REFORMED COAL PRODUCTION EQUIPMENT, AND METHOD FOR CONTROLLING SAME

Reformed coal production equipment includes: a combustion furnace (124) generating heated gas; dry distillation gas supply pipe (101) supplying dry distillation gas (14) generated at the inner cylinder (122) of a dry distillation device (121) to the combustion furnace; vapor generator (125) to which a portion of the heated gas (11) generated at the combustion furnace is supplied and which generates waste heat gas (13) by subjecting the heated gas to heat exchange; and discharge pipe (52), waste heat gas delivery pipe (53), mixed gas delivery pipe (55), blower (126), mixed gas supply pipe (56), mixed gas branching pipe (102), flow rate adjustment valve (103), and mixed gas allocation pipe (105) which supply and allocate, to the aforementioned inner cylinder, the waste heat gas and low-temperature heated gas (12) generated by indirectly heating dried coal (2) by the heated gas within the outer cylinder (123) of the dry distillation device.

MODE FOR CARRYING OUT THE INVENTION

Upgraded coal production equipment and a method for controlling the upgraded coal production equipment according to the present invention are described using embodiments.

Based onFIGS. 1 and 2, a description is given of upgraded coal production equipment according to a first embodiment of the present invention.

In upgraded coal production equipment100according to this embodiment, first, as shown inFIG. 1, low-rank coal1such as brown coal or subbituminous coal is supplied to a drying device111by a hopper or the like (not shown), the drying device111being drying means for drying the low-rank coal1. An outlet of the drying device111communicates with an inlet122aof a pyrolysis device121configured to perform pyrolysis on dried coal2. An outlet122bof the pyrolysis device121communicates with an inlet of a cooling device131being cooling means for cooling pyrolysis coal3.

The pyrolysis device121has an inner cylinder122and an outer cylinder123surrounding the inner cylinder122. The outer cylinder123is supplied with a heating gas11to be described later. Thereby, the dried coal2supplied into the inner cylinder122is indirectly heated and is subjected to pyrolysis, to generate the pyrolysis coal3. In other words, the pyrolysis device121is an indirect-heating device, such as, e.g., an external heating kiln, in which a hot gas (heating gas) being a heat source does not come into direct contact with the low-rank coal1. The pyrolysis device121forms indirect-heating pyrolysis means.

A gas exhaust port of the inner cylinder122of the pyrolysis device121communicates with a gas intake port of a combustion furnace124via a pyrolysis gas supply pipe101. Thereby, a pyrolysis gas14containing gaseous tar (pyrolysis oil) generated by the pyrolysis is supplied to the gas intake port of the combustion furnace124. The gas intake port of the combustion furnace124is also supplied with a fuel (not shown) such as a natural gas. The combustion furnace124generates the heating gas11by combusting the pyrolysis gas14and the fuel such as a natural gas. In other words, the combustion furnace124forms heating gas generation means. A gas exhaust port of the combustion furnace124communicates with a gas intake port of the outer cylinder123of the pyrolysis device121via a heating gas feed pipe51.

The heating gas feed pipe51communicates with a gas intake port of a steam generator125via a heating gas branch pipe53. The steam generator125forms waste-heat gas generation means for generating a waste-heat gas13through heat exchange between the heating gas11and water to thereby generate water vapor. A gas exhaust port of the steam generator125communicates with an exhaust pipe52to be described later via a waste-heat gas feed pipe54.

A gas exhaust port of the outer cylinder123of the pyrolysis device121communicates with a gas intake port of an exhaust-gas treatment device127via the exhaust pipe52, the exhaust-gas treatment device127being exhaust-gas purification means for purifying the waste-heat gas13and a low-temperature heating gas12which is generated when the heating gas11heats the inner cylinder122. The low-temperature heating gas12and the waste-heat gas13are discharged to the outside of the system after undergoing the purification treatment in the exhaust-gas treatment device127.

The exhaust pipe52communicates with a gas intake port of a blower126via a mixed gas feed pipe55. A gas exhaust port of the blower126communicates with a gas intake port of the combustion furnace124via a mixed gas supply pipe56. The mixed gas supply pipe56communicates with a mixed gas branch pipe102. The mixed gas branch pipe102communicates with a mixed gas communication pipe104via a flow rate adjustment valve (three-way valve)103, and also communicates with a mixed gas distribution pipe105via the flow rate adjustment valve103. The mixed gas communication pipe104communicates with the pyrolysis gas supply pipe101. The mixed gas distribution pipe105communicates with a gas intake port of the inlet122aside of the inner cylinder122of the pyrolysis device121.

