JP2020002332A - Waste plastic inputting device - Google Patents

Abstract

To effectively prevent blockage of a pocket of a piping or a rotary valve and surely maintaining input of a waste plastic at a constant amount when the waste plastic which is a raw material is input into a waste plastic decomposition device by the rotary valve.SOLUTION: A gas in spraying and inputting means 35 for spraying and inputting a gas into a pocket 34 between blades 29 of a rotor 30 below an exhaust port 34 of a rotary valve 6 from a downstream side of a rotation direction of the rotor 30.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a waste plastic input device that inputs waste plastic as a raw material into a waste plastic decomposition device.

The present inventor has provided a waste plastic oiling system described in Patent Literature 1 as a waste plastic oiling system for thermally decomposing crushed waste plastic into oil.
In this system, a rotary valve is used to continuously feed the pulverized waste plastic into a waste plastic decomposer at a constant rate.

JP-A-2017-75294

In the system of Patent Document 1, the rotary valve is connected by piping between a raw material input popper for temporarily storing crushed waste plastic and a decomposition evaporation tank of a waste plastic decomposition device.
The rotary valve has a hermetic structure because a rotor having radial blades rotates inside the casing to feed the raw material that has entered the pocket between the blades from the casing inlet to the outlet of the casing. It is a means of transportation.
However, the evaporative gas generated by dissolving the waste plastic at a high temperature in the decomposition evaporator tank becomes hot air, passes through the rotary valve, and flows back to the raw material input popper. Therefore, when it cools down, it condenses and liquefies, and the crushed waste plastic adheres to it (especially Styrofoam with a low specific gravity). There was fear.
A first object of the present invention is to effectively prevent such a problem with a simple structure.
A second object is to ensure that the hot air from the waste plastic decomposer does not flow to the rotary valve until the decomposable condition is reached in the waste plastic decomposer, so that it can be reliably shut off.

In order to achieve the first object, the present invention provides a gas injection means for injecting gas into a pocket between rotor blades from a downstream side of a rotation direction of a rotor below an outlet of a rotary valve. It is characterized by.
The gas injection means can be configured by installing an injection nozzle below the outlet of the rotary valve and connecting a gas supply pipe to the injection nozzle.
In order to achieve the second object, a stop valve is installed between the outlet of the rotary valve and the inlet of the waste plastic decomposition device.

The waste plastic that has entered the rotor pocket falls one after another from the pocket facing the outlet of the rotary valve with the rotation of the rotor. According to the present invention, at the same time, the pocket on the downstream side in the rotation direction of the rotor is rotated. Because gas is injected from below the outlet, waste plastic remaining in the pocket is forcibly blown off to the outlet, and hot air of evaporative gas from the waste plastic decomposition device is pushed back, Further, the rotor can be cooled. As a result, it is possible to block the hot air of the evaporative gas from entering the rotary valve, and it is also possible to suppress the adhesion of waste plastic to the rotor blades and the residue in the pocket, which effectively blocks the piping and the pocket of the rotary valve. It is possible to prevent waste, and to reliably maintain a fixed amount of waste plastic.
If the injection nozzle is provided below the outlet of the rotary valve and a gas supply pipe is connected to the injection nozzle, the above-described operation and effect can be obtained without changing the structure of the rotary valve itself.
If a stop valve is installed between the outlet of the rotary valve and the inlet of the waste plastic disintegrator, the stop valve will be closed and hot air will flow from the waste plastic disintegrator until it can be disassembled. It can shut off reliably so that it does not flow to the rotary valve.

1 is an overall configuration diagram of a waste plastic oiling system to which a waste plastic input device of the present invention is applied. 1 is a front view of one embodiment of a waste plastic charging device of the present invention. FIG. It is a simplified block diagram of the main part of the present invention.

First, an overall configuration of an example of a waste plastic oiling system including a waste plastic input device of the present invention will be described with reference to FIG.
Waste plastics containing a mixture of polypropylene (PP), polyethylene (PE), polystyrene (PS), polyethylene terephthalate (PET), polyvinyl chloride (PVC), styrofoam, etc. are subjected to pretreatment such as crushing, volume reduction and cooling. After that, it is pneumatically transported through the pipe to the waste plastic charging apparatus 1 of the present invention, and is referred to as “pulverized raw material”.

