JP2631180B2 - Air suction structure of hot plate heating type 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 FIG. 14 (Japanese Utility Model Application No. 4-74193) has already been proposed as a gas burner of the above type. According to the present invention, the burner pipe (21) is disposed below the hot plate (22) having an arc-shaped cross section, and the hot plate is formed by flames formed in a group of flame holes arranged at the ridge of the burner pipe. Since (22) is heated to a red-hot state, when it is used as a gas burner for a pottery apparatus of the above-mentioned type, both the radiant heat from this hot plate and the combustion exhaust gas fire the fish and meat or other objects to be fired. Therefore, firing efficiency is good, and
Since the degree of firing by radiant heat is large, the degree of burning of oil components from the object to be fired and emission of smoke and soot is reduced. In particular, since this prior art is of a so-called forced combustion type in which combustion air is supplied into the burner pipe by a fan, the heating temperature of the hot plate is high and the red plate becomes hot.
The ratio of the radiant heat is large, and the effect is further improved.

However, in the case of this prior art, since the hot plate is heated to a red-hot state, the radiant heat from this heats the burner pipe (21) and thermally expands.
The relationship between the nozzle inserted into the burner pipe and the primary air supply port is different, which adversely affects the combustion performance. The present invention has been made in view of the above point, and has been described in the form of `` a type in which a hot plate (22) is disposed at a predetermined interval above a burner pipe (21) having a large number of flame holes at a ridge portion. It is an object of the present invention to provide a hot plate heating type gas burner which does not adversely affect the flammability of the gas burner even when thermal expansion occurs in each part due to red heat of the hot plate.

[0004]

The technical means of the present invention for solving the above-mentioned problem is as follows: "The burner pipe (21) has a fixed closed end at the distal end and a fixed opening at the base end of the nozzle (24). The nozzle is slidably fitted on the outer wall of the burner pipe (21).
An air suction port is provided at a predetermined interval (D) from the end of (24), and the interval (D) in the combustion stopped state is set to be substantially the maximum value of the appropriate interval region. ”

[0005]

The above technical means operates as follows. At the start of combustion, since the burner pipe (21) is maintained at a relatively low temperature, the distance (D) between the air suction port and the tip of the nozzle (24)
Is an interval that is substantially equal to or close to the maximum value of the appropriate interval area. When the hot plate (22) is heated to a red heat state by heating, the burner pipe (21) is heated by the radiant heat from this, and the radiant heat and the transfer heat from the flame formed on the lower surface of the hot plate, and the predetermined heat is applied. It is in a state of thermal expansion.

Since the tip of the burner pipe (21) is fixed, the distance (D) in this state is reduced to the minimum value of the proper distance area or a distance close thereto. Then, air is sucked from the air suction port located at the appropriate interval, and combustion continues.

[0007]

[Effect] Regardless of whether the burner pipe (21) of the gas burner thermally expands or not, the interval between the air suction port and the tip of the nozzle (24) is maintained within an appropriate interval range, so that during ignition and during steady combustion. In either case, combustion is stable and combustion performance is ensured.

[0008]

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) (2) composed of 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 casing 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 is provided.
In (2), an air supply device for supplying primary air for combustion is accommodated, 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, each of 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. In addition, an auxiliary flame hole (26) having a diameter of 1.6 mm is provided near an end of the third flame hole (25c) on the closed end (23) side.
Two more flame holes are formed.

Above the burner pipe (21), hot plates (22) are laid back and forth with a certain interval. 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 together with the closed end (23) to the rear rail (11).
2b) and a rising piece (12
c), and a supporting portion (12a) projecting forward from the upper end thereof. The supporting portion (12a) is set so as to coincide with the inner periphery of the cross section of the hot plate (22), and the hot plate ( 22) The rear end is placed or 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 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.

Further, 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 (D) between the tip (gas discharge port) of the nozzle (24) and the edge of the primary air hole (29) (about 6 mm in diameter) in a state where thermal expansion does not occur is determined by the optimum distance in a normal Bunsen burner. Is set to be larger than the center value. Therefore,
Even in the state where the thermal expansion has occurred, the primary air holes (29) (2)
The distance between 9) and the tip of the nozzle (24) is properly maintained, and primary air shortage does not occur due to the inappropriate relationship between the two.

Particularly, in this embodiment, the distance (D)
Is such that the burner pipe (21) is in the region of an appropriate interval both in the case where the thermal expansion occurs and in the case where the thermal expansion does not occur. In the case of the all-primary air type as in this embodiment, the temperature when the hot plate (22) is in the glowing state is 83%.
In the case of a steel pipe burner pipe (21) having a temperature of about 0 ° C and an effective length of 369 mm, the distance (D) should be 3.4 mm.
If it is set to about
(D) is reduced to about 0.5mm.

