JPH0344977Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pot-type burner that burns liquid fuel or vaporized fuel in a bottomed cylindrical pot.

[Conventional technology]

Conventionally, a bottomed incandescent tube 7' has been used, as shown in FIG.
A pot-type burner in which a primary air hole 5 and a secondary air hole 4 are arranged around the pot 1 is disclosed in Japanese Utility Model Publication No. 54-10027 (or Japanese Utility Model Publication No. 1983-10027).
80410). Further, in this burner, a perforated mixing cylinder 15 is generally attached to the inner circumferential surface 8 side (or the opposite side) of the incandescent cylinder 7' by a stepped portion 16 (or directly). Conversely, there are cases where a red-hot tube is attached to a mixing tube. During steady combustion, a premixed gas is generated in the space between the red-hot tube 7' and the bottom of the pot, and this gas is supplied with secondary air to cause blue flame combustion.

[The problem that the idea attempts to solve]

However, in this burner, only about three stages of secondary air holes 4 are bored on the opposite surface of the glowing cylinder 7' in the pot periphery 6 and in the vicinity thereof, and the opening ratio of the primary air holes 5 and the secondary air holes 4 is small. Since the ratio is about 2:8, there is a limit to the combustion width, and generally during large combustion, CO/
CO ₂ will decrease, but during small combustion, there will be a lack of secondary air and CO / CO ₂ will increase, and of course there will be a bad odor (unburned gas).
HC) is also released. This characteristic can be understood from Figure 2, which shows turndown ratio (TDR) on the horizontal axis and CO/CO ₂ on the vertical axis, but the combustion width suitable for practical use with conventional burners is approximately TDR 0.4 to 1. It is.

In addition, during large combustion, there are many flames F that are spatially separated from the red-hot cylinder 7', so there is a problem of lifting of the flames F due to secondary air injection and cooling of the flame, as shown in Figure 7. are doing. Furthermore, in the case of the burner shown in the figure, the premixed gas of vaporized gas and primary air is directed toward the center of the upper part of the red-hot cylinder 7', where the temperature is highest, and due to the so-called draft effect, the premixed gas of vaporized gas and primary air flows as shown by the arrow in Figure 9. There is also the problem of lifting combustion, which occurs when the flame F is pulled in the direction of the arrow to form a flow.

By the way, if we try to solve the above-mentioned problem of small combustion width by simply increasing the number of secondary air holes 4, the flame will lift in the secondary air holes 4 that are sufficiently far from the red-hot tube 7 during large combustion, resulting in unstable combustion. As mentioned above, this occurs.

Therefore, the purpose of the present invention is to increase the combustion width and prevent lifting combustion. Another objective is to increase the area of the inner circumferential surface of the red-hot tube, increase radiant heat, and efficiently vaporize the supplied fuel.

[Means to solve the problem]

In order to achieve the above object, the present invention disposes a bottomed incandescent tube with the inner peripheral surface facing the bottom of the pot at the upper center of a cylindrical pot with a bottom through a support plate, and also provides primary air around the pot. In a pot type burner having a hole and a secondary air hole, the incandescent cylinder is formed with two or more steps to increase the vertical dimension of the incandescent cylinder, and the secondary air hole is formed in the pot. All of them are made to face the outer circumferential surface of the incandescent tube, and the opening ratio of the primary air hole and the secondary air hole is approximately 1:9.
It is characterized by being set to .

[Effect]

According to the present invention, since all of the secondary air holes and the outer peripheral surface of the glowing tube face each other, the flame formed in the secondary air holes hits the glowing tube, preventing the flame from expanding.

In addition, the space between the glowing tube and the pot where the secondary air holes are formed has a high atmosphere, which increases the combustion rate.

Furthermore, cooling of the pot is prevented due to the decrease in the amount of primary air, and by forming a stepped portion on the incandescent tube, the area of the inner circumferential surface of the incandescent tube increases, and the amount of radiant heat generated increases.

〔Example〕

Embodiments of the present invention will be described below mainly with reference to FIG.

In Fig. 3, reference numeral 1 denotes a cylindrical pot with a bottom, and an outer cylinder 2 is provided on the outer periphery of the pot 1 to form a blowing passage 3 for combustion air. (both not shown). Reference numerals 4 and 5 denote secondary air holes and primary air holes provided above and below the periphery 6 of the pot 1, respectively, and the opening ratio of these secondary air holes 4 and primary air holes 5 is approximately 9:1. . Reference numeral 7 designates a bottomed glowing tube, which is placed above the center of the pot by a support plate 9 with its inner circumferential surface 8 facing toward the bottom of the pot. Reference numeral 10 denotes a heating device that penetrates through the outer cylinder 2 and the pot periphery 6 to face the inside of the pot. A pipe 13 is inserted through the metal pipe 13, and a fuel supply pipe 14 is connected to one end of the metal pipe 13.

By the way, the above-mentioned glowing cylinder 7 is a perforated mixing cylinder 15.
A first step 16 is formed which fits into the first step 16.
Since the second step portion 17 is formed on the outer periphery of the step portion 16, the vertical dimensions are relatively large.

As is clear from Fig. 4, the secondary air hole 4
are all opposed to the outer circumferential surface of this incandescent cylinder 7.

When burning liquid fuel in the pot-type burner configured as described above, first the planar heating element 12 is made to generate heat to maintain the ceramic pipe 11 at a high temperature, while the fuel supply device (not shown) is turned off. It is driven to transfer the liquid fuel into the pot 1 through the fuel supply pipe 14 and the metal pipe 13. During the transfer of this liquid fuel, the fuel is transferred to the metal pipe 1 heated by the ceramic pipe 11.
3 and becomes vaporized gas.

