JP4063174B2 - Tubular flame burner - Google Patents

Description

  The present invention relates to a burner provided in a furnace or a combustor.

  A burner provided in a furnace or a combustor has a tubular combustion chamber with one end opened, and a nozzle for blowing fuel gas and a nozzle for blowing oxygen-containing gas in the vicinity of the closed end of the combustion chamber are provided inside the combustion chamber. A tubular flame burner provided in the tangential direction of the peripheral surface is shown (for example, see Patent Document 1).

In this tubular flame burner, a stable flame is formed in the burner in a high-speed swirling flow, so that downsizing of the combustion equipment is achieved, the temperature variation of the combustion flame is small, and a local high temperature region is generated. In addition to being difficult to form, the burner is capable of stable combustion even when the oxygen ratio or air ratio is lowered. Therefore, the burner can reduce environmental pollution sources such as harmful substances such as NOx, unburned components such as hydrocarbons, and smoke.
JP-A-11-281015

  In general, when fuel gas with a small calorific value is used, the air ratio range that can be ignited by electric sparks is very narrow, and it is extremely difficult to supply fuel gas and oxygen-containing gas without premixing Ignition is difficult.

  Even in the above tubular flame burner, the region where the fuel gas and the oxygen-containing gas are mixed in an air ratio range suitable for ignition is limited in the combustion chamber, and therefore there is a problem that ignition by electric spark is extremely difficult, In some cases, a pilot burner for ignition is required.

  The present invention has been made to solve the above problems, and provides a tubular flame burner capable of stably igniting with an electric spark in a tubular flame burner that forms a tubular flame in a tubular combustion chamber. It is intended.

  In order to solve the above problems, the present invention has the following features.

[1] A tubular combustion chamber having a front end opened and an ignition spark plug attached to the rear end, and a nozzle injection port opened on the inner surface of the combustion chamber, so that fuel and oxygen-containing gas are separately or premixed. In the tubular flame burner in which the injection direction of each nozzle substantially coincides with the tangential direction of the circumferential surface of the combustion chamber, the ignition spark plug is connected to the tube axis of the combustion chamber with r / 3 (however, The tubular flame burner is provided between the positions r: radius of the combustion chamber) and on the rear end side of the combustion chamber from the position of the nozzle .

  In the present invention, since the ignition spark plug is attached at an appropriate position near the tube axis of the combustion chamber, the gas mixed with the fuel gas and the oxygen-containing gas in the combustion chamber can be reliably ignited. Therefore, it is possible to reduce the size and cost of the tubular flame burner.

  One embodiment of the present invention is shown in FIGS. FIG. 1 is a side view of a tubular flame burner according to this embodiment, and FIG. 2 is a cross-sectional view taken along the line AA in FIG. FIG. 3 is an explanatory view for explaining the ignition state of the tubular flame burner according to this embodiment.

  In FIG. 1, reference numeral 10 denotes a tubular combustion chamber, the tip 10a of which is opened to serve as an exhaust port for combustion exhaust gas. A nozzle that blows fuel gas into the combustion chamber 10 and a nozzle that blows oxygen-containing gas are attached in the vicinity of the rear end 10b of the combustion chamber 10 at a distance L. Further, an ignition spark plug 21 is attached to the rear end 10 b of the combustion chamber 10, and the ignition spark plug 21 blows a spark into the combustion chamber 10 by an igniter 22 and a power source 23.

  As shown in FIG. 1 and FIG. 2, four elongated slits 12 along the pipe axis direction are formed at four locations on the same pipe circumference of the combustion chamber 10 as nozzle injection ports to the combustion chamber 10. The nozzles 11a, 11b, 11c, and 11d, which are elongated in the tube axis direction, are connected. The injection directions of the nozzles 11 a, 11 b, 11 c, and 11 d are provided so as to be tangential to the inner peripheral surface of the combustion chamber 10 and in the same rotational direction. Of these four nozzles, two nozzles 11a and 11c are fuel gas blowing nozzles, and two nozzles 11b and 11d are oxygen-containing gas blowing nozzles.

