Patent Publication Number: US-2019195490-A1

Title: Boiler apparatus for waste incineration

Description:
TECHNICAL FIELD 
     The present invention relates to a boiler apparatus for waste incineration and, more particularly, a boiler apparatus for waste incineration with increased combustion efficiency, which can completely burn waste such waste tires or waste plastic as well typical wood fuel to thus eliminate a risk of air pollution caused by harmful gas, and may use combustion heat generated while burning the waste to thus heat water. 
     BACKGROUND ART 
     Typically, waste is material losing value after use in living and industrial activities and includes waste tires, waste plastic, garbage, etc., as representative examples thereof. Such waste is usually buried or incinerated if recycling or reuse of the waste is restricted. However, a landfill process causes serious soil and water contamination and has recently become an object of strict regulation. Under such background, an incineration method is most commonly employed in the art. Incineration serves to remove waste by burning the same, which is a chemical treatment method involving directly applying flame to waste to combust the same. 
     However, such incineration method has difficulty in complete combustion of the waste due to different factors such as water content, density, load capacity of waste, combustion temperature, etc. For this reason, a large amount of exhaust gases including soot, dust and harmful gases due to incomplete combustion may be generated during incineration, hence causing a problem of air pollution. Further, when the waste is burnt at high temperatures, flames may be emitted outside along the exhaust gas stream, leading to fire. 
     DISCLOSURE 
     Technical Problem 
     The present invention has been proposed to solve the problems described above, and an object of the present invention is to provide a boiler apparatus for waste incineration, which senses a lower combustion temperature site in a combustion chamber for incinerating waste, supplies air required for the combustion and increases a retention time of ignited flame, thereby implementing complete combustion of the waste without generating harmful gases. 
     Another object of the present invention is to provide a boiler apparatus for water incineration, having a structure capable of heating water with combustion heat of a combustion chamber wherein flame is generated, whereby hot water supply and power generation may be possible by utilizing waste heat generated while burning the waste, and occurrence of fire may be prevented beforehand by cooling a hot exhaust gas discharged along an exhaust line. 
     Technical Solution 
     According to a feature of the present invention, there is provided a boiler apparatus for waste incineration, including: a combustion chamber  110  which has a waste inlet  111  formed on one side and a combustion space  112  for incinerating the introduced waste formed inside the chamber; plural air injection pipes  120 , which are disposed and vertically spaced apart from one another in an upward direction from a lower part of the combustion chamber  110 , extend around the combustion chamber  110 , and have a plurality of injection holes  121  formed along an extended length of the air injection pipes, in order to inject air toward the center of the combustion space  112 ; an air supply unit  130  for supplying air to each of the air injection pipes  120 , separately, in response to a control signal; a temperature sensor  140  mounted in each of combustion spaces ( 112   a  to  112   d ) on respective stages, which are vertically separated with reference to the respective air injection pipes  120  within the combustion chamber  112 , in order to measure a combustion temperature of the combustion space in each stage; and a control module  150  for controlling operation of the air supply unit  130 , in order to adjust an injected amount of air fed to the combustion space in each stage on the basis of a measured combustion temperature by each temperature sensor  140 . 
     According to another feature of the present invention, the control module  150  in the boiler apparatus for waste incineration is characterized by: comparing the measured combustion temperature input by each of the temperature sensors  140  with a preset reference value of combustion temperature (‘reference combustion temperature’) in each stage; and, if the measured combustion temperature input by any temperature sensor  140  is lower than the reference combustion temperature of the corresponding stage, controlling operation of the air supply unit  130  such that an amount of air injected into the combustion space in the stage, in which the corresponding temperature sensor is disposed, is increased. 
     According to another feature of the present invention, the boiler apparatus for waste incineration may further include: a water tank unit  165  including a first water tank  166  for receiving and storing water and a second water tank  167  for receiving and storing primarily heated water; and a water heating chamber  160  which is mounted on an upper part of the combustion chamber  110  and has a heating space  161  in vertical communication with the combustion space  112 , wherein the water heating chamber  160  is provided with a preheating chamber  162  around the heating space  161  so as to primarily heat the water fed from the first water tank  166  with combustion heat of the combustion space  112  and then discharge the heated water to the second water tank  167 , and is further provided with a heating tube  163  in the heating space  161  so as to secondarily heat the water fed from the second water tank  167  with the combustion heat of the combustion space  112  and then discharge the heated water to a place where the hot water is to be used. 
