JP7630153B2 - Dry distillation gasification incineration treatment equipment - Google Patents

Description

The present invention relates to a dry distillation gasification incineration treatment device.

Conventionally, there is known a dry distillation gasification incineration treatment apparatus that includes a dry distillation furnace and a combustion furnace, and introduces the combustible gas generated in the dry distillation furnace into the combustion furnace for complete combustion (see, for example, Patent Document 1).

In the dry distillation and gasification incineration treatment device, a portion of the waste, such as waste tires, stored in the dry distillation furnace is burned, and the remaining portion of the waste is dry-distilled (thermally decomposed) by the heat of combustion to generate combustible gas. The combustible gas generated by the dry distillation and gasification is introduced from the dry distillation furnace to the combustion furnace for combustion. The combustion exhaust from the combustion furnace is cooled, desulfurized, and deodorized in a cooling furnace and a quenching tower, and then removed from fly ash, soot, etc. by a bag filter before being released into the atmosphere from a chimney.

At this time, the amount of flammable gas generated in the dry distillation furnace is feedback-controlled by adjusting the amount of oxygen supplied required for the dry distillation of the waste, and as a result, the temperature inside the combustion furnace is maintained at a predetermined temperature by the combustion of the flammable gas.

On the other hand, the dry distillation furnace needs to be protected from the heat generated by the dry distillation of the waste, but if the furnace body is made of a refractory material such as firebricks, there is a problem that the refractory material stores heat, making the feedback control difficult. To solve this problem, the dry distillation furnace is provided with a water jacket in the furnace wall that is isolated from the inside of the furnace, and the furnace body is cooled and protected by water supplied to the water jacket.

In addition, in the cooling furnace, the combustion exhaust gas is cooled by heat exchange between the combustion exhaust gas and water circulated through a water channel provided in the furnace wall.

JP 2020-133990 A

In the dry distillation gasification incineration treatment device, when the dry distillation of the waste is completed in the dry distillation furnace, the waste is incinerated. At this time, the temperature inside the dry distillation furnace reaches about 1000°C, and the water in the water jacket boils and evaporates, so the amount lost due to evaporation must be replenished. Similarly, the water circulating in the cooling furnace must be replenished to make up for the amount lost due to evaporation.

However, when the dry distillation gasification incineration treatment device is installed in a location where industrial water is scarce, such as a mountainous region, it can be difficult to secure a sufficient amount of water, and it is desirable to minimize the amount of water supplied to the water jacket or cooling furnace.

In view of the above circumstances, the present invention aims to provide a dry distillation gasification incineration treatment device that can reduce the amount of water supplied to the water jacket or the cooling furnace.

In order to achieve the above object, the dry distillation gasification incineration treatment apparatus of the present invention comprises a dry distillation furnace which burns a part of the stored waste while dry distilling the remainder of the waste with the combustion heat to generate combustible gas, a combustion furnace which burns the combustible gas introduced from the dry distillation furnace, a discharge means which discharges the combustion exhaust gas discharged from the combustion furnace, and a cooling furnace which cools the combustion exhaust gas midway through the discharge means, and the dry distillation furnace is provided with a water jacket in the furnace wall which is isolated from the inside of the furnace, and further comprises a supply means which supplies cooling water to the water jacket, and a hot water extraction means which extracts hot water from the water jacket or the cooling furnace. the hot water extraction means for extracting hot water from the water jacket, a cooling means for cooling the hot water extracted by the hot water extraction means to obtain cold water, and a cold water supply means for supplying the cold water cooled by the cooling means to the water jacket or the cooling furnace, and at the stage where the waste is incinerated in the dry distillation furnace, the supply means supplies the water jacket with the minimum amount of cooling water necessary to maintain the water level at a safe level , and the supply of oxygen to the dry distillation furnace is reduced to reduce the combustion heat of the waste when the waste is incinerated , and in this state the hot water extracted from the water jacket by the hot water extraction means is cooled by the cooling means.
In the dry distillation gasification incineration treatment apparatus of the present invention, the hot water taken out from the water jacket or the cooling furnace by the hot water taking-out means is cooled by the cooling means to produce cold water, and the cold water is supplied to the water jacket or the cooling furnace by the cold water supplying means. Therefore, boiling and evaporation of water in the water jacket or the cooling furnace can be suppressed, and the amount of water supplied to the water jacket or the cooling furnace can be reduced.

