JP2003004217A - Discarded tire burning boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the operating cost of a discarded tire burning boiler by continuously supplying discarded tires to the boiler without pretreatment and to improve the thermal efficiency of the boiler by reducing the quantity of excessive air required for burning the tires, and then, to improve the availability factor and thermal efficiency of a incineration plant by performing heat utilization and power generation by means of generated steam. SOLUTION: A rotary fore hearth is provided in front of this burning boiler and is made continuously operable by mechanically supplying discarded tires. The tires are burnt into a carbonization gas and residual carbon in the fore hearth under an air-dificent condition. The residual carbon is burnt on a chain grate stoker and the flue gas generated by burning the residual carbon and the carbonization gas discharged from the fore hearth are efficiently burnt in a second combustion chamber by satisfactorily mixing the gases with each other so as to prevent the generation of black smoke. In addition, the thermal efficiency of the incineration plant is improved by burning the mixed gas with a small amount of excessive air. Moreover, the availability factor and total fuel heat utilization of the plant are improved by utilizing the heat of the steam generated from the boiler and performing power generation by jointly using a steam turbine power generation system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention burns waste tires, which are difficult to dispose, as fuel at the lowest possible cost, recovers the generated heat energy with a boiler, and utilizes the generated steam. The steam turbine generator is used to generate electricity and provide electric power for effective and rational utilization of industrial waste.

[0002]

2. Description of the Related Art Conventionally, various types of incinerators and incinerators that use waste tires as fuel have already been proposed or used, but there are many devices for merely incineration, and limited resources are effective. It has not come to be used for.

[0003]

DISCLOSURE OF THE INVENTION It is possible to continuously supply and incinerate waste tires.

In order to incinerate the waste tire, it is desirable that the dry distillation gas discharged from the dry distillation of the waste tire is supplied to the combustion chamber as a gaseous fuel for efficient combustion.

Since the waste tire is gasified by dry distillation to be used as a gaseous fuel, it is necessary to burn it in a state of insufficient air amount.

On the other hand, the incompletely combusted waste tire remaining as carbon residue is completely incinerated by a conversion type transfer bed change stoker with good combustion efficiency.

Since steel materials such as wires are used for the waste tires, it causes difficulty in the treatment of the steel materials, but the waste tires can be easily and continuously incinerated by directly supplying them to the incinerator without pretreatment. To do so.

After the incineration, the steel material produced as a residual material is recovered,
Make it easily reusable as a resource.

The steam generated from the waste tire incineration boiler is
Not only is it used as steam, but it is also converted into electric power by a steam turbine generator, and the thermal energy of waste tires is effectively used.

The amount of environmental pollutants such as sulfur oxides generated from a waste tire incineration boiler is reduced as much as possible.

[0011]

[Means for solving the problem] Continuous supply as fuel without special pretreatment such as cutting of waste tires,
Reduce the cost of incineration.

[0012] In order to gasify the waste tire by dry distillation and use it as a gaseous fuel, a rotary forehearth is provided in front of the incineration boiler, and the waste tire is burned in an insufficient amount of air and the waste tire is incompletely burned.

Waste tires are used as carbonized gas and residual carbonized tires, which are burned separately, efficiently burned with a small excess of air, the thermal efficiency of the plant is improved, and resources are effectively used.

After incineration, the steel material used for the tire material is stored in a hopper provided at the rear end of the stoker, transferred to a transport vehicle at a suitable time and discharged.

A steel material produced as a residual material by incineration is conveyed to a melting furnace by a carrier and reused as a steel material.

The waste tire incineration boiler is required to have a considerably large capacity in order to take advantage of the scale, but in order to effectively recover the heat energy generated by incinerating the waste tire,
A water tube boiler having a structure as shown in FIG. 1 is used.

The boiler structure is designed and manufactured according to the scale of incineration. The structure can be sufficiently supported by existing technology.

Incomplete combustion of waste tires in a rotary forehearth,
The temperature inside the forehearth is kept low to reduce troubles such as damage to the furnace wall and melting of the wire.

Considering the design of the incinerator boiler, the amount of environmental pollutants generated when incinerating waste tires is reduced as much as possible.

Environmental pollutants such as sulfurous acid gas contained in waste tires optimize the structure of the incineration boiler and reduce the amount produced, and further reduce the amount emitted using existing technology.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A steel material such as a wire is mixed in a waste tire. However, a difficult pretreatment such as cutting the wire for each waste tire is not particularly performed, and the wire is directly left as it is. Supply to incinerator boiler equipment.

Before the waste tires are directly supplied to the combustion device of the incineration boiler, a rotary front furnace is provided, and the waste tire supply stoker mechanically continuously supplies the waste tires from the fixed front wall.

Surrounding the waste tire supply stoker with a steel plate, etc., to prevent excessive air from entering the rotary forehearth,
Also, prevent accidents due to backflow of flames.

By providing a burner on the fixed front wall of the rotary forehearth,
It supplies the amount of heat required to carbonize waste tires.

Combustion air is supplied from the periphery of the burner in order to incompletely burn the waste tire, but the amount of air supplied is adjusted and controlled to an amount smaller than the theoretical combustion value.

If possible, a gas analysis of the concentration of carbon dioxide, carbon monoxide, etc. in the exhaust gas at the outlet of the rotary pre-furnace is performed, and the supply air amount is adjusted according to the measurement result.

Ventilation (draft) control of the waste tire incineration boiler is performed by equilibrium ventilation so that the second combustion chamber has a slight negative flow. Therefore, the draft in the rotary forehearth becomes negative, and the combustion gas is prevented from being ejected to the outside.

The length, diameter, rotation speed, rotation axis angle, etc. of the rotary forehearth are selected according to the speed at which the waste tire is supplied to the rotary forehearth, that is, the amount of waste tire processed per hour. The burner combustion amount and the supplied combustion air amount can be controlled.

The residual carbon-like waste tire discharged from the rotary forehearth does not give a shock to the front of the conversion type transfer bed change stoker from the water pipe (b) having a gradient formed by gravity due to the cresoon. So as to supply it gently.

Since the waste tires are incompletely combusted in the rotary forehearth, the temperature in the forehearth can be kept low, damage to the furnace wall refractory material can be suppressed, and troubles such as wire melting can be reduced.

A burner for auxiliary combustion is provided on the front side wall of the first combustion chamber, and measures are taken when there is an obstacle to the continuation of combustion on the conversion type transfer bed change stoker.

The waste tire having carbon residue should be completely incinerated before reaching the rear end of the stoker.
The combustion speed is adjusted by adjusting the feed rate of the stoker, the supply air amount, and the combustion amount of the auxiliary burner.

In the conversion type transfer bed changer stoker, a wind box in which the lengthwise direction of the stoker is divided into several is provided inside the changer grates, and the windbox is long at the inlet of the windbox. A rotary damper is provided so that the amount of supplied air is as uniform as possible in the width direction of the stoker.

Depending on the combustion state, the opening of the damper provided on the wind box is adjusted to adjust the required air amount in the longitudinal direction of the stoker. The combustion imbalance that tends to occur partially in the longitudinal direction is adjusted to reduce excess air and improve the combustion efficiency of waste tire incineration.

Inspection holes are provided on the upper side wall and the rear wall of the stoker at a position where the combustion state on the stoker can be monitored, so that the supply air amount can be easily adjusted. Or, if necessary, provide a monitor to enable remote control.

Since the residual carbon-like waste tire discharged from the rotary forehearth is apt to be biased toward the center in the width direction of the stoker,
A drainage pipe (d) of "Fig. 2" is provided so that the thickness of the waste tire layer is averaged and burned.

In the combustion of waste tires on the stoker, the residual carbonized waste tire layer serving as a fuel is apt to be partially biased, and a difference in ventilation resistance is generated, which easily causes air blow-through. The height of the combustion chamber is made low so that combustion can be performed efficiently with a supply amount as small as possible.

When the waste tire is incompletely combusted in the rotary forehearth, the dry distillation gas generated is supplied to the second combustion chamber and merged with the combustion gas discharged from the first combustion chamber. Steam (or air) is blown from the side wall of the inlet to mix and agitate both combustion gases well, efficiently burn with a small amount of excess air, and prevent the generation of black smoke.

The combustion gas is heated at the upper outlet of the second combustion chamber to the superheater and then to the economizer, the gas flow is reversed at the lower end thereof, and then the gas is guided to the outside of the boiler. The residual heat of is collected by the combustion air and discharged to the chimney through the induction fan.

Steel materials such as wires left after burning incinerated waste tires as a residual material are temporarily retained in the hopper provided at the rear end of the stoker, the tamper provided in the hopper is opened at any time, and taken out to the transport vehicle prepared below it. , It is transferred to the wire melting furnace, melted and reused as steel.

The waste tire incineration boiler is required to have a considerably large capacity in order to take advantage of the scale, but for recovering the heat generated by burning the waste tire, a structure as shown in FIG. 1 is used. Use a water tube boiler.

The boiler structure is designed and manufactured according to the scale of incineration. The structure can be sufficiently supported by existing technology.

Not only the steam generated in the waste tire incineration boiler is directly used for heat supply, but also excess steam is supplied to the steam turbine generator to generate electric power, thereby directly using the steam. The amount of waste tires to be incinerated can be freely decided without considering the balance, and the amount of heat generated from the waste tires can be effectively recovered.

When the required steam conditions of various destinations vary, adoption of a system that uses a condenser and extraction / exhaust for the steam turbine makes it possible to comply with a wider range, and to further enhance the plant total. The thermal efficiency of can be improved.

The power generation capacity of the incineration boiler is, for example, 5,000 kW
/ H, unitize it to a scale suitable for H / H, standardize the steam pressure and steam temperature conditions sent to the steam turbine generator,
It will be used as a reference when making next.

In the heat calculation of the boiler design, the structure such as the water cooling pipe heat transfer area of the second combustion chamber is designed in consideration of the combustion chamber temperature not exceeding the required limit value.

If the combustion gas temperature is lower than the expected value as a result of the operation of the incineration boiler, the water cooling pipe in the second combustion chamber is covered with a refractory material for adjustment.

The temperature in the furnace of the second combustion chamber or the temperature of the combustion gas at the combustion chamber outlet is measured, the air supply amount is adjusted, and the temperature in the furnace, that is, the combustion gas temperature in the combustion chamber is easily controlled.

Combustion gas at the outlet of the second combustion chamber (carbon dioxide.
The concentration of oxygen and carbon monoxide) is measured to control the amount of combustion air to improve combustion efficiency and prevent gas explosion due to retention of unburned gas.

The nitrogen oxides generated from the waste tire incineration boiler control the amount of combustion air to maintain the second combustion chamber at an appropriate temperature of, for example, 900 ° C. or lower, and reduce the amount of emission from the boiler. We will also use existing technologies to reduce their emissions.

Further, after the flue gas is discharged from the boiler device, sulfur oxides and nitrogen oxides can be further reduced in atmospheric emission by using existing techniques such as desulfurization and denitration.

[0052]

INDUSTRIAL APPLICABILITY The waste tire incineration boiler of the present invention can continuously incinerate steel materials such as wires used for tires without pretreatment, thus improving plant operation rate and operating costs. Can be reduced.

Considering the calorific balance between the amount of waste tires incinerated and the amount of steam generated, the steam generated in the waste tire incineration boiler is used as hot steam and electric power is supplied by using various power generation systems. Instead, waste tires can be incinerated, and the operating rate of the incineration plant and thermal efficiency can be further improved.

The boiler design is effectively carried out so that the thermal energy of the waste tires can be utilized with good heat efficiency and the environmental pollutants can be discharged less.

It is possible to collect the material wires and the like mixed in the waste tires and reuse them as steel materials.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a waste tire incineration boiler.

FIG. 2 is an explanatory view of the structure of a water pipe screen at the outlet of the rotary forehearth.

[Explanation of symbols]

B ... Burner D ... ・ Unheated downcomer (arranged outside the furnace wall) ECO ... Economizer (coal saver) MH ... manhole N ... Steam (or air) nozzle S ・ ・ ・ ・ Inspection port (peep hole) SC: Side cooler SH: Super heater (superheater) SP: Can water circulation pump ST: Steam turbine generator WWT ... Water cooling wall water pipe a ... Ring-shaped water pipe b ... Screen water pipe c ··· Pipe water pipe (1) d ... ・ Heading water pipe (2) e ... f ... Circulating water pipe

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F23G 5/027 F23G 5/027 A 5/14 5/14 F

Claims (9)

[Claims] 1. An incineration boiler using waste tires as fuel, wherein a rotary furnace type front furnace is provided in front of the combustion chamber of the incinerator boiler, and the waste tires are burned in a state of insufficient air content to generate dry distillation gas. A waste tire incineration boiler characterized in that it is supplied to the second combustion chamber for combustion. 2. In the waste tire incineration boiler having the structure according to claim 1, the residual carbonaceous waste tire left after carbonization in the rotary forehearth with insufficient air content is used for the rotary forehearth. A waste tire incineration boiler characterized by a structure in which gravity is applied from the outlet to a conversion-type transfer bed conversion stoker installed below the second combustion chamber, which is then supplied and burned as solid fuel on the stoker. 3. The dry distillation gas discharged from the rotary forehearth according to claim 1 is combined with the conversion type transfer bed change stoker and the combustion gas discharged in the first combustion chamber and discharged. , A waste tire incineration boiler characterized by completing combustion in the second combustion chamber. 4. A first combustion chamber is provided above the conversion type transfer bed change stoker according to claim 2.
A waste tire incineration boiler characterized by a low ceiling refractory wall such as a hanging arch type that suppresses excess air, effectively burns with a small amount of combustion air, and improves combustion efficiency. 5. The outlet combustion gas of the first combustion chamber where the excess air tends to increase and the carbonization gas discharged from the rotary forehearth are jetted out of steam or air from the side wall of the inlet of the second combustion chamber, A waste tire incineration boiler characterized by thoroughly mixing the dry distillation gas discharged from the rotary forehearth with a small amount of excess air in the second combustion chamber to improve combustion efficiency and improve boiler efficiency by mixing well . 6. The front end of the front furnace is provided with a ring-shaped water cooling pipe (a) as shown in FIG. 2 at the tip of the rotary front furnace on the combustion chamber side according to claim 1. A waste tire incineration boiler, which is characterized by preventing overheating. 7. A ring water cooling pipe (c) according to claim 6 is provided in the upper front part of the stoker according to claim 2 by providing a horizontal pipe (c) in a direction orthogonal to the stoker in the horizontal direction. The a) and the heading water pipe (c) are connected by a graded screen water pipe (b), and the carbonized residual carbon waste tires discharged from the rotary forehearth are connected to the screen water pipe (b).
A waste tire incineration boiler characterized by supplying it to the front of the stoker without impact while sliding on it. 8. A residual carbon-like waste tire, which is apt to be biased toward the center of the stalker, by installing a sloping water pipe (d) behind the stalking pipe (c) according to claim 7. A waste tire incineration boiler characterized in that the air is uniformly supplied in the width direction, and the excess air is prevented from entering due to blow-by of combustion air. 9. The waste tire is completely incinerated on the conversion type transfer bed change stoker according to claim 2, and steel materials such as wires remaining in the waste tire are burned together with combustion residues to the rear end of the stoker. A waste tire incineration boiler characterized in that it is temporarily stored in the hopper, and the exhaust dumper provided in the hopper is opened and closed at any time to be received by a transport vehicle prepared outside the hopper and discharged.