JPS61261279A - Manufacture of heat insulative refractory block - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to.

PRIOR ART It is known to line high temperature processing enclosures with insulating particles. Refractory bricks are primitively used as the heat insulating particles. Although widely used, this technology suffers from high cost, high liner weight, susceptibility to thermal shock, and, in some applications, high heat capacity and heat loss.

Recently, it has been proposed to replace traditional refractory bricks with fibrous sheets. First, in the first conventional example, a backing sheet whose base material is a heat-resistant sheet such as ceramic fiber is wrapped around the wall. These sheets are
It is fixed parallel to the wall of the furnace with metal rods. These metal bars are
It bridges the heat and is susceptible to corrosion, accelerating corrosion of the walls of the furnace itself and peeling of the backing sheet.

``Problems to be Solved by the Invention'' In order to eliminate these drawbacks, in the second conventional example, a heat-resistant material whose back side is fixed to the wall and whose ends are laminated or folded is needed to eliminate heat bridging. It is proposed to use a laminate of fiber sheets. This technique requires the use of an expensive high-temperature heat-resistant sheet that uniformly insulates from the high-temperature surface to the low-temperature surface even in the low-temperature region, which unnecessarily increases the cost.

GB 1296681 proposes laminating successive layers of foamed ceramic fibers by means of vacuum.

In this method, a graded stacking is obtained without interpenetration of the main layers, but the actual thickness is limited by the suction technique within the layers.

"Means for Solving the Problems" The purpose of the present invention is to change the material and porosity of the high temperature side that contacts the furnace and the low temperature side that contacts the room temperature environment, so that the material can be used as a lining for furnaces, etc. An object of the present invention is to provide a method for manufacturing a heat-insulating fireproof block.

According to this manufacturing method, a first suspension containing a first heat-resistant fiber and at least one type of second suspension containing a second heat-resistant fiber are provided.
and a suspension of filtration filters are installed to plug the separator, and these first and second suspensions each contain a low proportion of ceramized particles, and these suspensions are at least localized in the vicinity of the separator during removal of the separator. the water is simultaneously discharged through a filtration filter to form a block which, after drying, is heat treated until the ceramized particles are combusted and sintered.

In other words, the present invention combines the suspensions with a separating plate in order to, on the one hand, associate the ceramized particles within each suspension and, on the other hand, induce interpenetration of each suspension in the vicinity of the separation region. It consists of removing the separator plate with nearby stirring, simultaneously removing the water, and finally heating to a temperature sufficient to cause the ceramized particles to burn out and become ceramic.

Indeed, these heat-resistant fibers are advantageously ceramic fibers. In a first embodiment, the ceramized particles have the advantage of not increasing the electrical conductivity of the final product, for example.
tb kaolin, or clay particles that provide water swelling benefits, especially inorganic particles such as expanded clay particles such as bentonite.

In a second embodiment, the ceramized particles are also paper epals or paper fibers, especially waste paper, which facilitate the handling of the blocks before combustion and provide good resistance.

This paper fiber is contained in an amount of 1 to 5% by weight of the dry heat-resistant fiber. If this ratio is less than 1%, sufficient ash, or binding component, cannot be obtained after heating.

If this ratio is more than 5%, the bonding components become like cardboard and crack after drying.

Although the ceramic fiber concentrations of these suspensions differ from one another, the amount of suspension poured into each compartment is the same to prevent overflow from one compartment to another.

Bulky fibers are preferably used and dispersed in water in a known manner.

To prepare each suspension, first a suspension is made containing especially bulky heat-resistant fibers, possibly high-temperature fibers with added wetting agents, and then a separate suspension containing ceramized particles is added to this suspension. suspensions are mixed.

The concentration of each suspension is between 50 and 80 grams per liter; below this the amount of water discharged is excessive, and above this the fibers are insufficiently dispersed.

These suspensions are stirred in a known manner, for example by means of a vibratory stirrer or by forming comb-like cross-sections on the side walls or lower end of the separator plate, during removal of the separator plate.

