JP2019178847A - Waste moisture percentage measuring apparatus, stoker-type waste incinerator, waste moisture percentage measuring method, and waste incineration method - Google Patents

Abstract

To provide a waste moisture percentage measuring apparatus and waste moisture percentage measuring method which can acquire the moisture percentage of wastes just before fed into a combustion chamber and control the operation of a waste incinerator in an adequate operation condition.SOLUTION: A chute 15 by which wastes P are fell and supplied into a combustion chamber 13 has a pair of parallel wall parts 15A, 15B, and is provided with a moisture percentage meter 20 for measuring the moisture percentage of the wastes in the chute 15. The moisture percentage meter 20 is a type of a microwave transmission, and has a transmitting part 20A-2 which transmits microwave and a receiving part 20B-2 which receives the microwave. The transmitting part is placed in a window part 17B formed in one of the pair of the parallel wall parts 15A, 15B of the chute 15, and the receiving part 20B-2 is placed in a window part 17B formed in the other parallel wall part 15B. A transmission frequency of the transmitting part 20A-2 is equal to or more than 15 MHz and equal to or less than 120 MHz.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a waste water content measuring device and a waste water content measuring method for measuring the water content in order to incinerate waste according to the water content as a property of waste, and incineration waste such as municipal waste. The present invention relates to a grate-type waste incinerator and a waste incineration method.

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

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

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

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

  In the combustion of waste in such a waste incinerator, in recent years, there has been an increasing interest in the recovery of thermal energy generated by incineration of waste in a waste incinerator, and steam is generated by this thermal energy. The number of waste incinerators installed with boiler power generation equipment to be driven increases, and a combustion operation capable of realizing heat recovery with high efficiency is required. On the other hand, as regulations on environmental pollutants released from the waste incinerator to the atmosphere become stricter, a combustion operation for reducing emission of harmful substances derived from combustion such as dioxins and nitrogen oxides is also required.

  Thus, since advanced combustion operation control is desired for a waste incinerator, conventionally, operation control that satisfies the above-described requirements has been performed by an automatic combustion control device. In this automatic combustion control device, when the incinerator is, for example, a stoker type incinerator, the operation amount of dust supply (waste supply to the grate), combustion grate feed rate, combustion air amount, cooling air amount, etc. In order to stabilize the amount of steam generated and to control the concentration of dioxins and nitrogen oxides in the exhaust gas, and to reduce the unburned components in the ash, the waste should be stably burned. It is driving. However, such conventional combustion control does not monitor the properties of the waste at the time of the introduction of the waste, and does not monitor the combustion gas temperature, oxygen concentration in the combustion gas, carbon monoxide in the combustion gas. It is a method of detecting the concentration as a factor to monitor and feeding back to the control value of each manipulated variable.Therefore, it becomes a follow-up type control, and this fluctuation is changed when the property of the waste put into the incinerator fluctuates. Tracking may be delayed, and stable operation control may not always be achieved.

  A major factor that disturbs the stability of the combustion operation of a waste incinerator is that the amount of heat generated from the waste fluctuates because the properties of the input waste are not constant. Since the properties of the waste thrown into the incinerator vary greatly depending on the area where the waste is collected, the time of collection, the weather, and the season, the calorific value of the waste varies greatly. Therefore, Patent Document 1 proposes a control method for a waste incinerator in which the properties of the waste to be charged are obtained before being charged, and combustion control is performed based on the properties of the obtained waste. Among the properties of waste, the factor that greatly affects the heat generation amount is the moisture content of the waste. In Patent Document 1, the middle portion in the height direction of the chute hanging from the inlet of the waste incinerator toward the combustion chamber A capacitance meter is disposed as a moisture meter, and the moisture content of the waste is obtained by measuring the capacitance of the waste between the pair of electrodes. The capacitance meter is connected to a moisture content calculator that has a correspondence relationship between the capacitance value and the moisture content, and the above correspondence relationship is obtained from the measured value measured by the capacitance meter. Based on this, the moisture content can be calculated.

JP2010-216990

  There are not only a wide variety of wastes, but there are also local wastes with a high moisture content in the chute. In a chute that supplies waste to an incinerator, the moisture content of the waste before incineration is measured, but the distribution of the moisture content of the waste in the chute varies.

  According to Patent Document 1, a capacitance moisture meter is attached to a chute to measure the moisture content of waste, but the moisture content is measured for waste in a region close to the portion in contact with the sensor unit. , The range of waste that can measure the moisture content of the waste in the chute is narrowed, and the moisture content cannot be accurately measured for the entire waste thrown into the incinerator via the chute, There was a problem that the calorific value could not be accurately grasped. Even when a plurality of sensor portions are arranged on the chute, no particular consideration has been given to how much moisture in the waste can be measured relative to the chute width to sufficiently grasp the heat generation amount of the waste.

  As the moisture meter, a microwave transmission moisture meter is known in addition to the capacitance moisture meter described above. This microwave transmission moisture meter is an attenuation format that measures the moisture content of waste from the attenuation rate of the received microwave by transmitting the transmitted microwave to the waste, and widens the range of waste that can be measured Since it can be secured, it is suitable for measurement when the moisture content is unevenly distributed, such as waste in a chute.

  When measuring the moisture content of waste with an attenuation-type microwave transmission moisture meter, the transmission characteristics and attenuation characteristics in the waste may differ depending on the transmitted microwave frequency. Therefore, it is required to measure the moisture content at a suitable transmission microwave frequency capable of measuring the moisture content of the waste in the chute with high sensitivity and accuracy, but the appropriate range of the transmission microwave frequency is required. There is not enough consideration.

  In addition, for stable combustion of waste in the combustion chamber, the moisture content of the waste supplied to the combustion chamber is accurately measured, and the calorific value of the waste is calculated and grasped from the measured moisture content. When the calorific value fluctuates, it is necessary to grasp the fluctuation of the waste heat generation amount and cope with the fluctuation of the waste heat generation amount.

  If the control of the operating conditions of the waste incinerator such as the primary air supply amount is not properly handled following the fluctuation of the heat generation amount of the waste, the combustion of the waste becomes unstable and the Problems that the amount of steam generated by heat recovery fluctuates, or that the temperature and gas composition of combustion exhaust gas cannot be maintained within a predetermined appropriate range, and the CO concentration and NOx concentration in the exhaust gas increase. Occurs.

  However, in a situation where the moisture content of waste cannot be measured accurately, fluctuations in waste heat generation cannot be ascertained. May fluctuate or the concentration of harmful substances in the exhaust gas may increase.

  In view of such circumstances, the present invention can accurately measure the moisture content of the waste when measuring the moisture content of the waste in the chute using a microwave transmission moisture meter, and change the amount of waste heat generated. It is an object of the present invention to provide a waste water content measuring apparatus and a waste water content measuring method capable of grasping the above and controlling the operation of a waste incinerator under appropriate operating conditions.

  In order to perform measurement using a microwave transmission moisture meter, a microwave transmitter and a receiver are installed on opposite wall surfaces of the chute. Since the microwave has a characteristic of being absorbed by moisture, the microwave transmitted from the transmitter is attenuated by moisture in the waste when passing through the waste, and is received by the receiver disposed on the other wall surface of the chute. To reach. By measuring the attenuation rate of this microwave, the moisture content contained in the waste can be measured, and this method is called an attenuation type.

  The present invention relates to a waste moisture content measuring apparatus and method using an attenuation type microwave transmission moisture meter.

  The present invention that provides such a function is configured as follows as a waste water content measuring device, a grate-type waste incinerator, a waste water content measuring method, and a waste incineration method.

<First invention: Waste water content measuring device>
A chute for supplying waste to the combustion chamber has a pair of parallel walls facing each other in a lateral direction perpendicular to the direction in which the waste falls, and measuring the moisture content of the waste in the chute. In a waste water content measuring apparatus provided with a moisture meter on the chute,
The moisture meter is a microwave transmission moisture meter having a transmitter for transmitting microwaves and a receiver for receiving the microwaves, and is formed on one of a pair of parallel wall portions of the chute. A waste water content measuring device, wherein a transmitter is disposed in the window portion formed and a receiver is disposed in the window portion formed on the other, and the transmitter microwave frequency is 15 MHz or more and 120 MHz or less. .

<Second invention: Waste incinerator>
A grate-type waste incinerator comprising a grate and a combustion chamber for burning waste on the grate, and primary air blowing means for blowing combustion primary air into the combustion chamber from under the grate In a waste incinerator having a dust feeder for supplying waste on a grate,
Incineration based on the waste water content measuring device of the first invention and the waste water content measured value measured by the waste water content measuring device or the waste heat value calculated from the water content measured value A waste incinerator comprising a control device for controlling operating conditions of the furnace.

  In the present invention, the control device preferably controls at least one of the dust supply waste supply speed, the grate waste conveyance speed, and the combustion primary air supply amount as the operation condition of the incinerator. .

<Third invention: Waste water content measuring method>
A chute for supplying waste to the combustion chamber has a pair of parallel walls facing each other in a lateral direction perpendicular to the direction in which the waste falls, and measuring the moisture content of the waste in the chute. In the waste water content measuring method by the waste water content measuring device provided with a moisture content meter on the chute,
A microwave transmission moisture meter is used as a moisture meter, a window formed on one of a pair of parallel wall portions of a chute, a transmission portion of the moisture meter, and a window formed on the other parallel wall portion The moisture content meter is characterized in that a receiving portion of the moisture content meter is disposed in a portion, a microwave having a transmitted microwave frequency of 15 MHz or more and 120 MHz or more is transmitted from the transmitting portion, and the microwave is received by the receiving portion. Measuring method.

<Fourth Invention: Waste Incineration Method>
A waste incineration method using a grate-type waste incinerator, in which waste is burned on a grate provided in a combustion chamber, waste is supplied onto the grate by a dust feeder, and primary air for combustion In a waste incineration method using a grate-type waste incinerator that blows into the combustion chamber from under the grate,
Measure the moisture content of the waste by the waste moisture content measuring method of the third invention, and incinerate based on the measured moisture content measurement value of the waste or the calorific value calculation value of the waste calculated from the measured moisture content value A waste incineration method using a grate-type waste incinerator characterized in that the operating conditions of the furnace are controlled by a control device.

  In the present invention, the control by the control device is performed for at least one of the dust supply waste supply speed, the grate waste transport speed, and the combustion primary air supply amount as the operating condition of the incinerator. Is preferred.

<Invention Principle>
In such a waste fraction measuring apparatus and waste moisture measuring method of the present invention, the principle of the microwave transmission moisture meter is that when microwaves pass through the waste in the chute. Attenuation due to moisture is measured to measure the moisture content of waste. The microwave intensity transmitted and received by the receiver is measured, the difference between the transmitted intensity and the received intensity is measured as an attenuation amount, for example, a differential voltage value, and a predetermined correspondence between the differential voltage value and the moisture content The moisture content is obtained from the relationship. The greater the differential voltage value, the greater the attenuation of microwaves due to moisture in the waste, and the higher the moisture content, and the smaller the moisture voltage value, the lower the waste moisture content.

  Microwaves are more attenuated as the moisture content of the waste is higher, but even in the case of the same moisture content, the transmission characteristics and attenuation characteristics in the waste differ depending on the transmitted microwave frequency. Therefore, an investigation was conducted to find an appropriate range of the transmitted microwave frequency that can measure the moisture content of the waste in the chute with high sensitivity and high accuracy. For wastes having different moisture percentages, the attenuation of microwaves in the waste is measured at various transmission frequencies, and the moisture percentage is obtained from a predetermined correspondence between the attenuation and the moisture percentage. On the other hand, as another method for obtaining the moisture content, the calculated moisture content of the waste calculated based on the measured heat data of the exhaust gas from the waste incinerator is obtained. Compare the time-dependent change in moisture content from the microwave attenuation measurement obtained from the microwave transmission moisture meter and the time-dependent change in the calculated moisture content obtained from the exhaust gas heat data. The total time was examined and the ratio with respect to a predetermined period was evaluated as the coincidence rate (%). By evaluating with such a coincidence rate, it is possible to appropriately evaluate by excluding detailed influences due to instantaneous fluctuations and variations in moisture content. If the coincidence rate is 70% or more, the measured moisture content by microwave attenuation measurement means that the moisture content of the waste can be measured with high sensitivity and high accuracy. It was confirmed that control can be performed without any problem. For this reason, when a preferable range of the transmitted microwave frequency such that the coincidence rate is 70% or more is obtained, it has been found that it is appropriate to set the transmitted microwave frequency to 120 MHz or less. If the transmission microwave frequency is higher than 120 MHz, the coincidence rate is lower than 70%, which is not preferable. Based on such examination, it is preferable that the transmission microwave frequency of the microwave transmission moisture meter is 120 MHz or less.

  Also, the lower the transmission frequency of the microwave, the larger the size of the transmission part. Therefore, the lower the transmission frequency, the larger the notch part provided in the chute for taking a larger window for arranging the transmission part. Need to be larger. That is, when the transmission frequency is set to a low frequency, the transmission portion becomes a large transmission portion, and thus the size of the transmission portion is restricted by the size of the chute wall provided with the window portion.

  On the other hand, the structure of the chute of the grate-type waste incinerator is often as follows. The upper part of the chute is mostly a steel structure, and the lower part of the chute is often an inclined part, and it is a refractory structure so that it can withstand high heat from the combustion chamber. ing. Further, the chute parallel wall portion is provided with a chute opening / closing gate that closes in the chute and closes inflow of air from the hopper side to the combustion chamber. The area where the transmitter can be placed on the chute of the grate-type waste incinerator is below the lower end position of the chute opening / closing gate so as not to interfere with the operation of the chute opening / closing gate, and the upper end position of the refractory structure part of the chute It is the range of the steel structure part above. In many grate-type waste incinerators, the area in the height direction of the area where the transmission part can be arranged on this chute is 1500 to 2000 mm, and the transmission part having a maximum height of 2000 mm is provided. In this case, the transmission frequency is about 15 MHz. In other words, if the transmission frequency is not 15 MHz or more, the size of the transmission unit exceeds 2000 mm, and cannot be within the height direction range of the chute area where the transmission unit can be placed, satisfying the restrictions. You can't. For this reason, in many grate-type waste incinerators, in order to meet the restrictions on the size of the chute where the transmitter is placed, Is required to be 15 MHz or more. Based on such examination, it is preferable that the transmission microwave frequency of the microwave transmission moisture meter is 15 MHz or more.

  As a result of such studies, it has been clarified that the microwave transmission frequency of the microwave transmission moisture meter is preferably 15 MHz or more and 120 MHz or less.

  As described above, according to the present invention, in the apparatus and method for measuring the moisture content of the waste in the chute, the moisture meter is a microwave transmission moisture meter, the transmitter for transmitting microwaves, and the microwave A receiving portion for receiving a wave, a transmitting portion is disposed in a window portion formed in one of a pair of parallel wall portions of the chute, and a receiving portion is disposed in a window portion formed in the other parallel wall portion, Since the transmission microwave frequency of the transmitter is 15 MHz or more and 120 MHz or less, the range of the suitable transmission microwave frequency that can measure the moisture content of the waste in the chute with high sensitivity and accuracy is clarified. We were able to.

  Furthermore, in the grate-type waste incinerator and the waste incineration method of the present invention, by accurately measuring the moisture content of the waste in the chute, the heat generation amount of the waste can be accurately grasped, and the waste heat generation Since the waste can be stably combusted by appropriately controlling the operating conditions of the incinerator in response to fluctuations in the volume, fluctuations in the amount of steam generated by heat recovery from the exhaust gas can be suppressed. CO concentration and NOx concentration can be suppressed low.

It is a schematic block diagram of the waste incinerator apparatus as one Embodiment provided with the waste-water-content measuring apparatus of this invention. It is a longitudinal cross-sectional view which shows schematic structure of the moisture content measuring apparatus used for the apparatus of FIG. 2 is a comparative diagram showing the moisture voltage measured by the apparatus and the (calculated) moisture content obtained from the thermal data of the incinerator exhaust gas over time.

  FIG. 1 shows the configuration of a grate-type waste incinerator 1 (hereinafter referred to as a waste incinerator) as an example of a waste incinerator equipped with the moisture content measuring apparatus of the present invention. The present invention is applicable not only to the grate type but also to other types of waste incinerators.

  The waste incinerator 1 is provided with a grate 11 for burning while moving waste to the bottom of the combustion chamber 13, and combustion air for supplying combustion air into the combustion chamber 13 from below the grate 11. The combustion air is received from the supply pipe 9, and the waste P on the grate 11 is incinerated. The combustion air supply pipe 9 is provided with a blower 8 and a damper 10 as a combustion air supply amount adjusting mechanism. The grate 11 is configured to convey the waste P toward the right in FIG. 1 in conjunction with a drive mechanism (not shown). A dust supply device 14, for example, a pusher is provided at a position above the left end of the grate 11 so as to send waste to the grate 11. A chute 15 extends upward above the dust supply device 14, and a hopper 16 serving as a charging port is provided at the upper end thereof. A waste pit (not shown) is disposed outside the waste incinerator 1, and the waste P is taken out from the waste pit by a waste crane (not shown) to the hopper 16. It has come to drop.

  Operation amounts such as the combustion air supply amount supplied from the combustion air supply pipe 9, the waste conveyance speed of the grate 11 and the waste supply speed of the dust supply device 14 are variable, and will be described later. 30 is controlled.

  The chute 15 is formed in a vertically long cylindrical shape having a pair of parallel wall portions 15A and 15B. As shown in FIG. 1, a microwave transmission moisture meter 20 comprising a transmitting device 20A and a receiving device 20B is attached to the chute 15, and the moisture meter 20 sends a measurement signal to the control device 30. Is connected to the control device 30.

  As shown in the enlarged view of FIG. 2, the moisture meter 20 has a transmitter 20A attached to a window portion 17A formed on one wall portion 15A of the pair of parallel wall portions 15A and 15B of the chute 15. The receiving device 20B is attached to a window portion 17B formed on the other wall portion 15B. In this embodiment, when viewed in the horizontal direction in FIG. 2, the receiving device 20B is disposed at a position facing the transmitting device 20A and has the same shape and size as the transmitting unit.

  The transmitting device 20A includes a transmitting unit 20A-2 configured to transmit a microwave M disposed on the back side of the microwave transmitting material 20A-1 such as plastic positioned in the window portion 17A. The transmitting unit 20A- 2, the transmitter front surface faces the back surface of the microwave transmitting material 20 </ b> A- 1 toward the receiving device 20 </ b> B, and the transmitter and the rear surface of the transmitter 20 </ b> A- 2 are microplates such as iron plates. It is covered with a wave reflector 20A-3.

  Next, as in the case of the transmitting device 20A, the receiving device 20B is disposed on the back side of the microwave transmitting material 20B-1 such as plastic located in the window portion 17B and receives a microwave. 20B-2, and the receiving unit 20B-2 has the front surface of the receiving unit facing the back surface of the microwave transmitting material 20B-1 toward the transmitting device 20A, and the receiving unit 20B- 2 is covered with a microwave reflecting material 20B-3 such as an iron plate.

  The moisture content meter 20 is an attenuation-type moisture content meter in this embodiment, and is a voltage ratio (or voltage difference) between the reception microwave intensity at the reception unit 20B-2 and the transmission microwave intensity at the transmission unit 20A-2. ) That is, the voltage ratio (or voltage difference) of the reception voltage at the reception unit 20B-2 with respect to the transmission voltage at the transmission unit 20A-2 is obtained as an attenuation rate (or attenuation amount) when the microwave passes through the waste, The receiver 20B-2 is connected to the control device 30 via a moisture content calculator (not shown) that calculates the moisture content from the attenuation rate. In the moisture content calculator, the correlation between the attenuation rate of the microwave and the moisture content of the waste is held in advance, and the moisture content of the waste is calculated from the attenuation rate obtained as the actually measured voltage ratio. This is transmitted to the control device 30.

  The control device 30 calculates an accurate heat generation amount of the waste from the moisture content value received from the moisture content calculator based on the correspondence relationship held in advance, and holds it in advance according to the heat generation amount. The damper 10 as a combustion air supply amount adjusting mechanism provided in the combustion air supply pipe 9, the grate 11, and the dust supply so that the stable waste incineration processing is performed based on the control flow being performed. A command signal is sent to the device 14 to control the operation amounts such as the combustion air supply amount, the waste conveyance speed of the grate 11, the waste supply speed of the dust supply device 14, and the like. In this way, the waste P is transmitted through the microwave in the chute 15, that is, immediately before being sent to the combustion chamber 13, and the moisture content is obtained from the microwave attenuation rate at that time. Thus, the calorific value of the waste is calculated based on the moisture content measurement value, and the waste incinerator 1 is controlled by the control device 30 based on the waste calorific value. The operating conditions of the waste incinerator 1 can be optimally controlled, and the incineration can be stably performed even when the waste heat generation amount fluctuates.

  In the present embodiment, the waste P supplied to the waste incinerator 1 is processed in the following manner.

  The waste P is thrown into the hopper 16 from the waste pit by a waste crane. The waste P is pushed out onto the grate 11 by a dust supply device 14 (pusher) installed at the lower part of the chute 15. The waste P on the grate 11 is burned by the combustion air blown from the combustion air supply pipe 9 below the grate 11.

  As described above, the moisture content of the waste P put into the hopper 16 is measured by the moisture meter 20 in the chute 15 before being pushed out onto the grate 11 by the dust supply device 14. The microwave M is transmitted from the transmitter 20A-2 of the moisture content meter 20, passes through the waste P, and is received by the receiver 20B-2. Since the microwave M is transmitted (radiated) as a spherical wave from the transmitter 20A-2, the microwave M is directly directed from the front surface of the transmitter 20A-2 to the receiver 20B-2 and travels. In addition, the microwave M directed toward the back surface and the peripheral surface of the transmitter 20A-2 is reflected by the microwave reflector 20A-3, and the microwave M transmitted from the transmitter 20A-2 is After passing through the waste P, it reaches the receiving unit 20B-2 and is received.

  The microwave M permeates the waste P and attenuates differently depending on the moisture content of the waste P. The attenuation rate is measured as the ratio of the reception voltage at the reception unit 20B-2 to the transmission voltage at the transmission unit 20A-2, and the attenuation rate and the moisture rate held in advance by a moisture rate calculator (not shown) From the correlation, a moisture content corresponding to the measured attenuation rate is obtained.

  This moisture content is sent to the control device 30. The control device 30 calculates an accurate heat generation amount of the waste from the moisture content value sent from the moisture content calculator based on the correspondence relationship retained in advance, and the control retained in advance accordingly. Based on the flow, instructions are given to the damper 10, the grate 11, and the dust supply device 14 as the combustion air supply amount adjusting mechanism provided in the combustion air supply pipe 9 so that the stable waste incineration processing is performed. A signal is sent to control the operation amount of the combustion air supply amount, the waste conveyance speed of the grate 11, the waste supply speed of the dust supply device 14, and the like, thereby controlling the combustion state of the waste.

  FIG. 3 shows the test results comparing the moisture content obtained from the attenuation rate of the microwave transmission moisture meter and the moisture content obtained by other methods. According to the present invention, the microwave transmitted from the transmitter with a constant transmission intensity is transmitted through the waste, then reaches the receiver and is received, the received microwave intensity is measured, and the transmission intensity corresponding to the attenuation amount And the received intensity are measured as a moisture voltage value, and the moisture content is obtained from a predetermined correspondence between the moisture voltage value and the moisture content. The greater the moisture voltage value, the higher the moisture content, that is, the smaller the amount of heat generated, and the smaller the moisture voltage value, the lower the moisture content, that is, the greater the amount of heat generated. The time variation of the moisture voltage is indicated by [I] line, which corresponds to the time variation of the moisture content obtained from the attenuation rate of the microwave. On the other hand, as another method, the calculated moisture percentage calculated based on the measured heat data of the exhaust gas from the waste incinerator is shown as [(calculated) moisture percentage], and the time change is shown by the line [II]. When the microwave frequency shown in FIG. 3 (A) is 52 MHz and the microwave frequency shown in FIG. 3 (B) is 116 MHz, the moisture content obtained from the attenuation rate of the microwave transmission moisture meter is It has a correlation with the calculated moisture content calculated based on the measured heat data of the exhaust gas from the waste incinerator, and it was confirmed that the moisture content can be accurately measured with a microwave transmission moisture meter. .

13 Combustion chamber 15 Chute 15A, 15B Parallel wall 17A, 17B Window 20A-2 Transmitter 20B-2 Receiver

Claims (6)

A chute for supplying waste to the combustion chamber has a pair of parallel walls facing each other in a lateral direction perpendicular to the direction in which the waste falls, and measuring the moisture content of the waste in the chute. In a waste water content measuring apparatus provided with a moisture meter on the chute,
The moisture meter is a microwave transmission moisture meter having a transmitter for transmitting microwaves and a receiver for receiving the microwaves, and is formed on one of a pair of parallel wall portions of the chute. A transmitter having a transmitter and a receiver disposed in a window formed on the other parallel wall, wherein the transmitter has a microwave frequency of 15 MHz to 120 MHz. Moisture content measuring device. A grate-type waste incinerator comprising a grate and a combustion chamber for burning waste on the grate, and primary air blowing means for blowing combustion primary air into the combustion chamber from under the grate In a waste incinerator having a dust feeder for supplying waste on a grate,
The waste water content measuring device according to claim 1 and the waste water content measured by the waste water content measuring device or the waste heat value calculated from the water content measured value. And a waste incinerator comprising a control device for controlling operating conditions of the incinerator.   The control apparatus controls at least one of a dust supply waste supply speed, a grate waste conveyance speed, and a combustion primary air supply amount as an operation condition of the incinerator. The waste incinerator described. A chute for supplying waste to the combustion chamber has a pair of parallel walls facing each other in a lateral direction perpendicular to the direction in which the waste falls, and measuring the moisture content of the waste in the chute. In the waste water content measuring method by the waste water content measuring device provided with a moisture content meter on the chute,
A microwave transmission moisture meter is used as the moisture meter, and a transmitter portion of the moisture meter is provided in one of the pair of parallel wall portions, and a window portion formed in the other parallel wall portion. A waste water content measuring method, comprising: a receiving unit of the moisture content meter; transmitting a microwave having a transmission microwave frequency of 15 MHz to 120 MHz from the transmitting unit; and receiving the microwave by the receiving unit. . A waste incineration method using a grate-type waste incinerator, in which waste is burned on a grate provided in a combustion chamber, waste is supplied onto the grate by a dust feeder, and primary air for combustion In a waste incineration method using a grate-type waste incinerator that blows into the combustion chamber from under the grate,
The moisture content of the waste is measured by the waste moisture content measuring method according to claim 4, and based on the measured moisture content measurement value of the waste or the calorific value calculation value of the waste calculated from the measured moisture content value. A waste incineration method using a grate-type waste incinerator, wherein the operating conditions of the incinerator are controlled by a control device.   The control by the control device is performed on at least one of a dust feeder waste supply speed, a grate waste transport speed, and a combustion primary air supply amount as an operation condition of the incinerator. 6. A waste incineration method using a grate-type waste incinerator according to 5.

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