JPH102541A - Waste gas treating facility for waste treating furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit the re-utilization of active carbon by separating and recovering the active carbon injected into a waste gas flow passage. SOLUTION: The waste gas treating facility of a waste treating furnace is provided with a reactor 3, injecting the powder of active carbon 4, limestone 5 and the like to remove dioxine, chlorine gas and the like contained in exhaust gas 2, and a filter type or electric dust collector 7, collecting dust from the exhaust gas 2, which has passed through the reactor 3, on the flow passage R of the exhaust gas, discharged out of a waste treating furnace. The grain size of active carbon 4, injected into the reactor 3, is set so as to be larger than that of flying ash 6 and limestone 5 while a centrifugal dust collector 8, separating and recovering only the active carbon 4, is provided between the reactor 3 and the filter type or electric dust collector 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to dioxin contained in exhaust gas by injecting powder such as activated carbon and limestone onto a flow path of exhaust gas discharged from a waste treatment furnace.
The present invention relates to an exhaust gas treatment facility for a waste treatment furnace including a reactor for removing chlorine gas and the like, and a filtration or electric dust collector for collecting dust from exhaust gas passing through the reactor.

[0002]

2. Description of the Related Art Conventionally, in an exhaust gas treatment facility of this kind of waste treatment furnace, first, powder such as activated carbon and limestone is opposed to a flow of exhaust gas inside a reactor provided below the waste treatment furnace. To remove dioxin and chlorine gas in the exhaust gas. Thereafter, the activated carbon and the like conveyed along the exhaust gas flow path were collected using a filtration type or an electric type dust collector provided at the lower part of the reactor, and substantially all of the collected amount was discarded.

[0003]

However, the above-mentioned conventional exhaust gas treatment equipment has the following problems. Among the impurities contained in the exhaust gas, dioxin is particularly harmful and must be reliably removed. Therefore, the activated carbon used to adsorb dioxin has a fine particle size to increase the adsorption area, and a sufficient amount of activated carbon is injected into the reactor in comparison with the amount of dioxin present. However, in this method, although the adsorption of dioxin can be performed almost certainly, the total amount of activated carbon contributing to the adsorption of dioxin is small, so that the consumption of activated carbon tends to increase. Moreover, since the particle size of the activated carbon injected in the reactor was equal to the particle size of the fly ash contained in the limestone or the exhaust gas injected at the same time, only the activated carbon was extracted from those collected by the dust collector. It was difficult, and it was impossible to reuse activated carbon.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide an exhaust gas treatment facility of a waste treatment furnace capable of separating and recovering activated carbon injected into an exhaust gas passage and reusing the activated carbon. Is to do.

[0005]

[Means for Solving the Problems]

(Configuration 1) The exhaust gas treatment equipment of a waste treatment furnace according to the present invention, as described in claim 1, sets the particle size of activated carbon injected into the reactor larger than the particle size of fly ash and limestone, It is characterized in that a centrifugal dust collector for separating and recovering only activated carbon is provided between the reactor and a filtration or electric dust collector. (Operation / Effect) In the exhaust gas treatment equipment of this configuration, the particle size of the activated carbon is set particularly large, and accordingly, the mass of each activated carbon particle is also greatly increased. For this reason, it is possible to use a centrifugal dust collector in which the powder separation performance increases as the mass difference increases. Therefore, the activated carbon once injected into the exhaust gas flow path can be reliably recovered in a state separated from other limestones and the like, and the consumption of the activated carbon can be reduced by reusing the activated carbon, which is economical. Advantageous exhaust gas treatment can be realized. Also, since the centrifugal dust collector has no moving parts and has a simple structure, it is easy to maintain and manage.
No inconvenience is caused by providing the centrifugal dust collector.

(Structure 2) The exhaust gas treatment equipment of a waste treatment furnace according to the present invention is provided with an activated carbon circulation mechanism for supplying the separated and recovered activated carbon to the reactor again, as described in claim 2. Can be configured. (Operation / Effect) If an activated carbon circulation mechanism is provided as in the present configuration, the recovered activated carbon can be continuously circulated and supplied to the reactor. At that time, the amount of activated carbon circulated and the like can be arbitrarily set according to the dioxin concentration in the exhaust gas, so that the dioxin treatment capacity of the reactor is maintained. Further, in a specific part of the activated carbon circulation mechanism, a predetermined amount of activated carbon can be discarded and new activated carbon can be added, so that the dioxin adsorption capacity of the activated carbon to be circulated can be maintained at a certain level or more. Easy to do.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. (Overview) As shown in FIG. 1, an exhaust gas treatment facility of a waste treatment furnace 1 according to the present invention includes a reactor 3 for removing dioxin or chlorine gas or the like in an exhaust gas 2 flowing through an exhaust gas flow path R; Usually, a filtration type or an electric type dust collection is provided on the lower side of the reactor 3 to collect the activated carbon 4, limestone 5, etc. and the fly ash 6 contained in the exhaust gas 2 injected into the interior of the reactor 3. A centrifugal force dust collecting device 8 is provided between the device 7 and the activated carbon circulating mechanism K is provided between the centrifugal force dust collecting device 8 and the reactor 3. That is, only the activated carbon 4 is recovered by using the centrifugal dust collector 8, and thereafter, a part of the recovered activated carbon 4 is exchanged for new activated carbon 4 by using the activated carbon circulation mechanism K, and the reactor 3 Again. Hereinafter, an exhaust gas treatment facility of a waste treatment furnace according to the present invention will be described.

