JPS60202259A - Catalytic combustion type hot water supplier - Google Patents

Abstract

PURPOSE:To effectively transfer the radiant heat characterizing catalytic combustion to a heat exchanger by a constitution wherein a catalytic body consists in carrying various catalytic substances on a tubular ceramic carrier with vent pores and the heat exchanger is provided in close vicinity to the outer periphery of the catalytic body. CONSTITUTION:A bottomed tubular catalytic body 3 employing heat-resistant ceramic as a carrier, on which platinum group metals or metallic oxides having catalytic effect are carried, is vertically installed and a uniformalizing plate 5, which is made of heat-resistant metal and has small bored holes 4, is placed inside the body 3 with some gap therebetween. In addition, a double tubular heat exchanger 9 consisting of an outer tube 7 and an inner tube 8 is arranged on the outer periphery of the catalytic body 3 so as to have a combustion chamber 6 with some similar gap therebetween. A thin flame is formed on the outer peripheral part of the catalytic body 3 at the early stage of ignition and, after a short period of time, the red hot part shifts to the center of the catalytic body and flame combustion proceeds to catalytic combustion.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention supplies gas or vaporized liquid fuel to a catalyst body together with combustion air, causes an oxidation reaction to occur on the surface of the catalyst body, and converts the amount of heat generated into the heat generated in the vicinity. This relates to the configuration of the water heater that transmits information to the exchanger.

Conventional Structure and Problems The conventional structure of this type of catalytic combustion water heater is as shown in FIG. It had become. However, with this configuration, the radiant heat from the catalyst body 1 cannot be sufficiently applied to the heat exchanger 2, and the heat exchange efficiency tends to be insufficient. Further, since the structure does not allow sufficient heat dissipation from the catalyst body 1, it is difficult to combust the combustion air at a level close to the theoretical air amount. As a result, the excess air is heated, making it unsuitable as a combustion method for heat exchange. ()\In high-temperature catalytic combustion using a nicham catalyst, dilution combustion is normally performed. The purpose is to adopt a configuration that effectively transmits radiant heat, which is a characteristic of combustion, to the heat exchanger, and at the same time effectively dissipates the heat trapped in the catalyst body, so that catalytic combustion is possible without dilute combustion with excess air. do.

Structure of the Invention In order to achieve this object, the present invention comprises a catalyst body in which various catalysts are supported on a cylindrical ceramic carrier having ventilation pores, and a heat exchanger is provided close to the outer periphery of the catalyst body. This is the structure.

With this configuration, the catalyst body effectively emits radiant heat, which is captured by the heat exchanger. Furthermore, by adding fins to the surface of the heat exchanger or by making the heat exchanger itself into a pipe shape and forming a spiral shape around the catalyst body, heat exchange from hot exhaust gas can be made more effective. I can do it.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 to 4.

In Fig. 2, a catalyst body 3 in the form of a cylinder with a bottom and a heat-resistant ceramic with ventilation pores is used as a carrier, and a platinum group metal or a metal oxide having a catalytic effect is supported on the carrier. A leveling plate 5 made of heat-resistant metal and having small holes 4 is placed inside thereof with a slight gap. Also, there is a slight gap around the outer periphery of the catalyst body 3.
Outer cylinder 7 sandwiching the combustion chamber 6. A double cylindrical heat exchanger 9 consisting of an inner cylinder 8 is installed. A water supply pipe 10 is connected to the lower part of the heat exchanger 9, and a hot water outlet pipe 11 is connected to the upper part. The upper part of the combustion chamber 6 is an exhaust pipe 12 for discharging combustion gas, and the lower part is a drain port 13 for discharging dew water separated from the combustion gas, and a cock 14 is provided in the middle of the exhaust pipe 12. ing. Above the catalyst body 3 is a fuel supply pipe 1 that feeds a mixture of fuel gas and combustion air.
5 is connected to the catalyst body 3, and an IR electrode 16 for ignition is provided at the outer upper corner of the catalyst body 3.

Next, its action on L structural acids will be explained.

