JP2001311511A - Method of incinerating refuse and incinerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of efficiently incinerating industrial refuse, a general refuse and the like and an incinerator therefore. SOLUTION: The incinerator for incinerating refuse by charging the same into a rotary kiln circumferentially rotatable in an inclined state, supplying combustion air thereto and igniting fuel supplied from a burner, comprises nozzles formed in a refractory material 4 provided in a wind box 3 surrounding an opening 2 in a rotary kiln 1 at the inclined upstream side thereof for jetting the combustion air toward the refuse therefrom, and a clearance 7 formed between the rotary kiln 1 and the refractory material 4 for supplying sealing air into the rotary kiln 1 therethrough.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for incinerating industrial waste and general waste and a furnace for incineration.

[0002]

2. Description of the Related Art Conventionally, a rotary kiln type incinerator has been used as an apparatus for incinerating industrial waste, general waste and the like (hereinafter simply referred to as waste). FIG. 7 shows an example of a conventional rotary kiln type incinerator,
The opening b on the inclined upper side of the cylindrical rotary kiln a having a predetermined inclination angle and being rotatable in the circumferential direction is tightly surrounded by a wind box c, and as shown in FIGS. 8 and 9, A refractory material d is provided in the wind box c.

A refractory material d having an outer diameter smaller than the inner diameter of the rotary kiln a protects the wind box c from high-temperature combustion heat in the rotary kiln a. An inlet e for waste, a burner f for injecting fuel such as kerosene, heavy oil, propane gas, and pyrolysis gas, and the like are provided toward the rotary kiln a.

When the combustion air is supplied from the air fan g into the wind box c while rotating the rotary kiln a in the circumferential direction, the combustion air is supplied to the wind box c and the refractory material d as shown in FIG.
The air flow in the wind box c is circulated in one direction indicated by an arrow A by the partition wall h provided between the inner wall surface of the rotary kiln a and about 1/3 of the amount of air sent into the wind box d. The air is blown into the rotary kiln a through an annular clearance i formed between the rotary kiln a and the outer peripheral surface of the refractory material d. Is blown into

[0005] In this way, the fuel is fed from the burner f while the combustion air is supplied into the rotary kiln a to ignite, and the inputted waste is dried and burned. When the waste with high calorific value burns sufficiently, the rotary kiln a
Since the temperature in the inside rises, the supply of fuel is stopped, and then self-combustion is performed by supplying combustion air. Then, the incinerated ash obtained by drying → combustion is discharged from the discharge port k on the lower side of the slope of the rotary kiln a, and solidified as it is or after using cement or the like, and then landfilled.

[0006]

In the case of the rotary kiln a, waste and combustion air can be supplied only from the opening b, so that the temperature atmosphere near the opening b tends to decrease. It is a phenomenon that solid or liquid waste emits a flame and burns, after it becomes a flammable gas by evaporation or thermal decomposition, and then mixes with air and is oxidized. The concentration needs to be kept within a certain range.

[0007] If air is blown to the waste which is not sufficiently burned, the concentration of the combustible gas cannot be maintained and the flame cannot be maintained. For this reason, ignition was delayed, and efficient combustion was not possible. Therefore, maintaining the combustion in the opening b is very important in the case of the rotary kiln a. However, in the conventional rotary kiln type incinerator, contact between the waste and the combustion air near the opening b is made. When the excess air ratio is increased, it is difficult to burn near the opening b of the rotary kiln a, and there is a disadvantage that the burning loss increases.

[0008] Further, an updraft is generated in the rotary kiln a due to the combustion temperature at which the waste is incinerated. Then, a part of the air blown through the wind box c passes through the space above the rotary kiln a along the ascending airflow, is flowed as it is in the direction of the discharge port k without being used for combustion, and is discharged to the outside. (The flow shown in the direction of arrow B in FIG. 7).

[0009] Since the rotary kiln a is inclined downward, when the air is released in the upward airflow, the oxygen concentration required for combustion gradually decreases in the middle of the rotary kiln a, and the combustion gas and the combustion gas are reduced. Therefore, there is a problem that the combustion temperature in the rotary kiln a decreases and the contact with the waste (incineration) decreases, and unburned components easily remain in the rotary kiln a.

The present invention has been made in view of the above-mentioned problems of the conventional waste incineration method and the incinerator, and sends the combustion air toward a position close to the opening of the rotary kiln or an intermediate portion while generating a swirling flow. It is an object of the present invention to provide a waste incineration method which improves the combustion efficiency of the waste. Another object of the present invention is to provide a waste incinerator that can improve the mixing with air by inverting and stirring the waste in the rotary kiln, thereby improving the combustion efficiency. is there.

[0011]

In order to achieve the above object, the incineration method of the present invention is to supply waste air into a rotary kiln that can rotate in a circumferential direction in a tilted state and to supply combustion air. In the method of igniting waste supplied by a fuel supplied from a burner, waste is incinerated from an outlet formed in a refractory material 4 provided in a wind box 3 surrounding an opening 2 on an inclined upper side of a rotary kiln 1. The air for combustion is blown out, and the air for sealing is fed from the clearance 7 between the rotary kiln 1 and the refractory material 4.

Further, the incinerator of the present invention puts waste into a rotary kiln rotatable in a circumferential direction in an inclined state, supplies combustion air, ignites fuel supplied from a burner, and discharges waste. In the furnace for incineration, waste is put on the inner surface of the rotary kiln 1
Is provided with a lifter 12 which can be lifted upside down and rotated and stirred.

Further, the incinerator according to the present invention is characterized in that the waste is thrown into a rotary kiln which is rotatable in a circumferential direction in an inclined state, while the combustion air is supplied, and the fuel supplied from the burner is ignited to discharge the waste. In the furnace for incineration, the refractory material 4 provided in the wind box 3 surrounding the opening 2 on the inclined upper side of the rotary kiln 1 is provided with an outlet capable of blowing out combustion air toward waste, and the rotary kiln 1 Air for sealing is sent from the clearance 7 with the refractory material 4, and the waste is raised and reversed on the inner circumferential surface of the rotary kiln 1 along the rotation direction of the rotary kiln 1.
A lifter 12 capable of stirring is provided.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2, the opening 2 on the upper side of the cylindrical rotary kiln 1 having a predetermined inclination angle and being rotatable in the circumferential direction is tightly surrounded by the wind box 3 and is inserted into the wind box 3. Is provided with a refractory material 4, and a burner 6 for injecting fuel such as kerosene, heavy oil, propane gas, and pyrolysis gas is provided toward the inside of the rotary kiln 1 through the refractory material 4. Then, while blowing combustion air sent from an air fan (not shown) into the rotary kiln 1, fuel is sent from the burner 6 and ignited, the input waste is dried and burned, and incinerated ash is disposed of as waste. Same as before.

In the present invention, in addition to blowing combustion air from an annular clearance 7 formed between the rotary kiln 1 and the refractory material 4, combustion air outlets 8 and 9 are formed in the refractory material 4 to form a rotary kiln. A small amount of combustion air is blown from a clearance 7 formed between the refractory material 1 and the refractory material 4 and the remaining amount of combustion air is blown into the rotary kiln 1 from each of the outlets 8 and 9 so as to increase the combustion efficiency. It has features.

That is, the amount of air blown from the clearance 7 is set to be approximately 1/3 of the total amount of air blown into the rotary kiln 1 and the remaining 2/3 of the air is blown into the rotary kiln 1 from the outlets 8 and 9. It has been adjusted as follows. However, this numerical value is not limited, and can be appropriately adjusted according to the size of the rotary kiln 1 and the contents of the waste.

The air sent from the clearance 7 has a role of sealing the clearance 7 in addition to combustion. That is, the internal pressure of the rotary kiln 1 is -5 to
It is adjusted to -10 mm water column, and there is a possibility that the waste and the combustion waste gas in the rotary kiln 1 may flow backward unless the air is constantly sent into the wind box 3 to make the pressure positive due to the pressure fluctuation. Backflow is prevented by the sealing air. Further, the refractory material 4 has high heat due to the combustion heat in the rotary kiln 1, and the air box 3 is cooled by supplying air into the wind box 3.

As described above, by reducing the amount of air supplied from the clearance 7, the concentration and temperature of the combustible gas in the vicinity of the opening 2 are maintained, so that ignition is accelerated and thermal decomposition is promoted to increase initial combustion efficiency. Thereafter, waste is efficiently burned by a large amount of combustion air sent into the rotary kiln 1 from the outlets 8 and 9.

For this purpose, the outlets 8 and 9 are provided at two places on one side along the circumferential direction of the refractory material 4, for example, at 45 ° and 135 ° clockwise from the center of the refractory material 4 in FIG. The outlets 8 and 9 are provided in FIG. 3 and FIG.
As shown in FIG. 1, the rotary kiln 1 is oriented in the axial direction and inclined with respect to the rotation direction of the rotary kiln 1.

Normally, the rotary kiln 1 is rotated left or right, but in the present invention, the rotary kiln 1 is rotated rightward as shown in FIG. The waste 10 is not located at the bottom of the rotary kiln 1, but the contact friction acts between the rotary kiln 1 and the waste 10 so that the waste 10 tends to be pushed up in the rotational direction,
On the other hand, since the waste 10 has a function of trying to lower by its own weight, by the cooperative action of both, the waste 10 is placed in the rotary kiln 1 in the rotary kiln 1 in an oblique left direction along the rotation direction as shown in FIG. What is located. Therefore,
It is desirable that the combustion air blown out from the blowout ports 8 and 9 hits the waste 10.

Further, the distance of the combustion air from the outlets 8 and 9 to the waste 10 in the rotary kiln 1 is different. The reach from the outlets 8 and 9 is
Depending on the size of the rotary kiln 1, the lower outlet 9
１ ／ × L to ３ × L from the opening 2, 上方 × L to か ら from the opening 2 from the upper outlet 8
What is necessary is just to reach within the range of × L.

For example, in the case of the rotary kiln 1 having an inner diameter D = 4 m and a length L = 14 m, the lower outlet 9 reaches the waste 10 at a position 3 to 4 m from the opening 2, and the upper part thereof has From the outlet 8, the waste 11 was reached at a position 5 to 7 m from the opening 2, and fresh air was sent to the waste 10. As a result, an optimal combustion effect was obtained. In addition, the combustion air branched from the supply path 11 of the combustion air sent from the air fan (not shown) to the wind box 3 from the air outlets (not shown) into the rotary kiln 1 from the outlets 8 and 9 or the combustion air sent from the independent air fan. The working air is blown out.

In the above configuration, if air for combustion is sent from the outlets 8 and 9 into the rotary kiln 1 while air for sealing is sent from the clearance 7, waste is directly discharged from the outlets 8 and 9 to waste. As the air is blown to agitate the waste, the waste can be incinerated efficiently.

In particular, since the flame generated when the waste is burned rises, if the combustion air is blown out from the outlets 8 and 9 so as to swirl, the air will hit from below the waste. And it becomes easier for fresh air to enter the combustion part.

In the above description, the outlets 8, 9
Is a case where two places are provided in the refractory material 4, but the present invention is not limited to this. The number of outlets may be one, or two or more. Irrespective of the number of outlets, it is necessary that combustion air be blown toward the waste and the waste be efficiently burned while being stirred.

FIGS. 5 and 6 show another embodiment of the present invention, in which the same parts as those of the above embodiment are denoted by the same reference numerals. This embodiment is characterized in that a lifter 12 for inverting and stirring the waste is provided on the inner circumferential surface of the rotary kiln 1. Refractory material 4
A lifter 12 made of the same material as that of the rotary kiln 1 is elongated along the length direction of the rotary kiln 1 and has a triangular cross section. A plurality of single lifters 12 are equally spaced along the circumferential direction of the rotary kiln 1. And are arranged in a dispersed manner within a certain distance range from the opening 2 of the rotary kiln 1.

This distance range may be in the range of 2/5 × L to 3/5 × L, depending on the scale of the rotary kiln 1, and is desirably set at a position close to the opening 2. For example, in the case of a rotary kiln 1 having a length L of 14 m, the waste is dispersed within a range of 6 m from the opening 2, and is dispersed within a range of 8 m from the opening 2 at the longest. And good combustion results were obtained.

With the inside of the rotary kiln 1 having the above-described configuration, the input waste is transported upward by the lifter 12 along the rotation direction of the rotary kiln 1, falls upside down, and repeats. Since the waste is stirred, the entire waste is incinerated on average, and an efficient incineration effect is obtained.

As shown in FIGS. 5 and 6, the lifters 12 are provided at equal intervals at four locations along the circumferential direction of the rotary kiln 1, and the odd and even rows have a phase of 45 °.
The arrangement of the lifters 12 may be arbitrarily selected.

Further, the refractory material 4 described in the above embodiment is used.
By using the lifter 12 in common with the blowing of the combustion air from the blowing ports 8 and 9 provided in the above, the efficiency of the combustion of the waste to be inverted and stirred can be increased.

In the above description, the waste is incinerated and disposed. However, in recent years, it has become difficult to secure landfill sites for incinerated ash, and it has also become difficult to landfill itself due to pollution problems such as dioxin.
Therefore, the incineration ash is melted by raising the incineration temperature using a rotary kiln that can withstand high temperatures. For example, as shown in FIG.
The molten slag is discharged from the discharge port k, and granulated slag is generated in a cooling water tank n provided below the duct m, and the granulated slag is disposed of. The present invention
Such a rotary kiln 1 can be applied to waste incineration and melting techniques.