In the dry distillation gasification incineration treatment device of the present invention, it is preferable that the cooling means controls the temperature of the hot water to be in the range of 80 to 95°C. By controlling the temperature of the hot water to be in the above range, boiling and evaporation of water in the water jacket or the cooling furnace can be reliably suppressed.

In addition, in the dry distillation gasification incineration treatment device of the present invention, the cooling means can be, for example, a radiator equipped with a cooling fan that blows air onto the hot water extracted by the hot water extraction means to cool it.

FIG. 1 is a system configuration diagram showing one example of the configuration of a dry distillation gasification incineration treatment apparatus of the present invention. FIG . 2 is a diagram showing the configuration of piping between a dry distillation furnace and a cooling furnace and a radiator in the dry distillation gasification incineration treatment apparatus of the present invention.

Next, an embodiment of the present invention will be described in more detail with reference to the attached drawings.

The dry distillation gasification incineration treatment device 1 of this embodiment, as shown in FIG. 1, includes two dry distillation furnaces 2a and 2b that store waste A, such as waste tires, and dry distillation, gasification, and incineration of the waste A, and a combustion furnace 4 that is connected to the dry distillation furnaces 2a and 2b via gas passages 3a and 3b.

The dry distillation furnaces 2a, 2b are formed with inlets 6a, 6b equipped with opening and closing doors 5a, 5b on the top surface thereof, respectively, so that waste A can be put into the dry distillation furnaces 2a, 2b through the inlets 6a, 6b. The lower parts of the dry distillation furnaces 2a, 2b are provided with bottom doors 7a, 7b which can be opened and closed. When the inlet doors 5a, 5b and bottom doors 7a, 7b are closed, the inside of the dry distillation furnaces 2a, 2b is essentially isolated from the outside.

The dry distillation furnaces 2a and 2b are also equipped with water jackets (not shown) in their furnace walls. The water jackets are configured to be isolated from the inside of the dry distillation furnaces 2a and 2b.

Below the bottom doors 7a, 7b, empty chambers 8a, 8b are formed which are isolated from the inside of the dry distillation furnaces 2a, 2b, and the empty chambers 8a, 8b are connected to the inside of the dry distillation furnaces 2a, 2b via a number of air supply nozzles 9a, 9b provided on the bottom doors 7a, 7b. Dry distillation oxygen supply lines 10a, 10b are connected to the empty chambers 8a, 8b at the bottom of the dry distillation furnaces 2a, 2b, respectively, and the dry distillation oxygen supply lines 10a, 10b are connected to an oxygen supply source 12 constituted by a forced draft fan or the like via an oxygen supply line 11.

The dry distillation oxygen supply lines 10a and 10b are provided with control valves 13a and 13b, respectively, and the opening degree of the control valves 13a and 13b is controlled by valve drivers 14a and 14b. In this case, the valve drivers 14a and 14b are controlled by a control device 15 composed of an electronic circuit including a CPU, etc.

Furthermore, ignition devices 16a, 16b for igniting the waste A stored in the dry distillation furnaces 2a, 2b are attached to the bottom of the dry distillation furnaces 2a, 2b, respectively. The ignition devices 16a, 16b are composed of ignition burners or the like, and supply a combustion flame to the waste A by burning auxiliary fuel supplied from fuel supply devices 17a, 17b via fuel supply paths 18a, 18b.

The combustion furnace 4 consists of a burner section 19 that mixes the combustible gas produced by the dry distillation of waste A with the oxygen (air) necessary for its complete combustion, and a combustion section 20 that burns the combustible gas mixed with oxygen (air), and the combustion section 20 is connected to the burner section 19 on the downstream side of the burner section 19. Gas passages 3a and 3b are connected to the upstream side of the burner section 19 via dampers 21a and 21b, respectively, and the combustible gas produced by the dry distillation of waste A in the dry distillation furnaces 2a and 2b is introduced into the burner section 19 via the gas passages 3a and 3b.

