EP1952062A1

EP1952062A1 - Dust recycling and re-treating system and method for the dust generated from hazardous waste melting process

Info

Publication number: EP1952062A1
Application number: EP06812232A
Authority: EP
Inventors: Jong Ho Bae; Young Hwan You; Choong Keun Kim; Jong Seo Choi; Sang Woon Shin; Tae Won Hwang; Seung Chul Park; Seok Mo Choi
Original assignee: Rotem Co
Current assignee: Korea Hydro and Nuclear Power Co Ltd; Hyundai Rotem Co
Priority date: 2005-11-03
Filing date: 2006-10-26
Publication date: 2008-08-06
Also published as: US20080282943A1; WO2007052919A1; KR20070047965A; KR100779879B1

Abstract

The present invention relates to a dust recycling and re-treating system and a method for the same, and in particular, to a dust recycling and re-treating system and a method for the same, which produces dusts generated from an incinerating and melting processing equipment for hazardous wastes, particularly, radioactive wastes, in a slurry form, and recycles and re-treats them within an existing melting furnace.

Description

DUST RECYCLING AND RE-TREATING SYSTEM AND METHOD FOR THE DUST GENERATED FROM HAZARDOUS

WASTE MELTING PROCESS

Technical Field

[1] The present invention relates to a dust recycling and re-treating system and a method for the same, and in particular, to a dust recycling and re-treating system and a method for the same, which produces dusts generated from an incinerating and melting equipment for hazardous wastes, particularly, radioactive wastes, in a slurry form, and recycles and re-retreats them within an existing melting furnace. Background Art

[2] Solid phase and liquid phase particles such as unburned carbon, lime, heavy metal or the like are contained in an off-gas when hazardous wastes are incinerated or molten (e.g., glass solidified) as it is generally done in a waste incinerating furnace and/or a waste melting furnace.

[3] In order to treat these particles (i.e., dusts), they are first separated from gaseous materials within the off-gas and then collected, and at this time, wasted residuals generated from a dust collection device such as a high temperature ceramic filter or the like, that is, dusts (e.g., bottoms ashes and fly ashes) need to be separately treated as a secondary waste.

[4] In particular, radioactivity is contained within the dusts which are generated at the time of treating radioactive wastes, so that a separate solidification process is required instead of a general burial process.

[5] The hazardous waste also requires a suitable solidification process to be carried out because of environmental contamination due to eluted hazardous components such as various heavy metals within the dust.

[6] The solidification process includes a cement solidification process, a paraffin solidification process, and so forth, however, which is inadvantageous in terms of damage due to contained moistures, volume reduction, and physical hardness of the solidified material itself during the process.

[7] A glass solidification method is suitable for a melting solidification method which obtains a sufficient volume reduction while stabilizing generated dusts. Disclosure of Invention Technical Problem

[8] The conventional incinerating and melting processing apparatus for radioactive wastes and the method for the same are disclosed in Korean Patent Publications No. 2001-26585 and 2003-94612.

[9] However, according to the conventional art, the dusts were separately solidified or hermetically sealed, which caused a volume reduction of the corresponding melting equipment to decrease and made long-term management difficult.

[10] In particular, it is very difficult to treat dusts due to the flying property of the dusts in the case of radioactive wastes. A separate treatment equipment is required to treat the dusts, which increases a cost and a complexity of the associated apparatus and also causes an economical efficiency to decrease in terms of leach stability and volume reduction when the dusts are treated by the existing cement solidification process or the like. Technical Solution

[11] Embodiments of the present invention provide a dust recycling and re-treating system and a method for the dust generated from a hazardous waste melting process, which collects dusts generated from an incinerating and melting equipment for hazardous wastes, in particular, radioactive wastes, and produces them in a slurry form and transport them into a melting furnace for melting and solidifying the dusts to retreat the dusts, so that a volume reduction ratio of the corresponding equipment increases, the hazardous wastes are not separately treated, and the dusts are transformed into a stabilized solid phase material by the existing melting equipment to enhance stability and economical efficiency.

[12] In one aspect, the invention is directed to a system of recycling and re-retreating dusts generated from an incinerating and melting equipment for hazardous waste, which includes a dust collection device of separating and collecting dusts from an off- gas generated in the incinerating and melting equipment; a slurry production device of mixing the dusts collected from the dust collection device with a water to produce a slurry; and a slurry treatment device of feeding the slurry produced by the slurry production device to an existing melting furnace for treatment.

