JP2001355818A - Method for melting solid waste and partially incinerating waste oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for melting solid waste and partially incinerating waste oil by which the melting of solid wastes and incineration of waste oil can be performed simultaneously and, at the same time, a gas containing much carbon monoxide and hydrogen can be obtained. SOLUTION: Combustion equipment 11 provided with an oxygen burner 14 inserted into the screw shaft 13 of a screw type transport 12 and oxygen nozzles 16 on the outer periphery of a screw casing 15 is installed to face downward to the ceiling section of a melting furnace. The solid wastes are fed by means of the equipment 11 and melted by combustion flames by causing partial combustion by supplying the waste oil as the fuel of an oxygen burner and, at the same time, supplying oxygen to the burner by adjusting the total supplied mount of the oxygen so that the oxygen ratio of the fuel may become <1.0. Simultaneously, the carbon monoxide and hydrogen are generated by the partial combustion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for melting solid waste and a method for partially burning waste oil. More specifically, the present invention relates to a method for melting solid waste such as incinerated ash and incinerated fly ash, as well as impurities such as heavy metals. The present invention relates to a method for partially combusting waste oil containing nitrogen to trap impurities in molten slag and to generate a gas rich in carbon monoxide and hydrogen.

[0002]

2. Description of the Related Art As a method for melting solid waste such as incinerated ash and incinerated fly ash,
A method of charging solid waste into a burner flame has been used. However, in the conventional method, since the solid waste is transported by air, there is a disadvantage that the transport efficiency is poor depending on the properties of the solid waste.

[0003] Further, a gas containing a large amount of carbon monoxide and hydrogen used as a raw material for organic synthesis has been obtained by partially burning the fuel with the oxygen ratio to the fuel being less than 1.0. The use of air to transport objects also hinders high concentrations of carbon monoxide and hydrogen. In addition, it is conceivable to transport solid waste with oxygen.However, if the components in the solid waste are unknown and if flammable components are contained, there is a risk that a combustion reaction may occur during transportation, and safety may be reduced. It cannot be adopted if considered.

Further, waste oil containing heavy metals as impurities, such as engine oil, cannot be subjected to combustion treatment.
Had been treated as industrial waste.

Accordingly, the present invention provides a method for melting solid waste and a partial combustion of waste oil, which can simultaneously perform a melting treatment of solid waste and a combustion treatment of waste oil, and can also obtain a gas rich in carbon monoxide and hydrogen. It is intended to provide a processing method.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above objects, the present invention provides a method for melting solid waste and partially burning waste oil. In the method, an oxygen burner is inserted into the screw shaft of the screw-type transfer device for transferring the solid waste, and a combustion device provided with an oxygen nozzle on the outer periphery of the screw casing of the transfer device is provided on the ceiling of the melting furnace. Installed downward, the solid waste is transported to the lower end of the combustion device by the transport device and sent out, and waste oil is supplied as at least a part of the fuel of the oxygen burner,
The total amount of oxygen supplied to the oxygen burner and the oxygen supplied to the oxygen nozzle is set so that the oxygen ratio to the fuel is less than 1.0, and the fuel is partially burned. The material is melted into molten slag, and the molten slag is temporarily held in a slag holding section at the lower part of the melting furnace and then taken out through a slag discharge port, and a gas containing carbon monoxide and hydrogen generated by partial combustion is taken out from an exhaust port. It is characterized by:

Further, the present invention is characterized in that impurities in the waste oil are trapped in the molten slag.
The apparatus is characterized in that it comprises means for adjusting the oxygen ratio of the oxygen burner. Further, the slag holding portion is formed below the slag discharge port, convective heat transfer of a combustion gas flow generated by the combustion device, and radiant heat transfer from the flame to maintain the molten slag at a predetermined temperature, An oxygen burner is provided on the side wall of the melting furnace above the slag holding section, and the flame and the combustion gas of the oxygen burner maintain the temperature of the molten slag and prevent the slag discharge port from being blocked.

