JPH02149337A - Gas-solid phase reaction vessel - Google Patents

Abstract

PURPOSE:To make gas-solid phase reaction active and prevent formation of a not reacted material remain and of intermediate products by forming a solid molding holding part of a reaction container to be uneven and holding the solid molding on the tips of projected parts of the uneven surface and ventilating a gas in recessed parts. CONSTITUTION:A gas is led to a solid molding 7 contained in a container to carry out gas-solid phase reaction. The solid molding 7 holding part of the gas-solid phase reaction container is so formed to have projected parts and recessed parts and the solid molding 7 is held in the tips of the projected parts 4 and the gas is ventilated in the recessed parts. As a result, the gas-solid phase reaction is made active and formation of a not reacted material remain and of intermediate products can be prevented as much as possible, and the purity of the products such as AlN, BN, Si3N4, etc., can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas-solid phase reaction vessel which accommodates a solid molded product therein and causes the solid molded product to undergo a gas-solid phase reaction by flowing gas therein.

In recent years, the use of fine ceramics has been expanding in various fields, and among these, for example, AQN, BN, S
J, N, etc., oxides are reduced and nitrided at high temperatures using gas-solid reactions (for example, AQ20.+3C+N, →
2AQN+3CO) are becoming increasingly available.

In this case, in a gas-solid phase reaction, it is important to increase the contact area between the reacting gas and the solid, and to quickly discharge the gas produced by the reaction out of the system in order to carry out the reaction actively and completely. is important.

Conventionally, as a reaction vessel used in such a gas-solid phase channel, a vessel consisting of a rectangular cylindrical vessel body a as shown in Figs. At the same time, it is configured so that a raw material gas (reactant gas) flows in through one opening d, and a generated gas produced by the reaction is discharged through the other opening e. Note that the arrow in the figure indicates the direction of gas flow.

■ is going to happen However, such conventional reaction vessels.

Since the inner bottom surface of the container body a is formed flat, the lower surface of the solid molded product (reactant) C placed on the inner bottom surface is prevented from coming into contact with the reaction gas. As a result, not only is it difficult for the reaction to proceed actively, but also incomplete reactants may be produced or unreacted products may remain. Especially AQN, BN.

When obtaining ceramics such as Si3N4, high purity is required, so the generation of unreacted products and intermediate reactants is a serious problem.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a gas-solid phase reaction vessel that can activate gas-solid phase reactions and prevent as much as possible the residual of unreacted substances and the generation of intermediate reactants. shall be.

In order to achieve the above object, the present invention provides a low solid phase reaction vessel in which gas is caused to flow through a solid molded product housed therein to cause a gas solid phase reaction. The solid molded product mounting portion is formed into an uneven shape so that the solid molded product is supported at the top of the recessed portion and gas is allowed to flow between the recessed portions.

Here, the interval between the protrusions of the uneven part is smaller than the size of the bottom of the solid molded product, and the solid molded product is supported at the top of the protrusions so that a gas circulation space is formed between the recesses. It is.

In addition, as the solid molded product, a single or mixed molded product of oxides such as alumina, silica, boric acid, aluminum hydroxide, carbon, etc. can be used, and as the gas, nitrogen, hydrogen, ammonia, - A gas such as carbon oxide gas can be used.

Therefore, the reaction vessel of the present invention can be made of, for example, An, 03°Si
o2. It is suitably used in the reduction nitridation reaction of oxides such as B2O3, and by reacting these oxides or a mixture of them with carbon with N2 gas, NH, gas, etc., AQN,
It is used to obtain nitrides such as BN and Si3N4.

According to the present invention, the solid molded product mounting portion of the gas-solid phase reaction vessel is formed in an uneven shape, and the solid molded product is supported at the top of the solid molded product, and the gas is configured to flow between the recessed portions. Therefore, even if the bottom surface of the solid molded product is flat, the contact area between the mounting portion and the solid molded product becomes extremely small, and the substantial reaction surface area of the solid molded product increases. In addition, the four provided portions form a gas circulation space in the gas flow direction, and the reaction gas quickly flows and flows between the uneven portions to ensure reliable contact with the bottom surface of the solid molded product, and the generated gas also flows into the gas flow direction. It flows easily in the recess and is discharged from the reaction vessel as quickly as possible. As a result, the reaction between the solid reactant and the gas becomes active even on the side where the solid reactant is placed, and the generation of intermediate products and unreacted products can be prevented as much as possible. .

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

Figure 1 shows an embodiment of the low solid phase reaction vessel according to the present invention. Wave-shaped grooves and convex portions (uneven portions) 4 having rounded bottoms and rounded tops are formed along the gas flow direction from the gas inlet 5 side end to the gas discharge hole 6 side end. The inner bottom surface 3 (the uneven portion 4) is configured as a mounting portion for the solid molded product 7.

