JP2009149830A - Pyrolysis direct oil drainer - Google Patents

Abstract

[PROBLEMS] To provide an oil collection method that does not vaporize cracked oil obtained by decomposing waste plastics and waste rubber, and does not solidify even if the liquid discharged directly from the cracking tank drops to room temperature. To do.
SOLUTION: A hollow agitation shaft 4 accommodated in a decomposition tank is perforated and slides on a bearing 5 provided in a lower part of the decomposition tank, and a through hole is provided in the bearing 5 so that the hollow agitation shaft 4 to the bearing 5 are provided. By making the decomposition tank communicate with the outside of the tank, the decomposed oil enters the hollow shaft 4 through the perforations and is discharged from the bearing 5 while being heated in the stirring shaft.
[Selection] Figure 2

Description

  The present invention relates to a method for directly removing from a cracking tank, as a liquid, cracked oil that has been decomposed to a level that does not lead to vaporization due to lower molecular weight in the thermal decomposition of waste plastic made of a polymer.

Today, 7.6 million tons of plastic products are manufactured and discarded every year, and the use of waste plastic is not complete, and many are disposed of by incineration or landfill.
In removing plastic oil from these waste plastics, thermal decomposition is performed.

The main method is to store the waste plastic in a heating furnace or a heating tank and heat it from the outside with a burner or the like, and there are also documents in which heated gas is inserted into a partially stored furnace.
In many literatures, the mainstream is a type in which raw material is supplied into a tank by a screw feeder, and the oil vapor decomposed and vaporized by heating the tank by external heating is liquefied by cooling with a condenser.

  In the process of breaking the binding molecules by thermal decomposition, we want to extract the cracked oil in the cracking tank before vaporizing and evaporating, but if the waste plastic oil taken out is undegraded or insufficiently decomposed, Solidification proceeds as the oil temperature decreases from around the take-out container where heat exchange gradually proceeds.

In order to extract cracked oil at the time of cracking without excessive decomposition without using a catalyst, it is necessary to further heat in the process of cracking the plastic and to perform fractional drawing while preventing mixing with undegraded oil.
JP 2005-264104 A JP 2005-154518 A Japanese Patent Laid-Open No. 11-118129

  The problem to be solved is that during the process of thermal decomposition of waste plastic, solidification occurs in the lower part of the decomposition tank and the part where the heating temperature is deprived by heat transfer. However, is it possible to extract waste plastic oil pyrolyzed by low-temperature heating without vaporizing it from the decomposition tank?

In the present invention, the stirring shaft in the cracker tank is made hollow, and a perforated hole is provided at a part of the hollow shaft so that cracked oil enters the hollow shaft.
When the hollow shaft is rotated while immersed in the decomposed plastic oil, the decomposed oil and the oil under decomposition enter the hollow shaft, and the oil under decomposition is further decomposed by the heat transfer of the decomposed oil around the shaft, Pull out from the through hole provided in the bearing in the lower part of the decomposition tank.

  In the present invention, in the thermal decomposition of waste plastics, the solid plastic is directly drawn out in a state where it is thermally decomposed to some extent, without producing a cracked oil that has been decomposed and vaporized to a lower molecule and cooled and liquefied by a condenser. The extracted cracked oil does not solidify even when cooled to room temperature.

  The cracking tank is placed vertically or obliquely to provide a hollow stirring shaft inside, and a hole into which a large number of cracked oil enters is provided on the outer periphery of the hollow shaft, and slides into a bearing that supports the shaft at the lower part of the cracking tank. The through hole provided in the bearing is communicated with the hollow hole.

  An embodiment of the waste plastic cracking and oiling apparatus of the present invention will be described with reference to FIG. Thermal decomposition in this apparatus is in an oxygen-free state. The mechanism is described in Japanese Patent Application No. 2007-284363.

Raw material waste plastic is 1. From the raw material inlet 2. 8. supplied to the decomposition tank and housed inside the tank; 10. maintained at decomposition temperature by high frequency electromagnetic induction heating. In dissolved oil, 4. It is immersed by a blade attached to the hollow stirring shaft.
The dissolved oil surface is positioned higher than the raw material charging opening of the cracking tank to prevent the raw material from floating on the dissolved oil surface as it is after being charged.

  The waste plastic pushed into the oil is melted and assimilated into dissolved oil, and moves in the decomposition tank while being slowly stirred. Since the tank constituting the cracker is placed with an inclination, there is a space on the upstream side of the inclination, and in this space, waste plastic oil whose molecular weight has been reduced by thermal decomposition becomes oil vapor from the oil surface. Evaporate.

2. Evaporate oil vapor with an ejector pump. Although it is discharged from the exhaust port and liquefied by a condenser to collect waste plastic cracked oil, the molecular weight is not completely reduced by a process that is insufficiently decomposed immediately under the raw material input of the cracker.
The waste plastic melted in the lower part of the cracking tank just below the raw material is further thermally decomposed, and the specific gravity decreases with the progress of thermal decomposition. 15. Displace the oil in the dissolved oil and move it to the upper part of the decomposition tank. become that way. Furthermore, the supernatant cracked oil was provided on the hollow stirring shaft above the dissolved oil surface. Pull out from small hole.

  Dissolved oil with high specific gravity is desired, but even if it is almost equivalent to the waste plastic cracked oil, both dissolved oil and cracked oil can produce a relatively low molecular weight cracked oil with a small specific gravity by the above action. .

  The operation of the cracker in the present invention is a continuous batch type, and the small-diameter hole is positioned higher than the dissolved oil surface rising by the initial input amount, and further vaporized by continuously charging and decomposing. The oil level of the cracked oil that has not been reached reaches the position of the small-diameter hole and flows out.

  Decomposed oil that has penetrated into the hollow stirring shaft from the small-diameter hole or is in the process of decomposing has a low molecular weight due to the action of heating the oil enclosed in the heated dissolved oil and heating the oil in the hollow shaft. Is achieved.

  In order to prevent generation of oil vapor from the cracked oil that has entered through the small-diameter holes and accumulation in the space of the hollow stirring shaft, 13. Ventilation holes are provided to discharge oil vapor from the hollow stirring shaft.

  The bearing at the lower position of the stirring shaft is 11. When sliding with a low-abrasion bearing material, the dissolved oil plays the role of lubricating oil, and wear is reduced because the shaft rotates in the lubricating oil.

  The bearing provided in the lower part of the pyrolysis tank is provided with a through-hole penetrating to the outside of the tank, and the waste plastic oil reduced in molecular weight in the hollow stirring shaft is extracted. The control of the extraction amount is 6. Use a valve or timer.

It is explanatory drawing which showed the implementation method of this invention. It is explanatory drawing which showed the implementation method of a stirring shaft, a bearing, and a small diameter hole.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Raw material inlet 2 Decomposition tank 3 Exhaust port 4 Hollow stirring shaft 5 Tank lower part bearing 6 Decomposition oil discharge valve 7 Ground box 8 Geared motor 9 High frequency electromagnetic induction heating coil 10 Dissolved oil 11 Low wear bearing material 12 Decomposed oil intrusion small diameter Hole 13 Shaft vent 14 Supernatant cracked oil

Claims (1)

  In the waste plastic pyrolyzer, the stirrer shaft housed in the cracking tank is made hollow, and the outer periphery of the hollow shaft is drilled to slide on the bearing provided at the lower portion of the stirring shaft, and the bearing is drilled to break the cracking tank and the tank. A direct waste oil system that communicates outside.

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