JP2005274018A - Indirect heating working system and indirect heating working method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively use a treated gas generating in a direct heat working and prevent the treated gas generated in indirect heating furnaces from leaking. <P>SOLUTION: A hot gas provided in a combustion furnace 3a is fed to the indirect heating furnaces 21 and 22 according to a temperature in the combustion furnace 3a of a gas combustion means 3 in an indirect heat working system. In high temperature operation, the supply of the hot gas to the indirect heating furnaces 21 and 22 is cut off. Thus, the processed gas such as thermally decomposed gas can be prevented from generating from the indirect heating furnaces 21 and 22 in high temperature operation. Also, the hot gas cut off to supply to the indirect heating furnaces 21 and 22 is, for example, discharged to the outdoor after cooling through a heat exchanger 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an indirect heat processing method and an indirect heat processing method, which have been conventionally discarded organic materials (for example, plant-derived scrap materials, polymer materials derived from petroleum products including plastics), inorganic The present invention relates to processing of various workpieces such as volatile substances and various hydrated substances (eg, sludge, soil, earth and sand).

  Conventionally discarded organic materials (for example, plant-derived scrap materials, polymer materials derived from petroleum products including plastics), inorganic materials, various water-containing materials (for example, sludge, soil, earth and sand) With respect to substances such as materials (hereinafter referred to as workpieces), various types of workpieces using means capable of processing such as drying and carbonization using indirect heating (hereinafter referred to as indirect heating means) are used. Attempts have been made to effectively use processed materials such as dried products, carbides, incinerated products, and soil-purified products obtained by removing moisture and organic substances contained therein.

In the indirect heating means, for example, a rotary furnace or an indirect heating furnace provided with a gas duct disposed on the outer peripheral side of the rotary furnace, and heating the indirect heating furnace (for example, supplying heat into the gas duct) And a gas combustion means for combusting a gas component (hereinafter referred to as a gas to be treated) such as a pyrolysis gas generated by indirect heating processing is known. (For example, Patent Document 1).
JP 2000-314511 A.

  Depending on the workpiece, the gas to be processed generated by the indirect heating process may contain harmful components (for example, components that cause environmental pollution or damage to each means of the indirect heating processing system). Therefore, even if the gas to be processed is at a high temperature, the heat of the gas to be processed is used for heating in the indirect heating furnace (for example, the gas to be processed is reused together with the heat of the hot stove). This is not preferable from the viewpoint of safety and the like.

On the other hand, for example, in order to save fuel required for indirect heating processing (for example, fuel consumed by the gas combustion means) and to save energy, the above-mentioned gas to be treated is combusted in a combustion furnace of the gas combustion means, Attempts have been made to supply hot gas obtained by combustion treatment to an indirect heating furnace and use it for heating in the indirect heating furnace (for example, Patent Documents 2, 3, and 4).
JP 2002-263626 A. JP 2000-183429 A. Japanese Patent No. 3321669.

  FIG. 2 is a schematic explanatory diagram of a general indirect heating processing system in which a gas to be processed generated by indirect heating processing is combusted by gas combustion means and a hot gas obtained by the combustion processing is used.

  In FIG. 2, reference numeral 2 indicates an indirect heating means, which includes, for example, two indirect heating furnaces (hereinafter referred to as a first indirect heating furnace and a second indirect heating furnace) 21, 22, etc. For example, an organic substance, an inorganic substance, various water-containing substances, etc.) can be indirectly heated (dried, carbonized, etc.) to obtain a processed product such as a carbide.

  The first indirect heating furnace 21 includes a rotatable rotary furnace 21a adopting a rotary kiln system, and hot gas (heat from a combustion furnace described later) introduced through a duct or the like located on the outer peripheral side of the rotary furnace 21a. A heating jacket 21b as an external heating means capable of heating the inside of the rotary furnace 21a from the outside by gas), and a support roller 210 for rotatably supporting the rotary furnace 21a at both ends of the rotary furnace 21a. And a rotational drive source 211 for rotationally driving the rotary furnace 21a. In addition, the said hot gas is introduce | transduced from the gas combustion means 3 mentioned later.

  A supply port (not shown) for introducing a workpiece is provided on one end side of the rotary furnace 21a, and a discharge port (not shown) is provided on the other end side. In addition, a plurality of feed blades (not shown) are provided inside the rotary furnace 21a for transferring the workpiece while stirring. Then, the workpiece supplied from the duct 20 is introduced into the rotary furnace 21a from the supply port side, and the rotary furnace 21a is rotated to transfer the workpiece to the discharge port side while stirring. It becomes possible. The duct 20 is provided with a hopper facility 201 for feeding a workpiece.

