JPS59134407A - Catalytic burner - Google Patents

Abstract

PURPOSE:To lower the temperature of a catalyzer and consequently prevent the catalyzer from being deteriorated due to high temperature by a structure wherein the red-hot catalyzer is placed as near as possible to a liquid fuel evaporating cylinder so that the energy required by evaporating liquid fuel can be supplied by the heat of catalytic combustion and at the same time heat is released from the catalyzer. CONSTITUTION:A combustion cylinder 4 made of aluminum or cast iron, a fuel evaporating cylinder 5, which evaporates liquid fuel by heating, and a flow straightening plate 7 for uniformly supplying evaporated fuel-and-air mixture to a catalyzer 6 are made into an integral body in a catalytic burner with a catalyzer temperature of more than 1,000 deg.C for application to a space heater or the like. The catalyzer 6, on the periphery of which heat insulating material 8 is wound, is inserted in the inside of the combustion cylinder 4 so as to leave a gap between the flow straightening plate 7 and the catalyzer 6 with a distance less than 20mm.. A large number of small holes 9 are bored over the flow straightening plate 7 so as to set the velocity of fuel gas passing through the small holes 9 faster than the burning velocity of the fuel gas burning on the catalyzer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention supplies various evaporated or atomized liquid fuels together with combustion air onto a catalyst body, causes an oxidation reaction on that surface, and reduces the amount of heat generated. The present invention relates to the structure of a catalytic combustor having a catalyst temperature of 100° C. or higher, which is used in heaters and the like.

Conventional configuration and its problems The conventional configuration of this type of catalytic combustor is as shown in FIG.
is installed, and a flame plate 3 is placed in front of it, and in the early stage of combustion, a small flame is formed on the flame plate 3 to H, and the catalyst body 1 is heated to the extent that it can exhibit its oxidizing ability. The company had shifted to catalytic thermal sintering. However, with this method, it is difficult to replenish the energy for evaporating the liquid fuel with the heat generated from the catalyst (in the example shown in Fig. In addition, in the configuration shown in Figure 1, the position where the temperature rises the most is on the back side of the catalyst body 1, that is, near the gap between the catalyst body 1 and the flashback prevention plate 2, and if the temperature rise is too significant, There is concern about deterioration of the catalyst.

Purpose of the Invention The present invention solves the problems of the prior art.The purpose of the present invention is to place the red-hot catalyst as close to the liquid fuel vaporization tube as possible, and to utilize the energy for vaporization of the liquid fuel by catalytic combustion without relying on electrical energy such as a sheathed heater. By replenishing with heat and releasing heat from the catalyst, the temperature of the catalyst is lowered and deterioration of the catalyst due to high temperatures is prevented.

Structure of the Invention In order to achieve this object, the present invention replaces the flashback prevention plate and the flame port plate (the flame port plate is used to temporarily form a flame when igniting catalytic combustion), which have been used in the conventional structure. During normal catalytic combustion, it is used as a rectifier plate that has the role of rectifying the fuel). Moreover, since this integrated plate (hereinafter referred to as a rectifying plate) is also integrated with the liquid fuel vaporization tube and the combustion tube, the transfer of heat from the loaf can be made extremely smooth.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 2. Vertical cylindrical combustion tube made of aluminum or cast iron4. A fuel vaporization node 5 that heats and vaporizes liquid fuel and a baffle plate 7 that uniformly supplies a mixed gas of vaporized fuel and air to the catalyst body 6 are integrated.

A catalyst body 6 whose circumference is wrapped with a heat insulating material 8 is fitted inside the combustion cylinder 4 with a gap of 20 mm or less between it and the current plate 7 . A large number of small holes 9 are bored in the current plate 7, and the speed of the fuel gas passing through the small holes 9 is adjusted to the catalyst body 6.
The combustion speed is set to be higher than the combustion speed of the fuel gas combusted above. A sheathed heater 1o is installed inside the fuel carburetor 5.
is embedded in the sheathed heater 1o, and the heat from the sheathed heater 1o is efficiently transferred to the rectifying plate 7. The structure is such that both the fuel vaporization cylinders 6 are heated.

The fuel vaporization cylinder 6 is connected to a burner case 11, and a motor 12 for feeding fuel air and turning liquid fuel into fine particles is installed in the burner case 11 so that its main axis is oriented vertically. Main shaft 1 extending above the motor 12
The tip of No. 3 protrudes into the fuel vaporization tube -6, and the tip of the tip is a liquid fuel atomization plate 15 that sprays the liquid fuel as fine particles onto the vaporization surface 14, and a liquid fuel atomization plate 15 that sprays the atomized liquid fuel in the axial direction. A truncated cone-shaped cone 17 is placed between the liquid fuel atomizing plate 16 and the main shaft 13 to spread the liquid fuel smoothly to the liquid fuel atomizing plate 16. It plays a role in guiding. A turbo fan 1 fixed to the main shaft 13 is located at the center of the main shaft 13.
8 are provided in multiple stages (two stages in FIG. 2), and a blowing chamber 20 is configured by a combination of guide vanes 19 fixed to the burner case 11 for discharging to each turbo fan 18 (Ill). The static pressure can be increased by increasing the number of stages in combination.In addition, an air intake port 21 is provided on the lower flank of the burner case, and the burner case 1
There is a primary air inlet 22 on the front side of the fuel carburetor 6.
It is opened inward. The supplied liquid fuel reaches the surface of the cone 17 through a liquid fuel introduction pipe 23 by an electromagnetic pump (not shown). Furthermore, the catalyst body 6
An electrode 24 is installed on the top surface of the catalyst to form a flame on the top surface of the catalyst at the initial stage of combustion.

Next, the operation of the above configuration will be explained.

First, an electric current flows through the sheathed heater 10 embedded inside the fuel vaporization cylinder 6, and the fuel vaporization cylinder 6 itself is heated.

The temperature at the vaporization surface 14 of the fuel vaporization tube 5 is 250°C to 3
When the temperature reaches 30°C, the motor 12 starts to rotate, and after a few seconds, an electromagnetic pump (not shown) to feed the liquid fuel starts to operate, passing through the liquid fuel introduction pipe 23 to the main shaft 13 connected to the motor 12. A truncated cone located at the tip 1
The liquid fuel flows along the side wall of the liquid fuel atomizing plate 16 and becomes fine particles from the edge of the liquid fuel atomizing plate 16 and is blown off to the vaporizing surface 14.

On the way, the blown particles are further spread in the axial direction by the liquid fuel diffusion plate 16, and the particles are further made finer.

These liquid fuel particles hit the vaporization surface 14, are heated, and vaporized at that location. On the other hand, as the motor 12 rotates, the turbo fan 18 connected to the main shaft 13 is also rotated. When the turbo fan 18 generates wind pressure, combustion air passes through the air intake port 21 → the blowing chamber 20 → the secondary air introduction port 22, enters the fuel vaporization cylinder 5, and the liquid evaporated by the vaporization surface 14. It passes through the small holes 9 of the baffle plate 7 together with the fuel gas, causing oxidative heat generation on the surface of the catalyst body 6.

When the present combustor is ignited, the ignition electrode 24 generates a spark L7 and a flame is formed on the upper surface of the catalyst body 6. At this time, A7y...the air/fuel ratio is set to be 1.1 to 1.5, making it easy to ignite. After a while, the catalyst body 6 is gradually heated by the flame on the top surface of the catalyst body 6, and the transition to catalytic combustion begins, and the catalyst body 6
The flame on the surface disappears. At this time, it is better to increase the A/F value to -L by about 1.7 to 2.7 (it is better to use slightly diluted combustion in catalytic combustion) and shift to steady combustion. During steady combustion, the back surface of the catalyst body 6 becomes quite red hot, and the radiant heat is transferred to the rectifier plate 7.
It flows into the connected liquid fuel vaporization cylinder 5 and is used for heating the liquid fuel sprayed on the vaporization surface 14 and the secondary air. Although the baffle plate 7 is located near the red-hot catalyst body 60, it is made of a material and shape with good heat conductivity, so the temperature does not rise that much, and even if it reaches its maximum temperature, it will reach about 350°C. . Moreover, the temperature around this range was convenient because it was the optimum temperature for vaporizing liquid fuel such as kerosene.

Note that the area near the current plate T is quite high and is in an environment where backfire is likely to occur on the side of the flow from the current plate 7, but the small hole 9 is made small and the speed of the fuel airflow passing through the small hole is set to this temperature. There is no need to worry as long as the fuel combustion speed is set at or above the fuel combustion speed.

Effects of the Invention According to the catalytic combustor of the present invention, the following effects can be obtained.

(1) It is now possible to feed the combustion heat to the liquid fuel vaporization section, which was impossible in conventional catalytic combustors, and there is almost no need for anything other than a heater during initial preheating.

(2) The temperature on the back surface of the catalyst could be lowered.

Although the temperature on the back side of the catalyst differs depending on the combustion conditions, the conventional maximum temperature was about 1500°C, but by using this method, it was possible to lower it by about 200°C to about 1300°C. This can extend the life of the catalyst. Note that the above values are based on the size of the catalyst body: 110φ×201. combustion i
(Actually, this is when 5A was performed at 3,200K, p/h.

(3) Since the catalyst body is placed directly above the rectifying plate with almost no gap between them, and combustion is completed within the catalyst body, the structure can be made significantly more compact than the conventional structure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an analytical view showing an example of a conventional catalytic combustor, and FIG. 2 is a sectional view of a catalytic combustor according to an embodiment of the present invention. 4... Combustion tube, 5... Liquid fuel vaporization tube, 6.
... Catalyst body, 7... Current plate. Name of agent: Patent attorney Toshio Nakao and 1 other person2

Claims (2)

[Claims] (1) It has a structure that allows high-temperature catalytic combustion (1000°C or higher) on the surface of the catalyst body, and includes a rectifier plate installed at the end of the catalyst body, a liquid fuel vaporization tube that heats and vaporizes the liquid fuel, and the catalyst body. The combustion tube held therein is integrally constructed, and the distance between the catalyst body and the rectifier plate (ri 20
Catalytic combustor with a temperature within am. (2) The catalytic combustor according to claim 1, wherein the baffle plate, liquid fuel vaporization tube, and combustion tube integral structure are made of a single block of aluminum die-casting or cast iron die-casting.