JP2000257835A - Apparatus for cleaning incinerator exhaust gas by high- temperature solid packed bed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an incinerator exhaust gas cleaning apparatus capable of restraining generation of dust and dioxins at the same time. SOLUTION: The cleaning apparatus comprises a high-temperature solid packed layers 30 supported by supporting members, wherein exhaust gas is introduced from an exhaust gas duct 20, and an afterburner 40 is provided on a lower part side surface of a vertical structure to maintain the high-temperature solid packed layers 30 consisting of high- temperature solids with diameters of at least 15 mm at an arbitrary temperature in the range of 800-1100 deg.C to feed high temperature combustion air, and the high-temperature solid packed layers 30, coming into contact with burner flame, is maintained at the arbitrary temperature in the range of 800-1100 deg.C. The exhaust gas is forced to pass through the high- temperature solid packed layers 30 and exhausted from an outlet of an upper part of the apparatus after burnable dust and passed, unburned components collected by dust collection through particle adhesive force and filtering in the high-temperature solid packed layers 30 are burned secondarily. In cases where only the afterburner 40 provides insufficient combustion air, combustion air is introduced from combustion air ports provided between a start edge of the exhaust gas duct 20 and the high-temperature solid packed layers 30. Mixing and combustion is allowed sufficiently to be conducted in the high-temperature solid packed layers 30, and the exhaust gas is collected and burned secondarily efficiently by the same, and clogging is hard to occur comparing to that in low-temperature dust collection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an exhaust gas purifying apparatus for a waste incinerator or a carbonization furnace, which combines a reburning structure for effectively performing a high-temperature solid contact effect of exhaust gas with high-temperature particulate adhesion and dust collection by filtration. It is a thing. As a result, the invention is an invention that reduces dust and unburned components in exhaust gas and contributes to suppression of dioxins.

[0002]

2. Description of the Related Art A general small incinerator has a combustion chamber in which waste is introduced, combustion air is taken in and burnt, and a secondary combustion chamber in which exhaust gas is introduced and unburned components of the exhaust gas are burned. And then exhaust from the chimney.
In a conventional small incinerator, the secondary combustion chamber doubles as a space for exhaust gas combustion and simple dust collection.

[0003]

However, conventionally, incinerators using a combustion chamber that combines the exhaust gas combustion and a simple dust collection space in the secondary combustion chamber have the following problems. Conventional combustion chambers cannot sufficiently perform secondary combustion of exhaust gas due to restrictions on initials and running costs, and as for the dust collection function, it does not have a dust collection device, or even if it is equipped, the cyclone stops, so as a result It did not fulfill its role as an exhaust gas collection chamber.

[0004] In recent years, due to the issue of dioxin emission control, soot emission standards have been strengthened. It is said that dioxins in exhaust gas are partially present in gaseous form, but it is said that most of them are adsorbed to dust and fly ash. This is a report to the Environment Agency. In response to this, the new furnace's dust emission regulation value was 0.15g /
m ³ N.

[0005] The basis of this dioxin generation control is as follows.
One is complete combustion of flue gas, and three important conditions for the complete combustion are combustion temperature, residence time, and stirring and mixing.

[0004] In the dioxin emission control described in the above, combustion temperature and residence time are proposed by numbers, but there is no specific condition for another numerical expression of combustion stirring and mixing. For this reason, in a general small incinerator, only the conditions of combustion temperature and residence time are satisfied,
In most furnaces, stirring and mixing are neglected and exhaust gas cannot be sufficiently burned, that is, so-called dioxins are not sufficiently suppressed. The second example is a conventional filter dust collector. The first is a bag filter dust collector, which filters fibers with a bag-shaped filter made of a special weave. Next is the demister dust collector. A multi-layer mesh filter composed of extremely thin metal filaments is used to filter the exhaust gas in the form of water mist, and collectively use it for dust removal. However, in small furnaces, those that had been cooled for about several hours in the daytime and used during the night had to be replaced before use the next morning, cleaned by tapping or washed with water. When collecting using a filter, an eye filter with a diameter of 10 mm or more is placed at the outlet of the primary combustion chamber. The eyes are too coarse and the dust collection effect is insufficient. The eyes are clogged in less than 1 mm in a short period of time. Insufficient effect due to filter thickness of 50 mm or less, insufficient effect due to filter thickness of 200 mm or more, easy clogging, long heat-up time, large fuel consumption, immediately before the filter because without a relapse burners, filters can not be maintained above 800 ° C., which hot solid contact effect is not sufficiently obtained, since the filter unit is not less than 1100 ° C., what concentration of nO _x is high, the combustion of the filter upstream Insufficient amount of air was introduced, the backwashing equipment was required, and the use of a ceramic bag filter system increased the introduction cost. Stuff, natural ore packed without any ingenuity,
Exhaust gas dust concentration due to thermal shock increases, and expensive precious metal catalysts and titanium oxide catalysts are used at 650 ° C or less, which does not thermally degrade, so an exhaust gas cooling device must be installed upstream or because of low temperature There were various problems such as a short catalyst replacement period due to the attachment of catalyst poisons such as tar, sulfide, chloride, heavy metal, and steam.

[0006]

Means for Solving the Problems The problem solving means according to the present invention is provided in the middle of a vertical exhaust gas purifying apparatus for promoting the collection and reburning of exhaust gas from waste incinerators, carbonization furnaces and the like. This is a method for purifying exhaust gas by a high-temperature solid packed bed.

[0007] First, the structure of the exhaust gas purifying apparatus is such that the flue gas is introduced from the smoke duct, and then the fuel high temperature solid packed bed is filled with 8 fl.
In order to maintain an arbitrary temperature of from 00 ° C. to 1100 ° C. and to supply high-temperature combustion air, a burner device is arranged on the lower side surface of the vertical structure, so that the burner flame and exhaust gas come into contact with each other. is there. In the exhaust gas combustion device, a ceramic or heat-resistant metal having a large contact area, such as a cylinder, a saddle, a gravel, a granule, or a column, is formed by holding the inside of the device at an arbitrary temperature range of 800 ° C. to 1100 ° C. , A high-temperature solid packed layer filled (laminated) with a high-temperature solid such as a perforated plate or flocculent (bulk) is received by a support material. Utilizes a high-temperature solid contact effect that promotes dust collection and reburning of exhaust gas.The collected combustible dust is completely burned with ash remaining on the surface of the stored high-temperature solid, so it is less likely to block than low-temperature dust collection . Therefore, carbon monoxide, odor components, black smoke, dust, hydrocarbons, dioxin precursors, and dioxins themselves can be more effectively reduced as compared with an exhaust gas combustion apparatus having no high-temperature solid packed bed of the same volume.

The high-temperature solid contact effect of the high-temperature solid of 800 ° C. or higher used in the present invention has the following advantages. -At high temperatures, the adhesive force (weak force between molecules) of fine particles smaller than the gaps or through holes between high-temperature solids increases 5 to 10 times that at normal temperature, so that the collection power is larger than low-temperature solids. The aggregation effect of the collected fine particles is also increased.・ The unburned gas is oxidized and decomposed in a short time due to solid heat conduction when the unburned gas comes in contact with the high-temperature solid (which has much higher heat conduction than that in a high-temperature atmosphere). The collected combustible dust is also efficiently ignited on the high-temperature solid surface by solid heat conduction.
Because it reburns, it is less likely to block than low-temperature dust collection. -Acceleration of oxidative decomposition by activation of molecules and atoms in exhaust gas by infrared radiation. Ceramics and metals having a low catalytic effect at a temperature of 800 ° C. or less exhibit a useful oxidation catalytic effect even at a small specific surface area at a temperature of 800 ° C. or more. -Thermal agitation that occurs when colliding with a high-temperature solid having a large surface area.・ Turbulence generation when passing through high-temperature solid ventilation holes (gap) (orifice effect) ・ High heat efficiency due to heat exchange by high-temperature heat storage. The high-temperature solids radiate heat mainly to the exhaust gas upstream after absorbing heat, so that the fuel cost of the reburning burner can be saved, and if the exhaust gas is cooled to 200 ° C or less downstream of the high-temperature solid packed bed to suppress dioxin resynthesis, heat storage In the discontinuous operation, the cooling cost is reduced, and the amount of increase in the exhaust gas after cooling is smaller than the cooling by water spray or air dilution alone. By the above effects, the high-temperature pyrolysis effect of the unburned components in the exhaust gas and the dust collecting effect can be sufficiently obtained.

[0009] If there is a possibility that ash generated by reburning of combustible dust on the surface of the high-temperature solid, thermal shock, mechanical stress, and fragments generated by the reaction of the high-temperature solid with the exhaust gas and scattered, may be scattered. A part of the upper layer of the solid packed layer is composed of a high-temperature solid packed layer with smaller air holes (gap) than the lower layer, for example, a plate-like porous material or a fibrous refractory material with small air holes, and ash and high-temperature solid debris To collect effectively.

In the high-temperature solid packed bed, the position of the high-temperature solid is shifted due to the pressure of the exhaust gas or the thermal expansion of the exhaust gas due to solid heat conduction by the high-temperature solid, or the thermal expansion of the high-temperature solid itself. Clogging is suppressed. Dividing the high-temperature solid packed layer of the same thickness into multiple layers to reduce the thickness per layer has the advantage that the position of the high-temperature solid is easily shifted. Therefore, the effect of the high-temperature solid is great when a mixture of materials having irregular shapes and materials having greatly different coefficients of thermal expansion is used. If necessary, reduce the ventilation resistance and easily cause the displacement of the high-temperature solids, and more effectively suppress the clogging of the high-temperature solid packed layer.
The high-temperature solid packed layer is divided as much as possible so that the thickness per layer is at most 200 mm or less, preferably 50 to 70 mm.
The thinner the better, the more the number of divisions, the more effective the collision between the exhaust gas and the high-temperature solid, and the higher the effect of the high-temperature solid contact. It is preferable that the distance between layers is at least 25 mm or more. However, if there is room for drafting and you want to reduce the cost of the support material, another layer can be placed directly on the high-temperature solid-packed layer or thermally insulated for buffering thermal expansion. A high temperature solid packed layer may be stacked with a material sheet or the like sandwiched therebetween.

When a high-temperature solid having individual vent holes is used, the orifice effect and the geometric surface area for oxidizing the exhaust gas become large, so that a high-temperature solid contact effect can be effectively obtained, and at the same time, the exhaust gas passage is formed only by a gap between the high-temperature solids. The airflow resistance is lower than in the case. In addition, since the heat storage capacity is small, the heat can be heated up in a short time. In order to store heat in a high-temperature solid in a short period of time, besides providing ventilation holes in individual high-temperature solids, it is preferable that the heat capacity per unit volume is small, such as fibrous, porous (non-connected vents are also possible), thin, etc. Examples include calcium silicate heat insulating material pieces, flocculent refractory material (bulk), pearlite grains, porous natural stones, foamed particles of coal ash, and hollow ceramic spheres. In addition, when each high-temperature solid is lightened (small), the position of the high-temperature solid easily shifts. Further, if the high-temperature solid is sufficiently small and light, the high-temperature solid flows and the clogging is less likely to occur. In this case, the high-temperature solid must be multi-layered to compensate for a decrease in the dust collecting power.

First, the hole (gap) from which the exhaust gas of the high-temperature solid itself or the supporting material thereof escapes has an opening ratio of 30% or more in terms of the projected area ratio from above the vertical furnace, and the hole size is restricted by clogging. When the thickness is 10 mm or more, a sufficient dust collecting effect cannot be expected with respect to fine incombustible dust even with the synergistic effect of high-temperature fine particle adhesion and filtration and dust collection. In addition, when a container is used to support the high-temperature solid packed bed at a support material interval larger than the high-temperature solid dimension, the container for storing the high-temperature solid is opened at the top, and the bottom is provided with a hole through which the exhaust gas is discharged at an opening ratio of 40% or more. It is open and the size of the hole may be any size as long as the high-temperature solid does not leak. When a container is not used, a perforated plate having a hole size smaller than the size of the high-temperature solid and having an opening ratio of 40% or more may be sandwiched between the support material and the high-temperature solid to combine support and rectification of the support and a high-temperature solid contact effect.

When the production cost is not to be hindered, a backwashing device by air injection or water washing, and a mechanism for preventing clogging by rocking (vibration) of a container containing a high-temperature solid by power such as electric power, hydraulic pressure, or pneumatic pressure are provided. Dust collection and reburning device structure that extends the maintenance period of the high-temperature solid packed bed.

Further, the high-temperature solid may be a material carrying a catalyst capable of decomposing an unburned gas. In addition, you may shape | mold the high temperature solid itself with a catalyst. However, even a catalyst whose catalytic activity is degraded below 800 ° C. due to thermal deterioration due to burner heating or catalyst poison in exhaust gas is required to be able to exhibit a sufficiently effective oxidizing ability at 800 ° C. or higher than a non-catalyst. If noble metal (oxide) particles can be dispersed on a washcoat with a large specific surface area even at a high temperature to which rare earth is added, it becomes an expensive but highly active high-temperature catalyst, and it is difficult to decompose dioxins and CFCs at a lower space velocity. The substance can be oxidatively decomposed. Aluminum compounds such as aluminum hydroxide, aluminum oxide, and aluminum phosphate,
Silica-based catalysts such as cristobalite, zeolite, sepiolite and tourmaline, and alumina-silica-based catalysts, all or part of which are alkaline earth metals such as Mg, Ca, Sr and Ba, or rare earths such as Y, La, Ce and Pr , R
Noble metals such as u, Rh, Pd, Pt, Ag, Au, etc., T
i, Zr, V, Cr, Mo, W, Mn, Fe, Co, N
A compound substituted with a transition element such as i or Cu or a heavy metal element such as Zn or Sn becomes a catalyst having sufficient activity at a high temperature of 800 ° C. or higher. In addition, since it is used at a temperature of 800 ° C. to 1100 ° C., there is an advantage that it is free from the influence of catalyst poisons such as tar, sulfide, and steam.

When the cost of the high-temperature solid is not reluctant, the high-temperature solid is treated with slaked lime, calcium oxide, calcium carbonate, calcium phosphate, calcium sulfate, magnesium hydroxide, magnesium oxide, magnesium carbonate, potassium oxide, potassium hydroxide, potassium carbonate, water. Sodium oxide, sodium carbonate, sodium bicarbonate, lithium hydroxide, lithium carbonate, dolomite, talc, granite, nepheline,
By molding an alkaline material such as feldspar or coal ash singly or as a mixture, or by using a high-temperature solid impregnated or coated with an alkaline material, it has an ability to remove acidic gases such as hydrogen chloride gas and sulfur dioxide. Further, the alkaline material may be replaced with another inorganic material having adsorption or resolution of acid gas, dioxin precursor or dioxin itself. Aluminum compounds such as aluminum hydroxide, aluminum oxide, aluminum phosphate, cristobalite, zeolite, sepiolite,
Examples thereof include silica-based and alumina-silica-based adsorbents such as tourmaline, granite, nepheline, perlite, shirasu, and foamed particles of coal ash, and materials having ion exchange properties. Alkaline metals such as Li, Na, K, Mg, C
a, Sr, alkaline earth metal such as Ba, or Y,
Rare earths such as La, Ce, Pr, Ru, Rh, Pd, P
noble metals such as t, Ag, Au, Ti, Zr, V, Cr,
Transition elements such as Mo, W, Mn, Fe, Co, Ni and Cu, metal elements such as Zn and Sn, and compounds substituted with B are preferable adsorbents and ion exchange materials.

When the combustion air is insufficient with only the reburning burner, the combustion air is introduced from the combustion air hole provided between the start end of the smoke duct and the high-temperature solid packed bed, and the combustion air is supplied to the high-temperature solid packed bed. A reburning structure in which air holes for combustion are arranged between the start of the smoke duct and the high-temperature solid packed bed in order to mix and combust unburned gas and particulate matter.

[0017]

The operation procedure for collecting and reburning exhaust gas using this combustion device is as follows. First, a reburn burner arranged on the lower side of the vertical structure so that the burner flame contacts the exhaust gas introduced from the smoke duct. To rapidly heat the combustion device. The operation control of the burner is controlled so as to be in a temperature range set according to a measurement instruction of a thermocouple provided after the high-temperature solid packed bed. 800 ° C for this device
１1100 ° C. The set temperature is reached in 15 to 60 minutes, and then the operation of the incinerator connected by the smoke duct is started.

In operation of the incinerator, waste mainly composed of garbage such as paper waste is introduced from a waste inlet of the incinerator.
After igniting the upper part of the input waste, the blower is started by a switch on the operation panel of the incinerator and the operation is started. Subsequently, the incineration of the waste is continued by the operation of charging the target waste.

The combustion gas is continuously led to a partitioned chamber called a secondary combustion chamber in the incinerator, and reburns the unburned gas. In the secondary combustion chamber, in the initial stage of combustion, during unstable combustion at the time of additional injection, excessive incineration, or when foreign matter such as plastic is mixed in, it is not possible to completely burn with the incineration chamber that only inputs waste. It is often technically difficult. Therefore, the secondary combustion chamber has a role as a buffer area of the incineration chamber.

However,

In the incinerator using the secondary combustion chamber described in
Generally, it is not easy to reburn black smoke, unburned gas, and the like that do not burn out in an incinerator. Further, the conventional secondary combustion chamber has a combustion exhaust gas combustion residence time of about 0.3 to 0.7 seconds, and has a design structure that focuses on the thermal decomposition of odor components. In addition, the passage structure of the combustion gas led from the incinerator is configured to pass through the lower part of the vertically partitioned partition wall, and does not have effective stirring and mixing of the exhaust gas at high temperature, and often He was about to experience fuming. Further, such a structure alone cannot sufficiently secure the combustion temperature of the exhaust gas, and as a result, has not fulfilled the role of the exhaust gas combustion chamber. Naturally, there is no dust collecting effect.

[0021]

When the exhaust gas from the incinerator described in the above section was introduced into the exhaust gas purifier of the present invention, the outlet of the incinerator and the exhaust gas purifier were connected by a smoke duct. The smoke duct is required not to lower the temperature of the exhaust gas, and the duct has heat insulation.

The unburned exhaust gas is introduced from the smoke duct, comes into contact with the burner flame, and is collected and reburned in the hot solid packed bed.

The unburned exhaust gas is heated and stirred by using a reburning burner arranged on the lower side surface of the vertical structure so that the flame contacts the exhaust gas rising to the high-temperature solid packed bed. Is maintained so as not to lower the temperature. It is assumed that the temperature is always controlled to an arbitrary temperature range of 800 ° C. to 1100 ° C. by this reburn burner. When the combustion air is insufficient with only the reburn burner, the combustion air may be introduced from the combustion air hole between the start end of the smoke duct and the high-temperature solid packed bed.

Next, the inside of the apparatus is covered with 8 so as to cover the support material.
Ceramics or refractory metal, which has a large contact area and a diameter of 15 which is maintained in an arbitrary temperature range of 00 ° C to 1100 ° C.
mm or less solid, for example, cylindrical, saddle-shaped, gravel-shaped, granular,
A method of installing a high-temperature solid packed layer filled (laminated) with a high-temperature solid such as a column, a perforated plate, or a flocculent (bulk), and making it pass through and contact the high-temperature solid packed layer to thermally decompose unburned gas components. Is very effective.

Further, the high-temperature solid covering the support may be a functional material such as a material carrying a catalyst capable of oxidizing unburned gas at a high temperature, an alkali material for neutralizing a dioxin precursor, an adsorbent, and an ion exchange material. . In addition, you may shape | mold the high temperature solid itself with a functional material.

After contact with the burner flame, the exhaust gas that has passed through the heat-stored high-temperature solid packed bed, collected and reburned, rises to the upper exhaust port of the device that is open to the ceiling, and is discharged from the tip of the chimney. In addition, an ejector mechanism must be provided in the middle of the chimney to cover the ventilation resistance in the exhaust gas purification device, and to introduce the target combustion gas while always maintaining the furnace pressure at a negative pressure. .

Due to these structures and effective arrangement, the unburned gas introduced into the exhaust gas purifying apparatus is sufficiently promoted in combustion, and at the same time, the dust concentration is suppressed to a low level by the high-temperature particle adhesion and the dust collecting effect by filtration. . The collected combustible dust is reburned on the high-temperature solid surface and becomes ash, so that it is less likely to be clogged than low-temperature dust. As a result, unburned components generated by incomplete combustion in the incinerator, so-called carbon monoxide, black smoke, odor components including nitrogen such as ammonia and trimethylamine, odor components including sulfur such as methyl mercaptan and hydrogen sulfide, and hydrocarbons In addition, dioxin precursors and dioxins are reduced by thermal decomposition. Dust often adsorbs dioxin and its precursors, and trapping soot leads to suppression of dioxins. As a result, it is possible to stably suppress the thermal decomposition of dioxins.

For comparison, other methods for removing dioxins include a method of spraying powdered activated carbon and adsorbing and removing it with a bag filter, a method of adsorbing by passing through a granular activated carbon (activated coke) layer, and a method of removing titanium oxide. There is a catalytic decomposition method using a catalytic filter.

The spraying method of powdered activated carbon requires an expensive bag filter dust collector, an exhaust gas quenching device is installed in front of the dust collector to protect the filter cloth having a low heat-resistant temperature, and the exhaust gas is condensed at the dust collector inlet. It must be rapidly cooled to 150 ° C. or higher and the temperature range of 250 ° C. or lower where dioxin can be collected in a solid state, ie, usually 150 to 200 ° C. The activated carbon atomizer and activated carbon storage tank used are also required. In general, an apparatus for spraying slaked lime is separately provided. When spraying activated carbon into the flue, it is operated to prevent dust explosion, but there is no danger of explosion.

In the method of passing through a granular activated carbon (activated coke) layer, the exhaust gas must be cooled and introduced to 400 ° C. or less, which is the heat-resistant temperature of activated carbon. Nevertheless, there is no danger of a fire accident. Countermeasures such as monitoring devices and fire extinguishing devices are required. Recycling equipment for used activated carbon is an expensive equipment that heats and agitates in a reducing atmosphere, and is expensive to manufacture and operate. Even if outsourcing is outsourced, there are still few facilities with regeneration equipment, and transport to remote locations Often forced to do. In some large furnaces, they are returned to the incinerator for incineration, but activated carbon is classified as a flame-retardant, and incineration in small incinerators is not easy. There is no small possibility that unburned gas such as carbon monoxide increases to cause an increase in dioxin concentration. Therefore, it is necessary to perform operation adjustment or remodeling so that good operation can be performed even in co-firing.

The titanium oxide catalyst does not ignite, but the exhaust gas must be cooled to 600 ° C. or lower so as not to lose the catalytic activity. Usually, it is used in the equipment after the bag filter dust collector. However, since the catalytic activity becomes effective at 200 ° C. or higher, it must be reheated. As described above, in comparison with these devices, the exhaust gas purification method does not require an exhaust gas cooling device before introducing exhaust gas into the exhaust gas purification device. A bag filter dust collector is not required unless a dust collection effect that satisfies the regulation value or a dioxin concentration comparable to that of a city furnace is required.

High-temperature solids that are not a functional material type such as catalysts do not ignite and have a long life like activated carbon and activated coke.
Since it passes through a high temperature range of 00 ° C or more, it is possible to omit troublesome regeneration steps such as used activated carbon adsorbing dioxins and co-firing of used activated carbon and activated coke, thereby reducing operating costs as well as production costs. Since the ventilation resistance is small, the output of the exhaust fan is also small. The number of exhaust gas treatment equipment is only one, and the volume of the unit itself is small, saving space. Compared with the primary combustion chamber main body sometimes seen in small incinerators, the exhaust gas treatment equipment in the subsequent stage is unusually large and wide. It is not necessary to occupy the installation space. Manufacturing,
It is also an invention in which all costs for operation and maintenance are low and economic benefits are great. If there is no restriction on cost and installation space, wastewater treatment equipment is provided, and if there is no risk of generating white smoke, a water spray device is installed at the subsequent stage of the combustion furnace to rapidly cool the exhaust gas temperature to 150 to 200 ° C and dioxin. It may be possible to thoroughly prevent the re-synthesis of products and prevent global warming.

[0033]

The exhaust gas purifying apparatus of the present invention introduces an existing odor source or an unburned gas from an incinerator, and after contact with a burner flame, a high-temperature solid-filled layer installed on a supporting material allows the object to be treated. The same residence time results in more reliable reburning, where the unburned gas is effectively pyrolyzed by the hot solids contact effect. The residence time is shorter than in a secondary combustion furnace without a high-temperature solid packed bed, so that a small-volume secondary combustion furnace can be used.
It is capable of oxidatively decomposing unburned components such as carbon monoxide, odorous components, black smoke, hydrocarbons, and dioxin precursors and dioxins themselves, thereby suppressing generation of toxic dioxins and reducing decomposition. In addition, since the temperature is high, the adhesion (weak force between molecules) of fine particles such as dust is 5 to 10 times that of normal temperature, and even if the material is not porous, the fine particles below the through-hole or the gap between the high-temperature solids are collected. Power is high. Unlike activated carbon (activated coke) adsorption method, even after trapping in the high-temperature solid packed bed, unburned harmful substances are oxidized and decomposed on the surface of the high-temperature solid due to the thermal effect of solid heat conduction and far-infrared radiation due to heat storage, and the catalytic effect for functional material types. I do.

[0034]

In order to control dioxin generation and decomposition at low cost, (1) plastic waste containing chlorine, such as vinyl chloride resin and vinylidene chloride, and preservative treatment, For combustion, it is important to separate construction materials and plywood impregnated with bromine and chlorine-based materials, and to separate and treat waste that is liable to generate dioxins. (2) It is said that proper operation of the incinerator is an important factor. Further, in the case of the present invention, it is necessary to devise a method of controlling the amount of the unburned gas to be introduced so as not to exceed the decomposition maintaining ability of the exhaust gas purifying device. For this purpose, the air volume can be varied by controlling the number of revolutions of the motor of the combustion blower (by the inverter) and the furnace pressure can be controlled by the equilibrium ventilation by the ejector mechanism. An effective technique is to continuously measure the concentration of carbon monoxide and control the amount of combustion air and combustion temperature. If cost and installation space allow, to prevent dioxins from re-synthesizing in the cooling zone after the chimney of the exhaust gas purifier, equipment and bag filters for rapidly cooling the chimney exhaust gas to 150 to 200 ° C If a dust machine, a dioxin decomposition catalyst tower, an activated carbon (activated coke) packed tower, or a combination thereof is provided, dioxins can be removed to an extremely small amount.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an example of a cross section of an exhaust gas purifying apparatus. In FIG. 1, reference numeral 10 denotes a main body of the exhaust gas purifying apparatus. The main body 10 is composed of a calcium silicate heat insulating material 12, a castable or fire-resistant heat-insulating brick 13 which is a fire-resistant heat-insulating furnace material 13 inside a casing 11 made of a metal material, and a combustion chamber is formed therein. An inspection door 42 is provided on the main body 10 so that the support member 21 and the high-temperature solid filling layer 30 can be taken in and out and inspected. In the lower part of the main body 10, there is an introduction duct 20. Further, a reburn burner 40 is mounted on the lower side surface of the main body 10 using a burner tile 41 so that the inside of the main body 10 can be maintained at an arbitrary temperature range of 800 ° C. to 1100 ° C. On the ceiling 50 of the main body 10, an upper device exhaust port 51 is opened on the ceiling.

A support member 21 is disposed in the middle of the main body 10, and a high-temperature solid packed bed 30 is placed thereon, and an introduced gas is passed therethrough. On the lower side of the body 10 where the burner flame contacts the rising gas flow to the hot solid packed bed 30,
No. 0 is attached via the burner tile 41 to effectively store heat in the high-temperature solid packed layer 30. The exhaust gas reburned and collected in the high-temperature solid packed bed 30 is guided to an upper exhaust port 51 opened in the ceiling 50 and exhausted from the chimney.

FIG. 2 shows an example in which three high-temperature solid-filled layers 30 are directly stacked on a support 21 on the main body 10. Compared with a single high-temperature solid packed layer having the same thickness, the ventilation resistance of the exhaust gas is reduced and the position of the high-temperature solid is easily shifted, thereby suppressing clogging.

FIGS. 3 and 4 are enlarged views of the high-temperature solid filling layer 30. FIG. The example of FIG. 3 is a form in which a box-shaped container having an open top is filled with a high-temperature solid-filled layer-lower layer 31 filled with a high-temperature solid 32 (rubble-shaped in the example of FIG. 3) with a support 21 so that exhaust gas can escape. It is. A vent is provided at the bottom of the box-shaped container, and the opening ratio of the vent needs to be 40% or more in view of the exhaust gas ventilation resistance. The size of the vent is set so that the high-temperature solid does not leak. FIG. 4 shows a high-temperature solid-filled layer--a lower layer 31 and a high-temperature solid-filled layer--an upper layer 33 which is placed on the lower layer to prevent ash generated by reburning in the layer (in the example of FIG. (Filter plate).

FIGS. 5, 6, and 7 show the types of the high-temperature solids 32. FIG. In the demonstration example, a gravel shape such as 32-3 in FIG. 7 was used as the high-temperature solid, but if the solid has a large contact area,
For example, a cylindrical shape such as the high-temperature solid 32-1 in FIG. 5, a saddle shape, a granular shape, a columnar shape, a perforated plate shape, a cotton shape (bulk), or the like as in 32-2 in FIG.

The exhaust gas purifying apparatus 1 configured as described above
An example in which unburned gas from an incinerator is treated using 0 will be described with reference to FIGS. Garbage discharged from the factory,
Paper waste, paper bags, packaging materials, wooden crates, packaging materials, waste cloth,
Incinerator 100 for incinerating mixed waste such as oil waste, plastic films and containers, tea rag, cigarette wick, etc.
FIG. 2 is a view of an exhaust gas purifying device main body 10 connected from the primary combustion chamber outlet through a smoke guide duct 20. A control panel 60, a reburn burner 40, an air chamber 104, an incinerator outlet measurement port 110, a chimney measurement port 53, and a chimney 52 are provided independently on the side surface of the main body 10.

Opening door 101 of incinerator 100 is opened and waste is introduced. After the input waste is ignited, the combustion blower 102 is started on the operation panel 103 of the incinerator, and the combustion air is distributed and supplied to the air chamber 104 in order to distribute the combustion air to an appropriate place in the incinerator. With this air supply, the waste starts burning rapidly. Thereafter, the waste is incinerated by repeating the charging 5 to 7 times an hour. The incinerator exhaust gas thus burnt is introduced into the exhaust gas purifier main body 10 via the smoke duct 20.

The operation of the exhaust gas purifying apparatus 10 is controlled by the control panel 60.
Is controlled in Set the temperature inside the exhaust gas purifier to 800
The temperature of the reburn burner 40 is controlled by the temperature controller 131 in the range of 800 ° C. to 860 ° C. in this time from the temperature range of 1 ° C. to 1100 ° C. Further, the exhaust power of the chimney 52 is increased by the air discharged from the ejector elbow 121 by the exhaust fan 120 so that the furnace pressure of the incinerator 100 becomes a negative pressure.
After stopping the operation of the incinerator, the exhaust gas purifying apparatus main body 10
By stopping the operation, purification of unburned exhaust gas is achieved, and the present invention can be implemented.

Table 1 shows the measurement results of one embodiment of the present invention. The waste put into the incinerator 100 is industrial waste at a machine factory. The incinerator 100 is an incinerator type, with an incineration capacity of 40 to 5
5 kg / h. The combustion chamber volume of the incinerator 100 is 0.6
0 m ³ . The incinerator 100 was repeatedly charged with 8 to 10 kg of waste every about 10 minutes. Regarding the behavior of the exhaust gas during operation, first, the exhaust gas oxygen concentration is in the range of 5.3% to 14%, and stable combustion is possible at an average value of 12.7%. The exhaust gas purifier 10 stabilizes the introduced gas by securing the high temperature and residence time and operating under the complete combustion conditions with stirring and mixing. As a result, the carbon monoxide concentration at the chimney measuring port 53 is increased to an average of 19 ppm. Reduced. In Table 1, O2 represents oxygen, CO represents carbon monoxide, HCL represents hydrogen chloride gas, and SOx represents sulfur oxide.

The so-called dioxins are basically a group of organic compounds consisting of two benzene nuclei and chlorine. It is a substance that would otherwise be pyrolyzed at high temperatures during the combustion process.
However, unintentional generation in an incomplete combustion state accompanied by generation of carbon monoxide and cooling process of exhaust gas following combustion,
It has been revealed that unburned hydrocarbons and hydrogen chloride are re-synthesized and generated by the catalytic action of a metal compound contained in dust (De Novo synthesis). Most dioxins are adsorbed on dust.
Therefore, the most important point is how to collect soot in exhaust gas and how to completely thermally decompose unburned organic substances (suppression of generation). In order to prove this, the result of measuring the dust concentration at the measuring port 53 is 0.05 g / m ³ N and the regulated value is 0. Clears 15 g / m ³ N. Comparing the dioxin concentrations measured at the incinerator outlet measurement port 110 and the chimney measurement port 53, 11 ng-TEQ / m ³ N
From about 97% to 0.33 ng-TEQ / m ³ N, and high dust collection capacity and dioxin removal performance were obtained. This is the emission standard for dioxins: 5ng-TEQ
/ M ³ N is greatly cleared.
It has been confirmed that the present invention is extremely effective as a device for suppressing and reducing dust collection and dioxins in a measure having a waste incineration capacity of less than 200 kg / h.

Table 1 shows the measurement results at the time of the demonstration operation using the apparatus shown in FIG.

[Table 1]

[Brief description of the drawings]

Fig. 1 Vertical section of an exhaust gas purification device

FIG. 2 is a vertical cross section of an exhaust gas purifying apparatus having a three-layer structure of a high-temperature solid packed bed.

Fig. 3 High-temperature solid packed bed-lower layer

Fig. 4 High-temperature solid-filled layer-lower layer + upper layer

Fig. 5 High temperature solid-cylindrical

FIG. 6: High temperature solid-saddle

FIG. 7: High-temperature solid-rubble

FIG. 8: Demonstration example-connection diagram

FIG. 9: Demonstration example-operation control flow

[Description of Signs] 10 Exhaust gas purification device main body 11 Casing 12 Calcium silicate heat insulating material 13 Refractory heat insulating furnace material (castable, brick, etc.) 20 Smoke guide duct 21 Support material 30 High temperature solid filling layer 31 High temperature solid filling layer-lower layer 32 -1 High-temperature solid-cylindrical 32-2 High-temperature solid-saddle-shaped 32-3 High-temperature solid-brake 33 High-temperature solid packed bed-upper layer 40 Reburner 41 Burner tile 42 Inspection door 50 Ceiling 51 Upper exhaust outlet 52 Chimney 53 Chimney 53 Measuring port 60 Control panel 100 Incinerator 101 Inlet door 102 Combustion blower 103 Incinerator operation panel 104 Air chamber 110 Incinerator outlet measuring port 120 Air exhaust 121 Ejector elbow 131 Temperature controller

Claims (8)

[Claims] 1. An incinerator exhaust gas purifying apparatus, comprising a high-temperature solid packed bed made of a high-temperature solid having a diameter of 15 mm or less.
In order to maintain an arbitrary temperature of 0 ° C to 1100 ° C and to supply high-temperature combustion air, a reburn burner is arranged on the lower side surface of the vertical structure, and a ceramic having heat storage properties is provided in the middle of the device. Alternatively, a high-temperature solid-filled layer filled (laminated) with a high-temperature solid made of a heat-resistant metal having a large contact area, for example, a cylindrical, saddle-shaped, gravel-shaped, granular, cylindrical, perforated plate-like, or cotton-like (bulk) -like solid. The exhaust gas containing unburned components is introduced from the smoke duct, and after the exhaust gas comes into contact with the burner flame, the diameter is maintained at an arbitrary temperature range of 800 ° C. to 1100 ° C. and has a large number of vent holes (gap). It passes through a packed bed of hot solids of 15 mm or less. The combustible dust collected in the bed is completely burned on the surface of the stored high-temperature solid, leaving ash. As a result, compared to an exhaust gas combustion device of the same volume,
An exhaust gas purifying method and structure characterized in that carbon monoxide, odor components, black smoke, soot and dust, hydrocarbons, dioxin precursors, and dioxins themselves can be more effectively reduced, and are less likely to be clogged than low-temperature dust collection. 2. The exhaust gas purifying apparatus according to claim 1, wherein a part of the upper layer of the high-temperature solid packed layer is formed through the lower layer to form a vent hole as required to suppress scattering of ash and high-temperature solid debris generated on the surface of the high-temperature solid. Composed of a high-temperature solid packed bed with a small gap)
Exhaust gas purification structure that effectively collects ash and high-temperature solid debris. 3. The exhaust gas purifying apparatus according to claim 1, wherein, if necessary, the ventilation resistance is reduced, and the position of the high-temperature solid is easily shifted intentionally, whereby the clogging of the high-temperature solid packed bed is more effectively suppressed. The exhaust gas purifying apparatus structure in which the high-temperature solid packed bed is divided as much as possible so that the thickness per layer is at most 200 mm or less, preferably about 50 to 70 mm. It is preferable that the distance between layers is at least 25 mm or more. However, if there is room for drafting and you want to reduce the cost of the support material, another layer can be placed directly on the high-temperature solid-packed layer or thermally insulated for buffering thermal expansion. Material sheet etc.,
High temperature solid packed layers may be stacked. 4. The exhaust gas purifying apparatus according to claim 1, wherein each of the high-temperature solids has a vent hole to effectively obtain a high-temperature solid contact effect, reduce ventilation resistance, reduce heat storage capacity, and heat up in a short time. Exhaust gas purification device structure having In order to store heat of a high-temperature solid in a short time, it is preferable that each high-temperature solid has a small heat capacity per unit volume, such as a fibrous or porous material (a non-connected vent may be used) or a thin material. Examples include heat insulation pieces, flocculent refractory material (bulk), pearlite particles, porous natural stone, foamed particles of coal ash, and hollow ceramic spheres. Further, when the individual high-temperature solids are lightened (small), the displacement of the high-temperature solids described in claim 1 easily occurs. Further, if the high-temperature solid is sufficiently small and light, the high-temperature solid flows and the clogging is less likely to occur. In this case, the high-temperature solid must be multi-layered to compensate for a decrease in the dust collecting power. 5. The exhaust gas purifying apparatus according to claim 1, wherein a backwashing device by air injection or water washing or a container containing a high-temperature solid by power such as electric power, hydraulic pressure, or pneumatic pressure is shaken when the production cost is not tolerated. Exhaust gas purifier structure that has a mechanism to prevent clogging due to movement (vibration) and extends the maintenance period of the high-temperature solid packed bed. 6. An exhaust gas purifying apparatus according to claim 1, wherein a high temperature solid carrying a catalyst for improving the oxidation resolution of the unburned gas is provided, if necessary, without raising the cost of the high temperature solid. In addition, you may shape | mold the high temperature solid itself with a catalyst. The volume of the high-temperature solid packed bed can be reduced by supporting the catalyst, and the ventilation resistance can be reduced. Exhaust gas purifier with higher oxidation resolution than high-temperature solid packed bed of the same volume without catalyst. As candidates thereof, aluminum compounds such as aluminum hydroxide, aluminum oxide, and aluminum phosphate, silica-based catalysts such as cristobalite, zeolite, sepiolite and tourmaline, and alumina-silica-based catalysts, the whole or a part of which is made of Mg, Ca, Sr, Ba Alkaline earth metals such as Y, La, Ce, Pr
Rare earths such as Ru, Rh, Pd, Pt, Ag, and Au, Ti, Zr, V, Cr, Mo, W, Mn,
Compounds substituted with transition elements such as Fe, Co, Ni, and Cu, and heavy metal elements such as Zn and Sn provide a catalyst having sufficient activity at a high temperature of 800 ° C. or higher. 7. The exhaust gas purifying apparatus according to claim 1, wherein the high-temperature solid is treated with slaked lime, calcium oxide, calcium carbonate, calcium phosphate, calcium sulfate, magnesium hydroxide, magnesium oxide, if necessary without raising the cost of the high-temperature solid. Alkaline materials such as magnesium carbonate, potassium oxide, potassium hydroxide, potassium carbonate, sodium hydroxide, sodium carbonate, sodium bicarbonate, lithium hydroxide, lithium carbonate, dolomite, talc, granite, nepheline, feldspar, and coal ash An exhaust gas purifying apparatus having the ability to remove acidic gases and dioxin precursors or dioxins themselves by using a high-temperature solid formed alone or in a mixture, or impregnated or coated with an alkaline material. In addition, this alkaline material,
It may be replaced with another inorganic material having adsorption or resolution of acid gas, dioxin precursor or dioxin itself. Aluminum compounds such as aluminum hydroxide, aluminum oxide, and aluminum phosphate, cristobalite, zeolite, sepiolite, tourmaline, granite,
Examples of the adsorbent include silica-based and alumina-silica-based adsorbents such as expanded particles of nepheline, perlite, shirasu, and coal ash, and materials having ion exchange properties. Li or N
alkaline metals such as a and K, alkaline earth metals such as Mg, Ca, Sr and Ba, or Y, La, Ce and Pr
Rare earths such as Ru, Rh, Pd, Pt, Ag, Au and the like, Ti, Zr, V, Cr, Mo, W, Mn,
Transition elements such as Fe, Co, Ni, Cu, Zn, Sn
Compounds substituted with heavy metal elements such as B and B are preferable adsorption (decomposition) materials and ion exchange materials. 8. In the exhaust gas purifying apparatus according to claim 1, when the combustion air is insufficient with only the reburn burner, the combustion air is introduced into an arbitrary position between the start end of the smoke duct and the high-temperature solid packed bed, and the high-temperature Exhaust gas purification device structure in which combustion air holes are arranged at an arbitrary position between the beginning of the smoke duct and the high-temperature solid packed bed because the combustion air and unburned gas and dust are mixed and burned well in the solid packed bed.