JP2017116252A - Grate type waste incinerator and waste incineration method with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grate type waste incinerator and a waste incineration method capable of detecting and optimizing a state of waste on a grate at an upstream side of a combustion region in a combustion chamber.SOLUTION: A grate type waste incinerator 1 comprises: a combustion chamber 2 which has a grate 5 and performs combustion of waste W on the grate 5; primary air blowing means 7 and 9 which blows primary combustion air into the combustion chamber 2 from beneath the grate 5; and a waste feeder 12 which feeds the waste W onto the grate 5. The grate type waste incinerator 1 also has: an infrared camera 13 which is installed on a downstream side wall face in the combustion chamber 2 and obtains thermal image information about the waste on the grate 5; a data processing device 14 which obtains waste state information from the thermal image information; and a control device 15 which controls an operation condition of the grate type waste incinerator on the basis of the waste state information.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a grate-type waste incinerator for incinerating waste such as municipal waste and a waste incineration method using a grate-type waste incinerator.

  Grate-type waste incinerators are widely used as incinerators for incinerating waste such as municipal waste. The outline of the configuration of the representative one will be described below.

  The grate-type waste incinerator has a three-stage grate (dry grate, combustion grate, and post-combustion grate) that is arranged in the direction of waste movement at the bottom of the combustion chamber that burns the waste. The secondary combustion chamber is connected to the outlet of the combustion chamber located above the post-combustion grate. The combustion chamber is provided with a waste inlet located above the dry grate. An ash discharge port is provided at the downstream side of the post-combustion grate waste in the moving direction. Usually, the secondary combustion chamber is also a part of a waste heat boiler for waste heat recovery, and is in the vicinity of the inlet. Further, a combustion primary air blowing mechanism for blowing combustion primary air from below the grate of each of the dry grate, the combustion grate, and the post-combustion grate is provided.

  In such a grate-type waste incinerator, waste thrown into the combustion chamber from the waste inlet is deposited on the dry grate and dried by air from the bottom of the dry grate and radiant heat in the furnace. At the same time, the temperature is raised and ignition occurs. That is, immediately above the dry grate, a dry region is formed in the upstream space in the waste movement direction, and combustion occurs from the downstream space directly above the dry grate to the upstream space directly above the combustion grate. A starting region is formed. The waste that ignites in the combustion start area and starts combustion is sent from the dry grate onto the combustion grate, and the waste is pyrolyzed to generate combustible gas, and the combustion sent from the bottom of the combustion grate The combustible gas forms a flame by the primary air for combustion and burns, and further, the solid content burns to form a main combustion region in the space immediately above the combustion grate. Further, unburned components such as fixed carbon are completely burned on the post-combustion grate, and a post-combustion region is formed in a space immediately above the post-combustion grate. Thereafter, the ash remaining after combustion is discharged to the outside through the ash discharge port.

  Thus, in the grate-type waste incinerator, the waste is burned by the primary combustion air blown from below the three-stage grate in the combustion chamber. Furthermore, unburned combustible gas contained in the combustion gas from the combustion chamber (referred to as unburned gas) receives and burns secondary combustion air in the secondary combustion chamber that is part of the waste heat boiler. (Called secondary combustion). After the secondary combustion, the combustion exhaust gas is recovered by a waste heat boiler to generate steam, and the steam is supplied to the generator.

  In such a grate-type waste incinerator, a dry region, a combustion start region, a main combustion region, and a post-combustion region are sequentially formed in the furnace from the upstream side in the waste movement direction. In the main combustion zone, the waste on the combustion grate is pyrolyzed and partially oxidized to generate a combustible gas, and the combustible gas and the solid content of the waste are combusted. When combustible gas burns, it forms a flame and burns. Thereafter, in the post-combustion region, unburned solids such as fixed carbon in the remaining waste are completely burned on the post-combustion grate. When solids burn, no flame is generated and soot burns.

  The main combustion region is a combustion region in which waste is thermally decomposed and partially oxidized to generate a combustible gas, and the combustible gas is combusted with a flame and the solid content of the waste is combusted. . The point at which combustion with a flame is substantially completed is called a burnout point, and becomes a boundary between the main combustion region and the post-combustion region. In the area after the burn-off point, a soot combustion area (post-combustion area) in which the unburned solid content in the waste is combusted.

  In the combustion of waste in such a waste incinerator, in order to perform the heat recovery well and suppress the generation of harmful substances such as CO and NOx generated by the combustion, so as to stabilize the combustion, The combustion conditions are monitored to control the operating conditions of the incinerator.

  In order to monitor the combustion state of waste in the combustion chamber in a grate-type waste incinerator, for example, the flame in the combustion chamber can be monitored from a monitoring window provided on the wall surface on the downstream side (ash outlet side) of the combustion chamber. The situation is photographed with a CCD camera, and the operation condition of the incinerator is controlled so as to obtain an appropriate situation by monitoring an image of a flame situation.

  Further, as another method for controlling the combustion by grasping the situation in the incinerator, as disclosed in Patent Document 1, the surface of the waste itself on the grate without monitoring the flame situation is disclosed. It is also known to detect the temperature and control the operating conditions of the incinerator.

