JP2631181B2 - Hot plate heating gas burner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas burner used for a pottery for fish and meat, and more particularly, to a heating plate which is heated to a red hot state by a gas burner of a forced combustion system, and radiant heat from the heating plate and combustion exhaust gas. The present invention relates to a so-called hot plate heating type gas burner of a type in which the object to be baked is baked by heating.

[0002]

2. Description of the Related Art As a gas burner of the above type, a gas burner shown in FIG. 14 (Japanese Utility Model Application No. 4-74193) has already been proposed.
In this invention, a burner pipe (21) is arranged below a hot plate (22) having an arc-shaped cross section, and the hot plate is formed by a flame formed in a group of flame holes arranged at the ridge of the burner pipe. (2
Since 2) is heated to a red-hot state, when used as a gas burner for a pottery apparatus of the type described above, both the radiant heat from the hot plate and the combustion exhaust gas burn the object to be fired such as fish and meat. Therefore, since the firing efficiency is good and the firing degree due to the radiant heat is high, the degree of burning of the oil component from the object to be fired and emission of smoke and soot is reduced.

[0003] However, even with this prior art, the latter problem, that is, the problem that the degree of generation of smoke and soot cannot be sufficiently reduced remains. In the prior art, since the hot plate (22) is heated by the flame formed in the flame hole of the burner pipe (21), the heating temperature of the hot plate (22) is relatively low. This is because the degree of radiant heat is insufficient.

The present invention has been made in view of the above point, and has been made in view of the problem that a hot plate (22) is provided at a predetermined interval above a burner pipe having a large number of flame holes at a ridge. It is an object of the present invention to make it possible to significantly reduce the generation of smoke and soot when baking an object to be fired.

[0005]

The technical means of the present invention for solving the above-mentioned problem is as follows: "The hot plate (22) is parallel to the burner pipe (21) as an elongated structure having a substantially semi-circular cross section that opens downward. And an excess air ratio of 1.0 to 1.0 in the burner pipe (21).
About 1.2 air-gas mixture is forcibly supplied and injected from the burner pipe flame so that the injected gas is burned in a thin film in an area along the cross section of the hot plate (22). I did. "

[0006]

The above technical means operates as follows. Since an air-gas mixture having an excess air ratio of about 1.0 to 1.2 is supplied into the burner pipe (21) at a predetermined pressure, the injected gas burns at a portion where it has collided with the inner surface of the hot plate (22). On the other hand, since the hot plate (22) has an elongated configuration in which a substantially semicircular cross section is uniformly continuous in the longitudinal direction, the combustion flame is
It is formed in the cross section of the hot plate (22). Further, since the excess air ratio is set high as described above, the temperature of the combustion flame is also higher than that of the type in which the flame extends from the flame hole.

Accordingly, the hot plate (22) is directly heated by the high-temperature combustion flame formed in a thin film along substantially the entire lower surface of the hot plate as described above. Higher than the ones. Further, the combustion flame does not overflow to the outside of the hot plate (22).

[0008]

[Effect] The temperature of the hot plate (22) is higher than that of the prior art, and the thin-film combustion flame formed along the inner surface of the hot plate (22) overflows to the outside of the hot plate (22). Since it does not come out, the radiant heat component of the gas burner is large, and the oil component dripped from the combustion flame and the material to be fired is less likely to come into direct contact with the combustion flame. Greatly reduced.

In addition, since the distance between the hot plate and the burner can be made closer as compared with Bunsen combustion, the thermal efficiency is increased.

[0010]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, a gas burner having the above-described configuration is arranged in parallel with a rectangular grate, and the present invention is applied to a pottery apparatus of a type in which an object to be baked is baked in an upper area thereof. The details of the pottery apparatus will be described below.

As shown in FIGS. 1 and 2, this pottery has a rectangular grate (10) which is open on the top of a casing (1).
A plurality of gas burners (2) and (2) comprising a burner pipe (21) and a hot plate (22) are arranged in parallel between the front and rear side walls in the grate (10), and the ( At the upper part of the front wall of (1), a front box (3) having an operation unit is provided, and a fan (30) is provided in the front box (3), and each of the gas burners (2) is used for combustion. An air supply device for supplying primary air is housed, and an ignition device is provided. On the other hand, a flame detection device is provided on the rear wall of the fire bed (10).

