JPH01111115A - Preheating device for oxidization catalyst combustion type gas heater - Google Patents

Abstract

PURPOSE:To provide a safe preheating unit, facilitate its handling and enable it to be used for multi-purpose both at indoor and outdoor areas by a method wherein preheating flame and igniting means and preheating flame diminishing means are provided near a mixing pipe in a gas heating unit provided with an oxidization catalyst plate for fuel gas at an upper part of a combustion chamber. CONSTITUTION:An extremity end of a mixing pipe 3 is provided with a preheating flame igniting means 6. A bottom surface of the combustion chamber 4 is made such that it has a deep depth at an inserting side of an air mixing pipe 3, the depth is shallow as it approaches an opposite side and a central depth is made shallow in particular so as to expand in a rightward or a leftward direction. Even if an oxidization combustion surface 11 is inclined, an approximate uniform combustion surface can be attained. A temperature sensor 20 is arranged within the combustion chamber 4, an extremity end sensing part 21 is abutted against a bottom surface of the oxidization catalyst plate 5, and a safety device is arranged to make a rapid closing of a gas valve in reference to a difference in temperature in respect to a main sensing part 22. A flame port opening or closing plate 12 biased by a bimetal plate 19 at an open end port of porous pipe 18 of a mixing pipe 3 is made close to it under a normal temperature. As a preheating flame is ignited, a temperature of the bimetal 19 is increased, an open end port of the porous pipe 18 is fully opened to eliminate the preheating flame and then only mixture is continued to be supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a preheating device for raising the temperature of a catalyst in an oxidation catalyst combustion type gas heater to an appropriate temperature required for oxidation of gas by the oxidation catalyst.

<Prior art> An oxidation catalyst combustion type gas heater burns butane or propane gas to an oxidation catalyst consisting of platinum, rhodium, baradium, iron, nickel, chromium, etc., or their oxides, or a mixture of two or more of these. LPG (liquefied petroleum gas), natural gas, city gas, etc. are supplied and oxidized and burned in a flameless state, and the generated heat is used for heating, space heating, etc.

In order for the catalyst to enable oxidative combustion, it is necessary to heat the catalyst at an early stage until it reaches a predetermined temperature above the catalyst active point.

Conventionally, as a method for heating this oxidation catalyst, which is used in cooking appliances, for example, a method has been adopted in which flaming combustion occurs at the top of the oxidation catalyst layer and the catalyst is warmed by radiant heat that is transmitted downward. was.

<Problems to be Solved by the Invention> However, such conventional methods cannot meet the demand for rapid heating of the catalyst, and also have the disadvantage of extinguishing fires due to strong winds. In other words, it cannot be used as a multi-purpose gas heater that can be used outdoors or with the oxidation catalyst surface tilted.

In order to solve this problem, the present invention provides a combustion chamber (4) to which air-mixed gas is supplied below the flameless oxidation combustion surface (11) in which the oxidation catalyst plate (5) is housed. 4)
A preheating flame ignites means (6) and a preheating flame extinguishing means near the mixing pipe (3) that sends the mixture to the combustion chamber (4). We decided to solve this problem by providing a .

In order to achieve such a structure, it was particularly important to develop a preheating flame extinguishing means that burns without stopping the gas supply.

<Means for Solving the Problems> Therefore, in the present invention, various studies were carried out, and in particular, a new structure of the preheating flame extinguishing means was studied, and the structure has now been completed.

Its structure is based on the heating of a bimetallic plate (19) that partially closes the end of the mixing tube (3) led into the combustion chamber (4).
The opening area has been expanded, the combustion speed has been accelerated to accelerate the combustion inside the combustion chamber (4), and a large amount of air-fuel mixture is supplied to the mixing tube (3). Air supply such as bimetal drive of mixing pipe (3) Opening adjustment plate (
15) can be exemplified by a structure in which the air supply port (16) is opened.

Effect> By adopting the above structure, the oxidation catalyst plate (5
) is preheated by flame combustion in the combustion chamber (4) until it reaches the activation temperature, and when the predetermined temperature is reached, the combustion chamber (4
) When the internal temperature rises, oxidation by the catalyst begins, and the combustion rate is accelerated, and the bimetal plate (19) that partially blocks the outlet of the mixing tube (3) recedes, reducing the opening area and increasing the mixing speed. The air supply port (16) can be opened by passing a large amount of air, or by using the air supply port opening adjustment plate (15).
By opening the gas flame, excessive air will blow out the gas flame.
The preheating flame is extinguished while the gas supply continues.

<Example> Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a cross-sectional view of a catalytic combustion type gas heater equipped with a preheating device of the present invention toward the center of FIG. 2, and FIG. 2 is a plan view with an oxidation catalyst plate removed.

The illustrated catalytic combustion gas heater mainly consists of a gas supply section (1) and a gas combustion section (2), and the gas combustion section (2) has a combustion chamber (3) with a mixing pipe (3). 4) has a fuel gas oxidation catalyst plate (5) above it. A preheating flame ignition means (6) is provided inside or at the outlet of the mixing tube (3). The gas supply section (1) has a cartridge filling chamber (7) in which a gas cylinder (8) is loaded and held.
A conventionally known piezoelectric element or the like is provided in the cartridge filling chamber (7), and a spark discharge or the like is generated by operating an ignition knob (1o) attached thereto that adjusts the gas flow rate.

The gas combustion section (2) is characterized in that it enables catalytic oxidation of fuel gas. Oxidizing combustion surface (11) of gas combustion section (2)
) The fuel gas enters the combustion chamber (4) from the air mixing pipe (3) connected to the combustion chamber (4), and then enters the catalyst holding chamber (13).
supplied to A discharge plug (14) of a preheating flame ignition means (6) is provided at the tip or inside of the air mixing tube (3). Any fuel gas can be used as long as it is a gas at room temperature, but in the case of the present invention,
LPG (liquefied petroleum gas) such as butane and propane gas,
Natural gas, city gas, etc. are suitable.

An oxidation catalyst plate (5) supported on a lattice-shaped inorganic carrier is held on the upper surface of the catalyst holding chamber (13).

After this oxidation catalyst plate (5) is heated by a preheating device which will be described in detail later, it is possible to generate heat by catalytic oxidation of the fuel gas. As an oxidation catalyst, platinum, rhodium, baradium,
Iron, nickel, chromium, etc., their oxides, or mixtures of two or more of these are known, but they have good oxidizing properties to fuel gas at low temperatures, can be used in a wide temperature range, and have a long life. In this example, a platinum catalyst was used as a catalyst that satisfies these conditions. As a carrier for such a catalyst, an inorganic carrier such as rock wool, silica, alumina fiber, glass fiber, etc. is preferable. The preheating mechanism of the oxidation catalyst is the most characteristic feature of the present invention; This point will be explained in detail.

FIG. 1 shows a first embodiment of the preheating device of the present invention. A gas conduit (17) is connected to the air mixing tube (3) connected to the combustion chamber (4), and an air supply port (16) is also provided near the gas conduit (17). A discharge plug (14) as a preheating flame ignition means (6) is provided at the tip of the mixing tube (3) or inside it. This preheating flame young means (6)
Other structures may be used, for example, a piezoelectric terminal may be provided near the open end of the mixing tube (3), or known means such as a current-carrying heating element such as a nichrome wire may be used.

As shown in Figure 1, the bottom of the combustion chamber (4) is deep on the insertion side of the air mixing pipe (3), shallower toward the opposite side (right side), and is especially shallow in the center, spreading out to the left and right. is encouraging. As a result, even if the oxidizing combustion surface (11) is inclined as shown by the dashed line in FIG. 1, a fairly uniform combustion surface can be obtained. In order to prevent raw gas from being ejected due to a misfire, a temperature sensor (20) is installed in the combustion chamber (4), and its tip detection part (21) is brought into contact with the bottom of the oxidation catalyst plate (5), A safety device is provided to emergency shut off the gas valve due to the temperature difference with the detection part (22).

A first example of the preheating flame extinguishing means is shown in FIG. Mixing tube (3
) A porous pipe (18) is inserted into the outlet of the porous pipe (18), and a stainless steel flame opening/closing plate ( 12) are close to each other at room temperature. When the preheating flame is ignited, the temperature of the bimetal (19) rises due to the flame in the flame hole, and the open end of the porous pipe (18) is completely opened to expand the flame opening area, extinguishing the preheating flame, and mixing. It is possible to continue supplying only Qi.

