JPH11244645A - Treatment of generated gas of waste drying apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drastically reduce the consumption of kerosene necessary for deodorization and non-pollution without requiring deodorization equipment by kerosene by subjecting generated gas to gas-liquid sepn. and feeding the gas after the sepn. to the combustion chamber of a combustion device and the liquid into the waste combustion gas of the combustion device. SOLUTION: Waste 26 and vapor 28 of a heat source medium for drying are supplied to a drying apparatus 20 and the dried matter 27 of the waste 26 dried by heating is sent to the ensuing stage. In the combustion device 21, the waste combustion gas 35 generated by the combustion of the kerosene 34 is subjected to heat recovery by a waste heat boiler 22 and the generated vapor 28 is used as a heat source for drying. The waste 26 is used as a drain 29 after heating in the drying apparatus 20 and is circulated to the waste heat boiler 22. The generated gas 30 from the waste 26 in the drying apparatus 20 is cooled by cooling water 33 in a condenser 25 and is subjected to the gas-liquid sepn. The dry generated gas 32 after the sepn. is subjected to the deodorization and non-pollution in a combustion chamber of the combustion device 21. The separated condensed water 31 is injected and supplied as a cooling medium for diluting the combustion gas to the combustion chamber of the combustion device 21, by which the condensed water is subjected to the deodorization and non-pollution. The need for a deodorization furnace, or the like, using the kerosene is eliminated and the rationalization and cost reduction of the process are made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating generated gas in a waste drying apparatus.

[0002]

2. Description of the Related Art In recent years, regarding waste treatment technology, (1) It has been required to strengthen emission standards for trace toxic substances such as dioxins emitted from municipal solid waste incinerators and to create a waste recycling society. Solid waste conversion facility for municipal solid waste, which has been increasing in the recent social situation (2) The purpose of new waste disposal is to increase the calories of waste and stabilize its quality The demand for optimizing the drying process, which is the main process of a dry fluff manufacturing facility for municipal solid waste, is increasing day by day.

In particular, in the waste drying process, which is a main process of the solid fuel production, kerosene is used as a heat source for drying and a heat source for deodorizing and detoxifying gas generated from waste in a drying device. Drying processes have been put to practical use. FIG. 4 is a flow sheet showing this.
The waste 2 supplied to the drying drum 1 is heated and dried by a heating medium 5 heated by a hot blast stove 4 using kerosene 3 as a heat source, and is discharged from the drying drum 1 as a dried product 6. The heat medium 5 obtained by drying the waste 2 is dust-removed through the cyclone 7, passes through the circulation fan 8, and is partially sent to the hot blast stove 4 to be circulated and used as the heat medium 5. The rest is heat exchanger 9
After being heated in, it is sent to a deodorizing furnace 10 using kerosene 3 as a heat source, heated to about 800 ° C, and deodorized and made harmless. Then, after exchanging heat with the heat medium 5 as a high-temperature heat source in the heat exchanger 9, the heat is exchanged with the combustion air 13 sent from the combustion air fan 12 to the exhaust fan 14. After that, it is discharged from the chimney 15. The combustion air 13 is used for burning a kerosene burner of the hot blast stove 4 and the deodorization furnace 10.

[0004] In recent years, as a drying heat source in such a drying process, for example, Japanese Patent Application Laid-Open No. 6-82023 has proposed a technique using solid fuel produced from waste.

[0005]

However, in recent years, (1) the demand for energy saving on the consumer side of the solid fuel production equipment, and (2) the reduction of CO ₂ emissions from fossil fuels as part of measures against global warming. Due to changes in the surrounding environment, such as demands, the efficiency of the drying process, which consumes the largest amount of energy, in each process of solid fuel production of waste is required.

Accordingly, the present invention does not require a deodorizing facility using kerosene for deodorizing and detoxifying gas generated from waste in a drying process which is a main process of producing solid fuel for waste, and furthermore, the above-mentioned generation is not required. The purpose is to significantly reduce the amount of kerosene used to deodorize and detoxify gas.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and has the following technical means. That is, in the generated gas treatment method of the waste drying device using the combustion exhaust gas generated from the combustion device as a heat source, the generated gas is separated into gas and liquid, the separated gas is supplied to the combustion chamber of the combustion device, A method for treating a generated gas in a waste drying device, wherein the liquid is fed into the combustion exhaust gas of the combustion device.