Hereinafter, these units will be described. [About gas burner (2)] The gas burner (2) is shown in FIG.
As shown in FIG. 5, it is composed of a burner pipe (21) and a hot plate (22). The burner pipe (21) is made of a metal pipe that is open at the front and has a flattened rear end and is closed.A pair of primary air holes (29) and (29) are provided near the open end. It is formed on the side wall. The closed end (23) is screwed to a rear bar (11) provided along the wall in the rear wall of the grate (10), and the other front open end is housed in an air supply device described later. It is supported by being fitted over the nozzle (24). Burner pipe (2
1) Since the rear end is screwed by the rear crosspiece (11), even if the front open end only fits outside the nozzle (24), the burner pipe (21) is in the grate (10). The arrangement position in the front-back direction is fixed. And multiple burner pipes (2
1) (21) are similarly supported and arranged in parallel.

As shown in FIG. 4, a large number of flame holes are arranged at predetermined intervals along the longitudinal direction on the top surface of each burner pipe (21), and a plurality of flame holes are provided near the closed end (23). Auxiliary flame hole (26)
(26) is formed. The opening direction of the auxiliary flame holes (26) is set in the radial direction of the cross section of the burner pipe (21) as shown in FIG. The gas burner (2) of this embodiment is used for natural gas.
(25a) (25a) group, the second flame hole (25b) (25b) group of the central part, and divided into three types of third flame hole (25c) (25c) group on the closed end (23) side,
The diameter of the flame hole on the closed end (23) side is set smaller than that of the other.

In this embodiment, in which the amount of combustion by one burner pipe (21) is 1200 Kcal, the first flame holes (25a) have a diameter of 1.9 mm, the number thereof is 16, and the second flame holes (25b). Is the diameter: 1.
The diameter of the third flame hole (25c) is set to 1.7 mm and the number is set to 23. The auxiliary flame hole (26) near the closed end (23) side of the third flame hole (25c) has a diameter.
Two 1.6mm flame holes are formed.

Above the burner pipe (21), a hot plate (22) is laid back and forth at regular intervals. This hot plate
(22), as shown in FIG. 3, is a configuration in which a heat-resistant strip-shaped metal plate is bent so as to have a semicircular cross-section, and is supported in a posture in which an open portion of the cross-section faces downward. In order to maintain the space between the burner pipe (21) and the hot plate (22),
As shown in FIG. 2, the rear end of the hot plate (22)
, And is supported by a bracket (12) protruding into a grate (10), and the other front end is supported by a bracket (27) provided on a burner pipe (21).

As shown in FIG. 6, the bracket (12) has a mounting piece (1) which is screwed to the rear rail (11) together with the closed end (23).
2b) and a rising piece bent upward from the front end;
It consists of a support part (12a) projecting forward from its upper end, and this support part (12a) is set so as to coincide with the inner periphery of the cross section of the hot plate (22). The ends are spot welded.

As shown in FIGS. 4 and 5, the other bracket (27) has a backing plate (27a) having an upright plate larger than the projection surface at the front end of the hot plate (22), and a base end portion thereof. And a receiving plate (27b) projecting in the longitudinal direction of the burner pipe (21).
A pair of mounting tongues connected to both sides of a horizontal plate extending from the lower end of the backing plate (27a) are fixed to both sides of the cross section of the burner pipe (21) by spot welding. Thereby, the receiving plate (27b) is arranged in parallel along the top of the burner pipe (21). Upright pieces (27c) and (27c) are continuously provided on both left and right sides of the receiving plate (27b).
2) the upright piece (27c)
The front end of the hot plate (22) is placed between (27c) and the front end surface of the hot plate (22) faces the backing plate (27a) at a predetermined interval.

By providing a predetermined height difference between the height of the receiving plate (27b) and the height of the support portion (12a), both ends of the rear bar (11) and the bracket (27) are provided. The hot plate (22) supporting is parallel to the burner pipe (21). In the gas burner (2), the hot plate (22) is heated by the gas blown out from the flame hole of the burner pipe (21), and becomes a red heat state. Therefore, the burner pipe (21) and the hot plate
Although thermal expansion occurs during use in (22), the burner pipe (21)
About, only the closed end (23) of the rear end is screwed,
Since the front open end only fits outside the nozzle (24), even if the thermal expansion occurs, it can be absorbed. Note that, due to this thermal expansion, the position of the primary air holes (29) (29) also moves to the nozzle (24) side, but in this embodiment,
The distance between the tip (gas discharge port) of the nozzle (24) and the primary air hole (29) in a state where no thermal expansion occurs is set to be longer than that of a normal Bunsen burner. The ejector effect due to the nozzle jet was weakened, and the control of the primary air by the fan was dominant, facilitating control.
Therefore, even in the state where the thermal expansion has occurred, the distance between the primary air holes (29) and (29) and the tip of the nozzle (24) is properly maintained under the above conditions, and the relative position between the two is improper. Adequate primary air will not occur.

