Sodium Metal Processing System

Abstract

The present invention provides a sodium metal processing system capable of oxidizing sodium metal and treating the same. The sodium metal processing system (10) comprises: a melting furnace (20) for melting sodium metal; a reaction furnace (30) for contacting hot air with sodium metal supplied from the melting furnace (20) to oxidize the sodium metal and discharge oxidation reaction products and exhaust gas; a neutralization tank (40) for introducing exhaust gas and oxidation reaction products and storing treated water fed with oxidation reaction products; and a supply device (50) for supplying a neutralizing agent to the neutralization tank (40).

Description

Technical Field

[0001] The invention relates to a metallic sodium processing system. Background Art

[0002] Patent document 1 describes a waste treatment device for sodium metal, which can treat sodium metal and burn the sodium metal in air to form combustion products so as to not contain unreacted sodium metal. The waste treatment device for sodium metal is characterized in that it comprises: a metal container arranged in a reaction tank to store the sodium metal to be treated; an exhaust side duct connected via a blower that supplies air to the metal container or exhausts air from the metal container; a smoke treatment device connected to the exhaust side duct; and a belt conveyor provided on the metal container.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 58-64129 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The object of the present invention is to provide a sodium metal processing system capable of oxidizing sodium metal and processing the sodium metal.

[0008] Means for solving problems

[0009] Scheme 1 of the present invention is a sodium metal processing system, which comprises: a melting furnace for melting sodium metal; a reaction furnace for bringing hot air into contact with the sodium metal supplied from the melting furnace to oxidize the sodium metal and discharge oxidation reactants and exhaust gases; a neutralization tank into which the oxidation reactants and the exhaust gases are introduced and into which treated water for injecting the oxidation reactants is stored, and a supply device for injecting a neutralizing agent into the neutralization tank.

[0010] The invention described in Scheme 2 is the metallic sodium treatment system described in Scheme 1, wherein the neutralization tank further has a pressure relief valve for releasing internal pressure.

[0011] The invention described in Scheme 3 is the metallic sodium processing system described in Scheme 2, wherein the reaction furnace is a rotary kiln.

[0012] The invention described in claim 4 is the metallic sodium processing system described in claim 2, wherein the reaction furnace has a hot air generating portion for generating hot air and a furnace for bringing the hot air into contact with the metallic sodium.

[0013] The invention described in claim 5 is the metallic sodium processing system described in claim 4, wherein the hot air generating section includes a burner for burning fuel and a hot air chamber in which air is heated by the burner.

[0014] The invention described in claim 6 is the metallic sodium processing system described in claim 5, wherein the hot air chamber covers the furnace and heats the furnace from the outside.

[0015] The invention described in Scheme 7 is a metallic sodium treatment system according to any one of Schemes 2 to 6, wherein the neutralization tank has a partition that separates the upper space inside that is not filled with treated water, and the oxidation reactant is added to one partition separated by the partition, and the neutralizing agent is added to the other partition.

[0016] The invention described in Scheme 8 is a metallic sodium treatment system according to any one of Schemes 2 to 6, wherein the neutralization tank has a first partition and a second partition for separating the interior, and is divided into first to third partitions when viewed from above, the oxidation reactant is added to the first partition, and the neutralizing agent is added to the second partition.

[0017] The invention described in Scheme 9 is the metallic sodium treatment system described in Scheme 7 or 8, wherein the system further comprises a purification device for purifying the exhaust gas introduced from the neutralization tank, and the treated water is supplied from the neutralization tank to the purification device.

[0018] The invention described in Scheme 10 is a metallic sodium treatment system described in Scheme 7 or 8, wherein the system is further provided with a scrubber for purifying the exhaust gas introduced from the neutralization tank, the scrubber having a spray nozzle for spraying the treated water, the treated water being supplied from the third partition, and the treated water that has purified the exhaust gas is returned to the third partition.

[0019] Effects of the Invention

[0020] According to the present invention, it is possible to provide a sodium metal processing system capable of processing sodium metal by oxidizing the sodium metal. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an explanatory diagram showing the structure of a metallic sodium processing system according to one embodiment of the present invention.

[0022] Figure 2 This is an explanatory diagram of a neutralization tank provided in the metallic sodium treatment system, viewed from above. DETAILED DESCRIPTION

[0023] Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention. It should be noted that in the drawings, portions not related to the description may be omitted.

[0024] like Figure 1 As shown, a sodium metal processing system 10 according to an embodiment of the present invention includes a melting furnace 20, a reaction furnace 30, a neutralization tank 40, a supply device 50, and a scrubber 60, and can process sodium metal by oxidizing it.

[0025] The waste metallic sodium is put into the melting furnace 20 .

