JPH068202B2 - Ceramic sound absorbing body manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a ceramic sound absorbing body applied to a sound absorbing body of a silencer.

[Conventional technology]

Conventionally, as a sound absorbing material for a silencer, a maintenance sound absorbing material such as glass wool having excellent sound absorbing characteristics has been widely used.

[Problems to be Solved by the Invention] However, the maintenance type sound absorbing material has a drawback that complete water removal becomes difficult once water is absorbed by water vapor or rainfall, and the sound absorption rate is remarkably lowered by water absorption. Further, the maintenance type sound absorbing material poses a problem of scattering of the sound absorbing material under the environment where it is exposed to a high temperature and high speed air flow.

As described above, the fibrous sound absorber has many drawbacks as a sound absorbing material for a silencer that absorbs noise emitted from an exhaust pipe that discharges steam and high-temperature exhaust gas discharged from a factory or the like.

Ceramic sound absorbing materials are being used to improve these drawbacks.

The present invention provides a ceramic sound absorbing material capable of improving the above drawbacks,
It is intended to provide a method that can be manufactured at low cost.

[Means for solving problems]

The present inventors added low-melting glassy particles to refractory ceramic particles that are raw materials used in manufacturing a ceramic sound absorber, and by specifying the particle size of refractory ceramic particles and the addition amount of low-melting glassy particles. Excellent sound absorption characteristics,
In addition, it was confirmed that a ceramic sound absorber having high strength and excellent fireproof vapor property could be manufactured, and the present invention was completed.

That is, in the present invention, refractory ceramic particles having a particle size of 0.5 mm or more and 2 mm or less and low melting glassy particles having a lower melting point than the ceramic particles are added so as to be 7 to 20% by weight of the whole, mixed and pressed. After that, it is a method for producing a high-strength, steam-resistant ceramic sound absorbing body, which is characterized by firing.

The preferred embodiment is that the particle size of the refractory ceramic particles is 1 mm or more and 2 mm or less, and the firing temperature is in the vicinity of the melting point of the low-melting glass particles, preferably from the melting point to 50 to 150 ° C. higher than the melting point. A temperature range is a preferred embodiment.

[Action]

According to the method of the present invention, it is possible to manufacture a ceramic sound absorbing body having low cost, excellent productivity, and steam resistance.

〔Example〕

 An embodiment of the present invention will be described below.

As the refractory ceramic particles, particles obtained by crushing ceramic materials such as silica stone, chamotte, mullite, etc., as well as porcelain, pottery, and refractory materials are used. Considering the use in a high temperature atmosphere and the availability of the low melting point glassy particles, it is preferable to use refractory ceramic particles having a fire resistance of 1000 ° C. or more. Further, generally, as a low melting point glass, Na ₂ O / K ₂ O; 50 to 51%, MgO; 33 to 34
%, CaO; 0.5 to 0.6%, Al ₂ O ₃ ; 13.2 to 13.
3%, SiO ₂ ; a composition of 77.8 to 77.9% is used.

As an example, the effectiveness of the present invention will be described with reference to an example in which the shuttle particles are used. As the low-melting glassy particles, a glaze having the above composition and a melting point of 1300 ° C. was used.

The particle size of the chamotte particles is 0.5 mm or less, 0.5 mm to 1.
4 types of 0 mm, 1.0 to 2.0 mm and 1.0 to 3.0 mm are used, and the above glaze particles of low melting point glass are
The bending strength of the ceramic sound absorber obtained by adding 0 wt% so that it was fired at 1300 ° C. and the bending strength after autoclaving at 100 ° C. for 100 hours under saturated steam pressure are shown in FIG. 1 and It is shown in FIG.

As is clear from these results, it can be seen that a high-strength ceramic sound absorbing body excellent in steam resistance can be obtained by using refractory ceramic particles having a particle size of 0.5 to 2 mm, preferably 1 to 2 mm. Particles having a small particle size have a large surface area, and the surface of the particle is not uniformly covered with glassy particles, resulting in a decrease in strength, and particles having a coarse particle size have a high porosity and a decrease in strength.

Bending strength of the ceramic sound absorber when the amount of low-melting glassy particles was changed, and bending strength after autoclaving at 300 ° C. under saturated steam pressure for 100 hours, using chamotte particles with a particle size of 1 to 2 mm. This is shown in FIGS. 3 and 4.

The bending strength becomes constant when the addition amount of the low-melting glass particles is 7% or more, but the bending strength after autoclaving decreases when the addition amount is 7% or less and 20% or more. This is because if the low-melting glass particles are small, the surfaces of the refractory ceramic particles are not uniformly covered, and the refractory ceramic particles are deteriorated by steam, and if the low-melting glass particles are excessive, the glass quality is deteriorated by steam.

Bending strength of the ceramic sound absorber when the sintering temperature was changed to 10% by weight of the low-melting glassy particles with the use of Sheamot particles having a particle size of 1 to 2 mm, and after autoclaving at 300 ° C. under saturated steam pressure for 100 hours The flexural strength of is shown in FIGS. 5 and 6.

As is clear from the figure, firing is effective in the vicinity of the melting point of the low melting point glass of 1300 ° C, and particularly 1300 ° C to 1350 ° C.
Is preferred.

The normal incident sound absorption coefficient of the ceramic sound absorbing plate thus obtained,
The measurement results are shown in FIG. 7, and an excellent ceramic sound absorbing material having a peak sound absorption rate of 95% or more was obtained. The “1/3 OCT Feq” on the horizontal axis in FIG. 7 is the center frequency of the 1/3 octave band.

〔The invention's effect〕

As described in detail above, according to the present invention, it is possible to manufacture a ceramic sound absorbing body having excellent steam resistance at low cost.

[Brief description of drawings]

1 and 2 are diagrams showing the influence of the particle size of ceramic particles, FIGS. 3 and 4 are the diagrams showing the effect of the addition amount of low-melting glass particles, and FIGS. 5 and 6 are firings. FIG. 7 is a diagram showing the influence of temperature, and FIG. 7 is a diagram showing the measurement results of the normal incident sound absorption coefficient.

Front page continuation (72) Inventor Hikaru Motomura 1-1 1-1 Atsunoura-machi, Nagasaki-shi, Nagasaki Mitsubishi Heavy Industries, Ltd. Nagasaki Research Institute (72) Inventor Shoji Nishimura 2-1-1 Shinhama, Arai-cho, Takasago-shi, Hyogo Mitsubishi Heavy Industries Takasago Research Institute Co., Ltd. (72) Inventor Kiyoshi Nagashima 1-1, Atsunoura-machi, Nagasaki-shi, Nagasaki Mitsubishi Heavy Industries Ltd. Nagasaki Shipyard Co., Ltd. (72) Tomio Yoshida 1-1, Atsunoura-cho, Nagasaki-shi, Nagasaki Mitsubishi Heavy Industries Nagasaki Shipyard Co., Ltd. (72) Inventor Shigeru Watanabe 1-1, Atsunoura-machi, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard Co., Ltd. (72) Inventor Yajima, 1-1, Atsunoura-cho, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries Nagasaki Shipyard Co., Ltd. (72) Inventor Masanori Nishida 1-1 No. 1 Satinouramachi, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard Co., Ltd.

Claims (1)

[Claims] 1. Refractory ceramic particles having a particle size of 0.5 mm or more and 2 mm or less and low melting glassy particles having a melting point lower than that of ceramic particles are added so as to be 7 to 20% by weight of the whole, mixed and pressed. Machine, a method for producing a high-strength, steam-resistant ceramic sound absorbing body, characterized by firing.