JP2012067951A - Multiple swirl fluid bed type incinerator and incineration system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multiple swirl fluid bed type incinerator of a rational constitution, and an incineration system incorporating the same, capable of making primary combustion in a fluid bed more complete, and solving problems due to flowing-out of a bed material.SOLUTION: In the fluid bed type incinerator having the fluid bed, an air feeder for primary combustion, fluidizing the fluid bed and supplying the air for primary combustion to the fluid bed, and a free board as a space for secondary combustion, this multiple swirl fluid bed type incinerator and the incineration system using the same, includes the air feeder for primary combustion having both of a vertical swirl flow applicator for fluidizing the fluid bed by applying the vertical swirl flow to the fluid bed, and a horizontal swirl flow applicator for applying horizontal swirl flow to the fluid bed fluidized by the application of the vertical swirl flow.

Description

  The present invention is a new type of multiple swirling fluidized bed incinerator capable of efficiently incinerating various kinds of wastes from low-level radioactive wastes to PCBs, various waste liquids, general wastes, etc. And incineration system using the same.

  Various types of incinerators are conventionally known, such as a fluidized bed incinerator, a stoker-type incinerator, and a rotary incinerator incorporating a rotary kiln. Of these, a fluidized bed (fluidized sand) is formed in the furnace, and primary combustion is mainly performed in the fluidized bed, and secondary combustion is performed in the freeboard above the fluidized bed. For example, a fluidized bed incinerator capable of almost complete combustion can be constructed relatively simply because there is no drive part in the furnace itself. This has the advantage that it can be easily stopped in a short time.

  In a fluidized bed incinerator, usually, a fluidized medium (fluidized sand) is heated to about 650 to 800 ° C. and fluidized by wind pressure from below, and the fluidized fluidized bed is formed in the furnace. The incinerated product is charged in a state of being pulverized to a small size, most of it is burned by primary combustion, and the rest is subjected to secondary combustion with a free board formed as a space above it. In order to form a fluidized bed, it is generally considered that an air flow from below (usually given as a swirling flow of primary combustion air in the vertical direction) is necessary.

  In the conventional fluidized bed incinerator, the air flow from the lower side to the fluidized bed is usually from the primary combustion air jets (usually provided in plural) provided in the hearth (aeration bed). Is given as an air jet flow for primary combustion. Although it is possible to fluidize the fluid medium (fluid sand) by applying such an air flow, the outflow of the fluid medium to the free board substantially above the fluid bed is completely prevented. Since it is not possible, the fluid medium that has flowed out from the free board portion or the outside of the furnace must be returned to the original fluidized bed portion. The outflow of the fluidized medium from the fluidized bed leads to a decrease in the primary combustion capacity and efficiency in the fluidized bed part and a decrease in the efficiency and capacity of the secondary combustion in the freeboard part. The incineration operation and control are complicated, the structure of the entire apparatus is complicated and large, and the cost is increased.

  Conventionally, attempts have been made to improve each part of the fluidized bed incinerator. However, basically, an improvement in the primary combustion air jet structure that ejects air in the vertical direction (for example, Patent Document 1) and a free board. The performance of the secondary combustion air in Japan has been improved (for example, Patent Document 2), and there are no improvements aimed at improving the fluidized state of the fluidized bed itself and improving the combustion and preventing the fluid medium from flowing out. Nothing has been found to improve the efficiency of the fluidized bed incinerator or to simplify the structure.

JP 2007-327742 A JP 2005-273999 A

  Therefore, the object of the present invention is to return to the function originally required for the fluidized bed in the fluidized bed incinerator, to make the primary combustion in the fluidized bed more complete, and to solve the problems associated with the outflow of the fluidized medium all at once. It is an object of the present invention to provide a novel multiple swirling fluidized bed incinerator having an extremely rational configuration that can be eliminated, and an incineration system incorporating the same.

  In order to solve the above problems, a multiple swirling fluidized bed incinerator according to the present invention has a fluidized bed formed of a fluidized fluid medium in a lower part of the furnace, and fluidizes the fluidized bed with respect to the fluidized bed. A primary combustion air supply means for supplying primary combustion air is provided, and a free board as a secondary combustion space is formed in the upper part of the furnace, and the secondary combustion air is supplied to the free board. In a fluidized bed incinerator provided with a secondary combustion air supply means, the primary combustion air supply means applies a vertical swirl flow to the fluidized bed to fluidize the fluidized bed. It comprises a flow imparting means and a horizontal swirl flow imparting means for imparting a horizontal swirl flow to a fluidized bed to which a vertical swirl flow is imparted and fluidized.