[0026] The melting furnace 20 includes a heater 202 that can heat the solid sodium metal to, for example, 98° C. or higher to melt the sodium metal.

[0027] The reaction furnace 30 receives the molten sodium metal supplied from the melting furnace 20 and can oxidize the sodium metal by bringing hot air into contact with the sodium metal. Oxidation reaction products and exhaust gas generated by oxidation of the sodium metal are discharged from the reaction furnace 30.

[0028] The reaction furnace 30 is, for example, a rotary kiln. The reaction furnace 30 is made of steel.

[0029] The reaction furnace 30 includes a burner 306 , a hot air chamber 304 , and a furnace 302 .

[0030] The burner 306 is provided adjacent to the hot air chamber 304 , and can heat the air inside the hot air chamber 304 by burning fuel such as kerosene or heavy oil supplied from the outside.

[0031] Air required for the combustion reaction of the burner 306 is sucked in from an air intake port 308 provided in the hot air chamber 304 .

[0032] The hot air chamber 304 is a space for generating hot air by introducing the combustion flame of the burner 306. In order to insulate and protect the components forming the hot air chamber 304 from the combustion flame, a furnace is constructed around the portion where the combustion flame is introduced.

[0033] The hot air chamber 304 is cylindrical and is formed so as to cover the outer side of the outer peripheral surface of the furnace 302. Since the hot air chamber 304 covers the outer peripheral surface of the furnace 302, the furnace 302 is heated from the outside.

[0034] In addition, the burner 306 and the hot air chamber 304 are examples of a hot air generating unit that generates hot air.

[0035] The furnace 302 is a cylindrical furnace extending in one direction, and is driven by a driving device (not shown) and can rotate around a central axis extending in the longitudinal direction. Molten metal sodium is supplied from the melting furnace 20 to one end of the furnace 302. The furnace 302 is tilted so that the neutralization tank 40 is lower. The inner diameter of the furnace 302 is calculated according to the air volume of the hot air, and is set to, for example, 280 mm to 350 mm.

[0036] The interior of the furnace 302 becomes negative pressure due to the blower 426 described later, so the air heated in the hot air chamber 304 is introduced from the hot air chamber 304 into the interior of the furnace 302 through the hot air pipe 310 extending to one end of the furnace 302 to become hot air.

[0037] Therefore, the introduced hot air contacts the metallic sodium inside the furnace 302, whereby the metallic sodium is oxidized to generate sodium oxide and sodium peroxide as oxidation reaction products.

[0038] It should be noted that the hot air that has come into contact with the metallic sodium is exhausted as exhaust gas.

[0039] The neutralization tank 40 is a tank disposed at the other end side of the reaction furnace 30 and at a position lower than the furnace 302. The upper side is covered by a top cover and the treated water is stored inside. The oxidation reaction product and exhaust gas discharged from the reaction furnace 30 are introduced into the neutralization tank 40.

[0040] The neutralization tank 40 includes a first separator 401 , a second separator 402 , and a pressure relief valve 404 .

[0041] The first partition 401 extends downward from the top surface of the neutralization tank 40, and the front end of the first partition 401 is located in the middle of the water level of the treated water. Therefore, the first partition 401 separates the upper space inside the neutralization tank 40 that is not filled with treated water.

[0042] The second partition 402 extends upward from the bottom surface of the neutralization tank 40 , and the front end of the second partition 402 is located in the middle of the water surface height of the treated water.

[0043] like Figure 2 As shown, the neutralization tank 40 is divided into the first partition S1 to the third partition S3 in a plan view by the first partition 401 and the second partition 402. The first partition S1 is a partition on the side of the reaction furnace 30 divided by the first partition 401. The second partition S2 is a partition divided by the first partition 401 and the second partition 402. The third partition S3 is a partition divided by the second partition 402, and is formed on the opposite side of the first partition S1 across the second partition S2.

[0044] In the treated water filling the first partition S1, add Figure 1 The oxidation reaction product is supplied to the reactor 30 shown in the figure. The supplied oxidation reaction product reacts with the moisture in the treated water to form sodium hydroxide, so the pH of the treated water tends to be strongly alkaline.

[0045] The exhaust gas is introduced into the first partition S1 from the reaction furnace 30 . The exhaust gas is blocked by the first partition 401 .

[0046] An exhaust gas pipe 406 for exhausting the exhaust gas is connected to the upper portion of the first partition S1, and a blower 426 is connected to the exhaust gas pipe 406. Therefore, the exhaust gas exhausted from the reaction furnace 30 is sucked by the blower 426, passes through the upper space of the neutralization tank 40 that is not filled with treated water, and is sent to the scrubber 60.

[0047] A neutralizing agent is added to the treated water filling the second partition S2, and the neutralizing agent is used to neutralize the treated water having a pH tending to be strongly alkaline. In addition, a stirrer 408 for stirring the treated water is arranged in the second partition S2.

[0048] The third section S3 is connected to a spray water supply pipe 410 and a circulation water pipe 412 extending to the scrubber 60. In addition, the third section S3 is connected to a water supply pipe 414 for supplying water to the inside of the third section S3.

[0049] The third section S3 is provided with a water level meter 416 for detecting the height position of the water surface of the treated water and a pH meter 418 for measuring the pH of the treated water.

[0050] It should be noted that the second partition 402 that partitions the second section S2 and the third section S3 suppresses the flow of the treated water from one section to the other section.

[0051] The pressure relief valve 404 is provided at the upper portion of the first partition S1 and is a safety valve for relieving abnormally increased pressure inside the neutralization tank 40 in the event that the metallic sodium remaining without being oxidized in the reactor 30 undergoes a violent oxidation reaction.

[0052] The supply device 50 includes a reagent injection tank 502 and a reagent injection pump 504, and can supply a neutralizer for neutralizing the treated water to the neutralization tank 40. The neutralizer is stored in the reagent injection tank 502 and supplied to the second section S2 by the reagent injection pump 504. The neutralizer is, for example, an acid.

[0053] The scrubber (an example of a purification device) 60 is connected to the exhaust gas piping 406, the spray water supply piping 410 and the circulating water piping 412 extending from the neutralization tank 40, and can purify the exhaust gas by wet cleaning. The purified exhaust gas is discharged to the outside from the exhaust pipe 601.

[0054] The scrubber 60 includes a spray nozzle 602 and a packing material 604 .

[0055] The spray nozzle 602 is disposed at the upper portion, and can spray the treated water supplied from the spray water supply pipe 410 as a cleaning liquid downward.

[0056] The filling material 604 is disposed below the spray nozzle 602 to increase the contact area between the cleaning liquid spray and the exhaust gas introduced from below.

[0057] Next, the operation of the sodium metal processing system 10 will be described. The sodium metal processing system 10 operates as follows.

[0058] First, while the furnace 302 rotates, the burner 306 burns fuel supplied from the outside to heat the air in the hot air chamber 304. It should be noted that the temperature inside the hot air chamber 304 is measured by the temperature sensor 312, and based on the measurement data, the controller (not shown) adjusts the combustion amount of the fuel in the burner 306 to control the internal temperature of the hot air chamber 304 to be maintained at, for example, 500°C or above.

[0059] The hot air generated in the hot air chamber 304 is introduced into the interior of the furnace 302 through the hot air pipe 310 .

[0060] Next, the metallic sodium after degreasing is taken out from a storage container (not shown) filled with oil, and a certain amount is added to the melting furnace 20 at a time.

[0061] The metallic sodium introduced into the melting furnace 20 is heated to a temperature higher than the melting point and melted.

[0062] The molten metallic sodium drips into the interior of the furnace 302. As the furnace 302 rotates, the dripping metallic sodium forms a thin film of sodium on the inner surface, maximizing the surface area to be heated.

[0063] The metallic sodium is heated and oxidized by the heat conduction from the hot air chamber 304 and the hot air introduced into the furnace 302 to generate sodium oxide and sodium peroxide. The generated sodium oxide and sodium peroxide fall into the neutralization tank 40.

[0064] On the other hand, hot air that has heated the metallic sodium is discharged as exhaust gas from the reaction furnace 30. The temperature of the exhaust gas is measured by the temperature sensor 314.

[0065] The oxidation reaction product mainly containing sodium oxide and sodium peroxide supplied from the reaction furnace 30 reacts with the moisture in the treated water to generate sodium hydroxide. The pH of the treated water shows strong alkalinity due to the generated sodium hydroxide. The pH of the treated water is measured by the pH meter 418, and the reagent injection pump 504 injects the neutralizer entering the reagent injection tank 502 into the neutralization tank 40 to neutralize the treated water so that the pH of the treated water is neutral.

[0066] The neutralized treated water can be discharged from the drain port 424 when it meets predetermined conditions.

[0067] It should be noted that if the metallic sodium that has not been oxidized in the reactor 30 is added to the treated water, a violent oxidation reaction will occur, and the internal pressure of the neutralization tank 40 will increase. The pressure relief valve 404 can reduce the abnormally increased internal pressure.

[0068] The exhaust gas discharged from the reaction furnace 30 is introduced into the neutralization tank 40. The exhaust gas enters the upper space of the neutralization tank 40 that is not filled with treated water, and is sent to the scrubber 60 through the exhaust gas pipe 406 by the blower 426.

[0069] The exhaust gas introduced into the scrubber 60 is purified by the treated water mist sprayed from the spray nozzle 602 and discharged to the outside through the exhaust pipe 601.

[0070] It should be noted that the treated water mist sprayed from the spray nozzle 602 of the scrubber 60 is supplied by the jet pump 420 through the spray water supply pipe 410. The supplied treated water is sprayed from the spray nozzle 602 to purify the exhaust gas and is accumulated in the lower part of the scrubber 60. The accumulated treated water is sent to the circulating water pipe 412 by the circulating pump 422 and returned to the neutralization tank 40.

[0071] As described above, according to the metallic sodium processing system 10 of the present embodiment, metallic sodium can be oxidized and processed.

[0072] As mentioned above, although embodiment of this invention was described, this invention is not limited to the said form, and the change etc. which do not deviate from the summary belong to the applicable scope of this invention.

[0073] [Explanation of symbols]

[0074] 10. Sodium Metal Processing System

[0075] 20 Melting Furnace

[0076] 30 Reactor

[0077] 40 Neutralization Tank

[0078] 50 Supply device

[0079] 60 Scrubber

[0080] 202 Heater

[0081] 302 Furnace

[0082] 304 Hot air chamber

[0083] 306 Burner

[0084] 308 Air intake

[0085] 310 Hot air pipe

[0086] 312 Temperature Sensor

[0087] 314 Temperature Sensor

[0088] 401 1st separator

[0089] 402 Second separator

[0090] 404 Pressure Relief Valve

[0091] 406 Exhaust gas piping

[0092] 408 Blender

[0093] 410 Spray water supply piping

[0094] 412 Circulating water piping

[0095] 414 Water supply piping

[0096] 416 Water level gauge

[0097] 418 pH meter

[0098] 420 Jet Pump

[0099] 422 Circulation Pump

[0100] 424 Drain

[0101] 426 Blower

[0102] 502 Reagent injection tank

[0103] 504 Reagent injection pump

[0104] 601 Exhaust pipe

[0105] 602 Spray Nozzle

[0106] 604 Filling material

[0107] S1 Partition 1

[0108] S2 Partition 2

[0109] S3 Partition 3

Claims

1. A sodium metal processing system, wherein: The sodium metal processing system comprises: A melting furnace to melt the sodium metal; A rotary kiln for oxidizing the metallic sodium supplied from the melting furnace by contacting hot air with the metallic sodium and discharging oxidation reaction products and exhaust gases; a neutralization tank, the upper side of which is covered by a top cover; and a supply device for feeding a neutralizing agent into the neutralization tank, The oxidation reaction product and the exhaust gas are introduced into the neutralization tank, and the neutralization tank stores treated water into which the oxidation reaction product is introduced.

2. The sodium metal processing system according to claim 1, wherein: The neutralization tank is arranged at a position lower than the rotary kiln.

3. The sodium metal processing system according to claim 1, wherein: The neutralization tank also has a pressure relief valve for releasing the internal pressure.

4. The sodium metal processing system according to claim 3, wherein: The rotary kiln comprises: a hot air generating section for generating hot air; and a furnace for bringing the hot air into contact with the metallic sodium.

5. The sodium metal processing system according to claim 4, wherein: The hot air generating unit comprises: a burner for burning fuel; The air in the hot air chamber is heated by the burner.

6. The sodium metal processing system according to claim 5, wherein: The hot air chamber covers the furnace and heats the furnace from the outside.

7. The sodium metal processing system according to any one of claims 3 to 6, wherein: The neutralization tank has a partition that separates an upper space inside that is not filled with treated water. The oxidation reactant is charged into one partition separated by the partition, and the neutralizing agent is charged into the other partition.

8. The sodium metal processing system according to any one of claims 3 to 6, wherein: The neutralization tank has a first partition and a second partition for partitioning the interior, and the first to third partitions are partitioned in a plan view. The oxidation reactant is introduced into the first partition, The neutralizing agent is added into the second partition.

9. The sodium metal processing system according to claim 7, wherein: The system further includes a purifier for purifying the exhaust gas introduced from the neutralization tank, and the treated water is supplied from the neutralization tank to the purifier.

10. The sodium metal processing system according to claim 8, wherein: The system further includes a purifier for purifying the exhaust gas introduced from the neutralization tank, and the treated water is supplied from the neutralization tank to the purifier.

11. The sodium metal processing system according to claim 8, wherein: The system further comprises a scrubber for purifying the exhaust gas introduced from the neutralization tank. The scrubber has a spray nozzle for spraying the treated water. supplying the treated water from the third partition, The treated water obtained by purifying the exhaust gas is returned to the third partition.

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