A chamber (not shown) isolated from the interior of the burner section 19 is formed on the outer periphery of the burner section 19, and the chamber is connected to the interior of the burner section 19 via a number of nozzle holes (not shown) drilled in the inner periphery of the burner section 19. A combustion oxygen supply passage 22 branching off from the oxygen supply passage 11 is connected to the chamber.

A control valve 23 is provided in the combustion oxygen supply passage 22, and the opening degree of the control valve 23 is controlled by a valve driver 24. In this case, the valve driver 24 is controlled by the control device 15.

A combustion device 25 is attached upstream of the burner section 19. The combustion device 25 is composed of an ignition burner or the like, and ignites the combustible gas introduced into the burner section 19 or heats the combustion furnace 4 by burning auxiliary fuel supplied from a fuel supply device 26 via a fuel supply line 27.

A hot water boiler 28 is attached downstream of the combustion section 20 and is heated by the exhaust gas generated by the combustion of the combustible gas in the combustion furnace 4. The exhaust gas discharged from the combustion furnace 4 has a temperature of about 1000°C, and after heating the hot water boiler 28, is discharged to a duct 29a provided on the outlet side of the hot water boiler 28. The duct 29a is connected to the upper end of the cooling furnace 31 via an on-off valve 30. The cooling furnace 31 is provided with a water passage through which cooling water flows in the furnace wall, and the exhaust gas at a temperature of about 1000°C is cooled to a temperature of about 500 to 600°C by heat exchange with the water flowing in the water passage, and is discharged to a duct 29b connected to the lower part of the cooling furnace 31 via an on-off valve 32.

On the other hand, duct 29c branches off from duct 29a upstream of on-off valve 30, and duct 29c is connected to the upper end of quench tower 34 via on-off valve 33. Quench tower 34 is equipped with spray 35 that sprays water on the combustion exhaust gas introduced from duct 29c to cool it, and spray 35 is connected to a water supply device (not shown) that supplies cooling water and an air compressor (not shown).

The combustion exhaust cooled in the quench tower 34 is taken out through duct 29d connected to the bottom of the quench tower 34 via an on-off valve 36. Duct 29d merges with duct 29b downstream of the on-off valves 32 and 36.

Duct 29b is connected to one end of bag filter 37, and the exhaust combustion air introduced from duct 29b into bag filter 37 is mixed with hydrated lime and activated carbon supplied from chemical silo 38 for desulfurization and deodorization. Duct 29e is connected to the other end of bag filter 37, and duct 29e is connected to chimney 40 via induction fan 39 that induces the exhaust combustion air in combustion furnace 4. As a result, the exhaust combustion air flowing through duct 29e is released into the atmosphere from chimney 40.

In addition, downstream of the combustion furnace 4, a duct 29f is provided for discharging the combustion exhaust gas when the hot water boiler 28 is not used, and the duct 29f is connected to the duct 29a via an on-off valve 41.

Next, the incineration process of waste A in the dry distillation gasification incineration process device 1 will be explained using the dry distillation furnace 2a as an example. Note that the process when using the dry distillation furnace 2b is the same as when using the dry distillation furnace 2a, except that a is replaced with b.

When waste A is incinerated in the dry distillation gasification incineration treatment device 1, first, the input door 5a of the dry distillation furnace 2a is opened with the bottom door 7a closed, and waste A such as waste tires is input into the dry distillation furnace 2a through the input port 6a. Next, when the control device 15 detects that the input of waste A into the dry distillation furnace 2a is complete and that waste A is contained in the dry distillation furnace 2a, the input door 5a is closed to seal the inside of the dry distillation furnace 2a, and the combustion device 25 of the combustion furnace 4 is operated to start preheating the combustion furnace 4.

Next, when the temperature inside the combustion furnace 4 reaches, for example, 760°C, the control device 15 drives the valve driver 14a to set the opening of the control valve 13a to a predetermined opening, for example, 25%, and the supply of oxygen (air) to the dry distillation furnace 2a begins. Next, when the control device 15 detects that the waste A has been completely fed into the dry distillation furnace 2a, that the waste A is contained in the dry distillation furnace 2a, and that the damper 21a is open, the ignition device 16a of the dry distillation furnace 2a is activated to ignite the waste A, and partial combustion of the waste A begins.

Next, in the dry distillation furnace 2a, the valve driver 14a is controlled by the control device 15, and the opening of the control valve 13a is increased stepwise. As a result, the partial combustion of the waste A in the dry distillation furnace 2a gradually expands and stabilizes, and a fire bed is formed at the bottom of the waste A. When the fire bed is formed, the ignition device 16a is stopped, and the heat from the partial combustion of the waste A starts the dry distillation of the other parts of the waste A, starting the generation of flammable gas, which is introduced into the burner section 19 via the gas passage 3a.

In the burner section 19, the control device 15 drives the valve driver 24 to set the opening of the control valve 23 to a predetermined opening, and oxygen (air) is supplied from the oxygen supply source 12 via the oxygen supply path 11 and the combustion oxygen supply path 22. The combustible gas is then mixed with the oxygen (air) supplied via the combustion oxygen supply path 22 and ignited by the combustion flame supplied from the combustion device 25, starting combustion in the combustion section 20.

When the generation of combustible gas in the dry distillation furnace 2a becomes active and the combustible gas starts to spontaneously combust in the combustion furnace 4, the temperature inside the combustion furnace 4 gradually rises and reaches a first preset temperature, for example 1000°C.

When the temperature inside the combustion furnace 4 reaches the first set temperature due to the combustion of the combustible gas, the combustion device 25 is stopped, and the control device 15 adjusts the opening of the control valve 13a so that the temperature inside the combustion furnace 4 is maintained at the first set temperature through the combustion of the combustible gas, thereby feedback controlling the generation of the combustible gas in the dry distillation furnace 2a.

The combustion exhaust gas generated by the combustion of the combustible gas in the combustion section 20 is cooled in the hot water boiler 28 and discharged to the duct 29a, or is discharged to the duct 29a via the duct 29f without passing through the hot water boiler 28.

If the combustion exhaust gas discharged into duct 29a passes through hot water boiler 28, it is introduced from duct 29a into cooling furnace 31, where it is further cooled, and then discharged into duct 29b. If the combustion exhaust gas does not pass through hot water boiler 28, it is introduced from duct 29c into quench tower 34, where it is cooled, and then discharged into duct 29b via duct 29d.

The exhaust gas discharged into duct 29b is then mixed with hydrated lime and activated carbon supplied from chemical silo 38 for desulfurization and deodorization, introduced into bag filter 37 to remove fly ash, dust, etc., and then discharged into duct 29e and further released into the atmosphere from chimney 40.

In the incineration process of waste A in the dry distillation gasification incineration treatment device 1, the dry distillation furnaces 2a and 2b are cooled by the water contained in the water jacket, thereby protecting the furnace body from the heat caused by the dry distillation of the waste, and in the cooling tower 31, the combustion exhaust gas introduced into the cooling tower 31 is cooled by the water circulated through the water channel.

In the dry distillation gasification incineration treatment device 1, the water stored in the water jacket can be circulated to the water channel of the cooling tower 31. In this case, when the dry distillation of the waste A in the dry distillation furnace 2a is completed and the waste A is incinerated, the temperature inside the dry distillation furnace 2a reaches about 1000°C, and the water in the water jacket boils and evaporates. This makes it necessary to replenish the water lost through evaporation, but in mountainous areas and other places where industrial water is scarce, it is difficult to secure a sufficient amount of water.

2, the dry distillation gasification incineration treatment apparatus 1 is provided with a first hot water conduit 43 as hot water extraction means for extracting hot water from the water jackets 41a , 41b of the dry distillation furnaces 2a, 2b, and the first hot water conduit 43 is connected to a plurality of radiators 44 as cooling means for cooling the hot water to obtain cold water, as shown in FIG. 2. Each radiator 44 is provided with a cooling fan 45 for cooling the hot water circulating inside, and for example, 18 radiators 44 for the cooling tower 31 and two radiators 44 for the dry distillation furnace 2a or 2b are connected in parallel to the first hot water conduit 43.

Each radiator 44 is equipped with an outlet pipe 46 for extracting the cold water, and each outlet pipe 46 joins together to form a first cold water pipe 47 as a cold water supply means for supplying cold water to the water jacket 41a, and the first cold water pipe 47 is connected to the water jacket 41a via a first circulation pump 48.

The water passage 42 of the cooling tower 31 is provided with a second hot water pipe 49 as hot water extraction means for extracting hot water from the water passage 42, and the second hot water pipe 49 is connected to the first hot water pipe 43 upstream of the multiple radiators 44. On the other hand, a second cold water pipe 50 as cold water supply means for supplying cold water to the water passage 42 branches off from the first cold water pipe 47, and the second cold water pipe 50 is connected to the water passage 42 via a second circulating pump 51.

In the dry distillation gasification incineration treatment device 1, when the operation of the device is started, for example, the first and second circulation pumps 48, 51 are operated in accordance with the operation of the combustion device 25 of the combustion furnace 4. In the water jacket 41a of the dry distillation furnace 2a, when the first circulation pump 48 is operated, hot water taken out from the water jacket 41a is supplied to the radiator 44 via the first hot water conduit 43, and cold water cooled by the radiator 44 is supplied to the water jacket 41a via the extraction conduit 46 and the first cold water conduit 47, thereby circulating.

In addition, in the water passage 42 of the cooling tower 31, when the second circulation pump 51 is operated, the hot water extracted from the water passage 42 is supplied to the radiator 44 via the hot water conduit 49 and the second first hot water conduit 43, and the cold water cooled in the radiator 44 is supplied to the water passage 42 via the extraction conduit 46, the first cold water conduit 47, and the second cold water conduit 50, thereby circulating.

Here, the radiator 44 controls the temperature of the water stored in the water jacket 41a or the water flowing through the water passage 42 to be in the range of 80 to 95°C by operating or stopping the cooling fan 45. The temperature can be controlled, for example, by providing a temperature detection means such as a temperature sensor (not shown) in the water jacket 41a and the water passage 42, and operating the cooling fan 45 when the temperature detected by the temperature detection means exceeds 90°C, and stopping the cooling fan 45 when it falls below 80°C. In addition, detection of the temperature detected by the temperature detection means and operation or stopping of the cooling fan 45 can be performed by the control device 15 shown in FIG. 1.

As a result, in the dry distillation gasification incineration treatment apparatus 1 of this embodiment, it is possible to suppress boiling and evaporation of the water stored in the water jackets 41a , 41b of the dry distillation furnaces 2a, 2b or the water circulating in the water passage 42 of the cooling furnace 31, and it is possible to reduce the amount of water replenished to the water jackets 41a , 41b or the water passage 42.

However, in the dry distillation gasification incineration treatment device 1, even if the radiator 44 is used, the temperature of the cooling water in the cooling furnace 31 may rise, boil, and evaporate, causing an increase in the amount of water to be replenished to the cooling furnace 31.

In such a case, the amount of water supplied to the cooling furnace 31 is increased by the minimum necessary amount to keep the water level of the cooling furnace 31 at a safe level, while the first set temperature in the combustion furnace 4 is lowered, for example, from 1000° C. to 900° C. Then, by cooling the cooling water using the radiator 44 while reducing the amount of combustion and exhaust gas of the combustible gas, boiling and evaporation of the cooling water can be suppressed, and the operation of the dry distillation gasification incineration treatment device 1 can be continued.

In the dry distillation gasification incineration treatment device 1, for example, when the temperature of the cooling water in the cooling furnace 31 reaches 97°C, the first set temperature can be lowered to 900°C, and when the temperature of the cooling water in the cooling furnace 31 drops to 94°C, the first set temperature can be returned to 1000°C.

In addition, in the dry distillation gasification incineration treatment device 1, even if the radiator 44 is used at the stage where waste A is incinerated in the dry distillation furnace 2a, the temperature of the water jacket 41a of the dry distillation furnace 2a may rise, boil, and evaporate, causing an increase in the amount of water supplied to the water jacket 41a.

In such a case, the amount of water supplied to the water jacket 41a is increased by the minimum necessary amount to maintain the water level in the water jacket 41a at a safe level, while the opening degree of the control valve 13a is reduced, for example, from 80% to 50%. Then, by cooling the cooling water using the radiator 44 in a state in which the amount of heat generated when the waste A is incinerated is reduced, the boiling and evaporation of the cooling water can be suppressed, and the operation of the dry distillation gasification incineration treatment device 1 can be continued.

In the dry distillation gasification incineration treatment device 1, for example, when the temperature of the cooling water in the water jacket 41a reaches 97°C, the opening degree of the control valve 13a can be reduced to 50%, and when the temperature of the cooling water in the water jacket 41a drops to 94°C, the opening degree of the control valve 13a can be returned to 80%.

In addition, if the opening degree of the control valve 13a is reduced at the stage where waste A is incinerated in the dry distillation furnace 2a, unburned gas is generated and flows into the combustion furnace 4, and the unburned gas must be burned in the other dry distillation furnace 2b. However, by reducing the opening degree of the control valve 13a, the time for incinerating waste A in the dry distillation furnace 2a is extended, and if the first set temperature in the combustion furnace 4 is reduced from 1000°C to 900°C, for example, the time for the combustible gas generated in the dry distillation furnace 2a to self-combust in the combustion furnace 4 can be extended, and the time for incinerating waste A can be sufficiently secured. As a result, even if the first set temperature in the combustion furnace 4 is reduced, there is no need to burn auxiliary fuel in the fuel supply device 26, and the dry distillation gasification incineration treatment device 1 can be operated economically.

Note that when lowering the first set temperature in the combustion furnace 4 or reducing the opening of the control valve 13a in the dry distillation furnace 2a, care must be taken because the amount of waste A incinerated per unit time will decrease.

1... dry distillation gasification incineration treatment device, 2a, 2b... dry distillation furnace, 4... combustion furnace, 29... discharge stage, 31... cooling tower, 41a, 41b... water jacket, 43, 49... hot water extraction means, 44... cooling means, 47, 50... cold water supply means.

Claims (3)

A dry distillation and gasification incineration treatment apparatus comprising: a dry distillation furnace for burning a part of stored waste and dry distilling the remainder of the waste using the heat of combustion to generate a combustible gas; a combustion furnace for burning the combustible gas introduced from the dry distillation furnace; exhaust means for exhausting the combustion exhaust gas discharged from the combustion furnace; and a cooling furnace for cooling the combustion exhaust gas midway through the exhaust means, the dry distillation furnace being provided with a water jacket in the furnace wall isolated from the inside of the furnace,
a supplying means for supplying cooling water to the water jacket, a hot water taking-out means for taking out hot water from the water jacket or the cooling furnace, a cooling means for cooling the hot water taken out by the hot water taking-out means to obtain cold water, and a cold water supplying means for supplying the cold water cooled by the cooling means to the water jacket or the cooling furnace,
A dry distillation gasification incineration treatment apparatus characterized in that, at the stage when the waste is incinerated in the dry distillation furnace , the supply means supplies the water jacket with the minimum amount of cooling water necessary to maintain the water level at a safe level , and the supply of oxygen to the dry distillation furnace is reduced to reduce the combustion heat of the waste when the waste is incinerated , and in this state, the hot water extracted from the water jacket by the hot water extraction means is cooled by the cooling means. The dry distillation gasification incineration treatment apparatus according to claim 1, characterized in that the cooling means controls the temperature of the hot water to be in the range of 80 to 95°C. The dry distillation gasification incineration treatment apparatus according to claim 1 or 2, characterized in that the cooling means is a radiator equipped with a cooling fan that blows air onto the hot water extracted by the hot water extraction means to cool it.

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