[13] In another aspect, the invention is directed to a method of recycling and re-treating dusts generated from an incinerating and melting equipment for hazardous waste, which includes separating and collecting dusts from an off-gas generated in the incinerating and melting equipment; mixing the dusts with a water to produce a slurry; and feeding the slurry to an existing melting furnace.

Advantageous Effects

[14] According to a system of recycling and re-treating dusts generated from an incinerating and melting equipment for hazardous waste and a method for the same, the following effects are obtained. [15] Firstly, dusts generated from the incinerating and melting equipment for hazardous waste are collected, and then produced and transported in a slurry form to be recycled and re-treated within a melting furnace capable of melting and solidifying the dusts, so that a volume reduction of the corresponding equipment can be enhanced, and the hazardous wastes need not to be separately treated and can be transformed into a stable solid form by an existing melting equipment to enhance stability and economical efficiency.

[16] Secondly, dusts subjected to a difficult separate treatment can be recycled and retreated within an existing melting furnace.

[17] Water can be used for recycling to easily produce the slurry and adjust its concentration. In addition, the dusts can be produced in a slurry form so that transport and feed thereof can be facilitated. A feed rate of the slurry can be adjusted in accordance with a condition of the melting furnace, and a fixed amount of the slurry can be fed in accordance with the adjustment.

[18] In a case of a melting furnace, in particular, a glass solidification melting furnace, this is suitable for treating the slurry, which may simultaneously treat the corresponding waste and the slurry or may treat the slurry only. In the case of the glass solidification melting furnace, main components of the glass, that is, boron (B), lithium (Li), natrium (Na), or the like, are contained within generated dusts by volatilization or the like resulted from a high temperature treatment. When these main components are kept to be volatilized and deviated from the molten glass, the glass viscosity gradually increases and the solubility with respect to an inorganic material within the waste decreases to affect a stable drive, e.g., to cause the discharge of the molten glass to be difficult. In this case, when the generated dusts are recycled in a slurry form to be supplied into the melting furnace, constitutional components within a molten glass pool can be constantly kept. When the components within the molten glass pool are kept constant in drive, the overall drive status can be predicted and the discharge of the molten glass can be facilitated.

[19] In addition, in a case of a radioactive slurry, it contains radionuclides such as cesium (Cs), cobalt (Co), or the like, which can be recycled in the same way as described above to be supplied into the melting furnace so that radioactive dusts can be treated by the existing melting furnace without requiring a separate treatment equipment. The present invention allows the slurry containing these elements to be repeatedly recycled and re-treated.

[20] Thirdly, a remote drive applying an automatic drive concept is possible in terms of drive/maintenance. In addition, harmless water is used to produce the slurry so that the dusts can be safely controlled. When radioactive dusts are treated for maintenance, internal dusts are transported to a production unit when an operator has an access to a measurement unit, and are transported to a storing unit when the operator has an access to the production unit. The dusts are transported again to a pre- storing hopper when the operator has an access to the storing unit, and the pre-storing hopper is coupled with a transport unit so that the slurry of the pre-storing hopper can be transported to the storing unit again. As such, the recycling structure can minimize radioactive bombardment resulting from radioactive materials at the time of operator access.

[21] Incinerated residuals of the radioactive dusts or the hazardous wastes cannot be buried in terms of dust treatment. A conventional cement solidification, a chemical treatment, or the like, does not have a sufficient effect on volume reduction, and radionuclides or heavy metals may be leached out over a long period of time so that it is dangerous to perform these methods. In contrast, when a melting solidification method, in particular, a glass solidification melting treatment is applied for the device of the present invention, dusts can be treated to be significantly good solids in terms of volume reduction, and physical and chemical stability of the solids.

[22] Fourthly, the present invention uses waters for treating the generated dusts, so that the device structure is simple and production, transport, feed, and so forth of the slurry is facilitated. In addition, the dusts can be flexibly treated within a suitable range of the slurry concentration even when the amount of the generated dusts is not constant.

[23] A stirrer mounted in a production hopper is first used to mix dusts with waters at the time of producing the slurry, however, the present invention has a recycling function using a first return pipe of a slurry transport unit before the slurry is transported in order to uniformly and completely mix them. That is, a transport pump is operated after a first discharge valve below the production hopper and a first return valve are opened to have a repeating section of the production hopper-transport pump- first return pipe until the slurry is sufficiently mixed. By doing so, the slurry sufficient enough to be transported is produced. In addition, when an adding material for adjusting a function of the slurry needs to be fed to the slurry at the time of producing the slurry, a material adding unit can be mounted on the production hopper so that the feed of the adding material can be facilitated.