On the other hand, a blower fan (not shown) is driven to supply air into the pot 1 through the blower path 3 and the primary air holes 5 and secondary air holes 4 provided around the pot 6.

In this state, the vaporized gas in the metal pipe 13 of the heating device 10 first comes into contact with the air at the tip of the pipe 13, ignites and spreads the flame, and at the same time, the air from the primary air hole 5 below the glowing cylinder 7 and vaporized gas are mixed. This premixed gas is then supplied with air from the secondary air hole 4 and combusts with a blue flame.

During combustion, the ceramic pipe 11 and the bottom of the pot are mainly heated by the radiant heat from the inner peripheral surface of the incandescent cylinder 7 and the combustion flame, and the liquid fuel is vaporized.

By the way, during a small combustion, a flame F is formed in the lower secondary air hole 4 as shown in Fig. 5, and during a large combustion, a flame F is formed in the entire secondary air hole 4 as shown in Fig. 6.
is formed.

Therefore, since the premixed gas is completely combusted through the secondary air holes 4 even during small combustion, the amount of CO/CO ₂ , that is, carbon monoxide in the exhaust gas, is significantly reduced as shown in the characteristic diagram shown in Figure 2. Of course, there is no unburned gas odor.

On the other hand, all of the secondary air holes 4 and the outer peripheral surface 1 of the incandescent tube 7
8, the flame F formed in the secondary air hole 4 hits the incandescent tube 7 as shown in FIG. 8, and the expansion of the flame F is prevented. As a result, lifting of the flame F can be physically prevented.

Furthermore, since the space between the incandescent tube 7 and the pot portion where the secondary air hole 4 is formed has a high atmosphere, the combustion speed increases and the probability of the lifting phenomenon occurring is further reduced.

Furthermore, the mixed gas mixed at the bottom of the glowing tube 7 is guided almost linearly as shown in FIG. stable.

Moreover, cooling of the pot 1 is prevented due to a decrease in the amount of primary air, and by forming the steps 16 and 17 on the incandescent cylinder 7, the area of the inner peripheral surface 8 of the incandescent cylinder 7 is increased, and the amount of radiant heat generated is increased. There will also be more. As a result, the fuel at the bottom of the pot can be quickly vaporized, allowing continued good combustion.

Furthermore, the concentration of the premixed gas becomes uniform due to the reduction in the amount of primary air, and the range of blue flame combustion is wide.

In the embodiment, the incandescent cylinder 7 is provided with a first step 16 that fits into the perforated mixing cylinder 15, and a second step 17 is provided on the outer periphery of the step 16, so that there are two steps in total. However, three or more step portions may be formed by reducing the step difference. Furthermore, although a special type of heating device that vaporizes and ignites the fuel is shown, the same effect as described above can be obtained even if a conventional general ignition heater is installed.

[Effect of idea]

As described above, in the present invention, all of the secondary air holes and the outer peripheral surface of the glowing tube face each other, so the flame formed in the secondary air holes hits the glowing tube, preventing the flame from spreading. As a result, flame lifting can be physically prevented.

Furthermore, since the space between the red-hot tube and the pot where the secondary air holes are formed has a high atmosphere, the combustion rate increases and the probability of the lifting phenomenon occurring is further reduced.

Furthermore, the mixed gas mixed at the bottom of the glowing cylinder is guided almost linearly by the vertical extension of the glowing cylinder, so the influence of drafts is reduced and the flame is stable.

Moreover, cooling of the pot is prevented due to the decrease in the amount of primary air, and by forming the stepped portion on the incandescent cylinder, the area of the inner circumferential surface of the incandescent cylinder increases, and the amount of radiant heat generated increases. As a result, the fuel at the bottom of the pot can be quickly vaporized, so that good combustion can be continued.

Furthermore, the reduction in the amount of primary air makes the concentration of the premixed gas uniform, which has the effect of widening the range of blue flame combustion.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the main parts of a conventional pot-type burner, Fig. 2 is a comparative characteristic diagram of the conventional burner and the burner of the present invention, Fig. 3 is a sectional view of the embodiment of the present invention, and Fig. 4
The figure is an enlarged cross-sectional view of a main part of a similar embodiment, FIG. 5 is an explanatory diagram of the operation of the same embodiment, showing a state where the amount of combustion is small, and FIG. 6 shows a state where the amount of combustion is large. 7th
8 are comparison diagrams of the combustion states of the conventional burner and the burner of the present invention, and FIGS. 9 and 10 are similar comparison diagrams, and are diagrams showing the influence of premixed gas on combustion. . 1...Pot, 2...Outer tube, 3...Air duct, 4
...Secondary air hole, 5...Primary air hole, 6...Pot periphery, 7...Incandescent tube, 8...Inner peripheral surface of the incandescent tube, 9
... Support plate, 10 ... Heating device, 11 ... Ceramic pipe, 12 ... Planar heating element, 13 ... Metal pipe, 14 ... Fuel supply pipe, 15 ... Mixing cylinder,
16...First step, 17...Second step, 18
...The outer circumferential surface of the red-hot cylinder.

Claims (1)

[Scope of utility model registration request] A bottomed incandescent cylinder with its inner peripheral surface facing the bottom of the pot was placed above the center of the bottomed cylindrical pot via a support plate, and primary air holes and secondary air holes were bored around the pot. In the pot-type burner, two or more steps are formed in the incandescent tube to increase the vertical dimensions of the incandescent tube, and all of the secondary air holes formed in the pot are formed on the outer peripheral surface of the incandescent tube. A pot-type burner characterized in that the primary air holes and the secondary air holes are opposed to each other, and the opening ratio of the primary air holes and the secondary air holes is set to approximately 1:9.