     According to another feature of the present invention, the boiler apparatus for waste incineration may further include: an exhaust port  164  provided at a top end of the water heating chamber  160  to discharge the exhaust gas generated while burning the waste; and a cold chamber  170  formed in a tubular shape extending by a predetermined length and connected to the exhaust port  164  at one side thereof to transport the exhaust gas to the other side, wherein the cold chamber is equipped with a partition  171  for partitioning off an internal space into a plurality of cooling spaces in an extended length direction, and a cooling tube  172  is disposed to extend in a length direction within each of the cooling spaces in order to circulate cold water. 
     Advantageous Effects 
     As such, the present invention has the following features. First, it is possible to sufficiently supply oxygen required for complete combustion based on air injected into the combustion chamber  110  for incineration of waste, thereby improving combustion efficiency. Further, it is possible to sense a position at which the combustion temperature is low, and then, increase an amount of air fed to the sensed position. Further, a retention time of flame may be increased by laterally injecting the air at a circumferential position of the combustion chamber  110  toward the center of the combustion space  112  to swirl the outer skirt of the flame, thereby achieving complete combustion of the waste without generation of harmful gases. Second, the combustion space  112  is partitioned into a plurality of combustion spaces ( 112   a  to  112   d ) with reference to the air injection pipes vertically spaced apart from one another on the combustion chamber  110 , and different amounts of air are supplied according to the combustion temperatures in respective stages, thereby minimizing an amount of the injected air for complete combustion while preventing incomplete combustion. 
     Third, the water heating chamber  160  is mounted on an upper part of the combustion chamber  110  for flame generation and heats the water with combustion heat flowing from the combustion space  112 , thereby having advantages such as hot water supply and power generation while incinerating the waste. 
     Fourth, the water heating chamber  160  has a heating space  161  in vertical communication with the combustion space  112 , is provided with a preheating chamber  162  which is disposed around the heating space  161  in order to primarily heat the water fed from the first water tank  166  with the combustion heat of the combustion space  112  and then discharge the heated water to the second water tank  167 , and is further provided with the heating tube  163  in the heating space  161  in order to secondly heat the water fed from the second water tank  167  with the combustion heat of the combustion space  112  and then discharge the heated water to a place where the hot water is to be used, whereby a water heating temperature may be remarkably raised and a time required for heating the water to a desired temperature may be shortened so as to increase a hot water supply amount. 
     Fifth, the cold chamber  170  is provided on an exhaust line through which the exhaust gas generated while burning the waste is discharged outside, which is formed in a tubular shape extending by a predetermined length and connected to the exhaust port  164  of the water heating chamber  164  at one side thereof to transport the exhaust gas to the other side, and includes: a partition  171  for partitioning off an internal space into a plurality of cooling spaces in an extended length direction; and a cooling tube  172  disposed to extend in a length direction within each of the cooling spaces in order to circulate cold water, thereby preventing the exhaust line from overheating. Further, the cooling water heated by the cooling tube  172  may be fed to the place where the hot water is to be used or circulated to the first water tank  166 , thereby utilizing waste heat and increasing economic value of the boiler apparatus for waste incineration. 
     Sixth, the combustion chamber  110  is characterized in that a first exhaust hole  118  is formed on the bottom surface  116  of the combustion chamber  110  in order to discharge ash remaining after burning the waste to a lower part, a switch plate  189  is provided below the bottom surface  116  to selectively open or close the first exhaust hole  118  while rotating, wherein, if the combustion temperature of the bottom surface  116  is lower than a preset standard value for judgment of extinguishing, the first exhaust hole  118  is opened using a switch-drive member  197  to provide driving force required for rotating the switch plate  189  to automatically discharge the ash, thereby greatly improving user convenience. 
     Seventh, a supporter  187  is mounted on the center of the bottom surface  116  of the combustion chamber  110  in order to space the introduced waste apart from the bottom surface  116 , wherein the supporter  187  is axially coupled to the switch plate  189  and rotates along with the same, and crusher rods  187   a  are formed to laterally extend around the supporter  187  so as to crush agglomerated ash not discharged out of the first exhaust hole  118 . 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view illustrating an external configuration of the boiler apparatus for waste incineration according to a preferred embodiment of the present invention. 
