JP2013006900A - Reforming furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eave on a flow path for a molten slag, thereby: preventing the molten slag from intruding into gaps formed by a closing body and a through-hole; and facilitating inserting and removing the closing bodies.SOLUTION: A reforming furnace 120 for reforming a gas in a cylindrical body 250 with its central axis directed vertically includes: the through-hole 254 provided in the body 250; the closing body 256 capable of closing the through-hole 254; and a protrusion portion 260 which is provided inside of the body, the lower end of which is located above the through-hole 254, and which is formed more protrusively to a central axis side than to an inner surface.

Description

  The present invention relates to a reforming furnace for reforming a gasification gas generated by gasifying a gasification raw material.

  2. Description of the Related Art In recent years, a technology has been developed that gasifies solid raw materials such as coal, biomass, and tire chips to generate gasified gas instead of petroleum. The gasified gas generated in this way can be used for efficient power generation systems such as Integrated Coal Gasification Combined Cycle (IGCC), hydrogen production, synthetic fuel (synthetic petroleum) production, chemical fertilizer ( (Urea) and other chemical products. Among solid raw materials used as raw materials for gasification gas, coal, in particular, has a recoverable period of about 150 years, more than three times the recoverable period of oil, and reserves are unevenly distributed compared to oil. Therefore, it is expected as a natural resource that can be stably supplied over a long period of time.

  Conventionally, the coal gasification process has been performed by partial oxidation using oxygen or air, but since it has a high temperature of about 1800 ° C. and a high pressure of about 3 MPa, it requires special heat and pressure resistant materials, There was a drawback that the cost of the gasifier was high. In order to solve this problem, a technique for gasifying coal using steam at a low temperature of about 700 ° C. to 900 ° C. and normal pressure has been developed. This technology has the advantage that a pressure-resistant structure is not required by setting temperature and pressure low, and that a commercially available product can be used. However, the produced gasification gas contains a larger amount of tar than the gasification gas partially oxidized at a high temperature of about 1800 ° C. Therefore, a technique for removing tar content contained in the gasification gas by adding oxygen or air to the generated gasification gas to 1000 ° C. or higher and oxidative reforming is disclosed (for example, Patent Document 1). 2).

  In a reforming furnace that performs such oxidation reforming, a through-hole that allows a person to enter and exit is provided in the outer wall for maintenance in the furnace. In order to reduce heat radiation from the reforming furnace, a refractory material is applied throughout the furnace, and a pluggable body made of refractory brick is fitted into the through hole. Since there is a gap for inserting and removing the plug from the reforming furnace between the plug and the through hole, molten slag generated in the reforming furnace has entered the gap. As a result, the closed body and the through-hole adhere to each other due to the molten slag, and the closed body cannot be pulled out from the reforming furnace during maintenance, which hinders internal inspection. Further, if such a closed body is forcibly pulled out by a hoist or the like, the firebrick of the closed body or the refractory material of the reforming furnace may be damaged. Furthermore, depending on the size of the reforming furnace, the closed body becomes 10 to 15 kg, and there is concern about the safety of workers when forcibly pulling out.

  Therefore, a technique for solidifying and removing molten ash by cooling a part of the gas reaction unit furnace wall with cooling water and preventing adhesion of the molten ash is disclosed (for example, Patent Document 3). In addition, a technique is known in which a part of the gas reaction unit furnace wall is cooled with cooling water to solidify the molten slag, and the solidified slag is removed by impacting with a striking device (for example, Patent Document 4). .

JP 2009-40862 A JP 2007-45857 A JP-A-6-228578 JP-A-8-94265

  However, when the techniques of Patent Document 3 and Patent Document 4 are used, the molten slag that has entered the gap between the closed body and the through-hole cannot be removed, but also solidifies positively, resulting in a more difficult to pull out the closed body. I will invite you. Moreover, in the technique of patent document 4, there was a possibility that the firebrick of a closed body might be damaged by giving an impact with a striking device.

  An object of the present invention is to provide a reforming furnace that can prevent the molten slag from entering the gap between the closed body and the through-hole itself and can easily insert and remove the closed body.

  In order to solve the above problems, a reforming furnace of the present invention for reforming a gas in a main body is provided on a through hole provided in the main body, a closing body capable of closing the through hole, and an inner surface of the main body, The lower end is located vertically above the through-hole, and has a protrusion that protrudes from the inner surface toward the center of the main body.

  The protrusion has an inclined surface that protrudes toward the center of the main body as it goes vertically downward, and the top of the protrusion is further centered from the virtual inclined surface that is separated from the upper end of the through hole toward the center of the main body as it goes vertically upward. It may be located on the side.

  The surface on the opposite side of the inclined surface with respect to the top of the protrusion may be erected from the inner surface toward the center of the main body.

  The horizontal width along the main body of the protrusion may be longer than the width of the through hole.

  According to the present invention, a slag is provided in the flow path of the molten slag to prevent the molten slag from entering the gap between the closed body and the through hole, thereby facilitating the insertion and removal of the closed body.

It is explanatory drawing for demonstrating a gasification gas purification system. It is the perspective view which showed the external appearance of the reforming furnace typically. It is explanatory drawing for demonstrating a projection part. It is a cross-sectional view for demonstrating the cross-sectional shape of a projection part. It is the cross-sectional view which showed the other example of the projection part.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  The reforming furnace is a furnace formed for the purpose of reforming a gasification gas generated by gasifying a gasification raw material. In the present embodiment, a description will be given of a through hole that guides the inside and outside of the reforming furnace and a closing body that closes the through hole, which are used during maintenance of the reforming furnace. Here, in order to grasp the purpose of the reforming furnace, the overall configuration for generating gasification gas will be described based on the gasification gas purification system 100, and then the specific configuration of the reforming furnace will be described in detail. .

(Gasification gas purification system 100)
FIG. 1 is an explanatory diagram for explaining a gasification gas purification system 100 according to the present embodiment. As shown in FIG. 1, the gasification gas purification system 100 includes a gasification gas generation device 110, a reforming furnace 120, a heat exchanger 130, a purification gasification gas extraction device 140, and a waste water treatment device 150. Consists of including. In FIG. 1, the raw material flow is indicated by broken-line arrows, the gas flow is indicated by solid-line arrows, and the flow of sand and water is indicated by dashed-dotted arrows.

(Gasified gas generator 110)
In the present embodiment, the gasification gas generator 110 will be described with a two-column fluidized bed gasification furnace. A gasification gas generation apparatus 110 using a two-column fluidized bed gasification furnace includes a gasification furnace 210, a combustion furnace 212, and a medium separation device 214. Here, a fluidized bed gasification furnace that circulates fluidized sand will be described as an example of the gasified gas generation device 110, but the moving bed is formed by the sand flowing down vertically by its own weight. A moving bed type gasification furnace can also be used.

  In the gasification gas generator 110, as a whole, a fluid medium made of sand such as silica sand (silica sand) is circulated as a heat medium. Focusing on the flow of sand as a fluid medium, first, high-temperature sand heated to about 1000 ° C. in the combustion furnace 212 is introduced into the medium separation device 214 together with the combustion exhaust gas, Separated into combustion exhaust gas. The combustion exhaust gas separated by the medium separator 214 is heat recovered by a boiler (not shown) or the like. Further, the high-temperature sand separated by the medium separation device 214 is introduced into the gasification furnace 210, and in the gasification furnace 210, water vapor, nitrogen, air, oxygen, carbon dioxide, etc. introduced from below the gasification furnace 210. A fluidized bed is formed by the gasifying agent.

  In the gasifier 210, coal such as lignite, petroleum coke (petro coke), biomass, tire chips and other gasification raw materials are supplied to the fluidized bed, and the gasification raw material is heated to an atmospheric temperature of 700 by the heat of steam and sand. Gasification gas is produced by gasification at a temperature of from 900C to 900C. The sand finally returns to the combustion furnace 212 to form a circulating fluidized bed.

  If the gasification raw material is coal, the generated gas is mainly composed of hydrogen, carbon monoxide, carbon dioxide and methane, and contains a small amount of ash, tar, nitrogen and nitrogen compounds, sulfur and sulfur compounds.

(Reforming furnace 120)
The reforming furnace (oxidation reforming furnace) 120 adds oxygen and air to the gasification gas generated in the gasification furnace 210, and reforms (oxidizes and reforms) the tar content contained in the gasification gas at 900 ° C to 1500 ° C. Quality). Thus, most of the tar is removed by the reforming furnace 120. Further, the ash contained in the gasification gas together with the tar content becomes molten slag by the heat of the reforming furnace 120. The structure of the reforming furnace 120 will be described in detail later.

(Heat exchanger 130)
The heat exchanger 130 performs heat exchange between the gasification gas introduced from the gasification gas generator 110 and water vapor, collects the sensible heat of the gasification gas with water vapor, and sets the outlet temperature of the gasification gas to 300 ° C. Bring to ~ 600 ° C.

(Purified gasification gas extraction device 140)
The purified gasification gas extraction apparatus 140 includes a first cooler 220, a second cooler 222, a booster 224, a desulfurizer 230, a deammonizer 232, and a demineralizer 234. . The 1st cooler 220 further cools the gasification gas which became 300 to 600 degreeC by spraying water. Thereby, tar content and dust remaining in the gasification gas are condensed and removed from the gasification gas. The second cooler 222 further cools the gasification gas to 30 ° C. or lower using seawater, brine, etc., and condenses and removes remaining tar, mist, and dust. The booster 224 includes a turbo-type or volume-type compressor or pump, and boosts the gasification gas that has passed through the second cooler 222 to 1 MPa to 5 MPa. The desulfurizer 230 removes sulfur and sulfur compounds contained in the gasification gas. The deammonizer 232 removes nitrogen compounds such as ammonia contained in the gasification gas. The desalinator 234 removes chlorine and chlorine compounds contained in the gasification gas.

(Wastewater treatment device 150)
The waste water treatment device 150 is composed of SS (floating solid), ammonia and waste water containing tar and dust collected by the heat exchanger 130, the first cooler 220, the second cooler 222, and the booster 224. Cyan is removed, organic matter and ammonia are oxidized, and the process is executed to meet the discharge standard. Water (treated water) after being treated by the waste water treatment device 150 is reused for the heat exchanger 130, the first cooler 220, and the like.

  In this way, the gasified gas generated by the gasified gas generation device 110 is removed of tar and dust in the heat exchanger 130, the first cooler 220, the second cooler 222, and the booster 224, and the desulfurizer 230. Then, the sulfur is purified by removing ammonia by the deammonizer 232 and chlorine by the demineralizer 234 to be purified gasified gas. Hereinafter, the structure of the reforming furnace 120 of the gasification gas purification system 100 will be described in detail.

(Specific configuration of the reforming furnace 120)
FIG. 2 is a perspective view schematically showing the appearance of the reforming furnace 120. As shown in FIG. 2A, the reforming furnace 120 includes a cylindrical body (here, a cylindrical shape) 250 having a central axis in the vertical direction. The main body 250 of the reforming furnace is composed of an outer casing material and a refractory material attached to the inside thereof. The gasification gas generated in the gasification furnace 210 is introduced from an inlet 250a on the upper side of the main body 250 of the reforming furnace 120, and is heated to 900 ° C. to 1500 ° C. by a heat source 252 installed on the upper portion of the main body 250. It is derived from the outlet 250b at the lower side of the 250 side surface. At this time, the tar content contained in the gasification gas is thermally decomposed. Further, the ash contained in the gasification gas together with the tar content becomes molten slag by the heat of the heat source 252.

  The main body 250 of the reforming furnace 120 has a through-hole 254 that allows a person to go in and out for maintenance in the furnace (for example, 1 m in length × 1 m in width × 1 m in penetration thickness) as shown in FIG. Two closures are provided on the top and bottom of the outer wall, and a closing body 256 capable of closing the through hole 254 is fitted into the through hole 254. As shown in FIG. 2B, the closing body 256 is composed of a plurality (eight in this case) of refractory bricks 256 a for reducing heat radiation from the through holes 254, and corresponds to the outer surface of the reforming furnace 120. The surface is provided with a protruding member 256b for holding with a pulling jig and a pulling hand 256c.

  However, since there is a gap of several mm to several tens of mm between the closing body 256 and the through hole 254 for inserting and removing the closing body 256 from the reforming furnace 120, the gap is generated in the reforming furnace 120. The molten slag that has entered may stick and stick to the maintenance work. Therefore, in the present embodiment, the protrusion 260 that functions as a ridge is formed on the inner wall of the reforming furnace 120 so as to separate the vertically downward flow path of the gasified gas including the molten slag from the through hole 254.

  FIG. 3 is an explanatory diagram for explaining the protrusion 260. In particular, FIG. 3 (a) corresponds to a front view, FIG. 3 (b) shows an AA cross-sectional view of FIG. 3 (a), and FIG. 3 (c) shows a BB vertical cross-sectional view of FIG. 3 (a). . The protrusion 260 is provided on the inner surface of the main body 250 of the reforming furnace 120, and the lower end of the protrusion 260 is positioned vertically above the through hole 254 and protrudes inward from the inner wall of the reforming furnace 120. In the present embodiment, the protrusion 260 is integrally formed with a refractory material that is an inner wall of the main body 250. Therefore, the material of the protrusion 260 is equal to the refractory material of the inner wall of the main body 250. However, the protrusion 260 may be provided separately from the main body, and the material thereof is not only the same as that of the refractory material on the inner wall of the main body 250, but another material having higher rigidity may be used.

  Further, the horizontal width W1 along the main body 250 of the protrusion 260 is the width of the through hole 254 in order to prevent the molten slag from flowing from the side surface of the protrusion 260 in order to function as a flange of the through hole 254. It is formed longer than W2. In this way, it is possible to prevent the molten slag from entering the gap between the closing body 256 and the through hole 254 itself.

  FIG. 4 is a cross-sectional view for explaining the cross-sectional shape of the protrusion 260. As shown in FIG. 4A, the protrusion 260 has an inclined surface 262 that protrudes toward the central axis (center side of the main body 250) as it goes vertically downward. With such a configuration, the flow path of the gasified gas and the molten slag is formed as shown in FIG. 4B, and it is possible to prevent the molten slag from entering the gap between the closing body 256 and the through hole 254 itself. .

  In addition, the top portion 264 of the protrusion 260 is located further on the central axis side than the virtual inclined surface 266 that is separated toward the central axis side from the upper end of the through-hole 254 toward the vertical direction. Here, it is assumed that the virtual inclined surface 266 is a surface protruding W4 = 1 cm toward the central axis, W3 = 1 m vertically above the upper end of the through hole 254.

  Therefore, when the vertical position of the protrusion 260 is focused, the length W5 of the protrusion 260 protruding from the top 264 of the protrusion 260 is assumed that the vertical position of the protrusion 260 is at the upper end of the through hole 254. If it is 0 or more and is located at a position 0.5 m vertically above the upper end of the through hole 254, it is 0.5 cm or more, and if it is located 1 m vertically above the upper end of the through hole 254, it is 1 cm or more. . This length is the lower limit of the length W5 at which the protrusion 260 protrudes. However, the vertical position of the top 264 of the protrusion 260 is better as it is closer to the through hole 254.

  The upper limit of the protruding length W5 of the protruding portion 260 is not particularly limited, but is preferably 20 cm or less in consideration of the material and rigidity of the protruding portion 260. Further, the surface 268 extending from the inclined surface 262 to the top portion 264 (the surface 268 on the opposite side of the inclined surface 262 from the top portion 264) gradually decreases in cross-sectional thickness toward the inner surface side as it goes vertically downward. In addition, it is desirable to vertically stand from the inner surface to the central axis side, and it is further desirable that the cross-sectional thickness gradually decreases toward the central axis side as it goes vertically downward. However, if the angle α formed between the inner surface of the main body 250 and the surface 268 is in the range of 0 ° ≦ α ≦ 110 °, the protrusion 260 can serve as a ridge.

  As described above, according to the reforming furnace 120 described above, since the through hole 254 of the reforming furnace 120 is closed by the closing body 256, the heat radiation from the reforming furnace 120 can be reduced, and the protrusions 260 Since the molten slag that hangs down under its own weight or falls together with the gasification gas is prevented from entering the gap between the closed body 256 and the through-hole 254, the closed body 256 can be inserted and removed without causing damage to the closed body 256. Can be facilitated. Therefore, it is possible to easily check the inside of the reforming furnace 120 during maintenance.

  Further, as shown in FIG. 4B, the gasification gas flowing vertically downward collides with the projection 260 and is disturbed by the projection 260, thereby avoiding the temperature distribution of the gasification gas and making it uniform. Therefore, the reforming efficiency (decomposition rate) of tar contained in the gasification gas is improved. Furthermore, since the gasification gas that collided with the protrusion 260 has a longer residence time in the reforming furnace 120 due to agitation, a sufficient tar reforming time can be secured. Further, the protrusion 260 can prevent the deterioration of the closing body 256 from being promoted by the radiant heat of the heat source 252 located above the reforming furnace 120.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  For example, in the above-described embodiment, the projecting portion 260 having a triangular longitudinal section as illustrated in FIG. 5A has been described. However, the projecting portion 260 has a central axis as it goes vertically downward. It is sufficient to have the inclined surface 262 protruding to the side, and the longitudinal section as shown in FIG. 5B is trapezoidal, as shown in FIG. 5C, the inclined surface 262 is a convex curved surface, Moreover, as shown in FIG.5 (d), a concave curved surface may be sufficient.

  The present invention relates to a reforming furnace for reforming a gasification gas generated by gasifying a gasification raw material.

DESCRIPTION OF SYMBOLS 100 ... Gasification gas purification system 110 ... Gasification gas production | generation apparatus 120 ... Reforming furnace 130 ... Heat exchanger 140 ... Purification gasification gas extraction apparatus 150 ... Waste water treatment device 250 ... Main body 254 ... Through-hole 256 ... Closure body 260 ... Projection 262 ... inclined surface 264 ... top 266 ... virtual inclined surface 268 ... surface

Claims (4)

A reforming furnace for reforming gas in the body,
A through hole provided in the main body;
A closing body capable of closing the through hole;
A protrusion formed on the inner surface of the main body, the lower end of which is positioned vertically above the through-hole, and protrudes from the inner surface toward the center of the main body;
A reforming furnace characterized by comprising:   The protrusion has an inclined surface that protrudes toward the center of the main body as it goes vertically downward, and a top portion of the protrusion further than a virtual inclined surface that separates toward the center of the main body as it goes vertically upward from the upper end of the through hole. The reforming furnace according to claim 1, wherein the reforming furnace is located on the center side of the main body.   The reforming furnace according to claim 2, wherein a surface that is opposite to the inclined surface with respect to a top portion of the protrusion is erected from the inner surface toward the center of the main body.   The reforming furnace according to any one of claims 1 to 3, wherein a horizontal width along the main body of the protrusion is longer than a width of the through hole.

Images