JPH0639227Y2 - Fluidized bed incinerator - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a fluidized bed incineration suitable for combustion and incineration of high water content residues such as tofu meal, beer meal and sludge containing a large amount of water. It is about the furnace.

[Conventional technology]

Conventionally, a fluidized bed incinerator has an air chamber at the bottom,
A combustion chamber is provided above the air chamber via a gas dispersion plate provided across the furnace, and the combustion and fluidizing air supplied from the air chamber is dispersed from the gas dispersion plate in the combustion chamber. The fluidized medium is fluidized to form a fluidized bed, and the incinerated material is put into the fluidized bed and fluidized and burned to incinerate the incinerated material. Further, the gas dispersion plate is configured by a large number of gas dispersion pipes (distributors) fixedly attached by partition plates and provided across the furnace, but since the gas dispersion plate is exposed to high temperatures, In order to provide heat resistance and prevent deformation, the gas dispersion pipe and partition plate are covered with heat insulating material, and a water cooling pipe is attached, and boiler water is supplied from the steam drum to the water cooling pipe to supply the gas dispersion plate itself. Is cooling. The steam of the boiler water heated by the water-cooled tube is separated by the steam drum and used in appropriate places.

[Problems to be solved by the device]

By the way, as described above, the method of circulating the boiler water through the air dispersion plate to cool the air distribution plate is convenient when the entire furnace is constructed as a boiler system, but when the steam is not required, It is inconvenient. That is, for example, the incineration amount is not so large, the structure may be relatively simple, and the usage as a general incinerator is sufficient.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a fluidized bed type incinerator having high thermal efficiency and capable of simplifying the apparatus.

[Means for Solving the Problems]

In order to achieve the above object, the fluidized bed type incinerator of the present invention is provided with an air chamber in the lower part of the furnace, and the combustion chamber is provided in the upper part of the air chamber through a gas dispersion plate provided across the furnace. The fluidizing medium is fluidized by the air for combustion and fluidization supplied from the air chamber through the gas dispersion plate in the combustion chamber to form a fluidized bed, and the incinerated matter is combusted and incinerated in the fluidized bed. In a floor-type incinerator, an air-cooling tube for cooling the gas distribution plate is provided on the gas distribution plate, an air preheater using the combustion exhaust gas of the furnace as a heating source is provided, and a heated fluid inlet of the air preheater and the gas dispersion are provided. The air outlet of the plate air-cooling pipe is connected by the first air pipe, and the heated fluid outlet of the air preheater and the combustion and fluidizing air supply port of the air chamber are connected by the second air pipe. , The air preheated by the air-cooling tube of the gas dispersion plate, the combustion gas of the furnace by the air preheater Then, it is preheated and used as combustion and fluidizing air.

[Action]

High temperature air as combustion and fluidizing air dispersed and introduced into the combustion chamber from the air chamber by the gas dispersion plate fluidizes the fluid medium on the gas dispersion plate to form a fluidized bed. The fluidized bed temperature is kept at a higher temperature by the combustion of the high temperature air for combustion and fluidization and the residue, and a high water content residue such as tofu meal containing a large amount of water is contained in this fluidized bed. It is charged, and its water content is instantly evaporated and burned.

Then, the gas dispersion plate is exposed to a high temperature atmosphere and overheated, but, for example, normal temperature air is introduced into the air-cooled tube to be cooled and maintained at a predetermined low temperature. The air that has passed through the air-cooled tube and cooled the gas dispersion plate is heated and raised to a predetermined temperature.
It is introduced into the air preheater via the air-cooling tube of. This air is further heated in the air preheater by the high temperature combustion exhaust gas of the incinerator, preheated and raised in temperature, introduced into the air chamber of the incinerator through the second air-cooling tube, and used as combustion and fluidizing air. used.

In this way, the cooling air of the gas dispersion plate is used as combustion and fluidizing air, and this combustion and fluidizing air is further heated by the combustion exhaust gas of the furnace. The thermal efficiency of the incinerator is extremely good. Also, instead of preheating the combustion and fluidizing air by introducing cold air at room temperature into the air preheater as it is, the air preheated by the gas dispersion plate and heated to a relatively high temperature is used as the air preheater. Since it is introduced, even if the combustion exhaust gas containing a large amount of water after burning the high water content residue is used as a heating source, it is possible to prevent the water in the combustion exhaust gas from being condensed in the air preheater. The operation is smooth.

〔Example〕

 Embodiments will be described below with reference to the drawings.

FIG. 1 is a system diagram showing an overall configuration of a fluidized bed incinerator (partial schematic vertical sectional view), FIG. 2 is a plan view of a gas dispersion plate, and FIG.
The drawing is a sectional view taken along the line III in FIG.

The fluidized bed incinerator book 10 is provided with an air chamber 11 at the lowermost stage, a primary combustion chamber 12 at an upper part thereof via a gas dispersion plate 16, and a secondary combustion chamber 13 at an upper stage thereof via a gas dispersion plate 17. Is configured. The air chamber 11 is provided with an auxiliary combustion burner 62 and an air supply port 11a for combustion and fluidization in the vicinity thereof. The auxiliary combustion burner 62 has a propane gas cylinder 60 as an auxiliary fuel source.
To the gas supply pipe 61. Reference numeral 61a is an automatic temperature control valve for automatically adjusting the gas supply amount based on the temperature of the air chamber 11 in order to keep the air temperature of the air chamber 11 constant, and 61b is an opening / closing valve. A primary combustion chamber 12 defined by a gas distribution plate 16 is located above the air chamber 11, and a freeboard above the primary combustion chamber 12 has a tofu meal containing a large amount of water, which is an incineration product. A high water content residue feeder (screw feeder in this embodiment) 41 is attached, and the feeder 41 is attached to the bottom of the residue hopper 40. In the primary combustion chamber 12, the fluidized medium made of sand such as silica sand having a particle size of 0.4 to 1 mm is fluidized by the high temperature air supplied from the air chamber 11 through the gas dispersion plate 16 to form the primary fluidized bed 14.

A secondary combustion chamber 13 defined by a gas distribution plate 17 is located above the primary combustion chamber 12, and here, the primary combustion chamber 12 is provided.
A fluidized medium of sand having a particle size similar to that of the primary fluidized bed 14 is fluidized by the combustion gas entrained with unburned components supplied from the gas dispersion plate 17 to form a secondary fluidized bed 15. .

On the other hand, an air preheater 20 is installed separately from the furnace body 10. The heating source fluid inlet 21 of the air preheater 20 has a furnace body 10
Exhaust gas exhaust pipe between exhaust gas exhaust port 18 of secondary combustion chamber 13 of
63 is connected to the heating source fluid outlet 22, and a cyclone 30 for collecting dust such as ash is installed via a pipe 64. Reference numeral 31 is an exhaust gas discharge pipe of the cyclone 30, 32 is a rotary valve that also serves as an air seal, and 33 is a dust extraction container.

Reference numeral 50 denotes a combustion and fluidizing air pushing fan, and 50a is a silencer provided on the suction side of the fan 50 and also serving as an air suction port. A pipe 51 is connected to the air outlet of the pushing fan 50, and the pipe 53 is connected to the inlet side air headers 53a and 54a of the lower and upper gas distribution plates 16 and 17, respectively.
And the pipe 54 is connected. 53b and 54b are the respective pipes
It is an air amount adjusting valve interposed in the middle of 53, 54. Reference numeral 51a is an air amount adjusting valve provided in the middle of the pipe 51. 55a is an air header for supplying cooling air to the freeboard of the primary combustion chamber 12, and this air header 55a has pipe 5
A pipe 55 branched from 1 and having an air regulating valve 55b interposed therein is connected. Incidentally, the air regulating valves 53b, 54b, 55b may be provided with orifices instead of these to regulate the air amount.

As shown in FIGS. 2 and 3 in detail, the gas dispersion plates 16 and 17 are vertically divided into a large number of gas dispersion pipes (distributors) by a partition plate 71 provided across the furnace body 10.
72 is attached, and this gas dispersion pipe is attached to the partition plate 71.
A large number of air-cooling tubes 70 are horizontally installed so as to sandwich 72. As shown in FIG.
A refractory material 75 is attached and configured so as to cover the gas dispersion pipe 72 and the air cooling pipe 70. A plurality of gas ejection holes 74 are opened around the upper portion of the gas dispersion pipe 72. Also,
Each of the air-cooling tubes 70 has an inlet-side air header 53a (54a) and an outlet-side air header 57a installed outside the furnace with the furnace body 10 interposed therebetween.
(56a) and is connected to.

The pipe 57 is connected to the outlet side header 57a of the air cooling pipe 70 of the lower gas distribution plate 16, the pipe 56 is connected to the outlet side air header 56a of the air cooling pipe 70 of the upper gas distribution plate 17, and the pipe 5
6 and 57 join the pipe 58 and are connected to the heated fluid inlet 23 of the air preheater 20. The pipes 56, 57 and 58 form the first air pipe in the present invention. On the other hand, the heated fluid outlet 24 of the air preheater 20 and the combustion / fluidization air supply hole 11a of the air chamber 11 are connected by a pipe 59 which is a second air pipe. Reference numeral 52 is a bypass pipe provided with an air amount adjusting valve 52a.