  The second indirect heating furnace 22 can be indirectly heated at a temperature higher than the first indirect heating furnace 21 (the work dried in the first indirect heating furnace 21 is pyrolyzed). It has the same configuration as the first indirect heating furnace 21 adopting the rotary kiln system, and includes a rotary furnace 22a, a heating jacket 22b, a duct 22c, a support roller 220, and a rotation drive source 221.

  As shown in the drawing, the first indirect heating furnace 21 and the second indirect heating furnace 22 are arranged so that the discharge port of the first indirect heating furnace 21 and the supply port of the second indirect heating furnace 22 communicate with each other. The In this case, the discharge port of the first indirect heating furnace 21 and the supply port of the second indirect heating furnace 22 are provided with a communication duct 23 that covers and communicates with the discharge port and the supply port. A guide 23 a for guiding the dried workpiece into the second indirect heating furnace 22 is provided in the communication duct 23.

  Reference numeral 3 denotes a gas combustion means, which is provided with a combustion burner 3b for generating hot gas in the combustion furnace 3a. The hot gas is supplied to a heating jacket 22b of the second indirect heating furnace 22 through a hot gas supply duct (hereinafter referred to as a hot gas supply duct) 31 (for example, via a suction force of a blower 42 described later). And the inside of the rotary furnace 22a is indirectly heated. Then, the hot gas which heated the inside of the said rotary furnace 22a is supplied to the heating jacket 21b of the 1st indirect heating furnace 21, and the inside of the rotary furnace 21a is heated indirectly.

  By using the hot gas as described above, the workpiece introduced into the rotary furnace 21b of the first indirect heating furnace 21 is dried and then indirectly heated in the rotary furnace 22b of the second indirect heating furnace 22. Processed into a workpiece such as carbide.

  In the communication duct 23, the gas to be treated such as water vapor and pyrolysis gas generated from the workpiece in the first indirect heating furnace 21 and the second indirect heating furnace 22 is transferred into the combustion furnace 3a. (In the case of water vapor in FIG. 2, ducts (hereinafter referred to as to-be-processed gas transfer ducts) 24 and 25 for transfer via a blower (forced transfer blower or the like) 51 are connected. The gas to be processed transferred through the gas transfer ducts 24 and 25 is burned in the combustion furnace 3a to be harmless, and the hot gas generated during the combustion process is the first indirect heating furnace 21. The second indirect heating furnace 22 is used.

  The hot gas used in the first indirect heating furnace 21 and the second indirect heating furnace 22 passes through a duct (hereinafter referred to as a post-use hot gas duct) 50 as a heat exchanger (for example, a gas having air as a cooling medium). It is transferred to a gas heat exchange system heat exchanger 4 and cooled (for example, cooled to about 150 ° C. to 200 ° C.) and then supplied to the bag filter 41 and then blower (in FIG. 2, the latter stage of the bag filter, that is, The blower 42) capable of sucking and exhausting the hot gas used in the first indirect heating furnace 21 and the second indirect heating furnace 22 is opened to the outside from the chimney 43.

  A part of the discharged hot gas may be supplied to the ejector 30 via a blower (circulation blower or the like) 52 and used as ejector driving gas for the combustion furnace 3a. When the heat exchanger 4 is a gas-gas heat exchange system, a cooling medium (for example, air) heated by the heat exchanger 4 is combusted between the heat exchanger 4 and the combustion furnace 3a. By providing a duct (hereinafter referred to as a cooling medium transfer duct) 44 for transfer into the furnace 3a, it is possible to contribute to a temperature increase in the combustion furnace 3a.

  As described above, air for temperature adjustment is injected into the hot gas supplied to the heating jackets 22a and 22b and the ejector 30 and the hot gas released to the outside from the heat exchanger 4 as required (in FIG. 2). The hot gas supplied to the ejector 30 is injected through a blower (ejector blower or the like) 53, and the gas temperature is appropriately adjusted (for example, the hot gas supplied to the heating jacket 22b is 600 ° C. to 750 ° C. Adjusted).

  When the gas to be treated is sufficiently flammable and sufficiently generated, the heat of the high calorie contributes to the temperature rise in the combustion furnace due to the combustion treatment of the gas to be treated (that is, the hot gas having a high temperature). Therefore, the fuel cost can be saved by regulating the fuel supply of the combustion burner 3b.

  In the indirect heating processing system as shown in FIG. 2, the gas to be processed generated by indirectly heating the workpiece may include an odor component depending on the workpiece. If the temperature in the combustion furnace of the gas combustion means 3 is 800 ° C. or higher, the odor component can be burned in the combustion furnace and sufficiently decomposed (detoxified).