  In such a multiple swirling fluidized bed incinerator according to the present invention, the fluidized bed is fluidized by applying the swirling flow in the vertical direction by the vertical swirling flow applying means, as in the conventional apparatus, but in the fluidized state. At the same time, a horizontal swirling flow is applied by the horizontal swirling flow applying means. That is, the fluidized medium in the fluidized bed is swirled in the vertical direction, and at the same time, swirled like a vortex in the horizontal direction as a whole. The swirling flow such as the horizontal vortex flow exerts a force in the settling direction on the fluidized bed, so that the fluidized medium forming the fluidized bed is almost completely discharged upward (that is, to the freeboard side). Thus, the fluidized state of the fluidized bed is maintained and the outflow of the fluidized medium is prevented. By preventing the fluid medium from flowing out, the capacity of the fluidized bed is maintained at the desired set capacity as it is, so that the performance and efficiency of the primary combustion state in the fluidized bed are prevented from being reduced, and fluctuations are suppressed, enabling more complete primary combustion. become. In addition, since there is no flow out of the fluid medium from the fluidized bed to the freeboard, the secondary combustion state in the freeboard is also maintained in the desired stable and good state and functions ideally in each part of the incinerator. The separated excellent combustion state is realized. In addition, since the fluid medium return mechanism and the like are not required by preventing the fluid medium from flowing out, the fluidized bed incinerator as a whole, as well as the equipment attached to it, can be simplified, downsized, and reduced in cost. Become.

  In the multiple swirling fluidized bed incinerator according to the present invention, the horizontal swirling flow applying means includes means for applying a horizontal swirling flow of an centripetal flow from the furnace wall portion to the core to the fluidized bed. Is preferred. Such a centripetal horizontal swirl can express a force in the subsidence direction such as a vortex of an ocean current, so that the outflow of the fluid medium can be more effectively prevented.

  In addition, the horizontal swirl flow imparting means preferably has a plurality of horizontal primary combustion air jets for ejecting primary combustion air in the furnace horizontal direction. By having a plurality of horizontal primary combustion air outlets, a desired horizontal swirl flow can be easily imparted over the entire fluidized bed. By arranging a plurality of horizontal primary combustion air outlets at an equal pitch in the circumferential direction of the furnace, for example, it becomes possible to impart a more desirable horizontal swirl flow more uniformly. It should be noted that such a plurality of horizontal primary combustion air jets can be arranged in a single row in the circumferential direction of the furnace, or in a plurality of rows in the vertical direction.

  The horizontal primary combustion air outlet may be configured such that the angle in the ejection direction can be finely adjusted at least in the vertical direction. If comprised in this way, according to the kind and form of the incinerated material thrown in, it will become controllable to the more optimal flow state for primary combustion. Note that the angle of the horizontal primary combustion air outlet with respect to the circumferential direction of the furnace may basically be a tangential direction of the furnace wall or a fixed angle close thereto, but this direction can also be finely adjusted. It is also possible to keep it.

  As the vertical swirl flow imparting means, basically the same structure as the conventional structure can be adopted, but in order to obtain a good fluidized state over the entire fluidized bed, the primary combustion air is jetted upward. It is preferable that a plurality of upward primary combustion air outlets are provided in an appropriate arrangement.

  The input position of the incinerated material is not particularly limited as long as it is positioned higher than the fluidized bed. For example, it may take a configuration in which the input port of the incinerated material is opened from the side with respect to the free board. it can.

  Further, in the present invention, since the outflow of the fluid medium from the fluidized bed to the freeboard is basically avoided, the configuration of the secondary combustion air supply means is not particularly limited. For example, the secondary combustion air It is possible to employ a configuration in which the supply means is configured to supply secondary combustion air into the furnace in a swirling flow, particularly in a horizontal swirling flow. This horizontal swirl flow may be applied in multiple stages.

  Although it depends on the type of incinerated material, when it is secondarily burned in the freeboard section, it becomes almost completely burned, so the gas after the second combustion passes through the exhaust port, to the outside, or to further processing that follows. What is necessary is just to be sent to a process. For this purpose, for example, a structure in which an exhaust port from a free board is provided at the top of the furnace can be adopted.

Further, in the present invention, the fluidized medium does not flow out of the fluidized bed, and the fluidized bed portion and the freeboard portion are almost completely functionally separated and always maintained in a stable state. As a whole, finer control to the optimum state is possible. In order to control to the optimum state, it is preferable that a sensor for detecting the combustion state is provided at an appropriate place in the furnace (that is, at a place where the state of each part can be recognized). As such a sensor, for example, an ultraviolet sensor, a temperature sensor, a flow rate sensor, and various gas sensors such as CO ₂ , CO, and O ₂ can be used.

