Catalytic combustion apparatus and method

A catalytic combustion apparatus comprising:

• a conductive self-heating type catalyst (referred to as a catalyst hereinafter) including electrodes for supplying power source to the catalyst;
• and
• electrically energizing means for energizing electrically the catalyst, wherein the catalyst is such that a catalyst support is coated which catalyst support is made of material selected from the group consisting of SiC, TiB.sub.2, ceramic mainly made of SIC, and ceramic mainly made of TiB.sub.2 ;
• and
• wherein a cross section orthogonal to reaction-gas flow direction is a disc shape, insulating means is provided so as to divide the catalyst in two portions, and an electrode is provided in each peripheral portion of the catalyst divided in two portions.

A catalytic combustion apparatus comprising:

• a conductive self-heating type catalyst (referred to as a catalyst hereinafter) including electrodes for supplying power source to the catalyst;
• and
• electrically energizing means for energizing electrically the catalyst, wherein the catalyst is such that a catalyst support is coated which catalyst support is made of material selected from the group consisting of SiC, TiB.sub.2, ceramic mainly made of SIC, and ceramic mainly made of TiB.sub.2 ;
• and
• wherein a cross section orthogonal to reaction-gas flow direction is a disc shape, insulating means is provided so as to divide the catalyst in two portions, and an electrode is provided in each peripheral portion of the catalyst divided in two portions;
• and
• wherein a distance between the two divided portions of the catalyst is equal or less than a distance between adjacent unit cells of the catalyst.

A catalytic combustion apparatus comprising:

• a conductive self-heating type catalyst (referred to as a catalyst hereinafter) including electrodes for supplying power source to the catalyst;
• electrically energizing means for energizing electrically the catalyst;
• reaction gas supply means for supplying reaction gas comprising fuel and air to the catalyst;
• temperature detection means for detecting a temperature of the catalyst;
• and
• control means by which the electrically energizing means are so controlled at the time of ignition that the catalyst is preheated to a predetermined temperature and the reaction gas supply means is so controlled that the reaction gas is supplied to the catalyst after the temperature detected by the temperature detection means reaches the predetermined preheating temperature,
• wherein a pair of electrodes are disposed counter to each other with the catalyst therebetween, and around the electrodes there is provided a small portion that is not coated with catalyst;
• and
• wherein a radiation fin is provided with the electrodes.

A catalytic combustion apparatus comprising:

• a conductive self-heating type catalyst (referred to as a catalyst hereinafter) including electrodes for supplying power source to the catalyst;
• electrically energizing means for energizing electrically the catalyst;
• reaction gas supply means for supplying reaction gas comprising fuel and air to the catalyst;
• temperature detection means, provided in an upstream side over the catalyst, for detecting a temperature of the catalyst, wherein the temperature of the catalyst is detected by a non-contact type infrared detector;
• and
• control means by which the electrically energizing means are so controlled at the time of ignition that the catalyst is preheated to a predetermined temperature and the reaction gas supply means is so controlled that the reaction gas is supplied to the catalyst after the temperature detected by the temperature detection means reaches the predetermined preheating temperature.

A catalytic combustion apparatus comprising:

• a conductive self-heating type catalyst (referred to as a catalyst hereinafter) including electrodes for supplying power source to the catalyst;
• electrically energizing means for energizing electrically the catalyst;
• reaction gas supply means for supplying reaction gas comprising fuel and air to the catalyst;
• temperature detection means for detecting a temperature of the catalyst, wherein the temperature of the catalyst is detected in a manner that an electric resistance of the catalyst represents the temperature of the catalyst thereof according to a functional relationship between the electric resistance and the temperature of the catalyst;
• and
• control means by which the electrically energizing means are so controlled at the time of ignition that the catalyst is preheated to a predetermined temperature and the reaction gas supply means is so controlled that the reaction gas is supplied to the catalyst after the temperature detected by the temperature detection means reaches the predetermined preheating temperature.

A catalytic combustion apparatus comprising:

• a conductive self-heating type catalyst (referred to as a catalyst hereinafter) including electrodes for supplying power source to the catalyst;
• electrically energizing means for energizing electrically the catalyst;
• reaction gas supply means for supplying reaction gas comprising fuel and air to the catalyst;
• temperature detection means for detecting a temperature of the catalyst;
• control means by which the electrically energizing means are so controlled at the time of ignition that the catalyst is preheated to a predetermined temperature and the reaction gas supply means is so controlled that the reaction gas is supplied to the catalyst after the temperature detected by the temperature detection means reaches the predetermined preheating temperature;
• and
• monitor means for indicating that the catalyst is deteriorated and not usable further.

A catalytic combustion apparatus comprising:

• a conductive self-heating type catalyst (referred to as a catalyst hereinafter) including electrodes for supplying power source to the catalyst, a catalyst support thereof being coated, and the catalyst support being made of material selected from the group consisting of SiC, TiB.sub.2, ceramic mainly made of SiC, and ceramic mainly made of TiB.sub.2 ;
• electrically energizing means for energizing electrically the catalyst;
• reaction gas supply means for supplying reaction gas comprising fuel and air to the catalyst;
• temperature detection means for detecting a temperature of the catalyst;
• and
• control means by which the electrically energizing means are so controlled at the time of ignition that the catalyst is preheated to a predetermined temperature and the reaction gas supply means is so controlled that the reaction gas is supplied to the catalyst after the temperature detected by the temperature detection means reaches the predetermined preheating temperature,
• wherein a cross section orthogonal to reaction-gas flow direction is a disc shape, insulating means is provided so as to divide the catalyst in two portions, and an electrode is provided in each peripheral portion of the catalyst divided in two portions.

A method of catalytic combustion, comprising the steps of:

• electrically energizing a conductive self-heating type catalyst (referred to as a catalyst hereinafter);
• supplying reaction gas comprising a mixture of fuel and air to the catalyst;
• detecting a temperature of the catalyst;
• igniting the reaction gas using the catalyst;
• controlling the level of the electrical energizing;
• judging whether or not the reaction gas using the catalyst is ignited after the reaction gas is supplied;
• switching off the electrical energization when ignited, or shutting off supply of the reaction gas when not ignited;
• and
• re-igniting the reaction gas using the catalyst at a newly predetermined temperature which is higher than the previously predetermined catalyst activation temperature after purging unburnt reaction gas, when the reaction gas using the catalyst is not ignited,
• wherein the igniting step comprises the sequential steps of:
• preheating the catalyst by electrically energizing the catalyst mass before the reaction gas is supplied;
• and
• supplying the reaction gas to the catalyst when the catalyst temperature becomes greater than a predetermined minimum temperature which is sufficiently active against the reaction gas.

A method of catalytic combustion, comprising the steps of:

• electrically energizing a conductive self-heating type catalyst (referred to as a catalyst hereinafter);
• supplying reaction gas comprising a mixture of fuel and air to the catalyst;
• detecting a temperature of the catalyst by measuring an electric resistance of the catalyst electrically energized;
• igniting the reaction gas using the catalyst;
• and
• controlling the level of the electrical energizing;
• wherein the igniting step comprises the sequential steps of:
• preheating the catalyst by electrically energizing the catalyst mass before the reaction gas is supplied;
• and
• supplying the reaction gas to the catalyst when the catalyst temperature become greater than a predetermined minimum temperature which is sufficiently active against the reaction gas.