Drying Conveyer, and Thermal Electric Power Generation System Provided with Same

Abstract

[Problem] To provide a drying conveyer apparatus capable of efficiently and uniformly drying coarse particles. [Solution] The present invention is characterized in that a gas get portion ( 29 ) is provided on a bottom part of a conveyance member ( 25 ), a wind box ( 35 ) is provided for supplying drying gas ( 49 ) from blow the conveyance member ( 25 ), an object to be conveyed ( 2 ) is inputted within the conveyance member ( 25 ), the drying gas ( 35 ) is jetted from the gas jet portion ( 29 ) into the conveyance member ( 25 ) when the conveyance member ( 25 ) passes over the wind box ( 35 ), and the object to be conveyed ( 2 ) is dried while a fluidized bed thereof is formed.

1 . A drying conveyer apparatus comprising:
 a pair of driving shaft bodies which are disposed at a predetermined distance from each other; and   conveyance members which are provided between the driving shaft bodies and which are rotated around the driving shaft bodies so as to store and convey an object to be conveyed; wherein:   the conveyance members are fluidized bed forming conveyance members each provided with a gas jet portion in a bottom part thereof, the gas jet portion jetting drying gas;   a wind box is provided for supplying the drying gas from below the fluidized bed forming conveyance members which are moving; and   when each of the fluidized bed forming conveyance members passes over the wind box, the drying gas is jetted from the gas jet portion into the fluidized bed forming conveyance member so as to dry the object while forming a fluidized bed of the object.   
     
     
         2 . A drying conveyer apparatus according to  claim 1 , wherein:
 a flow rate or a temperature of the drying gas supplied to the wind box can be adjusted in accordance with a dried state of the object.   
     
     
         3 . A drying conveyer apparatus according to  claim 1 , wherein:
 the wind box includes a plurality of wind boxes provided in a conveyance direction of the object, and a flow rate or a temperature of the dying gas supplied to an upstream one of the wind boxes disposed upstream in the conveyance direction of the object is different from a flow rate or a temperature of the drying gas supplied to a downstream one of the wind boxes disposed downstream in the conveyance direction of the object.   
     
     
         4 . A drying conveyer apparatus according to  claim 1 , further comprising:
 a housing which receives a body of the conveyer apparatus so as to isolate the body of the conveyer apparatus from outside air and which has a discharge port for taking out the dried object; wherein:   each of the fluidized bed forming conveyance members includes a bottom plate provided with the gas jet portion, and a back plate provided erectly from a downstream end part of the bottom plate in a moving direction of the fluidized bed forming conveyance member so that an upstream side of the fluidized bed forming conveyance member in the moving direction thereof and an upper side of the fluidized bed forming conveyance member are opened;   blow-through prevention members are placed within the housing so that the blow-through prevention members extend from one of the driving shaft bodies to the other of the driving shaft bodies correspondingly to left and right side faces of the fluidized bed forming conveyance members; and   the upstream side of each of the fluidized bed forming conveyance members in the moving direction thereof is closed with the back plate of the adjacent and previous one of the fluidized bed forming conveyance members and the left and right side faces of the fluidized bed forming conveyance members are covered with the blow-through prevention members, so that a space which can receive pulverized pieces of the object can be formed on the inside of the fluidized bed forming conveyance member.   
     
     
         5 . A drying conveyer apparatus according to  claim 1 , wherein:
 a bottom plate of the wind box is inclined to be lower in level from one end part thereof toward the other end part thereof, and a falling particle discharge port through which particles of the object falling down from the fluidized bed forming conveyance members are discharged from the wind box is formed in the lower end part of the bottom plate or a lower end part of the side plate connected to the lower end part of the bottom plate.   
     
     
         6 . A drying conveyer apparatus according to  claim 1 , wherein:
 a to-be-conveyed object supply unit which inputs the object into the fluidized bed forming conveyance members is provided above one of the paired driving shaft bodies;   the to-be-conveyed object supply unit includes:   a pre-drying hopper which stores the object;   a first gate valve which is provided in a lower part of the pre-drying hopper;   a measuring tube portion which is provided in a lower part of the first gate valve; and   a second gate valve which is provided in a lower part of the measuring tube portion;   a position sensor which detects arrival of each of the fluidized bed forming conveyance members is provided under the to-be-conveyed object supply unit;   the second gate valve is closed, the first gate valve is opened, and a part of the object stored in the pre-drying hopper is loaded in the measuring tube portion so as to be measured; and   when the arrival of each of the fluidized bed forming conveyance members is detected by the position sensor in a state where the first gate valve and the second gate valve are closed, the second gate valve is opened so that the object loaded in the measuring tube portion can be inputted into the fluidized bed forming conveyance member.   
     
