JPH049516A - Igniting and flame stabilizer - Google Patents

Abstract

PURPOSE:To simplify the construction of a burning device and ensure high performance by storing static electricity for ignition and flame stabilizing. CONSTITUTION:There are disposed coaxially at a predetermined interval an inner conductor pipe 13 including an insulator A on the middle thereof and an outer conductor pipe C. Static electricity is generated by directing through MF (main flow) passage powder such as Air+SiO, etc., liable to be charged with static electricity at the velocity of several meters/s (abbreviated as m/s, hereinafter)-several tens of m/s, and electric charges are stored between the inner pipe B and the outer pipe C. By directing combustible mixture gas to a SF (subflow) passage at a low velocity, spark is made for ignition of the mixture gas in the SF passage at the time when voltage across a spark gap A exceeds discharge voltage owing to the stored electric charges. At this time, by changing the flow in the MF passage to flows of combustible gas feed, spraying liquid fuel, and fine ash fuel, etc., the fuel is fierd. Hereby, ignition and flame stabilizing are ensured without use of a firing torch and a spark plug, etc., and hence the arrangement 12 greatly simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flame-holding device for igniting and holding a flame in a burner or the like in a commercial or industrial boiler.

[Prior Art] Conventionally, a burner nozzle was lit with an ignition torch (a small-diameter burner). Flame holding was also carried out using a flame holder attached near the tip of the burner nozzle. On the other hand, a spark plug is used for ignition inside the cylinder of a gasoline engine. These devices are characterized in that they are constructed in such a way that they achieve their intended purpose by applying energy from the outside.

[Problem to be solved by invention E] Conventional large burners for business or industrial use require an ignition torch, which is an external energy supply device, in order to ignite and hold the flame. Spark plugs were essential. This has resulted in the drawback that the structure of the combustion device is complicated and large.

By the way, generally when gas, powder, liquid, etc. flow inside a pipe, static electricity is generated and charged by these fluids, and charges of opposite polarity remain on surrounding members. When such electrostatic charging occurs, the charged static electricity may spontaneously ignite the fuel, causing an explosion or an uncontrollable ignition. To avoid this, the entire device is generally grounded to release static electricity to the ground (
do.

The present invention was made in consideration of these circumstances, and its purpose is to save energy by accumulating the above-mentioned static electricity and using it for ignition and flame stabilization, and to improve the configuration of combustion equipment. The object of the present invention is to provide a flame ignition device that is simple and has high performance.

[Means for Solving the Problems] In order to solve the above problems and achieve the objectives, the present invention takes the following measures.

(1) The inner tube made of a conductor through which fluid such as gas, powder, or liquid flows is electrically insulated from the ground potential using an insulator such as Teflon.

(2) Provide means to store static electricity generated by the flow of fluid. For example, from the inner tube to 0.5 to 2. By coaxially surrounding the inner tube with an outer tube made of a conductor with a gap of 0 cm, a type of capacitor is created between the two, and static electricity is stored in this capacitor portion.

(3) Attach a spark cap near the tip of the burner nozzle to discharge the stored charge in a timely manner and use it for ignition and flame stabilization.

(4) Discharge energy, discharge frequency (time interval), etc. are adjusted by fluid flow rate (flow restriction, etc.), spark gap interval, etc.

[Effect] As a result of taking the above measures, the following effects occur.

A type of capacitor is formed between the inner tube wall through which fluid flows and the outer tube, which is electrically floating from ground potential and is made of a conductor surrounding the inner tube wall. Therefore, static electricity generated by the fluid is efficiently stored. This stored static electricity charge is then discharged in a timely manner by the spark gap. Therefore, the above-mentioned discharge ignites the fuel and stabilizes the flame well. Note that the discharge is determined by the electric field strength between the discharge gaps and the composition of the RIJ fuel assembly that exists between the gaps, so by making the gear and knob spacing variable, the discharge energy, discharge time interval, etc. can be changed. . Incidentally, the gap interval shall be adjusted appropriately so that in one discharge, a discharge energy greater than the minimum spark energy of the combustible material passing between the gaps is released.

