JP4658638B2 - Induction heating type distillation furnace - Google Patents

Description

  The present invention relates to an induction heating type carbonization furnace that removes polymer components such as paint and resin from waste such as used beverage cans.

  Induction heating type distillation furnaces inductively heat the furnace body containing the to-be-dried object by the magnetic flux generated by the heating coil, and heat the to-be-dried object in the furnace body in an inert gas atmosphere by radiant heat and heat conduction from the furnace wall. It is one that is carbonized. In that case, the to-be-dried product in the periphery of the furnace is quickly heated by radiant heat and heat conduction from the furnace wall. Therefore, the temperature rise is delayed. Therefore, in the induction heating type dry distillation furnace described in Patent Document 1, the gas in the furnace is forcibly circulated by a fan, and the heat of the high temperature dry matter near the furnace wall is used as a medium for the low temperature in the center of the furnace. The temperature difference of the to-be-distilled material between the peripheral part in the furnace and the central part in the furnace is reduced.

  FIG. 5 is a longitudinal sectional view showing the induction heating type carbonization furnace described in Patent Document 1. As shown in FIG. In FIG. 5, a furnace body 1 made of a magnetic material (steel iron) is an upright cylindrical body, and is supported coaxially through an annular space 15 in a bottomed upright cylindrical body 4 made of a heat insulating wall. At the upper and lower portions of the furnace body 1, flow windows 16 and 17 that communicate between the interior of the furnace and the annular space 15 are provided at a plurality of locations in the circumferential direction. The upper surface of the furnace body 1 is closed by a steel plate cover 5, and the outer side of the cover 5 to which the suspension bolt 6 is attached is covered with a heat insulating material 7. At the center of the bottom of the furnace body 1, a fan 8 is installed vertically with the discharge side up, and a dry matter support 9 for supporting the dry matter 3 is horizontally installed above the fan 8. The to-be-dried material support 9 is comprised by the punching metal etc. so that an inert gas can pass freely.

  The fan 8 is surrounded by a conical ventilation guide 10, and the ventilation guide 10 has an opening on the lower side (suction side) of the fan 8 and is closed between the peripheral edge and the furnace body 1. The fan 8 is driven from the outside of the structure 4 by a motor 12. The heating coil 2 is disposed outside the structure 4 and is excited by an excitation power source 13. The temperature of the furnace body 1 is detected by the temperature sensor 14, and the excitation power supply 13 supplies electric power to the heating coil 2 based on the detection signal so that the temperature of the furnace body 1 is maintained at a certain dry distillation temperature, for example, 550 ° C. Control.

  When the dry distillation furnace of FIG. 5 is operated, the dry distillation object 3, for example, an empty can is charged on the dry distillation object support 9, and the inside of the furnace is replaced with an inert gas such as nitrogen or argon. The alternating current is energized, and the fan 8 is started at the same time. The magnetic flux generated by the excitation of the heating coil 2 passes through the structure body 4 and is linked to the furnace body 1 to generate an induced current in the furnace body 1. Thereby, the furnace body 1 generates heat, and heats the dry matter 3 in the furnace. In that case, the to-be-dried product 3 in the periphery of the furnace adjacent to the furnace body 1 is heated by both radiant heat and heat conduction from the furnace body 1 and rapidly rises in temperature. On the other hand, the to-be-dried product 3 in the center of the furnace is heated by heat conduction from the to-be-dried product 3 on the outer side, and the temperature rises with a delay from the periphery in the furnace.

On the other hand, when the fan 8 is started, the inert gas in the furnace circulates as shown by an arrow. That is, the inert gas that has flowed upward in the axial direction of the furnace body 1 through the dry matter 3 in the center of the furnace returns to the furnace through the flow window 16, the annular space 15, and the flow window 17 and is sucked into the fan 8. It is. By this circulation, the inert gas that has taken heat from the high temperature dry matter 3 in the vicinity of the furnace wall gives this heat to the low temperature dry matter 3 in the center of the furnace to raise the temperature. As a result, heat transfer is performed from the high temperature dry matter 3 near the furnace wall to the low temperature dry matter 3 in the center of the furnace using an inert gas as a medium, and the rise of the dry matter 3 in the center of the furnace is increased. The temperature is urged.
Japanese Patent Laid-Open No. 2004-44824

  By the way, in the dry distillation furnace as shown in FIG. 5, after the temperature of the dry matter in the furnace is raised to a certain temperature, the temperature is maintained at that temperature for a predetermined time and the dry distillation treatment is performed. If it is shortened, the processing capacity can be increased. However, since the heat generation amount of the furnace body is determined by the heat generation area of the furnace body if the temperature of the furnace body and the gas circulation speed are determined, it is necessary to increase the heat generation area in order to increase the heat generation amount and shorten the heating time. However, increasing the diameter and height of the furnace body to increase the heat generation area increases the size of the furnace body, which increases the installation area and the manufacturing cost of the furnace.

  Accordingly, an object of the present invention is to increase the heat generation area without increasing the size of the furnace body and to improve the treatment capacity of the dry distillation furnace.