  For this reason, in the indirect heating processing system, in order to sufficiently decompose the odor component as described above, first, the workpiece is introduced into the indirect heating furnace (in the rotary furnace 21b in FIG. 2) of the indirect heating means. Before the indirect heating processing system is operated for a predetermined time and the temperature in the combustion furnace becomes sufficiently high (that is, after the odor component can be decomposed in the combustion furnace), Is introduced into an indirect heating furnace and a desired indirect heating process is performed.

  In the case where the indirect heating processing system is operated until the temperature in the combustion furnace sufficiently rises as described above (hereinafter referred to as “temperature increase operation”), a relatively low temperature (for example, a temperature of 300 ° C. from the combustion furnace). The hot gas of about ˜600 ° C. is supplied to the indirect heating furnace (heating jackets 21b and 22b in FIG. 2) through the hot gas supply duct.

  Therefore, when there is an unintended work piece in the indirect heating furnace during temperature rising operation (for example, adhering to the indirect heating furnace and remaining in the indirect heating process), the indirect heating of the work piece is performed. Because the odor components in the gas to be processed generated from the workpiece are processed and cannot be sufficiently decomposed into the combustion furnace (that is, the temperature in the combustion furnace is relatively low) Therefore, the odor component is not decomposed and circulates in the indirect heating processing system (for example, circulates each duct) and leaks to the outside, for example, and may cause environmental problems.

  As a method for preventing leakage of the odor component as described above, for example, after indirect heating processing for a target amount of workpiece is finished, indirect heating is performed until the workpiece remaining in the indirect heating furnace is reliably discharged. A method of operating the processing system for a predetermined time (that is, supplying hot gas to the indirect heating furnace via the hot gas supply duct) can be considered, but it may take a long time for the workpiece to be discharged. For example, there is a possibility that running cost (fuel cost required for indirect heating processing, etc.) may increase.

  The present invention has been made based on the above-described problem, and effectively uses the gas to be processed generated in the indirect heating process, and also generates the gas to be processed (for example, in the gas to be processed) generated in the indirect heating furnace. An object of the present invention is to provide an indirect heating processing system and an indirect heating processing method capable of preventing leakage of contained odor components.

  In order to solve the above-mentioned problems, the present invention provides an indirect heating means including an indirect heating furnace capable of indirectly heating a workpiece, and the indirect heating furnace. It is possible to supply to the indirect heating furnace the gas to be processed for transferring the gas to be processed generated from the workpiece to the gas combustion means and the hot gas obtained in the combustion furnace of the gas combustion means. A hot gas supply duct, a post-use hot gas duct capable of transferring the hot gas supplied to the indirect heating furnace to a heat exchanger, and the combustion furnace and the heat exchanger are communicated with each other, and The system comprises a pre-use hot gas duct connected to a hot gas supply duct via a switching valve. The switching valve transfers the hot gas of the combustion furnace to the heat exchanger via the pre-use hot gas duct during the temperature rise operation of the system, and after the temperature rise operation, the switching valve passes through the hot gas supply duct. It can be operated to supply hot gas to an indirect heating furnace.

  According to a second aspect of the present invention, in the first aspect of the present invention, the heat exchanger is a gas-gas heat exchange system using a gas as a cooling medium.

  According to a third aspect of the present invention, there is provided the cooling medium duct according to the first or second aspect, wherein the heat exchanger and the combustion furnace communicate with each other and the cooling medium can be introduced into the combustion furnace. It is provided with.

  According to a fourth aspect of the present invention, the workpiece is indirectly heated by the indirect heating means provided with the indirect heating furnace, and the gas to be processed generated from the workpiece during the indirect heating process is transferred to the gas combustion means. The hot gas obtained in the combustion furnace of the gas combustion means is supplied to the indirect heating furnace through the hot gas supply duct, and the hot gas supplied to the indirect heating furnace is used to heat the hot gas through the hot gas duct. It is a method using a system for transferring to an exchanger. When the system rises in temperature, the combustion furnace and the heat exchanger communicate with each other and are connected to the hot gas supply duct via a switching valve to use the hot gas duct before use. The hot gas is transferred to a heat exchanger, and after the temperature rise operation, the switching valve is operated to supply the hot gas of the combustion furnace to the indirect heating furnace through the hot gas supply duct.

  According to a fifth aspect of the present invention, in the invention of the fourth aspect, the cooling medium is supplied via a cooling medium duct that communicates between the heat exchanger and the combustion furnace when the temperature of the system is increased. It is characterized by being introduced into a combustion furnace.