[Example] FIG. 1 is a side cross-sectional view of an electrostatic ignition flame-holding burner nozzle according to an example of the present invention, and FIG. 2 is a front view of the tip of the nozzle as viewed from the line 2 in FIG. In FIGS. 1 and 2, an inner tube B made of a conductor with an insulator A in the middle, and an outer tube C also made of a conductor are coaxially arranged with a predetermined gap. D is a subak gap, E is a flame-holding plate, and F and G are spark needles.

The ignition and flame holding sequence is performed as follows.

■ In the MF (main flow) passage in Figure 1, Air +
Powder that is easily charged with static electricity, such as SiO, is flowed through several meters at a speed of 7 seconds (hereinafter abbreviated as m/s) to several tens of n1/s. When this happens, static electricity is generated and charges are accumulated between the inner tube B and the outer tube C (electrostatic capacitance of several hundred pF).

■ A few seconds after starting to pour the powder into the MF passage,
A flammable gas mixture is flowed through the SF (subflow) passage at low speed (several tens of cm/s to several m/s).

■ When the electric charge accumulated in the process of step exceeds the voltage of the spark gear D or the discharge voltage, a spark will fly.
The mixture gas in the SF passage is ignited.

(2) When the mixed gas in the SF passage is ignited, the flow in the MF communication passage is converted into a flow of flammable gas fuel, atomized liquid fuel, pulverized ash fuel, etc. In this way, the fuel is ignited.

(2) During the steady combustion of the fuel, charges are continuously accumulated between the inner tube B and the outer tube C, similar to (2). Thus, in the spark gap D, sparks fly at regular intervals. When a premixed gas of methane + air is passed as the MF communication passage fluid, the speed is 10 m/s, and the capacitance between inner tube B and outer tube C is 100 pF, a spark with an energy of 1 to 2 mJ will be generated. It is estimated that they fly at intervals of 1 second.

(2) The MF communication passage fluid is charged with a polarity opposite to that on the inner tube B. Therefore, sparks fly between the MF communication passage combustible fluid and the spark needle FSG, and flame stability during combustion is maintained via the flame stabilizing plate E.

If a flammable gas or liquid with a small minimum ignition energy (0.2 to 1.0 *J), such as hydrogen, is used as the fluid flowing through the MF communication passage, ignition will not occur even if step (2) is omitted. It is possible.

Note that the present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] According to the present invention, the following effects can be expected. It is possible to ignite and hold the flame without using any equipment that supplies energy from the outside, such as a torch or spark plug, and the configuration is significantly simplified. In particular, it is possible to prevent accidents and uncontrollable sparks caused by static electricity charging, and moreover, the static electricity can be effectively utilized.

In other words, the present invention provides a flame ignition device that stores static electricity and uses it for ignition and flame stabilization, thereby saving energy and simplifying the configuration and improving the performance of the combustion device. can.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an electrostatically ignited flame-stabilizing burner nozzle according to an embodiment of the present invention, and FIG. 2 is a front view of the tip of the nozzle taken along the line ■-n in FIG. A...Insulator, B...Inner tube of burner nozzle, C...
・Burner nozzle outer tube, D...Spark gap, E
...Flame holding plate, F, G...Spark needle. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] An inner tube that has a wall surface through which fluid flows and is placed in the fuel device in a state where it is electrically floating from ground potential, and an outer tube that is placed so as to coaxially surround this inner tube with a predetermined gap between them. and a means for accumulating static electricity as an energy source for ignition and flame holding between the inner tube and the outer tube by passing a fluid through the inner tube, and the static electricity accumulated by this means. 1. A flame-holding device characterized by comprising means for igniting and holding a flame by timely discharging the fuel.