JP7588934B2 - Ash treatment equipment - Google Patents

Description

The present invention relates to an incineration ash treatment device and incineration ash treatment method that adds water to incineration ash transported by an ash transport means using a water adding means, or adds water to the incineration ash using the water adding means and then dries the ash using a drying means.

As the ash discharged from incinerators may still contain burning garbage, it must be cooled and the fire completely extinguished before being transported off-site. The main components of incineration ash are silicon oxide, calcium oxide, and alumina, and it has properties that make it suitable for effective use as a civil engineering resource. However, incineration ash contains trace amounts of harmful heavy metals, including lead, which can leach out, hindering the effective use of incineration ash.

Patent Document 1 discloses a technology that adds water to the incineration ash during transportation to cool it down and extinguish the fire, and also uses the aging effect to suppress the elution of heavy metals from the incineration ash.

In the technology described in Patent Document 1, the moisture content of the incineration ash being transported is measured by a moisture meter, and the operation of adding water to the incineration ash is controlled based on the obtained measurement value. The moisture meter used is one that can continuously measure the moisture content of the incineration ash being transported without contacting the incineration ash being transported. Examples of moisture meters that can be used include an attenuation type microwave moisture meter that measures the moisture content by converting the electrical change in the attenuation of microwaves irradiated to the incineration ash into a moisture value, and a near-infrared moisture meter that measures the moisture content from the reflectance of light, including near-infrared rays, irradiated to the incineration ash.

Patent No. 6738949

The attenuation type microwave moisture meter disclosed in Patent Document 1 has the problem that if the volumetric filling rate (mixture rate of ash and air, etc.) of the incineration ash being transported fluctuates, the measured value changes, and the moisture content of the incineration ash cannot be measured accurately. In addition, near-infrared moisture meters have the problem that they measure only the surface of the incineration ash being transported, and therefore lack accuracy. In order to accurately adjust the moisture content of the incineration ash for the purpose of suppressing the elution of heavy metals during the treatment of incineration ash, it is necessary to accurately measure the moisture content of the incineration ash without being affected by fluctuations in the volumetric filling rate of the incineration ash.

The present invention has been made in consideration of the above problems, and aims to provide an incineration ash processing device and an incineration ash processing method that can accurately measure the moisture content of incineration ash without being affected by fluctuations in the volumetric filling rate of the incineration ash, thereby accurately adjusting the moisture content of the incineration ash.

The characteristic configuration of the incineration ash treatment device according to the present invention for solving the above problems is as follows:
An incineration ash treatment device that adds water to incineration ash transported by an ash transport means,
A means for adding water to the incineration ash;
A non-contact moisture meter that irradiates electromagnetic waves onto the incineration ash and measures the moisture content of the incineration ash based on the ratio of the amplitude change and phase difference of the electromagnetic waves;
A control means for controlling the hydration means based on the moisture percentage measured by the non-contact moisture meter;
The purpose of this study is to provide

Changes in the volumetric filling rate (mixture rate of incineration ash and air, etc.) of the measurement target (incineration ash transported by the ash transport means) are detected as the ratio (amplitude change/phase difference) of the amplitude change (attenuation) and phase difference (phase delay) of the electromagnetic waves. Therefore, if the volumetric filling rate of the measurement target is changed and the amplitude change and phase difference of the electromagnetic waves are measured and plotted, they will line up on a straight line, and the slope of the equation of this line is not affected by changes in the volumetric filling rate of the measurement target. Therefore, for incineration ash with various known moisture content values, the volumetric filling rate is changed at each moisture content, the amplitude change and phase difference of the electromagnetic waves are measured, the slope of the equation of the line at each moisture content is found, and the relationship between the slope and the moisture content is also found in advance. Next, the measurement object is irradiated with electromagnetic waves, the amplitude change and phase difference of the electromagnetic waves that pass through the measurement object are measured, the slope (ratio) of the amplitude change and phase difference is calculated, and the calculated slope value is applied to the relationship between the previously calculated slope and moisture content, making it possible to accurately calculate the moisture content of the incineration ash without being affected by changes in the volumetric filling rate of the measurement object.

The incineration ash treatment device of this configuration is equipped with a non-contact moisture meter that irradiates electromagnetic waves to the incineration ash and measures the moisture content of the incineration ash based on the ratio of the amplitude change and phase difference of the electromagnetic waves, so that the moisture content of the incineration ash can be measured with high accuracy without being affected by fluctuations in the volumetric filling rate of the incineration ash. The control means controls the hydration means based on the moisture content of the incineration ash measured with high accuracy by the non-contact moisture meter, so that the moisture content of the incineration ash can be accurately adjusted.

In the incineration ash treatment device according to the present invention,
Further provided is a drying means for drying the incineration ash to which water has been added by the water adding means,
It is preferable that the control means controls the drying means based on the moisture percentage measured by the non-contact moisture meter.

The incineration ash treatment device of this configuration further includes a drying means for drying the incineration ash that has been hydrated by the hydration means, and the drying means is controlled by the control means, so that the moisture content of the wet incineration ash can be adjusted more accurately.

In the incineration ash treatment device according to the present invention,
The ash conveying means is
A casing for accommodating incineration ash;
an electromagnetic wave transmitting member attached to an opening provided in the casing;
Equipped with
It is preferable that the incineration ash in the casing is irradiated with electromagnetic waves through the electromagnetic wave transmitting member.

According to the incineration ash treatment device of this configuration, an opening is provided in the casing that contains the incineration ash to be transported, and electromagnetic waves are irradiated to the incineration ash inside the casing through an electromagnetic wave transparent member attached to this opening. With this configuration, the electromagnetic wave transparent member can prevent dust and other particles that fly up from the incineration ash during transportation from adhering to the electromagnetic wave transmitter and receiver of the non-contact moisture meter. Therefore, it is possible to prevent poor transmission and reception of electromagnetic waves in advance, and accurate measurement values can be obtained stably over a long period of time.

In the incineration ash treatment device according to the present invention,
The non-contact moisture meter is preferably a transmission type non-contact moisture meter that measures the moisture content of the incineration ash by electromagnetic waves transmitted through the incineration ash.

The incineration ash treatment device of this configuration employs a non-contact moisture meter that uses electromagnetic waves transmitted through the incineration ash to measure the moisture content of the ash, making it possible to accurately measure the moisture content of the ash even if an air layer exists between the ash and the incineration ash.

In the incineration ash treatment device according to the present invention,
The non-contact moisture meter is preferably a reflection type non-contact moisture meter that measures the moisture content of the incineration ash by electromagnetic waves that are transmitted through the incineration ash and reflected.

The incineration ash treatment device of this configuration employs a non-contact reflective moisture meter that measures the moisture content of the incineration ash using electromagnetic waves that are transmitted through the incineration ash and reflected, eliminating the need to provide a separate receiving unit just for receiving the electromagnetic waves, thus simplifying the structure.

In the incineration ash treatment device according to the present invention,
It is preferable to provide a dew condensation prevention means for preventing dew condensation from occurring on the surface of the electromagnetic wave transmitting member facing the incineration ash inside the casing.

With this incineration ash treatment device, the condensation prevention means can prevent condensation from occurring on the surface of the electromagnetic wave-transmitting member facing the incineration ash inside the casing, making it possible to prevent measurement errors caused by the effects of water droplets.

In the incineration ash treatment device according to the present invention,
It is preferable to provide a water droplet removing means for removing water droplets adhering to the surface of the electromagnetic wave transmitting member on the side facing the incineration ash inside the casing.

