Supplying apparatus for supplying combustible material, a gasification apparatus for gasifying combustible material and method for gasifying combustible material

A supplying apparatus supplies a combustible material capable of enhancing the sealing effects of a supplying system for supplying a combustible material, such as combustible wastes, to a fluidized-bed chamber, stably supplies a combustible material having an undefined shape, and reduces cost for installation. A facility is also provided for gasifying a combustible material using the supplying apparatus for supplying a combustible material, and a method of gasifying combustible materials is also provided. The supplying apparatus supplies a combustible material onto the fluidized bed of a fluidized-bed gasifier chamber or a fluidized-bed combustion chamber. A screw conveyor is inclined, with transportation of the combustible material directed upward, at an angle of 20 degrees or more and 80 degrees or less with respect to a horizontal plane, causing a bed material to flow into a conveyor casing of the screw conveyor.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a supplying apparatus for supplying a combustible material to a fluidized-bed gasifier chamber or a fluidized-bed combustion chamber, a gasification apparatus for gasifying a combustible material and a method for gasifying combustible materials in a fluidized-bed gasifier chamber or a fluidized-bed combustion chamber for use in a facility for gasifying or incinerating combustible materials such as municipal wastes, industrial wastes, waste plastic, biomass (thinned plants, wood chips, construction scrap wood, sludge, etc.), coal, RDF, wastes of high water contents, and the like.

2. Description of the Related Art

In recent years, a gasification and slagging combustion method has been employed as a treatment method of combustible wastes such as various wastes. In the gasification and slagging combustion method, combustible wastes are pyrolyzed and gasified. If the amount of oxygen supplied is larger than a required amount of oxygen, then the combustible wastes are excessively combusted to increase the temperature of a furnace. In such a case, stable operation may be inhibited. Thus, it has been desired to strictly manage the amount of air to be supplied.

However, a treatment system of combustible wastes is generally operated at a pressure lower than an atmospheric pressure in many cases in order to prevent ejection of a gas. Accordingly, the treatment system is problematic in that the system cannot sufficiently prevent leakage of air from a waste supplying system, which supplies combustible wastes into a furnace. Although a mechanical device such as a sealing valve has been used to prevent leakage of air, such a mechanical device has problems such as engagement into a sealing portion and generation of a bridge at a sealing portion because of undefined shapes of wastes. Thus, it has practically been difficult to provide a sealing system to achieve stable operation.

As described above, it has been attempted in recent years to gasify combustible wastes into a generated gas without complete combustion, then purify the generated gas, and utilize the purified gas as a raw material. In such a case, if unnecessary air flows into the generated gas, then the quality of the generated gas is degraded. Therefore, a system which can stably supply combustible wastes having undefined shapes and minimize leakage of air has been desired.

This invention has been made in view of the problems described above. It is therefore an object of the invention to provide: a combustible material supplying apparatus capable of enhancing the sealing effects of a supplying system for supplying a combustible material, such as combustible wastes, to a fluidized-bed chamber, stably supplying a combustible material having an undefined shape, and reducing costs for installation; and further to provide a facility for gasifying a combustible material using the combustible material supplying apparatus; and further to provide a method of gasifying combustible materials.

SUMMARY OF THE INVENTION

In order to achieve the above object, as shown inFIG. 1for example, an aspect of the present invention is a supplying apparatus10for supplying a combustible material102to an upper portion of a fluidized bed23of a fluidized-bed gasifier chamber or a fluidized-bed combustion chamber (i.e., a fluidized-bed chamber)20. The apparatus includes a hopper configured to store a combustible material102, and a mechanical supplying apparatus configured to supply a combustible material102from the hopper to the fluidized-bed gasifier chamber or the fluidized-bed combustion chamber20through a flow passage of the combustible material with a flow line directed upward, inclined at an angle of 20 degrees or more and 80 degrees or less with respect to a horizontal plane.

Since, as described above, the supplying apparatus for supplying a combustible material comprises a mechanical supplying apparatus configured to supply a combustible material from the hopper to the fluidized-bed gasifier chamber or the fluidized-bed combustion chamber through a flow passage of the combustible material with a flow line directed upward, inclined at an angle of 20 degrees or more and 80 degrees or less with respect to a horizontal plane, the position where the combustible material is supplied can be lowered. For example, the height of a building in which the facility with the supplying apparatus for supplying a combustible material is installed can be reduced by a lowered position of the material supplying means such as a waste crane.

In one aspect of the present invention, as shown inFIG. 1for example, the mechanical supplying apparatus comprises a conveyor10having a rotating helical vane13configured to supply combustible material102by means of a rotational action of the rotating helical vane13.

Since, as described above, the mechanical supplying apparatus is a so called screw conveyor or a spiral conveyor in which a helical vane is rotated, a combustible material is forced upward and supplied. As a result, it is possible to achieve high material sealing effects especially by filling the conveyor casing with a bed material to promote crushing of a raw material, which prevents both the leakage of air into the chamber and the leak of a gas out of the chamber.

In another aspect of the present invention, as shown inFIG. 6for example, the conveyor10has a plurality of helical vanes13disposed generally in parallel.

Since, as described above, the conveyor has two or more helical vanes disposed generally in parallel, crushing of a raw material is promoted especially by filling the conveyor casing with a bed material.

In another aspect of the present invention, as shown inFIG. 3for example, a conveyor casing11is provided to contain the helical vane13. The conveyor casing13has a projection111on the inner surface of the conveyor casing11, and the projection is configured to maintain the efficiency of transportation.

In such a configuration, the combustible material does not rotate together with the rotating helical vanes. The combustible material therefore does not remain in a position and is securely forced upward.

In another aspect of the present invention, as shown inFIG. 1for example, the supplying apparatus10for supplying a combustible material further comprises a medium supplying apparatus configured to supply medium101to the mechanical supplying apparatus, and the inside of the mechanical supplying apparatus is stuffed with the medium101to prevent gas communication therein.

In such a configuration, a medium for preventing gas communication fills the medium supplying apparatus. It is therefore possible to promote crushing of a raw material, suppressing of the variation of the amount of a combustible material to be supplied, and achievement of high material sealing effects.

In another aspect of the present invention, as shown inFIG. 4for example, the medium supplying apparatus further comprises a flow passage16of medium101not being identical to (different from) the flow passage of combustible material102.

In such a configuration, the medium is securely supplied to the mechanical supplying apparatus through the flow passage of the medium to fill it with the medium.

In another aspect of the present invention, as shown inFIG. 8for example, a gasification apparatus for gasifying a combustible material102comprises a supplying apparatus10for supplying a combustible material and a fluidized-bed gasifier chamber30supplied with a combustible material102from the supplying apparatus10for supplying a combustible material.

Since, as described above, the supplying apparatus for supplying a combustible material is a mechanical supplying apparatus configured to supply a combustible material from the hopper to the fluidized-bed gasifier chamber or the fluidized-bed combustion chamber through a flow passage of the combustible material with a flow line directed upward, inclined at an angle of 20 degrees or more and 80 degrees or less with respect to a horizontal plane, the height of a building in which the gasification apparatus for gasifying a combustible material is installed can be reduced.

In another aspect of the present invention, as shown inFIG. 9for example, the gasification apparatus for gasifying a combustible material102comprises a supplying apparatus10for supplying a combustible material102, a fluidized-bed gasifier chamber60configured to gasify combustible material102supplied by supplying apparatus10for supplying a combustible material, and a bypass line configured to bypass gasifier chamber60to lead a gas103generated from the combustible material102in supplying apparatus10for supplying a combustible material.

Since, as described above, there is provided a bypass line which bypasses the gasifier chamber to lead a gas generated from the combustible material in the supplying apparatus for supplying a combustible material, to the downstream of the gasifier chamber, it is possible to suppress the variation of the amount of the gas generated in the gasifier chamber and also possible to securely treat the gas generated in the supplying apparatus for supplying a combustible material with no leakage of the gas outside.

In another aspect of the present invention, as shown inFIG. 8for example, the gasification apparatus for gasifying a combustible material comprises a supplying apparatus10for supplying a combustible material102, and a fluidized-bed gasifier chamber30configured to gasify combustible material102supplied by supplying apparatus10for supplying a combustible material102. At least one of moisture and volatile matter is vaporized from the combustible material102within supplying apparatus10for supplying a combustible material102.

Since, as described above, moisture and volatile matter is vaporized from the combustible material within the supplying apparatus for supplying a combustible material, and then the combustible material from which the moisture and volatile matter was vaporized is supplied to the fluidized-bed gasifier chamber, it is possible to suppress the variation of the amount of the gas generated in the gasifier chamber and also to suppress the variation of the moisture therein.

In one aspect of the present invention, as shown inFIG. 9for example, the gasification apparatus for gasifying a combustible material further comprises a bypass line configured to bypass gasifier chamber60to lead at least one of moisture and volatile matter103vaporized in supplying apparatus10for supplying a combustible material102, to the downstream of gasifier chamber60.

Since, as described above, the moisture and volatile matter vaporized in supplying apparatus for supplying a combustible material bypasses the fluidized-bed gasifier chamber and is led to the downstream of the fluidized-bed gasifier chamber, it is possible to securely treat the gas generated in the supplying apparatus for supplying a combustible material with no leakage of the gas outside.

In another aspect of the present invention, as shown inFIG. 9for example, a method for gasifying a combustible material102in a fluidized-bed gasifier chamber or a fluidized-bed combustion chamber60, comprises the steps of storing combustible material102in a hopper40, supplying combustible material102upwardly from hopper40to fluidized-bed gasifier chamber or the fluidized-bed combustion chamber60by a mechanical supplying apparatus, to enhance a material sealing function of the apparatus by filling an inside with medium101which constitutes a fluidized-bed62, and gasifying combustible material102supplied to fluidized-bed gasifier chamber or said fluidized bed combustion chamber60by the mechanical supplying apparatus.

Since, as described above, the combustible material is supplied upwardly by the mechanical supplying apparatus and then a bed material is filled in the mechanical supplying apparatus, it is possible to promote crushing of the combustible material and suppress the variation of the amount of the combustible material to be supplied. Furthermore, the combustible material can be gasified while achieving high material sealing effects.

Another aspect of the present invention is, as shown inFIG. 1for example, a supplying apparatus10for supplying a combustible material102to a fluidized-bed gasifier chamber or a fluidized-bed combustion chamber20comprises a hopper configured to store a combustible material102, and a mechanical supplying apparatus configured to supply a combustible material102from the hopper to the fluidized-bed gasifier chamber or the fluidized-bed combustion chamber20through a flow passage of the combustible material with a flow line directed upward, wherein combustible material102is supplied together with a medium101to prevent gas communication through mechanical supplying apparatus.

Since, as described above, the combustible material is supplied together with a medium to prevent gas communication by supplying apparatus10for supplying a combustible material with a flow line directed upward, a mixture of the combustible material and the medium to prevent gas communication is transported, resulting in a supplying apparatus for supplying a combustible material having high material sealing effects.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The above and other objects, features, and advantages of the invention will be apparent from the following description when taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the invention by way of example.

FIG. 1is a schematic view, showing an example of a supplying apparatus for supplying a combustible material of the invention. InFIG. 1, the hopper to store the combustible material is omitted for simplifying the illustration. The reference numeral20denotes a chamber such as a fluidized-bed gasifier chamber or a combustion chamber. The chamber20has a chamber casing21, a fire-resistant layer22disposed inside of the chamber casing21, and a fluidized bed23in which a bed material101is fluidized. The reference numeral10denotes a screw conveyor serving as a supplying apparatus for supplying a combustible material including combustible wastes or the like into the chamber20. The combustible material includes municipal wastes, industrial wastes, waste plastic, biomass (thinned plants, wood chips, construction scrap wood, sludge, etc.), coal, RDF, wastes of high water contents, where the biomass and wastes of high water contents are known as materials not to provide high material sealing effects. A supplying apparatus for supplying a combustible material according to the present invention, however, allows high material sealing effects of the biomass and wastes of high water content as well as the other combustible materials.

The screw conveyor10has a cylindrical conveyor casing11, a screw14disposed within the conveyor casing11, and a steam jacket15provided around the conveyor casing11. The screw14has a rotational shaft12and a helical vane13attached thereto. The screw conveyor10is inclined at an angle of 20 degrees or more and 80 degrees or less with respect to the horizontal plane so that a flow line of the flow passage of the combustible material is directed upward at the same angle of the screw conveyor10. Thus, transportation by the screw conveyor10is directed upward. The conveyor casing11has an end connected to a raw material supply port24of the chamber20. The screw14has an end inserted into the raw material supply port24.

The raw material supply port24is located above the fluidized bed23, (i.e., above an surface of a dense fluidized bed). When the screw14of the screw conveyor10is rotated, a combustible material102is supplied through the raw material supply port24to the chamber20above the surface of the dense fluidized bed. A high-temperature bed material101ejected from the fluidized bed23flows through the raw material supply port24into the conveyor casing11of the screw conveyor10, and the inside of the conveyor casing11is filled with the high-temperature bed material101. Specifically, the entire inside of the conveyor casing11is filled with the high-temperature bed material101in a clearance between the screw14and the conveyor casing11.

As described above, the inside of the conveyor casing11is filled with the combustible material102and the bed material101to achieve material sealing effects. In other words, the bed material101, which is smaller than the combustible material102, enters spaces formed in the combustible material102to enhance material sealing effects. The “material sealing effect” means a function of the combustible material102and the bed material101to prevent gas communication under condition of being not completely airtight, but not easy for a gas to communicate even if there exists more or less gas communication. A gas includes air, moisture (vaporized water), combustible gas and combustion gas. A medium having a function to prevent gas communication is, for example, a fine particle material, such as bed material101, having an average particle diameter of 1 mm or smaller, or a sludged material containing moisture. As a fine particle material, the bed material101which forms the fluidized bed23is preferable. Use of the bed material101prevents a different material from mixing in the fluidized bed23and does not require any other material as a medium to prevent gas communication. The bed material101may be introduced through the raw material supply port24from the fluidized bed23. Alternatively, if the bed material supplying port16(seeFIG. 4) is provided at (i.e., communicating with) the conveyor casing11, as described later, then the bed material101may be introduced directly from the fluidized bed23or may be introduced from the apparatus for processing incombustible extracting51(seeFIG. 8) through a piping as a flow passage of the bed material101. Introduction from the apparatus for processing incombustible extracting51(FIG. 8) provides the bed material101having a lower temperature. Further, in a flow passage from the apparatus for processing incombustible extracting51(seeFIG. 8) to the conveyor casing11may be additionally disposed a device for lowering the temperature of the bed material101. Fly ash55(seeFIG. 8) recovered in treatment of gas emission may be used as fine particle material. The fly ash55is generally finer particles and therefore enhances material sealing effects. Alternatively, silica sands may also be supplied outside of a system. A sludge produced in a sewage treatment plant may be used as sludged material. Use of the sludge as a medium to prevent gas communication enhances the material sealing effects of the combustible material supplying apparatus10and allows the sludge to be treated.

Material sealing effects of supplied small and large cakes of a combustible material may be enhanced by setting small cakes of a combustible material (co-fuel, etc.) into the space among large cakes of a combustible material. For example, a combustible material crushed to a cake with a diameter of about 30 cm by a reciprocation crushing machine, or crushed to a cake with a diameter of about 15 cm by a rotating crushing machine may be supplied as large cakes, where biomass (chips, chaffs, wooden pellets, granulated sludge, etc.) with a diameter of about 5 cm or smaller, RDF, other wastes pressed and formed, and the like may be supplied as small cakes, resulting in the aforementioned material sealing effects.

