JP4438488B2 - Gasifier - Google Patents

Description

  The present invention relates to a gasifier that gasifies a solid combustible material.

For example, Japanese Patent Application Laid-Open No. 2003-176486 discloses an integrated circulating fluidized bed gasification furnace including a gasification chamber, a collection device, and a combustion chamber as an example of a gasification device. This integrated circulating fluidized bed gasification furnace gasifies the raw material using the heat of the scattered particles in the gasification chamber, separates the scattered particles from the combustible gas in the collection device and collects the scattered particles, In this case, the scattered particles are heated by burning the combustible component such as char contained in the scattered particles, and the heated scattered particles are supplied to the gasification chamber as a heat source.
JP 2003-176486 A

  By the way, the integrated circulating fluidized bed gasification furnace has a problem that the apparatus cost is high because the gasification chamber and the combustion chamber are configured as a facility having a fluidized bed. Moreover, since it is necessary to supply air, oxygen, and water vapor to the fluidized bed in order to fluidize the scattered particles at a sufficient flow rate, power (electric power) is required for fluidizing the scattered particles, and thus energy efficiency is low. There are also problems.

  The present invention has been made in view of the above-described circumstances, and aims to reduce apparatus costs and improve energy efficiency in a gasifier.

  In order to achieve the above object, in the present invention, the particle heating means for heating and discharging the heat transfer particles, and the heat transfer particles heated by the particle heating means are taken in from the upper part and lowered, and the gas is recovered at a midpoint. A downcomer provided with a mouth, a raw material supply device for supplying a raw material to a portion below the gas recovery port in the downcomer, and a water vapor supply means for supplying water vapor upward from the lower end of the downcomer The solution is adopted.

  According to the present invention, by supplying the raw material to be gasified to the intermediate portion in the downcomer where the heat transfer particles heated at high temperature by the particle heating means descend and the heated steam rises, the raw material becomes the heat transfer particles Gas is reformed by the reaction of this gas and water vapor, and the gas is reformed and discharged from the gas recovery port. That is, according to the present invention, since the raw material can be gasified and reformed by steam without using a conventional gasification chamber having a fluidized bed, the apparatus cost is reduced and the energy efficiency is improved. be able to.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a conceptual diagram showing a system configuration of a gasifier according to this embodiment. In FIG. 1, reference numeral 1 is a combustion chamber (particle heating means), 2 is a cyclone (bed material recovery means), 3 is a bed material reservoir, 4 is a downcomer, 5 is a raw material supply device, 6 is a return line, 7 is a gate valve, 8 is a heat transfer section, 9 is a water supply pump, 10 is a economizer, 11 is a steam drum, 12 is a superheater, 13 is a pushing fan, 14 is a preheater, X is a bed material (heat transfer particles ) And Y is a raw material.

  The combustion chamber 1 is a cylindrical body fixed in a vertical posture as shown in the figure, and has a fluidized bed in which the bed material X flows by flowing air in the lower part, and the atmosphere in which the bed material X scatters on the fluidized bed. Underneath, the fuel that is input from the outside is burned, and the exhaust material including the bed material X is discharged from the upper part. The bed material X is either sand or a granular catalyst (for example, dolomite) or a mixture of both. In addition, the said granular catalyst is for accelerating | stimulating the effect which water vapor reduces the tar component which generate | occur | produces in the downcomer 4.

  The fluidized bed composed of the bed material X is formed by injecting fluidized air upward from the lower end of the combustion chamber 1 to the bed material X densely located in the lower portion of the combustion chamber 1. Further, part of the bed material X is scattered on the fluidized bed by such injection of the fluidized air, moves upward together with the combustion gas, and is discharged from the upper part of the combustion chamber 1. More precisely, combustion residues such as ash are also discharged from the upper part of the combustion chamber 1 together with the combustion gas and the bed material X.

  That is, the cyclone 2 is discharged from the combustion chamber 1 consisting of the bed material X scattered in the combustion chamber 1, the combustion gas generated by returning the fuel introduced into the combustion chamber 1, and the combustion residue from the combustion of the fuel. Things are supplied. The cyclone 2 separates and collects the bed material and combustion residue, which are solid components, from such emissions. The combustion gas, which is a gas component contained in the exhaust, is separated from the solid component by the cyclone 2 and supplied to the heat transfer unit 9.

  The bed material storage unit 3 is located below the cyclone 2 and temporarily stores the bed material X separated and collected by the cyclone 2. The downcomer 4 is a conduit fixed in a vertical posture, and its upper end communicates with the lower end of the bed material reservoir 3 and its lower end communicates with the lower end of the combustion chamber 1 via the return conduit 7. ing. Further, the downcomer 4 is provided with a gas recovery port 4a in the middle of the downcomer 4, and heated steam is jetted upward from the lower end portion. That is, in the downcomer 4, the bed material X discharged from the bed material storage unit 3 sequentially descends from the direction opposite to the jet direction of the heated steam, that is, from the upper side to the lower side.

  The raw material supply device 5 supplies the raw material Y to a portion below the gas recovery port 4a in the downcomer 4. This raw material Y generates combustible gas by being vaporized, and is, for example, municipal waste, industrial waste, sludge, agricultural waste and other solid waste, coal or other solid fuel or biomass. The return pipe 6 is a pipe fixed in an inclined posture as shown in the figure, the upper end communicates with the lower end of the downcomer 4, and the lower end communicates with the lower end of the combustion chamber 1. Yes. Such a return line 6 is provided for returning the bed material X lowered in the downcomer 4 to the combustion chamber 1. The gate valve 7 is provided in the middle of the return pipe 6 and adjusts the amount of the bed material X returned from the downcomer 4 to the combustion chamber 1.

  The heat transfer section 8 is a cylindrical body that communicates with the cyclone 2, and the combustion gas discharged from the cyclone 2 passes therethrough. In the heat transfer section 8, a economizer 10, a superheater 12, and a preheater 14 are provided as shown. The water supply pump 9 is a pump that supplies water to the economizer 10. The economizer 10 is a thin tube through which the water supplied from the water supply pump 9 flows, and heats the water by heat exchange with the combustion gas and supplies it to the steam drum 11. The steam drum 11 separates mixed water of water (warm water) and steam supplied from the economizer 10 into warm water and steam (saturated steam), and supplies saturated steam to the superheater 12. Hot water is supplied to a furnace wall tube provided on the wall surface of the combustion chamber 1.

  The superheater 12 is a thin tube through which the saturated steam supplied from the steam drum 11 flows. The saturated steam is heated by heat exchange with the combustion gas to generate heated steam, and the heated steam is supplied to the lower end of the downcomer 4. Supply. The water supply pump 9, the economizer 10, the steam drum 11, and the superheater 12 constitute a water vapor supply unit in this embodiment.

  The pushing fan 13 is a fan that takes in outside air (air) and supplies it to the preheater 14. The preheater 14 generates fluidized air by preheating the air supplied from the pushing fan 13 by heat exchange with the combustion gas, and supplies it to the lower end of the combustion chamber 1. Such a pushing fan 13 and the preheater 14 constitute a fluidized air supply means in the present embodiment, and fluidize the bed material by supplying fluidized air to the lower end portion of the combustion chamber 1.

Next, the main part operation | movement of the gasification apparatus comprised in this way is demonstrated in detail.
In the combustion chamber 1 of the gasifier, the fluidized bed formed of the bed material X is formed by fluidizing the bed material X by injecting fluidized air from the fluidized air supply means to the lower part of the combustion chamber 1 to form a fluidized bed. In addition, a part of the bed material X is scattered in a fluidized bed. Then, the bed material X rises in the combustion chamber 1 together with the combustion gas and combustion residue generated by the combustion of the fuel dropped from the outside under the scattering atmosphere of the bed material X, and is directed to the cyclone 2 from above. Discharged.

  Here, the bed material X supplied from the combustion chamber 1 to the cyclone 2 is heated to a high temperature by the combustion in the combustion chamber 1. The bed material X in such a high temperature state is separated and collected by the cyclone 2 and temporarily stored in the bed material storage unit 3, and then falls into the downcomer 4 from the lower end of the bed material storage unit 3. It descends sequentially in 4 toward the bottom.

  Here, the heated steam is sprayed into the downcomer 4 in the direction opposite to the descending direction of the bed material X, that is, upward from the lower end portion. Therefore, the bed material X receives the lifting force by the heated steam. While descending downcomer 4. Then, when the raw material Y is supplied to an intermediate portion of the downcomer 4 in which the internal atmosphere is an atmosphere in which the high temperature bed material X and the heated steam are mixed, the following reaction phenomenon occurs in the downcomer 4. Will occur.

  That is, the bed material X is gradually cooled by heat exchange with heated steam and other generated gas in the process of descending the downcomer 4, but mainly in the region B below the supply site A of the raw material Y, The heated steam is heated by heat exchange with the bed material X and rises. And in the supply site A of the raw material Y, the heated steam heated by the bed material X and the raw material Y react with the heat of the bed material X to generate pyrolysis gas.

  Further, in the region C above the supply site A of the raw material Y, the tar component contained in the pyrolysis gas is converted into a light gas by the heat of the bed material X. In addition, when the bed material X contains the granular catalyst, the lightening of the tar component by water vapor | steam is accelerated | stimulated by the effect | action of a granular catalyst. The combustible gas, in which the raw material Y is decomposed and generated by the heat of the bed material X in this way, is pushed up by the heated steam flowing upward in the downcomer 4 to the outside from the gas recovery port 4a located above the region C. It is discharged and collected.

  On the other hand, the bed material X descending to the lower end in the downcomer 4 is returned to the fluidized bed at the lower end of the combustion chamber 1 via the return pipe 6. The bed material X returned to the fluidized bed contains combustion residues collected together with the bed material X in the cyclone 2, and the combustion residues are burned in the combustion chamber 1.

  According to the present embodiment, the raw material Y is supplied by supplying the raw material Y to be gasified to the intermediate portion in the downcomer 4 where the heated bed material X descends and the heated steam rises in the combustion chamber 1. Is gasified by the heat of the bed material X and converted into combustible gas. That is, according to this embodiment, since the raw material Y can be gasified without using a conventional gasification chamber having a fluidized bed, the apparatus cost can be reduced and the energy efficiency can be improved. .

It is a conceptual diagram which shows the system configuration | structure of the gasifier concerning one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Combustion chamber (particle heating means), 2 ... Cyclone (bed material collection | recovery means), 3 ... Bed material storage part, 4 ... Downcomer, 5 ... Raw material supply apparatus, 6 ... Return line, 7 ... Gate valve, 8 DESCRIPTION OF SYMBOLS ... Heat-transfer part, 9 ... Feed water pump, 10 ... Carbon-saving device, 11 ... Steam drum, 12 ... Superheater, 13 ... Pusher fan, 14 ... Preheater, X ... Bed material (heat-transfer particle), Y ... Raw material

Claims (5)

Particle heating means for heating and discharging the heat transfer particles;
A downcomer in which the heat transfer particles heated by the particle heating means are taken in from the upper part and lowered, and a gas recovery port is provided in the middle part; and
A raw material supply device for supplying a raw material to a portion below the gas recovery port in the downcomer;
Water vapor supply means for supplying water vapor upward from the lower end of the downcomer,
The particle heating means has a fluidized bed in which the bed material, which is a heat transfer particle, flows by the fluidized air supplied to the lower part, and the fuel is burned in the scattering atmosphere of the bed material on the fluidized bed. It is a combustion chamber that heats the bed material and discharges the waste containing the bed material from the upper part,
Fluid air supply means for supplying the fluid air to the lower part of the combustion chamber;
Bed material recovery means for separating and recovering the bed material from the exhaust discharged from the upper part of the combustion chamber;
A bed material whose upper end communicates with the lower end of the bed material recovery means and whose lower end communicates with the upper end of the downcomer, temporarily stores the bed material supplied from the bed material recovery means and discharges it to the downcomer A reservoir,
A bed material returning means for returning the bed material from the lower end of the downcomer to the lower part of the combustion chamber;
The gasifier is characterized in that the steam supply means heats saturated steam using the heat of the combustion gas discharged from the bed material recovery means and supplies it to the lower end of the downcomer.   The gasifier according to claim 1, wherein the heat transfer particles are any one or a mixture of particulate catalysts that promote gasification in sand or downcomer.   The gasifier according to claim 2, wherein the granular catalyst is dolomite.   The gasification apparatus according to any one of claims 1 to 3, wherein the fluidized air supply means generates fluidized air by preheating the air using the heat of the combustion gas discharged from the bed material recovery means. .   The gasification apparatus according to any one of claims 1 to 4, wherein the bed material recovery means is a cyclone.

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