JP3984275B2 - Waste plastic processing equipment - Google Patents

Description

  The present invention relates to a waste plastic processing apparatus that thermally decomposes and processes waste plastic.

  In general, waste plastic is melted in a desalting apparatus, desalted, and transferred to a melting tank. In the melting tank, the molten plastic is stirred while being heated, and the desalted gas is efficiently released. Thereafter, the molten plastic that has been desalted substantially completely is transferred to the thermal decomposition apparatus via a discharge mechanism provided in the melting tank.

  The thermal decomposition apparatus thermally decomposes molten plastic to generate oil gas and residue. The oil gas is produced as a product oil by a product oil recovery tower or the like and reused as fuel. The residue is collected in a residue collection container and is also reused as solid fuel or the like.

  In the conventional waste plastic processing apparatus, when the waste plastic is put into the desalting apparatus, the waste plastic may form a so-called “bridge”, and the throwing into the desalting apparatus may not be performed smoothly.

  Moreover, in the conventional waste plastic processing apparatus, it is not preferable in view of safe operation of the apparatus that the heat on the desalination apparatus side is transferred to the waste plastic charging machine. In particular, if the concentration of oxygen that can be present on the input side is high, there may even be a fire or explosion hazard.

  The present invention has been made in consideration of the above points, and a waste plastic processing apparatus in which waste plastic is smoothly introduced into a desalination apparatus and the risk of fire and explosion is remarkably reduced. The purpose is to provide.

The present invention includes a hopper into which granulated waste plastic is charged, a discharge device that discharges the waste plastic charged into the hopper, a storage device that can temporarily store the waste plastic discharged from the discharge device, An inert gas introduction device capable of purging the storage device with an inert gas, a desalination device for dechlorinating waste plastic that has passed through the storage device, and heat from the desalination device being prevented from being transferred to the storage device A cooling device, and the inert gas introduction device is provided with an introduction amount control device that controls the amount of inert gas introduced into the storage device, and an oxygen concentration meter that measures the oxygen concentration in the storage device. provided, introduction amount control device based on the measurement result of the oxygen concentration meter, it is adapted to control the inert gas introduction amount to the storage device in waste plastic processing apparatus according to claim That.

According to the present invention, since the storage device serves as a so-called “buffer”, it is possible to always smoothly put waste plastic into the desalination device. Further, the provision of the cooling device prevents the heat on the desalination device side from being transmitted to the hopper. Furthermore, since the storage device can be purged with the inert gas by the inert gas introduction device, the concentration of oxygen mixed in the storage device can be reduced, and the occurrence of fire or the like can be further suppressed. Further, since the inert gas introduction device is provided with an introduction amount control device for controlling the amount of inert gas introduced into the storage device, it is possible to always introduce an appropriate amount of inert gas into the storage device. is there. Specifically, the oxygen concentration meter is provided for measuring the oxygen concentration in the reservoir device, by introducing amount control device controls the inert gas supply amount to the storage device based on the measurement result of the oxygen concentration meter, It is possible to always introduce an appropriate amount of inert gas into the storage device.

  Preferably, the storage device has a storage pipe arranged in a substantially vertical direction, and an upper level sensor for detecting whether waste plastic is stored up to the position is provided at an upper position of the storage pipe. The lower position of the storage pipe is provided with a lower level sensor for detecting whether or not the waste plastic is stored up to the position. When the sensor detects, the waste plastic thrown into the hopper is discharged until the upper level sensor detects that the waste plastic is stored up to the upper position. In this case, the function as a “buffer” of the storage device can be efficiently realized, and quantitative supply of waste plastic to the desalting device can be easily realized.

  The discharge device is, for example, a circle feeder having an opening for discharging waste plastic. In this case, preferably, the opening area of the opening is variable, and the rotation speed of the circle feeder is variable.

  Alternatively, the discharge device is a rotary valve having a rotation mechanism for discharging the waste plastic. In this case, preferably, the rotation speed of the rotation mechanism is variable.

  Further, it is preferable to purge not only the storage device but also the cooling device with an inert gas. For this reason, it is preferable to provide a second inert gas introduction device for purging the cooling device with an inert gas.

  In addition, it is preferable that the cooling device is provided with a cooling amount control device for controlling the degree of cooling when the waste plastic discharged from the storage device is cooled. In this case, the waste plastic can be properly cooled at all times. For example, when a thermometer for measuring the temperature of waste plastic in the storage device or the cooling device is provided, the cooling amount control device preferably controls the degree of cooling of the waste plastic based on the measurement result of the thermometer. .

As described above, in the waste plastic processing apparatus of the present invention, the storage device plays a role of a so-called “buffer”, so that the waste plastic can be smoothly and constantly charged into the demineralizer. Further, the provision of the cooling device prevents the heat on the desalination device side from being transmitted to the hopper. Furthermore, since the storage device is purged with the inert gas by the inert gas introduction device, the concentration of oxygen mixed in the storage device can be reduced, and the occurrence of a fire or the like can be further suppressed. Further, since the inert gas introduction device is provided with an introduction amount control device for controlling the amount of inert gas introduced into the storage device, it is possible to always introduce an appropriate amount of inert gas into the storage device. is there.

  An embodiment of a waste plastic processing apparatus according to the present invention will be described below with reference to FIG.

  As shown in FIG. 1, the waste plastic processing apparatus 1 of this Embodiment is provided with the hopper 11 into which the granulated waste plastic is thrown. A discharge port 11 d is provided in the lower portion of the hopper 11. The discharge port 11d is connected to the connection pipe 13 via a circle feeder 12 (discharge device) that discharges waste plastic that has been input to the hopper 11.

  The circle feeder 12 is a rotating body having an opening, and the number of rotations is variable. Furthermore, the circle feeder of the present embodiment is configured such that the opening area of the opening is variable. When the opening of the circle feeder 12 overlaps the discharge port 11d of the hopper 11, the waste plastic is discharged to the connection pipe 13 through the discharge port 11d and the opening. On the other hand, if the circle feeder 12 stops in a state where the opening of the circle feeder 12 does not overlap the discharge port 11 d of the hopper 11, the waste plastic is not discharged to the connection pipe 13.

  A storage pipe (storage device) 15 capable of temporarily storing waste plastic is connected to the connection pipe 13. The storage pipe 15 of the present embodiment is arranged in a substantially vertical direction and is connected to the connection pipe 13 at the upper end. A valve 16 (storage device) is provided at the lower end, and the opening and closing of the valve 16 is controlled, so that waste plastic can be temporarily stored. The opening and closing of the valve 16 can be appropriately controlled in accordance with an operation processing amount of the desalination apparatus 20 described later.

  In the present embodiment, an upper level sensor 15a (for example, a limit switch or the like) that detects whether waste plastic is stored up to the position is provided at the upper position of the storage pipe 15. Similarly, a lower level sensor 15b (for example, a limit switch or the like) that detects whether waste plastic is stored up to the position is provided at a lower position of the storage pipe 15. The upper level sensor 15 a and the lower level sensor 15 a are connected to a control device 30 for controlling the circle feeder 12.

  When the lower level sensor 15b detects that the waste plastic is not stored up to the lower position, the control device 30 continues until the upper level sensor 15a detects that the waste plastic is stored up to the upper position. The feeder 12 is rotated at a predetermined rotational speed, that is, waste plastic in the hopper 11 is discharged to the storage pipe 15.

  An inert gas introduction pipe 41 is connected to the inside of the storage pipe 15. The other end side of the inert gas introduction pipe 41 is connected to an inert gas introduction source (not shown), and it is possible to introduce an inert gas into the storage pipe 15 and purge the inside of the storage pipe 15. Yes.

  The inert gas introduction pipe 41 is provided with an inert gas introduction amount control device 42 for controlling the introduction amount of the inert gas into the storage pipe 15. The inert gas introduction amount control device 42 may be configured by a valve whose opening degree can be adjusted, for example. On the other hand, the storage pipe 15 is provided with an oxygen concentration meter 43 that measures the oxygen concentration in the storage device 15. Then, the inert gas introduction amount control device 42 controls the amount of inert gas introduced into the storage tube 15 based on the measurement result of the oxygen concentration meter 43.

  A cooling device 18 capable of cooling waste plastic discharged from the storage pipe 15 is disposed below the valve 16. As the cooling device 18, any known cooling device can be adopted, but the cooling device 18 according to the present embodiment is disposed so as to surround the passage pipe 18 p through which the waste plastic passes and the circumference of the passage pipe 18 p. And a cooling jacket 18j that can be introduced.

  In the cooling jacket 18j of the present embodiment, cooling water as a refrigerant is introduced from a lower portion of the cooling jacket 18j through a cooling water introduction pipe 18a. This cooling water is discharged from a cooling water discharge pipe 18b provided in an upper portion of the cooling jacket 18j after the waste plastic passing through the communication pipe 18p is cooled.

  The cooling water introduction pipe 18a is provided with a cooling water introduction amount control device 51 for controlling the introduction amount of the cooling water into the cooling jacket 18j. If the introduction amount of the cooling water is increased, the cooling effect of the waste plastic by the cooling water is increased, that is, the degree of cooling is increased. On the other hand, if the introduction amount of the cooling water is reduced, the cooling effect of the waste plastic by the cooling water is reduced, that is, the degree of cooling is reduced. The cooling water introduction amount control device 51 can be constituted by, for example, a valve whose opening degree can be adjusted.

  On the other hand, the passage pipe 18p is provided with a thermometer 52 for measuring the temperature of waste plastic in the passage pipe 18p. The cooling water introduction amount control device 51 controls the amount of cooling water introduced into the cooling jacket 18j based on the measurement result of the thermometer 52.

  A second inert gas introduction pipe 61 is connected below the passage pipe 18p. The other end side of the second inert gas introduction pipe 61 is connected to an inert gas introduction source (not shown), and it is possible to introduce an inert gas into the passage pipe 18p and purge the passage pipe 18p with an inert gas. It has become.

  The second inert gas introduction pipe 61 is provided with a second inert gas introduction amount control device 62 for controlling the introduction amount of the inert gas into the passage pipe 18p. The second inert gas introduction amount control device 62 can be constituted by a valve whose opening degree can be adjusted, for example. The second inert gas introduction amount control device 62, for example, introduces the inert gas into the passage pipe 18p based on the measurement result of an oxygen concentration meter (not shown) that measures the oxygen concentration in the passage pipe 18p. Is to control.

  Connected to the lower end of the cooling device 18 is an inlet 20a of a desalting device 20 that dechlorinates waste plastic that has passed through the cooling device 18.

  Next, the operation of the waste plastic processing apparatus 1 according to this embodiment will be described.

  The granulated waste plastic is appropriately put into the hopper 11. The waste plastic thrown into the hopper 11 is discharged to the storage pipe 15 through the discharge port 11d and the connection pipe 13 when the circle feeder 12 rotates.

  In the present embodiment, before the waste plastic is discharged to the storage pipe 15, the inert gas is introduced into the storage pipe 15 from the inert gas introduction pipe 41 in advance, and the inside of the storage pipe 15 is purged with the inert gas. . At this time, the valve 16 is preferably closed.

  The introduction of the inert gas from the inert gas introduction pipe 41 continues to be performed at the time of discharging the waste plastic to the storage pipe 15 and further from the storage pipe 15 through the valve 16. The introduction amount of the inert gas is suitably controlled by the inert gas introduction amount control device 42 according to the oxygen concentration in the storage pipe 15 measured by the oxygen concentration meter 43.

  Specifically, when the oxygen concentration is equal to or higher than a predetermined value, the inert gas introduction amount is increased, and when the oxygen concentration is equal to or lower than the predetermined value, the inert gas introduction amount is decreased. Thereby, even when oxygen in the air is mixed into the storage pipe 15 due to a gap in the waste plastic or the like, the oxygen concentration in the storage pipe 15 is always maintained at a low level with high introduction efficiency of the inert gas. Can do.

  Preferably, the valve 16 is opened after it is confirmed that the oxygen concentration is maintained below a predetermined level. Thereby, it is possible to prevent oxygen mixed in the storage pipe 15 from passing through the storage pipe 15 and entering the cooling device 18 and the desalination device 20.

  If the oxygen concentration does not sufficiently decrease even when the inert gas introduction amount is set to the maximum amount, it is preferable that the valve 16 is closed considering that it is a dangerous state. At this time, the circle feeder 12 stops, and the discharge of waste plastic from the hopper 11 to the storage pipe 15 can also be stopped. In addition, the operation of the desalting apparatus 20 can be stopped.

  The rotation of the circle feeder 12 is controlled by the control device 30 depending on the storage state of the waste plastic in the storage pipe 15. That is, in the present embodiment, since the lower level sensor 15b detects that the waste plastic is not stored up to the lower position of the storage pipe 15, the waste plastic is stored up to the upper position of the storage pipe 15. Until this is detected by the upper level sensor 15a, the circle feeder 12 rotates at a predetermined rotational speed.

  By controlling the circle feeder 12 as described above, the level of waste plastic in the storage tube 15 can be generally adjusted between the upper position and the lower position. Thereby, supply of the waste plastic from the storage pipe 15 to the desalting apparatus 20 via the valve 16 can be performed with a desired supply amount (for example, substantially quantitatively).

  The waste plastic discharged from the storage pipe 15 via the valve 16 passes through the cooling device 18 before reaching the desalting device 20 and is then supplied to the desalting device 20. This cooling device prevents the heat on the desalination device 20 side from being transferred to the storage tube 15 side.

  Further, in the cooling device 18 of the present embodiment, the cooling water introduction amount control device 51 controls the introduction amount of the cooling water according to the temperature of the waste plastic passing through the passage pipe 18p. As a result, the cooling efficiency of the waste plastic is improved.

  If the temperature of the waste plastic does not sufficiently decrease even when the cooling water introduction amount is set to the maximum amount, it is preferable that the valve 16 is closed considering that it is a dangerous state. At this time, the circle feeder 12 stops, and the discharge of waste plastic from the hopper 11 to the storage pipe 15 can also be stopped. In addition, the operation of the desalting apparatus 20 can be stopped.

  Further, in the cooling device 18 of the present embodiment, an inert gas is appropriately introduced into the passage pipe 18p from the second inert gas introduction pipe 61. As a result, the inside of the passage pipe 18p is also purged with an inert gas, and the risk of fire and explosion is further reduced.

  As described above, according to the present embodiment, since the storage pipe 15 serves as a so-called “buffer”, it is possible to always smoothly put the waste plastic into the desalting apparatus 20. Further, the cooling device 18 prevents the heat on the desalination device 20 side from being transmitted to the hopper 11. Furthermore, since the storage pipe 15 is purged with the inert gas by the inert gas introduction pipe 41, the concentration of oxygen mixed in the storage pipe 15 can be reduced, and the occurrence of a fire or the like can be further suppressed.

  In particular, according to the control of the circle feeder 12 using the upper level sensor 15a and the lower level sensor 15b as described above, it is possible to make the level of waste plastic in the storage pipe 15 substantially constant. Supply to the desalting apparatus 20 can be carried out substantially quantitatively.

  Note that a further inert gas introduction pipe can be connected between the hopper 11 and the storage pipe 15 or in the melting tank. Thereby, the oxygen concentration in the movement route of waste plastic can be further reduced, and the risk of fire and explosion can be further reduced.

  In addition, the control device 30 of the present embodiment controls only the ON (operation) / OFF (stop) of the rotation of the circle feeder 12, but the rotation speed of the circle feeder 12 and the opening area of the opening. You may come to control. For example, when the lower level sensor 15b is activated (when the level of waste plastic is lower than the lower position), it is also effective to increase the rotational speed of the circle feeder 12 or to increase the opening area of the opening. Similarly, when the upper level sensor 15a is actuated (when the level of waste plastic is above the upper position), it is also effective to reduce the rotational speed of the circle feeder 12 or reduce the opening area of the opening. .

In addition, a rotary valve can be used instead of the circle feeder 12. The rotary valve has a rotation mechanism for discharging waste plastic from the discharge port 11d of the hopper 11, for example. In this case, ON (operation) / OFF (stop) of rotation of the rotation mechanism can be controlled by the control device 30. Alternatively, the control device 30 increases the rotation speed of the rotation mechanism when the lower level sensor 15b is operated, and decreases the rotation speed of the rotation mechanism when the upper level sensor 15a is operated. Also according to such an embodiment, substantially the same effect as the above-described embodiment can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS The block schematic diagram of the waste plastic processing apparatus which shows one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Waste plastic processing apparatus 11 Hopper 11d Discharge port 12 Circle feeder 13 Connection pipe 15 Storage pipe 15a Upper level sensor 15b Lower level sensor 16 Valve 18 Cooling device 18p Passing pipe 18j Cooling jacket 18a Cooling water introduction pipe 18b Cooling water discharge pipe 20 Desorption Salt device 20a Input port 30 Control device 41 Inert gas introduction tube 42 Inert gas introduction amount control device 43 Oxygen concentration meter 51 Cooling water introduction amount control device 52 Thermometer 61 Second inert gas introduction tube 62 Second inert gas Introduction amount control device

Claims (5)

A hopper into which the granulated waste plastic is put,
A discharge device for discharging the waste plastic put into the hopper;
A storage device capable of temporarily storing waste plastic discharged from the discharge device;
An inert gas introduction device capable of purging the storage device with an inert gas;
A demineralizer that dechlorinates waste plastic that has passed through the storage device;
A cooling device for preventing the heat of the desalination device from being transmitted to the storage device;
With
The inert gas introduction device is provided with an introduction amount control device for controlling the amount of inert gas introduced into the storage device ,
An oxygen concentration meter is provided to measure the oxygen concentration in the storage device,
The waste plastic processing apparatus , wherein the introduction amount control device controls an introduction amount of the inert gas to the storage device based on a measurement result of the oximeter . The storage device has a storage pipe arranged in a substantially vertical direction,
An upper level sensor that detects whether waste plastic is stored up to the position is provided at the upper position of the storage pipe,
A lower level sensor that detects whether waste plastic is stored up to the position is provided at the lower position of the storage pipe,
When the lower level sensor detects that the waste plastic is not stored up to the lower position, the discharge device is disposed of in the hopper until the upper level sensor detects that the waste plastic is stored up to the upper position. 2. The waste plastic processing apparatus according to claim 1 , wherein the plastic is discharged. The waste plastic treatment apparatus according to claim 1 , further comprising a second inert gas introduction device for purging the cooling device with an inert gas. The waste plastic according to any one of claims 1 to 3 , wherein the cooling device is provided with a cooling amount control device that controls a degree of cooling when the waste plastic discharged from the storage device is cooled. Processing equipment. A thermometer is provided to measure the temperature of waste plastic in the storage device or cooling device,
The waste plastic processing apparatus according to claim 4 , wherein the cooling amount control device controls the degree of cooling of the waste plastic based on a measurement result of the thermometer.

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