JP2007245040A - Granular material storing method and granular material storing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a granular material storing method which stabilizes a granular material having exothermic property due to a low-temperature oxidation reaction or the like in an early time while storing it without causing thermorunaway and allows the granular material to be in a high-safety state enough to cause no ignition or fire without reducing a value as a fuel substitution, and also to provide a granular material storing device. <P>SOLUTION: Exothermic reaction of the granular material such as low-temperature oxidation reaction is promoted by supplying a gas such as an air to be an oxygen supply source to a storing container 1 for storing the granular material and heating it, and then the air supply is stopped to store the granular material. Preferably the air is supplied to the storing container 1 to stir the granular material. The granular material storing device has a function which prevents the thermorunaway of the granular material in the storing container 1 by cooling the granular material in the storing container 1. The exothermic reaction such as the low-temperature oxidation is controlled by controlling a gas supply amount into the storing container 1, a heating amount in the storing container, and a cooling amount based on temperature information in the storing container 1. The exothermic reaction such as the low-temperature oxidation is controlled by controlling temperature of the granular material within a range of 50-150°C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a powder storage method and a powder storage device for making a safe state without causing thermal runaway while storing powder particles such as carbide obtained by processing waste. is there.

Conventionally, when processing waste such as waste, in order to extend the life of the final disposal site (landfill), the amount of waste has been reduced by incineration, gasification and melting methods, and the like. On the other hand, recently, in response to a request for reduction of global warming gas (CO ₂ ), waste such as waste is not incinerated, but carbonized in a carbonization furnace and recovered as granular carbide, enabling effective use A method has been proposed. This carbide can be used, for example, as an alternative material such as coal or coke as a fuel, or as a heat insulating material on the surface of a molten metal in a metal electric furnace, and thus is further effective for resource saving.

  This particulate carbide contains many reactive groups such as free radicals and functional groups, and has a property of generating heat due to a low-temperature oxidation reaction or the like. Therefore, when the calorific value is larger than the heat dissipation amount of the granular material, the granular material accumulates heat, and this heat further promotes an exothermic reaction such as low-temperature oxidation of the granular material, and heat exceeds when a certain temperature is exceeded. Runaway, in the worst case it could ignite and cause a fire.

  The carbide recovered from the carbonization furnace is temporarily stored in a storage tank such as a silo until shipment (for example, for 3 days), and is stored in a flexible container or the like for storage and transportation from the storage tank. The granular material stored in the storage tank does not move in the storage tank except when stored in a flexible container or the like. Therefore, the granular material stays in a certain place in the storage tank and is stored, and heat is easily stored. When the granular material reaches a certain temperature or more, the granular material may run out of heat, and in the worst case, ignition or fire may occur. When the powder is ignited and becomes in a combustion state, there is a risk that oxygen in the storage tank will be insufficient, flammable gas such as CO (carbon monoxide) will be generated, and the storage tank will explode. .

  In order to avoid the above problem, if an abnormality is detected by the temperature rise inside the storage tank or detection of flammable gas, the fire is extinguished by the release of inert gas, water sprinkling, etc. by the fire extinguishing device At the same time, the particulate matter is urgently discharged from the storage tank, but the particulate carbide discharged while sprinkling water increases the moisture content and reduces the solid calorific value (low calorific value). The value as a substitute product is significantly reduced.

  On the other hand, if the air flowing into the storage tank is blocked in order to prevent the above problem, exothermic reactions such as low-temperature oxidation of the granular material are suppressed, and the granular material is stored by the weight of the granular material itself. Since it is compressed in the tank and stored in the storage tank in a dense state, exothermic reactions such as low-temperature oxidation do not proceed, and the powder particles are still stable when discharged and stored in a flexible container etc. Not. As a result, when the granular material is stored in small containers from a storage tank to a flexible container, the granular material comes into contact with air, so an exothermic reaction occurs due to low-temperature oxidation or the like, and in the worst case, ignition or fire occurs. There was a problem.

  For this reason, exothermic reactions such as low-temperature oxidation, which is the most reactive in the initial stage, have progressed relatively stably in order to prevent ignition of the powder and granular materials being stored and transported in flexible containers, etc. Until a state is reached, it is necessary to store the granular material in a flexible container or the like for a certain period of time (for example, 150 hours), and to monitor the storage so as not to cause thermal runaway during storage. Accordingly, there has been a demand for the development of a new storage method in which low-temperature oxidation is promoted in the storage tank and the reaction is settled to some extent and can be discharged as highly safe carbide during the storage of the carbide.

