JP2001116219A - Spontaneous mixing type gas burner, and mixer for gas and air - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the mixer for gas and air in a spontaneous mixing type gas burner in which the flow of gas injected from a nozzle can be adjusted without dropping the combustion efficiency. SOLUTION: The inner face of the top wall 22a of a nozzle 2 is made into an inclined plane which inclines the tip of the nozzle, and a gas flow adjusting member 26 is provided along the inclined plane, shiftably in the direction crossing obliquely the direction of gas injection. Then, the flow rate of the gas injected from a gas injection port 24 can be adjusted steplessly, and the combustion efficiency can be enhanced, by shifting the gas flow adjusting member 26 along the inclined plane, thereby adjusting the crossing area of a clearance 27 for gas circulation made between the tip inner face of the gas flow adjusting member and the tip inner face of the nozzle opposed to the member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a naturally mixed gas burner which naturally sucks air by an injected gas flow and mixes the gas and air to supply a mixed gas to a burner head. It relates to a mixing device incorporated in the required burner.

[0002]

2. Description of the Related Art In a natural mixing type gas burner, a gas and air mixing apparatus conventionally used generally includes a nozzle having a gas injection port at a tip and a mixing pipe. One end of the mixing tube is formed as a venturi portion having a drum-shaped internal shape, and the other end of the mixing tube is formed as a mixing portion, and a nozzle is attached to one end of the venturi portion.

[0003] In such a natural mixing type gas burner, mixing of gas and air is performed as follows. That is,
When the gas is injected from the gas injection port provided at the tip of the nozzle and passes through the inside of the venturi portion, the upstream side of the gas flow has a negative pressure due to the nature of the venturi portion, so the base end side of the venturi portion Air is drawn in from an air suction port provided in the air conditioner. The sucked air and the injected gas pass through the throat unit as a unit and are naturally mixed in the mixing pipe. By the way, it is necessary to adjust the gas flow according to the size of the cooker, but in the conventional gas flow adjustment, a valve is provided at a position before the tip of the nozzle, and the opening of the valve is adjusted. However, since it is performed by changing the gas flow rate passing therethrough to the nozzle tip, the following problem occurs.

[0004]

That is, when the gas flow rate is adjusted at a position before the tip of the nozzle, the gas pressure decreases inside the nozzle and the gas injection speed decreases.
For this reason, there is a problem that the amount of air sucked from the air suction port decreases, the mixing ratio of gas and air changes, and the combustion efficiency decreases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in consideration of the above-described problems. It is an object of the present invention to provide a mixing device.

[0006]

The object of the present invention is to provide a nozzle having a gas injection port at a tip thereof and a mixing pipe, wherein air is naturally sucked in by a gas flow injected from the gas injection port,
And in a gas and air mixing device in a natural mixing gas burner in which both are mixed in a mixing pipe, at least a part of the inner surface of the nozzle is formed in an inclined portion inclined toward a nozzle tip, and A gas flow rate adjusting member is provided movably along the inclined portion in a direction obliquely intersecting the gas injection direction, and the movement of the gas flow rate adjusting member causes the inner surface of the distal end portion of the gas flow rate adjusting member and the nozzle facing the gas flow rate adjusting member to move. The problem is solved by a gas and air mixing device in a natural mixing gas burner, characterized in that the cross-sectional area of a gap for injection gas flow formed between the inner surface of the tip and the inner surface is adjustable.

According to this mixing device, the flow rate of the gas injected from the gas injection port is adjusted by adjusting the cross-sectional area of the injection gas flow gap, so that the gas pressure does not decrease inside the nozzle. The gas injection speed is prevented from lowering, and the gas and air can be efficiently mixed. Further, since the cross-sectional area of the gap is adjusted by moving the gas flow rate adjusting member along the inclined surface of the nozzle, continuous gas flow rate adjustment can be performed easily and reliably. Moreover, since the gas flow rate adjusting member is moved in a direction obliquely intersecting the gas injection direction,
The amount of change in the cross-sectional area of the gas flow gap is small with respect to the large amount of movement of the gas flow rate adjusting member. This means that it is possible to finely adjust the opening area of the gas injection port with high accuracy, and thus it is possible to adjust the gas injection amount with high accuracy, and obtain a more efficient gas-air mixing state. be able to.

The cross-sectional area of the gas flow gap is formed to be constant in the gas injection direction over a predetermined length. As a result, the gas can flow stably.

An air inlet is formed in the mixing pipe, and an opening / closing valve is provided in the air inlet, so that the opening / closing valve and the gas flow rate adjusting member are controlled in conjunction with each other. In this case, the flow rate of the gas injected from the gas injection port of the nozzle and the flow rate of the air suctioned from the air suction port are appropriately controlled, so that the combustion efficiency can be further improved.

[0010]

1 to 4 show an embodiment in which the present invention is applied to a Bunsen type burner which is a natural mixing type gas burner. 1 to 4, (A) is a mixing device, and the mixing device (A) is composed of a mixing pipe (1) and a nozzle (2) attached to a base end of the mixing pipe (1). ing. The tip of the mixing tube (1) is connected to the burner head (B) to form a Bunsen-type burner.

The mixing tube (1) has a venturi section (11) formed at the base end thereof, while a venturi section (1) is formed.
A mixing section (12) having an elliptical cross section is formed continuously from 1). The venturi portion (11) has a drum shape in which the cross-sectional area of the hollow interior continuously decreases from the base end portion toward the mixing portion (12) and then expands in the opposite direction, and the cross-sectional area is the smallest. The part is the throat part (1
3). On the other hand, the mixing section (12) is formed in a Taber tube whose internal cross-sectional area continuously increases as it approaches the burner head (B) side from the portion connected to the venturi section (11).

A rectangular nozzle for projecting the tip of the nozzle (2) into the venturi (11) at the center of the rear surface (11a) of the base end of the venturi (11). An air inlet (15) for sucking primary air is provided at a position between the nozzle insertion hole (14) and an outer peripheral portion of the rear surface (11a) of the base end while an insertion hole (14) is formed. Are drilled. The air inlet (15) is provided with an on-off valve (16) slidable in the radial direction along the rear surface (11a) of the base end, and the on-off valve (16) further includes a control unit (3). ) Is connected to an actuator (17) controlled by For this reason, when a signal for air amount adjustment is transmitted from the control unit (3) to the actuator (17), the actuator (1) receiving the signal receives the signal.
7) causes the on-off valve (16) to move in the radially increasing or decreasing direction, so that the opening area of the air inlet (15) is enlarged or reduced, and the amount of air sucked into the air inlet (15) is adjusted. It is supposed to be.

The nozzle (2) is, as shown in FIG.
A base end (23) extending vertically with its lower end attached to a vertical gas supply pipe (4); and a side of the mixing pipe (1) connected to the upper end of the base end (23). Bent part (2
1) and the gas ejection portion (22) communicated with the tip of the bent portion (21), the whole shape is formed in an inverted L-shape in vertical section.

The gas ejection section (22) has an upper wall section (22).
a) and the lower wall portion (22b) are formed in a tapered shape approaching each other toward the tip, and accordingly, the inner surface of the upper wall portion (22a) is formed as an inclined surface inclined toward the nozzle tip. I have. The inner surface (22c) (shown in FIG. 3) of the distal end of the lower wall (22b) is formed in a horizontal plane parallel to the axial direction of the mixing tube (1). As described above, the distal end of the gas ejection part (22) is connected to the venturi part (1) through the nozzle insertion hole (14) of the mixing pipe (1).
It protrudes into 1).

A substantially rectangular parallelepiped gas flow control member (26) is slidably provided along the inclined inner surface of the upper wall portion (22a) constituting the gas ejection portion (22).
The gas flow rate adjusting member (26) has a width substantially equal to the width of the inclined surface of the upper wall portion (22a) (in the thickness direction of the paper surface of FIG. 1), and has a predetermined length from the upper wall portion (22a). It is formed short by the length. Further, the inner surface (26a) (shown in FIG. 3) of the distal end portion of the gas flow rate adjusting member (26) is formed on a horizontal plane parallel to the axial direction of the mixing pipe (1). ) At the tip inner surface (2
A gap (27) having a constant cross-sectional area in the gas ejection direction is formed between 6a) and the inner surface (22c) of the distal end of the lower wall (22b).

The gap (27) is formed to have a horizontal cross section that is long in the thickness direction of the paper of FIGS. 1 and 2, and a hollow gas flow hole (25) in the nozzle (2) and a horizontal length of the tip of the nozzle. Slit-shaped (shown in FIG. 5) gas injection port (24)
The gas supplied from the gas supply pipe (4) passes through the gas flow hole (25) and further passes through the gap (2).
7) through the gas injection port (24) to the venturi section (1).
1) It is supposed to be ejected inward.

