JPS63271016A - Refuse incinerating fluidized bed furnace - Google Patents

Abstract

PURPOSE:To perform a steady burning by inhibiting air from partially blowing through and facilitate the removal of noncombustible objects by forming the furnace bed to downwardly incline toward its center at which a noncombustible objects removal port is disposed, and forming compartmental air boxes between the removal opening and the air box assembly side wall, each air box having a valve to regulate the flow rate. CONSTITUTION:Air introduced from a blower is divided into three lines each of which is supplied to air boxes 2a-2c situated at symmetrical positions, and is supplied into the furnace 1 from air nozzles 6. Because of this air injection, a filling fluidizing medium 8 is fluidized to form a fluidized bed 7. So that the air feed rate may be smaller from the center air box 2a to the intermediate air box 2b to the end air box 2c, each flow rate is regulated by valves 15 to maintain the fluidized bed 7 formed in the furnace in a good condition. At the central area of the fluidized bed 7, the air load is great and the fluidization is active, and so, the dropped refuse 13 is efficiently and stably incinerated. Noncombustible objects 9 contained in the refuse 13 descend and are removed from a noncombustible objects removal port 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluidized bed furnace for incinerating waste containing incombustible materials such as metal pieces and clay.

[Conventional technology]

In a fluidized bed furnace, the hearth is filled with a fluidized medium such as silica sand, air is jetted out from air nozzles placed in the hearth to form a fluidized bed, and waste materials are placed in the fluidized bed kept at a high temperature. It is a furnace-temperature type that continuously charges and incinerates. However, if the waste contains non-combustible materials such as metal pieces and rocks, these non-combustible materials will settle and accumulate on the hearth, inhibiting the formation of a fluidized bed, and making it impossible to maintain good combustion conditions. For this reason, various improvements have been made in the past regarding the shape of the hearth and the discharge mechanism for discharging incombustible materials to the outside of the furnace.

Examples of conventional techniques include those disclosed in Japanese Patent Publication No. 59-22123 and Japanese Patent Application Laid-Open No. 61-223421.

FIG. 3 is a partial sectional view of a fluidized bed furnace described in Japanese Patent Publication No. 59-22123. In Fig. 3, 1 is a furnace main body, 2 is a wind box main body connected to the lower end of the furnace main body I, and 3 is a wind box main body provided between the furnace main body 1 and the wind box main body 2, with the center side of the furnace main body 1 facing downward. A tilted funnel-shaped rectifying plate, 4 is a non-combustible material fall prevention member provided on the upper part of the rectifying plate 3 and has the same shape as the rectifying plate 3, and 5 is joined to the central part of the rectifying plate 3 and the non-combustible material fall prevention member 4. , a cylindrical non-combustible material discharge port for discharging non-combustible materials, and 6 are air nozzles arranged in multiple stages on the rectifying plate 3.

In this fluidized bed reactor, the diameter of the air nozzle 6 placed in the core is large and gradually decreases toward the outer periphery, so that the distribution ratio of the amount of air to be supplied is adjusted in stages from the core in the radial direction. I'm trying to make it smaller. Due to this air distribution, the upward flow of the fluidized bed 7 is strong at the core and weak at the outer periphery, and the fluidized medium 8 is forcibly moved toward the core. Due to this action, the incombustible materials 9 in the waste inputted from the waste inlet (not shown) provided on the side wall of the reactor body 1 move sequentially from the outer periphery toward the core, and the noncombustible waste is removed. It is discharged from outlet 5.

FIG. 4 is a sectional view of a rectangular fluidized bed furnace described in Japanese Patent Application Laid-Open No. 61-223421. This fluidized bed furnace is
The hearth 10 has a raised shape in which the central part is high and both wall sides of the furnace body 1 are low, and the incombustible material discharge ports 5 are provided on both sides of the furnace body. The wind box main body 2 is divided into three parts, the center and both sides.
The air flow rate supplied from the air supply pipe 11 to each divided air box is adjusted so that the upward flow of the fluidized bed 8 is weak at the center and strong at both sides. The incombustibles 9 in the waste 13 inputted from the waste inlet 12 provided at the center of the upper part of the furnace body 1 move to both sides of the hearth 10 and are discharged from the incombustibles outlet 5.

[Problem that the invention seeks to solve]

However, the prior art has some problems that need to be solved.

In a fluidized bed furnace as shown in Figure 3, which has a funnel-shaped hearth with a lower center and an inclined hearth, the bed height of the fluidized medium is thinner at the outer periphery than at the center, resulting in lower ventilation resistance. So,
The air supplied from the wind box main body blows through from this outer peripheral part where ventilation resistance is low, and as a result, the amount of air in the central part is reduced.

When the amount of air in the central portion decreases, the flow condition of the fluid medium in the central portion deteriorates, and an accumulation area of the fluid medium is generated. In such a state, the combustion condition of the waste deteriorates and it becomes difficult to discharge incombustible materials.

In order to solve these problems, the special public
In Publication No. 23, as mentioned above, the diameter of the air nozzle is made smaller from the core toward the outer periphery, and the distribution ratio of the amount of air is made smaller in stages.

However, this method is applicable only when the combustion air supplied to the fluidized bed is constant, and is not versatile. In normal operation of an incinerator, the amount of air is adjusted as appropriate according to changes in the combustion load, so it is not possible to maintain a constant ratio of the amount of air in the core and the outer periphery. To further explain this point, the ventilation resistance of an air nozzle is proportional to the square of the flow velocity of the air flowing inside the air nozzle, so as the amount of air supplied to the fluidized bed changes, This is because the ratio of ventilation resistance of the air nozzle varies. In addition, if the noncombustible material discharge port is located in the center of the hearth, the size of the noncombustible material that can be discharged is limited by the inner diameter of the noncombustible material discharge port, making it difficult to discharge long noncombustible materials such as sticks. It is. On the other hand, in a fluidized bed furnace with discharge ports on both sides as shown in Figure 4,
Since the incombustible material discharge port extends over one side of the furnace body, it is possible to discharge long objects, but since there are two discharge ports, the noncombustible material transportation system becomes complicated. Furthermore, a common problem with the fluidized bed furnaces shown in Figures 3 and 4 is that the distance that non-combustible materials must travel within the furnace is long before being discharged, and when large-sized non-combustible materials are introduced or the furnace is large. In this case, it becomes difficult to discharge incombustibles, and the formation of a good fluidized bed may be inhibited due to the accumulation of incombustibles.

The present BA#'i solves the problems of the conventional technology +1q as described above, allows stable combustion without allowing the supplied air to partially blow through even if the hearth is tilted, and makes it easy to discharge incombustibles. The purpose of the present invention is to provide a fluidized bed furnace for incinerating waste containing incombustible materials, which can be applied to large-sized furnaces.

[Failure to solve the problem]

The present invention provides a waste inlet at the center of the upper part of the furnace body, the hearth is formed to be inclined downward from both opposing wall surfaces of the furnace body toward the center, and the hearth is formed at the center of the hearth. A non-combustible material discharge port opening in the shape of a long hole is formed along the bottom of the valley, and a partition wall is provided in the wind box main body to separate the central part from the peripheral part, so that the central part and the side wall of the wind box main body are separated from each other. The present invention is characterized in that a plurality of wind boxes are formed in between, and air supply pipes each having a valve for adjusting the flow rate are connected to each of the wind boxes, so that the air supplied to the wind boxes can be adjusted.

[Effect]

Since the hearth is inclined downward from both opposing walls of the furnace body toward the center, forming a roughly V-shape, non-combustibles move toward the bottom of the hearth, leading to the non-combustibles discharge port. is discharged from. At this time, since the waste inlet is located in the center of the furnace body, the distance traveled by the incombustibles until they are discharged is short.
Easily excreted. In addition, the incombustible material discharge port has an opening cross section in the shape of a long hole along the bottom of the valley), making it possible to discharge long noncombustible materials. The wind box main body is divided into multiple wind boxes by partition walls, and the air supply pipes connected to these wind boxes are each equipped with a valve that adjusts the flow rate, so that the ventilation resistance in each part of the fluidized bed is reduced. The appropriate amount of air can be supplied.

〔Example〕

FIG. 1 is a sectional view of a fluidized bed furnace showing an embodiment of the present invention, and FIG. 2 is a perspective view showing the inside of the fluidized bed furnace of FIG.

In FIG. 1, 1 is a rectangular furnace body, 2 is a wind box body provided at the lower part of the furnace body 1, and 10 is a hearth provided at the boundary between the furnace body 1 and the wind box body 2, separating the two. , 6 is the hearth 10
5 is a non-combustible material discharge port,
14 is a partition wall for dividing the wind box main body 2 into a plurality of wind boxes, 2a to 2C are wind boxes, and 12 is a waste input port provided at the center of the upper part of the furnace main body 1. In addition, II is branched into three systems, and air supply pipes 15 are connected to the wind boxes 2a to 2c, respectively.
16 is a valve that adjusts the flow rate of supplied air, and 16 is a blower that introduces air. Next, the structure inside the furnace will be explained with reference to FIG. The hearth 10 is inclined from both opposing ends with the central portion of the furnace body 1 facing downward, and is formed into a substantially V-shaped cross section. A long hole-shaped opening 17 is provided in the center of the hearth 10 along the bottom of the valley of the furnace body 1.
A non-combustible material discharge port 5 is provided which penetrates through the wind box main body 2 and protrudes to the outside of the furnace. A partition wall 14 that divides the wind box main body 2 into a plurality of wind boxes is provided in parallel with the incombustible material discharge port 5, and is joined to the bottom wall of the wind box main body 2 and the hearth 10.

By installing the partition wall 14, three wind boxes 2a to 2c are arranged in the lower part of the furnace body 1 from the center toward the opposing wall surfaces. The number of 20 divisions of the wind box body is determined by the scale of the fluidized bed furnace. For example, if the amount of waste incinerated is 2 tons/
If it is a small furnace of about 100 ft, one side may be divided into two parts.

In the fluidized bed furnace of FIG. 1 constructed in this manner, air introduced from the blower 15 is divided into three systems and supplied to the wind boxes 2a to 2C located at symmetrical positions. This air is temporarily stored in the wind boxes 22 to 2c, and is ejected from the air nozzle 6 into the furnace body 1. Due to this air blowout, the fluidized medium 8 that has been filled in advance flows and the fluidized bed 7
is formed. At this time, since the hearth 10 is inclined,
The bed height of the fluidized bed 7 is thinner than the slope of the hearth 10, so that it becomes thinner from the center toward the furnace wall, and the ventilation resistance becomes smaller in proportion to the bed height of the fluidized bed 7. Therefore, the amount of air supplied to the wind boxes 2a to 2cVc is determined by the air load per unit area of the hearth 10 (N
m”/m”・H) is the central wind box 2m, the middle wind box 2
b, so that the wind boxes 2c at both ends become smaller step by step,
Adjust the valves 15 that control each flow rate. By this operation, the supply of air to each part of the hearth 10 can be appropriately adjusted, so that the fluidized bed 7 formed in the furnace body 1 can always be kept in good condition. After the fluidized bed 7 is stabilized, waste 13 is introduced from the waste inlet 12 provided at the center of the furnace body 1, dropped into the center of the fluidized bed 7, and burned. Since the air load is large in the center of the fluidized bed 7 and the flow is active, the waste material 3 that falls there burns efficiently and in a stable state. Therefore, by charging the waste 13 from the center of the furnace, it is possible to increase the combustion load of the fluidized bed furnace. On the other hand, the noncombustibles 9 contained in the waste 13 fall and are discharged from the noncombustibles discharge port 5.

In this case, the noncombustibles 9 fall near the noncombustibles discharge port 5, so the moving distance to discharge is short, the incombustibles 9 can be easily discharged, and the residence time of the noncombustibles 9 in the furnace body 1 is shortened. Since it is short, there is no possibility of inhibiting the formation of the fluidized bed 7. In addition, since the incombustible material discharge port 5 has an elongated opening cross section, long noncombustible materials can also be discharged without any problem.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the wind box main body is divided into a plurality of wind boxes, and the air supply pipes connected to these wind boxes are each equipped with a valve for adjusting the flow rate. Since the amount of air to be supplied can be adjusted appropriately, the fluidized bed is always formed in good condition without partial blow-through, and stable combustion is possible. In addition, by charging the waste into the fluidized bed in the center where the fluid is active, combustion is performed efficiently and it becomes possible to increase the combustion load of the fluidized bed furnace.

Furthermore, since the waste inlet and incombustible material outlet are both located in the center, it is easy to discharge incombustibles even in large furnaces, and the residence time of noncombustibles in the furnace body is short, resulting in the formation of a fluidized bed. There is also no risk of interfering with the Furthermore, since the opening cross section of the noncombustible material discharge port is in the shape of a long hole, long noncombustible materials can also be discharged without any problem.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a fluidized bed furnace showing one embodiment of the present invention. FIG. 2 is a perspective view showing the inside of the fluidized bed furnace of FIG. 1. FIGS. 3 and 4 are cross-sectional views showing a conventional fluidized bed furnace. 1... Furnace body, 2... Wind box body, 2a to 2c...
Wind box, 5... Incombustible material discharge port, 7... Fluidized bed, 8...
・Fluidized medium, 10... Hearth, II... Air supply pipe,
13...Waste, 14...Partition wall, 15...Valve. Applicant's agent Patent attorney Takeshi Suzue Otonazuka

Claims (1)

[Claims] A furnace body filled with a fluidized medium to form a fluidized bed to burn waste; a wind box body provided at the bottom of the furnace body for temporarily storing air to be supplied to the furnace body; and the furnace body and the wind box. In a fluidized bed furnace equipped with a hearth provided at the boundary with the main body, the furnace main body has a waste inlet at the center of its upper part, and the hearth has a waste inlet in the center from both opposing walls of the furnace main body. A non-combustible material discharge port is formed so as to be inclined downward toward the wind box, and is opened in the shape of a long hole along the bottom of the valley in the center of the hearth, and further includes a central part and a peripheral part in the wind box main body. A plurality of wind boxes are formed between the central part and the side wall of the wind box main body by providing a partition wall that partitions the wind box, and an air supply pipe equipped with a valve for adjusting the flow rate is connected to each of the wind boxes. A fluidized bed furnace for waste incineration, characterized in that the air supplied to each box can be adjusted.