Title of Invention

"A WET RAW MATERIAL DRYER INCLUDING A FLUIDIZED BED DRYER AND DRYING MEHOD"

Abstract

A wet raw material dryer including a fluidized bed dryer for drying a wet raw material, a duct and a blower for introducing an exhaust gas of a coke oven to the fluidized bed dryer and a dust collector for collecting fine particles contained in an exhaust gas of the fluidized bed dryer, and using the exhaust gas of the coke oven as a heating and fluidizing gas for the fluidized bed dryer, comprising a binder adding device adding a binder to the fine particles discharged from the dust collector and having a mechanism for adjusting a binder addition amount in a constant ratio with respect to a fine particles amount according to a change in the fine particles discharged from the dust collector.

Full Text

The present invention relates to a wet raw material dryer including a fluidized bed dryer and drying method. Technical Field [0001] The present invention relates to a wet raw material dryer and drying method, for drying wet raw material such as coal to be charged to a coke oven with a fluidized bed dryer. Background Art [0002] When producing cokes, charging coal is dried prior to be charged into a coke oven for the purpose of improving the quality of cokes and productivity in the coke oven. Contained moisture in undried coke oven coals is approximately 9% to 13% in general, and the coals are dried with a coal dryer so as to contain moisture of 5% to 6%. In general, as the moisture contained in the coal reduces, an amount of coal fines generated from the coal increases. [0003] It is conventionally known to use a fluidized bed dryer for this drying of coals. For example, Patent document 1 discloses a method of drying coals by introducing a flue exhaust gas of a coke oven as a heating and fluidizing gas into a fluidized bed dryer. Most of the coal powder charged into the fluidized bed dryer is discharged from a discharging chute communicating with a fluidized bed and transferred to the coke oven. Further, coal fines are generated due to drying the coal powder. The coal fines are discharged with exhaust gas from an exhaust gas outlet, which is disposed above the fluidized bed and collected by a dust collector provided to an exhaust gas pipe. [0004] Temperature of the coke oven exhaust gas used as a heating and fluidizing gas for the fluidized bed dryer changes due to an operation load condition, a fuel condition or a combustion control condition of the coke oven. For example, when the production of the coke oven temporarily reduces, a higher-temperature exhaust gas may be introduced, which is higher than a temperature condition determined when the dryer is designed. This causes that the moisture contained in the coal is dried much more than an expectation of the time the dryer is designed so that the amount of coal fines generated from the coal increases and the amount of the coal fines corrected by the dust collector also increases. Further, when a heating value of coke oven fuel temporarily reduces, the lower-temperature exhaust gas may be introduced, which is lower than the temperature condition determined when the dryer is designed. This causes a decrease in the amount of coal fines generated from the coal, and also, a decrease in the amount of the coal fines corrected by the dust collector. As described above, when the coke oven exhaust gas is used as a heating and fluidizing gas for the fluidized bed dryer, the temperature of the gas may change. Accordingly, corresponding to a change in drying condition of the wet raw material in the fluidized bed dryer, the amount of coal fines generated from the coal changes and the amount of coal fines collected into and discharged from the dust collector also changes. [0005] The coke oven typically has two combustion gas systems for each oven and the systems are switched with one another in every predetermined operation time length. In general, the switch of the systems is implemented in every 15 to 30 minutes. As shown in Fig. 4, when the combustion gas systems are switched, the combustion gas flow rate of current system (system A) is gradually reduced and, when its flow rate becomes zero, the combustion gas flow rate of another system (system B) is gradually increased. Thus, during a.switch of the combustion gas systems, the coke oven exhaust gas amount reduces once, and then, increases again. The time required for switching the combustion gas systems is from 0.5 to 3 minutes in general. [0006] As described above, when the coke oven exhaust gas is used as a heating and fluidizing gas for the fluidized bed dryer, the coke oven exhaust gas amount decreases when the coke oven combustion gas systems are switched. Consequently, in Patent Document 1, when the coke oven exhaust gas supply is stopped or reduced, the gas discharged from the iiuiaizea Ded dryer is circulated to reuse as a fluidizing gas for the fluidized bed dryer in order to maintain the flow condition of the fluidized bed. However, since the gas discharged from the fluidized bed dryer is a gas already used to dry the coal powder, its temperature is much lower than the temperature of the coke oven exhaust gas. Accordingly, when the coke oven combustion gas systems are switched, the temperature of the gas introduced to the fluidized