The pulverized raw material is collected by the cyclone 2 and temporarily stored in the raw material input hopper 3 of the waste plastic input device 1, and the catalyst separately transported in the pipe is also temporarily stored in the catalyst input hopper 4. The pulverized raw material in the raw material input hopper 3 is sent out by the paddle screw conveyor 5 and enters the electric rotary valve 6 of the waste plastic input device 1 connected to the lower side from the front end thereof, whereby the input pipe is charged by a fixed amount. The waste plastics are introduced into a drum-type decomposition / evaporation tank 9 of a waste plastic decomposition apparatus 8 through the same 7.
On the other hand, the catalyst in the catalyst loading hopper 4 that has been transported by air is also fed into the loading pipe 7 from the middle of the loading pipe 7 by the catalyst transport screw 10 and is loaded into the decomposition and evaporation tank 9 together with the pulverized raw material.
FIG. 2 and FIG. 3 show these transport portions in an enlarged manner.

  In the cracking evaporator 9, as described in Patent Literature 1, while the pulverized raw material and the catalyst are mixed by the charging agitator 11 on the vertical axis, near the peripheral wall of the cracking evaporator 9 having the double wall structure. While being indirectly heated by the heat medium circulating on the bottom wall and the inside of the bottom wall and the inside of the surrounding wall, the heat is stirred by the first stirring unit of the decomposition stirrer 12 along the surrounding wall. Decomposed. Further, after being dispersed by the second stirring section of the decomposition stirrer 12, the mixture is stirred on the bottom wall toward the central residue discharge port, whereby the thermal decomposition proceeds and the thermal decomposition is completed. The residue is discharged by the residue discharge device 13.

  The cracked gas evaporated by the thermal decomposition in the cracking and evaporation tank 9 is sent to the neutralization tank 15 of the alkali spray device 14 installed above the cracking and evaporation tank 9 and connected to the pipe, where the terephthal in the cracking gas is sent. Acid components such as acids are neutralized by spraying an alkaline solution. The spray recovery liquid in the neutralization tank 15 flows down to the sedimentation separation tank 16 to separate tar components and catalyst components, and is returned to the neutralization tank 15 for circulating use. Therefore, the neutralization treatment by spraying the alkali liquid here can prevent the clogging of the pipe due to the terephthalic acid, tar component, and catalyst components contained in the raw material PET, and can adjust the pH of the oiled product. it can.

  The alkali-neutralized decomposition gas is cooled by a first condenser 17 connected to a neutralization tank 15 by piping. This condenser 17 functions as a primary cracked oil generator, and the primary cracked oil is generated by cooling here. This primary cracked oil falls into the distillation tank 19 of the distillation stabilizer 18 installed below the condenser 17 and connected to the piping.

  The distillation stabilizing device 18 indirectly heats the distillation tank 19 by circulating the heat medium in the cavity having the double wall structure, similarly to the decomposition evaporation tank 9. The gas evaporated in the distillation tank 19 is cooled by a second condenser 20 installed above and connected to a pipe. The condenser 20 functions as a secondary cracked oil generator, and the secondary cracked oil is generated by cooling here.

  The secondary cracked oil generated by the second condenser 20 once flows into a separation tank 21 installed below and connected to a pipe to precipitate impurities and the like, and then adjusts a flash point installed therebelow. It enters the constant temperature heating tank 23 of the device 22, where it is again indirectly heated by the heating medium. The flash point adjusting device 22 evaporates those having a low flash point by heating the secondary cracked oil in the constant temperature heating tank 23 at a substantially constant temperature while stirring. The non-evaporated oil is stored in the product storage tank 24 as a target product oil.

  As described above, the waste plastic input device 1 of the present invention is to feed the pulverized raw material sent out from the raw material input hopper 3 to the decomposition evaporating tank 9 of the waste plastic decomposition device 8 by the rotary valve 6 in a fixed amount. The embodiment will be described with reference to FIGS. 2, 3, and 4. FIG.

