JP2877695B2 - Waste treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the treatment of waste containing radioisotopes from hospitals and other medical institutions and research and educational institutions, and more particularly to a method of treating waste containing radioisotopes by incineration. It is about.

[0002]

2. Description of the Related Art Solid waste from hospitals and other medical institutions and research and educational institutions is mostly composed of combustible materials, that is, plastics and papers such as test tubes. Metals such as lead plates and glass such as chemical bottles may be contained in small amounts. If these wastes are to be incinerated, the volume of
After filling the incinerator in a state of being packed in a transparent polyethylene bag of about 1 liter, the incineration exhaust gas is filtered with a ceramic filter and a HEPA filter (High Efficiency Particulate Fillte
The method of complete filtration according to r) is adopted.

However, lead sublimes at high temperatures when incinerated,
In order to protect the HEPA filter provided at the subsequent stage, there is a problem that when the incineration gas is cooled, it sublimates on the surface of the HEPA filter and clogs the HEPA filter. Further, there is a problem that when incinerated, glass melts at a high temperature, penetrates into the refractory constituting the incinerator, and causes structural deterioration of the refractory. For this reason, prior to the incinerator, the waste packed in a transparent polyethylene bag of about 20 liters was visually checked by an operator at an inspection and sorting stand to remove lead and glass. Checking was not possible, and rarely lead and glass were injected into the incinerator, clogging the HEPA filter and degrading the refractory. As a result, it is necessary to stop the incinerator for the replacement work of the HEPA filter and the repair work of the refractory, and there is a problem that the operation rate of the incinerator is reduced.

[0004]

DISCLOSURE OF THE INVENTION The present invention separates bags containing lead and glass that are not suitable for incineration from bags that do not.
An object of the present invention is to provide a method for treating solid waste containing radioisotopes from hospitals and other medical institutions and research and educational institutions, which can solve the problem of a decrease in the operating rate of incinerators.

[0005]

Means for Solving the Problems According to a first aspect of the present invention, there is provided a method for producing X-rays having a strength capable of distinguishing metal, glass, and combustible material from bagged waste. Irradiation from a predetermined direction, image processing of the irradiation image obtained by the X-ray irradiation light receiving unit, counting the total number of pixels in the portion where the metal light receiving unit gradation is within a predetermined range on the image, Bags with a number of pixels equal to or greater than the preset number of pixels
Of metal, and bags of less than specified size
Of the glass, and similarly, counting the total number of pixels in the portion where the light receiving portion gradation of the glass is within a predetermined range on the image, and determining that the total number of pixels is equal to or larger than the preset number of pixels. Must contain glass of a specified size or more
And, a Do a less bag contains a predetermined size or more glass
It is characterized in that it is separated as

A second invention has been made to solve the above-mentioned problem. The present invention is directed to a strength capable of distinguishing a metal, a glass, and a combustible from a bagged waste at a stage before an inlet of an incinerator. X-rays are radiated from a predetermined direction, image processing is performed on the irradiation image obtained by the X-ray irradiation light-receiving unit, and the total number of pixels in a portion where the metal light-receiving unit gradation is within a predetermined range on the image is counted. In addition to removing bags whose total number of pixels is equal to or greater than the preset number of pixels, the total number of pixels in the portion of the image in which the light receiving portion gradation of the glass is within a predetermined range is counted, and the total number of these pixels is set in advance. The number of pixels equal to or larger than the set number of pixels is removed, and only the number of bags smaller than the set number of pixels are put into an incinerator and incinerated. It is more preferable that the packed waste is irradiated with X-rays from a plurality of directions relatively and the bags are sorted based on a plurality of obtained irradiation images.

[0007]

According to the present invention, the packaged waste is irradiated with X-rays from a predetermined direction, the irradiation image obtained at the X-ray irradiation light receiving unit is image-processed, and the metal and glass images are displayed on the image. It is possible to automatically separate metals, glass, and combustibles by counting the total number of pixels in a portion where the light-receiving part gradation is within a predetermined range, and comparing the total number of pixels with a preset number of pixels. it can. For this reason, it is necessary to separate bags containing metal and glass of a specified size or more into the incinerator from the charging line before incineration, and incinerate only bags without inconvenience by incineration without relying on humans as in the past. Can be.

[0008]

The present invention will be described below in more detail with reference to the illustrated embodiments. FIG. 1 is a diagram conceptually showing a waste 1 packed in a bag, 2 is a transparent polyethylene bag having a capacity of about 20 liters, and 3 is the contents thereof. Most of the contents 3 are combustibles, that is, plastics and papers like the test tube 4, but some are glasses such as the chemical bottle 5 and metals such as the lead plate 6 for radiation shielding. It is included.

FIG. 2 and FIG. 3 show an incineration facility for bagged waste 1 as described above. The bagged waste 1 is conveyed by a conveyor 7 to a position immediately above an inlet 9 of an incinerator 8. To the incinerator 8 when the double damper 10 is opened.
They are put inside and incinerated. Further, the exhaust gas from the incinerator 8 is completely filtered by the ceramic filter 11 and the HEPA filter 12, and then guided to the chimney 14 by the blower 13 to be discharged.

In the present invention, the inlet 9 of the incinerator 8
The X-ray irradiating device 15 irradiates X-rays from a predetermined direction to the bagged waste 1 at a stage before entering. This X
The intensity of the line is such that the light receiving part gradation of the metal is 140 to 160 so that the metal, the glass, and the combustible material can be distinguished from each other.
When the number of pixels is from 0 to 1000 and the light receiving part gradation of the glass is 160 to 180, and the preset number of pixels to be compared with the total number of pixels of these portions is 1000 to 3000, X-ray generation is performed. The voltage is preferably 50 KV to 110 KV, and the X-ray generation current is preferably 1 mA to 3 mA, particularly preferably 65 KV and 2 mA.
In the embodiment, the line is irradiated from only a predetermined direction, that is, only one direction.
X-rays are radiated by one X-ray irradiator in the same manner as in the embodiment while irradiating the X-rays or rotating the waste packed in the bag, and a plurality of irradiations obtained by the X-ray irradiation light-receiving unit are obtained. Each image is image-processed, and the total number of pixels in the portion where the metal light-receiving part gradation is within a predetermined range on each image is counted, and the average of these total pixels is equal to or larger than a preset number of pixels. It is more preferable if the same process is performed on glass as well as the bag is separated into smaller bags.

[0011] In this way, X-rays of moderate intensity are irradiated,
When the image of the bagged waste 1 is captured, the metal such as the lead plate 6 for radiation shielding appears dark in the image as shown in FIG. 3, and the glass such as the chemical bottle 5 appears slightly dark in the image. Tube 4
Plastics and papers like are hardly visible. Next, this image is subjected to the following image processing.

First, A of FIG. 4 shows an original image, a black portion indicates a lead plate 6, a hatched portion indicates a glass bottle 5, and a white frame portion indicates a combustible material. Next, when this image is sequentially read along a scanning line, a signal level as shown in B is obtained. In each of the graphs B to F in FIG. 4, the vertical axis represents the light receiving section gradation, and the horizontal axis represents the number of pixels.

Next, by performing a smoothing process to remove noise on the image, an image as shown in C is obtained. On the other hand, when the restoration processing is performed, an image in which the edges are enhanced as shown in D is obtained. When the image is further emphasized to clarify the shading, an image of E is obtained. Finally, as shown in F, the threshold value and the signal level are compared. If this threshold value is set in two steps, the total number of pixels in the portion where the metal light receiving portion gradation is within the predetermined range and the total number of pixels in the portion where the glass light receiving portion gradation is within the predetermined range are calculated. By comparing the number of pixels with a predetermined number of pixels, metal, glass, and combustible material can be identified. For example, in the example of FIG. 5, the total number of pixels in a portion where the metal light-receiving portion tone is in a certain range is 3 × 4 = 12, and the total number of pixels in a glass light-receiving portion tone is in a certain range. 4x6
= 24.

In practice, the total number of pixels of the entire screen is 512 ×
256 = 131072, for example, the predetermined number of pixels of a portion of the metal light-receiving portion in a certain range is set to 500,
The predetermined number of pixels in a predetermined range of the light receiving portion gradation of the glass is set to 2000. If the total number of pixels in a part of the light receiving section gradation within a certain range exceeds any of these values, the waste in which lead and glass of a predetermined size or more, which are not suitable for incineration, are bagged. It is assumed that
The bagged waste is removed, and if not exceeded, the bagged waste is incinerated.

For this reason, the waste 1 incinerated in the incineration path 8 does not include the lead plate 6 and the glass bottle 5 having a predetermined size or more, so that the HEPA filter is clogged with the vaporized lead, or the fire resistance of the incinerator is caused by the molten glass. There is no deterioration of the material structure.

[0016]

As described above, according to the present invention, metal and glass bottles, such as lead plates, which are mixed with bagged waste and are not suitable for incineration, are subjected to X-ray and image processing techniques. The bag containing them can be removed before entering the incinerator. For this reason, it is possible to prevent the HEPA filter from being clogged by the vaporized lead and to prevent the refractory structure of the incinerator from deteriorating due to the molten glass, and to prevent the operating rate of the incinerator from decreasing. Further, according to the present invention, it is not necessary for the worker to directly check the waste unlike the related art, so that the danger of the worker can be prevented and the load can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view conceptually showing bagged waste.

FIG. 2 is a system diagram showing incineration equipment.

FIG. 3 is a cross-sectional view illustrating an X-ray irradiation unit.

FIG. 4 is a process chart of image processing.

FIG. 5 is an enlarged front view showing an image.

[Explanation of symbols]

1 bagged waste, 2 polyethylene bags, 3 contents, 4 plastic test tubes, 5 glass bottle for chemical solution, 6 lead plate for radiation shielding, 7 conveyor, 8 incinerator, 9 inlet, 10 damper, 11 ceramic filter, 12 HEPA filter, 13 blower, 14 chimney, 15 X-ray irradiation device

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G21F 9/32 B03B 13/06 G01V 5/00

Claims (5)

(57) [Claims] 1. A bag-filled waste is irradiated with X-rays having a strength capable of distinguishing metal, glass, and combustible material from a predetermined direction, and an irradiation image obtained by an X-ray irradiation light receiving unit is imaged. Process, count the total number of pixels in the portion where the metal light-receiving part gradation is within a predetermined range on the image, and if the total number of pixels is equal to or greater than a predetermined number of pixels, the bag contains metal of a predetermined size or more.
If the bag is smaller than the specified size and does not contain metal
While Itoshite fractionation, likewise counts the total number of pixels of the partial light receiving portion tone of the glass in a predetermined range on the image, the pixels more than the number of bags that total number of pixels are set in advance
Waste treatment method characterized by fractionating the was to include a predetermined size or more glass, not the less of the bag contains a predetermined size or more glass. 2. An X-ray irradiating / receiving unit for irradiating a bagged waste with X-rays having a strength capable of distinguishing metal, glass, and combustible material from a predetermined direction at a stage before an inlet of an incinerator. Image processing of the obtained irradiation image, counting the total number of pixels of the portion where the metal light receiving portion gradation is within a predetermined range on the image, and selecting a bag whose total number of pixels is equal to or greater than a preset number of pixels. At the same time, the total number of pixels in the portion where the light-receiving portion gradation of the glass is within a predetermined range on the image is counted, and the bags whose total number of pixels is equal to or greater than a preset number of pixels are removed, and the number of pixels is smaller than the set number of pixels. A waste disposal method characterized in that only the bags are put into an incinerator and incinerated. 3. The bagged waste according to claim 1, wherein the packed waste is irradiated with X-rays relatively from a plurality of directions, and the bags are sorted based on a plurality of obtained irradiation images. Waste treatment method. 4. An X-ray intensity at which an X-ray capable of distinguishing a metal, a glass, and a combustible material irradiated from an X-ray irradiation device has an X-ray generation voltage of 50 or more.
KV to 110 KV, X-ray generation current is 1 mA to 3 mA.
4. The waste disposal method according to any one of 3. 5. The light receiving part gradation of metal is 140 to 160, and the predetermined number of pixels to be compared with the total number of pixels of these parts is 100 to 1000. Is 16
The number of pixels, which is 0 to 180, and the predetermined number of pixels to be compared with the total number of pixels of these portions is 1000 to 3000.
The waste disposal method according to any one of claims 1 to 3.