On the other hand, a similar thermal expansion occurs in the hot plate (22), but the rear end of the hot plate (22) is fixed to the bracket (12), and the other front end is connected to the burner pipe (21 ) Are slidably supported by a bracket (27) fixed to the bracket (27). And the front end face of this hot plate (22) and bracket (27)
A predetermined gap is formed between the contact plate (27a). Therefore, even if thermal expansion occurs in the hot plate (22), the thermal expansion can be absorbed by the relative movement of the support portion by the bracket (27). In particular, in this embodiment, the bracket (27) is fixed to the burner pipe (21). Will move forward, so the bracket (27)
The amount of relative movement of the front end of the hot plate (22) in the support portion is also extremely small, and the inconvenience due to thermal expansion hardly occurs. [Air supply device] The air supply device includes the above-mentioned fan (30) and an air supply chamber (31) communicating with the discharge port of the fan (30). As shown in FIG. The nozzle (24) and the vicinity of the open end of the burner pipe (21) are accommodated therein. And
The pair of primary air holes (29) (29) of the burner pipe (21) is located in the air supply chamber (31).

The air supply device has a configuration in which one fan (30) and an air supply chamber (31) correspond to three gas burners (2) (2) arranged in parallel in the grate (10). The opening (32) formed below the juxtaposed portion of the three nozzles (24) and (24) on the bottom wall of the air supply chamber (31) formed in a rectangular parallelepiped box and the discharge of the fan (30). The outlet is communicated with the guide duct (33). Therefore, primary air for combustion is forcibly sent from the discharge port of the fan (30) into the air supply chamber (31), and this is the three burner pipes (21) (21).
Is forcibly supplied through the primary air holes (29) (29).

This gas burner (2) is of an all-primary air type, and air required for combustion is supplied by the supply air. A temperature fuse (34) is mounted on the upper surface of the air supply chamber (31) on the upper surface of the air supply chamber (31) in order to increase the safety of each gas burner (2) during backfire. This is inserted into an electric circuit for driving a solenoid valve as a gas switch which is inserted into the gas circuit, and the air supply chamber (3
1) When the temperature inside of the
(34) is turned off, combustion is stopped, and safety is ensured. [Ignition Apparatus] An ignition apparatus is provided for each gas burner (2), and is disposed below the burner pipe (21) in the front box (3) as shown in FIGS.

The igniter includes a pilot burner (41) formed by bending a relatively thin metal pipe into an L-shape, and a cathode portion attached to a horizontal tube extending horizontally at the upper end of the pilot burner (41). It comprises an electrode (43) opposed to (42) and a guide cylinder (44) arranged to face the horizontal tube and guiding the flame of the pilot burner (41) upward. The guide cylinder (44) is a box body having a rectangular cross section, and has a wall (45) whose tip wall faces obliquely upward and upward.

In this apparatus, when a gas is discharged from a pilot nozzle (46) provided at the lower end of the pilot burner (41) by the output of the ignition control device, at this time, the electrode (43) is moved from the electrode (43) to the cathode (42) for a certain period of time. ), Whereby the pilot burner (41) is ignited, and the flame of the pilot burner is guided upward, and from the opening (45) through the cross-sectional outer periphery of the burner pipe (21) as shown in FIG. Burner pipe (21)
And the hot plate (22). A certain time before this ignition operation, the fan (30) is turned on,
Since the gas circuit to the nozzle (24) is opened at the same time as the ignition operation, the air-gas mixture discharged from the flame hole formed at the top of the cross section of the burner pipe (21) is ignited and the gas burner ( 2) becomes a combustion state. Thereafter, the gas circuit to the pilot burner (41) is shut off and the pilot burner
(41) is extinguished, and only the gas burner (2) becomes in a combustion state. [Flame detector] Each gas burner (2) is provided with a flame detector near the closed end (23).