         FIG. 2  is a cross-sectional side view illustrating an internal configuration of the boiler apparatus for waste incineration according to a preferred embodiment of the present invention. 
         FIG. 3  is a block diagram illustrating a functional construction of the boiler apparatus for waste incineration according to a preferred embodiment of the present invention. 
         FIG. 4  is a perspective view illustrating a configuration of an air injection pipe mounted on the combustion chamber according to a preferred embodiment of the present invention. 
         FIG. 5  is a schematic view illustrating a state of injecting air into ignited flame in the combustion chamber according to a preferred embodiment of the present invention. 
         FIG. 6  and  FIG. 7  are a cross-sectional side view and a perspective view illustrating configurations of the water tank unit and the water heating chamber unit, respectively, according to a preferred embodiment of the present invention. 
         FIG. 8  is a perspective view illustrating a configuration of the cold chamber according to a preferred embodiment of the present invention. 
         FIG. 9  is an exploded perspective view illustrating a configuration of automatic rotation of the switch plate according to a preferred embodiment of the present invention. 
         FIG. 10  is a perspective view illustrating a configuration of the exhaust pipe according to a preferred embodiment of the present invention. 
         FIG. 11  is a perspective view illustrating a configuration of the steam turbine generator according to a preferred embodiment of the present invention. 
     
    
    
     BEST MODE 
     Purposes, features and advantages of the present invention described above will be more apparent by means of the following detailed description. Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. 
     The boiler apparatus for waste incineration  100  according to a preferred embodiment of the present invention has improved combustion efficiency to completely burn waste such as waste tire, waste plastic, etc. as well as typical wood fuel, thereby eliminating a risk of air pollution caused by harmful gas, and can heat water with the combustion heat generated while burning the waste. As shown in  FIGS. 1 to 3 , the boiler apparatus may include a combustion chamber  110 , an air injection pipe  120 , an air supply unit  130 , a temperature sensor  140  and a control module  150 . 
     First, the combustion chamber  110  is a chamber in which the waste is incinerated, wherein a waste inlet  111  for introducing the waste into the combustion chamber is provided at one side of the chamber, and a combustion space  112 , in which the introduced waste is burnt, is formed inside the chamber. 
     Herein, as shown in  FIGS. 1 and 2 , a protective cover  181  is provided on an outer periphery of the combustion chamber  110  and spaced apart from the peripheral surface of the same at a predetermined interval, thereby preventing a user from being burned or surrounding objects from overheating due to contact with the heated combustion chamber  110 . Further, a door  113  is installed at the waste inlet  111  to open/close the same in order to prevent leakage of internal flame or combustion heat to the outside, while another door  183  is installed on the protective cover  181  at a location corresponding to the waste inlet  111 . 
     Further, an exhaust hole  118  is formed on the bottom surface of the combustion chamber  110  to discharge ash remaining after burning the waste to the lower part, wherein a switch plate  189  is provided at a site below the bottom surface to selectively open/close the exhaust hole  118 , and an ignition port  184  is provided at one side of the combustion chamber  110  as well as the protective cover  181 , thereby enabling external ignition of the waste introduced from the outside. 
     Further, although not illustrated, an ignition means such as an igniter automatically igniting in response to a control signal from a control module  150  to initiate flame; or a means for injecting inflammable liquid such as petroleum to generate flame at initial ignition may be provided inside the combustion chamber  110 . Further, a collection box for gathering the ash discharged to the lower part is provided at a lower site of the switch plate  189 . Further, as shown in  FIG. 11 , it is preferable to provide a door  196  for withdrawing the collection box to the outside. 
     The air injection pipe  120  is a means for supplying oxygen required for burning the waste by injecting the air fed from the air supply unit  130  to the inside of the combustion space  112 . In particular, as shown in  FIGS. 2 and 4 , plural air injection pipes are disposed and vertically spaced apart from one another in an upward direction from the lower part of the combustion chamber  110 , extend around the combustion chamber  110 , and have plural injection holes  121  along an extended length, in order to laterally inject air toward the center of the combustion space  112 . 
     In this case, as shown in the enlarged view of  FIG. 2 , the injection holes  121  may include an injection hole group continuously opening in a longitudinal direction and another injection hole group continuously opening in a transverse direction wherein both of the injection hole groups are arranged alternately along the extended length direction of the air injection pipes  120 , whereby the oxygen required for combustion is more smoothly injected to thus improve combustion efficiency, and ignition is performed at a lower position of the combustion space  112  to partially swirl the flame burning upward. 
     Further, although not illustrated, if a rectangular injection hole extending in a vertical direction and another rectangular injection hole extending in a lateral direction are arranged alternately, oxygen may be supplied to the flame in a wider vertical range by air injected through the vertically rectangular injection hole, while an air barrier layer for swirling the flame may be effectively formed by air injected through the laterally rectangular injection hole. Moreover, as shown in  FIG. 2 , the air injection pipes  120  may be vertically spaced apart from one another in the combustion chamber  110  to thus divide the internal combustion space  112  into respective stages. 
     The air supply unit  130  is a means for supplying air to the air injection pipes  120 , respectively, in response to a control signal of the control module  150 . In particular, a single air supply unit  130  and each of the air injection pipes  120  are connected to each air supply line, wherein the air supply line has an air amount control valve to feed air to the corresponding air injection pipe  120 . Otherwise, each of the air injection pipes  120  may be equipped with a single air supply unit  130  to feed air, separately. 
     Herein, in order to inject the air into an internal center of the combustion space  112  through the injection hole  121 , air compressed at a high pressure is preferably fed through the injection hole  121 . For this purpose, the air supply unit  130  may include an air compression device as a compressor or a high pressure air blower, and the air amount fed to each stage may be controlled via a program installed in the control module  150 . 
     The temperature sensor  140  is a sensing means for measuring an internal temperature of the combustion space  112  and may be mounted on each of combustion spaces ( 112   a  to  112   d ) in the respective stages vertically separated in the combustion chamber  110  with reference to the air injection pipes  120 , respectively, in order to measure the combustion temperature of the combustion space in each stage. 
     In this regard, the plural temperature sensors  140  may be mounted on or close to pipe conduits (‘duct’) of the air injection pipes  120 , thereby being arranged in the combustion spaces ( 112   a  to  112   d ) in the corresponding stages, respectively. Further, as illustrated in the drawings, the temperature sensors  140  may be mounted on different sides within the water heating chamber  160 , so as to measure the combustion temperature of flame ignited in the combustion space  112  in various angles. 
     The control module  150  is a microcontroller for controlling operation of the air supply unit  130  to thus control the air amount injected through the air injection pipes  120 , wherein the air supply unit  130  is drive-controlled in order to adjust the air injection amount fed to the combustion spaces ( 112   a  to  112   d ) in the corresponding stages on the basis of a measured value of combustion temperature (‘measured combustion temperature’) by each of the temperature sensors  140 . 
     Herein, the control module  150  may receive a user input signal from an operation unit  151  for generating the user input signal by the operation of the user, and then, regulate various setting conditions and/or operational states of the boiler apparatus for waste incineration  100 . 
     Further, the control module  150  may compare the measured combustion temperature input from any of the temperature sensors  140  with a temperature reference value preset at each side and (‘reference value’), if the measured combustion temperature input from a specific temperature sensor  140  is relatively lower than the reference value at the corresponding side, may control operation of the air supply unit  130  in order to increase an air amount injected into the combustion space of a corresponding stage wherein the above temperature sensor  140  is mounted. For instance, if a preset combustion temperature in the combustion space  112   a  of a first stage (‘first combustion space’) among the combustion spaces  112  of the combustion chamber  110  is 250° C. and when a temperature of 249° C. or less is measured by the temperature sensor  140   a  mounted in the first combustion space  112   a , the control module  160  may control the operation of the air supply unit  130  in accordance with programmed conditions, so as to supply air to the air injection pipe  120   a  in the first combustion space  112   a  and increase an air supply amount if the air is being supplied. 
     Further, when the temperature is raised by feeding the air to the first combustion space  112   a  and the combustion temperature of 250° C. or more is measured, the control module  150  may control the air supply unit in order to reduce the air amount fed to the air injection pipe  120   a  in the first combustion space  112   a.    
