JP5446382B2 - Manufacturing method of cooling structure - Google Patents

Description

  The present invention relates to a cooling structure including a heat receiving plate attached to an object to be cooled and a cooling pipe that is inserted into the heat receiving plate and through which a cooling medium flows, and in particular, cools a furnace body of a blast furnace or other industrial furnaces. The present invention relates to a method of manufacturing a cooling structure used for the purpose.

  For example, in a blast furnace, in order to suppress deterioration of the furnace body due to heat generated in the furnace, operation is performed while cooling the furnace body using a stave cooler as a cooling structure.

  FIG. 2 is a cross-sectional view of the furnace wall of the blast furnace. The stave cooler 1 includes a heat receiving plate 1a attached to the iron shell 3 via an irregular refractory 2 and a cooling pipe 1b that is inserted into the heat receiving plate 1a and through which cooling water flows. The furnace body is cooled by the cooling water flowing inside the cooling pipe 1b through the cooling pipe 1b and the heat receiving board 1a.

  Under a severe heat environment in the blast furnace, a crack may occur in the heat receiving platen 1a due to a heat load. If a crack occurs in the heat receiving platen 1a, if it propagates to the cooling pipe 1b, a water leak occurs, which hinders the operation of the blast furnace. Therefore, in order to prevent the propagation of cracks from the heat receiving platen 1a to the cooling pipe 1b, a minute gap G is secured between them (see, for example, Patent Document 1).

  However, the presence of the minute gap G hinders the movement of heat from the heat receiving platen 1a to the cooling pipe 1b, and as a result, reduces the cooling capacity of the stave cooler 1.

  Therefore, a thin copper plate (Patent Document 2) or a kneaded material (Patent Document 3) in which a low melting point metal powder is kneaded at a pitch is interposed in the portion of the minute gap G in FIG. Proposals have been made to reduce the thermal resistance between the heat receiving platen 1a and the cooling pipe 1b and prevent the cooling capacity of the stave cooler 1 from being lowered, while retaining the effect of preventing the propagation of cracks to 1b.

Japanese Patent Publication No. 50-21420 JP 2002-146418 A Japanese Utility Model Publication No. 48-36086 JP 2008-156133 A JP-A-53-133217

  If it is the thin copper plate of patent document 2, the minute gap G cannot be filled without a gap, and a gap will remain. For this reason, the thermal resistance between the heat receiving board 1a and the cooling pipe 1b cannot be reduced sufficiently.

  With the non-aqueous kneaded material of Patent Document 3, the minute gap G can be filled without any gap, but since a pitch with poor thermal conductivity is used for kneading, the thermal resistance between the heat receiving platen 1a and the cooling pipe 1b. Cannot be reduced sufficiently.

  In addition, not only pitch but also so-called non-aqueous binders including liquid resin and tar have poor thermal conductivity. Even so, the effect of improving the thermal conductivity is reduced.

  The objective of this invention is providing the manufacturing method of the cooling structure which can aim at the improvement of a cooling capability by fully reducing the thermal resistance between a heat receiving board and a cooling pipe.

According to an aspect of the present invention, (a) a heat receiving plate that is attached to a cooling pipe through which a cooling medium flows and a cooling target, and covers the cooling pipe with a minute gap between the cooling pipe and the outer surface. preparing a preparative, and (b) in the minute gap, the powder composition have a step of encapsulating the kneaded product kneaded with water and / or alcohol, the powder composition, water-soluble polymer A method for manufacturing a cooling structure is provided.

  Water and / or alcohol is excellent in thermal conductivity as compared with a non-aqueous binder. Since the kneaded material of the present invention is used in an enclosed state between the heat receiving plate and the cooling pipe, water and / or alcohol in the kneaded material is not easily dissipated even during operation of the cooling structure. For this reason, the good thermal conductivity of water and / or alcohol is fully utilized.

  Therefore, even if the composition of the powder composition to be used is the same, the thermal resistance between the cooling pipe and the heat receiving panel can be reduced as compared with the conventional case using a non-aqueous binder, and the cooling capacity of the cooling structure is improved. can do.

  In addition, the water-based kneaded material itself using water for the kneading liquid is well known. Moreover, the examination which raises the heat conductivity is also made | formed conventionally (refer patent documents 4 and 5). However, any conventional water-based kneaded product is premised on use after being dried and solidified, and is not based on the technical idea of utilizing the good thermal conductivity of water itself.