The pyrolysis gas supply pipe101is provided with a gas temperature measurement instrument106which is gas temperature measurement means for measuring the temperature of a gas inside the pipe. The gas temperature measurement instrument106is connected to a control device109such that the measured gas temperature can be sent to the control device109. The pyrolysis gas supply pipe101is provided with differential-pressure measurement instruments107a,107bconfigured to measure the differential pressure inside the pipe. The differential-pressure measurement instruments107a,107bare connected to the control device109such that the measured differential pressure inside the pipe can be sent to the control device109.

The outlet122bof the inner cylinder122of the pyrolysis device121is provided with an inner-cylinder gas temperature measurement instrument108which is gas temperature measurement means for measuring the temperature of a gas inside the inner cylinder122. The inner-cylinder gas temperature measurement instrument108is connected to the control device109such that the measured gas temperature inside the inner cylinder can be sent to the control device109.

The exhaust pipe52, the waste-heat gas feed pipe54, the mixed gas feed pipe55, the blower126, the mixed gas supply pipe56, the mixed gas branch pipe102, the flow rate adjustment valve103, the mixed gas distribution pipe105, and the like form mixed gas distribution supply means. The flow rate adjustment valve103forms gas flow rate adjustment means for adjusting the amount of the low-temperature heating gas12and the waste-heat gas13supplied to the pyrolysis device121.

Based on the measurement values obtained by the various measurement instruments, the control device109controls the flow rate adjustment valve103, the amount of fuel supplied to the combustion furnace124, the amount of the low-rank coal1supplied to the drying device111, the amount of the heating gas11supplied to the pyrolysis device121, and the like. In other words, the control device109forms control means for adjusting the valve position of the flow rate adjustment valve103and the like based on the measurement values obtained by the various measurement instruments.

In the upgraded coal production equipment100according to this embodiment thus configured, when the low-rank coal1is charged into the hopper, the hopper supplies the low-rank coal1at a room temperature to the drying device111a predetermined amount at a time. The low-rank coal1supplied to the drying device111is removed of water and becomes the dried coal2by being heated up to about 200° C. by a drying combustion gas (about 150 to 300° C.) from a drying combustor (not shown). Then, the dried coal2is transferred into the inner cylinder122of the pyrolysis device121. The dried coal2transferred to the pyrolysis device121is subjected to pyrolysis by being indirectly heated by the heating gas11(gas temperature: about 1050° C., oxygen concentration: about 2 to 3%) from the combustion furnace124. Thereby, the dried coal2becomes the pyrolysis coal3as a result of removal of components such as the pyrolysis gas14containing gaseous tar, and the pyrolysis coal3is fed to the cooling device131. The pyrolysis coal3fed to the cooling device131becomes upgraded coal4by being cooled down to about 50° C.

Meanwhile, the heating gas11(gas temperature: about 1050° C., oxygen concentration: about 2 to 3%) generated in the combustion furnace124is fed to the outer cylinder123of the pyrolysis device121via the heating gas feed pipe51. The heating gas11used inside the outer cylinder123to heat the inner cylinder122becomes the low-temperature heating gas12(gas temperature: about 350° C., oxygen concentration: about 2 to 3%). The low-temperature heating gas12is fed to the exhaust pipe52. Meanwhile, the heating gas11is also fed to the steam generator125via the heating gas feed pipe51and the heating gas branch pipe53. The heating gas11used in the steam generator125for generation of water vapor becomes the waste-heat gas13(gas temperature: about 350° C., oxygen concentration: about 2 to 3%). The waste-heat gas13is fed to the exhaust pipe52via the waste-heat gas feed pipe54.

Part of the low-temperature heating gas12and the waste-heat gas13is supplied to the exhaust-gas treatment device127. The low-temperature heating gas12and the waste-heat gas13undergo the purification treatment in the exhaust-gas treatment device127and are then discharged to the outside of the system. The rest of the low-temperature heating gas12and the waste-heat gas13(gas temperature: about 350° C., oxygen concentration: about 2 to 3%) is fed to the blower126via the mixed gas feed pipe55.

Part of the low-temperature heating gas12and the waste-heat gas13fed to the blower126is supplied to the combustion furnace124via the mixed gas supply pipe56. The rest of the low-temperature heating gas12and the waste-heat gas13(gas temperature: about 350° C., oxygen concentration: about 2 to 3%) fed to the blower126is supplied to the mixed gas branch pipe102. The rest of the low-temperature heating gas12and the waste-heat gas13(gas temperature: about 350° C., oxygen concentration: about 2 to 3%) supplied to the mixed gas branch pipe102is supplied to the pyrolysis gas supply pipe101via the flow rate adjustment valve103and the mixed gas communication pipe104, or supplied to the inlet122aside of the inner cylinder122of the pyrolysis device121via the flow rate adjustment valve103and the mixed gas distribution pipe105.

The valve position of the flow rate adjustment valve103is controlled by the control device109based on the gas temperature measured by the gas temperature measurement instrument106. For example, the control device109adjusts the flow rate adjustment valve103by opening it to increase the aperture when the gas temperature measured by the gas temperature measurement instrument106is equal to or higher than 400° C., and adjusts the flow rate adjustment valve103by narrowing it when the gas temperature exceeds 550° C. Thereby, the low-temperature heating gas12and the waste-heat gas13(oxygen concentration: about 2 to 3%) are mixed with the pyrolysis gas14(gas temperature: about 400° C., oxygen concentration: about 0%), and this mixed gas has an oxygen concentration adjusted to about 1 to 2%. As a result, gaseous tar (pyrolysis oil) is oxidatively decomposed (decoking) to become light in weight, and thereby attachment of the tar to the pyrolysis gas supply pipe101can be prevented. The tar is reduced in weight to become a light gas, and this light gas is combusted. Thus, decrease in the gas temperature is prevented. Thereby, attachment of the tar to the pyrolysis gas supply pipe101can be prevented. Specifically, the decoking is performed just when the tar is about to be attached to the inner wall surface of the pyrolysis gas supply pipe101by adjustment of the amount of the low-temperature heating gas12and the waste-heat gas13supplied to the pyrolysis gas supply pipe101based on the gas temperature inside the pyrolysis gas supply pipe101. Hence, the tar can be efficiently removed.

With reference toFIG. 2, a description is given of operation performed when shutting down the upgraded coal production equipment100according to this embodiment configured as above.

As shown inFIG. 2, first, the upgraded coal production equipment100is in steady operation (Step SA1). To shut down this upgraded coal production equipment100, transfer of the dried coal2to the inner cylinder122of the pyrolysis device121is stopped (Step SA2).

Next, the flow proceeds to Step SA3as well as to Step SA11. In Step SA11, since the dried coal2is not newly transferred to the inner cylinder122of the pyrolysis device121, the amount of the pyrolysis gas14generated decreases. The decrease in the generated amount of the pyrolysis gas14results in a decreased amount of the pyrolysis gas14supplied to the combustion furnace124. However, by increasing the amount of fuel, such as a natural gas, supplied to the combustion furnace124to increase the amount of additional gas to be supplied to the combustion furnace124, decrease in the gas temperature and generated amount of the heating gas11can be suppressed. In sum, the amount of additional gas to be supplied to the combustion furnace is increased (Step SA12). Thereafter, all the pyrolysis coal3is discharged from the pyrolysis device121(Step SA13). This means that the pyrolysis device121generates no more pyrolysis gas14.

Meanwhile, in Step SA3, the control device109adjusts the flow rate adjustment valve103to start supply of the low-temperature heating gas12and the waste-heat gas13to the inlet122aside of the inner cylinder122of the pyrolysis device121via the mixed gas distribution pipe105. In other words, the low-temperature heating gas12and the waste-heat gas13are forcibly supplied into the inner cylinder122of the pyrolysis device121from the inlet122aside thereof. Thereby, the inner cylinder122of the pyrolysis device121and the pyrolysis gas supply pipe101are purged of the pyrolysis gas14.

Subsequently, since all the pyrolysis coal3is discharged from the inside of the inner cylinder122of the pyrolysis device121, no pyrolysis gas14is generated by the indirect heating of the dried coal2. As a result, no pyrolysis gas14is supplied to the combustion furnace124. Thus, the amount of additional gas to be supplied to the combustion furnace124is decreased (Step SA4). This consequently decreases the gas temperature and generated amount of the heating gas11generated in the combustion furnace124(Step SA5).