  Further, when incombustible material that could not be combusted in the fluidized bed is generated, for example, a downward discharge path is connected to the hearth, and the incombustible material is appropriately discharged through the discharge path. It is also possible to do.

  An incineration system according to the present invention incorporates the above-described multiple swirling fluidized bed incinerator, at least means for charging the incinerated material into the multiple swirling fluidized bed incinerator, from the multiple swirling fluidized bed incinerator. It consists of a system including exhaust treatment means. The incineration material input means is controlled to the optimum amount of incinerated material according to the type and form of the incinerated material, and the processing requirements at that time. Depending on the type and properties, further processing is appropriately added to the exhaust.

  According to the multiple swirling fluidized bed incinerator according to the present invention, by giving the fluidized bed a vertical swirling flow and a horizontal swirling flow together, it is possible to prevent outflow of the fluid medium from the fluidized bed, Both primary combustion in the floor and secondary combustion in the freeboard can be maintained in a stable and more ideal state, and the performance and efficiency of the entire incinerator can be significantly improved. By preventing the fluid medium from flowing out, the structure of the incinerator can be simplified, downsized, easy to operate and control, and cost can be reduced. Furthermore, an incineration system incorporating this multiple swirling fluidized bed incinerator does not have to consider the return mechanism of the spilled fluid medium, and the performance and stability of the incinerator itself are improved. The performance makes it possible to build a small and inexpensive system.

It is a schematic longitudinal cross-sectional view of the multiple swirling fluidized-bed incinerator which concerns on one embodiment of this invention. It is a schematic cross-sectional view of an incinerator showing the concept of horizontal swirl flow in the present invention. It is a schematic cross-sectional view of an incinerator showing an example of arrangement of a plurality of horizontal primary combustion air jets in the present invention. It is an expanded partial longitudinal cross-sectional view which shows an example of the angle fine adjustment mechanism of the horizontal direction primary combustion air jet outlet. It is a schematic cross-sectional view of an incinerator showing an example of attachment of various sensors. It is a graph which shows the example of the measurement sensitivity area | region by various sensors. It is an equipment distribution diagram showing an example of a system incorporating a multiple swirling fluidized bed incinerator of the present invention.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a multiple swirling fluidized bed incinerator according to an embodiment of the present invention. In FIG. 1, a multiple swirling fluidized bed incinerator 1 has a substantially cylindrical furnace 2 in this embodiment, and a fluidized bed 3 is formed in the lower part of the furnace 2 by a fluid medium that can flow. . A free board 4 as a secondary combustion space is formed in the upper part of the furnace 2 above the fluidized bed 3. The furnace 2 is provided with an inlet 5 that opens to the lower side of the free board 4 and from which an incinerated object (not shown) can be introduced toward the fluidized bed 3. An exhaust port 6 from the free board 4 is provided. The bottom of the furnace 2 is provided with a discharge path 8 for selectively discharging incombustibles 7 and the like that could not be primarily combusted in the fluidized bed 3 downward, and the incombustibles 7 discharged from the discharge path 8 are provided. For example, processing such as feeding and classification is performed by the screw feeder 9, the vibrating sieve 10, and the like.

  The fluidized bed 3 is provided with primary combustion air supply means for flowing the fluidized bed 3 and supplying primary combustion air. The primary combustion air supply means includes a vertical swirl flow imparting means for imparting a vertical swirl flow to the fluidized bed 3 to fluidize the fluidized bed 3, and a vertical swirl flow imparted and fluidized. Both of the horizontal direction swirl flow applying means for applying a horizontal swirl flow to the fluidized bed 3 are provided. In this embodiment, the fluidized bed 3 is formed on the diffuser wall 11, and the vertical swirl flow imparting means is provided on the diffuser wall 11 from the primary combustion air supply port 12 via the wind box 13. The primary combustion air that has been supplied is composed of a plurality of upward primary combustion air jets 14 for jetting upward toward the fluidized bed 3. The air ejected from these upward primary combustion air jets 14 imparts a vertical swirl flow 15 to the fluidized bed 3, whereby the fluidized bed 3 enters a fluidized state. The horizontal swirl flow imparting means includes a plurality of horizontal primary combustions that are provided on the furnace wall 16 and eject the primary combustion air toward the substantially tangential direction of the furnace wall 16 and toward the horizontal direction in the furnace. The air jet outlet 17 is used. As shown in FIG. 2, the air jetted from these horizontal primary combustion air jets 17 gives the fluidized bed 3 a centripetal horizontal swirl flow 18 from the furnace wall 16 to the core. To do. That is, both the vertical swirl flow 15 and the horizontal swirl flow 18 are applied to the fluidized fluidized bed 3.

