JP7634971B2 - Sludge incineration facility - Google Patents

Description

The present invention relates to a sludge incineration facility and a sludge incineration method in which sludge is supplied to an incinerator by a sludge supplying means and incinerated.

Conventionally, when incinerating sewage sludge, it is generally first dehydrated in a dehydrator such as a centrifuge to produce dehydrated sludge, and this dehydrated sludge is then fed into an incinerator. However, since the dehydrated sludge still has a high moisture content, a large amount of combustion improver is required to incinerate it as is. Therefore, in order to reduce the amount of combustion improver used, the dehydrated sludge is dried using a sludge dryer to produce dried sludge with a moisture content below a specified level, which is then fed into an incinerator for combustion (see, for example, Patent Document 1).

In incinerators, the amount of heat generated can vary depending on the properties of the sludge, and localized high temperatures (over 1,200°C) can occur. In these high-temperature areas, the ash melts and becomes clinker, which then becomes entangled with non-combustible materials (low-melting-point metals, glass wool, etc.). This can then adhere to and grow on the walls of the incinerator, obstructing the flow of exhaust gas and causing other problems.

In order to suppress the generation of clinker, it is important to suppress fluctuations in the amount of heat generated in the incinerator and stabilize the operation of the incinerator so that the furnace temperature remains within a certain range, for example not exceeding 900°C. Among the properties of sludge, the factor that greatly affects the amount of heat generated is the moisture percentage (water content) of the sludge. Therefore, if combustion control is performed according to the moisture percentage of the sludge, combustion operation will be stabilized.

Patent Document 2 discloses a technology in which a dry cake (dried sludge) made by dehydrating and drying sewage sludge is incinerated in a stoker furnace having a hearth composed of multiple stages of movable fire grates while being moved by the fire grates from the front stage to the rear stage of the hearth, and the dry cake is reliably incinerated by spontaneous combustion by controlling the moving speed of the dry cake by the fire grates based on the moisture content of the dry cake supplied into the furnace.

Patent Document 3 discloses a technology that calculates the necessary amount of auxiliary fuel to be used based on the results of a neutron moisture meter that continuously measures the moisture content of the material to be treated (sludge) immediately before it is supplied to the incinerator, and controls combustion so that the calculated amount of auxiliary fuel is used.

JP 2018-1062 A JP 2005-257131 A JP 2005-16914 A

In sludge incineration facilities that incinerate sludge, the more frequently the incinerator temperature becomes locally high, the more likely it is that clinker will adhere to and grow on the furnace walls, etc. Such an event will hinder the stable operation of the sludge incineration facility, but Patent Document 1 does not take any specific measures to prevent clinker from adhering to the furnace walls, etc.

Patent document 2 does not disclose how the moisture content of the dried cake is specifically measured.

The neutron moisture meter used in the technology disclosed in Patent Document 3 utilizes the phenomenon in which neutrons emitted from radioactive materials are decelerated and become thermal neutrons when they collide with hydrogen atoms. The technology disclosed in Patent Document 3 requires the handling of radioactive materials, which in addition to the high risk of exposure to radiation, requires measures to prevent exposure, and there is a problem in that the moisture content of the material being treated (sludge) cannot be easily measured.

The present invention was made in consideration of the above problems, and aims to provide a sludge incineration facility and a sludge incineration method that can easily and accurately measure the moisture content of sludge supplied to an incinerator and stabilize the combustion operation of the incinerator.

The characteristic configuration of the sludge incineration equipment according to the present invention to solve the above problems is as follows:
A sludge incineration facility in which sludge is supplied to an incinerator by a sludge supplying means and incinerated,
a non-contact moisture meter that irradiates electromagnetic waves onto the sludge to be supplied to the incinerator to measure the moisture content of the sludge;
A combustion state control means for controlling the combustion state of the incinerator based on the moisture content measured by the non-contact moisture meter;
The purpose of this study is to provide

The sludge incineration equipment of this configuration is equipped with a non-contact moisture meter that measures the moisture content of sludge supplied to the incinerator by a sludge supplying means by irradiating the sludge with electromagnetic waves. This allows the moisture content of the sludge supplied to the incinerator to be easily and accurately measured by the non-contact moisture meter. The combustion state of the incinerator is then controlled by the combustion state control means based on the moisture content measured by the non-contact moisture meter, so that fluctuations in the amount of heat generated in the incinerator can be suppressed and the combustion operation of the incinerator can be stabilized.

In the sludge incineration facility according to the present invention,
The sludge supplying means is
a casing for containing sludge;
an electromagnetic wave transmitting member attached to an opening provided in the casing;
Equipped with
It is preferable that the sludge in the casing is irradiated with electromagnetic waves through the electromagnetic wave transmitting member.

In the sludge incineration equipment of this configuration, an opening is provided in the casing that contains the sludge, and electromagnetic waves are irradiated onto the sludge inside the casing through an electromagnetic wave transparent member that is attached to this opening. With this configuration, the electromagnetic wave transparent member can prevent dust and other particles that fly up from the sludge while the sludge is being fed from adhering to the electromagnetic wave transmitter and receiver of the non-contact moisture meter. Therefore, problems with the transmission and reception of electromagnetic waves can be prevented in advance, and accurate measurement values can be obtained stably over a long period of time.

In the sludge incineration facility 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 on the side facing the sludge inside the casing.

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

In the sludge incineration facility 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 sludge inside the casing.

With this sludge incineration equipment, even if water droplets resulting from the moisture contained in the sludge adhere to the surface of the electromagnetic wave-transmitting member facing the sludge inside the casing, the water droplets can be removed by the water droplet removal means. This makes it possible to prevent measurement errors caused by the influence of water droplets.

In the sludge incineration facility according to the present invention,
The electromagnetic wave transmitting member preferably has water repellency.

In the sludge incineration equipment 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 sludge 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 sludge incineration facility according to the present invention,
It is preferable that the combustion state control means controls the combustion state of the incinerator by adjusting the amount of sludge supplied to the incinerator by the sludge supply means.

In the sludge incineration system of this configuration, the combustion state control means controls the combustion state of the incinerator by adjusting the amount of sludge supplied to the incinerator by the sludge supply means. This ensures stable combustion operation of the incinerator.

In the sludge incineration facility according to the present invention,
The incinerator has a combustion chamber for burning sludge, and at least one of a sludge supply device for supplying sludge into the combustion chamber, a fire grate for sending sludge into the combustion chamber, a combustion air damper for adjusting the amount of combustion air supplied into the combustion chamber, and a recirculated exhaust gas damper for adjusting the amount of recirculated exhaust gas supplied into the combustion chamber,
It is preferable that the combustion state control means controls the combustion state of the incinerator by adjusting at least one of the amount of sludge supplied into the combustion chamber by the sludge supply device, the sludge transport speed within the combustion chamber by the grate, the amount of combustion air supplied into the combustion chamber by the combustion air damper, and the amount of recirculated exhaust gas supplied into the combustion chamber by the recirculated exhaust gas damper.

According to the sludge incineration equipment of this configuration, the incinerator has a combustion chamber for burning sludge, and at least one of a sludge supply device that supplies sludge into the combustion chamber, a grate that sends sludge through the combustion chamber, a combustion air damper that adjusts the amount of combustion air supplied to the combustion chamber, and a recirculated exhaust gas damper that adjusts the amount of recirculated exhaust gas supplied to the combustion chamber. The combustion state control means controls the combustion state of the incinerator by adjusting at least one of the amount of sludge supplied to the combustion chamber by the sludge supply device, the speed at which the sludge is sent through the combustion chamber by the grate, the amount of combustion air supplied to the combustion chamber by the combustion air damper, and the amount of recirculated exhaust gas supplied to the combustion chamber by the recirculated exhaust gas damper. This ensures stable combustion operation of the incinerator.

In the sludge incineration facility according to the present invention,
The dewatered sludge dryer dries the dewatered sludge, which is the sludge after the dewatering process.
The dewatered sludge dryer is configured to supply dried sludge to the incinerator by the sludge supplying means,
It is preferable that the combustion condition control means controls the combustion condition of the incinerator by adjusting at least one of the amount of dewatered sludge supplied to the dewatered sludge dryer, the drying temperature for the dewatered sludge in the dewatered sludge dryer, and the drying time for the dewatered sludge in the dewatered sludge dryer.

In the sludge incineration equipment of this configuration, the combustion state control means controls the combustion state of the incinerator by adjusting at least one of the amount of dewatered sludge supplied to the dewatered sludge dryer, the drying temperature for the dewatered sludge in the dewatered sludge dryer, and the drying time for the dewatered sludge in the dewatered sludge dryer. This ensures that the combustion operation of the incinerator can be stabilized.

Next, the characteristic configuration of the sludge incineration method according to the present invention for solving the above problems is as follows:
A sludge incineration method in which sludge is supplied to an incinerator by a sludge supplying means and incinerated, comprising:
a moisture content measuring step of measuring the moisture content of the sludge supplied to the incinerator by irradiating the sludge with electromagnetic waves;
A combustion state control step of controlling the combustion state of the incinerator based on the moisture content measured in the moisture content measurement step;
The purpose of this study is to encompass the above.

The sludge incineration method of this configuration includes a moisture content measurement step in which electromagnetic waves are applied to the sludge supplied to the incinerator by the sludge supply means to measure the moisture content of the sludge. This makes it possible to easily and accurately measure the moisture content of the sludge supplied to the incinerator. Then, a combustion state control step is carried out to control the combustion state of the incinerator based on the moisture content measured in the moisture content measurement step, so that fluctuations in the amount of heat generated in the incinerator can be suppressed and the combustion operation of the incinerator can be stabilized.

FIG. 1 is a schematic diagram showing the general configuration of a sludge incineration facility according to one embodiment of the present invention. Figure 2 shows a schematic diagram of the structure of a sludge transport conveyor installed in a sludge incineration facility according to one embodiment of the present invention, where (a) is a side view with a portion cut away, and (b) is an end view taken along line A-A of (a). FIG. 3 is a schematic diagram showing another structure of a sludge transport conveyor provided in a sludge incineration facility according to one embodiment of the present invention. FIG. 4 is a diagram showing examples of equipment related to preventing condensation and removing water droplets that is installed on a sludge transport conveyor, where (a) is a heater, (b) is a wiper device, and (c) and (d) are air blowing devices. FIG. 5 is a block diagram showing a schematic configuration of a control system for a sludge incineration facility according to one embodiment of the present invention. FIG. 6 is a functional block diagram of a control system for a sludge incineration facility according to one embodiment of the present invention. 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 schematic diagram illustrating another embodiment of the sludge incineration facility of the present invention, where (a) is another embodiment (1) and (b) is another embodiment (2). FIG. 9 is a schematic diagram illustrating another embodiment of the sludge incineration facility of the present invention, where (a) is another embodiment (3) and (b) is another embodiment (4). FIG. 10 is a schematic diagram illustrating another embodiment (5) of the sludge incineration facility of the present invention. FIG. 11 is a schematic diagram illustrating another embodiment (6) of the sludge incineration facility 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.

<Overall composition>
Fig. 1 is a schematic diagram showing the general configuration of a sludge incineration facility according to one embodiment of the present invention. As shown in Fig. 1, the sludge incineration facility 1 includes an incinerator 2 equipped with a dewatering sludge dryer 10. Downstream of the incinerator 2, a boiler 3, an economizer 4, a temperature reducing tower 5, a filter-type dust collector 6, an induced draft fan 7, and a chimney 8 are arranged in this order.

In the sludge incineration facility 1, dehydrated sludge, which is sludge that has been dehydrated in advance in a dehydrator such as a centrifuge (not shown), is dried in a dehydrated sludge dryer 10, and the dried sludge, which is sludge that has been dried in the dehydrated sludge dryer 10, is burned and incinerated in combustion chambers 51, 52 (described later) in the incinerator 2. In this specification, "sludge" refers to a muddy substance that is generated during the process of wastewater treatment or sewage treatment, and is a mixture of organic and inorganic matter. In the following explanation, dehydrated sludge and dried sludge may be collectively referred to simply as "sludge", unless it is necessary to specifically distinguish between dehydrated sludge and dried sludge.

The combustion exhaust gas generated by the combustion in the incinerator 2 is sent in turn to the boiler 3, economizer 4, cooling tower 5, and filter-type dust collector 6 by the induction action of the induced draft fan 7.

The boiler 3 uses the heat of the exhaust gas to generate steam, the economizer 4 uses the residual heat of the exhaust gas to heat the water supplied to the boiler 3, the temperature reducing tower 5 cools the exhaust gas from the economizer 4 to a predetermined temperature, and the filter-type dust collector 6 removes fly ash (dust) and other substances contained in the exhaust gas.

The combustion exhaust gas from which fly ash and other substances have been removed is discharged to the outside through a chimney 8 by an induced draft fan 7. Note that in a combustion boiler facility including an incinerator 2 and a boiler 3, a turbine (not shown) connected to the boiler 3 may be used to drive a generator to generate electricity.

<Incinerator>
The incinerator 2 is provided with a furnace body 50 having a primary combustion chamber 51 and a secondary combustion chamber 52. On one side (left side in FIG. 1) of the furnace body 50, a sludge supplying device 55 for supplying sludge into the furnace body 50 is provided, and a hopper 56 for feeding sludge to the sludge supplying device 55 is provided. The hopper 56 has an inverted pyramidal receiving section 56a and a square cylindrical chute section 56b that is integrally attached to the receiving section 56a, and is configured such that the receiving section 56a and the chute section 56b are arranged in order in the sludge feeding direction. On the lower side of the furnace body 50, a stoker 60 is provided, and a primary combustion air supplying device 61 for supplying primary combustion air to the stoker 60 is provided. In the incinerator 2, secondary combustion air is supplied to the secondary combustion chamber 52 by a secondary combustion air supplying device 62. In the incinerator 2, the recirculated exhaust gas is supplied into the incinerator 2 by a recirculated exhaust gas supply device 63. The furnace temperature of the furnace body 50 is detected by a furnace temperature sensor 58, and a detection signal is transmitted to a control device 201 described later.

<Sludge supply device>
The sludge supplying device 55 is a pusher type supplying device that pushes the sludge in the chute portion 56b into the furnace body 50 by the reciprocating motion of a pusher 65. The pusher 65 is reciprocated by a pusher driving device 66 such as a hydraulic cylinder.

<Grate>
The stoker 60 is a stepped stoker in which movable grates 70a and fixed grates 70b are alternately arranged in a stepped manner. The stoker 60 is divided into a drying stoker 71 forming a drying stage, a combustion stoker 72 forming a combustion stage, and a post-combustion stoker 73 forming a post-combustion stage, in order from the upstream side to the downstream side in the sludge feed direction. A drying stoker drive device 75 that reciprocates the movable grate 70a in the drying stoker 71 is connected to the drying stoker 71. A combustion stoker drive device 76 that reciprocates the movable grate 70a in the combustion stoker 72 is connected to the combustion stoker 72. A post-combustion stoker drive device 77 that reciprocates the movable grate 70a in the post-combustion stoker 73 is connected to the post-combustion stoker 73.

A wind box 78 is attached to the lower side of each of the drying stoker 71, the combustion stoker 72, and the post-combustion stoker 73. Primary combustion air from the primary combustion air supply device 61 is supplied to the drying stoker 71, the combustion stoker 72, and the post-combustion stoker 73 via the wind box 78.

<Primary combustion air supply system>
The primary combustion air supply device 61 includes a blower 79 that blows out primary combustion air, a main duct 80 through which the primary combustion air from the blower 79 flows, and a first branch duct 81, a second branch duct 82 and a third branch duct 83 that branch off from the main duct 80 and are connected to wind boxes 78 corresponding to the drying stoker 71, the combustion stoker 72 and the post-combustion stoker 73, respectively, and is configured so that the primary combustion air from the blower 79 can be supplied from the main duct 80 via the first branch duct 81, the second branch duct 82 and the third branch duct 83 to the drying stoker 71, the combustion stoker 72 and the post-combustion stoker 73, respectively.

A main flow rate adjustment damper device 85 is provided in the main line 80. A first flow rate adjustment damper device 86, a second flow rate adjustment damper device 87, and a third flow rate adjustment damper device 88 are provided in the first branch line 81, the second branch line 82, and the third branch line 83, respectively.

<Secondary combustion air supply device>
The secondary combustion air supply device 62 includes a blower 90 that blows out secondary combustion air, and a pipe 91 that guides the secondary combustion air from the blower 90 to the secondary combustion chamber 52, and is configured so that the secondary combustion air from the blower 90 can be supplied into the secondary combustion chamber 52 through the pipe 91. A flow rate adjustment damper device 92 is provided in the pipe 91.

<Recirculating exhaust gas supply device>
The recirculated exhaust gas supply device 63 is equipped with a blower 95 that sends out a portion of the low-temperature exhaust gas discharged from the chimney 8 into the atmosphere as recirculated exhaust gas, and a pipe 96 that guides the recirculated exhaust gas from the blower 95 into the incinerator 2, and is configured so that the recirculated exhaust gas from the blower 95 can be supplied to the incinerator 2 through the pipe 96. A flow rate control damper device 97 is provided in the pipe 96.

<Sludge dryer>
The dewatered sludge dryer 10 is a groove-type (trough-type) low-speed agitation type conduction heat transfer dryer, and is equipped with a trough 12 having a heat transfer jacket 11 and a heat transfer body 13 supported by the trough 12 so as to be freely rotatable.

The trough 12 has a sludge receiving port 15 at one end for receiving dehydrated sludge, which is the sludge to be treated, and a sludge discharge port 16 at the other end for discharging dried sludge. A heat medium inlet 21 is provided on one side of the heat transfer jacket 11, and a heat medium discharge port 22 is provided on the other side of the heat transfer jacket 11, so that the heat medium introduced from the heat medium inlet 21 passes through the inside of the heat transfer jacket 11 and is discharged from the heat medium discharge port 22.

A carrier gas inlet 17 is provided near the other end of the trough 12 to introduce sludge drying carrier gas into the trough 12, and a carrier gas outlet 18 is provided near one end of the trough 12 to discharge the sludge drying carrier gas introduced into the trough 12 to the outside of the trough 12.

For example, air from the dewatered sludge storage 30 described later is heated by an inlet carrier gas heater (not shown) inside the trough 12, and the heated air is introduced into the trough 12 through the carrier gas inlet 17 as sludge drying carrier gas. The sludge drying carrier gas takes in the evaporants that evaporate as the dewatered sludge is dried, and then discharged together with the evaporants from the carrier gas outlet 18. The discharged sludge drying carrier gas is introduced back into the dewatered sludge dryer 10 through a return passage (not shown) in which a dehumidification device (not shown) is installed, and is used again as sludge drying carrier gas, or is pumped to the secondary combustion chamber 52 after dust removal, also serving as secondary combustion air.

The heat transfer body 13 is formed by arranging a plurality of heat transfer blades (paddle blades) 24 on a rotating shaft 23 at appropriate intervals in the axial direction, and has a hollow structure in which the rotating shaft 23 and the heat transfer blades 24 communicate with each other. A heat medium inlet 25 is provided on one end of the rotating shaft 23, and a heat medium outlet 26 is provided on the other end of the rotating shaft 23. The heat medium introduced from the heat medium inlet 25 passes through the hollow parts of the rotating shaft 23 and the heat transfer blades 24 and is discharged from the heat medium outlet 26. In addition, the rotational power of a drive motor 27 is transmitted to the rotating shaft 23 via a power transmission mechanism 28.

In the dewatered sludge dryer 10, for example, steam, heat transfer oil, or high-temperature water is used as the heat medium. The heat medium heats the trough 12 as it passes from the heat medium inlet 21 through the inside of the heat transfer jacket 11 and out through the heat medium outlet 22, and also heats the heat transfer body 13 as it passes from the heat medium inlet 25 through the hollow parts of the rotating shaft 23 and heat transfer blades 24 and out through the heat medium outlet 26. A heat exchanger 29 is interposed in the heat medium supply pipe.

In the dewatered sludge dryer 10, the drying time for the dewatered sludge can be adjusted by controlling the rotation speed of the heat transfer body 13. Also, in the dewatered sludge dryer 10, the drying temperature for the dewatered sludge can be adjusted by adjusting the temperature of the heat medium by controlling the amount of heat exchange in the heat exchanger 29.

A dehydrated sludge storage tank 31 is disposed upstream of the sludge receiving inlet 15 of the dehydrated sludge dryer 10. The dehydrated sludge storage tank 31 stores dehydrated sludge that has been dehydrated in advance by a dehydrator such as a centrifuge (not shown). The dehydrated sludge storage tank 31 is stored in a dehydrated sludge storage facility 30 to prevent odor leakage. A feeder 32 such as a screw feeder is attached to the dehydrated sludge storage tank 31, and a dehydrated sludge supply pump 33 is disposed between the feeder 32 and the sludge receiving inlet 15 of the dehydrated sludge dryer 10. The dehydrated sludge stored in the dehydrated sludge storage tank 31 is cut out by the feeder 32, and the cut out dehydrated sludge is pumped to the sludge receiving inlet 15 of the dehydrated sludge dryer 10 by the dehydrated sludge supply pump 33.

A dry sludge storage tank 35 in which dry sludge is stored is disposed downstream of the sludge discharge port 16 in the dewatering sludge dryer 10. A sludge transport conveyor 36 is disposed between the sludge discharge port 16 and the dry sludge storage tank 35. A sludge transport conveyor 40 is disposed between the dry sludge storage tank 35 and the hopper 56 in the incinerator 2. A dry sludge cutting device 38 consisting of a screw feeder or the like is attached to the dry sludge storage tank 35. In this way, the dry sludge discharged from the sludge discharge port 16 is transported by the sludge transport conveyor 36 to the dry sludge storage tank 35 and stored therein, and the dry sludge stored in the dry sludge storage tank 35 is cut out by the dry sludge cutting device 38. The extracted dried sludge is transported from the inlet 102 of the sludge transport conveyor 40 to the outlet 103 located above the hopper 56, and is discharged from the outlet 103 and placed into the hopper 56.

<Sludge transport conveyor>
Figure 2 shows a schematic diagram of a sludge transport conveyor provided in a sludge incineration facility according to one embodiment of the present invention, with (a) being a partially cutaway side view and (b) being a cut end view taken along line A-A in (a). As shown in Figure 2(a), the sludge transport conveyor 40 is configured by disposing a flight conveyor 110 within a casing 100. The sludge transport conveyor 40 corresponds to the "sludge supply means" of the present invention.

<Casing>
As shown in FIG. 2(a), the casing 100 includes a casing body 101 having a rectangular cylindrical cross section, an inlet 102 for introducing sludge, and a discharge outlet 103 for discharging the sludge.

The casing body 101 has a lower horizontal section 101a, an upper horizontal section 101b, and an inclined section 101c. The lower horizontal section 101a extends horizontally near the floor, the upper horizontal section 101b extends horizontally above the hopper 56 (see FIG. 1), and the inclined section 101c extends diagonally to connect one end of the upper horizontal section 101b with the other end of the lower horizontal section 101a. The inlet 102 is formed in an open state on the upper surface side near one end of the lower horizontal section 101a. The outlet 103 is formed in an open state on the lower surface side near the other end of the upper horizontal section 101b.

<Flight conveyor>
The flight conveyor 110 includes a driving wheel 111, a driven wheel 112, a first idler wheel 113, and a second idler wheel 114. The driving wheel 111 is disposed inside the other end side of the upper horizontal portion 101b, and is connected to the output shaft of the driving motor 116 via a rotational power transmission mechanism 115. The driven wheel 112 is disposed inside one end side of the lower horizontal portion 101a. The first idler wheel 113 is disposed inside the intersection between the upper end side of the inclined portion 101c and one end side of the upper horizontal portion 101b. The second idler wheel 114 is disposed inside the intersection between the lower end side of the inclined portion 101c and the other end side of the lower horizontal portion 101a.

The flight conveyor 110 further includes an endless chain 120 and a number of scrapers 121. The endless chain 120 is wound around the driven wheel 112 from the driving wheel 111 via the first idler wheel 113 and the second idler wheel 114. When the driving wheel 111 is rotated by the operation of the driving motor 116, the endless chain 120 moves in a circle between the driving wheel 111 and the driven wheel 112, guided by the first idler wheel 113 and the second idler wheel 114. The multiple scrapers 121 are attached to the endless chain 120 at a predetermined interval so that they can move close to the bottom plate 132 of the casing body 101, which will be described later.

In the flight conveyor 110, the sludge, indicated by the symbol M in FIG. 2(a), is dropped onto the bottom plate 132 of the casing 100 through the inlet 102 of the casing 100, and the sludge on the bottom plate 132 of the casing 100 is scraped off by a scraper 121 attached to an endless chain 120 that is driven to move in an orbit by the operation of a drive motor 116, and is transported to the outlet 103 of the casing 100.

As shown in FIG. 2(b), the casing body 101 is configured by integrally connecting a top plate 131 and a bottom plate 132 arranged opposite each other in the vertical direction, and a left plate 133 and a right plate 134 arranged opposite each other in the left-right direction. The endless chain 120 is configured with a pair of chain members 125 arranged at a predetermined interval in a horizontal direction (left-right direction) perpendicular to the conveying direction (a direction perpendicular to the paper surface in FIG. 2(b) and away from the paper surface).

<Electromagnetic wave transmitting material>
A pair of openings 140 are formed in the top plate 131 and the bottom plate 132 of the casing body 101 at positions facing each other so as to sandwich a space between a pair of left and right chain members 125 constituting the endless chain 120. A plate-shaped electromagnetic wave transmitting member 141 is attached to each opening 140 so as to be flush with the inner surface of the casing body 101. The electromagnetic wave transmitting member 141 is made of a material having corrosion resistance and capable of transmitting microwaves, which are electromagnetic waves with a frequency of about 300 MHz to 300 GHz (wavelength: about 1 m to 1 mm). The material constituting the electromagnetic wave transmitting member 141 is not particularly limited as long as it is capable of transmitting microwaves and has corrosion resistance, but a corrosion-resistant resin is preferable, and examples of such materials include polytetrafluoroethylene resin, liquid crystal polymer, polyether ether ketone resin, polyetherimide resin, polyamideimide resin, and polyphenylene sulfide resin. Among these, polytetrafluoroethylene resin, known by the trade name Teflon (registered trademark), is particularly preferable.

<Non-contact moisture meter>
A transmission-type non-contact moisture meter 145 is attached to the casing body 101, which measures the moisture content of the sludge by irradiating microwaves onto the sludge transported by the flight conveyor 110 inside the casing body 101. By employing the transmission-type non-contact moisture meter 145, the moisture content of the sludge can be accurately measured even if an air layer exists between the sludge and the sludge.

The non-contact moisture meter 145 has a microwave transmitter 145a, a microwave receiver 145b, and a moisture percentage calculation unit 210 (see FIG. 6) described later. The microwave transmitter 145a is disposed on the back side of the electromagnetic wave transparent member 141 attached to the top plate 131 of the casing body 101. The microwave receiver 145b is disposed on the back side of the electromagnetic wave transparent member 141 attached to the bottom plate 132 of the casing body 101. The microwaves emitted from the microwave transmitter 145a pass through the electromagnetic wave transparent member 141 attached to the top plate 131 of the casing body 101, pass through the space between the pair of left and right chain members 125, and are irradiated to the sludge indicated by symbol M in FIG. 2(b) on the bottom plate 132. The irradiated microwaves pass through the sludge on the bottom plate 132 and are received by the microwave receiver 145b through the electromagnetic wave transmission member 141 attached to the bottom plate 132. The moisture content calculator 210 (see FIG. 6) calculates the moisture content of the sludge transported by the flight conveyor 110 based on the microwaves received by the microwave receiver 145b.

Figure 3 is a schematic diagram showing another structure of the sludge transport conveyor provided in the sludge incineration facility according to one embodiment of the present invention. The structure of the sludge transport conveyor 40 is not limited to that shown in Figures 2(a) and (b) described above, and the structure of the sludge transport conveyor 40 shown in Figures 3(a) to (c) may be adopted. In the following description of the structure of the sludge transport conveyor 40 shown in Figures 3(a) to (c), the same or similar structures as those of the sludge transport conveyor 40 shown in Figures 2(a) and (b) are simply given the same reference numerals in the figures and detailed description is omitted. In the following, the parts that are different from the structure of the sludge transport conveyor 40 shown in Figures 2(a) and (b) will be mainly described.

In the sludge transport conveyor 40 shown in FIG. 3(a), a reflection-type non-contact moisture meter 148 is used, which measures the moisture content of the sludge by electromagnetic waves that penetrate and reflect the sludge indicated by the symbol M in FIG. 3(a) transported by the flight conveyor 110 in the casing body 101. The non-contact moisture meter 148 has a microwave transmitter/receiver 148a that combines the functions of a microwave transmitter and a microwave receiver, and a moisture content calculator 210 (see FIG. 6). An opening 140 is formed in the top plate 131 of the casing body 101 so as to be located above the sludge indicated by the symbol M in FIG. 3(a) on the bottom plate 132. A plate-shaped electromagnetic wave transmitting member 141 is attached to the opening 140 so as to be flush with the inner surface of the casing body 101. The microwave transmitting/receiving unit 148a is disposed on the rear side of the electromagnetic wave transmitting member 141 attached to the top plate 131 of the casing body 101. The microwaves transmitted from the microwave transmitting/receiving unit 148a are irradiated to the sludge shown by the symbol M in Fig. 3(a) on the bottom plate 132 through the electromagnetic wave transmitting member 141 attached to the top plate 131 of the casing body 101. The irradiated microwaves penetrate the sludge on the bottom plate 132, are reflected at the boundary between the sludge and the bottom plate 132, pass through the sludge on the bottom plate 132 again, and are received by the microwave transmitting/receiving unit 148a. The moisture percentage calculation unit 210 (see Fig. 6) calculates the moisture percentage of the sludge on the bottom plate 132 based on the microwaves received by the microwave transmitting/receiving unit 148a. By adopting the reflection-type non-contact moisture meter 148, there is no need to provide a separate microwave receiving unit 145b, which is provided in the sludge transport conveyor 40 shown in Figures 2(a) and (b), so there is no need to provide an opening 140 or an electromagnetic wave transmitting member 141 in the bottom plate 132, making it possible to further simplify the structure.

In the sludge transport conveyor 40 shown in FIG. 3(b), the top of the casing body 101 is open. A pair of openings 140 are formed in the left side plate 133 and the right side plate 134 of the casing body 101 so as to face each other across the sludge indicated by the symbol M in FIG. 3(b) on the bottom plate 132. A plate-shaped electromagnetic wave transmitting member 141 is attached to each opening 140 so as to be flush with the inner surface of the casing body 101. The microwave transmitting unit 145a is disposed on the rear side of the electromagnetic wave transmitting member 141 attached to the left side plate 133 of the casing body 101. The microwave receiving unit 145b is disposed on the rear side of the electromagnetic wave transmitting member 141 attached to the right side plate 134 of the casing body 101. The microwaves emitted from the microwave transmitter 145a are irradiated to the sludge indicated by the symbol M in FIG. 3B on the bottom plate 132 through an electromagnetic wave transmitting member 141 attached to the left side plate 133 of the casing body 101. The irradiated microwaves pass through the sludge on the bottom plate 132 and are received by the microwave receiver 145b through the electromagnetic wave transmitting member 141 attached to the right side plate 134 of the casing body 101. The moisture percentage calculator 210 (see FIG. 6) calculates the moisture percentage of the sludge transported by the flight conveyor 110 based on the microwaves received by the microwave receiver 145b.

In the sludge transport conveyor 40 shown in FIG. 3(c), the top of the casing body 101 is also open. In the sludge transport conveyor 40 shown in FIG. 3(c), a reflection-type non-contact moisture meter 148 is used. The opening 140 is formed in the right side plate 134 of the casing body 101 so as to face the sludge indicated by the symbol M in FIG. 3(c) on the bottom plate 132. A plate-shaped electromagnetic wave transmitting member 141 is attached to the opening 140 so as to be flush with the inner surface of the casing body 101. The microwave transmitting/receiving unit 148a is disposed on the back side of the electromagnetic wave transmitting member 141 attached to the right side plate 134 of the casing body 101. The microwaves transmitted from the microwave transmitting/receiving unit 148a are irradiated to the sludge indicated by the symbol M in FIG. 3(c) on the bottom plate 132 through the electromagnetic wave transmitting member 141 attached to the right side plate 134 of the casing body 101. The irradiated microwaves pass through the sludge on the bottom plate 132, are reflected by the left side plate 133 of the casing body 101, pass through the sludge on the bottom plate 132 again, and are received by the microwave transmitter/receiver 148a. The moisture percentage calculation unit 210 (see FIG. 6) calculates the moisture percentage of the sludge transported by the flight conveyor 110 based on the microwaves received by the microwave transmitter/receiver 148a.

The positions of the microwave transmitter 145a and the microwave receiver 145b shown in Figures 2(a) and (b) may be interchanged in the vertical direction. In the sludge transport conveyor 40 shown in Figure 3(a), the electromagnetic wave transparent member 141 and the microwave transmitter/receiver 148a may be arranged on the bottom plate 132 of the casing body. In the sludge transport conveyor 40 shown in Figure 3(b), the positions of the microwave transmitter 145a and the microwave receiver 145b may be interchanged in the horizontal direction. In the sludge transport conveyor 40 shown in Figure 3(c), the electromagnetic wave transparent member 141 and the microwave transmitter/receiver 148a may be arranged on the left side plate 133 of the casing body.
Furthermore, in the sludge transport conveyor 40, when either the microwave transmitting unit 145a or the microwave receiving unit 145b is arranged on the left side plate 133 or the right side plate 134, and the other is arranged on the right side plate 134 or the left side plate 133, or when the microwave transmitting/receiving unit 148a is arranged on the left side plate 133 or the right side plate 134, the structure is not limited to one in which the top of the casing body 101 is open, as shown in Figures 3(b) and (c), but may also be one in which the top of the casing body 101 is not open, as shown in Figures 2(b) and 3(a), i.e., the top of the casing body 101 is covered with a top plate 131.

Figure 4 is a diagram illustrating equipment related to condensation prevention and water droplet removal that is installed on a sludge transport conveyor, 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 141 attached to the top plate 131 of the casing main body 101 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 141 attached to the left side plate 133 (see Figure 3 (b)) and the electromagnetic wave transparent member 141 attached to the right side plate 134 (see Figures 3 (b) and (c)).

<Heater>
4A functions as a condensation prevention means for preventing condensation from occurring on the surface 141a of the electromagnetic wave transmitting member 141 facing the sludge in the casing 100 (casing main body 101), and as a water droplet removal means for removing water droplets attached to the surface 141a of the electromagnetic wave transmitting member 141. The heater 151 includes an electric heating wire 152 attached or embedded in an area of the electromagnetic wave transmitting member 141 through which microwaves do not pass, and is configured to be able to keep the surface of the electromagnetic wave transmitting member 141 at a temperature higher than the dew point to prevent condensation from occurring, and to dry and remove water droplets that have adhered to the surface of the electromagnetic wave transmitting member 141, by controlling the current supply to the electric heating wire 152 from a power supply unit (not shown).

<Wiper device>
As shown in Fig. 4B, a wiper device 155 is attached to the top plate 131 of the casing body 101. The wiper device 155 functions as a water droplet removing means for removing water droplets adhering to the surface 141a of the electromagnetic wave transmitting member 141. The wiper device 155 includes a device body 156 attached to the inner surface of the top plate 131 of the casing body 101, and a wiping member 157 attached to the device body 156 so as to be swingable along the surface 141a of the electromagnetic wave transmitting member 141. The wiper device 155 is configured so that the wiping member 157 can wipe off water droplets adhering to the surface 141a of the electromagnetic wave transmitting member 141 by driving the wiping member 157 to swing by the operation of an electric motor (not shown) built into the device body 156.

<Air blowing device>
4(c) and (d), air blowing devices 161, 161' are attached to the top plate 131 of the casing main body 101. The air blowing devices 161, 161' function as condensation prevention means for preventing condensation from occurring on the surface 141a of the electromagnetic wave transmitting member 141 and as water droplet removal means for removing water droplets adhering to the surface 141a of the electromagnetic wave transmitting member 141.

The air blowing device 161 shown in FIG. 4(c) is configured with an air blowing nozzle 162 that blows compressed air from a compressed air supply source (not shown) along the surface 141a of the electromagnetic wave transmitting member 141. In the air blowing device 161, compressed air is constantly blown out from the air blowing nozzle 162 to form an air curtain along the surface 141a of the electromagnetic wave transmitting member 141 so that water vapor derived from sludge does not remain near the surface of the electromagnetic wave transmitting member 141, thereby preventing condensation from occurring on the surface 141a of the electromagnetic wave transmitting member 141. In addition, in the air blowing device 161, when water droplets adhere to the surface 141a of the electromagnetic wave transmitting member 141, compressed air is blown out from the air blowing nozzle 162 to blow off and remove the water droplets adhered to the surface 141a of the electromagnetic wave transmitting member 141.

The air blowing device 161' shown in FIG. 4(d) is configured with an air blowing nozzle 162' that blows compressed air from a compressed air supply source (not shown) toward the surface 141a of the electromagnetic wave transmitting member 141. In the air blowing device 161', compressed air is blown directly from the air blowing nozzle 162' toward the surface 141a of the electromagnetic wave transmitting member 141, thereby preventing condensation from occurring on the surface 141a of the electromagnetic wave transmitting member 141. In addition, in the air blowing device 161', when water droplets adhere to the surface 141a of the electromagnetic wave transmitting member 141, compressed air is blown directly from the air blowing nozzle 162' toward the surface 141a of the electromagnetic wave transmitting member 141, thereby reliably blowing off and removing the water droplets adhered to the surface 141a of the electromagnetic wave transmitting member 141.

By appropriately selecting and using one or more of the devices related to condensation prevention and water droplet removal shown in Figures 4 (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 141a of the electromagnetic wave transmitting member 141 in FIG. 2B, the surface 141a of the electromagnetic wave transmitting member 141 is preferably subjected to a water-repellent treatment. For example, the water-repellent treatment may be performed by forming a coating 165 of fluororesin, silicone, or the like on the surface 141a of the electromagnetic wave transmitting member 141. In this way, by subjecting the surface 141a of the electromagnetic wave transmitting member 141 to a water-repellent treatment, the electromagnetic wave transmitting member 141 has water repellency. Even if condensation occurs on the surface 141a of the electromagnetic wave transmitting member 141, the water droplets are immediately repelled and can be prevented from adhering to the surface 141a of the electromagnetic wave transmitting member 141 as they are. Even if water droplets are attached to the surface 141a of the electromagnetic wave transmitting member 141, 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 155 or the air blowing device 161, 161'. Therefore, measurement errors caused by the influence of water droplets can be suppressed.

Figure 5 is a block diagram showing the schematic configuration of a control system for a sludge incineration facility according to one embodiment of the present invention. The sludge incineration facility 1 is equipped with a control system 200 as shown in Figure 5. The sludge incineration control system 200 shown in Figure 2 is composed of a control device 201 mainly composed of a microcomputer incorporating a CPU 201a, a memory 201b, an I/O port 201c, etc., and various devices 202 connected to the control device 201 so as to be able to transmit signals. The various devices 202 include a drive motor 27, a heat exchanger 29, a feeder 32, a dewatered sludge supply pump 33, a furnace temperature sensor 58, a pusher drive device 66, a drying stoker drive device 75, a combustion stoker drive device 76, a post-combustion stoker drive device 77, flow rate adjustment damper devices 85 to 88 related to the primary combustion air supply, a flow rate adjustment damper device 92 related to the secondary combustion air supply, a flow rate adjustment damper device 97 related to the recirculated exhaust gas supply, a drive motor 116, and non-contact moisture meters 145, 148.

In the control device 201, the memory 201b 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 145b (microwave transmitter/receiver 148a) for the microwaves transmitted from the microwave transmitter 145a (microwave transmitter/receiver 148a, 108a), and other data necessary for combustion control, etc. In the control device 201, the CPU 201a reads the predetermined programs and various data stored in the memory 201b and executes predetermined processing, thereby exerting the functions of the various functional units as shown in the functional block diagram of FIG. 6.

Figure 6 is a functional block diagram of a control system for a sludge incineration facility according to one embodiment of the present invention. The various functional units of the control device 201 shown in the functional block diagram of Figure 6 include a moisture percentage calculation unit 210.

The moisture percentage calculation unit 210 shown in FIG. 6 reads data such as that shown in FIG. 7 that is pre-stored in memory 201b (see FIG. 5), and calculates the moisture percentage of the sludge 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 sludge and air, etc.) of the measurement object (sludge in the casing 100) of the non-contact moisture meter 145, 148 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 line up 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, sludge with various moisture content values known in advance is measured for the volumetric filling rate at each moisture content, the microwave amplitude change and phase difference are measured, 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 are measured. The slope of the amplitude change and phase difference (amplitude-phase ratio) is calculated, and the calculated slope value is applied to the previously calculated relationship between the slope (amplitude-phase ratio) and the moisture percentage, i.e., the graph shown in Figure 7. This makes it possible to accurately calculate the moisture percentage without being affected by changes in the volume filling rate of the object to be measured.

When a non-contact moisture meter 145 of the transmission type is used, the moisture content calculation unit 210 shown in FIG. 6 reads from the memory 201b (see FIG. 5) data (see FIG. 7) on the positive correlation between the amplitude and phase ratio of the microwaves transmitted from the microwave transmission unit 145a and received by the microwave reception unit 145b, and the official moisture content (dry weight method), which data is stored in advance in the memory 201b, and calculates the moisture content of the sludge in the casing 100 based on the read data and the amplitude and phase ratio of the microwaves received by the microwave reception unit 145b.

When a reflective non-contact moisture meter 148 is used, the moisture content calculation unit 210 shown in FIG. 6 reads from memory 201b data (see FIG. 7) on the positive correlation between the amplitude phase ratio and the official moisture content (dry weight method) for the microwaves received by the microwave transmitting/receiving unit 148a relative to the microwaves transmitted from the microwave transmitting/receiving unit 148a, which data is stored in advance in memory 201b, and calculates the moisture content of the sludge in the casing 100 based on the read data and the microwaves received by the microwave transmitting/receiving unit 148a.

The various functional units of the control device 201 shown in the functional block diagram of FIG. 6 include, in addition to the moisture percentage calculation unit 210, a temperature measurement unit 211, a motor control unit 212, a heat exchanger control unit 213, a feeder control unit 214, a pump control unit 215, a pusher control unit 216, a stoker control unit 217, a damper control unit 218, and a memory unit 220.

The temperature measurement unit 211 calculates the temperature inside the furnace body 50 based on the detection signal from the furnace temperature sensor 58.

The motor control unit 212 transmits a predetermined control signal to the drive motor 27 based on the moisture content of the sludge measured by the non-contact moisture meters 145 and 148. This controls the rotation speed of the heat transfer body 13, and the drying time for the dewatered sludge in the dewatered sludge dryer 10 can be adjusted.

The heat exchanger control unit 213 transmits a predetermined control signal to the heat exchanger 29 based on the moisture content of the sludge measured by the non-contact moisture meters 145 and 148. This controls the amount of heat exchanged in the heat exchanger 29, and makes it possible to adjust the drying temperature for the dehydrated sludge in the dehydrated sludge dryer 10.

The feeder control unit 214 transmits a predetermined control signal to the feeder 32 based on the moisture content of the sludge measured by the non-contact moisture meters 145 and 148. This controls the amount of dewatered sludge stored in the dewatered sludge storage tank 31 to adjust the amount of dewatered sludge supplied to the dewatered sludge dryer 10.

The pump control unit 215 transmits a predetermined control signal to the dewatered sludge supply pump 33 based on the moisture content of the sludge measured by the non-contact moisture meters 145, 148. This controls the amount of dewatered sludge discharged from the dewatered sludge supply pump 33, and adjusts the amount of dewatered sludge supplied to the dewatered sludge dryer 10.

The pusher control unit 216 transmits a predetermined control signal to the pusher drive device 66 based on the moisture content of the sludge measured by the non-contact moisture meters 145, 148. This adjusts the stroke, operating speed, and operating interval of the pusher 65, thereby controlling the amount of dried sludge supplied to the furnace body 50.

The stoker control unit 217 transmits a predetermined control signal to the drying stoker drive unit 75, the combustion stoker drive unit 76, and the post-combustion stoker drive unit 77 based on the moisture content of the sludge measured by the non-contact moisture meters 145 and 148. This controls the speed at which the movable grates 70a of the drying stoker 71, the combustion stoker 72, and the post-combustion stoker 73 reciprocate, i.e., the speed at which the dried sludge is fed through the furnace body 50 by the stokers 71, 72, and 73.

The damper control unit 218 transmits a predetermined control signal to each flow rate adjustment damper device 85-88, 92, 97 based on the moisture content of the sludge measured by the non-contact moisture meters 145, 148. This controls the supply amount of primary combustion air, secondary combustion air, and recirculated exhaust gas.

The memory unit 220 functions as a storage device that holds data used by the CPU 201a when performing predetermined calculation processing, as well as other data necessary for combustion control, etc.

<Basic operation explanation>
In the sludge incineration plant 1 shown in Fig. 1 configured as described above, the dewatered sludge stored in the dewatered sludge storage tank 31 is fed by the feeder 32, and the fed dewatered sludge is pumped to the sludge receiving port 15 of the dewatered sludge dryer 10 by the dewatered sludge supply pump 33. The dewatered sludge pumped to the sludge receiving port 15 is fed into the trough 12 through the sludge receiving port 15. The dewatered sludge fed into the trough 12 is transported toward the sludge discharge port 16 of the trough 12 by the rotation of the heat transfer body 13 heated by the heat medium, and is heated and dried by the trough 12 and the heat transfer body 13 while being transported, to become dried sludge.

The dried sludge discharged from the sludge discharge port 16 is transported by the sludge transport conveyor 36 to the dried sludge storage tank 35 where it is temporarily stored. The dried sludge stored in the dried sludge storage tank 35 is cut out by the dried sludge cut-out device 38, and the cut-out dried sludge is supplied to the hopper 56 by the sludge transport conveyor 40.

Dried sludge discharged from the discharge port 103 of the sludge transport conveyor 40 is fed into the hopper 56. The dried sludge fed into the hopper 56 is supplied to the primary combustion chamber 51 via the chute section 56b and combusted.

Next, we will explain the moisture content measurement process and combustion state control process carried out in the sludge incineration equipment 1.

<Moisture content measurement process>
In the moisture content measuring step, the moisture content of the dried sludge being transported by the sludge transport conveyor 40 is measured by a non-contact moisture meter 145 (148).

<Combustion state control process>
In the combustion state control step, the combustion state of the incinerator 2 is controlled based on the moisture percentage measured in the moisture percentage measurement step so that the temperature inside the furnace body 50 measured by the temperature measurement unit 211 based on the detection signal from the furnace temperature sensor 58 is within a predetermined range (e.g., 850 to 900°C) that can suppress the generation of clinker while suppressing the generation of NOx. Specific examples of controlling the combustion state include the following specific examples (1) to (9).

[Specific Example (1)]
For example, if an increasing or decreasing trend in the heat generation rate of the dried sludge can be predicted from the moisture content of the dried sludge measured by the non-contact moisture meter 145 (148), the feeder control unit 214 sends a predetermined control signal to the feeder 32. In addition, the pump control unit 215 sends a predetermined control signal to the dewatered sludge supply pump 33. In this way, the amount of dewatered sludge fed to the dewatered sludge dryer 10 is adjusted by controlling the amount of dewatered sludge fed from the dewatered sludge storage tank 31 and the amount of dewatered sludge fed from the dewatered sludge supply pump 33. This adjusts the amount of dried sludge supplied from the dewatered sludge dryer 10 to the incinerator 2 via the mud transport conveyor 36, the dried sludge storage tank 35, the dried sludge excavation device 38, and the sludge transport conveyor 40, thereby adjusting the amount of heat generated in the incinerator 2, suppressing excessive combustion or poor combustion, and stabilizing the combustion operation of the incinerator 2 so that the furnace temperature of the incinerator 2 is within a specified range (e.g., 850 to 900°C).

[Specific Example (2)]
For example, if the tendency of the heat generation amount of the dried sludge to increase or decrease can be predicted from the moisture content of the dried sludge measured by the non-contact moisture meter 145 (148), the heat exchanger control unit 213 transmits a predetermined control signal to the heat exchanger 29, controls the amount of heat exchange in the heat exchanger 29, and adjusts the drying temperature for the dehydrated sludge in the dehydrated sludge dryer 10. In this way, the moisture content of the dried sludge to be dried in the dehydrated sludge dryer 10 is adjusted. This adjusts the moisture content of the dried sludge supplied from the dehydrated sludge dryer 10 to the incinerator 2 via the mud conveyor 36, the dried sludge storage tank 35, the dried sludge cut-out device 38, and the sludge conveyor 40, making it possible to adjust the heat generation amount in the incinerator 2, suppress excessive combustion or poor combustion, and stabilize the combustion operation of the incinerator 2 so that the furnace temperature of the incinerator 2 is within a predetermined range (for example, 850 to 900 ° C).

[Specific Example (3)]
For example, if the tendency of the heat generation amount of the dried sludge to increase or decrease can be predicted from the moisture content of the dried sludge measured by the non-contact moisture meter 145 (148), the motor control unit 212 transmits a predetermined control signal to the drive motor 27, controls the rotation speed of the heat transfer body 13, and adjusts the drying time for the dewatered sludge in the dewatered sludge dryer 10. In this way, the moisture content of the dried sludge to be dried in the dewatered sludge dryer 10 is adjusted. As a result, the moisture content of the dried sludge supplied from the dewatered sludge dryer 10 to the incinerator 2 via the mud conveyor 36, the dried sludge storage tank 35, the dried sludge cut-out device 38, and the sludge conveyor 40 is adjusted, so that the heat generation amount in the incinerator 2 can be adjusted, excessive combustion or poor combustion can be suppressed, and the combustion operation of the incinerator 2 can be stabilized so that the furnace temperature of the incinerator 2 is in a predetermined range (for example, 850 to 900 ° C.).

[Specific Example (4)]
For example, if an increasing or decreasing trend in the heat generation rate of the dried sludge can be predicted from the moisture content of the dried sludge measured by the non-contact moisture meter 145 (148), the motor control unit 212 sends a predetermined control signal to the drive motor 116 (see FIG. 2(a)) to adjust the amount of dewatered sludge transported by the sludge transport conveyor 40. This adjusts the amount of dried sludge supplied to the incinerator 2, making it possible to adjust the amount of heat generated in the incinerator 2, suppress excessive combustion or poor combustion, and stabilize the combustion operation of the incinerator 2 so that the furnace temperature of the incinerator 2 is within a predetermined range (e.g., 850 to 900°C).

[Specific Example (5)]
For example, if an increasing or decreasing trend in the heat generation amount of the dried sludge can be predicted from the moisture content of the dried sludge measured by the non-contact moisture meter 145 (148), the pusher control unit 216 transmits a predetermined control signal to the pusher driving device 66 to adjust the amount of dried sludge supplied to the combustion chamber 51. This makes it possible to adjust the heat generation amount in the incinerator 2, suppress excessive combustion or poor combustion, and stabilize the combustion operation of the incinerator 2 so that the furnace temperature of the incinerator 2 is within a predetermined range (for example, 850 to 900°C).

[Specific Example (6)]
For example, if the tendency of the heat generation amount of the dried sludge to increase or decrease can be predicted from the moisture content of the dried sludge measured by the non-contact moisture meter 145 (148), the stoker control unit 217 transmits a predetermined control signal to at least one of the drying stoker driving device 75, the combustion stoker driving device 76, and the post-combustion stoker driving device 77 to adjust the feed speed of the dried sludge by the movable grate 70a. This makes it possible to adjust the heat generation amount in the incinerator 2, suppress excessive combustion or poor combustion, and stabilize the combustion operation of the incinerator 2 so that the furnace temperature of the incinerator 2 is within a predetermined range (for example, 850 to 900°C).

[Specific Example (7)]
For example, if the moisture content of the dried sludge measured by the non-contact moisture meter 145 (148) can predict an increasing or decreasing trend in the heat generation rate of the dried sludge, the damper control unit 218 will transmit the information to the flow rate adjustment damper devices 85-88, 92 to adjust the damper opening of each of the flow rate adjustment damper devices 85-88, 92. This adjusts the amount of combustion air supplied, making it possible to adjust the heat generation rate in the incinerator 2, suppress excessive combustion or poor combustion, and stabilize the combustion operation of the incinerator 2 so that the furnace temperature of the incinerator 2 is within a predetermined range (for example, 850 to 900°C).

[Specific Example (8)]
For example, if an increasing or decreasing trend in the heat generation rate of the dried sludge can be predicted from the moisture content of the dried sludge measured by the non-contact moisture meter 145 (148), the damper control unit 218 transmits a predetermined control signal to the flow rate adjustment damper device 97 to adjust the damper opening of the flow rate adjustment damper device 97. This adjusts the supply amount of recirculated exhaust gas, making it possible to adjust the heat generation rate in the incinerator 2, suppress excessive combustion or poor combustion, and stabilize the combustion operation of the incinerator 2 so that the furnace temperature of the incinerator 2 is within a predetermined range (for example, 850 to 900°C).

[Specific example (9)]
For example, if an increasing or decreasing trend in the heat generation rate of the dried sludge can be predicted from the moisture content of the dried sludge measured by the non-contact moisture meter 145 (148), the damper control unit 218 transmits a predetermined control signal to the flow rate adjustment damper device 92 to adjust the damper opening of the flow rate adjustment damper device 92. This adjusts the amount of combustion air supplied, making it possible to adjust the heat generation rate in the incinerator 2, suppress excessive combustion or poor combustion, and stabilize the combustion operation of the incinerator 2 so that the furnace temperature of the incinerator 2 is within a predetermined range (for example, 850 to 900°C).

The above-mentioned combustion control stabilizes the temperature and exhaust gas volume inside the furnace body 50, stabilizing the combustion operation of the incinerator 2. This makes it possible to suppress the generation of clinker. Furthermore, stabilizing the combustion operation stabilizes the amount of steam generated in the boiler 3, and therefore the amount of heat recovered. If you want to suppress the amount of steam generated in the boiler 3, you can simply put sludge with a high moisture content into the hopper 56. Furthermore, stabilizing the combustion operation stabilizes the load on various equipment, reducing equipment wear and the amount of operation. Reducing the amount of operation reduces power costs. Furthermore, by automating the combustion control and utilizing the learning function of AI (artificial intelligence), more optimal combustion operation can be achieved, making it possible to significantly reduce operating costs.

In addition, in the sludge incineration system 1, a non-contact moisture meter 145 (148) is used to measure the moisture content of the sludge based on correlation data (see FIG. 7) between the amplitude phase ratio of the microwaves transmitted through the sludge and the official moisture content. By measuring the moisture content based on the amplitude phase ratio in this way, the moisture content of the sludge can be measured with high accuracy without being affected by fluctuations in the volumetric filling rate of the object to be measured (the sludge in the casing 100), thereby achieving more stable combustion control.

The sludge incineration equipment and sludge incineration method of the present invention have been described above based on one embodiment, but the present invention is not limited to the configuration described in the above embodiment, and the configuration can be changed as appropriate within the scope of the spirit of the invention. Specific alternative embodiments are as follows.

Figures 8 to 11 are schematic diagrams illustrating other embodiments of the sludge incineration system of the present invention. Note that in each of the other embodiments described below, parts that are the same as or similar to the above embodiment will be given the same reference numerals in the figures and detailed descriptions will be omitted. The following description will focus on the parts that are unique to each of the other embodiments.

[Another embodiment (1)]
In another embodiment (1) shown in FIG. 8(a), a sludge transport conveyor 40 to which a dewatered sludge injector 300 is attached is provided in parallel with a sludge transport conveyor 40 for transporting dried sludge from a dried sludge storage tank 35. The dewatered sludge injector 300 includes a dewatered sludge storage tank 301 for storing dewatered sludge, and a feeder 302 attached to the dewatered sludge storage tank 301, and the dewatered sludge stored in the dewatered sludge storage tank 301 is fed by the feeder 302. The fed dewatered sludge is transported from an inlet 102 of the sludge transport conveyor 40 to an outlet 103 located above the hopper 56. The dewatered sludge and dried sludge transported by each sludge transport conveyor 40 are mixed in a mixer 310, and the mixed dewatered sludge and dried sludge (mixed sludge) is fed into the hopper 56.

In another embodiment (1) shown in FIG. 8(a), a non-contact moisture meter 145 (148) is provided on each sludge transport conveyor 40, and a non-contact moisture meter 145 (148) is provided on the mixer 310 to measure the moisture content of the mixed sludge after mixing in the mixer 310. In this case, the moisture content of each sludge before mixing is measured using the non-contact moisture meter 145 (148) provided on each sludge transport conveyor 40, and based on the measurement result, the optimal mixing ratio of each sludge to make the moisture content of the mixed sludge a desired value is calculated, and each sludge is introduced into the mixer 310 according to the calculated mixing ratio, and each introduced sludge is mixed in the mixer 310. In this way, the moisture content of the mixed sludge can be brought closer to the desired moisture content. The actual moisture content of the mixed sludge is then measured using a non-contact moisture meter 145 (148) installed in the mixer 310 for measuring the moisture content of the mixed sludge, and the combustion state of the incinerator 2 is controlled based on the measurement results, as exemplified above.

[Another embodiment (2)]
In another embodiment (2) shown in Figure 8 (b), a sludge transport conveyor 40 for transporting dewatered sludge from the dewatered sludge storage tank 301 and a sludge transport conveyor 40 for transporting dried sludge from the dried sludge storage tank 35 are arranged in parallel, and the dewatered sludge and dried sludge transported by each sludge transport conveyor 40 are separately and independently charged into a hopper 56. In this case, the combustion state of the incinerator 2 is controlled as exemplified above, based on the measurement results by the non-contact moisture meter 145 (148) arranged on each sludge transport conveyor 40.

[Another embodiment (3)]
In another embodiment (3) shown in FIG. 9(a), an additive transport conveyor 400 to which a chemical supply device 320 is attached is provided in parallel with a sludge transport conveyor 40 that transports dried sludge from a dried sludge storage tank 35. The chemical supply device 320 includes a chemical tank 321 for storing chemicals, a feeder 322 attached to the chemical tank 321, and a chemical supply pipe 323 arranged between the feeder 322 and the additive transport conveyor 400, and is configured to feed the chemicals stored in the chemical tank 321 by the feeder 322 and to supply the fed chemicals to the inside of the additive transport conveyor 400 via the chemical supply pipe 323. On the other hand, the additive transport conveyor 400 is configured by arranging a belt conveyor in a casing, and is configured by arranging a non-contact moisture meter 145 (148) in the casing, similar to the sludge transport conveyor 40. Here, the additives supplied to the hopper 56 by the additive transport conveyor 400 include, for example, combustible material indicated by symbol K in Fig. 9(a) to which an agent from the agent supply device 320 has been attached. The agent includes, for example, a clinker inhibitor. The clinker inhibitor includes, for example, one or more of a magnesium compound, a silicon compound, a calcium compound, an iron compound, and an aluminum compound, and a dispersion or an aqueous solution thereof.

The dewatered sludge transported by the sludge transport conveyor 40 and the additives transported by the additive transport conveyor 400 are mixed in the mixer 310, and the mixed dewatered sludge and additives (mixed sludge) are fed into the hopper 56.

In another embodiment (3) shown in FIG. 9(a), the moisture content of the dried sludge is measured using a non-contact moisture meter 145 (148) arranged on the sludge transport conveyor 40, and the moisture content of the additive is measured using a non-contact moisture meter 145 (148) arranged on the additive transport conveyor 400. Based on the measurement results, the optimal mixing ratio of the dried sludge and the additive is calculated to make the moisture content of the mixed sludge a desired value, and the dried sludge and the additive are introduced into the mixer 310 according to the calculated mixing ratio, and the introduced dried sludge and the additive are mixed in the mixer 310. In this way, the moisture content of the mixed sludge can be brought close to the desired moisture content. Then, the actual moisture content of the mixed sludge is measured using a non-contact moisture meter 145 (148) arranged on the mixer 310 for measuring the moisture content of the mixed sludge, and the combustion state of the incinerator 2 is controlled based on the measurement results, as exemplified above.

[Another embodiment (4)]
In another embodiment (4) shown in Fig. 9(b), an additive transport conveyor 400 for transporting the additives with chemicals attached thereto from the chemical supply device 320 and a sludge transport conveyor 40 for transporting the dried sludge from the dried sludge storage tank 35 are arranged in parallel, and the additives and the dried sludge transported by each transport conveyor 40, 400 are separately and independently fed into the hopper 56. In this case, the combustion state of the incinerator 2 is controlled as exemplified above, based on the measurement results by the non-contact moisture meter 145 (148) arranged on each transport conveyor 40, 400.

[Another embodiment (5)]
In another embodiment (5) shown in Figure 10, dewatered sludge extracted from the dewatered sludge storage tank 31 by a feeder 32 and additives transported by an additive transport conveyor 400 are pressurized by a dewatered sludge supply pump 33 to the sludge receiving inlet 15 of the dewatered sludge dryer 10, and the dewatered sludge and additives introduced into the dewatered sludge dryer 10 through the sludge receiving inlet 15 are mixed and dried by the dewatered sludge dryer 10.

In another embodiment (5) shown in FIG. 10, the moisture content of the additives is measured using a non-contact moisture meter 145 (148) arranged on the additive transport conveyor 400, and based on the measurement results, the optimal mixing ratio of the dewatered sludge and additives to make the moisture content of the mixed sludge a desired value is calculated, and the dewatered sludge and additives are introduced into the dewatered sludge dryer 10 according to the calculated mixing ratio. In this way, the moisture content of the dried sludge after the drying process in the dewatered sludge dryer 10 can be made close to the desired moisture content. Then, the actual moisture content of the dried sludge is measured using a non-contact moisture meter 145 (148) arranged on the sludge transport conveyor 40, and based on the measurement results, the combustion state of the incinerator 2 is controlled as exemplified above.

[Another embodiment (6)]
In another embodiment (6) shown in Fig. 11, the additives transported by the additive transport conveyor 400 are introduced into the dewatered sludge dryer 10 through an inlet provided upstream of the sludge receiving inlet 15 in the trough 12 of the dewatered sludge dryer 10, mixed with the dewatered sludge introduced into the dewatered sludge dryer 10 through the sludge receiving inlet 15, and the mixed dewatered sludge and additives (mixed sludge) are dried by the dewatered sludge dryer 10. The moisture content of the dried sludge after the drying process in the dewatered sludge dryer 10 is measured using a non-contact moisture meter 145 (148) arranged on the sludge transport conveyor 40, and the combustion state of the incinerator 2 is controlled based on the measurement result, as exemplified above.

[Another embodiment (7)]
In the embodiment shown in Figure 1 and each of the other embodiments (5) and (6) shown in Figures 10 and 11, a non-contact moisture meter 145 (148) may be arranged upstream of the dewatered sludge dryer 10 to measure the moisture content of the dewatered sludge introduced into the dewatered sludge dryer 10.

The sludge incineration equipment and sludge incineration method of the present invention can be used for incinerating sludge.

1 Sludge incineration equipment 2 Incinerator 10 Dewatered sludge dryer 40 Sludge transport conveyor (sludge supply means)
51 Primary combustion chamber 52 Secondary combustion chamber 55 Sludge supply device 70a Movable grate 70b Fixed grate 85 to 88 Flow rate control damper device (damper for primary combustion air)
92 Flow rate control damper device (damper for secondary combustion air)
97 Flow rate control damper device (damper for recirculated exhaust gas)
100 Casing 140 Opening 141 Electromagnetic wave transmitting member 145 Non-contact moisture meter (transmission type)
148 Non-contact moisture meter (reflection type)
151 Heater (means for preventing condensation, means for removing water droplets)
155 Wiper device (water droplet removal means)
161 Air blowing device (condensation prevention means, water droplet removal means)
161' Air blowing device (condensation prevention means, water droplet removal means)
165 Coating 201 Control device (combustion state control means)

Claims (5)

A sludge incineration facility in which sludge is supplied to an incinerator by a sludge supplying means and incinerated,
a non-contact moisture meter that irradiates electromagnetic waves onto the sludge to be supplied to the incinerator to measure the moisture content of the sludge;
A combustion state control means for controlling the combustion state of the incinerator based on the moisture content measured by the non-contact moisture meter;
Equipped with
The sludge supplying means is
a casing for containing sludge;
an electromagnetic wave transmitting member attached to an opening provided in the casing;
Equipped with
The sludge transported by the flight conveyor in the casing is irradiated with electromagnetic waves through the electromagnetic wave transmitting member,
A sludge incineration facility equipped with an air blowing device comprising an air blowing nozzle that blows compressed air along the surface of the electromagnetic wave transparent member facing the sludge in the casing, or an air blowing nozzle that blows compressed air toward the surface. The sludge incineration facility according to claim 1, wherein the electromagnetic wave transparent member has water repellency. The sludge incineration facility according to claim 1 or 2, wherein the combustion state control means controls the combustion state of the incinerator by adjusting the amount of sludge supplied to the incinerator by the sludge supply means. The incinerator has a combustion chamber for burning sludge, and at least one of a sludge supply device for supplying sludge into the combustion chamber, a fire grate for sending sludge into the combustion chamber, a combustion air damper for adjusting the amount of combustion air supplied into the combustion chamber, and a recirculated exhaust gas damper for adjusting the amount of recirculated exhaust gas supplied into the combustion chamber,
The sludge incineration equipment according to any one of claims 1 to 3, wherein the combustion state control means controls the combustion state of the incinerator by adjusting at least one of the amount of sludge supplied into the combustion chamber by the sludge supply device, the sludge transport speed within the combustion chamber by the grate, the amount of combustion air supplied into the combustion chamber by the combustion air damper, and the amount of recirculated exhaust gas supplied into the combustion chamber by the recirculated exhaust gas damper. The dewatered sludge dryer dries the dewatered sludge, which is the sludge after the dewatering process.
The dewatered sludge dryer is configured to supply dried sludge to the incinerator by the sludge supplying means,
A sludge incineration equipment as described in any one of claims 1 to 4, wherein the combustion state control means controls the combustion state of the incinerator by adjusting at least one of the amount of dewatered sludge supplied to the dewatered sludge dryer, the drying temperature for the dewatered sludge in the dewatered sludge dryer, and the drying time for the dewatered sludge in the dewatered sludge dryer.

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