DE906253C - Water gas generator and method of operating the same - Google Patents

Description

Water gas generator and method of operating the same The invention relates to a water gas generator with a hot-blow room and a gasification room, through which the fuel is passed one after the other, so that a continuous Bubble gas flow and water gas flow is generated. Such water gas generators are has already been described in the literature (cf. Dr.-Ing.Paul Dolch, "Wassergas", Leipzig, 1936, p.236bisa38).

These gas generators use a powdered or fine-grained fuel used. The same is z. B. blown up with the hot air wind in the blow room, like this that the hot-blowing takes place in suspension, and the hot-blown fuel sets in a pocket in which it is gassed with steam. From the gassing room the fuel is discharged from below and partly fed back into the hot-blowing room. It may be left open whether these gas generators achieve useful results as practical experience is not available. At least it is a disadvantage that only worked with pulverulent or fine-grain fuels can be.

In the water gas generator according to the invention, any fuel can be used Lumpiness can be processed. It has a vertical or nearly vertical Shaft with a loading device arranged at the top and one arranged at the bottom Discharge device to maintain a constant, in constant downward flow located Fuel column, in the middle of the height of the shaft of the hot bladder wind and on lower end of the gasification steam are introduced while the water-gas-steam mixture -something is discharged below the feed point for the hot-blowing wind, so that the fuel migrating downward in the fuel column in the upper part of the shaft is blown hot and gasified in the lower part of the shaft. For easier separation of Gas and wind can flow through the shaft between the entry point for the hot-blow wind and the exit point for the water gas receive a constriction. Furthermore can for the same purpose control devices are provided with which the gas pressure Can be regulated at the water gas outlet point depending on the wind pressure.

The water gas generator according to the invention can be in the most varied Operated wisely. It is Z. B. with the help of the aforementioned control devices possible, a water gas with any nitrogen content up to practically nitrogen-free To generate water gas. To generate a practically nitrogen-free water gas, how it z. B. is used for hydrogenation plants, the gas pressure at the water gas outlet point kept higher than the wind pressure at the point of entry for the hot-blow wind. A little water gas then constantly flows over into the hot-blowing room, where it comes with a Part of the hot blow wind burns. The resulting heat is not needed to be blown with carbon and is fed back into the water gas process. There are no losses here, only the gas generator output drops slightly away.

If a certain nitrogen content is to be regulated in the water gas, z. B. for nitrogen synthesis, the gas pressure at the water gas outlet point kept slightly lower than the wind pressure at the point of entry for the hot-bubble wind. Depending on the pressure difference, a larger or smaller amount of hot-blowing wind is then generated enter the gasification room, where the oxygen burns with the water gas, while the nitrogen is removed with the water gas.

Regarding the nature of the fuel with which in the shaft the most diverse variations are possible. Preferably will a fuel cycle applied. It can e.g. B. carried out on the 'manhole base Fuel-ash mixture after washing out the released ash with addition of fresh fuel can be fed back into the shaft above. Instead of this only part of the fuel-ash mixture discharged from the lower part of the shaft can do this can be diverted to wash away the released ashes, while the other Part immediately together with the washed fuel with the addition of fresh fuel is entered into the shaft. In this case, the shaft will have a high ash content worked. This has several advantages. With the loosening achieved thereby of the fuel, as this is widely distributed in the ash, the formation of CO will occur held back, and a blow gas with a high C 02 content is obtained. Also received the facilities for washing the fuel smaller dimensions. One can in the endeavor to distribute the fuel widely in the shaft, go so far that predominantly Ash or slag is kept in circulation and only at the top of the shaft the fuel required for a cycle is added so that at the bottom of the shaft practically pure ash is discharged; thus falling facilities for washing the Fuel completely gone.

The fuel-ash mixture in the lower part of the shaft The heat contained can be used to generate the gasification steam. This can be done in such a way that in the lower part of the shaft in the fuel-ash mixture Water is injected. But you can also use the fuel-ash mixture run a water bath, which also acts as a T seal for the gasification shaft serves. In this way, any water, including smoldering water, can be used.

Another possibility of waste heat recovery is that the sensible heat of the withdrawing water gas / steam mixture through heat exchange is transferred to the hot blower wind. The heat exchange can take place in any heat exchangers working according to the recuperative principle or according to the regenerative principle known design. However, it is of particular importance in the present case Case of using a heat exchanger in which a granular material Heat transfer medium passed through a vertical shaft, filling this, in the circuit is, through which the gases to be brought into heat exchange in separate sections led - ground. Such a heat exchanger has the property that it against the very hot and dusty gas is insensitive, while the other known ones Heat exchangers under such conditions with rapid encrustation of the heating surfaces is to be expected.

When using the aforementioned heat exchanger can be used as a heat transfer medium for the heat exchange between water gas and wind also that from the gas generator shaft The fuel-ash mixture discharged below or a part thereof can be used. This: measure comes into consideration in particular when in the shaft with high Ash content is worked, so that the fuel-ash mixture discharged below contains little fuel. The remaining fuel then burns with part of the hot blower wind to be preheated and is thus made usable.

The gas generator according to the invention is suitable for any fuel, so z. B. also for the gasification of bituminous fuels. For fuel with predominantly baking character, in particular those processes come into consideration, which work with a high ash content. Since in this case the fuel grains, in ashes embedded, second are distributed, is not an opportunity for caking of the fuel grains.

When gasifying bituminous fuels, the The fuel layer above the entry point for the hot blower wind is kept so low that that the withdrawn gases have a temperature high enough for tar removal. Otherwise tar would precipitate in the upper fuel layers, which would soon lead to a clogging of the gas generator. The departing tarred Hot blow gases containing degassing products can be incinerated and e.g. B. for the wind generation, steam generation or the like. Can be used.

The invention is explained in more detail with reference to the drawings.

In Fig. I, a gas generator according to the invention is shown schematically. The vertically arranged gasification shaft is denoted by i. Above is that Shaft i a loading device with a rotatable bowl 2 arranged, into which the fuel is entered and from which it is drawn with the help of fixed Räumschaufeln 3 is conveyed into the shaft when the bowl is rotated. Below the shaft i dips into a water bowl 4, from which is also fixed Räumschaufeln 5 the fuel-ash mixture is discharged. With the help of the loading device and the discharge device, the throughput speed of the fuel in the Shaft can be adjusted precisely, and by coordinating the conveying speed of the two devices, a constant fuel level in the shaft can be achieved will.

The line 6 opens into it a little above the middle of the height of the shaft for the introduction of the hot blower wind. The hot air wind flows through the one above Part of the fuel column and the hot blow gases exit through the top of the gas vent. In the vicinity of the lower end, a line 8 is used for gasification Water vapor introduced into the fuel column. The water-gas-steam mixture pulls just below the entry point of the line 6 for the supply of the hot blower wind through a line 9.

In the upper part of the shaft, the fuel is blown hot, d. H. By burning part of the fuel, it becomes necessary for the production of water gas required heat supplied. The hot-blown fuel then enters the between the lines 8 and 9 located gasification zone in which its temperature decreases from top to bottom. Because the temperature conditions in the gasification room constantly remain the same, a constant degree of gasification can also be expected, namely, a high degree of gasification is to be expected, since the water gas / steam mixture in the upper part of the gasification room constantly at the highest temperature comes into contact with hot blown fuel.

In Fig. 2 is another embodiment of the gasification shaft shown. As a special feature, it should be mentioned that the shaft is roughly in the middle of the height between the inlet line 6 for the hot-blowing wind and the outlet line 9 has a constriction io for the water gas / steam mixture. The constriction has the purpose of enabling an easier separation between gas and wind. Further A special feature that should be emphasized is that the hot-blow room has a small diameter has, while the manhole base used for gas generation expanded considerably is. This ensures that the blowing takes place at a high speed, as a result of which the CO content of the blast gas is known to be considerably reduced. The actual water gas generation takes place as a result of the large shaft cross-section in the gasification chamber at a low flow velocity, i.e. also under favorable conditions Conditions in place.

While in the embodiment according to Fig. I, the supply and discharge the media through ring lines with radial branches outside the manhole takes place, are in the embodiment according to Fig. 2 at the inlet and outlet points Recessed in the shaft annular spaces i i and i2, in which the fuel for formation of cavities is at the angle of repose. The introduction line 8 for the water vapor is not provided in Fig.2. The reason for this is discussed in more detail below.

To separate wind and gas are also not shown in the drawing Control devices of a known type are provided that depend on the Wind pressure in line 6 is the pressure of the water gas / steam mixture in the line 9 rules. With the help of these control devices, as already mentioned above, for Achieving a nitrogen-free water gas in the water gas outlet line 9 a slightly higher pressure than can be regulated in the wind inlet line 6, so that some water gas constantly flows over into the hot-blowing room and there with a part of the blown gas burns. The reverse can be done by setting a lower pressure in the water gas outlet line 9 can be achieved that from the hot-blowing room hot-blowing wind passes into the gasification room, where its oxygen with part of the generated The water gas burns while the nitrogen is removed with the water gas. In this way, a water gas with a desired nitrogen content can be generated will.

In Figs. 3 to 5 are different options for the implementation a fuel cycle shown.

