JP2019199991A - Waste incinerator and waste incineration method - Google Patents

Abstract

To provide a waste incinerator that can improve a property of quantitative supply of waste into a furnace body, and thereby contribute to stable combustion of the waste.SOLUTION: A waste incinerator drops waste charged into a hopper 3, onto a receiving floor 5 via a chute 4, pushes the waste dropped onto the receiving floor 5, by using a pusher to drop it onto a fire grate 7 of a furnace body 1, and burns the waste while conveying it on the fire grate 7. The pusher comprises: a main pusher 12 arranged on the receiving floor 5 so as to be capable of reciprocating, and for pushing the waste dropped onto the receiving floor 5, to drop it onto the fire grate 7; and a sub pusher 18 arranged above the main pusher 12 so as to be capable of reciprocating, and for dropping the waste in front of the main pusher 12, onto the fire grate 7.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a waste incinerator and a waste incineration method for incinerating waste such as municipal waste.

  As a waste incinerator that incinerates waste such as municipal waste, a grate type incinerator that incinerates waste using a grate is known (see Patent Document 1). In this grate-type incinerator, the waste thrown into the hopper falls onto the receiving floor through a chute. A pusher is installed on the floor so as to be able to reciprocate. The pusher pushes the waste that has fallen onto the floor and drops it onto the grate of the furnace body. The grate burns while conveying the waste that falls on the grate.

JP-A-2005-164121

  By the way, the property (for example, shape, size, compressibility, etc.) of the waste supplied to the waste incinerator is not uniform. If the properties of the waste are non-uniform, even if the waste that has fallen on the floor is pushed out with a pusher, the waste may only be pressed and not supplied onto the grate. If such a state continues, there is a problem that the amount of waste combusted in the furnace body becomes insufficient, and stable combustion is hindered (for example, exhaust gas temperature decrease, CO concentration increase in exhaust gas, etc.).

  Further, when the operation of the pusher is continued in the above state, the waste that has been compacted at a certain point of time falls on the grate at a stretch. When this happens, the amount of waste on the grate increases, and combustion of the waste starts at once after the end of drying, so stable combustion is hindered (for example, exhaust gas temperature rise, CO concentration in exhaust gas, NOx concentration rise, etc.) ). In addition, the burnout position on the grate may move to the ash drop opening side, and there is a concern about an increase in the unburned amount in ash (an increase in the amount of heat and heat).

  The present invention has been made in view of such problems, and improves the quantitative supply of waste to the furnace body, thereby contributing to stable combustion of waste and waste incinerator and waste The purpose is to provide an incineration method.

  In order to solve the above problems, according to one aspect of the present invention, waste thrown into a hopper is dropped onto a receiving floor through a chute, and the waste dropped onto the receiving floor is pushed out by a pusher to In a waste incinerator that falls on a grate and burns while transporting the waste on the grate, the pusher is disposed so as to be able to reciprocate on the floor and the waste that has fallen on the floor A main pusher that pushes out an object and drops it onto the grate; and a sub-pusher that is arranged to be reciprocally movable above the main pusher and drops the waste in front of the main pusher onto the grate. It is a waste incinerator.

  In another aspect of the present invention, the waste thrown into the hopper is dropped onto a receiving floor through a chute, the waste dropped onto the receiving floor is pushed out by a pusher and dropped onto a grate of a furnace body, In a waste incineration method in which the waste is burned while being conveyed on the grate, a main pusher arranged to be reciprocally movable on the floor receives the waste that has fallen on the floor. A main pusher pushing step for dropping, and a sub pusher pushing step for dropping the waste in front of the main pusher onto the grate, wherein the sub pusher is disposed so as to be reciprocally movable above the main pusher. Incineration method.

  According to the present invention, in addition to the main pusher, the sub pusher for dropping the waste in front of the main pusher onto the grate is provided, so that the waste in front of the main pusher can be quantitatively supplied into the furnace body. it can. Thereby, it is possible to prevent the waste in front of the main pusher from being pressed. Further, even when the waste in front of the main pusher is compressed and protrudes into the furnace body, it is possible to prevent the waste compressed by the operation of the sub pusher from being supplied into the furnace body at once. Thereby, the imbalance between the amount of waste and the combustion air can be eliminated, and combustion can be stabilized (small fluctuations in exhaust gas temperature and exhaust gas composition, small fluctuations in evaporation amount, CO reduction, NOx reduction, etc.).

