DD227216A1 - METHOD FOR ACCESSORIES OR STEPS OF A CARBON FIRING - Google Patents

Abstract

The invention relates to a method for starting and Stuetzbetrieb a pulverized coal firing, in particular for steam generators, being conveyed through the pulverized coal pulverized coal dust to the main burner. It is to be achieved that the processed pulverized coal to be introduced ensures fine pulverization and reliable drying of the pulverized coal. This is achieved in that the pulverized coal mill is supplied with a delivery air quantity l0,1 and the processed pulverized coal is controllably fed to pulverized coal mill by means of an inert driving medium by injector action. figure

Description

Title of the invention

Method for start-up or support operation of a pulverized coal furnace

Field of application of the invention

The invention relates to a method for start-up or support operation of a pulverized coal furnace.

Characteristic of the known technical solutions

For the start-up or support operation of a pulverized coal combustion, it is known

a) to promote treated coal dust in pilot burners and to ignite and at a certain combustion chamber temperature to take the pulverized coal mill into operation (DR-PS 755 552) <

b) give up treated coal dust instead of fresh coal to the pulverized coal mill, to feed to main burners, to ignite and, after reaching a certain combustion chamber temperature, to give up fresh coal from the mill (DR-PS 755 552) ₄

c) to promote treated pulverized coal directly into the main burner and to ignite and to take after reaching the combustion chamber temperature, the pulverized coal mill in operation (DD-PS 148 669);

-7 P, Η-ΓΗ 90255

d) cold start the Kohlenstaubraühle, abandon a small amount of coal with a small amount of conveying air, thereby producing a very fine pulverized coal and give up as concentrated dust flow either a partial burner of the main burner or a pilot burner (DD-PS 151 993).

These known measures require a high investment, control and operational overhead for treatment, wear protection and inerting, without a particularly favorable start-up or support operation could be achieved ·

Thus, in the mill operation during startup, an ignitable coal dust produced by the mill and fed to the main burners. The delivery rate (ballast) is very high, so that a poor ignition stability at the main burners with low mill performance can be achieved. Regarding compliance with the starting gradient of the steam generator, there are difficulties in Anfahrmühlenbetrieb by large circulating streams with significant dead times.

Object of the invention

The aim of the invention is to improve the start-up or support operation significantly.

Explanation of the essence of the invention

The invention has for its object to operate the mill so that the processed pulverized coal to be introduced ensures Feinstaufmahlung and safe drying of coal dust.

This is achieved in that according to the invention, the coal dust mill with a conveying air amount yl ύ 0.1 applied and the processed coal dust by means of an inert

Treibraedium is given by injector controllable after pulverized coal mill. -

embodiment

In one embodiment, the invention is explained in detail. The drawing shows the arrangement of incorporation for the processed coal dust into the coal dust main channel.

The pulverized coal fan mill 2 is connected to the pulverized coal main burner 3 via the main pulverized coal duct 1 and through the pulverized coal ducts 12.

In the coal dust main channel 1 of the pulverized coal duct IO is integrated, which has the ejector 4 with the driving medium line 13 and valve 9. As a driving medium is steam, hot air, compressed air or flue gas usable.

The coal dust channel 10 is connected via the pulverized coal conveying line 7 with the pulverized coal bunker 6, the z. B. is designed as a transportable silo truck. In the inflow region of the coal dust channel 10, the constriction 11 is provided, so that · coal dust deposits are avoided with certainty.

Depending on the amount of pulverized coal to be abandoned, the temperature of the sucked-back flue gases and the abandoned amount of raw lignite coal, one or more pulverized coal ducts 10 are distributed over the circumference of the pulverized coal main channel 1.

The mode of action is the following:

The coal dust fan mill 2 is approached in the cold state without raw coal task, with a delivery air amount Λ S, 0.1 is driven.

The valve 9 is opened and the driving medium, for. As steam, acts on the ejector 4, which promotes the processed coal dust 5 from the pulverized coal bunker 6 in the coal dust channel 10. Due to the vapor deposition, an inert

tization of the system achieved, so that no further expenses for operational safety. The task of the pulverized coal vapor mixture takes place in the flow direction 8 of the coal dust fan mill 2 conveyed air into the coal dust main channel 1. The pulverized coal steam Geraisch is mixed with the funded by the pulverized coal fan 2 air, the main burner. 3 promoted and ignited there.

It is advantageous if this mixture is only conveyed via one of the pulverized coal pipes 12 to one of the partial burners of the main pulverized coal burner 3 and ignited there. If the combustion gases in the combustion chamber reach a temperature which permits ignition of ground crude lignite due to the combustion of the treated pulverized coal, a small amount of raw lignite coal or pulverized coal fan mill 2 is abandoned.

By the sucked-back combustion gases drying of the abandoned raw lignite coal is carried out by the abandoned coal dust-steam mixture further drying of the coal dust produced in the pulverized coal fan mill 2, so that an ever better ignitability of the ground coal dust is achieved because a Feinstraahlung occurs.

Hit this improvement at the same time increases the task of Rohbraunkohlemenge and reduces the task of the pulverized coal-steam mixture on reaching the ignition stability and finally stopped.

If in the meantime ignition difficulties occur, then again the coal dust-vapor mixture is abandoned. Likewise, when partial load or support operation is necessary or deterioration of the raw lignite quality occurs, with a full or less coal application is made in the pulverized coal mill.

The invention achieves the following advantages:

1. Safe start-up operation of the pulverized coal mill.

2. Safe ignition stability during start-up operation.

3. More power operation of the pulverized coal mill ·

4. Reduction of the grinding material circulation.

5. Improved support operation at T _e illast or reduction of Rohbraunkohlequalität.

6. Due to the steaming an inerting of the system is achieved.

7. Low equipment costs and operating costs.

8. If the treated coal dust is given up in the classifier, fine clouds of fine material are prevented.

Claims (10)

invention claim 1. A method for start-up and support operation of a pulverized coal firing, especially for steam generators, being conveyed by the pulverized coal pulverized coal to the main burner, characterized in that the coal dust mill with a Förderluftmengej ^ < 0.1 applied and the processed coal dust by means of an inert Driving medium is given by injector controllable after pulverized coal mill, 2. The method according to item 1, characterized in that the processed coal dust is fed by means of hot steam by injector action. 3. The method according to item 1, characterized in that the processed coal dust in the coal dust main channel, in the classifier space and / or a pulverized coal main burner is abandoned. 4. The method according to item 1 to 3, characterized in that the processed coal dust is abandoned in countercurrent to the conveying direction of the pulverized coal mill. 5. The method according to item 1 to 3, characterized in that the processed coal dust is fed in cocurrent to the conveying direction of the pulverized coal mill. 6. The method according to item 1 to 5, characterized in that the processed pulverized coal is placed on task sites in a floor after pulverized coal mill. 7. The method according to item 1 to 5, characterized in that the processed coal dust is placed on task sites in several floors after pulverized coal mill. 8. The method of item 1 and 7, characterized in that the abandoned pulverized coal hot steam mixture is conveyed together with the conveying air to a partial burner of the pulverized coal main burner. 9. Method nachf items 1 to 8, characterized in that the pulverized coal mill is started in the cold state without coal task. 10. The method according to item 1 to 8, characterized in that the pulverized coal mill is driven in the warm state with little or complete coal application. For this 1 sheet drawing