JPH05256424A - Method of burning dusts - Google Patents

Abstract

PURPOSE:To inject combustible dusts from a burner after their drying and making fine ponder to cause them to be floated and burn and to enable a heat amount generated upon combustion of dusts to be maintained at a constant value. CONSTITUTION:Combustible dusts dried by a drying device 6 are crushed into fine powders by a hammer mill 7 to make fine powders, other fuels are properly mixed so as to correct the heating amount generated upon combustion of the fine powdered dusts, injected from a burner 9 together with primary air and then the dusts are floated and burned under a dust combustion method. Accordingly, the dusts are dried, the variation of combustion temperature of the combustible dusts can be restricted and the variation of the heat transfer can also be restricted, the dusts are changed into some fine powders and the air transportation can be made possible, the dusts can be injected and then floated and burned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust burning method.

[0002]

2. Description of the Related Art FIG. 2 is a sectional view schematically showing an example of a conventional general continuous combustion type refuse incinerator. The combustible waste a that has been separated and collected is dropped from the collection vehicle b to the waste pit c, and the crane d provided above the waste pit c.
It is picked up by the bucket e and is put into the inlet hopper f of the furnace. The dust a thrown into the inlet hopper f gradually slides down into the furnace due to its own weight, and while slowly moving on the stoker g, is burned by the heated air blown by the pushing fan h from below the stoker g.

The stalker g normally has an inclination angle of about 30 degrees and has some sort of dust transfer function. Therefore, the dust a on the stoker g is layered from the bottom to the top in the unburned layer, the combustion layer, and the ash layer, and the combustion is constantly continued by supplying new dust a.

Then, the combustion gas i generated by the combustion of the dust a is fed from the combustion chamber j to the boiler k, and the high temperature and high pressure steam generated by the boiler k is used as a heat source.

Further, in recent years, the number of cases in which a power generation facility for utilizing the steam to obtain inexpensive electric power is additionally provided is increasing.

[0006]

However, in the above-mentioned dust burning method, the amount of heat obtained by burning is not constant and low because the dust quality is extremely non-uniform and the amount of water in raw dust is large. Therefore, there was a problem of low power generation efficiency.

In view of the above-mentioned situation, the present invention is to combustible dust by drying it, atomizing it, and mixing it with other fuel, so that the amount of heat obtained can be corrected to a predetermined amount and burned by a burner. The purpose is to provide a method.

[0008]

According to the present invention, combustible dust is dried and then pulverized into fine powder, and another fuel is appropriately mixed so as to make the amount of heat generated during combustion constant. As the fuel, the pulverized mixed fuel is jetted from the burner together with the combustion air for floating combustion.

[0009]

Therefore, in the present invention, when combustible dust is burned, the amount of heat obtained can be kept constant, air can be conveyed, and it can be jetted from the burner for floating combustion.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the outline of an embodiment of the dust burning method of the present invention. 1 is a collection vehicle and 2 is a garbage pit. A cutting device 3 is provided below the dust pit 2, and a magnetic separator 4 for selecting the metals mixed in the dust is provided above the tip of the cutting device 3.

In order to dry the dust and reduce the water content to a predetermined amount or less, a dryer 6 is connected to the tip of the cutting device 3 via a chute 5, and the dust dried by the dryer 6 is kept to a predetermined amount. In order to pulverize into fine powder particles (particle diameter of about 70 μm), a hammer mill 7 is provided below the outlet of the dryer 6, and primary air for sending finely pulverized dry dust to a burner 9 provided in a boiler 8 is provided in the hammer mill 7. A blower 10 is connected to the hammer mill 7 for delivery to.

A coal feeder 11 for supplying coal to be added to the dry dust in the hammer mill 7 is connected to the hammer mill 7 in order to correct the amount of heat generated during combustion. The coal feeder 11
Is connected to a bunker and a coal meter (not shown) so that the required coal can be appropriately supplied.

Further, an oil burner 12 for starting is provided in parallel with the burner 9 provided in the boiler 8, and a pipe 14 for supplying steam generated in the boiler 8 to a steam turbine 13 of the power generation facility is connected to a pipe 15. Is branched and connected to the dryer 6, so that steam can be used as a drying heat source of the dryer 6, and a pressure holding valve 16 is provided in the middle of a pipe 15 connected to the dryer 6 to connect to the steam turbine 13. It is formed so as to maintain the pressure of the supplied steam. Reference numeral 17 is a condenser that cools and condenses the exhaust gas of the steam turbine 13 to reduce the turbine exhaust pressure, collects the condensate, and supplies it to the boiler 8.

Next, the operation will be described. The flammable dust that has been separately collected by the collection vehicle 1 is once put into the dust pit 2 from the collection vehicle. The cutting device 3 is operated to cut out the dust from the dust pit 2, and the dust is supplied to the dryer 6 through the chute 5. At this time, when a metal piece is mixed in the dust that is cut out from the dust pit 2 by the cutting device 3 and flows out to the chute 5, the metal piece is provided above the tip of the cutting device 3 by a magnetic separator. When it passes under 4, it is adsorbed by the magnetic separator 4 and extracted from the dust. The dust thrown into the dryer 6 is fed from the boiler 8 to the pipes 14 and 15
Water is removed by using the steam supplied via the heat source as a drying heat source to be dried. The dried trash is then hammered 7
In order to correct the amount of heat generated during combustion, a bunker and a coal meter (not shown) are crushed together with the coal added into the hammer mill 7 through the coal feeder 11 to give a predetermined fine powder (particle size of about 70 μm). ), Is mixed with the primary air sent from the blower 10 and is sent to the burner 9, and is jetted from the burner 9 into the boiler 8 to perform floating combustion. Thus,
Electric power is generated by sending the steam generated in the boiler 8 to the steam turbine 13 of the power generation facility through the pipe 14.
At the same time, it is fed to the dryer 6 via the pipe 15.

According to the above, the amount of heat generated during combustion of dust is obtained by drying the dust by the dryer 6 and pulverizing the dried dust by the hammer mill 7 and simultaneously introducing coal into the hammer mill 7 and pulverizing the dust together with the dust. Therefore, it is possible to burn dust in a pulverized coal burning boiler, suppress variations in combustion temperature and boiler heat transfer, and improve power generation efficiency.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0018]

According to the dust burning method of the present invention, various excellent effects as described below can be obtained.

I) By drying the dust, it is possible to keep the water content, which is the main cause of fluctuations in the heat quantity generated during combustion, constant, and to suppress fluctuations in the combustion temperature fluctuation heat quantity. In addition, fluctuations in combustion temperature and boiler heat transfer can be suppressed.

II) By properly mixing the dust with other fuel, it is possible to correct the variation in the heat quantity generated during combustion due to the type of dust, and therefore the boiler output can be regulated. Furthermore, if the mixing ratio of the other fuel is 10% or more, it can contribute to stabilizing the flame for auxiliary combustion.

III) By crushing dust with a crusher and pulverizing it, air can be conveyed, and the same combustion method as in the conventional pulverized coal burning boiler can be used. Further, since a low NOx burner or the like can be used, it is possible to systemize a plant that is excellent in terms of measures against environmental problems.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an outline of an embodiment of a dust burning method of the present invention.

FIG. 2 is a cross-sectional view schematically showing an example of a conventional general continuous combustion type refuse incinerator.

[Explanation of symbols]

 6 Dryer 7 Hammer Mill (Crusher) 9 Burner

Claims (1)

[Claims] 1. Combustible dust is dried and then pulverized into a fine powder, and another fuel is appropriately mixed to obtain a pulverized mixed fuel so that the amount of heat generated during combustion becomes a fixed value. A method for burning dust, which comprises jetting air from a burner together with combustion air to perform floating combustion.