JP4831309B2 - Waste treatment facility and waste treatment method - Google Patents

Description

  The present invention relates to waste incineration technology, and more particularly, to a waste treatment facility including an incinerator and a supercharger, and a waste treatment method using the supercharger and the incinerator.

2 and 3 are block diagrams of conventional waste incineration facilities.
In the conventional incineration processing equipment 101 for the waste X10, the exhaust gas X40 discharged from the incinerator 20 in accordance with the incineration processing of the waste X10 and the appropriate fuel X20 is guided to the preheater 30 and supplied to the incinerator 20. It uses for heating of compressed air X30 'for combustion.
In addition, in the incineration processing equipment 101 for the waste X10, the exhaust gas X40 from the incinerator 20 may be processed by the exhaust gas wet processing device 70. In this case, white smoke prevention of the exhaust gas discharged from the smoke stack 90 (chimney) Processing is generally performed. As a method for preventing white smoke, an air preheater 50 for preventing white smoke is provided at the front stage of the exhaust gas wet treatment 70, and the heated compressed air X50 'from the preheater 50 is mixed with the exhaust gas subjected to the wet treatment. Is done.
In the conventional equipment 101, the air X30 and X50 for heat exchange are used for the preheater 30 for the compressed air X30 ′ for combustion and the preheater 50 for preventing white smoke using the blowers B1 and B2. Supply.
However, since the operation of the blowers B1 and B2 requires a large amount of power, reduction is required.
Thus, it has been attempted to recover the exhaust gas from the incinerator as steam with a waste heat boiler and use a part of the electric power obtained by generating electricity as a power source for the blower.
In particular, in the conventional waste incineration equipment 101 that employs the pressurized fluidized bed incinerator 20 shown in FIG. 3, the high-temperature high-pressure exhaust gas X40 from the incinerator 20 is introduced into the supercharger 40, and the pressurized air Attempts have been made to prevent the use of the blower B1 by generating air and using it for combustion air or the like.
JP 2005-028251

However, the method of generating electricity using the exhaust gas from the incinerator requires various facilities such as a waste heat boiler and steam turbine power generation equipment, and the cost of equipment and maintenance is high. However, many other small and medium-sized facilities are not suitable because the economic burden is worsened.
Further, in the method of FIG. 3, since it is necessary to introduce the high-temperature and high-pressure exhaust gas X41 into the supercharger 40, the pressurized combustion furnace 20 is an essential requirement. For this reason, it is not suitable for an incinerator near normal pressure.
Therefore, the main problem of the present invention can be applied regardless of whether it is a normal pressure type incinerator or a pressure type incinerator, and also generates compressed air for combustion and compressed air for white smoke prevention. An object of the present invention is to provide a waste incineration facility and a processing method that do not require a blower for supplying a preheater and are excellent in energy efficiency.

The present invention and effects obtained by solving the above problems are as follows.
<Invention of Claim 1>
A first preheater that preheats compressed air for combustion supplied to the fluidized bed incinerator by continuous gas-gas heat exchange between the fluidized bed incinerator and the exhaust gas from the fluidized bed incinerator;
The turbine is rotated by compressed air for combustion that is heated by the first preheater and goes to the fluidized bed incinerator, and by this rotation, the compressed air supplied to the first preheater is generated and blown by the compressor. A first supercharger;
A first air supply device for starting that is provided upstream of the first preheater and rotates the turbine at the start of operation ;
Waste treatment facility characterized by that.

(Function and effect)
A blower for generating compressed air to be supplied to the first preheater is not necessary. Further, since a supercharger that does not require power is used to obtain the compressed air, power reduction is achieved.

<Invention of Claim 2>
An exhaust gas wet processing apparatus for performing wet processing of exhaust gas from a fluidized bed incinerator;
A second preheater for heating the compressed air to be mixed with the exhaust gas treated by the wet treatment device by continuous gas-gas heat exchange with the exhaust gas from the fluidized bed incinerator;
A turbine is rotated by heated compressed air heated by the second preheater, and a second supercharger that generates and blows compressed air to be supplied to the second preheater by the compressor by this rotation. Prepare
The waste treatment facility according to claim 1.

(Function and effect)
A white smoke prevention process is performed, and a blower for generating compressed air to be supplied to the second preheater becomes unnecessary. Further, since a supercharger that does not require power is used to obtain the compressed air, power reduction is achieved.

<Invention of Claim 3>
Preheating the compressed air for combustion supplied to the fluidized bed incinerator by a first preheater by continuous gas-gas heat exchange with the exhaust gas discharged from the fluidized bed incinerator;
The first turbocharger turbine is started to rotate by a first start-up air supply device provided upstream of the first preheater ,
The combustion compressed air towards the fluidized bed incinerator is heated by the first preheater, causes continuously rotating the turbine is supplied to the first turbocharger, the compressor of the turbocharger Generating and blowing compressed air to be supplied to the first preheater at
A waste treatment method characterized by the above.

(Function and effect)
The same effect as that of the first aspect of the invention can be obtained.

<Invention of Claim 4>
In performing the white smoke prevention treatment of mixing heated compressed air to the exhaust gas treated by the exhaust gas wet treatment apparatus,
The compressed air used for the white smoke prevention treatment is heated by continuous gas-gas heat exchange using a second preheater using the exhaust gas discharged from the fluidized bed incinerator as a heat source, and
The heated compressed air heated by the second preheater is supplied to the second supercharger to continuously rotate the turbine, and supplied to the second preheater by the compressor of the supercharger. Generate and blow compressed air,
The waste disposal method according to claim 3.

(Function and effect)
The same effect as that of the invention of claim 2 can be obtained.

According to the present invention, the turbine of the supercharger is rotated by the compressed air that has exchanged heat with the exhaust gas generated in the fluidized bed incinerator, and the compressed air is obtained by the compressor. Then, this compressed air is supplied to the preheater. Therefore, conventionally, a blower is required to generate the compressed air, and electric power for this operation is required. However, this blower (electric power) is unnecessary, and this is an economically superior system.
Moreover, since it is only necessary to install a supercharger in existing equipment, it can be easily constructed. Furthermore, unlike the energy saving by the conventional power recovery method, no power generation equipment is required, and an energy saving effect can be obtained even in small and medium scale equipment.

Hereinafter, an embodiment of a sludge treatment facility and method according to the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of a waste treatment facility 1 that uses the waste treatment method according to the present invention. In this figure, reference numeral 2 is a bubble fluidized bed furnace (combustion furnace), 3 is a first preheater (heat exchanger), 4 is a first supercharger (turbocharger), and 5 is a second preheater (heat exchanger). ), 6 is a second supercharger (turbocharger), 7 is an exhaust gas wet processing device, 8 is an induction fan, 9 is a smoke stack, and 10 and 11 are air supply devices for starting.

  The waste treatment facility 1 treats, for example, by burning waste X1 such as sludge containing a large amount of moisture as fuel in a sewage treatment plant. In addition, the bubbling fluidized bed furnace 2 of the waste treatment facility 1 in the present embodiment has an ability to treat the waste X1 of about 20 to 300 t per day, and the waste treatment facility 1 in the present embodiment is Such a waste X1 has a system configuration with high energy efficiency for the small fluidized bed furnace 2 having a processing capacity of about 35 t / day.

  The bubbling fluidized bed furnace 2 performs combustion using the waste X1 supplied from the outside and the auxiliary combustion fuel X2 supplied as necessary. This bubbling fluidized bed furnace 2 is capable of continuously treating the waste X1 by maintaining a fluid state in the furnace with compressed air X3 'supplied from below.

  In addition, as the auxiliary fuel X2, flammable substances such as heavy oil, kerosene, city gas, and coal can be mentioned. When the pressure and temperature of the compressed air X3 ′ are sufficiently high or when the retained energy of the sludge X1 is high, Even if the auxiliary fuel X2 is not supplied to the bubbling fluidized bed furnace 2, the waste X1 can be continuously burned.

  The first preheater 3 is provided in the subsequent stage of the bubbling fluidized bed furnace 2, and indirectly exchanges heat between the exhaust gas X4 generated by the bubbling fluidized bed furnace 2 and the compressed air X3, thereby generating compressed air X3. Heating to a predetermined temperature.

  The first supercharger 4 is connected to the first preheater 3. The first supercharger 4 is rotated by compressed air X3 ′ heated by indirect heat exchange with the exhaust gas X4 flowing through the first preheater 3, and the rotational power of the turbine 4b is transmitted. Thus, the compressor 4a is configured to generate the compressed air X3 from the outside air and send it into the first preheater 3. That is, the compressed air X3 'that is the power source of the first supercharger 4 is supplied to the bubble fluidized bed furnace 2 as compressed air for combustion. Here, the inventors rotate the turbine 4b with the compressed air X3 ′ obtained by preheating the compressed air X3 compressed with the first supercharger 4 with the first preheater 3, and further serve as a power source. It has been found that the cycle of supplying the compressed air X3 ′ to the bubble fluidized bed furnace 2 as combustion air is sufficiently established. As an example of the starting method, combustion air is supplied from a starting air supply device 10 such as a blower or a compressor, and the burner is ignited and the furnace is heated. In the process, the flow path between the compressor air and the combustion air of the supercharger is switched by a valve or the like.

  As this 1st supercharger 4, it is preferable to use the thing for ships. This is because marine superchargers are already in widespread use and a wide variety of types are available.

  The 2nd preheater 5 is installed in the back | latter stage of a 1st preheater, and the waste gas X4 which distribute | circulated the 1st preheater is distribute | circulated. The exhaust gas X4 and the compressed air X5 sent from the second supercharger 6 are indirectly heat-exchanged to heat the compressed air X5.

The second supercharger 6 is connected to the second preheater 5. The second supercharger 6 is rotated by compressed air X5 ′ heated by heat exchange with the exhaust gas X4 flowing through the second preheater 5, and the rotational power of the turbine 6b is transmitted. The compressor 6a is configured to generate compressed air X5 from the outside air and send it into the second preheater 5. The heated compressed air X5 ′ is used as compressed air for white smoke prevention described later. Here, the inventors rotate the turbine 6b with the compressed air X5 ′ obtained by preheating the compressed air X5 compressed by the second supercharger 6 with the second preheater 5, and further serve as a power source. It has been found that a cycle in which the compressed air X5 ′ is used as compressed air for white smoke prevention is sufficiently established.
As an example of the starting method, first, air is supplied to the second preheater 5 from the starting air supply device 11 such as a blower or a compressor. The compressed air X5 from the second supercharger 6 is discharged to the atmosphere. After the temperature of the exhaust gas X4 becomes high, the air from the starting air supply device 11 and the compressed air X5 from the second supercharger 6 are switched using a valve or the like.

  The exhaust gas wet treatment device 7 is provided in the subsequent stage of the second preheater 5. The exhaust gas wet processing apparatus is for cleaning and processing harmful components such as sulfur components in exhaust gas by injecting, for example, water, an alkaline liquid or the like into the combustion gas X4. The spray liquid is appropriately selected depending on the exhaust gas properties.

  At the subsequent stage of the exhaust gas wet processing apparatus 7, a smoke exhaust tube 9 is provided. The treated exhaust gas is finally released to the atmosphere from the smoke exhaust tube 9.

  An induction fan 8 is provided in the middle of the pipe line from the exhaust gas wet processing apparatus 7 to the smoke exhaust tube 9. By this induction fan 8, the treatment exhaust gas X 6 is guided from the exhaust gas wet processing device 7 to the smoke exhaust tube 9. Note that this attracting fan may not be necessary.

  In the middle of the pipeline that leads from the induction fan 8 to the smoke exhaust tube 9, a pipeline 5 </ b> P that continues from the turbine 6 b of the second supercharger 6 is connected. In the exhaust gas wet processing apparatus 7, a large amount of steam is generated because a liquid is sprayed on the high temperature exhaust gas. Therefore, when the treated gas is supplied as it is to the subsequent smoke exhaust tube 9 after the treatment, white smoke is emitted from the smoke exhaust tube, but in this equipment, heated compressed air obtained by the operation of the second supercharger 6 is used. Since X5 ′ is appropriately mixed with the treated exhaust gas X6 at the front stage of the flue tube 9, the treated exhaust gas X6 is reheated to prevent white smoke. Although not shown, the mixing ratio of the compressed air X5 'uses a valve provided in the pipe 5P and an appropriate control device that controls the opening and closing thereof.

  In the facilities according to the present invention as described above, the compressed air for combustion and the white smoke prevention treatment of the exhaust gas are performed as in the conventional facilities, but both are generated using a supercharger that does not require electric power. Therefore, it is an economical waste treatment facility and waste treatment method compared to conventional facilities.

Here, an operation example of this facility will be described by way of an example of a waste treatment facility for treating sewage sludge of about 35 t per day. From the general flow rate and temperature of the exhaust gas supplied to the first preheater with this scale of equipment, the first supercharger supplies the first preheater with compressed air of 0.12 MPaG and a flow rate of 2600 m ³ N / h. Along with that, compressed air X3 ′ at 0.032 MPaG and 600 ° C. can be obtained. In addition to being able to operate the supercharger sufficiently, it is possible to supply compressed air for combustion into the bubble incinerator.

Furthermore, the second supercharger can supply compressed air of 0.036 MPaG and 4000 m ³ N / h to the second preheater, and can obtain compressed air of 0.003 MPaG and a temperature of 300 ° C. It is. It is possible to sufficiently operate the supercharger and to obtain compressed air for preventing white smoke having a sufficient temperature and amount.

  The conventional equipment shown in FIG. 2 having the same processing capacity requires approximately 90 kW for a blower for obtaining compressed air for combustion and 18.5 kW for a blower for obtaining compressed air for preventing white smoke.

  As a result, the equipment according to the present invention can be applied to the supercharger even in a bubble fluidized bed furnace that is not a pressurized type, and moreover it requires less power than conventional equipment using a blower. , Energy saving is achieved.

  The present invention can be used for various kinds of waste processing using a fluidized bed incinerator.

It is a block diagram of the waste treatment facility using the waste treatment method according to the present invention. It is a block diagram of the waste disposal facility using the conventional waste disposal method. It is a block diagram of a waste disposal facility using another conventional waste disposal method.

  DESCRIPTION OF SYMBOLS 1 ... Sludge processing equipment, 2 ... Bubble fluidized bed furnace, 3 ... 1st preheater, 4 ... 1st supercharger, 4a ... Compressor, 4b ... Turbine, 5 ... 2nd preheater, 6 ... 2nd supercharger , 6a ... compressor, 6b ... turbine, 7 ... wet exhaust gas treatment device, 8,80 ... attraction fan, 9 ... smoke stack, 20 ... incinerator, 30 ... preheater, 40 ... supercharger, 50 ... preheater.

Claims (4)

A first preheater that preheats compressed air for combustion supplied to the fluidized bed incinerator by continuous gas-gas heat exchange between the fluidized bed incinerator and the exhaust gas from the fluidized bed incinerator;
The turbine is rotated by compressed air for combustion that is heated by the first preheater and goes to the fluidized bed incinerator, and by this rotation, the compressed air supplied to the first preheater is generated and blown by the compressor. A first supercharger;
A first air supply device for starting that is provided upstream of the first preheater and rotates the turbine at the start of operation ;
Waste treatment facility characterized by that. An exhaust gas wet processing apparatus for performing wet processing of exhaust gas from a fluidized bed incinerator;
A second preheater for heating the compressed air to be mixed with the exhaust gas treated by the wet treatment device by continuous gas-gas heat exchange with the exhaust gas from the fluidized bed incinerator;
A turbine is rotated by heated compressed air heated by the second preheater, and a second supercharger that generates and blows compressed air to be supplied to the second preheater by the compressor by this rotation. Prepare
The waste treatment facility according to claim 1. Preheating the compressed air for combustion supplied to the fluidized bed incinerator by a first preheater by continuous gas-gas heat exchange with the exhaust gas discharged from the fluidized bed incinerator;
The first turbocharger turbine is started to rotate by a first start-up air supply device provided upstream of the first preheater ,
The combustion compressed air towards the fluidized bed incinerator is heated by the first preheater, causes continuously rotating the turbine is supplied to the first turbocharger, the compressor of the turbocharger Generating and blowing compressed air to be supplied to the first preheater at
A waste treatment method characterized by the above. In performing the white smoke prevention treatment of mixing heated compressed air to the exhaust gas treated by the exhaust gas wet treatment apparatus,
The compressed air used for the white smoke prevention treatment is heated by continuous gas-gas heat exchange using a second preheater using the exhaust gas discharged from the fluidized bed incinerator as a heat source, and
The heated compressed air heated by the second preheater is supplied to the second supercharger to continuously rotate the turbine, and supplied to the second preheater by the compressor of the supercharger. Generate and blow compressed air,
The waste disposal method according to claim 3.

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