JPS6230834B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting and separating small pieces of black plastic or rubber contaminating pulp raw materials such as wood chips and grains such as wheat and noodles. Actively utilizes the difference in heat ray absorption ability with black substances such as plastic and rubber that contain carbon black,
The purpose is to detect the presence of the black material pieces using a heat ray detection sensor and separate and remove them. In recent years, plastic products have been widely used in a variety of fields, and their applications have been expanding more and more, but on the other hand, small pieces of disused plastic products have been mixed into pulp raw materials and grains, and this has caused problems. This has caused problems in the processing of pulp raw materials and grains. For example, if small pieces of plastic bags, strings, tags, name tags, containers, toys, and other plastic products and rubber products (hereinafter collectively referred to as "plastics") are contaminated with wood chips, If this pulp is made into paper as it is, plastics will get mixed into the paper layer, causing holes in the paper and paper breakage. The same is true when non-wood pulp raw materials such as straw, bagasse, hemp, rags, cotton, linters, and even waste paper are contaminated with plastics, and the above situation occurs when wood chips are used. There is no difference at all. Plastics are generally chemically stable, so even when they are treated with chemicals under high temperature and high pressure during the pulping process, they are only deformed by heat at most, and even further broken into fine pieces by mechanical action such as a beating machine. Because of the crushing, it is extremely difficult to remove plastics from pulp slurry using conventional screens. Further, even if a centrifugal force type cleaner is used, since the difference in specific gravity between pulp and plastics is small, there is the disadvantage that separation efficiency is low despite consuming a large amount of power. Therefore, if the pulp raw material is contaminated with plastics, it is preferable to remove the plastics in advance. When grains such as soybeans are contaminated with plastics, it is desirable that the plastics be removed before processing, even if the grain is intended to be eaten. However, there is currently no effective means for removing plastics mixed into pulp raw materials or grains, and currently the discovery and extraction of plastics scattered in pulp raw materials or grains relies entirely on manual labor. The reality is that it is true. In view of this situation, the present inventors previously detected the presence of plastics in wood chips mixed with plastics using an electrometer, using the difference in chargeability between plastics and wood chips. How to remove this (Japanese Patent Application No. 113564/1983)
proposed. However, this method cannot be applied to plastics, especially plastics that contain a relatively large amount of carbon black and have a black color (hereinafter referred to as
These are used for the purpose of separating and removing small pieces of black plastics (collectively referred to as "black plastics"). It has become clear that black plastics are difficult to charge even if they are charged using a method of electrification, and as a result, the presence of black plastics cannot be sufficiently detected. If paper is made while containing such black plastics, for example in OCR paper, the black plastics present in the paper layer will cause malfunctions in character reading. Therefore, it is desired to reliably separate and remove such pieces of black material. Therefore, the present inventors have conducted extensive research into methods for efficiently separating such pieces of black material, and have found that since black material pieces have an extremely high heat ray absorption ability, they can be treated with heat rays using, for example, an infrared heater, for a short period of time. Although the temperature rises over time, pulp raw materials such as wood chips and grains generally contain a large amount of moisture, so their heat ray absorption capacity is small and their heat capacity is large, so it is important to note that their temperature does not rise even when irradiated with heat rays. However, we succeeded in developing a separation method that utilizes this difference in heat ray absorption ability. In the present invention, pulp raw materials such as wood chips and grains such as wheat and noodles, which are contaminated with small pieces of black plastics containing carbon black, are subjected to heat irradiation treatment, and the black plastics and the pulp raw materials and grains are treated with heat rays. This detection and separation method is characterized in that the presence of black plastics is detected by a heat ray detection sensor using the difference in heat ray absorption ability of the two, and the plastics are separated from the pulp raw materials and grains. The method of the present invention is to subject black plastics contaminant to pulp raw materials or grains that are being transferred to heat ray irradiation treatment and measure the amount of radiated heat rays by using a heat ray detection sensor. After connecting a comparator (potential comparator) to the
A timer is activated by the signal from the comparator.
After the set time of the timer has elapsed, the transfer device is stopped by the output signal of the timer, or the black plastic removal device described later is activated. The timer stops the transfer device after a certain time delay after the heat ray detection sensor detects plastics contaminant in the pulp raw material or grains, or stops the transfer device. It is used to operate automatic pulp material or grain removal equipment. Hereinafter, specific means for separating and removing black plastics from wood chips using this method will be summarized. (1) After introducing the output of the heat ray detection sensor into a comparator, the output signal of the comparator is introduced into a display device such as an alarm. In such a case, if the amount of radiant heat rays captured by the heat ray detection sensor exceeds a certain value, a lamp will turn on or an alarm will sound. On the other hand, since the output signal of the comparator is also supplied to a separately provided timer, the transfer device such as a belt conveyor is stopped after a predetermined time delay through the timer. In other words, if the wood chips are contaminated with black plastics, the presence of the plastics is detected by the heat ray detection sensor, and when the amount of radiant heat rays exceeds a certain value, the comparator is activated and an alarm sounds and the pilot lamp lights up. In addition, this method uses a timer to stop the belt conveyor after a certain period of time and manually removes only the black plastic from the wood chips. (2) When the presence of black plastics is detected by a comparator connected to a heat ray detection sensor, the pilot lamp lights up, an alarm sounds, and a timer causes the wood chip remover to move on the transfer device after a short delay. To automatically remove wood chips containing black plastics in the lateral direction of a belt conveyor. (3) As a device for removing black plastics from wood chips, this device is installed at the discharge end of the transfer device, and it is automatically moved at a timely manner to remove the wood chips containing the plastic. There is also a method of removing black plastics by moving them to another location. Note that the comparator used in the present invention is operated so that the lower limit of the absolute value of the measured potential is set in advance and it automatically determines whether the measured value is greater than the lower limit, and is used as a type of potential comparison. It is a vessel. In addition, in order to effectively perform heat irradiation treatment on the pulp raw materials or grains transferred on the transfer device and to be able to effectively detect the amount of radiant heat rays on black plastics, it is necessary to simply irradiate the pulp raw materials or grains. Preferably, it is flowed over the transfer device in layers. As mentioned above, when carrying out the present invention, pulp raw materials or grains that move on a transfer device often have dust attached to them, so the attached dust is removed via a vibrating screen before being irradiated with heat rays. Treatment is effective in increasing the heat absorption capacity of black plastics. Such heat ray irradiation treatment is performed using a heat ray irradiator such as a heater or lamp that emits infrared rays, and the heat ray irradiators may be installed in one or more rows in parallel perpendicular to the flow direction of the transfer device. preferable. The output of the heat ray irradiator is usually used in the range of 50W to 1KW, and depends on the moving speed of the transfer device such as a conveyor, the slope of the inclined plate, the distance to the heat ray detection sensor, and the distance between the heat ray irradiator and the transfer device. It can be decided as appropriate.
In addition, the distance between the heat ray irradiator and the transfer device is 3 to 20 cm.
Generally, it is adjusted to a certain degree. Further, the heat ray detection sensor is also called an infrared sensor or a heat ray sensor, and detects an extremely small amount of radiant heat ray, and is broadly classified into a quantum type and a thermal type. The quantum type converts infrared rays directly into an electrical signal, while the thermal type converts the radiant heat rays into a temperature rise of an element with charge raising property, and then secondarily converts it into an electrical signal. The former quantum type is used when high performance is required. and,
The heat ray detection sensors are preferably arranged in an array at positions that prevent the heat irradiated black material from cooling, and are spaced apart so that the heat rays from the heat ray irradiator do not directly enter the heat ray detection sensor. Alternatively, a heat ray shield cover made of a metal plate or the like may be provided between the heat ray irradiator and the heat ray detection sensor. Further, it is preferable that the distance between the heat ray detection sensor and the transfer device is such that the heat ray detection sensor is as close as possible to the flowing layer of pulp raw material or grain, etc.
Installed in a location that does not come into contact with pulp raw materials or grains. Furthermore, when the moving speed of a conveyor or the like increases when detecting and separating black substances, the performance can be increased by providing a differential amplification circuit for the detection output of the heat ray detection sensor. Black substances that can be detected by a heat ray detection sensor by heat irradiation include, for example, carbon black in natural rubber, synthetic rubbers such as butadiene and isoprene, or plastics such as polyvinyl chloride, polyethylene, polystyrene, and polyester. , acetylene black, lamp black, iron black, graphite, mineral black, aniline black, etc. are added to give a black color.
Compared to pulp materials such as bagasse, hemp, rags, cotton, linters, and waste paper, and grains such as wheat and noodles, it has a significantly greater ability to absorb heat rays. Hereinafter, the present invention will be specifically explained based on the accompanying drawings. Embodiment 1 As shown in FIG. 1, wood chips are transported from a storage container 1 containing wood chips via a vibrating feeder 3 to a belt conveyor 2 with a mesh size of 32, for example.
The chips are smoothed into a single layer on a conveyor. On the other hand, above the transfer surface of the conveyor 2 is a 300W
Two infrared heaters 4 are provided, and the wood chips being transported are subjected to heat irradiation treatment. The transfer speed of the belt conveyor is, for example, 20 m/min. Also, approximately 1.5 mm is placed behind the infrared heater 4.
Quantum type heat ray detection sensors 5 arranged in an array at a distance of about m are installed perpendicular to the conveying direction of the conveyor, and are configured to measure the amount of radiant heat rays irradiated to the chips. Furthermore, a heat ray shield cover 6 is installed approximately 90 cm away from the infrared heater 4 to prevent the heat rays from the infrared heater from directly entering the heat ray detection sensor. The output measured by the heat ray detection sensor 5 is introduced into the comparator 7 shown in FIG. 1, and the comparator detects whether or not the potential is higher in absolute value than the reference potential. For example, if the lower limit potential of the comparator 7 is set to -3 volts and a higher potential is detected in absolute value, the pilot lamp 8 is turned on by the detection signal, or the alarm 9 is turned on at the same time. make a sound. As mentioned above, when the detection signal of the comparator is emitted, it indicates that black plastics are contained in the wood chips.
The presence of plastics is notified by the above means, and at the same time, a separately installed timer 12 is activated in response to the signal, and the driving drum 2a of the conveyor 2 is stopped after a certain period of time has elapsed. Thereafter, the plastics contained in the chips on the belt conveyor are manually removed. Thus, the present invention also includes a method for automatically detecting black plastics contained in wood chips and manually removing them. Example 2 Next, an example will be presented in which wood chips containing black plastics are automatically and locally removed without using human hands. In the apparatus shown in FIG. 1, a hopper 11 is attached to the discharge end of the belt conveyor 2, branch pipes 13a and 13b having a sorting damper 12 are disposed in this hopper, and the drive source 14 of the damper 12 is connected to the above-mentioned drive source 14. The timer 10 signal is supplied. Therefore, the damper 12 is normally set at the position shown by the chain line in the figure, so that the chips discharged from the conveyor 2 are stored in the receiver 15. If black plastics are mixed in the wood chips, their presence is automatically detected as described above, the timer 10 is activated, and the damper 12 is activated after a predetermined period of time has elapsed.
is switched to the position shown with a solid line in the figure. In such a case, the chips containing black plastics are stored in the receiver 16 via the branch pipe 13b. Embodiment 3 In the case shown in FIG. 2, a reciprocating plastic receiver 18 attached to the piston rod of a cylinder 17 is disposed at the discharge end of the conveyor 2. The electromagnetic solenoid type spool valve 19 switches,
Black plastics are thereby automatically removed. The time from detecting the presence of black plastic as described above to activating the damper 12 or the reciprocating plastic receiver 18 is as follows:
The transfer speed of the belt conveyor 2 is related to the mounting position of the heat ray detection sensor 5, and it also depends on the distance to the end of the conveyor, so it is set appropriately taking these into consideration. The relative relationships in each of the above-mentioned Examples are listed below. 【table】

[Brief explanation of the drawing]

Fig. 1 is a side view schematically showing an example of an apparatus for carrying out the method of the present invention, Fig. 2 is a longitudinal sectional view of a part showing another embodiment of the removal apparatus, and Fig. 3 is a heat ray detection FIG. 2 is a layout diagram showing sensors in an array. 1: Storage device, 2: Belt conveyor, 3: Vibration feeder, 4: Infrared heater, 5: Heat ray detection sensor, 6: Heat ray shield cover, 7: Comparator, 8: Lamp, 9: Alarm, 10: Timer,
11: Hopper, 12: Damper, 13a, 13b:
Branch pipe, 14: Damper drive device, 15, 16, 1
8: Receptor, 17: Cylinder, 19: Spool valve.

Claims (1)

[Claims] 1 Pulp raw materials or grains contaminated with black material pieces are subjected to heat irradiation treatment, and the black material pieces are removed by utilizing the difference in heat ray absorption ability between the pulp raw materials or grains and the black material pieces. 1. A method for detecting and separating contaminated black material fragments, the method comprising: detecting the presence of contaminated black material fragments using a heat ray detection sensor, and separating the black material fragments from pulp raw materials and grains. 2. Pulp raw materials and grains contaminated with black material pieces are distributed in a thin layer on a conveyor or inclined plate, and while being transported, heat ray detection sensors arranged in an array above the material are distributed. Therefore, a claim is made in which the difference in heat ray absorption ability between them is detected, and the detection signal is used to stop the transfer device and separate the black material pieces, or to activate a removal means installed in the transfer device. range 1
The method described in section. 3. The output of the heat ray detection sensor is introduced into a comparator, and the output signal of the comparator is used to operate a display device such as a pilot lamp or an alarm, and the output signal is guided to a timer, and after the set time of the timer has elapsed, a piece of black material is detected. 3. The method according to claim 1, further comprising activating a device for removing. 4. Claim 1, wherein a hopper having a branch pipe is disposed in the discharge pipe of the transfer device, and a damper for distribution is attached to a branching part of the branch pipe.
3. The method described in Section 2, Section 2, or Section 3. 5. The method according to claim 1, 2 or 3, wherein a reciprocating black material particle receiver is attached to the discharge pipe of the transfer device. 6. The method according to claim 1, wherein the black material pieces are black plastics.