JP3909975B2 - Method and apparatus for processing raw materials - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for processing a material by controlling the furnace pressure of the incinerator or gasifier incinerating or gasifying various wastes such as municipal wastes and industrial wastes.
[0002]
[Prior art]
Generally, in an incinerator, it is necessary to always keep the pressure inside the furnace negative for safety measures. However, if the negative pressure is too strong in this case, the amount of air leaking from the furnace, gas cooling device, gas processing device, exhaust gas duct, etc. increases, so that the amount of exhaust gas increases and the power of the blower increases. Therefore, it has been necessary to control the pressure in the furnace so as to be an appropriate negative pressure.
[0003]
Conventionally, in the in-furnace pressure control of a general incinerator, control by a simple controller is performed as shown in FIG. Here, 1 is an incinerator, 2 is a gas cooler, 3 is a gas processing device, 4 is a damper for adjusting the exhaust gas flow rate, 5 is an induction fan for exhaust gas suction, and 6 is a chimney. A raw material 7 and combustion air 8 are supplied to the incinerator 1. 13 indicates a leak.
The pressure in the furnace detected by the detection end 9 is sent to the controller 12 including the PID controller 11 by the pressure transmitter 10 and is compared with the set value in the furnace pressure, and the adjustment which is the operation end based on the obtained operation amount signal. The damper 4 is operated, the exhaust gas flow rate is adjusted, and the furnace pressure is controlled.
[0004]
However, in the above-described control system, when municipal waste or industrial waste is incinerated, the pressure in the furnace is greatly fluctuated and stable control is difficult. Therefore, the present inventor disclosed in Japanese Patent Application Laid-Open No. 61-49929. The improvement of the furnace pressure control was attempted by changing the gain of the control system based on the set value and the detected value of the furnace pressure.
[0005]
However, recently, with the advancement of exhaust gas treatment equipment, the pressure loss of the exhaust gas treatment equipment tends to increase. In this case, in the method proposed in Japanese Patent Laid-Open No. 61-49929, there is a fear that the pressure in the furnace becomes a positive pressure due to a transient shortage of the induction blower due to a delay in the operation of the adjustment damper. In order to solve this, the present inventor in JP-A-5-272734 provides an additive gas line for adding gas upstream from the inlet of the induction fan, an additive gas control damper is provided in the additive gas line, and the furnace pressure is adjusted. Based on the output of the meter, the opening of the additive gas control damper is controlled by decreasing the additive gas flow rate when the furnace pressure is high and increasing the additive gas flow rate when the furnace pressure is low. As a result, the pressure control in the fluidized bed incinerator with advanced exhaust gas treatment equipment was improved.
[0006]
[Problems to be solved by the invention]
However, in the method proposed in Japanese Patent Laid-Open No. 5-272734, when the amount of combustion exhaust gas in the furnace decreases, the amount of return exhaust gas increases, so the amount of gas passing through the induction blower does not decrease and the amount of power decreases accordingly. However, it was wasteful from the viewpoint of energy saving. This situation is the same in the case of a gasification furnace in which various types of waste such as municipal waste and industrial waste are gasified by partial combustion.
[0007]
In order to eliminate the above-mentioned drawbacks, the present invention provides an adjustment damper in the fluidized air line fed from the lower part of the fluidized bed, or by providing a bypass line in the fluidized air line and an adjustment damper in the bypass line. If the pressure rises, by slow controlled fluidizing combustion air quantity by the installed regulatory damper fluidizing air line or bypass line, it is possible to suppress the increase of the pressure suppressing gasification amount RuHara It is an object of the present invention to provide a method and an apparatus for processing a fee.
[0008]
[Means for Solving the Problems]
In order to achieve the above-described object, one aspect of the raw material processing apparatus of the present invention includes a fluidized bed gasification furnace to which a raw material and combustion air are supplied, a melting furnace to which secondary combustion air is supplied, and a furnace In an apparatus for processing a raw material, including an induction blower that maintains an internal pressure at a negative pressure, a detection end for detecting the pressure in the fluidized bed gasification furnace, and a pressure in the furnace detected by the detection end A pressure transmitter for output as PV0, a calculator for calculating the output PV0 of the pressure transmitter to obtain a calculation output CV0, a fluidized air line for supplying combustion air to the fluidized bed gasifier, and the fluidized air A bypass line that is provided in the line and blows combustion air into the melting furnace, and an adjustment damper that is provided in the bypass line and that operates the opening degree using the calculation output CV0 as a control signal.
