JP4847216B2 - Molten slag recovery container and molten slag recovery method - Google Patents

Description

  The present invention relates to a technique for recovering and disposing of molten slag generated by melting municipal waste, hazardous waste, industrial waste, and the like with a plasma melting furnace or the like.

  Conventionally, as a means for melting various kinds of waste as described above, the waste is put in an appropriate melting furnace and melted by a method such as plasma arc, induction heating or combustion heating, and the resulting molten slag is removed. There is known a technique for pouring and solidifying a dedicated molten slag collection container from the melting furnace, and discarding or reusing it. As described in Patent Document 1, for example, this technique is a so-called batch-type melting process in which the melting furnace is inclined and discharged from the slag discharge portion whenever the molten slag accumulated in the melting furnace reaches a certain amount. It is suitable for. Further, even when the molten slag is continuously discharged, it can be applied as long as the slag is carried out and handled batchwise.

  Here, the method for recovering the molten slag injected into the molten slag recovery container and solidified is roughly divided into the following two.

  A) The molten slag collection container is collected together with the molten slag and discarded or reused.

B) The inner surface of the molten slag collection container is tapered so as to increase in diameter toward the upper side, and after the molten slag solidifies in the container, the entire container is turned over or when the molten slag is solidified. The lifting metal fitting is charged and the molten slag and the lifting metal fitting are integrated by solidification, and the solidified molten slag is lifted from the container using the lifting metal fitting.
Japanese Patent Laid-Open No. 2002-5424

  In the method A), the molten slag recovery container must be replaced every time the molten slag is recovered. Moreover, in this molten slag recovery container, it is necessary to reliably prevent the molten slag from leaking due to the bottom wall and side walls being broken, and the inlet portion of the container can be connected to the slag discharge part of the waste melting furnace. Therefore, it is necessary to make the entire container somewhat heavy and expensive, and it is economical to replace the molten slag recovery container with such a structure for recovering the molten slag. Not preferable. Further, the weight of the container itself is large and its handling is not easy.

  On the other hand, in the method B), special equipment and labor are required to invert the entire molten slag collection container or to load the lifting bracket at a predetermined position in the container. In addition, even if the inner surface of the container is tapered, the molten slag cannot be easily extracted from the container, and in practice, a special treatment such as forming a release layer on the inner surface of the container must be performed. There is. The molten slag collection container is repeatedly contacted and solidified by high-temperature molten slag, and the molten slag taken out from the collection container and the inner peripheral surface of the container are rubbed strongly. The container is easily damaged and has a short life. If that life is reached, the container must be replaced as in A).

  In view of such circumstances, an object of the present invention is to improve the efficiency and economy of the recovery operation of molten slag discharged from a waste melting furnace.

As means for solving the above problems, the present invention is a molten slag recovery container for recovering molten slag discharged from a waste melting furnace, and has a bottomed first container that opens upward, A second container that is detachably installed inside the first container and that opens upward; the molten slag is injected into the second container and the molten slag is solidified; The slag and the second container are configured to be integrally removable from the first container. The second container has a cylindrical shape that opens up and down, and its lower opening is formed by the bottom of the first container. The bottom of the second container is formed by laying a heat-resistant particle layer on the bottom wall of the second container, and the lower end of the second container is formed on the particle layer. The second container by inserting the part from above It is intended to be held in the state upright within the first container.

Further, the present invention is such that the lower end portion of the second container is inserted into the particle layer of the first container of the molten slag recovery container from above so that the second container is held in the upright state in the first container. a step of placing the second container to the first container Te, a step of injecting molten slag discharged from the waste melting furnace to the second container in a state of being installed in the first container, this And a step of taking the molten slag and the second container together from the first container in a state where the molten slag is solidified.

  According to the above configuration, the molten slag is injected into the second container installed in the first container, and the molten slag solidified in the second container is integrated with the second container from the first container. Since it is made to take out, molten slag can be collect | recovered easily compared with the method of taking out only molten slag from the inside of the container for molten slag collection | recovery conventionally.

  In addition, even if the second container is torn and the molten slag flows out of the second container, the molten slag flows out of the container because the second container is installed in the first container. Can be prevented. As described above, since the fail safe when the second container is damaged or the like can be ensured, the safety factor can be lowered when designing the second container. As a result, the thin wall of the second container can be reduced. Thus, the weight can be reduced, and thereby the second container can be made inexpensive and easy to handle.

