JP2002005439A - Burner combustion state determination method - Google Patents

Abstract

(57) [Summary] [Problem] To reliably determine the combustion state of a burner inserted in a furnace without providing a viewing window. A burner body is provided with a vibration sensor. The detection signal of the vibration sensor is sent to the monitor, and the combustion state of the burner is determined based on the vibration intensity. In the determination of the combustion state, ignition of the burner is determined when the detected vibration intensity exceeds a predetermined value, and the burner is extinguished or misfired when the detected vibration intensity is lower than the predetermined value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining the combustion state of a burner, and more particularly to a method for determining the combustion state of a burner which can be suitably used for determining the combustion state of an oxygen burner used in an incineration fly ash melting furnace.

[0002]

2. Description of the Related Art Conventionally, burners such as ignition, misfire, and fire extinguishing in various types of combustion furnaces have been confirmed by using a sensor for directly detecting a fire with ultraviolet rays, or through a viewing window provided on a furnace wall. On the other hand, with the demand for environmental protection in recent years, an oxygen burner type melting furnace suitable for volume reduction and detoxification of waste incineration fly ash etc. has been attracting attention, and this melting furnace has been described above during the high temperature flame of the oxygen burner. This is a method of producing detoxified slag by completely transporting incinerated fly ash and the like by gas melting high melting point substances.

[0003]

The melting furnace has an extremely high temperature of 1450 ° C. or more in the furnace,
Since the furnace is filled with fine powder particles, there is a problem that a viewing window cannot be provided to check the combustion state of the burner.

Accordingly, the present invention has been made to solve such a problem, and a method for determining the combustion state of a burner which can reliably determine the combustion state of a burner inserted in a furnace without providing a viewing window. The purpose is to provide.

[0005]

In order to achieve the above object, a method for determining the combustion state of a burner according to the present invention comprises a method of determining the magnitude of vibration (hereinafter referred to as vibration acceleration, vibration velocity, vibration displacement, etc.) generated in a burner body. Vibration intensity) is detected, and the combustion state of the burner is determined based on the detected vibration intensity. The determination of the combustion state is to determine the ignition of the burner when the detected vibration intensity exceeds a predetermined value, and to judge the burning or misfire of the burner when the detected vibration intensity falls below the predetermined value. can do. Further, the determination of the combustion state may be a determination of the burn rate of the burner from the detected vibration intensity.

In the present invention, the combustion state such as ignition, digestion, misfire, and combustion rate of the burner can be determined from the vibration intensity of the burner main body. The combustion state of the installed burner can be reliably determined.

[0007] The reference numerals in parentheses indicate the correspondence with specific means described in the embodiments described later.

[0008]

FIG. 1 shows the entire structure of a melting furnace using an oxygen burner. In FIG. 1, the furnace main body of the melting furnace 1 is a vertical furnace having a furnace wall made of refractory, and a pool 111 for storing a molten slag as a melt is formed at a furnace bottom 11 through a solidification slag 112. Then, a slag port 14 for discharging the molten slag Mt is opened in the furnace wall 12 near the furnace bottom 11, and the molten slag Mt is discharged into a water tank 15 below.
An oxygen burner 2 is provided on the furnace top wall 16 so as to extend vertically therethrough. The oxygen burner 2 has a tip 21 projecting into the furnace, and a periphery of the burner tip is a secondary combustion space 17.
It has become. An exhaust gas discharge port 18 is opened at a peripheral portion of the furnace top wall 16 facing the secondary combustion space 17.

Fuel is supplied to the oxygen burner 2 through a supply pipe 31 to a main nozzle (not shown) at the burner axis, and a plurality of sub-nozzles provided concentrically around the main nozzle from the inside. The primary combustion supporting gas from the supply pipe 32, the incinerated fly ash carried by the air and the like from the supply pipe 33, and the supply pipe 3
4 are supplied respectively. In addition, PSA (Pressure Swing A)
A gas having an oxygen concentration of 90% or more generated by a device or the like is used.

An oxygen burner 4 for facilitating slag is provided on a partition wall 19 which branches off from the furnace wall 12 and extends vertically downward at an interval therefrom. The tip is opposed to the slag port 14. A jet jet flame F2 extends horizontally from the oxygen burner 4, and the leading end of the flame F2 enters the rectangular slag port 14 almost without spreading, and locally melts slag Mt passing therethrough. Heating.

FIG. 2 shows the appearance of the oxygen burner 2. The oxygen burner 2 is mounted and fixed to the furnace top wall 16 (FIG. 1) by a mounting flange 22. Base end of burner body (upper end)
24 is connected to a fuel supply pipe 31, and pipe joints 25, 26, 27 projecting from side surfaces of the burner main body are respectively connected to the primary combustion supporting gas supply pipe 3 from the side near the base end 24.
2. The incineration fly ash supply pipe 33 and the secondary combustion supporting gas supply pipe 34 are connected. The pipe joints 28 and 29 are connected to a cooling water supply pipe 35 and a cooling water discharge pipe 36 to a water cooling jacket in the outer peripheral portion of the burner main body.

A vibration acceleration sensor 5 is mounted on a flange portion 231 of the primary oxygen introducing pipe 23 constituting the burner body. The output signal of the vibration acceleration sensor 5 is input to a separate monitor 6, where it is displayed as a voltage value according to the vibration intensity (magnitude of vibration acceleration). As the vibration acceleration sensor, a commercially available tool breakage sensor or the like can be used. The specification of the vibration acceleration sensor in the present embodiment has a minimum detection acceleration of 0.98 m / s ² and a response frequency of 40.
Hz to 8 kHz.

FIG. 3 shows the measured vibration intensity of the oxygen burner 2 from ignition to fire extinguishing by using such a vibration acceleration sensor. In FIG. 3, when the supply of the fuel oil is started at time t1, the burner main body of the oxygen burner 2 starts fine vibration, and when ignited at time t2, the vibration of the burner main body exceeds a predetermined threshold value VH and sharply increases. During the combustion of the oxygen burner 2, the vibration intensity of the oxygen burner 2 changes depending on the supply ratio between the primary combustion supporting gas and the secondary combustion supporting gas and the combustion rate (μ). Then, when the fire is extinguished at time t3, the vibration intensity of the oxygen burner 2 drops below the threshold value VH and sharply decreases. Even when a misfire occurs due to a shortage of fuel or the like during the combustion, the vibration intensity of the oxygen burner 2 sharply drops below the threshold value VH as shown by a chain line in FIG. In this way, by comparing the monitor output with the appropriate threshold value VH, it is possible to reliably determine ignition, extinction, and misfire of the oxygen burner 2.

FIG. 4 shows how the monitor output (ie, vibration intensity) changes when the combustion ratio (η) during burner combustion is changed while the supply ratio between the primary combustion supporting gas and the secondary combustion supporting gas is kept constant. Is shown. As is clear from the figure, the monitor output is uniquely determined for each combustion rate, and control such as optimally changing the combustion rate according to the supply amount of incineration fly ash can be performed while checking the monitor output. it can. In the above embodiment, the vibration acceleration sensor 5 is connected to the flange portion 23 of the primary oxygen introduction pipe 23.
1, but may be provided at another place of the burner main body. Further, the present invention is not limited to the determination of combustion of an oxygen burner, but can be used for determination of combustion of another burner. In addition, other vibration sensors such as a vibration speed sensor and a vibration displacement sensor can be used instead of the vibration acceleration sensor.

[0015]

As described above, according to the method for determining the combustion state of a burner of the present invention, the combustion state of the burner can be reliably determined without providing a viewing window.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a melting furnace provided with an oxygen burner.

FIG. 2 is an overall side view of the oxygen burner.

FIG. 3 is a diagram showing a temporal change of a monitor output from burner ignition to fire extinguishing.

FIG. 4 is a graph showing a relationship between a burner combustion rate and a monitor output.

[Explanation of symbols]

 2: oxygen burner, 5: vibration sensor, 6: monitor.

Claims (3)

[Claims] 1. A method for judging a combustion state of a burner, comprising detecting a vibration intensity generated in a burner body and judging a combustion state of the burner based on the detected vibration intensity. 2. A burner ignition is determined when the detected vibration intensity exceeds a predetermined value, and a burnout or misfire of the burner is determined when the detected vibration intensity falls below a predetermined value. The method for determining a combustion state of a burner according to claim 1, wherein: 3. The method for determining a combustion state of a burner according to claim 1, wherein the combustion rate of the burner is determined from the detected vibration intensity.