JP2009063222A - Portable tubular flame burner system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable tubular flame burner system capable of being carried without needing air supply equipment so that a tubular flame is made more familiar. <P>SOLUTION: This portable tubular flame burner system comprises a cylinder 1 storing liquefied fuel, a burner 3 having a tubular inner wall face and forming the tubular flame inside, an air-fuel mixture producing device 14 producing jet flow of evaporated fuel, sucking the air by utilizing a negative pressure of the jet flow, and mixing the fuel and the air to produce the tubular flame, a supply portion 3a for supplying the air-fuel mixture along the inner wall face of the burner 3 and forming the circulation flow of the air-fuel mixture in the burner 3, and an ignition device for igniting the air-fuel mixture. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tubular flame burner system for forming a tubular flame inside a burner, and more particularly to a portable portable tubular flame burner system.

  Tubular flames have been studied from the standpoint of basic combustion studies as flame elements in a cylindrical coordinate system. In particular, tubular flames formed in a rotating and extending field are being applied to practical combustors because of their convenient shape and the simplicity that they can be formed simply by blowing the premixed gas into the tube in the tangential direction.

The flame is a hollow tube. In order to form a tubular flame, a premixed gas mixture of fuel and air is blown into a burner having a tubular inner wall surface in a tangential direction, or a plurality of outlets are prepared in the burner, and fuel and air are separately supplied. Blowing in a tangential direction from a blowout port has been performed (see Patent Document 1).
JP-A-11-281015

  However, in order to form a tubular flame, it is necessary to blow out the air-fuel mixture at a high speed, and there is a tendency for the apparatus to be enlarged due to the accompanying facilities. Specifically, in the conventional tubular flame burner system, an air supply facility such as a compressor is required because of the necessity of blowing the air-fuel mixture at a high speed. Then, the fuel / air mixture was blown into the burner using the “air supply pressure”. The necessity of the air supply equipment leads to an increase in the size of the tubular flame burner system, so that the tubular flame can be formed only in a laboratory or a factory.

  Therefore, an object of the present invention is to provide a portable tubular flame burner system that can be carried without requiring an air supply facility in order to make the tubular flame more familiar.

  In order to solve the above-mentioned problems, the invention described in claim 1 is a cylinder for storing liquefied fuel, a burner having a tubular inner wall surface for forming a tubular flame, and vaporized gaseous fuel. An air-fuel mixture forming device that mixes gaseous fuel and air so as to form a tubular flame, and blows out air-fuel mixture along the inner wall surface of the burner, It is a portable tubular flame burner system comprising a blow-out unit that creates a swirling flow of an air-fuel mixture in the burner and an ignition device that ignites the air-fuel mixture.

  According to a second aspect of the present invention, in the portable tubular flame burner system according to the first aspect, the air-fuel mixture forming device mixes gaseous fuel and air at a concentration higher than the theoretical air-fuel mixture. .

  According to a third aspect of the present invention, in the portable tubular flame burner system according to the first or second aspect of the present invention, a plurality of the blowing portions are provided with their positions shifted in the circumferential direction of the burner.

  According to a fourth aspect of the present invention, in the portable tubular flame burner system according to any one of the first to third aspects, a plurality of the blowing portions are provided at different positions in the axial direction of the burner. .

  According to a fifth aspect of the present invention, in the portable tubular flame burner system according to any one of the first to fourth aspects, the burner includes a transparent material so that the tubular flame inside the burner can be visually recognized. It is characterized by.

  The invention according to claim 6 is the portable tubular flame burner system according to any one of claims 1 to 5, wherein the inner diameter of the burner is a cylindrical shape having a diameter of 10 mm or less or a polygonal shape having a diameter of 10 mm or less. It is characterized by.

  A seventh aspect of the present invention is the portable tubular flame burner system according to any one of the first to sixth aspects, wherein the inner wall surface of the burner is open at one end in the axial direction and at the other end in the axial direction. Is closed, and the ignition device ignites the air-fuel mixture between the blowing portion and the closed end surface in the axial direction of the burner.

  According to the present invention, the “fuel vapor pressure” is used to take in an amount of air suitable for the tubular flame and blow out the fuel / air mixture into the burner. As a result of eliminating the need for air supply equipment that has been required to form a tubular flame, it is possible to produce a portable tubular flame burner that is easily portable.

