JP3267570B2 - Waste plastic processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for treating waste plastic and recovering it as a recycle resource such as fuel oil, and more particularly to detecting a storage amount in a molten plastic storage tank for storing heated and molten plastic. The present invention also relates to a waste plastic treatment facility capable of controlling the amount of molten plastic introduced from a pre-process device into a molten plastic storage tank.

[0002]

2. Description of the Related Art In recent years, due to the shortage of waste disposal facilities and the enactment of a recycling law, waste plastic processing equipment for processing waste plastic to produce fuel oil and solid fuel has attracted attention.

FIG. 6 is a configuration diagram showing a conventional waste plastic processing facility.

As shown in FIG. 6, a waste plastic processing equipment 1 includes a molten plastic storage tank 2 for storing molten plastic, and a pre-process apparatus 3 for pre-processing for introducing molten plastic into the molten plastic storage tank 2. ,
An oil vapor pipe 4 for discharging the evaporated oil vapor to the outside of the molten plastic storage tank 2, a nitrogen gas pipe 5 for preventing ignition, and a next process device 6 for discharging the residue from the molten plastic storage tank 2. Consists of

[0005] The molten plastic storage tank 2 is a pre-process device 3
The molten plastic sent from the molten plastic storage tank 2 is introduced into the molten plastic storage tank 2 through an inlet and stored therein, and the oil in the molten plastic is evaporated by heating from the outer peripheral portion of the molten plastic storage tank 2. The evaporated oil vapor flows out of the molten plastic storage tank 2 through the oil vapor pipe 4, and nitrogen gas supplied for preventing ignition of the high-temperature molten plastic is supplied through the nitrogen gas pipe 5 into the molten plastic storage tank 2. Will be introduced. The plastic melt in the molten plastic storage tank 2 in which the oil has evaporated becomes a so-called “residue” containing carbon as a main component. The residue is discharged from the lower outlet of the molten plastic storage tank 2 and sent to the next process device 6.

[0006]

However, in a conventional molten plastic storage tank, when the molten plastic is stored in the molten plastic storage tank, the heated molten plastic has a high temperature and a high viscosity, and the plastic made of vinyl chloride has a disadvantage. There is no method for detecting the amount of storage in the molten plastic storage tank because chlorine gas generated upon heating and smoke generated from the liquid level of the molten plastic fill the upper space of the molten plastic storage tank. For this reason,
There was a problem that the amount of molten plastic introduced into the molten plastic storage tank from the pre-process apparatus could not be determined, and efficient operation could not be performed.

The present invention has been made in order to solve the above-mentioned problem, and even if a high-temperature, high-viscosity molten plastic is used, the characteristics of the molten plastic can be utilized.
By providing a detection control mechanism that detects the amount of molten plastic stored in the storage tank and controls the amount of molten plastic introduced into the molten plastic storage tank from the pre-process equipment, waste plastic processing equipment that can efficiently process waste plastic is provided. The purpose is to provide.

[0008]

According to the first aspect of the present invention,
In the molten plastic storage tank that stores the molten plastic, the amount of the molten plastic stored in the molten plastic storage tank is detected by utilizing the characteristics of the molten plastic, and the amount of the molten plastic introduced into the molten plastic storage tank from the pre-process device is controlled. A waste plastic processing equipment provided with a detection control mechanism, wherein the detection control mechanism is provided on a laser beam path from a laser type liquid level detection unit provided at an upper portion of a molten plastic storage tank and a laser beam path from the liquid level detection unit. Smoke removing means for removing generated smoke by introducing nitrogen gas, introducing means for changing the amount of molten plastic introduced into the molten plastic storage tank from the preceding process apparatus, the liquid level detecting means, the smoke removing means and the And control means for controlling the introduction means.

According to a second aspect of the present invention, in the molten plastic storage tank for storing the molten plastic, the amount of the molten plastic stored in the molten plastic storage tank is detected by utilizing the characteristics of the molten plastic, and the molten plastic storage tank is supplied from a pre-processing device. A waste plastic processing facility provided with a detection control mechanism for controlling the amount of molten plastic introduced into a storage tank, wherein the detection control mechanism includes an inert gas having a tip portion disposed at a different height in the molten plastic storage tank. And a flow rate detecting means for detecting a flow rate of an inert gas flowing in each pipe in which each tip portion of the pipe group is arranged at a different height, and detecting a temperature of the molten plastic in the molten plastic storage tank. Temperature detecting means, and introducing means for changing the amount of molten plastic introduced into the molten plastic storage tank from the pre-process device; Characterized in that the flow rate detecting unit and the signal from the temperature detecting means is composed of a control means for controlling the introducing means.

According to a third aspect of the present invention, the molten plastic storage tank for storing the molten plastic detects the amount of storage in the molten plastic storage tank by utilizing the characteristics of the molten plastic, and transmits the molten plastic from a pre-process device to the molten plastic storage tank. A waste plastic processing facility provided with a detection control mechanism for controlling the amount of molten plastic introduced into a storage tank, wherein a difference between the temperature of the molten plastic stored and the temperature of the molten plastic stored in an upper space portion of the molten plastic storage tank is provided. And the detection control mechanism is disposed in a vertical direction in the molten plastic storage tank and detects the temperature of the molten plastic in the molten plastic storage tank and the temperature of the upper space portion. Means, introduction means for changing the amount of molten plastic to be introduced from the pre-process apparatus to the molten plastic storage tank, Serial characterized in that it is composed of a control means for controlling the introducing means based on the temperature difference signal between the temperature of the temperature and the upper space of the molten plastic from the temperature detecting means.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment (FIG. 1) FIG. 1 is a block diagram of a waste plastic processing facility provided with a detection control mechanism using a laser type liquid level gauge.

As shown in FIG. 1, a waste plastic processing facility 1 includes a molten plastic storage tank 2 for storing molten plastic, and a pre-process apparatus 3 for performing a pretreatment for introducing molten plastic into the molten plastic storage tank 2. ,
An oil vapor pipe 4 for discharging the evaporated oil vapor to the outside of the molten plastic storage tank 2, a nitrogen gas pipe 5 for preventing ignition, a next process device 6 for discharging the residue from the molten plastic storage tank 2, and A detection control mechanism 7 for detecting the amount of storage in the molten plastic storage tank 2 and controlling the amount of molten plastic introduced into the molten plastic storage tank 2 from the pre-process apparatus 3.

The detection control mechanism 7 includes a liquid level detecting means 8 for detecting the storage amount in the molten plastic storage tank 2, a smoke removing means 9 for removing smoke to ensure the liquid level detecting means 8, a molten plastic Introduction means 1 that can change the introduction amount of
0 and the liquid level detecting means 8, the smoke removing means 9 and the control means 11 for controlling the introducing means 10.

As a liquid level detecting means 8, a laser type liquid level gauge 12 is provided above the molten plastic storage tank 2.

A cylinder 13, a nitrogen gas nozzle 14 and a nitrogen gas valve 15 are provided as smoke removing means 9.
Is provided below the laser-type liquid level gauge 12,
It has holes arranged in the vertical direction on the side surface and a glass plate transmitting laser light on the upper surface, and the lower end is open near the bottom of the tank. A nitrogen gas nozzle 14 for supplying nitrogen gas is provided on the side surface of the cylinder 13, and a nitrogen gas valve 15 is installed at the other end of the nitrogen gas nozzle 14.
The nitrogen gas is supplied into the cylinder 13 by opening and closing.

As the introduction means 10, the rotary valve 1
6 is provided, and by changing the rotation speed of the rotary valve 16, the amount of molten plastic introduced from the pre-process apparatus 3 into the molten plastic storage tank 2 is changed.

A controller 17 is provided as the control means 11. The controller 17 measures the laser level gauge 12, the opening / closing timing of the nitrogen gas valve 15, and the rotational speed of the rotary valve 16 based on the measured liquid level. Control.

When the liquid level is measured by the laser liquid level gauge 12 in the waste plastic processing equipment 1 having the above-described structure, the nitrogen gas valve 15 is opened by the controller 17 before the measurement and the nitrogen gas is supplied into the cylinder 13. And the cylinder 1
The smoke filled in 3 is discharged out of the cylinder 13 through the hole on the side.

By providing such a detection control mechanism 7, the laser light reaches the liquid surface without being confused by smoke, and the liquid level can be measured. The rotational speed of the rotary valve 16 is appropriately controlled by the controller 17 based on the obtained liquid level, and the molten plastic storage tank 2
It is possible to appropriately control the amount of the molten plastic stored in the tank.

Second Embodiment (FIG. 2) FIG. 2 is a configuration diagram of a waste plastic processing facility provided with a detection control mechanism for detecting a reaction force of molten plastic.

As shown in FIG. 2, the waste plastic processing equipment 1 includes a molten plastic storage tank 2 for storing molten plastic, and a pre-process device 3 for performing a pretreatment for introducing molten plastic into the molten plastic storage tank 2. ,
An oil vapor pipe 4 for discharging the evaporated oil vapor to the outside of the molten plastic storage tank 2, a nitrogen gas pipe 5 for preventing ignition, a next process device 6 for discharging the residue from the molten plastic storage tank 2, and A detection control mechanism 7 for detecting the amount of storage in the molten plastic storage tank 2 and controlling the amount of molten plastic introduced into the molten plastic storage tank from the pre-process apparatus.

The detection control mechanism 7 includes a moving body 18 which directly receives the reaction force of the molten plastic, a driving means 19 for driving the moving body 18, and a reaction force detecting means 20 for measuring a stress applied to the moving body 18 in the axial direction. Moving amount detecting means 21 for measuring the moving amount of the moving body 18, introducing means 22 capable of changing the amount of molten plastic introduced, and the driving means 1
9, a control means 23 for controlling the reaction force detecting means 20 and the introducing means 22.

As the moving body 18, a probe 24 is provided above the molten plastic storage tank 1. The probe 24 has a flat plate at its lower end and is isolated from the outside by a container 26 connected to the molten plastic storage tank 1 by a short pipe 25. The interior of the container 26 is in the same atmosphere as the interior of the molten plastic storage tank 1.

As the driving means 19, a driving device 27 is provided on the side surface of the probe 24.

As the reaction force detecting means 20, a load cell 28
Are provided on the side surface of the probe 24 and below the driving device 27.

As the movement amount detecting means 21, the position sensor 2
9 is provided above the container 26.

As the introduction means 22, the rotary valve 3
0 is provided, and by changing the rotation speed of the rotary valve 30, the amount of molten plastic introduced from the pre-process apparatus 3 into the molten plastic storage tank 2 is changed.

A controller 31 is provided as the control means 23. The controller 31 controls the operation of the driving device 27, calculates the liquid level based on the signal from the load cell 28, and calculates the liquid level based on the obtained liquid level. Is performed.

In the waste plastic processing equipment 1 having the above configuration, when measuring the liquid level, the driving device 27 measures the amount of movement of the probe 24 and sends a signal to the controller 31. When the flat plate at the lower end of the probe 24 reaches the liquid level, the viscosity of the molten plastic is as high as about 1000 Pa · s, so that the probe 22 receives a large reaction force. This reaction force is applied to the load cell 28
And sends a signal to the controller 30. The controller 31 calculates the liquid level based on the signal from the position sensor 29 at this time. At this time, the driving device 27 and a part of the probe 24 were isolated from the outside by the container 26 and were in the same atmosphere as the inside of the molten plastic storage tank 2, and the driving device 27 and a part of the probe 24 were provided in the external atmosphere. There is no required sealing part. For this reason, it is possible to accurately measure the liquid level without the resistance of the seal portion which becomes an obstacle when measuring the reaction force of the liquid surface by the load cell 28.

By providing such a detection control mechanism 7, the number of revolutions of the rotary valve 30 is appropriately controlled by the controller 31 based on the obtained liquid level, and the amount of introduction into the molten plastic storage tank 2 is appropriately controlled. can do.

Third Embodiment (FIG. 3) FIG. 3 is a configuration diagram of a waste plastic processing facility provided with a detection control mechanism for detecting resistance from molten plastic.

As shown in FIG. 3, the waste plastic processing equipment 1 includes a molten plastic storage tank 2 for storing molten plastic, and a pre-process apparatus 3 for performing a pretreatment for introducing the molten plastic into the molten plastic storage tank 2. ,
An oil vapor pipe 4 for discharging the evaporated oil vapor to the outside of the molten plastic storage tank 2, a nitrogen gas pipe 5 for preventing ignition, a next process device 6 for discharging the residue from the molten plastic storage tank 2, and A detection control mechanism 7 for detecting the amount of storage in the molten plastic storage tank 2 and controlling the amount of molten plastic introduced into the molten plastic storage tank 2 from the pre-process apparatus 3.

The detection control mechanism 7 includes a rotating body 32 which directly receives the resistance of the molten plastic, a driving means 33 for driving the rotating body 32, a reaction force detecting means 34 for measuring the resistance applied to the rotating body 32, a molten plastic storage tank. Temperature detecting means 35 for detecting the temperature in the inside 2, introducing means 36 capable of changing the amount of molten plastic introduced, and said reaction force detecting means 3
4. Control means 37 for controlling the temperature detecting means 35 and the introducing means 36.

As the rotating body 32, a rotating blade 38 is provided in the molten plastic storage tank 2.

As the driving means 33, a driving device 39 is provided above the rotary blade 38.

As the reaction force detecting means 34, a torque meter 40 is provided between the rotary blade 38 and the driving device 39, and the torque meter 40 measures the resistance that the rotary blade 38 receives from the molten plastic. Drive 39 and torque meter 40
Is outside the molten plastic storage tank 2, but is connected to the molten plastic storage tank 2 by the short pipe 41, is isolated from the outside by the container 42, and is in the same atmosphere as the inside of the molten plastic storage tank 2.

As a temperature detecting means 35, a thermometer 43 is provided at a lower portion in the molten plastic storage tank 2 to measure the temperature of the molten plastic.

As the introducing means 36, the rotary valve 4
4 is provided, and by changing the number of revolutions of the rotary valve 44, the amount of molten plastic introduced from the pre-process apparatus 3 into the molten plastic storage tank 2 is changed.

A controller 45 is provided as the control means 37, and the controller 45 controls the torque meter 49 and the thermometer 43.
The control of the rotation speed of the rotary valve 44 is performed based on the calculation of the liquid level based on the signals from and the obtained liquid level.

When the rotating blades 38 are rotated by the driving device 39 in the waste plastic processing equipment 1 having the above-described configuration, the viscosity of the molten plastic is as high as about 1000 Pa · s, so that the rotating blades 38 receive a large resistance. This resistance is detected by the torque meter 40 and a signal is sent to the controller 45.
The thermometer 43 measures the temperature of the molten plastic in the molten plastic storage tank 2 and sends a signal to the controller 45. The resistance that the rotating blades 38 receive from the molten plastic increases as the amount of the molten plastic increases, and decreases as the temperature of the molten plastic increases and the viscosity decreases. These relationships are input to the controller 45 in advance, and the liquid level is calculated from the obtained signals. At this time, although the driving device 39 and the torque meter 40 are outside the molten plastic storage tank 2, they are isolated from the outside by the container 42 connected to the molten plastic storage tank 2 by the short pipe 41, and the inside of the molten plastic storage tank 2. In the same atmosphere, there is no resistance of the seal portion which becomes an obstacle when measuring the resistance applied to the rotating blades 38 by the driving device 38 and the torque meter 40, and the liquid level can be accurately measured.

By providing such a detection control mechanism 7, the number of rotations of the rotary valve 44 is appropriately controlled by the controller 45 based on the liquid level in the molten plastic storage tank.
The amount introduced into the molten plastic storage tank 2 can be appropriately controlled.

Fourth Embodiment (FIG. 4) FIG. 4 is a configuration diagram of a waste plastic processing facility provided with a detection control mechanism for detecting a nitrogen gas flow rate.

As shown in FIG. 4, the waste plastic processing equipment 1 includes a molten plastic storage tank 2 for storing molten plastic, and a pre-process apparatus 3 for performing a pretreatment for introducing molten plastic into the molten plastic storage tank 2. ,
An oil vapor pipe 4 for discharging the evaporated oil vapor to the outside of the molten plastic storage tank 2, a nitrogen gas pipe 5 for preventing ignition, a next process device 6 for discharging the residue from the molten plastic storage tank 2, and A detection control mechanism 7 for detecting the amount of storage in the molten plastic storage tank 2 and controlling the amount of molten plastic introduced into the molten plastic storage tank 2 from the pre-process apparatus 3.

The detection control mechanism 7 includes a piping group 46 for blowing nitrogen gas into the molten plastic storage tank, a flow rate detecting means 47 for measuring the flow rate of the nitrogen gas, a temperature detecting means 48 for measuring the temperature of the molten plastic, Introducing means 49 capable of changing the introduced amount and the flow rate detecting means 4
7, a control means 50 for controlling the temperature detecting means 48 and the introducing means 49.

The piping group 46 includes a blowing pipe 51 and a nitrogen gas supply pipe 52. The blowing pipe 51 is provided in the molten plastic storage tank 2 and blows nitrogen gas into the molten plastic. The blowing ports of the blowing pipe 51 are provided at different heights. The nitrogen gas is supplied by a nitrogen gas supply pipe 52 to which a group of blowout pipes 51 are connected in parallel.

As flow rate detecting means 48, a flow meter 53 is provided above the blowing pipes 51, and measures the flow rate of nitrogen gas in each blowing pipe 51.

As a temperature detecting means 48, a thermometer 54 is provided at a lower portion in the molten plastic storage tank 2 to measure the temperature of the molten plastic.

As the introduction means 49, the rotary valve 5
5 is provided, and by changing the rotation speed of the rotary valve 55, the amount of the molten plastic introduced from the pre-process apparatus 3 into the molten plastic storage tank 2 is changed.

A controller 56 is provided as the control means 50. The controller 56 calculates the liquid level based on signals from the flow meter 53 and the thermometer 54, and controls the rotary valve 55 based on the obtained liquid level. Performs rotation speed control.

In the waste plastic processing equipment 1 having the above configuration, the flow rate of the nitrogen gas flowing through the blowing pipes 51 varies depending on the relationship between the height of the blowing port of each blowing pipe 51 and the height of the liquid level of the molten plastic. When the outlet is lower than the liquid level, the nitrogen gas is supplied according to the difference between the internal pressure of the molten plastic near the outlet and the pressure at which the nitrogen gas is supplied, which is determined by the difference between the height of the outlet and the liquid level of the molten plastic. The flow rate changes, and the nitrogen gas flow rate changes according to the magnitude of the resistance of the liquid level near the outlet where the internal pressure of the molten plastic is higher than the pressure at which the nitrogen gas is supplied.

The change in the nitrogen gas flow rate is detected by the flow meter 53 and a signal is sent to the controller 56. The thermometer 54 measures the temperature of the molten plastic in the molten plastic storage tank 2 and sends a signal to the controller 56. When the outlet is lower than the liquid level, the flow rate of the nitrogen gas flowing through the outlet pipe 51 is such that when the level of the liquid level of the molten plastic is the same, the temperature of the molten plastic rises, the density decreases, and the internal pressure of the molten plastic near the outlet increases. Increases as the size decreases. These relationships are input to the controller 56 in advance, and the liquid level is calculated from signals obtained by the flow meter 53 and the thermometer 54.

By providing such a detection control mechanism 7, the number of revolutions of the rotary valve 55 is appropriately controlled by the controller 56 based on the obtained liquid level, and the amount of introduction into the molten plastic storage tank 2 is appropriately controlled. can do.

Fifth Embodiment (FIG. 5) FIG. 5 is a configuration diagram of a waste plastic processing facility provided with a detection control mechanism for detecting the temperature of molten plastic.

As shown in FIG. 5, the waste plastic processing equipment 1 includes a molten plastic storage tank 2 for storing molten plastic, and a pre-process apparatus 3 for performing a pretreatment for introducing molten plastic into the molten plastic storage tank 2. ,
An oil vapor pipe 4 for discharging the evaporated oil vapor to the outside of the molten plastic storage tank 2, a nitrogen gas pipe 5 for preventing ignition, a next process device 6 for discharging the residue from the molten plastic storage tank 2, and A detection control mechanism 7 for detecting the amount of storage in the molten plastic storage tank 2 and controlling the amount of molten plastic introduced into the molten plastic storage tank 2 from the pre-process apparatus 3.

The detection control mechanism 7 controls the temperature detecting means 57 for detecting the temperature in the molten plastic storage tank 2, the introducing means 58 capable of changing the amount of molten plastic introduced, and the temperature detecting means 57 and the introducing means 58. And control means 59 for performing the operation.

As a temperature detecting means 57, a group of thermometers 60 is arranged vertically on the side surface of the molten plastic storage tank 2, and the thermometer group 60 detects the temperature in the molten plastic storage tank 2.

As the introduction means 58, the rotary valve 6
1, the amount of molten plastic introduced into the molten plastic storage tank 2 from the pre-process apparatus 3 is changed by changing the number of revolutions of the rotary valve 61.

As a control means 59, a controller 62 is provided. The controller 62 calculates the liquid level based on the signal from the thermometer group 60, appropriately controls the rotation speed of the rotary valve 61, and controls the molten plastic. The amount introduced into the storage tank 2 is appropriately controlled.

In the waste plastic processing equipment 1 having the above-mentioned structure, the upper space of the molten plastic storage tank 2 is always supplied with nitrogen gas through the nitrogen gas pipe 5 and the oil vapor is discharged. There is a temperature difference between the molten plastic inside and the upper space. The thermometer group 60 detects the temperature of the molten plastic and the mixed gas in the molten plastic storage tank 2 and sends a signal to the controller 62.

By providing such a detection control mechanism 7, the amount introduced into the molten plastic storage tank 2 can be appropriately controlled.

[0061]

As described above, according to the present invention, the amount of the molten plastic stored in the molten plastic storage tank in the waste plastic processing equipment is detected, and the amount of the molten plastic introduced into the molten plastic storage tank from the pre-process device is measured. By providing a detection control mechanism for controlling waste plastic, waste plastic processing equipment capable of efficiently processing waste plastic can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing waste plastic processing equipment for explaining a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a waste plastic processing facility for explaining a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing a waste plastic processing facility for explaining a third embodiment of the present invention.

FIG. 4 is a configuration diagram showing a waste plastic processing facility for explaining a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram showing a waste plastic processing facility for explaining a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram showing a conventional waste plastic processing facility.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Waste plastic processing equipment 2 Molten plastic storage tank 3 Pre-process equipment 4 Oil vapor piping 5 Nitrogen gas piping 6 Secondary processing equipment 7 Detection control mechanism 8 Liquid level detection means 9 Smoke removal means 10 Introduction means 11 Control means 12 Laser type Level gauge 13 cylinder 14 nozzle for nitrogen gas 15 valve for nitrogen gas 16 rotary valve 17 controller

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-146680 (JP, A) JP-A-9-89628 (JP, A) JP-A-11-281457 (JP, A) JP-A-7-896 268353 (JP, A) JP-A-9-21676 (JP, A) JP-A-8-300121 (JP, A) JP-A-7-174606 (JP, A) Japanese Utility Model Laid-Open No. 61-99020 (JP, U) Jpn. Sho 62-135927 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B09B 3/00 B29B 17/00 C10G 1/10 G01F 23/14 G01F 23/22 G01F 23 / 292

Claims (3)

(57) [Claims] 1. A molten plastic storage tank for storing a molten plastic, wherein the amount of the molten plastic stored in the molten plastic storage tank is detected by utilizing the characteristics of the molten plastic, and the molten plastic is introduced into the molten plastic storage tank from a pre-process device. Waste plastic processing equipment provided with a detection control mechanism for controlling the amount of plastic, wherein the detection control mechanism is a laser type liquid level detection means provided on the upper part of the molten plastic storage tank, from the liquid level detection means Smoke removing means for removing smoke generated on the laser beam path by introducing nitrogen gas,
An introduction unit for changing an amount of molten plastic introduced into the molten plastic storage tank from the pre-process apparatus, and a control unit for controlling the liquid level detection unit, the smoke removal unit, and the introduction unit, and Waste plastic processing equipment. 2. A molten plastic storage tank for storing the molten plastic, wherein the amount of the molten plastic stored in the molten plastic storage tank is detected by utilizing the characteristics of the molten plastic, and the molten plastic is introduced into the molten plastic storage tank from a pre-process device. Waste plastic processing equipment provided with a detection control mechanism for controlling the amount of plastic, said detection control mechanism, a group of pipes that blow out an inert gas by disposing a tip portion at a different height in a molten plastic storage tank, Flow rate detecting means for detecting the flow rate of the inert gas flowing in each pipe arranged at a different height each tip portion of the pipe group, and a temperature detecting means for detecting the temperature of the molten plastic in the molten plastic storage tank, Introduction means for changing the amount of molten plastic introduced into the molten plastic storage tank from the pre-process device; And a control means for controlling the introduction means in accordance with a signal from the temperature detection means. 3. A molten plastic storage tank for storing the molten plastic, wherein the amount of the molten plastic stored in the molten plastic storage tank is detected by utilizing the characteristics of the molten plastic, and the molten plastic is introduced into the molten plastic storage tank from a pre-process device. In a waste plastic processing facility provided with a detection control mechanism for controlling the amount of plastic, nitrogen gas is always supplied to the upper space of the molten plastic storage tank in order to clarify the difference from the temperature of the stored molten plastic. The detection control mechanism is provided in the molten plastic storage tank in a vertical direction, the temperature control means for detecting the temperature of the molten plastic in the molten plastic storage tank and the temperature of the upper space portion, and a pre-process device From the introduction means for changing the amount of molten plastic introduced into the molten plastic storage tank from the temperature detection means A waste plastic processing facility, comprising: control means for controlling the introduction means based on a temperature difference signal between the temperature of the molten plastic and the temperature of the upper space.