JP2017161187A - Waste gasification fusion equipment and waste gasification fusion method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste gasification fusion furnace and a waste gasification fusion method which can use provided coke as fuel in an appropriate moisture content even if the coke is high moisture content coke.SOLUTION: Waste gasification fusion equipment 1 where waste is pyrolized, gasified and burnt in shaft furnace-type waste gasification fusion furnace and ash content is melted comprises: coke moisture content measuring and separating equipment 23 measuring moisture content of coke and separating coke whose moisture content is not more than an appointed moisture content; and coke feeding equipment 21 receiving the coke whose moisture content is not more than the appointed moisture content from the coke moisture content measuring and separating equipment 23 and feeding the coke to the gasification fusion furnace 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a waste gasification and melting apparatus and a waste gasification and melting method for thermally decomposing and burning waste in a shaft furnace type gasification and melting furnace to melt ash.

  As a technique for treating waste such as municipal waste and shredder dust, a waste melting process is known in which waste is pyrolyzed and burned to melt ash to form slag.

  In this treatment method, the heat of combustion can be recovered by pyrolyzing and gasifying the waste, and after the ash is melted and discharged as slag, the amount of final disposal such as landfill disposal is reduced. It has the advantage that it can be accommodated. There are several methods for such melting treatment, and one of them is a method using a shaft furnace type waste gasification melting furnace.

  This shaft furnace type waste gasification melting furnace, for example, burns coke deposited in the lower part of the furnace, throws the waste on this high-temperature coke, pyrolyzes and partially oxidizes it, gasifies and ash Is a furnace that performs a process of melting slag into slag (see Patent Document 1).

  In the shaft furnace type waste gasification melting furnace of Patent Document 1, the interior of the vertical cylindrical furnace body is roughly divided into three regions in the vertical (vertical) direction. That is, a high-temperature combustion zone having a coke bed with coke deposited at the lower part of the furnace is formed, a waste layer is formed on the high-temperature combustion zone, and a large space is freed above the waste layer in the upper part of the furnace. A board portion is formed.

  In such a waste gasification and melting furnace, oxygen-containing gas is blown into the furnace in each of the three regions. A main tuyere is provided in the high-temperature combustion zone at the lower part of the furnace, and oxygen-enriched air is blown in. In the high-temperature combustion zone, the coke in the coke bed that has been thrown in and burned burns to melt the ash. It has become. Further, the waste layer is provided with a sub tuyere, air is blown in, and the waste deposited and flowed gently, and the waste is thermally decomposed and partially oxidized. In addition, the free board part is provided with a three-stage tuyere, air is blown in, and a part of the pyrolysis gas (combustible gas) generated by pyrolyzing the waste is partially burned to bring the inside to a predetermined temperature. To maintain.

  As described above, the shaft furnace type waste gasification and melting furnace is a facility capable of performing both pyrolysis gasification treatment and melting treatment in one furnace as the waste falls in the furnace. The input waste is pyrolyzed to produce gas and ash. In the lower part of the furnace, coke in the coke floor is combusted by blowing oxygen-enriched air from the main tuyere to form a high-temperature combustion zone, and the ash content of the waste is melted and discharged as slag and metal. The coke floor is a gap created between cokes, and as a high-temperature grate that allows oxygen-enriched air from the main tuyere and high-temperature gas generated by coke combustion to rise and let molten slag and metal descend. It is functioning. The high-temperature gas generated by coke combustion in the high-temperature combustion zone heats the waste in the waste layer formed on the high-temperature combustion zone, and the waste is thermally decomposed by blowing air from the sub tuyere. The gas containing the combustible gas generated by the gas rises in the waste layer, passes through the free board portion, and is discharged from the discharge port provided in the upper portion of the furnace to the secondary combustion chamber outside the furnace. The gas contains a large amount of combustible gas and is combusted in the secondary combustion chamber, and heat is recovered by the boiler to generate steam, which is used for power generation and the like. Exhaust gas treatment, such as removing relatively coarse dust with a cyclone, cooling with a temperature reducing device, removing harmful gas by reaction with a hazardous substance remover, and removing dust with a dust collector And then released from the chimney to the atmosphere.

  The coke used in the shaft furnace type gasification and melting furnace is, for example, a dense, strong, high-temperature strength, low-reactivity, and low-reactivity coal coke used in steelmaking coke and casting coke. It is suitable and used as a high-temperature grate in order to maintain a gap between cokes. Also, in shaft furnace type waste gasification and melting furnace, by using petroleum coke generated during oil refining as a substitute for part of coal coke, by using cheap petroleum coke instead of expensive coal coke Attempts have been made to reduce operating costs.

JP 09-060830 A

  Coal coke and petroleum coke (sometimes collectively called coke) are stored in open-air storage yards, so the moisture content may increase due to heavy rain such as typhoons. Conventionally, the water content of coke has the effect of reducing the calorific value of the coke. Even when the moisture content is high, the amount of coke that is fed into the gasification and melting furnace is increased so that the amount of coke relative to the amount of waste treated is increased. It was said that the operation of the waste gasification and melting furnace could be maintained if the amount of heat input by was made constant. However, when the moisture content of the coke is considerably high, there arises a problem that the in-furnace situation becomes unstable, such as the molten state of ash rapidly deteriorating.

