JPH02132183A - Recycling system for by-product gas in dry coke extinguishing equipment - Google Patents

Abstract

PURPOSE:To efficiently and safely produce clean by-product gases in a high concentration at low temperatures at a low cost by mounting a cyclone combustion furnace in coke dry extinguishing equipment and producing the by-product gases under specific conditions. CONSTITUTION:Low-temperature by-product gases are fed from a by-product gas duct III 5, inserted and installed in the top of coke dry extinguishing equipment (CDQ) 1 and a by-product gas duct IV 6, inserted and installed in a duct 3 into combustion gases to keep the combustion gas temperature at about 80 deg.C. Gases after completing reaction are passed through the duct 3, fed into a boiler 7 and cooled by heat exchange and dust is removed by the first duct collector 9. The resultant gases are made to flow into an induced blower 10. The by- product gases under boosted pressure therein are then burned and released from a diffusion cylinder 11 during the time of a low CO concentration in the gases at the time of starting or stopping a cyclone coal combustion furnace 2. The gases are further cleaned with the second duct collector 12 and pressurized while the designed value of CO concentration is kept. Part of the gases are subsequently recycled for regulating gas temperature in the CDQ 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is aimed at installing a cyclone coal combustion furnace or the like in an idle coke dry fire extinguishing facility (+i (hereinafter referred to as CDQ) in a steelworks, etc.). There is a combustion gas temperature when a gasification reaction is carried out in a CDQ.

[Conventional technology] Figure 2 shows an example of the prior art.
87) It is a conceptual diagram of a CDQ process flow used in steel works and the like, which cools red-hot coke extruded from a coke oven and recovers waste heat obtained during cooling, as described in J. In Figure 2, 5] is CD
Q, 52 is a baguette transport vehicle, 53 is a coke baguette conveyor 1.
, 54 is a crane, 55 is a charging hopper, 56 is a cooling coke discharge device, 57 is a duct, 58 is a primary dust remover, 59 is a boiler, 60 is a secondary dust remover, and 61 is a circulating gas blower! ). Approximately 800 ~ extruded from the coke oven
Red-hot coke at 900°C is charged into a coke baguette 53 and transported to the vicinity of the CDQ by a packet carrier 52. The transported red hot coke is loaded into a coke packet 53 and lifted up by a crane 54 or the like, and is charged into the CDQ5 1 via the charging hopper 55.The red hot coke charged into the CDQ5 1 is CDQ
5 It is cooled by the boiler 59 fed from the bottom of the furnace 1,
Dust is removed by the primary dust remover 58 and the secondary dust remover 60, and the pressure is increased by the circulating gas blower 61 to approximately 100 to 200°C.
After being cooled by the clean exhaust gas of CDQ5 1
Cooled coke U is discharged from the bottom of the coke to the outside by a discharging device 56. On the other hand, the gas that has cooled the red-hot coke is heated to about 900 to 1000°C, and passes from the top of the CDQ5 1 through the duct 57 to the primary dust remover 58 and the boiler 59.
Then, it is sent to the secondary dust remover 60 where it absorbs heat and removes dust, and most of it is recycled for cooling the red hot coke in CDQ51, while a part of it is released into the atmosphere. [Problem to be solved by the invention] As described above, CDQ was originally manufactured and used for the purpose of cooling red-hot coke, recovering the high-temperature gas used for cooling, and recovering the heat of the high-temperature gas. It's here. Therefore, in order to improve the efficiency of heat recovery, the structure is such that the entire amount of circulating gas is introduced from the bottom of the CDQ. When this CDQ5 1 is shut down due to the suspension of operations of blast furnaces and coke ovens at steel plants, a cyclone coal combustion furnace, etc. is installed in the CDQ, and the combustion discharged from the cyclone coal combustion furnace is carried out in the CDQ5 1. The gas is maintained at a high temperature and a gasification reaction of C+H20→co-t-H2 is performed using, for example, char and water vapor to generate a by-product gas. When attempting to cool the CDQ5 1 exhaust gas in order to prevent the occurrence of talin power troubles in the boiler 59, etc., the position of the exhaust gas inlet for red hot coke cooling in the conventional CDQ51 is used to cool the cyclone coal combustion fed into the CDQ51. There was a problem in that the temperature of the gas generated in the furnace decreased excessively, making it difficult to generate by-product gas from the above reaction in CDQ51. [j! Means for Solving the Problem] A means for solving the above problem is the byproduct gas recirculation system in the CDQ described in the claims. In other words, in equipment that generates byproduct gas by installing a cyclone combustion furnace in coke dry extinguishing equipment, the flow rate of the low-temperature byproduct gas is controlled between the coke dry extinguishing equipment itself and the outlet of the coke dry extinguishing equipment. This is a byproduct gas recirculation system in coke dry extinguishing equipment. Hereinafter, the effects of the present invention will be explained based on examples. [Example] Figure 1 shows an example based on the present invention, in which a cyclone coal combustion furnace is installed in a CDQ, and low-temperature by-product gas is used to control the temperature of high-temperature combustion gas fed into the CDQ. FIG. 2 is a conceptual diagram of a by-product gas recirculation system in CDQ using . In Fig. 1, ■ is a CDQ, 2 is a cyclone coal combustion furnace, 3 is a duct, 4 is a by-product gas duct 1-■, 5 is a by-product gas duct 1[. 6 is a by-product gas duct ■, 7 is a boiler, 8 is a duct, 9 is a primary 4A1m unit, IO is an induced blower, 11 is a dissipation fan, 12 is a secondary dust collector, ] 3 is a boost blower, 14 is a by-product There is a gas duct I. Fuel such as pulverized coal put into the cyclone coal combustion furnace 2 is heated inside the combustion furnace 2 under an atmosphere of high temperature and high heat load by combustion air with a low air-fuel ratio (weight ratio of air to fuel). It burns with strong swirling, and most of the combustion ash adheres to the inner peripheral wall of the combustion furnace 2, melts 7 yen, and is discharged from the lower part of the combustion furnace 2.
Combustion gas at a high temperature of 500°C flows into the CDQI in a state containing a portion of combustion ash and unburned char. In the combustion furnace 2, the reaction 2C-to 0 2→ 2CO mainly takes place by combustion using combustion air with a low air-fuel ratio, but the combustion furnace 2 has a small volume. As a result, the residence time in the combustion furnace 2 from fuel injection to discharge is as short as approximately 0.2 seconds, and the above reaction is not necessarily completed, and a portion of the fuel remains in the CDQl in an unburned char state. Inflow. In CDQ1, the by-product gas is cooled by the boiler 7, removed by the primary dust collector 9, and pressurized by the induced blower].
At the side or bottom of DQI, by-product gas duct 5 is sent to the top of CDQ1. The by-product gas is mixed into the combustion gas at about 1500'C fed from the combustion furnace 2 through the by-product gas duct ■4, and the by-product gas is mixed into the combustion gas at about 1500'C.
In CDQI, where the ambient temperature is maintained at 0°C, char in the combustion gas reacts with water vapor and carbon dioxide, resulting in c+}12o→CO+H. As shown in C+CO■→2CO, CO gas is produced. If combustion gas at approximately 1,200°C is directly fed into the boiler 7, the char or combustion ash in the combustion gas becomes clinker-like, which causes adverse effects on the boiler heat transfer surface. To prevent this, CDQI
By-product gas duct ■5 and duct 3 inserted in the upper part of
A low-temperature by-product gas is fed into the combustion gas from the by-product gas duct ■6 inserted in the duct, and the temperature of the combustion gas is maintained at approximately 800'C. This eliminates the adverse effects on the heat transfer surface of the boiler 7. After the reaction has been completed, the gas is sent to the boiler 7 via the duct 3, cooled by heat exchange, and then dust removed by the primary evaporator 9, and then sent to the induced blower 10.
flows into. The by-product gas pressurized by the induced blower 10 is combusted and released into the atmosphere from the diffusion tube 11 when the CO concentration in the gas is low, such as when the cyclone coal combustion furnace 2 is started or stopped. However, while the COdA degree remains at the planned value, it is further cleaned by the secondary precipitator 12, pressurized to the required value by the booster blower, and then sent to other processes and The part is CDQ
It is returned to CDQI for the purpose of gas temperature regulation within CDQI.

[Effects of the Invention] Since the present invention is configured as described above, it produces the effects described below. In other words, a cyclone coal combustion furnace was installed in the idle CDQ, and the red-hot coke cooling gas inlet, which was originally installed at the bottom of the CDQ, was also installed at the top of the CDQ and in the CDQ outlet duct. By adjusting the flow rate of each gas, it is possible to adjust the gas temperature waste in the CDQ to conditions suitable for continuing the CHAR gasification reaction, and as a result, a low temperature and clean high concentration by-product gas can be produced. It has the effect of being able to generate gas efficiently and safely at low cost.

Figure 2 is an example of a promotion technique.

■...CDQ, 2...Cyclone coal-fired r furnace, 3...Duct, 4...By-product gas duct■, 5...Sub Raw gas dac 1・1■,6・
・・・・By-product Kasdak L・■, 7・・・・Boiler,
8...Duc 1, 9...Primary dust collector, 1
0...Induced blower, 1l, old...dissipation cylinder, 2...
... Secondary dust collector, 13 ... Boosting blower, 14 ...
...Byproduct gas duct 1, 51...CDQ, 5
2...Packet carrier, 53...Coke packet, 54...Crane, 55...
・Charging hopper 56...Cooled coke discharge device,
57...Duct, 58...Primary dust remover, 59...
...Boiler, 00...Secondary removal a! vessel, 6
I... Circulating gas pro.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment based on the present invention, in which a cyclone coal combustion furnace is installed in a CDQ, and low-temperature by-product gas is used to control the temperature of high-temperature combustion gas fed into the CDQ. It is a conceptual diagram of a by-product gas recirculation system in CDQ.

Claims (1)

[Claims] In equipment that generates byproduct gas by installing a cyclone combustion furnace in coke dry extinguishing equipment, low-temperature byproduct gas is sent to the coke dry extinguishing equipment itself and the exit duct of the coke dry extinguishing equipment with flow rate control. A by-product gas recirculation system in coke dry extinguishing equipment.