CA2036018C - Method and system for handling exhaust gas in a boiler - Google Patents
Method and system for handling exhaust gas in a boilerInfo
- Publication number
- CA2036018C CA2036018C CA 2036018 CA2036018A CA2036018C CA 2036018 C CA2036018 C CA 2036018C CA 2036018 CA2036018 CA 2036018 CA 2036018 A CA2036018 A CA 2036018A CA 2036018 C CA2036018 C CA 2036018C
- Authority
- CA
- Canada
- Prior art keywords
- gas
- exhaust gas
- electrostatic precipitator
- dust
- dry electrostatic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 title claims description 17
- 239000000428 dust Substances 0.000 claims abstract description 79
- 239000012718 dry electrostatic precipitator Substances 0.000 claims abstract description 49
- 238000006477 desulfuration reaction Methods 0.000 claims abstract description 34
- 230000023556 desulfurization Effects 0.000 claims abstract description 34
- 238000011084 recovery Methods 0.000 claims abstract description 26
- 238000001816 cooling Methods 0.000 claims abstract description 10
- 238000011144 upstream manufacturing Methods 0.000 claims abstract description 6
- 238000010438 heat treatment Methods 0.000 claims description 15
- 238000003303 reheating Methods 0.000 claims description 12
- 239000012717 electrostatic precipitator Substances 0.000 abstract description 18
- 239000012719 wet electrostatic precipitator Substances 0.000 abstract description 9
- 239000010440 gypsum Substances 0.000 description 10
- 229910052602 gypsum Inorganic materials 0.000 description 10
- 238000010586 diagram Methods 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 2
- 235000011941 Tilia x europaea Nutrition 0.000 description 2
- 239000004571 lime Substances 0.000 description 2
- 235000019738 Limestone Nutrition 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J15/00—Arrangements of devices for treating smoke or fumes
- F23J15/006—Layout of treatment plant
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
- B03C3/01—Pretreatment of the gases prior to electrostatic precipitation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
- B03C3/01—Pretreatment of the gases prior to electrostatic precipitation
- B03C3/014—Addition of water; Heat exchange, e.g. by condensation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
- B03C3/019—Post-treatment of gases
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
- B03C3/34—Constructional details or accessories or operation thereof
- B03C3/74—Cleaning the electrodes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J2215/00—Preventing emissions
- F23J2215/20—Sulfur; Compounds thereof
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J2217/00—Intercepting solids
- F23J2217/10—Intercepting solids by filters
- F23J2217/102—Intercepting solids by filters electrostatic
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J2219/00—Treatment devices
- F23J2219/60—Sorption with dry devices, e.g. beds
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Electrostatic Separation (AREA)
- Treating Waste Gases (AREA)
- Chimneys And Flues (AREA)
Abstract
In a coal-fired boiler, a heat recovery unit is located upstream of a dry electrostatic precipitator so as to reduce the temperature of exhaust gas at the inlet of the dry electrostatic precipitator and thus, prevent reverse ionization in the electrostatic precipitator.
The heat recovery unit located upstream of the dry electrostatic precipitator will in no way by corroded even if the concentration of dust is reduced in the dry electrostatic precipitator. A desulfurization unit does not require a cooling/dust removing section and eliminates the need for a wet electrostatic precipitator. The dry electrostatic precipitator includes a gas passage divided into a plurality of parallel passages and dampers operable to close the passages. This arrangement prevents dust from being dispersed as a result of hammering without charge.
The heat recovery unit located upstream of the dry electrostatic precipitator will in no way by corroded even if the concentration of dust is reduced in the dry electrostatic precipitator. A desulfurization unit does not require a cooling/dust removing section and eliminates the need for a wet electrostatic precipitator. The dry electrostatic precipitator includes a gas passage divided into a plurality of parallel passages and dampers operable to close the passages. This arrangement prevents dust from being dispersed as a result of hammering without charge.
Description
METHOD AND SYSTEM FOR HANDLING EXHAUST GAS
IN A BOILER
BACKGROUND OF THE INVENTION
1. Field of the Invention The present invention relates to a handling method and system for removing dust and Sox from exhaust gas in a coal-fired boiler.
IN A BOILER
BACKGROUND OF THE INVENTION
1. Field of the Invention The present invention relates to a handling method and system for removing dust and Sox from exhaust gas in a coal-fired boiler.
2. Description of the Related Art Figs. 4 and 5 are block diagrams of conventional systems for removing dust and SOx from exhaust gas in a coal-fired boiler.
With reference first to Fig. 4, a system includes a coal-fired boiler 1. The temperature of exhaust gas from the boiler 1 is reduced to 120 to 160~ in an air preheater 2. Dust is removed from the exhaust gas in a dry electro-static precipitator 4 until its concentration is reduced to about 100 mg/m3N or slightly higher. Heat recovery is effected in a regeneration-type gas-gas heater 7. There-after, the temperature of the exhaust gas is reduced to its saturation temperature in a cooling/dust removing section 6a of a wet desulfurization unit 6, and dust is further removed from the exhaust gas. The concentration of SOx is also reduced in a SOx absorbing section 6b.
Finally, the exhaust gas is reheated in the gas-gas heater 7 and then, directed to a chimney.
20360~8 This prior system suffers from the following problems:
tl) As shown in Fig. 6, the temperature of exhaust gas in the dry electrostatic precipitator is high, and the specific resistance of dust arising from burning of some coals is above 10 1 Q-cm. When the specific resistance of the dust exceeds 1011 Q-cm, reverse ioniza-tion occurs in the electrostatic precipitator. This substantially deteriorates the performance of the electro-static precipitator. To this end, a large electrostatic precipitator is needed to collect dust at a required rate.
