JPS59202311A - Catalytic burner - Google Patents

Abstract

PURPOSE:To enable cleaning of exhaust gas through stable and efficient flameless combustion of fuel on a catalyst body in a ratio of the air to the fuel which covers a wide range, by a method wherein bored holes in an injection plate are ununiformly disposed. CONSTITUTION:An injection plate 10, having a number of bored holes 9 which are divided into 6 blocks for arrangement, is disposed ahead of evaporation premixing cylinder 5 so that it is formed integrally with the evaporation premixing cylinder 5. A cylindrical combustion cylinder 11 of a heat resisting metal is further joined thereto. A back fire preventing plate 12, a catalyst body 13, and a honeycomb shut-off plate 14 for preventing the cooling action of the open air on the catalyst body 13, are disposed, in order as one faces the front, to the combustion cylinder 11. This minimizes the possibility of the occurrence of back fire even if an excess rate is decreased, enables to perform combustion in the vicinity of a theoretical combustion air amount, allows to obtain a wide combustion width, and permits stable combustion of the fuel.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides premixing of various gaseous fuels or vaporized liquid fuels with combustion air and supplying the mixture to a catalyst body, causing an oxidation reaction on the surface of the catalyst body, and then catalyzing the catalyst. This invention relates to a catalytic combustor that generates heat in a medium and utilizes the generated heat.

Conventional 9-hole structure and its problems In a conventional catalytic combustor, as shown in Figs. 1 and 2, the perforations 3 in the ejection plate 2 behind the catalyst body 1 are uniformly distributed over the entire surface of the ejection plate 2. was taking it. Therefore, when the amount of air is reduced and the combustion area is moved to the vicinity of the back surface of the catalyst body 1, when the radiant heat from the catalyst body 1 is received, the perforations 3 of the jet plate 2 are evenly distributed, so the jet plate 2 Since the temperature of the entire unit was uniformly high, the flashback temperature was reached early, and a flame was formed on the blowout plate 2, causing a so-called flashback condition.

Therefore, in order to maintain flameless combustion on the catalyst body, the amount of air can only be reduced to a certain extent, and as a result, it has been difficult to obtain a wide combustion width.

Purpose of the Invention The present invention is capable of solving such conventional problems, and enables stable and efficient flameless combustion of fuel on a catalyst body even under a wide range of air-fuel ratios, while at the same time producing clean exhaust gas. The purpose of the present invention is to provide a fuel combustor.

Structure of the Invention In order to achieve the above object, in the present invention, the perforations of the ejection plate are arranged non-uniformly. That is, the ejection plate was divided into several blocks, a perforation collecting part was arranged in each block, and a non-perforated part was provided between each perforation collecting part. With this configuration, even if the combustion area can be moved closer to the back side of the catalyst by restricting the amount of air, even if it receives radiant heat from the catalyst due to the uneven perforation distribution of the ejection plate and the presence of non-porous areas, The temperature of the entire blowout plate does not rise uniformly, and some cooling parts remain, making it difficult for flashbacks to occur. Therefore, even if the amount of air is further reduced, flameless combustion can be achieved safely, and combustion can be performed with an amount of air closer to the theoretical amount than before.

As a result, the combustion width is wider than before, and the TDR is wider than before.
It is now possible to secure

Description of examples FIG. 3 shows an embodiment of a catalytic combustor according to the present invention.

It is shown in FIG. 4 and will be explained accordingly.

A resistance plate 6 made of wire mesh or punching metal is installed inside the vaporization premixing cylinder 5 in which the sheathed heater 4 is buried, and a fixed plate 8 having an air lower in the center is installed behind the vaporization premixing cylinder 5.
are joined.

On the other hand, in front of the vaporization premixing cylinder 6, an ejection plate 10 in which a large number of perforations 9 according to the present invention are divided into six perforation collection parts is installed so as to form an integral structure with the vaporization premixing cylinder 5. Furthermore, a cylindrical combustion tube 11 made of heat-resistant metal is joined. Inside the combustion tube 11, a flashback prevention plate 12, a catalyst body 13, and a honeycomb shielding plate 14 for suppressing the cooling effect of outside air on the catalyst body 13 are sequentially installed in the front thereof. '-1, there is 17 in the sacrum 1 just in front of the ejection plate 10.
A war plug 15 is installed so as to penetrate through the combustion tube 11. On the other hand, at the tip of the shaft 16 facing into the vaporization premixing cylinder 5, there is a circular trapezoidal cone 1 whose diameter is larger toward the front.
7. Rotating plate 18, mixing plate 1 having small stirring blades on the peripheral edge
℃ is fixed sequentially.

The tip of the cut oil supply pipe 20 is installed so as to open to the side of the cone 17.