This device, as shown in FIGS. 2 and 6,
Auxiliary flame holes (26) (26) provided near the closed end (23)
Heated thermocouple (51) and its thermoelectromotive force start ignition operation
After the specified output level is reached within the set time,
Flame detection circuit (C ₁) And this flame detection circuit (C₁)
Is inserted into the gas circuit when the specified output from the
Output device (C_Two)
You. Therefore, the flame detection is performed within the set time after the start of the ignition operation.
Knowledge circuit (C₁) From the output device (C_Two)
The main valve is kept open and the gas burner (2)
Combustion continues, and conversely, even after the set time
Thermoelectromotive force from the thermocouple (51) does not reach the specified output level
In this case, the main valve will not be kept open,
In other words, the main valve is closed, and the ignition failure
Safety is ensured.

The thermocouple (51) generates a thermoelectromotive force when its tip is heated to a predetermined temperature. In this embodiment, the thermocouple (51) includes a bracket (12) and a backing plate (13). It is mounted so as to penetrate the rising pieces (12c) (13c), is held in a horizontal position by a holding plate (53) screwed to the rear crosspiece (11), and its tip end is an auxiliary flame hole (26) The holding position is determined so as to be located near and above (26).

Therefore, when the gas burner (2) is in a combustion state, the combustion flame from the auxiliary flame holes (26), (26), in particular, the stable combustion flame due to the impingement action, causes the tip of the thermocouple (51) to move. Is surely heated. [About Combustion of Gas Burner (2)] As described above, in the gas burner (2) of this embodiment, the primary air is forcibly supplied by the fan (30) and burns. Since the excess ratio is set to 1 to 1.2, the air-gas mixture discharged from each of the flame holes burns in a thin film state while colliding with the inner surface of the hot plate (22) having a semicircular cross section. In addition, the fire foot of this combustion flame is much shorter than that of the Bunsen burner, and its temperature becomes extremely high.

Accordingly, the combustion flame separates from the flame hole of the burner pipe (21), and forms a so-called thin-film combustion formed along the inner surface of the hot plate (22) as shown in FIG. In particular, since the hot plate (22) has a semicircular cross section, the combustion flame does not overflow outside the hot plate (22). Therefore, the hot plate (22) is efficiently heated, and the entire cross section of the hot plate (22) is uniformly heated.

The same applies to the flame formed by the auxiliary flame holes (26). In addition, natural gas and LP
In the case of a gas burner (2) for gas, if the combustion speed and the flow rate of the air-fuel mixture are to be ensured to ensure stable combustion, the total area of the flame holes in the burner pipe (21) will be reduced to other low wobbe gas species (except for A gas ) Are significantly larger than those for Therefore, when the air-gas mixture is forcibly supplied into the burner pipe (21) at the excess air ratio, the pressure distribution in the burner pipe (21) due to this supply pressure is reduced as shown in FIG. When the pressure increases from the upstream side to the downstream side and the diameter of the flame holes is kept constant, the distribution of the amount of gas ejected from each flame hole follows the pressure distribution.

However, in this embodiment, as described above, the group of flame holes of the burner pipe (21) is changed to the first flame holes (2
5a) (25a) group, 2nd flame hole (25b) (25b) group in the middle area, and 3rd flame hole (25c) (25c) group on the downstream side are divided into three groups, from upstream to downstream The diameter of the flame hole is gradually reduced toward.
Accordingly, the distribution of the jet gas amount when the flame hole diameter is fixed is corrected, and the amount of gas ejected from each part of the burn hole group of the burner pipe (21) can be made uniform. In the case of a low wobbe gas type (except for the A gas), the flame holes having a constant diameter may be arranged at a predetermined pitch because the flame hole total area is small. [Relationship between hot plate (22) and burner pipe (21)] In the above embodiment, as shown in FIG. 10, a hot plate (22) having a semicircular cross section with a radius of 10 mm was made to correspond to a pipe having a diameter of 13.8 mm. . In this embodiment, one gas burner (2) is used for 800 Kcal / h to 1200 Kcal.
cal / h range, in which case, as shown in the figure, the top of the hot plate (22) and the burner pipe (2
When the distance from the flame hole arrangement part (section top) of 1) was set to 12 mm, stable combustion could be ensured in the above combustion amount range, and the degree of generation of CO could be reduced.

