JPS60247465A - Heater for lining of metallurgical pan - Google Patents

Abstract

PURPOSE:To provide a titled device which dries and heat efficiently a pan for metallurgy by consisting of the guiding structure of the gas for combustion preheated in the space partitioned of air permeable heat resistant plates to the bottom of the pan by a down pipe and burning the gas by a burner. CONSTITUTION:A heater (a) is constituted by providing the air permeable heat resistant plates 2A, B to the top and bottom of a cylindrical body 1 disposed to the top end of the metallurgical pan (q), disposing bent pipings 51a, b for a heat exchange in the space S partitioned by said plates and providing further the heating burner 4 to the bottom end of the down pipe 3 suspended from the bottom surface of the lower plate 2A near the bottom of the pan. The gas for combustion introduced through supply pipings 5a, b is supplied through the pipings 51a, b and the conduit 3 to the above-mentioned burner 4 by which the gas is burned. The combustion gas rises after heating the refractory lining 13, corner bricks 14, etc. in the bottom of the pan and heats directly castable refractory lining 12. The gas heats further the plate 2a to generate radiation heat and to accelerate the internal heating. The gas enters the space S to preheat the gas for combustion.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a heating device for lining a metallurgical pot, and more particularly, to a device suitable for heating and drying the lining of a metallurgical pot. .

[Conventional technology]

In the steelmaking process, hot metal pots for storing hot metal and molten steel,
Various pots such as molten steel pots and tanditshu are used.
In addition, a wide variety of similar metallurgical pots are used in other out-of-furnace refining processes, non-ferrous metal refining processes, and the like. Generally, these pots are lined with refractory bricks or monolithic refractories, but such lining refractories are susceptible to abrasion caused by the agitation of molten metal and its flow, reaction with slag, and even heating and cooling. If the lining is worn out or damaged due to repeated use, and as a result, the 9-proof lining exceeds its service life, intermediate repairs or rebuilding will be performed.

By the way, such refractories contain moisture when lined as they are, and therefore, if they are used as they are for receiving molten metal, they will explode due to rapid heating.

For this reason, these pots are used after sufficiently removing the moisture in the inner tension refractories. In addition to the purpose of removing moisture, a method is generally adopted in which the lining refractory is heated to raise the temperature inside the pot, and then the molten metal is cut.

For this reason, conventionally, pots have been dried and heated by the method shown in FIG. The figure shows a ladle,
The structure is such that an inner wall <11) (permanent lining) made of refractory bricks is constructed inside the outer shell α1, and an inner lining (6) made of castable refractory material is poured inside and installed by pouring. The bottom of the pot is also provided with a refractory lining αJ, the outside of which is made of poured cast monolithic refractory, and the inside of which is made of refractory bricks. Also, a4 is a corner brick to protect a corner part that is severely damaged by the use of a pot. and,
When drying and heating such a pot ←), an opening for installing a heating burner αQ and multiple combustion exhaust gas ports αη are required.
A device that seals the pot (B) with a pot lid αQ equipped with a lid αQ, burns fuel such as C gas with a heating burner αQ, injects the combustion gas downward, and discharges the combustion gas from the combustion exhaust gas port α. It is. In this method, the flow of combustion gas is generally as shown, and the lining is heated by radiant heat and convective heat transfer of the combustion gas.

[Problem that the invention seeks to solve]

However, in this conventional method, the thermal efficiency (absorbed heat amount of large lining material/generated heat amount x 100) is extremely low at a few inches, and the high temperature combustion gas is discarded from the exhaust gas port a'f). This is the actual situation. To improve this, it is possible to introduce high-temperature exhaust gas into a recuperator to preheat the fuel gas and combustion air, but in order to sufficiently recover the sensible heat of the high-temperature exhaust gas, it is necessary to increase the overall size of the recuperator. There is a problem with the equipment.

In addition, from the viewpoint of drying and heating effects, since the combustion gas flows as shown in the figure, the bottom lining (2) and the area around the corner part of the brick α◆ are heated.・
There is a problem in that it takes 50 to 60 hours to complete heating and an extremely large amount of heat is required to dry and heat one pot.

The present invention has been made in view of these conventional problems, and it is an object of the present invention to provide an apparatus that can efficiently and economically dry and heat metallurgical pots.

[Means to solve the problem-]

For this reason, the present invention provides a cylindrical body to be positioned at the upper end of the steel, breathable heat-resistant plates provided inside the body in at least two upper and lower stages spaced apart, and a breathable heat-resistant plate at the bottom facing the inside of the pot. A hanging conduit is installed vertically from the heat-resistant plate so that its lower end extends toward the bottom of the pot, a heating burner is provided at the lower end of the hanging conduit, and the inside of the main body is partitioned by upper and lower air-permeable heat-resistant plates. connected to the hanging conduit through the space;
Its basic feature is that it comprises a combustion gas supply pipe which is bent and arranged for heat exchange within the space so that the combustion gas flowing therein is preheated.

[For production]

According to the above configuration, the combustion gas from the heating burner held in the hanging conduit is introduced into the bottom of the pot, appropriately heats the bottom of the n1 pot and the lining material in the vicinity, and rises along the inner wall of the pot. The process directly heats the inner wall lining material. The rising combustion gas is discharged to the outside through the breathable heat-resistant plate, but the passing combustion gas heats the breathable heat-resistant plate to a high temperature, and the radiant heat of this breathable heat-resistant plate further heats the inside of the pot below it. Ru. In addition, the combustion gas in the combustion gas supply pipe located in the space between the upper and lower breathable heat-resistant plates is efficiently preheated by heat exchange with the heat of the combustion gas and the radiant heat of the breathable heat-resistant plates, resulting in thermal efficiency. is enhanced.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

1 and 2 show an embodiment of the present invention, in which the device (1) is a lid-like body that can be placed on the upper end of the pot, and a cylindrical body (1) to be placed on the upper end of the pot. ), breathable heat-resistant plates (for two people) installed in upper and lower levels inside the main body, and (
2B) Heat exchange in the space between the hanging conduit (3) attached to the lower breathable heat-resistant plate, the heating burner (4) attached to the lower end of the core hanging conduit, and the upper and lower breathable heat-resistant plates Combustion gas supply pipe (5
).

The main body (1) constitutes an airtight structural member, and its lower end can be brought into contact with the upper edge of the pot. The main body (1) is composed of, for example, a cylinder made of heat-resistant steel and a refractory lined therein.

The breathable heat-resistant plates (2 people) and (2B) have a cylindrical body (
This air-permeable heat-resistant board (2) is made of heat-resistant metal or ceramic, etc., and is stretched on the inside of the drawing board with a space (S) formed between the drawing board bodies. ,
By making it into a net shape, fiber shape, or porous plate shape, breathability can be provided. Generally, air-permeable plates in the form of nets, fibers, or porous branches are laminated as appropriate to a thickness of about 10 to 20 m, so as to obtain a large thermal emissivity and appropriate combustion gas flow resistance. There is. An example of this air-permeable heat-resistant plate is one in which 10 to 15 high Ni-high Cr stainless steel wire meshes with a wire diameter of 0.8 wn and an opening of 24 are laminated to form a plate-like body of 10 to 15 m+.

Ceramic plates used include so-called ceramic foam (ceramic porous material), plates in which thin thread-like ceramics are arranged vertically and horizontally, and plates obtained by firing ceramics woven into fibers. .

This air-permeable heat-resistant plate (2) has a large porosity, so the heat capacity per unit volume (l) is apparently small, but the finer the mesh is, Heat transfer is good, so that gas enthalpy is effectively returned to the interior of the pot as radiant energy.

The hanging conduit (3) connects the supply pipe (5) and the heating burner (4) in order to supply combustion gas, and is installed vertically from the lower heating burner (j), and its lower end is connected to the pot. It extends near the bottom. A mounting portion (6) is provided in the center of the breathable heat-resistant plate (for two people), and the hanging conduit (3) is mounted so as to pass through this mounting portion (6). This mounting part (6) is attached to the main body (12) to provide strength.
61). The hanging conduit (3) has a double pipe structure in this embodiment, with an air supply pipe (5h) shown below in the outer pipe (31) and a fuel supply pipe (5a) in the inner pipe (32). It is connected.

The heating burner (4) is connected downward to the lower end of the hanging conduit (3) and is located near the bottom of the pot (for example, the distance between the tip of the burner and the bottom of the pot is about 500 mm).