[0032]

According to the present invention described above, in the incineration using a co-current rotary kiln for supplying combustion air from the same direction as the input of waste, the refractory material 4 provided in the wind box 3 is used. The outlets 8 and 9 are formed in the outlet, and the combustion air is blown from the outlets 8 and 9 toward the waste, so that the waste is stirred by the blown air and the combustion efficiency can be increased. It is.

In particular, since a small amount of air for sealing is blown from the clearance 7 formed between the rotary kiln 1 and the refractory material 4, waste and combustion waste gas are discharged by the pressure in the rotary kiln 1. There is no backflow, and the concentration and temperature of the combustible gas are maintained in the vicinity of the opening 2 to accelerate ignition and promote thermal decomposition to increase combustion efficiency.

A lifter 1 is provided on the inner circumferential surface of the rotary kiln 1 for raising, turning over, and dropping waste.
By providing a plurality of the fuel cells 2, the waste can be inverted and stirred to increase the combustion efficiency. Further, the combustion air is blown from the outlets 8 and 9 formed in the refractory material 4, and the lifter 12 is used. It is possible to further increase the efficiency of waste combustion by sharing the same.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a rotary kiln type incinerator used in the present invention.

FIG. 2 is a cross-sectional view of a rotary kiln-type incinerator used in the present invention as viewed from an opening side.

FIG. 3 is a cross-sectional view of the rotary kiln showing a blowing direction of air blown from a blowing port formed in a refractory material.

FIG. 4 is a cross-sectional view of the rotary kiln showing a blowing direction of air blown from a blowing port formed in a refractory material.

FIG. 5 is a longitudinal sectional view showing another embodiment of a rotary kiln incinerator used in the present invention.

FIG. 6 is a sectional view taken along line XX of FIG. 5;

FIG. 7 is a front view schematically showing a conventional rotary kiln incinerator.

FIG. 8 is a sectional view of a main part of a conventional rotary kiln incinerator.

FIG. 9 is a cross-sectional view of a conventional rotary kiln-type incinerator as viewed from the opening side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary kiln 2 Opening 3 Wind box 4 Refractory material 5 Waste inlet 6 Burner burner 7 Clearance 8 Combustion air outlet 9 Combustion air outlet 10 Waste 11 Combustion air supply path 12 Lifter

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Atsushi Ito 2-17-15 Tsukushima, Chuo-ku, Tokyo Inside Tsukishima Machinery Co., Ltd. (72) Inventor Yasushi Okino 2-17-15 Tsukushima, Chuo-ku, Tokyo Machinery F-term (reference) 3K023 AA08 KA02 KB05 KB11 KD02 3K061 KA02 KA06 KA09 KA10 KA15 3K065 AA08 AB01 BA04 GA04 GA08 GA12 GA23 GA32 GA43

Claims (3)

[Claims] 1. A method of incinerating waste by injecting waste into a rotary kiln rotatable in a circumferential direction in an inclined state, supplying combustion air, igniting fuel supplied from a burner, and incinerating the waste. The combustion air is blown out toward the waste from the outlet formed in the refractory material 4 provided in the wind box 3 surrounding the opening 2 on the upper side of the slope and the seal is provided from the clearance 7 between the rotary kiln 1 and the refractory material 4. A waste incineration method characterized by feeding air for use. 2. A rotary kiln that injects waste into a rotary kiln that is rotatable in a circumferential direction in an inclined state, supplies combustion air, ignites fuel supplied from a burner, and incinerates the waste. A waste incinerator characterized in that a waste lifter 12 is provided on a circumferential inner surface of the waste so as to ascend and reverse the waste along the rotation direction of the rotary kiln 1. 3. A rotary kiln in which a waste is thrown into a rotary kiln rotatable in a circumferential direction in an inclined state, combustion air is supplied, a fuel supplied from a burner is ignited, and the waste is incinerated. In the refractory material 4 provided in the wind box 3 surrounding the opening 2 on the upper side of the slope, an outlet capable of blowing out combustion air toward waste is formed, and a clearance 7 between the rotary kiln 1 and the refractory material 4 is formed. From the inside of the rotary kiln 1, the waste is lifted upside down along the rotation direction of the rotary kiln 1, and the stirrer lifter 12 is rotated.
A waste incinerator characterized by the following.