(2) If the concentration of dust at the outlet of the electrostatic precipitator is reduced to 100 mg/m3N
or lower, then S03 is atomized while the exhaust gas is being cooled by the gas-gas heater. S03 thus atomized is then deposited in the gas-gas heater. This results in corrosion of the same. It is thus necessary to raise the concentration of dust above 100 mg/m3N so as to neutralize SO3. As a result, the concentration of dust is approxi-mately 20 mg/m3N at the outlet of the desulfurization unit 6. Gas leakage ~approximately 10%) takes place in the gas-gas heater 7. As such, the concentration of dust is reduced only to as low as 30 mg/m N at the inlet of the chimney.
With reference first to Fig. 4, a system includes a coal-fired boiler 1. The temperature of exhaust gas from the boiler 1 is reduced to 120 to 160~ in an air preheater 2. Dust is removed from the exhaust gas in a dry electro-static precipitator 4 until its concentration is reduced to about 100 mg/m3N or slightly higher. Heat recovery is effected in a regeneration-type gas-gas heater 7. There-after, the temperature of the exhaust gas is reduced to its saturation temperature in a cooling/dust removing section 6a of a wet desulfurization unit 6, and dust is further removed from the exhaust gas. The concentration of SOx is also reduced in a SOx absorbing section 6b.
Finally, the exhaust gas is reheated in the gas-gas heater 7 and then, directed to a chimney.
20360~8 This prior system suffers from the following problems:
tl) As shown in Fig. 6, the temperature of exhaust gas in the dry electrostatic precipitator is high, and the specific resistance of dust arising from burning of some coals is above 10 1 Q-cm. When the specific resistance of the dust exceeds 1011 Q-cm, reverse ioniza-tion occurs in the electrostatic precipitator. This substantially deteriorates the performance of the electro-static precipitator. To this end, a large electrostatic precipitator is needed to collect dust at a required rate.
(2) If the concentration of dust at the outlet of the electrostatic precipitator is reduced to 100 mg/m3N
or lower, then S03 is atomized while the exhaust gas is being cooled by the gas-gas heater. S03 thus atomized is then deposited in the gas-gas heater. This results in corrosion of the same. It is thus necessary to raise the concentration of dust above 100 mg/m3N so as to neutralize SO3. As a result, the concentration of dust is approxi-mately 20 mg/m3N at the outlet of the desulfurization unit 6. Gas leakage ~approximately 10%) takes place in the gas-gas heater 7. As such, the concentration of dust is reduced only to as low as 30 mg/m N at the inlet of the chimney.
(3) The desulfurization unit uses lime (limestone) - gypsum method. When gypsum as collected is used, dust mixed therewith deteriorates the quality of the gypsum. In order to maintain the purity of gypsum at a predetermined level, the desulfurization unit must be of so-called twin-tower type including a cooling/dust removing section 6a and an absorbing section 6b. This results in an increase in the consumption of space and the production cost.
With reference next to Fig. 5, there is shown a system adapted to reduce the concentration of dust to for example, 10 mg/m3N. This system includes a leak-free type gas-gas heater wherein heat exchange is effected through a heating medium. The system is different from the system of Fig. 4 in that a heat recovery section 3a is separated from a reheater section 3b, and a wet electrostatic pre-cipitator 8 is located downstream of the purifier 6.
However, this system suffers from the problems (1) and (3).
A more critical problem of this system is that the wet electrostatic precipitator 8 consumes larger space and results in an increase in the production cost of the system.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a system for handling exhaust gas which is able to solve the foregoing problems encountered 20360~8 in the prior art and meet the following needs:
(l) A dry electrostatic precipitator can main-tains its high performance regardless of types of coals to be used and can be made compact.
(2) Those units located downstream of the dry electrostatic precipitator should not be adversely affected if the concentration of dust is approximately below 100 mg/m3N at the outlet of the dry electrostatic precipitator.
(3) The concentration of dust at the inlet of the desulfurization unit can be reduced to the extent that the quality of the gypsum is maintained at a predetermined level if dust is mixed with the gypsum as collected in a single-tower type desulfurization unit wherein the gas cooling/dust removing section and the absorbing section are integrated together.
With reference next to Fig. 5, there is shown a system adapted to reduce the concentration of dust to for example, 10 mg/m3N. This system includes a leak-free type gas-gas heater wherein heat exchange is effected through a heating medium. The system is different from the system of Fig. 4 in that a heat recovery section 3a is separated from a reheater section 3b, and a wet electrostatic pre-cipitator 8 is located downstream of the purifier 6.
However, this system suffers from the problems (1) and (3).
A more critical problem of this system is that the wet electrostatic precipitator 8 consumes larger space and results in an increase in the production cost of the system.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a system for handling exhaust gas which is able to solve the foregoing problems encountered 20360~8 in the prior art and meet the following needs:
(l) A dry electrostatic precipitator can main-tains its high performance regardless of types of coals to be used and can be made compact.
(2) Those units located downstream of the dry electrostatic precipitator should not be adversely affected if the concentration of dust is approximately below 100 mg/m3N at the outlet of the dry electrostatic precipitator.
(3) The concentration of dust at the inlet of the desulfurization unit can be reduced to the extent that the quality of the gypsum is maintained at a predetermined level if dust is mixed with the gypsum as collected in a single-tower type desulfurization unit wherein the gas cooling/dust removing section and the absorbing section are integrated together.
(4) The concentration of dust can be reduced below 10 mg/m N at the inlet of a chimney without the need for a wet electrostatic precipitator.
In order to achieve the foregoing objects, the present invention provides a method for handling exhaust gas in a boiler which comprises the steps of cooling exhaust gas from a coal-fired boiler to a temperature of between 80 and 110~ by an air preheater and a heat recovery unit, reducing the concentration of dust to as high as 100 mg/m3N by a dry electrostatic precipitator, and ~' Z036018 introducing the exhaust gas to a desulfurization unit so as to reduce SOx.
According to the present invention, there is also provided a system for handling exhaust gas in a boiler which comprises a gas flue of a coal-fired boiler in which an air heater, a heat recovery unit, a dry electrostatic precipitator, and a desulfurization unit are provided in that order, the dry electrostatic precipitator including a gas passage divided into a plurality of parallel passages, and dampers provided in said parallel passages respectively and operable to inhibit exhaust gas flow therethrough.
In the present invention, the heat recovery unit is located upstream of the dry electrostatic precipi-tator so as to reduce the temperature of exhaust gas to 80 to 110~ at the inlet of the electrostatic precipitator.
This results in a corresponding decrease in the specific resistance of dust and thus, prevents reverse ionization in the electrostatic precipitator and improves the per-formance of the dry electrostatic precipitator. With this arrangement, the heat recovery unit is not suffer from corrosion due to SO3 if the concentration of dust is reduced to 100 mg/m3N in the electrostatic precipitator, because the heat recovery unit is not located downstream of the dry electrostatic precipitator. Since the dry electrostatic precipitator is able to substantially reduce ~ 8 ~!
the concentration of dust, the desulfurization unit does not require a cooling/dust removing section and can be of the single-tower type. Also, a wet electrostatic precipitator is unnecessary.
Accordingly, in one of its aspects, the present invention relates to a system for handling exhaust gas in a coal-fired boiler, said system comprising: an air preheater of the boiler, a leak free type of gas-gas heater having a heat recovery section and a reheating section through which heating medium is circulated, a dry electrostatic precipitator, and a desulfurization unit all disposed in a gas flue of the boiler, said air preheater being disposed at an upstream location in the gas flue so as to reduce the temperature of the exhaust gas to a predetermined temperature, the heat recovery section of said gas-gas heater being disposed downstream of said air preheater in the gas flue so as to further reduce the temperature of the exhaust gas, said dry electrostatic precipitator being disposed downstream of said heat recovery section in the gas flue so as to reduce the concentration of dust in the exhaust gas to a predetermined level, said desulfurization unit being disposed downstream of said dry electrostatic precipitator in the gas flue so as to reduce the concentration of SOx in the exhaust gas and further reduce the temperature thereof and the concentration of dust therein, and the reheating section ~ ~ 3 ~
of said gas-gas heater being disposed downstream of said desulfurization unit in the gas flue so as to reheat the exhaust gas that has been desulfurized in said desulfurization unit.
In a further aspect, the present invention provides a method for handling exhaust gas in a coal-fired boiler, said method comprising the steps of:
cooling the exhaust gas from the coal-fired boiler to a temperature of between 80 and llOC. by directing the exhaust gas through an air preheater of the boiler and a heat recovery section of a leak free type of gas-gas heater; subsequently reducing the concentration of dust in the exhaust gas to 100 mg/m3N by directing the gas through a dry electrostatic precipitator; subsequently reducing SOx in the exhaust gas by passing the exhaust gas through a desulfurization unit; and subsequently heating the exhaust gas by passing the exhaust gas through a reheating section of the gas-gas heater and circulating heating medium between the reheating and heat recovery sections of the gas-gas heater.
In a still further aspect, the present invention provides a method for handling exhaust gas in a coal-fired boiler, said method comprising the steps of: cooling the exhaust gas from the coal-fired boiler to a temperature of between 80 and llOC by directing the exhaust gas through an air preheater of the boiler and a - 6a -~_ ~n 3~
heat recovery section of a leak free type gas-gas heater; subsequently reducing the concentration of dust in the exhaust gas to 100 mg/m3N by directing the gas through a dry electrostatic precipitator; subsequently reducing SOx in the exhaust gas and lowering the concentration of dust in the exhaust gas to 10 mg/m3N or lower by passing the exhaust gas through a desulfurization unit; and subsequently heating the exhaust gas by passing the exhaust gas through a reheating section of the gas-gas heater, said gas-gas heater being of the type using a heating medium flowing in a heating medium line such that the exhaust gas from the reheating section has a concentration of dust 10 mg/m3N or lower.
Also, in the present invention, by successively closing the plurality of parallel passages in the dry electrostatic precipitator and hammering without charge, dispersion of dust can be substantially reduced, thereby improving the performance of the electrostatic precipitator.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention may be had by reference to the following description of a preferred embodiment when taken in conjunction with the accompanying drawings, in which:
Fig. 1 is a block diagram of a system made according to one embodiment of the present invention;
- 6b -B
, Fig. 2 is a vertical schematic view of a dry electrostatic precipitator included in the system shown in Fig. 1;
Fig. 3 is a graph showing the flow rate of exhaust gas vs. gas ratio;
Figs. 4 and 5 are block diagrams of conventional systems for handling exhaust gas in a coal-fired boiler;
Fig. 6 is a graph showing the temperature of exhaust gas vs. specific resistance of dust;
_ 6c -Fig. 7 is a graph showing the results of test, that is, the relationship between the temperature of exhaust gas and the rate of dust collection in the dry electrostatic precipitator;
Fig. 8 is a graph showing time after hammering has been effected without charge vs. the concentration of dust at the outlet of the dry electrostatic precipitator;
Fig. 9 is a graph showing the flow speed of exhaust gas within the electrostatic precipitator vs. the concentration of dust at the outlet of the dry electro-static precipitator; and Fig. 10 is a graph showing the dust collection characteristics of the desulfurization in the present system and the prior art system, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Fig. 1 is a block diagram of a system according to one embodiment of the present invention. Fig. 2 is a vertical sectional view schematically showing a dry electrostatic precipitator. Fig. 3 is a graph showing the flow rate of exhaust gas under control of the electro-static precipitator shown in Fig. 2.
With reference now to Fig. 1, there is shown a system which includes a coal-fired boiler 1. Exhaust gas from the boiler 1 includes SOx and dust. The temperature of the exhaust gas is reduced to 120 to 160~ in an air ., ~
20360~8 preheater 2. A gas-gas heater 3a is of the leak-free type and uses a heating medium. The gas-gas heater 3a includes a heat recovery section 3a in which the temper-ature of the exhaust gas is further reduced to 80 to 110~.
The concentration of dust is reduced to 100 mg/m N in a dry electrostatic precipitator 4. Further removal of dust from the exhaust gas is effected in a desulfurization unit 5. The desulfurization unit 5 is of the single-tower type and employs lime - gypsum method and said unit 5 reduces the concentration of SOx to a predetermined level.
The exhaust gas as cooled to a saturation temperature is then reheated in a reheater section 3b of the gas-gas heater of the leak-free type and is directed to a chimney.
A denitrification unit or a gas fan (suction fan or pressure fan) which may be located between the boiler 1 and the air heater 2 and a heating medium line of the gas-gas heater are not shown in Fig. 1.
In the illustrated embodiment, the heat recovery section 3a of the gas-gas heater is located upstream of the dry electrostatic precipitator 4 so as to reduce the temperature of the exhaust gas to 80 to 110~ as compared to 120 to 160~ in the conventional systems. In this way, the specific resistance of dust, regardless of types of coals, is reduced to 101 Q-cm where no reverse ionization occurs. This provides an improved charging condition of ~ ~n3~ ~8 the dry electrostatic precipitator and ensures high per-formance of same. The dry electrostatic precipitator can thus be made compact.
Also, in the illustrated embodiment, the con-centration of dust at the inlet of the heat recovery section 3a of the gas-gas heater is the same as that at the outlet of the air preheater 2 (usually 10 - 20 g/m3N) and sufficient to fully prevent corrosion of the former due to the presence of SO3. The gas-gas heater is of the leak-free type, and therefore, no leakage of dust takes place at the inlet of the chimney.
Moreover, the concentration of dust at the outlet of the dry electrostatic precipitator 4 is suffi-ciently reduced below 100 mg/m3N. Accordingly, the purity of the gypsum as collected can be maintained at a pre-determined level when a single-tower type desulfurization unit is used. The concentration of dust at the outlet of the desulfurization unit is reduced below a predetermined level by the dry electrostatic precipitator. This elimi-nates the need for a wet electrostatic precipitator.
Reference will next be made to the results of a test carried out by the inventors, with a pilot plant to which the present system is applied, as well as to an improvement in the system.
The specific resistance of dust arising from ~ _ g 20;~60~8 burning of several kinds of coals is measured. Fig. 6 shows the results of measurement of three typical kinds of coals. The specific resistance of dust is 10 Q-cm or higher in the prior art systems. In the present invention, the temperature of the exhaust gas is reduced to 90 to 100~
to ensure that the specific resistance of the dust is below Q-cm. As a result, the dry electrostatic precipitator no longer suffers from reverse ionization. This ensures constant charging.
Fig. 7 is a graph showing the temperature of exhaust gas vs. the rate of dust collectable by the dry electrostatic precipitator. Dust is effectively attracted to collector elements in the electrostatic precipitator as shown by the line A in Fig. 7 since charging conditions have been improved as stated earlier. The exhaust gas is saturated at a temperature of 110~ or lower. However, the dust are again dispersed due to hammering, etc. This results in a rapid increase in the dust discharged from the electrostatic precipitator. In fact, the rate of dust collection is reduced as shown by the line B in Fig. 7.
Dust dispersed from the collector elements is shown by a shaded area C in Fig. 7.
Various attempts have been made to prevent dust from being dispersed from the collector elements. As a result, it has been found that dispersion of dust can be ,. -~ ~ 3 ~
substantially reduced, and the dust can be highly effec-tively collected by including dampers in the electrostatic precipitator, and ha lering without charge. In Fig. 2, reference numeral 11 is a body of the dry electrostatic precipitator, 12 is an inlet duct, 13 is an outlet duct, 14 are partitions by which a gas passage within the electrostatic precipitator body 11 is divided into a plurality of parallel passages (eight passages in Fig.
2). Reference numerals 15 and 16 are inlet and outlet dampers provided for the respective passages.
Fig. 8 shows the concentration of dust at the o~tlet of the electrostatic precipitator vs. time after hammering has been effected without charge. It has been found that the amount of dust dispersed is kept low for a period of two to three hours after hammering has been effected. With the arrangement shown in Fig. 2, hammering is carried out for about fifteen minutes without charge while the eight gas passages are subsequently closed by the respective dampers. In this way, the hammering can be repeated every two hours so as to prevent an increase in the dispersion of dust.
Fig. 9 shows the flow speed of exhaust gas vs.
the concentration of dust or the amount of dust dispersed as a result of hammering. From Fig. 9, it is clear that dust is rapidly and substantially dispersed when the flow speed of the exhaust gas is below 0.5 m/s. This means 20360~8 that the electrostatic precipitator is less effective when the boiler is operated under low load. To this end, the number of the passages closed by the dampers in the electrostatic precipitator is changed in response to the flow of the exhaust gas so as to control the flow speed of the exhaust gas flowing therethrough.
Fig. 10 shows dust collection characteristics of the desulfurization unit. It has been found that the desulfurization unit of this embodiment provides a sub-stantial improvement in dust collection over the prior artdesulfurization unit. In the illustrated embodiment, the ratio of dust dispersed as a result of hammering is rela-tively high in the outlet duct of the dry electrostatic precipitator, and this dust is largely agglomerated. This results in a further advantage of the system which effec-tively and efficiently removes dust without the need for a wet electrostatic precipitator.
In the present invention, the wet desulfuriza-tion unit can use method other than the lime-gypsum method.
In order to further reduce the concentration of dust, a wet electrostatic precipitator of a small capacity may be provided downstream of the desulfurization unit.
The present invention provides a method and system for handling exhaust gas in a coal-fired boiler which consumes less space and is economical to manufacture.
20360~8 Advantages of the present invention are as follows:
(1) A compact dry electrostatic precipitator can be used regardless of coals having a wide variety of characteristics.
(2) The quality of gypsum as collected can be maintained with a compact single-tower type desulfuriza-tion unit.
(3) Dust can be greatly removed without the need for a wet electrostatic precipitator.
In order to achieve the foregoing objects, the present invention provides a method for handling exhaust gas in a boiler which comprises the steps of cooling exhaust gas from a coal-fired boiler to a temperature of between 80 and 110~ by an air preheater and a heat recovery unit, reducing the concentration of dust to as high as 100 mg/m3N by a dry electrostatic precipitator, and ~' Z036018 introducing the exhaust gas to a desulfurization unit so as to reduce SOx.
According to the present invention, there is also provided a system for handling exhaust gas in a boiler which comprises a gas flue of a coal-fired boiler in which an air heater, a heat recovery unit, a dry electrostatic precipitator, and a desulfurization unit are provided in that order, the dry electrostatic precipitator including a gas passage divided into a plurality of parallel passages, and dampers provided in said parallel passages respectively and operable to inhibit exhaust gas flow therethrough.
In the present invention, the heat recovery unit is located upstream of the dry electrostatic precipi-tator so as to reduce the temperature of exhaust gas to 80 to 110~ at the inlet of the electrostatic precipitator.
This results in a corresponding decrease in the specific resistance of dust and thus, prevents reverse ionization in the electrostatic precipitator and improves the per-formance of the dry electrostatic precipitator. With this arrangement, the heat recovery unit is not suffer from corrosion due to SO3 if the concentration of dust is reduced to 100 mg/m3N in the electrostatic precipitator, because the heat recovery unit is not located downstream of the dry electrostatic precipitator. Since the dry electrostatic precipitator is able to substantially reduce ~ 8 ~!
the concentration of dust, the desulfurization unit does not require a cooling/dust removing section and can be of the single-tower type. Also, a wet electrostatic precipitator is unnecessary.
Accordingly, in one of its aspects, the present invention relates to a system for handling exhaust gas in a coal-fired boiler, said system comprising: an air preheater of the boiler, a leak free type of gas-gas heater having a heat recovery section and a reheating section through which heating medium is circulated, a dry electrostatic precipitator, and a desulfurization unit all disposed in a gas flue of the boiler, said air preheater being disposed at an upstream location in the gas flue so as to reduce the temperature of the exhaust gas to a predetermined temperature, the heat recovery section of said gas-gas heater being disposed downstream of said air preheater in the gas flue so as to further reduce the temperature of the exhaust gas, said dry electrostatic precipitator being disposed downstream of said heat recovery section in the gas flue so as to reduce the concentration of dust in the exhaust gas to a predetermined level, said desulfurization unit being disposed downstream of said dry electrostatic precipitator in the gas flue so as to reduce the concentration of SOx in the exhaust gas and further reduce the temperature thereof and the concentration of dust therein, and the reheating section ~ ~ 3 ~
of said gas-gas heater being disposed downstream of said desulfurization unit in the gas flue so as to reheat the exhaust gas that has been desulfurized in said desulfurization unit.
In a further aspect, the present invention provides a method for handling exhaust gas in a coal-fired boiler, said method comprising the steps of:
cooling the exhaust gas from the coal-fired boiler to a temperature of between 80 and llOC. by directing the exhaust gas through an air preheater of the boiler and a heat recovery section of a leak free type of gas-gas heater; subsequently reducing the concentration of dust in the exhaust gas to 100 mg/m3N by directing the gas through a dry electrostatic precipitator; subsequently reducing SOx in the exhaust gas by passing the exhaust gas through a desulfurization unit; and subsequently heating the exhaust gas by passing the exhaust gas through a reheating section of the gas-gas heater and circulating heating medium between the reheating and heat recovery sections of the gas-gas heater.
In a still further aspect, the present invention provides a method for handling exhaust gas in a coal-fired boiler, said method comprising the steps of: cooling the exhaust gas from the coal-fired boiler to a temperature of between 80 and llOC by directing the exhaust gas through an air preheater of the boiler and a - 6a -~_ ~n 3~
heat recovery section of a leak free type gas-gas heater; subsequently reducing the concentration of dust in the exhaust gas to 100 mg/m3N by directing the gas through a dry electrostatic precipitator; subsequently reducing SOx in the exhaust gas and lowering the concentration of dust in the exhaust gas to 10 mg/m3N or lower by passing the exhaust gas through a desulfurization unit; and subsequently heating the exhaust gas by passing the exhaust gas through a reheating section of the gas-gas heater, said gas-gas heater being of the type using a heating medium flowing in a heating medium line such that the exhaust gas from the reheating section has a concentration of dust 10 mg/m3N or lower.
Also, in the present invention, by successively closing the plurality of parallel passages in the dry electrostatic precipitator and hammering without charge, dispersion of dust can be substantially reduced, thereby improving the performance of the electrostatic precipitator.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention may be had by reference to the following description of a preferred embodiment when taken in conjunction with the accompanying drawings, in which:
Fig. 1 is a block diagram of a system made according to one embodiment of the present invention;
- 6b -B
, Fig. 2 is a vertical schematic view of a dry electrostatic precipitator included in the system shown in Fig. 1;
Fig. 3 is a graph showing the flow rate of exhaust gas vs. gas ratio;
Figs. 4 and 5 are block diagrams of conventional systems for handling exhaust gas in a coal-fired boiler;
Fig. 6 is a graph showing the temperature of exhaust gas vs. specific resistance of dust;
_ 6c -Fig. 7 is a graph showing the results of test, that is, the relationship between the temperature of exhaust gas and the rate of dust collection in the dry electrostatic precipitator;
Fig. 8 is a graph showing time after hammering has been effected without charge vs. the concentration of dust at the outlet of the dry electrostatic precipitator;
Fig. 9 is a graph showing the flow speed of exhaust gas within the electrostatic precipitator vs. the concentration of dust at the outlet of the dry electro-static precipitator; and Fig. 10 is a graph showing the dust collection characteristics of the desulfurization in the present system and the prior art system, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Fig. 1 is a block diagram of a system according to one embodiment of the present invention. Fig. 2 is a vertical sectional view schematically showing a dry electrostatic precipitator. Fig. 3 is a graph showing the flow rate of exhaust gas under control of the electro-static precipitator shown in Fig. 2.
With reference now to Fig. 1, there is shown a system which includes a coal-fired boiler 1. Exhaust gas from the boiler 1 includes SOx and dust. The temperature of the exhaust gas is reduced to 120 to 160~ in an air ., ~
20360~8 preheater 2. A gas-gas heater 3a is of the leak-free type and uses a heating medium. The gas-gas heater 3a includes a heat recovery section 3a in which the temper-ature of the exhaust gas is further reduced to 80 to 110~.
The concentration of dust is reduced to 100 mg/m N in a dry electrostatic precipitator 4. Further removal of dust from the exhaust gas is effected in a desulfurization unit 5. The desulfurization unit 5 is of the single-tower type and employs lime - gypsum method and said unit 5 reduces the concentration of SOx to a predetermined level.
The exhaust gas as cooled to a saturation temperature is then reheated in a reheater section 3b of the gas-gas heater of the leak-free type and is directed to a chimney.
A denitrification unit or a gas fan (suction fan or pressure fan) which may be located between the boiler 1 and the air heater 2 and a heating medium line of the gas-gas heater are not shown in Fig. 1.
In the illustrated embodiment, the heat recovery section 3a of the gas-gas heater is located upstream of the dry electrostatic precipitator 4 so as to reduce the temperature of the exhaust gas to 80 to 110~ as compared to 120 to 160~ in the conventional systems. In this way, the specific resistance of dust, regardless of types of coals, is reduced to 101 Q-cm where no reverse ionization occurs. This provides an improved charging condition of ~ ~n3~ ~8 the dry electrostatic precipitator and ensures high per-formance of same. The dry electrostatic precipitator can thus be made compact.
Also, in the illustrated embodiment, the con-centration of dust at the inlet of the heat recovery section 3a of the gas-gas heater is the same as that at the outlet of the air preheater 2 (usually 10 - 20 g/m3N) and sufficient to fully prevent corrosion of the former due to the presence of SO3. The gas-gas heater is of the leak-free type, and therefore, no leakage of dust takes place at the inlet of the chimney.
Moreover, the concentration of dust at the outlet of the dry electrostatic precipitator 4 is suffi-ciently reduced below 100 mg/m3N. Accordingly, the purity of the gypsum as collected can be maintained at a pre-determined level when a single-tower type desulfurization unit is used. The concentration of dust at the outlet of the desulfurization unit is reduced below a predetermined level by the dry electrostatic precipitator. This elimi-nates the need for a wet electrostatic precipitator.
Reference will next be made to the results of a test carried out by the inventors, with a pilot plant to which the present system is applied, as well as to an improvement in the system.
The specific resistance of dust arising from ~ _ g 20;~60~8 burning of several kinds of coals is measured. Fig. 6 shows the results of measurement of three typical kinds of coals. The specific resistance of dust is 10 Q-cm or higher in the prior art systems. In the present invention, the temperature of the exhaust gas is reduced to 90 to 100~
to ensure that the specific resistance of the dust is below Q-cm. As a result, the dry electrostatic precipitator no longer suffers from reverse ionization. This ensures constant charging.
Fig. 7 is a graph showing the temperature of exhaust gas vs. the rate of dust collectable by the dry electrostatic precipitator. Dust is effectively attracted to collector elements in the electrostatic precipitator as shown by the line A in Fig. 7 since charging conditions have been improved as stated earlier. The exhaust gas is saturated at a temperature of 110~ or lower. However, the dust are again dispersed due to hammering, etc. This results in a rapid increase in the dust discharged from the electrostatic precipitator. In fact, the rate of dust collection is reduced as shown by the line B in Fig. 7.
Dust dispersed from the collector elements is shown by a shaded area C in Fig. 7.
Various attempts have been made to prevent dust from being dispersed from the collector elements. As a result, it has been found that dispersion of dust can be ,. -~ ~ 3 ~
substantially reduced, and the dust can be highly effec-tively collected by including dampers in the electrostatic precipitator, and ha lering without charge. In Fig. 2, reference numeral 11 is a body of the dry electrostatic precipitator, 12 is an inlet duct, 13 is an outlet duct, 14 are partitions by which a gas passage within the electrostatic precipitator body 11 is divided into a plurality of parallel passages (eight passages in Fig.
2). Reference numerals 15 and 16 are inlet and outlet dampers provided for the respective passages.
Fig. 8 shows the concentration of dust at the o~tlet of the electrostatic precipitator vs. time after hammering has been effected without charge. It has been found that the amount of dust dispersed is kept low for a period of two to three hours after hammering has been effected. With the arrangement shown in Fig. 2, hammering is carried out for about fifteen minutes without charge while the eight gas passages are subsequently closed by the respective dampers. In this way, the hammering can be repeated every two hours so as to prevent an increase in the dispersion of dust.
Fig. 9 shows the flow speed of exhaust gas vs.
the concentration of dust or the amount of dust dispersed as a result of hammering. From Fig. 9, it is clear that dust is rapidly and substantially dispersed when the flow speed of the exhaust gas is below 0.5 m/s. This means 20360~8 that the electrostatic precipitator is less effective when the boiler is operated under low load. To this end, the number of the passages closed by the dampers in the electrostatic precipitator is changed in response to the flow of the exhaust gas so as to control the flow speed of the exhaust gas flowing therethrough.
Fig. 10 shows dust collection characteristics of the desulfurization unit. It has been found that the desulfurization unit of this embodiment provides a sub-stantial improvement in dust collection over the prior artdesulfurization unit. In the illustrated embodiment, the ratio of dust dispersed as a result of hammering is rela-tively high in the outlet duct of the dry electrostatic precipitator, and this dust is largely agglomerated. This results in a further advantage of the system which effec-tively and efficiently removes dust without the need for a wet electrostatic precipitator.
In the present invention, the wet desulfuriza-tion unit can use method other than the lime-gypsum method.
In order to further reduce the concentration of dust, a wet electrostatic precipitator of a small capacity may be provided downstream of the desulfurization unit.
The present invention provides a method and system for handling exhaust gas in a coal-fired boiler which consumes less space and is economical to manufacture.
20360~8 Advantages of the present invention are as follows:
(1) A compact dry electrostatic precipitator can be used regardless of coals having a wide variety of characteristics.
(2) The quality of gypsum as collected can be maintained with a compact single-tower type desulfuriza-tion unit.
(3) Dust can be greatly removed without the need for a wet electrostatic precipitator.
Claims (5)
1. A system for handling exhaust gas in a coal-fired boiler, said system comprising: an air preheater of the boiler, a leak free type of gas-gas heater having a heat recovery section and a reheating section through which heating medium is circulated, a dry electrostatic precipitator, and a desulfurization unit all disposed in a gas flue of the boiler, said air preheater being disposed at an upstream location in the gas flue so as to reduce the temperature of the exhaust gas to a predetermined temperature, the heat recovery section of said gas-gas heater being disposed downstream of said air preheater in the gas flue so as to further reduce the temperature of the exhaust gas, said dry electrostatic precipitator being disposed downstream of said heat recovery section in the gas flue so as to reduce the concentration of dust in the exhaust gas to a predetermined level, said desulfurization unit being disposed downstream of said dry electrostatic precipitator in the gas flue so as to reduce the concentration of SOx in the exhaust gas and further reduce the temperature thereof and the concentration of dust therein, and the reheating section of said gas-gas heater being disposed downstream of said desulfurization unit in the gas flue so as to reheat the exhaust gas that has been desulfurized in said desulfurization unit.
.
.
2. A system for handling exhaust gas in a coal-fired boiler as claimed in claim 1, wherein said dry electrostatic precipitator defines a plurality of gas passages therethrough communicating with both the heat recovery section of said gas-gas heater and said desulfurization unit, and said dry electrostatic precipitator includes a plurality of dampers disposed in said gas passages, said dampers being adjustable to inhibit the flow of exhaust gas through said passages to various degrees.
3. A system for handling exhaust gas in a coal-fired boiler as claimed in claim 1, wherein said dry electrostatic precipitator defines a plurality of gas passages therethrough communicating with both the heat recovery section of said gas-gas heater and said desulfurization unit, and said dry electrostatic precipitator includes a plurality of dampers disposed in said gas passages, said dampers being selectively openable and closable so as to control the flow speed of the exhaust gas through the dry electrostatic precipitator.
4. A method for handling exhaust gas in a coal-fired boiler, said method comprising the steps of:
cooling the exhaust gas from the coal-fired boiler to a temperature of between 80 and 110°C. by directing the exhaust gas through an air preheater of the boiler and a heat recovery section of a leak free type of gas-gas heater;
subsequently reducing the concentration of dust in the exhaust gas to 100 mg/m3N by directing the gas through a dry electrostatic precipitator;
subsequently reducing SOx in the exhaust gas by passing the exhaust gas through a desulfurization unit;
and subsequently heating the exhaust gas by passing the exhaust gas through a reheating section of the gas-gas heater and circulating heating medium between the reheating and heat recovery sections of the gas-gas heater.
cooling the exhaust gas from the coal-fired boiler to a temperature of between 80 and 110°C. by directing the exhaust gas through an air preheater of the boiler and a heat recovery section of a leak free type of gas-gas heater;
subsequently reducing the concentration of dust in the exhaust gas to 100 mg/m3N by directing the gas through a dry electrostatic precipitator;
subsequently reducing SOx in the exhaust gas by passing the exhaust gas through a desulfurization unit;
and subsequently heating the exhaust gas by passing the exhaust gas through a reheating section of the gas-gas heater and circulating heating medium between the reheating and heat recovery sections of the gas-gas heater.
5. A method for handling exhaust gas in a coal-fired boiler, said method comprising the steps of:
cooling the exhaust gas from the coal-fired boiler to a temperature of between 80 and 110°C by directing the exhaust gas through an air preheater of the boiler and a heat recovery section of a leak free type gas-gas heater;
subsequently reducing the concentration of dust in the exhaust gas to 100 mg/m3N by directing the gas through a dry electrostatic precipitator;
subsequently reducing SOx in the exhaust gas and lowering the concentration of dust in the exhaust gas to 10 mg/m3N or lower by passing the exhaust gas through a desulfurization unit; and subsequently heating the exhaust gas by passing the exhaust gas through a reheating section of the gas-gas heater, said gas-gas heater being of the type using a heating medium flowing in a heating medium line such that the exhaust gas from the reheating section has a concentration of dust 10 mg/m3N or lower.
cooling the exhaust gas from the coal-fired boiler to a temperature of between 80 and 110°C by directing the exhaust gas through an air preheater of the boiler and a heat recovery section of a leak free type gas-gas heater;
subsequently reducing the concentration of dust in the exhaust gas to 100 mg/m3N by directing the gas through a dry electrostatic precipitator;
subsequently reducing SOx in the exhaust gas and lowering the concentration of dust in the exhaust gas to 10 mg/m3N or lower by passing the exhaust gas through a desulfurization unit; and subsequently heating the exhaust gas by passing the exhaust gas through a reheating section of the gas-gas heater, said gas-gas heater being of the type using a heating medium flowing in a heating medium line such that the exhaust gas from the reheating section has a concentration of dust 10 mg/m3N or lower.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1204591A JPH0756377B2 (en) | 1989-08-09 | 1989-08-09 | Method and apparatus for treating boiler exhaust gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2036018A1 CA2036018A1 (en) | 1992-08-09 |
| CA2036018C true CA2036018C (en) | 1998-06-30 |
Family
ID=16493004
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2036018 Expired - Lifetime CA2036018C (en) | 1989-08-09 | 1991-02-08 | Method and system for handling exhaust gas in a boiler |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0498020B1 (en) |
| JP (1) | JPH0756377B2 (en) |
| CA (1) | CA2036018C (en) |
| DE (1) | DE69120927T2 (en) |
| DK (1) | DK0498020T3 (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4306228A1 (en) * | 1993-02-27 | 1994-09-01 | Abb Patent Gmbh | Flue gas filter arrangement for dusts and gaseous pollutants |
| JP3216743B2 (en) * | 1993-04-22 | 2001-10-09 | 富士電機株式会社 | Protection diode for transistor |
| JP2826560B2 (en) * | 1996-06-03 | 1998-11-18 | バブコック日立株式会社 | Exhaust gas treatment method |
| JP3611272B2 (en) | 1997-12-19 | 2005-01-19 | 三菱重工業株式会社 | Rotating regenerative heat exchanger |
| JP3546132B2 (en) * | 1997-12-22 | 2004-07-21 | 三菱重工業株式会社 | Exhaust gas treatment method |
| US6710295B1 (en) | 2000-06-15 | 2004-03-23 | Hitachi Global Storage Technologies Netherlands, B.V. | Slider curvature modification by substrate melting effect produced with a pulsed laser beam |
| JP2011094962A (en) * | 2004-11-29 | 2011-05-12 | Mitsubishi Heavy Ind Ltd | Heat recovery equipment |
| JP2006295062A (en) | 2005-04-14 | 2006-10-26 | Rohm Co Ltd | Semiconductor device |
| JP5209952B2 (en) * | 2007-12-19 | 2013-06-12 | 三菱重工メカトロシステムズ株式会社 | High dust exhaust gas heat recovery treatment equipment |
| JP5281858B2 (en) * | 2008-09-22 | 2013-09-04 | バブコック日立株式会社 | Exhaust gas treatment equipment |
| PL2354651T3 (en) | 2010-01-18 | 2014-11-28 | General Electric Technology Gmbh | System for combined flue heat recovery and dust precipitation improvement as retrofit solution for existing coal-fired power stations |
| CA2867042C (en) | 2012-03-14 | 2016-07-05 | Ihi Corporation | Oxyfuel combustion boiler system |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS521144B2 (en) * | 1974-05-15 | 1977-01-12 | ||
| US3988127A (en) * | 1975-05-07 | 1976-10-26 | John Louis Schumann | Electrostatic precipitator apparatus and method |
| DE2520957C3 (en) * | 1975-05-10 | 1978-08-31 | Metallgesellschaft Ag, 6000 Frankfurt | Process for removing dusty and gaseous pollutants from starter exhaust gas |
| JPS521144A (en) * | 1975-06-20 | 1977-01-06 | Toshiba Machine Co Ltd | Cut wire detector for wire twister |
| DE2724372C2 (en) * | 1977-05-28 | 1986-02-13 | Klöckner-Humboldt-Deutz AG, 5000 Köln | Process for conditioning bypass gases |
| AU500466B2 (en) * | 1977-08-01 | 1979-05-24 | Metallgesellschaft Ag | Cleaning gases from sintering plants |
| JPS5792614A (en) * | 1980-12-02 | 1982-06-09 | Mitsui Eng & Shipbuild Co Ltd | Equipment for disposal of waste gas |
| JPS58120020A (en) * | 1982-01-13 | 1983-07-16 | Mitsubishi Heavy Ind Ltd | Disposal of exhaust smoke |
| US4559211A (en) * | 1983-08-05 | 1985-12-17 | Research-Cottrell, Inc. | Method for reduced temperature operation of flue gas collectors |
| US4582122A (en) * | 1983-08-10 | 1986-04-15 | Linde Aktiengesellschaft | Efficient waste heat recovery process from sulfur containing flue gas |
| JPS60227844A (en) * | 1984-04-27 | 1985-11-13 | Mitsubishi Heavy Ind Ltd | Treating equipment of stack gas |
| JPS61111125A (en) * | 1984-11-02 | 1986-05-29 | Mitsubishi Heavy Ind Ltd | Treatment of stack gas |
| FR2572952B1 (en) * | 1984-11-14 | 1987-02-06 | Kaiser Victor | PROCESS AND INSTALLATION FOR PURIFYING SMOKE |
| DE3604946C2 (en) * | 1986-02-17 | 1987-04-09 | Mehdi Haji Dr.-Ing. 7259 Friolzheim Javad | Method and device for cleaning flue gases |
| DE3608690A1 (en) * | 1986-03-15 | 1987-09-17 | Rennebeck Klaus | Process for material separation or exhaust gas purification |
| JP2573589B2 (en) * | 1987-01-09 | 1997-01-22 | バブコツク日立株式会社 | Flue gas treatment equipment |
-
1989
- 1989-08-09 JP JP1204591A patent/JPH0756377B2/en not_active Expired - Lifetime
-
1991
- 1991-02-08 DE DE1991620927 patent/DE69120927T2/en not_active Expired - Lifetime
- 1991-02-08 DK DK91101801T patent/DK0498020T3/en active
- 1991-02-08 EP EP19910101801 patent/EP0498020B1/en not_active Expired - Lifetime
- 1991-02-08 CA CA 2036018 patent/CA2036018C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0498020A1 (en) | 1992-08-12 |
| EP0498020B1 (en) | 1996-07-17 |
| DE69120927D1 (en) | 1996-08-22 |
| DK0498020T3 (en) | 1996-12-16 |
| CA2036018A1 (en) | 1992-08-09 |
| JPH0756377B2 (en) | 1995-06-14 |
| JPH0370907A (en) | 1991-03-26 |
| DE69120927T2 (en) | 1996-12-05 |
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