During pouring of the suspension into the compartments of the vat, the filtration filter at the bottom of the vat is occluded with the top surface of the water.

This water is removed in a drain process after removing the separator plate.

After draining the water and before drying, the block is compressed, for example in stages, in a hydraulic compressor. Also, during drainage, the block can be agitated to improve fiber dispersion.

The ash obtained from the combustion of paper fibers is at least 1000
It is sintered at a temperature of C.

After sintering, the cooled block is coated with an inorganic dry bonding composition, such as an aqueous alumina phosphate solution, and then stove dried.

"Example" Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

1 to 4 show an apparatus for carrying out the method of the invention. The device essentially comprises a butt 1 which is open at the top 2 and whose bottom 3 is a highly perforated but resistive grid through which the dispersed substance cannot pass. This bat l is made, for example, from an iron plate and has an optimal number of slots 4,5,6,7 formed at its two opposite ends, these slots 4 and 6
Alternatively, separation plates 10 made of iron plates are inserted between 5 and 7 to form compartments 8 and 9. This removable separating plate 10 has dimensions corresponding to the internal cross-section of the bat l, and tabs 11 and 12 protruding from both sides of the upper part to be inserted into the slots 4 and 6 or 5 and 7 are formed on the separating plate. 10 can be easily removed. Furthermore, a second slightly curved transverse plate 13 that contacts the filter 15 located at the bottom 3 of the vat 1 is fixed, for example, by welding, to the lower part of the separating plate IO. This transverse plate 13 is formed with a plurality of comb-shaped main ends 14 . As already mentioned, the bottom 3, consisting of a highly perforated grid, is covered with a metal filtration filter 15 with a mesh size of 0.5 mm.

The bottom 3 of the vat l holds the filter 15 and the main body 17
A flange 16 is provided to connect to the flange 16. This main body 17 is supported by legs 18 and 19 and is provided with a drain valve 20 on the front side.

EXAMPLE 1 A 10 liter packet contained 500 grams of 1400 degrees Celsius endurance temperature ceramic fiber. This ceramic fiber has a length of around ten and is called La by the trade name of K2O.
large Refractaire
It is sold by Le Laugh Tile.

At the same time, 25 grams of paper industry pulp (paper industry fiber) obtained from waste paper is mixed into 0.5 liters of water.

This aqueous solution of paper fibers was mixed with an aqueous solution of ceramic fibers at room temperature to add 500 grams of ceramic fibers and 2
A 10° 5 liter first suspension containing 5 grams of paper fiber is prepared.

Similarly to the above, Lafarge
4 of 500 Durhams sold by Refra Tile
1 containing 5 ceramic fibers and 25 grams of paper fibers.
0.5 liters of a second suspension is prepared.

Next, a first suspension based on K60 ceramic fibers is supplied to the first compartment 8, and a second suspension based on K45 ceramic fibers is supplied to the second compartment 9. Ru. The bottom 3 of the vat 1 where the filter 15 is placed is
The camphor of the main body 17 is sealed with a sheet of water filled with water.

This sheet of water thus seals between the two compartments 8 and 9, and the first and second suspensions supplied to each compartment 8 and 9, respectively, are separated by the separator plate 10. The separating plate 10 is then removed by lifting the tabs 11 and 12. In this lifting action, the comb-like ends 14 of the transverse plate 13 locally stir the first and second suspensions in the compartments 8 and 9 in the vicinity of the separator plate 10, forming a crow; The suspension near the separation plate IO is mixed. At the same time, the drain valve 20 is opened and the suspension is drained of water very quickly since it does not hold water.

If necessary, the upper part of the fabric mast (block) to be produced is compressed by means of a template to obtain a flat top surface.