First, the spark electrode 16 is energized, and a mixed gas of fuel gas and combustion air is supplied into the cylindrical catalyst body 3 through the fuel supply pipe 15. The mixed gas passes through the small holes 4 of the equalizing plate 5 and exits through the ventilation holes of the catalyst body 30 to the outside thereof. The mixed gas passes through the ventilation pores of the catalyst body 3 and reaches the spark electrode 16 on the outside thereof.
ignited by. At the initial stage of ignition, a thin flame is formed around the outer periphery of the catalyst body 3, but within a short time, the red hot part moves to the center of the catalyst body, and combustion shifts from flame combustion to catalytic combustion. During normal catalytic combustion, the temperature of the catalyst body 3 is approximately 1000'C.
The temperature is maintained between ~1200'C, but the small hole 4 of the leveling plate 5
If it is not made sufficiently small and the speed when passing through the small hole 4 is not higher than the combustion speed, there is a risk of backfire. The combustion heat of the catalyst body 37 is radiated into the combustion chamber 6 as radiant heat and high-temperature exhaust gas, but unlike in the case of normal flame combustion, the proportion of radiant heat is extremely high. These heats are received by the surface of the inner shell 8 of the nearby heat exchanger 9 and transferred to the water in the heat exchanger 9. Exhaust gas is transferred to the exhaust pipe 12, and dew water is transferred to the drain port 13.
released to the outside.

The example in FIG. 3 shows another embodiment of the heat exchanger 17, in which (,) is a plan sectional view and (b) is a side sectional view. In this embodiment, fins 19 are provided on the inner shell 18 of the heat exchanger 17 in order to more efficiently capture the radiant heat and exhaust heat generated from the catalyst body 3.

In the example shown in FIG. 4, the heat exchanger 20 has a spiral shape and is completely built into the combustion chamber 21, with the outer shell shown in FIGS. The problem of heat dissipation has been improved, the heat transfer area has been increased, and the structure has been simplified.

The other configurations and functions of the example shown in FIGS. 3 and 4 are the same as in the case of FIG. 1, so their explanation will be omitted.

According to the catalytic combustion water heater of the present invention, compared to the conventional flame combustion case, the size can be reduced to about half for the same calories, and the heat exchange efficiency is 90% in both cases.
As described above, in the case of the example shown in FIG. 4, a high efficiency of 96% is achieved.

Effects of the Invention As described in section 2, the catalytic combustion water heater of the present invention has the effects listed below.

(1) Unlike normal flame combustion, since flameless combustion is performed at high temperatures, there is no need for any space for flame formation, and the structure of the water heater can be made smaller.

(2) Since it uses catalytic combustion, there is no combustion noise, making it possible to create a quiet water heater.

(3) Heat from the catalyst (radiant energy - hot exhaust gas) is effectively absorbed by the heat exchanger, making it possible to lower the temperature of the catalyst, something that cannot be done with ordinary high-temperature catalytic combustors. Combustion becomes possible near the theoretical combustion air amount (〃2-1).

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional catalytic combustion water heater in which a heat exchanger is arranged at the rear of a honeycomb-shaped catalyst body; Fig. 2 is a side sectional view of a catalytic combustor according to an embodiment of the present invention; Figure 3 (a)
, (b) is an open-plan cross-sectional view and a side cross-sectional view, and FIG. 4 is a same-side cross-sectional view. 3... Catalyst body, 9... Heat exchanger, 17
...Heat exchanger, 19...Fin, 20...
···Heat exchanger. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 2 /4 /3 Figure 3 Figure 4

Claims (1)

[Scope of Claims] (1) The catalyst body is a cylindrical heat-resistant ceramic carrier with ventilation pores, and a platinum group metal or a metal oxide having a catalytic effect is supported on the carrier. , a catalytic combustion water heater with a heat exchanger installed close to its outer periphery. (2) The catalytic combustion water heater according to claim 1, wherein the heat-resistant ceramic is made of alumina, mullite, cordierite, zirconia, mullite-zircon, aluminum titanate, silicon carbide, or the like. (3) The catalytic combustion water heater according to claim 1, wherein the heat exchanger has a cylindrical shape and is spaced at regular intervals around the outer periphery of the catalyst body. (The catalytic combustion water heater according to claim 3, which has a structure in which a plurality of vertical fins are connected to the inner periphery of a 4-cylindrical heat exchanger. (5) The heat exchanger is located close to the outer periphery of the catalyst body. The catalytic combustion water heater according to claim 1, which is a spiral heat exchange pipe. (6) The catalytic combustion water heater according to claim 1, wherein the catalyst body is combusted at a temperature in the range of 700'C to 1.400°C. Catalytic combustion water heater as described in section.