  Fuel gas is blown from the fuel gas blowing nozzles 11 a and 11 c at a high speed toward the tangential direction of the inner circumferential surface of the combustion chamber 10, and oxygen-containing gas is blown from the oxygen-containing gas blowing nozzles 11 b and 11 d to the inner circumference of the combustion chamber 10. A swirling flow is formed while the fuel gas and the oxygen-containing gas are efficiently mixed in a region close to the inner peripheral surface of the combustion chamber 10 while being blown at high speed toward the tangential direction of the surface. When the mixed gas in the swirl flow is appropriately ignited by the ignition spark plug 21, a tubular flame is generated in the combustion chamber 10. The combustion gas is discharged from the tip 10 a of the combustion chamber 10.

  The oxygen-containing gas mentioned above refers to a gas that supplies oxygen for combustion, such as air, oxygen, oxygen-enriched air, oxygen / exhaust gas mixture gas.

  In this embodiment, the ignition spark plug 21 is attached between the tube axis of the combustion chamber 10 and the r / 2 (where r is the radius of the combustion chamber) position.

  FIG. 3 shows the relationship between the mounting position of the spark plug 21 for ignition in the radial direction of the combustion chamber 10 and the ignition state obtained by the spark plug 21 for ignition, and between the tube axis and the r / 2 position. It is shown that a good ignition can be performed by attaching the spark plug 21 for ignition.

  This is because, in the vicinity of the tube axis of the combustion chamber 10, the flow velocity of the swirling flow in which the fuel gas and the oxygen-containing gas are mixed becomes relatively slow and is mixed in an appropriate air ratio range, so that ignition can be ensured. Because.

  As a result, a pilot flame burner for ignition is not required, and the tubular flame burner can be reduced in size and cost.

  Further, when the distance L between the nozzles 11a to 11d and the rear end 10b of the combustion chamber 10 is shortened in order to further reduce the size of the tubular flame burner, it is suitable for mixing the fuel gas and the oxygen-containing gas. In such a case, the distance cannot be obtained, and the region where the fuel gas and the oxygen-containing gas are mixed in an appropriate air ratio range in the vicinity of the rear end 10b of the combustion chamber 10 may be narrowed in the radial direction. It is preferable to attach an ignition spark plug 21 between the tube axis and the r / 3 position. Thereby, even when the nozzles 11a to 11d and the spark plug 21 for ignition are close to each other (L≈0), it is possible to surely perform good ignition.

  In this embodiment, the fuel gas injection nozzle and the oxygen-containing gas injection nozzle are provided so that the injection direction coincides with the tangential direction of the combustion chamber peripheral surface, but it does not necessarily match the tangential direction of the combustion chamber peripheral surface. The injection direction may be deviated from the tangential direction of the circumferential surface of the combustion chamber to such an extent that a swirl flow of gas can be formed in the combustion chamber.

  In this embodiment, a slit is provided along the tube axis direction as an injection port to the combustion chamber, and a flat fuel gas injection nozzle and an oxygen-containing gas injection nozzle are connected to the slit. A plurality of small holes may be arranged in the direction of the tube axis as nozzles of the nozzles, and nozzles for injecting fuel gas or oxygen-containing gas may be connected to the small hole rows.

  In this embodiment, fuel gas is blown in, but liquid fuel may be blown in. As the liquid fuel, those which vaporize at a relatively low temperature such as kerosene, light oil, alcohol, A heavy oil and the like are suitable.

  In this embodiment, the fuel gas and the oxygen-containing gas are blown separately, but the fuel gas and the oxygen-containing gas may be premixed and blown.

It is a side view of the tubular flame burner concerning one embodiment of the present invention. It is AA sectional drawing of FIG. It is explanatory drawing of the ignition state of the tubular flame burner which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Combustion chamber 10a Front end of combustion chamber 10b Rear end of combustion chamber 11a, 11c Fuel gas injection nozzle 11b, 11d Oxygen-containing gas injection nozzle 12 Slit 21 Spark plug for ignition 22 Igniter 23 Power supply

Claims (1)

A tubular combustion chamber having a front end opened and an ignition spark plug attached to the rear end, and a nozzle injection port are opened on the inner surface of the combustion chamber, and fuel and oxygen-containing gas are blown separately or premixed. In a tubular flame burner provided with nozzles, in which the injection direction of each nozzle substantially coincides with the tangential direction of the peripheral surface of the combustion chamber, the spark plug for ignition is r / 3 (where r: combustion) A tubular flame burner provided between the positions of the chamber radii) and on the rear end side of the combustion chamber from the position of the nozzle .

Images