It is a longitudinal cross-sectional view of the waste incinerator of one Embodiment of this invention. It is a figure which shows the state which the protrusion part generate | occur | produced in the waste extruded by the pusher. It is a figure which shows the state which the protrusion part of the waste fell on the grate. It is detail drawing of a main pusher and a sub pusher. It is a figure which shows the thermal image information which an infrared camera produces | generates.

  Hereinafter, a waste incinerator according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the waste incinerator of the present invention can be embodied in various forms and is not limited to the embodiments described in the specification. This embodiment is provided with the intention of enabling those skilled in the art to fully understand the invention by fully disclosing the specification.

  FIG. 1 is a longitudinal sectional view of a waste incinerator according to an embodiment of the present invention. The waste incinerator of this embodiment includes a furnace main body 1 having a main combustion chamber 2 and a secondary combustion chamber 10 inside, a hopper 3 into which waste is charged, and a chute 4 that guides the waste onto a receiving floor 5. And comprising.

  Waste thrown into the hopper 3 by a crane (not shown) falls on the receiving floor 5 via the chute 4. A main pusher 12 is disposed on the receiving floor 5 so as to be reciprocally movable in the horizontal direction. The main pusher 12 reciprocates between a retracted end indicated by a solid line and an advanced end indicated by a broken line. The main pusher 12 is driven by a drive mechanism 12a including a cylinder, a link mechanism, and the like. The main pusher 12 has a width substantially equal to the width of the furnace body 1. When the main pusher 12 moves from the retracted end to the advanced end, the main pusher 12 pushes out the waste on the front surface and drops it onto the grate 7 of the furnace body 1. When the main pusher 12 moves from the forward end to the backward end, waste is supplied to the front surface of the main pusher 12. The waste falls on the grate 7 from the outlet 16 at the front end of the receiving floor 5. The furnace body 1 is provided with a drop wall 8 that forms a step for dropping between the receiving floor 5 and the grate 7.

  A sub pusher 18 is disposed above the main pusher 12 so as to be reciprocally movable. The sub pusher 18 reciprocates between a retracted end indicated by a solid line and an advanced end indicated by a broken line. The sub pusher 18 pushes the waste in front of the main pusher 12 obliquely downward and drops it onto the grate 7. The sub pusher 18 is driven by a drive mechanism 18a including a cylinder, a link mechanism, and the like. The number of sub pushers 18 is appropriately set according to the width of the furnace body 1. For example, the sub pusher 18 can be arranged at one central position in the width direction of the furnace body 1, or a plurality of sub pushers 18 can be arranged at a certain interval in the width direction of the furnace body 1. Further, one sub pusher 18 having the same width as that of the furnace body 1 can be arranged.

  The grate 7 is provided below the main combustion chamber 2. The grate 7 burns while conveying the waste dropped on the grate 7. The grate 7 includes a dry grate 7a, a combustion grate 7b, and a post-combustion grate 7c from the upstream side. Each of the dry grate 7a, the combustion grate 7b, and the post-combustion grate 7c is divided into a movable grate and a fixed grate, and transports and agitates the waste by sliding movement of the movable grate. Waste moves on the grate 7 from the upstream side (left side in FIG. 1) to the downstream side (right side in FIG. 1) in the furnace length direction.

  The dry grate 7a performs drying of the waste and thermal decomposition of a part of the waste. The combustion grate 7b burns combustible gas and solid content generated by thermal decomposition of waste. The post-combustion grate 7c burns unburned components such as fixed carbon. The ash after combustion is discharged from the ash drop opening 6.

  Wind boxes 17a, 17b, and 17c are provided below the dry grate 7a, the combustion grate 7b, and the post-combustion grate 7c. The primary combustion air supplied by the blower 19 is supplied to the wind box 17 through the air supply pipe 9, and supplied to the main combustion chamber 2 through the dry grate 7a, the combustion grate 7b, and the post-combustion grate 7c. Is done. The temperature of the primary air is adjusted by the heating device 20 that performs heat exchange with the steam. The supply amount of primary air is adjusted by the damper 11.

  The secondary combustion chamber 10 is located at the downstream end of the combustion gas of the main combustion chamber 2. In the secondary combustion chamber 10, the unburned gas in the exhaust gas discharged from the main combustion chamber 2 is subjected to secondary combustion. A secondary combustion gas for causing the unburned gas to undergo secondary combustion is blown into the secondary combustion chamber 10. The exhaust gas after the secondary combustion is discharged outside after being recovered by the waste heat boiler.

