JP4319199B2 - Powder storage device - Google Patents

Description

  The present invention relates to a granular material storage device capable of curing while safely storing a granular material having exothermic reactivity due to low-temperature oxidation or the like such as carbide or RDF using waste as a raw material.

  Conventionally, waste disposal methods such as municipal waste have mainly been buried or incinerated, but recently, technologies for use as fuel and other energy sources have been developed. However, carbides and RDF using waste as a raw material have exothermic reactivity due to low-temperature oxidation or the like, and react with oxygen in the air to gradually increase the temperature and ignite. Carbides produced by heating municipal waste in a carbonization furnace have free radicals, functional groups, etc. on the surface, so if shipped immediately after being discharged from the carbonization furnace, it will ignite during transportation or at the shipping destination. There is a fear. Therefore, it is necessary to carry out curing with a storage device for several days to reduce exothermic reactivity before shipping.

  However, if carbide is stored in a large storage tank, the heat radiation area per volume of the granular material decreases, so heat accumulates inside and the center becomes hot, and in the worst case, thermal runaway occurs and ignition occurs. Sometimes. Therefore, in order to avoid this danger, when a large number of small storage tanks are installed and the distributed storage method is adopted, there is a problem that not only a large installation area is required but also management is troublesome.

The above situation is the same in the case of RDF, and there is a risk of ignition if RDF is stored in a large storage tank. Therefore, as in Patent Document 1, a proposal has been made to fill the entire storage tank with nitrogen gas to prevent reaction with oxygen in the air. However, since the entire structure must be an airtight structure, the equipment cost increases, and nitrogen There is a problem that the cost of gas is high. Moreover, since the exothermic reactivity does not change even when stored in nitrogen gas, the purpose of curing cannot be achieved.
JP 2005-178934 A

  The present invention solves the above-mentioned conventional problems, and does not require a large installation area and requires a lot of manpower to manage powder particles such as carbide and RDF having exothermic reactivity due to low-temperature oxidation or the like. Therefore, the present invention has been made in order to provide a granular material storage device having exothermic reactivity that can be safely stored and cured at low cost.

  The exothermic reactive powder storage device of the present invention made to solve the above problems is a vertically long storage tank body provided with an inlet at the upper end and an outlet at the lower end in the vertical direction. The stage is divided into a plurality of stages, and each stage is used as a storage chamber for the granular material having exothermic reactivity due to low-temperature oxidation or the like. A transfer means for moving the granules, and an emergency discharge port for quickly discharging the granules from the storage chamber of each stage is provided on the side wall of the storage tank.

  Note that the transfer means is a screw feeder and an emergency discharge port is provided at the transfer end in the reverse direction, and the transfer means is a rotary blade of a circle feeder, which can be opened and closed on the side wall of the storage tank body. A structure with an emergency outlet can be provided. Moreover, it is preferable to set it as the structure which can cool any one or more of the floor board which divides the inside of a storage tank body, the screw shaft of a screw feeder, and the rotary blade of a circle feeder, and the temperature of a granular material is set to a storage tank body. It is preferable to provide a sensor, a temperature control means for the granular material, and a speed control means for the transfer means so that an exothermic reaction such as low-temperature oxidation can be controlled.

  The storage device of the present invention is similar to a normal silo type storage device in which powder particles such as carbides and RDF are input from the upper end inlet and discharged from the lower end outlet. Is divided into a plurality of stages in the vertical direction, so that the granular material is stored in a state of being divided into storage chambers in each stage. For this reason, it becomes easy to ensure a heat radiation area, and it can prevent thermal runaway inside. In particular, if a floor plate or the like that partitions the inside of the storage tank body is structured to be cooled, thermal runaway can be prevented more reliably. And since nitrogen gas like patent document 1 is not required, a running cost can be suppressed.

  In addition, since the storage device of the present invention has the storage chambers of each stage formed in upper and lower stages, a large installation area is unnecessary, and the construction cost is suppressed compared to the case where a large number of small storage tanks are installed. And easy to manage. In addition, if the internal temperature rises abnormally, the granular material in the storage chamber of each stage can be quickly discharged from the emergency outlet provided on the side wall of the storage tank body, so avoid the risk of ignition. Can do. The granular material fed from the top loading port is cured in contact with oxygen in the air while sequentially moving through each stage, and can be taken out as a safe product that can be shipped. In addition, by providing a gas supply device that supplies a gas such as air that can serve as an oxygen supply source into the storage tank as needed, an exothermic reaction such as low-temperature oxidation can be promoted and the curing time can be shortened.

Preferred embodiments of the present invention are shown below.
1 and 2 show a first embodiment of the present invention. Reference numeral 1 denotes a vertically long storage tank body for storing powder particles having exothermic reactivity due to low-temperature oxidation or the like, and at the upper end thereof. An input port 2 is provided, and a discharge port 3 is provided at the lower end. The interior of the storage tank body 1 is partitioned into a plurality of stages in the vertical direction by the floor plate 4, and each stage is a storage chamber 5. The floor plate 4 may be horizontal or slightly inclined toward the opening 6 described later. The storage tank body 1 may be circular or square in horizontal section, but in this embodiment is a quadrangle as shown in FIG. The number of stages is arbitrary as long as it is two or more.

  The storage chamber 5 at each stage is provided with an opening 6 for dropping the granular material to the lower stage and a transfer means 7 for moving the granular material to the opening 6. In this embodiment, the transfer means 7 is a plurality of screw conveyors, and the opening 6 is formed at one end of the floor plate 4. It should be noted that the position of the opening 6 is changed for each step so that the granular material does not fall vertically down to two or more steps.

  In addition, the side wall 8 of the storage tank body 1 is provided with an emergency discharge port 9 for quickly discharging the granular material from the storage chamber 5 for each stage. In this embodiment, the emergency discharge port 9 is formed by projecting the transfer end of the screw conveyor in the reverse direction outward. For this reason, when the screw conveyor is rotated forward, the powder particles are transferred toward the opening 6. However, when the screw conveyor is reversed in an emergency, it is transferred toward the emergency discharge port 9, and is simultaneously transferred to the outside from each stage. It becomes possible to discharge.

  The storage device configured in this manner is to sequentially move the granular material charged from the upper inlet 2 toward the lower stage and take it out from the lower outlet 3, during which the granular material is Gradually, an exothermic reaction such as low-temperature oxidation proceeds and is cured. As shown in FIG. 1, since the granular materials are dispersed and stored in the storage chambers 5 of each stage, a large heat radiation area per volume can be secured, and thermal runaway in which the internal temperature rises abnormally is suppressed. , Safe storage is possible. Moreover, since the installation area may be small and the whole is housed in a single storage tank body 1, construction costs can be reduced and managed compared to the case where a large number of small storage tanks are installed. Is easy.

  In addition, if an abnormal rise in internal temperature is detected, the powder conveyors are transferred toward the emergency discharge port 9 by reversing the screw conveyor at each stage, and discharged simultaneously from each stage to the outside. Can do. In this case, the discharge speed is N times or more (N is the number of stages) during normal operation, so that a fire does not occur. Moreover, since it is possible to discharge urgently only from the abnormally elevated section, it is possible to reduce the number of granular materials that lose their value as fuel when cooled by water spraying or the like at the time of discharge.

  As shown in FIG. 3, if the floor plate 4 is provided with a cooling pipe 10 to form a water cooling structure, or the floor plate 4 has a hollow structure capable of air cooling, the heat radiation effect at each stage can be enhanced. It is possible to more reliably prevent thermal runaway in which the internal temperature abnormally rises by suppressing the progress of an exothermic reaction such as oxidation. Moreover, the cooling mechanism can also utilize the screw shaft of a screw feeder, or the rotary blade of a circle feeder.

  Further, as shown in FIG. 4, a level sensor 11, a temperature sensor 12, an oxygen sensor 13, and the like are provided inside the storage tank body 1 to monitor the state of the powder and the temperature of the powder is controlled by the control device 14. If the heating device 15 and the cooling device 16 can be operated, the progress of an exothermic reaction such as low-temperature oxidation can be controlled more reliably. In this case, an electric heater or a steam heating device can be used as the heating device 15, and the above-described water cooling structure or the like can be used as the cooling device 16. Further, it is more preferable that the control device 14 controls the operating speed of the screw feeder or the like as the transfer means 7 so that the moving speed of the powder particles can be controlled. Further, it is more preferable to provide a gas supply device that supplies a gas (for example, air) that is a fresh oxygen supply source because it is possible to promote an exothermic reaction such as low-temperature oxidation.

  In the second embodiment shown in FIG. 5 and subsequent figures, the storage tank body 1 is cylindrical, and the inside thereof is partitioned into upper and lower multistages by the floor plate 4. As shown in FIG. 6, the floor plate 4 is provided with an opening 6 for dropping the granular material to the lower stage and an emergency discharge opening 17. These are all near the outer periphery of the floor plate 4. A rotating shaft 18 is provided at the center of the storage tank body 1, and a rotating blade 19 that rotates at a position immediately above the floor plate 4 of each stage is provided on the rotating shaft 18. The rotary blade 19 includes a number of feed plates 20 inclined on the lower surface thereof, and the lower surface of each feed plate 20 reaches a position close to the floor plate 4. The feed plate 20 has an angle at which the granular material is moved in the outer circumferential direction when the rotary blade 19 rotates forward.

