JP2000074312A - Catalytic combustion equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dissipation of a radiant heat from a self-heating type catalyst member of a catalytic combustion equipment by providing the catalyst member in a gas passage, and providing a first heat dissipation preventive member at the upstream side of the member. SOLUTION: A self-heating type catalyst member 2 formed by simultaneously spirally winding a catalyst carrying member 6 of a corrugated plate shape made of stainless steel and an electric insulation member 7 of a flat plate shape is provided at a gas passage 1 to be supplied with pre-mixed gas, and a first heat dissipation preventive member 3 is arranged at the upstream side of the member 2. A premixing gas supply tube 4 for supplying pre-mixed gas obtained by mixing fuel and combustion air by a suitable means in advance is provided at the upstream side of the passage 1, and a regulating valve 5 for regulating a supply amount of the pre-mixed gas is provided at the tube 4. A heat insulator 11 for heat dissipation prevention is provided at an outside of the passage 1. Thus, a catalytic combustion can be started in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic combustion device.

[0002]

2. Description of the Related Art With the rise of environmental problems in recent years, social demands for reducing the emission of air pollutants from automobiles, industrial machines, and the like have become even more severe.
For, reduction of emissions is required. Various measures for reducing air pollutants have been proposed in the past, and as one of them, the catalytic combustion method has been spotlighted. In this catalytic combustion method, by utilizing a catalyst surface reaction, C
There is an advantage that the combustion temperature can be lowered without increasing the amount of generated O, and the amount of generated NOx can be reduced.

As an apparatus utilizing such a catalytic combustion method, there is a catalytic combustion apparatus (see Japanese Patent Application Laid-Open No. 10-103614) shown in FIG. This catalytic combustion device preheats the catalyst by using the electric resistance of the catalyst unit 21 by energizing the catalyst member 21, and supplies a catalyst / air mixture to the catalyst member 21. This is to start combustion.

[0004]

SUMMARY OF THE INVENTION According to the present invention, there is provided a catalytic combustion apparatus capable of preventing radiation of radiant heat from a catalyst member of the catalytic combustion apparatus, starting catalytic combustion in a shorter time, and performing more stable catalytic combustion. It is intended to provide a device.

[0005]

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 is provided with a self-heating type catalyst member in a gas passage, A first heat radiation preventing member is provided upstream of the heat generating catalyst member.

The invention according to claim 2 is characterized in that a second heat radiation preventing member is provided downstream of the self-heating type catalyst member.

Further, the invention according to claim 3 is characterized in that a catalyst member is provided downstream of the self-heating type catalyst member.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a first embodiment of the present invention will be described. In the present invention, a self-heating type catalyst member is provided in a gas passage, and a self-heating type catalyst member is provided upstream of the self-heating type catalyst member. This is realized in a catalytic combustion device having a configuration provided with one heat radiation preventing member.

The self-heating type catalyst member has a configuration in which, for example, a corrugated member made of stainless steel and a plate-shaped member serving as an electrical insulating material are simultaneously spirally wound.
The corrugated plate-like member includes, for example, A having high low-temperature activity.
Noble metals such as g, Pt, and Pd are supported as a catalyst.
In addition, both ends of the corrugated plate-shaped member are connected to a power source and energized to generate heat using the electric resistance of the corrugated member itself, thereby increasing the temperature. On the other hand, the first heat radiation preventing member has a configuration in which, for example, a stainless steel corrugated member and a stainless steel flat plate member are simultaneously spirally wound.

According to the catalytic combustion apparatus having the above-described structure, the self-heating type catalyst member is energized and heated to a predetermined temperature at which catalytic activity occurs, and then a premixed gas is supplied to perform catalytic combustion. During the catalytic combustion, the energization of the self-heating type catalyst member is ON / OFF controlled at a predetermined temperature. The radiant heat generated by the heat generated by the self-heating type catalyst member is absorbed by the first heat radiation preventing member, and the temperature of the premix gas to be supplied can be increased by the absorbed radiant heat, so that the catalytic combustion can be accelerated. In addition, by raising the temperature of the premixed gas, catalytic combustion can be performed even with a high air ratio that is difficult to burn.

Next, a second embodiment of the present invention will be described. In the second embodiment, in the catalytic combustion device described in the first embodiment, a second heat radiation preventing member is provided downstream of the self-heating type catalyst member. Therefore, the radiant heat to the downstream side of the self-heating type catalyst member is cut off by the second heat radiation prevention plate, and the amount of heat radiation to the downstream side can be reduced. , And more stable catalytic combustion can be achieved.

Further, a third embodiment of the present invention will be described. The third embodiment has a configuration in which a catalyst member is added when the amount of combustion is large. That is, in the first embodiment or the second embodiment, at least one ordinary catalyst member is provided immediately downstream of the self-heating type catalyst member. The normal catalyst member is a member other than the self-heating type catalyst member, for example, a member having a catalyst supported on the first heat dissipation preventing member, a member having a catalyst supported on a honeycomb-shaped ceramic structure, and the like. Used.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory view schematically showing a configuration of a first embodiment of a catalytic combustion device embodying the present invention.

In FIG. 1, the catalytic combustion device includes a self-heating type catalyst member 2 provided in a gas passage 1 for receiving a premixed gas, and a first heat radiation preventing member 3 upstream of the self-heating type catalyst member 2. It is arranged and configured. An upstream side of the gas passage 1 is provided with a premixed gas supply pipe 4 for supplying a premixed gas in which fuel and combustion air are previously mixed by appropriate means. The premix gas supply pipe 4 is provided with a control valve 5 for adjusting the supply amount of the premix gas. Further, a heat insulating material 11 for preventing heat radiation is provided outside the gas passage 1.