  In the present embodiment, the strength of the jet flow from the plurality of upward primary combustion air jet ports 14 can be adjusted to be strong or weak, and thereby the state of the vertical swirl flow 15 can be more appropriately adjusted. The fluidized state of the fluidized bed 3 can be controlled to a desired state. Further, as shown in FIG. 3, the plurality of horizontal primary combustion air jets 17 are arranged at equal pitches (equal intervals) in the circumferential direction of the furnace 2 (for example, circumferential angle in the circumferential direction). In other words, the desired horizontal swirl flow 18 can be generated more smoothly. These horizontal primary combustion air jets 17 may be arranged in a plurality of stages in the vertical direction as shown in FIG. Further, as shown in FIG. 4, each horizontal primary combustion air outlet 17 finely adjusts the angle of the ejection direction at least in the vertical direction, for example, within a range of about −5 degrees to +15 degrees (for example, 1 degree). It can also be configured to be fine-adjustable in units. This fine adjustment mechanism can also be developed for fine angle adjustment in the horizontal direction.

  Further, for the freeboard 4 formed as a secondary combustion space in the upper part of the furnace, there is a secondary combustion air jet 19 as a secondary combustion air supply means for supplying secondary combustion air. Is provided. In this embodiment, a plurality of secondary combustion air jets 19 are also provided in the circumferential direction, and are arranged in multiple stages in the vertical direction. The air ejected from the secondary combustion air jets 19 can generate a horizontal swirling flow 20 of the secondary combustion air in the free board 4 in a plurality of stages. . In this embodiment, a preliminary burner 21 that can be heated as necessary is provided so that secondary combustion in the freeboard 4 can be performed more efficiently and smoothly.

Furthermore, in the incinerator 1, as illustrated in FIG. 5, a sensor for detecting the combustion state can be appropriately disposed at an appropriate place in the furnace 2 in order to enable control to a more optimal incineration state. For example, an ultraviolet sensor 22, it is possible to make a sensor 23 for detecting the state of the temperature and flow rate, CO ₂ and CO, and sensors 24 for detecting various gases such as O ₂ provided. By providing such various sensors, for example, as illustrated in FIG. 6, it is possible to detect the state of relative sensitivity and the intensity of radiant heat for each wavelength region, and to achieve a more optimal combustion state. It can be used for controlling the discharge of harmful substances, grasping the necessity of additional processing, and confirming the safety of the furnace wall against the heat-resistant temperature.

  In the multiple swirling fluidized bed incinerator 1 as described above, since the vertical swirling flow 15 for fluidizing the fluidized bed 3 and the horizontal swirling flow 18 are applied to the fluidized bed 3 at the same time, While the necessary fluidized state is obtained, the fluid medium forming the fluidized bed 3 is prevented from flowing upward. As a result, the desired primary combustion state in the fluidized bed 3 is stably continued, and at the same time, the desired secondary combustion state in the free board 4 is stably maintained. It is always kept in a desirable combustion and incineration state. Further, by preventing the fluid medium from flowing out, a return mechanism for the fluid medium that has flowed out is unnecessary, and the incinerator 1 and the accompanying equipment can be simplified, downsized, and reduced in cost.

  The multiple swirling fluidized bed incinerator 1 having such excellent performance can be incorporated in an incineration system constituting an incineration plant. For example, an incineration system can be constructed as illustrated in FIG. In the incineration system 31 shown in FIG. 7, the multiple swirling fluidized bed incinerator 1 as described above is incorporated, and a starter burner 32 is attached thereto. The fluidized bed incinerator 1 is supplied with the incinerated material from the supply means 36 of the incinerated material including the quantitative feeder 33, the pressure gauge 34, the flow meter 35, and the like, and the other supplying means 37, and the auxiliary fuel 38 and the like. Is used for combustion. The amount of heat of the exhaust gas 39 from the incinerator 1 can be used for preheating primary combustion air and secondary combustion air via an air preheater 40 and the like, and the introduced air 41 is heated to form preheated air 42 as an incinerator. 1 can be supplied. Furthermore, white smoke prevention processing by the white smoke prevention preheater 44 can also be added using the introduction air 43. The high-temperature exhaust gas can be cooled and separated in the cooling tower 45, and the separated ash is introduced into the ash hopper 47 through the feeder 46, and from there, the ash humidifier 48 is easily handled as necessary. It can also be humidified. The gas component separated by the cooling tower 45 can be filtered by, for example, a bag filter 49, and the captured component can be introduced into the ash hopper 47 in the same manner as described above. The gas component filtered by the bag filter 49 is introduced into, for example, the flue gas processing tower 50, subjected to the treatment with the caustic soda 51 and the cooling treatment with the cooling water 52, and is then discharged from the chimney 54 by the induction fan 53. If it is rendered harmless at the stage of the white smoke prevention preheater 44, it can be discharged directly from the chimney 54. Thus, the multiple swirling fluidized bed incinerator 1 according to the present invention can be effectively incorporated into various incineration systems.