Further, one aspect of the raw material processing method of the present invention is a method for supplying a raw material and combustion air to a fluidized bed gasification furnace, supplying secondary combustion air to a melting furnace, and processing the raw material. Is used to detect the pressure in the fluidized bed gasification furnace, output the pressure in the furnace detected by the detection end as PV0 by the pressure transmitter, and calculate the output PV0 of the pressure transmitter by the calculator. A bypass for obtaining the output CV0, supplying combustion air to the fluidized bed gasification furnace through the fluidized air line, and using the calculated output CV0 as a control signal and blowing the combustion air into the melting furnace while being provided in the fluidized air line The opening degree of the adjustment damper provided in the line is operated.
According to a preferred aspect of the in-furnace pressure control method of the present invention, in the in-furnace pressure control method for a fluidized bed incinerator or fluidized bed gasification furnace for incineration or gasification of municipal waste or industrial waste, etc., from the lower part of the fluidized bed. established a regulatory damper flow air line for feeding combustion air, that controls the controlled furnace pressure blowing combustion air into the furnace by the regulating damper.
[0009]
According to another preferred aspect of the in-furnace pressure control method of the present invention, in the in-furnace pressure control method of a fluidized bed incinerator or fluidized bed gasification furnace for incineration or gasification of municipal waste or industrial waste, etc. the bypass line is provided from the underfloor portion flowing air line for feeding combustion air, an adjustable damper installed in the bypass line, that controls the controlled furnace pressure blowing combustion air into the furnace by the regulating damper.
Moreover, it is preferable to install the inlet of the said bypass line in the upper part of an incinerator, or the back | latter stage of a gasification furnace.
In another aspect of the raw material processing apparatus of the present invention, a fluidized bed gasification furnace to which the raw material and combustion air are supplied, a melting furnace to which secondary combustion air is supplied, and the furnace pressure are maintained at a negative pressure. And a pressure transmitter for detecting the pressure in the fluidized bed gasification furnace and outputting the pressure in the furnace detected by the detection terminal as PV0. A first-order lag filter for obtaining an output PV1 that absorbs the pulsation of PV0 at the furnace pressure, and a PID controller for obtaining a control output MV1 by PID calculation of the output PV1, and the control output MV1 by either control the frequency of the VVVF inverter of the attractant blower, or Ru der controls the damper installed at the entrance of the attraction blower.
Further, another aspect of the raw material processing method of the present invention is a method in which a raw material and combustion air are supplied to a fluidized bed gasification furnace, a secondary combustion air is supplied to a melting furnace, and the raw material is processed. The internal pressure of the fluidized bed gasifier is detected by the end, the internal pressure detected by the detection end is output as PV0 by the pressure transmitter, and the pulsation of PV0 of the internal pressure is absorbed by the first-order lag filter. The output PV1 is obtained, and the output PV1 is PID-calculated by a PID controller to obtain the control output MV1, and the control output MV1 is used to control the frequency of the VVVF inverter of the induction fan or is installed at the entrance of the induction fan Ru der controls the furnace pressure by controlling the damper.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the furnace pressure control method according to the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a first embodiment of the present invention. In FIG. 1, 1 is an incinerator, 2 is a gas cooler, 3 is a gas treatment device, 4 is an induction blower inlet damper, 5 is an induction blower for exhaust gas suction, and 6 is a chimney. The incinerator 1 is supplied with the raw material 7, combustion air 8-1 and secondary combustion air 8-2. The in-furnace pressure of the incinerator 1 detected by the detection end 9 is sent to the primary delay filter 14 as PV0 by the pressure transmitter 10, and the pulsation is absorbed and becomes the output PV1. The output PV1 is subjected to PID calculation by the PID controller 11 to obtain a control output MV1. This control output MV1 controls the frequency of a VVVF inverter (variable voltage variable frequency inverter) 51 of the induction fan 5 or controls the induction fan inlet damper 4 installed at the inlet of the induction fan 5 to control the pressure in the furnace. Perform gradual control.
[0011]
In the present embodiment, a bypass line BL is provided in the flowing air line of the combustion air 8-1, and an in-furnace pressure adjusting damper 81 is provided in the bypass line BL. The inlet of the bypass line BL is installed in the upper part of the incinerator 1. And the combustion air 8-1 is blown into the upper part of the incinerator 1 by the bypass line BL. The rapid fluctuation of the in-furnace pressure is controlled by controlling the blowing of the combustion air 8-1 to the upper part of the incinerator by the in-furnace pressure adjusting damper 81 installed in the bypass line BL.
[0012]
The output PV0 of the furnace pressure transmitter 10 is input to the calculator 61, and the calculation output CV0 is output to the furnace pressure adjustment damper 81 to adjust the furnace pressure.
The calculation contents of the calculator 61 include the following two methods.
(1) The operation indicated by the broken line in FIG. 2 is performed.
{Circle around (2)} As shown in FIG. 3, calculation is performed by (the broken line in FIG. 2 + differential calculation of output PV 0 + upper / lower limiter).
[0013]
Next, FIG. 2 and FIG. 3 will be described.
In FIG. 2, the output PV0 of the in-furnace pressure transmitter 10 is input as an input (X axis), and the control signal CV0 to the in-furnace pressure adjustment damper 81 is output as an output (Y axis). Here, when the furnace pressure is lower than a predetermined value, for example, −80 mmH ₂ O, the control signal to the furnace pressure adjustment damper is set to a predetermined value, for example, 0%, and all the furnace pressure adjustment dampers are set. Closed. When the in-furnace pressure gradually rises from −80 mmH ₂ O, the control signal to the in-furnace pressure adjustment damper is increased to operate the in-furnace pressure adjustment damper in the opening direction. As a result, the amount of fluidized air is reduced and fluidization is slowed down, the amount of gasification is suppressed, and the increase in the furnace pressure can be suppressed. Further, when the furnace pressure increases, the control signal to the furnace pressure adjustment damper is set to a predetermined value, for example, MH%, and the furnace pressure adjustment damper is set to the maximum opening (within the adjustment range). .
[0014]
3 differentiates the output PV0 of the in-furnace pressure transmitter 10 in addition to the broken line in FIG. 2 to catch a sudden change in the in-furnace pressure at an early stage, and adds this signal to the signal output in FIG. The control signal to the internal pressure adjusting damper is adjusted. Here, since the differential calculation signal may output an excessive signal, it is limited by an upper / lower limiter (MH / ML). If it is not limited, the amount of flowing air may be excessively reduced and flow failure may occur.
[0015]
FIG. 4 is a diagram showing a second embodiment of the present invention. In the second embodiment, an in-furnace pressure adjusting damper 81 is provided in the fluid air line of the combustion air 8-1. Other configurations are the same as those of the first embodiment shown in FIG.
In FIG. 4, the in-furnace pressure of the incinerator 1 is sent to the first-order lag filter 14 as PV0 by the pressure transmitter 10, and the pulsation is absorbed and becomes the output PV1. The output PV1 is subjected to PID calculation by a PID controller to obtain a control output MV1. The control output MV1 controls the frequency of the VVVF inverter 51 of the induction blower 5 or the induction blower inlet damper 4 installed at the entrance of the induction blower 5 to moderately control the furnace pressure. The rapid fluctuation of the in-furnace pressure is controlled by the in-furnace pressure adjusting damper 81 installed in the fluidized air line of the combustion air 8-1.
[0016]
The output PV0 of the furnace pressure transmitter 10 is input to the calculator 62, and the calculation output CV0 is output to the furnace pressure adjustment damper 81 to adjust the furnace pressure.
The calculation contents of the calculator 62 include the following two methods.
(1) The operation indicated by the broken line in FIG. 5 is performed.
{Circle around (2)} As shown in FIG. 6, calculation is performed by (the broken line in FIG. 5 + differential calculation of output PV 0 + upper / lower limiter).
[0017]
Next, FIG. 5 and FIG. 6 will be described.
In FIG. 5, PV0 is input as the output (X axis) of the output of the furnace pressure transmitter 10, and the control signal CV0 to the furnace pressure adjusting damper 81 is output as the output (Y axis). Here, when the furnace pressure is lower than a predetermined value, for example, −80 mmH ₂ O, the control signal to the furnace pressure adjustment damper is set to a predetermined value, for example, MH%, and the furnace pressure adjustment damper is set to The maximum opening (within the adjustment range). When the in-furnace pressure gradually rises from −80 mmH ₂ O, the control signal to the in-furnace pressure adjustment damper is decreased to operate the in-furnace pressure adjustment damper in the closing direction. Thereby, fluidization becomes slow by reducing the amount of flowing air, the amount of gasification is suppressed, and the rise in the furnace pressure can be suppressed. When the in-furnace pressure is higher than 80 mmH ₂ O, the control signal to the in-furnace pressure adjustment damper is set to a predetermined value, for example, ML%, and the in-furnace pressure adjustment damper is set to the minimum opening (within the adjustment range).
[0018]
FIG. 6 differentiates the output PV0 of the in-furnace pressure transmitter 10 in addition to the broken line in FIG. 5 to catch a sudden change in the in-furnace pressure at an early stage, and subtracts this signal from the signal output in FIG. The control signal to the internal pressure adjusting damper is adjusted. Here, since the differential calculation signal may output an excessive signal, it is limited by an upper / lower limiter (MH / ML). If it is not limited, there is a possibility that the amount of flowing air will increase too much and the fluctuations in the pressure in the furnace will become excessive, or the amount of flowing air will decrease too much to cause poor flow.
