JPH11193918A - Combustor having means for adsorbing/oxidizing unburnt components - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove unburnt components being produced at the time of firing or extinguishing through combination of an adsorbent and an oxidation catalyst. SOLUTION: An adsorbent 14 having function for adsorbing unburnt components under low temperature and desorbing the unburnt components under high temperature is set in a flue 13 for discharging combustion gas from a combustion room 12 and an oxidation catalyst 15 having function for oxidizing unburnt components is set on the downstream side thereof. A porous zeolite based catalyst is applied to the adsorbent 14. A metal or ceramic carrying a noble metal catalytic component (e.g. platinum) is applied to the oxidation catalyst 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to ignition of a combustion device,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device having an unburned portion adsorbing and oxidizing means for removing unburned portions generated during fire extinguishing by a combination of an adsorbent and an oxidation catalyst.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, in a combustion apparatus 1, unburned components (carbon monoxide, aldehyde, hydrocarbons, etc.) are discharged from a flue 3 by incomplete combustion during ignition or extinguishing in a combustion chamber 2. Discharging. Therefore, in the combustion device 1 having a large number of start and stop times, the unburned component is discharged each time, so that the discharge amount can be said to be very large. Therefore, as shown in FIG. 4, an oxidation catalyst 4 may be provided in the flue 3 at the outlet of the combustion chamber 2 to oxidize unburned components generated during combustion. If the exhaust gas temperature is too low to obtain catalytic activity, the exhaust gas temperature may be raised by using the preheating burner 5 or the catalyst may be heated by the heater 6 (see FIG. 5).
By the way, in the refrigerator, as shown in FIG. 6, a odor in the refrigerator is obtained by using a catalyst 7 in which a noble metal-based catalyst component having excellent oxidizing power, for example, platinum is dispersed on the surface of a porous body having a strong gas adsorption capacity. There is a technology to deodorize gas. In this method, the odor gas is adsorbed and held at a low temperature, and then the catalyst 7 is heated by the heater 8 to oxidize and decompose the odor gas adsorbed by the catalytic action of platinum.

[0003]

However, in the combustion apparatus 1 described above, (1) the unburned components are hydrocarbon compounds or aldehydes, which are harmful to the human body or unpleasant odor. Is to give. Therefore, if discharged untreated, it directly affects the human body. (2) When the emission concentration of the unburned portion is extremely high, there is a risk of explosion in the flue 3 or the like. (3) In order for the oxidation catalyst to oxidize unburned components, a catalyst temperature higher than the activation temperature is required. Therefore, raising the exhaust gas temperature by using the preheating burner 5 or heating the heater 6 is unnecessary consumption of energy. (4) In (3), in order to obtain catalytic activity,
When the exhaust and the heating of the catalyst are not performed, since the catalyst temperature is low at the time of ignition, the unburned portion passes through the catalyst without being reacted and is discharged despite the presence of the catalyst. (5) In the case of a refrigerator using the catalyst 7 having an adsorption ability, heating of the catalyst 7 is necessary for oxidative desorption of the adsorbed component, which consumes extra energy. The present invention has been made to solve such a problem, and is intended to remove unburned components generated at the time of ignition and extinguishing of a combustion device by a combination of an adsorbent and an oxidation catalyst. An object of the present invention is to provide a combustion device having an adsorption oxidation means.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a flue of a combustion chamber in a combustion device,
An adsorbent having a function of adsorbing unburned components generated at low temperatures and desorbing at high temperatures is provided, and an oxidation catalyst having a function of oxidizing unburned components is provided downstream thereof. In the above-described configuration, a porous zeolite-based catalyst can be applied to the adsorbent. Further, the oxidation catalyst may be configured by supporting a noble metal-based catalyst component on a metal. Further, the oxidation catalyst may be configured by supporting a noble metal-based catalyst component on ceramic. Further, one adsorption / oxidation unit having both adsorption and oxidation functions may be provided in the flue of the combustion chamber, so that unburned components are adsorbed to the unit, decomposed after oxidative decomposition, and then desorbed. Further, the adsorption oxidation unit uses a porous zeolite as an adsorbent,
A noble metal-based catalyst component can be dispersed in this porous zeolite to have an oxidation function.

[0005]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a combustion apparatus having an unburned portion adsorbing and oxidizing means according to the present invention. FIG.
A combustion device 10 is shown. This combustion device 10 adsorbs unburned components at a low temperature as a means for adsorbing and oxidizing unburned components from a combustion chamber 12 in which combustion is performed by a burner 11 to a flue 13 for discharging combustion gas. An adsorbent 14 having a function of desorbing at high temperatures is interposed, and an oxidation catalyst 15 having a function of oxidizing unburned components is interposed downstream thereof.

As the adsorbent 14, for example, a porous zeolite-based catalyst that can easily adsorb unburned components can be used. Further, as the oxidation catalyst 15, a catalyst in which a noble metal-based catalyst component having excellent oxidizing power (for example, platinum or the like) is supported on metal or ceramic can be used. In this case, the adsorbent 14 has an adsorption ability at 0 to 250 ° C and a desorption ability at 400 ° C. The oxidation catalyst 15 exhibits an oxidation activity at 200 ° C. or higher.

