KR100699519B1 - Circulating fluidized bed boiler for combustion of waste and RPF - Google Patents

Abstract

A circulating fluidized bed boiler for combustion of waste and RPF(Refused Plastic Fuel) is provided to improve energy recovery efficiency by making sewage slurry and waste plastic into RPF and supplying the RFP as fuel for an energy generating boiler. A circulating fluidized bed boiler for combustion of waste and RPF includes a cyclone(4), a circulation heat transfer member(7), an absorbing tower(9), a back filter(10), and a cleaning tower(11). A seal pot(5) is installed on the bottom side of the cyclone by supplying the fuel stored in a fuel reservoir(1) to a combustion furnace(3) connected to a fuel insertion device(2). An external heat exchanger(6) is connected to the top side and the circulation heat transfer member is connected to a center. A particle material circulation path(22) connects the seal pot to the external heat exchanger. A final over heating device(28) is installed inside the circulation heat transfer member and the external heat exchanger.

Description

Circulating fluidized bed boiler for combustion of waste and RPF}

1 is a state diagram of the installation of sludge mixed RPF combustion dedicated circulating fluidized bed boiler showing an embodiment of the present invention

2 is a partial cross-sectional view of the sludge mixed RPF combustion dedicated circulating fluidized bed boiler of the present invention

3 is a side view of FIG. 2 of the present invention;

[Description of Symbols for Main Parts of Drawing]

1: fuel reservoir 2: fuel injector

3: combustion furnace 4: cyclone

5: seal port 6: external heat exchanger

7: convection heat transfer unit 8: press-in blower

9: absorption tower 10: bag filter

11: washing tower 12: manned blower

13: chimney 20: drum

21, 22: particle recirculation path 23: particle transfer path

 24: down comer 25: economizer

 26: 1st super heater 27: 2nd super heater

28: final superheater (3rd super heater) 29: air preheater

 30: feed water pipe 31: steam out pipe

The present invention seeks to safely burn fuel and recover energy with high efficiency from solid fuel RDF or RPF made from flammable waste, dry sludge, waste plastic, etc. in a new concept circulating fluidized bed cogeneration boiler.

More specifically, RDF and RPF fuels having high volatility and high calorific value are burned without overheating of the furnace by using a circulating fluidized bed technology, and the non-mechanical particle circulator of the present invention is used in a waste fuel combustion atmosphere in an acid gas atmosphere. The final superheater is placed in the external heat exchanger to circulate the particles to the combustion furnace and external heat exchanger and to suppress the corrosion of the final superheater, supplying electricity or heat as a new solid fuel combustion circulation fluidized bed combustion furnace and boiler with high efficiency combustion and corrosion protection. It relates to a device to.

Incineration technologies that have been introduced and are in operation or under consideration in Korea include the plasma incineration method and the sludge incineration method for sludge, in addition to the stocker method. This incineration method has a disadvantage in that the operation cost is high due to the processing cost for ensuring the safety and proceeds in a batch processing process regardless of the harmfulness of the waste.

Although some research institutes and schools are conducting process development research, there is still a need for demonstration and technical verification in the design, operation, and large-scale technology of incineration. Renewable fuel technology is also a manufacturing technology for RDF that is classified as waste under current law. Since there are no statutory provisions regarding the use of recycle derived fuel (RDF), it must be combusted in a waste incineration plant.

Excessive chlorine in the manufacturing environment may limit the use of fuel, making it difficult to recover high-temperature steam. Due to the nature of the facility, it is restricted when installing industrial or densely populated areas.

Patent 2002-0066539 'Hot and hot air supply system using waste solid fuel incinerator (2002.08.19)' is a simple bed that does not have pollution prevention facilities and supplies heat for hot water and heating with primary combustion chamber and secondary combustion chamber in a fixed bed. In the case of a small system or the present invention, using a unique non-mechanical particle circulation device as a large industrial boiler for the production of steam or electricity using a circulating fluidized bed, the particles are circulated to a combustion furnace and an external heat exchanger and the corrosion of the final superheater is suppressed. The superheater is placed in an external heat exchanger to supply electricity or heat as a new solid fuel combustion circulating fluidized bed combustor and boiler with perfect high efficiency combustion and corrosion protection. It is a simple compact system with a primary combustion chamber and a secondary combustion chamber in a fixed bed and no pollution prevention facilities that supply hot water and heat for heating.

Patent 2002-0061283 'Incineration Boiler for Solid Fuel (2002.07.24)' installs a thermal insulation brick on the inner side of the case and installs a heat pipe on the bottom and wall of the cooling pipe equipped with an air nozzle, It is a simple compact system with no pollution prevention facilities for supply or heating.

The present invention is to mix the sewage sludge discharged from the sewage terminal treatment plant with the waste plastic of the living or workplace and to solidify the RPF produced in a new concept circulating fluidized bed cogeneration boiler to recover energy with high efficiency and maximize pollution prevention technology The purpose is to secure the use of waste.

The present invention relates to a device for supplying electricity or heat generated by steam by demonstrating complete combustion in a new domestic solid fuel combustion circulating fluidized bed boiler with perfect flue gas control and corrosion protection of a heat pipe. A large industrial boiler which uses a device to circulate particles into a combustion furnace and an external heat exchanger and places the final superheater in an external heat exchanger to suppress corrosion of the final superheater.

The present invention is the most economical for RPF (Refused Plastic Fuel) that can be transported and stored in a general facility for limited waste plastics and sewage sludge, including environmental pollutants discharge, and limited combustion heat available in a general solid combustion boiler In addition to developing a new concept of circulating fluidized bed process that can be produced by phosphorus method and safely incinerated and maximizing energy use, it can be immediately localized and commercialized.

Fluidized bed incineration of the present invention is gradually increasing as a sludge treatment method worldwide, because it has the following advantages.

First, because of good mixing within the bed, complete combustion is possible at relatively low temperatures and excess air rates.

Second, a large amount of inert material in the layer acts as a heat reservoir to prevent sudden temperature changes.

Small amounts of fuel or coal in the third bed allow for start-up or shut-down in minutes when the furnace is near operating temperature.

Fourth, a large amount of layer material reduces the damage of the refractory due to thermal shock and also low maintenance costs because there is no moving part in the hot part of the incinerator. In addition, the fluidized bed incinerator is applied in various fields because it not only has excellent heat transfer in the reactor, but also has the advantage of being able to suppress the emission of pollutants without a separate process and adapting it to fuel containing a lot of water. In particular, when the external heat exchange type circulating fluidized bed system is introduced, the corrosion of the final superheater can be suppressed, which is very effective in the management of the combustion furnace.

The present invention can not recover the heat by the conventional simple incineration method, waste heat boilers such as stoka is difficult to cope with changes in the heat of the waste, it is difficult to completely burn and environmental management, and the temperature of the generated steam is low and efficient use of energy Independently developed external heat exchange type circulating fluidized bed combustion system by improving the impossibility to enable high efficiency combustion, thorough and economical flue gas control, high temperature steam recovery, and further minimize the corrosion of boiler water pipe by acid gas. Can be. In addition, this method is easy to control the temperature of the boiler, so the load control and operation management performance is excellent.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

A fuel supply device 2 for quantitatively injecting fuel is installed under the fuel storage tank 1 storing the RPF, and the fuel supply device 2 is configured to inject a certain amount of solid flow material into the combustion furnace 3. .

The combustion furnace 3 is operated to fluidize the manned blower 12 and the press-fit blower (8).

The water pipe is installed inside the combustion furnace 3 or forms a space, and is connected to the cyclone 4 from the upper side, and the seal port 5 is connected to the lower side of the cyclone 4.

The seal port 5 has particle recirculation paths 21 and 22 separated on both sides, so that the particle recirculation path 21 is connected to the particle transfer path 23 and connected to the combustion furnace 3. 22 is connected to the external heat exchanger 6.

The external heat exchanger 6 is recycled according to the situation of the combustion furnace 3 without a mechanical shutoff (control) device to allow fuel to be burned.

The cyclone (4) is connected to the convection heat exchanger (7), the press-in blower (8) and the absorption tower (9) is connected, the bag filter 10 and the cleaning tower (11) in a continuous absorption tower (9) , Manned blower 12 and the chimney 13 is installed.

The steam drum 20 is connected to the combustion furnace 3 and the convection heat exchanger 7, and a down comer pipe 24 is connected to the lower side of the steam drum 20, and a feed water pipe 30 is connected to one side of the steam drum 20. And a steam outlet pipe 31 is connected.

A certain amount of solid fluid is introduced into the combustion furnace 3, and the manned blower 12 and the press-fit blower 8 are operated to fluidize. When the solid preheat burner is operated, the temperature of the solid fluid reaches the RPF combustion condition. If the RPF stored in the reservoir 1 is quantitatively injected through the fuel supply device 2, smooth combustion is possible. At this time, a part of the solid and ash are collected in the cyclone (4) accompanied by a droplet like gas, and recycled to the combustion furnace (3) through the seal port (5) and the external heat exchanger (6), and the gas and the fine particles are convective heat transfer. The part 7, the absorption tower 9, the bag filter 10, and the washing tower 11 are discharged through the chimney.

On the other hand, the process for the heat recovery is the pre-treated water is passed down from the steam drum (20) to the downcomer (24) through the economizer (25) through a pump (not shown) to the wall of the furnace 3 again While moving through the installed water pipe, the phase changes to steam by heat transfer and circulates to the steam drum 20.

Steam comes out of the steam drum 20, the first super heater 26, the second super heater 27, the third super heater 28 and has a constant temperature and pressure. This steam is used as energy through electricity production and heat recovery processes. In particular, in order to prevent direct contact with HCl at a temperature above 450 degrees where the water pipe reacts with HCl and causes high temperature corrosion during steam overheating after exiting the steam drum 20. 6) is installed.

Corrosive substances causing high temperature corrosion are transferred to the absorption tower 9 through the convection heat exchanger 7 and the final superheater 28 is installed in the external heat exchanger 6 so that the external heat exchanger 6 is not in direct contact. Therefore, there is no need to worry about corrosion.

The present invention enables efficient and environmentally friendly resource circulation by reusing sewage sludge and waste plastics as RPF, and can be used as a fuel in solid fuel boilers as well as to reduce marine pollution and extend landfill life, away from the conventional incinerator combustion. The technical ripple effect is excellent in temperature control and management function that is differentiated from the existing foreign technology and development of domestic circulating fluidized bed RPF combustion boiler resistant to corrosion and differentiated from demonstration incineration boiler can be installed in a residential environment or industrial place to use energy. Do.

In the present invention, the economic ripple effect is solid fueled by using sewage sludge and waste plastics (RPF) and supplied as a fuel of a power generation boiler to be used as an alternative energy, thereby ensuring greater energy replacement effect and recovering energy through the use of combustion heat. Is possible.

The present invention prevents direct contact with the HCL by more than 450 degrees by installing the final superheater in the external heat exchanger to prevent high temperature corrosion.

Claims (4)

The fuel stored in the fuel reservoir 1 is supplied to the combustion furnace 3 connected to the lower fuel injector 2 and combusted, and the cyclone 4 having the seal port 5 installed on the lower side and above and in the center thereof. Circulating fluidized bed discharged through the chimney through the external heat exchanger (6) and the convection heat exchanger (7) and the convection heat exchanger (7), absorption tower (9), bag filter (10), cleaning tower (11) In the boiler, A particle recirculation path 22 connects the seal port 5 and the external heat exchanger 6, and a final superheater 28 installed inside the convection heat exchanger 7 and the external heat exchanger 6 is connected. Circulating fluidized bed boiler dedicated to waste and RPF combustion. The method of claim 1, The seal port 5 is non-mechanically controlled without a mechanical device in proportion to the amount of gas in the flow rate controlling the air for the RPF combustion, and is burned according to the temperature difference between the amount of gas recycled to the combustion furnace and the solid. Waste and RPF combustion circulating fluidized bed boiler, characterized in that the improved condition and the temperature control of the furnace (3). The method of claim 1, The seal port 5 is non-mechanically controlled without a mechanical device in proportion to the flow rate of the solids for the PRF combustion flow rate control the air, and the particle recirculation passage (21, 22) is separated on both sides, The particle recirculation passage 21 is connected to the particle transfer passage 23 to the combustion furnace 3, and the particle recirculation passage 22 is connected to the external heat exchanger 6 and remains in the seal port 5. Blocks the inflow of acid gas back to the external heat exchanger (6) in the combustor, and installs the final superheater (28) inside the external heat exchanger (6) to produce steam of 450 degrees or more while preventing corrosion of the heat pipe. A circulating fluidized bed boiler dedicated to waste and RPF combustion, characterized by preventing corrosion by avoiding direct contact with HCl to prevent corrosion. The method of claim 1, The external heat exchanger 6 is connected to the fuel transport paths 21 and 22 in two directions at the seal port 5, and meets the fuel transport path 21 so that the fuel inlet 31 is connected to the combustion furnace 3. A circulating fluidized bed boiler dedicated to waste and RPF combustion.

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