According to Fig.3, the fuel discharged from the bottom of the water bowl 4 is a total of a laundry 13 supplied, in which the ash released from the Fuel is separated and discharged at 14, while at 15 the leached Fuel is discharged and returned to the top of the entry bowl 2. As a substitute for the ash washed out in the laundry 13, a corresponding Amount of fresh fuel entered continuously into entry bowl 2. the registration the fresh fuel takes place through the feed hopper marked 16.

According to Fig.q. is taken from the bowl d. discharged fuel-ash mixture only a part branched off into the laundry again designated by 13. The rest of the fuel and ash mixture is washed out directly into the entry bowl 2 together with that in the laundry 13 Fuel returned. According to the ash discharge in the laundry 13 is entered through the funnel 16 fresh fuel into the entry bowl. While According to Fig. 3, essentially pure fuel is fed into the shaft above, the ash only has bound form, is shown in Fig. 4 in the shaft with a fuel-ash mixture with a significant amount of free ash. The lower the portion of the fuel-ash mixture diverted after washing is, the higher the ash content in the gasification shaft.

According to Fig. 5, mostly only ash is kept in the cycle. Fresher Fuel is only approximately in such a way through the funnel again designated 16 The amount entered into entry key 2 is approximately that required for one cycle Fuel requirement is covered. The aim is to have practically pure ash below is discharged from the gasification shaft. From the discharged ash stream only a part was eliminated according to the addition of fresh fuel.

Instead of introducing water vapor through line 8 (Fig. I), it is possible water can also be injected into the fuel oil. That in the lower part of the shaft Accruing fuel-ash mixture, which is no longer responsible for the water-gas reaction is sufficiently hot, generally still contains enough heat to carry out the the gasification required to generate water vapor.

The injection line 8 can also be omitted entirely. The gasification vapor can then be generated in that the located in the lower part of the shaft Fuel-ash mixture is passed through a water bath. A suitable water bath is always present when the discharge at the lower end of the shaft is through a Water bowl takes place, which is designated in the figures with ¢. The one at the meeting The steam produced by the fuel-ash mixture with the water rises in the fuel column high and forms water gas with the hot-blown fuel. The excess steam withdraws with the water gas.

In Fig. 6 it is provided that the withdrawing water gas-steam mixture, which has a very high temperature, its sensible heat in a heat exchanger 18 gives off to the hot air wind, which by the fan ig over the heat exchanger to be led. In the example according to Fig. 6, a tubular heat exchanger is provided. The water gas / steam mixture withdrawn through line g flows, for example through the tubes and drains up through a vent 20 during the hot blow wind flows in front of the outside of the tubes and fed through the line 6 to the shaft will.

Fig. 7 also deals with the heat exchange between the withdrawing ones Water gas and the hot bubble wind. Instead of the tubular heat exchanger 18 is a Heat exchanger provided with circulating solid heat transfer medium, its application takes into account the fact that the gas emerging from the gas generator is very high high temperature has a significant dust content. This heat exchanger has a vertical shaft 2i. Through this shaft a granular, z. B. Existing heat transfer medium made of refractory material enforced the shaft completely filled up to a certain height. The throughput speed is fed by a loader 22 at the top and a loader at the bottom Discharge device 23 provided at the end of the shaft regulated. The loading device 22 and the discharge device 23 can be of a similar type to the corresponding ones Devices in the gas generator according to the invention. The heat transfer medium discharged below is entered again at the top and thus executes a cycle. The end -the line g exiting water gas is approximately in the middle of the height of the shaft 21 through a line 24 is introduced into the heat transfer medium and occurs after it has given off its heat to the heat transfer medium at the upper end of the shaft 2i through the line 25. Of the Hot bubble wind coming from a blower 26 is through line 27 in the Near the lower end of the shaft 2i in the heat transfer medium, introduced and occurs approximately below the point of introduction for the water gas through line 28 the shaft 21 in order to flow to the gas generator through the line 6. When flowing through of the heat transfer medium, the hot-blowing wind removes the water gas in the upper part of the shaft on the heat transferred to the heat transfer medium.

Fig.8 shows the use of the same heat exchanger, however with the difference that the heat transfer medium discharged from the gasification shaft below Fuel-ash mixture is used. This is at the top of the shaft 2i of the heat exchanger entered and discharged below. A circuit of the heat carrier within the heat exchanger is not scheduled. This method is used when the gas generator shaft i The fuel-ash mixture discharged from the bottom only has a very low fuel content Has. This is the case, for example, when, as shown in Fig. 5, there is predominantly ash in the Cycle is maintained. The low fuel content of the ash then burns on Lower part of the shaft 21 with a part of the hot-blowing wind flowing through and is thus made usable for the process. The one discharged from the shaft 21 below, becomes practically pure ash after part of it has been deposited, Introduced at the top of the gas generator shaft together with the fresh fuel required. Instead of the entire fuel-ash mixture discharged from the gas generator shaft below To give through the heat exchanger, only part of the heat exchanger can are supplied so that the other part immediately above in the gas generator shaft is returned.