In the combustion apparatus 10 described above, the burner 11 is ignited, and combustion in the combustion chamber 12 is started.
When the temperature of the exhaust gas from the combustion chamber 12 at the start increases from room temperature (immediately after ignition) to 500 ° C. (exhaust temperature in a steady state), unburned components generated at the time of ignition are adsorbed by the adsorbent 14 until the exhaust temperature reaches 250 ° C. And the exhaust temperature is 400 ° C
, The adsorbed unburned matter starts to desorb. At this time, the oxidation catalyst 15 on the downstream side of the adsorbent 14 has also reached a temperature (200 ° C. or higher) at which oxidation takes place due to exhaust heat. Will be done.

As described above, as long as the exhaust temperature is low at the beginning of ignition and the oxidation catalyst 15 does not exhibit oxidizing activity, unburned components generated at the time of ignition can be adsorbed by the adsorbent 14, and No minute is released.
Further, since the adsorbent 14 is heated by exhaust gas,
It is not necessary to separately heat in order to desorb the adsorbed unburned matter. Further, the adsorbent 14 has its adsorbing ability restored by the desorption reaction, and the unburned portion can be adsorbed at the next ignition.

[0009] The combustion apparatus having the unburned part adsorption oxidizing means according to the present invention may be configured as follows. That is, as shown in FIG. 2, in the combustion device 20, an adsorption oxidation unit 21 having both an adsorption function and an oxidation function is interposed in a flue 13 that discharges combustion gas from a combustion chamber 12. In this case, the adsorption oxidation unit 2
No. 1 uses a porous zeolite as a means for adsorption, and disperses a noble metal-based catalyst component (for example, platinum or the like) having excellent oxidizing power in the porous zeolite so as to have an oxidizing ability.

According to the combustion apparatus 20, the unburned component is adsorbed at the time of the initial low temperature by the adsorbing and oxidizing unit 21 having both the adsorbing and oxidizing functions. Oxidatively decomposes unburned components,
The elimination reaction can be caused by increasing the temperature. As described above, adsorption and oxidation can be achieved by one adsorption oxidation unit 21, the size can be reduced, and the time required for raising the temperature of the adsorption oxidation unit 21 can be shortened.

As described above, the combustion apparatus having the unburned portion adsorbing and oxidizing means according to the present invention has been described with reference to the combustion apparatuses 10 and 20. In any case, the amount of heat stored in the furnace at the time of ignition is small, and It is particularly effective in furnaces and boilers with low exhaust temperatures. Further, by using an adsorption oxidation unit having both adsorption and oxidation functions, it is possible to make the unit compact and shorten the time required for raising the temperature of the unit.

[0012]

As described above, according to the present invention, (1) by using an adsorbent, the unburned components discharged when the exhaust gas temperature is low and the catalyst has not yet obtained oxidation activity are adsorbed and trapped. , Can be prevented from being discharged outside. (2) Since the temperature of the adsorbent rises due to the heat of the exhaust gas, it is not necessary to perform heating again to cause a desorption reaction. (3) Since the unburned matter is desorbed from the adsorbent due to the rise in the exhaust gas temperature, the adsorbent resumes its adsorption function at the next ignition. (4) It is particularly effective in furnaces and boilers where the amount of heat stored in the furnace during ignition is small and the exhaust gas temperature during ignition is low. (5) By using the adsorption oxidation unit having both the adsorption and oxidation functions, it is possible to make the unit compact and shorten the time required for raising the temperature of the unit.

[0013]

[Brief description of the drawings]

FIG. 1 is a schematic structural explanatory view showing an example of a combustion device having an unburned portion adsorbing and oxidizing means in the present invention.

FIG. 2 is a schematic structural explanatory view showing another example of a combustion apparatus having an unburned portion adsorbing and oxidizing means in the present invention.

FIG. 3 is a schematic structural explanatory view showing an example of a conventional combustion device.

FIG. 4 is a schematic configuration explanatory view showing an example in which an unburned portion processing means is applied to the combustion device shown in FIG. 3;

FIG. 5 is a schematic structural explanatory view showing another example in which an unburned portion processing means is applied to the combustion device shown in FIG. 3;

FIG. 6 is a schematic diagram for explaining a technique employed in refrigerators for deodorizing odorous gas in the refrigerator.

[Explanation of symbols]

 10, 20 Combustion device 11 Burner 12 Combustion chamber 13 Flue 14 Adsorbent 15 Oxidation catalyst 21 Adsorption oxidation unit

Claims (6)

[Claims] 1. An adsorbent having a function of adsorbing generated unburned components at a low temperature and desorbing it at a high temperature in a flue of a combustion chamber in a combustion device, and a function of oxidizing the unburned components downstream thereof. A combustion apparatus having an unburned-parts adsorbing and oxidizing means, wherein the oxidation catalyst is provided. 2. A combustion apparatus having an unburned part adsorbing and oxidizing means according to claim 1, wherein a porous zeolite-based catalyst is applied to said adsorbent. 3. The combustion apparatus according to claim 1, wherein the oxidation catalyst is configured by supporting a noble metal-based catalyst component on a metal. 4. The combustion apparatus according to claim 1, wherein the oxidation catalyst is formed by supporting a noble metal-based catalyst component on ceramic. 5. A flue of the combustion chamber provided with one adsorption / oxidation unit having both an adsorption function and an oxidation function so that unburned components are adsorbed on the unit, decomposed after being oxidized and decomposed, and desorbed. A combustion apparatus having an unburned part adsorption oxidizing means according to claim 1. 6. The adsorption oxidation unit uses a porous zeolite as an adsorbent, and disperses a noble metal-based catalyst component in the porous zeolite to have an oxidation function. A combustion device having an unburned portion adsorption oxidation means.