  The multiple swirling fluidized bed incinerator according to the present invention can be used for various purposes for incineration of various kinds of wastes from low-level radioactive wastes to PCBs, various waste liquids, and general wastes.

DESCRIPTION OF SYMBOLS 1 Multiple swirling fluidized bed type incinerator 2 Furnace 3 Fluidized bed 4 Free board 5 Input port 6 Exhaust port 7 Incombustible material 8 Discharge path 9 Screw feeder 10 Vibrating sieve 11 Aeration wall 12 Primary combustion air supply port 13 Wind box 14 Top Primary combustion air outlet 15 Vertical swirl flow 16 Furnace wall 17 Horizontal primary combustion air spout 18 Horizontal swirl flow 19 Secondary combustion air spout 20 Horizontal swirl flow of secondary combustion air 21 Preliminary Burner 22, 23, 24 Sensor 31 Incineration system 32 Start burner 33 Metering feeder 34 Pressure gauge 35 Flow meter 36, 37 Supply means 38 Auxiliary fuel 39 Exhaust gas 40 Air preheater 41 Air 42 Preheated air 43 Introduced air 44 White smoke prevention preheat 45 Cooling tower 46 Feeder 47 Ash hopper 48 Ash humidifier 49 Bag filter 50 Smoke treatment tower 51 Caustic soda 52 Cooling water 53 Pull fan 54 chimney

Claims (11)

  A fluidized bed is formed in the lower part of the furnace with a fluidized fluid medium, and primary combustion air supply means for supplying the primary combustion air to the fluidized bed and flowing the fluidized bed to the fluidized bed is provided. In the fluidized bed incinerator, in which a freeboard is formed as a secondary combustion space, and a secondary combustion air supply means for supplying secondary combustion air to the freeboard is provided. The air supply means is provided with a vertical swirl flow applying means for applying a vertical swirl flow to the fluidized bed to fluidize the fluidized bed, and a fluidized bed provided with the vertical swirl flow and being fluidized. A multiple swirl fluidized bed incinerator characterized by having horizontal swirl flow imparting means for imparting a swirl flow in a direction.   2. The multiple swirl fluidized bed incinerator according to claim 1, wherein the horizontal swirl flow imparting unit includes a unit that imparts a countercurrent horizontal swirl flow from the furnace wall portion to the core to the fluidized bed.   3. The multiple swirl fluidized bed incinerator according to claim 1, wherein the horizontal swirl flow imparting means has a plurality of horizontal primary combustion air jets for ejecting primary combustion air toward the horizontal direction in the furnace. .   The multiple swirling fluidized bed incinerator according to claim 3, wherein the plurality of horizontal primary combustion air jets are arranged at an equal pitch in a circumferential direction of the furnace.   5. The multiple swirling fluidized bed incinerator according to claim 3, wherein the horizontal primary combustion air jet outlet is configured to allow fine adjustment of an angle in the jet direction at least in the vertical direction.   The multiple swirl fluidized bed incinerator according to any one of claims 1 to 5, wherein the vertical swirl flow imparting means has a plurality of upward primary combustion air jets for ejecting primary combustion air upward. .   The multiple swirling fluidized bed incinerator according to any one of claims 1 to 6, wherein an inlet for an incinerated object is opened with respect to the free board.   The multiple swirling fluidized bed incinerator according to any one of claims 1 to 7, wherein the secondary combustion air supply means includes means for supplying secondary combustion air into the furnace in a swirling flow.   The multiple swirling fluidized bed incinerator according to any one of claims 1 to 8, wherein an exhaust port from the free board is provided at the top of the furnace.   The multiple swirling fluidized bed incinerator according to any one of claims 1 to 9, wherein a sensor for detecting a combustion state is provided at an appropriate place in the furnace.   At least means for introducing an incinerated material into the multiple swirling fluidized bed incinerator, the exhaust from the multiple swirling fluidized bed incinerator incorporating the multiple swirling fluidized bed incinerator according to any one of claims 1 to 10. An incineration system that includes processing means.

Images