The fiber mast is then pulled through by means of a filter 15, the flange 16 being opened, and placed on the board. The fiber mast is stove dried at 90 degrees Celsius for 4 hours. The fiber mast after drying has dimensions of 21 x 29 cm, a thickness of 70 mm and 0.2 g/cm3, as shown in Figure 5. This dried fiber must was then heated in an oven at 1000 degrees Celsius for 3 hours. This temperature first causes the paper fibers to burn and then ceramizes the ash obtained during combustion, which is interconnected with the ceramic fibers of each suspension. The obtained block 25 shown in FIG. Temperature 6
a first portion 26 made of 0.0 ceramic fiber; a second portion 27 formed of 45 ceramic fiber forming a low-temperature surface on the opposite side of the first portion 26 and having a lower durability temperature than the above; A second section is an interpenetrating section formed around the bonding surface 29, and more particularly, an intermediate section 28 consisting of a first region enriched with K60 ceramic fibers and a second region enriched with K45 ceramic fibers. It consists of

The fibers of these three regions are uniformly interconnected by the ceramic Hokuten produced by the combustion of paper fibers.

Second Example A second example was carried out similarly to the first example, replacing the K60 ceramic fibers with 10 cm lengths of ceramic fibers sold by Morgan under the trade name Cerachrome. A block 25 similar to that of the first example was obtained, but the durability temperature was improved to 1450 degrees Celsius.

Third Example The third example uses K45 ceramic fibers with a concentration reduced by half.
That is, the same procedure as in Example 1 was carried out except that 258 g/liter of 60 ceramic fiber was used instead of 50 g/liter.

After being compressed to a uniform thickness, the block 25 had two surfaces with different densities.

Thus, the dense layer constitutes the cold surface and the less dense layer constitutes the hot surface.

Fourth Example The fourth example was carried out in the same manner as the first example, with the concentration of paper fibers varied from one section to another.

The compartments supplied with paper fibers with good binding strength provided better adhesion.

A fifth example batt is divided into three identical main compartments, in which a suspension containing 300 grams of 60 ceramic fibers and 15 grams of paper fibers is placed in 6 liters of water. The second compartment was filled with a suspension containing 300 grams of 45 ceramic fibers and 15 grams of paper fibers, also in 6 liters of water, and the third compartment was similarly filled with Six liters of water was filled with a suspension containing 300 grams of glass wool and 15 grams of paper fibers.

The block 25 has dimensions of 7X21X29 cm and is composed of a layer based on high temperature 60 ceramic fibers,
The cold surface consists of a layer of glass wool.

In this case, sintering is carried out after assembly in such a way that the temperature remains compatible with the glass wool.

Sixth Example The sixth example was carried out in the same manner as the fifth example by varying the volume of the main compartment in order to vary the thickness of each layer.

Seventh Example The block 25 of the first example was immersed in an organic bonding composition consisting of an aqueous solution of alumina phosphate before and after sintering. After soaking, the whole was dried at 90° C. for 2 hours.

Eighth Example The eighth example was implemented in the same manner as the first example with the following modifications. An ultrasonic generator was attached to the outer wall of the vat l, and this ultrasonic generator was energized for several seconds after the separation plate lO was removed. As a result, the ultrasound causes the suspension to be actively stirred, inducing more regular interpenetration of the suspension than with comb-like ends, and thus within the region 28 as a function of stirring time. A regular fiber concentration gradient was induced.

Ninth Embodiment In the ninth embodiment, after sintering, an inorganic filler such as kaolin is added to each suspension to change the properties (porosity, electrical conductivity, mechanical strength, workability, etc.) of a portion or the entire block 25. The procedure was carried out in the same manner as in the first example by adding the suspension or either of them.

1st O Example In the 10th example, K60 ceramic fiber is used at an endurance temperature of 1
Example 1 was carried out in the same manner as in the first example, substituting ceramic fibers sold by Carporundum under the trade name Fibermax, 600 [fC], in which the 45 suspension was
It is poured into the first section 8 with dimensions of 0 x 650 mm, and the second
Fibermax suspension is 250X310X650m
It was poured into a second compartment 9 with dimensions m.

The obtained block 25 has a low temperature surface 27 (0,26,
Hot surface 26 had a density of 0.15 and a thickness of 225+am.

EXAMPLE 11 Example 11 was carried out similarly to Example 1O, except that the fiber mast was compressed in a hydraulic compressor for 3 minutes at a pressure of 600 kg/sq Cl11 before drying after draining.

The resulting block 25 has a cold side 27 of 0.35 (instead of 0°26) and a hot side 26 (instead of 0.15).
It had a density of 0.20 and a thickness of 170 mm (instead of 225).

This block 25 can be easily cut, which would otherwise not be possible, and thus makes it possible to stack it in an arch.

Effects of the Invention The method according to the invention offers a number of advantages compared to previously known methods. For example, even with fairly large dimensions, optimal geometries can be manufactured easily, thus saving processing time.

Only the high temperature surface is made of high heat resistant ceramic fibers, so
The overall manufacturing cost can be reduced.

After heating, the ceramic Hokuten forms a uniform inorganic bond, improving its mechanical strength.

For example, the arch element in the furnace can be formed only by selecting the butt.

The presence of paper fibers facilitates handling, allowing the blocks to be stacked to form the furnace itself and then finally sintered.

We can manufacture specifications, predetermined shapes, and small blocks according to your requirements.

As a result, these blocks can be used to insulate the linings of furnaces operated at high temperatures.

[Brief explanation of the drawing]

FIG. 1 is a representative schematic diagram of an apparatus for carrying out the method according to the present invention, FIG. 2 is a sectional view taken along line 1-1 of the apparatus shown in FIG. 1, and FIG. 3 is a sectional view taken along line ■-■ of the apparatus shown in FIG. 4 is a perspective view of a removal plate of the device of FIG. 1, and FIG. 5 is a schematic perspective view of a heat insulating block according to the invention. 9゛・J l...bat, 2...top, 3...bottom, 4゜5.
6.7... Slot, 8.9... Section, 10...
Separation plate, 11.12...Tab, 13...Transverse plate, 1
4... Multiple ends, 15... Filter, 16...
・Flange, +7...Body, 20...Valve, 25...
·block. Applicant Prode Cellulosec Figure 4

Claims (10)

[Claims] (1) preparing a first suspension containing a first heat-resistant fiber and at least one type of second suspension containing a second heat-resistant fiber; are respectively poured into compartments in a vat partitioned by removable separation plates, and a filtration filter is attached to the bottom of the vat to temporarily block the path of the suspension, and the first and second suspensions each contain a low proportion of ceramized particles, and during removal of said separator plate, their suspension is agitated at least locally in the vicinity of said separator plate, and at the same time water is drained through said filtration filter. , forming a block, which block, after drying, is heat treated until the ceramized particles are combusted and sintered. (2) The method for manufacturing a heat-insulating fireproof block according to claim 1, wherein the first and second heat-resistant fibers are ceramic fibers. (3) The method for producing a heat-insulating fireproof block according to claim 1 or 2, wherein the ceramicized particles are paper fibers. (4) The paper fibers are 1 to 5 when the heat resistant fibers are dried.
% by weight. The method for producing a heat insulating fireproof block according to any one of claims 1 to 3. (5) The method for producing a heat-insulating fireproof block according to claim 1, wherein an inorganic filler is added to the at least one type of second suspension. (6) The insulation refractory according to claim 1, wherein the separator plate has an end that contacts the filtration filter and a series of transverse ends that form a stirring member during removal of the separator plate. How to make blocks. (7) The block to be dried after the discharge is at least 1
2. The method of manufacturing a heat insulating refractory block according to claim 1, wherein the block is sintered at 000 degrees Celsius. (8) Although the concentrations of the suspensions in the compartments are different from each other, the amount of suspension poured into each compartment is the same to prevent overflow from one compartment to another. A method for producing a heat insulating fireproof block according to claim 1. (9) The method for producing a heat-insulating fireproof block according to claim 1, wherein the block is coated with an inorganic dry bonding composition. (10) The method for manufacturing a heat insulating fireproof block according to claim 1, wherein the block is compressed before drying after being discharged.