Since the screw conveyor10is inclined at an angle 20 degrees or more and 80 degrees or less with respect to the horizontal plane so that transportation by the screw conveyor10is directed upward, the bed material101flows into the conveyor casing11. Thus, a ratio of filling in the conveyor casing11is increased. Correspondingly, the resistance to flow of a gas is increased so as to prevent a gas from leaking out from the screw conveyor10as a part of a combustible material supplying system into the chamber20. Specifically, it is possible to prevent air from leaking from the exterior of the chamber to the interior of the chamber. The angle of the screw conveyor10is preferably 30 degrees or larger, more preferably 40 degrees or larger. Increase of the angle increases the ratio of filling and further increases the material sealing effects. Meanwhile, the angle of screw conveyor10is preferably 60 degrees or smaller, more preferably 50 degrees or smaller. By limiting the angle of the screw conveyor10so as not to be excessively large, there occurs no interference between the screw conveyor10and the chamber casing21. Additionally, the efficiency of transportation of the screw conveyor10can be prevented from degrading. However, when the bed material101is filled for the purpose of an increase in the material sealing effects, then the angle of the screw conveyor10may be a predetermined angle out of the range defined above.

Now, inFIG. 2, a relation between the angle of inclination and the efficiency of transportation, of the combustible material supplying apparatus10is described.FIG. 2is a graph, showing a result of a measurement for the efficiency of transportation by using sand as an article to be transported, in which the angle of inclination of the screw conveyor10with respect to a horizontal plane varies, for each of different clearances between the outermost edge of the helical vane13(seeFIG. 1) and the inner face of the conveyor casing11. The reduction in the efficiency of transportation is less when the angle of inclination is approximately up to 45 degrees. When the angle exceeds 45 degrees, especially 60 degrees, the efficiency is reduced considerably. Beyond 75 degrees, the efficiency becomes near zero. It is believed that the reduction of the efficiency of transportation with the increase of the angle of inclination is caused by the reduction of friction between the article to be transported and the inner face of the conveyor casing11to rotate the article together with the helical vane13and thus the article is not pushed out in the axial direction.

Accordingly, as shown inFIG. 3, in the inner face of the conveyor casing as a shell for containing the helical vane13of the screw conveyor10, a projection111for preventing the combustible material102and the bed material101from rotating together with the helical vane13can be provided. Rotation of the transported article (the combustible material102and the bed material101) accompanying the helical vane13is disturbed by the projection111, or the clearance formed between the helical vane13and the projection111is diminished. Thus, rotation of the transported article around the rotary shaft12(so called co-rotation) is disturbed. In such a manner, since the rotation of the transported article accompanying the helical vane13is prevented, the transported article is axially moved by rotation of the helical vane13and securely pushed upward, resulting in maintaining the efficiency of transportation. That is, the reduction of the efficiency of transportation is prevented. The clearance between the helical vane13and the projection111is set 50 mm or less, preferably 20 mm or less, more preferably 5 mm or less. A preferable projection111has a shape continuously straightened in the longitudinal direction of the conveyor casing11in view of manufacturability and smaller friction in the direction of transportation. The projection111may include a plurality of short projections linearly spaced from each other. The projection111may be arranged helically or randomly. Although two projections111are shown inFIG. 3, the number of projections may be one and three or more.

As described above, since the raw material supply port24in fluid communication with the end of the conveyor casing11of the screw conveyor10is located above the surface of the dense fluidized bed, a bed material101ejected from the fluidized bed23flows through the raw material supply port24into the conveyor casing11. However, a pressure of the fluidized bed23is not applied to the interior of the screw conveyor10. A gas in the chamber20is therefore prevented from flowing through the screw conveyor10in a reverse direction and from leaking out of the chamber20.

The height and an opening angle of the raw material supply port24, the height of the fluidized bed23, and a fluidized state in the fluidized bed23are properly determined so that the bed material101ejected in the fluidized bed23due to fluidization is likely to flow into the conveyor casing11. Thus, the raw material supply port is used as a part of the medium supplying apparatus which transports the bed material101into the screw conveyor casing11.

Now, the constitution of the fluidized bed23is described. The fluidized bed23is composed of a dense fluidized bed which is located at a vertically lower portion of the fluidized bed23and densely contains the bed material101(silica sands, for example) fluidized by a fluidizing gas, and a splash zone, existing vertically above the dense fluidized bed. In the splash zone, the bed material101splashes vigorously. Above the fluidized bed23(that is, above the splash zone) is provided a freeboard which mainly contains a gas and merely contains the bed material101.

If the raw material supply port24is disposed in a stationary bed (a range where the bed material101is placed during no fluidizing), then a pressure (so called counter pressure) produced by the weight of the bed material101acts on the inside of the screw conveyor10. As a result, the screw conveyor10exposed to the counter pressure supplies the combustible material, which requires a large amount of energy to supply, otherwise the fluidized material102and the bed material101may be forced to flow back. Notwithstanding, the combustible material102is quantitatively supplied into the chamber casing21through the raw material supply port24because there exists a large amount of the bed material101around the raw material supply port24, resulting in a high scraping effect. The screw conveyor20is charged with a large amount of bed material101ejected therein. When the screw conveyor10having an opening angle through which the bed material101ejects into the screw conveyor10is inclined, for example, as shown inFIG. 1, a larger amount of bed material101ejects into and falls on the screw conveyor10. The angle of inclination is preferably between 30 and 60 degrees, also depending on different operation states.

If the raw material supply port24is installed on the freeboard33(seeFIG. 8) above the splash zone, where no bed material101exists, then the scraping effect and ejection of the bed material101into the screw conveyor10are scarcely expected because there exists no bed material, though there exists no counter pressure because of a negative pressure at the region.

If the raw material supply port24is installed in the upper portion of the dense fluidized bed, then the counter pressure is lower and a large amount of bed material101is ejected into the screw conveyor10. Further, if the bed material101is circling in the chamber20, then a high scraping effect is expected and the combustible material is quantitatively supplied into the chamber casing21from the raw material supply port24. If the raw material supply port24is installed in the splash zone, then no counter pressure exists and a large amount of the bed material101ejects into the screw conveyor10.

The screw conveyor10is subjected to a humid and reducing atmosphere, (i.e., a severely corrosive environment). Therefore, the conveyor casing11and the screw14are required to be heated so as to maintain their temperatures. In the illustrated example, steam is introduced into the steam jacket15provided around the conveyor casing11so as to maintain the temperatures of the conveyor casing11and the screw14. Thus, it is possible to prevent dew condensation and low-temperature corrosion on an inner surface of the conveyor casing11. It is desirable that a tip end of the screw14is replaceable, or is subjected to surface treatment such as thermal spraying if needed.

In the conveyor casing11of the screw conveyor10, the combustible material102and the high-temperature bed material101are brought into contact with each other so as to promote loosening of the combustible material. Accordingly, a mass of the combustible material102for an instant is prevented from falling down onto the chamber20. It is therefore possible to prevent the variation of the amount of combustible material102and pressure in the chamber20. When the combustible material102and the high-temperature bed material101are brought into contact with each other, moisture in the combustible material102is evaporated, and volatile matter in the combustible material102is pyrolyzed, to thereby generate steam and a pyrolysis gas103. A portion of the steam (water vapor) and pyrolysis gas103flows through the raw material supply port24into the chamber20and further flows downstream through a freeboard, which is located at an upper portion of the fluidized bed23. Near the material supply port24where the high temperature bed material101is injected, the combustible material102and the high temperature bed material101are brought in contact with each other to generate a gas. As described above, the combustible material102and the bed material101are provided with material sealing effects. Accordingly, the generated gas does not pass through the upstream side of the screw conveyor10but flows in the chamber20.