     
         7 . A drying conveyer apparatus according to  claim 1 , further comprising:
 a housing which receives a body of the drying conveyer apparatus so as to isolate the body of the drying conveyer apparatus from outside air and which has a discharge port for taking out the dried object; and   a scattering particle capturing unit which captures scattering particles of pulverized pieces of the object contained in drying gas staying in the housing when the drying gas is introduced to the scattering particle capturing unit.   
     
     
         8 . A drying conveyer apparatus according to  claim 7 , further comprising:
 a moisture removing unit which removes moisture from the gas which has passed through the scattering particle capturing unit and contains moisture;   a gas heating unit which heats the gas which has passed through the moisture removing unit; and   a circulating tube arrangement which extends from the scattering particle capturing unit and is connected to the wind box through the moisture removing unit and the gas heating unit, and by which the gas heated by the gas heating unit can be supplied as the drying gas to the wind box.   
     
     
         9 . A drying conveyer apparatus according to  claim 7 , wherein:
 the particles captured by the scattering particle capturing unit are stored in a post-drying hopper together with the dried object taken out from the discharge port of the housing.   
     
     
         10 . A drying conveyer apparatus according to  claim 9 , wherein:
 a heat transfer tube for keeping a moisture content of the stored object within a predetermined range is disposed in the post-drying hopper.   
     
     
         11 . A drying conveyer apparatus according to  claim 1 , wherein:
 a to-be-conveyed object supply unit which inputs the object into the fluidized bed forming conveyance members is provided above one of the paired driving shaft bodies; and   a supply-side closing member which closes the gas jet portion of each of the fluidized bed forming conveyance members having moved onto the supply-side closing member is placed under the to-be-conveyed object supply unit.   
     
     
         12 . A drying conveyer apparatus according to  claim 11 , wherein:
 a discharge-side closing member which closes the gas jet portion of each of the fluidized bed forming conveyance members having moved onto the discharge-side closing member is placed between the other driving shaft body of the paired driving shaft bodies and the most downstream wind box disposed most downstream in the conveyance direction of the object.   
     
     
         13 . A drying conveyer apparatus according to  claim 1 , further comprising:
 a housing which receives a body of the drying conveyer apparatus so as to isolate the body of the drying conveyer apparatus from outside air, the housing including a discharge port for taking out the dried object; and   a cleaning unit which collects the object falling down to an inside bottom of the housing and discharges the collected object from the discharge port.   
     
     
         14 . A drying conveyer apparatus according to  claim 1 , wherein:
 the object is coal, and the drying gas is the air whose temperature has been increased;   the drying conveyer apparatus further comprises:   a housing which receives a body of the drying conveyer apparatus so as to isolate the body of the drying conveyer apparatus from outside air and which has a discharge port for taking out the dried object;   an oxygen concentration meter which detects oxygen concentration in the drying gas; and   an inactive state forming unit which makes at least the interior of the housing inactive; and   the interior of the housing is made inactive by the inactive state forming unit when the oxygen concentration detected by the oxygen concentration meter exceeds a specified value.   
     
     
         15 . A drying conveyer apparatus according to  claim 1 , wherein:
 the object is coal, and the drying gas is the air whose temperature has been increased;   the drying conveyer apparatus further comprises:   a housing which receives a body of the drying conveyer apparatus so as to isolate the body of the drying conveyer apparatus from outside air and which has a discharge port for taking out the dried object;   a carbon monoxide concentration meter which detects carbon monoxide concentration in the drying gas; and   an inactive state forming unit which makes at least the interior of the housing inactive; and   the interior of the housing is made inactive by the inactive state forming unit when the carbon monoxide concentration detected by the carbon monoxide concentration meter exceeds a specified value.   
     
     
         16 . A drying conveyer apparatus according to  claim 1 , wherein:
 the object is coal, and the drying gas is the air whose temperature has been increased;   the drying conveyer apparatus further comprises:   a housing which receives a body of the drying conveyer apparatus so as to isolate the body of the drying conveyer apparatus from outside air and which has a discharge port for taking out the dried object;   a thermometer which detects a temperature of the drying gas; and   an inactive state forming unit which makes at least the interior of the housing inactive; and   the interior of the housing is made inactive by the inactive state forming unit when the temperature detected by the thermometer exceeds a specified value.   
     
     
         17 . A drying conveyer apparatus according to  claim 14 , further comprising:
 a scattering particle capturing unit which captures scattering particles of pulverized pieces of the object contained in drying gas staying in the housing when the drying gas is introduced to the scattering particle capturing unit; and   a post-drying hopper which stores the dried pulverized pieces discharged from the housing and the fine particles of the pulverized pieces captured by the scattering particle capturing unit; wherein:   the scattering particle capturing unit and the interior of the post-drying hopper are made inactive by the inactive state forming unit when a value detected by the oxygen concentration meter, the carbon monoxide concentration meter or the thermometer exceeds the specified value.   
     
     
         18 . A drying conveyer apparatus according to  claim 1 , wherein:
 the object is coal;   a to-be-conveyed object supply unit which inputs the object into the fluidized bed forming conveyance members is provided above one of the paired driving shaft bodies;   the to-be-conveyed object supply unit includes a pulverizer which pulverizes the object and a pre-drying hopper which stores pulverized pieces of the object;   the drying conveyer apparatus further comprises:   a carbon monoxide concentration meter which detects carbon monoxide concentration in the pre-drying hopper, and   an inactive state forming unit which makes the interior of the pre-drying hopper inactive; and   the interior of the pre-drying hopper is made inactive by the inactive state forming unit when the carbon monoxide concentration detected by the carbon monoxide concentration meter exceeds a specified value.   
     
     
         19 . A drying conveyer apparatus according to  claim 1 , further comprising:
 a pulverizer which pulverizes a raw material of the object so as to set the pulverized raw material as the object; wherein:   the pulverizer includes:   a rotor in which a jet port is formed in a circumferential wall thereof; and   a collision receiver member which is placed to surround the rotor, and   the raw material supplied into the rotor which is rotating is jetted from the jet port by centrifugal force so that the raw material colliding with the collision receiver member can be pulverized.   
     
     
         20 . A drying conveyer apparatus according to  claim 1 , wherein:
 the wind box includes a first wind box, a second wind box and a third wind box which are disposed sequentially from the upstream side to the downstream side in a conveyance direction of the object;   hot air supply tubes each provided with a blower and a heat exchanger are connected to the wind boxes respectively;   a first independent hood, a second independent hood and a third independent hood are disposed above the first wind box, the second wind box and the third wind box so as to be opposed to the first wind box, the second wind box and the third wind box through the fluidized bed forming conveyance members circulated among the first wind box, the second wind box and the third wind box;   exhaust tubes are connected to the independent hoods respectively;   a front end of the exhaust tube connected to the first independent hood is connected to a suction port of the blower provided in the second wind box; and   a front end of the exhaust tube connected to the second independent hood is connected to a suction port of the blower provided in the third wind box.   
     
     
         21 . A drying conveyer apparatus according to  claim 20 , wherein:
 soft plate materials are hung between adjacent ones of the independent hoods so as to face the fluidized bed forming conveyance members which are moving.   
     
     
         22 . A drying conveyer apparatus according to  claim 20 , wherein:
 the size of the wind box disposed downstream in the conveyance direction of the object is larger than the size of the wind box disposed upstream in the conveyance direction of the object.   
     
     
         23 . A drying conveyer apparatus according to  claim 1 , wherein:
 the object is brown coal.   
     
     
         24 . A thermal electric power generation plant comprising:
 a conveyer apparatus which conveys coal;   a coal fired boiler apparatus which burns the coal conveyed by the conveyer apparatus so as to generate steam; and   a stream turbine which is rotationally driven by the steam from the coal fired boiler apparatus; wherein:   the conveyer apparatus is a drying conveyer apparatus according to  claim 1 ; and   the air whose temperature is increased by the steam extracted from the steam turbine is used as the drying gas for the drying conveyer apparatus.   
     
     
         25 . A thermal electric power generation plant comprising:
 a conveyer apparatus which conveys coal;   a coal fired boiler apparatus which burns the coal conveyed by the conveyer apparatus so as to generate steam; and   a stream turbine which is rotationally driven by the steam from the coal fired boiler apparatus; wherein:   the conveyer apparatus is a drying conveyer apparatus according to  claim 1 ; and   the air whose temperature is increased by exhaust gas discharged from the coal fired boiler apparatus is used as the drying gas for the drying conveyer apparatus.   
     
     
         26 . A thermal electric power generation plant according to  claim 24 , wherein:
 the coal fired boiler apparatus is a two-pass type boiler apparatus in which a convection heat transfer portion is disposed in a rear part of a furnace so that combustion gas moving up in the furnace can flow to move down in the convection heat transfer portion.   
     
     
         27 . A thermal electric power generation plant according to  claim 24 , wherein:
 the coal is brown coal.