottom of a blast furnace is spirally formed from a peripheral part to a central part, and an inlet or an outlet of a cooling medium is provided at one point at the peripheral part and at the central part of the cooling pipe and at two points at an intermediate part.
Location , the cooling pipe is located in the peripheral part-intermediate part, intermediate part-center
A blast furnace furnace bottom cooling pipe, comprising two systems: 2. The cooling method using a blast furnace bottom cooling pipe according to claim 1, wherein when the temperature of the center, the middle, and the outer periphery of the furnace bottom is center>intermediate> outer periphery, two systems are used. The blast furnace bottom cooling pipes are connected in series, and the cooling medium is connected to two systems of the blast furnace bottom cooling pipes in the direction from the center to the outer periphery through the middle through the middle when the center is smaller than the middle. The cooling medium is connected in series in the direction from the outer peripheral portion to the central portion via the intermediate portion, and when the temperature of the intermediate portion is the highest, the two blast furnace bottom cooling pipes are connected in parallel to form the intermediate portion. In the direction from the central part and the outer peripheral part, when the temperature of the intermediate part is the lowest, two systems of the blast furnace bottom cooling pipes are connected in parallel, and in the direction from the central part and the outer peripheral part to the intermediate part, the central part, Middle
The temperature difference between the center and the periphery is small, but from the center to the periphery
In a direction leading to the central portion from the middle-section and the intermediate section headed a high-furnace hearth cooling pipes of two systems when the temperature is slightly higher connected in parallel from the periphery, the central portion, an intermediate portion, the periphery each
Although the temperature difference is small, the temperature increases from the center to the periphery.
In a direction extending from the peripheral portion and the central portion to the intermediate portion slightly from the high furnace furnace between in connecting the bottom cooling piping in parallel portion of the lower case 2 systems, such as cooling water temperature of the region to be strongly each cooling decreases A method for cooling a blast furnace bottom, characterized in that a temperature distribution is selected from the above, ..., ..., and a cooling medium is connected and a cooling medium flows in a cooling direction so that the temperature distribution is obtained.