JP4916922B2 - Coke oven combustion method and combustion apparatus - Google Patents

Description

  The present invention relates to a combustion method and combustion apparatus for a coke oven that centrally manages functions of suppressing carbon adhesion and suppressing small explosions in a combustion chamber of a coke oven that uses high-calorie gas such as COG gas as fuel.

  In general, a coke oven forms one furnace by a pair of carbonization chambers and combustion chambers arranged in a plurality of rows alternately in the furnace width direction (furnace group direction), and usually 50 to 100 furnaces gather to form one furnace. A group is formed. Each combustion chamber is adjacent to the carbonization chamber via a furnace wall (brick wall) and is partitioned into 20 to 40 small combustion chambers in the furnace length direction, and the bottom of each small combustion chamber is a heat storage chamber. (Patent Document 1, FIG. 1).

  Each small combustion chamber is supplied with fuel gas and air preheated in the heat storage chamber for preheating, and by these combustion, the carbonization chambers on both sides are heated through the furnace wall, and dry distillation of coal is performed. The exhaust gas generated in each small combustion chamber was drawn down to the heat recovery heat storage chamber and recovered, and further discharged to the furnace bottom side sole flue, which is a horizontal flue (sole flue) provided at the furnace bottom. The exhaust gas is distributed to the front and rear of the furnace and discharged from the chimney to the atmosphere. The heat storage chamber for preheating and the heat storage chamber for heat recovery are alternately switched at a control cycle of, for example, 20 minutes or 30 minutes.

  FIG. 3 shows the above-described combustion apparatus for a coke oven, in which the small combustion chamber 21 is divided into a first combustion chamber portion 23 and a second combustion chamber portion 24 by a partition wall 22 having a gap between the ceiling wall surface. It has been. Here, the thing related to the first combustion chamber section 23 divided in one small combustion chamber 21 is distinguished by attaching an odd number and the thing relating to the second combustion chamber by attaching an even number. When it is related to combustion and exhaust gas reduction, it is distinguished from that for withdrawal.

  Fuel gas (COG) from the odd fuel gas distribution pipe 25 is supplied to the first combustion chamber section 23 via the odd fuel distribution pipe 27, and combustion air from the furnace bottom side odd sole flue 29 is odd. It is supplied from the air branch pipe 31 through the odd-numbered heat storage chamber 33 (not shown) through the odd-numbered heat storage chamber 33. The fuel gas supplied to the first combustion chamber 23 is mixed with combustion air and combusted, and rises to heat the furnace wall.

  The combustion exhaust gas detours the partition wall 22 as indicated by an arrow, passes through the second combustion chamber portion 24 on the drawing side, passes through the even heat storage chamber (not shown) from the heat storage chamber even communication hole 32, and is even. It is discharged to the furnace bottom side even sole flue 28 through the exhaust gas branch pipe 26.

  The furnace bottom side odd sole flue 29 is connected to a flue (not shown) via an odd number change valve 35, and the furnace bottom side even sole flue 28 is similarly connected to the flue (not shown) via an even number change valve 30. These flues are connected to the chimney.

  When the first combustion chamber portion 23 is used on the combustion side, the odd change valve 35 is maintained in the closed state, the odd air cock 53 is opened, and combustion air is first supplied from the furnace bottom side odd sole flue 29. When the second combustion chamber portion 24 is supplied to the combustion chamber 23 and used on the withdrawal side, the even-numbered air cock 54 is closed and the even-number change valve 30 is opened, and the second combustion chamber portion 24 is opened. Exhaust gas from the chimney to the atmosphere.

  When the second combustion chamber 24 is used for combustion and the first combustion chamber portion 23 is used as the pulling side, the even number change valve 30 is maintained in the closed state, and the odd number change valve 35 is opened.

  On the other hand, when high-calorie gas such as COG is burned as fuel in a coke oven, carbon adheres to the tip of the gas burner in the combustion chamber and the burner, thereby inhibiting combustion.

  When a high operation rate operation is performed in a high calorie gas combustion coke oven, the carbon adhesion increases exponentially with the temperature rise (furnace temperature rise) in the combustion chamber.

  Therefore, as a countermeasure against carbon adhesion, the combustion chamber used as the withdrawal side is switched to use for combustion. Scarfing, which is a burning method, is performed.

  In addition, when combustion using high-calorie gas as fuel in a coke oven, gas accumulation occurs in the duct or piping when switching to combustion, and when scarfing is performed after switching, a small amount is generated in the duct or piping. There is a risk of explosion and damage to the furnace bricks and machinery. For this reason, as a countermeasure against a small explosion, a blowing method by blowing nitrogen gas into the pipe or blowing compressed air is performed.

  In the combustion apparatus of FIG. 3, a blow method by compressed air blowing is used as a countermeasure against small explosions. The compressed air blowing branch pipe 42 branches from the blower pipe 41 connected to the blower fan 40, and the compressed air blowing branch pipe 42 is an odd number. The branch pipe 43 and the even branch pipe 44 branch, and the odd branch pipe 43 is connected to an odd fuel switching cock 47 provided in the odd fuel distribution pipe 27 via an odd scarfing cock 45. Similarly, the even branch pipe 44 is connected to an even fuel switching cock 50 provided in the even fuel distribution pipe 48 via an even scarfing cock 46.

  The odd fuel switching cock 47 and the even fuel switching cock 50 communicate the fuel gas distribution pipe and the combustion chamber at the first switching position, and communicate the scarfing cock and the combustion chamber at the second switching position. The scarfing cock communicates the compressed air blowing branch pipe 42 and the switching cock at the first switching position, and communicates the switching cock with the atmosphere at the second switching position. 51 is an odd adjustment cock for fuel gas that adjusts the flow rate of fuel gas to the first combustion chamber 23, 52 is an even adjustment cock for fuel gas that adjusts the flow rate of fuel gas to the second combustion chamber 24, and 55 is the first adjustment cock. An odd adjustment cock for combustion air that adjusts the amount of combustion air to the combustion chamber 23, 56 is an even adjustment cock for combustion air that adjusts the amount of combustion air to the second combustion chamber 24, and 57 is from the fan 40. It is a ventilation adjustment valve that adjusts the blowing amount or blowing pressure.

When the first combustion chamber portion 23 is used for combustion and the second combustion chamber portion 24 is used for withdrawal, the odd scarfing cock 45 is set to the first switching position, and the even scarfing cock 46 is switched to the second. Switching to the position, the air in the atmosphere is naturally aspirated from the even scarfing cock 46 and supplied to the second combustion chamber 24 to burn off the carbon. Thereafter, the even scarfing cock 45 is switched to the first switching position, and a small explosion countermeasure is taken by blowing the pressure air from the blower fan 40 into the second combustion chamber 24 for a short period of time.
JP 11-035944 A JP 2000-351975 A

  By the way, in the method of burning off air in the atmosphere by introducing air by natural intake as a countermeasure against carbon adhesion, when the coke oven reaches a high operating rate, the amount of air shortage occurs. It is difficult to adjust the amount of air because air is introduced and heat efficiency is reduced.

  As a countermeasure against small explosions, if a blow method using compressed air blowing is employed as shown in FIG. 3, a dedicated piping line and a switching cock are required, resulting in complicated equipment and high equipment costs.

  The present invention has been made in view of such problems, and can supply air for scarfing and blow for countermeasures against small explosions in accordance with the operating rate of the coke oven, and the number of valves such as cocks. It is an object of the present invention to provide a combustion method and a combustion apparatus for a coke oven that can reduce the amount of coal.

  The present invention solves the above technical problem, and the gist of the invention is as follows.

  1. Combustion chamber extending in the length direction of the coke oven is composed of a number of small combustion chambers divided into two combustion chambers. The two combustion chambers are alternately switched between the combustion side and the withdrawal side to generate high calorie gas. In a combustion method of a coke oven in which combustion is performed by mixing with combustion air as fuel, the air blown during the combustion switching before scarfing, where the compressed air from the air blowing means with variable air flow is drawn into the combustion chamber on the side. It is characterized by having a blow process in which the compressed air from the means is made larger than that during the scarfing and is blown into the fuel piping system of the combustion side and the withdrawal side combustion chamber.

  2. Combustion chamber extending in the length direction of the coke oven is composed of many small combustion chambers divided into two combustion chamber portions, and the two combustion chamber portions are alternately switched between the combustion side and the withdrawal side, and each combustion chamber portion In a combustion apparatus of a coke oven that burns by mixing high-calorie gas as fuel with combustion air by switching the fuel switching cock corresponding to the above, supplying a blowing means capable of adjusting the amount of blowing air and compressed air from the blowing means A shutoff valve attached to the blower pipe, and a branch pipe branched from the blower pipe downstream from the shutoff valve and connected to each of the fuel switching cocks. At the time of scarfing when the compressed air from the means is pulled down and introduced into the combustion chamber portion on the side, the communication between the combustion chamber portion on the combustion side and the branch pipe is cut off and positioned at the first position where fuel is supplied, Fuel on the withdrawal side The replacement cock is positioned at a second position communicating with the branch pipe and the combustion chamber on the draw-down side, and during the combustion switching before the scarfing, the shut-off valve is opened so that the air volume of the compressed air from the blowing means is increased. Blow is blown toward the combustion switching cock and the withdrawal fuel switching cock located at the second position more than at the time of scarfing.

  According to the present invention, it is possible to realize scarfing by forced ventilation and blowing of a small explosion countermeasure blow by a single air blowing means, and also eliminate the need for a scarfing (SF) cock as in the conventional natural suction method. Therefore, the equipment can be simplified and the cost can be reduced.

  In addition, since the air flow rate of the air blowing means is variable, even if the operating rate of the coke oven fluctuates, the air flow rate for scarfing and blow for countermeasures against small explosions can be increased or decreased in accordance with the fluctuation of the operating rate. it can.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

  FIG. 1 is a schematic diagram showing an embodiment of a combustion apparatus for a coke oven to which the present invention is applied. The same members as those shown in FIG. In addition, an odd number is assigned to those relating to the first combustion chamber section 23 and an even number is assigned to those relating to the second combustion chamber. Is the same as the description of the conventional example in that it is distinguished from that for withdrawal.

  In the present embodiment shown in FIG. 1, air is supplied to the blower pipe 41 by the fan 1 that can adjust the amount of blown air by inverter control, and the shutoff valve 2 is attached on the way to stop the supply of air.

  An odd branch pipe 43 further branched from the compressed air blowing branch pipe 42 branched from the blow pipe 41 is connected to an odd fuel switching cock 47 which is a three-way cock, and similarly, the even branch pipe 44 is a three-way cock. The even fuel switching cock 50 is connected. In the conventional example shown in FIG. 3, the scarfing cocks 45 and 46 that are two-way cocks are used to carry out scarfing with air by natural intake, but in this embodiment, scarfing is performed by forced ventilation.

  That is, in FIG. 1, the even fuel switching cock 50, which is a three-way cock provided in the even fuel distribution pipe 48, is switched to the second position (a switching position where the even branch pipe 44 and the second combustion chamber portion 24 communicate with each other). Therefore, when the shut-off valve 2 is opened, the pressure air from the fan 1 is sent from the pressure air blowing branch pipe 42 to the even fuel switching cock 50 through the even branch pipe 44 and forced ventilation into the second combustion chamber portion 24. Is done.

  The scarfing is controlled so as to reduce the amount of blown air by inverter control of the fan 1 in order to perform gentle combustion.

  On the other hand, in this embodiment, the fan 1 is also used for blow for small explosion countermeasures. The blow for small explosion measures instantaneously draws a large amount of air and supplies it to the combustion chamber on the side, so that the amount of air blown by the inverter control of the fan 1 is made larger than the amount of air blown during scarfing. To control. At that time, the shutoff valve 2 is opened.

  In this way, by enabling control of the air flow rate of the fan 1, scarfing by forced ventilation and small explosion countermeasure blow can be operated by the same piping system, from the end of scarfing operation to the start of small explosion countermeasure blow. In the meantime, by closing the shutoff valve 2, it is possible to prevent the exhaust gas in the combustion chamber on the draw-down side from flowing back from the fuel distribution pipe on the draw-down side to the blower pipe 41.

  In the present embodiment, the flow rate of the fan 1 for scarfing by forced ventilation and blow for preventing small explosions is shown by the inverter control function of the fan 1, but a flow rate control valve or a pressure control valve is provided, It is also possible to control the pressure.

  Moreover, it is preferable to change the setting of the amount of air flow for scarfing by forced ventilation according to the operating rate of the coke oven. For example, when the operation rate is high, the carbon deposition amount increases, so the air flow rate for scarfing is set high, and the air flow rate for carbon combustion is increased, and when the operation rate is low, the air flow rate for scarfing is set low. And it is preferable to prevent that air is introduced more than necessary and thermal efficiency falls.

  The odd-numbered air cock 53 is opened to supply combustion air to the first combustion chamber portion 23 of the small combustion chamber 21, and the odd-numbered fuel switching cock 47 is switched to the first position so that COG or the like is supplied from the odd-numbered fuel gas pipe 25. The high-calorie gas is supplied to burn the fuel gas, and the exhaust gas is drawn down from the heat storage chamber even communication hole 32 of the second combustion chamber 24 and is drawn down to the furnace bottom side even sole flue 28 through the side heat storage chamber. At that time, scarfing is performed, and after the supply of the fuel gas to the first combustion chamber portion 23 is stopped, a small explosion countermeasure blow operation is performed. Thereafter, the combustion is switched from the first combustion chamber portion 23 to the second combustion chamber portion 24. The flow rate of the fuel gas supplied to the first combustion chamber portion 23 and the second combustion chamber portion 24 is adjusted by the odd adjustment cock 51 for fuel gas and the even adjustment cock 52 for combustion gas, and the first combustion chamber portion 23 and The flow rate of the combustion air supplied to the second combustion chamber section 24 is adjusted by the combustion air odd adjustment cock 55 and the combustion air even adjustment cock 56.

  The above series of combustion operations will be described below with reference to the timing chart shown in FIG.

  In FIG. 2, the odd combustion for the COG cock shows the odd fuel switching cock 47 which is the three-way cock of FIG. 1, and the even combustion for the COG cock shows the even fuel switching cock 50 which is the three-way cock. The odd combustion for the AIR cock shows the odd air switching cock 53 in FIG. 1, and the even combustion for the AIR cock shows the even air switching cock 54. 1 for odd-numbered withdrawal of the change valve indicates the odd-numbered change valve 35 of FIG. 1 and for even-numbered withdrawal indicates the even-numbered change valve 30 of FIG. The odd number change valve 35 and the even number change valve 30 are shown in the closed state. The odd air switching cock 53 and the even air switching cock 54 can adjust the air flow rate by adjusting the valve opening.

  In the item of scarfing (SF), the shut-off valve indicates the shut-off valve 2 in FIG. 1, and the blower indicates the blower 1 in FIG. 1, and the height represents the magnitude of the ventilation rate per unit time. Moreover, AIR ventilation shows either scarfing or a small explosion countermeasure blow.

  In FIG. 2, odd-numbered F combustion indicates combustion in the odd-numbered combustion chamber 23, and even-numbered F combustion indicates combustion in the even-numbered combustion chamber 24. Further, in the intermediate stop, the fuel gas is not supplied to the odd combustion chamber 23 and the even combustion chamber 24 between the odd F combustion and the even F combustion, and the odd air cock 53 and the even air cock 54 are opened. An air amount smaller than the air amount at the time of combustion is supplied to the furnace bottom side odd sole flue 29 and the furnace bottom side even sole flue 28, and both the odd number change valve 35 and the even number change valve 30 are in the open state.

  During the intermediate stop, the odd-numbered air cock 53 and the even-numbered air cock 54 are not fully closed, but are slightly opened, and a minute amount of air is supplied to the furnace bottom-side odd sole flue 29 and the furnace bottom-side even sole flue 28. This is for preventing surging of the blower when the fuel air is supplied by the blower for fuel air.

  In the case of odd-number F combustion in which combustion is performed in the first (odd) combustion chamber section 23, the odd-numbered air cock 53 is opened and combustion air is supplied to the odd-number combustion chamber section 23, and then the odd-number fuel switching cock 47 is set to the first position. The fuel gas COG is switched to be supplied to the odd combustion chamber portion 23 and the fuel gas supply is stopped by switching the odd fuel switching cock 47 to the second position before the intermediate stop, but the odd air cock 53 is open. Until an intermediate stop.

  The odd change valve 35 is closed simultaneously with the switching of the odd air cock 53 to the open state, and the closed state is maintained until the start of the intermediate stop where the combustion is switched. The even number change valve 30 is maintained in an open state when the odd number change valve 35 is closed, and discharges exhaust gas from the furnace bottom side even sole flue 28 to the chimney.

  On the other hand, the even fuel switching cock 50 is switched to the second position. When the shutoff valve 2 is opened by controlling the blower 1 so as to reduce the air flow rate, the even number combustion chamber 24 is scarfed. Air is ventilated. Once the shutoff valve 2 is closed and the supply of the fuel gas to the odd-numbered combustion chambers 23 is stopped, the shutoff valve 2 is opened again and a blow for small explosion countermeasures is ventilated from the blower 1 into the pipe. This blow for small explosion measures increases the amount of blown air by inverter control of the blower 1. After that, an intermediate stop occurs.

  Then, the combustion is switched from the combustion in the odd-numbered combustion chamber to the combustion in the even-numbered combustion chamber. Similarly, the fuel gas and the combustion air are supplied into the even-numbered combustion chamber 24, and the above-described scarfing is performed in the odd-numbered combustion chamber 23. The exhaust gas from the odd combustion chamber 23 side is discharged from the furnace bottom side odd sole flue 29 to the chimney.

  That is, the small explosion countermeasure blow is executed during the combustion switching before the scarfing, and both the odd fuel switching cock 47 and the even fuel switching cock 50 are switched to the second position. Blow is instantaneously blown into the distribution pipe 48 and the remaining fuel gas and the like are discharged into the first combustion chamber portion 23 and the second combustion chamber portion 24. At that time, since the odd-numbered air cock 53 is open and air is supplied into the first combustion chamber portion 23, the fuel gas or the like exhausted by the blow burns, and is discharged from the second combustion chamber portion 24 as exhaust gas. It is discharged to the chimney through the bottom-side even sole flue 28.

Schematic which shows the combustion apparatus of the coke oven which shows one Embodiment of this invention. The timing chart which shows the combustion method of the combustion apparatus of FIG. Schematic which shows the combustion apparatus of the conventional coke oven.

Explanation of symbols

1 Blower 2 Shut-off Valve 21 Small Combustion Chamber 22 Partition Wall 23 First Combustion Chamber (Odd Combustion Chamber)
24 Second combustion chamber (even number combustion chamber)
25 Odd fuel gas distribution pipe 26 Even exhaust gas branch pipe 27 Odd fuel distribution pipe 28 Furnace bottom side even sole flue 29 Furnace bottom side odd sole flue 30 Even number change valve 31 Odd air branch pipe 32 Heat storage chamber even communication hole 35 Odd change valve 40 Blowing fan 41 Blowing pipe 42 Pressure air blowing branch pipe 43 Odd branch pipe 44 Even branch pipe 45 Odd scarfing cock 46 Even scarfing cock 47 Odd fuel switching cock 48 Even fuel distribution pipe 50 Even fuel switching cock 51 Odd adjustment for fuel gas Cock 52 Even adjustment cock 53 for fuel gas Odd air switching cock 54 Even air switching cock 55 Odd adjustment cock 56 for combustion air Even adjustment cock 57 for combustion air Blow adjustment valve

Claims (2)

Combustion chamber extending in the length direction of the coke oven is composed of a number of small combustion chambers divided into two combustion chambers. The two combustion chambers are alternately switched between the combustion side and the withdrawal side to generate high calorie gas. In a combustion method of a coke oven that performs combustion by mixing with combustion air as fuel,
During combustion switching before scarfing, the compressed air from the air blowing means with variable air flow is drawn down and introduced into the combustion chamber on the side, the pressure air from the air blowing means is increased more than that during the scarfing and the combustion side and the air drawn down. A combustion method for a coke oven, comprising: a blow step for blowing into a fuel piping system in a side combustion chamber. Combustion chamber extending in the length direction of the coke oven is composed of many small combustion chambers divided into two combustion chamber portions, and the two combustion chamber portions are alternately switched between the combustion side and the withdrawal side, and each combustion chamber portion In a combustion apparatus of a coke oven that performs combustion by mixing high-calorie gas as fuel with combustion air by switching the fuel switching cock corresponding to
An air blowing means capable of adjusting the air flow;
A shutoff valve attached to a blower pipe for supplying compressed air from the blower means;
A branch pipe branched from the blower pipe downstream from the shutoff valve and connected to each of the fuel switching cocks;
Have
During scarfing in which the shutoff valve is opened and the compressed air from the blowing means is pulled down and introduced into the combustion chamber portion on the side, the communication between the combustion chamber portion on the combustion side and the branch pipe is shut off to supply fuel The fuel switch cock on the draw-down side is located at a second position communicating with the branch pipe and the combustion chamber on the draw-down side during the combustion switching before the scarfing. Opening a shut-off valve to increase the amount of compressed air from the blowing means more than at the time of the scarfing, and blowing blow toward the combustion side and withdrawal side fuel switching cocks located at the second position. Coke oven combustion equipment.

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