  Moreover, in order to solve the said problem, the carbide | carbonized_material production | generation facility as shown to patent document 1 is proposed. This carbide generation facility is a facility that supplies at least one of a deoxygenating agent and a deoxygenated aqueous solution to the carbide, performs degassing, and performs bagging in a state where the oxygen concentration in the bag is reduced. However, in order to prevent heat generation of the granular material by this method, there is a problem that large-scale equipment is required, and that a deoxygenating agent and a deoxygenated aqueous solution are necessary, resulting in high running costs.

Japanese Patent Laid-Open No. 2004-256122

  The present invention solves the above problems, stabilizes powder particles having exothermic properties due to low-temperature oxidation reaction, etc. at an early stage while storing them without thermal runaway, and has value as a fuel substitute. The present invention has been completed for the purpose of providing a granular material storage method and a granular material storage device for achieving a high safety state that does not cause ignition and fire without lowering.

  The present invention made to solve the above problem is to supply an oxygen supply source such as air into a storage tank for storing the granular material, and promote an exothermic reaction such as low-temperature oxidation of the granular material, The supply of gas that can be an oxygen supply source such as air is stopped and stored.

  In addition, it is preferable to stir the granular material with a gas such as air supplied into the storage tank to promote an exothermic reaction such as low-temperature oxidation of the granular material.

  Moreover, it is preferable to heat the exothermic reaction of a granular material by heating the granular material in a storage tank.

  In addition, it is preferable to promote exothermic reaction such as low-temperature oxidation while cooling the granular material in the storage tank to prevent thermal runaway in the storage tank.

  Furthermore, based on the temperature information in the storage tank, one or more of the supply amount of gas that can be an oxygen supply source such as air into the storage tank, the heating amount in the storage tank, and the cooling amount in the storage tank are controlled. Thus, it is preferable to control an exothermic reaction such as low-temperature oxidation of the granular material.

  In addition, it is preferable to control the temperature of the granular material in the storage tank within a range of 50 to 150 ° C. to control the exothermic reaction of the granular material.

  It is preferable that the apparatus of the present invention is provided with a gas supply device such as air for supplying air into the storage tank.

  The storage tank is preferably provided with at least one of a heating device for heating the powder and a cooling device for cooling the powder, and the temperature sensor provided in the storage tank and the temperature sensor It is preferable that a control device is provided for controlling one or more of the gas supply amount of the gas supply device, the heating amount of the heating device, and the cooling amount of the cooling device based on the temperature information obtained in (1).

  In addition, it is preferable that a control apparatus temperature-controls the temperature of a granular material in the range of 50-150 degreeC.

  According to the granular material storage method and the granular material storage device of the present invention, since the granular material is stirred by supplying gas such as air into the storage tank, the granular material is constant in the storage tank. It is possible to prevent ignition / fire due to staying at the place and storing heat, and to prevent loss of value as a fuel substitute for carbide by watering when ignited.

  In addition, if a gas that can serve as an oxygen supply source such as air is supplied into the storage tank to promote an exothermic reaction such as low-temperature oxidation and stabilize early while storing, the carbide will run away in a flexible container. Therefore, it is possible to save the labor of storing for a long time while monitoring so that the running cost is low and the granular material is in a high safety state without using large-scale equipment.

  In addition, heating the granular material in the storage tank to promote exothermic reaction such as low-temperature oxidation of the granular material efficiently promotes exothermic reaction such as low-temperature oxidation of the granular material, The body can be brought into a highly safe state at an early stage.

  If the granular material in the storage tank is cooled to promote an exothermic reaction such as low-temperature oxidation, an exothermic reaction such as low-temperature oxidation of the granular material can be safely performed while preventing thermal runaway in the storage tank. It becomes possible to promote.

  Furthermore, based on the temperature sensor that measures the temperature of the granular material and the temperature information obtained by this temperature sensor, 1 of the gas supply amount into the storage tank, the heating amount of the granular material, and the cooling amount of the granular material Or, if two or more are controlled to control the low temperature oxidation of the granular material, an exothermic reaction such as low temperature oxidation of the granular material is promoted efficiently and safely while preventing thermal runaway of the granular material. Thus, it becomes possible to make the powder and granule a highly safe state.

  Furthermore, when the temperature of the granular material is controlled within the range of 50 to 150 ° C., it prevents thermal runaway of the granular material and promotes an exothermic reaction such as low-temperature oxidation of the granular material more efficiently and safely. Thus, it becomes possible to make the powder and granule a highly safe state.

  When the granular material storage method according to the present invention promotes the reaction from a state of high exothermic reactivity such as relatively low-temperature oxidation to a highly safe state, the granular material is combustible. According to actual results, the rate of decrease in the amount of heat and solid heat generation is within 3%, and the product value as a fuel substitute product does not decrease.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view of a storage device showing an embodiment of the present invention. Reference numeral 1 denotes a storage tank such as a silo, which is used to temporarily store (for example, 3 days) the granular material collected from the carbonization furnace. The shape of the storage tank 1 is, for example, a substantially cylindrical shape or a substantially rectangular parallelepiped shape, and the capacity is, for example, 20 to 30 m ³ . Reference numeral 2 denotes a supply device for charging the granular material collected from the carbonization furnace into the storage tank 1. Reference numeral 3 denotes an outlet for subdividing and storing the flexible container 4 or the like, and is provided at the bottom of the storage tank 1.

  When the oxygen in the storage tank 1 is consumed by the low temperature oxidation of the powder and the oxygen concentration is lowered, exothermic reaction such as low temperature oxidation of the powder is inhibited. Therefore, the inventor of the present invention supplies a gas that can be an oxygen supply source such as fresh air into the storage tank 1 to promote an exothermic reaction such as low-temperature oxidation of the granular material 5. It was decided to provide.

  This gas supply device 5 may be provided outside the storage tank 1 as shown in FIG. 1, for example, or may be provided inside the storage tank 1. A gas such as air is supplied from the gas supply pipe 6 into the storage tank 1 by the gas supply device 5. The gas supply pipe 6 is, for example, a substantially circular pipe or a substantially square pipe, and is attached so as to face the inside of the storage tank 1. As shown in FIG. 1, the gas supply pipe 6 has a structure protruding into the storage tank 1, for example. The tip of the gas supply pipe 6 may be closed or may be opened.

  A plurality of holes penetrating from the outer surface of the gas supply pipe 6 into the gas supply pipe 6 are formed in the gas supply pipe 6, and a gas such as air inside the gas supply pipe 6 is supplied to the storage tank 1 from the hole. . The gas supply pipe 6 may be made of a porous material such as metal, resin, porcelain, ceramic, etc., and gas such as air inside the gas supply pipe 6 may be supplied into the storage tank 1 from the porous. .

  The gas supply pipe 6 may be attached so as to penetrate the storage tank 1. When it is attached so as to penetrate the storage tank 1, a part of the gas such as air inside the gas supply pipe 6 is connected by connecting the gas supply pipe 6 penetrating the storage tank 1 to the gas supply device 5. It is good also as a structure which circulates. The gas supply pipe 6 may be U-shaped so that a part of the air inside the gas supply pipe 6 circulates. The gas supply pipe 6 is not limited to one, and two or more gas supply pipes 6 may be provided in the storage tank 1. The gas supply pipe 6 is preferably attached in the vicinity of the bottom of the storage tank 1 in order to more effectively promote an exothermic reaction such as low-temperature oxidation of the granular material.

  After promoting an exothermic reaction such as low-temperature oxidation of the granular material in the storage tank 1, the gas supply device 5 may be stopped to stop the supply of air or the like into the storage tank 1, or the gas supply It does not matter if the device 5 is not stopped.

  The gas such as air supplied from the gas supply device 5 to the inside of the storage tank 1 not only promotes an exothermic reaction such as low-temperature oxidation of the granular material, but also the heat storage part of the granular material causes the gas such as air to flow. Since it circulates, there also exists an effect which cools this thermal storage part.

  As another embodiment, instead of the gas supply pipe 6, as shown in FIG. 2, a plurality of nozzles 21 opening upward in the storage tank 1 are connected to the gas supply pipe 22. It is good also as supplying gas, such as air, into the storage tank 1 inside as a structure.

  As another embodiment, as shown in FIG. 3, as a structure in which a gas supply plate 31 is provided at the bottom of the storage tank 1, air or the like is supplied into the storage tank 1. Also good. The gas supply plate 31 may be formed with a plurality of holes penetrating the plate, but the gas supply plate 21 may be made of a porous material such as metal, resin, ceramic, ceramic, or the like.

  The granular material has a property that an exothermic reaction such as low-temperature oxidation is promoted when the temperature rises. Therefore, in order to heat the granular material and promote an exothermic reaction such as low-temperature oxidation, the storage tank 1 is preferably provided with a heating device 13. This heating device 13 may be heated by generating heat with, for example, a heating wire or the like. However, the heating device 13 has a function of generating heat in the storage tank 1 itself, for example, a function of circulating a heating medium in the jacket portion, and the like. The granular material may be heated while storing the granular material, or the heating device 13 may be provided in the gas supply device 5 to supply hot air into the storage tank 1 to heat the granular material. . It is preferable to promote the exothermic reaction such as low-temperature oxidation of the granular material by controlling the inside of the storage tank 1 to, for example, 50 ° C. to 150 ° C. with the heating device 13.

  By supplying a gas such as air from the gas supply pipe 6 (22) or the gas supply plate 31, the granular material in the storage tank 1 is agitated. Since this granular material is agitated, it is possible to promote an exothermic reaction such as low-temperature oxidation of the granular material uniformly. In addition, since the granular material does not stay in a certain place in the storage tank 1, it promotes an exothermic reaction such as low-temperature oxidation of the granular material while preventing thermal ignition and fire without storing heat. It becomes possible. In addition, even if a granular material is stirred with a mechanical apparatus, it does not interfere.

  However, when the temperature of the granular material reaches a certain level or more, as described above, there is a possibility that the thermal runaway may cause ignition and fire. Therefore, in order to control the temperature inside the storage tank 1 and to cool the granular material in an emergency in which thermal runaway of the granular material is likely to occur, the storage tank 1 is provided with a cooling device 7. It is preferable. When the temperature in the storage tank 1 exceeds, for example, 150 ° C., the cooling device 7 is operated to cool the storage tank 1, and the low temperature oxidation reaction of the granular material is suppressed to prevent thermal runaway. For example, as shown in FIGS. 1 to 3, the cooling device 7 is provided with a cooling pipe 8 in the storage tank 1, a cooling medium is fed into the cooling pipe 8, and the inside of the cooling pipe 8 is circulated. The inside of the storage tank 1 is cooled by the cooling medium to cool the granular material. The cooling medium flowing through the inside of the cooling pipe 8 is, for example, water, may be a liquid such as ethylene glycol or propylene glycol, or may be a gas such as air. Or it is good also as cooling gas, such as air supplied from the gas supply apparatus 5, and cooling a granular material.

  In order to promote exothermic reaction such as low-temperature oxidation of the granular material, and to promote exothermic reaction such as low-temperature oxidation of the granular material efficiently without causing thermal runaway in the storage tank 1 It is preferable to control the gas supply amount, heating amount or cooling amount inside the tank 1. Therefore, for example, a storage tank center temperature sensor 9 is provided near the center of the storage tank 1, a storage tank bottom temperature sensor 10 is provided at the bottom of the storage tank 1, and a storage tank upper temperature sensor 11 is provided above the storage tank 1, and these temperatures are provided. It is preferable to provide a control device 12 that controls the gas supply amount of the gas supply device 5, the heating amount of the heating device 13, and the cooling amount of the cooling device 7 based on temperature information measured from the sensor.

  When the temperature measured by each of the storage tank center temperature sensor 9, the storage tank bottom temperature sensor 10, and the storage tank upper temperature sensor 11 exceeds a specified threshold value (for example, 150 ° C.), or When it is determined that the abnormality is caused by the combination, the control device 12 determines that there is a risk that the granular material in the storage tank 1 is thermally runaway.

  Based on the determination, the control device 12 controls the gas supply device 5 so that the amount of air supplied into the storage tank 1 is less than the normal amount, or the supply of air into the storage tank 1 is shut off. Thus, an exothermic reaction such as low-temperature oxidation of the granular material is suppressed.

  Further, based on the above determination, the control device 12 controls the heating device 13 to weaken the heating amount of the granular material by the heating device 13 than usual, or to stop the heating of the granular material, Prevents exothermic reactions such as low-temperature oxidation from being promoted.

  Further, based on the determination, the control device 12 operates the cooling device 7 to cool the granular material and suppress exothermic reactions such as low-temperature oxidation of the granular material.

  Further, as described above, the control device 12 not only prevents thermal runaway of the granular material, but also supplies the gas supplied into the storage tank 1 by the gas supply device 5, the heating amount by the heating device 13, and the cooling device 7. By controlling the amount of cooling and controlling the temperature in the storage tank 1 within a range of 50 to 150 ° C., for example, the exothermic reaction such as low-temperature oxidation of the powder is controlled, and the powder is efficiently and safely It becomes possible to make a state with high property.

  As described above, according to the present invention, without using a large-scale apparatus, the granular material having exothermic properties due to a low-temperature oxidation reaction or the like is stabilized at an early stage, and ignition by thermal runaway of the granular material is surely performed.・ Fire can be prevented.

  In addition, the granular material storage tank of the present invention not only stores and stores carbides generated when wastes are processed in a carbonization furnace, but also heats RDF (dust solidified fuel), metal cutting waste, and the like during storage. Needless to say, it can also be used to store materials that are at risk of running away and catching fire.

  Although the present invention has been described above in connection with the most practical and preferred embodiments at the present time, the present invention is not limited to the embodiments disclosed herein. The powder storage method and the powder storage device with such changes are also within the technical scope without departing from the spirit or idea of the invention that can be read from the claims and the entire specification. It must be understood as included.

It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Storage tank 2 Supply apparatus 3 Outlet 4 Flexible container 5 Gas supply apparatus 6 Gas supply pipe 7 Cooling apparatus 8 Cooling pipe 9 Reservoir temperature sensor 10 Reservoir bottom temperature sensor 11 Reservoir upper temperature sensor 12 Control apparatus 13 Heating apparatus 21 Nozzle 22 Gas supply pipe 31 Gas supply plate

Claims (13)

  A gas that can be an oxygen supply source is supplied into a storage tank that stores exothermic granular material stored in the storage tank, and can be an oxygen supply source after promoting an exothermic reaction of the granular material. A granular material storage method, wherein gas supply is stopped and stored.   The granular material storage method according to claim 1, wherein the granular material is stirred by a gas supplied into the storage tank to promote an exothermic reaction of the granular material.   The granular material storage method according to claim 1, wherein the granular material in the storage tank is heated to promote an exothermic reaction of the granular material.   The granular material storage method according to any one of claims 1 to 3, wherein the granular material in the storage tank is cooled to prevent thermal runaway in the storage tank and promote an exothermic reaction. .   Based on the temperature information in the storage tank, one or more of the supply amount of gas that can be an oxygen supply source into the storage tank, the heating amount in the storage tank, and the cooling amount in the storage tank are controlled, and An exothermic reaction is controlled, The granular material storage method in any one of Claims 1 thru | or 4 characterized by the above-mentioned.   The temperature of the granular material in a storage tank is temperature-controlled within the range of 50-150 degreeC, and the exothermic reaction of a granular material is accelerated | stimulated, The granular material in any one of Claim 1 thru | or 5 characterized by the above-mentioned. Body storage method.   The granular material storage method according to claim 1, wherein the exothermic reaction is a low-temperature oxidation reaction.   The method for storing granular materials according to claim 1, wherein the gas that can serve as an oxygen supply source is air.   In the granular material storage apparatus which stores the granular material which has exothermic property, the gas supply apparatus which supplies gas into the inside of a storage tank was provided, The granular material storage apparatus characterized by the above-mentioned.   The storage tank is provided with at least one of a heating device for heating the granular material in the storage tank and a cooling device for cooling the granular material in the storage tank. Powder storage device.   Based on the temperature sensor provided in the storage tank and the temperature information obtained by the temperature sensor, one or more of the gas supply amount of the gas supply device, the heating amount of the heating device, and the cooling amount of the cooling device are controlled. The control apparatus which performs is provided, The granular material storage apparatus in any one of Claim 9 or 10 characterized by the above-mentioned.   The control apparatus controls the temperature of the granular material in the storage tank within a range of 50 to 150 ° C, and the granular storage apparatus according to claim 11.   The powder storage device according to any one of claims 9 to 12, wherein the gas supplied to the inside of the storage tank is air.

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