  The present invention has been made to solve the above-described problems, and even when the moisture content of coke is high, coke can be supplied to a waste gasification and melting furnace under an appropriate moisture content. An object of the present invention is to provide a waste gasification and melting apparatus and a waste gasification and melting method that enable stable operation of a waste gasification and melting furnace.

<Principle of the present invention, analysis leading to the present invention>
<In-furnace behavior of high moisture content coke>
(1) The behavior of coke with a high moisture content in the gasification and melting furnace was analyzed. Coke having a high moisture content is supplied into the gasification melting furnace and exposed to a high temperature, and collapses due to rapid vaporization of moisture inside the coke. The collapsed coke increases in reaction rate during gasification due to an increase in specific surface area, and thus gasifies and disappears before reaching the lower part of the furnace. For this reason, coke with a high moisture content cannot function as a heat source and high-temperature grate for melting ash in the high-temperature combustion zone at the bottom of the furnace. In addition, the collapsed coke has an endothermic reaction with CO _{2 at the} top of the waste layer, which lowers the furnace temperature. In addition, a part of the collapsed coke reaches the high temperature grate at the bottom of the furnace and enters and closes the grate gap, so that oxygen-enriched air and generated combustion gas are sufficiently ventilated and molten slag is sufficiently passed. It becomes impossible to do so, and there will be a situation that will impede the operation of the waste gasification and melting furnace.

Since the apparent density of coal coke and petroleum coke is about the same (1.0 to 1.2 g / cm ³ ), the porosity is also about the same. Since moisture is contained in the internal voids of the coke, the coal coke and the petroleum coke are deposited in the outdoor storage yard, and thus the moisture content is similarly increased due to rain or the like. Petroleum coke, which has low coke strength, tends to collapse in the gasification and melting furnace due to the rapid vaporization of the water inside the coke, and even if coal coke with high coke strength has a high moisture content, It was found that it collapses due to water vaporization.

  (2) Petroleum coke has a structure in which small particles having a diameter of about 3 mm are lightly fused to each other. Petroleum coke with a high moisture content is exposed to a high temperature in the furnace when it is supplied alone in the gasification and melting furnace, and collapses due to the rapid vaporization of the water inside the coke. Although a phenomenon in which the fused state is easily broken and pulverized also occurs, the small particles after pulverization are difficult to be pulverized, have low reactivity at high temperatures, and tend not to disappear in the gasification melting furnace. When small particles do not disappear and reach the coke bed at the lower part of the furnace, the small particles block the voids in the coke bed and inhibit gas ascending and dripping of molten slag. As a result, the molten slag discharge is delayed and the operation of the gasification melting furnace is hindered.

  Not only when petroleum coke is used alone in the gasification and melting furnace, but also when petroleum coke is used as a substitute for part of coal coke, it is the same as the case of petroleum coke alone due to the collapse and cracking of petroleum coke. The problem described above arises.

  We investigated the relationship between the coke collapse of coal coke and petroleum coke in a gasification melting furnace and the moisture content of coke, and elucidated that the collapse would occur significantly when the moisture content of coke exceeded 10% by weight. did.

  In this way, as a result of elucidating the relationship between the moisture content of coke and the decay phenomenon, it is easy to understand the decay rate by grasping the moisture content of coke and supplying coke with a moisture content below the specified moisture content to the gasification melting furnace. It has been found that a stable operation of the gasification melting furnace can be performed without any occurrence.

  As a result of analyzing the relationship between the moisture content of coke and the occurrence of the above-mentioned phenomenon, it is possible to use coke having a moisture content of 10% by weight or less, more preferably 5% by weight or less. It was confirmed that the coke can reach the lower part of the gasification melting furnace and function as a heat source and a high-temperature grate while avoiding the occurrence of the collapse phenomenon. By specifying the moisture content of the coke in this way, the gas component ascending aeration and dripping of the molten slag can be maintained smoothly in the coke bed, and the gasification melting furnace can be stably operated.

  According to the present invention, the waste gasification and melting apparatus and the waste gasification and melting method are configured as follows.

[Waste gasification and melting equipment]
With regard to the waste gasification and melting apparatus, the present invention can be constituted by any of the following first to fourth inventions.

<First invention>
In a waste gasification and melting device that thermally decomposes, gasifies and burns waste in a shaft furnace type waste gasification and melting furnace, and melts ash,
A coke moisture content measuring and sorting device that measures the moisture content of coke and sorts coke below a predetermined moisture content;
A coke supply device for receiving coke having a predetermined moisture content or less from the coke moisture content measuring and sorting device and supplying the coke to the gasification melting furnace,
A waste gasification and melting apparatus characterized by that.

<Second invention>
In a waste gasification and melting device that thermally decomposes, gasifies and burns waste in a shaft furnace type waste gasification and melting furnace, and melts ash,
A coal coke moisture content measuring and sorting device for measuring the moisture content of coal coke and sorting coal coke below a predetermined moisture content;
A coal coke supply device that receives coal coke having a predetermined moisture content or less from the coal coke moisture content measurement and selection device and supplies the coal coke to the gasification melting furnace;
A petroleum coke moisture content measuring and sorting device for measuring the moisture content of petroleum coke and sorting petroleum coke below a predetermined moisture content;
A petroleum coke supply unit that receives petroleum coke having a predetermined moisture content or less from a petroleum coke moisture measurement and sorting device and supplies the petroleum coke to a gasification melting furnace,
A waste gasification and melting apparatus characterized by that.

<Third invention>
In a waste gasification and melting device that thermally decomposes, gasifies and burns waste in a shaft furnace type waste gasification and melting furnace, and melts ash,
A coke moisture content measurement / separation device that measures the moisture content of coke and separates it into coke below a predetermined moisture content and coke exceeding a predetermined moisture content;
A drying device that accepts coke that exceeds a predetermined moisture content from the coke moisture content measurement and separation device, and dries to a predetermined moisture content or less;
A coke supply unit that receives coke having a predetermined moisture content or less from the coke moisture content measurement and separation device, and receives coke that has been dried from the drying device and supplies coke having a predetermined moisture content or less to the gasification melting furnace.
A waste gasification and melting apparatus characterized by that.

<Fourth Invention>
In a waste gasification and melting device that thermally decomposes, gasifies and burns waste in a shaft furnace type waste gasification and melting furnace, and melts ash,
A coal coke moisture content measuring and separating device for measuring the moisture content of coal coke and separating coal coke below a predetermined moisture content;
A coal coke drying apparatus that accepts coal coke exceeding a predetermined moisture content from a coal coke moisture content measurement separation device and dries it to a predetermined moisture content or less,
Coal coke that receives coal coke with a predetermined moisture content or less from the coal coke moisture content measurement and separation device, and receives coal coke that has been dried from the coal coke dryer to supply coal coke with a moisture content of less than the specified value to the gasification and melting furnace. A feeding device;
A petroleum coke moisture content measuring and separating device for measuring the moisture content of petroleum coke and separating petroleum coke below a predetermined moisture content;
Petroleum coke drying apparatus that accepts petroleum coke exceeding the predetermined moisture content from the petroleum coke moisture content measuring and separating device and dries to a predetermined moisture content or less,
Petroleum coke that accepts petroleum coke with a predetermined moisture content or less from the oil coke moisture measurement fractionator, and receives petroleum coke that has been dried from the petroleum coke dryer, and supplies petroleum coke with a prescribed moisture content or less to the gasification and melting furnace. A supply device;
A waste gasification and melting apparatus characterized by that.

[Waste gasification melting method]
With regard to the waste gasification and melting method, the present invention can be constituted by any of the following fifth to eighth inventions.

<Fifth invention>
In a waste gasification and melting method in which waste is pyrolyzed, gasified and burned in a shaft furnace type waste gasification and melting furnace to melt ash,
Measure the moisture content of coke and select coke below the specified moisture content,
Supply the selected coke below the predetermined moisture content to the gasification melting furnace.
A waste gasification melting method characterized by the above.

<Sixth Invention>
In a waste gasification and melting method in which waste is pyrolyzed, gasified and burned in a shaft furnace type waste gasification and melting furnace to melt ash,
Measure the moisture content of coal coke and select coal coke below the specified moisture content,
Supply the selected coal coke below the predetermined moisture content to the gasification melting furnace,
Measure the moisture content of petroleum coke to select petroleum coke below the specified moisture content,
Supply the selected petroleum coke below the specified moisture content to the gasification melting furnace.
A waste gasification melting method characterized by the above.

<Seventh invention>
In a waste gasification and melting method in which waste is pyrolyzed, gasified and burned in a shaft furnace type waste gasification and melting furnace to melt ash,
Measure the moisture content of coke and separate it into coke below the specified moisture content and coke above the specified moisture content,
Coke that exceeds the predetermined moisture content that has been separated is dried to a predetermined moisture content or less,
Supplying the coke having a predetermined moisture content or less and the coke which has been dried after the separation to a predetermined moisture content or less to the gasification melting furnace,
A waste gasification melting method characterized by the above.

<Eighth invention>
In a waste gasification and melting method in which waste is pyrolyzed, gasified and burned in a shaft furnace type waste gasification and melting furnace to melt ash,
Measure the moisture content of coal coke and separate it into coal coke below the predetermined moisture content and coal coke above the prescribed moisture content,
Drying the coal coke that exceeds the specified moisture content to a predetermined moisture content or less,
Supplying the coal coke having a predetermined moisture content or less and the coal coke having been dried after the separation to a gas moisture melting furnace,
Measure the moisture content of petroleum coke and separate it into petroleum coke below the specified moisture content and petroleum coke above the specified moisture content,
Drying petroleum coke exceeding the specified moisture content to a predetermined moisture content or less,
Supply the separated petroleum coke with a predetermined moisture content or less and the petroleum coke dried after the separation to a predetermined moisture content or less to the gasification melting furnace,
A waste gasification melting method characterized by the above.

  In the fifth to eighth inventions, the predetermined moisture content is 10% by weight or less, preferably 5% by weight or less, with respect to each of coke, coal coke and petroleum coke.

  In the first to eighth inventions, when a control device for controlling the coke supply amount is provided, the control device supplies the coke supply amount from the coke supply device, and supplies coke separately to coal coke and petroleum coke. It is preferable that the coal coke supply amount from the coal coke supply device and the petroleum coke supply amount from the petroleum coke supply device are controlled according to the in-furnace condition of the gasification melting furnace.

  The present invention measures the moisture content of coke, coal coke, and petroleum coke as described above, and selects the one with a predetermined moisture content or less or supplies it to the waste gasification and melting furnace after reducing it to a prescribed moisture content or less. Therefore, even when the moisture content of coke is high, coke can be supplied to the waste gasification and melting furnace with an appropriate moisture content, enabling stable operation of the waste gasification and melting furnace. A waste gasification melting apparatus and a waste gasification melting method can be provided.

  Further, in the present invention, as described above, when the waste is pyrolyzed in the shaft furnace type gasification melting furnace and the ash is melted, the petroleum coke supply amount is set to be within an appropriate range. Therefore, it is possible to realize an economical operation that can reduce the operation cost by substituting a part of coal coke with petroleum coke while ensuring stable operation.

1 is a diagram illustrating a schematic configuration of a device according to a first embodiment of the present invention. It is a figure which shows schematic structure of 2nd embodiment apparatus of this invention. It is a figure which shows schematic structure of the 3rd embodiment apparatus of this invention. It is a figure which shows schematic structure of 4th embodiment apparatus of this invention.

<First embodiment>
Hereinafter, a first embodiment of the present invention will be described based on FIG. 1 of the accompanying drawings. The waste gasification and melting apparatus of the present embodiment supplies coke (whether it is coal coke or petroleum coke) as fuel, and shaft furnace type waste that blows oxygen-enriched air from the main tuyere into the lower part of the furnace The product gasification melting furnace and its peripheral equipment are provided.

  The shaft furnace type waste gasification and melting furnace of the first embodiment of the present invention shown in FIG. 1 includes waste as a processing object and coke as a fuel in the upper part of the waste gasification and melting furnace 1. An inlet 2 for introducing limestone as a component adjusting material of the generated slag into the furnace is provided, and a gas outlet 3 for discharging the gas in the furnace to the outside of the furnace on the upper side. Is provided. In addition, an outlet 4 for discharging molten slag and molten metal is provided at the bottom of the waste gasification melting furnace 1.

  Above the waste gasification melting furnace 1, a waste supply device 20, a coke supply device 21, and a limestone supply device 22 for supplying waste such as municipal waste, coke, and limestone are disposed as peripheral devices. The coke and limestone supplied from each supply device 21 to 22 are transported by a transport conveyor (not shown), and are put together with the waste from the waste supply device 20 into the furnace through the inlet 2 at the top of the furnace. Is done. In front of the coke supply device 21, a coke moisture content measuring / selecting device 23 is provided. The coke is received before being supplied to the waste gasification melting furnace 1, and the moisture content of the coke is measured. Coke having a moisture content equal to or lower than the moisture content is selected and sent to the coke supply device 21 to eliminate coke having a higher moisture content than a predetermined moisture content.

  A secondary combustion chamber 10 is connected to the gas discharge port 3 of the waste gasification melting furnace 1 and burns combustible gas generated by pyrolyzing the waste. The secondary combustion chamber 10 is provided with an air blowing port 11 for blowing air for secondary combustion. Further, the secondary combustion chamber 10 is provided with a boiler 12 adjacent to which heat is recovered from the combustion gas obtained by burning the combustible gas in the secondary combustion chamber 10.

  In such a shaft furnace type waste gasification and melting furnace 1, the internal space in the furnace is divided into four regions in the vertical direction, and from below, the coke packed bed A, the moving bed B, and the gasification bed C A free board portion D is formed.

  In the waste gasification and melting furnace 1, tuyere is provided in each of the coke packed bed A and the gasification layer C, and oxygen-containing gas is blown into the furnace.

  A main tuyere 5 is provided in the coke packed bed A in the lower part of the furnace, and oxygen-enriched air is blown into the main tuyere. The gasification layer C is provided with a sub tuyere 6 and air is blown in.

  When coke is charged into the waste gasification melting furnace 1 having such tuyere, the coke descends to the lower part of the furnace, and the coke is combusted by the oxygen-enriched air blown from the main tuyere 5. The high-temperature combustion gas generated by combustion serves as a heat source for thermal decomposition of waste, and further serves as a heat source for melting ash.

