Combustion device

Abstract

A combustion device includes a device main body having a combustion chamber installed above a cyclone melting furnace configured to combust a pyrolysis gas generated from a waste material after incineration while turning the pyrolysis gas, and configured to combust an unburnt gas discharged from the cyclone melting furnace. Further, the combustion device includes a plurality of sidewall boiler water pipes configured to cover a sidewall of the device main body from a periphery thereof and extending along the sidewall throughout upward and downward directions of the device main body.

Claims

1. A combustion device comprising: a device main body having a combustion chamber installed above a cyclone melting furnace configured to combust a pyrolysis gas generated from a waste material, and configured to combust an unburnt gas discharged from the cyclone melting furnace; a plurality of sidewall boiler water pipes configured to cover a sidewall of the device main body from a periphery thereof and extending along the sidewall throughout upward and downward directions of the device main body; a bottom section boiler water pipe extending in a vortex shape when seen from a plan view and installed at a bottom section of the device main body; and a protrusion protruding from an inner wall of the device main body toward the center of a space being formed by the inner wall and being placed in a lower position of the cyclone melting furnace, wherein the bottom section boiler water pipe is slidably laid on the protrusion, the combustion device further comprises a support frame disposed between the bottom section boiler water pipe and the protrusion, and the bottom section boiler water pipe is fixed to the support frame which is slidably laid on the upper surface of the protrusion.

2. The combustion device according to claim 1, further comprising a boiler water supply unit configured to recover boiler feed water after flowing through the bottom section boiler water pipe and introduce the boiler feed water into the sidewall boiler water pipe from a lower side thereof via a water reservoir section.

3. The combustion device according to claim 1, wherein a throttling section is formed between the cyclone melting furnace and the combustion chamber by reducing a portion of the sidewall of the device main body in diameter in upward and downward directions, and some of the plurality of sidewall boiler water pipes are spaced apart from the sidewall section.

4. The combustion device according to claim 2, wherein a throttling section is formed between the cyclone melting furnace and the combustion chamber by reducing a portion of the sidewall of the device main body in diameter in upward and downward directions, and some of the plurality of sidewall boiler water pipes are spaced apart from the sidewall section.

5. The combustion device according to claim 1, wherein at least four blowing ports configured to introduce air into an upper portion of the combustion chamber are installed in a circumferential direction thereof at an interval.

6. The combustion device according to claim 2, wherein at least four blowing ports configured to introduce air into an upper portion of the combustion chamber are installed in a circumferential direction thereof at an interval.

7. The combustion device according to claim 3, wherein at least four blowing ports configured to introduce air into an upper portion of the combustion chamber are installed in a circumferential direction thereof at an interval.

8. The combustion device according to claim 4, wherein at least four blowing ports configured to introduce air into an upper portion of the combustion chamber are installed in a circumferential direction thereof at an interval.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a longitudinal cross-sectional view of a combustion device according to a first embodiment of the present invention when seen from the front.

(2) FIG. 2 is a view taken along line A-A of FIG. 1, showing a bottom section boiler water pipe installed at a bottom section of a cyclone melting furnace constituting the combustion device according to the first embodiment of the present invention.

(3) FIG. 3 is a view taken along line B-B of FIG. 1, showing an air blowing port installed at a combustion chamber constituting the combustion device according to the first embodiment of the present invention.

MODE FOR CARRYING OUT THE INVENTION

(4) Hereinafter, a combustion device 1 of a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

(5) The combustion device 1 is used when a pyrolysis gas W including ash and char generated upon waste material incineration is introduced into a device and combusted at a high temperature while turning the pyrolysis gas W, performing melting processing.

(6) The combustion device 1 includes a device main body 2 having a cyclone melting furnace 3 and a combustion chamber 6 therein, a plurality of sidewall boiler water pipes 7, a bottom section boiler water pipe 8, a boiler water supply unit 9, and a blowing port 12.

(7) The device main body 2 has a tubular sidewall 13 extending in a vertical direction. The sidewall 13 has a portion reduced in a diameter in upward and downward directions, and the diameter-reduced portion is a throttling section 14 of the device main body 2.

(8) A space under the throttling section 14 in the device main body 2 is the cyclone melting furnace 3, and a slag hole 5 configured to discharge a melted slag 4 generated by the cyclone melting furnace 3 is installed at a lower portion of the cyclone melting furnace 3, i.e., a lower portion of the device main body 2.

(9) In addition, a space over the throttling section 14 in the device main body 2 is the combustion chamber 6 having a tapered shape in which a diameter is gradually increased as the sidewall 13 goes upward.

(10) That is, in this embodiment, the combustion chamber 6 is continuously formed above the cyclone melting furnace 3 via the throttling section 14 to constitute the device main body 2.

(11) The sidewall boiler water pipes 7 are installed to cover the entire sidewall 13 of the device main body 2 from a periphery thereof upward in a vertical direction of the device main body 2 from above to below the sidewall 13 of the device main body 2, i.e., from a lower end of the cyclone melting furnace 3 to an upper end of the combustion chamber 6.

(12) In addition, in the throttling section 14, some of the sidewall boiler water pipes 7 (in this embodiment, half of the sidewall boiler water pipes 7) are spaced apart from the sidewall 13 of the device main body 2, and configured as non-heating pipes that do not recover waste heat. Then, the non-heating pipes become heating pipes again formed to cover the sidewall 13 of the device main body 2 again at a position at which the sidewall 13 of the device main body 2 above the throttling section 14 is somewhat increased in diameter.

(13) The bottom section boiler water pipe 8, which is a water pipe extending in a vortex shape when seen from a plan view as shown in FIG. 2, is disposed at a bottom section of the cyclone melting furnace 3. The bottom section boiler water pipe 8 is fixed to a support frame 15, and disposed on a protrusion 16 protruding from an inner wall of a lower space of the cyclone melting furnace 3 toward a center of the space. The protrusion 16 and the support frame 15 are not completely fixed to each other and have a structure allowing expansion and contraction due to a variation in temperature of the bottom section boiler water pipe 8 itself. Further, a gap is formed between the bottom section boiler water pipe 8 and the sidewall boiler water pipe 7.

(14) The boiler water supply unit 9 is constituted by a deaeration water feeder 18 configured to supply a boiler feed water W2 into the bottom section boiler water pipe 8, a first pump 11 configured to pump the boiler feed water W2 into the bottom section boiler water pipe 8 and recover the water, a drum (a water reservoir section) 10 configured to recover and store the boiler feed water W2 from the sidewall boiler water pipe 7 above the device main body 2 and supply the boiler feed water W2 into the sidewall boiler water pipe 7 again, and a second pump 17 configured to pump the boiler feed water W2 recovered by the bottom section boiler water pipe 8 from the deaeration water feeder 18 to the drum (the water reservoir section) 10.

(15) Then, the boiler water supply unit 9 of this embodiment is configured to provide two systems of forced circulation and natural circulation. That is, the bottom section boiler water pipe employs a forced circulation type, and the boiler feed water W2 from the deaeration water feeder 18 is pumped and circulated in the bottom section boiler water pipe 8 and then returned to the deaeration water feeder 18 again.

(16) Next, the boiler feed water W2 circulated in the bottom section boiler water pipe 8 and having recovered the waste heat is introduced from a lower side of the sidewall boiler water pipe 7 via the drum (the water reservoir section) 10 and absorbs heat in the sidewall boiler water pipe 7. Accordingly, the boiler feed water W2 is decreased in specific gravity and raised upward. In this way, the sidewall boiler water pipe 7 employs a natural circulation type in which the boiler feed water W2 is naturally raised to ultimately become steam.

(17) The blowing port 12 is an air introduction port in communication with the inside and the outside of the combustion chamber 6 and formed toward a center of the combustion chamber 6, and at least four (in this embodiment, eight) blowing ports are formed in a circumferential direction with respect to an upper portion of the combustion chamber 6.

(18) Next, an operation of the above-mentioned combustion device 1 will be described.

(19) In the combustion device 1, the pyrolysis gas W including ash and char generated upon waste material incineration passes through a pyrolysis gas duct (not shown) to be introduced into the cyclone melting furnace 3. The pyrolysis gas W is turned and combusted to melt the ash and char, then the melted slag 4 is resultantly generated and discharged through the slag hole 5.

(20) Further, some of the sidewall boiler water pipes 7 are installed to be spaced apart from the sidewall 13 in the throttling section 14. Accordingly, even though the sidewall 13 of the device main body 2 in the throttling section 14 is reduced in diameter, interference between the sidewall boiler water pipes 7 can be avoided, and the entire sidewall 13 can be covered without variation in the number of sidewall boiler water pipes 7. In addition, as a result of spacing the sidewall boiler water pipes 7 from the sidewall 13, a space is formed between the non-heating pipe and the sidewall 13.

(21) Further, in this embodiment, as a space between the protrusion 16 and the support frame 15 is a slidable structure, generation of cracks due to thermal expansion and contraction when the bottom section boiler water pipe 8 recovers the waste heat is avoided. In addition, as the sidewall boiler water pipes 7 are installed to form a gap with the bottom section boiler water pipe 8, generation of cracks due to thermal expansion and contraction caused by a temperature difference between the sidewall boiler water pipe 7 and the bottom section boiler water pipe 8 can be prevented. Accordingly, the bottom section boiler water pipe 8 can be installed at the bottom section of the cyclone melting furnace 3 without damage to the bottom section boiler water pipe 8.

(22) Then, in the boiler water supply unit 9 of this embodiment, as the forced circulation and the natural circulation of the boiler feed water W2 coexist, the waste heat recovery in the bottom section of the cyclone melting furnace 3 can be performed using the bottom section boiler water pipe 8, in which the natural circulation is difficult due to extension in the horizontal direction.

(23) In addition, in the combustion chamber 6 disposed at an upper portion of the combustion device 1, re-combustion of the unburnt gas discharged from the cyclone melting furnace 3 is performed. Here, in this embodiment, the air is blown from the eight blowing ports 12 disposed at the upper portion of the combustion chamber 6 toward the center section of the combustion chamber 6 to improve combustion efficiency of the unburnt gas.

(24) In the above-mentioned combustion device 1, the waste heat generated from the combustion device 1 can be recovered more by the sidewall boiler water pipe 7 that can recover the waste heat from the entire sidewall 13 of the cyclone melting furnace 3 and the combustion chamber 6 and by the bottom section boiler water pipe 8 that can recover the waste heat generated from the bottom section of the cyclone melting furnace 3. Then, power can be obtained using the steam generated by the recovered waste heat as a power source of a steam turbine. A cost reduction can be accomplished through sale or the like of the obtained power, and further, waste of the waste heat from the combustion device 1 is reduced to contribute to the prevention of global warming.

(25) Further, since maintenance of the device main body 2 is easily performed through a space formed between the non-heating pipe and the sidewall 13 of the device main body 2, a cost reduction effect can be accomplished.

(26) In addition, here, since unburnt combustibles in the cyclone melting furnace 3 can be efficiently combusted due to the eight blowing ports 12 installed at the upper portion of the combustion chamber 6, a reduction effect of toxic substances contained in the exhaust gas such as CO or the like is accomplished to contribute to protection of the global environment. However, the number of blowing ports 12 installed to combust the unburnt combustibles is not limited to be equal to or more than four, since such numbers do not depart from the spirit of the present invention.

(27) In addition, in the combustion device 1 of this embodiment, a built-in type soot blow may be installed as a stuck ash removal unit in the device main body 2. In this case, since an installation space of the combustion device 1 can be reduced in comparison with a detachable type soot blow, a cost reduction effect can be accomplished. The built-in type soot blow should be formed of a special material capable of enduring corrosion and creep destruction in a high temperature environment of 400° C. or more.

REFERENCE SIGNS LIST

(28) 1 combustion device 2 device main body 3 cyclone melting furnace 4 melted slag 5 slag hole 6 combustion chamber 7 sidewall boiler water pipe 8 bottom section boiler water pipe 9 boiler water supply unit 10 drum (water reservoir section) 11 first pump 12 blowing port 13 sidewall 14 throttling section 15 support frame 16 protrusion 17 second pump 18 deaeration water feeder W pyrolysis gas W2 boiler feed water