  For this reason, when the rotating shaft 18 is rotated, the granular material at each stage is pushed in the outer circumferential direction by the feed plate 20 and falls from the opening 6 to the lower stage. The emergency discharge opening 17 is connected to a chute-type emergency discharge port 21 that extends through the side wall 8 of the storage tank body 1 to the outside. The emergency discharge port 21 is normally closed by a valve 22 that can be opened and closed. However, when an abnormal rise in the internal temperature is detected, if the emergency discharge port 21 is opened at each stage by the valve 22, the powder particles dropped from the opening 17 are discharged from the emergency discharge port 21 at each stage all at once. The Also during this time, the rotating shaft 18 is rotated to promote the discharge of the granular material. Moreover, the valve | bulb 24 which closes at the time of abnormality is installed in the opening 6, and it can prevent that an abnormal granular material falls to the lower division. The valve 22 and the valve 23 may be a switching damper having an integral structure.

  If the number of stages is large, it may be difficult to rotate all the rotary blades 19 by a single motor 23. In that case, the rotating shaft 18 may be divided into upper and lower parts and each may be driven by a separate motor.

  Also in the storage device of the second embodiment, the granular material introduced from the upper inlet 2 is sequentially moved from the upper stage toward the lower stage and taken out from the lower outlet 3. Heat treatment such as low-temperature oxidation progresses and is cured, thermal runaway that abnormally increases the internal temperature is suppressed, safe storage is possible, installation area is small, and management is easy In addition, when an abnormal increase in the internal temperature is detected, it is all the same as in the first embodiment described above that the powder particles can be discharged from each stage all at once. Further, as shown in FIG. 7, it is the same as in the first embodiment that a floor plate 4 cooling structure or a control mechanism as shown in FIG. 4 can be incorporated.

  As described above, the storage device of the present invention gradually proceeds to low-temperature oxidation etc. while safely storing carbides made of waste as raw materials and powders having exothermic reactivity due to low-temperature oxidation such as RDF. Curing can be performed, and the discharged granular material can be immediately transported to the user as a safe product.

It is a longitudinal cross-sectional view which shows 1st Embodiment. It is a horizontal sectional view which shows a transfer means. It is a longitudinal cross-sectional view which shows a modification. It is a longitudinal cross-sectional view which shows another modification. It is a longitudinal cross-sectional view which shows 2nd Embodiment. It is a horizontal sectional view which shows a transfer means. It is a longitudinal cross-sectional view which shows a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reservoir body 2 Input port 3 Discharge port 4 Floor board 5 Storage chamber 6 Opening 7 Transfer means 8 Side wall 9 Emergency discharge port 10 Cooling pipe 11 Level sensor 12 Temperature sensor 13 Oxygen sensor 14 Control device 15 Heating device 16 Cooling device 17 Emergency discharge Opening 18 Rotating shaft 19 Rotating blade 20 Feed plate 21 Emergency discharge port 22 Valve 23 Motor 24 Valve

Claims (5)

  The interior of the vertically long storage tank body provided with the inlet at the upper end and the outlet at the lower end is partitioned into a plurality of stages in the vertical direction, and each stage is used as a storage chamber for exothermic reactive powder. The storage chamber is provided with an opening for dropping the granular material to the lower stage, and a transfer means for moving the granular material to the opening. Further, on the side wall of the storage tank body, the granular material is supplied from the storage chamber of each stage. An apparatus for storing granular material having exothermic reactivity, characterized in that an emergency discharge port for rapid discharge is provided.   2. The granular material storage device according to claim 1, wherein the transfer means is a screw feeder, and an emergency discharge port is provided at a transfer end in the reverse direction.   2. The granular material storage apparatus according to claim 1, wherein the transfer means is a rotary blade of a circle feeder, and a chute-type emergency discharge port that can be opened and closed is provided on a side wall of the storage tank body.   The granular material according to claim 2, wherein at least one of a floor plate partitioning the inside of the storage tank body, a screw shaft of a screw feeder, and a rotary blade of a circle feeder has a cooling structure. Storage device.   2. The granular material storage device according to claim 1, wherein a temperature sensor for the granular material, a temperature control means for the granular material, and a speed control means for the transfer means are provided in the storage tank body.

Images