  According to the method of Patent Document 1, a scanning infrared radiation thermometer is installed above the combustion chamber, the waste surface temperature of each part on the grate is scanned and detected, and the position indicating the maximum temperature of the waste surface temperature is indicated. Is the waste combustion center position on the grate, and the position of the waste on the grate is the position where the maximum rate of change of the waste surface temperature with respect to the movement distance of the waste in the grate waste transport direction is shown. By detecting the burnout position and maintaining both the waste combustion center position and the burnout position at the set position, changing the grate feed speed as the operating condition, the waste feed rate per unit time, the primary The distribution amount of combustion air (air supply amount per unit time) is controlled.

JP-A-2005-214513

  In order to stably burn the waste in the combustion chamber, it is necessary to grasp the state of the waste on the grate upstream from the combustion region and cope with the change in the state of the waste.

  In the combustion region, the waste is thermally decomposed and partially oxidized to generate a combustible gas, which generates a flame and burns. Further, in the drying region upstream of the combustion region, the waste on the grate is dried, heated, and in a stage just before combustion starts. The state of the waste on the grate in the dry area upstream from the combustion area is the property of the waste, the amount of waste supplied to the grate (dust supply speed of the dust dispenser), It fluctuates depending on the conveyance amount of the waste toward the downstream (conveyance speed of the grate) and the primary air supply amount for combustion for drying and burning the waste.

  Under such circumstances, the control of the operating conditions of the waste incinerator such as the primary air supply amount is appropriately handled following the fluctuation of the state of the waste on the grate upstream of the combustion region. If not, the combustion of waste becomes unstable, the temperature and gas composition of the combustion exhaust gas cannot be maintained within the predetermined appropriate range, and the problem arises that the CO concentration and NOx concentration in the exhaust gas increase. Or the amount of steam generated by heat recovery from the exhaust gas fluctuates.

  However, even in a conventional method for monitoring the state of a flame with an image taken by a CCD camera, or in a method for detecting the surface temperature of waste during combustion according to Patent Document 1, a grate Although it is possible to detect changes in the combustion status, a phenomenon that appears as a result of fluctuations in the state of the waste above, disposal on the grate upstream of the combustion zone (upstream from the zone where the flame is formed and burning) Since it is impossible to detect the state of the waste, it is impossible to grasp the change in the state of the waste on the grate. There may be a problem that the concentration of harmful substances increases or the amount of steam fluctuates.

  In view of such circumstances, the present invention grasps the state of the waste on the grate upstream from the combustion region, appropriately controls the operating conditions in response to the change in the state of the waste, and discards the waste. It is an object of the present invention to provide a grate-type waste incinerator capable of stably burning an object and a waste incineration method using a grate-type waste incinerator.

  In the present invention, the above-described problems are solved by a waste incineration method using a grate-type waste incinerator or a grate-type waste incinerator configured as follows.

<Grate-type waste incinerator>
A grate-type waste incinerator according to the present invention includes a combustion chamber that includes a grate and burns waste on the grate, and primary air blowing means that blows primary combustion air into the combustion chamber from below the grate. And an infrared camera for obtaining thermal image information of waste on the grate provided on the downstream side wall surface of the combustion chamber in a grate-type waste incinerator having a dust feeder for supplying waste on the grate And a data processing device for obtaining waste state information from the thermal image information, and a control device for controlling operating conditions of the incinerator based on the waste state information.

  In the present invention having such a configuration, a thermal image of the waste layer is obtained as thermal image information in the layer thickness direction and the furnace width direction with respect to the waste on the grate upstream of the combustion region by an infrared camera. Then, this is subjected to data processing to obtain waste state information, and the operation condition is controlled by the control device based on the waste state information.

  In the present invention, the waste state information may be at least one of waste layer thickness information indicating the thickness of the waste layer on the grate and waste dry information indicating the dry state of the waste layer. .

  In the present invention, the control device, based on the waste state information, includes, as operating conditions, a dust supply waste supply speed, a grate waste conveyance speed, a combustion primary air supply amount, and a combustion primary air temperature. At least one of the above can be controlled.

<Waste incineration method with grate-type waste incinerator>
A waste incineration method using a grate-type waste incinerator according to the present invention burns waste on a grate provided in a combustion chamber, supplies waste on the grate by a dust feeder, In a waste incineration method using a grate-type waste incinerator that blows air from under the grate into the combustion chamber, thermal image information of the waste on the grate with an infrared camera provided on the downstream side wall surface of the combustion chamber The thermal image information is processed to obtain waste state information, and the operation condition of the incinerator is controlled by the control device based on the waste state information.

  In the present invention, the waste state information may be at least one of waste layer thickness information indicating the thickness of the waste layer on the grate and waste dry information indicating the dry state of the waste layer. .

  In the present invention, the control by the control device is based on the waste state information, and includes at least one of a dust supply waste supply speed, a grate waste conveyance speed, a combustion primary air supply amount, and a combustion primary air temperature. It can be done about one thing.

  As described above, the present invention obtains the thermal image information of the waste with the infrared camera for the waste on the grate upstream from the combustion region, and processes the thermal image information by processing the thermal image information. By grasping the state and changing the waste state, it is possible to stably burn the waste by controlling the operating conditions appropriately in response to the change. The variation in gas composition can be minimized to reduce the CO concentration and NOx concentration in the exhaust gas, and the variation in the amount of steam generated due to heat recovery from the exhaust gas can be suppressed.

It is a longitudinal section showing a schematic structure of a grate type waste incinerator concerning one embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The technical scope of the present invention is not limited by these embodiments, and can be implemented in various forms without changing the gist of the invention. Further, the technical scope of the present invention extends to an equivalent range.

  Hereinafter, the basic configuration, each component device, and operation of a grate-type waste incinerator according to an embodiment of the present invention will be described.

<Basic configuration of grate-type waste incinerator>
FIG. 1 shows a schematic configuration of a grate-type waste incinerator according to an embodiment of the present invention. First, the basic configuration of the grate-type waste incinerator and the outline of the incineration method according to one embodiment of the present invention will be described, and then the details of each component device will be described. In this embodiment, the upstream side (left side in FIG. 1) of the combustion chamber in the movement direction (furnace length direction) of the waste in the combustion chamber is referred to as a front portion, and the downstream side is referred to as a rear portion.

  The grate-type waste incinerator 1 according to the present embodiment is disposed on the combustion chamber 2 and on the upstream side (left side in FIG. 1) in the waste flow direction of the combustion chamber 2, and the waste is disposed in the combustion chamber 2. Waste heat inlet 3 formed at the upper end of the charging cylinder 4 for charging into the inside, and waste heat connected continuously above the downstream side (right side in FIG. 1) in the waste flow direction of the combustion chamber 2. A grate-type waste incinerator provided with a boiler (not shown). On the receiving floor 4A located at the lower end of the charging cylinder 4, a dust feeder 12 described later is provided.

  At the bottom of the combustion chamber 2, there is provided a grate (stoker) 5 that burns while moving the waste. The grate 5 is provided in the order of the dry grate 5a, the combustion grate 5b, and the post-combustion grate 5c from the side closer to the waste inlet 3, that is, from the upstream side. A waste layer W is formed on the lattice 5b. These grates 5a to 5c are interlocked by a drive mechanism described later to convey waste forward and downstream.

  In the dry grate 5a, waste is mainly dried and ignited. In the combustion grate 5b, waste is thermally decomposed and partially oxidized, and the combustible gas and solid matter generated by the thermal decomposition are combusted. When the combustible gas burns, a flame is formed. On the post-combustion grate 5c, the unburned solids in the remaining waste are completely burned. When the solids in the waste burn, no flame is generated and the soot burns. The combustion ash after complete combustion is discharged from the ash discharge port 6.

  In such a grate-type waste incinerator of this embodiment, the following regions are formed in a space immediately above the waste layer in the combustion chamber 2.

  A drying region is formed immediately above the drying grate 5a and above the upstream range (front) in the waste flow direction of the drying grate 5a located adjacent to the receiving floor 4A.

  A combustion start region is formed above the upstream range (front) of the combustion grate 5b from the downstream range (rear) of the dry grate 5a. That is, the waste in the dry grate 5a is dried in the upstream range, ignited in the downstream range, and combustion starts in the range up to the upstream range (front) of the combustion grate 5b.

  The waste on the combustion grate 5b is thermally decomposed and partially oxidized here to generate a combustible gas, and the combustible gas and the solid content of the waste are combusted. The waste is substantially burned on the combustion grate 5b. Thus, a main combustion region is formed above the combustion grate 5b.

  Thereafter, the unburned matter such as fixed carbon in the remaining waste is completely burned on the post-burning grate 5c. A post-combustion region is formed above the post-combustion grate 5c.

  When the waste is incinerated, water evaporation occurs first, followed by thermal decomposition and partial oxidation reaction, and combustible gas begins to be generated. Combustion of waste begins in the combustion start region, and combustible gas begins to be generated by thermal decomposition and partial oxidation of the waste. In the main combustion area, the waste is thermally decomposed and partially oxidized to generate a combustible gas. The combustible gas is burned with a flame and the solid content of the waste is burned. The main combustion region is a region up to a point (combustion point) where combustion with a flame is completed. In the area after the burnout point, it becomes a soot combustion area (post-combustion area) in which solid unburned matter in the waste burns.

  Wind boxes 7a, 7b, and 7c are provided below the dry grate 5a, the combustion grate 5b, and the post-combustion grate 5c in the combustion chamber 2, respectively. The combustion primary air P supplied by the blower 8 is supplied to the wind boxes 7a, 7b, 7c through the combustion primary air supply pipe 9, and passes through the grate 5a, 5b, 5c to the combustion chamber 2. Supplied in. The primary combustion air P supplied from below the grate is used for drying and burning the waste on the grate 5a, 5b, 5c, cooling action of the grate 5a, 5b, 5c, Has a stirring action.

  A waste heat boiler (not shown) is connected to an outlet on the downstream side of the combustion chamber 2, and the vicinity of the waste heat boiler inlet is an unburned portion of unburned combustible gas in the gas discharged from the combustion chamber 2. The secondary combustion chamber 10 combusts the combustion gas). The secondary combustion gas is blown in the secondary combustion chamber 10 which is a part of the waste heat boiler, the unburned gas is subjected to secondary combustion, and after this secondary combustion, the combustion exhaust gas is heat recovered by the waste heat boiler, Steam is generated and used for the generator. After heat recovery, the combustion exhaust gas discharged from the waste heat boiler is neutralized with acid gas by slaked lime, etc. and dioxins are adsorbed by activated carbon in an exhaust gas treatment system (not shown), and further to a dust removal equipment (not shown). The neutralized reaction product, activated carbon, dust and the like are collected. The combustion exhaust gas that has been dedusted and detoxified by the dust removing device is attracted by an attraction fan (not shown) and released from the chimney into the atmosphere.

  In the grate-type waste incinerator having such a basic configuration, the grate-type waste incinerator 1 according to the present embodiment is a primary that supplies the combustion primary air P from below the grate 5 into the furnace. Air blowing means, dust feeder 12 for sending waste thrown into the waste grate 3 to the grate 5, a drive mechanism for the grate, and infrared rays for detecting a thermal image of the waste on the grate 5 on the upstream side It has a camera 13 and a data processing device 14 for processing the detected thermal image information to derive waste state information, and a control device 15 for controlling the operating conditions of the waste incinerator based on the waste state information. Hereinafter, these devices will be described.

<Primary air blowing means>
In the present embodiment, the grate-type waste incinerator 1 includes primary air blowing means for blowing the primary air P for combustion as described above. The primary air blowing means sends the primary air P for combustion from the air supply source through the primary air supply pipe 9 for combustion to each wind box 7a of the dry grate 5a, the combustion grate 5b, and the post-combustion grate 5c. , 7b, 7c are fed from a branch supply pipe. The combustion primary air supply pipe 9 is provided with a blower 8, a damper 11 as a primary air supply amount adjusting mechanism, and a combustion primary air heating device 16. It has been.

  The primary air P for combustion is heated by the primary air heating device 16 from the outside by the blower 8 and passes through the primary air supply pipe 9 for combustion to dry grate 5a, combustion grate 5b, and post-combustion grate. After being supplied to wind boxes 7a, 7b, 7c provided at the lower parts of 5c, they are supplied into the combustion chamber 2 through the grate 5a, 5b, 5c. The supply amount of the combustion primary air P supplied into the combustion chamber 2 is adjusted by a damper 11 for adjusting the primary air supply amount provided in the combustion primary air supply pipe 9. The temperature of the combustion primary air P is adjusted by controlling heat exchange conditions with steam generated in, for example, a boiler in the primary air heating device 16. Further, the configurations of the air boxes 7a, 7b, 7c and the combustion primary air supply pipe 9 for supplying the combustion primary air P are not limited to those shown in the drawings, and may be appropriately determined depending on the scale, shape, use, etc. of the incinerator. Can be selected.

<Dust feeder>
In the present embodiment, dust supply having a rod-shaped pushing member that reciprocates in the front-rear direction (left-right direction in FIG. 1) immediately above the receiving floor 4A located at the lower end of the input cylinder 4 (see arrow X in FIG. 1). A machine 12 is provided.

  The dust feeder 12 repeats reciprocation between the extrusion start point (left end position) and the extrusion end point (right end position), and pushes out the waste W during the forward movement (advance toward the combustion chamber 2). The waste W is dropped and supplied onto the dry grate 5a in the upstream portion (the left end side portion in FIG. 1) in the combustion chamber 2. The dust feeder 12 controls the supply speed (supply amount per unit time) of the waste W to the dry grate 5a by changing the number of reciprocations or the reciprocating speed of the dust feeder 12 per unit time. It is possible.

<Grate drive mechanism>
When the dry grate 5a, the combustion grate 5b, and the post-combustion grate 5c are connected to each other by a link and reciprocate back and forth by a drive mechanism (not shown) and move backward toward the downstream side. The waste is transported downstream. The drive mechanism can control the transport speed (waste transport amount per unit time) of the grate by changing the number of reciprocations or the reciprocation speed of the grate 5 per unit time.

<Infrared camera and data processing device>
An infrared camera 13 is disposed on the side wall 2 </ b> A on the downstream side of the combustion chamber 2. The infrared camera 13 may be disposed outside the furnace in the vicinity of the monitoring window provided on the side wall 2A, or may be disposed in the furnace having a water cooling structure. The infrared camera 13 has a measurement visual field extending in the vertical direction of the furnace and in the furnace width direction (perpendicular to the paper surface), and obtains thermographic information of waste on the grate in the measurement visual field as thermal image information. Can do. Since the wavelength of infrared rays emitted from the waste layer is different from the wavelength of infrared rays emitted from high-temperature gas and flames in the space, the infrared camera 13 appropriately sets the infrared wavelength to be measured so that the flame is generated within the measurement field of view. Even if it exists, the thermal image information corresponding to the temperature distribution for only the waste layer can be obtained. Further, the measurement range in the furnace length direction by the infrared camera 13 can be set, and the thermal image information of the waste layer on the grate 5a at the position upstream from the combustion region (upstream from the flame) can be obtained.

  The infrared camera 13 is connected to a data processing device 14 for processing the obtained thermal image information. The data processing device 14 performs data processing on the thermal image information received from the infrared camera 13, recognizes the surface position of the waste layer on the grate, obtains the shape and dimension information of the waste layer, Waste layer thickness information is obtained as waste state information.

  Further, the data processing device 14 performs data processing on the thermal image information received from the infrared camera 13, recognizes the temperature of the waste layer on the grate, and obtains the temperature and waste of the waste layer obtained in advance. Based on the relationship with the dry state of the layer, waste dry information is obtained as waste state information.

  The data processing device 14 is connected to the control device 15. The control device 15 receives the waste layer thickness information from the data processing device 14, determines whether or not the waste layer thickness is within a set range, and supplies the waste to the grate 5 according to the determination result. The dust feeder 12, the grate 5, the feed mechanism (not shown) of the grate 5, the damper 11 of the primary air blowing means, and the command signal for controlling the primary air heating device 16 are sent. 5, the damper 11, and the primary air heater 16 are connected.

  The data processing procedure in the data processing device 14 and the control method by the control device 15 will be described in detail in <Combustion control>, which will be described later.

  Next, an overview of the incineration status, acquisition of waste state information, and waste combustion control in the apparatus of the present embodiment configured as described above will be sequentially described.

<Overview of incineration>
First, when waste is thrown into the feed cylinder 4 from the waste feed port 3, the waste that has fallen on the receiving floor 4 </ b> A is reciprocated by the dust feeder 12, and the dry grate 5 a in the combustion chamber 2 is moved forward. When the reciprocation of each grate 5a to 5c supplied and deposited and driven by the drive mechanism moves forward, it sequentially moves on the combustion grate 5b and on the rear combustion grate 5c, and on each grate. A layer of waste W is formed. From the lower side of each grate 5a-5c, the combustion primary air P, which is flow-controlled by the damper 11 and heated by the primary air heating device 16, is supplied through the wind boxes 7a, 7b, 7c. Waste on the grid is dried and burned.

  Wastes are mainly dried and ignited on the dry grate 5a. That is, the waste of the dry grate 5a is dried in the upstream range of the dry grate 5a, ignited in the downstream range of the dry grate 5a, and up to the upstream range (front part) of the combustion grate 5b. Combustion starts in the range. On the combustion grate 5b, pyrolysis and partial oxidation of waste are mainly performed to generate a combustible gas. The combustible gas burns with a flame, and solids in the waste are combusted. The combustion of the waste is substantially completed on the combustion grate 5b. On the post-combustion grate 5c, unburned components such as fixed carbon in the remaining waste are completely burned. In the region after the burn-out point, the solid unburned portion (char) in the waste is burned, and the burned ash after complete combustion is discharged from the ash outlet 6.

  As described above, a waste heat boiler is connected to the outlet of the combustion chamber 2, and the vicinity of the inlet of the waste heat boiler is the secondary combustion chamber 10. Therefore, the unburned gas generated in the combustion chamber 2 is guided to the secondary combustion chamber 10 where it is mixed and stirred with the secondary combustion air and subjected to secondary combustion. After the secondary combustion, the exhaust gas is recovered by a waste heat boiler. After heat recovery, the exhaust gas discharged from the waste heat boiler is neutralized with acid gas by slaked lime, etc., and adsorbed dioxins with activated carbon, and further sent to a dust removal device (not shown) for neutralization. Reaction products, activated carbon, dust, etc. are recovered. The exhaust gas that has been dedusted and detoxified by the dust remover is attracted by an attracting fan (not shown) and released from the chimney into the atmosphere. In addition, as said dust removal apparatus, dust removal apparatuses, such as a bag filter system and an electrostatic dust collection system, can be used, for example.

<Acquisition of waste state information>
(1) Thermal image information of waste layer The infrared camera 13 obtains thermal image information (thermographic information) of the waste layer on the dry grate 5a at a position upstream of the combustion region. Since the wavelength of infrared rays emitted from the waste layer is different from the wavelength of infrared rays emitted from high-temperature gas and flame in the space, the infrared camera 13 can select a wavelength to be measured even if a flame exists in the measurement field of view. The thermal image information corresponding to the temperature distribution for only the waste layer can be obtained.

(2) Waste layer thickness information When the thermal image information in the measurement visual field obtained by the infrared camera 13 is provided to the data processing device 14, the data processing device 14 transmits the thermal image information to the vertical axis ( Vertical axis) and furnace width direction axis (horizontal axis) are expanded on the orthogonal coordinates, and the waste layer thickness distribution in the furnace width direction is obtained from the boundary between the waste and the space to obtain the furnace width direction distribution of the waste layer surface position. It is converted into waste layer thickness information indicating the distribution status and waste layer shape. Thus, waste layer thickness information indicating the thickness of the waste layer on the grate as waste state information is obtained.

(3) Waste drying information When the thermal image information in the measurement visual field obtained by the infrared camera 13 is provided to the data processing device 14, the data processing device 14 obtains the temperature of the waste layer from the thermal image information. Thus, based on the relationship between the temperature of the waste layer obtained in advance and the dry state of the waste layer, waste dry information indicating the dry state of the waste layer is obtained as waste state information. By monitoring and measuring the operating status of the incinerator, the temperature range of the waste layer when it is determined that the drying is not enough and the degree of drying is low, or the degree of drying is excessive due to excessive drying The temperature range of the waste layer when it is determined to be in a very high state is obtained, and the relationship between the temperature of the waste layer and the dry state of the waste layer can be obtained in advance.

<Combustion control>
In this embodiment, as will be described later, the data processing device 14 obtains the waste layer thickness information and the waste drying information from the thermal image information, and the control device 15 obtains the waste layer thickness information and the waste drying information. Combustion control is performed based on at least one of the above. Hereinafter, combustion control based only on waste layer thickness information, combustion control based only on waste drying information, and combustion control based on both waste layer thickness information and waste drying information will be described in order.

<Combustion control based on waste layer thickness information only>
The control device 15 obtains the waste layer thickness information from the data processing device 14, obtains a representative layer thickness value representing the waste layer thickness, and sets the representative layer thickness value to an appropriate predetermined range (hereinafter, “ It is referred to as “predetermined layer thickness range”). The representative layer thickness value can be determined by various methods. However, since the waste layer thickness varies in the furnace width direction, for example, it is obtained as an area average value of the waste layer thickness distribution or in the furnace width direction. Obtain the maximum layer thickness and minimum layer thickness at different positions, and determine whether the area average value or the representative layer thickness value represented by the maximum layer thickness and minimum layer thickness is within the specified layer thickness range. To do.

  When the representative layer thickness value is within the predetermined layer thickness range, the control device 15 determines that the waste layer thickness on the grate upstream from the combustion region, that is, the amount of waste is appropriate, and combustion is good. And the operation conditions such as the dust feeder waste supply speed, the grate waste transport speed, the primary combustion air amount, and the primary combustion air temperature are maintained without change.

  Next, if the representative layer thickness value of the waste layer thickness is higher than the predetermined layer thickness range, it is confirmed that the amount of waste on the grate is larger than the appropriate amount in the current operating conditions. As such, to change the operating conditions to reduce the amount of waste on the grate, the controller 15 reduces the waste feed rate to the dust feeder 12 and reduces the waste to the grate. Command to decrease the supply amount, increase the waste transport speed to the drive mechanism of the grate 5, quickly transport the waste on the grate to the downstream grate and stir to waste and primary combustion A command to promote contact with air to promote combustion of waste, a command to increase the amount of primary combustion air to increase the amount of primary combustion air with respect to the damper 11, and a primary air heating device 16 To increase the primary combustion air temperature and promote the combustion of waste Emitting at least one command of the command for, promote combustion of waste on the grate, to reduce the amount of waste on the grate. As a result, the amount of waste on the grate becomes an appropriate amount, and the representative layer thickness value can fall within a predetermined layer thickness range, that is, the waste layer thickness can fall within a preferable range.

  Next, if the representative layer thickness value of the waste layer thickness is lower than the predetermined layer thickness range, the amount of waste on the grate is less than the appropriate amount in the operating conditions at that time. This means that in order to change the operating conditions to increase the amount of waste on the grate, the controller 15 increases the waste feed rate to the dust feeder 12 and increases the waste to the grate. A command to increase the supply amount, the transport mechanism of the grate 5 is decreased, the transport speed of the waste is decreased, the transport of the waste on the grate to the downstream grate is decreased, and the waste and the primary combustion air are A command to reduce contact and reduce the combustion of waste, a command to reduce the amount of primary combustion air by reducing the opening of the damper 11, and a command to reduce the combustion of waste, to the primary air heating device 16 Among the directives to lower the primary combustion air temperature and mitigate waste combustion Even without emitting a single command, relieve combustion of waste on the grate, to increase the amount of waste on the grate. As a result, the amount of waste on the grate becomes an appropriate amount, and the representative layer thickness value can fall within a predetermined layer thickness range, that is, the waste layer thickness can fall within a preferable range.

  In the above embodiment, the thermal image information of the waste layer on the grate is data-processed to obtain the shape and size information of the waste layer on the grate, and the waste layer thickness information is obtained as waste state information. However, the waste amount information on the grate may be obtained as the waste state information. In that case, waste volume information is obtained by combining the obtained waste layer thickness information with the bulk density of the waste.

<Control based on waste drying information only>
The control device 15 obtains the waste drying information from the data processing device 14, and the waste drying state indicated by the waste drying information is already set to an appropriate predetermined range (hereinafter referred to as “predetermined drying state range”). Compare with

  When the waste layer dry state is within the predetermined dry state range, the control device 15 determines that the dry state of the waste layer on the grate is appropriate, and discards the dust feeder at that time. The operating conditions such as the material supply speed, the grate waste transport speed, the primary combustion air amount, and the primary combustion air temperature are maintained without change.

  Next, when the dry state of the waste layer is lower than the predetermined dry state range, the control device 15 causes the dust feeder 12 to change the operation condition so as to promote the drying of the waste on the grate. In contrast, a command to reduce the waste supply speed to reduce the amount of waste supplied to the grate, to increase the waste conveyance speed with respect to the drive mechanism of the grate 5, and to dispose the waste on the grate to the downstream fire Directly convey to the grid and agitate to promote contact between the waste and primary combustion air to promote drying of the waste, and increase the opening to the damper 11 to increase the amount of primary combustion air Dispose of waste on the grate by issuing at least one of a command to increase drying and promote waste drying, and a command to increase primary combustion air temperature to the primary air heating device 16 to promote drying of waste. Promotes the drying of things. As a result, the dry state of the waste on the grate can be within a preferable range.

  Next, when the dry state of the waste layer is higher than the predetermined dry state range, the control device 15 causes the dust feeder 12 to change the operation condition so as to alleviate the drying of the waste on the grate. In contrast, a command to increase the waste supply speed to increase the amount of waste supplied to the grate, and to reduce the waste transport speed with respect to the drive mechanism of the grate 5, the fire on the downstream side of the waste on the grate A command to reduce the transport to the grid and reduce the contact between the waste and the primary combustion air to alleviate the drying of the waste, and reduce the amount of primary combustion air by reducing the opening to the damper 11 and discarding At least one command out of a command for relaxing the drying of the material and a command for lowering the primary combustion air temperature to the primary air heating device 16 to reduce the drying of the waste, and drying the waste on the grate To ease. As a result, the dry state of the waste on the grate can be within a preferable range.

<Control based on both waste layer thickness information and waste drying information>
The data processor 14 obtains both waste layer thickness information and waste drying information as waste state information from the thermal image information from the infrared camera 13 in the same manner as described above.

  The control device 15 obtains a representative layer thickness value from the waste layer thickness information obtained from the data processing device 14 in the same manner as described above, and this representative layer thickness value is set to a predetermined layer thickness range that has already been set. Compare. Hereinafter, when the representative layer thickness value is within the predetermined layer thickness range, when the representative layer thickness value is higher than the predetermined layer thickness range, or when the representative layer thickness value is lower than the predetermined layer thickness range. The combustion control will be described separately.

[When the representative layer thickness value is within the specified layer thickness range]
The control device 15 obtains the dry state of the waste layer from the waste dry information obtained from the data processing device 14 in the same manner as described above, and the predetermined dry state range in which the waste layer dry state is already set. Compare with Then, the control device 15 determines whether the waste layer dry state is within the predetermined dry state range, lower than the predetermined dry state range, or higher than the predetermined dry state range as described above < The operation conditions are changed in the same manner as described in the item of “Control based on waste drying information only”.

[When the representative layer thickness value is higher than the specified layer thickness range]
The control device 15 compares the waste drying information with a predetermined dry state range that has already been set. When the waste dry state is within the predetermined dry state range, the control device 15 changes the operation condition in the same manner as described in the item <Control based only on waste layer thickness information>.

  When the dry state of the waste layer is lower than the predetermined dry state range, the control device 15 instructs the dust feeder 12 to change the operation conditions so as to promote the combustion and drying of the waste on the grate. Command to reduce the waste supply rate to reduce the amount of waste supplied to the grate, increase the waste transport speed to the drive mechanism of the grate 5, and dispose the waste on the grate to the downstream grate A command to accelerate the contact between the waste and the primary combustion air by agitation and promote the drying of the waste, and increase the opening of the damper 11 to increase the amount of primary combustion air The waste on the grate is issued by issuing at least one command among the command for promoting the drying of waste and the command for increasing the primary combustion air temperature to the primary air heating device 16 to promote the drying of the waste. Promotes drying. As a result, the dry state of the waste on the grate can be within a preferable range. In addition, as a result of promoting the combustion of waste, the amount of waste on the grate decreases, so the amount of waste on the grate becomes an appropriate amount, and the representative layer thickness value falls within the predetermined layer thickness range, that is, the waste layer thickness is increased. It can be in a preferable range.

  On the other hand, when the dry state of the waste layer is higher than the predetermined dry state range, the control device 15 sets the representative layer thickness value to the predetermined layer rather than keeping the dry state of the waste layer within the predetermined dry state range. Priority is given to the thickness range, and the operating conditions are changed to reduce the amount of waste on the grate. That is, the controller 15 instructs the dust feeder 12 to reduce the waste supply speed and reduce the amount of waste supplied to the grate, and increases the waste conveyance speed to the drive mechanism of the grate 5. To the damper 11, which promptly conveys the waste on the grate to the downstream grate and accelerates the contact between the waste and the primary combustion air to promote the combustion of the waste. At least one of a command to increase the amount of primary combustion air to promote combustion of waste by increasing the opening degree, and a command to increase the temperature of primary combustion air to the primary air heating device 16 to promote combustion of waste Issue one command to promote the burning of waste on the grate and reduce the amount of waste on the grate. As a result, the amount of waste on the grate becomes an appropriate amount, and the representative layer thickness value can fall within a predetermined layer thickness range, that is, the waste layer thickness can fall within a preferable range.

[When the representative layer thickness value is lower than the specified layer thickness range]
The control device 15 compares the waste drying information with a predetermined dry state range that has already been set. When the waste layer dry state is within the predetermined dry state range, the control device 15 changes the operation condition in the same manner as described in the item <Control based only on waste layer thickness information>. .

  When the dry state of the waste layer is lower than the predetermined dry state range, the control device 15 sets the dry state of the waste layer within the predetermined dry state range rather than keeping the representative layer thickness value within the predetermined layer thickness range. Prioritize storage, change operating conditions to promote drying of waste on the grate. That is, the controller 15 instructs the dust feeder 12 to reduce the waste supply speed and reduce the amount of waste supplied to the grate, and increases the waste conveyance speed to the drive mechanism of the grate 5. To the damper 11, which promptly conveys the waste on the grate to the downstream grate and promotes the contact between the waste and the primary combustion air to promote the drying of the waste. At least among a command to increase the amount of primary combustion air to increase the amount of primary combustion air to promote drying of waste, and a command to increase the temperature of primary combustion air to the primary air heating device 16 to promote drying of waste Issue a directive to promote the drying of waste on the grate. As a result, the dry state of the waste on the grate can be within a preferable range.

  On the other hand, when the dry state of the waste layer is higher than the predetermined dry state range, the control device 15 is configured to change the operation conditions so as to reduce the combustion and drying of the waste on the grate. 12 to increase the waste supply speed to increase the amount of waste supplied to the grate, lower the waste conveyance speed to the drive mechanism of the grate 5, and downstream of the waste on the grate Command to reduce the contact between the waste and the primary combustion air to reduce the drying and combustion of the waste and reduce the opening of the damper 11 and reduce the amount of primary combustion air And at least one command among the commands to reduce the waste drying and combustion, and the command to lower the primary combustion air temperature to the primary air heating device 16 to reduce the drying and combustion of the waste. Mitigates drying and burning of the above waste. As a result, the dry state of the waste on the grate can be within a preferable range. In addition, the amount of waste on the grate increases as a result of mitigating the combustion of waste, so the amount of waste on the grate becomes an appropriate amount, and the representative layer thickness value falls within the predetermined layer thickness range, that is, the waste layer thickness It can be in a preferable range.

  Regarding the control based on both the waste layer thickness information and the waste drying information, the above control content is an example, and the priority of the control based on the waste layer thickness information and the control based on the waste drying information is not limited to this. The priority can be selected in consideration of other operation control indexes (in-furnace temperature, exhaust gas temperature, exhaust gas composition, etc.) of the incinerator.

  In addition, when controlling based on both waste layer thickness information and waste drying information, when deriving control fluctuation amount such as increase / decrease of operation amount at each operation end such as waste supply speed of dust feeder, It is also possible to set parameters so that the control based on the information is weighted. An example in which parameter setting is performed for control will be described below.

[Control by parameter setting]
For example, when the dust supply waste supply speed V is operated at 0.3 reciprocations / minute before the start of control, the operation command based on the waste layer thickness information is increased by 20%, and the waste drying information When the operation command from is a 10% deceleration, parameters (X, Y) for weighting the control based on each information are set, and the waste supply speed V is calculated by the following equation (1). Send a driving command.
X: waste layer thickness information parameter Y: waste drying information parameter V = 0.3 reciprocation / minute × (1.2X + 0.9Y) / (X + Y) (1)

DESCRIPTION OF SYMBOLS 1 Grate-type waste incinerator 2 Combustion chamber 5 (5a-5c) Grate 7 (7a-7c) Primary air blowing means (wind box)
9 Primary air blowing means (combustion primary air supply pipe)
DESCRIPTION OF SYMBOLS 12 Dust feeder 13 Infrared camera 14 Data processing device 15 Control device 16 Primary air heating device W Waste

Claims (6)

A grate-type waste incinerator comprising a grate and a combustion chamber for burning waste on the grate, and primary air blowing means for blowing combustion primary air into the combustion chamber from under the grate In a grate-type waste incinerator having a dust feeder for supplying waste on a grate,
An infrared camera provided on the downstream side wall surface of the combustion chamber to obtain thermal image information of waste on the grate,
A data processing device for obtaining waste state information from thermal image information;
A grate-type waste incinerator comprising a control device for controlling operating conditions of the incinerator based on waste state information.   The waste state information is at least one of waste layer thickness information indicating a thickness of the waste layer on the grate and waste drying information indicating a dry state of the waste layer. Grate-type waste incinerator.   The control device controls at least one of the dust supply waste supply speed, the grate waste transport speed, the combustion primary air supply amount, and the combustion primary air temperature based on the waste state information. The grate-type waste incinerator according to claim 1 or 2.   A waste incineration method using a grate-type waste incinerator, in which waste is burned on a grate provided in a combustion chamber, waste is supplied onto the grate by a dust feeder, and primary air for combustion In a waste incineration method using a grate-type waste incinerator that blows into the combustion chamber from below the grate, thermal image information of the waste on the grate is obtained with an infrared camera provided on the downstream side wall surface of the combustion chamber. Disposal using a grate-type waste incinerator characterized in that the thermal image information is processed to obtain waste state information, and the operating conditions of the incinerator are controlled by a control device based on the waste state information Incineration method.   The waste state information is at least one of waste layer thickness information indicating a thickness of the waste layer on the grate and waste drying information indicating a dry state of the waste layer. Waste incineration method using a grate-type waste incinerator.   The control by the control device is performed on at least one of the dust supply waste supply speed, the grate waste transport speed, the combustion primary air supply amount, and the combustion primary air temperature based on the waste state information. A waste incineration method using a grate-type waste incinerator according to claim 4 or 5.

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