As shown in FIG. 2, the self-heating type catalyst member 2 is formed by, for example, simultaneously winding a stainless steel corrugated catalyst supporting member 6 and a flat electric insulating member 7 in a spiral shape. Things. And, it is used as a heating element by utilizing the electric resistance of the catalyst supporting member 6 itself. Therefore, both ends of the catalyst supporting member 6 are connected to the power source 8 by appropriate means. In addition, the electric insulating member 7 is interposed to prevent the short-circuit of the catalyst supporting member 6 and to allow the electric current to flow through the entire catalyst supporting member 6.

As shown in FIG. 3, the first heat radiation preventing member 3 is formed by, for example, simultaneously spirally winding a stainless steel corrugated plate member 9 and a stainless steel flat plate member 10.

According to the catalytic combustion apparatus having the above-described structure, first,
After the catalyst supporting member 6 is energized to raise the temperature of the catalyst supporting member 6 to a predetermined temperature at which catalytic activity occurs, a premixed gas is supplied to perform catalytic combustion. During the catalytic combustion, the power supply to the catalyst supporting member 6 is ON / OFF controlled at a predetermined temperature. During the energization, the catalyst supporting member 6 generates heat by itself, and radiant heat due to the heat is radiated. The first heat radiation preventing member 3 absorbs the radiant heat radiated to the upstream side and raises the temperature by the absorbed heat. Therefore, the temperature rise of the catalyst supporting member 6 can be accelerated by the temperature rise of the first heat radiation preventing member 3. Next, a predetermined amount of premixed gas is supplied from the premixed gas supply pipe 4 into the gas passage 1. The temperature of the premixed gas is increased in the course of flowing through the first heat radiation preventing member 3, so that the next catalytic combustion in the catalyst supporting member 6 can be accelerated. The first heat radiation preventing member 3 also has a rectifying effect of preventing the premixed gas from drifting. Further, on the downstream side of the self-heating type catalyst member 2,
A configuration in which a second heat radiation prevention member (not shown) having the same configuration as the first heat radiation prevention member 3 may be provided. By providing the second heat radiation preventing member, heat radiation to the downstream side can be blocked. Therefore, the temperature of the catalyst supporting member 6 is maintained at a high temperature, and more stable catalytic combustion can be performed. In addition, by raising the temperature of the premixed gas, catalytic combustion can be performed even with a high air ratio that is difficult to burn.

Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, a catalyst member is additionally provided when the amount of combustion is large. Therefore, the embodiment shown in FIG. 4 is an explanatory diagram schematically showing the configuration of the catalytic combustion device. In addition, the same members as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

In FIG. 4, the catalytic combustion device of the second embodiment is provided with a first heat radiation preventing member 3 on the upstream side of the gas passage 1,
On the downstream side of the first heat radiating member 3, a self-heating type catalyst member 2 having a lower volume than the self-heating type catalyst member 2 described in the first embodiment is provided.
An ordinary catalyst member 12 for processing a predetermined amount of combustion is provided, and a second heat radiation preventing member 13 is arranged downstream of the catalyst member 12. Also, when the amount of combustion is even greater,
A plurality of the catalyst members 12 may be provided.

The power consumption is reduced by reducing the volume of the self-heating type catalyst member 2. Further, the normal catalyst member 12 may be formed by supporting a catalyst on a member having the same configuration as the first heat radiation member 3, for example. Further, the catalyst may be supported on a ceramic structure formed in a honeycomb shape.

Since the self-heating type catalyst member 2 has a low volume, a small amount of premixed gas is supplied at the start of combustion, and the control valve 5 is adjusted by appropriate means at the start of catalytic combustion.
The supply amount of the premix gas is increased in several steps. The catalyst member 12 discharges the unburned gas from the self-heating type catalyst member 2 after completely burning the catalyst. Further, since the second heat radiation preventing member 13 blocks the heat radiation to the downstream side of the catalyst member 12, the catalyst member 12 can perform more stable catalytic combustion.

[0022]

As described above, according to the present invention, it is possible to prevent the radiation of radiant heat from the catalyst member, to start catalytic combustion in a shorter time, and to achieve stable catalytic combustion at a higher temperature. be able to.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a first embodiment schematically showing a configuration of a catalytic combustion device embodying the present invention.

FIG. 2 is an explanatory view schematically showing a configuration of a self-heating type catalyst member of FIG.

FIG. 3 is an explanatory view schematically showing a configuration of a first heat radiation preventing member of FIG. 1;

FIG. 4 is an explanatory view schematically showing a configuration of a second embodiment of the present invention.

FIG. 5 is an explanatory view schematically showing a configuration of a conventional catalytic combustion device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas passage 2 Self-heating type catalyst member 3 First heat dissipation prevention member 12 Catalyst member 13 Second heat dissipation prevention member

Continued on the front page F term (reference) 3K017 BA06 BB08 BB09 BC10 BE03 BE05 3K065 TA01 TK02 TK09

Claims (3)

[Claims] 1. A catalytic combustion device comprising: a self-heating type catalyst member provided in a gas passage; and a first heat radiation preventing member provided upstream of the self-heating type catalyst member. 2. A heat radiation preventing member (13) provided downstream of the self-heating type catalyst member (2).
3. The catalytic combustion device according to item 1. 3. The catalytic combustion device according to claim 1, wherein a catalyst member is provided downstream of the self-heating type catalyst member.