[24] An automatic drive ranging from dust collection and measurement to slurry production and transport is possible so that the drive is facilitated. The slurry can be continuously and smoothly fed into a melting furnace at any time when the condition of the melting furnace is ready.

[25] Fifthly, a suitable concentration of the slurry can be set to prevent the slurry from being deposited within a pipe so that the pipe can be prevented from being declogged in drive. In addition, a production hopper, a transport pump, and a coupling pipe, which might have the most contaminations due to the dusts, can be flushed by supplied waters because of their structures after the slurry is produced, so that they can be kept clean. A nitrogen injection unit can also be mounted at an end of a slurry feed line within a melting furnace to prevent the pipe from being clogged. [26] Sixthly, when the device of the present invention is coupled with an existing melting equipment, the existing melting equipment can be used to make the dusts molten solids having a chemically and physically good stability and the entire waste volume reduction of the corresponding melting equipment can be enhanced to reduce its treatment cost. [27] Seventhly, the present invention provides a simple equipment compared to other methods, and utilizes a melting furnace equipment without requiring a separate high temperature process, thereby having a simple dust treatment.

Brief Description of the Drawings [28] FIG. 1 is a schematic structure of a system of recycling and re-treating dusts in accordance with embodiments of the present invention. [29] FIG. 2 is a flow chart of a method of recycling and re-treating dusts in accordance with embodiments of the present invention. [30] [Reference Numerals]

[31] 10: dust collection unit 12: housing

[32] 14: rotary valve 20: dust transport unit

[33] 22: transport screw 24: first coupling pipe

[34] 30: dust measurement unit 32: measurement hopper

[35] 34: first adjustment valve 36: discharge pipe

[36] 40: slurry production unit 42: production hopper

[37] 44,64,82: stirrer 46: first discharge valve

[38] 50: slurry transport unit 52: transport pump

[39] 53: second coupling pipe 54: third coupling pipe

[40] 57: fifth adjustment valve 58: first return pipe

[41] 59: first return valve 60: slurry storing unit

[42] 62: storing hopper 66: second discharge valve

[43] 70: slurry feed unit 72: feed pump

[44] 73: fourth coupling pipe 74: fifth coupling pipe

[45] 75: fifth adjustment valve 76: sixth adjustment valve

[46] 78: nitrogen injection unit 80: slurry pre-storing unit

[47] 81: pre-storing hopper 83: sixth coupling pipe

[48] 84: seventh coupling pipe 85: second return pipe

[49] 86: third discharge valve 87: fourth discharge valve

[50] 88: seventh adjustment valve 89: second return valve

[51] 90: melting furnace 100: water supply pipe [52] 102: water adjustment valve

[53] SlO: step of collecting the dusts

[54] S20: step of transporting the dusts

[55] S30: step of measuring the dusts

[56] S40: step of producing the slurry

[57] S50: step of transporting the slurry

[58] S60: step of storing the slurry

[59] S70: step of feeding the slurry

[60] S80: step of pre-storing the slurry

Best Mode for Carrying Out the Invention

[61] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to accompanying drawings.

[62] FIG. 1 is a schematic structure of a system of recycling and re-treating dusts in accordance with embodiments of the present invention.

[63] The present invention produces dusts in a slurry form to feed them into the existing melting furnace for treatment, and mainly includes a dust collection device of separating and collecting dusts from an off-gas generated from an incinerating and melting equipment for hazardous waste (in particular, radioactive waste), a slurry production device of mixing the dusts collected from the dust collection device with a water to produce the slurry, and a slurry treatment device of feeding the slurry produced by the slurry production device to the existing melting furnace for treatment.

[64] As shown in FIG. 1, the dust collection device includes a dust collection unit 10, a dust transport unit 20, and a dust measurement unit 30, the dust production device is composed of a slurry production unit 40 and a slurry transport unit 50, and the slurry treatment device is composed of a slurry storing unit 60, a slurry feed unit 70, a nitrogen injection unit 78, and a melting furnace 90.

[65] In this case, the slurry treatment device preferably further includes a slurry pre- storing unit 80.

[66] The dust collection unit 10 acts to separate and collect dusts from an off-gas, and is composed of a housing 12, a dust collection filter (not shown), a declogging unit (not shown), and a rotary valve 14.