  The rotary valve 6 is connected to the paddle screw conveyor 5 below a distal end portion of the horizontally long casing 5 a by a connection pipe 25. A manual stop valve 26 is connected to a lower side of the rotary valve 6, and a charging pipe 7 is connected to a lower side of the stop valve 26 and leads to a charging port of the decomposition evaporation tank 9. In order to prevent outside air from entering these connection paths, a noncombustible gas such as nitrogen gas is supplied from a noncombustible gas supply pipe 27 connected in the middle of the connection pipe 25. Further, a water-cooled heat circuit breaker 28 that circulates water is installed on the outer periphery of the charging pipe 7 in order to cut off heat from the decomposition evaporation tank 9.

  As shown in a simplified form in FIG. 4, the rotary valve 6 is configured such that a rotor 30 having a plurality of blades 29 provided radially rotates inside a casing 31 by a motor (not shown). The pockets 32 between the two 29 are sequentially switched to an upward inlet 33 and a downward outlet 34 of the casing 31 so as to face each other. In this example, the number of the blades 29 is eight, the rotation direction of the rotor 30 is clockwise, and the pocket 32 is clockwise in the eight chambers A, B, C, D, E, F, G, and H, facing upward. When the two pockets 32 face the inlet 33, the two pockets 32 facing downward face the outlet 34.

  The casing 31 is provided with an injection nozzle 35 for injecting gas upward from the discharge port 34 into the pocket 32, and a gas supply pipe 36 is connected to the injection nozzle 35, and air or nitrogen gas or the like is supplied through the gas supply pipe 36. A noncombustible gas is externally supplied with pressure. The two downwardly facing pockets 32 face the discharge port 34 as described above. However, the installation position and the ejection direction of the ejection nozzle 35 are only one of the two pockets 32 on the downstream side in the rotation direction ( It is set so as to inject gas into the pocket (F in FIG. 4).

  According to the rotary valve 6 thus configured, the pulverized raw material from the connecting pipe 25 falls into the two pockets A and B facing the inlet 33, and the two pockets E and F facing the discharge port 34. At E on the upstream side in the rotation direction of 32, the pulverized raw material stored up to that point falls from the discharge port 34, and at F on the downstream side in the rotation direction, the non-combustible material such as air or nitrogen gas flows from the injection nozzle 35. Gas will be injected. These operations are sequentially switched as the rotor 30 rotates.

  In the pocket 32 of F, an incombustible gas such as air or nitrogen gas is injected immediately after the stored pulverized raw material falls, so that even if pulverized raw material remains, it is forcibly blown off to the outlet 34 and The hot air of the evaporated gas from the decomposition evaporation tank 9 is pushed back, and the rotor 30 can be further cooled. Thereby, the hot air of the evaporative gas can be shut off so as not to enter the rotary valve 6, and the adhesion of the pulverized raw material to the blade plate 29 and the residual in the pocket 32 can be suppressed even if the polystyrene foam is contained. Blockage of the connection pipe 25 and the like and the pocket 32 can be effectively prevented, and the constant supply of the pulverized raw material can be reliably maintained.

  Since the stop valve 26 is connected to the lower side of the rotary valve 6, the stop valve 26 is closed until the inside of the decomposition evaporation tank 9 becomes decomposable when operating this waste plastic oiling system. Thereby, the hot air from the decomposition evaporation tank 9 can be reliably shut off here.

REFERENCE SIGNS LIST 1 waste plastic input device 3 raw material input hopper 8 waste plastic decomposition device 9 decomposition evaporation tank 26 stop valve 29 wing plate 30 rotor 31 casing 32 pocket 33 inlet 34 outlet 35 injection nozzle 36 gas supply pipe

Claims (3)

  In a waste plastic input device for feeding raw waste plastic into a waste plastic decomposing device by a rotary valve, a lower portion of the rotary valve and a downstream side in the rotation direction of the rotor, into a pocket between rotor blades. What is claimed is: 1. A waste plastic charging device, comprising: gas injection means for gas injection.   The waste plastic charging device according to claim 1, wherein the gas injection means includes an injection nozzle provided below an outlet of the rotary valve, and a gas supply pipe connected to the injection nozzle.   The waste plastic input device according to claim 1 or 2, wherein a stop valve is provided between an outlet of the rotary valve and an input port of the waste plastic decomposition device.