KR20030085467A - Circulation fluidized bed incinerator - Google Patents

Abstract

The present invention suppresses the blockage of solids (S) in the return pipe (3) to the circulating fluidized bed and reliably conveys the fluid medium (M) to the fluidized bed (1), thereby providing a stable and reliable flow of the processed material (D). It is a task to plan a process.

A fluidized bed (1) for flowing the processed material (D) supplied therein, a cyclone (2) for collecting the solids (S) by separating the exhaust gas (G) discharged from the fluidized bed (1) into solids and gases; And a return pipe (3) for conveying the solids (S) collected by the cyclone (2) to the fluidized bed (1). Compressed air (E) is introduced into the return pipe (3). It is provided with the blockage blocking means which removes the solid content S which stayed in the return pipe | tube 3 which consists of air blasters 22 and 23 which are blown.

Description

Circulating fluidized bed furnace {CIRCULATION FLUIDIZED BED INCINERATOR}

The present invention provides a fluidized bed for flowing a processed material supplied therein, a cyclone for separating solids and gases from the exhaust gas discharged from the fluidized bed, and collecting solids, and returning the solids collected in the cyclones to the fluidized bed. It is related with the circulating fluidized bed furnace provided with a return pipe and used for the incineration process of waste, such as sewage mud and dust, for example.

As a circulating fluidized bed furnace used for incineration of such wastes, it is combusted while supplying a fluid (waste) to the fluidized bed while flowing it, and the exhaust gas discharged from the fluidized bed is supplied to a hot cyclone to be separated into solids and gases and returned. It is known to circulate solids into the fluidized bed through a tube. In such a circulating fluidized bed furnace, the treated material supplied to the fluidized bed is first dried and heated up, and then thermally decomposed into a combustible gas such as hydrogen, methane, carbon monoxide and ammonia and solids (unburned carbon) mainly composed of carbon. The combustible gas and unburned carbon thermally decomposed in this way are a part of a fluid (usually hot air) supplied to the fluidized bed, combustion gas generated by combustion in the fluidized bed, or a fluid medium (usually silica sand). At the same time, it is discharged and supplied to the hot cyclone as described above, and solid content such as unburned carbon having a large flow medium or particles is collected and separated by the cyclone, thereby being returned to the lower portion of the fluidized bed and circulated. In addition, hydrogen, methane, and the like, which have a high combustion rate in the combustible gas, are burned by oxygen in the air as the flow fluid discharged together while being supplied to the hot cyclone in the fluidized bed or even in the hot cyclone, and the combustion gas and Simultaneously discharged, it is processed by an exhaust gas treatment facility or a waste heat recovery facility.

However, this circulation in the case of incineration to be treated, such as waste, as described above by the furnace fluidized-bed, low-melting substance such as an alkali metal salt or a compound such as Na ₂ O, K ₂ O due to the waste fluid medium By adhering to and concentrating on the surface, the flow media tend to adhere to each other (sintering phenomenon) and adhere to the return tube, which may cause clogging in the return tube. Moreover, in the incineration of such wastes, the furnace internal temperature must be increased in order to sufficiently burn carbon monoxide and ammonia, or unburned carbon, which is also slowly burning in the combustible gas. Sintering due to adhesion and concentration of substances is also more likely to occur. In addition, the blockage of the return pipe is, for example, the fragments of the refractory material lining the inner wall of the fluidized bed falls off and falls to the bottom of the fluidized bed, thereby blocking the supply means (dispersion pipe or dispersion plate) of the flow air installed at the bottom of the fluidized bed to the fluidized bed. It may be caused by the poor flow of the fluid medium around the connection part of the return pipe, and thus also by the rise of the level of the fluid medium in the return pipe, and if such blockage of the return pipe occurs, the fluid medium to be conveyed to the fluidized bed is conveyed. Since it is not possible, the flow of the processed material by the fluidized bed becomes impossible and the processing becomes impossible.

The present invention has been made under such a background. As described above, the circulating fluidized bed which can suppress the blockage of solids in the return pipe and reliably convey the fluidized medium to the fluidized bed, allows the processing by the flow of a stable and reliable processed material. The purpose is to provide a furnace.

1 is a side cross-sectional view showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view of WW in FIG. 1.

It is XX sectional drawing in FIG.

FIG. 4 is a side sectional view showing the air blaster 22 as the blockage blocking means in the embodiment shown in FIG. 1.

5 is a sectional view taken along line YY in FIG. 1.

6 is a sectional view taken along line ZZ in FIG. 1.

7 is an example of the flowchart at the time of operating a blockage blocking means (air blaster) based on the detection result by a blockage detection means in the embodiment shown in FIG.

8 is a side cross-sectional view of the return pipe 3 showing another embodiment of the present invention.

9 is a side cross-sectional view of a return tube 3 showing a state in which (a) the balloon 41 is contracted and (b) the state in which the balloon 41 is expanded, as another embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

1: fluidized bed

2: cyclone

3: return tube

5: dispersion pipe [supply means of flowing air (A)]

7: connection part of return pipe 3 to fluidized bed 1

8: blowing nozzle

10: supply pipe of combustion air (B)

11: flow meter (block detection means)

12: pressure gauge (obstruction detection means)

13: supporting burner

15: supply pipe of the processed material (D)

22 (22A-22E), 23 (23A-23D): air blaster (block blocking means)

31: vibrating device (block blocking means)

41: balloon (block obstruction means)

A: flow air

B: combustion air

D: processed material

E: compressed air

G: exhaust gas

S: Solid content

M: flow medium

In order to solve the above problems and to achieve this object, the present invention provides a fluidized bed for flowing a processed material supplied therein, a cyclone for separating solids and gases from the exhaust gas discharged from the fluidized bed to collect solids, and the cyclone And a return pipe for conveying the solid content collected in the fluid stream to the fluidized bed, and the return pipe is provided with a blockage blocking means for removing the solid content remaining in the return pipe. Therefore, according to such a circulating fluidized bed furnace, even if blockage of solid content occurs in the return pipe due to sintering phenomenon or poor flow of the fluid medium as described above, the solid content retained in the return pipe causing the blockage is transferred to the blockage blocking means. It can remove by this, and by suppressing the blockage of a return pipe | tube, it can circulate a fluid medium reliably and can flow the processed material stably and smoothly.

Here, as the blockage blocking means, first, an air blaster that blows compressed air into the return pipe can be used, and the solid matter attached to the return pipe blows off by the compressed air blown from the air blaster, and returns. The level of the flowing medium in the tube can be lowered to remove the solids retained. Also, secondly, a vibrating device that imparts vibration to the return pipe can be used, and the vibration medium imparted to the return pipe by the vibration device separates the flow medium that has risen from the solid matter or fluidized bed attached to the inner wall of the return pipe. Can be removed to remove the retention. Further, thirdly, an expansion-shrinkable balloon accommodated in the return pipe can be used, and when the blockage occurs in the return pipe, the balloon is inflated to break down and remove solids attached to the inner wall of the return pipe. The fall of the fluid medium level can be aimed at.

On the other hand, if the fluidized bed or the return pipe is provided with a block detection means for detecting the retention of the solid content in the return pipe, and the blockage blocking means is operable based on the detection result by the block detection means, While the retention of solids in the return pipe does not affect the flow in the fluidized bed, removal of the retained solids can be achieved, and a more reliable and stable treatment can be achieved. Here, in the case of incineration of the treatment product by the circulating fluidized bed furnace, when the fluidized bed is provided with a supply means of combustion air for combusting the treatment product, a retention is generated in the return pipe and the fluid medium in the fluidized bed is reduced. Since the ratio of the flow rate and the pressure of the combustion air rises, the occlusion detecting means measures the flow rate and the pressure of the combustion air to detect the retention of the solid content. For example, the ratio of the flow rate and the pressure of the combustion air By setting the blockage blocking means to operate at a location exceeding a predetermined value, it becomes possible to promote a more stable treatment by removing the solids remaining in the return pipe at the initial stage without burdening the operator. The return pipe is provided at the bottom of the fluidized bed when the return pipe is connected to the fluidized bed above the supply means for the fluidized air. Between the connection to the fluidized bed and the supply means, a blower nozzle for blowing a part of the fluidized air into the fluidized bed can stably supply the fluidized air into the fluidized bed even if the supply means is blocked by falling of the refractory as described above. In this way, it is possible to prevent a poor flow of the flow medium and to prevent a rise in the level of the flow medium in the return pipe.

1 to 7 show one embodiment when the present invention is applied to a circulating fluidized bed furnace used for incineration of waste such as sewage mud or dust. The circulating fluidized bed furnace according to the present embodiment includes a fluidized bed 1 for allowing the processed material D supplied therein to flow together with a fluid medium M such as silica sand, and the exhaust gas G discharged from the fluidized bed 1. ) Is composed of a cyclone (2) for collecting solids (S) by separating solids and gases, and a return pipe (3) for returning solids (S) collected in the cyclones (2) to the fluidized bed (1). have. In addition, the fluidized bed 1, the cyclone 2, and the return pipe 3 are made of metal, and the inner wall is lined with a fireproof material.

