JPH08226627A - Coal feeder - Google Patents

Abstract

PURPOSE: To permit the keeping of a given mixing ratio and prevent the generation of vibration in a mill by a method wherein coal or coke, having different natures respectively, are sent to a coal feeder by a plurality of conveyors to throw them into one set of mill from the common outlet port of the coal feeder. CONSTITUTION: Coal and coke, having different natures respectively, are charged into two sets of respectively independent bunkers 1 while the coal or the coke are thrown into one set of vertical mill 4 from the common outlet port of a coal feeder 2, accommodating two sets of belt conveyors 2a provided so as to be opposed mutually. Two sets of belt conveyors 2a are provided with a measuring device and a speed regulating mechanism respectively to permit regulation by measuring the throwing amount of coal or coke. According to this method, the mixing ratio of coal to coke can be kept in constant at all times and, therefore, the vertical mill 4 can be prevented from generating vibration even when coal or coke having different natures such as pulverizability or friction coefficient and the like are thrown into one set of vertical mill 4.

Description

Detailed Description of the Invention

[0001]

The present invention relates to coal and petroleum coke,
Alternatively, the present invention relates to a coal feeding device applied to a boiler or the like that co-fires coal having different properties.

[0002]

2. Description of the Related Art FIG. 3 is an explanatory diagram of a conventional coal feeder used in a boiler for cofiring coal and petroleum coke, or coal having different properties. In the figure, when coal and petroleum coke having different coal types are conventionally mixed and burned, they are mixed on a conveyor (not shown) before entering the bunker 1, and even if they fall into the bunker 1, the particle sizes are different from each other. In the bunker 1, the smaller particle size reaches the lower part of the bunker 1 earlier and enters the compact mill 2 earlier than the larger one.
The larger the particle size, the later it tends to enter the rigid mill 2. As described above, if the particle diameters are different from each other, the mixing property is deteriorated, so that the particles cannot always enter the rigid mill 2 at a constant mixing ratio. For example, when coal and petroleum coke, or bituminous coal and anthracite are mixed and used, the properties such as pulverizability and friction coefficient are greatly different from each other, so that the mixing ratio is changed so that they alternately enter the compact mill 2. Then, vibration occurs in the rigid mill 2. For this reason, conventionally, coal, petroleum coke, etc. are thrown into different hard mills 4 and burned by different burners.

[0003]

As described above, in the conventional coal feeder, when coal and petroleum coke having different coal types are mixed and burned, the properties such as pulverizability and friction coefficient are greatly different from each other, and thus the mixing ratio is large. Changes, and the rigid mill 2 alternately
Since there is a possibility that vibration will occur in the rigid mill 2 when it enters inside, coal, petroleum coke, etc. are put into different rigid mills 4 and burned by different burners.

[0004]

A coal feeding apparatus according to the present invention is intended to solve the above-mentioned problems, and a plurality of conveyors for feeding coal or coke having different properties and a mill common to the plurality of conveyors are provided. And an input port of

[0005]

That is, in the coal feeding apparatus according to the present invention, coal or coke having different properties is sent by a plurality of conveyors and is fed into the mill from a common outlet. Alternatively, coal having different properties such as bituminous coal and anthracite, or a position where the coke is mixed is in front of the mill inlet, so that a constant mixing ratio can be maintained at all times, such as coal and coke having different properties such as crushability and friction coefficient. No vibration occurs in the mill even if it is charged into one mill through this coal feeding device. Further, since the position where the coal, coke, etc. are mixed approaches the burner in front of the entrance of the mill, the responsiveness of the boiler is improved and the controllability is also improved.

