JP2920344B2 - Waste plastic oiling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste plastic oiling system.

[0002]

2. Description of the Related Art Waste plastics include general wastes discharged as separated waste and industrial wastes discharged from plastic producers. Conventionally, general waste is mostly incinerated and landfilled, and reuse of a part of industrial waste by converting it into a fuel by thermal decomposition has been promoted. However,
In recent years, all waste plastics have been reused by being converted into fuel. The conversion of waste plastics into fuel is performed by a method in which waste plastics as a raw material is melted and thermally decomposed, and the generated pyrolysis gas is cooled and condensed, and recovered as pyrolysis oil.

[0003] Conventionally, as a liquefaction system for converting waste plastics into fuel, a pyrolysis reactor in which waste plastics are melted and thermally decomposed therein,
A condenser arranged downstream of the pyrolysis reactor and cooling and condensing the pyrolysis gas generated in the pyrolysis reactor to obtain pyrolysis oil; and a condenser arranged downstream of the condenser and not condensing at the condenser There is known a device provided with a pyrolysis gas recovery device for recovering combustible pyrolysis gas or a pyrolysis gas combustion device for burning.

By the way, foreign materials such as metal, glass, earth and sand are mixed in the waste plastic as a raw material, and such foreign materials are released into a molten liquid at the time of melting and accumulate in a pyrolysis reactor. Problems arise. Therefore, in the oiling system, these foreign substances are removed from the inside of the thermal decomposition reactor by a vacuum method. Therefore, the pyrolysis gas flows backward due to the negative pressure in the system, and if a pyrolysis gas recovery device is arranged downstream of the condenser, the pyrolysis gas cannot be collected by this device. There is. Further, when a pyrolysis gas combustion device is disposed downstream of the condenser, there is a problem that backfire occurs in the system. Further, even when the operation of the thermal decomposition reactor is stopped and the temperature in the system decreases, the pressure in the system becomes negative and the thermal decomposition gas flows backward, causing the same problem as described above.

[0005] In order to solve such a problem, the following three oiling systems have been considered.

The first oil conversion system is the same as the conventional oil conversion system described above, except that a water seal is provided between the condenser and the pyrolysis gas recovery device or the pyrolysis gas combustion device. The oiling system is a conventional oiling system in which compressed air injection means for injecting compressed air to the downstream side is provided between the condenser and the pyrolysis gas recovery device or the pyrolysis gas combustion device. In addition, the third oiling system includes a blower for forcibly sucking the pyrolysis gas to the downstream side.

However, even in the first and second oiling systems described above, it is not possible to completely prevent the generation of backfire caused by the backflow of the pyrolysis gas when the pressure in the system becomes negative. There was found. In addition, it has also been found that, in particular, in the second oiling system, there is a problem that the water in the water seal flows backward and mixes with the pyrolysis oil obtained in the condenser. Further, it has been found that the third oiling system has a problem in explosion-proof property at the blower portion.

An object of the present invention is to provide a waste plastic oiling system which solves the above problems.

[0009]

SUMMARY OF THE INVENTION A waste plastic liquefaction system according to the present invention includes a pyrolysis reactor in which waste plastic is melted and thermally decomposed, a pyrolysis reactor disposed downstream of the pyrolysis reactor and a thermolysis reactor. A condenser that cools and condenses the pyrolysis gas generated in the cracking reactor to obtain pyrolysis oil, and a pyrolysis gas that is located on the downstream side of the condenser and collects the flammable pyrolysis gas that has not condensed in the condenser A waste plastic oil conversion system comprising a recovery device or a pyrolysis gas combustion device for burning, wherein a driving liquid is supplied from a nozzle at a high speed between a condenser and the pyrolysis gas recovery device or the pyrolysis gas combustion device. An ejector for injecting and sucking the pyrolysis gas and sending it to the downstream side, and a water seal for preventing the backflow of the pyrolysis gas are arranged.

In the above, it is preferable to use water as the driving liquid for the ejector. In this case, the cost is reduced and the handling becomes easy.

