DE835492C - Process and system for gas generation from fine-grain fuels - Google Patents

Description

Process and system for gas generation from fine-grain fuels Patent 829 483 is based on the discontinuous gasification of fine-grain fuels with periodic processing: the fuel bed. The downward gassing or blowing takes place with the fuel bed at rest. The periodic processing takes place in such a way that inert gases, which can also be partially or wholly replaced by gasification agents, are brought into flowing motion from below via the hot coal bed, the coal freshly entering the coal bed is dried, smoldered and degassed and the Smoldering vapors and water vapors add to the gas produced in the upward period. The high dust and tar content of the upward gases is undesirable because: it makes processing too difficult. According to patent 829483 , this problem can be eliminated in a simple manner by the fact that the upward gas contaminated with dust and smoldering vapors and possibly diluted with water vapor or inert gases passes through the glowing zone of a second generator during its downward period. The dust is retained and gasified, the smoldering vapors are reduced and the water vapor is largely decomposed.

In order to avoid that when the gases and vapors come together the up period of one generator with the gasifier of the down period of the other generator is an explosive oxygen or oxygen mixture Forms gas mixture, you can, the generator rooms located above the coal filling before Start: the fuel preparation and the passage of the upward gases and vapors of one generator in the downward gear into the glowing zone of the other generator rinse with steam.

The charging of the down period of one generator with the up gases and steaming of the other generator can be used if the previous flushing lasts for a longer period of time the generators with steam result in such a cooling of the fuel bed have that the output of the generators decreases and the decomposition of the in the upward gas tar and water vapors carried along is insufficient.

The invention 'is based on the knowledge that in particular in the made possible by alternator operation according to patent 829 483, for fine-grain fuels comparatively low generator design no explosions occur when the fuel gas produced during the upward period with the above Coal filling existing oxygen-containing gasifying agent meets. at the high temperature prevailing in the generator head burn if there is enough oxygen is present, the fuel gases, with the accompanying tar and water vapors be largely split up before reaching the glowing bed of coal. The two steam decomposition the resulting oxygen is then converted to CO in the coal bed, whereby a particularly effective conversion of the upward gases of one generator takes place in the downward gear of the other generator. According to the present invention one therefore goes from the gas down to the reciprocal upward operation of the two Generators and vice versa from reciprocal upward operation to downward gassing without the activation of a flushing period immediately above, so that practically constant gas is produced.

When using a mixture of oxygen and steam as the downgas agent (Water gas generation) can occur during the passage of the upward gases and vapors of the one generator in the down cycle of the other generator on a simultaneous one Charging of the downward period with oxygen can be completely or partially dispensed with, because the fuel bed then contains a lot of sensible heat. Is the down gasifier on the other hand, air (lean gas generation) is simultaneous with the charging of the Ember zone of a generator with the upward gas also recommend the introduction of air.

In the drawing .is an embodiment of the invention is shown.

According to Fig. I, the common supply line is used to produce weak gas i Air is blown into the twin lower shaft generator 2, 3 and from top to bottom passed through the two fuel beds 4 and 5. The beds are heated in. the upper layer, the coal gasified, leaving behind slag will. The gas is discharged through lines 6 and 7. After the end of heating If, according to Fig. 2, the generator 2 is charged with steam from below through line 6, which brings the bed 4 in surging motion so that the slags sink on the grate and can be carried out. At the same time, this generator is fed through the feed hopper 8 charged with fuel, from which the upward flowing stream turned into dusty Components are taken along and fed into the bed 5 of the generator 3 from above. The supply of air or other down gasifier from the line i is not interrupted, and no flushing period is switched on; the Operation according to Fig.2 immediately follows that according to Fig. I.

After bed 4 has been prepared, it is switched over as shown in Fig. 3, Steam blown through 7 into bed 5 to settle - blow gas into bed from above 4 passed and withdrawn by 6. At the same time, the filling takes place through the Nozzle 9. Then the work cycle starts again (Fig. I).

In the example, the @ 7organg is used for combustion as it does when they come together the upward gases with the downward gasification means takes place over the fuel bed, in order not to let the coal bed temperature drop. Should the Coal bed temperature can be greatly increased, as is the case with the production of water gas If this is the case, in addition to the upward gases from one generator, there are additional gases Amount of gas burned and the resulting sensible heat to the coal filling released, which serves to decompose water vapor.

If water gas is to be produced, it is expedient through line i Oxygen, optionally with the addition of steam, is introduced. depending on the operating conditions either, the supply line i is kept open all the time, as is the case with lean gas production, whereby in the upward periods according to Fig. 2 and 3 already due to the pressure conditions the Amount of supplied oxygen is reduced. But you can also do it in addition provide a restriction for the oxygen in the supply line i and in the upward periods work according to Fig. 2 and 3 with reduced oxygen supply.

In the exemplary embodiments, the method is based on two generators or a twin generator explained. Instead, there can also be several Generators work in alternation. The assembly of two generators each is appropriate in any case.

The application is essential for all types of execution of the method from relatively low generators. So far, the gasification has been finer-grained Fuels in generators with a relatively large or high gasification chamber carried out because otherwise, the relatively large amounts of dust in particular when gasifying agents were blown in under the grate could not be mastered. At the new procedures are the amounts of dust on the top layer of each downward working Generator added. It can da'liei- worked with a generator which has a smaller gasification space than was previously the case with fine-grain gasification was possible, and this small volume is again favorable for the .direct Transition from one process step to another without the need for a flushing period.

Claims (6)

PATENT CLAIMS: i. Process for generating gas from fine-grain fuels in two generators or generator groups according to patent 829483, characterized by the direct transition from downward gassing (Fig. I) to alternating upward operation of the generators (Fig. 2 and 3) and vice versa from alternating operation to downward gassing. 2. The method according to claim i, characterized characterized in that simultaneously with the passage of the upward gases and vapors of one generator through the glowing zone of the other generator (Fig. 2 or 3) also the downward gasification means (line i) in whole or in part in the generator to be introduced. 3. Method .according to claims i and 2, characterized in that that for the purpose of heating the fuel bed in particular for the production of water gas in addition to the upward gases from one generator, there are also other combustible gases above the Fuel bed of the other generator are burned. 4. Installation for execution of the method according to one or more of the preceding claims, characterized in that that generators one for the gasification of fine-grain fuels relatively low design can be used. 5. Plant according to claim 4, characterized in that that two generators or generator groups are connected to a common line for the Downward gases are coupled. 6. Plant according to claim 4 and 5, characterized in that that two generators are assembled to form a generator unit.