JPH0663945A - Apparatus for discriminating waste plastic - Google Patents

Abstract

PURPOSE:To prevent the exposure of a gas detector to high concentration gas in the title apparatus judging whether a vinyl chloride composing substance is contained in the gas generated from heated waste plastic to discriminate whether waste plastic is polyvinyl chloride. CONSTITUTION:A waste plastic discriminating apparatus is equipped with a probe 5 for collecting gas, a gas detector 4 judging whether a vinyl chloride composing substance is contained in gas, the gas introducing passage 7 sending the gas from the probe 5 to the gas detector 7, a gas purging atmosphere introducing passage 8 and an introducing passage changeover device 1 selectively connecting either one of the atmosphere introducing passage 8 and the gas introducing passage 7 to the gas detector 4. When the concn. of the gas in the detector 4 is a detectable level or more, the atmosphere intoruding passage 8 is connected to the detector 4 and, when the concn. of the gas in the detector 4 is below the detectable level, the gas introducing passage 7 is connected to the detector 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention determines that waste plastic is vinyl chloride by determining whether or not the gas generated from the heated waste plastic contains vinyl chloride composition substances such as hydrogen chloride and chlorine. The present invention relates to a waste plastic identifying device for identifying whether or not

[0002]

2. Description of the Related Art Conventionally, as a waste plastic identification device of this kind, a probe for collecting gas generated from heated waste plastic and a gas detector for judging whether or not chlorine is contained in this gas. And a gas introduction path for sending gas from the probe to the gas detector are known.

[0003]

In the above-mentioned conventional waste plastic identification device, it is necessary to use a highly sensitive chlorine gas detector in order to judge whether or not chlorine is contained in a low concentration gas. However, with such a high-sensitivity detector, when a gas with a concentration higher than that required for determination is introduced into the gas detector, the gas is still present for a long time even after the gas is removed. There is a problem that there is a saturation phenomenon that continues to output as if it is happening, that you have to wait until the next measurement is subsided, the sensitivity of the gas detector deteriorates, or the gas detector is damaged. there were.

An object of the present invention is that the gas detector is not exposed to a high-concentration gas, and therefore the saturation phenomenon does not occur even when a highly sensitive gas detector is used, so that the next measurement is performed immediately. It is an object of the present invention to provide a waste plastic identification device that can be used and does not deteriorate the sensitivity of the detector or damage the detector.

[0005]

A waste plastic identification device according to the present invention includes a probe for collecting gas generated from heated waste plastic and a vinyl chloride composition substance such as hydrogen chloride or chlorine contained in the gas. In the waste plastic identification device for identifying whether the waste plastic is vinyl chloride, a gas detector for determining whether the waste plastic is vinyl chloride is provided, and a gas introduction path for sending gas from the probe to the gas detector. An atmosphere introduction path and an introduction path switching device that selectively connects one of the atmosphere introduction path and the gas introduction path to the detector are provided, and the atmosphere is introduced when the gas concentration in the detector is above the detectable level. The passage is connected to the detector, and the gas introduction passage is connected to the detector when the gas concentration in the detector is below a detectable level. Than it is.

[0006]

According to the waste plastic identification device of the present invention,
When the gas concentration in the detector reaches the detectable level and measurement becomes possible, the air introduction path is connected to the detector,
The gas in the gas detector is expelled by the atmosphere, and the gas concentration drops. Therefore, the gas detector is not exposed to high concentration gas. When the measurement is completed, the gas introduction path is connected to the detector, and the next measurement can be performed immediately.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a waste plastic identifying apparatus of the present invention, which is a probe for collecting gas generated from heated waste plastic.
(5), a probe contact sensor (6) that detects whether the probe (5) is in contact with the waste plastic, and whether the gas contains vinyl chloride composition substances such as hydrogen chloride and chlorine. Gas detector (4) for determining whether or not the introduction path switching device is arranged between the probe (5) and the gas detector (4).
(1), a switching device driving device (2), and a switching signal generator (3).

The probe (5) and the introduction path switch (1) are connected by a gas introduction path (7), and the introduction path changer is connected.
At (1), there is an air introduction path (8) with one end open to the atmosphere,
An introduction passage switch (1) and a gas discharge passage (10) for discharging the gas in the gas introduction passage (7) are provided. The introduction path switch (1) and the gas detector (4) are connected to the connection path (9).
The gas detector (4) is provided with a gas discharge path (11) for discharging the gas in the gas detector (4).

The introduction passage switch (1) is connected to the gas introduction passage (7).
And either the air introduction path (8)
It is connected to the detector (4) via (9) and is driven by a switching device driving device (2) which operates according to the signal output from the switching signal generator (3).

As the detector (4), for example, a detector capable of detecting a gas concentration of about 5 ppm is used. As will be described later, when the gas concentration in the detector (4) is above the detectable level, it is introduced into the atmosphere. The line (8) is connected to the detector (4) so that the gas inlet line (7) is connected to the detector (4) when the gas concentration in the detector (4) is below the detectable level. ing.

FIG. 2 shows a time chart of various signals.

FIG. 2A shows the gas concentration in the gas detector (4), and FIG. 2B shows the gas detectable level. S1 in FIG. 2 indicates a gas detection signal. S1 is on when the gas concentration A in the gas detector (4) is higher than the gas detectable level B, and S1 is off when the gas concentration A is less than the gas detectable level B. Signal is input to the switching signal generator (3). S2 in FIG. 2 shows the output signal of the probe contact sensor (6). S2 is off when the probe (5) is not in contact with the plastic and S2 is on when the probe (5) is in contact with the plastic. Signal is input to the switching signal generator (3). S3 of FIG. 2 shows a switching signal output from the switching signal generator (3),
A switch driving device is a signal of S3 on when the gas detection signal S1 and the output signal S2 of the probe contact sensor (6) are both on, and a signal of S3 off when both S1 and S2 are off.
It is output to (2). If S3 is on, the introduction path switch (1) is driven so that the atmosphere introduction path (8) is connected to the detector (4), and if S3 is off, the gas introduction path (7) ) Is connected to the detector (4), the introduction path switch (1) is driven.

At the initial stage when the probe (5) whose time is from 0 to t1 is not in contact with the plastic, S1, S2,
Both S3 are off.

When the probe (5) is brought into contact with the plastic at time t1, S2 is turned on and the gas concentration A in the gas detector begins to increase.

Then, at time t2 when A becomes the gas detectable level B or higher, S1 and S3 are turned on. At this stage, since the gas concentration A in the gas detector is at the detectable level B or higher, the gas detector (4) detects the presence of vinyl chloride composition substances such as hydrogen chloride and chlorine in the gas generated from the waste plastic. Whether it is included or not can be determined to identify whether the plastic is vinyl chloride.

When S3 is turned on at time t2, the introduction path switching device
(1) is driven and the air introduction path (8) is connected to the detector (4). Then, the gas concentration A in the gas detector (4) temporarily rises slightly due to the residual gas in the connection path (9),
After that, the gas inflow into the gas detector (4) is stopped, and the gas in the gas detector (4) is expelled by the atmosphere, and the gas concentration A drops. Therefore, the gas detector (4)
Are not exposed to high concentrations of gas.

At time t3, the probe (5) is separated from the plastic and S2 is turned off.

At time t4, A becomes less than the gas detectable level B, and S1 is turned off.

If S2 is off and S1 is off, S
3 is also turned off, the introduction passage switching device (1) is driven, the gas introduction passage (7) is connected to the detector (4), and the next measurement can be performed. Since S3 is designed to generate an off signal when both S1 and S2 are off,
No further measurements can be taken while the probe (5) is in contact with the plastic.

In the above embodiment, the probe contact sensor (6)
And the switching signal S3 output from the switching signal generator (3) is output to the output signal S of the probe contact sensor (6).
Although it is determined by the calculation of 2 and the gas detection signal S1, the probe contact sensor (6) can be omitted and the gas detection signal S1 itself can be used as the switching signal S3. In this case, install a timer circuit and wait for a certain period of time after the gas concentration A in the gas detector (4) becomes less than the gas detectable level B before the gas introduction path (7) is detected. It is preferable to connect to (4).

[0022]

According to the waste plastic identifying apparatus of the present invention, when the gas concentration in the detector is above the detectable level, the gas in the gas detector is expelled by the atmosphere and the gas concentration decreases, and the gas detector Is not exposed to high-concentration gas, the saturation phenomenon does not occur even when using a highly sensitive gas detector. Further, the sensitivity of the detector is not deteriorated and the detector is not damaged. Then, when the gas concentration falls below the detection level, the gas introduction path is connected to the detector, and the next measurement can be performed immediately.

[Brief description of drawings]

FIG. 1 is a block diagram showing a waste plastic identification device according to the present invention.

FIG. 2 is a time chart showing changes in various signals in the waste plastic identification device according to the present invention.

[Explanation of symbols]

 (1) Inlet switching device (4) Gas detector (5) Probe (7) Gas inlet (8) Atmosphere inlet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideki Shiozaki Inventor, Hideki Shiozaki 5-3-3, Nishikujo 5-chome, Konohana-ku, Osaka City Hitachi Shipbuilding Co., Ltd.

Claims (1)

[Claims] 1. A probe (5) for collecting gas generated from heated waste plastic, and a gas detector for judging whether or not a vinyl chloride composition substance such as hydrogen chloride or chlorine is contained in this gas. (4) and the gas introduction path (7) that sends gas from the probe (5) to the gas detector (4), and in the waste plastic identification device that identifies whether the waste plastic is vinyl chloride, the gas purge Air introduction path for
(8) and an introduction path switching device (1) that selectively connects one of the air introduction path (8) and the gas introduction path (7) to the detector (4). ) Is connected to the detector (4) when the gas concentration in the detector (4) is above the detectable level, and when the gas concentration in the detector (4) is below the detectable level (). Waste plastic identification device, characterized in that 7) is adapted to be connected to the detector (4).