  Not only can you make a flame with a convenient shape like a tube, but you can form a flame stably (in a strong centrifugal force field) regardless of whether it is handy or upward, downward, pilot frame, torch frame, microfabrication work, In addition, it can be used in various fields as an ornamental flame.

  This tubular flame has the peculiarity that a flame having a small diameter can be formed on the fuel excess side of the theoretical mixture.

  Furthermore, if a cylindrical burner having a diameter of 10 mm or less is used, a flame having a diameter of 2 mm or less can be formed. Conventionally, it is difficult to form a flame having a diameter of about 2 mm, and a flame having a diameter of about 1 mm has not been formed worldwide.

  An embodiment of the tubular flame burner system of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a schematic block diagram of a tubular flame burner system. The cylinder 1 is pressurized and liquefied with propane, butane, or a mixed gas fuel of propane and butane. A tubular flame can be formed in the tubular burner 3 by twisting the fuel opening / closing knob 2 of the cylinder 1 and igniting it with an ignition device.

  First, the geometric features of the tubular flame will be described. FIG. 2 shows a tubular flame 4 formed in the burner 3. The burner 3 has a tubular inner wall surface. One end of the burner 3 in the axial direction is closed and the other end is open. The air-fuel mixture blown in the tangential direction of the burner 3 moves into the tubular flame 4 and burns. Since a swirl flow is formed in the burner 3, the heavy gas before combustion is separated around the burner 3 by the centrifugal force, and the light gas after combustion is concentrically separated at the center of the burner 3. The hot light gas after combustion is discharged in the axial direction of the burner 3.

  The streamline 5 of the air-fuel mixture is divided into a component 5a perpendicular to the flame surface and a component 5b in the tangential direction of the flame surface. The tubular flame 4 is formed at a fixed position in the burner 3 by balancing the flow velocity in the vertical direction of the flame surface and the combustion speed.

  In developing a portable tubular flame burner system, the formation limit, flame diameter, and flame length of a tubular flame with a burner diameter of 10 mm or less are fundamentally investigated, and then a fuel / air mixture suitable for this flame formation is determined. An apparatus for forming the fuel jet by using the negative pressure of the fuel jet was manufactured. Finally, the apparatus was attached to an actual burner to confirm the success or failure as a portable tubular flame burner. The success or failure of the experimental device, flame appearance, flame formation limit, mixture formation device, burner, ignition device, and portable tubular flame burner system will be described in order.

[Experimental device]
FIG. 3 shows an outline of an apparatus for basic experiments. As the inner diameter of the burner, four types of 10, 7.6, 6, and 4 mm were adopted according to the standard of the heat-resistant hard glass tube. The length of the heat-resistant hard glass tube was constant at 100 mm. On the other hand, in order to blow out the air-fuel mixture in the tangential direction, two blowing holes having a diameter of 1.5 mm in the tangential direction were attached at two symmetrical positions to form a blowing portion. A quartz glass window was provided at the lower end of the blowing portion so that the flame formed inside could be observed from below and from the side. The length from the lower end of the blowing portion to the Pyrex (registered trademark) tube outlet is 107.5 mm.

  As the fuel used in the portable burner, propane, butane, or a mixed fuel of butane and propane filled in a cassette cylinder is assumed. Therefore, we decided to use propane with abundant experimental data for basic experiments. Air and propane are respectively supplied from the compressor 6 and the cylinder 7, mixed through the flow rate measuring orifices 8 a and 8 b and the flow rate adjusting valves 9 a and 9 b, and supplied to the burner 3.

[Flame appearance]
A tubular flame is formed in the burner 3 for an appropriate combination of air flow and fuel flow. FIG. 4 shows the appearance of the burner 3 and the appearance of a flame photographed from the horizontal direction and from below. In the theoretical mixture (FIG. 4 (b)), the flame is short, but as the equivalence ratio becomes more lean or rich, the flame diameter decreases and the flame becomes longer. After passing through a slightly unstable region, if the air-fuel mixture is made leaner or richer, the flame blows off from the burner root and extinguishes.

[Flame formation limit]
FIG. 5 shows the flame formation limit obtained by systematically changing the air flow rate and the fuel flow rate using a burner having an inner diameter of 10 mm. It can be seen that the tubular flame is formed to a fuel concentration close to the lean / super-rich flammability limit.

