DE926024C - Method for operating ignition devices for dust firings with injection mills - Google Patents

Description

Process for operating ignition devices for dust firing systems with injection mills The invention relates to a method for operating Ignition devices for dust firing with injection mills according to patent 923-213, according to which from the burner: dust air flow that flows to the main burners, with the help a fine grain sifter sifted out, separated, bunkered and for the operation of the Ignition muffle is used. It consists in the fact that the extracted ignition dust on the Ways from suction to separating tied.le an additional drying through hot Air, hot gases extracted from the furnace, or a mixture of both will. It is known that igniter operated with coal dust to a To supply a good pilot light, require a very dry dust. Will be the ignition dust from the grinding shaft of a coin-operated furnace or the dust air line of a single-blast mill vacuumed, the degree of dryness of the dust is sufficient. in the rarest cases .den Requirements of the pilot firing, since the drying of the fuel for the main firing does not need to be driven as far as when preparing the ignition dust. The extraction of the ignition dust from the main furnace would therefore, in the case of the method proposed in the main patent, on the few cases must remain limited, at which the initial moisture of the fuel burned is so low that the final moisture of the reached after the mill drying Dust is sufficient for the ignition.

To at. Combustion of moist fuels the storage of a special To avoid ignition dust is therefore proposed according to the invention, from the partial flow branched off from the Mahltrocknungsänlage, from which the ignition dust is sifted and, being deposited, subject to additional drying in order to obtain the for the ignition system to ensure the necessary drying of the dust. This additional Drying is carried out on the way of the extracted partial flow from the extraction point to to the separator and depending on the degree of drying required Hot air, hot gases extracted from the furnace, or a mixture of both be made, with the supply of the desiccant immediately behind the extraction point or behind the sifter. It can also be a adjustable bypass lines can be arranged around the bag, if in addition to drying influencing the sifting of the dust is also desired.

In the drawing, a device for performing .des is proposed Procedure shown in a simplified representation.

A beater mill i, to which the raw fuel is fed through pipe 2 works in the known way as mill firing on the combustion chamber 3.

From the grinding shaft q. a partial flow of dust air is generated via the pipe 5 sucked out of which. Looked out the coarse grain in sachet 6 and read it over Pipe 7 back into the grinding shaft q. is returned while the carrier gas with the fine grain flows through the pipe 8 to the dust separator 9. The separated dust is stammered in the bunker io, from which he is known for the operation taken from the ignition device. can; the carrier gas becomes with the residual dust sucked in by the fan i i and pressed through the pipe 12 of the combustion chamber 3.

According to the invention learns from the grinding shaft q. sucked Dust on the way through the pipe 5, classifier 6, pipe 8 and separator 9 an additional Drying. Hot air from the hot air duct is used as the drying agent 13 is fed to the trunk air line 5 via the lines 1q., 15. Is that enough The temperature of the hot air for the required drying of the dust is not sufficient, this can be done by adding an appropriate amount of hot gases from the combustion chamber 3 to the hot air, the temperature of the drying agent to any temperature set between the temperature of the hot air and the temperature of the fire gases will.

By arranging a line 16 which runs parallel to the viewer 6 the line 15 connects to the line 8, on the one hand, the drying section can be shortened on the other hand, with the appropriate setting of the flaps 17 and 18, the Viewing the dust by changing the amount of gas supplied by the classifier 6 can be changed within wide limits.

When commissioning the collection device, it is advisable to do so first sucking in pure hot air or hot gases through the system for a while and only if. all ducts are sufficiently heated to start vacuuming, so that the otherwise occurring Sch- # vitzwasser formation and deposition of dust in the lines is avoided. The flap i9 in line 5: closed, while it is in normal operation with suction of the dust is opened.

Claims (2)

PATENT APPEAL: i. Method of operating ignition devices for dust firing with injection mill according to patent 923 213, according to which from the Dust air stream that flows to the main burners with the help of a sifter Fine grain sifted out, deposited, bunkered and used to operate the ignition muffle is, thereby gelcennze.ichnet that the extracted ignition dust on the way-from the Extraction points to the separator for additional drying with hot air the hot gases sucked off or a mixture of the two is subjected to the furnace. 2. The method according to claim i, characterized in that the feed, the hot air or the fire gases in the drying section for the ignition dust in front of or behind the classifier or both. Places is done at the same time.