JP5472848B2 - Combustion chamber temperature control device in waste melting furnace equipment - Google Patents

Description

  The present invention controls the temperature of the combustion chamber for burning the combustible gas and the combustible residue generated from the waste melting furnace for melting the waste by adjusting the amount of air blown from the tuyere to the waste melting furnace, The present invention relates to temperature control of a combustion chamber in a waste melting furnace facility.

  Exhaust gas containing combustible gas and combustible residue (char) generated when melting waste such as general waste, industrial waste, and shredder dust in a shaft furnace type waste melting furnace is installed at the latter stage of the melting furnace. The high-temperature combustion exhaust gas that is introduced into the combustion chamber and burned and discharged is recovered by a boiler (see Patent Documents 1 and 2).

  Since the waste quality of the waste introduced into the waste melting furnace is not constant and fluctuates, the combustible gas components and the amount of char in the exhaust gas discharged from the waste melting furnace fluctuate. For example, when waste containing a small particle size, such as waste containing plastic such as automobile shredder dust (ASR), and containing a large amount of plastics, which is susceptible to rapid thermal decomposition, is put into a waste melting furnace and processed. Later combustible gas and char are scattered and introduced into the combustion chamber, and the temperature of the combustion chamber rises rapidly. A sudden rise in the temperature of the combustion chamber is undesirable because the amount of steam in subsequent boilers fluctuates rapidly.

JP-A-8-159436 Japanese Patent Laid-Open No. 2006-266619

  Conventionally, when the temperature of the combustion chamber suddenly rises, the amount of diluted air blown into the combustion chamber is increased and dealt with. However, there is a case where the temperature rise cannot be suppressed due to the controllability limit of the combustion air amount of the main burner for burning the combustible gas or char. Furthermore, in the worst case, clinker was generated in the combustion chamber and the operation could not be continued.

Therefore, the present invention prevents the sudden increase in the temperature of the combustion chamber by suppressing the amount of scattered combustible gas and char after pyrolysis in the waste melting furnace, and enables optimal combustion chamber temperature maintenance management. , there is provided a combustion room temperature-controlling device that put the waste melting furnace facilities.

Combustion chamber temperature control device of the present invention, disposal by introducing waste from the furnace top, and supplies the oxygen source from the tuyere of a plurality of stages which is disposed in the lower part of the furnace and melted by the heat of reaction from the discharging hole of the furnace bottom portion In a combustion chamber temperature control apparatus for combusting combustible gas and combustible residue generated in a waste melting furnace that discharges ash and non-combustibles in waste, the upper and middle tuyere of the tuyere are disposed in the waste melting furnace. Installed at intervals on the outer periphery, and arranged to be shifted in the circumferential direction of the waste melting furnace so as not to overlap in the vertical direction, and a burner for burning the combustible gas and combustible residue is disposed in the combustion chamber, A flowmeter that adjusts the flow rate of the oxygen source blown from the upper tuyeres and / or the middle tuyeres, with a thermometer that measures the temperature of the combustion gas exhausted from the burner disposed at a level at which the combustion gases are exhausted Adjust the control valve to the upper Each we established the oxygen source supply pipe of the tuyere and middle tuyere sets an adjustment amount of the individual flow control valves for each of said upper tuyeres and middle tuyere were measured this setting by the thermometer An air supply control device that adjusts according to temperature is provided .

  In the present invention, when the combustion chamber temperature suddenly rises, the amount of air in the upper blower tuyeres, the middle blower tuyeres and the lower blower tuyeres of the waste melting furnace is individually determined according to the temperature rise width. By adjusting with the set control amount, a rapid increase in the temperature of the combustion chamber is suppressed, and it becomes possible to maintain and manage the temperature within an appropriate range.

  The conventional technology does not control the generation amount of combustible gas and char after pyrolysis generated from the waste melting furnace, and can only control the combustion chamber temperature by the combustion air amount in the combustion chamber. Although there was a limit, it was difficult to suppress a rapid temperature rise, but according to the present invention, it is possible to adjust the amount of thermal decomposition in the furnace by automatic blowing control on the waste melting furnace side, and it depends on the amount of combustion air In addition to temperature control, it became possible to control the amount of combustible gas and char generation, so that it was possible to greatly suppress the rapid increase in the combustion chamber temperature.

  Further, according to the present invention, it is possible to adjust the flow rate of the air flow while maintaining the air flow rate balance that can maintain the stable melting state of the melting furnace.

It is explanatory drawing of the temperature control of the melting furnace and combustion chamber by this invention. The arrangement | positioning of the upper tuyere of the melting furnace by this invention is shown, (a) is an upper stage tuyere, (b) is a layout drawing of a middle stage tuyere. It is a graph which shows the relationship between the air quantity of an upper tuyere, and a combustion chamber temperature. It is a graph which shows the relationship between the air quantity and combustion chamber temperature of an upper stage tuyere and a middle stage tuyere.

  Embodiments of the present invention will be described with reference to the drawings.

  In FIG. 1, a combustion chamber 2 is arranged at the rear stage of the shaft furnace type waste melting furnace 1. Exhaust gas containing combustible gas and char discharged from the melting furnace 1 is introduced into the main burner of the combustion chamber 2 from the exhaust gas duct 5 connected to the melting furnace 1 and the combustion chamber 2, and is ejected into the combustion chamber 2 Form. For example, the main burner is supplied with combustible gas and char from the exhaust gas duct 5 to the burner described in the patent document.

