JP2020041098A - Coke dry extinguishment facility and method for removing coke dust from boiler of coke dry extinguishment facility - Google Patents

Abstract

To provide the coke dry extinguishment facility and the method for removing the coke dust from the boiler of the coke dry extinguishment facility, that can remove the coke dust deposited and attached to the boiler.SOLUTION: The coke dry extinguishment facility 100 comprises: a chamber 10; a dust collector 20 including a cyclone; a boiler 30; a first duct 40 connecting the chamber 10 and the cyclone 20; a second duct 50 connecting the cyclone 20 and the boiler 30, and a third duct 60 connecting the boiler 30 and the chamber 10, wherein the coke dust collected by the dust collector 20 is supplied to the boiler 30 as removal dust for removing the coke dust accumulated in the boiler 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coke dry fire extinguishing facility and a method for removing coke dust in a boiler of a coke dry fire extinguishing facility.

Coke dry quenching equipment (CDQ: Coke Dry Quenching) is equipment that cools red hot coke steamed in a coke oven and produces high-temperature, high-pressure steam using the recovered heat. It is commonly used as power for production and process steam. The CDQ mainly has two heat exchangers, a chamber and a boiler. In the chamber, a circulating cooling gas (in which nitrogen is a main component, CO ₂ , H ₂ O, a small amount of CO, red hot coke is cooled by utilizing the gas, etc.) that contains H _2. The chamber and the boiler are connected to a primary dust collector (primary dust catcher) via a first duct, and further connected to the boiler via a second duct. The boiler is connected to a secondary dust collector (secondary dust catcher) via a third duct, and is connected to a chamber via a third duct via a blower such as a gas blower.

  When the flow and action of the circulating cooling gas in the CDQ are outlined, a low-temperature circulating cooling gas of, for example, 200 ° C. or less is supplied to the lower part of the chamber by a blower constituting the circulating equipment, and the circulating cooling gas rises upward in the chamber. In the process, the hot red coke is cooled by contact with the hot red hot coke falling from above. Then, the circulating cooling gas heated by the contact with the red hot coke passes through the ring duct on the outer periphery above the chamber, enters the primary dust catcher from the first duct, and flows from the primary dust catcher to the boiler. As described above, the circulating cooling gas contains unburned gas such as CO. In order to complete the combustion reaction of the unburned gas before the circulating cooling gas reaches the inlet of the boiler, the unburned gas is unburned. An air introduction passage for gas combustion is provided in a ring duct or the like above the chamber, from which combustion air is introduced and supplied to the circulating cooling gas. Thus, by completing the combustion of the unburned gas before the circulating cooling gas reaches the boiler, the temperature of the circulating cooling gas can be increased to increase the amount of heat recovered by the boiler. The temperature of the circulating cooling gas rising from the chamber to the ring duct is raised to about 800 to 900 ° C., and the circulating cooling gas is further heated to 1000 ° C. by supplying combustion air to the circulating cooling gas. It becomes a high temperature atmosphere.

  By the way, the circulating cooling gas flowing through the first duct generally contains a large amount of coke dust having a high abrasion property, but about 20 to 30% of the entire coke dust is roughly collected by a primary dust catcher. The remaining coke dust is collected by the secondary dust catcher. As described above, since the efficiency of collecting the coke dust in the primary dust catcher is low, in the conventional coke dry-type fire extinguishing equipment, abrasion due to the coke dust in the boiler has been a problem. Therefore, as a measure for preventing the wear, a wear-resistant material (sprayed material) is applied in the boiler, and a low flow rate control of the circulating cooling gas in the system of the equipment has been performed. However, since such measures for preventing abrasion particularly cause the cost and scale of the boiler to increase, the measures for preventing abrasion caused by coke dust in the boiler have had a great effect on the manufacturing cost of the entire equipment.

  In order to solve such a problem, by applying an air introduction path provided in a ring duct or the like above the chamber to a second duct connecting the primary dust collector and the boiler, a temperature of about 800 to 900 ° C. can be obtained. A coke dry fire extinguishing system has been proposed in which the suppressed circulating cooling gas can be introduced into a primary dust collector, whereby a cyclone can be applied to the primary dust collector (for example, see Patent Document 1). If a high-temperature circulating cooling gas of about 1000 ° C. is supplied to the cyclone, it becomes difficult to employ a general heat-resistant steel such as stainless steel as a material for forming the cyclone. Since it must be used, the problem of equipment cost cannot be solved. According to the coke dry fire extinguishing equipment described in Patent Document 1, by supplying a relatively low-temperature circulating cooling gas to the primary dust catcher, it is possible to apply a cyclone to the primary dust catcher to collect coke dust. Efficiency can be increased and a secondary dust catcher can be eliminated.

Japanese Patent No. 5202751

  By applying a cyclone to a dust collector upstream of the gas flow of a boiler as in the coke dry fire extinguishing equipment described in Patent Document 1, most of the coke dust is collected by the cyclone. Therefore, coke dust scattered from the cyclone into the boiler via the secondary duct is only coke dust having a small particle diameter. By the way, coke dust having a small particle diameter tends to adhere to a heat transfer tube or the like in a boiler and accumulate. When coke dust having a small particle diameter adheres to and accumulates on the heat transfer tube, the heat transfer area of the heat transfer tube decreases, and this decrease in the heat transfer area leads to a decrease in steam production capacity of the boiler. In the coke dry fire extinguishing system in which the primary dust collector roughly collects about 20 to 30% of the entire coke dust, although there is a problem of abrasion in the boiler as described above, coke dust having a small particle diameter is generated. There was almost no phenomenon of adhesion and deposition, and the problem of a decrease in the heat transfer area of the heat transfer tube did not appear.