In the above waste plastic oiling system, there is provided a tank containing a driving liquid for the ejector, into which an inlet-side conduit through which pyrolysis gas not condensed in the condenser is fed, and into the tank. An outlet conduit for sending the pyrolysis gas to the pyrolysis gas recovery device or the pyrolysis gas combustion device is connected, an ejector is provided so as to face the inlet conduit, and a driving liquid supply pipe is provided between the ejector and the tank. The driving liquid supply pipe may be provided with a high-pressure liquid pump that sends the driving liquid in the tank to the ejector.

Further, in the waste plastic oiling system, an air suction pipe whose tip is open to the atmosphere may be connected near the nozzle of the ejector.

[0013] Further, in the waste plastic oiling system, a tank containing a drive liquid for the ejector is provided, an inlet-side conduit for feeding pyrolysis gas not condensed in the condenser to the tank, and a tank for sending the pyrolysis gas into the tank. An outlet conduit for sending the pyrolysis gas collected to a pyrolysis gas recovery device or a pyrolysis gas combustion device,
An ejector is provided so as to face the inlet side conduit, a driving liquid supply pipe is provided between the ejector and the tank, and a high-pressure liquid pump is provided in the driving liquid supply pipe for sending the driving liquid in the tank to the ejector. An air suction pipe whose tip is open to the atmosphere is connected to the downstream side of the nozzle, and the air suction pipe works in conjunction with the high-pressure liquid pump and opens when the high-pressure liquid pump operates, and closes when the high-pressure liquid pump is stopped. Valves may be provided.

[0014]

The ejector injects a driving liquid from a nozzle at a high speed, sucks the pyrolysis gas and sends it to the downstream side between the condenser and the pyrolysis gas recovery device or the pyrolysis gas combustion device, and the pyrolysis gas. If a water seal is installed to prevent backflow, the pyrolysis gas is forcibly sent to the downstream side by the ejector. In addition, backflow of the pyrolysis gas is completely prevented. In addition, since the pyrolysis gas is forcibly sent to the downstream side by the ejector, backflow of the water in the water seal is prevented.

A tank containing a driving liquid for the ejector; an inlet-side conduit for supplying pyrolysis gas not condensed in the condenser to the tank; and a pyrolysis gas recovery for the pyrolysis gas fed into the tank. An outlet pipe connected to the apparatus or the pyrolysis gas combustion apparatus is connected, an ejector is provided so as to face the inlet pipe, a driving liquid supply pipe is provided between the ejector and the tank, and the driving liquid supply pipe is provided with a tank. If a high-pressure liquid pump for sending the driving liquid in the inside to the ejector is provided, the driving liquid can be circulated and used.

If an air suction pipe whose tip is open to the air is connected near the nozzle of the ejector, the driving liquid is ejected from the nozzle of the ejector at a high speed. And this gas-liquid multiphase fluid is injected. Therefore, the suction capability of the pyrolysis gas is improved as compared with the case where the driving liquid is injected alone.

A tank containing a driving liquid for the ejector is provided. An inlet-side conduit for feeding pyrolysis gas not condensed in the condenser to the tank, and a pyrolysis gas recovered in the tank is recovered from the pyrolysis gas. An outlet pipe connected to the apparatus or the pyrolysis gas combustion apparatus is connected, an ejector is provided so as to face the inlet pipe, a driving liquid supply pipe is provided between the ejector and the tank, and the driving liquid supply pipe is provided with a tank. A high-pressure liquid pump is provided to send the driving liquid in the ejector to the ejector, and an air suction pipe whose tip is open to the atmosphere is connected to the downstream side of the nozzle of the ejector. If an electromagnetic valve which is opened when the pump operates and closed when the pump is stopped is provided, the driving liquid can be circulated. Further, the solenoid valve is opened only when the high-pressure liquid pump is operated, and is closed when the high-pressure liquid pump is stopped, so that it is possible to prevent air from entering the system when the high-pressure liquid pump is stopped.

[0018]

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

FIG. 1 shows an entire configuration of a waste plastic oiling system according to the present invention, and FIG. 2 shows a configuration of a main part thereof.