The fluidized bed 1 has a tubular shape having a vertical rough bottom having a length large in the direction of the center axis O with respect to the inner diameter thereof, and the bottom face has a concave conical shape which is concave downwards toward the inner circumferential side. The discharge port 4 of the flow medium M provided with the caster stopper 4A is formed in the center part of this bottom surface. In addition, in the bottom of the fluidized bed 1 directly above this bottom surface, a plurality of distribution pipes 5,... As a supply means of the flow air A in this embodiment (5 in this embodiment) are shown. 2, so as to be arranged in parallel on each other and at equal intervals on one horizontal plane orthogonal to the axis O over approximately the entire region of the inner circumferential portion of the fluidized bed 1 forming a cross-sectional circle, as shown in FIG. Inserted from the outside of the fluidized bed 1 and protruding into the fluidized bed 1, the end portions of the distribution pipes 5... Outside the fluidized bed 1 are connected to the supply pipe 6 of the fluidized air A, A plurality of air vents (not shown) are formed upward in the portion protruding into the fluidized bed 1.

Moreover, the connection part 7 to the fluidized bed 1 of the said return pipe 3 is opened in the upper part of these dispersion pipes 5 ... in the lower part of the fluidized bed 1, and this connection part 7 and the said dispersion | distribution are carried out. A blowing nozzle 8 is provided between the pipes 5... To blow off a part of the flowing air A to be supplied from these dispersion pipes 5. In this embodiment, a plurality of blow nozzles 8 (3 in this embodiment) are provided in this embodiment, and the blowing nozzles 8 are connected to the dispersion pipe 5 and the connecting portion 7 in the axis O direction. It is inserted in such a way as to be positioned substantially right below the connecting portion 7 in the center portion, in the circumferential direction, and to extend horizontally in the radial direction from the axis O, and to be equally spaced in the circumferential direction, respectively. However, the front end is opened to the inner wall part of the fluidized bed 1 just below the connection part 7. Further, at the same height in the direction of the axial line O with these blowing nozzles 8..., The plurality of gas guns 9 ..... (4 in the present embodiment) do not interfere with the blowing nozzles 8. Avoiding the blowing nozzles 8... So as to extend in a radial direction from the axis O at equal intervals in the circumferential direction, and incline downward at a very slight inclination toward the inner circumferential side (the axis O side) of the fluidized bed 1. The tip is inserted to open to the inner wall of the fluidized bed 1.

Moreover, at the same height as the said connection part 7 of the fluidized bed 1 lower part, as a supply means of the combustion air B in this embodiment, a plurality of supply pipes (6 in this embodiment) 10. 3 is inserted inclined downward at an oblique angle slightly more obliquely than the gas gun 9 toward the inner circumferential side and radially at substantially equal intervals in the circumferential direction, avoiding the connecting portion 7, as shown in FIG. The tip is opened to the inner wall of the fluidized bed 1. In addition, these supply pipes 10.. Have a flow meter 11 for measuring the flow rate of the combustion air B supplied from the respective supply pipes 10 and a pressure gauge for measuring the pressure as the blocking detection means in the present embodiment. 12) are provided in all the supply pipes 10, and the flow rate and pressure of the combustion air B supplied from the whole supply pipes 10 ... are measured at each time, and the arithmetic control by a computer etc. which do not show the measurement result is carried out. It is possible to input to the means.

Further, in the direction of the axis O, the supporting burner 13 is provided obliquely downward at a steeper slope than the supply pipe 10 toward the inner circumferential side above these supply pipes 10... And the connecting portion 7. On the slightly upper side of the supporting burner 13, the supply pipe 14 of the flow medium M is also obliquely downward, and at approximately the same height as the supply pipe 14, the supply pipe 15 of the processed material D. These horizontally installed respectively. In addition, in FIG. 1, 16 is an eye mirror for visually seeing the inside of the fluidized bed 1 and the return pipe 3, and 17 is a maintenance hole.

On the other hand, the cyclone (2) becomes a vertical multi-stage cylindrical that is reduced in diameter step by step through the tapered portion, by making the center axis (L) of the multi-stage cylinder in parallel with the center axis (O) The exhaust gas flow path 18 which is arrange | positioned at the upper side of the fluidized bed 1, and which is bent by L-shape downwards after extending in the horizontal direction on the upper side of this cyclone 2 is integrated with the said cyclone 2 integrally. The upper end opening part of the fluidized bed 1 is connected to the edge part bent downward of this exhaust gas flow path 18 via the expansion-contraction joint 19. As shown in FIG. In addition, a cylindrical exhaust pipe 20 is installed coaxially with the central axis L from the upper end of the cyclone 2 downward, while the lower end of the cyclone 2 is also stretched through the expansion joint 21, The return pipe 3 is connected. The return pipe 3 is integrally installed with the fluidized bed 1, and extends downward from the lower end of the cyclone 2 such that its center line N is coaxial with the center axis L of the cyclone 2. After this, the center line N is bent obliquely downward toward the fluidized bed 1 side along the plane including the center axes O and L to reach the connecting portion 7 of the fluidized bed 1. have.