It is desirable that the steam and pyrolysis gas103generated at an upstream portion of the conveyor casing11, i.e., on the upstream of the raw material supply port24, is extracted so as not to flow in a reverse direction and is introduced into a gas passage prior to heat recovery. With this modification, the steam and pyrolysis gas103can be prevented from leaking out of the screw conveyor10and processed certainly.

This modification is shown inFIG. 4, which is a schematic view, showing an example of a combustible material supplying apparatus according to the invention. InFIG. 4, like or corresponding parts are designated by the same reference numerals as inFIG. 1and will not be described repetitively. The combustible material supplying apparatus shown inFIG. 4has a bed material supply port16for supplying a bed material101from a bed material circulation line, which will be described later, into the conveyor casing11of the screw conveyor10, and a gas extracting port17for extracting steam and a pyrolysis gas103. The gas extracting port17is located upstream of the bed material supply port16. Thus, the steam and pyrolysis gas103generated in the conveyor casing11are prevented from flowing in the reverse direction and can be introduced into a gas passage prior to heat recovery process. Accordingly, the steam and pyrolysis gas103can be prevented from leaking out of the screw conveyor10and processed certainly.

The bed material101supplied from the chamber20is preferable as a medium to be supplied through the bed material supply port16. The bed material101of 300° C. or more vaporizes moisture and pyrolyzes volatile matter to generate steam and pyrolysis gas. A bed material of 350° C. or more is preferable for securely producing a gas. Also, a bed material of 100° C. or more can vaporize moisture to generate steam. In such a manner, moisture and volatile matter is vaporized from a combustible material102in the screw conveyor10, and then the combustible material102from which moisture and volatile matter was vaporized is supplied to the chamber20. Therefore, a sharp increase (that is, variation) of the amount of gas generated from the supplied combustible material102in the chamber20is suppressed and the moisture within the chamber20can also be suppressed. Further, the gas generated in the screw conveyor10is extracted through a gas extracting port17and then directly fed to a subsequent stage apparatus resistant to the variation of gas pressure with bypassing the chamber20, to thereby suppress variation of the amount of gas within the chamber20and to achieve stable operation of the chamber20. Any medium having incombustiblity resistant to high temperature other than the bed material101may be used.

The medium supplied through the fluid medium supply port16is not required to be high temperature. In such a case, moisture is not vaporized, volatile matter is not pyrolyzed, and therefore both steam and pyrolysis gas cannot be generated. Nevertheless, this medium still retains the same mechanical effects as of a high temperature bed material and also a function as a medium to prevent gas communication, in other words, material sealing effects. Additionally, existence of a medium suppresses entwinement and adhesion of the combustible material102to the vane13or the like, and achieves appropriate mixing of the combustible material102by shearing force generated between the medium and the combustible material102, thereby to improve a quantitative property of the combustible material to be transported. Since any steam and pyrolysis gas are not generated, the fluidized material supply port16is provided but not the gas extracting port17. Further, any particle material, such as mixed fuel and auxiliary fuel other than incombustible material, such as sand may be used and combusted in the chamber20.

As shown inFIG. 5, the bed material supply port16may be provided upstream of the gas drawing port17. This arrangement is preferable to make it difficult for air to flow to the gas drawing port17from the combustible material supply port (not shown) which forms the upstream end of the screw conveyor10. However, if high temperature bed material101is used, then a gas is generated by contact of the bed material101supplied through the bed material supply port16with the combustible material102and the generated gas is likely to flow outside through the combustible material supply port (not shown). It is therefore preferable to shorten the distance between the gas extracting port17and the bed material supply port16for securing leading the generated gas to the gas extracting port17.

As shown inFIG. 4, it is preferable to provide the gas extracting port17upstream of the bed material supply port16since, even if a gas is generated by contact of the bed material101supplied through the bed material supply port16with the combustible material102, the generated gas is introduced to the gas extracting port17located nearer than the combustible material supply port (not shown). It is therefore preferable to lengthen the distance between the gas extracting port17and the combustible material supply port (not shown) to prevent air from flowing in since air is apt to flow into the gas extracting port17from the combustible material supply port (not shown).

In the described embodiments of the combustible material supplying apparatus, the screw conveyor10has a screw14including a rotational shaft12and a helical vane13attached thereto. However, the screw conveyor10is not limited to those embodiments. As shown inFIG. 6, the screw conveyor10may have two screws14generally disposed parallel to each other. Alternatively, the screw conveyor10may have three or more screws disposed generally parallel to each other. With a plurality of screws, the screw conveyor10can convey a large amount of raw material and promote crushing of a combustible material102.

The combustible material supplying apparatus in the embodiments has the screw14disposed in the conveyor casing11. However, the combustible material supplying apparatus is not limited to these embodiments. For example, as shown inFIG. 7, the combustible material supplying apparatus may have a mechanical supplying device such as a spiral conveyor18including a rotational shaft12disposed in a conveyor casing11, and a helical vane13attached to an end of the rotational shaft12. In this case, a plurality of rotational shafts12each having a helical vane13may be arranged parallel to each other in the conveyor casing11.

FIG. 8is a schematic diagram showing an example of an incineration facility having the supplying apparatus10for supplying a combustible material102according to the invention and a fluidized-bed incineration furnace. InFIG. 8, the reference numeral30denotes a combustion chamber of a fluidized-bed incineration furnace. The fluidized-bed incineration chamber30has a raw material supply port31to which one end of the conveyor casing11of the screw conveyor10is connected. Another end of the conveyor casing11is connected to a raw material hopper40, into which a combustible material102is introduced. The raw material hopper40has a pusher41disposed at the bottom to push a combustible material102in the raw material hopper40into the end of the conveyor casing11. If the screw conveyor10is installed horizontally, then the combustible material102is supplied, by gravity, through a material hopper which has a vertical axis normal to the horizontal axis of the screw conveyor10and connected with an upper portion thereof. When the screw conveyor10is placed to be inclined, the combustible material102is not appropriately supplied only with gravity because the axis of the material flow comes near the horizontal axis from the vertical axis. It is therefore preferable to supply the combustible material102with assistance of a pusher41to push the combustible material102into the screw conveyor10.

When the screw14of the screw conveyor10is rotated, the combustible material102pushed by the pusher41is moved downstream and supplied through the raw material supply port31of the incineration chamber30to an upper portion of a fluidized bed32(above a surface of the dense fluidized bed). The supplied combustible material is combusted into a combustion gas104in the fluidized bed32. The combustion gas104flows through a freeboard33of the incineration chamber30into an apparatus for processing heat recovery50. An incombustible material105in the combustible material102is discharged from a bottom of the fluidized bed32together with a bed material101into an apparatus for processing incombustible extracted material51. In the apparatus for processing incombustible extracted material51, the incombustible material105is extracted (separated) from the bed material101.

A portion of a bed material (mainly silica sand)101flows through the raw material supply port31into the conveyor casing11of the screw conveyor10due to fluidization of the bed material101in the fluidized bed32. Simultaneously, a bed material101separated from the incombustible material105in the apparatus for processing incombustible extracted material51is supplied through the bed material supply port16of the screw conveyor10(seeFIG. 4) into the conveyor casing11. Thus, with a pass of the bed material101to the inside of the conveyor casing11separate from that through the raw material supply port31, the conveyor casing11is filled with the bed material101. Accordingly, by high material sealing effects caused by mixture of the bed material101and the combustible material102, external air is prevented from leaking through the screw conveyor10into the incineration chamber30, and the combustion gas104generated in the incineration chamber30is prevented from leaking out of the incineration chamber30through the screw conveyor10. Incombustible particles are used as a bed material.

By supplying the bed material101separated in the apparatus for processing incombustible extracted material51to the conveyor casing11of the screw conveyor10, it is possible to eliminate a bed material circulation line to return the bed material101separated in the apparatus for processing incombustible extracted material51to the fluidized bed32.

When the combustible material102and the high-temperature bed material101are brought into contact with each other in the conveyor casing11of the screw conveyor10, moisture in the combustible material102is evaporated and the combustible material102is pyrolyzed. Therefore, steam (water vapor) and pyrolysis gas103is generated. A portion of the steam (water vapor) and pyrolysis gas103generated in the conveyor casing11flows through the raw material supply port31into the freeboard33, and the rest is extracted from the gas extracting port17(seeFIG. 4) and supplied to the freeboard33.

The apparatus for processing heat recovery50has a waste heat boiler for producing steam52and an air preheater for producing preheated air53, which is used as fluidizing air or combustion air to be supplied to the incineration chamber30. Heat is recovered from the combustion gas104in the apparatus for processing heat recovery50to lower the temperature of the combustion gas104. The combustion gas104is then supplied to a bag filter or the like to remove fly ash55. Thereafter, the combustion gas104is supplied to an apparatus for processing dechlorination56to dechlorinate the combustion gas104and an apparatus for processing denitration57to denitrate the combustion gas104and then released as an exhaust gas106to atmosphere through a chimney (not shown).

FIG. 9is a schematic view showing an example of a gasification and slagging combustion facility, which is a model of a gasification apparatus, having the combustible material supplying apparatus according to the invention and a fluidized-bed gasifier which is equipped with a gasifier chamber. InFIG. 9, like or corresponding parts are designated by the same reference numerals as inFIG. 8and will not be described repetitively. A combustible material102is supplied through a raw material supply port61of a gasifier chamber60to an upper portion of a fluidized bed62(above an surface of a dense fluidized bed) by the screw conveyor10. The combustible material102is pyrolyzed and gasified in the fluidized bed62to generate a gas107. The generated gas107flows through a freeboard63of the gasifier chamber60into an apparatus for processing ash melting70. In the apparatus for processing ash melting70, the generated gas107is combusted at a high temperature together with char (fixed carbon) contained in the generated gas107to melt ash in the generated gas107into slag71, which is discharged to the exterior of the system. A combustion gas107′ from which ash has been removed is supplied to an apparatus for processing complete combustion72.

The conveyor casing11of the screw conveyor10is filled with a bed material101, as in the case ofFIG. 8. Accordingly, by high material sealing effects caused by mixture of the bed material101and the combustible material102, external air is prevented from leaking through the screw conveyor10into the gasifier chamber60, and the generated gas107generated in the gasifier chamber60is prevented from leaking out of the gasifier chamber60through the screw conveyor10.

When the combustible material102and the high-temperature bed material101are brought into contact with each other in the conveyor casing11of the screw conveyor10, moisture in the combustible material102is evaporated and combustible material102is pyrolyzed. Therefore, steam (water vapor) and pyrolysis gas103is generated. A portion of the steam (water vapor) and pyrolysis gas103flows through the raw material supply port61into the freeboard63, and the rest is extracted from the gas extracting port17(seeFIG. 4) and supplied to the apparatus for processing complete combustion72, in which the rest of the steam and pyrolysis gas103is completely combusted together with the combustion gas107′ supplied from the apparatus for processing ash melting70.

A combustion gas109generated by complete combustion in the apparatus for processing complete combustion72is subjected to heat recovery in an apparatus for processing heat recovery50. The combustion gas109is then supplied to an apparatus for processing dust removal54to remove fly ash55. Thereafter, the combustion gas109is supplied to an apparatus for processing dechlorination56to dechlorinate the combustion gas109and an apparatus for processing denitration57to denitrate the combustion gas109, and is then released as an exhaust gas206to atmosphere through a chimney (not shown).

FIG. 10is a schematic view, showing an example of a gasification reforming facility, which is a model of a gasification apparatus, having the combustible material supplying apparatus according to the invention. In FIG.10, like or corresponding parts are designated by the same reference numerals as inFIGS. 8 and 9and will not be described repetitively. A combustible material102is supplied through a raw material supply port61of a gasifier chamber60to an upper portion of a fluidized bed62(above a surface of a dense fluidized bed) by the screw conveyor10. The combustible material102is pyrolyzed and gasified in the fluidized bed62to generate a gas107. The generated gas107flows through a freeboard63of the gasifier chamber60into an apparatus for processing gas reforming and ash melting74. In the apparatus for processing gas reforming and ash melting74, the generated gas107is reformed, and simultaneously a portion of the generated gas107is combusted at a high temperature to melt ash into slag71, which is discharged to the exterior of the system. The combustion gas107is discharged from the apparatus for processing gas reforming and ash melting74to an apparatus for processing heat recovery50.

Heat is recovered from the generated gas107in the apparatus for processing heat recovery50to lower the temperature of the generated gas107. The generated gas107is then supplied to an apparatus for processing gas cleaning and dust removal75. In the apparatus for processing gas cleaning and dust removal75, water is ejected to the generated gas107to clean the generated gas107and drainage76and ash (fly ash)77is removed. The generated gas107which has been cleaned is supplied to an apparatus for processing gas refining78to generate a product gas108.

The conveyor casing11of the screw conveyor10is filled with a bed material101, as in the cases ofFIGS. 8 and 9. Accordingly, due to high material sealing effects due to a mixture of the bed material101and the combustible material102, external air is prevented from leaking through the screw conveyor10into the gasifier chamber60, and the generated gas107generated in the gasifier chamber60is prevented from leaking out of the gasifier chamber66through the screw conveyor10.

When the combustible material102and the high-temperature bed material101are brought into contact with each other in the conveyor casing11of the screw conveyor10, moisture in the combustible material102is evaporated and combustible material102is pyrolyzed. Therefore, steam (water vapor) and pyrolysis gas103is generated. A portion of the steam (water vapor) and pyrolysis gas103flows through the raw material supply port61into the freeboard63, and the rest is extracted from the gas extracting port17(seeFIG. 4) and supplied to the freeboard63.

FIG. 11is a schematic view, showing an example of a low-temperature gasification reforming facility, which is a model of a gasification apparatus, having a combustible material supplying apparatus according to the invention. InFIG. 11, like or corresponding parts are designated by the same reference numerals as inFIGS. 8 through 10and will not be described repetitively. A combustible material102is supplied through a raw material supply port61of a gasifier chamber60to on upper portion of a fluidized bed62(above an surface of a dense fluidized bed) by the screw conveyor10. The combustible material102is pyrolyzed and gasified in the fluidized bed62to generate a gas107. The generated gas107flows through a freeboard63of the gasifier chamber60into an apparatus for processing gas reforming80, where the generated gas107is reformed. Then, the generated gas107is supplied to an apparatus for processing heat recovery50, where heat is recovered from the generated gas107to lower the temperature of the generated gas107. The generated gas107is then supplied to an apparatus for processing gas cleaning and dust removal75. In the apparatus for processing gas cleaning and dust removal75, water is ejected to the generated gas107to clean the generated gas107and drainage76, and ash77is removed. The generated gas107which has been cleaned is supplied to an apparatus for processing gas refine78to generate a product gas108.

The conveyor casing11of the screw conveyor10is filled with a bed material101, as in the cases ofFIGS. 8 through 10. Accordingly, by high material sealing effects caused by mixture of the bed material101and the combustible material102, external air is prevented from leaking through the screw conveyor10into the gasifier chamber60, and the generated gas107generated in the gasifier chamber60is prevented from leaking out of the gasifier chamber60through the screw conveyor10.

When the combustible material102and the high-temperature bed material101are brought into contact with each other in the conveyor casing11of the screw conveyor10, moisture in the combustible material102is evaporated and combustible material102is pyrolyzed. Therefore, steam (water vapor) and pyrolysis gas103is generated. A portion of the steam (water vapor) and pyrolysis gas103flows through the raw material supply port61into the freeboard63, and the rest is extracted from the gas extracting port17(seeFIG. 4) and supplied to the freeboard63.

FIG. 12is a schematic view, showing an example of a gas reforming facility, which is a model of a gasification apparatus, having the combustible material supplying apparatus according to the invention and an integrated fluidized-bed gasifier. The integrated fluidized-bed gasifier is a gasification facility having a fluidized-bed gasifier90in which a gasifier chamber91for pyrolyzation and gasification and a combustion chamber92for combustion of char produced by pyrolyzation are included and a bed material101is allowed to circulate freely between both chambers91,92. A fluidized bed91bin the gasifier chamber91is fluidized by a gas which does not include oxygen such as steam, and is heated to keep a temperature between about 600 and 850° C. by a bed material101circulating from the combustion chamber92. The combustible material102supplied to the gasifier chamber91is pyrolyzed and gasified. A fluidized bed92bin the combustion chamber92is fluidized by an oxygen containing gas, such as air. A pyrolyzation residue fed from the gasifier chamber91is completely combusted in the combustion chamber92. Heat of combustion resulting from this combustion reaction heats the fluidized bed92bin the combustion chamber92. The fluidized bed92bin the combustion chamber92has a temperature kept between about 700 and 950° C., which is higher than that of the fluidized bed91bin the gasifier chamber91. InFIG. 12, like or corresponding parts are designated by the same reference numerals as inFIGS. 8 through 11and will not be described repetitively. The integrated fluidized-bed gasifier90has a raw material supply port93. An end of the conveyor casing11of the screw conveyor10is connected to the raw material supply port93of the gasifier chamber91. Another end of the conveyor casing11is connected to a raw material hopper40, into which a combustible material102is introduced. The raw material hopper40has a pusher41disposed at the bottom to push a combustible material102in the raw material hopper40into the other end of the conveyor casing11.

A combustible material102is supplied through the gasifier chamber91of the integrated gasifier90to an upper portion of a fluidized bed91b(above a surface of a dense fluidized bed) by the screw conveyor10. The combustible material102is pyrolyzed and gasified in the fluidized bed91bto generate a gas107. The generated gas107flows through a freeboard91aof the gasifier chamber91into an apparatus for processing gas reforming80, where the generated gas107is reformed. Then, the generated gas107is supplied to an apparatus for processing heat recovery50, where heat is recovered from the generated gas107to lower the temperature of the generated gas107. The generated gas107is then supplied to an apparatus for processing gas cleaning and dust removal75. In the apparatus for processing gas cleaning and dust removal75, water is ejected to the generated gas107to clean the generated gas107and drainage76, and ash77is removed. The generated gas107which has been cleaned is supplied to an apparatus for processing gas refining78to generate a product gas108.

The fluidized bed91bof the gasifier chamber91and a fluidized bed92bof the combustion chamber92communicate with each other below a lower end of a partition wall94. Thus, a bed material and char are moved from the fluidized bed91bof the gasifier chamber91to the combustion chamber92. The char is combusted in the combustion chamber92to generate a combustion gas104. The combustion gas104is supplied to an apparatus for processing heat recovery50, where heat is recovered from the combustion gas104to lower the temperature of the combustion gas104. The combustion gas104is then supplied to an apparatus for processing dust removal54to remove fly ash55. Thereafter, the combustion gas104is supplied to an apparatus for processing dechlorination56to dechlorinate the combustion gas104and an apparatus for processing denitration57to denitrate the combustion gas104and then released as an exhaust gas106to an atmosphere through a chimney (not shown).

An incombustible material105in the combustible material102is discharged from a bottom of the fluidized bed92bof the combustion chamber92together with a bed material101into an apparatus for processing incombustible extracted material51. In the apparatus for processing incombustible extracted material51, the incombustible material105is separated from the bed material101. The bed material101is supplied through the bed material supply port17of the screw conveyor10(seeFIG. 4) into the conveyor casing11. As in the cases ofFIGS. 8 through 11, the bed material101from the fluidized bed91balso flows into the conveyor casing11. Thus, the conveyor casing11of the screw conveyor10is filled with a bed material101. Accordingly, by high material sealing effects caused by mixture of the bed material101and the combustible material102, external air is prevented from leaking through the screw conveyor10into the gasifier chamber91, and the generated gas107generated in the gasifier chamber91is prevented from leaking out of the gasifier chamber91through the screw conveyor10.

When the combustible material102and the high-temperature bed material101are brought into contact with each other in the conveyor casing11of the screw conveyor10, moisture in the combustible material102is evaporated and combustible material102is pyrolyzed. Therefore, steam (water vapor) and pyrolysis gas103is generated. A portion of the steam (water vapor) and pyrolysis gas103flows through the raw material supply port93into the freeboard91a, and the rest is extracted from the gas extracting port17(seeFIG. 4) and supplied to the freeboard92aof the combustion chamber92.

A pressure of the freeboard91aof the gasifier chamber91should preferably be set to be higher than that of the freeboard92aof the combustion chamber92. In such a case, the steam and pyrolysis gas103generated in the conveyor casing11can certainly be supplied to the combustion chamber92to reduce fear of explosion or poisoning. Further, since the combustion chamber92can be disposed near the screw conveyor10, it is possible to prevent troubles in an introduction duct for the steam and pyrolysis gas103.

FIG. 13is a schematic view, showing an example of an advanced gasification and slagging combustion facility, which is a model of a gasification apparatus, having the combustible material supplying apparatus according to the invention and a gasification and slagging combustion furnace including an integrated gasifier. The advanced gasification and slagging combustion facility is a wastes treatment facility in which the integrated gasifier chamber90is combined with an apparatus for processing ash melting and complete combustion (ash melting chamber)81. In the advanced gasification and slagging combustion facility, only the generated gas107from the gasifier chamber91is heated at a high temperature and it is therefore possible to reduce the size of the ash melting chamber81and the exhaust gas treatment facility50,54,56and57as compared to the traditional gasification and slagging combustion facility. InFIG. 13, like or corresponding parts are designated by the same reference numerals as inFIGS. 8 through 12and will not be described repetitively. A combustible material102is supplied to the gasifier chamber91by the screw conveyor10. The combustible material102is pyrolyzed and gasified in the fluidized bed91bto generate a gas107. The generated gas107flows through a freeboard91aof the gasifier chamber91into an apparatus for processing ash melting and complete combustion81. In the apparatus for processing ash melting and complete combustion81, ash in the generated gas107is melted into slag71, which is discharged to the exterior of the system, and simultaneously the generated gas107is completely combusted. The combustion gas110which has been completely combusted is supplied through an apparatus for processing heat recovery50, an apparatus for processing dust removal54, an apparatus for processing dechlorination56, and an apparatus for processing denitration57and then released as an exhaust gas106to atmosphere.

As in the case ofFIG. 12, when the combustible material102and the high-temperature bed material101are brought into contact with each other in the conveyor casing11of the screw conveyor10, moisture in the combustible material102is evaporated and combustible material102is pyrolyzed. Therefore, steam (water vapor) and pyrolysis gas103is generated. A portion of the steam (water vapor) and pyrolysis gas103flows through the raw material supply port93into the freeboard91a, and the rest is extracted from the gas extracting port17(seeFIG. 4) and supplied to the freeboard92aof the combustion chamber92.

In the respective facilities shown inFIGS. 8 through 13, the screw conveyor10serving as a combustible material supplying apparatus has one screw14in the conveyor casing11. However, the screw conveyor10is not limited to these examples. As shown inFIG. 6, the screw conveyor10may have two or more screws14disposed substantially parallel to each other. Alternatively, as shown inFIG. 7, it is possible to use a spiral conveyor18having a rotational shaft12disposed in a conveyor casing11and a helical vane13attached to an end of the rotational shaft12. In this case, a plurality of rotational shafts12each having a helical vane13may be arranged in parallel each other in the conveyor casing11. It is also possible to use other mechanical combustible material supplying devices. Although the bed material101to be supplied to the screw conveyor10is, as shown in those drawings, located downstream of the gas drawing port17, it may be disposed upstream thereof as shown inFIG. 5.

As described above, a mechanical combustible material supplying device such as the screw conveyor10is inclined at an angle of 20 degrees or more and 80 degrees or less with respect to the horizontal plane so that transportation of the combustible material of the screw conveyor10is directed upward. As a result, it is possible to lower a position from which a raw material is supplied, to mix a raw material with a high-temperature bed material in advance, and to enhance sealing performance of a raw material supply port of a furnace. Accordingly, as shown inFIG. 14, the following effects can be obtained:

(S1) Since a raw material supplying position (i.e., a position of a raw material hopper40) can be lowered, the following effects can be obtained.(S1-1) It is possible to reduce the height of a crane for supplying a combustible material such as wastes into the raw material hopper40.(S1-2) Accordingly, the height of a building can be reduced.(S1-3) As a result, construction cost of the facility can be reduced.

(S2) Since the raw material is mixed with the high-temperature bed material in advance (i.e., the combustible material and the high-temperature bed material are mixed with each other in a screw conveyor10in advance), the following effects can be obtained.(S2-1) A combustible material is broken up.(S2-2) A raw material is homogenized before being supplied to a chamber,(S2-3) It is possible to prevent variations in the amount of raw material to be supplied,(S2-4) Therefore, it is possible to prevent variations in the amount of gas.(S2-5) Margins in a gas facility can be reduced,(S2-6) The combustible material is pyrolyzed before being supplied into a chamber. Specifically, since the combustible material is brought into contact with the high-temperature bed material before being supplied into the chamber, the combustible material is pyrolyzed and volatile matter is obtained.(S2-7) Accordingly, volatile matter is prevented from being released from the combustible material in the chamber.(S2-8) Thus, it is possible to prevent variations in the amount of gas generated, as with (S2-4),(S2-9) Therefore, it is possible to prevent variations in pressure in the chamber,(S2-10) Accordingly, the chamber can have a relatively high pressure therein. Thus, it is possible to prevent air from leaking out of the chamber, as described later in (S3-1),(S2-11) Moisture in the raw material is evaporated. Specifically, since the combustible material is brought into contact with the high-temperature bed material before the combustible material is supplied into the chamber, moisture in the raw material is evaporated.(S2-12) Thus, it is possible to prevent the evaporation of moisture in the chamber.(S2-13) As a result, the amount of moisture supplied to the chamber can be reduced. Accordingly, in a case of a gasification and slagging combustion furnace, it is possible to reduce consumption of auxiliary fuel, as described later in (S3-3).

(S3) Since sealing performance of a raw material supply port of a chamber can be enhanced (i.e., a conveyor casing11of a screw conveyor10is filled with a bed material to enhance material sealing effects), the following effects can be obtained.(S3-1) It is possible to prevent air from leaking into the chamber.(S3-2) Thus, it is possible to prevent uncontrollable gas flow from flowing into the chamber.(S3-3) Therefore, in a case of a gasification and slagging combustion chamber, consumption of auxiliary fuel can be reduced,(S3-4) It is possible to prevent leaking of a gas from the chamber,(S3-5) Therefore, it is possible to reduce risk of backfire,(S3-6) Simultaneously, it is possible to reduce risk of poisoning,(S3-7) As a result, safety can be ensured,(S3-8) Thus, cost for security countermeasures can be reduced.

(S4) Initial cost can be reduced because of reduction of construction cost (S1-3), reduction of margins in the gas facility (S2-5), and reduction of cost for security countermeasures (S3-8),

(S5) Running cost can be reduced because of reduction of consumption of auxiliary fuel in a case of a gasification and slagging combustion furnace (S3-3),

(S6) On the whole, it is possible to achieve customer satisfaction,

Here, as a first embodiment according to the invention, a combustible material supplying apparatus for supplying a combustible material to the upper portion of a fluidized bed of a fluidized-bed gasifier chamber or combustion chamber may be characterized in that means for mechanically supplying a raw material with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane.

Since, as described above, the combustible material supplying apparatus is a means for mechanically supplying a raw material with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane, the material supplying position can be lowered. For example, the height of a building in which the facility is installed can be reduced by a lowered position of the material supplying means such as a crane for carrying combustible materials such as wastes.

Further, as a second embodiment of the invention, the combustible material supplying apparatus of the first embodiment according to the invention may comprise a conveyor having a helical vane for rotation to supply the combustible material as means for mechanically supplying a raw material.

Since, as described above, the means for mechanically supplying a raw material is a so called screw conveyor or spiral conveyor in which a helical vane is rotated, a combustible raw material is forced upward and supplied. It is therefore possible to achieve high material sealing effects especially by filling the conveyor casing with a bed material to promote crushing of a raw material, which prevents both the leakage of air into the chamber and the leakage of a gas out of the chamber.

Further, as a third embodiment of the invention, the combustible material supplying apparatus of the second embodiment according to the invention may be characterized in that the conveyor has two or more helical vanes generally disposed in parallel.

Since, as described above, the conveyor has two or more helical vanes generally disposed in parallel, crushing of a raw material is especially promoted by filling the conveyor casing with a bed material.

Further, a fourth embodiment of the invention concerns a facility for gasifying a combustible material having a fluidized-bed gasifier chamber and a combustible material supplying means for supplying a combustible material to the gasifier chamber, and gasifying the combustible material supplied to the upper portion of the fluidized bed by the combustible material supplying means. The combustible material supplying means is a means for mechanically supplying a raw material which is inclined, with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane. A supplying means is provided for filling the means for mechanically supplying a raw material with a bed material to form a fluidized bed of the fluidized-bed gasifier chamber.

Since, as described above, the combustible material supplying means is a means for mechanically supplying a raw material which is disposed to be inclined, with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle, and a bed material supplying means is provided, it is possible to promote crushing of a raw material and suppress the variation of the amount of the raw material to be supplied, while achieving high material sealing effects when the bed material supplying means is filled with the bed material having a high temperature through the bed material supplying means.

Further, a fifth embodiment of the invention concerns a facility for gasifying a combustible material having a fluidized-bed gasifier chamber and a combustible material supplying means for supplying a combustible material to the gasifier chamber and for gasifying the combustible material supplied to the upper portion of the fluidized bed. The combustible material supplying means is a means for mechanically supplying a raw material which is inclined, with transportation of combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane. A bed material supplying means is provided for filling the means for mechanically supplying a raw material with a bed material to form a fluidized bed of the fluidized bed gasifier chamber. A bypass means is provided which bypasses the gasifier chamber and leads the gas generated by the contact of the combustible material with the bed material in the means for mechanically supplying a raw material, to the downstream of the gasifier chamber.

Since, as described above, there is provided a bypass means which bypasses the gasifier chamber and leads the gas generated from the combustible material in the means for mechanically supplying a raw material, to the downstream of the gasifier chamber, it is possible to suppress the variation of the amount of the gas generated in the gasifier chamber and also possible to securely treat the gas generated in the means for mechanically supplying a raw material with no leak of the gas outside, in addition to the effects of the fourth embodiment of the invention.

Further, a sixth embodiment of the invention concerns a combustible material gasification method of supplying a combustible material to a fluidized-bed gasifier chamber and gasifying the combustible material. The combustible material is supplied through a means for mechanically supplying a raw material which is inclined, with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane. The means for mechanically supplying a raw material is filled with a bed material to form a fluidized bed of the fluidized-bed gasifier chamber therein. The combustible material is supplied to the fluidized-bed gasifier chamber while enhancing material sealing effects of a material supplying system; and the combustible material is gasified.

Since, as described above, the combustible material is supplied through a means for mechanically supplying a raw material which is inclined, with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane, and the means for mechanically supplying a raw material is filled with a bed material, it is possible to promote crushing of a raw material, to suppress the variation of the amount of a raw material to be supplied and to achieve high material sealing effects during gasification.

Further, a seventh embodiment of the invention concerns a combustible material gasification method of supplying a combustible material to a fluidized-bed gasifier chamber and gasifying the combustible material. The combustible material is supplied through means for mechanically supplying a raw material which is inclined, with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane. The means for mechanically supplying a raw material is filled with a bed material to form a fluidized bed of the fluidized-bed gasifier chamber therein. The combustible material is supplied to the fluidized-bed gasifier chamber while enhancing material sealing effects of a material supplying system. The combustible material is positively contacted with the bed material in the means for mechanically supplying a raw material to evaporate the moisture and volatile matter from the combustible material. The combustible material, from which the moisture and volatile matter was removed, is supplied to the fluidized-bed gasifier chamber; and the combustible material is gasified.

Since, as described above, the combustible material and the bed material having a high temperature are positively placed in contact, moisture and volatile matter is vaporized from the combustible material, and the combustible material from which moisture and volatile matter was removed is supplied to the fluidized-bed gasifier chamber, it is possible to suppress the variation of the amount of the gas generated in the gasifier chamber and also suppress the variation of the amount of the moisture therein.

Further, an eighth embodiment of the invention concerns a combustible material gasification method of supplying a combustible material to a fluidized-bed gasifier chamber and gasifying the combustible material. The combustible material is supplied through means for mechanically supplying a raw material which is inclined, with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane. The means for mechanically supplying a raw material is filled with a bed material to form a fluidized bed of the fluidized-bed gasifier chamber therein. The combustible material is supplied to the fluidized-bed gasifier chamber while enhancing material sealing effects of a material supplying system. The combustible material is positively contacted with the bed material in the means for mechanically supplying a raw material to evaporate the moisture and volatile matter from the combustible material. The generated steam and volatile matter bypassing the fluidized-bed chamber is led to the downstream thereof. The combustible material, from which the moisture and volatile matter was removed, is supplied to the fluidized-bed gasifier chamber; and the combustible material is gasified.

Since, as described above, the steam and volatile matter generated in the means for mechanically supplying a raw material bypass the gasifier chamber and flow into the downstream thereof, it is possible to securely treat the gas generated in the means for mechanically supplying a raw material with no leakage of the gas outside, in addition to the effects of the seventh embodiment of the invention.

Further, a ninth embodiment of the invention concerns a combustible material supplying apparatus for supplying a combustible material together with incombustible particles. A means for mechanically supplying a raw material is inclined, with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane.

Since, as described above, the combustible material is supplied together with incombustible particles by the means for mechanically supplying a raw material which is inclined, with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane, a mixture of the combustible material and the incombustible particles is transported, resulting in a combustible material supplying apparatus having high material sealing effects.

According to the first embodiment, the combustible material supplying apparatus is the means for mechanically supplying a raw material and disposed to be inclined, with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane. The raw material supply position can be lowered and it is therefore possible to provide a combustible material supplying apparatus which can allow a reduction in the height of a building in which the facility is installed and which can allow the total construction cost of the entire facility to be reduced.

According to the second embodiment, the means for mechanically supplying a raw material is so called a screw conveyor or spiral conveyor in which a helical vane is rotated, and a combustible raw material is forced upward and supplied. It is therefore possible to provide a combustible material supplying apparatus having high safety and high material sealing effects especially by filling the conveyor casing with a bed material to promote crushing of a raw material, which prevents both the leakage of air into the chamber and the leakage of a gas out of the chamber, in addition to the effects of the first embodiment.

According to the third embodiment, the conveyor has two or more helical vanes generally disposed in parallel. It is therefore possible to provide a combustible material supplying apparatus which promotes crushing of a raw material especially by filling the conveyor casing with a bed material and which suppresses the variation of the amount of the combustible material to be supplied, in addition to the effects of the first and second embodiments.

According to the fourth embodiment, the combustible material supplying means is a means for mechanically supplying a raw material which is disposed to be inclined, with its downstream end directed upward, at an angle not smaller than a predetermined angle, and a bed material supplying means is provided. It is therefore possible to provide a facility for gasifying a combustible material having high safety and high material sealing effects, which promotes crushing of a raw material and suppresses the variation of the amount of the raw material to be supplied, while achieving high material sealing effects when the bed material supplying means is filled with the bed material having a high temperature through the bed material supplying means.

According to the fifth embodiment, there is provided a bypass means which bypasses the gasifier chamber and leads the gas generated from the combustible material in the means for mechanically supplying a raw material, to the downstream of the gasifier chamber. It is therefore possible to provide a facility for gasifying a combustible material having high safety and high material sealing effects, which suppresses the variation of the amount of the gas generated in the gasifier chamber and also securely treats the gas generated in the means for mechanically supplying a raw material with no leakage of the gas outside, in addition to the effects of the fourth embodiment of the invention.

According to the sixth embodiment, the combustible material is supplied through means for mechanically supplying a raw material which is inclined, with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane and the means for mechanically supplying a raw material is filled with a bed material. It is therefore possible to provide a method of gasifying a combustible material, which promotes crushing of a raw material, suppresses the variation of the amount of a raw material to be supplied and achieves high material sealing effects during gasification.

According to the seventh embodiment, the combustible material and the bed material having a high temperature are positively contacted in the means for mechanically supplying a raw material, moisture and volatile matter is vaporized from the combustible material, and the combustible material, from which moisture and volatile matter was removed is supplied to the fluidized-bed gasifier chamber. It is therefore possible to provide a method of gasifying a combustible material, which suppresses the variation of the amount of the gas generated in the gasifier chamber and also suppresses the amount of the moisture therein, in addition of the effects of the sixth embodiment.

According to the eighth embodiment, the steam and volatile matter generated in the means for mechanically supplying a raw material bypass the gasifier chamber and flow into the downstream thereof. Thus, it is possible to securely treat the gas generated in the means for mechanically supplying a raw material with no leakage of the gas outside, in addition to the effects of the seventh embodiment of the invention.

According to the ninth embodiment, since the combustible material is supplied together with incombustible particles by means for mechanically supplying a raw material which is inclined, with transportation of the combustible material directed upward, at an angle not smaller than a predetermined angle with respect to the horizontal plane, a mixture of the combustible material and the incombustible particles is transported. It is therefore possible to provide a combustible material supplying apparatus having high material sealing effects.

It should be noted that the detailed description and specific examples are preferred embodiments of the invention, only for the purpose of the description thereof. It is apparent to the person of ordinary skill in the art to modify and change the invention in a variety of manners, within the scope and spirit of the invention. The applicant does not intend to dedicate any disclosed embodiments to the public, and to the extent any disclosed modifications or alterations may not literally fall within the scope of the claims, they are considered to be part of the invention under the doctrine of equivalents.

As is described heretofore, according to the invention, it is possible to provide a combustible material supplying apparatus, a facility for gasifying a combustible material, and a method of gasifying a combustible material, which allow increased sealing effects of the supplying system for supplying a combustible material, such as combustible wastes, to the fluidized-bed chamber, a stable supply of undefined shapes of wastes, and a reduction of construction costs.