[0019]
FIG. 7 is a diagram showing a third embodiment of the present invention, and is a diagram showing an embodiment when the furnace pressure control method is applied to a gasification furnace. In FIG. 7, a melting furnace 22 is installed after the fluidized bed gasification furnace 21. The raw material 7 and fuel air 8-1 are supplied to the gasifier 21. Secondary melting air 8-2 is supplied to the melting furnace 22.
In the present embodiment, a bypass line BL is provided in the flowing air line of the combustion air 8-1, and an in-furnace pressure adjusting damper 81 is provided in the bypass line BL. The inlet of the bypass line BL is installed in the melting furnace 22. The combustion air 8-1 is blown into the melting furnace 22 by the bypass line BL. The rapid fluctuation of the in-furnace pressure is controlled by controlling the blowing of the combustion air 8-1 into the melting furnace 22 by the in-furnace pressure adjusting damper 81 installed in the bypass line BL. Other configurations are the same as the example shown in FIG. The operations shown in FIGS. 2 and 3 are similarly applied.
[0020]
【The invention's effect】
As described above, according to the present invention, the internal pressure of the furnace can be increased by providing an adjustment damper in the fluid air line fed from the lower part of the fluidized bed, or by providing a bypass line in the fluid air line and an adjustment damper in the bypass line. Is increased, the amount of combustion air is controlled by a regulating damper installed in the fluidized air line or the bypass line to slow the fluidization, thereby suppressing the gasification amount and suppressing the increase in pressure. Therefore, since the furnace pressure is stabilized and the amount of exhaust gas and the concentration of exhaust gas oxygen are stabilized, it is possible to optimize the ventilation system (IDF, CDF, gas cooling equipment, gas processing equipment) capacity, which is effective for energy saving. is there. In addition, the amount of secondary combustion air can be easily controlled.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a first embodiment of a furnace pressure control method according to the present invention.
FIG. 2 is a diagram showing a first example of calculation contents of a calculator 61 shown in FIG.
FIG. 3 is a diagram showing a second example of the calculation contents of the calculator 61 shown in FIG. 1;
FIG. 4 is a flowchart showing a second embodiment of the furnace pressure control method according to the present invention.
FIG. 5 is a diagram showing a first example of calculation contents of the calculator 62 shown in FIG. 4;
6 is a diagram showing a second example of calculation contents of the calculator 62 shown in FIG. 4. FIG.
FIG. 7 is a diagram showing a third embodiment of the present invention, and is a diagram showing an embodiment when a furnace pressure control method is applied to a gasification furnace.
FIG. 8 is a flowchart showing a conventional furnace pressure control method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Incinerator 2 Gas cooler 3 Gas processing apparatus 4 Induction blower inlet damper 5 Inductive blower 6 for exhaust gas suction Chimney 7 Fuel 8-1 Combustion air 8-2 Secondary combustion air 9 Detection end 10 In-furnace pressure transmitter 11 PID controller 12 Controller 13 Leak 14 Primary delay filter 21 Fluidized bed gasifier 22 Melting furnace 51 VVVF inverter 61, 62 Calculator 81 In-furnace pressure control damper BL Bypass line

Claims (2)

An apparatus for processing raw materials, comprising a fluidized bed gasification furnace to which raw materials and combustion air are supplied, a melting furnace to which secondary combustion air is supplied, and an induction blower for maintaining the pressure in the furnace at a negative pressure In
A detection end for detecting an in-furnace pressure of the fluidized bed gasification furnace;
A pressure transmitter that outputs the pressure in the furnace detected by the detection end as PV0;
A calculator for calculating the output PV0 of the pressure transmitter to obtain a calculation output CV0;
A fluidized air line for supplying combustion air to the fluidized bed gasifier;
A bypass line provided in the flowing air line, and blowing combustion air into the melting furnace;
A processing apparatus comprising: an adjustment damper provided in the bypass line, the opening of which is operated using the calculation output CV0 as a control signal. In a method of supplying raw materials and combustion air to a fluidized bed gasification furnace, supplying secondary combustion air to a melting furnace, and processing the raw materials,
Detecting the pressure in the fluidized bed gasifier by the detection end;
The furnace pressure detected by the detection end is output as PV0 by the pressure transmitter,
An arithmetic unit calculates the output PV0 of the pressure transmitter to obtain a calculation output CV0,
Supplying combustion air to the fluidized bed gasifier through a fluidized air line,
A processing method characterized by operating the opening degree of an adjustment damper provided in the flowing air line and in a bypass line for blowing combustion air into the melting furnace using the calculation output CV0 as a control signal.

Images