In this embodiment, the combustion gas supply pipe is a fuel supply pipe (
5a) and an air supply pipe (5b), these supply pipes (5a) (, 5b) are guided into the space (S) between the upper and lower ventilation heat-resistant plates through the main body (1), and are It is connected to the hanging conduit (3). Koboshi et al.'s supply pipe (5B)
(5b) are bent and piped (51a) (51b) for heat exchange so that the heat of the combustion gas itself and the radiant heat of the breathable heat-resistant plate can be exchanged in the space (S). In this example, the pipes are arranged so that they are wound concentrically. In addition, the structure of the piping can be made into an appropriate structure such as a serpentine tube shape.

The device (a) with the above configuration is held via the main body (1) by an elevating body (8) that can be raised and lowered along a guide body (7), and a pot ( The main body (1) is held in close contact with the upper edge of the pot (b).

FIG. 3 shows another embodiment of the present invention. In this embodiment, the breathable heat-resistant plates (2) are arranged in three stages, upper and lower, with the breathable heat-resistant plates (2C) and (2b) in the upper and middle parts. Space between (S2)
Connect the fuel supply pipe (5a) to the pipe (51a) L for heat exchange.
, and the breathable heat-resistant plates (2b) and (2) in the middle and lower parts.
a] In the space (Sl) between the air supply pipes (5b) and the same piping for heat exchange (51b), both supply pipes (5a) (5b)
'fc are each connected to a hanging conduit (3). In general, if fuel gas is preheated excessively, there is a risk of cracking. Therefore, in this embodiment, the space partitioned by the breathable heat-resistant plate (2) is divided into two stages, upper and lower, and the fuel gas is placed in the upper space (Ss) where the preheating effect is small. Supply pipe (5
a) is installed in the piping system. Furthermore, for the same reason, both this embodiment and the embodiment shown in FIG.
The piping for heat exchange in S1) (S2) is also shorter than the #1 fuel supply pipe (5a) and the air supply pipe (5b).

In each of the above embodiments, both the fuel gas and the combustion air are subject to preheating, but for example, the active preheating target may be limited to only the combustion air. In this case, only the air supply pipe (5b) is used for heat exchange.

In addition, in the present invention, as shown in FIG. 4, multiple stages of breathable heat-resistant plates (2) are provided in the main body (1), and the spaces (S) between each breathable heat-resistant plate are sequentially filled with pipes (51) C pieces. In the embodiment, the structure may be such that an air supply pipe) is passed therethrough. This provides a greater heat shielding effect and heat recovery effect.

In the apparatus of each embodiment as described above, the apparatus 0) is placed in a lid-like manner on the top of the pot (b), and the heating burner (4) is placed on top of the pot (b).
) are supplied with air and fuel gas through supply pipes (5a) and (5b) and a hanging conduit (3).

The heating burner (4) is connected via the hanging conduit (3).
) is led to the bottom of the pot and its vicinity, and then rises along the inner wall of the pot as shown by the arrow in the figure and is discharged to the outside through the air-permeable heat-resistant plate (2) and the space between them. be done. In this combustion gas distribution process, the combustion gas first reaches the lining 01 at the bottom of the pot and the corner brick α4 by passing through the hanging conduit (3).
The lining material in the vicinity is appropriately heated, and the lining material on the inner wall is directly heated in the process of rising along the inner wall of the pot. Furthermore, the combustion gas that rises completely inside the pan and passes through the air-permeable heat-resistant plates (2) completely heats these air-permeable heat-resistant plates (2) in the process of passing through. The radiant heat emitted from the lower air-permeable heat-resistant plates (2A) (2a) thus heated further promotes heating of the pot lining below.

Space (S) (SrX
The combustion gas flowing through Sg) heats the heat exchange piping (sxa) (slb) of each supply pipe in that space, and also heats the heat exchange piping (sxa) (slb) of each supply pipe in the space, and also The heating is further promoted by the radiant heat, and the air and fuel gas in the pipe (slaX51b) are efficiently preheated.

The combustion gas preheated in this way is sent to the heating burner (4).
and is efficiently burned.

Generally, the temperature of the combustion gas passing through the lower breathable heat-resistant plate (2A) (2a) is about 600 to 900°C, and the combustion gas is preheated by using the gas at such a temperature.