In the gasification of bituminous fuels «- one becomes the fuel column only keep low above the inlet line 6 for the hot air wind so that the withdrawing gases a sufficiently high temperature for tar formation or tar deposition have, depending on the desired tar quality zoo up to 45o ° C. The permanent Components of the degassing products in the hot blower wind can be used for any purpose burned "- earth.

It is advantageous to work with the gasification of strongly baking fuels with strong ash accumulation in the gasification shaft, especially according to Figure 8. the individual fuel parts are then separated from each other by ash, so that a Caking is impossible.

Claims (6)

PATENT CLAIMS: i. Water gas generator with a hot blow room and a gasification room through which the fuel is passed one after the other, characterized by a vertical or almost vertical shaft with a loading device mounted above and a discharge device located below to maintain a constant, in constant downward flow Fuel column, in the middle of the height of the shaft of the hot bladder wind and on lower end of the gasification steam are introduced while the water-gas-steam mixture is discharged slightly below the feed point for the hot-blowing wind, so that the fuel migrating downwards in the fuel column in the upper part of the shaft is blown hot and gasified in the lower part of the shaft. 2. Water gas generator according to Claim i, characterized in that the shaft between the entry point for the hot blower wind and the exit point for the water gas for easier separation is constricted by gas and wind. 3. Water gas generator according to claim i or 2, characterized by control devices with which the gas pressure at the water gas outlet point adjustable depending on the wind pressure at the point of entry for the hot-blowing wind is. 4. A method for operating the water gas generator according to claim 3, characterized characterized in that the water gas pressure is used to generate a nitrogen-free water gas at the exit point is kept greater than the wind pressure at the entry point for the hot blower wind, so that some water gas constantly passes into the hot blower room, where it burns with the hot blow wind. 5. Procedure for operating the water gas generator according to claim 3, characterized in that for regulating a certain nitrogen content in water gas, e.g. B. for nitrogen synthesis, the water gas pressure at the outlet is kept slightly lower than the wind pressure at the entry point for the hot-blow wind, so that wind constantly crosses into the gasification chamber, its oxygen with the water gas burns. 6. A method of operating the water gas generator according to any one of claims i to 3 or according to claim 4 or 5, characterized in that the fuel-ash mixture discharged from the lower part of the shaft is re-entered into the top of the shaft after washing out the released ash with the addition of fresh fuel will. i. Method for operating the water gas generator according to one of Claims 1 to 3 or according to Claim 4 or 5, characterized in that part of the fuel-ash mixture discharged from the lower part of the shaft is branched off for the purpose of washing out the released ash, while the other part is directly with it the washed fuel is added to the shaft above with the addition of fresh fuel. B. A method for operating the water gas generator according to one of claims i to 3 or according to claim 4 or 5, characterized in that predominantly ash or slag is kept in the cycle and only the fuel required for a cycle is added to the upper part of the shaft, so that practically pure ash is discharged from the lower part of the manhole. Process according to one of Claims 4 to 8, characterized in that the heat contained in the fuel-ash mixture occurring in the lower part of the shaft is used to generate the gasification steam by injecting water into this fuel-ash mixture or Ash mixture is passed through a water bath, which also serves as an immersion seal for the gasification shaft. ok Method according to one of Claims 4 to g, characterized in that the sensible heat of the withdrawing water-gas-steam mixture is transferred to the hot-blowing wind by heat exchange. i i. Method according to claim io, marked by using a heat exchanger in which a heat transfer medium consisting of granular material is circulated through a vertical shaft, filling this, through which the gases to be exchanged are conducted in separate sections. 12. The method according to claim ii, characterized in that the fuel-ash mixture discharged from the gas generator shaft below or a part of the same is used as a heat transfer medium for the heat exchange between water gas and wind, wherein the residual fuel burns with part of the hot-blower wind to be preheated. 13. The method according to any one of claims 8 to 12, characterized by the use of bituminous fuels, predominantly baking character, as starting material. 14. The method according to claim 13, characterized in that the fuel layer is kept so low above the entry point for the hot blowing wind that the exhausting gases have a temperature high enough for tar removal. 15. The method according to claim 1q., Characterized in that the withdrawing de-tarred hot-blown gases are burned, for. B. for wind heating, steam generation and the like. French patent no. 833 757; British Patents # 23 126, 1898. 21739 of 1913, 212671. U.S. Patent No. 2,239,801,: 2320318.