Experiments were also conducted on the flammability of the dimensional relationships shown in FIGS. In this figure, a skirt portion (22a) of 2 mm to 3 mm is provided on the cross section of the hot plate. In this case, although wind resistance is ensured, FIG.
As shown in Fig. 3, the area where CO / CO ₂ is 0.01 or more is large,
It was not suitable for practical use. In this figure, CO / CO ₂ is 0.
Regions 01 and above are indicated by solid lines in the case of the burner in FIG. 10, by broken lines in the case of the burner in FIG. 11, and by dashed lines in the case of the burner in FIG.

The lifting area is similar to any type, and the boundary of this area is indicated by a line connecting triangular points. Further, each square point in the figure indicates a set point at the time of ignition and when the thermal power is "strong", "medium", or "weak". In these embodiments, since the primary air is supplied by the fan (30), the rotation speed of the fan (30) is plotted on the vertical axis in the figure, and the number of revolutions per one gas burner corresponding to the amount of combustion gas is plotted on the horizontal axis. The calorific value was adopted. The fan rotation speed corresponds to the supplied primary air amount. [Others] The gas burner (2) is of the all-primary air type, which is forcibly supplied by the fan (30) as described above, and the flame holes which have collided and diffused on the lower surface of the hot plate (22) As shown in FIG. 7, the gas ejected from the combustion chamber is directly or by a thin high-temperature combustion film formed on the lower surface of the hot plate (22) above the auxiliary flame holes (26) and (26). The tip of the thermocouple (51) is heated by the radiant heat from the combustion film. Therefore, even if there is a gap between the auxiliary flame holes (26) and (26) and the tip of the thermocouple (51), the formation of a flame can be reliably detected.

The diameter of the auxiliary flame holes (26) is the third
Because it is set smaller than the main flame hole such as flame hole (25c),
The temperature of the combustion flame from the auxiliary flame holes (26) for heating the thermocouple (51) is lower than that from the main flame hole. Therefore, even if the burner is of a type in which the hot plate (22) glows red, there is no problem that the thermocouple (51) is abnormally overheated.

[Brief description of the drawings]

FIG. 1 is an overall view of a pottery apparatus using a gas burner (2) of the present invention.

FIG. 2 is a cross-sectional view of a main part thereof.

FIG. 3 is a sectional view of a gas burner (2) in a combustion state.

FIG. 4 is a plan view of a burner pipe (21).

FIG. 5 is a side view thereof.

FIG. 6 is a rear end supporting portion of a burner pipe (21) and a thermocouple (51).
Detailed view of the mounting part of

FIG. 7 is a sectional view of the combustion state of the auxiliary flame holes (26) (26).

FIG. 8 is a diagram showing the relationship between the guide cylinder (44) of the ignition device and the gas burner (2).

FIG. 9 is an explanatory diagram of a pressure distribution of gas ejected from a simulated burner pipe (21).

FIG. 10 is a detailed view showing a dimensional relationship between a cross section of the burner pipe (21) of the embodiment and a hot plate.

FIG. 11 is a detailed view of a dimensional relationship between a cross section of a burner pipe (21) of another comparative example and a hot plate.

FIG. 12 is a detailed view of a dimensional relationship between a cross section of a burner pipe (21) of another comparative example and a hot plate.

FIG. 13 is a graph showing results of a comparative experiment.

FIG. 14 is an explanatory view of a conventional example.

[Explanation of symbols]

 (21) ・ ・ ・ Burner pipe (22) ・ ・ ・ Hot plate

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masao Aramatsu 2-26 Fukuzumi-cho, Nakagawa-ku, Nagoya-shi Inside Linhai Co., Ltd. (56) References Shiro 55-6611 (JP, U) Shiro 57 −165929 (JP, U)

Claims (2)

(57) [Claims] 1. A hot plate heating type gas burner in which a hot plate (22) is disposed at a predetermined interval above a burner pipe (21) having a number of flame holes at a ridge line portion, 22)
The burner pipe (21) is disposed parallel to the burner pipe (21) as an elongated configuration having a substantially semicircular cross section that opens downward,
(21) An air-gas mixture having an excess air ratio of about 1.0 to 1.2 is forcibly supplied into the burner pipe and injected from the flame holes of the burner pipe so that the injected gas flows along the cross section of the hot plate (22). Hot plate heating type gas burner designed to burn in a thin film in a closed area. 2. The burner pipe (21) has a cross-sectional width of the hot plate (22).
12% to 16% larger than the diameter of the hot plate (2
The distance between the top of 2) and the ridge line of the burner pipe (21) is
2. The hot plate heating type gas burner according to claim 1, wherein the diameter is set to about 1 to 1.3 times the diameter of (21).