JP2001173921A - Burner equipped with stoker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a burner equipped with a stoker wherein a high moisture fuel is mixed with a low moisture fuel so as to effectively burn the former, while the thickness value of a fuel layer on a grate is made uniform for appropriately desiccating and/or burning the fuel layer, allowing these fuels to be burnt out with an augmented rate. SOLUTION: The burner equipped with the stoker has a combustion chamber provided with a step-like stoker 8, and a traveling grate stoker 12 sequentially located downstream of the step-like stoker 8. Upwardly of these stokers 8, 12, first and second sprinkling means are provided, wherein the first sprinkling means sprinkles the high moisture fuel onto the step-like stoker, while the second sprinkling means sprinkles the low moisture fuel onto the high moisture fuel loaded on both the step-like stoker and/or the traveling grate stoker 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stoker type combustion apparatus, and more particularly, to a fuel layer on a grate when co-firing high-moisture fuel and low-moisture fuel in order to incinerate high-moisture fuel efficiently. The present invention relates to a stoker type combustion apparatus capable of stabilizing combustion efficiency by surely equalizing the thickness of the fuel to an optimum value for drying and combustion, and increasing the incineration rate of these fuels.

[0002]

2. Description of the Related Art Conventionally, when incinerating a fuel having a high moisture content (hereinafter referred to as a high moisture fuel) such as scum, waste paper, chip dust, bark, bagasse, etc., it is subjected to a dehydration treatment to contain water. After the rate is reduced, a fuel having a low water content (hereinafter, referred to as a low moisture fuel) such as paper waste and wood waste (hereinafter referred to as a low moisture fuel) and a heavy oil fuel are mixed to perform co-firing, thereby stabilizing combustion. As the combustion device for co-firing, a stair stalker has been used in many cases. The stair stoker moves the grate arranged in steps in the front-back direction to loosen the fire layer, so even fuel with a high moisture content can be incinerated with higher efficiency than other combustion devices be able to.

[0003] In the case of performing the above-mentioned combustion using a stair stoker, conventionally, a fuel supply hopper is provided in two upper and lower stages near the most upstream part of the stoker. As the operation method,
First, a dehydrated high-moisture fuel is placed in the lower hopper, and a mixture of low-moisture fuel and heavy oil is placed in the upper hopper. Then, the fuel in the hopper is pushed out onto the grate by a pusher provided in each hopper. Thereby, each fuel is laminated on the grate such that the high-moisture fuel having poor flammability is located in the lower layer and the low-moisture fuel having excellent flammability is located in the upper layer. As a result, the low-moisture fuel excellent in combustibility ignites and burns early, and promotes drying and igniting combustion of the high-moisture fuel.

[0004]

However, in the conventional stair stoker, as described above, the fuel is sent to the grate by the pusher, so that the combustion efficiency may not be stable. In other words, in order to stabilize the combustion efficiency of the fuel, it is necessary to make the thickness of the fuel layer on the grate uniform to a predetermined value.However, when sending fuel using a pusher, the pushing speed of the pusher must be reduced. I had to adjust or change the height and width of the pusher. When changing the pusher extrusion speed, delicate speed adjustments must be made.On the other hand, changing the height and width of the pusher is actually performed due to the difficulty of replacement work and cost. There was no fact.
In addition, in the conventional stair stalker, all of the fuel is supplied from one end of the grate row by a pusher. Therefore, when the grate row is long, it is more difficult to make the thickness of the fuel layer uniform. there were.

[0005] The present invention has been made in view of such circumstances, and when performing high-moisture fuel and low-moisture fuel co-firing in order to incinerate high-moisture fuel efficiently, the thickness of the fuel layer on the grate is increased. It is an object of the present invention to provide a stoker-type combustion apparatus capable of stabilizing combustion efficiency by equalizing oil to an optimum value for drying and combustion, and increasing the incineration speed of these fuels.

[0006]

According to the first aspect of the present invention,
A stair stoker and a transfer stoker are provided in the combustion chamber, and the transfer stoker is arranged continuously downstream of the stair stalker, and a fuel with a high water content is sprayed on the stair stoker above the stoker. A first spraying means and a second spraying means for spraying a fuel with a low moisture content on the fuel with a high moisture content on the stair stoker and / or on the fuel with a high moisture content on the transfer stalker are provided. It is a stoker type combustion device characterized by the above-mentioned. The present invention solves all of the above problems by providing the present invention.

[0007]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partial sectional view showing a stoker type combustion device according to the present invention. FIG. 2 is an enlarged view showing a part of the stoker type combustion device shown in FIG. A stoker-type combustion device according to the present invention includes a combustion chamber (1).
A stair stalker (2) and a transfer stalker (3) are provided therein, and the transfer stalker (3) is continuously arranged downstream of the stair stalker (2). Above these stokers (2) and (3), a first spraying means (4) and a second spraying means (5) are provided. Hereinafter, regarding these components,
I will elaborate.

The stair stalker (2) is for drying the high water content fuel sprayed by the first spraying means (4). The type of fuel having a high water content is not particularly limited, and examples thereof include scum, waste paper, chip dust, bark, bagasse, and the like. The stair stalker (2) is provided with a drying grate (8) composed of a movable grate (6) and a fixed grate (7), and sequentially transfers the fuel having a high water content to the downstream side while sufficiently loosening the fuel. I do.
A hopper (9) for stair stalker is provided below the stair stalker (2), and a drying air blowing duct (10) is connected to the hopper (9). The drying air blowing duct (10) is supplied with high-temperature air for drying fuel having a high water content. This hot air reaches the drying grate (8) via the stair stalker hopper (9) where it dries the high moisture content fuel.

The transfer stoker (3) burns the high water content fuel transferred from the stair stoker (2) and the low water content fuel sprayed by the second spraying means (5). is there. The type of the fuel having a low water content is not particularly limited, and examples thereof include paper waste and wood waste. In the present invention, heavy oil fuel can be mixed with the waste. The uppermost stream portion of the transfer stalker (3) is located at a position substantially coincident with the lowermost stream portion of the stair stalker (2), and is in a state of being continuous with the lowermost stream portion of the stair stalker (2). Thereby, the transfer stalker (3) can receive the fuel with a high moisture content that has been dried to some extent by the step stoker (2), and can sequentially transfer it to the downstream side. The transfer stoker (3) includes a belt-like combustion grate (12) composed of a chain of grate (11), and the combustion grate (12) has two rotating shafts (13). ) For endless rotation.

Below the transfer stalker (3), a transfer hopper hopper (14) is provided, and a combustion air blowing duct (15) is connected to the hopper (14). The combustion air blowing duct (15) is supplied with medium-temperature air for burning low-moisture-content fuel and dried high-moisture-content fuel. The medium-temperature air reaches the combustion grate (12) through the transfer stalker hopper (14), where each fuel is burned. In addition,
The high moisture content fuel transferred from the stair stoker (2) is placed on the combustion grate (12), and the low moisture content fuel is sprayed and laminated thereon. The low water content fuel is excellent in combustibility and ignites and burns at an early stage, and promotes the drying and combustion of the high water content fuel located in the lower layer.

The first spraying means (4) is for uniformly spraying a fuel having a high water content to a desired thickness on the stair stoker (2). The first spraying means (4) is arranged above the stair stalker (2) and the transfer stalker (3). The structure of the first spraying means (4) is not particularly limited as long as the fuel having a high water content can be sprayed uniformly over a wide range. (Not shown) or the like that sprays the fuel by the injection of the fuel may be employed. In addition, it is preferable that the first spraying means (4) can adjust the spraying range.

[0012] The second spraying means (5) deposits the low moisture content fuel on the high moisture content fuel on the stair stoker (2) and / or on the high moisture content fuel on the transfer stalker (3). It is to be sprayed uniformly with a desired thickness. That is, the second spraying means (5) uniformly sprays the fuel having a low water content on the fuel already sprayed having a high water content. The second spraying means (5) is arranged above the stair stalker (2) and the transfer stalker (3). Second spraying means (5)
Is not particularly limited as long as the fuel having a low water content can be uniformly sprayed over a wide range. For example, the same structure as that of the first spraying means (4) can be employed. In addition, it is preferable that the second spraying means (5) can adjust the spraying range.

Second spraying means (5) and first spraying means (4)
Is not particularly limited, and the second spraying means (5) is located above the first spraying means (4) (see FIG. 1).
Or, conversely, a mode in which the first spraying means (4) is located above the second spraying means (5) (see FIG. 3) can be adopted. In either case, the first spraying means (4) sprays the fuel with high moisture content over the area of the stair stalker (2) (FIG. 1,
(See the two-dot chain line in FIG. 3). On the other hand, the second spraying means (5)
In the former case (see FIG. 1), the fuel with a low water content can be sprayed from the step stoker (2) to the transfer stoker (3) (see the dashed line in FIG. 1). In the latter case (see FIG. 3), the fuel with a low water content can be sprayed in the range of the transfer stoker (3) (see the dashed line in FIG. 3). This ensures that the low water content fuel is deposited on the high moisture content fuel at a desired uniform thickness on the transfer stoker (3), so that the high water content fuel is reduced to the low water content fuel. It burns reliably by obtaining the drying and burning action of.