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

When the sheathed heater 4 is energized and the inner wall surface of the vaporization premix cylinder 5 reaches a predetermined temperature, the fan and electromagnetic pump (both not shown) are energized and the supply of air and liquid fuel is started. The liquid fuel is supplied to the rotating cone 1 by the fuel supply pipe 20.
7 and along the rotary plate 18 along the taber of the coe 717.
When the temperature reaches 1, the particles are scattered in the circumferential direction due to the rotational force and collide with the inner wall surface of the vaporization premix cylinder 4, which is kept at a constant temperature.
Vaporizes immediately. On the other hand, the air fd taken in by the fan is sent into the vaporization premix cylinder 4 from the air lower, and is uniformly mixed with the vaporized liquid fuel by the mixing plate 19 to become premix head gas. After the premixed gas has passed through the resistance plate 6 and the ejection plate 10, it is ignited by the ignition glove 16 which is energized and generates a system spark. At the initial stage of ignition, a blue flame is formed in front of the ejection plate 10, and in this state, the catalyst body 13 reaches the activation temperature as it receives radiant heat from the flame and heat transfer from the combustion tube 11. After that, once the fuel supply is stopped to extinguish the flame, and then the fuel supply is immediately resumed, the premixed gas does not form a flame, but remains flameless on the catalyst body 13 that maintains the activation temperature. Combustion begins. At this time, the honeycomb shielding plate 14 installed in front of the catalyst body 13 receives radiant heat from the catalyst body 13 and is heated by the combustion exhaust gas flow, and the temperature rises to about 800 to 12 oo degrees Celsius. Therefore, since the catalyst body 13 receives radiant heat from the honeycomb shielding plate 14, the catalyst body 13 uniformly maintains the activation temperature. Therefore, the premixed gas is completely oxidized on the catalyst body 13, and the combustion state is stabilized. On the other hand, the perforation 9 of the ejection plate 10
As shown in FIGS. 3 and 4, they are assembled in blocks divided into six locations, and since there is a non-porous part between each block, the combustion area is moved to the vicinity of the back surface of the catalyst body 13. Even if the ejection plate 10 receives radiant heat from the catalyst body 13, the temperature of the entire ejection plate 10 does not rise uniformly, and a cooling portion remains, making backfire more difficult than before. Therefore, the stable combustion region can be expanded.

As data demonstrating the effects of the catalytic combustor of the present invention, FIG. 5 shows the difference in combustion characteristics when using the ejection plate seen in the conventional example and the ejection plate seen in the embodiment of the present invention. A conventional example and an example of the present invention were used. In the figure, white circles indicate the case where the ejection plate seen in the conventional example is used, and black circles show the case where the ejection plate seen in the embodiment of the present invention is used, with the upper limit indicating the upper limit of combustion and the lower limit indicating the lower limit of combustion. The definition of upper and lower combustion limits is that when the amount of combustion air is decreased and increased, respectively, the amount of CO in the exhaust gas increases.
001 degrees is the limit at which unburned gas starts to occur, and the difference between the upper and lower combustion limits is defined as the combustion width.

As seen in FIG. 6, when the ejection plate according to the present invention is used, the combustion upper limit is at a higher position and a wider combustion width is maintained. In other words, stable combustion is now possible even when the amount of air is reduced and combustion is performed at a location close to the theoretical combustion air amount.

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

(1) By having a perforation collecting part divided into several blocks and installing a blowout plate with a non-perforated part between each perforation collecting part, flashback is less likely to occur even if the excess air ratio is lower than before. , combustion is now possible near the theoretical combustion air amount.

(2) By bringing the excess air ratio at the flashback limit closer to 1, a wider combustion width than before can be obtained, making stable combustion possible.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the main part of a conventional catalytic combustor, FIG. 2 is a plan view of the same jet plate, FIG. 3 is a longitudinal sectional view of an embodiment of the catalytic combustor according to the present invention, and FIG. 4 Figure 5 shows a plan view of the same ejection plate.
Is the diagram conventional? 11 is a comparison diagram of combustion characteristics when using No. 11 and an example of the present invention. FIG. 9... Perforation, 10... Ejection plate, 13... Catalyst body, Name of agent Patent attorney Toshio Nakao Haga 1 Kebori 1 Figure 3 Figure 4

Claims (4)

[Claims] (1) A catalyst body supporting an oxidation catalyst on the downstream side of a premixed airflow of gaseous fuel or vaporized liquid fuel and combustion air;
A catalytic combustor that has a perforation collection section divided into several blocks on the upstream side, and an ejection plate that has a non-perforated section between each perforation collection section. (2) The catalytic combustor according to claim 1, in which the perforation gathering portion of the ejection plate is divided into 4 to 8 blocks. (3) The catalytic combustor according to claim 1, wherein the perforations of the ejection plate are circular in shape. (4) The catalyst contains Ni, Co, Fe, Cr on the carrier.
The catalytic combustor according to claim 1, which supports one or more types of transition metal oxides such as the following.