bed in the fluidized bed dryer is lowered, as shown in Fig. 4. As a result, drying degree of the wet raw material reduces and the coal fines amount generated during the drying and collected by the dust collector increases. In order to solve this problem, a heated gas generating oven or the like may be provided to heat to compensate the lack of heat quantity when the combustion gas systems are switched. However, it is not realistic to operate a heated gas generating oven to compensate the lack of heat quantity for drying the wet raw material in every time the coke oven combustion gas systems are switched since, as described above, the systems are switched in every 15 to 30 minutes and the changes in gas flow rate occur within a sort period of time, which is from 0.5 to 3 minutes. [0007] On the other hand, Patent Document 2 discloses a method for adding heavy oil to a collected coal fines to granulate in order to prevent a dust spread of coal fines discharged from the dust collector of the fluidized bed coal for drying coal introduced to a coke oven or a carbon adhesion in the coke oven. However, the invention of Paten Document 2 is not made in consideration of a gas flow rate of heated air as a coke oven exhaust gas and addition amount of the heavy oil is constant, that is about 250kg/hr with respect to a coal fines amount of about 95t/hr, according to its embodiment. [0008] Patent Document 1: Japanese Patent Application Laid- open No. 2001-55582 Patent Document 2: Japanese Patent Publication No. Shou 49-28241 Summary of the Invention [0009] An object of the present invention is to mix a coal fines (fine particles) and binder required for kneading and granulating in a fixed ratio in order to surely prevent a dust spread or a carbon adhesion even if an amount of the coal fines, which is discharged with a gas from a fluidized bed dryer and collected, increases or decreases due to a stop, decrease, or increase of a coke oven exhaust gas, which is a high temperature gas supplied to the fluidized bed dryer as a heating and fluidizing gas, or a change in temperature of the gas. [0010] The present invention provides a wet raw material dryer including a fluidized bed dryer for drying a wet raw material, a gas supply pipe (a duct and a blower) for introducing an exhaust gas of a coke oven to the fluidized bed dryer as a heating and fluidizing gas and a dust collector for collecting fine particles contained in an exhaust gas of the fluidized bed dryer. The wet raw material dryer has a binder adding device having a mechanism for manually or automatically adjusting a binder addition amount in a constant ratio with respect to a fine particles amount according to a change in a collected amount of fine particles collected by the dust collector due to a change in a drying condition of the wet raw material, caused by a change in temperature or flow rate of the exhaust gas of the coke oven. [0011] The present invention further provides the wet raw material dryer with a binder addition amount controller detecting a change in an exhaust gas supply from the coke oven or a change in exhaust gas temperature and adjusting the binder addition amount according to a detected signal. [0012] The present invention further provides the wet raw material dryer with a binder addition amount controller detecting a change in temperature or flow rate of the exhaust gas due to a change in a production amount of the coke oven and manually or automatically adjusting the binder addition amount added to the collected fine particles according to the change. [0013] The present invention further provides the wet raw material dryer with a binder addition amount controller detecting a change in temperature or flow rate of the exhaust gas due to a change in a heating value of a coke oven fuel and manually or automatically adjusting the binder addition amount added to the collected fine particles according to the change. [0014] The present invention further provides the wet raw material dryer with a binder addition amount controller detecting a stop or decrease of an exhaust gas supply from the coke oven and manually or automatically adjusting the binder addition amount added to the collected fine particles according to a detected signal. [0015] The present invention provides a drying method of the wet raw material dryer, for manually or automatically adjusting a binder addition amount in a constant ratio with respect to a fine particles amount according to a change in a collected amount of fine particles collected by the dust collector due to a change in a drying condition of the wet raw material, caused by a change in temperature or flow rate of the exhaust gas of the coke oven. [0016] The present invention provides the wet raw material drying method of the dryer, for detecting a change in temperature or flow rate of the exhaust gas due to a change in a production amount of the coke oven and adjusting the binder addition amount added to the collected fine particles according to the change. [0017] The present invention provides the wet raw material drying method of the dryer, for detecting a change in temperature or flow rate of the exhaust gas due to a change in a heating value of a coke oven fuel and adjusting the binder addition amount added to the collected fine particles according to the change. [0018] The present invention provides the wet raw material drying method of the dryer, for detecting a stop or decrease of an high-temperature gas supply from the coke oven and adjusting the binder addition amount added to the collected fine particles according to a detected signal. [0019] According to the present invention, a stop, decrease or increase of the coke oven exhaust gas supplied to the fluidized bed dryer or a change in the exhaust gas temperature can be detected according to a signal from the coke oven. [0020] According to the present invention, when the exhaust gas supply from the coke oven stops or decreases, an exhaust gas discharged from the fluidized bed dryer is circulated to reuse as a fluidizing gas for the fluidized bed dryer. Further, the stop or decrease of the exhaust gas supply from the coke oven can be detected according to a prediction signal or a start signal indicating a coke oven combustion system switching. [0021] According to the present invention, the stop, decrease or increase of the coke oven exhaust gas supply or a change in coke oven exhaust gas temperature is detected or predicted to adjust the binder addition amount in anticipation of an increase or decrease in the amount of the fine particles collected by the dust collector even if the amount of the fine particles, which is discharged with gas from the fluidized bed dryer and collected, changes due to the stop, decrease or increase of coke oven exhaust gas supplied to the fluidized bed dryer as a heating and fluidizing gas or a change in the coke oven exhaust gas temperature. Accordingly, the mixing ratio of the fine particles and the binder can be maintained to be a most preferable ratio. Therefore, adding a sufficient amount of binder to the fine particles prevents a dust spread or a carbon adhesion to a wall of the coke oven, and also, problems such as a contamination in the transferring path or wasted expense of binder caused by an excess of binder can besolved. Brief Description of the Drawings [0022] Fig. 1 is a schematic block diagram showing an embodiment of a dryer of the present invention; Fig. 2 is a schematic block diagram showing another embodiment of the dryer of the present invention; Fig. 3 is a diagram showing a condition of switching an exhaust combustion gas system of a coke oven according to the present invention; and Fig. 4 is a diagram showing a condition of switching an exhaust combustion gas system of a coke oven according to a conventional technique. Detailed Description of the Preferred Embodiments [0023] An embodiment of the present invention will be described based on an embodiment of applying the present invention to drying of coal powder for a coke oven (hereinafter simply referred to as "coal powder") . [0024] Fig. 1 is a schematic block diagram showing an embodiment of a dryer of the present invention. As shown in Fig. 1, a coke oven exhaust combustion gas generated in a coke oven 1 is discharged from a coke oven chimney 3 via a flue 2. Temperature of a flue exhaust gas (coke oven exhaust gas) 4 passing through the flue 2 is approximately 150°C to 250°C. The coke oven exhaust gas 4 flows in a gas supply pipe 5 branched from the flue 2 of the coke oven and, after pressurized by a blower 6, is supplied from under a fluidized bed dryer 8 as a heating and fluidizing gas 7. [0025] An exhaust gas 9 discharged from the fluidized bed dryer 8 is discharged into air from a chimney 13 through an exhaust gas pipe 10 passing through a dust collector 11 and a blower 12. [0026] Further, a gas circulating pipe 14 is branched from the exhaust gas pipe 10 and an end of the gas circulating pipe 14 is connected to the gas supply pipe 5 so as to circulate the exhaust gas 9 of the fluidized bed dryer 8 to reuse as a fluidizing gas for the fluidized bed dryer 8. [0027] The coal powder, that is the wet raw material, is charged into the fluidized bed dryer 8 through a charging chute 15 and forms a fluidized bed 16 by a rising air current due to the heating and fluidizing gas 7 introduced from the lower part of the fluidized bed dryer 8. The coal powder is dried in this fluidized bed 16 so as to have a predetermined temperature and a contained moisture ratio and is discharged from a discharging chute 17. The coal powder discharged from the discharging chute 17 is transferred to the coke oven through a transferring path (not shown). On the other hand, coal fines are generated while the coal powder in the fluidized bed 16 is dried. The coal fines are discharged with gas from an upper portion of the fluidized bed dryer 8 and collected by the dust collector 11 provided to the exhaust gas pipe 10. [0028] To the collected coal fines, a binder adding device 18 adds a binder such as heavy oil and a kneading and granulating device 19 kneads and granulates the coal fines. Then, the coal fines are transferred to the coke oven through a transferring path (not shown). The amount of the binder added by the binder adding device 18 is controlled by a binder addition controller 20. It is noted that the binder addition controller 20 may be installed in the binder adding device 18. Here, in case that the binder adding device 18 is adjusted manually, the binder addition controller 20 is not required. [0029] An exhaust gas flowmeter 21 is provided to the flue 2 of the coke oven, a flowmeter 23 and a first control valve 24 are provided to the gas supply pipe 5, a second control valve 25 is provided to the exhaust gas pipe 10, and a third control valve 26 is provided with the gas circulating pipe 14. The exhaust gas flowmeter 21 is not always essential and the exhaust gas flow rate may be estimated by calculating combustion of the coke oven. Each of opening degrees and flow rates of the first to third control valves 24 to 26 are controlled by control valve controllers 27 to 29. [0030] In the present embodiment, the binder adding device 18 is controlled according to a change in temperature or flow rate of the exhaust gas from the coke oven to regularly maintain a most preferable mixing ratio of the coal fines collected by the dust collector 11 and the binder. Details will be descried below with reference to Fig. I. [0031] In a steady state, since a constant amount of the coal fines are discharged from the dust collector 11, the binder addition amount is constant and any controller for controlling the binder adding device 18 is not necessary. The inventors of the present invention carefully studied the most preferable mixing ratio of the coal fines and the binder. As a result, it was found that the most preferable ratio is 0.1% to 15% binder to 1 part coal fines. [0032] On the other hand, when the flow rate of temperature of the coke oven exhaust gas 4 introduced into the fluidized bed dryer 8 changes due to some reasons such as a sudden change in production amount in the coke oven or a change in heating value of coke oven fuel, the amount of the coal fines collected by the dust collector 11 changes as described above. The binder reguired for kneading and granulating is added to the collected coal fines as described above; however, an excess or lack of binder is caused if the constant binder amount same as in a steady state is being added even when the quality of the exhaust gas of the coke oven is changed. In view of the above problem, according to the present invention, coal fines amount collected by the dust collector 11, which changes due to changes in the flow rate or temperature of the coke oven exhaust gas, is detected to adjust the binder adding device 18 manually or automatically according to the flow rate or temperature of the coke oven exhaust gas to maintain a fixed mixing ratio of the coal fines amount discharged from the dust collector 11. With this structure, problems such as a contamination in the transferring path due to binder excess, or a dust occurrence in the transferring path or a carbon adhesion in the coke oven due to the lack of binder can be prevented. [0033] The control of the binder adding device 18 may be implemented manually or automatically by detecting or predicting a change in the coke oven exhaust gas quality or may be implemented automatically by detecting a signal (such as a signal indicating an increase or decrease in production amount of the coke oven or a signal indicating an increase of decrease in the heating value of the coke oven fuel), which indicates a change in the coke oven exhaust gas quality, sent from the coke oven. [0034] Fig. 2 is a schematic block diagram showing another embodiment of the dryer of the present invention. As shown in Fig. 2, an exhaust combustion gas generated in a coke oven 1 is discharged from a coke oven chimney 3 via a flue 2. Temperature of the coke oven exhaust gas 4 passing through the flue 2 is approximately 150°C to 250°C. The coke oven exhaust gas 4 flows through a gas supply pipe 5 branched from the flue 2 of the coke oven and, after pressurized by a blower 6, is supplied from under a fluidized bed dryer 8 as a heating and fluidizing gas 7. [0035] An exhaust gas 9 discharged from the fluidized bed dryer 8 is discharged into air from a chimney 13 through an exhaust gas pipe 10 passing through a dust collector 11 and a blower 12. [0036] Further, a gas circulating pipe 14 is branched from the exhaust gas pipe 10 and an end of the gas circulating pipe 14 is connected to the gas supply pipe 5 so as to circulate the exhaust gas 9 of the fluidized bed dryer 8 to reuse as a fluidizing gas for the fluidized bed dryer 8. [0037] The coal powder, that is, the wet raw material is charged into the fluidized bed dryer 8 through a charging chute 15 and forms a fluidized bed 16 by a rising air current due to the heating and fluidizing gas 7 introduced from the lower part of the fluidized bed dryer 8. The coal powder is dried in this fluidized bed 16 so as to have a predetermined temperature and a contained moisture ratio and is mostly discharged from a discharging chute 17. The coal powder discharged from the discharging chute 17 is transferred to the coke oven through a transferring path (not shown). On the other hand, coal fines are generated while during the coal powder in the fluidized bed 16. The coal fines are discharged with gas from an upper portion of the fluidized bed dryer 8 and collected by the dust collector 11 provided to the exhaust gas pipe 10. [0038] To the collected coal fines, a binder adding device 18 adds a binder such as heavy oil and a kneading and granulating device 19 kneads and granulates the coal fines. Then, the coal fines are transferred to the coke oven through a transferring path (not shown). The amount of the binder added from the binder adding device 18 is controlled by a binder addition controller 20. It is noted that the binder addition controller 20 may be installed in the binder adding device 18. [0039] An exhaust gas flowmeter 21 is provided to the flue 2 of the coke oven, a flowmeter 23 and a first control valve 24 are provided to the gas supply pipe 5, a second control valve 25 is provided to the exhaust gas pipe 10, and a third control valve 26 is provided to the gas circulating pipe 14. The exhaust gas flowmeter 21 is not always essential and the exhaust gas flow rate may be estimated by calculating combustion of the coke oven. Each of opening degrees and flow rates of the first to third control valves 24 to 26 are controlled by control valve controllers 27 to 29. Further, a gas circulating system controller 30 is provided to give a control instruction to each of the controllers 27 to 29 of the first to third control valves 24 to 26 to control the circulation gas amount. [0040] As has been described in Description of the related art, the coke oven 1 typically has a two combustion gas systems for each oven and those systems are switched with one another by a predetermined operation time length. In general, the switch of the systems is implemented in every 15 to 30 minutes. [0041] As shown in Fig. 4, when the combustion gas systems are switched, the combustion gas flow rate of current system (system A) is gradually reduced and, when the flow rate becomes zero, the combustion gas flow rate of another system (system B) is gradually increased. Thus, during a switch of the combustion gas systems, the coke oven exhaust gas amount reduces once, and then, increases again. The time required for switching the combustion gas systems is from 0.5 to 3 minutes in general. [0042] In the present embodiment, when the coke oven exhaust gas supply is stopped or reduced, the exhaust gas discharged from the fluidized bed dryer 8 is circulated via the gas circulating pipe 14 and reused as a fluidizing gas for the fluidized bed dryer 8. Details will be described below with reference to Figs. 2 and 3. [0043] The third control valve 26 provided to the gas circulating pipe 14 is fully closed or slightly opened in a steady operation. That is, when the coke oven exhaust gas temperature is too high in a steady operation, it is preferable to lower the gas temperature by mixing some low temperature circulation gas. Or, the circulation gas may be used to adjust drying ability when the moisture contained in the supplied coal powder changes. [0044] When the switch of combustion gas systems of the coke oven is started, the fully-closed or slightly-opened third control valve 26 is opened at a predetermined opening degree. Accordingly, due to the work of the blower 6 and the blower 12, the circulation gas 31 flows through the gas circulating pipe 14 and a recycle flow is generated. At the timing that a constant amount of the flow rate of the circulation gas 31 is maintained, the opening degree of the first control valve 24 is gradually reduced. Accordingly, the coke oven exhaust gas 4 supplied to the fluidized bed dryer 8 is gradually reduced and, on the contrary, the flow rate to the coke oven chimney 3 is increased. The opening and closing speed of the first control valve 24 is not always the same and has to be determined respectively based on an operation condition of the coke oven 1 since the exhaust combustion gas amount (flue exhaust gas amount) changes due to the operation capacity of the coke oven 1 or combustion condition in the coke oven 1 . [0045] Each of the control valve controllers 27 to 29 control the first to third control valves 24 to 26 respectively in responding to an instruction from the gas circulating system controller 30. It is noted that a part of or the entire of the gas circulating system controller 30 and the control valve condolers 27 to 29 may be integrated within a single controlling device. [0046] When the coke oven combustion gas systems are switched, the control for switching gas supply to the fluidized bed dryer 8 may be started in responding to a start signal indicating the switch of the combustion gas systems from the coke oven 1 or according to a change in the flow rate detected by the exhaust gas flowmeter 21 of the flue 2. [0047] Further, as shown in Fig. 3, the control for switching the gas supply to the fluidized bed dryer 8 may be started in responding to a prediction signal received from the coke oven 1 at a predetermined timing prior to the start of the combustion gas system switch. For example, the prediction signal is received at a timing one minute earlier than the exhaust gas flow rate becomes zero and the recycling through the gas circulating pipe 14 is started. This structure prevents a lack of gas amount supplied to the fluidized bed dryer 8 (heating and fluidizing gas amount) when the recycling is not started, yet. [0048] Since the circulation gas 31 used in the coke oven combustion gas systems switch is a gas discharged after drying the coal powder in the fluidized bed dryer 8, its temperature is certainly lower than the coke oven exhaust gas 4. Thus, when the coke oven combustion gas systems are switched, as shown in Fig. 3, the temperature of the gas introduced to the fluidized bed in the fluidized bed dryer is lowered. Accordingly, the ability of drying the wet raw material reduces and the amount of the coal fines generated during drying and collected by the dust collector reduces. [0049] To the collected coal fines, a binder required for kneading and granulating is added as described above; however, if the binder of the same amount as the steady operation is added when the coal fines amount reduces due to the coke oven combustion gas system switching, the binder amount is to be excess. Therefore, according to the present invention, the coke oven combustion gas system switching is detected and the binder addition amount is reduced in anticipation of a reduction in the coal fines amount (see the bottom section in Fig. 3). The combustion gas system switching can be detected by receiving a prediction signal from the coke oven at a predetermined timing prior to the start of the combustion gas system switching as shown in Fig. 3. When receiving the prediction signal, the binder addition controller 20 predicts a reduction of the coal fines amount within "t" second and reduces binder addition amount added by the binder adding device 18 so as to the ratio of the coal fines and the binder is kept the- same as in the steady operation. Accordingly, the coal fines and the binder are constantly mixed in a fixed ratio and problems of contamination in the transferring path caused by binder excess can be prevented. [0050] The combustion gas system switching can be detected by receiving a start signal of the combustion gas system switching from the coke oven 1. In this case, the period of time before starting to adjust the binder addition amount is shortened compared to the case of detecting by the prediction signal; however, it should be long enough in the actual operation. Industrial Applicability [0051] The present invention is applicable not only to drying of coal powder to be charged into a coke oven, but also to drying of other wet raw materials such as granulated slag and limestone. WE CLAIM: 1. A wet raw material dryer including a fluidized bed dryer for drying a wet raw material, a duct and a blower for introducing an exhaust gas of a coke oven to the fluidized bed dryer and a dust collector for collecting fine particles contained in an exhaust gas of the fluidized bed dryer, and using the exhaust gas of the coke oven as a heating and fluidizing gas for the fluidized bed dryer, comprising a binder adding device adding a binder to the fine particles discharged from the dust collector and having a mechanism for adjusting a binder addition amount in a constant ratio with respect to a fine particles amount according to a change in the fine particles discharged from the dust collector. 2. The wet raw material dryer as claimed in claim 1, wherein: a binder addition amount controller detecting an increase or decrease in a production amount of the coke oven and adjusting the binder addition amount by the binder adding device according to a detected signal. 3. The wet raw material dryer as claimed in claim 1, wherein: a binder addition amovmt controller detecting a stop or decrease of an exhaust gas supply from the coke oven and adjusting the binder addition amount by the binder adding device according to a detected signal. 4. The wet raw material dryer as claimed in claim 1, wherein: a gas circulating pipe circulating the exhaust gas from the fiuidized bed dryer to resupply the gas to the fiuidized bed dryer; and a gas circulating system controller controlling, to circulate the exhaust gas from the fluidized bed dryer to reuse the gas as a fluidizing gas for the fluidized bed dryer when a exhaust gas supply from the coke oven is stopped or decreased. 5. A wet raw material drying method using a wet raw material dryer including a fluidized bed dryer for drying a wet raw material, a duct and a blower for introducing an exhaust gas of a coke oven to the fluidized bed dryer and a dust collector for collecting fine particles contained in an exhaust gas of the fluidized bed dryer, and using the exhaust gas of the coke oven as a heating and fluidizing gas for the fluidized bed dryer, the method comprising a binder adding step adding a binder to fine particles discharged from the dust collector by a binder adding device, wherein the binder adding step adjusts a binder addition amount in a constant ratio with respect to a fine particles amount according to a change in the fine particles discharged fi-om the dust collector. 6. The wet raw material drying method as claimed in claim 5, wherein the binder adding step detects an increase or decrease in a production amount of the coke oven and adjusts the binder addition amount by the binder adding device according to a detected signal. 7. The wet raw material drying method as claimed in claim 5, wherein the binder adding step detects a stop or decrease of an exhaust gas supply from the coke oven and adjusts the binder addition amount by the binder adding device according to a detected signal. 8. The wet raw material drying method as claimed in claim 5, wherein a gas circulating system controlling step controlling circulating the exhaust gas from the fiuidized bed dryer to reuse the gas as a fluidizing gas for the fluidized bed dryer when a exhaust gas supply from the coke oven is stopped or decreased.

Documents:

7565-DELNP-2007-Abstract-(21-06-2011).pdf

7565-delnp-2007-abstract.pdf

7565-DELNP-2007-Claims-(21-06-2011).pdf

7565-delnp-2007-claims.pdf

7565-DELNP-2007-Correspondence Others-(06-09-2011).pdf

7565-DELNP-2007-Correspondence Others-(21-06-2011).pdf

7565-delnp-2007-correspondence-others 1.pdf

7565-delnp-2007-Correspondence-Others-(06-04-2011).pdf

7565-delnp-2007-correspondence-others.pdf

7565-DELNP-2007-Description (Complete)-(21-06-2011).pdf

7565-delnp-2007-description (complete).pdf

7565-DELNP-2007-Drawings-(21-06-2011).pdf

7565-DELNP-2007-Drawings.pdf

7565-DELNP-2007-Form-1-(21-06-2011).pdf

7565-delnp-2007-form-1.pdf

7565-delnp-2007-form-18.pdf

7565-DELNP-2007-Form-2-(21-06-2011).pdf

7565-delnp-2007-form-2.pdf

7565-delnp-2007-Form-3-(06-04-2011).pdf

7565-DELNP-2007-Form-3-(06-09-2011).pdf

7565-DELNP-2007-Form-3-(21-06-2011).pdf

7565-delnp-2007-form-3.pdf

7565-delnp-2007-form-5.pdf

7565-DELNP-2007-GPA-(21-06-2011).pdf

7565-delnp-2007-pct-301.pdf

7565-delnp-2007-pct-304.pdf

7565-delnp-2007-pct-306.pdf

7565-delnp-2007-pct-308.pdf