[0008]

FIG. 1 is a sectional view showing an embodiment of a combustion apparatus used in the method of the present invention, and FIG. 2 is a sectional view of a main part of the combustion apparatus.

The combustion device 11 includes a screw-type transfer device (hereinafter referred to as a screw) 1 for transferring solid waste.
2, an oxygen burner 14 inserted into a screw shaft 13 formed by a hollow shaft, an oxygen nozzle 16 provided on the outer periphery of a screw casing 15, and an oxygen nozzle 16
Water cooling jacket 17 provided on the outer periphery of the
Solid waste supply means mounting portion 18 provided at the base end of
And a drive unit 19 that drives the screw shaft 13.

The oxygen burner 14 and the screw casing 15 are fixed by a suitable holding member or the like, and the screw shaft 13 is rotated by being driven by the motor 20 of the drive unit 19, the sprocket 21, and the chain 22,
The screw blade 23 is configured to convey the solid waste in the tip direction. Bearings 24 are provided at appropriate intervals between the inner periphery of the screw shaft 13 and the outer periphery of the oxygen burner 14 to maintain the positional relationship between the screw shaft 13 and the oxygen burner 14 and to maintain the screw shaft 13. Is able to rotate smoothly.

The oxygen passage 25 for supplying oxygen (tertiary oxygen) to the oxygen nozzle 16 and the water cooling jacket 17 are
The screw casing 15 is formed in a concentric multi-tube structure in which three cylinders are arranged on the outer periphery, and an oxygen supply pipe connection part 25a and a cooling water introduction / outtake pipe connection part 17a are provided on the base side.
Are provided respectively. Also, the oxygen nozzle 16
It is formed by a large number of small through holes provided in the end face member of the combustion device. Further, flanges 26 used for attaching a combustion furnace, assembling the device, and the like are provided at predetermined positions on the outer periphery of the combustion device.

The oxygen burner 14 may have a suitable structure, but the one having a nozzle structure as shown in the sectional view of the main part in FIG. 3 is most suitable. The oxygen burner 14 shown in FIG.
And a frusto-conical mixing chamber 32 with a widened front end is provided at the front end thereof. Oxygen jet holes 33 for jetting oxygen (secondary oxygen) are provided on the peripheral surface of the mixing chamber 32 at a predetermined angle with respect to the generating line of the truncated cone forming the mixing chamber 32 from the tangential direction. It is provided so that secondary oxygen may be spouted inside.

A fuel nozzle 34 for ejecting atomized liquid fuel is provided in the center of the mixing chamber 32 on the base side. The fuel nozzle 34 is connected to a fuel supply passage 35
Mixing chamber 37 for atomizing the fuel by mixing the liquid fuel supplied from the air with oxygen (primary oxygen) for atomizing the fuel supplied from the oxygen supply passage 36, and atomizing the fuel in the internal mixing chamber 37. And a plurality of fuel ejection holes 38 for ejecting the fuel into the mixing chamber 32.

The liquid fuel is ejected from the small through hole at the end of the passage 35 in the axial direction toward the center of the internal mixing chamber 37, and the primary oxygen is supplied from the annular slit formed at the end of the passage 36 through the annular slit. It is jetted into the internal mixing chamber 37 so as to envelop it. The fuel ejection holes 38 are formed so as to eject the atomized fuel at a predetermined opening angle about the axis, and eject (spray) the fuel in a seemingly hollow hollow shape.

As described above, after the liquid fuel and the primary oxygen are ejected into the internal mixing chamber 37 to be in a mixed state, they are ejected from the fuel ejection holes 38 into the mixing chamber 32, whereby the liquid fuel is atomized and the primary fuel is atomized. Combustion can be performed effectively and reliably. At this time, the fuel injection holes 38 of the internal mixing chamber 37
By forming the side wall in a dome shape, atomization of the fuel can be promoted, and the fuel injection holes 3 can be formed.
8 can be oriented in the normal direction of the dome, so that the fuel ejection state from each fuel ejection hole 38 can be made uniform.

The fine-grained fuel ejected in a hollow cone shape while performing primary combustion from the fuel ejection hole 38 is burned in a state of being mixed with the secondary oxygen ejected from the oxygen ejection hole 33 along the inner peripheral surface of the mixing chamber 32. The fuel is jetted from the tip of the device 11 to perform an oxidation reaction (secondary combustion) between the liquid fuel and oxygen. As described above, the liquid fuel is sufficiently atomized by the primary oxygen in the internal mixing chamber 37 and then jetted into the mixing chamber 32, and the secondary oxygen is jetted spirally into the mixing chamber 32 to form the liquid fuel and the secondary oxygen. The liquid fuel and the secondary oxygen can be sufficiently uniformly mixed by mixing and contacting with each other, whereby a homogeneous reaction (secondary combustion) between the liquid fuel and the secondary oxygen can be obtained.

The solid waste sent from the screw 12 can be homogeneously mixed with the tertiary oxygen ejected from the oxygen nozzle 16 by the combustion gas flow of the flame from the oxygen burner 14, and the liquid fuel and the tertiary oxygen can be mixed. Solid waste can be effectively melted in the tertiary combustion flame by the reaction of

The combustion device 11 formed as described above is shown in FIG.
As shown in the cross-sectional view of FIG. 2, the apparatus is mounted downward on the ceiling of the melting furnace 41 and used in a state where the supply pipes and the like are connected. That is, in the oxygen burner 14, the fuel supply passage 3
5 to supply oxygen to the fuel atomization oxygen supply passage 36, primary oxygen to be fuel atomization oxygen, secondary oxygen to the oxygen ejection holes 33, and cooling water to the water cooling jacket 31. In the apparatus main body, tertiary oxygen is supplied to the oxygen flow path 25 of the oxygen nozzle 16, cooling water is supplied to the water cooling jacket 17, and solid waste such as a screw feeder with a hopper mounted on the solid waste supply means mounting part 18 is provided. The solid waste is supplied from the supply means 42 to the screw 12 and transported toward the lower end of the combustion device, and is sent out of the lower end of the combustion device into the melting furnace 41.

Depending on the properties of the waste oil, waste oil alone or a mixture of waste oil and heavy oil or kerosene is used as fuel for the oxygen burner 14.
Then, the fuel is mixed with primary oxygen and is ejected from the fuel ejection holes 38, and is mixed with secondary oxygen and burned.

The solid waste sent from the screw 12 is dispersed in the outer peripheral direction by the combustion gas flow of the flame from the oxygen burner 14 and uniformly mixed with the tertiary oxygen jetted from the oxygen nozzle 16. Oxygen reacts with the unburned liquid fuel to form one flame as a whole, and solid waste is uniformly dispersed in the flame. Therefore, the solid waste sent out from the screw 12 is heated and melted by the high-temperature flame and combustion gas peculiar to the oxygen burner, and captures impurities such as heavy metals contained in the waste oil from the combustion gas while melting the solid waste. It falls into the slag holding part 43 under 41.

The molten slag in the slag holding section 43 maintains a predetermined temperature by the convective heat transfer of the combustion gas flow generated in the combustion device 11 and the radiant heat transfer from the flame. It is discharged into the cooling water of the cooling water tank 45 after overflowing the discharge port 44 provided on the side wall. Also,
The combustion exhaust gas passes through the discharge port 44 serving as both a slag discharge port and an exhaust port, and is extracted from the exhaust port 46.

Further, in the present embodiment, the slag holding portion 43
A heat retaining oxygen burner 47 is provided on the side wall facing the discharge port 44 above the outlet, and the temperature of the molten slag is maintained at a predetermined temperature by the high-temperature flame and combustion gas from the heat retaining oxygen burner 47 to thereby release the gas. And the like, and the discharge port 44 is reliably prevented from being blocked by the slag.