In this case, the separated liquid may be treated and discharged by water treatment means instead of being sent into the combustion exhaust gas of the combustion device, and a fluidized bed combustion furnace may be used in the combustion device. Then, it may be sent to the fluidized bed.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for drying wastes by using a waste heat boiler to recover heat of combustion exhaust gas from a combustion device using kerosene as fuel, and using generated steam as a heat source for drying. The gas to be separated is separated into gas and liquid by a condenser or a scrubber, and the separated gas is supplied to a combustion chamber of a combustion device for deodorization and detoxification. Further, the liquid (condensed water) after separation is mixed with the combustion exhaust gas of the combustion device as a cooling medium for diluting the combustion gas of the combustion device.

(2) Deodorize and detoxify by treating with water treatment means such as activated carbon and activated sludge, and discharge to rivers and the like. (3) When the combustion device is a fluidized bed combustion furnace using a self-made solid fuel as a fuel, it is charged into the fluidized bed as a cooling medium for controlling the fluidized bed temperature. Deodorization and detoxification treatment

FIG. 1 shows a first embodiment of the present invention. The waste 26 is supplied to the waste drying device 20, and steam 28 is supplied as a heat source for drying. The waste 26 heated and dried by the steam 28 is discharged as a dried product 27 and sent to the next step. Next, the combustion device 2
1 is supplied with kerosene 34, and the generated combustion exhaust gas 35 is recovered by the waste heat boiler 22 to generate steam 28. The steam 28 is used as a heat source for drying the waste 26 by the drying device 2.
The waste 26 is heated to become a drain 29 by heating the waste 26 and circulated to the waste heat boiler 22. The flue gas discharged from the waste heat boiler 22 is removed by a dust collector 23 and discharged through a chimney 24.

Further, the generated gas 30 generated from the waste in the drying device 20 is cooled by the cooling water 33 in the condenser 25 and separated into gas and liquid. Gas-liquid separated dry generated gas 32
Is supplied to the combustion chamber of the combustion device 21 to be deodorized and made harmless. The gas-liquid separated condensed water 31 is injected and supplied to a combustion chamber of the combustion device 21 as a cooling medium for diluting combustion gas, and is subjected to deodorization and detoxification processing.

Here, as for the supply of steam as a heat source for drying to be supplied to the drying device 20, as described above, a steam generating device such as a combustion device and a waste heat boiler is installed and supplied in the solid fuel production device. Is common. However, the solid fuel production equipment that is the object of the present invention is adjacent to a thermal power plant that uses solid fuel as a main fuel source, various production plants that use a large amount of steam as a heat source, or a high-rise building that has cogeneration equipment. In such a case, if excess low-pressure steam can be received from these steam generators, the steam generator in the solid fuel production device becomes unnecessary, and the construction cost of the solid fuel production device can be reduced.

FIG. 2 shows a second embodiment of the present invention.
Reference numerals 20 to 35 are the same as those in FIG. The difference from the embodiment of FIG. 1 is that the condensed water 31 subjected to gas-liquid separation is treated via a water treatment device 36 using activated carbon, deodorized and rendered harmless, and then discharged to a river or the like. . FIG. 3 shows a third embodiment of the present invention. Reference numerals 20 to 35 are the same as those in FIG. The difference from FIG. 1 is that the combustion apparatus is a fluidized bed combustion furnace 41 using a solid fuel 40 as a fuel source, and the condensed water 31 subjected to gas-liquid separation is introduced into a fluidized bed 42 as a cooling medium for fluidized bed temperature control. That is the point. Thus, the temperature of the fluidized bed 42 is appropriately suppressed.

[0015]

EXAMPLE A 3 ton / h municipal waste 26 (53% moisture) was dried using a waste drying apparatus shown in the flow chart of FIG. The drying device 20 dries the waste 26 by indirect heating with steam 28 to obtain a dried product 27 having a water content of 10%. The kerosene 34 is burned in the hot stove 21 at 90 liters / h,
Using the generated gas, steam 28 at 120 ° C. was generated using the waste heat boiler 22, and heat was supplied to the drying device 20. Gas generated from waste in the drying device 20 (about 2000 Nm ³ /
h) was cooled in the condenser 25 and separated into gas and liquid. The separated dry generated gas 32 is an odor gas containing waste odor, but by being introduced into the combustion chamber of the hot blast stove 21, a trace amount of organic substances causing odor are decomposed by the high-temperature combustion gas.
The water condensed in the condenser 25 (about 1.3 t / h) was supplied into a hot-air stove exhaust gas flow path to be used for temperature control of the hot-air stove exhaust gas.

On the other hand, in the waste drying treatment according to the conventional method shown in the flow chart of FIG.
h municipal solid waste 2 (water 53%) was dried by the drying drum 1 to obtain a dried product 6 having a water content of 10%. At this time, the gas generated from the drying drum 1 is a mixed gas of the dry gas supplied from the hot blast stove and steam generated from municipal solid waste (about 13600
The half of Nm ³ / h) was sent to the hot blast stove 4, reheated to 500 ° C., and circulated again to the drying drum 1.
For the reheating of the hot blast stove 4, kerosene 90 liter / h was used. The remaining half was heat-treated by the deodorizing furnace 10 and was emitted from the chimney 15. At this time, 45 liters / h of kerosene was used for the heat treatment in the deodorizing furnace 10. That is, in the conventional method, 135 l / h of kerosene was required for the drying treatment of the municipal waste at 3 t / h.

As described above, the use of the present invention has eliminated the use of kerosene in a deodorizing furnace in the drying treatment of 3 t / h of municipal solid waste.
Could be reduced.

[0018]

According to the present invention, when drying wastes using flue gas generated from a combustion device as a heat source, gas generated from the wastes in the process is separated into gas and liquid, and the separated gas is burned. Deodorization and detoxification by supplying to the combustion chamber of the device, and the separated liquid is deodorized and detoxified by supplying to the combustion device as a cooling medium for controlling the temperature of the combustion device, or treated by a water treatment device. Deodorization and detoxification. Therefore, a conventional deodorizing furnace or the like by using kerosene is not required, which greatly contributes to streamlining of the process and cost reduction.

[Brief description of the drawings]

FIG. 1 is a flow sheet of an example.

FIG. 2 is a flow sheet of an example.

FIG. 3 is a flow sheet of an example.

FIG. 4 is a flow sheet of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drying drum 2 Waste 3 Kerosene 4 Hot stove 5 Heat medium 6 Dry goods 7 Cyclone 8 Circulation fan 9 Heat exchanger 10 Deodorizing furnace 11 Heat exchanger 12 Combustion air fan 13 Combustion air 14 Exhaust fan 15 Chimney 20 Drying device 21 Combustion Apparatus 22 Waste heat boiler 23 Dust collector 24 Chimney 25 Condenser 26 Waste 27 Dry product 28 Steam 29 Drain 30 Dry exhaust gas 31 Condensed water 32 Dry generated gas 33 Cooling water 34 Kerosene 35 Combustion exhaust gas 36 Water treatment device 40 Solid fuel 41 Fluid bed Combustion furnace 42 Fluidized bed

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C02F 1/28 F23G 5/14 ZABF F23G 5/04 ZAB 5/30 ZABD 5/14 ZAB B09B 3/00 303H 5/30 ZAB ( 72) Inventor Tsuneo Aihara 2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Inside Kawasaki Steel Corporation (72) Inventor Fumihiro Miyoshi 2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Inside Kawasaki Steel Corporation

Claims (3)

[Claims] In a method for treating a generated gas of a waste drying device using a combustion exhaust gas generated from a combustion device as a heat source, the generated gas is separated into gas and liquid, and the separated gas is supplied to a combustion chamber of the combustion device. Wherein the separated liquid is sent into the flue gas of the combustion device. 2. The waste drying apparatus according to claim 1, wherein the separated liquid is treated and discharged by water treatment means instead of being sent into the combustion exhaust gas of the combustion apparatus. Gas treatment method. 3. A fluidized bed combustion furnace is used for the combustion device,
The generated gas treatment method for a waste drying device according to claim 1, wherein the separated liquid is sent to the fluidized bed instead of being sent to the combustion exhaust gas of the combustion device.