JP5377186B2 - Method for calculating the abundance ratio for each type of solid waste - Google Patents

Description

  The present invention divides a collection of solid waste carried into a waste treatment / disposal facility into fine areas and uses the remote sensing technology by infrared spectroscopy sensor to select the type of waste for each area. The present invention relates to a method for specifying and quantitatively calculating the existence ratio with respect to the total amount for each type. This technology is particularly useful for improving the operational efficiency of waste treatment and disposal facilities.

  In general, handling of solid waste (general waste / industrial waste) includes incineration processing as intermediate processing, recycling (recycling) processing, and landfilling as final disposal. In the past, these treatments and disposals were often handled separately, but in recent years there are an increasing number of facilities that can handle waste treatment and disposal comprehensively. For example, like “Eco Park Izumozaki”, a combined treatment facility that combines an incineration / crushing facility with a final disposal site (mainly landfill) and a leachate treatment facility, or “Eco Park Samukawa” or “Eco Park Abo” As in the case of “Shi”, incineration facilities and other facilities that are equipped with heat recovery and recycling facilities are being developed.

  The tendency to consistently conduct such waste incineration, recycling, and final disposal in one place will increase in the future in line with the viewpoint of creating a recycling society. is expected. In that case, it is extremely important to improve the operational efficiency of the combined treatment facility.

  Solid waste is usually carried into a facility by a transportation means such as a truck. There are various types of waste to be brought in, combustible waste (including paper waste, wood waste, fiber waste, etc.), waste plastics, metal waste, non-burnable waste (including glass waste, concrete waste, debris, etc.) and so on. These wastes are not necessarily classified into a single type and are transported by a single truck, but the actual situation is that a plurality of types of waste are carried in a mixed state. Therefore, the type and amount of the waste carried into the facility is managed by a method called development survey. In Japan, combustible waste is often incinerated. In this development survey, the amount of combustible waste is checked by an operator's direct visual observation (or camera image observation). Is roughly determined, thereby determining the processing method and procedure. However, depending on the type of incinerator, etc., there is a difference in the range of combustible waste, and not only combustible waste but also waste plastics may be included in the category of combustible waste. In the deployment survey, the type and amount of waste will be estimated in consideration of these circumstances.

The amount of combustible waste estimated by the above-described development survey is empirically determined visually by the operator, and may differ greatly from the actual amount. Therefore, if the combustible waste and other non-combustible waste can be properly distinguished and the amount of combustible waste can be quantitatively estimated with a certain degree of accuracy, improvement of combustion efficiency, reduction of energy costs through incineration, and deployment It can be expected to save labor and shorten the time required for waiting in the facility, which leads to the improvement of the operation efficiency of the treatment facility. Such quantitative estimation of combustible waste means that sequential combustion efficiency can be controlled, and it also leads to control of CO ₂ emissions at that time.

  In addition, waste plastics may be included in the category of combustible waste as described above depending on the type of the incinerator or the like, but if not included, they are recycled. In addition, metal waste is also recycled. Non-burning waste other than metal (glass scrap, concrete scrap, debris, etc.) is disposed of in landfills. In order to appropriately perform such disposal, it is important to make it possible to efficiently and quantitatively grasp the existence ratio of each type of waste collected in the facility. This is also useful as a judgment criterion when the waste carried into the stock yard of the treatment facility is carried out to the recycling facility or the like. For example, even if it is a recyclable waste, if it is less than a certain ratio, it can be sent directly to landfill, and if it is more than that ratio, it can be judged to be carried into a recycling facility. This leads to an improvement in processing efficiency in recycling facilities and the like, and can contribute to the establishment of a recycling-oriented society with little waste.

  By the way, some technologies for classifying solid waste by type have already been put into practical use. For example, there are technologies that use wind power to separate packaged foods into packaging materials and garbage, and technologies that sort waste using centrifugal force, buoyancy, and magnetic force in this order. In addition, there is a method for managing and monitoring waste in a disposal site, soil covering conditions, and the like using remote sensing technology using an infrared spectroscopic sensor (Patent Document 1). Here, waste and soil covering conditions are evaluated using a normalized difference index based on a combination of reflectivities in different wavelength bands, and the disposal site after soil covering is judged and determined for closure.

  However, these documents do not disclose a method for quantitatively grasping the existence ratio of each type of solid waste aggregate loaded on a truck bed or the like and carried into a facility.

JP 2005-199154 A

  The problem to be solved by the present invention is to make it possible to quantitatively grasp the existence ratio of each type of solid waste aggregate, thereby improving the proper operation of the treatment / disposal facility and the improvement of the operation efficiency. That is.

  The present invention irradiates a solid waste aggregate with white light, and reflects the reflectance in a plurality of wavelength bands from the red region to the short wavelength infrared region with respect to the reflected light spectrum from the waste. Normal measurement using a combination of reflectances in different wavelength bands for each area determined by the scanning interval and the measurement interval, while remotely measuring using an infrared spectroscopic sensor while scanning the measurement area corresponding to the aggregate in a planar manner Classify the waste types for each area by calculating the normalized difference index and determining the normalized difference index according to the preset judgment formula, extract the area corresponding to each waste type, and for each waste type The ratio of the total area of all areas is calculated, and the ratio of the total area to the total area is calculated to calculate the existence ratio of each type of waste in the total waste collection. In the existence ratio calculation method That.

  Specifically, for example, for each subdivided area, the types of waste are classified into waste plastics, combustible waste, metal waste, and non-burnable waste according to a judgment formula set in advance based on the normalized difference index. The existence ratio for each type of object is obtained.

  Further, for each area, the primary and secondary normalized differential indices can be calculated using the primary differential value and the secondary differential value of the reflected light spectrum, and finer classification can be performed according to a predetermined determination formula. . For example, combustible waste is further subdivided into flammable waste and flame retardant waste according to dry and wet conditions, and the amount of flammable waste and flame retardant waste is estimated based on the sum of the corresponding area areas. You can also.

  As a device for carrying out such a method for calculating the abundance ratio for each type of solid waste, a halogen light source that is positioned above the solid waste aggregate and emits white light to the waste aggregate. A camera for photographing a collection of waste, an infrared spectroscopic sensor for remotely measuring a reflected light spectrum from the waste, a sensor driving mechanism for moving the infrared spectroscopic sensor in vertical and horizontal planes, and infrared spectroscopy A computer that performs calculation processing based on sensor position data and measurement data, and displays the normalized difference index for each area superimposed on the camera image, and classifies the type of waste for each area by the computer. Then, the area corresponding to each waste type is extracted, and the area of each waste type is summed, and the ratio of the total area of all areas is calculated to calculate the ratio of the total solid waste. Configured so as to calculate the abundance ratio of each kind is desirable.

The method according to the present invention remotely measures the reflected light spectrum from solid waste using an infrared spectroscopic sensor, determines the type of waste for each subdivided area using a normalized difference index, Since it is a method of calculating the abundance ratio, it is possible to quantitatively and quickly and easily estimate the amount of each type of waste for the aggregate of solid waste. As a result, even when not only combustible waste but also waste plastics are included in the category of combustible waste, it is possible to roughly determine the amount of combustible waste and determine the processing method and procedure. In addition, according to the method of the present invention, combustible waste and other non-combustible waste can be appropriately distinguished, and the amount of combustible waste can be quantitatively estimated with a certain degree of accuracy. Reductions in energy costs due to incineration, labor savings in deployment surveys, shortening of waiting time in the facility, etc. can be expected, which leads to improvement in operation efficiency of the treatment facility. Such quantification of combustible waste means that sequential combustion efficiency can be controlled, and it also leads to control of CO ₂ emissions at that time.

  Furthermore, since the amount of each type of waste can be estimated according to the present invention, if waste plastics are not included in the category of flammable waste, they can be recycled according to the amount, and the amount of metal waste can also be increased. Can be recycled according to quality. If there is a lot of non-burnable garbage other than metal, landfill disposal can be selected. Since such processing disposal can be performed appropriately, it leads to improvement of processing efficiency in a recycling facility or the like, and the present invention can contribute to the establishment of a recycling society with little waste.

The schematic which shows an example of the system which implements the method of this invention, and its operation | movement. The graph which shows the example of a measurement of a reflected light spectrum. The graph which shows the relationship between the kind of waste, and a normalization difference parameter | index (NDTI). The flowchart which shows an example of the classification | category procedure of the waste kind by a normalization difference parameter | index (NDTI). The graph which shows the relationship between the kind of waste material, and a 1st-order normalization differential indicator (NDDI). The graph which shows the relationship between the kind of waste material, and a 2nd-order normalization differential indicator (NDDI). The flowchart which shows an example of the classification procedure of the combustible waste by a normalization differential parameter | index (NDDI). The flow figure which shows an example of the classification procedure of the noncombustible waste by a normalization differential index (NDDI). The flowchart which shows an example of the procedure of a waste treatment / disposal.

  In the present invention, the aggregate of solid waste is irradiated with white light, and the reflectance in a plurality of wavelength bands from the red region to the short wavelength infrared region is measured for the reflected light spectrum from the waste. Remote measurement is performed sequentially using an infrared spectroscopic sensor while scanning the measurement area corresponding to the aggregate in a planar manner. For each area determined by the scan interval and the measurement interval, calculate a normalized difference index using a combination of reflectances in different wavelength bands, and discard the normalized difference index according to a predetermined determination formula. Classify the type of object. Then, the area corresponding to each waste type is extracted, the area of each waste type is added together, and the ratio to the total area of all areas is calculated to calculate the waste type in the entire solid waste aggregate. The existence ratio for each is calculated.

  FIG. 1 is a schematic diagram showing an example of a system for implementing the method of the present invention and its operation. The waste 10 is loaded on an open loading platform of the truck 12 and carried into a treatment / disposal facility. The waste targeted by the present invention is solid, and is usually loaded in a collective state in which a plurality of types of waste are mixed. Above the truck bed, a halogen light source 14 for irradiating the entire collection of waste on the bed with white light and a camera 16 for photographing the entire collection of waste on the carriage are installed. In addition, an infrared spectroscopic sensor 18 that remotely measures a reflected light spectrum from waste vertically from above, and a sensor driving mechanism 20 that moves the infrared spectroscopic sensor 18 in a vertical and horizontal plane within the range (measurement region) of a truck bed. Is provided. Furthermore, a computer 22 that performs calculation processing using the position data and measurement data of the infrared spectroscopic sensor is provided. The infrared spectroscopic sensor 18 used here has a measurement wavelength of about 630 to 2500 nm.

  The above example assumes the stockyard of a treatment / disposal facility, but in addition, the present invention can also be used when grasping the type and amount of waste in a dumping box. Needless to say.

  FIG. 2 shows an example of the result of measuring the reflected light spectrum of the imported waste in the field survey at the treatment / disposal facility. Thus, the reflected light spectrum changes according to the type of waste. This is conventionally known, but the present invention basically utilizes such a phenomenon.

White light emitted from the halogen light source 14 is reflected by the aggregate of the waste 10. The reflected light spectrum is detected by the infrared spectroscopic sensor 18, and the reflectance in a plurality of wavelength bands from the red region to the short wavelength infrared region is measured. This measurement is performed sequentially while scanning in a planar manner not only at one point of the waste aggregate but also within the measurement region corresponding to the entire waste aggregate. FIG. 1B is a view of the aggregate of waste on the truck bed from above, and is measured intermittently by scanning in a plane as indicated by arrows. Thus, measurement data is obtained for each area determined by the scanning interval and the measurement interval. The computer 22 calculates a normalized differential index (NDTI) using a combination of reflectances in different wavelength bands for each area. The normalized difference index NDTI is defined by the following equation.
_{NDTI ij = (R i -R j} ) / (R i + R j)
Here, R _{i is} the reflectance in the i wavelength band, and R _j is the reflectance in the j wavelength band.
The type of waste is classified for each area by determining the obtained normalized difference index according to a predetermined determination formula. The waste type for each area can be superimposed and displayed on the image of the collection of wastes taken by the camera as shown in FIG. Then, the area corresponding to each waste type is extracted, the area of each waste type is added up, and the ratio to the total area of all the areas is calculated to calculate the ratio of each waste type in the entire collection of wastes. The existence ratio can be calculated. For example, if the cross-hatched portion is combustible waste, the area is extracted and the proportion of the combustible waste is calculated by calculating the proportion of the total area.

After specifying the type of waste, if further subdivision is required, such as dry and wet conditions, the reflected light spectrum (relationship between wavelength and reflectance) of each waste is first or second order differentiated A normalized differential index (NDDI) obtained from the value is used. Specifically, the calculation is performed as follows using the difference calculation method.
When the reflected light spectrum data is A ₁ , A ₂ , A ₃ ,..., A _i ,..., A _n (1 ≦ i ≦ n), the difference between the data for calculating the derivative is In terms of m,
The first derivative is Δ ¹ _{m, j} = A _j −A _{m + j} (1 ≦ j ≦ n−m)
The second derivative is Δ ² _{m, j} = Δ ¹ _{m, j} −Δ ¹ _{m, m + j} = A _j −2A _{m + j} + A _{2m + j} (1 ≦ j ≦ n−m)
It becomes. Using the differential value obtained by such a method, a normalized differential index (NDDI) represented by the following equation is calculated.
NDDI ⁿ _ij = (Δ ⁿ _i −Δ ⁿ _j ) / (Δ ⁿ _i + Δ ⁿ _j )

A plurality of wavelength bands from the red region to the short wavelength infrared region measured by the infrared spectroscopic sensor are as follows. The classification of the wavelength band usually follows the classification performed by the infrared spectroscopic sensor.
R: Red wavelength range (630 nm to 690 nm)
NIR: Near-infrared wavelength region (760 nm to 860 nm)
SWIR1: Short wavelength infrared wavelength range (1600nm-1700nm)
SWIR2: Short wavelength infrared wavelength region (2145 nm to 2185 nm)
SWIR3: Short wavelength infrared wavelength region (2185 nm to 2225 nm)
SWIR4: Short wavelength infrared wavelength region (2235 nm to 2285 nm)
SWIR5: Short wavelength infrared wavelength region (2295 nm to 2365 nm)
SWIR6: Short wavelength infrared wavelength region (2360 nm to 2430 nm)

The classification of waste types based on the normalized difference index is performed using, for example, SWIR1-NIR, SWIR5-SWIR1, R-SWIR1, SWIR6-SWIR2. FIG. 3 shows an example of a normalized difference index for various types of wastes that serve as a basis for specifying the type of waste. By using this numerical value, the waste type is specified according to the flow shown in FIG.
(1) First judgment formula: Those not satisfying NDTI ₆₂ <0.2 are judged as waste plastics.
(2) Second judgment formula: Those not satisfying NDTI _1N > −0.2 are judged as paper waste / fiber waste (combustible waste).
(3) Third judgment formula: Those that do not satisfy NDTI _R1 <−0.1 are judged as non-combustible mixed waste / metal scrap (non-combustible waste).
(4) Fourth judgment formula: Those that do not satisfy NDTI ₅₁ <−0.1 are judged as soil, concrete, asphalt, etc. (non-combustible waste).
(5) Fourth judgment formula: Those satisfying NDTI ₅₁ <−0.1 are judged as wood waste / combustible mixed waste (combustible waste).
In this way, waste can be classified into waste plastics, combustible waste, and non-combustible waste (including and not including metal scrap) for each measurement area.

  Further fine classification can be performed by calculating a primary normalized differential index and a secondary normalized differential index. FIG. 5 shows an example of a primary normalized differential index for various types of waste that is a basis for subdividing waste types, and FIG. 6 shows an example of a secondary normalized differential index.

Fig. 7 shows the flow of combustible waste fragmentation.
(A) Waste paper / fiber waste is wet paper waste / fiber waste (combustion efficiency: small) for those that do not satisfy the fifth judgment formula: NDDI ² ₆₃ <1.5, and dry waste / fiber waste for those that satisfy (5) Combustion efficiency: Large).
(D) First, wood scrap / combustible mixed waste is judged to be wet combustible mixed waste (combustion efficiency: small) if it does not satisfy the sixth judgment formula: NDDI ¹ _1N > −5.0. Next, what does not satisfy the seventh judgment formula: NDDI ² ₆₃ > 0.0 is judged as dry wood waste (combustion efficiency: high). Further, those that do not satisfy NDDI ² ₆₃ <2.0 are determined to be dry combustible mixed waste (combustion efficiency: high), and those that satisfy NDDI ² ₆₃ <2.0 are determined to be wet or debris (burning efficiency: low). Thus, a fine classification can be performed according to the wet state.

Fig. 8 shows the flow of non-combustible waste reclassification.
(B) Non-combustible mixed waste / metal waste is judged as metal waste or non-combustible mixed waste with water or earth attached to those that do not satisfy the eighth judgment formula: NDDI ¹ ₅₁ <-15, and cleaning is not required for those that satisfy Judge as scrap metal.
(C) Soil, concrete, asphalt waste, etc. are first judged as asphalt waste if they do not satisfy the ninth judgment formula: NDDI ¹ ₆₃ <10. Next, the thing which does not satisfy the 10th judgment formula: NDDI ² ₆₃ > 0.5 is judged as soil, and the thing which satisfies is judged as concrete waste. In this way, non-combustible waste can be subdivided.

  In this way, the measurement data is acquired for each area determined by the scanning interval and the measurement interval of the infrared spectroscopic sensor, and the type of waste in that area is specified by performing computer calculation processing for each subdivided area. The In this way, the type of waste for each area is obtained for all areas. Therefore, the ratio of the total area of the area corresponding to the specific waste (for example, waste plastics) to the total area of all the areas is obtained, and the ratio for each type of waste (for example, waste plastics) is calculated. be able to. By using this, it becomes possible to operate the waste treatment / disposal facility efficiently.

An example of a process for disposal / disposal of a collection of wastes is shown in FIG. Depending on the structure of the incinerator, waste plastics may be incinerated or recycled, and the processing / disposal flow will differ.
(1) First, when waste plastics are not incinerated, if the proportion of waste plastics is equal to or greater than a specified value, the process of recycling process is determined and the recycling process is performed.
(2) Next, when incinerating waste plastics, add up the proportion of combustible waste, including combustible waste and waste plastics. And if the ratio of combustible waste is more than the specified value, it will be incinerated. The ratio of the wet condition is calculated to determine the magnitude of the combustion efficiency, the priority of the incineration process is determined, and the incineration process is performed accordingly.
(3) If the ratio of scrap metal is equal to or higher than the specified value, the ratio of scrap metal that does not need to be cleaned is calculated, the process of the recycling process is determined, and the recycling process is performed.
(4) If the ratio of concrete and asphalt scrap is above the specified value, sorting and crushing is performed.
(5) All other items will be disposed of in landfills.
For each of the predetermined values, for example, about 60% is a rough standard, but an appropriate value is set according to the structure of the facility, the state of treatment / disposal, and the like.

  As described above, in the present invention, since the existence ratio for each type of waste can be estimated quantitatively, it becomes possible to carry out treatment and disposal consistently, appropriately and efficiently, and also enables recycling. Therefore, it can greatly contribute to the formation of a recycling society.

DESCRIPTION OF SYMBOLS 10 Waste 12 Track 14 Halogen light source 16 Camera 18 Infrared spectroscopic sensor 20 Sensor drive mechanism 22 Computer

Claims (4)

  Irradiate white light to a collection of solid waste, and reflect the reflectance of the reflected light spectrum in multiple wavelengths from the red range to the short-wavelength infrared range to the collection of waste. Remote measurement is performed sequentially using an infrared spectroscopic sensor while scanning the measurement area in a plane, and a normalized difference index using a combination of reflectivities in different wavelength bands is determined for each area determined by the scan interval and the measurement interval. Calculate and classify the waste type for each area by determining the normalized difference index according to the preset judgment formula, extract the area corresponding to each waste type, and the area of the area for each waste type And calculating the ratio of total waste to the total area by calculating the ratio of total waste to each type of waste by calculating the ratio of the total area to the total area. .   For each subdivided area, the types of waste are classified into waste plastics, combustible waste, metal waste, and non-burnable waste according to a preset judgment formula based on the normalized difference index. The existence ratio calculation method for each type of solid waste according to claim 1, wherein the ratio is obtained.   For each area, the primary and secondary normalized differential indices are calculated using the primary differential value and secondary differential value of the reflected light spectrum, and the combustible waste is further flammable according to the wet and dry conditions according to a preset judgment formula. 3. The type of solid waste according to claim 2, wherein the amount of flammable waste and the amount of flame retardant waste is estimated by subdividing into combustible waste and flame retardant waste, and further combustible waste is further calculated based on the sum of the corresponding area areas. Method for calculating the existence ratio for each. An apparatus for carrying out the abundance ratio calculation method for each type of solid waste according to any one of claims 1 to 3,
Located above the solid waste collection, the halogen light source that irradiates the waste collection with white light, a camera that captures the waste collection, and the reflected light spectrum from the waste is remotely measured. An infrared spectroscopic sensor, a sensor driving mechanism for moving the infrared spectroscopic sensor in vertical and horizontal planes, and a computer that performs calculation processing based on the position data and measurement data of the infrared spectroscopic sensor. In addition to displaying the normalized difference index for each area, the computer classifies the type of waste for each area, extracts the area corresponding to each type of waste, and adds up the area of the area for each type of waste. An existence ratio calculation system for each type of solid waste that calculates an existence ratio for each type of waste in the entire aggregate of waste by calculating a ratio of the total area to the total area.

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