  Therefore, it is necessary to remove small-sized coke dust adhered to and deposited on the heat transfer tube or the like in the boiler. However, removal of this small particle size coke dust involves various difficulties. First, since the circulating cooling gas flowing into the boiler has a very high temperature of about 1000 ° C., it is necessary to provide a removal device having a heat resistance of about 1000 ° C. or more. Further, since it is general that heat transfer tubes are arranged at a narrow pitch in a boiler to form a heat transfer tube group, coke dust in the heat transfer tube group is removed by wiping off or the like. There is a need. When a fin type heat transfer tube is applied to the heat transfer tube, it is necessary to remove coke dust accumulated between the fins, but this removal is extremely difficult. Furthermore, the boiler has a water-cooling wall or a hanging tube that hangs a heat transfer tube from the ceiling of the boiler.Coke dust adheres to the water-cooling wall and the hanging tube in addition to the heat transfer tube. Therefore, the coke dust needs to be widely removed in the boiler.

  The present invention has been made in view of the above problems, and is capable of removing coke dust adhering and accumulating in a boiler, coke dry fire extinguishing equipment, and coke dust removal in a boiler of a coke dry fire extinguishing equipment. It is intended to provide a way.

In order to achieve the above object, one embodiment of a coke dry fire extinguishing system according to the present invention includes a chamber, a dust collector including a cyclone, a boiler, a first duct connecting the chamber and the cyclone, and connecting the cyclone and the boiler. A circulating cooling gas flows in a system of a coke dry fire extinguishing system having a second duct and a third duct connecting the boiler and the chamber, and coke in which the coke dust in the circulating cooling gas is collected by the dust collector. Dry fire extinguishing equipment,
The coke dust collected by the dust collector is supplied to the boiler as removal dust for removing coke dust accumulated in the boiler.

  According to this aspect, the boiler is provided with a special removal facility or the like by supplying coke dust collected in the cyclone to the boiler as removal dust for removing coke dust accumulated in the boiler. Without removing the coke dust accumulated in the boiler. Compared with coke dust accumulated in the boiler, coke dust of relatively large particle size is collected in the cyclone, so this relatively large particle size of coke dust is applied to dust for removal. Things. In the conventional coke dry-fire extinguishing equipment, the large-diameter coke dust has caused abrasion of the equipment in the boiler. It enables the removal of small particle size coke dust. According to the empirical rule of the present inventors, the average particle size of the small particle size coke dust accumulated in the boiler is in the range of about 20 μm to 30 μm. On the other hand, the particle diameter of coke dust collected by the cyclone is about 30 μm to 5 mm.

  In another aspect of the coke dry fire extinguishing system according to the present invention, the supply of the coke dust collected by the dust collector into the boiler is performed intermittently.

  According to this aspect, the coke dust collected in the cyclone is intermittently supplied into the boiler, thereby suppressing the wear of the equipment in the boiler and coke having a small particle diameter accumulated in the boiler. Dust can be removed. Here, `` intermittent supply '' means that the supply of coke dust collected in the cyclone to the boiler is performed for a relatively short time, then the supply is stopped, and the operation of the coke dry-type fire extinguishing equipment is performed for a certain period of time. After that, it means running the next coke dust to the boiler for a relatively short time. For example, after supplying coke dust to the boiler for about 10 minutes to remove coke dust having a small particle size deposited in the boiler, the supply of coke dust is stopped, and the coke dry-type fire extinguishing equipment for several hours is stopped. After the operation, a control mode in which the coke dust is supplied to the boiler for about 10 minutes can be given.

Further, another aspect of the coke dry fire extinguishing equipment according to the present invention is such that in the system of the coke dry fire extinguishing equipment, the circulating cooling gas flows from the chamber to the boiler via the first duct and the second duct, Flowing from the boiler through the third duct to the chamber,
A fourth duct extends from the dust collector,
A blower is interposed in the third duct, and in the third duct, a fifth duct branches from a position on the gas flow downstream side of the blower and communicates with the second duct or the boiler,
Coke dust supplied from the dust collector to the fifth duct via the fourth duct is supplied to the boiler from the second duct with a circulating cooling gas, or supplied directly to the boiler with a circulating cooling gas. It is characterized by that.

  According to this aspect, by using the high-pressure circulating cooling gas from the blower, the coke dust collected by the cyclone can be air-flowed to the boiler via the second duct. As described in Patent Document 1, the second duct has a rising portion that rises upward from the top of the cyclone, and a horizontal portion that is bent from the rising portion and extends in the horizontal or substantially horizontal direction. In this embodiment, the communication point of the fifth duct to the second duct may be a rising portion or a horizontal portion. In this aspect, the fifth duct may be in direct communication with, for example, the upper space of the boiler. In this case, coke dust is directly transported to the boiler via the fifth duct.

Another aspect of the coke dry fire extinguishing system according to the present invention is a sixth duct extending from the dust collector, directly or indirectly communicating with a pressurized tank, and extending from the dust collector. Communicates with the second duct,
The coke dust supplied from the dust collector to the pressurized tank via the fourth duct is supplied to the second duct via the sixth duct by a circulating cooling gas or an inert gas pressurized in the pressurized tank. And supplied from the second duct to the boiler.

  According to this aspect, by using the circulating cooling gas or the inert gas pressurized in the pressurized tank, the coke dust collected in the cyclone can be air-flow conveyed to the boiler through the second duct. it can. Here, in "the fourth duct extends and communicates directly or indirectly with the pressurized tank", "indirectly communicates" means, for example, a conveyor or the like below the fourth duct, This means a mode in which coke dust is conveyed by a conveyor via a fourth duct, then the coke dust is stored in a storage tank, and the coke dust is supplied from the storage tank to a pressurized tank. The pressurized tank communicates with a duct extending from the inert gas supply source or a branch duct branched from a position downstream of the gas flow from the blower in the third duct. Supplies a circulating cooling gas or an inert gas. After the gas is pressurized in the pressurized tank, the open / close valve on the outlet side of the pressurized tank is opened, so that the coke dust can be conveyed by the pressurized circulating cooling gas or inert gas. Also in this embodiment, when the second duct has a rising portion and a horizontal portion, the communicating portion of the sixth duct to the second duct may be a rising portion or a horizontal portion. You may.

