JPH07329044A - Method for curing of ceramic - Google Patents

Abstract

PURPOSE:To uniformize distribution of temperature in raising temperature by shortening time for raising temperature in an autoclave curing method for ceramics like an exterior wall material or the like. CONSTITUTION:At least a plurality of pieces of molded products to be cured 2 are contained by being laminated laterally in an autoclave 1. At first water 3 reserved in a bottom part of the autoclave 1 is heated by high pressure steam. Besides, temperature is raised while the hot water 3 is sprayed on an molded product 2 with a water spraying device 4. Since raising of temperature in a central part of the molded products to be cured piled in a block manner is accelarated thereby, time for raising temperature can be extremely shortened, and distribution of temperature in raising temperature of each molded product is uniformized. Therefore curing reaction rate is uniformized, and the quality of the product can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for curing a ceramic product such as an outer wall material containing cement or calcium silicate as a main raw material.

[0002]

2. Description of the Related Art A conventional curing method of this type is, for example, as shown in Japanese Patent Application Laid-Open No. 54-14422, heating a plate-shaped product to be cured by heating only in high temperature and high pressure steam in an autoclave pot. It was a pressure. FIG. 6 shows this conventional method, in which a plate-shaped molded product 2 is vertically set in an autoclave kettle 1 and a large number of the molded products are housed in a block form and heated and pressurized by high-pressure saturated steam. , Was to accelerate the curing of the pre-cured plate material.

[0003]

However, in the above-mentioned conventional method, the gap A between the plate members 2 stacked in a block shape is used.
Since it is difficult for steam to pass through, it is difficult for the temperature in the center of the block to rise, and it takes time to raise the temperature, and in the molded product 2 located near the center of the block, the temperature distribution during temperature rise becomes uneven. There is a problem in that the curing reaction speeds of the respective parts are different from each other, which adversely affects the quality such as strength. Therefore, conventionally, as shown in FIG. 4 (b), the temperature rising rate is made gentle, and a soaking and keeping time of about 2 hours is provided during the temperature rising to wait for the temperature in the block to become uniform. Therefore, the temperature is further raised to a predetermined temperature and pressure. However, even during the soaking time, the hydration / hardening reaction proceeds under a non-uniform temperature distribution, which adversely affects the strength distribution of the product, and the soaking keep prevents the molded product from being hardened due to its nature. Since it is performed at such a low temperature, it consumes extra fuel and time, resulting in an increase in product cost. Moreover, in order to solve this problem, the molded product 2
It is conceivable to increase the gap A between them, but this requires a means such as a spacer and also has a drawback that the volume ratio is lowered and the manufacturing cost is also increased. In view of the above, the present invention, in the above-described method for curing a ceramic product, shortens the temperature rising time and reduces the temperature distribution during temperature rising without lowering the storage volume ratio of the cured product 2 in the autoclave kettle 1. The purpose is to prevent deterioration of product quality due to uniformity.

[0004]

As shown in FIG. 1, in a method for curing a ceramic product according to the present invention, for example, a plate-shaped product 2 to be cultured is vertically and block-shaped in an autoclave pot 1. Water that is stored in a stack and first stored in the bottom of the pot 1
Is heated with high-pressure steam, and this hot water 3 is sprayed with a sprinkler 4
The temperature is raised while being sprayed on the molded product 2 by means of which the hot water 3 is discharged to the outside of the kettle 1 and heated and pressurized only by the high-pressure steam, and the molded product 2 stacked in a block shape is heated. The characteristic feature is that the temperature rise time is shortened by performing the temperature rise with hot water, and the temperature distribution of each molded product 2 during the temperature rise is made uniform.

[0005]

In the conventional method, since there is no pressure difference between both ends of the gap A of the plate-shaped molded products 2 closely stacked with each other,
The flow of steam was difficult to form in the gap A, and rather, the convection of steam was hindered by the water droplets held in various places in the gap A by the capillary phenomenon. According to the method of the present invention, hot water is sprayed on the upper surface of the molded block when the temperature is raised, and a flow of hot water due to gravity is formed in the gap A just as in the atmosphere. Since the temperature rise of the central portion is promoted, the temperature rise time is shortened, the energy saving effect is obtained, and the temperature distribution of each molded product 2 is made uniform, and the curing reaction speed is also made uniform. The quality of can be improved.

[0006]

FIG. 1 shows an embodiment of an autoclave apparatus used in the method of the present invention. Inside a horizontal cylindrical autoclave pot 1, a rail 6 on which a basket-shaped carriage 5 runs is laid at the bottom. On this trolley 5, usually several 10 sheets of pre-cured building board materials 2 which are bundled in the lateral direction are bundled and placed with the board surface vertical. A saucer 4 made of a perforated plate is provided in the upper portion of the pot 1 as a water sprinkler.
Pipes 7 having hot water outlets arranged in rows are provided on both side walls of the pipe 8. Most of the hot water jetted from the pipes 8 rises along the side walls and falls into the receiving tray 4. It is sprinkled on the block by the perforated plate. The water accumulated at the bottom of the kettle 1 is heated by the high-temperature high-pressure steam ejected from the steam nozzle 8 projecting from the bottom surface, and is supplied to the hot water ejection pipe 8 through the heat-resistant pump 9 installed outside. It A boiler 10 supplies steam to the steam nozzle 8.

FIG. 3 shows a result (a) tested by the method of the present invention using the above autoclave apparatus in comparison with a conventional method (b). The plate-shaped molded product 2 is a kneaded molded product of 40% by weight of cement and 60% by weight of siliceous material, which has been steam-cured at atmospheric pressure. A plate of 100 mm in length, 1200 mm in length and 3600 mm in width is bundled into a block shape. It is tightened. 4 of this block
A temperature sensor was arranged between the 9th sheet and the 50th sheet as shown in FIG. 2 to measure the temperature at each point in the temperature rising process. (A)
(B) Both were heated with saturated steam of 2 kg / cm 2 G for 2 hours. At this time, in (a), a small amount of water was collected at the bottom and heated with steam to be used as hot water. , (B), only steam was used. In both cases, the constant temperature was maintained only by high-pressure steam and the condensed water was drained by the drain pipe.

In the case of the hot water temperature rise of (a), the temperature at each measurement point rises to the predetermined temperature almost at the same time, but in the steam temperature rise of (b), the temperature rise at each point varies. In particular, the point d did not reach the predetermined temperature during the heating time of 2 hours. Further, in (b), the fact that the temperature at point e oscillates is considered to be due to the effect of water droplets held between the plates due to the capillary phenomenon. From this test result, when performing the curing of the plate materials stacked in a block shape by the autoclave method, the method of the present invention using hot water is more advantageous than the conventional method using only high temperature and high pressure steam at the time of temperature rise. It is clear that the temperature distribution and the time required for raising the temperature are excellent. For this reason, conventionally, as shown in FIG. 4 (b), a soaking time was required during the temperature raising. As a result, the temperature rising time can be significantly shortened as shown in FIG. In the above embodiment, the temperature is maintained only by steam in the soaking and keeping process after the temperature is raised, but hot water may be continuously used in the keeping process. Further, even in the temperature lowering process, if hot water is used to gradually lower the temperature, the temperature distribution can be made uniform and the water can be prevented from being excessively evaporated.

[0009]

As described above, according to the method of the present invention, in the autoclave kettle 1, since the temperature rise of the central portion of the sheet to be cured which is stacked and bound in a block shape is promoted, the temperature raising time is increased. There is an advantage that it can be significantly shortened, and that the temperature distribution of each plate material at the time of temperature rise is made uniform, so that the curing reaction rate is made uniform and the quality of the product can be improved. In the above embodiment, the plate-shaped cultured product 2
5 shows a block formed by stacking a plurality of blocks in the horizontal direction. For example, as shown in FIG. 5A, when brick-shaped molded products 2 are stacked vertically and horizontally to form a block, As shown in b), when a block is formed by stacking a plurality of roof tiles stacked in a lateral direction in a plurality of stages,
It is obvious that the steam does not cause a pressure difference between the upper and lower ends of the gap A, but the hot water can have the same effect as that of the plate-shaped molded article in that it flows down through the gap A by gravity.

[Brief description of drawings]

FIG. 1 is a schematic system diagram of an apparatus used in the method of the present invention.

FIG. 2 is a diagram showing temperature measurement points of a plate material during the temperature rising test.

3A and 3B show results of a temperature rising test, in which FIG. 3A is a graph of a temperature change at each measurement point according to the method of the present invention and FIG.

4A is a temperature change diagram in an autoclave according to an embodiment of the method of the present invention, and FIG. 4B is a temperature change diagram according to a conventional method.

5 (a) and 5 (b) show another embodiment of the cured product in the method of the present invention.

FIG. 6 is a schematic system diagram of a conventional device.

[Explanation of symbols]

 1 Autoclave pot 2 Formed product 3 Hot water 4 Sprinkler or saucer 5 Truck 6 Rail 7 Hot water nozzle 8 Steam nozzle 9 Heat resistant pump 10 Boiler

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor St. Takahashi 4-1-2 Hiranocho, Chuo-ku, Osaka City Osaka Gas Co., Ltd. (72) Inventor Masaru Watanabe 4-1-2 Hiranocho, Chuo-ku, Osaka In Osaka Gas Co., Ltd. (72) Inventor Ichiko Yamada 1-47 Shishitsu Higashi, Naniwa-ku, Osaka City Stock Company Kubota (72) Inventor Shinobu Iida 1-47 Shikizu Higashi, Naniwa-ku, Osaka City Shares Company Kubota (72) Inventor Tadashi Yoshii 1-47 Shikitsu Higashi 1-47, Naniwa-ku, Osaka Stock Company Kubota (72) Inventor Hiroshi Yato 1-247 Shikitsu-Higashi Naniwa-ku, Osaka Kubota Corporation Within

Claims (3)

[Claims] 1. An autoclave kettle in which a plurality of products to be cultivated to be cultivated are stacked at least in the lateral direction, and the water stored in the bottom of the kettle is first heated by high-pressure steam, and the hot water is sprinkled to form the molded product. A method for curing a ceramic product, characterized in that the temperature is raised while being sprayed on the top, and then the hot water is discharged to the outside of the kettle and heated and pressurized only with high-pressure steam. 2. An autoclave kettle is provided with at least a plurality of products to be cultivated that are stacked in the lateral direction, the water stored in the bottom of the kettle is heated by high-pressure steam, and the hot water is sprayed onto the molded article by a sprinkler. A method for curing a ceramic product, characterized in that the temperature is raised while being sprayed on the substrate, and thereafter the hot water is sprayed while being heated and pressed at a constant temperature. 3. The method for curing a ceramic product according to claim 1, wherein the hot water is sprayed even in the temperature lowering process.