U.S. patent application number 12/091878 was filed with the patent office on 2008-11-20 for dust recycling and re-treating system and method for the dust generated from hazardous waste melting process.
Invention is credited to Jong Ho Bae, Jong Seo Choi, Seok Mo Choi, Seung Chul Daejeon, Tae Won Hwang, Choong Keun Kim, Sang Woon Shin, Young Hwan You.
Application Number | 20080282943 12/091878 |
Document ID | / |
Family ID | 38006040 |
Filed Date | 2008-11-20 |
United States Patent
Application |
20080282943 |
Kind Code |
A1 |
Bae; Jong Ho ; et
al. |
November 20, 2008 |
Dust Recycling and Re-Treating System and Method for the Dust
Generated from Hazardous Waste Melting Process
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.
Inventors: |
Bae; Jong Ho; (Seongnam,
KR) ; You; Young Hwan; (Suwon, KR) ; Kim;
Choong Keun; (Ulsan, KR) ; Choi; Jong Seo;
(Seoul, KR) ; Shin; Sang Woon; (Daejeon, KR)
; Hwang; Tae Won; (Daejeon, KR) ; Daejeon; Seung
Chul; (Daejeon, KR) ; Choi; Seok Mo; (Daejeon,
KR) |
Correspondence
Address: |
IPLA P.A.
3580 WILSHIRE BLVD., 17TH FLOOR
LOS ANGELES
CA
90010
US
|
Family ID: |
38006040 |
Appl. No.: |
12/091878 |
Filed: |
October 26, 2006 |
PCT Filed: |
October 26, 2006 |
PCT NO: |
PCT/KR06/04390 |
371 Date: |
April 28, 2008 |
Current U.S.
Class: |
110/215 |
Current CPC
Class: |
F23G 7/00 20130101; F23G
2201/70 20130101; F23G 2209/30 20130101; F23G 5/085 20130101; F23G
2202/20 20130101 |
Class at
Publication: |
110/215 |
International
Class: |
F23J 15/00 20060101
F23J015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 3, 2005 |
KR |
10-2005-0104901 |
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.
Description
TECHNICAL FIELD
[0001] 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
[0002] 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.
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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
[0008] 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.
[0009] 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.
[0010] 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
[0011] 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 re-treat 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.
[0012] 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.
[0013] 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
[0014] 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.
[0015] 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.
[0016] Secondly, dusts subjected to a difficult separate treatment
can be recycled and re-treated within an existing melting
furnace.
[0017] 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.
[0018] 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.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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.
[0026] 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.
[0027] 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
[0028] FIG. 1 is a schematic structure of a system of recycling and
re-treating dusts in accordance with embodiments of the present
invention.
[0029] FIG. 2 is a flow chart of a method of recycling and
re-treating dusts in accordance with embodiments of the present
invention.
REFERENCE NUMERALS
[0030] 10: dust collection unit 12: housing
[0031] 14: rotary valve 20: dust transport unit
[0032] 22: transport screw 24: first coupling pipe
[0033] 30: dust measurement unit 32: measurement hopper
[0034] 34: first adjustment valve 36: discharge pipe
[0035] 40: slurry production unit 42: production hopper
[0036] 44,64,82: stirrer 46: first discharge valve
[0037] 50: slurry transport unit 52: transport pump
[0038] 53: second coupling pipe 54: third coupling pipe
[0039] 57: fifth adjustment valve 58: first return pipe
[0040] 59: first return valve 60: slurry storing unit
[0041] 62: storing hopper 66: second discharge valve
[0042] 70: slurry feed unit 72: feed pump
[0043] 73: fourth coupling pipe 74: fifth coupling pipe
[0044] 75: fifth adjustment valve 76: sixth adjustment valve
[0045] 78: nitrogen injection unit 80: slurry pre-storing unit
[0046] 81: pre-storing hopper 83: sixth coupling pipe
[0047] 84: seventh coupling pipe 85: second return pipe
[0048] 86: third discharge valve 87: fourth discharge valve
[0049] 88: seventh adjustment valve 89: second return valve
[0050] 90: melting furnace 100: water supply pipe
[0051] 102: water adjustment valve
[0052] S10: step of collecting the dusts
[0053] S20: step of transporting the dusts
[0054] S30: step of measuring the dusts
[0055] S40: step of producing the slurry
[0056] S50: step of transporting the slurry
[0057] S60: step of storing the slurry
[0058] S70: step of feeding the slurry
[0059] S80: step of pre-storing the slurry
BEST MODE FOR CARRYING OUT THE INVENTION
[0060] Hereinafter, preferred embodiments of the present invention
will be described in detail with reference to accompanying
drawings.
[0061] FIG. 1 is a schematic structure of a system of recycling and
re-treating dusts in accordance with embodiments of the present
invention.
[0062] 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.
[0063] 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.
[0064] In this case, the slurry treatment device preferably further
includes a slurry pre-storing unit 80.
[0065] 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.
[0066] 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.
[0067] 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.
[0068] The collected dusts are delivered to the dust transport unit
20 through the rotary valve 14 mounted below the housing 12.
[0069] 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.
[0070] 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.
[0071] 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.
[0072] 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.
[0073] 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.
[0074] 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.
[0075] 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.
[0076] 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.
[0077] 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.
[0078] 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.
[0079] 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.
[0080] The amount of supplying the water is always set to be fixed
and supplied.
[0081] 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.
[0082] 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.
[0083] 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.
[0084] At least two transport pumps 52 are preferably disposed in
terms of redundancy.
[0085] 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.
[0086] 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.
[0087] 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.
[0088] The first return pipe 58 is used for effectively and
uniformly mixing the dusts with the water at the time of producing
the slurry.
[0089] 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.
[0090] 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.
[0091] 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.
[0092] 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.
[0093] 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.
[0094] The second discharge valve 66 is mounted below the storing
hopper 62 to couple/ disengage the hopper with/from the slurry feed
unit 70.
[0095] 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.
[0096] 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.
[0097] 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.
[0098] 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.
[0099] 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.
[0100] 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.
[0101] 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.
[0102] 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.
[0103] The melting furnace 90 acts to melt dusts and wastes, and is
preferably a glass solidification melting furnace.
[0104] 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.
[0105] 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.
[0106] 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.
[0107] 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.
[0108] 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.
[0109] 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.
[0110] 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.
[0111] 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.
[0112] 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.
[0113] 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.
[0114] A controller (not shown) is mounted to control each of the
above-described components in the present invention.
[0115] FIG. 2 is a flow chart of a method of recycling and
re-treating the dusts in accordance with embodiments of the present
invention.
[0116] The method of recycling and re-treating the dusts of the
present invention includes a step of collecting the dusts S10, a
step of producing the slurry S40, and a step of feeding the slurry
S70.
[0117] 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 S10 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.
[0118] In addition, the method preferably further includes a step
of pre-storing the slurry S80.
[0119] The step of collecting the dusts S10 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.
[0120] 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.
[0121] 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.
[0122] In this case, when the water containing ratio of the slurry
of 80 wt % or higher is an appropriate concentration, the one-time
maximum treatment amount of the dust corresponds to 20 kg when the
water of 80 kg is supplied in the step of producing the slurry
S40.
[0123] 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.
[0124] 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.
[0125] 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 the step
of storing the slurry S60 when the condition is not less than the
predetermined value.
[0126] 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 S80 when the input is present, and
transports it to the step of feeding the slurry S70 when the input
is not present.
[0127] 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.
[0128] In addition, the step of feeding the slurry S70 may feed the
slurry only or may continuously feed the slurry along with the
waste.
[0129] Hereinafter, an operation procedure of the present invention
will be described in detail.
[0130] 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.
[0131] 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.
[0132] 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.
[0133] 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.
[0134] 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.
[0135] 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.
[0136] After it is confirmed that the production hopper 42 is
empty, the transport pump 52 is stopped.
[0137] 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.
[0138] 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.
[0139] 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.
[0140] 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.
[0141] The above-described operations are repeatedly carried out to
transport the slurry to the slurry storing unit 60.
[0142] 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.
[0143] 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.
[0144] 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.
[0145] 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.
[0146] 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.
[0147] 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.
[0148] 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
[0149] 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.
* * * * *