The direction in which the tertiary oxygen is ejected from the oxygen nozzle 16 may be in the axial direction of the combustion device, but may be set to have an appropriate angle in the opening direction, the converging direction, and the twisting direction with respect to the axis. Furthermore, by appropriately selecting the diameter, number of installations, and the shape of the small holes through which the tertiary oxygen is ejected, the flow rate and the ejection state of the tertiary oxygen can be set to optimum conditions.

In addition, by preheating the oxygen supplied to the combustion device 11 to an appropriate temperature, for example, 300 ° C. or more, the solid waste can be more effectively melted.

The supply ratio of the primary oxygen, the secondary oxygen and the tertiary oxygen is arbitrary. By providing means for controlling the flow rate such as a flow control valve, the overall oxygen ratio and the supply ratio of each oxygen can be reduced. It can be adjusted to obtain an optimal combustion state.

As described above, by inserting the oxygen burner 14 into the screw shaft 13 of the screw 12 for transporting the solid waste and arranging the oxygen nozzle 16 on the outer periphery, the solid waste transported by the screw 12 can be removed. Oxygen burners can be reliably heated and melted by the high-temperature flame, and solid waste can be uniformly dispersed in the flame by the combustion gas flow. Volume and stabilization. Further, since the solid waste is transported by the screw 12, a stable transport state is obtained as compared with gas transport,
Solid wastes of various forms and properties can be transported reliably.

Further, by performing the solid waste melting treatment and the waste oil combustion treatment in this manner, the solid waste can be taken out as slag, and impurities such as heavy metals contained in the waste oil can be removed. It can be captured and immobilized in the slag.

Moreover, by burning the fuel with the oxygen ratio to the fuel being less than 1.0, it is possible to extract a gas containing a large amount of carbon monoxide and hydrogen. In particular, by using the oxygen burner 14 having the above structure, the liquid fuel containing waste oil can be uniformly dispersed in oxygen, so that the generation of local hot spots is suppressed, and the generation of soot and carbon dioxide is suppressed. As a result, carbon monoxide and hydrogen can be generated effectively.

[0029]

EXAMPLE The combustion apparatus having the structure described in the above embodiment was mounted vertically downward on the center of the ceiling of a cylindrical melting furnace having an inner diameter of 0.5 m and a length of 2.0 m lined with refractory bricks. As solid waste, fly ash is supplied at a rate of 80 kg / h, waste oil is supplied at a rate of 40 kg / h, primary oxygen is 10 Nm ³ / h, and secondary oxygen is set so that the oxygen ratio to fuel is 0.5. the 10 Nm ³ / h, and the tertiary oxygen are burned by supplying each with 20 Nm ³ / h.

As a result, the melting yield of fly ash was 98% or more, the yield of carbon monoxide and hydrogen in the combustion exhaust gas was 95% of the theoretical yield, and almost no lower hydrocarbon or soot was generated. Most of impurities such as heavy metals contained in the waste oil were trapped in the slag, and were not measured in the combustion exhaust gas.

[0031]

As described above, according to the present invention,
The melting treatment of solid waste such as incineration ash and incineration fly ash and the burning treatment of waste oil containing impurities such as heavy metals can be performed at the same time, and a combustion exhaust gas rich in carbon monoxide and hydrogen can be obtained. In particular, since solid waste was mechanically transported by screws instead of by air or other gas,
A stable transport and supply state can be obtained, and the concentration of carbon monoxide and hydrogen in the combustion exhaust gas can be increased.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a combustion apparatus used in the method of the present invention.

FIG. 2 is a sectional view of a main part of the combustion device.

FIG. 3 is a sectional view of a main part showing an example of an oxygen burner used for a combustion device.

FIG. 4 is a sectional view showing one embodiment of a melting furnace equipped with a combustion device.

[Explanation of symbols]

11: Combustion device, 12: Screw type conveyance device, 13:
Screw shaft, 14 ... Oxygen burner, 15 ... Screw casing, 16 ... Oxygen nozzle, 17 ... Water cooling jacket, 18 ... Solid waste supply means mounting part, 19 ... Drive part,
23 screw blade, 25 oxygen passage, 31 water cooling jacket, 32 mixing chamber, 33 oxygen outlet, 34 fuel nozzle, 35 fuel supply passage, 36 oxygen supply passage,
37: internal mixing chamber, 38: fuel outlet, 41: melting furnace,
42 solid waste supply means 43 slag holding part 44
... Exhaust port, 45 ... Cooling water tank, 46 ... Exhaust port, 47 ... Oxygen burner for heat retention

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F23G 5/44 ZAB F23G 5/50 ZABF 5/50 ZAB ZABH 7/05 ZABF 7/05 ZAB F23J 9/00 F23J 9/00 B01J 19/00 301A // B01J 19/00 301 B09B 3/00 303K 303L (72) Inventor Takashi Yajima 1-16-7 Nishi-Shimbashi, Minato-ku, Tokyo F-term in Nippon Oxygen Co., Ltd. ) 3K061 AA18 AA23 AB02 AB03 AC03 AC06 AC19 BA05 BA06 BA09 BA10 CA04 DA14 DB06 DB15 DB18 DB20 FA03 FA23 FA27 FA28 NB03 NB08 NB13 NB15 NB27 3K062 AA18 AA23 AC03 AC06 AC19 DA22 DB06 DB08 3K0BAA12 AC03 EA23 EA31 EA42 EA46 GA03 GA07 GA08 GA13 GA22 GA23 GA24 GA34 GA35 GA43 GA46 4D004 AA36 AA37 CA29 CA32 CB34 CB42 CB43 DA02 DA03 DA20 4G075 AA37 AA44 AA61 BA05 CA02 EA07 EB01 EC01

Claims (5)

[Claims] 1. A method for simultaneously performing a solid waste melting treatment and a waste oil combustion treatment, wherein an oxygen burner is inserted into a screw shaft of a screw-type transfer device for transferring the solid waste, A combustion device provided with an oxygen nozzle on the outer periphery of the screw casing of the device is installed downward on the ceiling of the melting furnace, and the solid waste is conveyed and sent out to the lower end of the combustion device by the conveyance device, and at least the fuel of the oxygen burner is sent out. A part of the waste oil is supplied, and the total amount of the oxygen supplied to the oxygen burner and the oxygen supplied to the oxygen nozzle is determined as follows.
The fuel is partially burned by setting it to be less than 0, and the solid waste is melted into molten slag by the generated combustion flame, and the molten slag is temporarily held in a slag holding portion at the lower part of the melting furnace, and then the slag is melted. A method for melting solid waste and partially combusting waste oil, comprising taking out a gas containing carbon monoxide and hydrogen generated by partial combustion through an exhaust port, and taking out a gas containing exhaust gas through an exhaust port. 2. The method for melting solid waste and partially burning waste oil according to claim 1, wherein impurities in said waste oil are captured in said molten slag. 3. The method for melting solid waste and partially burning waste oil according to claim 1, further comprising means for adjusting an oxygen ratio of the oxygen burner. 4. The slag holding portion is formed below the slag discharge port, and holds the molten slag at a predetermined temperature by convective heat transfer of a combustion gas flow generated by the combustion device and radiant heat transfer from a flame. 2. The method for melting solid waste and partially burning waste oil according to claim 1, wherein: 5. An oxygen burner is provided on a side wall of a melting furnace above the slag holding section, and a flame and a combustion gas of the oxygen burner maintain the temperature of the molten slag and prevent the slag discharge port from being blocked. The method for melting solid waste and the partial combustion of waste oil according to claim 1, characterized in that: