JP2012246385A - Gasifying installation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gasifying installation improved in push-in performance for pulverized fuel and capable of smoothly and stably charging a solid fuel therein.SOLUTION: The gasifying installation 1 is provided, which works as follows: a pulverized fuel stored in a fuel container is force-fed into a gasification furnace by means of an ejector 9 using a carrier gas G2 to produce a gaseous fuel. The ejector 9 includes: a casing 13 having an outlet 17 connected to a feed pipe 11 communicating with the gasifying furnace; and a nozzle 15 blowing off a carrier gas G2 into the casing 13; wherein the nozzle 15 is projected into the casing 13 and has a jet port close to the outlet 17 and facilitates introduction of a pulverized fuel fed from the fuel container into the feed pipe 11, by jetting the carrier gas G2 in the neighborhood of the outlet 17 coaxially with the feed pipe 11.

Description

  The present invention relates to a gasification facility that gasifies a solid fuel such as coal and supplies it as a gaseous fuel.

  Conventionally used solid fuels include coal, biomass, tire chips, etc. In recent years, it has been studied to gasify such solid fuels and supply them as gaseous fuels. Development of gasification equipment that gasifies by partial combustion and pyrolysis is underway.

  In general, when charging a solid material into a heating furnace, it is necessary to prevent the solid material from accumulating during the charging or preventing the gas in the heating furnace from flowing back to the charging side. In boilers and incinerators, It is designed to supply air for pushing into the furnace. In this regard, for example, in the solid fuel powder gasification facilities described in Patent Documents 1 and 2 below, in order to keep the inside of the gasification furnace in an inert atmosphere, air is not used and nitrogen or the like is not used. It is described to include an ejector that uses an active gas or water vapor to push the fuel powder.

JP 2001-139963 A JP 2010-254728 A

  The solid fuel supplied to the gasifier is supplied after being roughly crushed, but the supply pipe for introducing the solid fuel into the gasifier is designed to be relatively thin to prevent backflow from the gasifier. The ejector has a squeezing portion in which the lateral width is gradually sandwiched toward the supply pipe so that the solid fuel powder is easily pushed into the supply pipe and supplied. However, since the pushing portion such as an ejector is located between the fuel container kept at a low temperature and the high-temperature gasification furnace, the aggregation of the solid fuel powder due to temperature or humidity fluctuations is relatively likely to occur. For this reason, even if the fine powder contained in the fuel pulverized product is agglomerated in the vicinity of the outlet to the supply pipe and partially covers it, the flow of the fuel pulverized product may completely stop.

  An object of the present invention is to solve the above-described problems, improve the pushing performance of the solid fuel pulverized product, and provide a gasification facility capable of smoothly and stably charging the solid fuel pulverized product.

  Another object of the present invention is to provide a gasification facility that can effectively prevent the backflow from the gasification furnace by improving the pushing performance of the pulverized solid fuel and can safely and stably gasify the solid fuel. It is to be.

  In order to solve the above-mentioned problems, the present inventors have conducted extensive research and, as a result, devised the ejection of the carrier gas in the ejector to improve the indentation performance, thereby clogging the fuel pulverized material and from the gasifier. It has been found that backflow can be prevented, and the present invention has been completed.

  According to one aspect of the present invention, the gasification facility is a gasification facility that generates gaseous fuel by pushing and supplying the pulverized fuel contained in the fuel container to the gasification furnace with an ejector using a carrier gas. The ejector is a casing having an outlet connected to a supply pipe communicating with the gasification furnace; and a nozzle for injecting the carrier gas into the casing, and protrudes into the casing and close to the outlet And the nozzle for facilitating introduction of the fuel supplied from the fuel container into the supply pipe by ejecting the carrier gas near the outlet coaxially with the supply pipe. Is the gist.

  According to the present invention, the pushing performance of the ejector is improved, the crushing of the fuel pulverized material is prevented and the solid fuel can be smoothly introduced into the gasification furnace, and the backflow from the gasification furnace is efficiently utilized using the pushing performance. Therefore, it is possible to provide a gasification facility that can continue the gasification process safely and stably, and it is effective for reducing the maintenance frequency of the facility and improving the durability.

The schematic block diagram which shows the principal part of the gasification installation in this invention. Explanatory drawing explaining the effect | action of the ejector in this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows a main part of a gasification facility according to the present invention. A gasification facility is a facility that obtains gasified fuel by thermally decomposing a fuel pulverized product obtained by roughly pulverizing solid fuel such as coal, biomass, tire chips, etc., and a fuel that contains a pulverized fuel pulverized product containing fine particles A container, a gasification furnace (not shown) that thermally decomposes the pulverized fuel to generate gaseous fuel, and an ejector that pushes and supplies the pulverized fuel to the gasification furnace using a carrier gas. The gasification facility 1 of this embodiment processes coal pulverized material as a solid fuel and includes a coal hopper 3 as a fuel container. The coal hopper 3 is connected to an ejector 9 through a slide gate 5 and a pipe 7, and slides a pulverized coal (flow is indicated by a white arrow in the figure) falling vertically from the coal hopper 3 into the pipe 7. When the gate 5 is cut out, a predetermined amount of coal pulverized material is intermittently supplied to the ejector 9. In order to prevent air from flowing in from the coal hopper 3 together with the pulverized coal, an inert gas G1 such as nitrogen, rare gas, carbon dioxide or the like can be supplied into the pipe 7. In this embodiment, nitrogen gas is discharged into the pipe 7 as the inert gas G1, and the flow rate is appropriately controlled by a valve so as not to hinder the supply of the pulverized coal. The pulverized coal that has passed through the slide gate 5 falls to the ejector 9 and is pushed into the supply pipe 11 from the ejector 9 by the carrier gas G2 (shown by the arrow in the figure) and falls vertically in the supply pipe 11. Then, it is introduced into the gasification furnace together with the carrier gas G2.

  The ejector 9 has a casing 13 connected to the pipe 7 at the top for receiving the pulverized coal, and a nozzle 15 for ejecting the carrier gas G2 into the casing 13. The casing 13 is sandwiched toward the outlet 17 at the lower end. It has a squeezed portion to be squeezed, and the outlet 17 is connected to the supply pipe 11 in the vertical direction and communicates with the gasification furnace. In this embodiment, the casing 13 is formed in a substantially conical funnel shape and is configured as a squeezed portion in which the entire side wall of the casing is inclined, but the upper portion of the side wall is formed into a columnar shape with the same diameter and only the lower portion is formed. You may incline and may comprise as a pinching part.

  The nozzle 15 penetrates the top of the casing 13 from the outside and protrudes into the inside, extends coaxially with the supply pipe 11, and has a discharge port 19 having a hole diameter of about 3 to 7 mm near the outlet 17 of the casing 13. By ejecting the carrier gas G2 from the discharge port 19 near the outlet 17, a gas flow of the carrier gas G2 is generated coaxially with the supply pipe 11, and the coal pulverized material falling through the squeezed portion is supplied while being pressed by the fluid pressure. Pour into the tube 11. Further, the backflow from the gasifier to the ejector 9 is also suppressed by the gas flow. As the carrier gas G2, an inert gas such as nitrogen, rare gas, carbon dioxide, or water vapor, or a combination of these can be used. In this embodiment, water vapor is used. The gas flow of the carrier gas G2 may be narrower or wider than the hole diameter of the discharge port 19, but the flow of the gas flow at the outlet 17 so that the gas flow does not collide with the casing around the outlet 17 and disturb the flow. It is important that the width is equal to or smaller than the diameter of the outlet 17, and preferably smaller than the hole diameter. The gas flow flows into the supply pipe 11 from the outlet 17, thereby entraining the coal powder in the vicinity of the gas flow, and the coal powder remains around the outlet 17. To prevent. Therefore, the shape and size of the discharge port 19 of the nozzle 15 are adjusted so that the gas flow at the outlet 17 is entirely flowing into the supply pipe 11. The distance between the discharge port 19 of the nozzle 15 and the outlet 17 of the casing 13 is such that the nozzle 15 does not hinder the flow of the pulverized coal and the gas flow pressure loses the pushing force (flow pressure) at the outlet 17. It is not set to such an extent. Therefore, when the discharge pressure of the nozzle 15 is high (the gas flow rate is high), the distance between the discharge port 19 and the outlet 17 can be set long, but at this time, the viewpoint of suppressing an increase in the amount of carrier gas G2 used. Therefore, it is desirable to increase the discharge pressure and flow velocity while limiting the gas flow rate by narrowing the discharge width.

  In order for the pulverized coal introduced from the pipe 11 to be smoothly introduced into the outlet 17, considering the angle of repose (approximately 45 degrees) of the pulverized coal, the wall surface inclination angle of the squeezed portion is approximately 70 degrees or more. However, in the present invention, the carrier gas G2 is generated not only efficiently in the pulverized coal by the gas flow in the same direction as the coal powder supply direction but also around the gas flow discharged at a high flow rate. The effect of drawing the coal pulverized material by the negative pressure is to eliminate the possibility of the coal powder remaining around the outlet 17, and the introduction of the coal pulverized material supplied from the coal hopper 3 into the supply pipe 11 is promoted. . Therefore, even if the inclination angle of the compressed portion of the casing 13 decreases in the vicinity of the outlet 17, the pulverized coal is not drawn to the gentle inclination around the outlet 17 but is sucked into the outlet 17 by the gas flow. For example, the surface may be formed to be curved in a semi-elliptical spherical shape. In addition, the supply pipe 11 can be made thinner by promoting the introduction by the negative pressure, and the hole diameters of the outlet 17 and the supply pipe 11 in the above-described embodiment are set to about 40 mm. It is considerably thinner than the tube. The negative pressure due to the gas flow at a high flow rate acts to attract the pulverized coal falling through the slide gate 5 toward the axial center of the casing 13, so the impact of the pulverized coal falling on the casing 13 is slightly mitigated. can do. Note that the negative pressure generated in the ejector 9 by the gas flow may cause a suction action from the slide gate 5 side to the ejector 9, so that the inert gas G <b> 1 supplied to the pipe 7 is sent from the coal hopper 3 to the ejector 9. It is extremely useful in preventing air from entering.

  As described above, the gasification facility of the present invention can smoothly introduce the pulverized solid fuel such as coal into the gasification furnace, and can continue to gasify the solid fuel safely and stably. Similarly, gasified fuel can be obtained from solid fuel such as biomass and tire chips. The main part of the gasification facility of the present invention, that is, the structure of the fuel introduction part including the ejector can be applied to other gasification facilities. The push-in performance can be improved by replacing the body introduction part.

  Since the solid fuel is smoothly supplied to the gasification furnace, the certainty and safety of the work is improved, and a gasification facility capable of stably supplying the gas fuel with high demand from the solid fuel is provided. It is useful for the efficient use of energy resources, and contributes to a reduction in maintenance frequency, an increase in service life, and an improvement in operability.

1: Gasification equipment, 3: Coal hopper, 5: Slide gate, 7: Piping,
9: Ejector, 11: Supply pipe, 13: Casing, 15: Nozzle,
17: outlet, 19: discharge port, G1: inert gas, G2: carrier gas.

Claims (1)

A gasification facility for generating gaseous fuel by pushing and supplying a pulverized fuel contained in a fuel container to a gasification furnace with an ejector using a carrier gas, the ejector comprising:
A casing having an outlet connected to a supply pipe communicating with the gasifier, and
A nozzle for ejecting the carrier gas into the casing, having a discharge port projecting into the casing and near the outlet, and ejecting the carrier gas coaxially with the supply pipe near the outlet A gasification facility comprising the nozzle for accelerating the introduction of the pulverized fuel supplied from the fuel container into the supply pipe.

Images