When performing a gas-solid phase reaction using this reaction container, the solid molded product 7 is placed on the inner bottom surface 3 of the container body 2, so that the solid reactant 7 is placed on the top of the uneven portion 4 (-E). The top of the protruding portion). Next, a reaction gas is introduced from the gas inlet 5, and this reaction gas flows inside the container body 2, but at this time, it comes into contact with the top surface and both side surfaces of the solid molded product 7, and also contacts the grooves of the uneven portion 4. The solid molded article 7 flows through the inside thereof and also makes good contact with the lower surface of the solid molded article 7. Therefore, the reaction gas comes into contact with the entire surface of the solid molded product 7, and the reaction between the reaction gas and the solid molded product 7 is reliably and efficiently carried out, and the generated gas is also quickly released from the inside of the container body including the inside of the groove. This prevents incomplete reactions and unreacted substances from remaining as much as possible.

In this case, the uneven portion is formed of grooves and protrusions, and the tops of the protrusions are rounded, so the contact area with the solid molded product is very small, and the grooves through which the reaction gas flows are formed by gas ( Since it is formed continuously in the gas flow direction from the end on the side of the reaction gas inlet 5 to the end on the side of the gas (generated gas) outlet 6, the reaction gas flows smoothly into the groove. This allows the generated gas to flow and be discharged smoothly.

FIG. 3 shows another embodiment of the present invention. In this embodiment, similar to the embodiment shown in FIGS. 1.2, an uneven portion 4 is formed on the inner bottom surface of the container body 2. 4 is formed by a concave groove and a convex line, but the concave groove part has a cross section of 7.
The ridges are formed in an inverted V-shape in cross section.

Further, FIG. 4 shows still another embodiment of the present invention,
In this example, a mounting plate 8 is placed on the inner bottom surface 3 of the container body 2, on which uneven portions 4 are formed by protruding protrusions 4a having an inverted V-shaped cross section at regular intervals on the upper surface. That is,
This mounting plate 8 forms a mounting portion for the container body 2.

The other configurations and effects in Figures 3 and 4 are as shown in Figures 1 and 4.
Since it is the same as the embodiment shown in FIG. 2, its explanation will be omitted.

Here, the uneven portion provided in the gas-solid phase reaction vessel is not limited to the above embodiments, and may be, for example, not a continuous protruding line but a discontinuous protruding line, or a conical,
It is possible to make appropriate changes such as forming concave and convex portions by forming convex portions such as pyramid-shaped convex portions, and other configurations may also be variously changed within the scope of the gist of the present invention.

Next, the present invention will be explained in more detail using experimental examples.

Item 11 is 100 parts by weight of aluminum hydroxide with an average particle size of 0.9-
30 parts by weight of carbon black with an average particle size of 0.7- and 10 parts by weight of an organic binder were thoroughly mixed, and the mixture was molded into rectangular parallelepipeds of the same size (2, Ox 5, Ox 7.
Three molded bodies of 0an) were produced.

This molded body was placed on the inner bottom surfaces of gas-solid phase reaction vessels A, B, and C shown in FIGS. 5, 1, and 3 of the same size. Note that the distance between the tops of the convex stripes of the gas-solid phase reaction vessel B is 1.
0 am, the depth of the groove is 0.7 mm, the interval between the tops of the convex stripes of the gas-solid phase reaction vessel C is 1.0 mm, and the depth of the groove is 0.7 mm.

Next, a nitrogen stream of 20 Q/min was passed through these reaction vessels, and they were fired at 1650°C for 5 hours.

The obtained reaction product was pulverized, and the pulverized calcined powder was treated in air at 700° C. for 5 hours to oxidize and remove remaining carbon.

Oxygen and carbon in the obtained aluminum nitride powder were analyzed. The results are shown in Table 1.

Table 1 From Table 1, it can be seen that the products fired in the gas-solid phase reactor according to the present invention have less residual carbon and oxygen than those fired in the conventional gas-solid phase reactor, and the reaction is more complete. It was recognized that

As explained above, in the gas-solid phase reaction vessel of the present invention, the solid molded product placement part is formed in an uneven shape, so that the reactant gas reliably contacts the entire surface of the molded product, and the gas-solid phase reaction is carried out. is carried out reliably and efficiently, and the remaining unreacted substances and the generation of intermediate reactants can be prevented as much as possible, and AQN.

It is possible to improve the purity of produced substances such as BN and Si3N4.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, the 1st and 2nd figures are perspective views, the 2nd figures are sectional views, and the 3rd and 4th figures show other embodiments of the invention, respectively. A cross-sectional view, FIGS. 5 and 6 show a conventional gas-solid phase reaction vessel, and FIG. 5 is a perspective view, and FIG.
The figure is a sectional view. 1... Gas-solid phase reactor 2... Gas-solid phase reaction vessel main body 3... Inner bottom surface 4... Uneven portion 7... Solid molded product

Claims (1)

[Claims] 1. In a gas-solid phase reaction vessel in which a gas is caused to flow through a solid molded product housed therein to cause a gas-solid phase reaction, the solid molded product mounting portion of the reaction vessel is formed into an uneven shape, and the top of the uneven portion is formed. What is claimed is: 1. A gas-solid phase reaction vessel, characterized in that it is configured to support a solid molded product and to allow gas to flow between concave portions.