In the fluidized bed type incinerator configured in this way, the air chamber
For example, hot air of 535 ° C. from 11 flows into each of the gas dispersion pipes 72 of the gas dispersion plate 16 and is introduced into the primary combustion chamber 12 through the gas ejection holes 74 in the upper part of the gas dispersion pipe 16 to fluidize the fluidizing medium to cause primary flow. A floor 14 is formed. Hopper 40 in the primary combustion chamber 12
The high water content residue, which is tofu meal containing 65% of the water content, for example, introduced by the feeder 41 from the above, was heated to a high temperature to form a fluidized bed in the primary fluidized bed 14 whose temperature was maintained at 750 to 800 ° C. Moisture is instantly evaporated by contact with sand. The dewatered residue is easily burned while being stirred by the fluidized bed sand. An example of analysis of tofu meal as this residue is as follows: high heating value 5260 Kcal / dry kg, elemental components are carbon 48.6%, hydrogen 6.9%, oxygen 36.9%, nitrogen 4.2%,
Ash content is 3.3% and others. Approximately 80% of the residue is combusted in this primary fluidized bed 14, and the remaining approximately 20% of unburned carbon (unburned carbon) is accompanied by combustion gas and flows through the freeboard together with ash (ash) to disperse gas in the upper stage. The gas is introduced into the secondary combustion chamber 13 from the gas ejection holes 74 in the upper part of the plate 17 through a large number of the gas dispersion pipes 72, and the secondary fluidized bed 15 is formed. In the secondary fluidized bed 15, about 20% of the unburned matter is burned and completely burned. In this embodiment, the incinerator is thus configured with a two-stage fluidized bed, and unburned carbon is caught and completely combusted in the second fluidized bed (secondary fluidized bed 15), so that the combustion efficiency is good, Also, high hearth load can be obtained. In the case of this embodiment, the hearth load is 400 to 450 kg / m ² · hr. In addition, the empty space velocity is higher than that of an incinerator having a fluidized bed with only one stage, the fluidized bed area can be reduced, and the size of the furnace can be small.

On the other hand, the pushing fan 50 supplies room temperature air having a temperature of, for example, 30 ° C. from the pipe 51 to each air cooling pipe 70 of the lower gas distribution plate 16 via the pipe 53 and the inlet side air header 53a, and the pipe 51 From further piping 54, inlet side air header
It is supplied to each air-cooling pipe 70 of the upper gas dispersion plate 17 via 54a, and the lower and upper gas dispersion plates 16 and 17 are cooled by cold air. The air that has cooled the gas distribution plates 16 and 17 is heated, flows from the lower gas distribution plate 16 into the outlet side air header 57a and flows into the pipe 57, and the upper gas distribution plate 17
From the above, it flows into the outlet side air header 56a and flows into the pipe 56, and the exhaust air of both is joined by the pipe 58 and supplied to the air preheater 20. The air in the pipe 58 is heated to 175 ° C., for example. The high temperature combustion exhaust gas having a temperature of, for example, 705 ° C. is supplied as a heating source fluid from the exhaust gas outlet 18 of the secondary combustion chamber 13 to the air preheater 20 through the pipe 63. The air (temperature 175 ° C.) after cooling the lower and upper gas dispersion plates 16 and 17 which are fluids is further heated to be high temperature air having a temperature of 535 ° C., for example. In addition, the freeboard of the primary combustion chamber 12 has the above piping
A predetermined amount of room temperature air (cold air) is introduced through a pipe 55 branched from 51 and an air header 55a, and the temperature of the combustion exhaust gas introduced into the air preheater 20 from the secondary combustion chamber 13 through the pipe 63 is appropriately adjusted. The temperature (705 ° C. in this embodiment) is adjusted to ensure the heat resistance of the air preheater 20 and protect the air preheater 20. As described above, since the air for combustion and fluidization to be heated in the air preheater 20 is not at room temperature (cold air) but at a predetermined high temperature (175 ° C.) in advance, a large amount of the furnace as a heating source is used. The moisture in the combustion gas containing water does not condense on the heating surface of the air preheater 20 to cause dew condensation, and the heat exchange action is smoothly performed.

The high temperature air of 535 ° C. heated by the air preheater 20 is supplied from the heated fluid outlet 24 to the air chamber 11 through the pipe 59 and the combustion / fluidization air supply port 11a, and the gas dispersion plate 16 as described above. From the primary fluidized bed 14
And used as combustion air.

The combustion exhaust gas that has been subjected to heat exchange in the air preheater 20 is introduced from the heating source fluid outlet 22 to the cyclone 30 via the pipe 64, where the ash in the exhaust gas is removed, and the ash is removed by the rotary feeder 32 in the extraction container 33. Be recovered to. Note that an appropriate amount of cold air is supplied from the pipe 52 to the pipe 64, and the temperature of the combustion exhaust gas passing through the pipe 64 is set to 450 ° C., for example.
Further, at the start of operation, propane gas as auxiliary fuel is supplied from the propane gas cylinder 60 to the auxiliary combustion burner 62 through the gas supply pipe 61 and burned, and the fluidized medium (sand) at the time of startup
The temperature of the fluidized bed is adjusted to a predetermined temperature to prepare for the input of the incineration product, and the air temperature in the air chamber 11 is kept constant even during operation, for example, when the water content of the incineration product changes. It is burned as appropriate. In this embodiment, the air for combustion and fluidization is a gas dispersion plate.
Since it is preheated to a high temperature (535 ° C) by 16 and 17 and the air preheater 20, when the water content of the residue is about 65% or less, this auxiliary fuel is not required during operation due to heat balance. .

In the above examples, the case where the high water content residue as the incinerated matter is tofu meal, the fluidized bed type incinerator of the present invention has a high content such as beer meal, tangerine meal, coffee meal and sludge. It is also applicable to water-containing residues and other incinerated materials.

[Effect of device]

As described above, in the present invention, the gas dispersion plate exposed to a high temperature atmosphere can be air-cooled to maintain a predetermined low temperature to provide heat resistance and durability, and the cooled air of the gas dispersion plate can be burned. The combustion and fluidizing air is heated to a higher temperature in the air preheater by using the combustion exhaust gas from the furnace, and the thermal efficiency of the incinerator is extremely good. Can be one. In addition, since the air preheater guides preheated air after cooling the gas dispersion plate as described above to preheat it as combustion and fluidizing air, it contains a large amount of water (steam) in the incinerator. Even if the combustion gas containing a large amount of water is used as a heat source and introduced into the air preheater for heat exchange after burning the incinerator, the problem that the water in the combustion gas condenses and condenses in the air preheater is prevented. Stable and stable operation can be performed.

And by making the gas dispersion plate of the incinerator air-cooled, no steam drum or waste heat boiler is required, and
The air preheated to a predetermined high temperature as described above is taken into the air preheater as a fluid to be heated, so that the air preheater is provided with a heating device for preventing dew condensation of the fluid to be heated and a steam supply as a heating source therefor. Since it is not necessary to provide a device such as a device, the device can be simplified and made compact.

The fluidized bed incinerator of the present invention is particularly suitable for burning and incinerating a relatively small amount of high water content residue.

[Brief description of drawings]

Each of the drawings shows an embodiment of the present invention.
The figure is a system diagram (partial schematic vertical cross-sectional view) showing the overall structure of the fluidized bed incinerator, FIG. 2 is a plan view of the gas dispersion plate, and FIG. 3 is a cross-sectional view taken along the line III in FIG. . 10 …… Fluidized bed type incinerator body, 11 …… Air chamber, 11a …… Combustion / fluidization air supply port, 12 …… Primary combustion chamber, 13 ……
Secondary combustion chamber, 14 …… Primary fluidized bed, 15 …… Secondary fluidized bed, 1
6, 17 …… Gas dispersion plate, 70 …… Air-cooled pipe (gas dispersion plate), 7
1 …… Gas dispersion pipe, 20 …… Air preheater, 23 …… Heating fluid inlet, 24 …… Heating fluid outlet, 56,57,58 …… Piping (first air pipe), 59 …… Piping (Second air tube), 30 ...
… Cyclone, 40 …… High water content residue hopper, 41 …… Supplier, 50 …… Pushing fan, 60 …… Propane gas cylinder,
62 ... Burning burner.

Claims (1)

[Scope of utility model registration request] 1. A furnace is provided with an air chamber at a lower portion thereof, and a combustion chamber is provided at an upper portion of the air chamber through a gas dispersion plate provided across the furnace. In the combustion chamber, a gas dispersion plate is provided from the air chamber. In a fluidized bed type incinerator in which a fluidized medium is fluidized by combustion and fluidizing air supplied through the fluidized bed to form a fluidized bed, and incinerators are combusted and incinerated in the fluidized bed. In addition to providing an air cooling pipe for cooling the plate, an air preheater using the combustion exhaust gas of the furnace as a heating source is provided, and the heated fluid inlet of the air preheater and the air outlet of the air cooling pipe of the gas dispersion plate are provided as a first It was connected by an air pipe, the heated fluid outlet of the air preheater and the combustion and fluidizing air supply port of the air chamber were connected by a second air pipe, and it was preheated by the air cooling pipe of the gas dispersion plate. Air is further preheated with combustion exhaust gas from the furnace by an air preheater for combustion and fluidization Fluidized bed incinerator, characterized in that it has a structure to be used as a gas.