When combustion is performed by the stokers (2) and (3), high-temperature exhaust gas is generated, and the exhaust gas is directly discharged from an exhaust duct (not shown) provided at an upper portion of the combustion chamber (1). Alternatively, the secondary combustion is performed by the high-temperature air blown from the secondary combustion air blowing duct (17) provided in the upper part of the combustion chamber (1). When the secondary combustion is performed, the unburned gas contained in the exhaust gas is completely burned and discharged from the exhaust duct.

Next, the operation of the stoker type combustion device will be described. Here, a case where the second spraying means (5) is located above the first spraying means (4) (see FIG. 1) will be described. First, a high water content fuel such as scum is charged into a fuel charging hopper (16) provided above the first spraying means (4). Further, a low water content fuel such as wood chips is charged into a fuel input hopper (18) provided above the second spraying means (5). At this time, it is desirable to mix heavy oil fuel with wood chips and the like in order to further enhance the combustibility. Next, the first spraying means (4) uniformly sprays the fuel having a high moisture content on the upper side of the stair stoker (2) with a thickness optimum for drying. Further, the second spraying means (5) may be a stair stalker (2).
, And a low moisture content fuel is evenly sprayed at a thickness optimal for combustion from the transfer stoker (3).

As a result, a high moisture content fuel layer is formed uniformly on the stair stoker (2) with an optimum thickness for drying, and a low moisture content fuel layer is evenly formed thereon with an optimal thickness for combustion. You. This laminate is transferred downstream while being loosened by the movable grate (6). During that time, first, fuel with a low moisture content is ignited and burned. The high moisture content fuel is dried by the heat of combustion of the low moisture content fuel and the high temperature air from the drying air blowing duct (10), thereby reliably reducing the moisture content to a desired value.

The high-moisture content fuel having a reduced water content is transferred onto the transfer stoker (3) together with the low-moisture content fuel that has been burned or burned. On the transferred fuel, a new low-moisture-content fuel is uniformly deposited by the second spraying means (5) with a thickness optimal for combustion. Then, the fuel with a low water content ignites and burns. The fuel with a high water content is composed of the heat of combustion of the fuel with a low water content and the combustion air blowing duct (1).
Combustion by the medium temperature air from 5) ensures incineration. Further, among the low water content fuels sprayed by the second spraying means (5), the fine powder fuel is burned while floating in the combustion chamber (1), and the temperature in the combustion chamber (1) is evenly and uniformly. Work to keep Thereby, a more stable combustion state can be obtained. The burned high-moisture content fuel and low-moisture content fuel become ash, fall onto an ash carrying conveyor (not shown), and are continuously carried out of the combustion device. This eliminates the need for manual labor for ash extraction.

[0018]

According to the present invention, there is provided a stair stoker and a transfer stoker in a combustion chamber, and the transfer stalker is arranged continuously downstream of the stair stoker, and a high water content is provided above the stoker. A first spraying means for spraying fuel on said stair stoker; and a second spraying means for spraying low moisture content fuel on high moisture content fuel on said stair stoker and / or high moisture content fuel on a transfer stalker. Since the stoker-type combustion device is provided with two spraying means, the following effects can be obtained. That is, when co-firing high-moisture-content fuel and low-moisture-content fuel in order to incinerate high-moisture fuel efficiently, the thickness of the fuel layer on the grate is equalized to the optimum value for drying and combustion by each spraying means. can do. Therefore, the combustion efficiency of each fuel can be stabilized. Further, with the improvement of the combustion efficiency, the conveying speed of each stoker can be increased, so that the incineration processing speed can be increased.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a stoker type combustion apparatus according to the present invention.

FIG. 2 is an enlarged view showing a part of the stoker type combustion device shown in FIG. 1;

FIG. 3 is a partial sectional view showing another embodiment of the stoker type combustion device according to the present invention.

[Explanation of symbols]

 1 ···· Combustion chamber 2 ····· Stair stoker 3 ···· Transfer stoker 4 ····· First spraying means 5 ····· Second spraying means

Claims (1)

[Claims] 1. A stair stoker and a transfer stalker are provided in a combustion chamber, and the transfer stalker is continuously arranged downstream of the stair stalker, and a fuel having a high water content is supplied above the stoker. First spraying means for spraying on a stalker; second spraying means for spraying low moisture content fuel on high moisture content fuel on the stair stoker and / or high moisture content fuel on the transfer stalker. A stoker-type combustion device characterized by comprising: