JPS59183817A - Removal of harmful component and dust in waste gas from waste incinerator - Google Patents

Abstract

PURPOSE:To reduce the loss of heat as well as raise the utilizing rate of CaCO3 by a method in which a mixture of CaO activated in a waste fluidized bed incinerator and sand is used as a reactant and filter aid for a moving bed type harmful gas and dust remover and then reutilized in the fluidized bed incinerator. CONSTITUTION:CaCO3 of a fixed grain size as a desalting and desulfurizing agent is charged into a fluidized bed furnace 1 using sand (quartz sand) as a fluidizing medium. A mixture of CaO activated in the furnace 1 and sand is drawn out of the bottom of the furnace and filtered through a separator 2, e.g., vibrating screen, etc., to remove unburned substances, dust, reaction products (CaCl2 and CaSO4), etc., and then sent to a moving bed type harmful gas and dust remover 3, where the mixture of CaO and sand reacts with and absorbs HCl and SOx in waste gas while dropping by gravity in the supporters 7 and also collects dust. Dust and reaction products are removed from high-temp temperature discharged mixture from the remover 3 in a separator 11, and the mixture of CaO, CaCO3, and sand is charged into the furnace 1 for reutilization.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to exhaust gas containing HC, SOx, and dust, such as industrial waste incinerator exhaust gas, municipal waste incinerator exhaust gas, etc. (hereinafter simply referred to as waste incinerator exhaust gas). A method of processing ff1 efficiently and at low cost using limestone
g+.

General r, waste incinerator waste, for example, municipal waste incinerator waste vrtdHcIl is 200 to 100'Oppm,
Contains 10 to 1 ooppm of SOx, cNOHC6
, SOx & CaCO5f Ite chemical reaction process CaC
4. A dry method for separating and removing Ca SO< has been well known. In addition to this dry method, the wastewater must be treated using a wet method in which harmful scum is absorbed in an aqueous alkaline solution, fermented, and left as wastewater.
(D) It has the advantage of being inexpensive because it is a simple method without any problems, but it has problems such as the utilization rate of CaCO3 is not so high and there is a large amount of heat loss.

The present invention was made to solve the above problems, and is a method for removing HCβ and SOx from exhaust gas by introducing limestone (CaC03) into a waste incineration fluidized bed furnace.
After extracting the mixture of activated fluidized media such as C, aO, and silica sand, reaction products, noncombustibles, and dust from the bottom of the furnace and separating the reacted materials, noncombustibles, and dust,
CaO and a fluidized medium are introduced into a moving bed type harmful gas/dust removal device that falls between two supports at a low speed, and the exhaust gas from the fluidized bed furnace is passed through this moving bed.
After reacting O with HC (1, SOx) contained in the exhaust gas and collecting the tast in the exhaust gas, the reaction product and tast are separated into CaCO3, CaO and a fluidized medium, HCn, SOx, and dust can be removed at the same time at low cost by supplying fluidized bed furnace F and reusing it to remove generated HC1 and SOx. The purpose is to provide a method for removing harmful components and guests.

Hereinafter, an uninvented configuration will be explained based on the drawings.

1 is a one-bed furnace, in which a fluid medium such as silica sand (hereinafter referred to as sand) is used. When CaC0a of a certain particle size is introduced into the fluidized bed furnace 1 as a desalination/desulfurization agent, most of the molecules rica-
It is activated by thermal dissociation to zero and reacts with generated HC6 and SOx gas to perform desalination and desulfurization. This reaction &:t-Ca
This occurs on the surface of O particles, resulting in reaction products such as CaC4 and Ca504, but due to the stirring action of sand, the reaction products are peeled off and are entrained in the η1-gas in almost a powder state. It is discharged from the top of the fluidized bed furnace. Fluidized bed furnace 1
Inside, a reaction takes place.

CaCO3→CaO+CO2 CaO+ 2HC1→CaC4+H2OCaC0a
+2HCj? -+ CaC4+ Ii2 0
+ CO2CaO+S02 → Ca5O3 Ca 503 + 1/ 202 → Ca 504
On the other hand, activated CaO (partially reacted Ca (-
A mixture of sand and sand is extracted from the bottom of the fluidized bed furnace 1, and passed through a separation device 2 such as a 3-stage J Hi-Shin W1 sieve.
Incombustibles, lysts, reaction products (CaC4, Ca5O
4) is separated and removed, and CaO and # are conveyed to the single-layer noxious gas/dust removal device 3. 4 is a flow u1 medium discharge device, 5 is a medium capacity 1 hopper, and 6 is an excess CaO/sand extraction pipe.

Inside the $ layer type harmful gas/tast removal device 3, there are louvers,
Two supports 7 made of perforated plates, wire mesh, etc. are placed opposite each other, and these supports 7.7 are filled with πCaO and sand and fall at a low speed! It is configured to have eight dynamic layers. The conveyed mixture of CaO and sand has 1 and support 7
．． One by one, the dead weight falls between 7 and π in the exhaust gas.
At the same time as reacting and absorbing HCβ and SOx gas,
Dust in the exhaust gas is also collected in a layer of CaO and sand mixture. Note that IO is an exhaust gas cooling device such as a one-norm heat boiler, a gas cooling tower, or a heat exchanger. ＃Side layer type harmful gas・
The following 11] describes the reaction inside the strike removal device W3.

CaO+ 2HCn-+CaC4+ H20CaO+
SO3->Ca5O, + Ca 503 + 1/202 → Ca 504Ca
O+CO2→CaCO3 The mixture π discharged from the moving bed type harmful gas/dust removal device 3 contains Tast, reaction products (CaC4, Ca504
), it is removed from a separator such as a vibrating sieve, and a mixture of CaCO3, CaO and sand is put into a fluidized bed furnace and reused. 12 is a blower-1:l-11-Ikuun, 14 is an air distribution plate,
15 is a wind box.

After the mixture of CaO and 4 (J) is extracted from the bottom of the furnace, it is transported to a moving bed type self-harming gas and dust removal device.
) 1 is cooled by heat radiation, but 1 * 1J (J) In the 1-layer noxious gas/dust removal device 3, the sensible heat of the exhaust gas is given to it and heated again, which has the advantage of reducing the heat LJ. The fluid medium that is circulated for use is Ca
It is not limited to a mixture of a Ca-based compound and a 4-silicon compound, and a -Ca-based compound is also possible.

As I explained above, unreleased E! In the method of 1.1, rcacO3 is added as a desalination/desulfurization agent to a B6 waste incineration cost-bed furnace, and the mixture of aged CaO and sand is removed in a moving bed using a moving bed method. It is used as a reactant and filtration material in the equipment line, and after reacting and absorbing HC (J, SOx) contained in the exhaust gas and simultaneously collecting Tast,
Since the mixture of high-temperature CaO, CaCO5 and sand from which U products have been separated and removed is fed into the fluidized bed furnace f and reused, cheap fxCaCO3 can be used, and CaCO
The utilization rate of 7 is extremely low, the running cost is low, and the heat loss is small because the mixture of CaCO5 and sand, which is used by circulation, is heated with exhaust gas and then input into the fluidized bed furnace. It has the effect of becoming.

[Brief explanation of the drawing]

The drawings are schematic diagrams illustrating an example of an apparatus for implementing the method f/of the invention. DESCRIPTION OF SYMBOLS 1...Fluidized bed furnace, 2...Separation device, 3...Moving bed type noxious gas/gas 1-removal device, 4...Fluidized medium discharge device, 5...Intermediate hollow container, 6 ...Excess CaO/sand extraction pipe, 7...Support integrated, 8...Movement 1 layer, 10.
...Cooling device, 11...minutes i! 1ff(, device d,
l 2- sending JtL machine, 13 ・i-ik [J n, 14... constriction air dispersion plate, 15... wind box

Claims (1)

[Claims] 1 In the method of charging limestone into a waste incineration fluidized bed furnace to remove HC (1, SOx) from the exhaust gas, activated Caα fluidized medium, reaction products, incombustibles, dust in the fluidized bed furnace After extracting the mixture from the bottom of the furnace and separating the reaction products, incombustibles, and guests, the CaO and fluidized medium are transferred to a one-layer noxious gas/dust removal device and passed between two supports at low speed. While dropping, the exhaust gas from the fluidized bed furnace is passed through the moving bed to remove CaO and H contained in the exhaust gas.
After collecting dust in the exhaust gas at the same time as reacting Cβ and SOx, the reaction products and dust are combined with CaCO3
, CaO and a fluid medium, CaCO3, Ca
O and stream U, + medium are fed to a fluidized bed furnace to generate HCI
, a method for removing harmful components and guests from waste incinerator exhaust gas, which is characterized in that it is reused for removing SOx.