Next, since the heating gas11which is less in amount and lower in temperature than in the steady operation is supplied to the outer cylinder123of the pyrolysis device121, the temperature of the pyrolysis device121decreases (Step SA6). This consequently decreases the temperature of the low-temperature heating gas12itself and also the temperature of the waste-heat gas13(Step SA7).

Then, the flow proceeds to Step SA8in which the control device109makes a judgment based on the gas temperature inside the inner cylinder measured by the inner-cylinder gas temperature measurement instrument108. When the gas temperature near the outlet122bof the inner cylinder122of the pyrolysis device121is higher than 300° C., the flow returns to Step SA4. On the other hand, when the gas temperature near the outlet122bof the inner cylinder122of the pyrolysis device121is equal to or lower than 300° C., the flow proceeds to Step SA9in which the control device109controls the flow rate adjustment valve103to close the flow rate adjustment valve103. In other words, supply of the low-temperature heating gas12and the waste-heat gas13to the inner cylinder122of the pyrolysis device121is stopped.

Hence, in the upgraded coal production equipment100according to this embodiment, in shutting down the equipment, the low-temperature heating gas12and the waste-heat gas13are supplied to the inlet122aside of the inner cylinder122of the pyrolysis device121to forcibly discharge the pyrolysis gas14inside the inner cylinder122of the pyrolysis device121and inside the pyrolysis gas supply pipe101. Moreover, this pyrolysis gas14is combusted in the combustion furnace124.

Further, since the oxygen concentration of the low-temperature heating gas12and the waste-heat gas13is about 2 to 3%, tar can be oxidatively decomposed to become light in weight. The gas thus reduced in weight flows the combustion furnace124and combusted inside the combustion furnace124. Even if tar is attached to the inner wall surface of the inner cylinder122of the pyrolysis device121or the inner wall surface of the pyrolysis gas supply pipe101, the tar can be removed by combustion.

Thus, even in shutting down the equipment, tar can be efficiently removed without lowering the production volume of the upgraded coal4. In addition, since tar can be prevented from being attached to the inner wall surfaces of the inner cylinder122of the pyrolysis device121and the pyrolysis gas supply pipe101, maintenance and inspection work can be efficiently performed.

Based onFIGS. 3,4A, and4B, upgraded coal production equipment according to a second embodiment of the present invention is described.

As shown inFIG. 3, the upgraded coal production equipment according to this embodiment includes three upgraded coal production equipment main bodies100A,100B, and100C arranged in parallel. Like the upgraded coal production equipment100according to the first embodiment described above, the upgraded coal production equipment main bodies100A,100B, and100C each include a drying device111, a pyrolysis device121, and a cooling device131.

Like the upgraded coal production equipment100according to the first embodiment described above, the upgraded coal production equipment according to this embodiment includes one combustion furnace124, one blower126, and one exhaust-gas treatment device127. A gas exhaust port of the blower126communicates with a gas intake port of the combustion furnace124via a mixed gas supply pipe56. A gas exhaust port of the combustion furnace124communicates with an outer cylinder123of a pyrolysis device121of each of the equipment main bodies100A,100B, and100C via a corresponding one of heating gas feed pipes51ato51c.

The heating gas feed pipes51ato51ccommunicate with gas intake ports of steam generators125via heating gas branch pipes53ato53c, respectively. Gas exhaust ports of the steam generators125communicate with waste-heat gas feed pipes54ato54c, respectively.

Gas exhaust ports of the outer cylinders123of the pyrolysis devices121communicate with exhaust pipes52ato52c, respectively. Part of a waste-heat gas13and a low-temperature heating gas12which is generated when a heating gas11heats inner cylinders122is supplied via waste-heat gas feed pipe54ato54cor the exhaust pipes52ato52cto the exhaust-gas treatment device127being exhaust gas purification means for performing purification treatment on the low-temperature heating gas12and the waste-heat gas13, and is discharged to the outside of the system after undergoing the purification treatment in the exhaust-gas treatment device127. The rest of the low-temperature heating gas12and the waste-heat gas13is supplied to the blower126via the exhaust pipes52ato52cor the waste-heat gas feed pipes54ato54cand the mixed gas feed pipe55.

Gas exhaust ports of the inner cylinders122of the pyrolysis devices121communicate with gas intake ports of the combustion furnace124via pyrolysis gas supply pipes101ato101c, respectively.

The mixed gas supply pipe56communicates with mixed gas branch pipes102ato102c. The mixed gas branch pipes102ato102ccommunicate with mixed gas communication pipes104ato104cvia flow rate adjustment valves (three-way valves)103ato103c, respectively, and also communicate with mixed gas distribution pipes105ato105cvia the flow rate adjustment valves103ato103c, respectively. The mixed gas communication pipes104ato104ccommunicate with the pyrolysis gas supply pipes101ato101c, respectively. The mixed gas distribution pipes105ato105ccommunicate with gas intake ports of the inlet122aside of the inner cylinders122of the pyrolysis devices121, respectively.

The pyrolysis gas supply pipe101ais provided with a gas temperature measurement instrument106being gas temperature measurement means for measuring the gas temperature inside the pipe. The gas temperature measurement instrument106is connected to the control device109such that the measured gas temperature can be sent to the control device109. Like the pyrolysis gas supply pipe101a, the pyrolysis gas supply pipes101band101care each provided with a gas temperature measurement instrument (not shown), as well. These gas temperature measurement instruments are also connected to the control device109such that the gas temperature measured by the gas temperature measurement instruments can be sent to the control device109.

The pyrolysis gas supply pipe101ais provided with the differential-pressure measurement instruments107a,107bconfigured to measure the differential pressure in the pipe. The differential-pressure measurement instruments107a,107bare connected to the control device109such that the measured differential pressure in the pipe can be sent to the control device109. Like the pyrolysis gas supply pipe101a, the pyrolysis gas supply pipes101band101care each provided with differential-pressure measurement instruments (not shown), as well. These differential-pressure measurement instruments are also connected to the control device109such that the differential pressure in the pipe measured by the differential-pressure measurement instruments can be sent to the control device109.

The outlet122bof the inner cylinder122of the pyrolysis device121of the equipment main body100A is provided with an inner-cylinder gas temperature measurement instrument108configured to measure the temperature of the gas inside the inner cylinder122. The inner-cylinder gas temperature measurement instrument108is connected to the control device109such that the measured temperature of the gas inside the inner cylinder can be sent to the control device109. Like the equipment main body100A, the outlet122bof the inner cylinder122of the pyrolysis device121of each of the equipment main bodies100B and100C is also provided with an inner-cylinder gas temperature measurement instrument (not shown) configured to measure the temperature of the gas inside the inner cylinder122. These inner-cylinder gas temperature measurement instruments are also connected to the control device109such that the measured temperature of gas inside the inner cylinder can be sent to the control device109.

The exhaust pipes52ato52c, the waste-heat gas feed pipes54ato54c, the mixed gas feed pipe55, the blower126, the mixed gas supply pipe56, the mixed gas branch pipes102ato102c, the flow rate adjustment valves103ato103c, the mixed gas distribution pipes105ato105c, and the like form mixed gas distribution supply means. The flow rate adjustment valves103ato103cform gas flow rate adjustment means for adjusting the amount of the low-temperature heating gas12and the waste-heat gas13supplied to the pyrolysis devices121of the equipment main bodies100A,100B, and100C, respectively.

Based on the measurement values of the various measurement instruments, the control device109controls the flow rate adjustment valves103ato103c, the amount of fuel supplied to the combustion furnace124, the amount of the low-rank coal1supplied to the drying device111of each of the equipment main bodies100A,100B, and100C, the amount of the heating gas11supplied to the pyrolysis device121of each of the equipment main bodies100A,100B, and100C, and the like. In other words, the control device109forms control means for adjusting the valve positions of the flow rate adjustment valves103ato103cand the like based on the measurement values obtained by the various measurement instruments.

In the upgraded coal production equipment according to this embodiment thus configured, the operation for performing control to prevent attachment of tar to the pyrolysis gas supply pipes101a,101b, and101cduring the steady operation is the same as that performed by the upgraded coal production equipment100according to the first embodiment described above, and is therefore not described again here.

With reference toFIGS. 4A and 4B, operation performed when a upgraded coal production equipment main body of the upgraded coal production equipment according to this embodiment is shut down and then returns to a steady operation state.

In a case described, while the upgraded coal production equipment main bodies100E and100C are in a steady operation state, the upgraded coal production equipment main body100A is shut down and then returns to the steady operation state.

As shown inFIGS. 4A and 4B, first, the upgraded coal production equipment main body100A is in steady operation (Step SB1). The upgraded coal production equipment main bodies100B and100C are also in steady operation (Step SC1).

To shut down the upgraded coal production equipment main body100A, transfer of the dried coal2to the inner cylinder122of the pyrolysis device121is stopped (Step SB2). Since this decreases the amount of the dried coal2inside the inner cylinder122of the pyrolysis device121of the equipment main body100A, the amount of the heating gas11supplied from the combustion furnace124to the outer cylinder123of the pyrolysis device121is decreased (Step SB3). Thus, thermal load in the pyrolysis device121of the equipment main body100A decreases. Meanwhile, in the equipment main bodies100B and100C, the amount of the dried coal2transferred to the inner cylinder122of the pyrolysis device121of each of the equipment main bodies100E and100C is increased (Step SC2). Since this increases the amount of the dried coal2inside the inner cylinder122of the pyrolysis device121of each of the equipment main bodies100E and100C, the amount of the heating gas11supplied from the combustion furnace124to the outer cylinder123of each pyrolysis device121is increased (Step SC3). Thus, thermal load in the pyrolysis device121of each of the equipment main bodies100E and100C increases.

Subsequently, the control device109adjusts the flow rate adjustment valve103ato supply the low-temperature heating gas12and the waste-heat gas13to the inlet122aside of the inner cylinder122of the pyrolysis device121via the mixed gas distribution pipe105a(Step SB4). By the low-temperature heating gas12and the waste-heat gas13, the inner cylinder122of the pyrolysis device121and the pyrolysis gas supply pipe101aof the equipment main body100A are purged of the pyrolysis gas14. Moreover, the oxygen concentration of the gas inside the inner cylinder122and the pyrolysis gas supply pipe101abecomes about 1 to 2%, so that the tar is oxidatively decomposed to be reduced in weight. Then, the light gas obtained by the weight reduction is combusted. Hence, attachment of the tar to the wall surface of the inner cylinder122and the wall surface of the pyrolysis gas supply pipe101ais prevented.

Subsequently, all the pyrolysis coal3is discharged from the inner cylinder122of the pyrolysis device121of the equipment main body100A (Step SB5), and the supply of the heating gas11to the outer cylinder123of the pyrolysis device121of the equipment main body100A is stopped (Step SB6). Consequently, thermal load in the pyrolysis device121of the equipment main body100A decreases. Meanwhile, in the equipment main bodies100B and100C, the supply of the heating gas11to the outer cylinder123of the pyrolysis device121of each of the equipment main bodies100E and100C is brought to the steady state (Step SC4). Thereby, the pyrolysis device121of each of the equipment main bodies100E and100C maintains the state of the increased thermal load.

Next, in the equipment main body100A, when a predetermined period of time elapses after the stop of the supply of the heating gas11to the outer cylinder123of the pyrolysis device121of the equipment main body100A (Step SB7), the pyrolysis gas14is no longer in the inner cylinder122of the pyrolysis device121and the pyrolysis gas supply pipe101aof the equipment main body100A, and therefore no more supply of the low-temperature heating gas12and the waste-heat gas13is necessary. Thus, the supply of the low-temperature heating gas12and the waste-heat gas13to the inlet122aside of the inner cylinder122of the pyrolysis device121of the equipment main body100A is stopped (Step SB8). In this Step SB8, work such as maintenance and inspection is performed on the equipment main body100A when necessary.

Next, once the work such as maintenance and inspection is finished, to bring the equipment main body100A back to the steady operation state, first, in the equipment main body100A, transfer of the dried coal2from the drying device111into the inner cylinder122of the pyrolysis device121is started (Step SB9). Thereby, the amount of the dried coal2inside the inner cylinder122of the pyrolysis device121of the equipment main body100A increases. Thus, the amount of the heating gas11supplied from the combustion furnace124to the outer cylinder123of the pyrolysis device121is increased (Step SB10). Thereby, thermal load in the pyrolysis device121of the equipment main body100A increases. Meanwhile, in the equipment main bodies100E and100C, the amount of the dried coal2transferred to the inner cylinder122of the pyrolysis device121of each of the equipment main bodies100E and100C is decreased (Step SC5). Since this decreases the amount of the dried coal2inside the inner cylinder122of the pyrolysis device121of each of the equipment main bodies100E and100C, the amount of the heating gas11supplied from the combustion furnace124to the outer cylinder123of each pyrolysis device121is decreased (Step SC6). Consequently, thermal load in the pyrolysis device121of each of the equipment main bodies100E and100C decreases.

Thereafter, when the amount of the dried coal2supplied to the inner cylinder122of the pyrolysis device121of the equipment main body100A reaches a predetermined amount and also when the amount of the heating gas11supplied to the outer cylinder123of the pyrolysis device121reaches a predetermined amount, the equipment main body100A is back in the steady operation state (Step SB11). Meanwhile, when the amount of the dried coal2supplied to the inner cylinder122of the pyrolysis device121of each of the equipment main bodies100E and100C reaches a predetermined amount and also when the amount of the heating gas11supplied to the outer cylinder123of each pyrolysis device121reaches a predetermined amount, the equipment main bodies100E and100C are also back in the steady operation state (Step SC7).

In a case of shutting down the equipment main body100B or the equipment main body100C, operation according to the procedures as described for the equipment main body100A above can also prevent attachment of tar to the inner wall surfaces of the inner cylinder122of the pyrolysis device121and the pyrolysis gas supply pipe101bor101cof the equipment main body100B or100C. In other words, by performing the above-described operation sequentially on equipment main bodies to be shut down, tar can be efficiently removed in each equipment main body to be shut down, while suppressing lowering of the operating rate of the entire upgraded coal production equipment.

Hence, in the upgraded coal production equipment of this embodiment, like the upgraded coal production equipment100according to the first embodiment described above, to shut down an equipment main body, the low-temperature heating gas12and the waste-heat gas13are supplied to the inlet122aside of the inner cylinder122of the pyrolysis device121of the equipment main body to be shut down, in order to forcibly discharge the pyrolysis gas14inside the inner cylinder122of the pyrolysis device121and inside the pyrolysis gas supply pipe. This pyrolysis gas14is combusted in the combustion furnace124.

Further, since the oxygen concentration of the low-temperature heating gas12and the waste-heat gas13is about 2 to 3%, tar can be oxidatively decomposed to become light in weight. The gas thus reduced in weight flows the combustion furnace124and is combusted inside the combustion furnace124. Even if tar is attached to the inner wall surface of the inner cylinder122of the pyrolysis device121or the inner wall surface of the pyrolysis gas supply pipe, the tar can be removed by the combustion.

Thus, even in shutting down an equipment main body, tar can be efficiently removed without lowering the production volume of the upgraded coal4. In addition, since tar can be prevented from being attached to the inner wall surfaces of the inner cylinder122of the pyrolysis device121and the pyrolysis gas supply pipe, maintenance and inspection work can be efficiently performed.

Other Embodiments

Although the upgraded coal production equipment described above has three upgraded coal production equipment main bodies100A,100B, and100C arranged in parallel, the number of the upgraded coal production equipment main bodies is not limited to three, but the upgraded coal production equipment may have two or four or more upgraded coal production equipment main bodies arranged in parallel.

The upgraded coal production equipment described above is configured to stop supply of the low-temperature heating gas12and the waste-heat gas13to the inner cylinder122of the pyrolysis device121of the equipment main body100A based on a period of time elapsed after the stop of the supply of the heating gas11to the outer cylinder123of the pyrolysis device121of the equipment main body100A. The upgraded coal production equipment can also stop the supply of the low-temperature heating gas and the waste-heat gas to the inner cylinder of the pyrolysis device of the equipment main body to be shut down, based on measurement values obtained by measurement instruments, such as the differential-pressure measurement instruments107a,107b, of the equipment main body to be shut down.

INDUSTRIAL APPLICABILITY

The upgraded coal production equipment and the method for controlling the same according to the present invention can remove tar efficiently without lowering the production volume of upgraded coal even in shutting down the equipment, and can therefore be utilized significantly beneficially in various industries.

EXPLANATION OF REFERENCE NUMERALS