JP2005249236A - Kiln dryer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a kiln dryer small in size and low in treatment cost. <P>SOLUTION: This kiln dryer comprises a cylindrical kiln body 1 downward tilted from the upstream side to the downstream side and allowed to rotate, an inner tube 4 concentrically fixed in the kiln body 1 and having a gas hole 4b in the downstream side peripheral surface, a burner 5 injecting a flame F from an upstream side inlet into the inner tube 4, first and second hoods 2 and 3 covering the upstream end part and the downstream end part of the kiln body 1, a substance discharge passage 8 formed at the lower end part of the second hood 3 and discharging heat treated useful substances, and a gas discharge port 9 installed in the second hood 3 and discharging burned gas G. After a material M supplied from the upstream side into a passage 11 between the kiln body 1 and the inner tube 4 is heated by the radiation heat and a circulation gas Gb in the inner tube 4 to vaporize unnecessary harmful substances from the surface thereof, the material is discharged from the substance discharge passage 8, and by utilizing the jetting pressure of the burner 5, the burned gas G is led to the upstream side through the passage 11, drawn into the inner tube 4, circulated by the burner 5 so as to be further burned, and a part thereof is discharged from the gas discharge port 9. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention dissolves scrap materials made of iron or non-ferrous metals such as aluminum such as scraps (referred to as chips) from machining such as used can containers (UBC: Used Beverage Can). The present invention relates to an apparatus (kiln dryer) for volatilizing and removing unnecessary organic substances such as a paint film and oil / moisture on its surface for the purpose of high yield dissolution prior to reuse.

Conventionally, for example, before a beverage can container (UBC) made of non-ferrous metal such as aluminum is dissolved and reused, a kiln dryer has been used to volatilize and remove unnecessary organic substances such as paint film and oily moisture on the surface. in use.
Such kiln dryers include a so-called direct self-combustion rotary kiln type for chips as shown in FIG. 4 and an inner cylinder radiant heating counterflow type rotary kiln type for UBC as shown in FIG.

  Among these, the former self-combustion type rotary kiln type directly carries the chips (material M) into the kiln main body 30 rotated by the conveyor 31, and directly applies the flame F injected from the burner 32 to the material M. It is intended to volatilize and remove unnecessary oils such as cutting oil and other oils and moisture adhering to M.

The latter inner cylinder radiant heating counterflow type rotary kiln type is provided with an inner cylinder 34 in a rotating kiln main body 30, and a used can container (material M) is introduced into the kiln main body 30 from an inlet 35. The burner 32 is combusted in the afterburner 36, the heat is sent to the inner cylinder 34 by the circulation fan 37, and unnecessary organic substances such as a paint film adhering to the surface of the material M are volatilized and removed by radiant heat from the inner cylinder 34. Is.
For example, a related invention is disclosed in Patent Document 1.
Japanese Patent Laid-Open No. 10-17945

However, the prior art described above has the following problems.
The former self-combustion type rotary kiln type directly burns the flame F and combustion gas G of the burner 32 to the material M to cause self-combustion. The temperature of the flame in which oil and fat is combusted near the surface of the material M is low, Incomplete combustion occurs due to insufficient mixing and black smoke is generated. This black smoke contains CO, soot, and organic unburned components, and is released into the atmosphere as it is. Therefore, it is necessary to provide a reburning furnace 33 for completely burning the black smoke and the organic substance. Accordingly, the apparatus becomes larger and the processing cost becomes high.

  Further, the latter inner cylinder radiant heating counterflow rotary kiln type volatilizes the organic component without causing self-combustion in the kiln because the flame F is not directly applied to the material M and is brought into contact with the processing gas whose oxygen partial pressure is controlled. Later, the burner 32 is guided and burned into the afterburner 36 which is considerably separated from the kiln body 30, and the temperature and oxygen partial pressure are supplied to the inner cylinder 34 by the circulation fan 37 as controlled regeneration gas. There is a problem that the processing cost is high.

  Accordingly, an object of the present invention is to provide a kiln dryer that is small in size and low in processing cost.