As described above, since the diameter of the primary air hole (29) is set to the above value, even when the diameter is reduced in this way, the tip of the nozzle (24) and the center of the primary air hole (29) There is an interval of about 3.5 mm between them, and the tip of this nozzle has a tapered surface on the outer periphery, so that the nozzle has a dimensional relationship that produces a sufficient ejector effect. The interval (D) in the combustion stopped state is about 3.4 mm. In this case, the tip of the nozzle (24) and the primary air hole (2
Since the distance from the center of 9) is 6.4 mm, the ejector effect almost equal to that in the steady combustion state can be secured in this case as well.

Therefore, in the above-mentioned quantity state, the primary air holes
There is no variation in the amount of primary air sucked from (29), and combustion is always stable. On the other hand, a similar thermal expansion occurs in the hot plate (22), but the rear end of the hot plate (22) is mounted on the bracket (12) or fixed by spot welding, and The end is relatively slidably supported by a bracket (27) fixed to the burner pipe (21).
A predetermined gap is formed between the front end face of the hot plate (22) and the backing plate (27a) of the bracket (27). Therefore, even if thermal expansion occurs in this hot plate (22), the bracket (2
This can be absorbed by the relative movement of the support according to 7). In particular, in this embodiment, since the bracket (27) is fixed to the burner pipe (21), the burner pipe (21) thermally expands almost in synchronism with the thermal expansion of the hot plate (22) and its support position. Is moved forward, the amount of relative movement of the front end of the hot plate (22) by the bracket (27) in the support portion is extremely small, and the inconvenience due to thermal expansion hardly occurs. When the rear end of the hot plate (22) is fixed to the bracket (12), the supporting position of the hot plate (22) is stable, and the rear end of the hot plate (22) is In the case of a configuration only to be mounted on 12), it is convenient when removing and cleaning the hot plate (22). Even in this latter case, in the above embodiment, the cross-sectional shape of the support portion (12a) of the bracket (12) is
The supporting state can be stabilized because it is matched with that of the inner peripheral surface of (22). [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 enhance the safety of each gas burner (2) during backfire. This is inserted into an electric circuit for driving a solenoid valve as a gas switching device inserted into the gas circuit, and
When the inside of (31) reaches the abnormal heating temperature, the temperature fuse (34) is turned off, the 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 stop plate (13). It is mounted so as to penetrate the rising pieces (12c) (13c), is supported in a horizontal position by a stopper plate (13), and is held by this stopper plate or a holding plate (53) screwed to the rear rail (11). It is fixed in the horizontal posture. And the tip is an auxiliary flame hole
(26) The holding position is determined so as to be located above and near (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 example, a skirt portion (22a) of 2 mm to 3 mm is provided in each of the hot plate cross sections. In this case, although wind resistance is ensured, CO / CO ₂ is 0.01 or more as shown in FIG. Area was large and was not suitable for practical use. In the same figure, the area where CO / CO ₂ is 0.01 or more is indicated by a solid line in the case of the burner of FIG. 10, a broken line in the case of the burner of FIG. 11, and a dashed line in the case of the burner of FIG. Is shown.

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 examples, since the primary air is supplied by the fan (30), the rotation speed of the fan (30) is adopted on the vertical axis of the figure, and the calorific value corresponding to the amount of combustion gas is adopted on the horizontal axis. . 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. Since the ejected gas burns, as shown in FIG. 7, 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) (26). The tip of the thermocouple (51) is heated by the radiant heat from the film. Therefore, when a flame is formed by the auxiliary flame hole (26), even if there is a gap between the auxiliary flame hole (26) (26) and the tip of the thermocouple (51), the flame is formed. 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 (29) ・ ・ ・ Primary air hole (D) ・ ・ ・ Spacing (24) ・ ・ ・ Nozzle

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masao Aramatsu 2-26 Fukuzumi-cho, Nakagawa-ku, Nagoya-city Inside Linhai Corporation (56) References -150324 (JP, U) Fully open 1979-136634 (JP, U) Fully open 49-101975 (JP, U) Fully open 61-143527 (JP, U) Real publicly 44-13981 (JP, Y1) )

Claims (1)

(57) [Claims] 1. A hot plate heating type gas burner in which a hot plate (22) is arranged at a predetermined interval above a burner pipe (21) having a plurality of flame holes at a ridge line portion.
The closed end of the distal end of (21) is fixed, and the open part on the proximal end side is slidably fitted to the fixed nozzle (24), and the nozzle (24) is attached to the peripheral wall of the burner pipe (21). Predetermined distance from tip
An air suction structure for a hot plate heating type gas burner, in which an air suction port is disposed with (D) placed, and the interval (D) in the combustion stopped state is set to be substantially the maximum value of an appropriate interval region.