     According to the same control process as described above, an air amount supplied to each stage, that is, to each of the combustion spaces ( 112   b  to  112   d ) in the other stages may be regulated according to the measured combustion temperature with reference to the reference combustion temperature of each corresponding stage, thereby detecting the combustion space in the stage having insufficient air for complete combustion and feeding air to the respective stages, separately. 
     Because of a combinational structure of the combustion chamber  110 , the air injection pipe  120 , the air supply unit  130 , the temperature sensor  140  and the control module  150 , as shown in  FIG. 5 , the air containing oxygen sufficient to burn waste may be fed into the combustion chamber  110  for waste incineration to thus improve combustion efficiency. Further, the air supply amount may be increased by sensing a lower combustion temperature position. Further, the air may be laterally injected from a peripheral portion of the combustion chamber  110  toward the combustion space  112  to swirl an outer skirt of flame and increase a retention time of the flame, thereby accomplishing complete combustion of the waste without generating harmful gases. 
     Meanwhile, as shown in  FIGS. 6 and 7 , the boiler apparatus for waste incineration  100  according to a preferred embodiment of the present invention may further include a water tank unit  165  and a water heating chamber  160  to heat water using combustion heat of the combustion space  112 . The water tank unit  165  may include a first water tank  166  to receive and store unheated water, and a second water tank  167  to receive and store primarily heated water. 
     Further, the water heating chamber  160  is mounted on an upper part of the combustion chamber  110 , and may include: a heating space  161  in vertical communication with the combustion space  112 ; a preheating chamber  162  disposed around the heating space  161  so as to primarily heat the water fed from the first water tank  166  through a first feed duct  168   a  with combustion heat of the combustion space  112  and then discharge the heated water to the second water tank  167  through a second feed duct  168   b ; and a heating tube  163  disposed in the heating space  161  so as to secondarily heat the water fed from the second water tank  167  through a third feed duct  168   c  with the combustion heat of the combustion space  112  and then discharge the heated water to a place where the hot water is to be used. 
     Herein, water supply/recovery lines to transport water such as the first feed duct  168   a , the second feed duct  168   b  and the third feed duct  168   c , as well as the water tanks, may be connected to a motor pump unit ( 152 , see  FIG. 3 ), in order to compress the water at a high pressure and discharge the compressed water. As such, the water heating chamber  160  is mounted on the upper part of the combustion chamber for flame generation and heats circulating water with the combustion heat flowing from the combustion space  112 , thereby achieving hot water supply and power generation effects utilizing waste heat while incinerating the waste. 
     Further, because of a configuration of primarily heating water by a preheating chamber  162  then supplying the preheated water to the heating tube  163  for secondarily heating the same, the water heating temperature can be greatly increased and a time taken for heating the water to a desired temperature may be reduced, thereby increasing a hot water supply amount. 
     On the other hand, as shown in  FIG. 8 , an exhaust port  164  for discharging the exhaust gas generated while burning the waste may be provided at a top end of the water heating chamber  160  and a cold chamber  170  for cooling the discharged exhaust gas may be mounted on the exhaust port  164 . 
     The cold chamber  170  may be formed in a tubular shape extending by a predetermined length and connected to the exhaust port  164  at one side thereof to transport the exhaust gas to the other side, and may include: a partition  171  for partitioning off an internal space into a plurality of cooling spaces in an extended length direction; and a cooling tube  172  disposed to extend in a length direction within each of the cooling spaces in order to circulate cold water. 
     Accordingly, it is possible to prevent the exhaust line from overheating or the flame from escaping to the outside due to high heat of the exhaust gas. Further, the water heated in the cooling tube  172  may be supplied to the place where the hot water is to be used or circulated to the first water tank  166 , thereby utilizing waste heat and increasing economic value of the boiler apparatus for waste incineration. That is, using the cooling tube  172  may achieve two different effects of more quickly heating the water while cooling the exhaust gas, simultaneously. 
     Further, the exhaust gas discharged in a single stream form through the exhaust line is separated into two or more streams by the partition  171  and transported, and such separated exhaust gas streams are cooled in the corresponding cooling spaces, respectively. Therefore, compared to cooling a single stream by the cooling tube, cooling efficiency may be increased while achieving effects of shortening a length of the cold chamber  170 . 