  For example, when at least the second container is made of metal, the entire container can be made cheaper than when a special non-metallic refractory material is used for the container.

  Further, if the second container has a thinner side wall than the side wall of the first container, the second container can be reduced in weight and cost while the thickness of the first container is ensured. By doing, the fail safe function in the whole molten slag collection | recovery container containing these 1st containers and 2nd containers can be improved.

In the present invention, the second container has a cylindrical shape that opens up and down, and the lower opening is closed by the bottom of the first container, so the bottom wall of the second container is omitted. By doing so, the cost reduction and weight reduction of the second container can be further promoted. Moreover, since the lower opening of the second container is closed by the bottom of the first container in a state where the second container is installed in the first container, the second container is not bottomed. The molten slag can be poured into the second container without any inconvenience.

  Such a second container can be formed, for example, by cutting a tube material with a predetermined axial length, whereby mass production of the second container can be achieved.

The bottom of the second container is formed by laying a heat-resistant particle layer on the bottom wall of the second container, and the lower end of the second container is inserted into the particle layer from above. In this state, the second container is held in the upright state in the first container . Therefore, the second container can be held in the upright state in the first container using the particle layer. In addition, it is possible to effectively prevent the molten slag from leaking from under the second container. Moreover, when the second container is taken out from the first container, the separability between the solidified molten slag and the particle layer at the bottom of the first container can also be improved.

  In addition, since the first container can be thicker and stronger than the second container, a connection part connected to the slag discharge part of the waste melting furnace is provided at the upper end of the first container. It is possible to construct a waste melting apparatus in which this connecting portion is connected to the slag discharge portion. According to this apparatus, the molten slag discharged from the waste melting furnace can be reliably introduced into the molten slag collection container.

  As described above, according to the present invention, the first container as the molten slag collection container and the second container installed in the first container are provided and discharged from the waste melting furnace into the second container. By injecting molten slag and discarding only the second container together with the molten slag, the molten slag can be efficiently recovered with an inexpensive configuration, and the efficiency and economy of the recovery operation can be improved. There is an effect that can be done.

  3 (a) and 3 (b) show an example of a waste melting furnace to which the molten slag recovery container according to the present invention can be applied. The illustrated melting furnace is a batch-type melting furnace capable of melting waste under a negative pressure. The furnace main body 10 and a front support portion for supporting the front and rear portions of the furnace main body 10 from below. 12 and a rear support portion 14.

  Similar to the furnace body described in Patent Document 1, the furnace body 10 has a casing 16 lined with a refractory and a plasma (not shown) for melting waste introduced into the casing 16. With a torch. A slag discharge portion 18 is provided at the front end portion (left end portion in FIGS. 3A and 3B) of the furnace body 10, and the slag discharge portion 18 is connected to a molten slag collection container 30 described later. A bellows-like pipe 20 is connected.

  The front support portion 12 supports the front lower end portion of the furnace body 10 so as to be rotatable about a horizontal pin 22 as a fulcrum.

  The rear support portion 14 includes a support column 24 and a hydraulic cylinder 26.

  The support column 24 is erected at a position that supports the rear end portion (the right end portion in FIGS. 3A and 3B) of the furnace body 10 from below.

  The hydraulic cylinder 26 is for switching the furnace body 10 between a horizontal posture (normal use posture) shown in FIG. 3A and a forward leaning posture (slag discharge posture) shown in FIG. The end of the hydraulic cylinder 26 on the head side is connected to the base side (ground side) so as to be rotatable about a horizontal pin 27, and the end on the rod side is also connected to a horizontal pin 28. It is connected to the rear part of the furnace body 10 so as to be rotatable as a fulcrum. When the hydraulic cylinder 26 is contracted, the rear end portion of the furnace body 10 abuts on the upper end of the support column 24 and the furnace body 10 is supported in the horizontal posture shown in FIG. When the hydraulic cylinder 26 is extended, the rear end portion of the furnace body 10 is lifted up and switched to the forward inclined posture shown in FIG.

  The bottom wall of the furnace body 10 has a weir part 17 at a position on the near side of the slag discharge part 18, and the molten slag 50 is contained in the furnace body 10 within a range below the uppermost position of the weir part 17. It is possible to accumulate. The slag discharge part 18 has a guide wall 19 at a position connected to the weir 17, and the molten slag 50 overflowing from the weir 17 when the furnace body 10 is in the forward tilted position passes through the guide wall 19. To come down.

  Next, a specific structure of the molten slag recovery container 30 used in this apparatus will be described with reference to FIGS.

  The illustrated molten slag recovery container 30 includes a first container 32 and a second container 34 installed inside the first container 32.

  The first container 32 has a bottomed structure that opens upward. Specifically, a disc-shaped bottom wall 32a and a cylindrical peripheral wall (side wall) 32b extending upward from the periphery of the bottom wall 32a are integrally provided.

Further, a flange portion 32c protrudes radially outward from the upper end of the peripheral wall 32b.
The flange portion 32c constitutes a connecting portion that can be fastened to the pipe 20. The flange portion 32c is provided with a plurality of bolt insertion holes 33. Each bolt insertion hole 33 penetrates the flange portion 32 c in the thickness direction (vertical direction), and a fastening bolt for fastening the flange portion 32 c and the pipe 20 can be inserted into the bolt insertion hole 33. ing.

  A particle layer 36 is laid on the bottom wall 32a. This particle layer 36 constitutes the bottom of the first container 32 together with the bottom wall 32a, and is formed by spreading heat-resistant particles such as sand and ceramics on the bottom wall 32a by a predetermined thickness. .

  The thickness of the first container 32 is set to be thick enough to ensure sufficient strength. Specifically, a sufficient safety factor is given so that damage or the like can be surely avoided even if the container 32 is filled with high-temperature molten slag, and the flange portion 32c is attached to the pipe 20. It is set so as to ensure strength that does not hinder the connection. Although the specific dimension about this wall thickness can be set suitably, generally when using steel materials, it is preferable to set to about 10 mm or more.

  The second container 34 is made of metal and has a thin cylindrical shape that opens up and down. In the illustrated example, as the second container 34, a long steel pipe cut at an appropriate axial length is used.

  The second container 34 has an outer diameter smaller than the inner diameter of the first container 32, and is disposed at a position that is coaxial with the first container 32. Specifically, the second container 34 is held in an upright position by inserting the lower end portion into the particle layer 36 from above until the lower end portion of the second container 34 reaches the bottom wall 32a, and It is possible to form a state in which the lower end opening of the second container 34 is closed with the particle layer 36. In addition, a through hole 38 is provided at the upper end of the second container 34 for passing a lifting bracket or rope.

  The thickness of the second container 34 is smaller than the thickness of the first container 32, and can hold the molten slag 50 even when the molten slag 50 is injected into the second container 34. It is set to a thickness that can ensure strength (for example, about 2 to 5 mm when steel is used). In addition, the axial length of the second container 34 in the illustrated example is such that the upper end of the second container 34 is in the state where the second container 34 is installed on the bottom wall 32a of the first container 32. It is set to be equal to or lower than the upper end of 32.

  The pipe 20 has a bellows-like main body 40 that can be expanded and contracted, and flanges 42 and 44 that are fixed to both ends of the main body 40.

  On the other hand, a flange portion 46 is formed at the outlet portion of the slag discharge portion 18 in the furnace body 10 so as to surround the guide wall 19. One flange 44 of the pipe 20 is connected to the flange portion 46, and the other flange 42 can be fastened to the flange portion 32 c of the first container 32.

  And when the said furnace main body 10 inclines to the forward leaning attitude | position shown in the said FIG.3 (b) in the state which the said flange 42 and the flange part 32c were fastened, the molten slag 50 which flows down along the said guide wall 19 is flowed. The position of the guide wall 19 is set so that is injected into the substantially central position of the second container 34.

  Next, the operation of the waste melting apparatus and the usage procedure of the molten slag collection container will be described in order.

  1) At the initial stage, as shown in FIG. 3A, the hydraulic cylinder 26 of the rear support portion 14 is contracted to keep the furnace body 10 in a horizontal posture.

  2) In the molten slag recovery container 30, the second container 34 is installed at a predetermined position in the first container 32, and the flange portion 32 c of the first container 32 is fastened to the flange 42 of the pipe 20. Thereby, the inside of the molten slag collection container 30 is connected to the slag discharge part 18 of the furnace body 10 through the pipe 20. At this stage, the distal end portion of the guide wall 19 provided in the slag discharge portion 18 is in a state of being directed to a substantially central position of the second container 34.

  3) A waste container (for example, a drum can) filled with waste is introduced into the furnace body 10 from a container insertion port (not shown) provided in the furnace body 10. The waste container is melted by high-temperature plasma emitted from a plasma torch (not shown) together with the waste inside to become a liquid molten slag 50. The exhaust gas generated at the time of melting is discharged out of the furnace from an unillustrated exhaust gas outlet provided in the furnace body 10.

  4) While the waste and its container continue to melt in the same manner as in 3), the liquid level of the molten slag 50 accumulated in the furnace reaches a preset height position (a position lower than the uppermost end of the dam portion 17). At that time, the next waste container is temporarily stopped.

  5) By gradually expanding the hydraulic cylinder 26 of the rear support portion 14 at a predetermined speed and pushing up the rear portion of the furnace body 10, the furnace body 10 is gradually moved with contraction of the bellows-like body portion 40 of the pipe 20. Tilt to a forward leaning posture as shown in FIG. Thereby, the molten slag 50 generated in the furnace main body 10 overflows from the weir part 17, travels along the upper surface of the guide wall 19, passes through the pipe 20, and is approximately at the center position of the second container 34 of the molten slag recovery container 30. A predetermined amount is poured into.

  At this time, since the lower end opening of the second container 34 is blocked by the particle layer 36, the molten slag 50 is stored in the second container 34 without any inconvenience as shown in FIG. Even if the second container 34 is torn and the molten slag flows out of the second container 34, the second container 34 is accommodated in the first container 32. Outflow to the outside of the molten slag recovery container 30 is reliably prevented.

  6) After completion of the injection of the molten slag, the hydraulic cylinder 26 is contracted again to return to the horizontal posture shown in FIG.

  7) After the molten slag 50 stored in the second container 34 has cooled to some extent, the flange portion 32c and the flange 42 are separated to open the first container 32.

  8) After the molten slag 50 is solidified, a lifting fitting or rope is passed through the through hole 38 provided at the upper end of the second container 34, and the second container 34 and the inside thereof are solidified using the fitting or the like. The molten slag 50 is integrally lifted from the first container 32 and is transported as it is for disposal. Here, since the second container 34 is thinner, cheaper and lighter than the first container 32, it is economical and easy to handle. Furthermore, the slag cooled in the second container 34 is more brittle than the second container 34. Conversely, the thin second container 34 is richer in toughness than the slag. By applying a compressive force in the diametrical direction from the outside, the second container 34 can be taken out of the second container 34 by crushing or crushing only the slag inside without destroying the second container 34. As a result, the second container 34 can be reused, and the economy is further improved.

  9) Next, a new second container 34 is set in the first container 32, and the operations 2) to 9) are repeated. Therefore, the second container 34 is replaced every time the molten slag 50 is discarded, while the first container 32 is repeatedly used.

Incidentally, the case where the second container 34 is Ru bottomed der is susceptible to pooling of molten slag 50 without laying particle layer 36 on the bottom wall 32a of the first container 32, the second container 34 with cylindrical shape opening vertically as shown, the weight of the second container 34, can promote cost reduction, also possible such mass-produced second container 34 by cutting, for example, tubing become.

  The present invention is not limited to the above-described embodiment, and for example, the following embodiment can be adopted.

  The side wall of the second container 34 may have a thickness substantially equal to the thickness of the side wall of the first container 32. However, by making the side wall of the second container 34 thinner than the side wall of the first container 32 as shown in the figure, the second container 34 can be reduced in weight and cost while the first container 32 By ensuring the wall thickness, the fail-safe function of the entire molten slag collection container including the first container 32 and the second container 34 can be enhanced.

  -In this invention, it is possible to apply to the apparatus which melt | dissolves waste by methods, such as induction heating and combustion heating other than the heating by said plasma arc, regardless of the heating means in a waste melting furnace. Further, the means for injecting the molten slag from the waste melting furnace into the second container of the molten slag recovery container is not limited to the one inclining the furnace body 10 as shown in FIGS. A discharge port and its opening / closing means may be provided at the bottom of the furnace body 10, and the second container of the molten slag recovery container may be set directly below the discharge port to open the discharge port when discharging the molten slag. .

  In the waste melting apparatus shown in FIGS. 1 to 3, a plasma melting furnace having a plasma torch is applied to the furnace body 10, and various kinds of waste such as municipal waste, hazardous waste, and industrial waste are stored in the drum can. And put into the plasma melting furnace to melt and slag.

  On the other hand, both the first container 32 and the second container 34 of the molten slag collection container 30 are made of steel. The first container 32 has a bottom wall 32a, a side wall 32b, and a flange portion 32c having a thickness of 10 mm and a height and an inner diameter of 700 mm. The thickness (10 mm) of the first container 32 is a dimension obtained by multiplying the minimum dimension for preventing damage due to contact with the high-temperature molten slag by a sufficient safety factor, and for forming the flange portion 32c. It is a dimension that can provide sufficient strength.

  Sand is spread over the bottom wall 32a of the first container 32 to form a particle layer 36 having a thickness of 50 mm.

  The second container 34 is mass-produced by cutting a long steel pipe having an outer diameter of 600 mm and a thickness of 5 mm into a shaft length of 680 mm. The thickness (5 mm) of the second container 34 is a dimension obtained by multiplying the minimum dimension for preventing damage due to contact with the high-temperature molten slag by a safety factor lower than the safety factor of the first container 32.

  The second container 34 is inserted into the first container 32 at a position where the containers 32 and 34 are coaxial, and the lower end of the second container 34 is placed until the end surface reaches the upper surface of the bottom wall 32a. By inserting into the particle layer 36, the particle layer 36 keeps the second container 34 in the upright posture.

  Then, the molten slag 50 is solidified in the second container 34 by the above-described procedures 4) to 9), and the molten slag 50 is recovered integrally with the second container 34 and discarded.

It is a section front view of the container for molten slag collection concerning an embodiment of the invention. It is a top view of the said container for molten slag collection | recovery. (A) is a front view showing a state in which a furnace body of a waste melting apparatus in which the molten slag recovery container is used is in a horizontal position, and (b) is a front view showing a state in which the furnace body is in a forward tilted position. is there.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Furnace body 18 Slag discharge part 20 Piping 30 Molten slag collection | recovery container 32 1st container 32a Bottom wall 32b Side wall 32c Flange part 33 Bolt penetration hole 34 2nd container 36 Particle layer 50 Molten slag

Claims (7)

A molten slag recovery container for recovering molten slag discharged from a waste melting furnace, and is installed in a detachable manner inside a first container with a bottom that opens upward, A second container opening upward, and the molten slag is poured into the second container and the molten slag is solidified, and the solidified molten slag and the second container are integrally formed with the first container. The second container is disposed in the first container so that it can be taken out from the container. The second container has a cylindrical shape that opens up and down, and the lower opening is closed by the bottom of the first container. The bottom of the second container is formed by laying a heat-resistant particle layer on the bottom wall of the second container, and the lower end of the second container is on the particle layer. The second container is inserted into the first container Molten slag collecting vessel, characterized in that it is held in upright condition.   The molten slag collection container according to claim 1, wherein at least the second container is made of metal.   The molten slag collection container according to claim 1 or 2, wherein the second container has a thinner side wall than the side wall of the first container. The molten slag collection container according to any one of claims 1 to 3 , wherein the second container is formed by cutting a tube material with a predetermined axial length. The molten slag recovery container according to any one of claims 1 to 4 , wherein an upper end portion of the first container is provided with a connection portion connected to a slag discharge portion of the waste melting furnace. A container for molten slag recovery. A waste melting furnace for melting the charged waste and discharging it from the slag discharge part, and the molten slag recovery container according to claim 5, wherein a connecting part of the molten slag recovery container is connected to the slag discharge part. A waste melting apparatus characterized by being connected. A method for recovering and discarding molten slag discharged from a waste melting furnace using the molten slag recovery container according to any one of claims 1 to 6, wherein the molten slag recovery container The second container is inserted into the particle layer of the first container from above so that the second container is held in the upright state in the first container. A step of installing, a step of injecting molten slag discharged from the waste melting furnace into the second container installed in the first container, and the molten slag in a state where the molten slag is solidified. A method for recovering molten slag discharged from a waste melting furnace, comprising the step of taking out the second container integrally with the first container.

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