JP4908914B2 - Processing equipment such as aluminum chips - Google Patents

Description

  The present invention relates to a processing apparatus such as aluminum chips, and more particularly to a processing apparatus that continuously heat-treats raw materials such as aluminum chips to remove impurities and recover aluminum in a reusable manner. In this invention, aluminum chips and the like include aluminum-containing materials such as used scraps of aluminum products such as used aluminum cans in addition to aluminum scraps, cutting scraps and shredder scraps generated during the manufacture of aluminum products.

  The aluminum chips and the like are melted and regenerated in a melting furnace, recovered as aluminum resources, and reused. However, since the aluminum raw material before heat treatment such as aluminum chips generally contains moisture and oil, a method of performing a heat treatment prior to the melting treatment in a melting furnace is performed in order to remove these impurities. Yes.

  Conventionally, various patent applications have been filed as processing apparatuses and processing methods for the purpose of recycling aluminum chips and the like, but broadly classified, the processing object is limited to aluminum chips (for example, patent documents) 1 and 2) and those in which aluminum chips and the like are mixed with other wastes (see, for example, Patent Documents 3 and 4). Further, as a related processing technique, there is a waste processing apparatus (for example, refer to Patent Document 5) that processes general waste whose processing target does not include (or includes a small amount of) aluminum chips.

  Here, as a background art of the present invention, an outline of Patent Document 1 and Patent Document 5 that disclose a technique relatively close to a part of the configuration of the present invention will be described below.

  First, Patent Document 1 will be described. FIG. 4 is a schematic system diagram of an apparatus related to a method for processing aluminum cutting waste and the like disclosed in Patent Document 1. Patent document 1 quotes the description of the claim. “The furnace frame is fixed, and an internal stirring device comprising a stirring member provided on a rotating shaft having bearings at both ends of the furnace is provided. Supplied with combustible materials, such as aluminum scraps, and while stirring, the combustible materials were partially burned while controlling the oxygen concentration and maintaining the temperature at 300 to 500 ° C, and heated under low oxygen conditions. Disclosed is a method of continuously treating a combustible material-attached aluminum cutting waste or the like using a dry distillation furnace, which is characterized by performing a carbonization process.

In FIG. 4, 1 is a raw material hopper, 3 is a dry distillation furnace, 5 is a stirring blade provided in the dry distillation furnace, 12 is a reburning furnace for burning pyrolysis gas, 25 is a melting furnace, and 26 is aluminum recovered and reused. Indicates a product that contributes. In the case of the system of FIG. 4, most of the gas generated in the carbonization furnace 3 is introduced into the reburning furnace 12 from the gas discharge port 10, while fuel and air are supplied from the supply port 14, and about 800 to 1000 ° C. The generated gas is completely combusted at a temperature to oxidize the oil to CO ₂ and H ₂ O or the like, and at the same time, deodorization is also performed (for details, refer to Patent Document 1).

  Next, Patent Document 5 will be described. The invention of Patent Document 5 relates to a waste treatment apparatus that treats waste containing chlorine compounds such as vinyl chloride and polyethylene so that dioxins are not generated. The lower part of the cylindrical tire deployed at both ends is rotatably supported by the roller of the drive unit, and it is composed of a hollow cylindrical body that is sealed inside by the equipment deployed at the front and rear stages, and is carried from the front stage A kiln main body that generates a pyrolysis gas and a non-volatile residue by conveying a waste raw material containing a chlorine compound while being heated and held at a predetermined temperature, and disposed in a front stage of the kiln main body, Waste material input device having a screw feeder for conveying to the kiln main body, an induction heating coil for induction heating the kiln main body from the outer peripheral side, and a subsequent stage of the kiln main body With deployed to recover the non-volatile residue, and collect the pyrolysis gases, characterized in that a residue recovery chamber for discharging to a subsequent gas treatment device waste disposal device. "Discloses.

  Patent Document 5 aims to reduce the oxygen concentration in a zone where waste is heated and kept warm, and to prevent generation of harmful gas from chlorine gas contained in the pyrolysis gas. Also disclosed is “a configuration in which an inert gas introduction means for introducing an inert gas into the kiln body” is provided.

  By the way, the inventors of the present application aim to simplify the apparatus as compared with the conventional apparatus, and collect the oil in a liquid form without decomposing it into a combustible gas as much as possible from the viewpoint of reducing the risk of fire as much as possible. In addition, we have developed a processing equipment for aluminum chips and the like that uses an inert gas in the pyrolysis furnace and performs heat treatment. A schematic system diagram of the primary development apparatus is shown in FIG. This apparatus will be described below.

  In the apparatus shown in FIG. 3, the raw material such as aluminum chips containing moisture and oil is introduced into the hollow cylindrical body and conveyed while being heated to a predetermined temperature. A pyrolysis furnace for discharging a pyrolysis gas containing a hydrocarbon-based gas and heat-treated aluminum chips, and a raw material conveyance input means for conveying the aluminum chips and the like disposed before the pyrolysis furnace And a treated product discharging means for discharging the pyrolyzed gas and heat-treated aluminum chips disposed downstream of the pyrolysis furnace, and an inert gas introducing means for introducing an inert gas into the pyrolysis furnace. Prepare.

  The pyrolysis furnace includes a kiln 33, an induction heating coil 34 having an IH power source, a cooling blower 35, a kiln driving means 36, a cooling casing 38, and a manhole 39. Further, the raw material conveying and charging means includes a charging screw (1) 31 and a charging screw (2) 32, and the charging port indicated by 30 is included in aluminum chips or the like by a centrifugal separation process as a pretreatment process. Chips after centrifugation with reduced oil and moisture are added. Note that, for example, a plurality of scraping plates are provided inside the cylinder of the kiln 33 so that the aluminum chips can be scraped up and heated evenly, and the chips can be moved toward the discharge port of the kiln. ing.

Moreover, the said processed material discharge | emission means consists of all the apparatus of the back | latter stage of the condensing part in the discharge | emission screw 37 provided in the exit part of the kiln 33, and the cooling casing 38, and it mentions later with description of thermal decomposition operation | movement etc. for details. Further, the inert gas introduction means supplies, for example, N ₂ gas to the kiln 33 from a nitrogen gas generator 62 that obtains nitrogen gas by separating the high-pressure factory air 61 into oxygen and nitrogen by a polymer separation membrane. The structure to be provided is provided.

Next, the thermal decomposition operation and the like will be described. A raw material such as aluminum chips containing moisture and oil and N ₂ gas are supplied to the kiln 33 and conveyed while heating to a predetermined temperature in the range of 300 to 500 ° C. (for example, less than 400 ° C.). Reference sign A at the outlet of the kiln 33 indicates the processed dry chips, reference sign B indicates pyrolysis gas including steam, oil vapor, and hydrocarbon-based gas generated by pyrolysis, and N ₂ gas. Separated from below 33 and discharged. The hydrocarbon-based gas includes gases such as hexane, butane, toluene, xylene, benzene, propylene, propane, and acetylene, although depending on the processing temperature. Further, in addition to the hydrocarbon-based gas, CO gas is also included.

  The dried swarf A is transported for subsequent processes by the swarf transporting conveyor 40. On the other hand, the gas indicated by the symbol B is cooled to condense part of the water vapor and the oil vapor, and is introduced into the subsequent condenser 51 through the line indicated by the symbol W. The remaining gas is introduced above the condenser 51 by a line indicated by reference numeral G, but the condensable component in the gas is liquefied by the cooling water shower 53 attached to the condenser and cooled by using the condensed liquid. At the same time, water-soluble gas dissolves. Further, the remaining gas is cooled again by a cooling water shower 58 having a pump 57, and a part thereof is liquefied or dissolved. The cooling water shower 58 is further introduced with the gas (A) and (B) indicated by reference numeral C joined together. The gas of the code | symbol C is mainly gas (b) containing the water vapor | steam which generate | occur | produces from the dry chip A, the oil vapor, the residual hydrocarbon gas, etc. in the conveyor 40 for chip conveyance. In addition, the line | wire of (C) of the code | symbol C shown in the exit part of the kiln 33 shows the line which induce | occur | produces leakage gas by any chance when a leak generate | occur | produces in a kiln.

The two tanks 55a and 55b shown in addition to the condenser 51 are bubbling tanks. The blower 56 sucks the gas above the bubbling tank 55a and performs bubbling to liquefy the condensed components in the gas as much as possible. The water-soluble component is dissolved, and the condensate is discharged from the portion 59 to a waste liquid tank (not shown) via the pump 52. On the other hand, the remaining detoxified clean gas is exhausted outdoors. Note that the liquid levels of the condensate in the condenser 51, the two bubbling tanks 55a and 55b, and the cooling casing 38 are all at substantially the same level.
Japanese Patent Publication No. 6-17520 Japanese Patent Laid-Open No. 10-176227 Japanese Patent Laid-Open No. 10-226830 Japanese Patent Laid-Open No. 11-100611 JP-A-11-226542

  By the way, according to the processing apparatus such as aluminum chips shown in FIG. 3, the oil can be recovered in a liquid state without being decomposed into combustible gas as much as possible, and an inert gas is further introduced into the pyrolysis furnace. Since the heat treatment is performed, the equipment can be relatively simplified and the risk of fires can be considerably reduced. However, from the viewpoint of the risk of fires, the following problems have been found. did.

  In FIG. 3, as described above, the gas generated from the dry chip A conveyed by the chip conveying conveyor 40 is flowed toward the cooling water shower 58 through the line indicated by reference numeral C (b). Since the upper part of the conveyor of the dry chips A is in an open state, white smoke is often generated. As described above, the white smoke contains water vapor, oil vapor, hydrocarbon-based gas, and CO gas, so that there is a risk of ignition depending on conditions. Among the hydrocarbon gases, the gas having the lowest ignition point is 260 ° C of hexane, but the ignition point of oil vapor is about 162 ° C, and the temperature of the discharged chips is about 200 ° C. , Ignition troubles are likely to occur.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to recover oil in a liquid state without decomposing it into a combustible gas as much as possible, and further to an inert gas in a pyrolysis furnace. Is to perform a heat treatment, and to provide a processing apparatus for aluminum chips and the like that suppresses the risk of ignition.

In order to solve the above-described problems, the present invention is produced by introducing pyrolytic materials such as aluminum chips containing moisture and oil into a hollow cylindrical body and conveying them while heating to a predetermined temperature. A pyrolysis furnace that discharges pyrolysis gas containing steam, oil vapor, and hydrocarbon gas and heat-treated aluminum chips, and the aluminum chips disposed in the front stage of the pyrolysis furnace are transported and input. A raw material transfer and input means, a processed material discharge means for discharging the pyrolyzed gas and heat-treated aluminum chips disposed downstream of the pyrolysis furnace, and an inert gas for introducing an inert gas into the pyrolysis furnace In a processing apparatus such as aluminum chips provided with a gas introduction means, the processed material discharge means is provided along a discharge route of the aluminum chips, and a cooling means for forcibly cooling the aluminum chips, Serial and a inert gas introducing means for introducing at least a portion the inert gas discharge path, further, the treated product discharge means, by cooling to condense the water vapor and oil vapor of the pyrolysis in the gas, The condenser having a means for discharging the condensate to the waste liquid tank, and the uncondensed gas or the water-soluble gas in the pyrolysis gas are recycled by a cooling shower using the condensed liquid and / or bubbling into the liquid. And means for condensing or dissolving in water (claim 1).

  According to this invention, the aluminum chips are forcibly cooled to lower the temperature, and the inert gas is introduced around the chips to reduce the oxygen concentration, so that the risk of ignition is suppressed and safe. A processing device can be provided.

As an embodiment of the invention of claim 1, the inventions of claims 2 to 4 below are preferable .

  That is, in the processing apparatus according to claim 1, the pyrolysis furnace includes a rotatable kiln main body and an induction heating coil for electromagnetically heating the kiln main body from the outer peripheral side. 2). Furthermore, in the processing apparatus according to claim 1 or 2, the inert gas introducing means is nitrogen introducing means for introducing nitrogen separated from air (claim 3).

Moreover , in the processing apparatus according to any one of claims 1 to 3 , the processed material discharge means is connected to an aluminum chip discharge portion of a pyrolysis furnace in order, and a chip discharge screw feeder. A paddle screw feeder having an inert gas introduction unit and a cooling unit, a storage hopper for temporarily storing chips, and a conveying screw feeder for transferring the chips from the storage hopper to a subsequent process are provided. Item 4 ).

According to the fourth aspect of the invention, since the aluminum chips accumulated in the front part of the chip discharge screw feeder and the storage hopper block the front and rear of the paddle screw feeder part and prevent the gas flow, the paddle screw feeder part The supplied inert gas is difficult to flow out, and the fire suppression effect is further improved.

  According to this invention, the oil component is recovered in a liquid state without being decomposed into a combustible gas as much as possible, and a processing device for relatively simple aluminum chips and the like for performing heat treatment by introducing an inert gas into a pyrolysis furnace. Therefore, it is possible to provide a safe device in which the risk of ignition is suppressed.

  An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In addition, this invention is not limited by this Example.

  FIG. 1 is a schematic system diagram of an embodiment of a processing apparatus for aluminum chips and the like according to the present invention. 1, members that are the same as or have the same functions as those shown in FIG. 3 are given the same reference numerals, and detailed descriptions thereof are omitted. The substantial difference between FIG. 1 and FIG. 3 is mainly in the apparatus configuration at the rear stage of the processed material discharge means, particularly the discharge screw 37. Moreover, although the apparatus structure around the bubbling tank in FIG. 3 is also partially different, the basic functions are substantially the same. Details will be described later.

  1, the member numbers different from those in FIG. 3 are as follows. 41 is a paddle screw, 41a and 42a are cooling jackets, 42 is a storage hopper, 43 and 44 are screws, 46 is a seal lid used when starting the apparatus, 48 is a collector, 55 is a scrubber instead of a bubbling tank, 56a, 56b is a blower, 63, 64, 65, 66, 67 and 68 are nitrogen gas supply lines, 69 is an air introduction valve, 71 and 72 are oxygen sensors, and 74 is a chip level sensor. T1 to T5 are temperature sensors (for example, thermocouples), P is a pressure sensor, M1 to M7 are drive motors, FM is a flow meter, and LS is a level sensor.

  In the processed product discharge means of the apparatus of FIG. 1, a discharge screw 37 for discharging chips, a paddle screw 41, and a storage hopper 42 for temporarily storing chips are sequentially connected to the aluminum chip discharge unit of the kiln 33. And conveying screws 43 and 44 for conveying the chips from the storage hopper 42 to the subsequent process, and the dried chips A are passed from the kiln 33 to the position indicated by the part number 45 via the screws. From here, it is conveyed to the next process by a bucket conveyor. In addition, the plate-shaped member which does not attach | subject the part number between the paddle screw 41 and the discharge | emission screw 37 shows the bearing part of the rotating shaft for screw drive.

  The paddle screw 41 has a known configuration in which a hollow chamber having a U-shaped cross section is provided, and a tip of the screw provided inside the axial direction is provided with a scraping plate for chips. A water cooling jacket 41a is provided along the chamber axial direction on the outer periphery of the semi-cylindrical portion below the letter-shaped chamber so that chips in the chamber are forcibly water cooled. The water cooling jacket is also preferably provided on the outer periphery of the storage hopper 42 as indicated by 42a. As described above, the temperature of the aluminum chips in the storage hopper 42 is preferably set to 100 ° C. or less.

  Further, nitrogen gas supply lines 65 and 67 are connected to the paddle screw 41, and nitrogen gas is introduced from the nitrogen gas generator 62 through the nitrogen gas supply line 64. Furthermore, as indicated by part numbers 66 and 68, it is preferable to introduce nitrogen gas also into the inside of the storage hopper 42 and the penetration part of the chip level sensor 74. Other inert gas such as argon can be used instead of nitrogen gas. For forced cooling, air cooling or another cooling medium can be used instead of water cooling.

  According to the configuration of the treated product discharge means, the aluminum chips are forcibly cooled to lower the temperature, and nitrogen gas is introduced around the chips to reduce the oxygen concentration, so there is a risk of ignition. Deterred. Further, as described above, the aluminum chips accumulated in the front stage portion of the discharge screw 37 and the storage hopper 42 block the paddle screw 41 and the rear stage portion of the discharge screw and prevent the gas from flowing, and thus are supplied to the paddle screw portion. Nitrogen gas is difficult to flow out and the fire suppression effect is further improved.

  In the above configuration, the gas C containing water vapor, oil vapor, residual hydrocarbon gas, etc. generated from the dry swarf A is passed from the upper end of the screw 44 to the cooling water shower 58 via the collector 48. It is carried. The collector 48 collects solid dust by gravity sedimentation, and is provided as necessary.

  Next, similarly to the case of FIG. 3, the gas indicated by the symbol B is cooled to condense a part of the water vapor and the oil vapor, and is introduced into the subsequent condenser 51 through the line indicated by the symbol W. The remaining gas is introduced to the upper side of the condenser 51 through a line denoted by reference numeral G, and the condensable component in the gas is liquefied and the water-soluble gas is dissolved by the cooling water shower 53. In the case of FIG. 1, instead of the two bubbling tanks shown in FIG. 3, one scrubber 55 is provided to dissolve and clean the gas by stirring and bubbling with the gas. Is the same as in FIG.

  Next, the main points of the operation control method and abnormality monitoring of the apparatus of FIG. 1 will be described below. First, in the thermal decomposition treatment operation of aluminum chips or the like, the gauge pressure in the kiln 33 is preferably operated at a pressure of about +5 to −20 Pa (more preferably 0 to −20 Pa). The reason for this is that when the pressure inside the kiln and the screw inside the processing material discharge means is higher than the atmospheric pressure, as described above, when the apparatus leaks, water vapor, oil vapor, hydrocarbon gas and CO White smoke containing gas is generated, and there is a risk of ignition depending on the conditions. When the apparatus of FIG. 1 is functioning normally, although generation of white smoke is suppressed by water cooling and introduction of nitrogen gas in the paddle screw 41, a part of the gas is condensed inside the paddle screw 41. There is a problem that the dry chips A get wet.

  During operation of the apparatus, the front and rear of the kiln 33 are closed with aluminum chips or the like, so the suction amount is adjusted by controlling the rotational speed of the blower 56a provided above the scrubber 55, and the above-mentioned 0 to -20 Pa. Pressure. At the start of the apparatus before the aluminum chips are charged, the air introduction valve 69 and the seal lid 46 are closed, and the blower 56a provided above the scrubber 55 is started. Thereby, the air inside the apparatus is discharged. Thereafter, by introducing nitrogen gas and introducing aluminum chips, the rotational speed of the blower 56a is controlled based on the measured value of the pressure sensor in the kiln, and the operation mode is shifted.

  Next, when leakage occurs in the apparatus or when the oxygen concentration in the apparatus becomes abnormal for some reason, the apparatus is stopped urgently. For this purpose, oxygen sensors 71 and 72 are provided for monitoring. Moreover, the chip level sensor 74 is provided, and when the level reaches the upper limit, the driving of the kiln is stopped. In this case, it is preferable to maintain the heating state without stopping the induction heating coil. Further, when the gas flow path G toward the condenser 51 is clogged with tar or the like, the apparatus is urgently stopped. For this purpose, a temperature sensor T2 is provided, and when the measured value is equal to or lower than a predetermined temperature (for example, 70 ° C.), it is determined that the heated gas is not flowing normally, and the apparatus is stopped urgently.

  Next, an example of the operation result of the present invention will be described with reference to FIG. FIG. 2 shows a time transition of each part temperature (T1, T3, T4, T5) in FIG. As operating conditions in FIG. 2, the kiln temperature was set to a set value 385 ± 5 ° C., and the processing amount of aluminum chips and the like was 500 kg / H. In addition, this chip etc. shall contain water 15kg and oil 1kg by the centrifugation process as a pre-process. The motor frequency of the charging screw (1) 31 and the charging screw (2) 32 was set to 7.4 Hz.

  In FIG. 2, T1 is the kiln temperature, and shows a value close to the set value 385 ± 5 ° C. in the steady operation state. T3 is the chute temperature (the temperature at the top of the chip entrance of the discharge screw 37 in FIG. 1), and shows a value around 300 ° C. T4 is the screw exhaust gas temperature (the temperature of the exhaust gas C at the upper end of the screw 44 in FIG. 1), and shows a value around 70 ° C. T5 is the chip temperature in the storage hopper 42, showing a value of less than 70 ° C., and was confirmed to be lower than the target chip temperature.

1 is a schematic system diagram of an embodiment of a processing apparatus for aluminum chips and the like according to the present invention. The figure which shows the time transition of each part temperature as an example of the operation result of the apparatus of FIG. The general | schematic system system diagram of the primary development apparatus of processing apparatuses, such as aluminum chip which concerns on development of this inventor. FIG. 2 is a schematic system diagram of an apparatus according to a method for processing aluminum cutting waste and the like disclosed in Patent Document 1.

Explanation of symbols

31: Input screw (1), 32: Input screw (2), 33: Kiln, 34: Induction heating coil, 35: Cooling blower, 36: Kiln driving means, 37: Discharge screw, 38: Cooling casing, 39: Manhole 41: paddle screw, 41a, 42a: water cooling jacket, 42: storage hopper, 43, 44: screw, 46: seal lid, 48: collector, 51: condenser, 52: pump, 53, 58: cooling water Shower, 55: Scrubber, 56a, 56b: Blower, 57: Showering pump, 61: Factory air, 62: Nitrogen gas generator, 63, 64, 65, 66, 67, 68: Nitrogen gas supply line, 69: Air Introduction valve, 71, 72: oxygen sensor, 74: chip level sensor.

Claims (4)

Raw material such as aluminum chips containing moisture and oil is introduced into the hollow cylindrical body and conveyed while being heated to a predetermined temperature, and contains steam, oil vapor and hydrocarbon gas generated by thermal decomposition. A pyrolysis furnace for discharging the pyrolyzed gas and the heat-treated aluminum chips, a raw material conveying / injecting means disposed in a preceding stage of the pyrolysis furnace for conveying and feeding the aluminum chips, etc., and Aluminum chips provided with a processed material discharge means for discharging the pyrolyzed gas and heat-treated aluminum chips disposed in a subsequent stage, and an inert gas introducing means for introducing an inert gas into the pyrolysis furnace, etc. In the processing device,
The treated product discharge means is provided along an aluminum chip discharge path, a cooling means for forcibly cooling the aluminum chips, and an inert gas introduction means for introducing an inert gas into at least a part of the discharge path. And the treated product discharge means cools and condenses water vapor and oil vapor in the pyrolysis gas, and discharges the condensate to a waste liquid tank, and the pyrolysis gas. A non-condensable gas or a water-soluble gas contained therein, a cooling shower using condensed liquid and / or means for recondensing or dissolving in water by bubbling into the liquid, etc. Processing equipment. 2. The processing apparatus according to claim 1, wherein the pyrolysis furnace includes a rotatable kiln main body and an induction heating coil that electromagnetically heats the kiln main body from the outer peripheral side. Processing equipment. The processing apparatus according to claim 1 or 2, wherein the inert gas introducing means is a nitrogen introducing means for introducing nitrogen separated from air. The processing apparatus according to any one of claims 1 to 3 , wherein the processing product discharging means is connected to an aluminum chip discharging unit of a pyrolysis furnace, and in order, a chip discharging screw feeder, and an inert gas. A paddle screw feeder having an introducing means and a cooling means, a storage hopper for temporarily storing chips, and a conveying screw feeder for transferring the chips from the storage hopper to a subsequent process are provided. Processing equipment such as aluminum chips.

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