     Meanwhile, as shown in  FIG. 9 , the combustion chamber  110  may include: plural first exhaust holes  118  which are vertically open and horizontally symmetrical with respect to the center portion, and are horizontally disposed at a lower position of the bottom surface  116  and rotatably mounted thereon; plural second exhaust holes  188  which are vertically open and horizontally symmetrical with the center portion; a switch plate  189  provided to selectively open and close during rotation; and a switch-drive member  197  disposed at one side of the switch plate  189 , which is driven in response to a control signal of the control module  150  and provides driving force required to rotate the switch plate  189 . 
     Further, the control module  150  may receive input of a measured value of combustion temperature (‘measured combustion temperature’) (e.g., 60 to 80° C.) from the temperature sensor for measuring the combustion temperature near the bottom surface  116  and, if the measured combustion temperature of the bottom surface  116  is relatively lower than a preset standard value for judgment of extinguishing, may control operation of the switch-drive member  197  to rotate the switch plate  189 , which in turn allows vertical communication between the first exhaust holes  118  and the second exhaust holes  188 . Therefore, after the waste is completely burnt, a user does not need to discard ash to the lower part every time and the ash can be automatically discharged by determining whether combustion was terminated or not according to the combustion temperature, thereby remarkably increasing user convenience. 
     In addition, there is provided a supporter  187  in the center of the bottom surface  116  of the combustion chamber  110  in order to space the introduced waste apart from the bottom surface  116 , wherein the supporter  187  is axially coupled to the switch plate  189  and rotates along with the same, and a crusher rod  187   a  is formed to laterally extend around the supporter  187  in order to crush agglomerated ash, thereby easily discharging the ash not discharged out of the first exhaust holes  118  to the lower part. 
     Further, a vibrator  198  for generating vibration in response to a control signal of the control module  150  in order to run the switch plate  189  and the bottom surface  116  is preferably provided on the lower part of the switch plate  189 . Accordingly, if the lower combustion temperature than the standard value for judgment of extinguishing is sensed, the control module  150  preferably acts for automatic rotation of the switch plate  189  and, at the same time, sets the vibrator  198  in motion so as to easily discharge the ash gathered on the bottom surface  116  through vibration. 
     On the other hand, as shown in  FIG. 10 , a plurality of exhaust pipes  173 ,  174  for discharging the exhaust gas to the outside may be installed in the cold chamber  170 , and is preferably equipped with a filter means  195  for filtering out foreign substances and/or harmful components. In addition, since an exhaust line becomes longer due to the exhaust pipes  173 ,  174 , there is preferably provided a blower means for preventing reverse flow of the exhaust gas and smoothly discharging the same to the outside. 
     For this purpose, as shown in the drawing, a rotatably-mounted impeller  192  may be mounted in the exhaust pipe  174 , while an exhaust motor  191  may be installed outside the exhaust pipe  174  to provide driving force required to rotate the impeller  192 . Further, each of rotational axes of the impeller  192  and the exhaust motor  191  may be equipped with a power transmission unit  194  such as a chain or belt, thereby enabling rotation of the impeller  182  by the driving force of the exhaust motor  191 . 
     Further, the exhaust pipe  173 ,  174  may be provided with an exhaust sensor  196  to detect harmful components possibly contained in the discharged exhaust gas so that, when a harmful gas detection signal enters by the exhaust sensor  196 , the control module  150  may control operation of the air supply unit  130  to increase an air supply amount or inform a user through a display, thereby enabling immediate action by the user. 
     On the other hand, as shown in  FIG. 11 , the boiler apparatus for waste incineration  100  may further include a steam turbine generator  200  to receive the heated water from the heating tube  163  and then generate power while rotating a steam turbine (not shown) inside the same. Herein, the steam turbine generator  200  may be equipped with an additional control module  210  for different control operations required for power generation using steam, wherein the control module may be mounted on a base plate  182  for supporting the bottom of the combustion chamber  110  and, optionally, may be integrated with the combustion chamber  110 . 
     The present invention described above is not particularly limited to the afore-mentioned embodiments and the accompanying drawings. Further, it will be apparent to those skilled in the art to which the present invention pertains that various substitutions, modifications and alterations may be possible within the scope of the present invention without departing from the technical spirit thereof.