JPS5849586B2 - How to construct a fireproof wall in a coke oven - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for constructing a fireproof wall in a coke oven, and more specifically, a method for constructing a fireproof wall in a coke oven, and in particular, a method for constructing a fireproof wall in various parts of a coke oven, particularly in parts exposed to high temperatures such as a heating chamber and a carbonization chamber. The present invention relates to a construction method suitable for constructing fireproof walls.

The heating chamber, carbonization chamber, etc. of a coke oven (hereinafter referred to as the "heating chamber, etc.") are constructed mainly of fireproof bricks such as silica bricks because they are exposed to high temperatures. This causes damage to various parts.

If the damage to the heating chamber, etc. is minor, temporary measures such as installing a hot mortar ring may be sufficient, but if the damage is severe, it may be necessary to partially or completely remove the fireproof wall in the affected area. It must be dismantled and updated.

Fireproof walls are constructed by joining firebricks together with mortar.
The temperature is then gradually raised, but it is necessary to absorb the expansion of the refractory bricks as the temperature rises.

That is, firebricks thermally expand vertically and horizontally as the temperature rises, but if this expansion is not absorbed, unreasonable force will act on the joined firebricks, causing cracks in the firebricks.

These cracks are more noticeable in the lower part of the fireproof wall, where a considerable load is applied.

Such problems also occur when partially renewing fireproof walls by inserting new bricks between old bricks that have already expanded. Although a number of methods are known, a commonly used method is to mix vermiculite, asbestos, ceramic fiber, etc. into mortar and absorb expansion by compressing some of these additions.

However, in the case of the above method, a fairly large load (e.g. 5~lOk#/f
fl), but depending on the location of the refractory wall, it may not be able to substantially absorb the expansion.

Furthermore, when a certain amount of vermiculite or asbestos is added, their heat resistance is low, making them unsuitable for use in fireproof walls of heating chambers and the like exposed to high temperatures.

Furthermore, when the added material is ceramic fiber, it lacks flexibility, which makes it difficult to handle the mortar.

In view of the above-mentioned circumstances, the inventors of the present invention have conducted extensive studies and found that by using a refractory mortar containing fine particles of a specific combustible substance, the fine particles are burnt out when the temperature rises, creating pores. It was discovered that these pores have a sufficient cushioning effect to absorb even relatively small loads,
The invention has been completed.

That is, the gist of the present invention is that when constructing the fireproof walls of various parts of a coke oven by joining firebricks with mortar, it is water-insoluble and has an ignition temperature below the temperature of the firewall of the coke oven during operation. A method for constructing a refractory wall in a coke oven, characterized in that a refractory mortar made of fine particles of a commercially combustible solid is used as a bonding agent.

The present invention will be explained in detail below.The construction method of the present invention uses conventional construction methods as they are, except that combustible solid particles are mixed with fireproof mortar as a bonding material. Can be done.

Further, the composition of the refractory mortar containing the fine particles of the above-mentioned flammable solid may be of any conventionally known composition.

For example, the main component is refractory material powder (for example, silica powder, etc.), and optionally, machi plastic clay, binder (for example, inorganic substances such as alkali silicates, phosphates, borates, sulfates, carbonates, etc.). ) Organic thickeners (e.g., starch, alginates, gum arabic, natural polymers such as funori, semi-combined products such as methyl cellulose, carboxymethyl cellulose, starch, etc., composites such as polyvinyl alcohol, sodium polyacrylate, etc.) (e.g.) is used.

These materials are further blended according to the method of the present invention, and are water-insoluble, and the temperature of the refractory wall of the Ix furnace during operation (generally, the temperature of the refractory wall of the heating chamber is 1,000 to 1,500°C, and the temperature of the refractory wall of the carbonization chamber is 1,000 to 1,500°C, Solid combustible materials having an ignition temperature below 800-1,300°C include natural fibers such as cotton, linen, wool, silk, etc., recycled fibers such as viscose fibers, etc.
Synthetic fibers such as polyamide fibers, polyester fibers, Acrylic fibers, polyolefin fibers, etc., organic fibrous materials such as pulp fibers, sawdust, crushed rice husks, finely shredded newspapers, etc., polyethylene, polypropylene, polyvinyl chloride Examples include finely cut films such as polystyrene, and crushed pieces of composite resin as described above.

The size of these flammable substances must not be excessively large.

In other words, if it is too large, it will be difficult to disperse it well in the mortar matrix, and this compound will eventually burn or carbonize, forming pores in those areas, and the expansion volume of the refractory brick will increase. This is because it is desirable that the pores are uniformly dispersed in the mortar joints as small pores.

The specific size of the combustible material is determined because when using mortar as a joint, the thickness of the joint varies depending on the size of the refractory bricks to be joined and the location of construction (the standard joint thickness is approx. The size of the combustible material can vary depending on its thickness (the average fiber length is 207IL1n or less (lower limit). is 0.1 mvt
) with an average fiber diameter of 0. 8
mm or less (thin ones such as 0.01 mm are also acceptable)
It is desirable that

It is preferable that substances other than fibers have a similar size.

The amount of the combustible material added to the mortar is selected mainly depending on the coefficient of thermal expansion of the refractory bricks to be joined.

Usually, it is selected from within the range of 1 to 70 parts by weight based on the weight of the total formulation.