The breathable heat-resistant plate (2) has a large surface area, and especially when it is made of thin metal wires, its convection heat transfer coefficient is extremely high, so it is heated to a high temperature by the passage of combustion gas,
The radiant heat can be expected to have a sufficient heating effect on the pot lining (b) and the piping (51). In addition, the combustion gas is
$6 Rather than being exhausted from several exhaust ports as shown in the figure, the flow of combustion gas rises from the bottom of the pot because it is uniformly exhausted to the outside through the breathable heat-resistant plate (2). Since the heating and drying process is uniform in the local direction, the heating and drying in the steel scrap direction is uniform.

Furthermore, in the device shown in Fig. 793, the piping (51a) for fuel gas preheating is provided with an air permeable heat-resistant plate (2) in order to effectively preheat the combustion air flowing through the piping (51b). Since it is provided in the upper stage through the filter, excessive preheating that causes cranking is prevented.

When the pot (b) is heated by the device (a) of the present invention as described above, the temperature of the exhaust gas discharged from the uppermost breathable heat-resistant plate (2) is lowered to about 300 to 600'C. The heat energy of reeds and combustion gas can be used effectively.

FIG. 5 shows the difference between the device of the present invention as shown in FIG. 1 (however, there is no piping for preheating fuel gas) and the conventional device as shown in FIG. It shows the temperature change inside the pot lining material over time during the experiment.

The temperature measurement point inside the pot is 0 point (inside the side wall refractory) in each drawing.
and 0 point (part of the bottom corner inside the refractory).The specifications of the test pot and the heating device of the present invention at this time were as follows.

0 test pot Outer diameter x height: 11067m x 1050+
Lining conditions Materials: caster pull refractory material, side wall thickness = 50 mm, pot bottom thickness: 100 scale 0 heating device breathable heat-resistant plate silicon carbide = 30 scale porosity = 87% air preheating piping: 20 A e 22 m heating burner Location: 600 m from the top of the pot As can be seen from Figure 5, the apparatus of the present invention can achieve high thermal efficiency, and in this experimental example, the energy saving effect was 30 cm based on the amount of fuel input.

〔Effect of the invention〕

According to the present invention described above, it is possible to efficiently and appropriately heat the inner surface of the metallurgical pot including the bottom and its vicinity, and also to achieve such appropriate heating and efficient preheating of combustion gas. K, the thermal efficiency has been improved from the conventional several inches to more than 20 inches, making it possible to reduce the fuel consumption and the time required for drying the lining, etc., and to heat the lining of the pot.・There is an effect that drying can be carried out more efficiently and economically than in the past. In addition, since the device of the present invention has a structure in which the heating burner and the heat exchange device for preheating the combustion gas are integrated, the device preheats the combustion gas with higher thermal efficiency than when equipment such as a recuperator is provided externally. In addition, it has structural advantages such as eliminating the need for equipment such as an exhaust gas flue and making it possible to have a compact structure.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention, in which FIG. 1 is a longitudinal sectional view, and FIG. 2 is a sectional view taken along line 2-n in FIG. FIG. 3 is a longitudinal sectional view showing another embodiment of the present invention. FIG. 4 is a longitudinal sectional view showing another embodiment of the main body of the present invention. FIG. 5 shows the temperature change over time inside the pot inner eye heated by the device according to the present invention in comparison with that by the conventional device. FIG. 6 is an explanatory diagram showing a conventional device. In the figure, (1) is the main body, (2X2AX2BX2aX
2b) (2c) U breathable heat-resistant plate, (3) hanging conduit,
(4) is heating burner, (5a) (5b) is combustion gas supply pipe, (51X51a) (51b) is piping, (S)
(Sl) and (Sg) each indicate space. Patent applicant Nippon Kokan Co., Ltd. Inventor Akio Fujibayashi

Claims (1)

[Claims] A cylindrical body to be positioned at the upper end of the pot, breathable heat-resistant plates provided in at least two upper and lower stages at intervals inside the core body, and a lower end extending from the lowest breathable heat-resistant plate facing the inside of the pot. A hanging conduit installed vertically extending toward the bottom of the tin, a heating burner installed at the lower end of the hanging conduit, and connected to the hanging conduit through a space inside the main body partitioned by upper and lower breathable heat-resistant plates. and a combustion gas supply pipe which is bent and arranged for heat exchange within the space so that the combustion gas flowing therein is preheated.