And this return pipe 3 is equipped with the air blaster 22, 23 which blows compressed air E into the said return pipe 3 as a blockage blocking means in this embodiment. Here, in this embodiment, the plurality of air blasters 22 and 23 of the return pipe 3 are provided in the return pipe 3, In this embodiment, the air blaster 22 of the 1st group is provided. As shown in Fig. 4, the supertube 24 is hermetically inserted so as to pass through the inner wall portion lined with the refractory material from the outer wall portion of the return pipe 3, and the outer periphery of the supertube 24 is made of ceramic fibers or the like. The nozzle tube 26 thickly covered with the heat insulator 25 is also hermetically inserted so that the tip stays in the inner wall of the return tube 3 to be opened, and the nozzle tube 26 is opened to the outside of the return tube 3. At the rear end of the nozzle tube 26, a blaster body (tank) 28 holding compressed air E supplied from the air inlet 27 is connected via a solenoid valve 29. This solenoid valve By opening (29) intermittently the compressed air (E) is sent from the tip of the nozzle tube (26) into the return tube (3). It is to be enabled. In addition, the opening / closing operation of the solenoid valve 29 can be controlled by the arithmetic control means such as a computer connected to the flowmeter 11 and the pressure gauge 12 as the occlusion detecting means. On the other hand, in the air blaster 23 of the second group, the nozzle pipe 26 is hermetically inserted into the inner wall portion of the return pipe 3 without the super pipe 24 and the heat insulating material 25 being provided. The configuration of the air blaster 22 is the same as that described above.

Moreover, in this embodiment, such a several group of air blasters 22 and 23 are provided in multiple places along the longitudinal direction of the return pipe 3, respectively. That is, with respect to the air blaster 22 of the first group, two air blasters 22A and 22B are attached to each of the upper and lower portions of the bent portion of the return pipe 3, and these air blasters One air blaster 22C, 22D can be attached to the upper and lower sides of 22A, 22B. Moreover, the air blaster 22E can be attached to the taper part of the lower end side of the said cyclone 2 further above 22 C of upper air blasters. Moreover, these three air blasters 22C-22E may be attached to the return pipe | tube 3 and the cyclone 2 as a spare as needed.

In addition, the air blasters 22A to 22E of these first groups have a direction in which the air blaster 22D at the lowermost side makes the nozzle pipe 26 horizontally and orthogonal to the center line N of the return pipe 3. The other air blasters 22A to 22D have the nozzle tube 26 directed downward toward the center line N side (inner circumferential side of the return pipe 3). It is arrange | positioned so that it may extend in the direction crossing obliquely to the center line N, and is attached. In addition, the nozzle tube 26 of these 1st group air blasters 22A-22E has the inclination-angle with respect to the center line N also including the air blaster 22E, and adjoining the longitudinal direction of the return pipe 3, The blasters 22 are arranged at different angles. 3, 5 and 6, the air blasters 22A and 22B above and below the bent portion of the return pipe 3 are directed toward the fluidized bed 1 in the circumferential direction of the return pipe 3. For attachment to the facing position, the air blasters 22C and 22D are attached at positions oriented 90 ° in the circumferential direction about the centerline N at the mounting positions of these air blasters 22A and 22B, and also the cyclone 2 ) The lower portion of the air blaster 22E is attached at a position that is further deflected by 90 degrees, that is, 180 degrees from the mounting positions of the air blasters 22A and 22B, so that the tip of the nozzle tube 26 faces the fluidized bed 1 side. It is arranged to open toward.

On the other hand, the air blasters 23... Of the second group include four air blasters 23A to 23D in this embodiment of the air blaster 22E on the lowermost side of the first bladder 22. Slightly downward from the lower part over the connection part 7 to the fluidized bed 1 of the return pipe 3, and it arrange | positions at intervals up and down, The lowermost air blaster 23D is substantially the same as the said connection part 7 Located at the same height, the tip of the nozzle tube 26 is opened toward the connecting portion 7. However, the spaces between the air blasters 23... Which are adjacent to each other up and down are of different sizes. In this second group of air blasters 23A to 23D, the nozzle tube 26 has a tip thereof along the plane including the central axes O and L of the fluidized bed 1 and the cyclone 3. Is inserted into and attached to the return pipe 3 horizontally toward the fluidized bed 1, so that the center line N of the return pipe 3 is attached to the nozzle pipe 26 of each air blaster 23A to 23D. ) Are arranged to extend in the direction of the diagonal crossing at the same angle to each other.