  A dilution air introduction port 3 for introducing dilution air is connected to the combustion chamber 2, and the amount of dilution air to be introduced is adjusted by a dilution air adjustment valve 4. A main burner thermometer 6 is disposed in the combustion chamber 2. A radiation thermometer is used as the main burner thermometer 6 and is arranged at the same level as the main burner to measure the ambient temperature on the opposite side of the thermometer.

  The melting furnace 1 is provided with an upper tuyere and a lower tuyere 9 through which an oxygen source is blown. As an oxygen source, air is blown to the upper tuyere and oxygen-enriched air is blown to the lower tuyere 9. The upper tuyere is composed of an upper tuyere 7 and a middle tuyere 8 in this embodiment. A plurality of tuyere are arranged in the upper tuyere and the lower tuyere 9 at intervals on the outer periphery of the melting furnace 1. The upper tuyere is shifted in the circumferential direction of the melting furnace 1 so that the upper tuyere 7 shown in FIG. 2A and the middle tuyere 8 shown in FIG. The amount of air blown is made to flow uniformly in the furnace without being biased.

  The upper tuyere 7, the middle tuyere 8 and the lower tuyere 9 are respectively connected to the upper tuyeres header 14, the middle tuyeres header 15 and the lower tuyere header 16 branched from the oxygen source supply pipe 18 of the blower 13. Air is supplied from the connected upper tuyere air supply pipe 19, middle tuyere air supply pipe 20, and lower tuyere air supply pipe 21. The air supply pipes 19, 20, 21 are provided with flow rate adjusting valves 10, 11, 12, respectively. The temperature signal of the main burner thermometer 6 is input to the air supply control device 17, and a flow rate adjustment control signal is output to each flow rate adjustment valve 10, 11, 12.

  In the air supply control device 17, the adjustment amount of the individual flow control valve is set for each of the upper tuyere 7, the middle tuyere 8, and the lower tuyere 9 with respect to the combustion temperature of the combustion chamber 2. The set value of the adjustment amount of the flow rate control valve is output as a control signal to the flow rate control valve with respect to the temperature variation measured by the burner thermometer.

  As shown in the graph of FIG. 3, when combustible gas and char scattering from the melting furnace increase and the main burner temperature in the combustion chamber 2 rises, the temperature signal measured by the main burner thermometer 6 is the temperature control device 17. Is input to the temperature control device 17, the control signal of the adjustment amount of the flow adjustment valve 10 of the upper tuyere blown air amount 22 is output and reduced, thereby suppressing the burner combustion gas temperature 24 in the combustion chamber. . In this example, the flow rate was adjusted only for the upper tuyere and the burner temperature was adjusted.

  As shown in the graph of FIG. 4, when the combustible gas and char scattering from the melting furnace increase and the main burner temperature in the combustion chamber 2 rises, the temperature signal measured by the main burner thermometer 6 is the temperature control device 17. , The temperature control device 17 outputs control signals for the adjustment amounts of the flow control valves 10 and 11 according to the settings of the upper tuyere air volume 22 and the middle tuyer air quantity 23, respectively. By reducing the adjustment, it is possible to suppress an increase in the burner combustion gas temperature 24 in the combustion chamber 2. In this embodiment, the upper tuyere 7 is adjusted within the range of 50% and the middle tuyere 30%.

1: Melting furnace 2: Combustion chamber 3: Dilution air introduction port 4: Dilution air adjustment valve 5: Exhaust gas duct 6: Main burner thermometer 7: Upper tuyere 8: Middle tuyere 9: Lower tuyere 10: Upper tuyere Flow control valve 11: Flow control valve for middle tuyere 12: Flow control valve for lower tuyere 13: Blower 14: Header for upper tuyere 15: Header for middle tuyere 16: Header for lower tuyere 17: Air supply Control device 18: oxygen source supply pipe 19: upper stage tuyere air supply pipe 20: middle stage tuyere air supply pipe 21: lower stage tuyere air supply pipe 22: upper stage tuyere air supply 23: middle stage tuyere air supply 24: Main burner temperature

Claims (1)

Waste is introduced from the upper part of the furnace, oxygen sources are supplied from a plurality of tuyeres arranged at the lower part of the furnace, and ash and non-combustible substances in the waste melted by reaction heat are discharged from the discharge hole at the bottom of the furnace. In a combustion chamber temperature control device for burning combustible gas and combustible residue generated in a waste melting furnace,
Among the tuyere, the upper and middle tuyere are installed at an interval on the outer periphery of the waste melting furnace, and are shifted in the circumferential direction of the waste melting furnace so as not to overlap in the vertical direction,
Wherein the burner for burning a combustible gas and combustible residue located in the combustion chamber, a thermometer for measuring the temperature of the combustion gas discharged from the burner is arranged at the level of the combustion gas is discharged, further the upper tuyeres and A flow control valve for adjusting the amount of oxygen source blown from the middle tuyere is installed in each of the upper tuyere and middle tuyere oxygen source supply pipes, and each of the upper tuyere and middle tuyere A combustion chamber temperature control device comprising an air supply control device for setting an adjustment amount of an individual flow rate control valve and adjusting a set value according to a temperature measured by the thermometer .

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