In FIG. 1, the waste plastic liquefaction system is provided with a pyrolysis reactor (1) for melting and pyrolyzing waste plastic therein, and a downstream side of the pyrolysis reactor (1). A first condenser (2) for cooling and condensing a pyrolysis gas generated in the pyrolysis reactor (1) to obtain kerosene (pyrolysis oil); and a first condenser (2) disposed downstream of the first condenser (2); A second condenser (3) for cooling and condensing the pyrolysis gas not condensed in the first condenser (2) to obtain gasoline (pyrolyzed oil); and a downstream side of the second condenser (3). And a burner (4) (a pyrolysis gas combustion device) for burning the flammable pyrolysis gas not condensed in the condensers (2) and (3). 1st capacitor
The kerosene recovered in (2) is stored in the kerosene tank (5).
Gasoline collected by the second condenser (3) is stored in a gasoline tank (6).

The pyrolysis reactor (1) is arranged in a furnace (8) having a heating burner (7) using the recovered pyrolysis oil as fuel. The bottom surface of the pyrolysis reactor (1) has a concave spherical shape that is concave downward. Top wall (1a) of pyrolysis reactor (1)
Is provided with a waste plastic supply port (9) that can be opened and closed, and through this supply port (9), waste plastic conveyed from the waste plastic receiving tank (10) by the conveyor (11) is subjected to thermal decomposition reaction. It is supplied to the vessel (1). A pyrolysis gas discharge pipe (12) is provided on the top wall (1a) of the pyrolysis reactor (1), and the tip of the discharge pipe (12) is connected to the first condenser (2). I have.

In the middle of the discharge pipe (12), there is provided a reformer (13) for reforming the pyrolysis gas generated in the pyrolysis reactor (1) into a component having a low boiling point. The reformer (13) is heated by the combustion exhaust gas of the heating burner (7) that has heated the pyrolysis reactor (1). The combustion exhaust gas from the heating burner (7) that has heated the reformer (13) is released into the atmosphere.

In the middle of the discharge pipe (12) and downstream of the reformer (13), a heavy oil for collecting high-boiling components not sufficiently reformed by the reformer (13) is collected. A collecting device (14) is provided. The heavy oil collected by the heavy oil collecting device (14) is returned to the thermal cracking reactor (1).

The downstream side of the second condenser (3) and the burner
An ejector driving water tank (15) (driving liquid tank) is disposed at the upstream side of (4), and ejector driving water (driving liquid) is filled in a lower portion of this tank (15). I have. Also, one end of the second condenser is placed on the top wall of the tank (15).
The other end of the inlet-side conduit (16) for connecting the pyrolysis gas not condensed in the second condenser (3) to the upper space of the tank (15) is connected. As shown in FIG. 2, at the end of the inlet side conduit (16) on the tank (15) side, driving water is supplied into the inlet side conduit (16) from the nozzle (17a) at a high speed toward the tank (15). Injects, thereby
An ejector (17) for sucking the flammable pyrolysis gas not condensed in the condenser (3) and sending it to the tank (15) is provided so as to face the inlet side conduit (16). Ejector (1
Driving water supply pipe (18) extending from the lower end of tank (15) to 7)
(Drive liquid supply pipe) is connected. Drive water supply pipe (1
In the middle of 8), a high pressure water pump (19) (high pressure liquid pump), and a solenoid valve (20) that is linked to the high pressure water pump (19) and is opened when the pump (19) is operated and closed when stopped. )
Is provided. Also, the nozzle in the ejector (17)
An air suction pipe (21) having a tip open to the atmosphere is connected to a portion closer to the tank (15) than (17a). An electromagnetic valve (22) is provided which is opened when the operation of (19) is performed and closed when the operation is stopped.

At the downstream side of the drive water tank for ejector (15) and upstream of the burner (4), the pyrolysis gas sent into the upper space in the tank (15) is supplied to the burner (4). A water seal (24) is provided in the middle of the outlet-side conduit (23) for sending back the pyrolysis gas to prevent the backflow of the pyrolysis gas and the generation of backfire.