With the incineration ash treatment device of this configuration, even if water droplets resulting from the moisture contained in the incineration ash adhere to the surface of the electromagnetic wave transparent member facing the incineration ash inside the casing, the water droplets can be removed by the water droplet adhesion prevention means. Therefore, it is possible to prevent measurement errors caused by the influence of water droplets.

In the incineration ash treatment device according to the present invention,
The electromagnetic wave transmitting member preferably has water repellency.

According to the incineration ash treatment device of this configuration, the electromagnetic wave transparent member has water repellency. As a result, even if condensation occurs on the surface of the electromagnetic wave transparent member facing the incineration ash inside the casing, the water droplets are immediately repelled and prevented from adhering to the surface of the electromagnetic wave transparent member. Therefore, measurement errors caused by the influence of water droplets can be suppressed.

In the incineration ash treatment device according to the present invention,
The non-contact moisture meter comprises:
A first non-contact moisture meter for measuring the moisture content of the incineration ash hydrated by the hydration means;
A second non-contact moisture meter that measures the moisture content of the incineration ash that has been hydrated by the hydrating means and then dried by the drying means;
Including,
It is preferable that the control means controls the hydration means so that the moisture content measured by the first non-contact moisture meter becomes a first moisture content at which the amount of elution of heavy metals contained in the incineration ash becomes less than a reference value, and controls the drying means so that the moisture content measured by the second non-contact moisture meter becomes a second moisture content that is set lower than the first moisture content for the purpose of preventing the incineration ash from scattering.

According to the incineration ash treatment device of this configuration, the control means controls the hydration means so that the moisture content measured by the first non-contact moisture meter, which measures the moisture content of the incineration ash hydrated by the hydration means, is a first moisture content at which the amount of elution of heavy metals contained in the incineration ash is less than a reference value. This makes it possible to make the amount of elution of heavy metals less than the reference value. The control means also controls the drying means so that the moisture content measured by the second non-contact moisture meter, which measures the moisture content of the incineration ash hydrated by the hydration means and then dried by the drying means, is a second moisture content that is set lower than the first moisture content for the purpose of preventing the incineration ash from scattering. This makes it possible to prevent the incineration ash from scattering. Even if the incineration ash is soaked in water so that it has a first moisture content at which the amount of elution of heavy metals contained in the incineration ash is less than the standard value, and then the incineration ash is dried to a second moisture content determined for the purpose of preventing the incineration ash from scattering, the amount of elution of heavy metals will not increase to the amount when the moisture content of the incineration ash is the second moisture content, but will be maintained at the amount when the moisture content of the incineration ash is the first moisture content. Therefore, the elution of heavy metals can be suppressed to less than the standard value without adversely affecting the working environment or handling.

Next, the characteristic configuration of the incineration ash processing method according to the present invention for solving the above problems is as follows:
A water adding process for adding water to the transported incineration ash;
A moisture content measuring step of irradiating the incineration ash with an electromagnetic wave and measuring the moisture content of the incineration ash based on a ratio between an amplitude change and a phase difference of the electromagnetic wave;
A water addition control process for controlling the water addition operation to the incineration ash in the water addition process based on the moisture content measured in the moisture content measurement process;
The purpose of this study is to encompass the above.

The incineration ash processing method of this configuration includes a hydration step of adding water to the incineration ash being transported, a moisture content measurement step of irradiating the incineration ash with electromagnetic waves and measuring the moisture content of the incineration ash based on the ratio between the amplitude change and phase difference of the electromagnetic waves, and a hydration control step of controlling the hydration operation of the incineration ash in the hydration step based on the moisture content measured in the moisture content measurement step. This allows the moisture content of the incineration ash to be measured with high accuracy without being affected by fluctuations in the volumetric filling rate of the incineration ash. And, because the hydration control step of controlling the hydration operation of the incineration ash in the hydration step is performed based on the moisture content measured in the moisture content measurement step, the moisture content of the incineration ash can be accurately adjusted.

In the incineration ash processing method according to the present invention,
A drying process for drying the incineration ash to which water has been added in the water adding process;
A drying control process for controlling the drying operation of the incineration ash in the drying process based on the moisture content measured in the moisture content measurement process;
It is preferred that the compound further comprises:

According to the incineration ash processing method of this configuration, a drying process is performed to dry the incineration ash to which water has been added in the water addition process, and a drying control process is performed to control the drying operation of the incineration ash in the drying process based on the moisture content measured in the moisture content measurement process. This makes it possible to more accurately adjust the moisture content of the incineration ash in a wet state.

FIG. 1 is a block diagram showing a schematic configuration of an incineration ash treatment apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing the general structure of an ash discharge device used in the incineration ash treatment device according to the first embodiment of the present invention, in which (a) is a pusher type ash discharge device, (b) is a screw type ash discharge device, and (c) is a double damper type ash discharge device. FIG. 3 is a cross-sectional end view taken along line AA in FIG. 1 (FIGS. 8 and 10). FIG. 4 is a schematic diagram showing another structure of the ash transport device provided in the incineration ash treatment device according to the first embodiment of the present invention. FIG. 5 is a diagram illustrating devices related to preventing condensation and removing water droplets that are installed in the ash transport device, where (a) is a heater, (b) is a wiper device, and (c) and (d) are air blowing devices. FIG. 6 is a schematic diagram showing a control system for an incineration ash treatment apparatus according to a first embodiment of the present invention, in which (a) is a block diagram showing a general configuration, and (b) is a functional block diagram. FIG. 7 is a graph showing the correlation between the amplitude/phase ratio of microwaves and the official moisture content (dry weight method). FIG. 8 is a block diagram showing a schematic configuration of an incineration ash treatment apparatus according to a second embodiment of the present invention. FIG. 9 is a graph showing an example of the relationship between the amount of eluted heavy metals (lead) contained in incineration ash and the moisture content of the incineration ash according to the Environment Agency Notification No. 13 test. FIG. 10 is a block diagram showing a schematic configuration of an incineration ash treatment apparatus according to a third embodiment of the present invention.

The present invention will now be described with reference to the drawings. However, the present invention is not intended to be limited to the embodiments described below or the configurations shown in the drawings.

First Embodiment
<Overall composition>
Fig. 1 is a block diagram showing a schematic configuration of an incineration ash treatment device according to a first embodiment of the present invention. In Fig. 1, an incinerator 1 incinerates, for example, urban waste, industrial waste, etc. Downstream of the incineration flue gas flow from the incinerator 1, a boiler 2, an economizer 3, a temperature reducing tower 4, a bag filter 5, an induced draft fan 6, and a chimney 7 are arranged in this order. The incineration flue gas generated by the incineration treatment in the incinerator 1 is sent in turn to the boiler 2, the economizer 3, the temperature reducing tower 4, and the bag filter 5 by the induction action of the induced draft fan 6.

The boiler 2 generates steam using the heat of the incineration exhaust gas, and the economizer 3 heats the water supplied to the boiler 2 using the residual heat of the incineration exhaust gas. The temperature reducing tower 4 cools the incineration exhaust gas from the economizer 3 to a predetermined temperature. The bag filter 5 removes dust and other contaminants contained in the cooled incineration exhaust gas. The incineration exhaust gas from which the dust and other contaminants have been removed is discharged to the outside via a chimney 7 by an induced draft fan 6. The incineration exhaust gas from which the dust has been removed in the bag filter 5 contains 5 to 20% by volume of CO ₂ (temperature: 80 to 160°C).

The incineration ash treatment device 10A shown in FIG. 1 is equipped with an ash discharge device 11 as an ash discharge means, an ash conveying device 12 as an ash conveying means, and a water injection nozzle 13 as a water adding means.

<Ash discharge device>
The ash discharger 11 temporarily stores the incineration ash discharged from the incinerator 1 and discharges the incineration ash intermittently as necessary. Fig. 2 is a schematic diagram showing the general structure of the ash discharger used in the incineration ash treatment device according to the first embodiment of the present invention, in which (a) is a pusher type ash discharger, (b) is a screw type ash discharger, and (c) is a double damper type ash discharger. As the ash discharger 11, for example, a pusher type ash discharger 21, a screw type ash discharger 22, a double damper type ash discharger 23, etc., as shown in Figs. 2(a) to (c), can be used, and an appropriate one can be selected from these.

The pusher-type ash discharge device 21 shown in Fig. 2(a) is configured to include an incineration ash storage section 31 that stores incineration ash from the incinerator 1, and an ash pushing device 32 that pushes out and discharges the incineration ash stored in the incineration ash storage section 31 from the bottom. The screw-type ash discharge device 22 shown in Fig. 2(b) is configured to include a trough 33 that can receive incineration ash from the incinerator 1, and a shaft-mounted screw blade 34 arranged in the trough 33, and is configured to push the incineration ash in the trough 33 downstream by rotating the shaft-mounted screw blade 34 and discharge it. The double damper type ash discharge device 23 shown in FIG. 2(c) is equipped with an upper damper 36 and a lower damper 37 arranged vertically inside a chute 35 provided at the discharge outlet of the incinerator 1, and is configured so that the upper and lower dampers 36, 37 alternately drop the incineration ash accumulated on the upper and lower dampers 36, 37, causing the ash to drop and be discharged in stages.

<Ash transport device>
Next, we will explain the ash conveying device 12 that conveys the incineration ash discharged by the ash discharge device 11. As shown in Figure 1, a belt conveyor type ash conveying device is used as the ash conveying device 12. This ash conveying device 12 is configured with a casing 40 and a belt conveyor 42 arranged inside the casing 40.

[Casing]
The casing 40 includes a rectangular tubular casing body 41 extending in the conveying direction, with an inlet 43 opening upward at the upstream end of the casing body 41 in the conveying direction, and a discharge outlet 44 opening downward at the downstream end of the casing body 41 in the conveying direction. The inlet 43 is used to receive incineration ash discharged from the ash discharge device 11. The discharge outlet 44 is used to discharge incineration ash conveyed by the belt conveyor 42.

[Conveyor belt]
The belt conveyor 42 is equipped with a driving wheel 45 and a driven wheel 46 arranged at a predetermined interval in the conveying direction, an endless belt 47 wrapped around the driving wheel 45 and the driven wheel 46, and a driving motor 48 that drives the driving wheel 45. In the belt conveyor 42, the driving wheel 45 is driven by the operation of the driving motor 48, and the endless belt 47 that moves in a circumferential motion by the driving of the driving wheel 45 can transport the incineration ash indicated by the symbol M in FIG. 1 that has fallen onto the endless belt 47 through the inlet 43 of the casing 40 to the outlet 44 of the casing 40. The incineration ash discharged from the outlet 44 is stored in the incineration ash storage facility 49.

In the first embodiment, an example was shown in which a belt conveyor type ash conveying device was used as the ash conveying device 12, but this is not limited to this, and a flight conveyor type ash conveying device may also be used. A detailed explanation of the flight conveyor type ash conveying device using illustrations will be omitted, but a brief explanation is as follows.

The flight conveyor-type ash transport device is configured by disposing a flight conveyor inside a casing having the same structure as the casing 40 described above. The flight conveyor is equipped with drive wheels and driven wheels disposed at a predetermined interval in the transport direction, an endless chain wrapped around the drive wheels and driven wheels, a number of scrapers attached to the endless chain at predetermined intervals so that they can move close to the bottom plate of the casing, and a drive motor that drives the drive wheels. In this flight conveyor, the endless chain moves in an orbit when the drive motor is operated, and the scrapers attached to the endless chain scrape off the incineration ash accumulated on the bottom plate of the casing and transport it to the discharge port of the casing.

<Water injection nozzle>
The water injection nozzles 13 inject water onto the incineration ash being transported by the belt conveyor 42 to make the incineration ash soaked in water. A plurality of water injection nozzles 13 are provided on the upper part of the casing 40 so that water can be evenly added (sprayed) onto the incineration ash in the upstream area in the transport direction of the ash transport device 12 (for convenience of explanation, only one is shown in the figure).

The water injection nozzle 13 is connected to the water supply source 50 via a water supply pipe 51. Thus, water pumped from the water supply source 50 is supplied to the water injection nozzle 13 via the water supply pipe 51. A flow rate control valve 52 is provided in the water supply pipe 51 so that the flow rate of water flowing to the water injection nozzle 13 can be adjusted. In addition, a flow meter 53 is provided in the water supply pipe 51 so that the flow rate of water flowing to the water injection nozzle 13 can be measured.

<Electromagnetic wave transmitting material>
3 is a cross-sectional end view taken along line A-A in FIG. 1. As shown in FIG. 3, the casing body 41 has a top plate 61 and a bottom plate 62 arranged opposite to each other in the vertical direction, and a left plate 63 and a right plate 64 arranged opposite to each other in the horizontal direction. A pair of openings 70 are formed in the top plate 61 and the bottom plate 62 of the casing body 41 at positions facing each other across the incineration ash indicated by symbol M in FIG. 3 on the endless belt 47. A plate-shaped electromagnetic wave transmitting member 71 is attached to each opening 70 so as to be flush with the inner surface of the casing body 41. The electromagnetic wave transmitting member 71 is made of a corrosion-resistant material that can transmit microwaves, which are electromagnetic waves with frequencies of about 300 MHz to 300 GHz (wavelength: about 1 m to 1 mm). The material constituting the electromagnetic wave transparent member 71 is not particularly limited as long as it is microwave-transmissive and corrosion-resistant, but a corrosion-resistant resin is preferable, such as polytetrafluoroethylene resin, liquid crystal polymer, polyether ether ketone resin, polyetherimide resin, polyamide imide resin, polyphenylene sulfide resin, etc., and of these, polytetrafluoroethylene resin known under the trade name Teflon (registered trademark) is particularly preferable.

<Non-contact moisture meter>
A non-contact moisture meter 75 is disposed in the casing body 41 so as to be located downstream of the water injection nozzle 13 (see FIG. 1). The non-contact moisture meter 75 is a transmission type non-contact moisture meter that measures the moisture content of the incineration ash by irradiating microwaves to the incineration ash transported by the belt conveyor 42 in the casing body 41. By employing the transmission type non-contact moisture meter 75, the moisture content of the incineration ash can be accurately measured even if an air layer exists between the incineration ash and the incineration ash.

The non-contact moisture meter 75 has a microwave transmitter 75a, a microwave receiver 75b, and a calculation unit 110 (see FIG. 6B) described later. The microwave transmitter 75a is disposed on the back side of the electromagnetic wave-transmitting member 71 attached to the top plate 61 of the casing body 41. The microwave receiver 75b is disposed on the back side of the electromagnetic wave-transmitting member 71 attached to the bottom plate 62 of the casing body 41. The microwaves transmitted from the microwave transmitter 75a are irradiated to the incineration ash shown by the symbol M in FIG. 3 on the endless belt 47 through the electromagnetic wave-transmitting member 71 attached to the top plate 61 of the casing body 41. The irradiated microwaves penetrate the incineration ash on the endless belt 47, penetrate the endless belt 47, and are received by the microwave receiver 75b through the electromagnetic wave-transmitting member 71 attached to the bottom plate 62 of the casing body 41. The calculation unit 110 (see FIG. 6(b)) calculates the moisture content of the incineration ash transported by the endless belt 47 based on the microwaves received by the microwave receiving unit 75b.

Figure 4 is a schematic diagram showing another structure of an ash conveying device provided in the incineration ash processing apparatus according to the first embodiment of the present invention. The structure of the ash conveying device 12 is not limited to that shown in Figure 3, and the structures of the ash conveying device 12 shown in Figures 4(a) to (c) may be adopted. In the following description of the structure of the ash conveying device 12 shown in Figures 4(a) to (c), the same or similar structures as those of the ash conveying device 12 shown in Figure 3 are simply given the same reference numerals in the figure and detailed description is omitted. The following description will focus on the parts that differ from the structure of the ash conveying device 12 shown in Figure 3.

In the ash conveying device 12 shown in FIG. 4(a), a reflection-type non-contact moisture meter 78 is used, which measures the moisture content of the incineration ash by electromagnetic waves that penetrate the incineration ash indicated by symbol M in FIG. 4(a) conveyed by the endless belt 47 in the casing body 41 and are reflected. The non-contact moisture meter 78 has a microwave transmitter/receiver 78a, which combines the functions of a microwave transmitter and a microwave receiver, and a calculation unit 110 (see FIG. 6(b)). An opening 70 is formed in the top plate 61 of the casing body 41 so as to be located above the incineration ash indicated by symbol M in FIG. 4(a) on the endless belt 47. A plate-shaped electromagnetic wave transmitting member 71 is attached to the opening 70 so as to be flush with the inner surface of the casing body 41. The microwave transmitter/receiver 78a is arranged on the back side of the electromagnetic wave transmitting member 71 attached to the top plate 61 of the casing body 41. The microwaves emitted from the microwave transmitter/receiver 78a are irradiated to the incineration ash shown by the symbol M in FIG. 4(a) on the endless belt 47 through the electromagnetic wave transmitting member 71 attached to the top plate 61 of the casing body 41. The irradiated microwaves pass through the incineration ash on the endless belt 47, are reflected at the boundary between the incineration ash and the endless belt 47, pass through the incineration ash on the endless belt 47 again, and are received by the microwave transmitter/receiver 78a. The calculation unit 110 (see FIG. 6(b)) calculates the moisture content of the incineration ash on the endless belt 47 based on the microwaves received by the microwave transmitter/receiver 78a. By adopting the reflection-type non-contact moisture meter 78, it is no longer necessary to separately provide the microwave receiver 75b provided in the ash conveying device 12 shown in FIG. 3, so there is no need to provide an opening 70 or an electromagnetic wave transmitting member 71 in the bottom plate 62, and the structure can be further simplified.

In the ash conveying device 12 shown in FIG. 4(b), the top of the casing body 41 is open. A pair of openings 70 are formed in the left and right plates 63 and 64 of the casing body 41 so as to face each other across the incineration ash indicated by the symbol M in FIG. 4(b) on the endless belt 47. A plate-shaped electromagnetic wave transmitting member 71 is attached to each opening 70 so as to be flush with the inner surface of the casing body 41. The microwave transmitting unit 75a is disposed on the back side of the electromagnetic wave transmitting member 71 attached to the left plate 63 of the casing body 41. The microwave receiving unit 75b is disposed on the back side of the electromagnetic wave transmitting member 71 attached to the right plate 64 of the casing body 41. The microwaves transmitted from the microwave transmitting unit 75a are irradiated to the incineration ash indicated by the symbol M in FIG. 4(b) on the endless belt 47 through the electromagnetic wave transmitting member 71 attached to the left plate 63 of the casing body 41. The irradiated microwaves pass through the incineration ash on the endless belt 47 and are received by the microwave receiver 75b through the electromagnetic wave transmitting member 71 attached to the right side plate 64 of the casing body 41. The calculation unit 110 (see FIG. 6(b)) calculates the moisture content of the incineration ash transported by the endless belt 47 based on the microwaves received by the microwave receiver 75b.

In the ash conveying device 12 shown in FIG. 4(c), the top of the casing body 41 is also open. In the ash conveying device 12 shown in FIG. 4(c), a reflection-type non-contact moisture meter 78 is used. The opening 70 is formed in the right side plate 64 of the casing body 41 so as to face the incineration ash shown by the symbol M in FIG. 4(c) on the belt conveyor. A plate-shaped electromagnetic wave-transmitting member 71 is attached to the opening 70 so as to be flush with the inner surface of the casing body 41. The microwave transmitting/receiving unit 78a is disposed on the back side of the electromagnetic wave-transmitting member 71 attached to the right side plate 64 of the casing body 41. The microwaves transmitted from the microwave transmitting/receiving unit 78a are irradiated to the incineration ash shown by the symbol M in FIG. 4(c) on the endless belt 47 through the electromagnetic wave-transmitting member 71 attached to the right side plate 64 of the casing body 41. The irradiated microwaves pass through the incineration ash on the endless belt 47, are reflected by the left side plate 63 of the casing body 41, pass through the incineration ash on the endless belt 47 again, and are received by the microwave transmitter/receiver 78a. The calculation unit 110 (see FIG. 6(b)) calculates the moisture content of the incineration ash on the endless belt 47 based on the microwaves received by the microwave transmitter/receiver 78a.

In the ash transport device 12 shown in FIG. 3, the positions of the microwave transmitter 75a and the microwave receiver 75b may be swapped in the vertical direction. In the ash transport device 12 shown in FIG. 4(a), the electromagnetic wave transparent member 71 and the microwave transmitter/receiver 78a may be arranged on the bottom plate 62 of the casing body. In the ash transport device 12 shown in FIG. 4(b), the positions of the microwave transmitter 75a and the microwave receiver 75b may be swapped in the horizontal direction. In the ash transport device 12 shown in FIG. 4(c), the electromagnetic wave transparent member 71 and the microwave transmitter/receiver 78a may be arranged on the left side plate 63 of the casing body.

In addition, in the ash transport device 12, when either the microwave transmitter 75a or the microwave receiver 75b is arranged on the left side plate 63 or the right side plate 64 and the other is arranged on the right side plate 64 or the left side plate 63, or when the microwave transmitter/receiver 78a is arranged on the left side plate 63 or the right side plate 64, the structure is not limited to the structure shown in Figures 4(b) and (c) in which the top of the casing body 41 is open, but may be a structure shown in Figure 3 in which the top of the casing body 41 is not open, i.e., the top of the casing body 41 is covered with a top plate 61.

Figure 5 is a diagram illustrating equipment related to condensation prevention and water droplet removal that is equipped on the ash transport device, where (a) is a heater, (b) is a wiper device, and (c) and (d) are air blowing devices. In the following, the equipment related to condensation prevention and water droplet removal of the electromagnetic wave transparent member 71 attached to the top plate 61 of the casing body 41 will be described as a representative example, but the equipment related to condensation prevention and water droplet removal can also be applied to the electromagnetic wave transparent member 71 attached to the bottom plate 62 of the casing body 41 (see Figure 3), the electromagnetic wave transparent member 71 attached to the left side plate 63 (see Figure 4(b)), and the electromagnetic wave transparent member 71 attached to the right side plate 64 (see Figures 4(b) and (c)).

<Heater>
The heater 81 shown in Fig. 5 (a) functions as a dew condensation prevention means for preventing dew condensation from occurring on the surface 71a of the electromagnetic wave transmitting member 71 facing the incineration ash in the casing 40 (casing body 41), and as a water droplet removal means for removing water droplets attached to the surface 71a of the electromagnetic wave transmitting member 71. The heater 81 is provided with an electric heating wire 82 attached or embedded in an area of the electromagnetic wave transmitting member 71 through which microwaves do not pass, and is configured to be able to keep the surface of the electromagnetic wave transmitting member 71 at a temperature higher than the dew point to prevent dew condensation from occurring, or to dry and remove water droplets when they adhere to the surface of the electromagnetic wave transmitting member 71, by controlling the current supply to the electric heating wire 82 of a power supply unit (not shown).

<Wiper device>
5B functions as a water droplet removing means for removing water droplets adhering to the surface 71a of the electromagnetic wave transmitting member 71. The wiper device 85 includes a device main body 86 attached to the inner surface of the top plate 61 of the casing main body 41, and a wiping member 87 attached to the device main body 86 so as to be swingable along the surface 71a of the electromagnetic wave transmitting member 71. The wiper device 85 is configured so that the water droplets adhering to the surface 71a of the electromagnetic wave transmitting member 71 can be wiped away by the wiping member 87 by driving the wiping member 87 to swing by operation of an electric motor (not shown) built into the device main body 86.

<Air blowing device>
The air blowing devices 91, 91' shown in Figures 5 (c) and (d) function as a condensation prevention means for preventing condensation from occurring on the surface 71a of the electromagnetic wave transparent member 71, and as a water droplet removal means for removing water droplets adhering to the surface 71a of the electromagnetic wave transparent member 71.

The air blowing device 91 shown in FIG. 5(c) is configured with an air blowing nozzle 92 that blows compressed air from a compressed air supply source (not shown) along the surface 71a of the electromagnetic wave transmitting member 71. In the air blowing device 91, compressed air is constantly blown out from the air blowing nozzle 92 to form an air curtain along the surface 71a of the electromagnetic wave transmitting member 71 so that water vapor derived from the incineration ash does not remain near the surface of the electromagnetic wave transmitting member 71, thereby preventing condensation from occurring on the surface 71a of the electromagnetic wave transmitting member 71. In addition, in the air blowing device 91, when water droplets adhere to the surface 71a of the electromagnetic wave transmitting member 71, compressed air is blown out from the air blowing nozzle 92 to blow off and remove the water droplets adhered to the surface 71a of the electromagnetic wave transmitting member 71.

The air blowing device 91' shown in FIG. 5(d) is configured with an air blowing nozzle 92' that blows compressed air from a compressed air supply source (not shown) toward the surface 71a of the electromagnetic wave transparent member 71. In the air blowing device 91', compressed air is blown directly from the air blowing nozzle 92' toward the surface 71a of the electromagnetic wave transparent member 71, thereby preventing condensation from forming on the surface 71a of the electromagnetic wave transparent member 71. In addition, in the air blowing device 91', when water droplets adhere to the surface 71a of the electromagnetic wave transparent member 71, compressed air is blown directly from the air blowing nozzle 92' toward the surface 71a of the electromagnetic wave transparent member 71, thereby reliably blowing off and removing the water droplets adhered to the surface 71a of the electromagnetic wave transparent member 71.

By appropriately selecting and using one or more of the devices related to condensation prevention and water droplet removal shown in Figures 5 (a) to (d), it is possible to prevent errors in moisture content measurement caused by the influence of water droplets.

<Water-repellent finish>
As shown in the enlarged view of the vicinity of the surface 71a of the electromagnetic wave transmitting member 71 in FIG. 3, the surface 71a of the electromagnetic wave transmitting member 71 is preferably subjected to a water-repellent treatment. For example, the water-repellent treatment may be performed by forming a coating 95 made of fluororesin, silicone, or the like on the surface 71a of the electromagnetic wave transmitting member 71. In this way, by subjecting the surface 71a of the electromagnetic wave transmitting member 71 to a water-repellent treatment, the electromagnetic wave transmitting member 71 has water repellency. Even if condensation occurs on the surface 71a of the electromagnetic wave transmitting member 71, the water droplets are immediately repelled and can be prevented from adhering to the surface 71a of the electromagnetic wave transmitting member 71 as they are. Even if water droplets are attached to the surface 71a of the electromagnetic wave transmitting member 71, the adhesion of the water droplets is weak due to the effect of the water-repellent treatment, so that the water droplets can be easily and reliably removed using the wiper device 85 or the air blowing device 91, 91'. Therefore, measurement errors caused by the influence of water droplets can be suppressed.

Figure 6 shows a schematic diagram of a control system for an incineration ash treatment device according to a first embodiment of the present invention, where (a) is a block diagram showing a schematic configuration, and (b) is a functional block diagram. The incineration ash treatment device 10A is equipped with a control system 100 as shown in Figure 6 (a). The control system 100 shown in Figure 6 (a) is composed of a control device 101 mainly composed of a microcomputer incorporating a CPU 101a, a memory 101b, an I/O port 101c, etc., and various devices 102 connected to the control device 101 so as to be able to transmit signals. The various devices 102 include a drive motor 48, a flow rate control valve 52, a flow meter 53, a microwave transmission unit 75a, a microwave reception unit 75b, a microwave transmission/reception unit 78a, etc.

In the control device 101, the memory 101b stores predetermined programs created according to a predetermined algorithm, data on the positive correlation between the ratio of amplitude change and phase difference (amplitude phase ratio) and the official moisture content (dry weight method) as shown in FIG. 7, which is related to the microwaves received by the microwave receiver 75b (microwave transmitter/receiver 78a) for the microwaves transmitted from the microwave transmitter 75a (microwave transmitter/receiver 78a, 108a), and other data necessary for the treatment of incineration ash, etc. In the control device 101, the CPU 101a reads the predetermined programs and various data stored in the memory 101b and executes the predetermined processing, thereby exerting the functions of the various functional parts as shown in the functional block diagram of FIG. 6(b).

The various functional units of the control device 101 shown in the functional block diagram of FIG. 6(b) include a calculation unit 110. The calculation unit 110 reads data such as that shown in FIG. 7, which is prestored in memory 101b (see FIG. 6(a)), and calculates the moisture content of the incineration ash as follows.

Figure 7 is a graph showing the correlation between the microwave amplitude and phase ratio and the official moisture content (dry weight method). The change in the volumetric filling rate (mixture rate of incineration ash and air, etc.) of the measurement object (incineration ash in the casing 40) of the non-contact moisture meter 75, 78 is detected as the ratio (amplitude change/phase difference) of the microwave amplitude change (attenuation) and phase difference (phase delay). Therefore, if the volumetric filling rate of the measurement object is changed and the microwave amplitude change and phase difference are measured and plotted, they will be aligned on a straight line, and the slope of the equation of this line is not affected by the change in the volumetric filling rate of the measurement object. Therefore, the incineration ash with various moisture content values known in advance is measured for the amplitude change and phase difference of the microwave by changing the volumetric filling rate at each moisture content, the slope of the equation of the line at each moisture content is obtained, and the relationship between the slope and the moisture content is obtained in advance. Next, microwaves are irradiated onto the object to be measured, and the change in amplitude and phase difference of the microwaves that pass through the object to be measured are measured. The slope of the amplitude change and phase difference (amplitude-phase ratio) is then calculated. The calculated slope value is then applied to the previously calculated relationship between the slope (amplitude-phase ratio) and moisture percentage, i.e., the graph shown in Figure 7, and the moisture percentage can be accurately calculated without being affected by changes in the volume filling rate of the object to be measured.

When a non-contact moisture meter 75 of the transmission type is used, the calculation unit 110 shown in FIG. 6(b) reads from the memory 101b (see FIG. 6(a)) data on the positive correlation between the amplitude and phase ratio of the microwaves transmitted from the microwave transmitter 75a and received by the microwave receiver 75b, and the official moisture content (dry weight method) (see FIG. 7), which is previously stored in the memory 101b, and calculates the moisture content of the incineration ash in the casing 40 based on the read data and the amplitude and phase ratio of the microwaves received by the microwave receiver 75b.

When a reflective non-contact moisture meter 78 is used, the calculation unit 110 shown in FIG. 6(b) reads data (see FIG. 7) from the memory 101b, which is stored in advance in the memory 101b (see FIG. 6(a)), on the amplitude-phase ratio of the microwaves transmitted from the microwave transmitting/receiving unit 78a to the microwaves received by the microwave transmitting/receiving unit 78a, and on the positive correlation between the official moisture content (dry weight method), and the data. The calculation unit 110 calculates the moisture content of the incineration ash in the casing 40 based on the read data and the microwaves received by the microwave transmitting/receiving unit 78a.

The calculation unit 110 also calculates the flow rate of water to be supplied to the water injection nozzle 13 based on a detection signal from the flowmeter 53. Furthermore, the calculation unit 110 calculates a transported ash amount m and a target injection water amount _QT , which will be described later.

The various functional units of the control device 101 shown in the functional block diagram of FIG. 6(b) include, in addition to the calculation unit 110, a motor control unit 112, a valve control unit 113, a memory unit 115, etc.

The motor control unit 112 transmits a predetermined control signal to the drive motor 48 based on the moisture content of the incineration ash measured by the non-contact moisture meter 75 (78). This controls the conveying speed of the belt conveyor 42.

The valve control unit 113 transmits a predetermined control signal to the flow rate control valve 52 based on the moisture content of the incineration ash measured by the non-contact moisture meters 75, 78 and the amount of water supplied to the water injection nozzle 13 measured by the flow meter 53 and the calculation unit 110. This controls the valve opening of the flow rate control valve 52, and adjusts the amount of water supplied to the water injection nozzle 13.

The memory unit 115 functions as a storage for holding data used by the CPU 101a when performing a specified calculation process, such as data on the positive correlation between the amplitude-phase ratio and the official moisture content (dry weight method) for the microwaves received by the microwave receiver 75b (microwave transmitter/receiver 78a) in relation to the microwaves transmitted from the microwave transmitter 75a (microwave transmitter/receiver 78a) (see FIG. 7), and other data necessary for the processing of incineration ash.

<Operation description>
In the incineration ash treatment device 10A shown in Fig. 1, the incineration ash discharged from the incinerator 1 is stored in the incineration ash storage section 31 of the ash discharge device 11, specifically, for example, the pusher-type ash discharge device 21 shown in Fig. 2 (a) (incineration ash storage process). Next, the incineration ash stored in the incineration ash storage section 31 is discharged by the ash pusher device 32 (incineration ash discharge process). Next, the incineration ash discharged by the ash pusher device 32 is transported by the ash transport device 12 (incineration ash transport process). Next, water is sprayed by the water spray nozzle 13 onto the incineration ash transported by the ash transport device 12 (water spray process).

Then, the moisture content of the incineration ash into which water has been injected is measured by the non-contact moisture meter 75 (moisture content measurement process), and the amount of water injected is measured based on the detection signal of the flowmeter 53 (injection water volume measurement process). Based on the measured moisture content and amount of injected water, the amount of ash transported by the ash transport device 12 is calculated (transported ash volume calculation process), and based on the calculated transported ash volume, the target amount of water injection required for the actual moisture content of the incineration ash to reach the target moisture content is calculated (target injection water volume calculation process). Then, the amount of water injected from the water injection nozzle 13 is controlled to match the calculated target amount of water injection (injection water volume control process).

<Calculation method for transported ash amount and target water injection amount>
Here, the amount of incineration ash (dry ash) being transported by the ash transport device 12 (hereinafter referred to as the "transported ash amount") is m, the moisture content (%) measured by the non-contact moisture meter 75 is W, the amount of water injected (L/h) measured based on the detection signal of the flowmeter 53 is Q, the target moisture content (%) of the incineration ash that is set in advance is W _T , and the amount of water injected (target injected water amount) required for the actual moisture content of the incineration ash (moisture content W measured by the non-contact moisture meter 75) to become the target moisture content W _T is Q _T. The transported ash amount m can be calculated by the following formula (1), and the target injected water amount Q _T can be calculated by the following formula (2).
m = {(100-W)/W}・Q...(1)
Q _T = {W _T /(100-W _T )}・m (2)

In the injection water amount control process, the calculation unit 110 reads the moisture percentage measured by the non-contact moisture meter 75 and the injection water amount measured by the flow meter 53, and calculates the transported ash amount m using the above formula (1) based on the moisture percentage and injection water amount that were read in. Next, the calculation unit 110 calculates the target injection water amount _QT using the above formula (2) based on the calculated transported ash amount m.

Then, the valve control unit 113 sends a flow control signal corresponding to the calculated target water injection amount _QT to the flow rate adjustment valve 52, and controls the amount of water injection so that the actual amount of water injection from the water injection nozzle 13 measured by the flow meter 53 matches the target water injection amount _QT . This makes it possible to reliably bring the moisture content of the incineration ash close to the target moisture content _WT even if the amount of incineration ash transported by the ash transport device 12 fluctuates. The configuration including the flow rate adjustment valve 52, the flow meter 53, and the valve control unit 113 corresponds to the "control means" in this invention.

The incineration ash processing device 10A is equipped with a non-contact moisture meter 75 that irradiates microwaves onto the incineration ash and measures the moisture content of the incineration ash based on the ratio of the amplitude change and phase difference of the microwaves, so that the moisture content of the incineration ash can be measured with high accuracy without being affected by fluctuations in the volumetric filling rate of the incineration ash. The amount of water injected from the water injection nozzle 13 is controlled based on the moisture content of the incineration ash measured with high accuracy by the non-contact moisture meter 75, so that the moisture content of the incineration ash can be accurately adjusted.

In the first embodiment, a heavy metal stabilizing agent for preventing the elution of heavy metals may be directly sprayed onto the incineration ash transported by the ash transport device 12 from a dedicated nozzle (not shown) prepared separately from the water injection nozzle 13 described above, or the heavy metal stabilizing agent may be mixed with the water sprayed by the water injection nozzle 13 so that the heavy metal stabilizing agent adheres to the incineration ash. This allows the heavy metal stabilizing agent to be uniformly adhered to the incineration ash, thereby reliably preventing the elution of heavy metals from the incineration ash.

In addition, in the above embodiment, in order to reduce power consumption, the ash discharge device 11 may be operated intermittently, and the transport operation of the ash transport device 12 and the water injection operation of the water injection nozzle 13 may be linked in accordance with the operation of the ash discharge device 11.

Second Embodiment
8 is a block diagram showing a schematic configuration of an incineration ash treatment device according to a second embodiment of the present invention. In the second embodiment, the same or similar parts as those in the first embodiment are denoted by the same reference numerals in the figure, and detailed descriptions thereof are omitted. In the following, the description will focus on parts unique to the second embodiment (the same applies to the third embodiment described later).

<Blowpipe>
The incineration ash processing device 10B shown in Fig. 8 is equipped with a blowing pipe 14 as a drying means. The blowing pipe 14 is disposed in the upper part of the casing 40 so as to be located downstream of the installation position of the water injection nozzle 13 in the conveying direction of the ash conveying device 12 and upstream of the installation position of the non-contact moisture meter 75 in the conveying direction of the ash conveying device 12. The blowing pipe 14 is composed of a tubular member that opens toward the inside of the casing 40. The blowing pipe 14 blows drying gas (incinerator exhaust gas) into the incineration ash that is moistened by the water injected from the water injection nozzle 13 and conveyed by the belt conveyor 42. Here, the belt conveyor 42 functions as a drying means that dries the incineration ash that is moistened and conveyed by the belt conveyor 42 in cooperation with the blowing pipe 14.

An exhaust gas supply pipe 55 is connected to the blowing pipe 14 to supply the incineration exhaust gas after dust and other particles have been removed in the bag filter 5. An induced draft fan 56 is installed midway through the exhaust gas supply pipe 55, and the incineration exhaust gas after dust removal is supplied to the blowing pipe 14 by the induction action of the induced draft fan 56. As a result, the incineration exhaust gas is blown by the blowing pipe 14 into the incineration ash transported by the belt conveyor 42.

The casing 40 is provided with an exhaust section 57 located at the most downstream part in the transport direction of the ash transport device 12. The exhaust section 57 is composed of a tubular member that opens toward the outside of the casing 40 so that the incineration exhaust gas blown into the inside of the casing 40 through the blowing pipe 14 can be discharged to the outside of the casing 40. The exhaust section 57 is connected to an exhaust gas exhaust pipe 58 for guiding the incineration exhaust gas discharged to the outside of the casing 40 to the incinerator 1.

In the second embodiment, the motor control unit 112 (see FIG. 6(b)) transmits a predetermined control signal to the drive motor 48 based on the moisture content of the incineration ash measured by the non-contact moisture meter 75 (78). This controls the conveying speed of the belt conveyor 42 and the drying operation of the incineration ash, thereby adjusting the drying time for the wet incineration ash in the ash conveying device 12. The configuration including the motor control unit 112 and the drive motor 48 corresponds to the "control means" in this invention.

<Operation description>
In the incineration ash treatment apparatus 10B configured as described above, heavy metals are made less soluble by carrying out the steps described below.

<Water addition process>
The water injection nozzle 13 injects water onto the incineration ash being transported by the belt conveyor 42. When the amount of incineration ash transported by the belt conveyor 42 is approximately constant, if water at a predetermined flow rate or more is injected from the water injection nozzle 13 onto the incineration ash being transported by the belt conveyor 42, the moisture content of the incineration ash will be equal to or greater than a predetermined value.

9 is a graph showing an example of the relationship between the amount of elution of heavy metals (lead) contained in incineration ash and the moisture content of the incineration ash according to the Environment Agency Notification No. 13 test. As shown in the graph in FIG. 9, the higher the moisture content of the incineration ash, the less the amount of elution of lead tends to be, and if the moisture content of the incineration ash is 17% or more, the amount of elution of lead is surely less than the standard value of 0.3 mg/L. Therefore, in the second embodiment, the amount of water that is required to be contained in the incineration ash, which is transported by the belt conveyor 42 at a substantially constant amount, is determined in advance so that the moisture content of the incineration ash becomes about 17%. Then, the amount of water supplied from the water supply source 50 to the water injection nozzle 13 is adjusted by operating the flow rate control valve 52 based on the amount of water supplied to the water injection nozzle 13 measured by the flow meter 53 and the calculation unit 110, and water at the previously determined flow rate or a flow rate greater than the predetermined flow rate is injected from the water injection nozzle 13 onto the incineration ash transported by the belt conveyor 42. In the second embodiment, the target value of the moisture content of the incineration ash during the hydration process (first moisture content) is preferably 15% or more and 30% or less, and in this example, it is about 17%. This ensures that the amount of eluted heavy metals contained in the incineration ash is less than the standard value.

<Drying process>
The blowing pipe 14 blows the incineration flue gas supplied by the induction action of the induced draft fan 56 into the incineration ash that has been moistened by the water sprayed from the water injection nozzle 13 and is being transported by the belt conveyor 42. This dries the incineration ash moistened by the water addition process, and brings the CO ₂ contained in the incineration flue gas into contact with the incineration ash. Here, the incineration flue gas is supplied to the inside of the casing 40 for about 1 minute to 12 hours (preferably about 5 minutes to 1 hour). The incineration flue gas blown into the casing 40 from the blowing pipe 14 is exhausted to the incinerator 1 via the exhaust section 57 and the exhaust gas exhaust pipe 58.

Heavy metals contained in incineration ash react with _CO2 contained in the incineration exhaust gas to become carbonates, and their solubility in water decreases. Among the heavy metals contained in incineration ash, the heavy metals that are the subject of treatment are mainly lead, since the content of lead is particularly high. Lead changes from lead oxide (PbO) to lead carbonate ( _PbCO3 ), which reduces its solubility in water and makes it difficult to dissolve. In addition, incineration ash is basic and the pH of the eluate is high. Regarding the pH of incineration ash, calcium oxide (CaO) or calcium hydroxide (Ca(OH) ₂ ) contained in the incineration ash is reacted with _CO2 to form calcium carbonate ( _CaCO3 ), so that the pH of the incineration ash is set to a difficult-to-dissolve region in which heavy metals are difficult to dissolve. Lead is an amphoteric metal, and in incineration ash that is strongly basic, the amount of lead eluted can be reduced by lowering the pH of the eluate to a difficult-to-dissolve region.

<Moisture content measurement process>
The non-contact moisture meter 75 measures the moisture content of the incineration ash dried in the drying process. That is, the calculation unit 110 shown in Fig. 6(b) reads out data on the positive correlation between the amplitude/phase ratio and the official moisture content (dry weight method) shown in Fig. 7, which is stored in advance in the memory 101b (see Fig. 6(a)), from the memory 101b, and calculates the moisture content of the incineration ash in the casing 40 based on the read data and the amplitude/phase ratio of the microwave received by the microwave receiving unit 75b.

<Drying control process>
In the incineration ash processing device 10B, the actual moisture content of the incineration ash after drying (the moisture content measured by the non-contact moisture meter 75 _WK ) is set to the target moisture content _WKT . That is, the motor control unit 112 shown in FIG. 6(b) transmits a predetermined control signal to the drive motor 48, controls the conveyor speed of the belt conveyor 42, and controls the drying operation so that the moisture content measured by the non-contact moisture meter 75 _WK coincides with the target moisture content _WKT . In this way, the moisture content of the incineration ash can be accurately brought close to the target moisture content _WKT . Here, the target moisture content _WKT (second moisture content) is determined for the purpose of preventing the incineration ash from scattering, and is preferably set in the range of, for example, 10% to 15%, and is about 10% in this example. This makes it possible to prevent the incineration ash from scattering. If the moisture content of the incineration ash is less than 10%, the incineration ash may scatter, deteriorating the working environment and making handling difficult.

As described above, in the second embodiment, a hydration process and a drying process are carried out. In the hydration process, water is added to the incineration ash so that the incineration ash has a first moisture content (about 17%) at which the amount of elution of heavy metals contained in the incineration ash is less than the standard value. This makes it possible to make the amount of elution of heavy metals less than the standard value. On the other hand, in the drying process, the incineration ash that has been made wet by the hydration process is dried so that the incineration ash has a second moisture content (about 10%) at which the incineration ash does not scatter. This makes it possible to prevent the incineration ash from scattering. The amount of elution of heavy metals contained in the incineration ash does not become the amount of elution of heavy metals at the second moisture content after drying in the drying process, but the amount of elution of heavy metals at the first moisture content after water is added in the hydration process is maintained. Therefore, according to the first embodiment, the elution of heavy metals can be suppressed to less than the standard value without adversely affecting the working environment or handling.

The incineration ash that has been dried to a moisture content of about 10% is transported off-site and disposed of for recycling or other purposes. Processing costs are charged per weight. In the second embodiment, the moisture content is set to about 10%, which is as low as possible while still preventing the incineration ash from scattering, so that the incineration ash can be prevented from scattering during transportation and loading/unloading, and processing costs can be kept low.

In the second embodiment, the wet incineration ash is transported by the belt conveyor 42 while drying gas (incineration exhaust gas) is blown in through the blowing pipe 14 to dry it, so the incineration ash can be dried efficiently and the processing capacity of the incineration ash can be improved.

In the second embodiment, the moisture content of the incineration ash is measured using a non-contact moisture meter 75 (78) based on correlation data (see FIG. 7) between the amplitude phase ratio of the microwaves transmitted through the incineration ash and the official moisture content. By measuring the moisture content based on the amplitude phase ratio in this way, the moisture content of the incineration ash can be measured accurately without being affected by fluctuations in the volumetric filling rate of the measurement target (incineration ash transported by the ash transport device 12), and the moisture content of the incineration ash is accurately adjusted because hydration and drying processes are performed on the incineration ash based on the moisture content of the incineration ash measured accurately by the non-contact moisture meter 75 (78).

In the second embodiment, the ash discharge device 11 is also operated intermittently to discharge the incineration ash from the ash discharge device 11 to the ash conveying device 12 intermittently, and the conveying operation of the ash conveying device 12 and the blowing operation of drying gas into the incineration ash from the blowing pipe 14 by the induction action of the induction blower 56 are linked in accordance with this intermittent incineration ash discharge operation. In this way, it is possible to reduce power consumption by saving power while maintaining the incineration ash processing capacity at a certain level or higher.

Third Embodiment
10 is a block diagram showing a schematic configuration of an incineration ash treatment device according to a third embodiment of the present invention. In the incineration ash treatment device 10C of the second embodiment, a non-contact moisture meter 175 is disposed on the upper part of the casing 40 so as to be located between the water injection nozzle 13 and the blowing pipe 14 so that the moisture content of the incineration ash before drying can be measured after water is injected by the water injection nozzle 13. The non-contact moisture meter 175 is a transmission type non-contact moisture meter comprising a microwave transmission unit 75a, a microwave reception unit 75b, and a calculation unit 110, similar to the non-contact moisture meter 75. Note that a reflection type non-contact moisture meter similar to the non-contact moisture meter 78 may be used instead of the non-contact moisture meter 175.

In the third embodiment of the incineration ash treatment device 10C, the moisture content of the incineration ash before drying is measured by a non-contact moisture meter 175 after water is sprayed by the water spray nozzle 13 (moisture content measurement process).

<Water addition control process>
The calculation unit 110 reads the moisture content W _S measured by the non-contact moisture meter 175 and the amount of water injection Q measured by the flowmeter 53, and calculates the amount of ash transported m by the above formula (1). Next, the calculation unit 110 calculates the target amount of water injection Q _T by the above formula (2) based on the calculated amount of ash transported m. Then, the valve control unit 113 sends a flow control signal corresponding to the calculated target amount of water injection Q _T to the flow rate adjustment valve 52, and controls the amount of water injection so that the actual amount of water injection from the water injection nozzle 13 measured by the flowmeter 53 matches the target amount of water injection Q _T. This makes it possible to reliably bring the moisture content of the incineration ash close to the target moisture content W _ST .

It goes without saying that the third embodiment can achieve the same effects as the second embodiment. Furthermore, according to the third embodiment, the amount of water injected from the water injection nozzle 13 can be accurately controlled so that the moisture content measured by the non-contact moisture meter 175 is the first moisture content (in this example, about 17%), so that the moisture content of the incineration ash that is soaked with water by the water injection nozzle 13 can be reliably set to about 17%, and the amount of elution of heavy metals can be reliably kept below the standard value.

The incineration ash treatment device and incineration ash treatment method of the present invention have been described above based on several embodiments, but the present invention is not limited to the configurations described in the above embodiments, and the configuration can be changed as appropriate within the scope of the spirit of the present invention.

The incineration ash treatment device and incineration ash treatment method of the present invention can be used to cool the incineration ash generated when municipal solid waste or industrial waste is incinerated in an incinerator, and to suppress the elution of heavy metals contained in the incineration ash.

10A to 10C Incineration ash treatment device 12 Ash conveying device (ash conveying means)
13 Water injection nozzle (water adding means)
14 Blow pipe (drying means)
40 Casing 42 Belt conveyor (drying means)
48 Drive motor (drying control means)
52 Flow rate control valve (water addition control means)
53 Flow meter (water addition control means)
70 Opening 71 Electromagnetic wave transmitting member 75, 78 Non-contact moisture meter (second non-contact moisture meter)
81 Heater (means for preventing condensation, means for removing water droplets)
85 Wiper device (water droplet removal means)
91, 91' Air blowing device (condensation prevention means, water droplet removal means)
95 Coating 112 Motor control unit (drying control means)
113 Valve control unit (water addition control means)
175 Non-contact moisture meter (first non-contact moisture meter)

Claims (6)

An incineration ash treatment device that adds water to incineration ash transported by an ash transport means,
A means for adding water to the incineration ash;
A non-contact moisture meter that irradiates electromagnetic waves onto the incineration ash and measures the moisture content of the incineration ash based on the ratio of the amplitude change and phase difference of the electromagnetic waves;
A control means for controlling the hydration means based on the moisture percentage measured by the non-contact moisture meter;
Equipped with
The ash conveying means is
A casing for accommodating incineration ash;
an electromagnetic wave transmitting member attached to an opening provided in the casing;
Equipped with
The incineration ash in the casing is irradiated with electromagnetic waves through the electromagnetic wave transmitting member,
An incineration ash treatment device equipped with an air blowing device configured to have an air blowing nozzle that blows compressed air along the surface of the electromagnetic wave transparent member facing the incineration ash in the casing, or an air blowing nozzle that blows compressed air toward the surface . Further provided is a drying means for drying the incineration ash to which water has been added by the water adding means,
2. The incineration ash treatment apparatus according to claim 1, wherein the control means controls the drying means based on the moisture percentage measured by the non-contact moisture meter. 3. The incineration ash treating apparatus according to claim 1, wherein the non-contact moisture meter is a transmission type non-contact moisture meter that measures the moisture content of the incineration ash by electromagnetic waves transmitted through the incineration ash. 3. The incineration ash treatment device according to claim 1 , wherein the non-contact moisture meter is a reflection type non-contact moisture meter that measures the moisture content of the incineration ash by electromagnetic waves that are transmitted through the incineration ash and reflected. The incineration ash treatment device according to any one of claims 1 to 4 , wherein the electromagnetic wave transparent member has water repellency. The non-contact moisture meter comprises:
A first non-contact moisture meter for measuring the moisture content of the incineration ash hydrated by the hydration means;
A second non-contact moisture meter that measures the moisture content of the incineration ash that has been hydrated by the hydrating means and then dried by the drying means;
Including,
The incineration ash treatment device according to claim 2, wherein the control means controls the hydration means so that the moisture content measured by the first non-contact moisture meter becomes a first moisture content at which the amount of elution of heavy metals contained in the incineration ash is less than a reference value, and controls the drying means so that the moisture content measured by the second non-contact moisture meter becomes a second moisture content that is set lower than the first moisture content for the purpose of preventing the incineration ash from scattering.

Images