It is sectional drawing of a stave cooler. It is sectional drawing of the furnace wall in the shaft part of a blast furnace.

  FIG. 1 shows a cross-sectional view of a stave cooler used for cooling a blast furnace. The stave cooler includes a heat receiving plate 10 attached to the furnace body and a cooling pipe 11 that is inserted into the heat receiving plate 10 and through which cooling water flows. The cooling water flowing through the cooling pipe 11 causes the cooling pipe 11 and The furnace body is cooled through the heat receiving board 10.

  As a material for the heat receiving plate 10 and the cooling pipe 11, a conventional material, for example, iron or copper, or an alloy or other metal containing any of these is used.

  This stave cooler is characterized in that the kneaded material 12 using water and / or alcohol in the kneaded liquid is sealed between the inner surface of the heat receiving plate 10 and the outer surface of the cooling pipe 11.

  Since the kneaded product 12 is used in an enclosed state, water and / or alcohol in the kneaded product 12 is not easily dissipated even during operation of the stave cooler. For this reason, the good thermal conductivity of water and / or alcohol is utilized, and the kneaded material 12 can exhibit good thermal conductivity. This contributes to the improvement of the cooling capacity of the stave cooler.

  As described above, the aqueous kneaded material itself has been well known. However, water-based kneaded materials are not usually applied to industrial furnaces, particularly blast furnaces. This is because the lined refractory used in the blast furnace is resistant to oxidation by steam. In this respect, in this stave cooler, since the dissipation of water and / or alcohol is prevented by sealing, the use of the kneaded material 12 does not cause the above-mentioned problem of steam oxidation.

  In FIG. 1, it is conceivable to enclose only water and / or alcohol between the heat receiving board 10 and the cooling pipe 11, but it is difficult to enclose only water and / or alcohol in a liquid-tight manner. Even if the sealing can be performed, for example, when a crack is generated in the heat receiving panel 10 due to a heat load during use, there is a concern that water and / or alcohol easily flows out to the outside, that is, into the blast furnace through the crack.

  By using the powder composition together with water and / or alcohol, it is easy to enclose, and even if the heat receiving panel 10 is cracked, water and / or alcohol hardly flows out. The presence of the powder composition increases the effect of preventing the dissipation of water and / or alcohol.

  In addition, it is conceivable to enclose only the powder composition between the heat receiving platen 10 and the cooling pipe 11, but a gap is inevitably left between the particles in the powder composition. The thermal resistance between the two cannot be sufficiently reduced.

  Hereinafter, a method for manufacturing the stave cooler will be described.

  [First example]

  First, the cooling pipe 11 is prepared, and this is cast with a molten metal that becomes the heat receiving plate 10, for example, cast iron. However, a minute gap is formed between the cooling pipe 11 and the heat receiving plate 10 during casting.

  Specifically, a minute gap is formed by applying a refractory paste to the outer surface of the cooling pipe 11 and casting the heat receiving board 10. The refractory paste is composed of, for example, silica powder or clay.

  In addition, since the method of forming the minute gap in this way is known, detailed description is omitted (for example, refer to Patent Document 1).

  Next, the kneaded material 12 is press-fitted into the minute gap between the heat receiving plate 10 and the cooling pipe 11 from the outside.

  Next, the exposed portion of the kneaded material 12 on the surface of the heat receiving board 10 is closed with the sealing material 13. For the sealing material 13, for example, silicone can be used. Thereby, the kneaded material 12 will be in an encapsulated state.

  [Second example]

  First, the cooling pipe 11 and the heat receiving board 10 divided into a plurality of members combined so as to secure the minute gap and sandwich the cooling pipe 11 are prepared.

  Next, the kneaded material 12 is applied to the surface facing the other of at least one of the plurality of members and the cooling pipe 11.

  Next, the cooling pipe 11 is sandwiched between the plurality of members, and in this state, the plurality of members are connected with bolts or the like to form the heat receiving board 10.

  In addition, since the method which comprises the heat receiving board 10 by connecting several members in this way is well-known, detailed description is abbreviate | omitted (for example, refer patent document 2).

  In the first example described above, the opening area of the micro gap at the surface position of the heat receiving board 10 has to be secured wide enough to allow the kneaded material 12 to be press-fitted from the outside. According to the second example, Since there is no need to press-fit the kneaded material 12 from the outside, the opening area of the micro gap can be made as small as possible.