The preheating flame extinguishing means in the preheating device of the second example shown in FIG. The oxidation reaction also accelerates the combustion rate, thereby extinguishing the preheated flame. Even during such a process of extinguishing a fire, the gas supply is not stopped and the gas necessary for combustion can be supplied.

FIG. 4 shows a third example of the preheating flame extinguishing means.

In this example, an air supply port opening adjustment plate (15) is provided at the air supply port (16) of the mixing tube (3). The base of the air supply opening adjustment plate (15) is fixed to a bimetal (19) attached to the combustion chamber (4). The air supply port opening adjustment plate (15) is normally the air supply port (16).
The bimetal (19
), the air supply port (16) is opened by urging the air supply port opening adjustment plate (15), and the air supply is excessively supplied, thereby extinguishing the preheating flame. In order to provide the air supply port opening adjustment plate (15) so that the air supply port (16) is opened excessively when necessary, it is necessary to set the air supply port opening adjustment plate (15) in such a manner that the air supply port (16) is opened excessively when necessary.
It is also possible to construct a structure in which a cylindrical air supply port opening adjustment plate is extrapolated onto the plate and made slidable.

As explained above, in the preheating device for the oxidation catalyst combustion type gas heater of the present invention, the air mixture gas is supplied below the flameless oxidation combustion surface (11) in which the catalyst (5) is accommodated. A combustion chamber (4) is provided, and the structure is such that a preheating flame burns within the combustion chamber (4) to directly heat the catalyst from below, and the air-fuel mixture is sent to the combustion chamber (4) near the mixing pipe (3). It is characterized by providing a preheating flame ignition means (6) and a preheating flame extinguishing means. Therefore, neither the preheating flame ignition means (6) nor the preheating flame extinguishing means are limited to the above-mentioned embodiments, and may be modified as appropriate to the extent necessary to achieve the object of the present invention.

<Effects of the Invention> Since the present invention has the above-described structure, the preheating flame can reach the temperature at which the oxidation catalyst in the gas combustion section is activated in the combustion chamber (4) below the catalyst without fear of extinguishing. When the oxidation catalyst reaches a predetermined temperature, the preheating flame is automatically extinguished, and the only thing left to do is to supply the mixture of gas and air to the combustion surface of the oxidation catalyst. The oxidation catalyst combustion type gas heater that has been implemented is safe, easy to handle, and can be used for a variety of purposes both indoors and outdoors.

[Brief explanation of the drawing]

FIG. 1 is a sectional view taken along line AA in FIG. 2 of a catalytic combustion type gas heater equipped with a preheating device of the present invention, and FIG. 2 is a plan view with an oxidation catalyst plate removed. FIGS. 3 and 4 are sectional views of main parts showing other examples of the preheating device. (1) Gas supply section, (2) Gas combustion section (3)
Mixing tube (4) Combustion chamber (5) Oxidation catalyst plate
(6) Preheating flame ignition means (7) Cartridge filling chamber (8) Gas cylinder (10) Ignition knob (
11) Oxidizing combustion surface (12) Flame opening/closing plate (13)
Catalyst holding chamber (14) Discharge plug (15) Air supply port opening adjustment plate (16) Air supply port (17) Gas conduit (18) Porous pipe (19) Bimetal (20)
) Temperature sensor (21) Tip detection section (22) Main detection section

Claims (1)

[Claims] 1. Consisting of a gas supply section (1) and a gas combustion section (2), the gas combustion section (2) oxidizes fuel gas in the upper part of a combustion chamber (4) having a mixing pipe (3). In a gas heater equipped with a catalyst plate (5), a preheating flame ignition means (6) is provided near the mixing tube (3).
) and a preheating flame extinguishing means. 2. The oxidation method according to claim 1, wherein the preheating flame extinguishing means is an expansion of the opening area by heating a bimetallic plate (19) that partially closes the end of the mixing pipe (3) led into the combustion chamber (4). Preheating device for catalytic combustion type gas heater. 3. The oxidation catalytic combustion type gas heater according to claim 1, wherein the preheating flame extinguishing means supplies a large flow rate of the air-fuel mixture to the mixing tube (3) by accelerating the combustion rate as combustion progresses in the combustion chamber (4). preheating device. 4. The preheating flame extinguishing means is the one set forth in claim 1 by opening the air supply port (16) by the air supply port opening adjustment plate (15) of the mixing pipe (3) provided in the combustion chamber (4). Preheating device for oxidation catalyst combustion type gas heater.