JP2001340728A - Dioxin removing device and waste incineration furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide dioxins removing device and a waste incineration furnace with low installation cost and excellent dioxins removing ability, by solving the problems that a method for burning the waste at a high temperature is expensive, and a method for adsorbing dioxins with an adsorbent such as active carbon needs a difficult waste treatment of the used adsorbent. SOLUTION: The dioxin removing device 9 is installed midway a ventilation passage for exhausting combustion gas generated from a combustion chamber outside or at a terminal thereof. Surface temperature of a heating wire 15 is raised to or above thermal decomposition temperature of dioxin by energizing the heating wire 15, then dioxin in the combustion gas is thermally decomposed by bringing the combustion gas into contact with the heating wire 15 or by flowing the combustion gas into a high temperature region around the hearting wire.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dioxin removing apparatus used in a waste incinerator and a waste incinerator integrated with the dioxin removing apparatus.

[0002]

2. Description of the Related Art At present, dioxin generated when incinerating waste, particularly plastic waste, has become a problem. As a measure against this dioxin, there are a method of burning waste at a high temperature and a method of adsorbing dioxin using an adsorbent such as activated carbon.

[0003]

However, the method of burning waste at a high temperature is practically impossible for small and medium-sized enterprises to introduce it alone because the equipment is large and requires enormous investment. Also, the method of adsorbing dioxin on an adsorbent such as activated carbon involves a problem of secondary treatment of the used adsorbent. Most of the economic structure of Japan is small and medium-sized micro enterprises, and the dioxin problem cannot be essentially improved unless dioxins emitted from these are controlled.

[0004] The present invention has been made in view of the above, and an object of the present invention is to provide a dioxin removing apparatus and a waste incinerator which can be introduced with a small facility cost and exhibit excellent dioxin removing ability. is there.

[0005]

According to the present invention, in order to achieve the above object, the present invention is provided in the middle or at the end of an exhaust passage for discharging combustion gas generated from a combustion chamber to the outside. A dioxin removing device, in which a heating wire is energized to generate heat at a surface temperature of the heating wire equal to or higher than a thermal decomposition temperature of dioxin, and the combustion gas is brought into contact with the heating wire or a combustion gas is generated in a high-temperature region around the heating wire. Dioxin in combustion gas is thermally decomposed through the apparatus. Further, in this dioxin removing apparatus, it is preferable that a large number of small air holes are formed in a substrate having a shape that blocks the exhaust passage, and a heating wire is provided corresponding to an inlet or an outlet of the small air hole. Preferably, a plurality of the substrates are used, and the substrates are arranged in multiple layers.

Next, as set forth in claim 4, a combustion chamber for burning waste, an exhaust pipe for exhausting combustion gas generated in the combustion chamber, and dioxin removal provided in the middle or at the end of the exhaust pipe The dioxin removing device is configured to energize a heating wire to generate heat at a surface temperature of the heating wire equal to or higher than a thermal decomposition temperature of dioxin, and to contact the combustion gas with the heating wire or a high temperature around the heating wire. Provided is a waste incinerator in which dioxin in a combustion gas is thermally decomposed by passing a combustion gas into a region. Claim 5
As described in the above, the dioxin removal device is configured by forming a large number of small air holes in a substrate having a shape that blocks an exhaust path and extending a heating wire corresponding to an inlet or an outlet of the small air hole. Good to do. Further, as described in claim 6, the dioxin removing apparatus may use a plurality of the substrates and arrange them in a multilayer.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a longitudinal sectional view of a waste incinerator, FIG. 2 is a plan view of a substrate constituting a dioxin removing device, FIG. 3 is a longitudinal sectional view of a waste incinerator showing another embodiment, and FIG. FIG. 3 is a partially enlarged cross-sectional view of a substrate showing an embodiment.

[0008] As shown in FIG.
A furnace body 4 surrounding the periphery including the top section 3 with the heat-resistant wall 2, an exhaust tube 5 extending upward from the top section 3 of the furnace body 4, and a grate 6 provided at the bottom of the furnace body 4; It comprises a blower 7 for supplying air from under the grate 6 and a burner 8 for blowing a flame into the furnace body 4. The waste is put into the combustion chamber of the furnace body 4 and ignited by the burner 8. In the known method, air is blown in 7 to burn waste, and furthermore, combustion gas generated by the combustion is exhausted from the exhaust pipe 5 to the outside.

Thus, the dioxin removing device 9 of the present invention.
Is an exhaust pipe 5 at the end of the exhaust path as shown in FIG.
It is attached to the tip of. The dioxin removing device 9 is unitized so as to be detachable from the exhaust pipe 5, and has a cylindrical tubular body 10 and a cylindrical body 1.
, And a rainwater prevention cap 12 placed on the top of the cylindrical body 10.

As shown in FIGS. 1 and 2, each substrate 11 has parallel streak-like wiring grooves 13, and a number of small air holes 14 penetrating from the bottom to the rear surface of the wiring grooves 13. When,
The heating wire 15 is provided so as to traverse the outlets of the small air holes 14, 14,..., That is, to pass through substantially the center of the wiring groove 13. The substrate 11 is formed of a material having high heat resistance such as ceramics, and its size and shape follow the inner surface shape of the cylindrical body 10. For example, it is formed into a disc shape as shown in FIG. 2 in accordance with the cylindrical tubular body 10, or is made into a square in accordance with a rectangular tubular body (not shown). The size and shape of the exhaust cylinder 5 can be improved by adjusting only the fitting portion 10a of the cylindrical body 10 to the exhaust cylinder 5 so as to conform to the shape of the exhaust cylinder 5 and fixing the upper part of the cylindrical body 10 to a certain shape. However, since the standards of the substrate 11 can be unified even if they are scattered, the cost can be reduced by mass production.

A plurality of (preferably, three or four) downward leg-shaped spacers 16 are provided on the substrate 11 so as to protrude. There is a moderate space between each other. The spacer 16 does not need to be integrated with the substrate 11, and may be formed as a separate component and sandwiched between the substrates 11. By doing so, the shape of the substrate 11 is simplified, and the substrate 11 can be manufactured at low cost.

The number of substrates 11 installed in the cylindrical body 10 is arbitrary, and of course, the greater the number, the higher the dioxin removal capability. Since the amount of dioxin generated varies depending on the type of waste, combustion temperature, and the like, the number of substrates 11 to be installed may be selected according to the dioxin generation conditions.

On the other hand, as the heating wire 15, for example, a nichrome wire is used. The service temperature of Nichrome wire is 900 ℃ ～ 1200 ℃
800 ° C required to thermally decompose dioxin
It can withstand the above high heat sufficiently. The heating wire 15 may be a single wire or may be used by bundling a plurality of wires. Further, a heating wire 15 processed into a spiral shape may be used. Ideally, the heating wire 15 is stretched slightly above the wiring groove 13 as shown in the enlarged view of FIG. 1, but may be in a state of contacting the bottom of the wiring groove 13.

Next, the operation of the dioxin removing device 9 of the present invention will be described. First, the heating wire 15 is energized by using a commercial AC power supply of 100 V or 200 V. Then, the heating wire 15 generates heat and the surface temperature becomes 900 ° C. to 1200 ° C.
become. At this time, if the heating wire 15 is not in contact, the heat is not absorbed by the substrate 11, so there is no loss and the temperature easily rises in an extremely short time. Further, if a heat reflection layer (for example, a silver coating film) that reflects heat is formed on the surface of the substrate 11,
Since the amount of heat absorbed by the heating wire 15 is reduced, the thermal efficiency of the heating wire 15 is improved.

In this state, when the combustion gas rises from the exhaust stack 5 and reaches the dioxin removing device 9, the combustion gas is heated by the own gas pressure and the heat of the heating wire 15, causing the substrate 1 to rise.
It passes through one small air hole 14. As described above, the heating wire 15 which has been heated to a high temperature crosses the exit of the small ventilation hole 14, so that the combustion gas coming out of the small ventilation hole 14 contacts the heating wire 15, and Since a high temperature region of 800 ° C. or more is inevitably present, the combustion gas passes through the high temperature region. Then, dioxin contained in the combustion gas is thermally decomposed and made harmless. Then, the dioxin concentration decreases each time it rises to the second layer and the third layer and passes through the substrate 11, and the combustion gas finally discharged from the dioxin removing device 9 hardly contains dioxin.

The dioxin removing device 9 of the above embodiment
Is configured to be attached to and detached from the exhaust stack 5, so that it can be installed in the existing waste incinerator 1, and has the advantage that repair and maintenance at the time of failure become easy. Needless to say, the dioxin removing device 9 of the present invention may be integrated into the exhaust pipe 5 without being detachable from the exhaust pipe 5 as shown in FIG. In that case, the waste incinerator 100 is equipped with a dioxin removal device. In this case, since the repair and the maintenance of the substrate 11 are naturally required, a detachable cover member 17 is formed on a portion of the exhaust pipe 5 corresponding to the dioxin removing device 9, for example, as shown by a two-dot chain line in FIG. It is preferable to open the cover member 17 so that only the substrate 11 can be attached and detached.

Although the present invention has been described with reference to the embodiment, it is needless to say that the present invention is not limited to the above embodiment. For example, in the embodiment, the heating wire 15 is arranged on the exit side of the small ventilation hole 14 of the substrate 11, but may be arranged on the entrance side of the small ventilation hole 14. In addition, if the heating wires 15 are arranged on both the exit side and the entrance side of the small ventilation hole 14 as shown in FIG. 4, the dioxin removal ability of one substrate 11 can be doubled. By reducing the number of substrates by half, the size of the dioxin removing device 9 can be reduced. In the embodiment, the substrate 11 and the heating wire 15 are integrated. However, for example, a frame for wiring may be separately formed, the heating wire 15 may be wired there, and the frame may be installed on the substrate 11. By doing so, the broken heating wire 15 can be easily replaced, and the clogged substrate 11 can be easily cleaned. Further, the structure of the furnace main body 4 of the waste incinerator 1 may be any structure, and a blower for forced exhaust may be provided at the end of the exhaust path.

[0018]

According to the dioxin removing apparatus and the waste incinerator of the present invention, the combustion gas is brought into contact with the heating wire or the combustion gas is passed through a high-temperature region around the heating wire. Can be detoxified by thermal decomposition, and the heating wire can be heated to 800 ° C. or more, so that the power consumption is extremely low as compared with the case where the entire area of the exhaust stack is heated to 800 ° C. or more. -Operable at low cost. In addition, since the structure is simple and can be manufactured at low cost, it can be sufficiently introduced even by small and medium-sized enterprises.

Also, if a small ventilation hole is formed in the substrate to limit the flow path of the combustion gas, and the inlet or the outlet of the flow path is made to correspond to the heating wire so as to come into contact with the combustion gas, it is extremely efficient. Dioxin can be removed. If such substrates are arranged in multiple layers, the dioxin removal ability can be dramatically improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a waste incinerator.

FIG. 2 is a plan view of a substrate constituting the dioxin removing device.

FIG. 3 is a partially enlarged cross-sectional view of a substrate showing another embodiment.

FIG. 4 is a longitudinal sectional view of a waste incinerator showing another embodiment.

[Explanation of symbols]

 1,100 waste incinerator 5 exhaust stack 9 dioxin removal device 11 substrate 14 small vent 15 heating wire

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K065 AA18 AB01 AC01 AC13 HA01 HA03 3K070 DA05 DA30 DA54 4D002 AA21 AC04 BA12 BA20 CA20 HA03

Claims (6)

[Claims] 1. A dioxin removing device provided at the middle or at the end of an exhaust passage for discharging combustion gas generated from a combustion chamber to the outside, wherein a heating wire is energized and the surface temperature of the heating wire is reduced by thermal decomposition of dioxin. A dioxin removal apparatus characterized in that heat is generated at a temperature higher than or equal to a temperature, and the combustion gas is brought into contact with the heating wire or the combustion gas is passed through a high-temperature region around the heating wire to thermally decompose dioxin in the combustion gas. 2. A method according to claim 1, wherein a plurality of small air holes are formed in the substrate having a shape that blocks the exhaust path, and heating wires are provided corresponding to the inlets or outlets of the small air holes. The dioxin removing device according to the above. 3. The dioxin removing apparatus according to claim 2, wherein a plurality of the substrates are used, and the substrates are arranged in multiple layers. 4. A combustion chamber for burning waste, an exhaust pipe for exhausting combustion gas generated in the combustion chamber, and a dioxin removing device provided in the middle or at the end of the exhaust pipe. Energizing the heating wire to cause the surface temperature of the heating wire to generate heat above the thermal decomposition temperature of dioxin, contacting the combustion gas with the heating wire, or passing the combustion gas through a high-temperature region around the heating wire to dioxin in the combustion gas. Waste incinerator characterized in that it is thermally decomposed. 5. The dioxin removing device according to claim 1, wherein a large number of small air holes are formed in a substrate having a shape that blocks an exhaust path, and a heating wire is provided corresponding to an inlet or an outlet of the small air hole. The waste incinerator according to claim 4, wherein 6. The waste incinerator according to claim 5, wherein the dioxin removing apparatus uses a plurality of the substrates, and arranges the substrates in multiple layers.