JP5422291B2 - Water-cooled stoker furnace - Google Patents

Description

  The present invention relates to a water-cooled stoker furnace suitable for high-temperature reduction treatment of an object to be treated such as garbage.

  In recent years, development of a pyrolysis gasification melting furnace for garbage has been actively promoted. Pyrolysis gasification and melting furnaces are pyrolyzed into combustible gas, char and inorganic matter by steaming the object to be treated such as garbage in a high-temperature reducing atmosphere of about 500 ° C. It is used as a fuel for a chemical melting furnace and is combusted with char supplied from a separate line at a high temperature of 1300 ° C. or higher to make ash into slag.

  One type of pyrolysis gasification melting furnace is a combination of a gasification furnace and a melting furnace. For example, a pyrolysis gas generated in a pyrolysis drum such as a rotary kiln furnace is used as a high-temperature combustion melting furnace in the subsequent stage. In this method, the ash is combusted with char supplied from another line to slag the ash (for example, Patent Document 1).

  However, in the rotary kiln furnace, the workpiece is subjected to a drop impact in order to convey the workpiece by rotating the inclined pyrolysis drum. In the case of an object that is brittle due to the impact, the shape changes or is crushed in the pyrolysis drum. There is no problem when the shape of the object to be processed after processing is not limited, but it is not suitable for an object to be processed that is desired to avoid deformation or crushing, such as steelmaking dust obtained by processing powder into a pellet.

  Therefore, instead of the rotary kiln furnace, it is considered to use a so-called stoker furnace that has a gradual conveyance and an appropriate stirring function, and has a stoker like a stoker type incinerator regardless of the properties of the object to be treated. It is done.

  When high-temperature reduction treatment is attempted using such a stoker furnace, it is considered effective to supply high-temperature low-oxygen gas from the bottom of the grate.

Japanese Patent Laid-Open No. 2001-27411 Japanese Patent No. 3715430 Japanese Patent No. 2931958 Japanese Patent No. 3990463 Japanese Patent No. 396790 Japanese Patent No. 3838639

However, the conventional stoker-type incinerator has a high combustion air supplied from the lower part of the grate at about 300 ° C. and is designed for solid combustion on the upper surface of the grate. The back of the grid is not designed to withstand high temperatures of 500 ° C or higher. On the other hand, even a water-cooled grate (for example, Patent Documents 2 to 6) used for fuel with a high calorific value, the back surface of the grate is not designed to withstand a high temperature of 500 ° C or higher.
For this reason, when a conventional stoker-type incinerator is applied to perform a high-temperature reduction treatment, the frame supporting the grate is thermally damaged.

  The present invention has been devised in view of the problems described above, and the problem to be solved is a stoker furnace having a structure applicable to high-temperature reduction treatment, and gas in a gasification melting furnace. The object of the present invention is to provide a water-cooled stoker furnace that can also be used as a conversion furnace.

The water-cooled stoker furnace according to the present invention is a stoker furnace in which a fixed grate and a movable grate are alternately arranged in the front-rear direction. while being supported Te, the inside is a coolant frame-integrated type in which passing flows cooling water channel is formed, the movable grate is the manner is moved forward and backward depending on the drive device arranged outside the furnace, further The stoker furnace is detachably provided on the upper surface of the fixed grate and has a shoe for forming a gap through which the high-temperature combustion ash gas flows between the movable grate and the movable grate. A movable water cooling wall that closes the penetration part between the movable grate and the furnace side wall regardless of the back and forth movement of the lattice, and a movable grate and a furnace that are detachably provided on the fixed grate regardless of the back and forth movement of the movable grate Closes the penetrating part with the body side wall and adjusts the gap with the movable grate Characterized in that and a possible fixed-side water wall is stationary.

  When the movable grate is moved back and forth by the drive device, the workpieces on the fixed grate and the movable grate are conveyed in the front-rear direction. The fixed grate and the movable grate are integrated with the frame in which a cooling water channel is formed to allow cooling water to flow inside, so it is different from the conventional structure in which the grate is supported by the frame. A high-temperature low-oxygen exhaust gas can be introduced from the bottom of the grate. Since the drive device is provided outside the furnace, it is not exposed to high temperature gas. As a result, a stoker furnace having a structure applicable to high temperature reduction treatment can be obtained, and it can also be used as a gasification furnace for a gasification melting furnace.

  The in-furnace portions of the fixed grate and the movable grate are preferably coated with a refractory. If it does in this way, while being insulated by a refractory material, it can prevent cooling of a to-be-processed object, and can reduce the temperature fall of the hot gas from the lower part of a grate.

  It is preferable that the fixed grate and the movable grate are made of cast steel in which a water pipe serving as a cooling water channel is cast. In this way, the grate can be cooled uniformly and no air pockets are generated inside.

  On the side wall of the furnace body, there is provided a storage box for storing the pair of fixed grate and the movable grate outside the furnace, and the driving device is connected to the movable grate through the storage box. Is preferred. In this way, it is possible to prevent leakage of the in-furnace gas to the outside by purging the containment box with an inert gas or its own exhaust gas, and to move the movable grate back and forth depending on the driving device. it can.

It is preferable that the housing box is provided so as to be openable and closable and includes a lid for exchanging shoes and adjusting and moving the fixed water cooling wall. In this way, it is possible to replace the shoe by opening the lid and removing the fixed-side water-cooled wall, and to adjust the movement of the fixed-side water-cooled wall.

  It is preferable to supply high-temperature combustion exhaust gas having an oxygen concentration of 1% or less from the lower part of the grate to the gap between the fixed grate and the movable grate. In this way, the object to be processed on the grate can be subjected to a high temperature reduction process.

  The temperature of the high-temperature combustion exhaust gas supplied from the lower part of the grate is preferably 500 ° C. or higher. In this way, the object to be processed on the grate can be subjected to a high temperature reduction process.

  It is preferable that a burner for heating in the furnace is installed in the lower space of the grate. In this way, high-temperature combustion exhaust gas having a low oxygen concentration necessary for thermal decomposition of the object to be processed can be supplied to the lower part of the grate. The combustion exhaust gas supplied to the lower part of the grate rises on the grate through the grate, and the object to be treated is thermally decomposed.

  The refractory is preferably a removable refractory ceramic plate. In this way, long-term performance can be maintained by simply replacing the refractory ceramic plate.

According to the present invention, the following excellent effects can be achieved.
(1) A water-cooled structure that integrates the grate and the frame, and the grate and the like are protected by water cooling, so it is possible to inject high-temperature low-oxygen exhaust gas from the bottom of the grate, Can be reduced at high temperature.
(2) Since it is a stoker furnace with high sealing performance of the furnace body, the controllability of temperature and oxygen concentration is high.
(3) Since there is no falling stirring of the object to be processed unlike a rotary kiln furnace, it can be processed regardless of the properties of the object to be processed.
(4) Since the object to be treated is not exposed to the burner flame unlike a rotary kiln furnace or a rotary hearth furnace, an oxidation reaction of the object to be treated can be prevented and a high quality reduction treatment can be performed.

1 is a longitudinal side view showing a schematic structure of a water-cooled stoker furnace according to the present invention. The top view which shows the structure of a grate. The side view of FIG. The front view of FIG. The front view which shows a guide mechanism part. The top view which fractured | ruptured a part which shows the structure of a movable grate. The front view which fractured | ruptured a part of FIG. FIG. 7 is a central longitudinal front view of FIG. 6. The top view which fractured | ruptured a part which shows the structure of a fixed grate. The front view which fractured | ruptured a part of FIG. The center longitudinal cross-sectional front view of FIG. The top view which shows the time of reversal of a movable grate. The side view of FIG. The top view which shows the time of advance of a movable grate. The side view of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the water-cooled stoker furnace 1 was pushed out by using an inlet 2 for feeding the workpiece A, a pusher (not shown) for pushing the workpiece A, and the like. The grate 3 etc. which convey the to-be-processed object A are provided.
In the grate 3, the fixed grate 4 and the movable grate 5 are alternately arranged in an inclined manner in the front-rear direction (the left side is the front side in FIG. 1). As the movable grate 5 reciprocates in the forward / backward tilt direction, the workpiece A is sequentially conveyed to the downstream side.

  The water-cooled stoker furnace 1 is a stoker furnace having a structure suitable for high-temperature reduction treatment of the workpiece A, and is used for starting to radiate a flame to the workpiece on the grate like a conventional stoker-type incinerator. A burner is not provided, and a burner 7 that radiates a flame is installed in a wind box 6 that forms a lower space of the grate 3.

The wind box 6 has a box shape whose upper side is opened so that the high temperature combustion exhaust gas B can be supplied to the entire lower part of the grate 3, and is not shown in the figure, but the inner surface is lined with a refractory. .
The burner 7 generates a high-temperature combustion exhaust gas B having a low oxygen concentration by burning fuel such as fossil fuel, COG gas, biogas, etc., and supplies it to the lower part of the grate 3. The high-temperature combustion exhaust gas B having a low oxygen concentration supplied to the lower part of the grate 3 passes through the gap between the movable grate 4 and the fixed grate 5 and steams the object A on the grate 3 in a high-temperature reducing atmosphere. To do.

  The high-temperature combustion exhaust gas B is preferably supplied while being controlled to an oxygen concentration of 1% or less. For example, the oxygen concentration of the high-temperature combustion exhaust gas B is detected by an oxygen concentration meter (not shown) before being supplied to the lower part of the grate 3, and if the detected oxygen concentration exceeds 1%, the burner The oxygen concentration can be controlled to 1% or less by adjusting the air ratio of the combustion air supplied to 7 and the air-fuel ratio of the fuel gas and the combustion air.

  Thus, in addition to this, the water-cooled stoker furnace 1 includes a cooling water channel 8, a refractory 9, a shoe 10, a storage box 11, a lid 12, a guide mechanism 13, a driving device 14, a movable water cooling wall 15, and a fixed side. A water cooling wall 16 is provided.

The fixed grate 4 and the movable grate 5 are supported by penetrating through holes 18 formed in the furnace side wall 17 on both the left and right sides, and a cooling water channel 8 through which the cooling water C flows is formed. The frame is integrated.
That is, the fixed grate 4 and the movable grate 5 include the left and right support parts 19 that are supported through the through holes 18 of the furnace body side wall 17, the connecting parts 20 that connect both the support parts 19, and the support parts 19. And a cooling water passage 8 that is formed inside the connecting portion 20 and through which the cooling water C flows.

  The fixed grate 4 and the movable grate 5 are made of cast steel into which a water pipe 21 that becomes the cooling water channel 8 is cast.

The in-furnace portion of the fixed grate 4 and the movable grate 5, that is, the connecting portion 20, is made thinner than the support portion 19 and is covered with the refractory 9.
The thickness of the refractory 9 is made equal to the difference between the thickness of the support portion 19 and the thickness of the connection portion 20 so that the surfaces of the support portion 19 and the connection portion 20 are flush with each other. The refractory 9 is a refractory ceramic plate that can be attached to and detached from the connecting portion 20.

The fixed grate 4 has a horizontally long rectangular shape in the left-right direction, and support portions 19 on both the left and right sides penetrate through the through holes 18 in the furnace body side wall 17 and are integrally fixed thereto.
On the upper surface of the support part 19 of the fixed grate 4, the movable grate 5 is slidably contacted, and a shoe for forming a gap through which the high-temperature combustion ash gas B flows with the movable grate 5. 10 is provided so as to be detachable (exchangeable).
The fixed grate 4 is provided with a meandering water pipe 21 that forms the cooling water channel 8, and an inlet and an outlet are formed on the left and right sides (upper side in FIG. 2). An inlet and an outlet of the water pipe 21 are formed outside the furnace through the lid body 12 of the storage box 11, and a cooling water supply device is connected to them through a pipe or the like, although not shown. Yes.

As with the fixed grate 4, the movable grate 5 includes left and right support parts 19 and a connecting part 20 that connects them, and the support part 19 penetrates the through hole 18 of the furnace body side wall 17 in the front-rear direction. It is provided to be movable. The support portion 19 has a substantially L shape including a vertical piece extending in the front-rear direction and a horizontal piece extending from the rear portion to the outside in the left-right direction.
As with the fixed grate 4, the movable grate 5 is provided with meandering water pipes 21 that form the cooling water channels 8, and an inlet and an outlet are distributed on both the left and right sides. A pipe 22 extending forward and penetrating through the front side of the storage box 11 in the front-rear direction is connected to the inlet and outlet of the water pipe 21. Although not shown in the drawings, a cooling water supply device is connected to the pipe 22 via a flexible tube or the like.

The storage box 11 has a box shape in which one side is fixed to the furnace body side wall 17 and the other side is opened, and a majority of the pair of the fixed grate 4 and the movable grate 5 protruding from the outside of the furnace, that is, the left and right support parts 19. It is something to house.
The inside of the storage box 11 communicates with the inside of the furnace through the through-hole 18 in the side wall 17 of the furnace body, and is purged by an inert gas, its own exhaust gas, or the like to prevent intrusion of the furnace gas. Yes.
The number of the storage boxes 11 is increased according to the processing scale.

  The lid 12 is detachably provided so as to open and close the opening of the storage box 11, and is opened when the shoe 10 is exchanged or the stationary water cooling wall 16 is adjusted.

  The guide mechanism 13 is provided in the storage box 11 and has a guide rail 23 having a substantially horizontal C-shaped section, a slider 24 having a substantially inverted T-shaped section that is slidably fitted into the guide rail 23, and a guide rail 23 attached thereto. The support part 19 of the movable grate 5 is provided with a receiver 25 that is detachably fitted.

  The drive device 14 is provided outside the furnace and moves back and forth through the movable grate 5, and slidably penetrates the rear side of the storage box 11 and is connected to the receiving body 25 of the guide mechanism 13 so as to be lifted and lowered. A rod 26, a connecting body 27 that connects and synchronizes a plurality of (three in this example) rods 26, and a hydraulic cylinder 28 that is provided on the stationary side outside the furnace and connected to the connecting body 27 is provided. ing.

  The movable side water cooling wall 15 is attached to the rear side outside the furnace of the support portion 19 of the movable grate 5, and is close to the outside of the furnace body side wall 17 regardless of the back and forth movement of the movable grate 5. And a part of the through hole 18 between the through hole 18 and the through hole 18 are closed.

  The fixed-side water cooling wall 16 is provided with a refractory 29 inside the furnace, and is provided on the support 19 of the fixed grate 4 along the side wall 17 of the furnace. On the other hand, it is separable and detachable in the left-right direction. The attachment / detachment tool 30 includes a horizontally long slot provided in the stationary water cooling wall 16, a screw hole provided in the support portion of the fixed grate 4, a bolt inserted through the slot and screwed into the screw hole, It has. Thus, if the bolt as the attachment / detachment tool 30 is loosened, the fixed-side water cooling wall 16 can be adjusted and moved, and if the bolt as the attachment / detachment tool 30 is unscrewed, the fixed-side water cooling wall 16 is fixed to the fixed grate. 4 can be removed.

  The movable side water cooling wall 15 and the fixed side water cooling wall 16 form a so-called slide seal mechanism that allows the movable grate 5 to move back and forth and closes the through hole 18 of the furnace body side wall 17.

The furnace body side wall 17 includes a water-cooled wall 31 and a refractory 32 disposed on the inside of the furnace. Although not shown, the water cooling wall 31 is connected to a cooling water supply device, and the cooling water forcibly circulates in the internal space of the water cooling wall 31.
The movable side water cooling wall 15 and the fixed side water cooling wall 16 are also not shown, but are connected to a cooling water supply device, and the cooling water is forcibly circulating through the internal space of the water cooling wall.

Next, the operation will be described based on such a configuration.
When the cylinder 28 of the driving device 14 is operated, the movable grate 5 is reciprocated in the front-rear direction via the connecting body 27, the rod 26 and the receiving body 25 of the guide mechanism 13. At this time, the movable grate 5 is guided by the slider 24 and the guide rail 23 of the guide mechanism 13 and is prevented from being lifted. The movable grate 5 is closed by the movable side water cooling wall 15 and the fixed side water cooling wall 164 regardless of the back-and-forth movement thereof, and the through hole 18 of the furnace body side wall 17 is closed, and the inside of the containing box 11 is filled with inert gas or self. Together with being purged by the exhaust gas, the gas in the furnace does not pass through the through hole 18 and enter the storage box 11 or leak out of the furnace.
The fixed grate 4 and the movable grate 5 are cooled because the cooling water C from the cooling water supply device is supplied to the cooling water channel 8 and circulated. Since the connection part 20 of the fixed grate 4 and the movable grate 5 is covered with the refractory 9, the connection part 20 is protected from heat and a gap between the fixed grate 4 and the movable grate 5 is provided. It is possible to prevent the temperature of the high-temperature combustion exhaust gas B passing therethrough from decreasing.

The high-temperature combustion exhaust gas B having a low oxygen concentration supplied to the lower part of the grate 3 by the burner 7 passes through the gap between the fixed grate 4 and the movable grate 5, and the object A to be treated is reduced at a high temperature. Steamed in the atmosphere.
Since the grate and the frame are integrated into a so-called frame-integrated type in which the cooling water channel 8 is formed therein, the frame is not exposed to the high-temperature combustion exhaust gas B as in the prior art, and the lower part of the grate 3 Then, the high temperature gas can be introduced to the object A on the grate 3 for high temperature reduction. Since the drive device 14 is provided outside the furnace, there is no fear that it will be exposed to the high-temperature combustion exhaust gas B.
When the shoe 10 is worn and replaced due to the back and forth movement of the movable grate 5, this can be done by opening the lid 12 and removing the fixed water cooling wall 16 from the fixed grate 4. When the fixed water cooling wall 16 is adjusted and moved with respect to the movable grate 5, this can be done by opening the lid 12. Since the movable grate 5 is guided by the guide mechanism 13, the movable grate 5 can be moved back and forth appropriately, and is detachably attached to the receiving body 25 of the guide mechanism 13, so that it can be easily attached and detached.

In the above example, the fixed grate 4 and the movable grate 5 are alternately arranged in the inclined direction. However, the fixed grate 4 and the movable grate 5 are not limited to this. For example, the fixed grate 4 and the movable grate 5 may be alternately arranged stepwise in the horizontal direction. .
In the previous example, the fixed grate 4 was made of cast steel in which the water pipe 21 to be the cooling water channel 8 was cast. However, the fixed grate 4 is not limited to this, and is made of, for example, a solid material, and is subjected to deep hole processing to be cooled. The water channel 8 may be formed.

  The water-cooled stoker furnace according to the present invention includes high-temperature reduction treatment, carbonization treatment of organic waste such as sludge and municipal waste, drying furnace dried with high-temperature hot air, sintering furnace, firing furnace, contaminated soil treatment, etc. Can also be used.

  DESCRIPTION OF SYMBOLS 1 ... Water-cooled stoker furnace, 2 ... Input port, 3 ... Grate, 4 ... Fixed grate, 5 ... Movable grate, 6 ... Wind box, 7 ... Burner, 8 ... Cooling channel, 9 ... Refractory, 10 ... Shoe, 11 ... storage box, 12 ... lid, 13 ... guide mechanism, 14 ... driving device, 15 ... movable side water cooling wall, 16 ... fixed side water cooling wall, 17 ... furnace body side wall, 18 ... through hole, 19 ... support , 20 ... connecting part, 21 ... water pipe, 22 ... piping, 23 ... guide rail, 24 ... slider, 25 ... receiver, 26 ... rod, 27 ... connecting body, 28 ... cylinder, 29 ... refractory, 30 DESCRIPTION OF REFERENCE SYMBOLS: Detachable tool, 31 ... Water cooling wall, 32 ... Refractory material, A ... Material to be treated, B ... High temperature combustion exhaust gas, C ... Cooling water.

Claims (9)

In a stoker furnace in which a fixed grate and a movable grate are alternately arranged in the front-rear direction, the fixed grate and the movable grate are supported by penetrating the side wall of the furnace body, It is a frame-integrated type with a cooling water channel through which the cooling water flows, and the movable grate is moved back and forth by a drive device provided outside the furnace , and the stoker furnace is a fixed grate A shoe that is detachably provided on the upper surface and forms a gap for allowing high-temperature combustion ash gas to flow between the movable grate and a movable fire that is provided on the movable grate regardless of the back and forth movement of the movable grate. A movable-side water-cooled wall that closes the through-hole between the lattice and the furnace body side wall, and a removable grate that is detachably provided on the fixed grate and closes the through-hole between the movable grate and the furnace body side wall regardless of the longitudinal movement of the movable grate. Equipped with a fixed water cooling wall that can adjust the gap with the movable grate Water-cooled stoker furnace, characterized in that there.   The water-cooled stoker furnace according to claim 1, wherein portions of the fixed grate and the movable grate inside the furnace are covered with a refractory.   The water-cooled stoker furnace according to claim 1 or 2, wherein the fixed grate and the movable grate are made of cast steel in which a water pipe serving as a cooling water channel is cast.   On the side wall of the furnace body, there is provided a storage box for storing the pair of fixed grate and the movable grate outside the furnace, and the driving device is connected to the movable grate through the storage box. The water-cooled stoker furnace according to any one of claims 1 to 3. The water-cooled stalker furnace according to claim 4 , further comprising a lid body that is provided in the storage box so as to be openable and closable for exchanging shoes and adjusting and moving the fixed-side water-cooled wall .   The water-cooled stoker furnace according to any one of claims 1 to 5, wherein high-temperature combustion exhaust gas having an oxygen concentration of 1% or less is supplied from a lower part of the grate to a gap between the fixed grate and the movable grate. The water-cooled stoker furnace according to any one of claims 1 to 5, wherein the temperature of the high-temperature combustion exhaust gas supplied from the lower part of the grate is 500 ° C or higher.   The water-cooled stoker furnace according to any one of claims 1 to 5, wherein a burner for heating in the furnace is installed in a lower space of the grate.   The water-cooled stoker furnace according to claim 2, wherein the refractory is a detachable refractory ceramic plate.

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