As described above, the gas flow rate adjusting member (26)
Horizontal surface (26a) and the lower wall portion (22
The reason why the gap (27) having a constant interval and a length (L) is formed between the tip and the horizontal plane (22c) of b) is to allow the gas to flow stably. Reference numeral (30) denotes a support member for pressing the gas flow rate adjusting member (26) against the inclined inner surface of the upper wall portion (22a) with a predetermined elastic pressure. It is possible to slide while always making close contact with the inclined inner surface of (22a).

Furthermore, one end of a connecting member (28) that is movable in the inclination direction of the gas flow rate adjusting member (26) is connected to the rear end of the gas flow rate adjusting member (26), and the nozzle ( The other end of the connecting member (28) projecting outside through 2) is connected to an actuator (29) fixed to the outer surface of the nozzle and controlled by the control unit (3). Therefore, when a signal of the gas flow rate increase command is transmitted from the control unit (3) to the actuator (29), the actuator that has received the signal transmits the connecting member (2).
8) is retracted, and accordingly, the gas flow rate adjusting member (2)
6) retreats obliquely upward while sliding along the inclined inner surface of the upper wall portion (22a). as a result,
As shown in the dotted line of FIG. 2 and FIG. 3 (b), the horizontal plane (26a) of the distal end of the gas flow rate adjusting member (26) moves upward and parallel to the horizontal plane (22c) of the distal end of the lower wall (22b). The width G of the gap (27) formed by (1) and (2) is increased, the cross-sectional area thereof is increased, and the flow rate of gas injected from the gas injection port (24) is increased. Conversely, the control unit (3)
When a signal of the gas flow rate reduction command is transmitted from the actuator (29) to the actuator (29), the actuator (2) that receives the signal receives the signal.
9) The connecting member (28) is advanced, and accordingly, the gas flow rate adjusting member (26) slides along the inclined inner surface of the upper wall portion (22a) and advances obliquely downward toward the nozzle tip. It has been done. As a result, as shown in the solid line of FIG. 2 and FIG. 3A, the horizontal plane (26a) of the distal end of the gas flow rate adjusting member (26) moves horizontally downward, and the horizontal plane of the distal end of the lower wall (22b). (22c), the width G of the gap (27) formed is reduced, and its cross-sectional area is reduced.
The flow rate of gas injected from the gas injection port (24) is reduced. That is, the gas flow rate adjusting member (26)
, The flow rate of the gas injected from the gas injection port (24) can be adjusted.

Further, in this embodiment, the flow rate of the air sucked from the air suction port (15) in the mixing pipe (1) is also changed according to the change in the flow rate of the gas injected from the gas injection port (24). That is, the actuator 29 drives the gas flow rate adjusting member (26) forward and backward so that the gas and the air are mixed at a suitable ratio to further improve the combustion efficiency. The control unit (3) controls the forward / backward drive of the air opening / closing valve (16) in an interlocked manner. Specifically, when the gas flow rate adjusting member (26) advances and the gas injection amount decreases, the air on-off valve (16) moves in a direction to close the air intake port (15), and the secondary air also decreases. Conversely, when the gas flow rate adjusting member (26) retreats and the gas injection amount increases,
The air on-off valve (16) moves in a direction to open the air suction port (15), so that the amount of secondary air also increases.

In the mixing apparatus according to the embodiment shown in FIGS. 1 to 4, when gas is supplied from the gas supply pipe (4) to the inside of the nozzle (2), the gas flows from the gas inflow section (25) to the gas flow section. It reaches the injection port (24) through a gap (27) whose area is set to a predetermined value, and injects a predetermined flow rate in the axial direction from the injection port (24) into the venturi (11). Since the gas injection port (24) is formed in a horizontally elongated slit shape,
The injected gas also becomes a gas flow having a flat cross-sectional area corresponding to the slit shape, passes through the throat portion, and flows into the mixing portion (1).
Flow into 2). On the other hand, by the gas injection, the venturi section (11) becomes negative pressure, air is sucked around the gas flow from the suction opening, and the air and gas pass through the throat section (13) as one body, It flows into the mixing section (12).

As described above, in the mixing apparatus according to the illustrated embodiment, since the gas flow rate is adjusted by adjusting the cross-sectional area of the gap (27) through which the gas passes, the gas pressure decreases inside the nozzle (2). As a result, it is possible to prevent the gas injection speed from lowering, and to improve the combustion efficiency. Moreover, the gas flow rate can be adjusted by the gas flow rate adjusting member (2).
Since step 6) is performed by moving the nozzle 2 along the inclined surface, stepless, that is, continuous gas flow adjustment can be performed easily and reliably. In addition, since the gas flow rate adjusting member (26) moves in a direction obliquely intersecting with the gas injection direction, a large horizontal movement of the gas flow rate adjusting member (26) causes a horizontal plane at the distal end of the gas flow rate adjusting member (26). Since the vertical movement amount is small, the gap (2
7) The cross-sectional area can be finely adjusted with high accuracy, and the gas injection amount can be finely adjusted with high accuracy.

In the illustrated embodiment, the cross-sectional area of the gap (27) and the gas injection port (24) are formed in an elongated slit shape. However, the present invention is not limited to this. It may be. FIG.
As shown in (1), at least one of the horizontal surface at the distal end of the gas flow rate adjusting member (31) and the horizontal surface at the distal end of the lower wall portion (22b) opposed thereto is formed into a waveform, and is injected from the gas injection port (24). The gas and the air may be more uniformly mixed by increasing the contact area between the gas and the sucked air.

Although the mixing device of the illustrated embodiment is used with the gap (27) of the nozzle (2) being horizontal, the orientation and angle of the mixing device are not limited to the embodiment. For example, by rotating the mixing device of the illustrated embodiment by 90 degrees in a vertical plane, the gap (27) of the nozzle (2)
May be used in a vertical state.

[0024]

According to the first aspect of the present invention, the flow rate of the gas injected from the gas injection port is adjusted by adjusting the cross-sectional area of the gap through which the gas passes, so that the gas pressure is reduced inside the nozzle. And the reduction of the gas injection speed is prevented. Therefore, the gas and the air can be efficiently mixed, and the combustion efficiency can be improved.

Since the cross-sectional area of the gap is adjusted by sliding the gas flow rate adjusting member along the inclined surface of the nozzle, the stepless gas flow rate adjustment can be performed simply and reliably.

In addition, since the gas flow rate adjusting member is moved in a direction obliquely intersecting with the gas injection direction, the amount of change in the cross-sectional area of the gap is small with respect to the large movement amount of the gas flow rate adjusting member. The amount can be finely adjusted with high accuracy, and a more efficient mixture of gas and air can be obtained.

According to the second aspect of the present invention, the gas can flow stably due to the presence of the gap having the same cross-sectional shape over a certain length in the gas injection direction.

According to the third aspect of the present invention, since the flow rate of the gas injected from the gas injection port of the nozzle and the flow rate of the air sucked from the air suction port are appropriately controlled, the combustion efficiency can be improved. Can be improved.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing a gas burner provided with a mixing device according to an embodiment of the present invention, with a part thereof cut away.

FIG. 2 is an enlarged sectional view of a nozzle of the mixing device shown in FIG.

FIG. 3 is an enlarged sectional view showing a distal end portion of the gas burner.

FIG. 4 is a plan view of the nozzle shown in FIG. 2;

FIG. 5 is a front view of the nozzle shown in FIG. 2;

FIG. 6 is a partial sectional view of a nozzle according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Mixing pipe 2 ... Nozzle 3 ... Control part 4 ... Gas supply pipe 11 ... Venturi part 12 ... Mixing part 15 ... Air suction port 16 ... On-off valve 21 ... Bent portion 22 ... Gas ejection portion 24 ... Gas injection port 25 ... Gas flow hole 26 ... Gas flow rate adjusting member 27 ... Gap

Claims (3)

[Claims] 1. A natural mixing system comprising a nozzle having a gas injection port at a tip thereof and a mixing pipe, wherein air is naturally sucked in by a gas flow injected from the gas injection port and both are mixed in the mixing pipe. In a gas / air mixing device for a gas burner, at least a part of the inner surface of the nozzle is formed in an inclined portion inclined toward a nozzle tip, and a gas flow adjusting member is provided along the inclined portion in a gas injection direction. Is provided movably in a direction obliquely intersecting with the gas flow control member, and formed by the movement of the gas flow control member between the inner surface of the distal end of the gas flow control member and the inner surface of the distal end of the nozzle opposed thereto. A gas / air mixing device in a natural mixing gas burner, wherein a cross-sectional area of a circulation gap is adjustable. 2. The gas / air mixing device according to claim 1, wherein the cross-sectional area of the gap for flowing the injected gas is formed to be the same in the gas injection direction over a predetermined length. 3. An air suction port is formed in the mixing pipe, and an on-off valve is provided on the air suction port, so that the on-off valve and the gas flow rate adjusting member are controlled in conjunction with each other. An apparatus for mixing gas and air in the natural-mixing gas burner according to claim 1 or 2.