JP2002286706A - Plastic judging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic judging device unlikely to be influenced by the temperature and humidity and capable of sensing a pyrolysis gas stably. SOLUTION: The judging device is to judge the plastic contained in a test object by sensing the sort of the pyrolysis gas generated by pyrolysis of the plastic using a gas sensor, whereby inside the device is arranged capable of being air-cooled by introducing the atmosphere or the pyrolysis gas is introduced to the sensing surface of the gas sensor and the atmosphere is introduced to that portion of gas sensor excluding the sensing surface. The pyrolysis gas introduced to the sensing surface is subjected to sensing of its gas sort, and the temperature of the flow passage from the pyrolyzing part to the suction port and the temperature of the sensor are raised so that bedewing is prevented. The introduced atmosphere cools the temperature raised by the pyrolysis gas and suppresses an excessive temperature rise of the sensor and/or its holder so as to prevent a drop of the sensor performance and a deterioration of the sensor. This allows stable sensing of the pyrolysis gas where the temperature and humidity are unlikely to give influence.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic discriminating apparatus for discriminating a kind of plastic, which can be applied to discarding plastics and recycling plastics by discriminating specific plastics from various kinds of plastics.

[0002]

2. Description of the Related Art Various resins including plastics are contained in wastes such as industrial wastes. Here, the plastic is a polymer material, for example, a thermoplastic resin such as polyvinyl chloride, polyethylene, polystyrene, and polypropylene, and a thermosetting resin such as a phenol resin, an unsaturated polyester resin, and an epoxy resin. Are known.

In the disposal of waste, the waste is generally separated according to the type of waste, and is disposed of by reuse or incineration. Since plastic contains many components in plastic, it is necessary to separate the components according to the components contained in the plastic for disposal. In particular, since chlorine may generate harmful substances such as dioxins, it is required to distinguish plastics containing chlorine from plastics not containing chlorine.

[0004] The determination as to whether or not chlorine is contained in plastic is made, for example, by a Fourier transform infrared spectrophotometer (F).
The analysis can be performed by analyzing components contained in the plastic by infrared rays using an analyzer such as TIR) and determining whether or not chlorine is contained in the components.

However, discrimination using an analyzer as described above requires a large-sized analyzer, and also requires a pretreatment for removing the paint or the work adhered to the surface and exposing the analysis surface. Yes, it is assumed that the treatment is performed in a room such as a laboratory. For this reason, there is a problem that it is difficult to determine a waste collection place or a processing site.

Therefore, a portable discriminating apparatus has been proposed which heats plastic, detects a specific component contained in a pyrolysis gas generated by pyrolysis, and discriminates the plastic containing the specific component. For example, it is possible to carry out pyrolysis of a vinyl chloride resin in a pyrolysis unit, suck a part of the generated hydrogen chloride gas by a suction pipe, and introduce the suction gas to a sensor detection surface of an HCI sensor to detect the gas. A discriminating device has been proposed.

FIG. 4 is a schematic diagram for explaining a configuration example of the proposed plastic discriminating apparatus. The plastic discriminating device 101 includes a sensor 102 in a sensor holder 104.
The subject S is thermally decomposed by the pyrolysis means 106, and the generated pyrolysis gas is introduced into the sensor holder 104 through the air inlet 105 and detected by the sensor detection surface 103. The detected pyrolysis gas is exhausted through the exhaust port 107.

[0008]

Conventionally, in the proposed plastic discriminating apparatus, high-temperature pyrolysis gas hits the sensor detecting surface of the gas sensor, so that the temperature of the sensor rises and the performance of the sensor deteriorates, Is deteriorated. To prevent the temperature of this sensor from rising,
It is conceivable that the pyrolysis gas is cooled and then guided into the sensor holder. However, when the temperature of the pyrolysis gas is cooled in this way, dew condensation tends to occur, and the detection component contained in the pyrolysis gas is adsorbed by moisture before the pyrolysis gas reaches the sensor holder, or the sensor detection If condensation occurs on the surface, there is a problem that the sensor detection surface is covered with moisture and the pyrolysis gas does not reach the sensor detection surface.

Accordingly, an object of the present invention is to solve the above-mentioned conventional problems and to provide a plastic discriminating apparatus which is hardly affected by temperature and humidity and can stably detect a pyrolysis gas. I do.

[0010]

SUMMARY OF THE INVENTION The present invention suppresses an excessive rise in temperature of a sensor or a sensor holder and prevents the occurrence of dew condensation by introducing air together with a pyrolysis gas. It is possible to perform stable detection of the pyrolysis gas, which is hard to receive.

The plastic discriminating apparatus of the present invention is a plastic discriminating apparatus which discriminates a plastic contained in a subject by detecting a gas type of a pyrolysis gas generated by pyrolysis of the plastic with a gas sensor. By doing so, the inside of the apparatus can be cooled by air.

Further, the plastic discriminating apparatus of the present invention comprises:
A plastic discriminating apparatus for discriminating plastic contained in a subject by detecting a gas type of a pyrolysis gas generated by pyrolysis of plastic with a gas sensor,
The pyrolysis gas is introduced into the sensor detection surface of the gas sensor, and the atmosphere is introduced into a portion of the sensor holder other than the sensor detection surface. The pyrolysis gas led to the sensor detection surface is
The detection of the gas type is performed, and the temperature of the flow path from the thermal decomposition section to the intake port and the temperature of the sensor are increased to prevent the occurrence of dew condensation. Further, the introduced atmosphere cools the temperature increased by the pyrolysis gas to suppress an excessive increase in the temperature of the sensor or the sensor holder, thereby preventing the performance of the sensor from deteriorating and the sensor from deteriorating.

As a configuration for separating the thermal separation gas from the atmosphere, the plastic discriminating apparatus of the present invention can be provided with a partition wall at the sensor portion. The partition separates the introduced thermal separation gas from the atmosphere, guides only the thermal separation gas to the sensor detection surface of the gas sensor, and allows the atmosphere to come into contact with a portion other than the sensor detection surface. As a result, only the pyrolysis gas is introduced into the sensor detection surface to prevent the concentration of gas components from being reduced by the atmosphere. The partition walls air-cool the sensor surface and the inside of the device by heat exchange between the atmosphere and the heat separation gas.

As another configuration for separating the thermal separation gas from the atmosphere, the plastic discriminating apparatus of the present invention has a first inlet for introducing the pyrolysis gas and a second inlet for introducing the atmosphere. The first inlet guides the introduced pyrolysis gas to the sensor detection surface of the gas sensor, while the second inlet guides the introduced air into the gas holder excluding the sensor detection surface.
As a result, only the pyrolysis gas is introduced into the sensor detection surface to prevent the concentration of gas components from being reduced by the atmosphere. In addition, air is introduced into a portion other than the sensor detection surface to suppress an excessive rise in temperature of the sensor or the sensor detection surface that has risen due to the pyrolysis gas.

[0015] Further, the air inlet for introducing the atmosphere is configured to be openable and closable, thereby controlling the introduction of the air to the sensor. By stopping the introduction of air at a low temperature, the inside of the sensor holder is heated to prevent dew condensation. During measurement, introducing the atmosphere suppresses the temperature rise in the sensor and sensor holder, and also reduces the temperature and gas concentration of the exhaust gas on the exhaust side to suppress thermal and chemical damage to the exhaust pump. I do. In addition, a partition can be provided as needed.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram for explaining the outline of functions of the plastic discriminating apparatus of the present invention. In the plastic discriminating apparatus 1, FIG. 1 shows a schematic configuration of a sensor portion for detecting a component contained in a gas. The sensor 2 detects a gas type on the sensor detection surface 3 and is held at a predetermined position in the plastic discriminating device by the sensor holder 4. A pyrolysis gas generated by pyrolyzing the subject S (both not shown) by the pyrolysis means is introduced into the sensor surface 3, and is exhausted after detection.

The sensor holder 4 has a first inlet 5 for introducing a pyrolysis gas, a second inlet 6 for introducing the atmosphere, and an outlet 7. The exhaust port 7 discharges the introduced pyrolysis gas or a mixed gas of the pyrolysis gas and the atmosphere to the outside of the sensor holder 4. A partition 8 is provided in the sensor holder 4.
The partition wall 8 separates the introduced pyrolysis gas and the introduced air so as not to mix at least in the vicinity of the sensor detection surface 3, whereby the pyrolysis gas is detected on the sensor detection surface 3 of the sensor 2. Only the configuration is adopted. Further, the sensor and the device are air-cooled by performing heat exchange between the atmosphere and the pyrolysis gas through the partition 8.
At this time, the air-cooling efficiency can be increased by using a material having good thermal conductivity, such as a metal, for the partition. Air cooling is also performed by heat conduction by the sensor holder.

The pyrolysis gas after passing through the sensor detecting surface 3 is exhausted to the outside of the sensor holder 4 together with the atmosphere through an exhaust port 7. Further, the flow path from the pyrolysis section to the intake port and the inside of the sensor and the sensor holder are heated by the pyrolysis gas, thereby preventing dew condensation on the sensor, the sensor holder and the flow path. The second inlet 6 is provided with an opening / closing door 9 that opens and closes between the sensor holder 4 and the atmosphere. The opening / closing door 9 stops the introduction of the atmosphere into the sensor holder 4 by closing the second introduction port 6, while allowing the introduction of the atmosphere into the sensor holder 4 by opening the second introduction port 6. Figure 1
1A shows a state in which the door 9 is opened, and FIG. 1B shows a state in which the door 9 is closed.

Next, the normal operation will be described. The pyrolysis gas generated by pyrolyzing the plastic is introduced into the sensor holder 4 from the first inlet 5. The pyrolysis gas introduced into the sensor holder 4 is guided to the sensor detection surface 3 by the partition 8. The pyrolysis gas raises the temperature of the first inlet port 5 and a ventilation path (not shown) from the inlet portion to the first inlet port 5 to suppress the occurrence of condensation.

On the other hand, the atmosphere is introduced into the sensor holder 4 through the opened door 9. At this time, the atmosphere is separated from the pyrolysis gas by the partition walls 8 and does not mix.
Therefore, it is possible to prevent a decrease in the concentration of the gas component of the pyrolysis gas due to the atmosphere, and to prevent a decrease in the detection accuracy of the gas component. Further, the introduced atmosphere cools the sensor holder 4 and the sensor 2 by heat conduction through the partition 8 and the wall surface, and suppresses a temperature rise of the sensor holder 4 and the sensor 2.

The introduced atmosphere cools the pyrolysis gas by heat exchange performed through the partition 8. Further, since the pyrolysis gas is mixed with the atmosphere after passing through the sensor detection surface, the temperature and concentration of the pyrolysis gas decrease at the exhaust port 7,
Thermal and chemical damage to the exhaust pump and the like on the downstream side can be suppressed. On the other hand, since the temperature can be kept higher on the upstream side than the sensor holder 4, it is possible to prevent dew condensation from reaching the sensor holder.

Therefore, since the partition wall 8 separates and introduces the pyrolysis gas and the atmosphere, it is possible to detect the pyrolysis gas without lowering the gas concentration, and to efficiently transfer the pyrolysis gas to the sensor detection surface. Therefore, the detection accuracy of the gas due to the introduction of the atmosphere does not decrease.

Next, the operation at a low temperature will be described. At low temperatures, the second inlet 6 is closed by the opening / closing door 9 to stop the introduction of the atmosphere into the sensor holder 4, whereby only the pyrolysis gas is introduced into the sensor holder 4. The temperature of the sensor holder 4 rises in a short time due to the heat of the pyrolysis gas. With this temperature, the occurrence of dew condensation in the sensor holder 4 can be suppressed.

After the temperature in the sensor holder 4 has risen, the open / close door 9 is opened (FIG. 1A), and the atmosphere is introduced into the sensor holder 4 to suppress the temperature rise. Usually, sensor holder 4
Since the time required to heat the sensor holder 4 by introducing the pyrolysis gas into the inside is short, it is necessary to suppress thermal and chemical damage to an exhaust pump (not shown) downstream of the exhaust port 7. In addition, since the pumping speed of the pump does not change, even when the exhaust gas is used for cooling the high-temperature portion of the plastic discriminating apparatus, the cooling capacity does not change due to the opening and closing operation of the door.

The above-mentioned second inlet can be in various modes. Hereinafter, each embodiment will be described. FIG.
FIG. 4 is a schematic diagram for explaining an example of a second inlet in the plastic discriminating apparatus of the present invention. The configuration example of the mode illustrated in FIG. 2A is a configuration example in which the second inlet 6 is provided on the back side of the sensor holder 4. The side where the first inlet 5 is provided is the front side of the sensor holder 4. In this configuration example, by providing the second inlet 6 on the back side of the sensor holder 4, the introduced air is exhausted from the exhaust port 7 along with the pyrolysis gas through the back side and the side surface of the sensor holder 4.

FIGS. 2B and 2C show an example of a configuration in which the second inlet 6 is provided on the side of the sensor holder 4. In this configuration example, by providing the second inlet 6 on the side surface of the sensor holder 4, the introduced atmosphere is exhausted together with the pyrolysis gas from the exhaust port 7 through the side surface or the back side and the side surface of the sensor holder 4. Is done. The atmosphere can cool the sensor 2 and the sensor holder 4 during this passage.

In the example shown in FIGS. 2 (b) and 2 (c), the atmosphere passes through the sensor 2 and the sensor holder 4 when passing therethrough.
Can be cooled. Further, since only the pyrolysis gas introduced from the first inlet 5 passes through the vicinity of the sensor detection surface 3, the gas concentration does not decrease due to the atmosphere.
In addition, the opening / closing door 9 can be provided according to the installation position of the second introduction port 6. According to the configuration example illustrated in FIG. 2, the configuration can be such that the partition wall included in the configuration example illustrated in FIG. 1 is removed, and by flowing the air along the outer peripheral surface of the sensor holder 4, Can be efficiently cooled.

Next, control of an opening / closing door for opening / closing a second inlet for introducing air will be described. In a first mode of the opening / closing control of the opening / closing door, the opening / closing control is performed at a predetermined time. In this mode, the second introduction port is closed by the opening / closing door 9 for a certain period of time after the power is turned on, and only the pyrolysis gas is introduced. During this time, the temperature inside the sensor holder 4 is increased by the heat of the pyrolysis gas. After a certain period of time, the opening and closing door 9 is opened to introduce the atmosphere.

In this embodiment, the opening and closing of the opening and closing door 9 can be linked to the temperature control of the heater used for thermal decomposition. According to this configuration, control can be performed without adding a circuit or software for opening / closing control.

The second, third, and fourth aspects of the opening and closing control of the opening and closing door perform the opening and closing control of closing the opening and closing door 9 at the time of measurement. In the second mode, the second introduction port 6 is closed by the opening / closing door 9 while the pyrolysis unit provided in the plastic discriminating device is pressed against the plastic material to be measured to measure only the pyrolysis gas. Introduce. During this time, the temperature inside the sensor holder 4 is increased by the heat of the pyrolysis gas. When the measurement is completed, the pyrolysis section is separated from the plastic material to be measured, and the opening and closing door 9 is opened to introduce the atmosphere.

FIG. 3A is a schematic diagram for explaining the second mode. In the figure, a plastic discriminating device 1
Is provided with a movable slide cover 11 at the distal end so as to cover the heater 10, and the opening and closing door 9 can be interlocked with the sliding movement of the slide cover 11 via the interlocking rod 12. When measurement is performed by the plastic discriminating device 1, the tip of the plastic discriminating device 1 is
The heater 10 pressed against the plastic material is pressed against the subject S. Sensor 1 The pyrolysis gas generated by this heating is sucked through first inlet 5 to detect the gas species. At this time, when the tip of the slide cover 11 comes into contact with the subject S, the slide cover 11 is pushed toward the sensor 1, and is further closed by pressing the opening / closing door 9 against the second inlet 6 via the interlocking rod 12. I do. As a result, only the pyrolysis gas is guided to the sensor detection surface. The exhaust gas after the detection is discharged through the second inlet 7.

At the end of the measurement, the slide cover 11
When the front end is separated from the subject, the opening / closing door 9 opens the second inlet 6 to allow the introduction of air, thereby cooling the sensor 2 and the sensor holder 4. According to this second aspect,
At the time of measurement, the suction amount of the pyrolysis gas increases, so that even when the flow of the pyrolysis gas becomes gentle, an effect that the pyrolysis gas easily reaches the sensor surface can be expected.

In the above configuration example, the opening and closing of the opening and closing door 9 is performed in conjunction with the slide cover. However, the opening and closing of the opening and closing door 9 may be performed using an electric mechanism.

The third mode of the opening and closing control of the opening and closing door performs the opening and closing control based on the measurement result of the temperature sensor and the humidity sensor. In this embodiment, a temperature sensor and a humidity sensor are provided inside the sensor holder, at the sensor portion, or at the periphery thereof, and the temperature and humidity are monitored by the temperature sensor and the humidity sensor. For example, when the measured temperature is lower than a preset temperature, the opening and closing door 9 is closed and only the pyrolysis gas is introduced, and the temperature is raised to suppress the occurrence of dew condensation. on the other hand,
If the measured temperature is higher than the preset temperature,
The opening and closing door 9 is opened to introduce air in addition to the pyrolysis gas to lower the raised temperature and prevent damage to the sensor and the exhaust pump due to overheating.

When the measured humidity is higher than the preset humidity, the door 9 is closed to introduce only the pyrolysis gas, and the temperature is raised to suppress the occurrence of dew condensation. On the other hand, when the measured humidity is lower than the preset humidity, the opening and closing door 9 is opened to introduce air in addition to the pyrolysis gas, and the sensor is overheated by the pyrolysis gas or the exhaust pump is damaged by the high-temperature exhaust gas. To prevent Further, it is also possible to control the opening and closing of the door based on the measurement results of both the temperature sensor and the humidity sensor.

FIG. 3B is a schematic diagram for explaining the third mode. In the figure, a control unit 15 controls the drive of a drive motor 16 based on measurement signals from a temperature sensor 13 and a humidity sensor 14. The control means 15 can change the driving conditions of the driving motor 16 by adjusting the set temperature and the set humidity.

A fourth mode of the opening / closing control of the opening / closing door is a measuring switch (for example, FIG.
The opening / closing door is closed while the measurement switch 17) in (a) and (b) is pressed. In the plastic discriminating apparatus, when the power switch is turned on, the pyrolysis means is heated and the suction pump is driven to introduce the pyrolysis gas. Therefore, the thermal decomposition means and the suction pump are driven even during standby. In this embodiment, while the measurement switch is pressed to set the measurement mode, the opening / closing door is closed and only the pyrolysis gas is introduced.

According to the partition wall of the embodiment of the present invention, the temperature rise can be suppressed by cooling the sensor holder and the sensor by heat conduction. By introducing only the separation gas to the sensor detection surface of the gas sensor, it is possible to prevent the concentration of the gas component from being reduced by the atmosphere.

According to the aspect of the present invention, it is possible to prevent the sensor performance from deteriorating or deteriorating due to the high temperature of the pyrolysis gas. According to the aspect of the present invention, it is possible to prevent the detection sensitivity of the sensor from decreasing due to the humidity of dew condensation. According to the aspect of the present invention, the temperature of the exhaust gas flowing to the exhaust pump is reduced,
Further, by lowering the concentration of the gas component contained in the exhaust gas, it is possible to prevent the performance of the exhaust pump from lowering. According to the aspect of the present invention, since the flow rate of the exhaust pump is not changed, it is possible to prevent the cooling effect of the exhaust gas from being reduced due to the introduction of the atmosphere.

[0040]

As described above, according to the plastic discriminating apparatus of the present invention, it is hardly affected by the temperature and humidity, and the pyrolysis gas can be detected stably.

[Brief description of the drawings]

FIG. 1 is a view for explaining an outline of functions of a plastic discriminating apparatus of the present invention.

FIG. 2 shows a second embodiment of the plastic discriminating apparatus of the present invention.
It is the schematic for demonstrating the example of a mode of an inlet.

FIG. 3 is a schematic diagram for explaining a mode of opening / closing control of an opening / closing door of the plastic discriminating apparatus of the present invention.

FIG. 4 is a schematic diagram for explaining a configuration example of a conventionally proposed plastic discriminating apparatus.

[Explanation of symbols]

1, 101: plastic discriminator, 2, 102: sensor, 3, 103: sensor detection surface, 4, 104: sensor holder, 5: first inlet, 6: second inlet, 7, 107
Exhaust port, 8 ... partition, 9 ... door, 11 ... slide cover, 12 ... connecting rod, 13 ... temperature sensor, 14 ... humidity sensor, 15 ... control means, 16 ... drive motor, 17 ... measurement switch, 105 ... intake Mouth, 106: thermal decomposition means, S
... subject.

Claims (6)

[Claims] 1. A plastic discriminating apparatus for discriminating a plastic contained in a subject by detecting a gas type of a pyrolysis gas generated by pyrolysis of a plastic with a gas sensor. A plastic discriminator characterized by being configured to be air-coolable. 2. A plastic discriminating apparatus for discriminating a plastic contained in an object by detecting a gas type of a pyrolysis gas generated by pyrolysis of a plastic with a gas sensor, wherein the decomposition gas is detected by a sensor detection surface of the gas sensor. A plastic discriminating device, wherein air is introduced into a portion of the gas sensor other than the sensor detection surface. 3. The plastic discriminating apparatus according to claim 2, further comprising a partition for separating the introduced heat separation gas and the atmosphere and guiding only the heat separation gas to a sensor detection surface of the gas sensor. 4. The plastic discriminating apparatus according to claim 3, wherein said partition is made of a material having good thermal conductivity. 5. A first inlet for introducing a pyrolysis gas and a second inlet for introducing air, wherein the first inlet guides the introduced pyrolysis gas to a sensor detection surface of a gas sensor. 5. The plastic discriminating apparatus according to claim 2, wherein the introduction port guides the introduced atmosphere around the sensor excluding the sensor detection surface. 6. The plastic discriminating apparatus according to claim 1, wherein an inlet for introducing air is openable and closable.