  Air is blown into the gasification layer C from the sub tuyere 6, the waste is dried by the high-temperature combustion gas, and then pyrolyzed and partially oxidized to combust the combustible component.

  Moreover, in the free board part D, a part of pyrolysis gas (flammable gas) produced by pyrolyzing the waste is partially burned to maintain the inside of the furnace at a predetermined temperature.

  An oxygen-enriched air supply device (not shown) supplies oxygen-enriched air as an oxygen-containing gas obtained by mixing oxygen into air to the air supply pipe of the main tuyere 5.

  The coke moisture content measuring / selecting device 23 disposed above the coke supply device 21 measures the moisture content of the coke as described above, sorts coke having a predetermined moisture content or less, and sends the coke to the coke supply device 21. Although not shown in the drawings, the specific configuration thereof includes, for example, a hopper that receives input of coke whose moisture content is unknown, a chute connected to the hopper, and the coke from the hopper to the chute. And a moisture content measuring device provided at the portion that moves to. In the hopper, the delivery section is branched in two and one branch port communicates with the coke supply device 21 or the delivery section selectively moves between the two positions. , One can be in a position communicating with the inlet of the coke supply device 21. Thus, the moisture content of the coke is measured along the path from the hopper portion to the chute portion, and the coke having a predetermined moisture content or less is selected and sent from the delivery portion to the coke supply device 21, from which waste gas is collected. It is charged into the furnace through the charging port 2 of the chemical melting furnace 1.

  The moisture content measuring device is preferably an online moisture content measuring device that performs continuous measurement when the coke is continuously moved from the hopper portion to the chute portion. In this case, a moisture content measuring device that obtains the moisture content by collecting a part of the coke and measuring the weight loss due to drying may be used without measuring the moisture content of the total amount of coke. Examples of the on-line moisture content measuring device include an on-line moisture content measuring device using near-infrared rays, microwaves, capacitance, neutron rays and the like.

<Second embodiment>
In the present embodiment shown in FIG. 2, the waste gasification and melting furnace 1, that is, the charging port 2 to the boiler 12 is the same as the previous embodiment described based on FIG. 1, but the configuration of peripheral devices is different. Yes. 2, parts common to the parts in FIG. 1 are given the same reference numerals as those in FIG. 1, and descriptions thereof are omitted.

  In the present embodiment shown in FIG. 2, among the peripheral devices, the waste supply device 20 and the limestone supply device 22 are the same as those in the previous embodiment seen in FIG.

  In this embodiment, the coke supply apparatus is provided with a coal coke supply apparatus 21A and a petroleum coke supply apparatus 21B separately, and these coal coke supply apparatus 21A and the petroleum coke supply apparatus 21B are provided in front of each other. The coal coke moisture content measuring and sorting device 23A and the petroleum coke moisture content measuring and sorting device 23B are connected to each other. These coal coke moisture content measuring and sorting device 23A and petroleum coke moisture content measuring and sorting device 23B measure the moisture content of coal coke and petroleum coke, respectively, and supply the coal coke supply device 21A and petroleum coke to those having a predetermined moisture content or less. A device having a high moisture content higher than a predetermined moisture content is sent out to the apparatus 21B. The coal coke moisture content measuring and sorting device 23A and the petroleum coke moisture content measuring and sorting device 23B can have the same configuration as the coke moisture content measuring and sorting device in the previous embodiment.

  In this embodiment, the coal coke and the petroleum coke are supplied with coal coke only when the moisture content is measured by the coal coke moisture content measuring / selecting device 23A and the petroleum coke moisture content measuring / selecting device 23B, respectively. The waste gasification melting furnace 1 is charged through the device 21A and the petroleum coke supply device 21B. The high water content coal coke and the high water content petroleum coke higher than the predetermined water content that have not been charged into the waste gasification melting furnace 1 are discharged from the coal coke water content measurement / selection device 23A and the petroleum coke water content measurement / selection device 23B, respectively. And stored for later use.

<Third embodiment>
The present embodiment shown in FIG. 3 is different from the first embodiment of FIG. 1 only in the device connected to the coke supply device 21 as a peripheral device, and the other parts are the same. Are denoted by the same reference numerals in FIG.

  In FIG. 3, instead of the coke moisture content measuring and sorting device 21 in FIG. 1, a coke moisture content measuring and separating device 24 is provided in front of the coke supplying device 21.

  This coke moisture content measuring / separating device 24 is the same as the coke moisture content measuring / selecting device 23 in the first embodiment in that the moisture content of coke is measured and coke having a predetermined moisture content or less is sent to the coke supplying device 21. Yes, with the same structure and type, but with a high moisture content coke higher than a predetermined moisture content is sent to the drying device 25 described later, Is different.

  In the present embodiment, the drying device 25 is provided between the coke moisture content measurement / separation device 24 and the coke supply device 21 so that the drying device 25 is a coke moisture content measurement / separation device 24. After the fractionation, the high moisture content coke discharged from the coke moisture content measurement / separation device 24 is received, dried to a predetermined moisture content or less, and then sent to the coke supply device 21. For example, the drying device 25 stores a high moisture content coke higher than a predetermined moisture content in a container and blows and heats exhaust gas discharged from the waste gasification and melting furnace 1 or the boiler 12. Indirect heating using a part of the generated water vapor, heating by direct or indirect contact with high temperature gas generated by burning fuel, or heating and drying with a heater such as an electric heater can be used It is.

  In the present embodiment, coke having a predetermined moisture content or less separated by the coke moisture content measuring / separating device 24 is sent to the coke supply device 21, and a high moisture content coke higher than the predetermined moisture content is not discharged and is dried. 25, after being dried to a predetermined moisture content or less, it is fed into the coke feeder 21.

<Fourth embodiment>
In the fourth embodiment shown in FIG. 4, the coal coke supply device 21 </ b> A and the petroleum coke supply device 21 </ b> B shown in FIG. 2 in the second embodiment are the same as the coke moisture content measurement and separation device 24 in FIG. 3 of the third embodiment. Coal coke moisture content measurement / separation device 24A, coal coke drying device 25A, petroleum coke moisture content measurement / separation device 24B, and petroleum coke drying device 25B, which are provided separately for coal coke and petroleum coke, respectively. And are formed respectively. Fractionation and drying of coal coke and petroleum coke by moisture content measurement are performed in the same manner as in the third embodiment.

  In any of the first to fourth embodiments, when the coke, coal coke, and petroleum coke are sorted or separated and supplied to the furnace, the predetermined moisture content is not exceeded. The rate is 10% by weight, preferably 5% by weight, based on the coke weight.

  In the waste gasification and melting furnace apparatus according to the first to fourth embodiments configured as described above, the waste gasification and melting treatment is performed in the following manner.

<In the case of the first and third embodiments>
Waste from the waste supply device 20, coke from the coke supply device 21 with a predetermined water content or less, and limestone from the limestone supply device 22 pass through the inlet 2 provided in the upper part of the waste gasification melting furnace 1, A predetermined amount of each is introduced into the furnace, and oxygen-enriched air is blown into the furnace from the main tuyere 5 and air is blown into the furnace from the sub tuyere 6.

  Coke having a predetermined moisture content or less charged into the furnace descends to the lower part of the furnace, and the coke is burned by the oxygen-enriched air blown from the main tuyere 5 to provide a heat source for melting waste ash, Provided is a heat source that raises the generated high-temperature combustion gas and heats it for thermal decomposition of waste.

  Waste introduced from the inlet 2 accumulates in the furnace to form a gasification layer C of the waste, and passes through the moving bed B from the coke packed bed A at the lower part of the furnace and rises at high temperature. It is heated by gas and air blown from the sub tuyere 6, dried and then pyrolyzed. Combustion gas containing combustible gas generated by pyrolysis rises, a part of the combustible gas is combusted in freeboard part D, maintains the inside of the furnace at a predetermined temperature, and harmful substances and tar generated by pyrolysis It is used so that the process which decomposes | disassembles a part may be given. The gas that has passed through the freeboard part D is discharged from the discharge port 3 provided in the upper part of the furnace to the secondary combustion chamber 10 outside the furnace. The gas contains a large amount of combustible gas and is combusted in the secondary combustion chamber 10, and heat is recovered by the boiler 12 to generate steam, which is used for power generation and the like. The gas discharged from the boiler 12 has relatively coarse dust removed by a cyclone (not shown), further cooled by a temperature reducing device (not shown), and removed by reaction with a hazardous substance remover. Then, after exhaust gas treatment such as dust removal with a dust collector (not shown), it is emitted from the chimney (not shown) to the atmosphere.

The waste is thermally decomposed in the gasification layer C to generate gas, and the fixed carbon and ash generated by the thermal decomposition descend together with the coke and limestone to form the moving layer B. In the moving bed B, the temperature of the solid descending is increased by the high temperature gas rising from the coke packed bed A, and at the same time, the fixed carbon generated by the thermal decomposition of the waste is gasified by the high temperature CO ₂ gas. The In the coke packed bed A, the oxygen-enriched air blown from the main tuyere 5 burns the coke and the fixed carbon of the waste that remains without being gasified, and the heat of combustion melts the ash content of the waste, Molten metal is produced. Limestone works as a conditioner that makes the slag melted with ash preferable. Further, the generated high-temperature combustion gas rises and becomes a heat source for heating for thermal decomposition of the waste.

  In the lower part of the furnace below the main tuyere 5, coke packed bed A is formed in a state in which coke which is high in temperature but not burned out is filled while maintaining a gap between the coke lumps. Molten slag and molten metal Drops the gap between coke lumps and reaches the bottom of the furnace. The molten slag and molten metal are homogenized by the time they reach the bottom of the furnace, their properties are stabilized, discharged from the tap 4 provided at the bottom of the furnace, and supplied to a water granulator (not shown) provided outside the furnace. The supplied granulated slag and granulated metal are recovered by cooling and solidifying. The oxygen-enriched air blown from the main tuyere 5 and the high-temperature combustion gas generated by the combustion of coke and fixed carbon pass from the coke packed bed A through the moving bed B to the gasified bed C and are discarded. A thing is heated and the waste of the gasification layer C is partially oxidized and thermally decomposed by the air supplied from the sub tuyere. In the coke packed bed A, coke below a predetermined moisture content burns and becomes a heat source for ash melting and waste pyrolysis, while the coke is not collapsed and crushed and keeps the gaps between the lumps and oxygen-enriched air And a high-temperature combustion gas are allowed to flow, and the molten slag and the molten metal are allowed to flow through. This function is better in the case of coal coke. In this way, the moisture content of coke is measured, and those having a predetermined moisture content or less are selected or dried, and then supplied to the waste gasification melting furnace after being reduced to a prescribed moisture content or less. Even when the coke is high, coke can be supplied to the waste gasification and melting furnace under an appropriate moisture content, and the waste gasification and melting furnace can be stably operated.

<In the case of the second and fourth embodiments>
In the case of the second and fourth embodiments, the coke is supplied with coal coke and petroleum coke separately in a state of a predetermined moisture content or less, and is supplied into the waste gasification and melting furnace from the input port 2. . Coal coke and petroleum coke are burned in the furnace as in the case of the first and third embodiments described above, and become a heat source for thermal decomposition of ash and melting of ash. Further, coal coke and petroleum coke having a predetermined moisture content or less form a high-temperature grate without being easily collapsed or crushed. In this way, the moisture content of coal coke and petroleum coke was measured, and those with a predetermined moisture content or less were selected or dried to be supplied to the waste gasification and melting furnace after being reduced to a predetermined moisture content or less. Even when the moisture content of coal coke and petroleum coke is high, coal coke and petroleum coke can be supplied to the waste gasification and melting furnace with an appropriate moisture content, and stable operation of the waste gasification and melting furnace is possible. Is possible.

  When supplying petroleum coke as well as coal coke to be supplied to the waste gasification and melting furnace 1, by measuring and grasping the properties of the petroleum coke to be supplied, within the appropriate range based on the properties. It is preferable to supply a set amount of coal coke and petroleum coke into the furnace. Coal coke and petroleum coke are lowered at the lower part of the waste gasification and melting furnace 1 to form a moving bed B together with the ash and fixed carbon of the waste. It becomes a heat source for melting the ash content of the waste and a heat source for thermally decomposing the waste. The amount of coal coke charged into the furnace is an amount necessary to form a high-temperature grate, and the amount of heat necessary as a heat source is supplemented by petroleum coke.

  In such a process of gasification and melting of waste, among coal coke and petroleum coke as fuel, coal coke is in a lump from the beginning of supply to the furnace, and between the coal coke lump in the lower part of the furnace. The gaps ensure aeration and liquid flow to form a high-temperature grate. Petroleum coke is supplied at the maximum allowable supply amount, so the supply of oil coke is increased as much as possible without causing problems in the operation of the gasification melting furnace, such as the delay in molten slag discharge. It can be used as a waste gasification melting furnace, reducing the operating cost and stable operation.

  Thus, the amount of coal coke used can be suppressed as much as possible, and even low-cost petroleum coke can be used as fuel. In this way, the amount of coal coke used can be reduced to reduce the operating cost of the waste melting furnace, and the waste can be melted under stable operation.

DESCRIPTION OF SYMBOLS 1 Waste gasification melting furnace 21 Coke supply apparatus 21A Coal coke supply apparatus 21B Petroleum coke supply apparatus 23 Coke moisture content measurement and selection apparatus 23A Coal coke moisture content measurement and selection apparatus 23B Petroleum coke moisture content measurement and selection apparatus 24 Coke moisture measurement measurement separation Equipment 24A Coal coke moisture content fractionation device 24B Petroleum coke moisture content fractionation device 25 Dryer 25A Coal coke dryer 25B Petroleum coke dryer

Claims (10)

In a waste gasification and melting device that thermally decomposes, gasifies and burns waste in a shaft furnace type waste gasification and melting furnace, and melts ash,
A coke moisture content measuring and sorting device that measures the moisture content of coke and sorts coke below a predetermined moisture content;
A coke supply device for receiving coke having a predetermined moisture content or less from the coke moisture content measuring and sorting device and supplying the coke to the gasification melting furnace,
A waste gasification and melting apparatus characterized by that. In a waste gasification and melting device that thermally decomposes, gasifies and burns waste in a shaft furnace type waste gasification and melting furnace, and melts ash,
A coal coke moisture content measuring and sorting device for measuring the moisture content of coal coke and sorting coal coke below a predetermined moisture content;
A coal coke supply device that receives coal coke having a predetermined moisture content or less from the coal coke moisture content measurement and selection device and supplies the coal coke to the gasification melting furnace;
A petroleum coke moisture content measuring and sorting device for measuring the moisture content of petroleum coke and sorting petroleum coke below a predetermined moisture content;
A petroleum coke supply unit that receives petroleum coke having a predetermined moisture content or less from a petroleum coke moisture measurement and sorting device and supplies the petroleum coke to a gasification melting furnace,
A waste gasification and melting apparatus characterized by that. In a waste gasification and melting device that thermally decomposes, gasifies and burns waste in a shaft furnace type waste gasification and melting furnace, and melts ash,
A coke moisture content measurement / separation device that measures the moisture content of coke and separates it into coke below a predetermined moisture content and coke exceeding a predetermined moisture content;
A drying device that accepts coke that exceeds a predetermined moisture content from the coke moisture content measurement and separation device, and dries to a predetermined moisture content or less;
A coke supply unit that receives coke having a predetermined moisture content or less from the coke moisture content measurement and separation device, and receives coke that has been dried from the drying device and supplies coke having a predetermined moisture content or less to the gasification melting furnace.
A waste gasification and melting apparatus characterized by that. In a waste gasification and melting device that thermally decomposes, gasifies and burns waste in a shaft furnace type waste gasification and melting furnace, and melts ash,
A coal coke moisture content measuring and separating device for measuring the moisture content of coal coke and separating coal coke below a predetermined moisture content;
A coal coke drying apparatus that accepts coal coke exceeding a predetermined moisture content from a coal coke moisture content measurement separation device and dries it to a predetermined moisture content or less,
Coal coke that receives coal coke with a predetermined moisture content or less from the coal coke moisture content measurement and separation device, and receives coal coke that has been dried from the coal coke dryer to supply coal coke with a moisture content of less than the specified value to the gasification and melting furnace. A feeding device;
A petroleum coke moisture content measuring and separating device for measuring the moisture content of petroleum coke and separating petroleum coke below a predetermined moisture content;
Petroleum coke drying apparatus that accepts petroleum coke exceeding the predetermined moisture content from the petroleum coke moisture content measuring and separating device and dries to a predetermined moisture content or less,
Petroleum coke that accepts petroleum coke with a predetermined moisture content or less from the oil coke moisture measurement fractionator, and receives petroleum coke that has been dried from the petroleum coke dryer, and supplies petroleum coke with a prescribed moisture content or less to the gasification and melting furnace. A supply device;
A waste gasification and melting apparatus characterized by that. In a waste gasification and melting method in which waste is pyrolyzed, gasified and burned in a shaft furnace type waste gasification and melting furnace to melt ash,
Measure the moisture content of coke and select coke below the specified moisture content,
Supply the selected coke below the predetermined moisture content to the gasification melting furnace.
A waste gasification melting method characterized by the above. In a waste gasification and melting method in which waste is pyrolyzed, gasified and burned in a shaft furnace type waste gasification and melting furnace to melt ash,
Measure the moisture content of coal coke and select coal coke below the specified moisture content,
Supply the selected coal coke below the predetermined moisture content to the gasification melting furnace,
Measure the moisture content of petroleum coke to select petroleum coke below the specified moisture content,
Supply the selected petroleum coke below the specified moisture content to the gasification melting furnace.
A waste gasification melting method characterized by the above. In a waste gasification and melting method in which waste is pyrolyzed, gasified and burned in a shaft furnace type waste gasification and melting furnace to melt ash,
Measure the moisture content of coke and separate it into coke below the specified moisture content and coke above the specified moisture content,
Coke that exceeds the predetermined moisture content that has been separated is dried to a predetermined moisture content or less,
Supplying the coke having a predetermined moisture content or less and the coke which has been dried after the separation to a predetermined moisture content or less to the gasification melting furnace,
A waste gasification melting method characterized by the above. In a waste gasification and melting method in which waste is pyrolyzed, gasified and burned in a shaft furnace type waste gasification and melting furnace to melt ash,
Measure the moisture content of coal coke and separate it into coal coke below the predetermined moisture content and coal coke above the prescribed moisture content,
Drying the coal coke that exceeds the specified moisture content to a predetermined moisture content or less,
Supplying the coal coke having a predetermined moisture content or less and the coal coke having been dried after the separation to a gas moisture melting furnace,
Measure the moisture content of petroleum coke and separate it into petroleum coke below the specified moisture content and petroleum coke above the specified moisture content,
Drying petroleum coke exceeding the specified moisture content to a predetermined moisture content or less,
Supply the separated petroleum coke with a predetermined moisture content or less and the petroleum coke dried after the separation to a predetermined moisture content or less to the gasification melting furnace,
A waste gasification melting method characterized by the above.   The waste gasification and melting method according to any one of claims 5 to 8, wherein the predetermined moisture content is 10% by weight or less with respect to each of coke, coal coke, and petroleum coke.   The waste gasification and melting method according to any one of claims 5 to 8, wherein the predetermined moisture content is 5% by weight or less with respect to each of coke, coal coke, and petroleum coke.

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