  For reference, FIG. 6 shows changes in flame diameter obtained by decreasing or increasing the fuel flow rate while keeping the air flow rate constant at 53.4 ml / S. When diluting, the flame diameter does not change so much and extinguishes. However, when it becomes excessive, the flame diameter gradually decreases. In this case, the flame extinguishes at about 4.5 mm. In the propane / air mixture, the flame diameter cannot be reduced on the lean side, whereas it can be reduced on the rich side, which is consistent with the previously observed result due to the Lewis number effect of the so-called insufficient component.

  FIG. 7 shows the result of obtaining the flame formation limit when the burner inner diameter is reduced to 4 mm. The flame is hardly formed in the lean air-fuel mixture, and is formed on the fuel rich side with respect to the fuel concentration Ω = 4% of the theoretical air-fuel mixture. However, it can be seen that a flame cannot be formed unless the fuel concentration is approximately 7% or less, which is considerably lower than the fuel concentration of 9.5%, which is the overrich combustible limit.

  From the above results, the burner with an inner diameter of 10 mm can be combusted in almost the entire flammable range of propane. However, in the burner with an inner diameter of 4 mm, the flammable range is narrow and 4 to 7% on the fuel rich side. It was found that a tubular flame can be formed at the fuel concentration. As a characteristic of the tubular flame, unburned gas exists on the outer peripheral side of the hot gas after combustion, and the hot gas does not directly touch the wall surface of the burner. Since heat insulation is good and heat loss is small, even if a flame is formed on a burner having an inner diameter of 4 mm or less, the heat loss does not lead to extinction.

[Air-fuel mixture forming device]
FIG. 8 shows an external view of the air-fuel mixture forming apparatus, and FIG. 9 shows a cross-sectional view. In the portable tubular flame burner, liquid fuel filled in the cassette cylinder 1 is used, and the negative pressure of the jet of fuel is used for introducing air. Therefore, for example, an orifice plate 12 is inserted into a pipe 11 having an inner diameter of 1 mm and passed therethrough to create a fuel jet. On the other hand, an air introduction hole 13 of an appropriate size is provided downstream of the orifice plate 12 to supply air. Inhaled to create a flammable mixture suitable for tubular flame formation. That is, the fuel is supplied to the air-fuel mixture forming device 14 at a constant pressure, passes through the filter 15, and is ejected from the orifice plate 12. At this time, the pressure of the flow decreases, and the air provided immediately after the orifice 12 is drawn. Thereafter, the fuel and air are naturally mixed and ejected into the burner 3.

  An example of the results when propane is used is shown in FIG. When this air-fuel mixture forming device is attached to the burner, the pressure resistance changes depending on the burner diameter, so the propane supply pressure is actually changed while attached to a 10, 7.6, 6, 4 mm burner, When the air introduction hole 13 is closed and only fuel is blown out, the flow rate at the burner outlet is measured with a soap film flow meter in both cases where the air introduction hole 13 is opened and air is drawn in, and the total flow rate and fuel concentration are determined. Asked. For reference, FIG. 10 shows the flame formation limits determined for burners having an inner diameter of 10 mm and 4 mm.

[Burner]
For burner 3, (1) single suction burner, (2) vertical 3 suction burner and horizontal 3 suction burner, and (3) horizontal 2 suction burner were prepared.

(1) Single Suction Burner As shown in FIG. 11, a blowout hole 3 a that is a blowout portion of the air-fuel mixture is a single burner 3. In order to observe the flame structure from the side of the burner, the upper part of the burner was made of a glass tube, and to observe the cross-sectional structure of the flame, the lower part of the burner was made of a glass disk. The inner wall surface of the burner 3 has a cylindrical shape with one end closed.

  When a tubular flame was formed on this single suction burner, it was found that the flame cross-section was distorted and the flame had uneven brightness. As in the case of the prototype burner, the distortion of the flame cross section has only one blowing hole 3a, so the axial symmetry of the flow inside the burner is poor, and the amount of air-fuel mixture is small, so the flow of unburned air-fuel mixture This may be due to the narrow road. Further, since it is expected that the air-fuel mixture flows spirally from the blowout hole 3a to the burner outlet 3b, it is considered that there is a bright portion of the flame along the flowing locus. In a tubular flame burner using a conventional premixed gas, it is rare that uneven brightness is observed in the flame. However, since most of the air is supplied from the slit, the mixed gas is supplied from the slit to the burner outlet. This is considered to be because a place where the air-fuel mixture is difficult to be supplied is less likely to occur even if the gas flows spirally.

