JP2613736B2 - Screw feeder type powder cooler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for supplying PFBC combustion gas to a gas turbine in combined power generation by pressurized fluidized bed combustion (hereinafter, sometimes simply referred to as PFBC) which is being put into practical use recently. In addition, the present invention relates to a pressurized ash discharge system for taking out ash in a high temperature and high pressure atmosphere separated from combustion gas while continuously cooling it.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a first prior art.
BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the conveyance apparatus of the granular material described in Unexamined-Japanese-Patent No. 55-122949. In FIG. 6, 101 is a cylinder, 102 is an inlet, 103 is an outlet, 104 is a hollow shaft, 105 is a screw blade, and 106 is an outer cylinder. In the conventional example, first, the granular material supplied from the charging port 102 enters the cylindrical body 101. Inside the cylindrical body 101, a hollow shaft 104 for flowing a coolant through the hollow interior and a screw blade 105 mounted on the outer periphery of the hollow shaft 104 are rotatably inserted. An outer cylinder 106 is attached to the outer periphery of the cylinder 101 so that the coolant can flow between the two cylinders.

The inside of the hollow shaft 104, the cylindrical body 101 and the outer cylinder 1
06, and the hollow material 104 is rotated to rotate the hollow shaft 104, so that the granular material injected from the inlet 102 is cooled by the peripheral wall while rotating inside the cylindrical body 102, and the screw blade It is moved to the outlet 103 side by 105 and discharged.

[0004] As a second prior art example, a heating jacket is attached to a screw feeder to heat a granular material as in a granular material transporting apparatus described in Japanese Utility Model Laid-Open No. 59-108722. In some cases, the ash is smoothly transported while keeping the water content of the granular material at the discharge port constant.

[0005] Further, as a third prior art example, in order to increase the cooling efficiency, as in a power generator having an ash cooler with a screw conveyor described in Japanese Patent Publication No. 3-50577. In some cases, a fluidizing device is provided at the lower portion inside the screw feeder cylinder.

[0006]

As described above, also in the above-mentioned prior art, it was possible to smoothly transfer the supplied granular material while appropriately exchanging heat. However, for example, in the first and second conventional techniques, the conveyed powdery and granular materials are not filled in the screw feeder, but are deposited in a lower portion of the screw, that is, conveyed in a state having a space above the screw. Is performed, in a system where the differential pressure at the entrance and exit of the particulate matter fluctuates, the inflow of gas on the upstream side of the screw feeder or the backflow of downstream gas is prevented while preventing the Unable to transport objects. In addition, since the conveyed material is deposited on the lower portion of the screw, the contact area with the heat exchanging part is reduced, and the apparatus itself has a problem of being large. Further, in the third prior art, it is of a type that is installed at the next stage of the vacuum ash unloading device, and has a function of sealing the differential pressure between the entrance and the outlet, as in the first and second prior arts. It does not have.

[0007] The present invention has been made in view of such circumstances, and has a simple configuration and a low manufacturing cost.
It is an object of the present invention to provide a particulate cooling / transporting device having a function of blocking gas flow from an upstream side to a downstream side or vice versa in a high temperature / high pressure system.

[0008] The above object is achieved by a screw feeder type powder cooler described in the claims. That is, it has a cylindrical shape installed at an angle, has a powder inlet on the upper surface of the lower part of the cylinder, a powder outlet on the lower surface of the upper part of the cylinder, has a cylindrical outer shell structure, and has a screw shaft at the center of the cylinder. In a screw feeder-type cooler that has a hollow structure and conveys a heat exchange medium through the cylindrical shell and the screw shaft while cooling the powder moved by the screw, the cylindrical shell has a pressure-resistant structure, A hollow screw shaft, both ends of which are pressure-tightly sealed and supported, a plate-like screw blade attached to a lower powder inlet side and an upper powder outlet side of the lower hollow screw shaft, and an intermediate portion of the hollow screw shaft A hollow blade consisting of only a portion corresponding to the tip end of a screw blade by a narrow plate or a tubular material, which is attached to each of the plate-shaped screw blades in a continuous manner. A part is formed and supported by the screw shaft, and only the ash of the bottom part of the inner wall of the cylindrical shell is pushed up with the rotation of the screw shaft, and the pushed up ash corresponds to the tip of the screw blade and the screw shaft. It gradually overflows from the space formed between it and slides down the inside of the cylindrical shell inner wall in the lower direction, and is gradually pushed up again by the portion corresponding to the tip of the screw blade, and gradually accumulates from the lower direction while repeating the operation. A screw feeder type powder cooling having a hollow screw blade that forms a seal portion with ash that blocks gas flow between upstream and downstream in the screw feeder by filling the hollow blade portion in the feeder with ash. vessel.

The screw feeder type powder cooler according to the above description, wherein the cylindrical outer shell of the jacket structure has flanges formed directly at both ends. The connecting portion connecting the cylindrical outer shell both ends of the jacket structure and the supporting portion supporting the driven shafts connected to both ends of the hollow screw shaft by pressure-resistant sealing is formed from the cylinder having the heat exchange medium flow path and the flange. Or a screw feeder type powder cooler as described. On the outer periphery of the shaft located between the hollow portion of the hollow screw shaft and the support portion sealed at both ends, the powder in the cylinder is moved from the pressure-resistant seal portion side to the cylinder center portion side based on the rotation of the hollow screw shaft. A screw feeder-type powder cooler provided with or described with a screw blade in an extruding direction. It is. Hereinafter, the operation and the like of the present invention will be described based on examples.

[0010]

1 to 5 show an embodiment of a screw feeder type powder cooler according to the present invention. FIG. 1 is a partially cutaway side view, and FIG. 2 shows a plate-like blade and a hollow screw blade. FIG. 3 is an enlarged view of the attached screw, and FIG.
FIG. 4 is a sectional view taken along line bb in FIG. 2, and FIG. 5 is a partially enlarged view of an end of the drive shaft. Figures 1-5
1, 1 is a hollow screw shaft, 2, 21 are screw blades, 3 is a cylindrical shell, 4 is a powder inlet, 5 is a powder outlet, 6, 8, and 10 are heat exchange medium inlets, 7, 9, and 9. 11 is a heat exchange medium outlet, 12 is a horizontal level, 13 is a plate screw blade, 14 is a hollow screw blade, 15 is a powder level, 16 is an inner wall of a cylindrical outer shell, 17 is a support bracket, 18 is a flange, 19 and 19, 20 and 22 are heat exchange medium channels, and 23 and 24
Is a support portion, 25 is a region of a hollow screw blade, and 30 is a screw feeder.

The screw feeder 30 has a jacket-type pressure-resistant cylindrical outer shell 3 in which a heat exchange medium flow path 19 is formed inside, since the ash to be fed is at a high temperature and a high pressure. The portion is provided with a hollow screw shaft 1 having a channel 22 through which a heat exchange medium can flow,
The outer wall of the hollow screw shaft 1 has an inner wall 1
A screw blade 2 having a height substantially inscribed in 6 is attached.

A hollow screw shaft 1 on which a screw blade 2 is mounted is supported or rotated at both lower and upper ends of a cylindrical outer shell 3 or a supporting portion which rotates and copes with high temperature and high pressure to maintain a predetermined strength. 23 and 24 are provided. A powder inlet 4 is provided on the upper surface of the lower portion of the cylindrical outer shell 3, and a powder outlet 5 is provided on the lower surface of the upper portion. Further, a heat exchange medium inlet 8 or a heat exchange medium outlet 9 for feeding or sending the heat exchange medium into or out of the heat exchange medium flow path 19 of the cylindrical outer shell 3 are provided at a lower portion and an upper portion of the cylindrical outer shell, respectively. . At the lower and upper ends of the cylindrical shell 3, heat exchange medium inlets 10 and 10 'and outlets 11 and 11' for supplying and exchanging the heat exchange medium to and from the heat exchange medium flow path 20 are provided. I have.

In the PFBC combined cycle power generation system, the combustion gas discharged from the fluidized-bed boiler separates ash from the combustion gas in a high-temperature dust removing device such as a ceramic filter, and the purified combustion gas is sent to a gas turbine. The ash separated and removed is high temperature and high pressure (about 850
Screw feeder 30 at 900 ° C, 10 atm).
Sent to

Ash (hereinafter, also simply referred to as powder) flowing through the powder inlet 4 disposed on the lower surface of the screw feeder 30 is fed to the screw feeder 30.
After being moved above the screw feeder 30 with the rotation of the screw disposed inside, it is discharged through the powder feed port 5.

At this time, when the ash which is fed into and discharged from the screw feeder 30 is almost at atmospheric pressure,
Even if the screw feeder 30 is arranged horizontally and the screw blade 2 has a structure in which the plate-shaped screw blade is attached to the entire length of the hollow screw shaft 1, there is no problem. When the pressure is high, the gas on the upstream side of the screw feeder 30 passes through the inside of the screw feeder 30 and flows out to the downstream side at once, and there is a possibility that the devices disposed on the downstream side may be damaged. Further, when air is used for air diffusion or the like in the downstream device, the seal in the screw feeder 30 is not perfect, which has an adverse effect on ash falling from the high-temperature dedusting device on the upstream side.

[0016] Therefore, in the screw feeder 30, the gas flow between the upstream side and the downstream side of the screw feeder 30 is shut off by using the ash that has been fed, thereby preventing air from being blown up from downstream equipment and preventing the screw from being blown up. It is necessary to cool the hot gas together with the ash in the feeder 30 to a temperature that does not damage the downstream equipment.

The present application was invented to achieve the above object, and has the following configuration. First, as shown in FIGS. 1 and 2, the ash (powder) input side of the entire screw feeder 30 is lower than the horizontal level 12, and the ash (powder)
It is installed so as to be inclined so that the sending side of is higher. On the basis of this, the ash supplied from the charging port is pushed upward from below by the rotating screw blades, moves upwards while gradually filling the inside of the cylindrical shell 3, and is discharged from the powder feed port 5. . Therefore, the gas flow between the upstream side and the downstream side of the screw feeder 30 is blocked by the powder in the screw feeder 30, and the upstream high-temperature and high-pressure gas is prevented from flowing out to the downstream side.

However, according to the investigation by the present inventors, simply tilting the screw feeder 30 results in a low density of ash deposited at the lower portion of the screw feeder 30 and a small volume of ash. It was found that the high-temperature high-pressure gas on the upstream side 30 leaked to the downstream side through the gap between the screw blade 2 and the inner wall of the cylindrical shell 3, and that the fluidized air of the downstream side device flowed back.

Therefore, the present inventors have proposed that the screw blade 2
As shown in FIGS. 2 to 4, a conventional plate-like screw blade 13 is attached to the powder feed port 4 side and powder feed port 5 side of the screw feeder 30 as shown in FIGS. A hollow screw blade region 25 to which the hollow screw blade 14 was attached as shown in FIG. 3 was provided in the middle of the two plate-shaped screw blades 13.

The hollow screw blade 14 is formed by forming only a portion corresponding to the tip portion of the plate-shaped screw blade 13. Only the tip portion of the screw blade is formed by a thin plate or a tubular material, and both ends thereof are respectively formed. It is joined to the tip of the upstream or downstream plate-like screw blade 13, and the whole is firmly attached to the hollow screw shaft 1 by a plurality of support fittings 17 as shown in FIG. It is installed with enough space to allow free circulation.

As a result, the ash supplied from the powder supply port 4 is first moved in the screw feeder 30 by the lower plate-like screw blade 13 and is fed into the hollow screw blade 1.
4 to the region 25 of the hollow screw blades.
In the region 25, only the ash at the bottom of the cylindrical outer wall 16 is pushed upward by a thin plate or a tubular blade formed at the tip of the hollow screw blade 14,
Next, the pushed-up ash overflows from the hollow portion of the hollow screw blade 14, slides down in the cylindrical outer inner wall 16 in the lower direction, and gradually accumulates from the lower portion while repeating the operation of being pushed up again by the hollow screw blade 14, and finally, A level 15 of the powder is formed as shown by the phantom line in FIG. 2 and the lower part in the screw feeder 30 is filled with the ash which is slightly compacted.

As a result, even when a rapid pressure fluctuation occurs in the ash system such as a backwash of a high-temperature dedusting device arranged on the upstream side of the screw feeder 30, the screw feeder 30 can be used.
The gas which is condensed and accumulated in the inside prevents the gas flow and prevents the equipment downstream of the screw feeder 30 from being damaged by the hot gas, or fluidized air from the downstream equipment of the screw feeder 30. Backflow can be prevented.

The plate-shaped screw blade 13 is mounted on the powder feed port side above the hollow screw blade region 25 in the screw feeder 30. By means of the plate-like screw blades 13, the region 25 of the hollow screw blades
The powder that has been extruded by the plate-shaped screw blades 13 disposed on the lower side of the powder inlet and is deposited and consolidated in the region 25 of the hollow screw blades and has been pushed up while filling the inside of the cylinder is powder. It is smoothly discharged through the delivery port 5 to prevent the inside of the screw feeder 30 from being blocked by ash.

As shown in FIG. 5, a flange 18 is integrally formed at an end of the cylindrical outer shell 3 having a jacket structure. A part of the side surface of the flange 18 on the side of the cylindrical outer shell 3 constitutes a part of the wall surface of the heat exchange medium flow path 19 of the jacket.
Even when the screw feeder 30 is inserted into the screw feeder 30, it is possible to prevent the screw feeder 30 from being damaged or the like due to an abnormal rise in the temperature of the flange 18.

As shown in FIG. 5, a connecting portion for connecting the both ends of the outer shell of the jacket structure and the supporting portion for supporting both ends of the hollow screw shaft by pressure-tightly sealing the heat exchange medium flow inside the cylindrical portion. High temperature powder to be introduced by forming a flange at both ends thereof and forming a part of the opposite side of the flange as a part of the heat exchange medium flow path 20. The heat transfer from the body prevents the support portions provided at both ends of the screw feeder 30 from burning out.

[0026] Further, it is located substantially inside the connection portion.
A screw blade 21 as shown in FIG. 5 is provided on the outer periphery of the shaft located between the hollow portion of the hollow screw shaft and the support portions sealed at both ends with pressure resistance. The blade 21 has the powder feed port 4 at the lower part of the screw feeder 30 in the same direction as the plate-shaped screw blade 13 provided on the hollow screw shaft 1, and the powder feed port 5 at the upper part of the screw feeder 30.
The side is formed in a direction opposite to the plate-like screw blade 13. When the screw feeder 30 is operated based on this,
The powder at both ends in the screw feeder 30 is extruded toward the center part of the screw feeder 30 by the screw blades 21, and it is possible to prevent problems such as seizure caused by the powder entering the support at both ends. become.

[0027]

As described above, according to the present invention, as described in the above-described embodiment, the hollow screw blade is provided at a position slightly upstream of the plate-shaped screw blade near the outlet of the screw blade that conveys the ash. As a result, the ash sent by the screw blades is deposited and compacted in the hollow screw blades and temporarily stopped being sent, but the screw blades are continuously rotating and the screw feeder As the ash is supplied from below (upstream side), the inside of the cylinder on the inlet side of the screw feeder is gradually filled with ash and sent to the outlet side with the inside of the cylinder filled, and finally the space of the hollow screw blade section The ash compacted in the section is extruded, sent to the outlet and discharged. At this time, since the inside of the cylinder is filled with the ash, even if the pressure fluctuates on the entrance / exit side, the gas is in a gas-sealed state due to the filled ash.

Further, since the cylinder is filled with ash, the contact area between the hollow screw shaft, through which the heat exchange medium flows, and the ash on the inner surface of the cylinder is increased, and the effective heat transfer area is increased. The heat exchange capacity increases.

A flange is integrally formed at an end of the cylindrical shell of the jacket structure, and a part of the side surface of the flange on the cylindrical shell side forms a part of a wall surface of the heat exchange medium flow path of the jacket. Thus, it is possible to prevent the temperature of the flange from rising abnormally and the screw feeder from being damaged or the like.

A connecting portion between both ends of the cylindrical outer shell of the jacket structure and the support portion has a heat exchange medium flow path inside the cylindrical portion, and flanges are formed at both ends thereof. By making a part of the heat exchange medium flow path a part of the heat exchange medium flow path, it is possible to prevent burning of the support part due to heat conduction from the high-temperature powder to be supplied.

Screw blades are provided on the outer periphery of the shaft located between the hollow portion of the hollow screw shaft and the support portions at both ends of the screw feeder, and the powder inlet side is the same as the plate-shaped screw blade provided on the hollow screw shaft. And the powder outlet side is formed in the opposite direction to the plate-shaped screw blade. Thus, when the screw feeder is in operation, the powder near both ends of the support is pushed out toward the center of the screw feeder, so that the support can be prevented from burning due to intrusion of the powder.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a screw feeder type powder cooler according to the present invention.

FIG. 2 is an enlarged view of a screw to which a plate-like blade and a hollow screw blade are attached.

FIG. 3 is a sectional view taken along line aa in FIG. 2;

FIG. 4 is a sectional view taken along line bb in FIG. 2;

FIG. 5 is a partially enlarged view of an end of a drive shaft.

FIG. 6 is an example of the first prior art.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 Hollow screw shaft 2, 21 Screw blade 3 Cylindrical shell 4 Powder inlet 5 Powder outlet 6, 8, 10 Heat exchange medium inlet 7, 9, 11 Heat exchange medium outlet 12 Horizontal level 13 Plate screw blade 14 Hollow screw blade 15 Powder level 16 Cylindrical shell inner wall 17 Support bracket 18 Flange 19, 20, 22 Heat exchange medium flow path 23, 24 Support section 25 Hollow screw blade area 30 Screw feeder 101 Cylindrical body 102 Input port 103 Discharge Outlet 104 Hollow shaft 105 Screw blade 106 Outer cylinder

Claims (4)

(57) [Claims] 1. A cylinder having a cylindrical shape installed at an angle, a powder inlet on the upper surface of a lower portion of the cylinder, a powder outlet on a lower surface of the upper portion of the cylinder, a cylindrical outer shell having a jacket structure, and a central portion of the cylinder. A screw feeder-type cooler that has a screw shaft having a hollow structure and that conveys a heat exchange medium through the cylindrical shell and the screw shaft while cooling the powder moved by the screw, wherein the cylindrical shell has a pressure-resistant structure. A hollow screw shaft supported at both ends in a cylinder by pressure-sealing, a plate-like screw blade attached to a lower powder inlet side and an upper powder outlet side of the hollow screw shaft, and the hollow screw A narrow plate or tubular object attached to the middle of the shaft in succession to each of the plate screw blades
Only the part corresponding to the tip of the screw blade
Forming a hollow blade part consisting of and supporting it on the screw shaft,
Ash on the bottom of the inner wall of the cylindrical shell with the rotation of the screw shaft
Only the ash is pushed upwards,
Form between the portion corresponding to the tip of the blade and the screw shaft
Overflows from the formed space and the inside of the cylindrical shell inner wall in the downward direction
Sliding down again, the part corresponding to the tip of the screw blade again
While repeating the action of being pushed up by
First, deposits from the bottom direction, and the above in the screw feeder
Filling the hollow blades with ash allows the screw
Ash that blocks gas flow between upstream and downstream
A screw feeder-type powder cooler, comprising: a hollow screw blade for forming a seal portion formed by the screw feeder. 2. The screw feeder type powder cooler according to claim 1, wherein the cylindrical outer shell of the jacket structure has flanges directly formed at both ends. 3. A connecting portion for connecting both ends of a cylindrical outer shell of a jacket structure and a supporting portion for supporting both ends of a hollow screw shaft by pressure-tight sealing, comprising a cylinder having a heat exchange medium flow path and a flange. The screw feeder type powder cooler according to claim 1 or claim 2. 4. The powder in the cylinder is applied to the outer periphery of the shaft located between the hollow portion of the hollow screw shaft and the pressure-sealed support portions at both ends from the pressure-tight seal portion based on the rotation of the hollow screw shaft. 4. The screw feeder type powder cooler according to claim 1, wherein screw blades are provided in a direction toward the center of the cylinder so as to be pushed out.