[67] The housing 12 has a funnel shape for effectively collecting dusts, and a ceramic filter, a bag filter, a metal filter, or the like, is used as the dust collection filter.

[68] Gases are flown out of pores formed in the filters, and dusts are attached on the surface of the filters due to a mechanism such as impact, protection, diffusion, or the like, and then recovered to the housing 12 by an operation of the declogging unit, that is, by periodical declogging using a pressurized air. [69] The collected dusts are delivered to the dust transport unit 20 through the rotary valve 14 mounted below the housing 12. [70] The dust transport unit 20 transports dusts collected by the dust collection unit 10 to the dust measurement unit 30, and is composed of a transport screw 22 and a first coupling pipe 24. [71] The transport screw 22 is operated by a motor, and the first coupling pipe 24 couples the transport screw 22 with the dust measurement unit 30. [72] The dust measurement unit 30 measures the amount of dusts transported from the dust transport unit 20, and is composed of a measurement hopper 32, a first adjustment valve 34, a stirrer (not shown), and a discharge pipe 36. [73] The measurement hopper 32 acts as a storage which stores dusts transported from the dust transport unit 20, a load cell (not shown) is mounted in the measurement hopper 32 to measure the amount of dusts, and the stirrer uses a motor to stir the dusts stored in the measurement hopper 32. [74] The first adjustment valve 34 is mounted below the measurement hopper 32, and may be opened to feed the suitable amount of dusts, that is, the dusts not more than the maximum amount required for producing the slurry, to the slurry production unit 40 through the discharge pipe 36 in regardless of the change in amount of the generated dusts so that the slurry concentration can be adjusted. [75] In other words, the concentration range of the slurry that can be treated is set even when the amount of the generated dusts is not constant, so that the dusts not more than the predetermined maximum amount of the dusts are fed to the slurry production unit

40 within the suitable slurry concentration range in regardless of the change in amount of the generated dusts. [76] By doing so, the dusts not more than the maximum amount of dusts can be always fed to the slurry production unit so that the slurry can be easily produced within the suitable concentration range. [77] The slurry production unit 40 mixes the dusts fed from the dust measurement unit

30 with the water to produce the slurry, and is composed of a production hopper 42, a stirrer 44, a first discharge valve 46, a load cell (not shown), a water gauge (not shown), and so forth. [78] The production hopper 42 acts to contain the dusts and the water, the load cell is mounted in the production hopper 42 to measure the amount of slurry, and the water gauge aids the load cell to measure amounts of the slurry and the water contained in the production hopper 42 in terms of redundancy. [79] In addition, the stirrer 44 uses a motor to stir the dusts and the water stored in the production hopper 42 to be mixed together, and the first discharge valve 46 is mounted below the production hopper 42 and is opened/closed so that it is coupled with the slurry transport unit 50.

[80] In this case, the water supply pipe 100 for supplying the water may be directly coupled with the production hopper 42, however, it is preferably mounted in the second coupling pipe 53 of the slurry transport unit 50 as described later.

[81] The amount of supplying the water is always set to be fixed and supplied.

[82] The amount of generated dusts may be changed in accordance with a combustion condition, a waste feed treating rate, or the like, however, when the range of slurry concentration that can be treated is set, the slurry may be produced within the range in regardless of the change in amount of the generated dusts.

[83] In addition, when an operator needs to have an access for maintenance at the time of treating the radioactive slurry, the produced radioactive slurry is transported to the slurry storing unit 60 in terms of radioactive bombardment management.

[84] The slurry transport unit 50 uses the transport pump 52 such as a diaphragm pump or the like to transport the slurry produced from the slurry production unit 40 to the slurry storing unit 60, and is composed of the transport pump 52, second and third coupling pipes 53 and 54, second, third, and fourth adjustment valves 55, 56, 57, and so forth.

[85] At least two transport pumps 52 are preferably disposed in terms of redundancy.

[86] Second and third adjustment valves 55 and 56 are mounted in respective front and back of the transport pump 52, the second adjustment valve 55 mounted in front of the transport pump 52 is coupled with the first discharge valve 46 of the slurry production unit 40 by the second coupling pipe 53, the third adjustment valve 56 mounted in back of the transport pump 52 is coupled with the slurry storing unit 60 by the third coupling pipe 54, and the fourth adjustment valve 57 is mounted in the third coupling pipe 54.