  For this reason, the opening area of the minute gap is narrowed to such an extent that water and / or alcohol in the kneaded material 12 hardly dissipates to the outside of the heat receiving board 10, so that the sealing material 13 is not necessarily used. The encapsulated state of the kneaded material 12 is obtained simultaneously with the connection of the plurality of members.

  Specifically, when the maximum particle size of the powder composition constituting the kneaded product 12 is d, the maximum opening width of the fine gap is 12 d or less, without using the sealing material 13. The encapsulated state of the kneaded material 12 is obtained simultaneously with the connection of the plurality of members. The maximum opening width of the minute gap is preferably 6d or less.

  For example, when the maximum particle size of the powder composition is 150 μm, the maximum opening width of the fine gap is 1.8 mm or less, preferably 0.9 mm or less, and the kneaded material is simultaneously connected with the plurality of members. Twelve encapsulated states are obtained.

  However, the opening width of the minute gap may be increased, and the kneaded material 12 may be additionally press-fitted from the outside after the plurality of members are connected. In that case, similarly to the case of the first example, the exposed portion of the kneaded material 12 on the surface of the heat receiving board 10 is closed with the sealing material 13.

  Hereinafter, the structure of the kneaded material 12 is demonstrated concretely.

  The kneaded product 12 is obtained by kneading a powder composition with water and / or alcohol.

  For the powder composition, for example, one or more selected from carbonaceous raw materials, silicon carbide raw materials, alumina raw materials, siliceous raw materials, alumina-siliceous raw materials, other refractory powders, and metal powders are used. be able to.

  As the powder composition, those having better thermal conductivity than water and alcohol are preferred. Thereby, compared with the case where only water and / or alcohol are enclosed between the heat receiving board 10 and the cooling pipe 11, the thermal resistance between both can be reduced.

  As the powder composition, a carbonaceous raw material, particularly graphite, is preferable because it has not only good thermal conductivity but also acid resistance and alkali resistance. The proportion of the carbonaceous raw material in the powder composition is preferably 60% by mass or more, and more preferably 90% by mass or more.

Further, the powder composition Include the water-soluble polymer. Examples of the water-soluble polymer include methyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, hydroxypropyl cellulose, polyethylene oxide, and polyacrylamide.

  The water-soluble polymer has the following effects (a) to (d).

  (A) Even when a material having poor wettability to water and / or alcohol, such as a carbonaceous raw material, is used in the powder composition, it can be easily kneaded without being separated from water and / or alcohol. Effect.

  (A) The effect of preventing water and / or alcohol from escaping from the kneaded product due to water retention of the water-soluble polymer.

  (C) Even if water and / or alcohol in the kneaded material is somewhat dissipated, the decrease in the thermal conductivity of the kneaded material is suppressed by segregating the particles constituting the powder composition without isolating them. Effect.

  (D) Easiness of application that can adhere to a kneaded product without falling on a smooth surface, and can spread even a narrow gap without separating the powder composition from water and / or alcohol. The effect of giving ease of press-fitting.

  From the viewpoint of obtaining the effects (a) to (d) above, the blending amount of the water-soluble polymer is a proportion of the powder composition, and is preferably 0.5% by mass or more, for example.

  In addition to the above, the powder composition may contain an additive such as a dispersant such as β-naphthalene sulfonic acid soda and a curing agent such as alumina cement. However, it is preferable not to contain a curing agent. By not including the curing agent in the kneaded material 12, the effect of preventing the propagation of cracks from the heat receiving board 10 to the cooling pipe 11 can be made more reliable.

  The amount of water and / or alcohol added is not particularly limited. For example, workability capable of being press-fitted and applied to the kneaded product can be imparted by setting the powder composition to about 5 to 80% by volume with respect to 100% by volume. In addition, as alcohol, monohydric alcohols, such as methanol and ethanol, are preferable.

  In the present specification, the addition amount (volume%) of the kneading liquid is determined based on the loose bulk of the powder composition. The loose bulk refers to the volume occupied by the target powder when the target powder is gently poured into the container.

  The following experiment was conducted using the stave cooler of FIG.

  A lower surface (hereinafter referred to as a heat receiving surface) 10a of the heat receiving board 10 is heated by an electric heater. When the heat receiving surface 10a is stabilized at 800 ° C., about 25 ° C. industrial water is supplied as cooling water from the supply port 11a of the cooling pipe 11 while maintaining the heat generation amount of the electric heater. The flow rate of the cooling water is kept constant, and the cooling water discharged from the discharge port 11b of the cooling pipe 11 is discarded without being circulated.

In this way, the cooling water continues to flow for a certain period of time, and the temperature at the point A in FIG. 1 when the temperature distribution inside the heat receiving panel 10 reaches a steady state, that is, facing the cooling pipe 11 inside the heat receiving panel 10. temperature of the surface (hereinafter, referred to as the heat receiving plate temperature.) T _a and, the cooling water discharged from the cooling pipe 11 temperature (hereinafter, referred to as the water temperature.) measuring a T _B.

Table 1, which is interposed between the heat-receiving plate 10 and the cooling pipe 11 (hereinafter, referred to. Inclusions) to another, showing the the water outlet temperature T _B heat plate temperature T _A. Heat receiving plate temperature T _A is low, the higher the water temperature T _B, which means that higher cooling capacity of the stave cooler.

Example 1 uses a kneaded product obtained by kneading a powder composition composed of scaly graphite: 60% by mass and clay: 40% by mass with an amount of 30% by volume of water. temperature T _a is comparatively low, and since it is relatively high water outlet temperature T _B, it can be seen that the stave cooler is made exhibit good cooling capacity.

  Example 2 uses a kneaded product obtained by kneading a powder composition consisting of scaly graphite: 95% by mass and a thickener: 5% by mass with water in an amount of 30% by volume. Since the ratio of the scaly graphite to the body composition is higher than that of Example 1, the cooling ability superior to that of Example 1 can be exhibited.

  In Example 3, water that is the kneading liquid of Example 2 was changed to alcohol, and although it was slightly inferior to Example 2, it was possible to exhibit excellent cooling ability. From the comparison between Examples 2 and 3, it can be seen that water is preferable to alcohol as the kneading liquid.

  Comparative Example 1 is a comparative example with respect to Example 1, and the composition of the powder composition is the same as that of Example 1. However, since a pitch having poor thermal conductivity was used for the kneading liquid, compared with Example 1, The cooling capacity of the stave cooler is inferior.

  In Comparative Example 2, the proportion of scaly graphite in the powder composition is 100% by mass, which is higher than Examples 2 and 3, but compared to Examples 2 and 3 because a pitch having poor thermal conductivity was used for the construction liquid. And the cooling capacity of the stave cooler is remarkably inferior.

  The comparative example 3 uses only water as an inclusion, and is inferior to the cooling capability of a stave cooler than any of Examples 1-3. In Examples 1 and 2, since the powder composition having higher thermal conductivity than water is used together with water, the thermal conductivity of the entire kneaded product is higher than that of water.

Comparative Example 4 is one using a thin copper plate as a filler, it is impossible to completely fill the small gap, or because of a gap, the heat receiving plate temperature T _A is relatively high, and the water temperature T _B Relatively low. That is, the cooling capacity of the cooling pipe is not reflected in the cooling capacity of the stave cooler.

  Although the present invention has been specifically described above, the present invention is not limited to this. For example, it will be apparent to those skilled in the art that various combinations and improvements are possible.

  DESCRIPTION OF SYMBOLS 1 ... Stave cooler, 1a ... Heat receiving board, 1b ... Cooling pipe, 2 ... Indeterminate refractory, 3 ... Iron skin, G ... Fine gap, 10 ... Heat receiving board, 10a ... Heat receiving surface, 11 ... Cooling pipe, 11a ... Supply Mouth, 11b ... discharge port, 12 ... kneaded product, 13 ... sealing material.

Claims (3)

(A) preparing a cooling pipe through which a cooling medium flows, and a heat receiving plate attached to the object to be cooled and securing a minute gap between the cooling pipe outer surface and covering the cooling pipe; and (b ) wherein the minute gap, the powder composition have a step of encapsulating the kneaded product kneaded with water and / or alcohol, cooling structure the powder composition, characterized in that it comprises a water-soluble polymer How to make a body.   The manufacturing method according to claim 1, wherein the powder composition contains 60% by mass or more of graphite. The said kneaded material used for the manufacturing method of Claim 1 or 2 .

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