JPS6154125B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a catalytic combustor that burns gaseous or liquid fuel flamelessly on the surface using a catalyst.
The use of a woven catalyst prevents shortened service life and surface heat generation distribution due to dispersion and shedding of the catalyst material, as well as preventing the catalyst material from scattering indoors, and achieves catalytic combustion that significantly reduces the slip of raw fuel gas during steady combustion. The purpose is to obtain a vessel. Conventional combustors using catalytic combustion include portable body warmers that use liquid fuel, and stoves that use propane or the like as fuel for special purposes such as heating animal shelters. All of these combustion methods are not premixed gas combustion in which air and fuel are mixed in advance, but surface combustion is performed on the outermost catalyst surface using so-called tertiary air.The characteristics of this combustion are that it is different from premixed combustion. , it is possible to perform low-temperature combustion by keeping the combustion temperature low, and under these conditions, it is possible to provide the characteristics of so-called flameless planar combustion. According to this combustion method, it is theoretically possible to completely burn all combustion components, and it does not involve the generation of NO as a combustion product, so it can be said to be an ideal combustion method for an indoor combustor. Furthermore, when considered as a heater, the radiant energy from the combustion surface is in the infrared region, and is characterized by high absorption efficiency into the human body. For this reason, this surface combustion method using a catalyst is attracting attention from the viewpoint of energy saving and prevention of indoor air pollution. However, most of the catalysts used in conventional catalytic combustors are made by impregnating and adhering catalytic substances to nonwoven fabrics made of inorganic fibers, and they are susceptible to mechanical or local combustion on the catalyst surface, gas pressure fluctuations, etc. Disturbances caused by this can easily cause changes in the surface shape, resulting in uneven heat generation distribution, unburned release of raw gas, and indoor dispersion of catalytic materials, which can shorten the combustion life. The disadvantage was that there were many disadvantages, such as the fact that the advantages of catalytic combustion turned out to be disadvantages, such as reduced combustion. The present invention provides a novel catalytic combustor configuration that can maximize the effects of the catalytic combustor as described above and improves the conventional drawbacks. Hereinafter, the present invention will be described in detail with reference to drawings of embodiments. Example 1 As shown in Figure 1, a silica cloth whose silica purity has been made 90wt% or more by acid treatment has a shape with a thread density of 30 threads/25 mm in warp threads and 19 threads in weft threads.
4wt% silica on the surface of a plain weave cloth with a thickness of approximately 0.3mm and 15wt% alumina on the surface were separately soaked, dried, and
The material supported by firing is used as a carrier, and the surface of this carrier is immersed, dried, and washed in the usual manner so that the atomic ratio of platinum and palladium is 1:5 and the total metal amount is 0.5 g/m ² . A set of two catalyst cloths 1 supported by activation firing and a bulk density of 0.06 g/cc and a thickness of 5
Layer the inorganic fiber nonwoven fabric 2 of
Stack the sheets underneath, and add a bulk density of 0.06g/cc.
Inorganic fiber nonwoven fabric 4 with a thickness of 5 mm and bulk density
A combustion layer made by sequentially stacking inorganic fiber nonwoven fabrics 5 of 0.16 g/cc and 10 mm thickness on the lower side was housed in a case to form a combustor. Here, both the catalyst cloth 1 and the catalyst cloth 3 are catalyst cloths made of the same composition, and the case includes a lower case 8 having a lath plate 6 for holding the combustion layer and a combustion gas supply port 7, and a stainless wire mesh 9 for pressing the catalyst surface.
and an upper case 10 having a. In addition,
The nonwoven fabrics 2, 4, and 5 are fuel supply resistors that effectively uniformly diffuse the fuel to the combustion surface. Example 2 The catalyst cloth 1 in FIG. 1 is the same as the catalyst cloth in Example 1, and the lower layer catalyst cloth 3 is