Through the top wall (1a) of the pyrolysis reactor (1),
A hollow vertical rotation shaft (25) is arranged. Vertical rotation axis
The lower end of (25) is located near the bottom of the pyrolysis reactor (1). The upper end of the vertical rotation shaft (25) is located above the top wall (1a), and is connected to a drive motor via a reduction gear (not shown). A plurality of stirring blades (26) are fixedly provided at the lower end of the vertical rotation shaft (25). Each stirring blade
The lower edge of (26) is formed in a substantially arc shape in accordance with the shape of the bottom surface of the pyrolysis reactor (1).

A vertical foreign matter suction pipe (2) is provided in the vertical rotation shaft (25).
7) is located. The upper end of the foreign matter suction pipe (27) extends above the upper end of the vertical rotation shaft (25), and is connected to the foreign matter collecting container (29) by a conduit (28). Foreign matter collection container (29)
One end of the second condenser (3) and the tank (1)
The other end of the conduit (30) connected to the inlet-side conduit (16) that connects to (5) is connected. In the middle of the conduit (30), there is provided a vacuum pump (31) for sucking the contaminated molten liquid from the inside of the pyrolysis reactor (1) into the contaminant collecting container (29). In the part of the conduit (30) between the foreign matter collecting vessel (29) and the vacuum pump (31), the foreign matter mixed into the molten liquid sucked from the pyrolysis reactor (1) by the vacuum pump (31) is mixed. A condenser (32) for cooling and condensing the pyrolysis gas is provided. The pyrolysis oil collected by the condenser (32) is stored in a tank (33).

In such a configuration, the waste plastic containing foreign substances contained in the waste plastic receiving tank (10) is conveyed by the conveyor (11) and is supplied from the supply port (9) to the pyrolysis reactor (1). Supplied within. When a predetermined amount of waste plastic is supplied into the pyrolysis reactor (1), the supply port (9) is closed. This waste plastic is heated and melted by the combustion exhaust gas of the heating burner (7) to form a molten liquid. When the melt is maintained at a temperature equal to or higher than a predetermined temperature, a thermal decomposition reaction occurs, and a thermal decomposition gas is generated. Here, in order to promote the reaction, a vertical rotating shaft (2
5) Rotate the melt in the pyrolysis reactor (1) with stirring blades.
Stir according to (26). The generated pyrolysis gas is exhaust pipe (12)
Then, it is sent to the reformer (13), and is heated by the combustion exhaust gas of the heating burner (7), which has heated the pyrolysis reactor (1), to be reformed into low-boiling components. The pyrolysis gas reformed to a low boiling point component is sent to the first condenser (2) through the discharge pipe (12). The high-boiling components of the pyrolysis gas that have not been sufficiently reformed in the reformer (13) are collected as heavy oil in the heavy oil collector (14). The heavy oil collected by the heavy oil collecting device (14) is returned to the thermal cracking reactor (1).

The low-boiling component of the pyrolysis gas sent to the first condenser (2) is cooled and condensed here, thereby recovering kerosene. The recovered kerosene is a kerosene tank
Stored in (5). The low-boiling component of the pyrolysis gas that has passed without condensing in the first condenser (2) is sent to the second condenser (3) where it is cooled and condensed,
Thereby, gasoline is collected. The recovered gasoline is stored in a gas tank (6).

The pyrolysis gas not condensed in the second condenser (3) is sent to the upper space of the ejector driving water tank (15) through the inlet conduit (16). At this time, when the high-pressure water pump (19) is operated, the two solenoid valves (20) and (22) are respectively opened in conjunction with this, and the driving water in the tank (15) is discharged from the nozzle of the ejector (17). (17a) to inlet side conduit
(16) is injected at high speed toward the tank (15) side, first air is sucked from the air suction pipe (21) and mixed with water, and this gas-liquid multi-phase fluid becomes a driving high-speed fluid and becomes a conduit ( The pyrolysis gas injected into the second condenser (3) and not condensed in the second condenser (3) is sucked and forcibly sent into the upper space of the tank (15). Then, the water is sent to the burner (4) via the water seal (24), where it is burned. The driving water in the tank (15) is circulated.

When such operation is continued, foreign substances mixed in the waste plastic accumulate in the thermal decomposition reactor (1) by melting the waste plastic. Then, foreign matter having a large specific gravity, such as metal and glass, is stirred by the stirring blade (2).
Due to the agglomeration effect due to the shape of 6) and the shape of the bottom surface of the pyrolysis reactor (1), it accumulates at the center of the bottom surface of the pyrolysis reactor (1). When the amount of accumulated foreign matters increases, problems such as damage to the stirring blade (26) and burning of the melt at the bottom of the pyrolysis reactor (1) occur. To prevent this, a vacuum pump
Operate (31). Then, the inside of the foreign matter collection container (29) is evacuated, and the molten liquid in the pyrolysis reactor (1) passes along with the foreign matter through the foreign matter suction pipe (27) and the conduit (28) to the foreign matter collection vessel (2).
It is sucked into 9). Thus, foreign matter is removed without stopping the operation of the oiling system.

When the melt is sucked into the foreign matter collecting container (29), the pressure in the thermal decomposition reactor (1) becomes negative. Pyrolysis reactor
If the pressure in (1) becomes negative, an inert gas is sent into the pyrolysis reactor (1) to regulate the pressure, but the system still has a negative pressure. Inevitably, the pyrolysis gas sent from the pyrolysis reactor (1) may flow backward. However, the ejector (1
Since the pyrolysis gas is forcibly sent to the downstream side by (7), the backflow of the pyrolysis gas is completely prevented in conjunction with the function of the water seal (24), and the burner (4) is surely sent to the burner (4). Sent and burned here. Therefore, occurrence of backfire is completely prevented. In addition, the water seal (2
4) The backflow of water inside is also prevented, which
Water is prevented from entering the gasoline and kerosene tank in (6) and kerosene in (5).

In the above embodiment, the ejector (17)
By making the capacity of the high-pressure water pump (19), which is the driving source of the system, variable in conjunction with the system pressure, the system pressure can be maintained at a desired pressure. In addition, when the amount of generated pyrolysis gas in the pyrolysis reactor (1) was small and the pre-stream side became negative pressure by operating the ejector (17), it was injected from the ejector (17). A part of the air in the gas-liquid multiphase fluid may be supplied to the upstream side.

In the above embodiment, two condensers for cooling and condensing the pyrolysis gas are provided, but the number of such condensers is not limited to this.
In the above embodiment, the pyrolysis gas not condensed in the condenser is burned by the burner (4). Alternatively, the pyrolysis gas may be recovered by the recovery device. Good. Further, in the above embodiment, water is used as the driving liquid for the ejector, but the present invention is not limited to this.

[0035]

According to the waste plastic oiling system of the present invention, as described above, even when the pressure in the system becomes negative, the reverse flow of the pyrolysis gas is completely achieved in combination with the function of the water seal. Is prevented. Therefore, when the recovery device for the flammable pyrolysis gas that has not been condensed in the condenser is arranged on the downstream side of the condenser, the pyrolysis gas is reliably recovered. In addition, if a flammable pyrolysis gas combustion device that is not condensed in the condenser is provided on the downstream side of the condenser, the pyrolysis gas is reliably burned and backfire is prevented. You. Further, since the backflow of water in the water seal is prevented by the function of the ejector, it is possible to prevent water from being mixed into the pyrolysis oil recovered by the condenser.

Further, a tank is provided for holding a driving liquid for the ejector. An inlet-side conduit for feeding pyrolysis gas not condensed in the condenser into the tank, and a pyrolysis gas fed into the tank is pyrolyzed. An outlet conduit connected to the gas recovery device or the pyrolysis gas combustion device is connected, an ejector is provided so as to face the inlet conduit, a driving liquid supply pipe is provided between the ejector and the tank, and a driving liquid supply pipe is provided. If a high-pressure liquid pump for sending the driving liquid in the tank to the ejector is provided, the driving liquid can be circulated and used, so that it is not necessary to use a large amount of driving liquid and the cost is reduced.

Further, if an air suction pipe whose tip is open to the atmosphere is connected near the nozzle of the ejector, if the driving liquid is ejected from the nozzle of the ejector at a high speed, the air is sucked from the air suction pipe. The gas-liquid multi-phase fluid is mixed with the driving liquid and is jetted. Therefore, the suction capability of the pyrolysis gas is improved as compared with the case where the driving liquid is injected alone, and the backflow of the pyrolysis gas and the backflow of water in the water seal can be more completely prevented.

Further, the tank is provided with a tank in which a driving liquid for the ejector is stored, an inlet-side conduit for feeding pyrolysis gas not condensed in the condenser to the tank, and a pyrolysis gas fed into the tank. An outlet conduit connected to the gas recovery device or the pyrolysis gas combustion device is connected, an ejector is provided so as to face the inlet conduit, a driving liquid supply pipe is provided between the ejector and the tank, and a driving liquid supply pipe is provided. A high-pressure liquid pump for sending the driving liquid in the tank to the ejector is provided, and an air suction pipe whose tip is open to the atmosphere is connected to the downstream side of the nozzle of the ejector, and the air suction pipe is linked with the high-pressure liquid pump and If a solenoid valve that opens when the high-pressure liquid pump operates and closes when the high-pressure liquid pump is stopped is provided, the drive liquid can be circulated and used. , Cost is cheap and there is no need use a large amount of the driving liquid. Further, when the high-pressure liquid pump is stopped, air can be prevented from entering the system.

[Brief description of the drawings]

FIG. 1 is a schematic view showing the entire configuration of a waste plastic oiling system according to the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a main part.

[Explanation of symbols]

 (1) Pyrolysis reactor (2) First condenser (3) Second condenser (4) Burner (pyrolysis gas combustion device) (17) Ejector (24) Water seal

────────────────────────────────────────────────── (5) References JP-A-6-330053 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C10G 1/10 B09B 3/00 C08J 11 / 12

Claims (4)

(57) [Claims] 1. A pyrolysis reactor in which waste plastic is melted and pyrolyzed therein, and a pyrolysis gas disposed in a downstream side of the pyrolysis reactor and generated by the pyrolysis reactor is cooled and condensed. A condenser for obtaining pyrolysis oil, and a pyrolysis gas recovery device or a pyrolysis gas combustion device disposed on the downstream side of the condenser for recovering combustible pyrolysis gas not condensed in the condenser are provided. A waste plastic oil conversion system, in which a driving liquid is injected from a nozzle at a high speed and a pyrolysis gas is sucked and sent to a downstream side between a condenser and a pyrolysis gas recovery device or a pyrolysis gas combustion device. A waste plastic oiling system in which an ejector and a water seal that prevents backflow of pyrolysis gas are arranged. 2. A tank containing a driving liquid for an ejector, an inlet-side conduit for supplying pyrolysis gas not condensed in a condenser to the tank, and a pyrolysis gas fed into the tank. An outlet conduit connected to the gas recovery device or the pyrolysis gas combustion device is connected, an ejector is provided so as to face the inlet conduit, a driving liquid supply pipe is provided between the ejector and the tank, and a driving liquid supply pipe is provided. 2. The waste plastic oil liquefaction system according to claim 1, further comprising a high-pressure liquid pump for sending the driving liquid in the tank to the ejector. 3. The waste plastic oil conversion system according to claim 1, wherein an air suction pipe having a tip open to the atmosphere is connected near the nozzle of the ejector. 4. A tank in which a driving liquid for an ejector is stored, an inlet-side conduit for feeding pyrolysis gas not condensed in a condenser to the tank, and a pyrolysis gas fed into the tank. An outlet conduit connected to the gas recovery device or the pyrolysis gas combustion device is connected, an ejector is provided so as to face the inlet conduit, a driving liquid supply pipe is provided between the ejector and the tank, and a driving liquid supply pipe is provided. A high-pressure liquid pump for sending the driving liquid in the tank to the ejector is provided, and an air suction pipe whose tip is open to the atmosphere is connected to the downstream side of the nozzle of the ejector, and the air suction pipe is linked with the high-pressure liquid pump and 2. The waste plastics liquefaction system according to claim 1, further comprising an electromagnetic valve that is opened when the high-pressure liquid pump is operated and is closed when the high-pressure liquid pump is stopped.