In another aspect of the coke dry fire extinguishing equipment according to the present invention, the dust collector has a classification screen,
The coke dust collected by the dust collector is passed through the classification screen to select coke dust having a predetermined particle size range, and the selected coke dust is supplied to the fourth duct.

  According to this aspect, of the coke dust collected by the cyclone, coke dust having a particle size range suitable for removing coke dust accumulated in the boiler can be selected and supplied to the boiler. For example, as described above, coke dust having a large particle size range of about 0.5 mm to 5 mm can be selected and supplied to the boiler from a wide particle size range of about 30 μm to 5 mm.

One embodiment of a method of removing coke dust in a boiler of a coke dry-type fire extinguishing system according to the present invention includes a chamber, a dust collector including a cyclone, a boiler, a first duct connecting the chamber and the cyclone, the cyclone, A circulating cooling gas flows in a system of a coke dry fire extinguishing system having a second duct connecting the boiler and a third duct connecting the boiler and the chamber, and coke dust in the circulating cooling gas is collected by the dust collector. In a coke dry-type fire extinguishing system, a method of removing coke dust accumulated in the boiler, a method of removing coke dust in a boiler of a coke dry-type fire extinguishing system,
The coke dust collected by the dust collector is supplied to the boiler as removal dust for removing coke dust accumulated in the boiler.

  According to this aspect, the boiler is provided with a special removal facility or the like by supplying coke dust collected in the cyclone to the boiler as removal dust for removing coke dust accumulated in the boiler. Without removing the coke dust accumulated in the boiler.

  Another aspect of the method for removing coke dust in a boiler of a coke dry-type fire extinguishing system according to the present invention is characterized in that supply of coke dust collected by the dust collector into the boiler is performed intermittently. And

  According to this aspect, the coke dust collected in the cyclone is intermittently supplied into the boiler, thereby suppressing the wear of the equipment in the boiler and coke having a small particle diameter accumulated in the boiler. Dust can be removed.

Another aspect of the method for removing coke dust in a boiler of a coke dry fire extinguishing system according to the present invention is that in the system of the coke dry fire extinguishing system, the circulating cooling gas is supplied from the chamber to the first duct and the second duct. Flowing to the boiler via a duct, from the boiler to the chamber via the third duct,
A fourth duct extends from the dust collector,
A blower is interposed in the third duct, and a fifth duct branches off from a position on the gas flow downstream side of the blower in the third duct and communicates with the second duct.
The coke dust supplied from the dust collector to the fifth duct via the fourth duct is conveyed to the second duct by a circulating cooling gas, and is supplied to the boiler from the second duct.

  According to this aspect, by using the high-pressure circulating cooling gas from the blower, the coke dust collected by the cyclone can be air-flowed to the boiler via the second duct.

In another aspect of the method for removing coke dust in a boiler of a coke dry fire extinguishing system according to the present invention, a fourth duct extends from the dust collector and communicates directly or indirectly with a pressurized tank, and A sixth duct extending from the tank communicates with the second duct,
Coke dust supplied from the dust collector to the pressurized tank via the fourth duct is conveyed to the second duct via the sixth duct by a circulating cooling gas or an inert gas pressurized in the pressurized tank. And it supplies to the said boiler from this 2nd duct.

  According to this aspect, by using the circulating cooling gas or the inert gas pressurized in the pressurized tank, the coke dust collected in the cyclone can be air-flow conveyed to the boiler through the second duct. it can.

In another aspect of the method for removing coke dust in a boiler of a coke dry-type fire extinguishing system according to the present invention, the dust collector has a classification screen,
The coke dust collected by the dust collector is passed through the classification screen to select coke dust having a predetermined particle size range, and the selected coke dust is supplied to the fourth duct.

  According to this aspect, of the coke dust collected by the cyclone, coke dust having a particle size range suitable for removing coke dust accumulated in the boiler can be selected and supplied to the boiler.

  As can be understood from the above description, according to the coke dry extinguishing equipment of the present invention and the method for removing coke dust in the boiler of the coke dry extinguishing equipment, it is possible to remove the coke dust attached and accumulated in the boiler. Can be.

It is a mimetic diagram showing the schematic structure of the coke dry fire extinguishing equipment concerning a 1st embodiment. It is a schematic diagram which shows the internal structure of a boiler. FIG. 3 is a diagram illustrating an example of a hardware configuration of a controller. It is a mimetic diagram showing the schematic structure of the coke dry type fire extinguishing equipment concerning a 2nd embodiment.

  Hereinafter, a coke dry extinguishing system and a method for removing coke dust from a boiler of the coke dry extinguishing system according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the specification and the drawings, substantially the same components are denoted by the same reference numerals, and redundant description may be omitted.

[First Embodiment]
<Basic configuration of coke dry fire extinguishing equipment>
First, a coke dry fire extinguishing facility according to a first embodiment and a method for removing coke dust in a boiler of a coke dry fire extinguishing facility will be described with reference to FIGS. FIG. 1 is a schematic diagram showing a schematic configuration of a coke dry fire extinguishing facility according to the first embodiment, and FIG. 2 is a schematic diagram showing an internal configuration of a boiler. FIG. 3 is a diagram illustrating an example of a hardware configuration of the controller. As shown in FIG. 1, the coke dry fire extinguishing system 100 includes a chamber 10, a dust collector 20 including a cyclone, a boiler 30, a first duct 40 connecting the chamber 10 and the cyclone 20, and a second duct 40 connecting the cyclone 20 and the boiler 30. It has a second duct 50, a third duct 60 connecting the boiler 30 and the chamber 10, and a controller 80 for controlling the opening / closing and opening of various on-off valves and the like. In FIG. 1, the command signal line from the controller 80 is branched from the on-off valve 71 a of the fourth duct 71 immediately below the cyclone 20 and the gas flow downstream of the blower 61 (such as a circulation fan) of the third duct 60. Only the on-off valve 72a of the fifth duct 72 is shown. However, the command signal line from the controller 80 is in principle connected to all the on-off valves shown in the figure, and the command signal can be transmitted from the controller 80 to each on-off valve. This on-off valve is a valve whose opening degree can be adjusted in addition to opening and closing of the valve. Further, a temperature sensor (not shown) is provided at an appropriate place in the system, and a measurement signal from the temperature sensor is transmitted to the controller 80. Based on the measured temperature (such as the temperature of the circulating cooling gas and the temperature in the boiler) at each location, the controller 80 receives the temperature of the circulating cooling gas circulating in the system, for example, so that the temperature at each location becomes a predetermined temperature (range). Control.

  The main circulation route of the circulating cooling gas in the coke dry fire extinguishing system 100 is as follows. That is, the ring cooling gas flows from the chamber 10 to the first duct 40 in the X1 direction, flows from the first duct 40 to the cyclone 20 in the X2 direction, flows from the cyclone 20 to the second duct 50 in the X3 direction, and flows to the boiler 30 in the X4 direction. Enter the direction. The circulating cooling gas flowing through the boiler 30 flows in the third duct 60 in the X5 direction, and is supplied with flow velocity energy by a blower 61 provided at an intermediate position of the third duct 60 to flow in the third duct 60 in the X6 direction. A preheater 62 is interposed in the third duct 60, and the circulating cooling gas flows into the preheater 62 in the X7 direction, and then flows into the chamber 10. The preheater 62 is a heat exchanger such as an economizer, and preheats water by sensible heat of the circulating cooling gas flowing through the third duct 60, and the preheated water is supplied to the boiler 30 as water for generating steam.

  The chamber 10 is provided with a pre-chamber 12 for temporarily storing red hot coke fed through the coke input device 13, and communicates with the pre-chamber 12 to cool the red hot coke with the circulating cooling gas blown into the chamber 10. And a cooling chamber 11. Further, the chamber 10 has a ring duct 15 that is provided outside and above the cooling chamber 11, communicates with the cooling chamber 11, and communicates with one end of the primary duct 40. Further, the chamber 10 has a coke discharging device 14 that discharges coke cooled by the circulating cooling gas to the outside of the chamber 10 at a position below the cooling chamber 11. The circulating cooling gas blown into the cooling chamber 11 is a low-temperature gas of, for example, about 150 ° C. or less, and the circulating cooling gas comes into contact with red-hot coke while flowing upward in the X8 direction, and the temperature rises to about 800 to 900 ° C. Then, the circulating cooling gas whose temperature has been increased flows into the first duct 40.

  The second duct 50 extending upward from the top of the cyclone 20 has a rising portion 51 rising upward, and a horizontal portion 52 bent from the rising portion 51 and extending in the horizontal or substantially horizontal direction. . The rising portion 51 of the second duct 50 communicates with an air introduction duct 53 having an on-off valve 53a. The air introduction duct 53 may have an air introduction system that has a blower (not shown) and forcibly introduces outside air, in addition to an air introduction system that naturally introduces outside air.

  In the coke dry fire extinguishing system 100, the circulating cooling gas at about 800 to 900 ° C. flows into the dust collector 20, and most of the coke dust contained in the circulating cooling gas is collected by the cyclone dust collector 20, and after dust removal. Circulating cooling gas is introduced into the second duct 50.

Air is introduced into the second duct 50 in the Y1 direction via the air introduction duct 53, and the introduced air is supplied to the circulating cooling gas flowing through the second duct 50. Here, the circulating cooling gas is a gas that contains nitrogen as a main component and also contains unburned H ₂ and CO in addition to CO ₂ and H ₂ O. By supplying air to the circulating cooling gas through the air introducing duct 53, the temperature of the circulating cooling gas is raised to about 1000 ° C., such as unburned H ₂ and CO is completely burned. By supplying the circulating cooling gas thus heated to the boiler 30, the amount of heat recovered by the boiler 30 can be increased. In addition, the temperature of the circulating cooling gas introduced into the dust collector 20 is suppressed to about 900 ° C. or less, and the temperature of the circulating cooling gas is increased to about 1000 ° C. downstream of the gas flow of the dust collector 20, so that the dust is collected in the dust collector 20. It becomes possible to apply a highly efficient cyclone.

  As shown in FIG. 2, the boiler 30 has a water cooling wall 31, and inside the water cooling wall 31, an economizer heat transfer tube 33 forming an economizer and an evaporator heat transfer tube 34 forming an evaporator. And a primary superheater heat transfer tube 35 forming a primary superheater, a secondary superheater heat transfer tube 36 forming a secondary superheater, and a steam separator drum 37. Each of the heat transfer tubes 33, 34, 35, 36 forms a meandering channel, and the heat transfer tubes 33, 34, 35 communicate with a steam-water separation drum 37 via a communication tube 39. Further, the primary superheater heat transfer tube 35 and the secondary superheater heat transfer tube 36 communicate with each other via a connection tube 35A via a header 38 that forms a fluid distribution mechanism. Each of the heat transfer tubes 33, 34, 35 and the communication tube 39 are connected via a header 38. Each of the heat transfer tubes 33, 34, 35, 36 is suspended and fixed by a suspension tube 32 extending vertically from the ceiling of the boiler 30.

  In the boiler 30, high-temperature circulating cooling gas of about 1000 ° C. is introduced in the X4 direction from the ceiling side through the second duct 50, and sensible heat of the circulating cooling gas is transferred to each heat transfer tube in the course of flowing down the boiler 30 inside. After being supplied to 33, 34, 35, and 36, the circulating cooling gas is discharged to the third duct 60 in the X5 direction.

  After the water for steam generation preheated by the preheater 62 is introduced into the boiler 30 in the Z1 direction, the water is further preheated by the economizer heat transfer pipe 33, and steam and water is passed through the communication pipe 39 in the Z2 direction. It is sent to the separation drum 37. Water for steam generation is sent from the steam separator drum 37 to the evaporator heat transfer tube 34 in the Z3 direction via the communication tube 39, and steam is generated in the evaporator heat transfer tube 34. It is sent to the steam separator drum 37 in the Z4 direction. The steam sent from the steam separator drum 37 to the primary superheater heat transfer tube 35 in the Z5 direction via the connecting tube 39 is superheated in the process of flowing to the secondary superheater heat transfer tube 36 in the X6 direction via the connection tube 35A. Turns into steam.

  The superheated steam produced by the boiler 30 is discharged from the secondary superheater heat transfer tube 36 in the Z7 direction via a steam discharge tube (not shown). The steam discharge pipe communicates with a turbine generator (not shown), and the turbine generator generates power using superheated steam introduced from the boiler 30.

  Returning to FIG. 1, the temperature of the circulating cooling gas from which heat has been removed in the course of flowing through the boiler 30 has dropped to, for example, about 200 ° C. The low-temperature circulating cooling gas flows through the third duct 60, and is supplied with velocity energy by a blower 61 provided at an intermediate position of the third duct 60, and further flows through the third duct 60. That is, the circulation of the circulating cooling gas at a constant speed in the system of the coke dry fire extinguishing equipment 100 is ensured by the application of the speed energy from the blower 61.

  A bypass duct 63 different from the third duct 60 extends from the preheater 62 and communicates with the first duct 40 and the air introduction duct 53. For example, a temperature sensor (not shown) is provided in the second duct 50 or the like, and data measured by the temperature sensor is transmitted to the controller 80. When the temperature of the circulating cooling gas flowing from the chamber 10 into the first duct 40 is equal to or higher than a predetermined temperature, the opening / closing valve 63 a is controlled to be opened by the controller 80 so that the circulating cooling gas flows through the first duct through the bypass duct 63. The circulating cooling gas is supplied to the air introduction duct 53 in the X9 ′ direction, and further supplied to the second duct 50. Since the circulating cooling gas is lower in temperature than the circulating cooling gas flowing from the chamber 10 into the first duct 40, the supply of the circulating cooling gas through the bypass duct 63 in this manner allows the circulating cooling gas to flow into the boiler 30, for example. Can be controlled to a predetermined temperature (range). By controlling the temperature of the circulating cooling gas flowing into the boiler 30 to a predetermined temperature (range) in this way, the temperature of the circulating cooling gas supplied to the boiler 30 is stabilized, and the temperature of the heat transfer tubes and the like constituting the boiler 30 is increased. Breakage and deterioration are prevented. In the illustrated example, a low-temperature circulating cooling gas is supplied to both the first duct 40 and the second duct 50 via the air introduction duct 53 by the bypass duct 63. A configuration in which the circulating cooling gas is supplied to one of the two ducts 50 may be used.

  Further, a diffusion duct 64 different from the third duct 60 extends from the preheater 62. In the system of the coke dry fire extinguishing equipment 100, for example, a pressure sensor (not shown) is provided in the pre-chamber 12, and a signal measured by the pressure sensor is transmitted to the controller 80. For example, when the pressure in the pre-chamber 12 exceeds a predetermined pressure, the on-off valve 64a is controlled to be opened by the controller 80, so that part of the circulating cooling gas is diffused out of the system through the radiation duct 64, For example, control can be performed such that the pressure in the pre-chamber 12 falls within a predetermined pressure range. In addition, in addition to the pre-chamber 12, a pressure sensor is provided at an appropriate place in the system, and a unique pressure control value is set in each place, and a signal measured by the pressure sensor exceeds each pressure control value. Alternatively, the on / off valve 64a may be controlled to be opened by the controller 80, and a part of the circulating cooling gas may be released to the atmosphere.

  As shown in FIG. 3, the controller 80 includes a CPU (Central Processing Unit) 81, a ROM (Read Only Memory) 82, a RAM (Random Access Memory) 83, an NVRAM (Non-Volatile RAM) 84, a HDD (Hard Disc Drive). 85 and an input / output port 86, which are interconnected via a bus 87.

  The ROM 82 stores various programs, data used by the programs, and the like. The RAM 83 is used as a storage area for loading a program and a work area for the loaded program. The CPU 81 realizes various functions by processing the program loaded in the RAM 83. The NVRAM 84 stores various setting information and the like. The HDD 85 stores programs, various data used by the programs, and the like. For example, in the ROM 82, control values of the temperature and pressure of the circulating cooling gas in each part of the system of the coke dry fire extinguishing system 100 are input. The input / output port 86 inputs and outputs electrical signals to and from each on-off valve, temperature sensor, pressure sensor, and the like.

  The controller 80 controls so that a predetermined amount of the circulating cooling gas circulates in the system of the coke dry-type fire extinguishing equipment 100, thereby controlling the inside of the system to a predetermined pressure. Further, the temperature, pressure, etc. of the circulating cooling gas at each location in the system are controlled to management values unique to each location. For example, the temperature of the circulating cooling gas is controlled to about 800 to 900 ° C. in the first duct 40 upstream of the gas flow of the cyclone 20 and about 1000 ° C. in the second duct 50 upstream of the gas flow of the boiler 30. Is controlled. In the third duct 60, the temperature is controlled at about 200 ° C. on the upstream side of the gas flow of the preheater 62, and is controlled at about 100 to 150 ° C. on the downstream side of the gas flow of the preheater 62.