[0006]

FIG. 1 is an explanatory view of a coal feeder according to an embodiment of the present invention. In the figure, the coal feeder according to the present embodiment is used for a boiler or the like for co-firing coal and petroleum coke, or coal having different properties. As shown in FIG. Two different types of coal, etc. of different types are put in two independent bunkers 1, respectively, and the inside of one compact mill 4 from the outlet of the main coal feeder 2 that has two belt conveyors 2a installed facing each other. It is put into the furnace and mixed-fired in a boiler (not shown). Each of the two belt conveyors 2a is provided with a weighing device, a speed adjusting mechanism, and the like, and it is possible to measure and adjust the input amount of coal or petroleum coke. It should be noted that two belt conveyors 2a may be provided in parallel with each other as shown in FIG. 2B, or two belt conveyors 2a may be provided facing each other as shown in FIG.
A hopper 2c as a call chute input port may be installed below the exit of the belt conveyor 2a.

When cofiring coal and petroleum coke, the coal is put in one bunker 1 and the petroleum coke is put in the other bunker 2, respectively. Then, both of the belt conveyors 2a are operated, for example, a fixed amount of petroleum coke is charged, and the amount of coal is automatically controlled, whereby the boiler is master-controlled by coal and operated. In this case, since the input amounts of coal and petroleum coke are measured and adjusted in the coal feeder 2, the input amounts are stable compared to the case where separate lines are provided to the burner as in the conventional coal feeder, Further, as compared with the conventional coal feeder that mixes coal on the belt conveyor at the entrance of the bunker 1, the responsiveness is better because the weighing point is closer to the burner. The number of belt conveyors 2a is not limited to two, and it is possible to provide three or more. Further, when only coal or petroleum coke is exclusively burned, only the belt conveyor 2a on the bunker 1 side to be exclusively burned may be operated. As described above, in this coal feeder, since the position where coal and petroleum coke or bituminous coal and anthracite are mixed is in front of the inlet of the rigid mill 4, coal and petroleum coke, or bituminous coal and anthracite are alternately hardened. It is possible to maintain a constant mixing ratio without entering the shape mill 4, and even if coal, coke, etc. having greatly different properties such as pulverizability and friction coefficient are put into one rigid mill 4. Therefore, vibration does not occur in the rigid mill 4.

In a conventional coal feeder, when coal and petroleum coke having different coal types are mixed and burned, the properties such as pulverizability and friction coefficient are largely different from each other, so that the mixing ratio is changed, and they are alternately placed in a rigid mill. Since there is a possibility that vibration will occur in the rigid mill as it enters, coal and petroleum coke are put into different rigid mills and burned by different burners. In this machine, coal, petroleum coke, etc. supplied from two or more bunker 1 are put into the compact mill 4 from one common outlet, and the mixing ratio of coal, petroleum coke, etc. is always constant. Therefore, even if coal or petroleum coke whose properties such as crushability and friction coefficient are greatly different are put into one rigid mill 4, the rigid mill 4 does not vibrate, so Hard mill 4 Luo also advantageous in terms of cost even the burner configurational able to common equipment. Further, since the position where the coal, petroleum coke, or the like is mixed approaches the burner in front of the inlet of the rigid mill 4, the responsiveness of the boiler is improved and the controllability is also improved.

[0009]

The coal feeder according to the present invention is constructed as described above, and coal or coke having different properties such as pulverizability and friction coefficient is charged into one mill through the coal feeder. However, since vibration does not occur in the mill, the equipment after the mill becomes common, which is advantageous in terms of space and cost.

[Brief description of drawings]

FIG. 1 (a) is a cross-sectional view of a coal feeder according to an embodiment of the present invention, FIG. 1 (b) is a cross-sectional view of a coal feeder according to its application example, and FIG. FIG. 13 is a cross-sectional view of a coal feeder according to an application example of FIG.

FIG. 2 is a sectional view of a conventional coal feeder.

[Explanation of symbols]

 1 bunker 2 coal feeder 2a belt conveyor 2b coal feeding pipe 2c hopper 3 pulverized coal pipe 4 rigid mill

Claims (1)

[Claims] 1. A coal feeding apparatus comprising: a plurality of conveyors for feeding coal or coke having different properties; and a charging port into a mill common to the plurality of conveyors.