(Reactor 3) In the reactor 3, the exhaust gas 2
In order to remove dioxin or chlorine gas, NOx, SOx and the like therein, powders such as activated carbon 4 and limestone 5 are injected. This injection is performed using an injection device 9 attached to the reactor 3 and the like, and is performed via a stainless steel supply nozzle 10 installed in a state facing the flow of the exhaust gas 2. Among the powders sprayed here, especially activated carbon 4
Use a limestone 5 having a larger particle size than other limestones. In the conventional method, activated carbon 4 having a particle size of 10 to 50 μm was used. However, in the exhaust gas treatment equipment of the present invention, a particle size of 400 to 600 μm was considered in consideration of easiness of separation and recovery as described later. Is used. On the other hand, the particle size of the limestone 5 is 10 to 100 μm, which is the same as that of the conventional limestone. The particle size of fly ash 6 contained in exhaust gas 2 is usually 1 to 100 μm.

(Centrifugal Dust Collector) The exhaust gas 2 mixed with the various powders described above is led to the centrifugal dust collector 8 after passing through the reactor 3. The centrifugal dust collector 8 includes:
For example, cyclone 8A is used. Generally, the cyclone 8A can collect powder having a particle diameter of 10 μm or more, and is particularly effective when the specific gravity of the powder is large. Also, since there are no movable parts, maintenance and inspection are easy. The particle size of the activated carbon 4 used in the present embodiment is 400 to 60.
Since it is 0 μm, which is much larger than other powders, only the activated carbon 4 can be almost certainly separated by appropriately setting the exhaust gas flow rate inside the cyclone 8A.

(Activated carbon circulation mechanism) The centrifugal dust collector 8
An activated carbon circulation mechanism K is provided between the reactor and the reactor 3. The activated carbon circulation mechanism K mainly includes an activated carbon supply / discharge device 11, a circulation path 12, and a circulation blower 13.
In the activated carbon supply / discharge device 11, a part of the activated carbon 4 collected by the cyclone 8A is discarded,
The same amount of new activated carbon 4 is added and added. The disposal ratio of the activated carbon 4 is determined by, for example, the dioxin adsorption ability of the activated carbon 4. Usually, dioxins in the flue gas 2 is a 5~7ng / Nm ^3, it is necessary to reduce to approximately 0.5 ng / Nm ³ or less by an exhaust gas treatment facility. The amount of activated carbon 4 required in this case is about 10 g / Nm ³ . That is, in the case of this device,
10 to 5 of the activated carbon 4 recovered by the cyclone 8A
0% of activated carbon 4 will be replaced with new one.
Note that “Nm ³ ” is a standard state of gas, that is, 0 ° C.
Indicates the volume of gas at 1 atmosphere. Activated carbon 4 to be reused
Is again supplied to the reactor 3 via the circulation path 12 by the circulation blower 13. As described above, since the particle size of the activated carbon 4 used in the present embodiment is large, when the activated carbons 4 of the same mass are compared, the surface area is smaller than that of the activated carbon 4 having a small particle size. This seems as if the dioxin adsorption ability is inferior. In this case, by increasing the injection amount of the activated carbon 4, it is possible to exhibit a dioxin adsorption ability higher than that of the conventional method. In the case of the present embodiment, as described above, if about 10% of the activated carbon 4 recovered by the cyclone 8A is replaced, specific activated carbon particles can be reused approximately ten times. Even if the injection amount of the activated carbon 4 in the reactor 3 is doubled, a specific activated carbon particle can be used five times.

(Filtering or Electric Dust Collector) While the cyclone 8A separates and recovers the activated carbon 4 having a particle size of 400 to 600 μm, the filtering or electric dust collector 7 is particularly suitable for the cyclone 8A. , 0.1 to 100 μm can be effectively recovered. That is, the limestone 5 or fly ash 6 is almost certainly collected by the dust collecting device 7 and then discarded.

As described above, the exhaust gas treatment equipment of the present invention enables the reuse of the activated carbon 4, so that the activated carbon 4 injected into the reactor 3 is discarded as it is in the conventional method. The dioxin adsorption capacity of the sample No. 4 can be maximized. Therefore, according to the exhaust gas treatment equipment of the present invention, it is possible to reduce the consumption of the activated carbon 4 and perform economically advantageous exhaust gas treatment.

In the description of the appended claims, reference is made to the drawings and, in order to facilitate comparison with the drawings, reference numerals are used. However, it is not intended that the present invention be limited to the configuration shown in the accompanying drawings. Absent.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an exhaust gas treatment facility of a waste treatment furnace according to the present invention.

[Explanation of symbols]

 2 Exhaust gas 3 Reactor 4 Activated carbon 5 Limestone 6 Fly ash 7 Filtration or electric dust collector 8 Centrifugal dust collector K Activated carbon circulation mechanism R Flow path

Claims (2)

[Claims] A powder such as activated carbon (4) and limestone (5) is injected into a flow path (R) of an exhaust gas (2) discharged from a waste treatment furnace and contained in the exhaust gas (2). Reactor to remove dioxin, chlorine gas, etc. (3)
And a filter-type or electric-type dust collector (7) for collecting dust from the exhaust gas (2) passing through the reactor (3). The particle size of the activated carbon (4) injected into (3) is set to be larger than the particle size of fly ash (6) and the limestone (5), and the reactor (3) and the filtration type or electric type An exhaust gas treatment facility of a waste treatment furnace provided with a centrifugal dust collector (8) for separating and recovering only activated carbon (4) between the dust collector (7). 2. An activated carbon circulation mechanism (K) for supplying the separated and recovered activated carbon (4) to the reactor (3) again.
The waste gas treatment equipment for a waste treatment furnace according to claim 1, comprising: