JPH0833190B2 - Swirl melting furnace - Google Patents

Description

TECHNICAL FIELD The present invention burns a powdery combustible material containing an incombustible material such as dry sewage sludge and coal, and efficiently heats the incombustible material contained in the powdery combustible material. The present invention relates to a swirl flow melting furnace that can be melted, turned into slag, and taken out of the system.

[Conventional technology]

Conventionally, powdery combustible materials such as dry sewage sludge and coal containing incombustible materials are placed on the combustion air from the end surface or side surface of the cylindrical furnace body and injected so that a strong swirl flow is generated inside the furnace body. A swirl-flow melting furnace in which the incineration ash is melted by the heat of combustion while flowing while being made to flow out from the furnace body outlet is generally widely known (for example, JP-A-61-21).
(See Japanese Patent No. 3408).

This swirl flow melting furnace is, for example, as shown in FIG.
A cylindrical furnace body 1 is arranged with an inclination at a predetermined angle, and an auxiliary burner 4 having a heavy oil supply pipe 2 and an air supply pipe 3 for burning heavy oil is provided at one end surface portion (upstream end surface portion) of the furnace body 1. Is installed, and on the other end face portion (downstream end face portion) of the furnace body 1,
A discharge cylinder 7 having a waste gas outlet 5 and a melt outlet 6 at the top and bottom is connected, and a powdery combustible material supply port 8 and a powdery combustible material supply port 8 are provided on the outer peripheral surface near the one end of the furnace body 1. A combustion air port 9 is provided. And the above auxiliary burner 4
As shown in FIGS. 5 and 6, the swirler has a double structure of a heavy oil supply pipe 2 and an air supply pipe 3, and a guide blade 11 for swirling a nozzle flow is fixed to the tip end 10 of these. Part 12
Is attached.

[Problems to be solved by the invention]

However, in the conventional swirl flow melting furnace,
As the operating time elapses, the temperature around the auxiliary burner 4 provided at the upstream end surface of the furnace body 1 fluctuates and is not high enough, so that semi-molten incombustibles adhere and gradually increase. Grows and finally swirler part 12 of auxiliary burner 4
There was a problem that it may block. And this blockage phenomenon remarkably appears when the low heat generating substance which is hard to keep the inside of the furnace body 1 at a high temperature is supplied and burned. Further, since the auxiliary burner 4 is installed on the upstream end surface of the furnace body 1, it is not possible to attach a sight glass that allows the entire area of the furnace body 1 to be seen, and the molten state in the furnace body 1 can be observed. There was a problem that I could not do it.

The present invention has been made in view of the above circumstances, and an object thereof is to be able to efficiently burn a powdery combustible material, and to keep the temperature inside the furnace body at a constant and high temperature. An object of the present invention is to provide a swirl flow melting furnace that can completely melt an incombustible material contained in a powdery combustible material and smoothly discharge it to the outside of the furnace.

[Means for solving problems]

In order to achieve the above object, the present invention provides an auxiliary combustion furnace at an upper part of the cylindrical furnace body near one end surface, and the auxiliary combustion furnace is provided with a powdery combustible material and a combustion air supply port. Along with the tangential direction of the furnace body, provided with the furnace body, a blowing nozzle that blows at high speed a mixture of powdery combustible material and gas that have become partially hot in the auxiliary combustion furnace and have a high temperature, and It is connected to the furnace body while inclining to the one end face side.

Further, it is preferable that the auxiliary combustion furnace includes an auxiliary burner and further has a viewing window on one end surface.

[Action]

In the above swirl flow melting furnace, the powdery combustible material and the combustion air are supplied and mixed in the auxiliary combustion furnace, and the air ratio is changed.
Partially burned in a state of being suppressed to 1.0 or less and made high temperature,
Then, the mixture is blown into the furnace body by the blowing nozzle along the tangential direction thereof and toward the other end face side of the discharge side furnace body, and the spiral swirling flow is blown from the one end face side to the other side. Generate it toward the end face side to burn it efficiently,
And it completely melts the incombustibles.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

In the figure, 20 is a furnace body of a horizontal cylindrical swirling flow melting furnace,
The furnace body 20 is installed at a predetermined angle. A viewing window 21 for observing the inside is attached to one end surface portion (upstream end surface portion) of the furnace body 20. A discharge cylinder 24 having a waste gas outlet 22 and a melt outlet 23 is connected to the other end surface portion (downstream end surface portion) of the furnace body 20. Further, an auxiliary combustion furnace 25 and a combustion air port 26 are installed near the upper part of the outer peripheral surface on the upstream side of the furnace body 20.

A lower portion of the auxiliary combustion furnace 25 has a funnel-shaped diameter reduction, and a blowing nozzle 27 is arranged at a connecting portion with the furnace body 20. As shown in FIG. 2, the blowing direction of the blowing nozzle 27 is set substantially in the tangential direction along the outer peripheral surface of the furnace body 20 in the axial direction view of the furnace body 20. On the other hand, in the side view of the furnace body 20 as shown in FIG. 1, the blow nozzle 27 extends vertically while the furnace body 20 is inclined, that is, with respect to the furnace body 20. Are inclined and connected to the one end face side.
Therefore, the blowing direction of the blowing nozzle 27 in the side view is set to the direction inclining to the other side end face side according to the inclination of the furnace body 20. Further, at the upper part of the auxiliary combustion furnace 25, a fuel supply port for supplying powdery combustible material together with air
An auxiliary burner 31 having a heavy oil supply pipe 29 and an air supply pipe 30 for heavy oil fuel is arranged at the upper end of the auxiliary combustion furnace 25.

When burning a powdery combustible material using the swirl flow melting furnace configured as described above, first, the auxiliary combustion furnace 25 is operated by the heavy oil supply pipe 29 and the air supply pipe 30 of the auxiliary burner 31.
The heavy oil is burnt inside, and the combustion gas generated by this heavy oil fuel is blown into the furnace body 20 by the blowing nozzle 27, and the incombustible matter contained in the powdery combustible material is melted and flows down in the furnace body 20. Up to a sufficient temperature (eg 1400 ° C). Next, when the temperature inside the furnace body 20 rises, the auxiliary burner 31 is stopped, and a powdery combustible material (for example, a powdery sludge obtained by drying sewage sludge and crushing it to an average particle size of 200 μm or less) is supplied by fuel by air transportation. Supply from the mouth 28 into the auxiliary combustion furnace 25. The intake air amount at this time is 80% of the theoretical combustion air amount of sludge.
%, And the rest (for example, the theoretical combustion air amount of sludge
Blow from the combustion air port 26 (about 40%). As a result, in the auxiliary combustion furnace 25, a portion of the sludge having a high burning rate burns, and the temperature near 1200 ° C. is reached in the vicinity of the injection nozzle 27. Then, the partially burned powdery sludge is blown into the furnace body 20 together with the gas from the blowing nozzle 27 at a flow rate of 40 to 80 m / sec. In this case, since the blowing direction of the blowing nozzle 27 is set to a substantially tangential direction along the outer peripheral surface of the furnace body 20, the mixture blown into the furnace body 20 has a strong swirling flow along the furnace wall. And move. Moreover, the blowing nozzle 27 is attached to the furnace body 20 while being inclined toward one end surface side thereof, so that the blowing direction of the blowing nozzle 27 is inclined toward the other end surface side within the furnace body 20. From
The mixture blown in the tangential direction moves toward the other end face side while forming a spiral swirling flow.
By the way, at this time, the temperature inside the furnace body 20 rises to 1400 to 1500 ° C. due to the combustion of the supplied sludge.

In this state, of the sludge particles blown at high speed, the particles burn in the high temperature air stream, but the particles that cannot be burned reach the furnace wall surface by the cyclone effect and are trapped by the molten slag present there. The incombustibles that are burned and contained in the sludge flow down while melting on the furnace wall surface, and fall into the slag cooling equipment through the melt outlet 23. On the other hand, the combustion waste gas is sent to the waste gas treatment facility through the waste gas outlet 22.

When the calorific value of the powder sludge is low, the heavy oil combustion by the auxiliary burner 31 is continued even after the powder sludge is supplied.

Next, the result of a specific operation of the above swirl-flow melting furnace will be described together with the operation result of the conventional swirl-flow melting furnace.

a) When no auxiliary fuel is used The physical properties and operating conditions of the used dry sewage sludge are as follows.

Dry sewage sludge Water content 1.5% Ash content 35.8% Combustible content 62.7% Total calorific value 3890kCal / Kg / Dry matter average particle size 180μm Supply amount 120Kg / H Combustion air supply amount Auxiliary combustion furnace 0.8 Main furnace 0.4 Operated under the above conditions The results are shown in Table 1.

b) When using auxiliary fuel The physical properties and operating conditions of the used dry sewage sludge are as follows.

Dry sewage sludge Moisture 2.0% Ash 55.5% Combustible 42.5% Total calorific value 2900kCal / Kg / Dry matter average particle size 180μm Supply amount 120Kg / H Auxiliary fuel Heavy oil 1.0 / H Combustion air supply amount Auxiliary combustion furnace 0.8 Main body 0.4 Above Table 2 shows the results of operation under such conditions.

As is clear from the above two examples, the swirl-flow melting furnace according to the present invention enables efficient high-load combustion to be continuously operated for a long time. That is, as shown in FIG. 3, the temperature inside the furnace body 20 rises from the start of the operation, and after reaching a predetermined temperature (for example, 1400 ° C.) (after the powder sludge supply time t ₁ ), The operation is smoothly continued while keeping the temperature constant.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the present invention provides an auxiliary combustion furnace at an upper part of the cylindrical furnace body near one end surface, and the auxiliary combustion furnace is provided with a supply port for powdery combustible material and combustion air. A blowing nozzle that blows into the furnace body at a high speed a mixture of a powdery combustible material and a gas that have been partially burned in the auxiliary combustion furnace and have a high temperature, along the tangential direction of the furnace body, and Since it is connected to the body while inclining to the one end face side, it has the following excellent effects.

B) It is possible to always perform stable operation against changes in physical properties such as the particle size and heat generation amount of powdery combustible material.

B) It is possible to keep the temperature of the powdery combustible material into the furnace at a high temperature, and a spiral swirl flow is formed in the furnace from one end face side to the other end face side. For,
A semi-molten deposit is not generated on the one end surface of the furnace body to which the powdery combustible material is supplied, and continuous operation for a long time is possible.

C) Since a peephole can be attached to one end face of the furnace body, the inside of the furnace body can be completely observed, the combustion and melting states can be sufficiently monitored, and operation management can be easily performed. .

[Brief description of drawings]

1 to 3 show an embodiment of the present invention,
FIG. 1 is a cross-sectional view, FIG. 2 is an explanatory view showing a connected state of an auxiliary combustion furnace and a furnace body, FIG. 3 is a characteristic view showing a temperature change in the furnace body, and FIG. 4 is a conventional swirl flow melting furnace. 5 is a sectional view of the auxiliary burner, and FIG. 6 is a sectional view taken along the line VI-VI of FIG. 20 …… furnace body, 21 …… peep window, 25 …… auxiliary combustion furnace, 27 …… injection nozzle, 28 …… fuel supply port, 31 …… auxiliary burner.

 ─────────────────────────────────────────────────── ─── Continued front page (72) Teruji Kubota, 2-17-15 Tsukushima, Chuo-ku, Tokyo Tsukishima Machinery Co., Ltd. (72) Misao Igarashi 2-17-15 Tsukushima, Chuo-ku, Tokyo Tsukishima Machinery Co., Ltd. (72) Inventor Hochika Tanaka 2-17-15 Tsukushima, Chuo-ku, Tokyo Tsukishima Machinery Co., Ltd. (72) Inventor Yasuhiko Kamijo 2-17-15 Tsukushima, Chuo-ku, Tokyo Tsukishima Machinery Co., Ltd. Internal examiner Toshinaga Miyazaki (56) References “The 22nd Sewer Research Presentation Lecture”, (May 10, 1985), Japan Sewage Works Association, “11-50 Swirl melting furnace Combustion of sludge (1st report)

Claims (3)

[Claims] 1. An auxiliary combustion furnace is provided in an upper part of the cylindrical furnace body near one end surface, and a supply port for powder combustibles and combustion air is provided in the auxiliary combustion furnace, and the furnace body is provided with the auxiliary combustion furnace. , A blowing nozzle that blows a mixture of a powdery combustible substance and a gas that have become high temperature by partial combustion in the auxiliary combustion furnace and blows at high speed into the furnace body, along the tangential direction of the furnace body, and A swirling flow melting furnace, wherein the swirling flow melting furnace is connected to the furnace body while being inclined toward the one end face side. 2. The auxiliary combustion furnace according to claim 1, wherein the auxiliary combustion furnace is provided with an auxiliary burner for burning a powdery combustible material having a low calorific value to maintain a constant temperature. Swirl flow melting furnace. 3. The swirling flow melting furnace according to claim 1 or 2, wherein the furnace body has a viewing window on one end face thereof.