Figure 1 shows the expansion coefficient of an example of the refractory brick (silica brick) to be joined.

In FIG. 1, the vertical axis is the coefficient of linear expansion of the brick (d), and the horizontal axis is the temperature ('CXIOO).

As is clear from the curve shown here, the expansion rate of this test brick rapidly increases from around 200℃, and
Significant expansion stops near 00°C, and almost no expansion occurs at temperatures above about 700°C.

If this test brick is used to construct a furnace wall, the joints will be 2
It is most preferable that the contraction starts at around 00°C and that the contraction of the joint increases in response to the expansion of the brick which increases as the temperature rises.

That is, it is essential that the ignition temperature of the town refueling material blended into the mortar used in the method of the present invention is below the temperature of the refractory wall of the coke oven in operation, but it is particularly preferable that the ignition temperature It has an ignition temperature below the starting temperature.

The above-mentioned concrete examples of injected materials generally fall under this category and are preferable.

As mentioned earlier, the joint has a certain thickness, and holes are gradually formed inward from the outer surface of the joint layer, so it can accommodate the gradually increasing expansion of the bricks. and can absorb this.

By appropriately selecting the type of combustible material, the size of the fine particles, and the addition ratio according to the coefficient of thermal expansion of each type of refractory brick, the thickness of the mortar joint, etc.
It can absorb the thermal expansion of firebrick and prevent problems such as joint cracks that occur in the past.

Furthermore, since small pores are uniformly distributed and shaped inside the joint, a high degree of shrinkage can be obtained, which can be shrunk by a load or stress that is not as large as that shown in the left from any direction.

Furthermore, since the combustible material to be blended can be extremely small, the workability of the mortar containing it will not be impaired.

Furthermore, since this compound burns and the pores that have formed are crushed and disappear, the heat resistance of the mortar joints and other properties of the mortar are not impaired.

Next, embodiments of the present invention will be described.

Example A siliceous mortar base material consisting of siliceous powder, plastic clay powder, organic glue (carboxymethyl cellulose), and binder (alkali silicate) was coated with fibers having a fiber length of 0.5 to 0. Pulp fibers having a diameter of 1 mm and a fiber diameter of 0.02 mm (ignition temperature 200°C) were blended in the following proportions (parts by weight).

In the sample in the table above, A, B and C are included in the present invention. D is a conventional mortar.

After removing the refractory bricks from the damaged parts of the coke oven using the mortars A, B, and C above, we installed new refractory bricks, repaired the construction, and resumed operation, but no problems occurred. Ta.

Furthermore, the shrinkage ratio of the joints using the mortars A, B, C, and D above at each temperature was measured.

The results are shown in FIGS. 2 and 3.

In FIGS. 2 and 3, the vertical axis represents the shrinkage ratio (D), and the horizontal axis represents the temperature (°CXIOO).

Figure 2 shows the case when the load is 0.5kg/ffl, and Figure 3 shows the case when the load is 2. This is the case of 0 kg/crit.

In the figure, a value below 0 on the vertical axis, that is, a negative value, is the degree of contraction, and a value above 0 is the degree of expansion.

The town shrinkage rate was measured using the following method.

(a) 65 meters x 65 meters from JIS S-2 standard size brick
Cut out two specimens with a size of mX20mrn, and
A 65 mm surface was joined with a joint thickness of 5 using the shrinkable mortar shown in the example of the present invention, and a test piece was prepared after drying at 105° C. for 24 hours.

(Explanation) 0. A load of 5 kgf/1 to 2.0 kgf/1 is applied to the test piece (a) and heated at a temperature increase rate of 2°C/min, and the change in sample height (ie, shrinkage ratio) is measured.

As is clear from FIGS. 2 and 3, the mortar produced by the method of the present invention has a similar increase in shrinkage at each temperature corresponding to the thermal expansion coefficient of the refractory brick shown in FIG.

Therefore, it is extremely appropriate to use the mortar of the above-mentioned Example formulation for the refractory brick shown in FIG.

On the other hand, the conventional mortar D tends to expand and cannot be used.

What has been explained above and shown in the examples are typical examples to help the understanding of the present invention, and the present invention is not limited to these examples, and other examples may be used within the gist of the invention. Changes and variations are possible.

[Brief explanation of the drawing]

FIG. 1 is a chart showing the coefficient of thermal expansion of an example of a refractory brick used for constructing a coke oven refractory wall, where the vertical axis is the coefficient of linear expansion (D) and the horizontal axis is the temperature (° C.XIOO). 2 and 3 are charts showing the thermal shrinkage ratio of joints using mortar shown in the embodiment of the method of the present invention, in both of which the vertical axis is the shrinkage ratio (4), and the horizontal axis is the temperature (4). ℃XIOO). In the figure, A, B, C, and D are the thermal shrinkage rate curves of the mortar joints of samples A, B, C, and D described in the Examples section of the method of the present invention, respectively.

Claims (1)

[Scope of Claims] 1. When constructing the fireproof walls of various parts of a coke oven by joining firebricks with mortar, it is necessary to use a material that is insoluble in water and has an ignition temperature below the temperature of the firewall of the coke oven during operation. A method characterized in that a refractory mortar containing fine particles of combustible solid is used as a bonding material. 2. The method according to claim 1, wherein the combustible solid is an organic fibrous material.