  FIG. 2 shows a state in which the waste pushed out by the main pusher 12 is pressed and a protrusion P protruding inside the furnace body 1 is generated. 12b represents the forward end of the main pusher 12, 12c represents the backward end of the main pusher 12, and S1 represents the longitudinal stroke of the main pusher 12. The forward end 12 b of the main pusher 12 is disposed behind the drop wall 8 at the front end 5 a of the receiving floor 5. This is to prevent the main pusher 12 from being exposed from the waste and coming into contact with the high-temperature combustion gas in the furnace body 1 and deteriorating. For this reason, the waste ahead of the forward end 12b of the main pusher 12 is not pushed directly by the main pusher 12 but pushed through the subsequent waste. Depending on the properties of the waste, the waste pushed out by the main pusher 12 may not be dropped onto the grate 7 but may be pressed and protrude forward from the drop wall 8 at the front end 5 a of the receiving floor 5. This is the protrusion P.

  FIG. 3 shows a state in which the protruding portion P of the waste falls on the grate 7. When the protrusion P becomes large to the limit, it collapses due to its own weight and falls onto the grate 7 at once. As a result, the amount of waste combustion varies rapidly.

  FIG. 4 is a detailed view of the main pusher 12 and the sub pusher 18. The sub pusher 18 is disposed above the main pusher 12 and advances obliquely downward to push out waste in front of the main pusher 12. The forward end 18 b of the sub pusher 18 is disposed in front of the forward end 12 b of the main pusher 12. Reference numeral 18 c denotes a retracted end of the sub pusher 18. The stroke S2 of the sub pusher 18 is smaller than the stroke S1 of the main pusher 12.

  According to this embodiment, the following effects are produced. In addition to the main pusher 12, the sub pusher 18 that drops the waste in front of the main pusher 12 onto the grate 7 is provided, so that the waste in front of the main pusher 12 can be quantitatively supplied into the furnace body 1. it can. Thereby, it is possible to prevent the waste from being compressed in front of the main pusher 12. Further, even when the waste in front of the main pusher 12 is pressed and protrudes into the furnace main body 1, it is possible to prevent the waste compressed by the operation of the sub pusher 18 from being supplied into the furnace main body 1 at a stretch. . Thereby, the imbalance between the amount of waste and the combustion air can be eliminated, and combustion can be stabilized (small fluctuations in exhaust gas temperature and exhaust gas composition, small fluctuations in evaporation amount, CO reduction, NOx reduction, etc.).

  Since the advancing end 18b of the sub pusher 18 is disposed in front of the advancing end 12b of the main pusher 12, waste in front of the main pusher 12 can be efficiently dropped onto the grate 7.

  Since the sub pusher 18 advances obliquely downward and pushes the waste in front of the main pusher 12, the waste in front of the main pusher 12 can be efficiently dropped onto the grate 7.

  Next, the waste incinerator control device of this embodiment will be described. As shown in FIG. 1, an infrared camera 13 is installed on the side wall 2 a on the downstream side of the main combustion chamber 2. The infrared camera 13 has a viewing angle that extends in the vertical direction and the furnace width direction of the furnace body 1, and generates thermal image information in this measurement visual field.

  FIG. 5 shows thermal image information generated by the infrared camera 13. As shown in FIG. 5, the infrared camera 13 generates thermal image information of the waste layer w <b> 1 on the receiving floor 5 and thermal image information of the waste layer w <b> 2 on the grate 7. A filter is attached to the infrared camera 13 so that the temperature distribution of the waste layers w1 and w2 can be acquired even if a flame exists in the main combustion chamber 2.

  The infrared camera 13 is connected to a data processing device 14 (see FIG. 1). The data processing device 14 stores thermal image information generated by the infrared camera 13 in a memory and performs image processing on the thermal image information. And the protrusion amount L (refer FIG. 5) of the protrusion part P of the protrusion part P of the waste layer w1 on the receiving floor 5 is calculated, and the layer thickness and temperature of the waste layer w2 on the grate 7 are calculated. .

  A controller 15 (see FIG. 1) is connected to the data processor 14. The control device 15 controls the main pusher 12, the sub pusher 18, the feed mechanism of the grate 7, the damper 11, the heating device 20, and the like based on the thickness and temperature of the waste layer w2 on the grate 7.