  The invention described in claim 6 is the invention described in claim 4 or 5, wherein after the temperature raising operation, the gas to be processed generated from the workpiece in the indirect heating furnace is introduced into the combustion furnace for combustion treatment. It is characterized by that.

  According to the present invention, after the temperature in the combustion furnace of the gas combustion means becomes sufficiently high (for example, after the temperature becomes high enough to decompose the odor component in the gas to be treated (for example, the temperature in the combustion furnace is 800 ))), Because the hot gas of the combustion furnace is supplied to the indirect heating furnace, even if unintentional workpieces remain in the indirect heating furnace, The combustion treatment can be surely performed.

  As described above, according to the present invention, the gas to be processed generated in the indirect heating process does not cause environmental pollution and the like, and does not increase the running cost, even if the temperature rise operation. Since the gas to be treated can be reliably burned, leakage of the gas to be treated (for example, odor components in the gas to be treated) can be prevented, and the hot gas of the combustion furnace can be effectively used to save energy. Can be achieved.

  Hereinafter, an indirect heat processing system and an indirect heat processing method in an embodiment of the present invention will be described in detail with reference to the drawings. 2 that are the same as those shown in FIG. 2 are given the same reference numerals, and detailed descriptions thereof are omitted.

  In the present embodiment, in accordance with the temperature in the combustion furnace of the gas combustion means in the indirect heating processing system, the hot gas obtained in the combustion furnace is supplied to the indirect heating furnace (that is, the combustion furnace to such an extent that the odor component can be decomposed). When the temperature rises, the supply of hot gas to the indirect heating furnace can be shut off during the temperature raising operation.

  Thereby, it is possible to prevent generation of a gas to be processed such as a pyrolysis gas from the indirect heating furnace during the temperature raising operation. Moreover, the hot gas from which supply to the indirect heating furnace is shut off as described above can be cooled, for example, via a heat exchanger and discharged outdoors.

  FIG. 1 is a schematic explanatory diagram illustrating an example of an indirect heat processing system and an indirect heat processing method according to the present embodiment. In FIG. 1, the code | symbol 10 shows the duct (henceforth a heat gas duct before utilization) for transferring the hot gas from the inside of the combustion furnace 3a of the gas combustion means 3 to the heat exchanger 4. In FIG. The pre-use hot gas duct 10 is connected to, for example, the post-use hot gas duct 50 and is connected to the hot gas supply duct 31 with a switching valve (a valve having heat resistance and capable of switching the flow path). 11 to communicate with each other. That is, the combustion furnace 3 a and the heat exchanger 4 are communicated with each other and connected to the hot gas supply duct 31 via the switching valve 11.

  The switching valve 11 is capable of switching the flow path of the hot gas obtained in the combustion furnace 3a according to the temperature in the combustion furnace 3a when the indirect heating processing system is operating. .

  Next, an operation example of the indirect heat processing system shown in FIG. 1 will be described. First, in the temperature increasing operation of the indirect heating processing system, the switching valve 11 is operated so that the hot gas from the combustion furnace 3a is transferred to the heat exchanger 4 through the pre-use hot gas duct 10.

  As a result, when the temperature rise operation is performed, the hot gas from the combustion furnace 3a is transferred to the heat exchanger 4 through the pre-use hot gas duct 10 and supplied to the bag filter 41 before the blower (in FIG. Since the rear stage of the filter 42 is opened to the outside from the chimney 43, even if unintentional workpieces remain in the first indirect heating furnace 21 and the second indirect heating furnace 22, the remaining workpieces remain. Indirect heat processing is not performed (that is, a gas to be processed is not generated).

  Further, since the hot gas during the temperature rising operation is transferred to the heat exchanger 4 without being absorbed by, for example, the indirect heating means 2 or the like, the cooling medium of the heat exchanger 4 is transferred into the combustion furnace 3a. By transferring, it can contribute to the temperature rise in the combustion furnace 3a rather than the indirect heating processing system as shown in FIG.

  When the temperature in the combustion furnace 3a is equal to or higher than a predetermined temperature after the above-described temperature rise operation (a temperature at which the odor component in the gas to be treated can be decomposed (for example, 800 ° C. (more specifically, 850 ° C.)) In the case of exceeding, the flow path is switched by operating the switching valve 11, and the hot gas in the combustion furnace 3 a is transferred to the first indirect heating furnace 21 and the second indirect heating furnace 22 through the hot gas supply duct 31. The workpiece is supplied to the first indirect heating furnace 21 and the second indirect heating furnace 22 (for example, the temperature in the first indirect heating furnace 21 and the second indirect heating furnace 22 is about 350 ° C. to 650 ° C. The temperature is raised to 2).

  Thereby, while being able to perform indirect heating processing of a to-be-processed object, the to-be-processed gas generate | occur | produced by the indirect heating processing can be burned in the combustion furnace 3a, and can be made harmless.

  In the setting of the switching valve 11, the temperature in the combustion furnace 3a can be detected using, for example, a temperature sensor, and switching can be performed based on the detected value. Further, when the temperature in the combustion furnace 3a becomes equal to or lower than the predetermined temperature during the indirect heating process through the temperature raising operation as described above, the flow path is switched by operating the switching valve 11. Accordingly, the hot gas (the hot gas supplied into the indirect heating means 2) may be transferred to the heat exchanger 4.

  Although the present invention has been described in detail only for the specific examples described above, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical idea of the present invention. Such variations and modifications are naturally within the scope of the claims.

  For example, according to the present embodiment, various raw materials, for example, organic substances (for example, plant-derived scrap materials, high-molecular substances derived from petroleum products including plastics), inorganic substances, various water-containing substances (for example, Processed products such as dried products, incinerated products, and purified products of soils can be obtained from various processed products such as sludge, soil, and sand.

  Moreover, each processing temperature, such as a 1st indirect heating furnace, a 2nd indirect heating furnace, a gas combustion means, a heat exchanger, can be variously changed according to the kind and quantity of the raw material which are to-be-processed objects, for example.

Schematic explanatory drawing which shows an example of the indirect heating processing system and indirect heating processing method in this Embodiment. Schematic explanatory drawing of a general indirect heat processing system.

Explanation of symbols

2 ... Indirect heating means 3 ... Gas combustion means 4 ... Heat exchanger 10 ... Pre-use hot gas duct 11 ... Switching valve 21 ... First indirect heating furnace 22 ... Second indirect heating furnace 24, 25 ... Processed gas transfer duct 31 ... Hot gas supply duct 44 ... Cooling medium duct 50 ... Hot gas duct after use

Claims (6)

An indirect heating means including an indirect heating furnace capable of indirectly heating the workpiece;
A gas transfer duct to be processed for transferring the gas to be processed generated from the workpiece in the indirect heating furnace to the gas combustion means;
A hot gas supply duct capable of supplying hot gas obtained in the combustion furnace of the gas combustion means to the indirect heating furnace;
A post-use hot gas duct capable of transferring the hot gas supplied to the indirect heating furnace to a heat exchanger;
A pre-use hot gas duct that communicates between the combustion furnace and the heat exchanger and is connected to the hot gas supply duct via a switching valve,
The switching valve transfers the hot gas of the combustion furnace to the heat exchanger via the pre-use hot gas duct during the temperature rise operation of the system, and the hot gas of the combustion furnace via the hot gas supply duct after the temperature rise operation. An indirect heating processing system characterized in that it can be operated so as to be supplied to an indirect heating furnace.   The indirect heating processing system according to claim 1, wherein the heat exchanger is a gas-gas heat exchange method using a gas as a cooling medium.   The indirect heat processing system according to claim 1, further comprising a cooling medium duct that communicates between the heat exchanger and the combustion furnace and is capable of introducing the cooling medium into the combustion furnace. . The workpiece is indirectly heated by indirect heating means equipped with an indirect heating furnace,
The gas to be treated generated from the workpiece during the indirect heating process is transferred to the gas combustion means for combustion treatment,
The hot gas obtained in the combustion furnace of the gas combustion means is supplied to the indirect heating furnace through the hot gas supply duct,
A method using a system in which the hot gas supplied to the indirect heating furnace is transferred to a heat exchanger by a hot gas duct after use,
During the temperature rise operation of the system, the heat of the combustion furnace is obtained by the pre-use hot gas duct that is connected between the combustion furnace and the heat exchanger and is connected to the hot gas supply duct via a switching valve. Transfer gas to heat exchanger,
An indirect heating processing method characterized by operating a switching valve and supplying hot gas of a combustion furnace to an indirect heating furnace through a hot gas supply duct after the temperature rising operation.   The indirect heating according to claim 4, wherein the cooling medium is introduced into the combustion furnace through a cooling medium duct communicating between the heat exchanger and the combustion furnace when the temperature of the system is raised. Processing method.   6. The indirect heat processing method according to claim 4 or 5, wherein after the temperature raising operation, the gas to be processed generated from the work in the indirect heating furnace is introduced into the combustion furnace and burned.

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