In the circulating fluidized bed furnace configured as described above, the treated material D consisting of wastes such as sewage mud and dust supplied from the supply pipe 15 to the fluidized bed 1 is distributed from the supply pipe 6 to the distribution pipe 5... While flowing together with the fluid medium M by the flow air A supplied in the fluidized bed 1 through the nozzle 8..., It is finely crushed, while from the gas gun 9 or the supporting burner 13 as necessary. The combustion gas is burned by the combustion air B supplied from the supply pipe 10, together with the fuel to be supplied, and dried and heated to be pyrolyzed into combustible gases such as hydrogen, methane, carbon monoxide and ammonia, and unburned carbon mainly composed of carbon. The combustible gas and unburned carbon thus pyrolyzed are then taken as the exhaust gas G together with part of the flow medium M together with the flowing fluid A or the flowing air B and the combustion gases produced by the combustion. While discharged from the upper opening of the fluidized bed 1 and supplied to the cyclone 2 from the exhaust gas flow path 18, hydrogen or methane, which has a high combustion rate, of the combustible gas is transferred to the cyclone 2 in the fluidized bed 1. In the cyclone 2 or in the air, it is combusted by oxygen in the flowing air A or combustion air B discharged together. In addition, the exhaust gas G discharged to the cyclone 2 in this way is separated into a solid component and a gas, and the gaseous component, ie, the exhaust gas G, is discharged from the exhaust pipe 20 so that the exhaust gas treatment is appropriately performed. The unburned carbon and the fluid medium M separated from the solids S, that is, the exhaust gas G, are conveyed from the lower end of the cyclone 2 to the bottom of the fluidized bed 1 through the return pipe 3 and the fluid medium M ) Is flowed again to be used for the shredding of the treatment (D), while unburned carbon is shredded and burned more finely.

And in the circulating fluidized-bed furnace of the said structure, this return pipe 3 is equipped with the air blasters 22 and 23 as a blockage blocking means, and pressurized air from these air blasters 22 and 23 into the return pipe 3 is carried out. (E) can be blown in. For this reason, in the case of incineration of the processed material D made of waste as described above, a flow medium in which low melting point substances such as alkali metal salts or phosphorus compounds resulting from the waste are returned through the return pipe 3 By adhering and concentrating on the surface of (M), fluid media (M) becomes easy to adhere | attach, and a sintering phenomenon arises, it sticks in the return pipe | tube 3, or the fragment of the refractory material lining in the fluidized bed 1 falls out, The vents of the dispersion pipe 5... Of the bottom of the fluidized bed 1 are blocked, which causes the fluid medium M to flow poorly around the connecting portion 7 of the return pipe 3 and thus the fluid medium in the return pipe 3. Even if the level of (M) rises or the solid content S to be conveyed to the fluidized bed 1 is clogged in the return pipe 3 and is retained, the suspended solid content S is retained by the air blasters 22 and 23. By compressed air (E) blowing from Can be, by eliminating the clogging makes it possible to prevent the clogging of the return pipe (3).

That is, even if the fluid medium M is fixed in the return pipe 3 by the sintering phenomenon, it can be blown away by the compressed air E to be removed, and the fluid is returned by the poor flow in the fluidized bed 1. Even if the level of the flow medium M in the pipe 3 rises, the level of the flow medium M can be lowered by the compressed air E blown into the return pipe 3. Therefore, according to such a circulating fluidized bed furnace, the solid content S separated from the exhaust gas G in the cyclone 2 can be conveyed from the cyclone 2 to the fluidized bed 1 as it is through the return pipe 3, It is possible to reliably circulate the fluid medium M in the solid content S, and to prevent the fluid medium M in the fluidized bed 1 from being insufficient to maintain a stable flow state or to prevent the flow itself from becoming impossible. In addition, it becomes possible to plan the processing by the flow of the processed material D stably and smoothly.

Moreover, in this embodiment, the said blockage blocking means is comprised by the air blaster 22, 23 which can blow compressed air E into the return pipe 3 in this way, and stays in the return pipe 3 Since the solids (S) are blown off by the compressed air (E) and removed, the blockage is prevented. Therefore, even though the mechanical driving portion is small and the control is easy, the solids (S) can be more reliably removed. You can get the advantage that you can. In addition, in this embodiment, such air blasters 22 and 23 are provided in multiple places along the longitudinal direction of the return pipe 3, Therefore, solid content S in any position of the return pipe 3 in this longitudinal direction. ), Even if blockage occurs, it is possible to blow it off with certainty. Furthermore, these air blasters 22 and 23 are a plurality of groups of the first group of air blasters 22 on the cyclone 2 side and the second group of air blasters 23 on the fluidized bed 1 in this longitudinal direction. It is comprised by this and can further remove solid content S more reliably. Moreover, in this embodiment, these air blasters 22 and 23 of these multiple groups are provided also several in each group, and it is further blown in the compressed air E into the return pipe | tube 3 to every corner. It is possible.