[87] In this case, the water supply pipe 100 is preferably mounted in the second coupling pipe 53, and a first return pipe 58 linked to an upper portion of the production hopper 42 of the slurry production unit 40 is preferably mounted between the fourth adjustment valve 57 and the transport pump 52 in the third coupling pipe 54.

[88] In addition, a water adjustment valve 102 is mounted in the water supply pipe 100, and a first return valve 59 is mounted in the first return pipe 58.

[89] The first return pipe 58 is used for effectively and uniformly mixing the dusts with the water at the time of producing the slurry.

[90] That is, the dusts are mixed with the water by the stirrer 44 mounted in the production hopper 42 in an initial stage of the slurry production, however, when the slurry is mixed to some extent, the transport pump 52 may operate to make the slurry circulate between the production hopper 42, the second coupling pipe 53, and the first return pipe 58, thereby producing the uniform slurry while the first discharge valve 46, the second adjustment valve 55, the third adjustment valve 56, and the first return valve 59 only are opened. [91] When the slurry is sufficiently and uniformly produced, it is transported by making the fourth adjustment valve 57 open and then making the first return valve 59 closed. [92] In addition, a transparent pipe may be partially mounted or a camera may be mounted on the first return pipe 58 for viewing, so that the mixed condition and transport condition of the slurry may be checked. [93] The slurry storing unit 60 stores the slurry transported from the slurry transport unit

50, and is composed of a storing hopper 62, a stirrer 64, a second discharge valve 66, a load cell, a water gauge, and so forth. [94] The storing hopper 62 acts to store the slurry, and the stirrer 64 is mounted in the slurry to stir the slurry in order to prevent solids within the slurry stored in the storing hopper 62 from being precipitated. [95] The second discharge valve 66 is mounted below the storing hopper 62 to couple/ disengage the hopper with/from the slurry feed unit 70. [96] The load cell is mounted on the storing hopper 62 and measures the amount of slurry stored in the storing hopper 62, and the water gauge aids the load cell to measure the amount of slurry contained in the storing hopper 62 in terms of redundancy. [97] When the slurry stored in the storing hopper 62 is ready to be fed to the melting furnace 90, the second discharge valve 66 is opened to transport the slurry to the slurry feed unit 70. [98] In addition, when an operator needs to have an access for maintenance at the time of treating the radioactive slurry, the stored radioactive slurry is transported to the slurry pre-storing unit 80 in terms of radioactive bombardment management. [99] The slurry feed unit 70 acts to feed a fixed amount of the slurry stored in the slurry storing unit 60 to the melting furnace 90, and is composed of a feed pump 72, fourth and fifth coupling pipes 73 and 74, and fifth and sixth adjustment valves 75 and 76. [100] The feed pump 72 is preferably a tube pump or a mono pump, and at least two feed pumps are preferably disposed in terms of redundancy as applied for the transport pumps 52. [101] Fifth and sixth adjustment valves 75 and 76 are mounted in respective front and back of the feed pump 72, the fifth adjustment valve 75 mounted in front of the feed pump 72 is coupled with the second discharge valve 66 of the slurry storing unit 60 by the fourth coupling pipe 73, and the sixth adjustment valve 76 mounted in back of the feed pump 72 is coupled with the melting furnace 90 by the fifth coupling pipe 74. [102] In this case, the nitrogen injection unit 78 for injecting nitrogen is preferably mounted at the end of the fifth coupling pipe 74 of the slurry feed unit 70. [103] This is to prevent pipes from being clogged due to heat backflow from the melting furnace 90, precipitation of the solid slurry, or the like, so that nitrogen can be injected by the nitrogen injection unit 78 to prevent the pipes from being clogged.

[104] The melting furnace 90 acts to melt dusts and wastes, and is preferably a glass solidification melting furnace.

[105] The slurry pre-storing unit 80 linked with the slurry storing unit 60 acts to temporarily store the slurry, and one side thereof is coupled with the slurry storing unit 60 and the other side is coupled with the slurry transport unit 50.

[106] The slurry pre-storing unit includes the pre-storing hopper 81, the stirrer 82, the sixth and seventh coupling pipes, the second return pipe 85, the third and fourth discharge valves 86 and 87, the seventh adjustment valve 88, and the second return valve 89.

[107] The pre-storing hopper 81 acts as a storage which temporarily stores the slurry stored in the storing hopper 62 of the slurry storing unit 60, and is preferably disposed to be lower than the storing hopper 62 so that the slurry is transported from the storing hopper 62 by free fall.