<Coke dust removal mechanism and removal method in boiler>
Next, a mechanism and a method for removing coke dust in the boiler will be described. In the coke dry fire extinguishing system 100, most of the coke dust is collected by the cyclone 20 by applying the cyclone to the dust collector 20 on the gas flow upstream side of the boiler 30. Therefore, coke dust scattered from the cyclone 20 into the boiler 30 via the secondary duct 50 is only coke dust having a small particle diameter. The coke dust having such a small particle diameter easily adheres to and accumulates on various heat transfer tubes 33, 34, 35, and 36 in the boiler 30. When coke dust having a small particle size adheres to and accumulates on the heat transfer tubes 33, 34, 35, and 36, the heat transfer area in the heat transfer tubes 33, 34, 35, and 36 decreases. This leads to a decrease in steam production capacity. Further, the coke dust having a small particle diameter easily adheres to the water cooling wall 31 and the hanging pipe 32 that suspends the heat transfer pipes 33, 34, 35, and 36 from the ceiling of the boiler 30. Therefore, it is necessary to remove coke dust over a wide range in the boiler 30.

  Here, the coke dust collected by the cyclone 20 has a particle size of about 30 μm to 5 mm, and when introduced into the boiler 30, has a function of abrading equipment inside the boiler 30. In a coke dry fire extinguishing system not equipped with the cyclone 20, the relatively large particle size of coke dust is introduced into the boiler, causing a problem of wear of internal equipment and the like. On the other hand, the average particle size of the coke dust scattered into the boiler 30 without being collected by the cyclone 20 is in the range of about 20 μm to 30 μm, which is much smaller than the coke dust collected by the cyclone 20. The particle size.

  Therefore, in the coke dry fire extinguishing equipment 100 according to the present embodiment, a part of the relatively large particle coke dust collected by the cyclone 20 adheres to the boiler 30 and accumulates the small particle coke. It was decided to introduce into the boiler 30 as dust for removing coke dust. By aggressively utilizing the wear action of coke dust having a relatively large particle diameter, it adheres to various heat transfer tubes 33, 34, 35, 36, water cooling wall 31, and suspension tube 32 in boiler 30. In this way, it is possible to remove coke dust having a small particle size that has accumulated.

  As shown in FIG. 1, a fourth duct 71 extends from a lower end of the cyclone 20, and a classification screen 21 is provided below the fourth duct 71. The classifying screen 21 sorts coke dust having a large particle size range of, for example, about 0.5 mm to 5 mm from a particle size of about 30 μm to 5 mm. Then, the coke dust having a small particle size range that has not been sorted is sent to a hopper 22 below the classification screen 21 via a discharge duct 71 ′ extending from the classification screen 21, and is temporarily stored, for example, in the hopper. Discharged from 22. The classifying screen 21 may use a screen in which the mesh size of the screen is set in advance, or use a screen in which the mesh size is automatically changed in accordance with the mesh size input to the controller 80. May be.

  Below the classifying screen 21, a fourth duct 71 further extends, and the fourth duct 71 has an on-off valve 71a. When the on-off valve 71 a is controlled to be opened by the controller 80, for example, coke dust having a large particle size range selected by the classification screen 21 is introduced into the fourth duct 71 extending from below the classification screen 21.

  In the third duct 60, a fifth duct 72 having an on-off valve 72 a is branched from a position on the gas flow downstream side of the blower 61, and the fifth duct 72 communicates with the second duct 50. The fourth duct 71 extending from below the classification screen 21 communicates with the fifth duct 72. Although the fifth duct 72 communicates with the horizontal portion 52 of the second duct 50 in the illustrated example, the fifth duct 72 may communicate with the rising portion 51 of the second duct 50. Further, although not shown, the fifth duct 72 may directly communicate with the upper space of the boiler 30.

  The controller 80 stores a control program that causes the flow of the circulating cooling gas in the fifth duct 72 intermittently at predetermined time intervals during the operation of the coke dry fire extinguishing equipment 100. For example, in a continuous operation for 24 hours, control is performed to open and close both the on-off valve 71a of the fourth duct 71 and the on-off valve 72a of the fifth duct 72 every 8 hours, and to keep both of them open for about 10 minutes. Is executed.

  By such control, a part of the coke dust collected and sorted by the cyclone 20 is introduced in the X11 direction through the fourth duct 71, and the circulating cooling gas flowing in the fifth duct 72 in the X12 direction. Coke dust is introduced from the fourth duct 71, and the circulating cooling gas conveys the coke dust to the second duct 50. The coke dust conveyed to the second duct 50 is conveyed to the boiler 30 by the flow of the circulating cooling gas flowing in the second duct 50 in the X3 direction, and supplies the boiler 30 with coke dust having a relatively large particle size. be able to.

  By supplying coke dust having a relatively large particle size to the boiler 30, the coke dust adheres to the various heat transfer tubes 33, 34, 35, and 36, the water-cooling wall 31, the hanging tube 32, and the like in the boiler 30, and accumulates. The small coke dust having a small particle size can be effectively removed. Coke dust having a relatively large particle size has an excellent abrasion effect, but is adhered and accumulated in the boiler 30 by controlling the coke dust to be introduced into the boiler 30 only for a short time of, for example, about 10 minutes. It is possible to avoid abrasion of various devices in the boiler 30 while removing coke dust having a small particle diameter.

  For example, after operating the coke dry fire extinguishing equipment 100 for 8 hours, the supply of the large particle diameter coke dust from the cyclone 20 to the boiler 30 is performed for about 10 minutes, and again, after operating the coke dry fire extinguishing equipment 100 for 8 hours, Again, the supply of coke dust having a large particle size from the cyclone 20 to the boiler 30 is executed for about 10 minutes. By supplying intermittently large-diameter coke dust to the boiler 30 by air current conveyance, small-diameter coke dust adheres and accumulates on the heat transfer tubes 33, 34, 35, and 36. In addition, the heat transfer area of the heat transfer tubes 33, 34, 35, 36 is reduced, and the steam production capacity of the boiler 30 is reduced. Further, by applying the airflow conveyance by the circulating cooling gas, it becomes possible to supply coke dust over a wide range in the boiler 30. Further, it is not necessary to equip the boiler 30 with a special removing device having high heat resistance when removing coke dust having a small particle diameter, and the coke dust collected by the cyclone 20 is introduced into the boiler 30 by air flow. Therefore, there is no danger of soaring equipment costs.

  In the present embodiment, the controller 80 is provided with a timing for controlling the opening and closing of the on-off valves 71a and 72a, and has a coke dust removal mechanism automatically controlled by the controller 80. However, the opening and closing of the on-off valves 71a and 72a are performed. Manual control in which the control is performed by an administrator may be used. Further, the cyclone 20 does not necessarily have to have the classification screen 21. The coke dust collected by the cyclone 20 generally adheres to the inside of the boiler 30 and has a larger particle diameter than the accumulated coke dust, so that a part of the coke dust collected by the cyclone 20 The coke dust accumulated in the boiler 30 can be sufficiently removed even when the coke dust is used without classification.

[Second embodiment]
Next, a coke dry fire extinguishing system according to a second embodiment will be described with reference to FIG. FIG. 4 is a schematic diagram illustrating a schematic configuration of a coke dry-type fire extinguishing facility according to the second embodiment. The illustrated coke dry extinguishing equipment 200 has the same basic configuration as the coke dry extinguishing equipment 100 shown in FIG. Therefore, the description of the basic configuration of the coke dry fire extinguishing equipment 200 is omitted, and the mechanism and method for removing coke dust in the boiler will be described.

  In the coke dry fire extinguishing equipment 200, a fourth duct 71 having an on-off valve 71a extends at the lower end of the cyclone 20, and a flow conveyor 91 for transporting coke dust in a horizontal direction is provided below the fourth duct 71, for example. At the end of the flow conveyor 91, a bucket conveyor 92 for transporting coke dust in the vertical direction is provided. The coke dust transported to the top by the bucket conveyor 92 is temporarily stored in a storage tank 93. The lower end of the storage tank 93 communicates with a pressurized tank 94 below.

  An inert gas introduction duct 95 having an on-off valve 95a for introducing an inert gas such as nitrogen gas is communicated with the pressurized tank 94. Further, a sixth duct 96 having an on-off valve 96 a extends from the pressurized tank 94, and the sixth duct 96 communicates with the second duct 50. In the illustrated example, the sixth duct 96 communicates with the horizontal portion 52 of the second duct 50, but may communicate with the rising portion 51 of the second duct 50.

  After the coke dust having a predetermined range of particle size is classified by the classification screen 21 below the cyclone 20, the classified coke dust is discharged through the fourth duct 71 in the X11 direction. On the other hand, unsorted coke dust having a small particle size range, for example, is sent to a hopper 22 below the classification screen 21 via a discharge duct 71 ′ extending from the classification screen 21. The coke dust discharged through the fourth duct 71 extending below the classification screen 21 is conveyed in the X14 direction on the flow conveyor 91, then conveyed in the X15 direction on the bucket conveyor 92, and is stored in the storage tank 93. Will be stored.

  An inert gas is introduced into the pressurized tank 94 through an inert gas introduction duct 95 in the Y2 direction. The coke dust stored in the storage tank 93 is introduced into the pressurizing tank 94 in the X16 direction, mixed with the inert gas in the storage tank 93, and pressurized.

  The controller 80 controls the second duct 50 from the pressurized tank 94 via the sixth duct 96 by intermittently controlling the opening and closing of the on-off valve 96 a at predetermined time intervals during the operation of the coke dry fire extinguishing equipment 100. A control program for causing the flow of the inert gas pressurized is stored. For example, in a continuous operation for 24 hours, control is performed to open and close the on-off valve 96a every 8 hours and to keep the open state for about 10 minutes.

  With such control, a part of the coke dust collected and sorted by the cyclone 20 is transported to the second duct 50 by the inert gas flowing in the sixth duct 96 in the X17 direction. The coke dust conveyed to the second duct 50 is conveyed to the boiler 30 by the flow of the circulating cooling gas flowing in the second duct 50 in the X3 direction, and supplies the boiler 30 with coke dust having a relatively large particle size. be able to.

  Even with the coke dry fire extinguishing equipment 200 according to the present embodiment, the small particles that adhere to and accumulate on the various heat transfer tubes 33, 34, 35, and 36, the water cooling wall 31, and the hanging tubes 32 in the boiler 30 are also provided. Coke dust having a diameter can be effectively removed.

  In the illustrated example, an inert gas is introduced into the pressurized tank 94. For example, a branch duct is branched from the gas flow downstream of the blower 61 in the third duct 60, and this branch duct is connected to the pressurized tank. It may be connected to 94. That is, as in the case of the coke dry fire extinguishing equipment 100 shown in FIG. 1, a mode in which coke dust having a relatively large particle diameter is carried by airflow by using a circulating cooling gas having a high flow velocity energy downstream of the blower 61.

[Effect confirmation experiment by actual operation]
The present inventors made the actual operation of the coke dry-type fire extinguishing equipment 100 shown in FIG. 1, introduced large-diameter coke dust collected by the cyclone 20 into the boiler 30, adhered to the inside of the boiler 30, and deposited. An experiment was conducted to remove small particle size coke dust. The coke dry fire extinguishing system 100 is a facility that operates 24 hours a day. The introduction of coke dust into the boiler 30 was performed for 10 minutes every 8 hours of operation. That is, the intermittent introduction control of coke dust into the boiler 30 was executed three times a day.

  The coke dust introduced into the boiler 30 was selected from coke dust having a particle size range of about 0.5 mm to 5 mm. In the boiler 80, a temperature sensor was provided at a position corresponding to a secondary superheater or the like, and data measured by the temperature sensor was received by the controller 80 as needed, and a time-series change in temperature was obtained.

  As a result, it was found that in the process of operating the coke dry fire extinguishing equipment 100 continuously for 8 hours, the temperature by the temperature sensor slightly decreased in the latter half of the operation. This is because coke dust having a small particle diameter adheres to the heat transfer tube 36 and the like and accumulates, resulting in a decrease in the heat transfer area. After 8 hours of operation, it has been confirmed that the temperature sensor rises in the course of supplying coke dust having a large particle size to the boiler 30 for 10 minutes, and returns to the high temperature at the beginning of the operation.

  From this effect confirmation experiment, it has been proved that coke dust in the boiler 30 is effectively removed in the coke dry fire extinguishing equipment 100.

  It should be noted that other embodiments in which other components are combined with the configuration and the like described in the above embodiment may be employed, and the present invention is not limited to the configuration shown here. . This can be changed without departing from the spirit of the present invention, and can be appropriately determined according to the application form.

10: chamber 11: cooling chamber 12: pre-chamber 13: coke charging device 14: coke discharging device 20: dust collector (cyclone)
21: Classification screen 30: Boiler 31: Water cooling wall 32: Hanging pipe 33: Energy-saving heat transfer tube (heat transfer tube)
34: Evaporator heat transfer tube (heat transfer tube)
35: Primary superheater heat transfer tube (heat transfer tube)
36: Secondary superheater heat transfer tube (heat transfer tube)
37: steam-water separation drum 38: header 40: first duct 50: second duct 51: rising section 52: horizontal section 53: air introduction duct 60: third duct 61: blower 62: preheater 63: bypass duct 64: Dispersion duct 71: fourth duct 72: fifth duct 80: controller 91: flow conveyor 92: bucket conveyor 93: storage tank 94: pressurized tank 95: inert gas introduction duct 96: sixth duct 100, 200: coke dry type Fire extinguishing equipment

Claims (10)

It has a chamber, a dust collector composed of a cyclone, a boiler, a first duct connecting the chamber and the cyclone, a second duct connecting the cyclone and the boiler, and a third duct connecting the boiler and the chamber. A circulating cooling gas flows in the system of the coke dry-type fire extinguishing equipment, and coke dust in the circulating cooling gas is collected by the dust collector.
Coke dry fire extinguishing equipment, characterized in that coke dust collected by the dust collector is supplied to the boiler as removal dust for removing coke dust accumulated in the boiler.   2. The coke dry fire extinguishing system according to claim 1, wherein the supply of the coke dust collected by the dust collector into the boiler is performed intermittently. 3. In the system of the coke dry fire extinguishing equipment, the circulating cooling gas flows from the chamber to the boiler through the first duct and the second duct, and flows from the boiler to the chamber through the third duct. Yes,
A fourth duct extends from the dust collector,
A blower is interposed in the third duct, and in the third duct, a fifth duct branches from a position on the gas flow downstream side of the blower and communicates with the second duct or the boiler,
Coke dust supplied from the dust collector to the fifth duct via the fourth duct is supplied to the boiler from the second duct with a circulating cooling gas, or supplied directly to the boiler with a circulating cooling gas. The coke dry fire extinguishing equipment according to claim 1 or 2, characterized in that: A fourth duct extends from the dust collector and communicates directly or indirectly with the pressurized tank, and a sixth duct extending from the pressurized tank communicates with the second duct,
The coke dust supplied from the dust collector to the pressurized tank via the fourth duct is supplied to the second duct via the sixth duct by a circulating cooling gas or an inert gas pressurized in the pressurized tank. The coke dry fire extinguishing equipment according to claim 1 or 2, wherein the coke is conveyed to the boiler and supplied from the second duct to the boiler. The dust collector has a classification screen,
The coke dust collected in the dust collector is passed through the classification screen to select a coke dust of a predetermined particle size range, and the selected coke dust is supplied to the fourth duct, The coke dry fire extinguishing equipment according to claim 3 or 4. It has a chamber, a dust collector composed of a cyclone, a boiler, a first duct connecting the chamber and the cyclone, a second duct connecting the cyclone and the boiler, and a third duct connecting the boiler and the chamber. A circulating cooling gas flows in the system of the coke dry-type fire extinguishing equipment, and in a coke dry-type fire extinguishing equipment in which coke dust in the circulating cooling gas is collected by the dust collector, removes coke dust deposited in the boiler. A method for removing coke dust in a boiler of a coke dry fire extinguishing system,
The coke dust collected in the dust collector is supplied to the boiler as removal dust for removing coke dust accumulated in the boiler, and the coke dust in the boiler of the coke dry fire extinguishing equipment is provided. Removal method.   The method for removing coke dust in a boiler of a coke dry-type fire extinguishing facility according to claim 6, wherein the supply of coke dust collected by the dust collector into the boiler is performed intermittently. In the system of the coke dry fire extinguishing equipment, the circulating cooling gas flows from the chamber to the boiler through the first duct and the second duct, and flows from the boiler to the chamber through the third duct. Yes,
A fourth duct extends from the dust collector,
A blower is interposed in the third duct, and a fifth duct branches off from a position on the gas flow downstream side of the blower in the third duct and communicates with the second duct.
The coke dust supplied from the dust collector to the fifth duct via the fourth duct is conveyed to the second duct by circulating cooling gas, and supplied to the boiler from the second duct. Item 8. The method for removing coke dust in a boiler of a coke dry fire extinguishing system according to item 6 or 7. A fourth duct extends from the dust collector and communicates directly or indirectly with the pressurized tank, and a sixth duct extending from the pressurized tank communicates with the second duct,
Coke dust supplied from the dust collector to the pressurized tank via the fourth duct is conveyed to the second duct via the sixth duct by a circulating cooling gas or an inert gas pressurized in the pressurized tank. The method for removing coke dust in a boiler of a coke dry fire extinguishing system according to claim 6, wherein the coke is supplied to the boiler from the second duct. The dust collector has a classification screen,
The coke dust collected by the dust collector is passed through the classification screen to select coke dust in a predetermined particle size range, and the selected coke dust is supplied to the fourth duct, wherein 10. The method for removing coke dust in a boiler of a coke dry fire extinguishing system according to item 9.

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