In order to achieve the above object, a kiln dryer according to claim 1 of the present invention is a scrap material (M) made of ferrous or non-ferrous metal such as cutting waste from machining such as a used can container. Is a device that volatilizes and removes unnecessary organic substances such as paint film and oil / moisture adhering to the surface of the material (M) prior to the melting step, and descends from the upstream side to the downstream side. And a cylindrical kiln main body (1) that rotates about an axis, and an inner cylinder (4b) concentrically fixed in the kiln main body (1) and having a gas hole (4b) on the peripheral surface on the downstream side. ), A flame (F) into the inner cylinder (4), and a burner (5) that heats the inner cylinder (4) by injecting it from the upstream inlet, and an upstream end of the kiln body (1). A first hood (2) fixed to cover and under the kiln body (1) A second hood (3) fixed so as to cover the end, a substance discharge passage (8) provided at the lower end of the second hood (3) for discharging the heat-treated useful substance, and the first A gas outlet (9) provided in the two hoods (3) for discharging the combustion gas (G),
Using the injection pressure of the burner (5), the combustion gas (G) flows upstream through the gas hole (4b) and the passage (11) between the kiln body (1) and the inner cylinder (4). And is drawn from the upstream inlet (4a) of the inner cylinder (4) into the inner cylinder (4) and circulated so as to be further combusted by the burner (5), and a part of it is circulated in the gas outlet (9). It is a structure that discharges from the
When the material (M) is supplied to the passage (11) from the upstream side, the supplied material (M) is supplied upstream from the radiant heat of the inner cylinder (4) and the gas hole (4b). After heating and removing the unnecessary organic substances on the surface by heat transfer by bringing them into contact with the circulating gas (G: Gb), the material (M) is discharged from the substance discharge passage (8). The gas (G: Gc) containing the organic content after contacting is further burned by the burner (5) and circulated as a clean gas (G: Ga), and a part of the clean gas (G: Ga) is The gas is discharged from the gas discharge port (9).

  In the invention according to claim 2, a circulating gas suction adjusting pipe (12) is fitted to the upstream end of the inner cylinder (4) so as to be extendable in the axial direction, and the combustion gas (G) The circulation amount to the inner cylinder (4) is adjustable.

  In the invention according to claim 3, the rotating blade (16) is attached in the inner cylinder (4) to increase the temperature of the inner cylinder (4), and the organic after contacting the material (M). The organic component in the gas containing the component is mixed and contacted and burned.

  Furthermore, in the invention described in claim 4, a discharge passage (7) for discharging ash (flyback) is formed at the lower end of the first hood (2), and two discharge passages (7) are provided in the discharge passage (7). A first double damper mechanism (13) having an openable damper (15) attached in series and a second double damper mechanism having two openable dampers (15) attached in series in the substance discharge passage (8) (14) is provided, and the oxygen concentration of the combustion gas (G) is appropriately maintained.

  Symbols in parentheses indicate corresponding elements or corresponding matters described in the drawings and the best mode for carrying out the invention described later.

According to the kiln dryer of claim 1 of the present invention, the flame of the burner is injected into the inner cylinder to heat the inner cylinder, and the material is supplied to the passage between the kiln main body and the inner cylinder, Since the material is heated by the radiant heat of the inner cylinder and the heat transfer by contacting the circulating gas introduced upstream from the gas hole, the oxygen is controlled by the burner air-fuel ratio control, unlike the case where the flame is directly applied to the material. Can be adjusted appropriately. Therefore, generation | occurrence | production of black smoke can be suppressed and the recombustion furnace for burning the substance in black smoke is not required.
As a result, it is possible to reduce the size of the apparatus and the material processing cost.

  Further, since the flame of the burner is directly injected into the inner cylinder, an afterburner as shown in the conventional example is not required. Therefore, further downsizing of the apparatus can be achieved. At the same time, unlike supplying the heat obtained by burning with an afterburner to the inner cylinder, the inner cylinder is directly heated, so that the inner cylinder can be effectively heated, and radiant heat is given to the material more efficiently. be able to.

  Further, the combustion gas is led to the upstream side through the gas hole and the passage between the kiln body and the inner cylinder by the injection pressure of the burner, and is drawn into the inner cylinder from the upstream inlet of the inner cylinder and further burned by the burner. It circulates and part of it is discharged from the gas outlet, so no circulation fan is required. Therefore, the apparatus can be further reduced in size.

  According to the second aspect of the present invention, since the circulating gas suction adjusting pipe is fitted to the upstream side of the inner cylinder so as to be expandable and contractable in the axial direction, the circulating gas suction adjusting pipe is expanded and contracted in the axial direction. The circulation amount of the combustion gas can be adjusted. Thereby, the inner cylinder can be set to an appropriate heating temperature suitable for the material.

Further, according to the invention described in claim 3, since the rotary blade is provided in the inner cylinder, the convection heat transfer effect can be obtained by increasing the temperature of the rotary blade and stirring the combustion gas by the rotary blade. It is possible to increase the temperature of the inner cylinder efficiently. Thereby, the radiant heat of an inner cylinder can be heated rapidly, and a material can be heated more effectively.
Moreover, since this rotary blade agitates combustion gas, combustion of the organic substance contained in it is accelerated | stimulated. Therefore, the concentration of carbon monoxide contained in the combustion gas can be reduced.

  Furthermore, according to the invention of claim 4, a discharge passage for discharging ash (flyback) is formed in the first hood, a first double damper mechanism is provided therein, and a substance discharge passage for the second hood. In addition, since the second double damper mechanism having the same structure is provided, the oxygen concentration of the combustion gas in the apparatus can be appropriately maintained by opening and closing these dampers.

  With reference to FIG. 1, the kiln dryer which concerns on embodiment of this invention is demonstrated. FIG. 1 is a sectional view showing the kiln dryer.

In order to reuse a used aluminum can container (UBC material M), the kiln dryer according to the embodiment of the present invention has a paint film and moisture adhering to the surface of the material M prior to the melting step. A device that volatilizes and removes unnecessary organic substances such as oil, and includes a kiln main body 1, an inner cylinder 4, a burner 5, and a conveyor 6. Moreover, the thermometer 17 for measuring the temperature in the kiln main body 1 and the inner cylinder 4 and the pressure gauge 18 for measuring the pressure in an apparatus are provided.
In addition, this kiln dryer treats the state as it is as the material M without grind | pulverizing a can container, However, It can also grind | pulverize and grind | pulverize the material M.

  In the present embodiment, the kiln main body 1 is cylindrical, tilts downward at an angle that allows the material M to naturally fall from the upstream side to the downstream side, and rotates about the axis. This rotation is performed by a rotating body 20 that abuts on the outer peripheral surface of the kiln body 1. A first hood 2 that covers the upstream end of the kiln main body 1 is fixed to the upstream end, and a second hood 3 that covers the downstream end is fixed to the downstream end. A plurality of scrapers 1 a are provided on the inner wall of the kiln body 1.

  The inner cylinder 4 is concentrically fixed in the kiln body 1 and has a gas hole 4b through which the combustion gas G can pass on the peripheral surface on the downstream side. The burner 5 is attached to the first hood 2 and heats the inner cylinder 4 by injecting the flame F into the inner cylinder 4 from the upstream side. The conveyor 6 is attached to the first hood 2 and supplies the material M to the passage 11 between the kiln main body 1 and the inner cylinder 4 from the upstream side.

  In this kiln dryer, the material M supplied from the upstream side to the passage 11 by the conveyor 6 is brought into contact with the radiant heat of the inner cylinder 4 heated by the burner 5 and the circulating gas Gb guided upstream from the gas hole 4b. After heating and removing the unnecessary organic substances such as paint film adhering to the surface by volatilization and removal, the substance is discharged from the substance discharge passage 8 formed at the lower end of the second hood 3 and processed. Send to box (not shown). This material M is sent to a melting furnace to be melted and reused.

  Further, the combustion gas G is guided to the upstream side through the gas hole 4 b and the passage 11 between the kiln main body 1 and the inner cylinder 4 using the injection pressure of the burner 5, and from the upstream inlet 4 a of the inner cylinder 4. While being drawn into the inner cylinder 4 and circulated so as to be further burned by the burner 5, a part thereof is discharged from the gas discharge port 9. Thereby, the gas Gc containing the organic component after contacting the material M is further burned by the burner 5 and circulated as the clean gas Ga, and a part of the clean gas Ga is discharged from the gas discharge port 9.

  In the kiln dryer according to the present embodiment having the above-described configuration, the flame F of the burner 5 is injected into the inner cylinder 4 to heat the inner cylinder 4, and the material M is passed between the kiln main body 1 and the inner cylinder 4. 11 and heated by radiant heat of the inner cylinder 4 and heat transfer by contacting the circulating gas Gb guided upstream from the gas hole 4b. Therefore, unlike the case where the flame F is directly applied to the material M and heated, the oxygen supply amount can be appropriately adjusted by the air-fuel ratio control of the burner 5, and the generation of black smoke can be suppressed. Thereby, the reburning furnace is not required, and the downsizing of the apparatus and the processing cost of the material M can be reduced.

Moreover, since the flame F of the burner 5 is injected into the inner cylinder 4, an afterburner is not required, and thus the apparatus can be further miniaturized. At the same time, since the inner cylinder 4 is directly heated, the heating efficiency is good. Therefore, radiant heat can be effectively applied to the material M.
Further, since the combustion gas G is circulated by the injection pressure of the burner 5, no circulation fan is required. This also makes it possible to reduce the size of the apparatus.

  Moreover, the kiln dryer which concerns on this embodiment has fitted the circulating gas suction adjustment pipe | tube 12 to the upstream end part of the inner cylinder 4 so that expansion-contraction is possible in an axial direction. By extending and contracting the circulating gas suction adjusting pipe 12 in the axial direction, the amount of the combustion gas G supplied from the upstream side inlet 4a of the inner cylinder 4 can be adjusted to keep the temperature of the inner cylinder 4 constant.

  That is, the amount of the combustion gas G supplied from the upstream side inlet 4a of the inner cylinder 4 is reduced by extending the circulating gas suction adjusting pipe 12 and reducing the distance from the first hood 2. Since the combustion gas G contains an inflammable organic substance, if the circulation amount is reduced, the combustibles are reduced and the thermal power of the burner 5 is attenuated, so that the temperature of the inner cylinder 4 is lowered. On the contrary, when the circulating gas suction adjusting pipe 12 is contracted, the circulation amount of the combustion gas G is increased and the thermal power is increased, so that the temperature of the inner cylinder 4 is increased.

  Further, this kiln dryer is formed with a discharge passage 7 for discharging ash (flyback) facing downward at the lower end of the first hood 2, and two open / close dampers 15 are connected in series to the discharge passage 7. A first double damper mechanism 13 mounted on the top and bottom is provided. Similarly, a second double damper mechanism 14 in which two open / close dampers 15 are vertically attached in series is provided in the substance discharge passage 8 formed downward at the lower end of the second hood 3.

  In the first double damper mechanism 13 and the second double damper mechanism 14, when the two dampers 15 are both opened, the oxygen supply amount into the apparatus increases, and conversely, when the two dampers 15 are closed, the oxygen supply amount decreases. Further, only one of the two dampers 15 can be opened. By adjusting the damper 15 as described above, the oxygen concentration of the combustion gas G can be maintained appropriately.

  As shown in FIGS. 2 and 3, the kiln dryer can have rotating blades 16 that rotate together with the cylinder 4 in the inner cylinder 4. The rotating blade 16 is heated by the flame F of the burner 5 and the combustion gas G is agitated to increase the convective heat transfer effect, so that the temperature of the inner cylinder 4 can be increased more efficiently. Therefore, the material M can be more effectively heated by the radiant heat of the inner cylinder 4 having a high temperature, and unnecessary organic substances adhering to the material M can be burned and removed more rapidly.

Moreover, since this rotary blade 16 stirs and mixes the flame F of the burner 5 and the recirculation gas Gc and promotes the combustion of the organic matter contained therein, the unburned organic content and the carbon monoxide concentration can be reduced. Thereby, environmental pollution by the exhaust gas Ga can be suppressed. Incidentally, in the test data, the carbon monoxide concentration of the clean gas Ga that has passed through the inner cylinder 4 when the rotating blade 16 is not provided and when the rotating blade 16 is not provided with respect to the carbon monoxide concentration of 800 to 1200 ppm contained in the recirculation gas Gc. , Were confirmed to be reduced to 50 to 100 ppm and 5 to 10 ppm, respectively.
The rotary blade 16 may be twisted as shown on the right side of FIG. 4 or may be formed in a straight line. Further, a punching plate may be used to provide a contact effect.

It is sectional drawing which shows the kiln dryer which concerns on embodiment of this invention. It is a side view which shows the rotary blade which can be attached to the kiln dryer which concerns on embodiment of this invention. It is a front view of the rotary blade shown in FIG. It is sectional drawing which shows the kiln dryer which concerns on a prior art example. It is sectional drawing which shows the kiln dryer which concerns on another prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Kiln main body 1a Scraper 2 1st hood 3 2nd hood 4 Inner cylinder 4a Upstream side inlet 4b Gas hole 5 Burner 6 Conveyor 7 Discharge passage 8 Substance discharge passage 9 Gas exhaust port 11 Passage 12 Circulating gas suction adjustment pipe 13 1st Double damper mechanism 14 Second double damper mechanism 15 Damper 16 Rotating blade 17 Thermometer 18 Pressure gauge 20 Rotating body 30 Kiln body 31 Conveyor 32 Burner 33 Reburning furnace 34 Inner cylinder 35 Input port 36 Afterburner 37 Circulating fan M Material F Flame G Combustion Gas Ga Clean gas Gb Circulating gas Gc Gas containing organic components

Claims (4)

In order to reuse scrap materials made of ferrous or non-ferrous metals, such as scraps from machining, including used cans, paint coatings and oil moisture adhering to the surface of the material prior to the melting process A device that volatilizes and removes unnecessary organic substances such as
A cylindrical kiln body that tilts downward from the upstream side to the downstream side and rotates about the axis;
An inner cylinder fixed concentrically in the kiln body and having a gas hole on the downstream peripheral surface;
A burner that heats the inner cylinder by injecting flame into the inner cylinder from the upstream inlet;
A first hood fixed to cover the upstream end of the kiln body;
A second hood fixed to cover the downstream end of the kiln body;
A substance discharge passage that is provided at the lower end of the second hood and discharges the heat-treated useful substance;
Provided in the second hood, comprising a gas outlet for discharging combustion gas,
Combustion gas is guided to the upstream side through the gas hole and the passage between the kiln main body and the inner cylinder using the injection pressure of the burner, and is drawn into the inner cylinder from the upstream inlet of the inner cylinder by the burner. Further, it is circulated so as to be burned, and a part thereof is discharged from the gas discharge port,
When the material is supplied to the passage from the upstream side, the supplied material is heated by radiant heat of the inner cylinder and heat transfer by contacting the circulating gas guided upstream from the gas hole. Then, after volatilizing and removing unnecessary organic substances on the surface, the substance is discharged from the substance discharge passage, and the gas containing the organic content after contact with the material is further burned by the burner and circulated as a clean gas. A kiln dryer, wherein a part of gas is discharged from the gas discharge port.   The circulating gas suction adjusting pipe is fitted to the upstream end portion of the inner cylinder so as to be extendable in the axial direction so that the amount of circulation of the combustion gas to the inner cylinder is adjustable. The kiln dryer described.   A rotating blade is attached in the inner cylinder to increase the temperature of the inner cylinder, and the organic component in the gas containing the organic component after contact with the material is mixed and contacted and burned. The kiln dryer according to claim 1 or 2.   In the lower end of the first hood, a discharge passage for discharging ash is formed, and in the discharge passage, a first double damper mechanism in which two openable dampers are attached in series is provided, and in the substance discharge passage, The kiln dryer according to any one of claims 1 to 3, wherein a second double damper mechanism in which an open / close damper is attached in series is provided to maintain the oxygen concentration of the combustion gas appropriately.

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