  Next, a method for controlling the waste incinerator of this embodiment will be described. (1) The control device 15 periodically controls the sub pusher 18 or (2) the control device 15 controls the sub pusher 18 based on the feed speed of the main pusher 12 and the descending speed of the waste in the chute 4. (3) The control device 15 controls the sub pusher 18 based on the protrusion amount L of the protrusion P from the drop wall 8 obtained from the thermal image information of the infrared camera 13.

  (1) When the sub pusher 18 is periodically controlled, for example, the control device 15 operates the sub pusher 18 at regular time intervals, or the control device 15 causes the sub pusher 18 to interlock with the main pusher 12. When the sub pusher 18 is linked to the main pusher 12, for example, after the main pusher 12 moves from the forward end 12b to the forward end 12b, the sub pusher 18 moves from the backward end 18c to the forward end 18b. To be linked.

  (2) When the sub pusher 18 is controlled based on the feed speed of the main pusher 12 and the descent speed of the waste, for example, the control device 15 may set the operating condition of the main pusher 12 (the number of strokes per hour of the main pusher 12 Then, the supply speed of the main pusher 12 is calculated from the waste supply amount per stroke of the main pusher 12). Then, the control device 15 controls the sub pusher 18 based on the calculated feeding speed of the main pusher 12 and the input descent speed of the waste in the chute 4. For example, when the waste descent speed in the chute 4 is smaller than the feed speed of the main pusher 12, the possibility that the waste is being compacted is high. In such a case, the control device 15 operates the sub pusher 18. For example, a detection roller that can rotate when the waste descends and an encoder that detects the rotation of the detection roller can be used as the speed detection device that detects the descending speed of the waste in the chute 4.

  (3) When controlling the sub pusher 18 based on the protrusion amount L of the protrusion P from the head wall 8 obtained from the thermal image information of the infrared camera 13, for example, the control device 15 determines that the protrusion amount L of the protrusion P is When it becomes larger, the number of operations of the sub pusher 18 is increased.

  Note that the present invention is not limited to the embodiment described above, and can be changed to other embodiments without departing from the gist of the present invention. For example, in the above-described embodiment, the dry grate, the combustion grate, and the post-combustion grate are arranged in a horizontal plane. However, the dry grate, the combustion grate, and the post-combustion grate can be arranged in a step shape. .

DESCRIPTION OF SYMBOLS 1 ... Furnace body 3 ... Hopper 4 ... Chute 5 ... Floor 5a ... Front end of floor 7 ... Grate 12 ... Main pusher 12b ... Advance end of main pusher 13 ... Infrared camera 15 ... Control device 18 ... Sub pusher 18b ... Sub pusher Advance end P ... Projection of waste L ... Projection amount of projection

Claims (6)

The waste thrown into the hopper is dropped on a receiving floor through a chute, the waste dropped on the receiving floor is pushed out by a pusher and dropped onto a grate of a furnace main body, and the waste on the grate In a waste incinerator that burns while transporting
The pusher is
A main pusher that is arranged to be reciprocally movable on the floor and pushes the waste that has fallen on the floor to fall onto the grate;
A waste incinerator, comprising: a sub pusher arranged to be reciprocally movable above the main pusher and dropping the waste in front of the main pusher onto the grate.   The waste incinerator according to claim 1, wherein an advance end of the sub pusher is disposed in front of an advance end of the main pusher.   The waste incinerator according to claim 2, wherein the sub pusher moves obliquely downward to push out the waste.   The disposal according to any one of claims 1 to 3, further comprising a control device that controls the sub pusher based on a feeding speed of the main pusher and a descending speed of the waste in the chute. Incinerator.   The control apparatus which calculates | requires the protrusion amount of the said waste material from the fall wall of the said furnace main body from the thermal image information of an infrared camera, and controls the said sub pusher based on the calculated | required protrusion amount. The waste incinerator according to any one of 3 above. The waste thrown into the hopper is dropped on a receiving floor through a chute, the waste dropped on the receiving floor is pushed out by a pusher and dropped onto a grate of a furnace main body, and the waste on the grate In a waste incineration method that burns while transporting
A main pusher, which is disposed so as to be able to reciprocate on the floor, to drop the waste that has fallen on the floor onto the grate;
A sub-pusher pushing step in which a sub-pusher disposed so as to be reciprocally movable above the main pusher drops the waste in front of the main pusher onto the grate.

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