Two sheets of catalyst cloth with the same catalyst material composition as catalyst cloth 1 were stacked on top of each other, with a thread density of 10 warps/25 mm, weft 10 yarns/25 mm, and a thickness of about 0.4 mm. The inorganic fiber nonwoven fabrics 4 and 5 used as fuel gas diffusion resistance materials had the same structure as in Example 1, and the combined combustion layer was housed in the same case as in Example 1 to form a combustor. Example 3 As shown in FIG. 2, the catalyst cloth 1 was the same catalyst cloth as in Example 1, the nonwoven fabric 2 was also of the same shape as in Example 1, and the catalyst cloth 3 was the same as that in Example 2. and below these are the same catalyst cloths as those of Example 1.
A non-woven fabric 11 which is the same as the non-woven fabric 2 is further used as a base material, and below it is an open plain woven cloth with a thread density of 8 warps/25 mm, 8 wefts/25 mm, and a thickness of approximately 0.4 mm.
A combustor was constructed by combining catalyst cloth 1 and catalyst cloth 12 having the same catalyst material composition, and under it a combustion layer combining nonwoven fabrics 4 and 5, which were the same as in Example 1, in the same case as in Example 1. did. Example 4 The catalyst cloth 1 has the same configuration as in Fig. 1, and the base material is satin cloth with a thread density of 43 warps/25 mm, 37 wefts/25 mm, and a thickness of 0.7 mm. Using a catalyst cloth 1 carrying a catalyst material equivalent to that of 1,
Catalyst cloth 3 has a thread density of 32 warps/25mm and 22 wefts.
A pseudo-sawn cloth with a diameter of 25 mm and a thickness of 0.5 mm was used as the base material, and after supporting the same carrier as in Example 1 on the surface, it was found that the atomic ratio of platinum and rhodium was 10:1, and the total metal content was A combustor was prepared by using a catalytic metal supported at a concentration of 0.5 wt% and placed in the same case as in Example 1. As a comparative example for comparing with the above examples,
Three sheets of the same catalyst cloth as used in Example 1 are stacked, and below that, the same bulk density as used in Example 1 is placed.
Two sheets of 0.06g/cc, 5mm thick inorganic fiber nonwoven fabric,
Furthermore, a combustion layer made by sequentially stacking inorganic fiber nonwoven fabrics with a bulk density of 0.16 g/cc and a thickness of 10 mm on the bottom was housed in a case to prepare a comparative combustor. When propane gas (liquefied propane was used as fuel) was burned in the catalytic combustor according to each of the above examples and comparative examples, the slip rate of the combustion raw gas during steady combustion was as shown in the table below. In all cases, the concentration was 3% to 1.5%, and the surface temperature at that time was 480°C to 550°C, showing a nearly uniform temperature distribution. Furthermore, the increase in slip rate after 2000 hours of combustion was within 5% of the initial slip rate, making it an effective indoor combustor. On the other hand, in the catalytic combustor according to the comparative example, the slip rate of the combustion raw gas during steady combustion was 5.6%, and the surface temperature was in the range of 310℃ to 650℃, with the temperature being particularly high in the center and low in the periphery. It showed a distribution.
The increase in slip rate after 2000 hours of combustion was 9% higher than the initial slip rate.

[Table] However,
Combustible components in exhaust gas
Total calorific value (k〓〓h)
Slip rate =

Claims (1)

[Claims] 1. In a combustor that burns gaseous or liquid fuel flamelessly on the surface, a plurality of woven catalysts having different thread densities are sequentially introduced into the combustor from the open combustion surface,
In order to arrange the woven catalysts in descending order of yarn density and to isolate these woven catalysts from each other, an inorganic non-woven fabric to which no catalyst material is attached is 5 to 50 times as thick as the woven catalyst. What is claimed is: 1. A catalytic combustor comprising: a catalytic combustor disposed between woven catalysts; 2 The woven catalyst uses silica cloth as a base material,
The catalytic combustor according to claim 1, wherein the catalytic combustor is a catalyst having a catalytic material supported on its surface.