JPH046237B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Application of the Invention] The present invention relates to a burner for gasifying pulverized coal, and particularly to a coal gasifying burner that can be used without cooling. [Background of the Invention] The spouted bed gasification method gasifies pulverized coal (carbon-containing solid fuel) with oxygen-containing gas at high temperature _.
It is extremely suitable for producing CO gas, and various methods are being developed. In these systems, pulverized coal is transported by a carrier gas or a slurry medium liquid, and is atomized by a burner and fed into a gasifier. The temperature inside the gasifier is 1200-1800°C, and the temperature near the flame can exceed 2000°C. Therefore, the tip of the burner receives radiant heat from the gas and becomes high temperature. It also receives heat through heat conduction from the gasifier wall. Conventional burners therefore have a cooling mechanism. JP-A-58-213089 describes a burner for coal-water suspensions. The tip of the burner is surrounded by a conduit that guides water or steam, and a cooling path is also provided on the side facing the flame. In addition, the burners at the American Big Gas pilot plant are made of multiple tubes, and cooling water is run through the outer tubes to cool them (8th Annual
International Conference on COGLAC). According to the experience of the present inventors, in a burner equipped with a cooling mechanism, it was necessary to manage the flow rate of the coolant extremely carefully. That is, as described in Japanese Patent Application No. 58-92451, pressure and temperature detection ends are provided in the cooling system of the raw material supply nozzle, and the cooling system is appropriately controlled from the respective indicated values and the time rate of change of the indicated values. However, if the control limit is exceeded, the gasification raw material and gasification agent are reduced or stopped. According to the above-mentioned application, it is possible to prevent overheating of the raw material/gasifying agent supply device in response to fluctuations in the raw material, gasifying agent, cooling water, etc. to the gasifier. If a problem occurs in the cooling system of a burner with a cooling mechanism as described above, the worst case scenario is that the tip of the burner will melt and a large amount of coolant will be ejected into the gasifier, damaging the furnace or destroying the coolant. If the pressure in the gasifier is lower than the gasifier pressure, it is assumed that the gas inside the gasifier will blow out of the furnace. On the other hand, the gasification efficiency of a gasifier varies depending on various factors, and is also affected by the temperature of the gasifying agent. When the temperature of the gasification agent is high, the amount of heat carried into the gasification furnace increases, so the gasification reaction temperature becomes high and the gasification efficiency improves. However, with a burner equipped with a cooling mechanism, passing a high-temperature gasifying agent causes a decrease in the temperature of the gasifying agent and an increase in the temperature of the coolant. Can not do it. As described above, water-cooled burners have limitations in improving the safety and efficiency of gasifiers. [Object of the Invention] The present invention was made in view of the above circumstances, and its object is to obtain a coal gasification burner that can be used safely and efficiently without using a coolant. [Summary of the Invention] That is, the present invention is characterized by a coal gasification burner provided in the furnace wall of a coal gasification furnace, which penetrates the furnace wall and injects pulverized coal into the gasification furnace. A flow pipe made of a rod-shaped ceramic member that spouts out a mixture with a carrier gas and a gasification agent, and a metal attachment part that fixes the flow pipe to a flange on the outer wall of the furnace;
A circular cross-sectional shape comprising a heat-absorbing sealing member for sealing between the flow pipe and the metal attachment part, and transporting the mixture in the axial direction to the center of the flow pipe made of the ceramic rod-shaped member. The fuel distribution hole has a circular cross-sectional area that is constant in the axial direction, and the fuel distribution hole has a circular cross-sectional shape around the vicinity of the fuel distribution hole and is open in the axial direction, and the cross-sectional area is constant in the axial direction. The reason is that a plurality of constant gasifying agent flow holes are provided. When pulverized coal is transported by gas (air, nitrogen gas, carbon dioxide, etc.) and supplied to the gasifier, the transport speed is 5 to 10 m/s. Also, the flow rate of the gasifying agent is
It is 30-150m/s. As an example, pressure 20Kg/
When trying to supply 10t/d of pulverized coal with one burner to a cm ² G gasifier, the nozzle diameter of the pulverized coal is 6
~8mmφ, gasifying agent nozzle diameter is 6~ for one piece
12mmφ, 2.5~5mmφ in case of 6 pieces. The diameter of these nozzles increases in proportion to the square root of the amount of coal supplied. On the other hand, the length of the rod-shaped member is determined by the distance between the inner wall of the reaction region of the gasifier and the outer wall of the pressure vessel, and is generally close to the thickness of the heat insulating layer. Even in a gasification furnace with the above-mentioned throughput, the length is approximately 300 to 400 mm, and even if scaled up, the length will not become extremely long from this value. A hole of the above diameter, without changing the cross-sectional area,
It is possible to make the rod-shaped member open straight without any special method. Therefore, the burner according to the invention is, for example, shaped like a lotus root or a lotus root. By using such a simple shape, cracking due to stress concentration can be prevented. Next, there is a method of absorbing thermal deformation, but it is necessary to avoid joining with metal or fixing both ends of the burner. In the present invention, the pressure-resistant member is made of metal, the parts that become high temperature are made of ceramic, and the elongation caused by heat is absorbed between the metal and ceramic by a sealing material such as a gland packing. For attachment to the gasifier, the metal member is fixed to a burner attachment flange of the gasifier. The ceramic part should be completely contained within the pressure vessel so that no pressure is applied to it. As ceramic materials are used in a static state, thermal stress is almost negligible, so heat resistance, corrosion resistance, and abrasion resistance are particularly required. Since the tip of the burner is in an oxidizing atmosphere, oxide-based ceramics such as Al ₂ O ₃ -based are preferred. [Embodiments of the Invention] A burner embodying the present invention is shown in FIGS. 1 to 3, and the present invention will be described below with reference to the drawings. In this burner, a pressure vessel 7 is attached to a flange 12 of a gasifier made of an insulating and refractory material 6. The burner basically comprises a fuel introduction pipe 16 such as pulverized coal, a gasification agent introduction pipe 17 such as oxygen gas, a burner attachment part 13, and a flow pipe 5. The mounting part 13 is made of metal,
The flow pipe 5 is made of ceramics. The flow pipe 5 is fixed to a mounting portion 13 via a gland packing 10. The gland packing 10 is fixed by the packing holder 8 by tightening the screw 9. The fuel 1 flowing from the fuel introduction pipe 16 passes through the connecting pipe 11 and enters the fuel flow hole 3 of the flow pipe 5 .
Although the connecting pipe 11 is fixed to the attachment part 13 by welding, it is connected to the flow pipe 5 by grinding, so that the extension of the flow pipe 5 or the connecting pipe 11 can be absorbed. The gasifying agent 2 passes through the gasifying agent introduction pipe 17, enters the gas chamber 15 of the attachment part 13, and from there enters the gasifying agent flow hole 4 of the flow pipe 5. The fuel 1 and the gasification agent 2 react in the gasification reaction chamber 14 at the tip of the flow pipe 5. Figures 2 and 3 show cross sections of the flow pipe. In this embodiment, the fuel flow hole 3 is opened in the center of the flow pipe 5,
Six gasifying agent flow holes 4 were opened concentrically at equal intervals around it. By positioning the gasifying agent flow hole 4 as close to the fuel flow hole 3 as possible and reducing the diameter of the flow tube 5, the amount of radiant heat received by the tip of the flow tube 5 can be reduced. This burner is equipped with a measuring device for monitoring the burner temperature. As shown in FIG. 1, the thermocouple 19 is attached to the flow pipe 5 via the thermocouple fixed terminal 18. As shown in FIG. 2, a thermocouple insertion hole 20 is opened in the flow tube 5 to measure the temperature at the tip of the flow tube. A method of operating a gasifier equipped with a burner according to the present invention will be explained. To start up a gasifier at room temperature and pressure, the temperature of the gasifier is first raised using a gasifier preheater (not shown). In the present invention, prior to this, gas for fuel conveyance is passed through the fuel inlet pipe 16 of the burner, and then the gasifier preheater is operated. Use a propane burner or oil burner for the preheater. The temperature increase of the gasifier may be started under pressure depending on the performance of the preheating burner. The rate of temperature rise depends on the structure and material of the gasifier, but on average it is 100 to 300℃/
The temperature of the gasifier is raised to a temperature at which the fuel can be ignited and the gasification process can proceed directly. During this time, the surface temperature of the heat insulating and refractory material 6 and the temperature of the burner flow pipe 5 also rise, but since the temperature rises at the above rate while the fuel conveying gas is flowing through the flow pipe 5, the temperature of the ceramic due to the thermal change increases. We do not want to prevent any damage or breakage. When the gasifier reaches a predetermined temperature, fuel 1 is supplied from the fuel introduction pipe 16 while the preheating burner is kept operating. If the fuel is a solid such as pulverized coal, the fuel carrier gas is already flowing, so the fuel can be sent simply by operating a fuel supply feeder (not shown). When the gasifier is supplied with fuel, it reacts with the propane or oil combustion air of the preheat burner and burns. Thereafter, the gasifying agent 2 is gradually flowed through the gasifying agent introduction pipe 17 and reacts with the fuel at the tip of the flow pipe 5. Gradually increase the flow rate of the gasifier to a predetermined value while monitoring the temperature of the gasifier. After reaching a predetermined value, the supply of propane or oil and air to the preheating burner is stopped, and the original gasification process begins. Table 1 shows an example of the usage conditions of the burner of the present invention. As a result of testing with a burner having a flow tube made of ceramics containing Al ₂ O ₃ =99.7%, the burner tip temperature showed a temperature of 1480 to 1510°C when the gasifier temperature near the burner was 1770 to 1840°C. The burner of the present invention can be used for a long time under these conditions of use.

【table】

[Table] The company continued to provide a stable supply of pulverized coal. Table 1 shows the case where oxygen was used as the gasifying agent, but Table 2 shows examples where air was used as the gasifying agent. The example is a conventional multi-tube type water-cooled metal burner, and in order to ensure the stability of the burner, the preheating temperature of the air is limited to about 150 to 200°C. As a result, the coal ash melts and is stably discharged from the gasifier as slag.

〔Effect of the invention〕

According to the present invention, fuel and gasifying agent can be stably supplied to the gasifier without using a coolant, so there is an effect that the safety of the gasifier and the gasification efficiency can be improved.

[Brief explanation of drawings]

1 is a longitudinal sectional view of the coal burner of the present invention, FIG. 2 is a detailed longitudinal sectional view of section A in FIG. 1, and FIG. 3 is a sectional view taken along line BB in FIG. 2. 3...Fuel distribution hole, 4...Gasification agent distribution hole, 5...Flow pipe, 1...Fuel, 2...Gasification agent, 14...Gasification reaction chamber.

Claims (1)

[Claims] 1 A coal gasification burner installed on the wall of a coal gasification furnace, which is a rod-shaped ceramic rod that penetrates the furnace wall and spouts a mixture of pulverized coal and carrier gas and a gasifying agent into the gasification furnace. A flow pipe made of a member, a metal attachment part for fixing the flow pipe to a flange on the outer wall of the furnace, and a heat-absorbing seal member for sealing between the flow pipe and the metal attachment part, A fuel flow hole having a circular cross-sectional shape for conveying the mixture in the axial direction is provided in the center of the flow pipe made of the ceramic rod-shaped member, and the circular cross-sectional area of the fuel flow hole is constant in the axial direction. A coal gasification burner comprising a plurality of gasifying agent flow holes having a circular cross-sectional shape around the vicinity of the fuel flow holes, opening in the axial direction, and having a constant cross-sectional area.