In order to solve the above-described problems, the present invention is configured such that a cylindrical furnace body made of a magnetic material is installed through an annular space inside a structure that forms an inert gas atmosphere, and the structure is formed outside the structure. The furnace body is induction-heated by a heating coil disposed concentrically with the furnace body, and the to-be-distilled matter accommodated in the furnace body is dry-distilled. At that time, the gas in the furnace body is passed through the annular space by a fan. in was set to forcibly circulate induction heating dry distillation furnace, the outer peripheral portion of the furnace body, said projecting projecting into the annular space, the outer peripheral portion and the heat transfer fins formed on gutter-like semicircular arc cross-section of the furnace body It shall be attached in parallel with the axial direction of the furnace body.

  According to the present invention, the heat generating area that protrudes into the annular space between the outer peripheral portion of the furnace body and the structure body is attached in parallel to the axial direction of the furnace body, so that the heat generation area is not increased without increasing the size of the furnace body. Can be increased. A plurality of heat transfer fins can be provided at appropriate intervals in the circumferential direction of the furnace body. The heat of the heat transfer fins is transferred to the dry matter in the furnace body through the circulating gas flowing through the annular space.

  FIG. 1 is a longitudinal sectional view of a dry distillation furnace showing an embodiment of the present invention. 1 is different from the prior art of FIG. 5 in that heat transfer fins 18 projecting into the annular space 15 are attached to the outer peripheral portion of the furnace body 1 in parallel to the axial direction of the furnace body 1. FIG. 2 is a perspective view showing the furnace body 1. Heat transfer fins 18 made of steel plates are formed in a strip shape as shown in the figure, and are joined to a plurality of outer peripheral portions (four places in the figure) of the furnace body 1 by welding in a radial manner. ing.

  In FIG. 1, when the heating coil 2 is energized, the furnace body 1 generates heat due to the induction current, and this heat is transmitted to the heat transfer fins 18, and further, the circulating gas flowing through the annular space 15 is heated and transmitted to the dry distillation object 3. It is done. Since the heat generation area is increased by attaching the heat transfer fins 18, the amount of heat transferred from the furnace body 1 to the to-be-distilled material 3 is increased. Is done. Or, since the amount of heat taken by the circulating gas from the furnace body 1 is increased by the attachment of the heat transfer fins 18, the input power for controlling the temperature of the furnace body 1 to be constant is increased, and the temperature rise time of the dry matter 3 is shortened. It can be said that. In addition, since the heat transfer fins 18 are accommodated in the annular space 15 for circulating the gas in the furnace, the size of the furnace body 1 does not increase due to the attachment of the heat transfer fins 18 and increases the furnace cost and installation area. There is nothing.

  FIG. 4 is a longitudinal sectional view of the main part of the dry distillation furnace showing the magnetic flux distribution of the heating coil 2. Since the surface of the furnace body 1 facing the heating coil 2 generates heat due to the skin effect, the heat transfer fins 18 are preferably provided outside the furnace body 1 as shown in the figure. Further, by attaching the heat transfer fins 18 in parallel with the axial direction of the furnace body 1, the magnetic flux lines 19 shown in FIG. 4 become parallel to the heat transfer fins 18, and the magnetic flux lines 19 cross the heat transfer fins 18. Local heat generation of the heat fin 18 does not occur. In FIG. 4, an iron core 20 that prevents leakage of magnetic flux to the outside is provided outside the heating coil 2.

  FIG. 3 is a perspective view of the furnace body 1 showing a different embodiment of the present invention. In this case, the heat transfer fin 18 is formed in a bowl shape with a semicircular arc cross section. According to this embodiment, the bonding area between the furnace body 1 and the heat transfer fins 18 is increased, and heat conduction from the furnace body 1 to the heat transfer fins 18 is improved. In any case, the heat transfer fins 18 are preferably formed in a rail shape that is long in the axial direction of the furnace body 1 along the gas flow direction and the magnetic flux line direction. Further, the number of the heat transfer fins 18 attached is not limited to four in the drawing and is arbitrary.

It is a longitudinal cross-sectional view of the dry distillation furnace which shows embodiment of this invention. It is a perspective view of the furnace body in FIG. It is a perspective view of the furnace body which shows different embodiment of this invention. It is a principal part longitudinal cross-sectional view which shows the magnetic flux distribution in the carbonization furnace of FIG. It is a longitudinal cross-sectional view of the carbonization furnace which shows a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Furnace 2 Heating coil 3 Dry matter 4 Structure 8 Fan 9 Dry matter support 10 Ventilation guide 13 Excitation power source 14 Temperature sensor 15 Annular space 16 Current flow window 17 Current flow window 18 Heat transfer fin

Claims (1)

A cylindrical furnace body made of a magnetic material is installed through an annular space inside the structure forming an inert gas atmosphere, and a heating coil arranged concentrically with the furnace body outside the structure. In the induction heating type dry distillation furnace in which the furnace body is induction-heated, and the to-be-distilled matter accommodated in the furnace body is subjected to dry distillation, and the gas in the furnace body is forcibly circulated through the annular space by a fan. ,
Wherein the outer peripheral portion of the furnace body, said projecting annular space, fitted with the outer peripheral portion and a semi-arcuate cross-sectional heat transfer fins formed on trough of the furnace body in parallel with the axial direction of the furnace body Induction heating type carbonization furnace.

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