[108] In addition, the stirrer 82 is mounted within the pre-storing hopper 81, which keeps stirring the slurry to prevent the slurry from being precipitated.

[109] The pre-storing hopper 81 is coupled with the second discharge valve 66 of the slurry storing unit 60 by the sixth coupling pipe 83, and is coupled with the upper portion of the slurry storing unit 60 by the seventh coupling pipe 84.

[110] In this case, the seventh adjustment valve 88 is preferably mounted on the sixth coupling pipe 83 and the third discharge valve 86 is preferably mounted on the seventh coupling pipe 84.

[I l l] The sixth coupling pipe 83 and the seventh adjustment valve 88, as described above, act to transport the radioactive slurry to the pre-storing hopper 81 when the radioactive slurry is stored in the slurry storing unit 60.

[112] The seventh coupling pipe 84 and the third discharge valve 86 act to transport an overflown slurry to the pre-storing hopper 81 when the slurry stored in the storing hopper 62 becomes excessive to cause the overflow.

[113] The fourth discharge valve 87 is mounted below the pre-storing hopper 81, and the fourth discharge valve 87 is coupled with the second coupling pipe 53 of the slurry transport unit 50 by the second return pipe 85.

[114] In this case, a second return valve 89 is preferably mounted on the second return pipe 85 to be close to the second coupling pipe 53, and the second return pipe 85 is preferably disposed behind the water supply pipe 100.

[115] A controller (not shown) is mounted to control each of the above-described components in the present invention.

[116] FIG. 2 is a flow chart of a method of recycling and re-treating the dusts in accordance with embodiments of the present invention.

[117] The method of recycling and re-treating the dusts of the present invention includes a step of collecting the dusts SlO, a step of producing the slurry S40, and a step of feeding the slurry S70.

[118] A step of transporting the dusts S20 and/or a step of measuring the dusts S30 is preferably further included between the step of collecting the dusts SlO and the step of producing the slurry S40, and a step of transporting the slurry S50 and/or a step of storing the slurry S60 is preferably further included between the step of producing the slurry S40 and the step of feeding the slurry S70.

[119] In addition, the method preferably further includes a step of pre-storing the slurry

S80.

[120] The step of collecting the dusts SlO separates and collects the dusts from the off-gas using the above-described dust collection unit 10, the step of transporting the dusts S20 transports the dusts using the dust transport unit 20, and the step of measuring the dust S30 measures the amount of the dusts using the dust measurement unit 30.

[121] The step of measuring the dust S30 sets the concentration range of the slurry that can be treated even when the amount of the generated dusts is not constant to transport the dusts to the step of producing the slurry S40 at any time in a range not more than the predetermined maximum amount of the dusts in regardless of the change in amount of the generated dusts within the slurry concentration range, that is, in regardless of the amount of the generated dusts.

[122] The step of producing the slurry S40 mixes the dusts and the water using the slurry production unit 40 to produce the slurry, the step of transporting the slurry S50 transports the slurry using the slurry transport unit 50, the step of storing the slurry S60 stores the slurry using the slurry storing unit 60, the step of feeding the slurry S70 feeds the stored slurry to the melting furnace 90 using the slurry feed unit 70, and the step of pre-storing the slurry S80 temporarily stores the slurry stored in the step of storing the slurry S60.

[123] In this case, when the water containing ratio of the slurry of 80wt% or higher is an appropriate concentration, the one-time maximum treatment amount of the dust corresponds to 20kg when the water of 80kg is supplied in the step of producing the slurry S40.

[124] That is, the step of measuring the dust S30 transports the dusts to the step of producing the slurry S40 in a range not more than the predetermined maximum treatment amount, and the step S40 mixes the dusts with the water to produce the slurry.

[125] In this case, the amount of water can be kept constant and adjusted in accordance with the amount of dusts to be transported to the step of producing the slurry S40 by the step of measuring the dust S30, so that the concentration of the slurry can be easily controlled.

[126] The step of transporting the slurry S50 determines whether the slurry has a uniformly mixed condition S55, returns the slurry to the step of producing the slurry S40 when the condition is less than a predetermined value, and transports the slurry to t he step of storing the slurry S60 when the condition is not less than the predetermined value.

[127] The step of storing the slurry S60, as described above, determines whether an external input of an operator is present for maintenance, transports the stored slurry to the step of pre-storing the slurry S 80 when the input is present, and transports it to the step of feeding the slurry S70 when the input is not present.

[128] In this case, the step of storing the slurry S60, as described above, determines whether the slurry is excessively stored, transports the excessive amount of the slurry to the step of pre-storing the slurry S80 when the slurry is excessively stored, and transports it to the step of feeding the slurry S70 when the slurry is not excessively stored.

[129] In addition, the step of feeding the slurry S70 may feed the slurry only or may continuously feed the slurry along with the waste.

[130] Hereinafter, an operation procedure of the present invention will be described in detail.

[131] The rotary valve 14 of the dust collection unit 10 and the dust transport unit 20 communicate and operate each other, and all valves are closed.

[132] The dusts are transported to the dust measurement unit 30 by the dust transport unit

20, and the dust measurement unit 30 transports the dusts to the slurry production unit 40 at any time when the amount of the dusts are not more than the predetermined maximum amount of the dusts in regardless of the transported amount of the generated dusts.

[133] The stirrer 44 mounted within the production hopper 42 of the slurry production unit 40 operates, and dusts are fed from the dust measurement unit 30 to be mixed with the water already contained within the production hopper 42.

[134] After it is confirmed that the slurry has the mixed condition, the first discharge valve 46 below the production hopper 42, the second adjustment valve 55, the third adjustment valve 56, and the first return valve 59 mounted on the first return pipe 58 are opened and the transport pump 52 of the slurry transport unit 50 is made to operate so that the slurry is circulated through the production hopper 42, the transport pump 52, and the first return pipe 58 by a pump pressure to be completely and uniformly mixed.

[135] When the slurry has a sufficiently uniform mixed condition, the fourth adjustment valve 57 mounted on the third coupling pipe 54 is opened, and the first return valve 59 is closed to have the transport pump 52 transport the slurry to the slurry storing unit 60. [136] In this case, when the slurry does not have a sufficiently uniform mixed condition, the slurry is continuously circulated through the production hopper 42, the transport pump 52, and the first return pipe 58 so that it is completely and uniformly mixed. [137] After it is confirmed that the production hopper 42 is empty, the transport pump 52 is stopped. [138] The first return valve 59 is opened so that the slurry remaining in the third coupling pipe 54 and the first return pipe 58 are partially recovered to the production hopper 42 by free fall. [139] The fourth adjustment valve 57 and the first discharge valve 46 are closed, and the water supply pipe 100 is opened so that the water is supplied into the production hopper 42 through the second coupling pipe 53, the transport pump 52, and the first return pipe 58. [140] In this case, the slurry remaining in the second coupling pipe 53, the first return pipe 58, the transport pump 52, or the like, can be completely recovered to the production hopper 42 by the supplied water, and these locations can be always kept clean by the supplied water. [141] When a predetermined amount of the water is filled within the production hopper

42, the water supply pipe 100 and the first return pipe 58 are closed. [142] The above-described operations are repeatedly carried out to transport the slurry to the slurry storing unit 60. [143] Meanwhile, the slurry stored in the slurry storing unit 60 is fed to the melting furnace 90 through the fifth coupling pipe 74 by the operation of the feed pump 72 while the seventh adjustment valve 88 is closed and the second discharge valve 66 is opened in the slurry pre-storing unit 80. [144] In this case, when the excessive slurry is accumulated in the slurry storing unit 60, the third discharge valve 86 is opened so that the slurry is stacked in the pre-storing hopper 81 of the slurry pre-storing unit 80 through the seventh coupling pipe 84. [145] The slurry stored in the pre-storing hopper 81 is stored in the slurry storing unit 60 again through the second return pipe 85 and the slurry transport unit 50 by making the fourth discharge valve 87 and the second return valve 89 open. [146] The slurry stored in the slurry storing unit 60 is fed to the melting furnace 90 by the slurry feed unit 70 and treated as described above. [147] In addition, as described above, when an operator needs to have an access to the amount measurement unit for maintenance of the slurry production unit 40 or the slurry storing unit 60 at the time of treating the radioactive slurry, the produced slurry is transported to the slurry storing unit 60 or the stored slurry is transported to the slurry pre-storing unit 80 in terms of radioactive bombardment management. [148] The slurry transported to the slurry pre-storing unit 80 is transported to the slurry transport unit 50 by the second return pipe 85, which is then stored in the slurry storing unit 60. [149] The dust recycling and re-treating system and the method for the dust generated from the incinerating and melting equipment for hazardous wastes are not limited to the above-described embodiments, and may be varied without departing from the spirit of the present invention.

Industrial Applicability [150] The system and the method according to present invention is applicable to recycling and re-treating for the dust generated from the incinerating and melting equipment for hazardous wastes.

Claims

[1] A system of recycling and re-treating dusts generated from an incinerating and melting equipment for hazardous waste, comprising: a dust collection device of separating and collecting dusts from an off-gas generated from the incinerating and melting equipment for hazardous waste; a slurry production device of mixing the dusts collected from the dust collection device with a water to produce a slurry; and a slurry treatment device of feeding the slurry produced by the slurry production device to an existing melting furnace.

[2] The system according to claim 1, wherein the dust collection device comprises: a dust collection unit of separating the dusts from the off-gas and collecting the dusts; a dust transport unit of transporting the dusts collected by the dust collection unit; and a dust measurement unit of measuring the dusts transported from the dust transport unit.

[3] The system according to claim 2, wherein the dust measurement unit feeds the dusts to the slurry production device within a predetermined range of a maximum amount of the generated dusts in regardless of an amount of the dusts.

[4] The system according to claim 1, wherein the slurry production device comprises: a slurry production unit of mixing the dusts fed from the dust collection device with a water to produce a slurry; and a slurry transport unit of transporting the slurry produced from the slurry production unit.

[5] The system according to claim 1, wherein the slurry treatment device comprises: a slurry storing unit of storing the slurry produced by the slurry production device; a slurry feed unit of feeding the slurry stored in the slurry storing unit to the existing melting furnace; and a nitrogen injection unit mounted at an end of the slurry feed unit and injecting the nitrogen.

[6] The system according to claim 5, further comprising: a slurry pre-storing unit of which one end is coupled with the slurry storing unit and temporarily stores the slurry, wherein the other end of the slurry pre-storing unit is coupled between the slurry storing unit and the slurry transport unit.

[7] The system according to claim 4 or claim 6, wherein a transport pump is mounted in the slurry transport unit, a return pipe of returning the slurry from the slurry transport unit to the slurry production unit is mounted, and the slurry is repeatedly circulated by the slurry production unit, the slurry transport unit and the return pipe to be uniformly mixed.

[8] The system according to claim 2, wherein a stirrer is mounted in the dust measurement unit.

[9] The system according to claim 4, wherein a stirrer is mounted in the slurry production unit or the slurry storing unit.

[10] The system according to claim 6, wherein a stirrer is mounted in the slurry pre- storing unit.

[11] The system according to claim 1, wherein the melting furnace is a glass solidification melting furnace.

[12] The system according to claim 4, wherein when a radioactive slurry is treated, the radioactive slurry is transported to the slurry storing unit when an operator has an access to the slurry production unit.

[13] The system according to claim 6, wherein when a radioactive slurry is treated, the radioactive slurry is transported to the slurry pre-storing unit when an operator has an access to the slurry storing unit.

[14] The system according to claim 7, wherein a water supply pipe of supplying the water is mounted in the slurry transport unit, and the water supplied from the water supply pipe is flown into the slurry production unit through the slurry transport unit and the return valve.

[15] A method of recycling and re-treating dusts generated from an incinerating and melting equipment for hazardous waste, comprising: a step of separating dusts from an off-gas generated from the incinerating and melting equipment for hazardous waste and collecting the dusts; a step of mixing the dusts with a water to produce a slurry; and a step of feeding the slurry to an existing melting furnace.

[16] The method according to claim 15, further comprising: between the step of collecting the dusts and the step of producing the slurry, a step of transporting the collected dusts; and a step of measuring the transported dusts.

[17] The method according to claim 16, wherein the step of measuring the dusts feeds the dusts to the step of producing the slurry within a predetermined range of a maximum amount of the generated dusts in regardless of an amount of the dusts.

[18] The method according to claim 15, further comprising: between the step of producing the slurry and the step of feeding the slurry, a step of transporting the produced slurry; and a step of storing the transported slurry.

[19] The method according to claim 18, further comprising: a step of temporarily pre-storing the slurry, wherein it is determined whether an external input of an operator for maintenance is present after the step of storing the slurry, and the stored slurry is delivered to the step of pre-storing the slurry and the step of pre-storing the slurry returns the slurry to the step of transporting the slurry when the external input is present.

[20] The method according to claim 18, wherein the step of transporting the slurry measures whether the slurry has a uniform mixed condition, returns the slurry to the step of producing the slurry when the condition is less than a predetermined value, and transports the slurry to the step of storing the slurry when the condition is not less than the predetermined value.