Moreover, in this embodiment, among the air blasters 22 ... of the 1st group of the cyclone 2 side, except the lowest air blaster 22D provided in the vicinity of the air blaster 23 of 2nd group here, At least a part of the air blasters 22A to 22C and 22E are arranged such that the nozzle pipe 26 extends inclined downward as the nozzle pipe 26 is directed toward the center line N side of the return pipe 3. The solids S removed by E) can be discharged downward more reliably and conveyed to the fluidized bed 1. In addition, the inclination angle with respect to the centerline N of these nozzle pipes 26 also includes this, when said air blaster 22D is made 0 degree, and at least one air blaster 22 becomes an angle different from another, Therefore, since the blowing angle of the compressed air E into the return pipe 3 also becomes irregular along the longitudinal direction of the said return pipe 3, the pressure which the solid content S conveyed becomes irregular also becomes a sintering phenomenon. Fixation of solid content (S) by means of it can be prevented more reliably. Moreover, in this embodiment, since the inclination angles differ between the air blasters 22 adjacent to this longitudinal direction, it is more effective.

In addition, in this embodiment, the position of the air blaster 22A, 22B, the air blaster 22C, 22E, and the air blaster 22D is deflected by 90 degrees to the circumferential direction of the return pipe 3, ie, some air Since the blaster 22 is disposed at a position different from the other in the circumferential direction of the return pipe 3, the compressed air E is blown to the corners of the return pipe 3 even in the circumferential direction. It becomes possible to impede the blockage of occlusion. In particular, the air blaster 22A positioned immediately above the portion where the return pipe 3 is bent is bent, so that the nozzle tube 26 is opened toward the outside of the bent portion, whereby fixing due to sintering phenomenon is prevented. Also in the bent part of such a return pipe 3 which is easy to produce, it becomes possible to remove the retention of solid content S more reliably.

On the other hand, the second group of air blasters 23A to 23D disposed on the fluidized bed 1 side of the return pipe 3 have their nozzle pipes relative to the return pipe 3 extending obliquely downward toward the connecting portion 7. 26 is attached horizontally toward the fluidized bed 1, so that compressed air E can be blown toward the fluidized bed 1, thereby smoothly conveying the solids S conveyed from the cyclone 2. It is possible to circulate into the fluidized bed 1 and at the same time prevent the level rise of the fluidized medium M from the fluidized bed 1. In particular, since the lowermost air blaster 23D is disposed so that the nozzle tube 26 is opened toward the connecting portion 7, it is effective. Moreover, the air blasters 23... Which are adjacent to each other up and down are arranged at different intervals, and the solid content S conveyed to the fluidized bed 1 is irregularly caused by the compressed air E blown from the nozzle tube 26. The pressure is applied, and it is possible to more reliably prevent the solid matter S from sticking as if the inclination angles of the nozzle pipes 26... Of the first group of air blasters 23A to 23E are different.

In addition, the air blasters 22 and 23 as these blockage blocking means have the solenoid valve 29 based on the detection result by the blockage detection means which detects the retention of solid content S in the return pipe 3. By opening, the compressed air E is blown into the return pipe 3 so that it can be operated, and the solid content stayed before the blockage occurs in the return pipe 3 due to the retention of the solid content S ( S) can be removed and conveyed to the fluidized bed 1, the circulation of the stable fluid medium M can be always ensured, and the treatment of the processed material D can be further enhanced. In particular, in the present embodiment, the blockage blocking means is the air blasters 22 and 23 which remove the retention of the solid content S by blowing compressed air E into the return pipe 3. By being able to operate in a timely manner by the detecting means, it is supplied to the fluidized bed 1 together with the solid content S conveyed, and it is the fluidized medium M or the processed material in the fluidized bed 1 by compressed air E. The situation where the flow and processing (incineration) of (D) become unstable can also be prevented.

Here, in this embodiment, this blockage detection means consists of the flowmeter 11 and the pressure gauge 12 which were provided in the supply pipe 10 ... as supply means which supplies combustion air B to the fluidized bed 1, These The blockage blocking means can be operated by using the measurement results of the supply flow rate and the supply pressure of the combustion air B measured by the flowmeter 11 and the pressure gauge 12 as the detection results. That is, when the flow rate of the combustion air B is F (Nm ³ / h) and the header pressure is P (kPa), and the ratio is F / P = C, the solid content ( When the blockage due to the retention of S) occurs, the value of the ratio C rises due to the decrease in the flow medium M conveyed to the fluidized bed 1, so that the ratio C returns to a predetermined upper limit or higher. The retention of solid content S in the pipe 3 may be performed, and the blockage blocking means may be activated. When the ratio C falls below a predetermined lower limit, the operation may be stopped.

FIG. 7 shows an example of a flow chart when performing such control, in which the flow becomes stable after a predetermined time T (3 minutes) after supplying the flowing air A, and the supporting burner 13 After the temperature in the fluidized bed 1 has been raised to a predetermined temperature by combustion, the flow rate F and the pressure P are measured to calculate the ratio C, which is equal to or higher than the upper limit 600 and remains as it is. When a predetermined time T (5 seconds) has elapsed, an operation signal of the air blasters 22 and 23 is sent from the arithmetic and control means to open the solenoid valve 29 to bring the compressed air E into the return pipe 3. Infuse. And when the said ratio C becomes below the lower limit 550 and the state has passed predetermined time T (5 second), a stop signal is sent from arithmetic and control means, and air blaster 22, 23 is stopped. Let's do it. In addition, when the air blasters 22 and 23 do not stop even after a predetermined time T (10 seconds) have elapsed since the operation signal is sent, that is, when the ratio C does not fall below the lower limit, the return pipe 3 ), The return pipe 3 was blocked because the solid content S stayed in the) was not blocked, and the supply of the flow air A and the combustion air B, the gas gun 9 and the assisting burner 13 What is necessary is just to restrain supply of the fuel or the process D, ie, to stop the said circulating fluidized bed furnace, and to perform the restoration | restoration operation of the closed return pipe | tube 3.

Therefore, according to the circulating fluidized bed furnace of this embodiment provided with such an obstruction detection means, the retention of solid content S in the return pipe 3 can be detected promptly and removed at the initial stage, and the stable fluid medium M It becomes possible to perform a smooth process by circulation of (). Moreover, in this embodiment, the operation which operates an obstruction blocking means based on the detection result detected by such an obstruction detection means is an air blaster as the flowmeter 11 and the pressure gauge 12 as this obstruction detection means, and the obstruction prevention means. Since it is possible to control by the said arithmetic control means, such as a computer connected to the solenoid valve 29 of 22 and 23, it is possible to operate a blockage blocking means automatically, without putting a burden on an operator, It is also possible to reduce the labor required to manage the operation of a circulating fluidized bed. Moreover, in this embodiment, the blockage detection means is comprised by the said flowmeter 11 and the pressure gauge 12 with which the supply pipe 10 ... of the combustion air B of the fluidized bed 1 was comprised, and combustion air B The value of the ratio (C) is calculated from the flow rate (F) and the pressure (P) in order to indirectly detect the retention and blockage in the return pipe (3). Means for measuring the amount of solids (S) is provided, or means for photographing the conveyance state of the solids (S) in the snow mirror (16) provided in the return pipe (3) or return pipe (3) A blockage detecting means may be provided in the chamber to detect the blockage due to the retention and blockage of the solid content S directly.

On the other hand, in this embodiment, the dispersion pipe 5 as a supply means of the flow air A provided in the bottom part of the said fluidized bed 1, and the return pipe provided so that it may open to the inner wall part of the fluidized bed 1 upper than this ( A blowing nozzle 8... Is provided between the connecting portions 7 of 3), and a part of the flowing air A can always be blown into the fluidized bed 1 from these blowing nozzles 8. have. For this reason, for example, as described above, even if the blower is clogged because the refractory material lining the inner wall of the fluidized bed 1 falls off and falls on the dispersion pipe 5... It is possible to supply the flowing air A from the blowing nozzles 8... Without any problem, thereby preventing the flow failure of the fluid medium M from occurring in the fluidized bed 1. Therefore, according to the circulating fluidized bed furnace of this embodiment provided with such a blowing nozzle 8 ..., the flow medium M which stayed at the bottom of the fluidized bed 1 by such a flow defect is returned from the connection part 7 from the return pipe 3 By entering the inside), the level of the flow medium M in the return pipe 3 can be prevented from rising, and the effect of the blockage blocking means is also more reliably and more stable. Circulation and processing of the processed material D can be attained.

Next, FIG. 8 and FIG. 9 show sectional views of the return pipe 3 in another embodiment of the present invention, respectively, and the same reference numerals are used for elements common to those shown in FIGS. 1 to 7. The description is omitted. Among these, in the embodiment shown in FIG. 8, the vibration device 31 which gives a vibration to the return pipe 3 instead of the air blasters 22 and 23 in the said embodiment as an obstruction blocking means is provided. It is characterized by being provided. That is, in this embodiment, the vibrator 31 provided with the vibrator 32 which can be vibrated by the drive means, such as a motor not shown, is attached to the metal outer wall part of the return pipe 3, and this vibrator ( By vibrating 32, vibration propagates to the outer wall portion, and vibration is applied to the return pipe 3. Therefore, in the circulating fluidized-bed furnace provided with such a blockage blocking means, when the blockage by the retention of solid content S in the return pipe 3 generate | occur | produces, this vibration apparatus 31 is operated and the return pipe 3 from the vibrator 32 is carried out. By vibrating, the blockage can be prevented by dropping the solid content S attached to the inner wall of the return pipe 3 or the fluidized medium M raised from the fluidized bed 1 by the sintering phenomenon, thereby preventing the blockage. The same effect as the shape can be obtained.

In addition, the embodiment shown in FIG. 9 is characterized in that the balloon 41 capable of expanding and contracting is accommodated in the return pipe 3. That is, in this embodiment, the bag-shaped balloon 41 made of a material having heat resistance and flexibility, such as a metal fiber sheet, is usually contracted as shown in Fig. 9 (a) to return the tube 3. It is accommodated so as to be in close contact with the inner wall surface, the balloon 41 is connected to the supply and suction device of compressed air from the outside of the return pipe (3), the solid content (S) of the return pipe (3) When residence occurs, compressed air is supplied from the supply / suction device 42, so that the balloon 41 instantly expands like an air bag and attaches to the inner wall of the return pipe 3 as shown in Fig. 9B. It is possible to break down the solids (S) that have been used and to prevent the blockage by returning the fluid medium (M) that has risen from the fluidized bed (1), so that the same effect as in the above embodiment can be obtained. In particular, according to the present embodiment, when solid content S is fixed to the inner wall of the return pipe 3 by the sintering phenomenon, it can be reliably forcibly collapsed to prevent blockage, which is effective. . In addition, the balloon 41 inflated in this way sucks the compressed air supplied at the time of expansion by the supply / suction device 42, thereby rapidly contracting and returning to a state in which the balloon 41 is in close contact with the inner wall of the original return pipe 3. Therefore, the circulation of the fluid medium M does not occur after that.

Moreover, also in these embodiment, it is preferable that operation | movement and stop of the said vibration apparatus 31, and expansion and contraction of the balloon 41 are made based on the detection result by a blockage detection means as mentioned above. Moreover, if these vibration apparatus 31 and the balloon 41 are also provided in several places toward the longitudinal direction of the return pipe 3, it will more reliably and effectively block | close the return pipe 3 by the convection of solid content S. You can stop it.

As described above, according to the present invention, an air blaster capable of blowing compressed air into the return pipe that conveys solids from the cyclone to the fluidized bed, a vibration device that imparts vibration to the return pipe, or return By providing blockage blocking means such as an expandable / deflatable balloon housed in the pipe, the blockage of solids in the return pipe due to retention of solids due to sintering phenomenon or poor flow of the fluid is suppressed, and the fluid medium is reliably transferred to the fluidized bed. By conveying, it becomes possible to plan the process by the flow of a stable and reliable process material. If the blockage blocking means can be operated based on the detection result of the blockage detecting means for detecting the retention of solids in the return pipe, for example, by measuring the supply flow rate and the pressure of the combustion air to the fluidized bed, Solids can be removed at an early stage, which facilitates smoother processing without burdening the operator. Further, if a blowing nozzle for blowing a part of the flowing air is provided between the supply means of the flowing air at the bottom of the fluidized bed and the connection portion of the return pipe to the fluidized bed, even if the refractory material falls out in the fluidized bed, the flow state is stably maintained. I can keep it.

Claims (7)

A fluidized bed for flowing the processed material supplied therein, a cyclone for separating the exhaust gas discharged from the fluidized bed into solids and gases, and collecting solids, and a return pipe for conveying the solids collected in the cyclone to the fluidized bed. And, the return pipe is provided with a blockage blocking means for removing the solids remaining in the return pipe. The circulating fluidized bed furnace according to claim 1, wherein the blockage blocking means is an air blaster for blowing compressed air into the return pipe. The circulating fluidized bed furnace according to claim 1, wherein the blockage blocking means is a vibration device that imparts vibration to the return pipe. The circulating fluidized bed furnace of claim 1, wherein the blockage blocking means is an inflatable contractible balloon contained within the return tube. The said fluidized bed or return pipe | tube is equipped with the blockage detection means which detects the retention of solid content in the said return pipe | tube, The said blockage blocking means is in any one of Claims 1-4. The circulating fluidized bed furnace which is operable based on the detection result by this. The said fluidized bed is provided with the supply means of the combustion air for burning the said processed material, The said obstruction detection means detects the retention of the solid content by measuring the flow volume and the pressure of this combustion air. Characterized by a circulating fluidized bed furnace. The bottom part of the said fluidized bed is provided with the supply means of the flowing air which flows the said processed material, The said return pipe is connected to the said fluidized bed above the supply means of this fluidized air, and this return pipe And a blowing nozzle for blowing a part of the flow air into the fluidized bed between the connection to the fluidized bed and the supply means.