(2) Vertical 3-suction burner and horizontal 3-suction burner In the single-suction burner, problems such as poor axial symmetry of the flow in the burner and the location where premixed gas is difficult to be supplied were discovered. Therefore, in order to solve these problems, a burner having three blowing holes 3a for supplying air-fuel mixture into the burner 3 was manufactured. At this time, two types of arrangement of the blowout holes 3a are considered, one is a vertical three suction burner arranged by shifting the supply position in the vertical direction, and a horizontal position in which the supply position is installed every 120 degrees in the circumferential direction in the horizontal plane. Three suction burners were produced. 12 and 13 show an outline of these burners. Since these burners use the air-fuel mixture forming device at three locations, the fuel flow rate is three times that of the single suction burner.

  When a flame was formed in the vertical three-suction burner, it was found that the flame length was longer than that of the single-suction burner. It can also be seen that the flame cross section is approaching a circle. It is considered that the flame length became longer because the amount of the air-fuel mixture supplied to the burner 3 was increased as compared with the case of the single suction burner. On the other hand, the flame cross-section has a structure in which a sufficient amount of unburned air-fuel mixture is wrapped around the flame by increasing the flow rate of the air-fuel mixture. Therefore, it is considered that the flow of the air-fuel mixture approaches axial symmetry and the strain is reduced. The brightness unevenness in the flame was reduced compared to the case of single suction. This is considered to be because the air-fuel mixture was supplied more uniformly in the burner 3 due to the three blowout holes 3a.

  In the horizontal 3 suction burner, the flame had very good symmetry with respect to the burner central axis. In addition, it was found that there was little unevenness in the flame and it was a homogeneous flame. This is considered to be because the flow of the air-fuel mixture formed in the burner 3 is closer to the axial symmetry because the position where the air-fuel mixture is blown is arranged at a position more symmetrical with respect to the axis of the burner. .

  It is considered that the unevenness of the flame is caused by the uneven supply amount of the air-fuel mixture in the burner 3. However, in the place where the air-fuel mixture is easily supplied in the burner, the fuel is supplied into the burner 3 from the blowing holes 3 a. In this case, the speed in the circumferential direction of the burner is expected to be maximized, and the position is expected to have a spiral structure as shown in FIG. Although this spiral structure cannot be uniquely determined due to the influence of the swirl number of the burner and the volume expansion during combustion, the single suction burner is approximately (a), the vertical three suction burner is (b), The horizontal 3 suction burner is assumed as (c). From FIG. 14, it is expected that the structure of FIG. (C) is excellent in order to supply the air-fuel mixture into the burner in the most uniform state if the air-fuel mixture wraps the flame. The

(3) Horizontal 2-suction burner It has been clarified that the unevenness of the flame can be reduced by placing the air-fuel mixture outlet at the horizontal position shown in Fig. 14 (c). It can be said that it is disadvantageous for miniaturization because it is necessary to supply air. Therefore, as shown in FIG. 15, a horizontal two-suction burner in which the air-fuel mixture blowing holes 3a are installed in two horizontal directions was manufactured. This seems to facilitate the reduction of the size in the depth direction.

[Ignition device]
A piezoelectric ignition device or an igniter is used as the ignition device. Piezoelectric ignition devices use piezoelectric elements that generate high-voltage electricity when subjected to impact strain. As the piezoelectric element, for example, ternary piezoelectric ceramics such as lead titanate, lead zirconate, lead niobate, etc., quartz, and Rochelle circle, which are excellent in superelectricity and durability, can be used. The igniter utilizes an electrical spark of an electrode inserted into the burner. In addition to this, the ignition stone and the file may be rubbed together, and the spark generated at that time may be ignited in the air-fuel mixture.

  The ignition device ignites the air-fuel mixture between the blowing portion and the closed end face of the combustion chamber in the axial direction of the burner. If the inner diameter of the burner is up to 10, 7.6, 6 mm, the flame will enter the burner even if ignited at the upper part of the burner. However, when the burner inner diameter is 4 mm, the flame cannot enter the burner. This is because the flow rate of the air-fuel mixture in the axial direction of the burner increases. The position where the ignition device ignites (the position where the ignition device forms a spark) is preferably on the same plane as the blowing portion or slightly below.

[Success or failure as a portable tubular flame burner system]
FIG. 16 shows a photograph of a flame formed when the air-fuel mixture forming apparatus is actually attached to the burner and fuel is supplied from a butane cassette cylinder. The upper photo is from the side of the burner, and the lower photo is a flame photograph taken from below the burner through a mirror. In a burner having an inner diameter of 10, 7.6, and 6 mm, when ignited at the outlet, the flame propagates to the upstream end to form a flame. On the other hand, in the burner having an inner diameter of 4 mm, the flame cannot propagate to the upstream end, but when the glass tube length is halved, the flame propagates to the upstream end and a stable tubular flame can be obtained. From the figure, the flame length increases as the burner inner diameter decreases. This is probably because the flow rate of the air-fuel mixture supplied to the burner is almost equal, and the burner with a small inner diameter has an increased flame length in the axial direction in order to obtain the same flame area.

  In addition, this invention is not restricted to the said embodiment, In the range which does not change the summary of this invention, it can change variously. For example, the shape of the inner wall surface of the burner is not limited to a cylinder, but may be a polygon such as an octagon, a hexagon, a quadrangle, or a triangle. The polygon having a diameter of 10 mm or less means that the distance from one side of the polygon to the side or corner with respect to the one side is 10 mm or less. Through experiments, it was possible to form a tubular flame even when it was a square or larger.

  The portable tubular flame system of the present invention is used in an ignition device such as a writer used outdoors, mountain climbing or camping because it is burned in the pipe and does not extinguish due to the influence of disturbance such as wind. Applicable to cassette stoves and cassette burners. When applied to a writer, a layout design that compactly accommodates a cylinder, a burner, an air-fuel mixture forming device, and an ignition device in a hand-held case may be used. In addition, the weight of these portable tubular flame systems is preferably 500 g or less in a cylinder so that they can be carried.

The schematic block diagram of the tubular flame burner system in one Embodiment of this invention Sectional drawing which shows the tubular flame formed in a burner Schematic diagram of equipment for basic experiments Appearance of tubular flame ((a) shows a tubular flame burner (diameter 10 mm), (b) shows a flame of a theoretical mixture, and (c) shows a flame when it is over-rich) Graph showing flame formation limit (burner diameter 10 mm, fuel: propane) Graph showing change in flame diameter with fuel concentration Graph showing flame formation limit (burner diameter 4 mm, fuel: propane) External view of air-fuel mixture forming device Cross section of the air-fuel mixture forming device Graph showing fuel concentration and total flow rate of air-fuel mixture formed by air-fuel mixture forming device Perspective view showing a single suction burner Perspective view showing vertical 3 suction burner Perspective view showing horizontal 3 suction burner Model of the position of the maximum speed in the circumferential direction of the burner ((a) is a single suction burner, (b) is a vertical three suction burner, (c) is a horizontal three suction burner) Perspective view of horizontal 2 suction burner External view of tubular flame obtained by portable tubular flame burner system

Explanation of symbols

1 ... cylinder 3 ... burner 3a ... blowing hole (blowing part)
4 ... Tube flame 14 ... Air-fuel mixture forming device

Claims (7)

A cylinder for storing liquefied fuel;
A burner having a tubular inner wall and forming a tubular flame inside;
An air-fuel mixture forming device that creates a jet of vaporized gaseous fuel, sucks air using the negative pressure of the jet, and mixes gaseous fuel and air so that a tubular flame can be formed;
A blowout part that blows out the air-fuel mixture along the inner wall surface of the burner, and creates a swirling flow of the air-fuel mixture in the burner;
An ignition device for igniting the air-fuel mixture;
A portable tubular flame burner system comprising:   2. The portable tubular flame burner system according to claim 1, wherein the air-fuel mixture forming device mixes gaseous fuel and air at a concentration higher than that of the theoretical air-fuel mixture.   3. The portable tubular flame burner system according to claim 1, wherein a plurality of the blowing portions are provided with a position shifted in a circumferential direction of the burner.   The portable tubular flame burner system according to any one of claims 1 to 3, wherein a plurality of the blowing portions are provided at different positions in the axial direction of the burner.   The portable tubular flame burner system according to any one of claims 1 to 4, wherein the burner includes a transparent material so that the tubular flame inside the burner can be visually recognized.   The portable tubular flame burner system according to any one of claims 1 to 5, wherein an inner diameter of the burner is a cylindrical shape having a diameter of 10 mm or less or a polygonal shape having a diameter of 10 mm or less. The inner wall surface of the burner is open at one end in the axial direction and closed at the other end in the axial direction.
7. The portable tubular flame according to claim 1, wherein the ignition device ignites the air-fuel mixture between the blowing portion and the closed end surface in the axial direction of the burner. Burner system.