DE102014014899A1 - Fixed bed pressure gasification processes and apparatus for static and dynamic equalization of the flow - Google Patents

Abstract

1. Decisive for achieving a maximum carburetor performance is a low discharge of dust with the raw gas. To minimize the formation of fines, a uniform flow of the gasification substance through the gasification agent over the bed cross section is necessary. However, the known technical solutions provide an uneven flow profile. The illustrated method and the associated devices enable a controllable redistribution of the flow in the fixed-bed gasifier. 2. In order to allow a uniform flow through the fixed bed within a carburetor, the gasification agent is fed from the rotary grate with different sector loads in the sectors of the bed. At the level of the upper limit of the bed to the gas collection space sectors are also formed with different ratios of the gas outlet surface to the surface of the associated circular sector of the bed of the bed. 3. The invention relates to a method and the associated devices for fixed-bed pressure gasification for static and dynamic equalization of the flow, in particular for high specific gasifier services.

Description

The invention relates to a method and the associated devices for the fixed-bed pressure gasification for static and dynamic equalization of the flow, in particular for high specific gasifier services.

Carburettors for fixed-bed gasification are operated at high power for economic reasons. Crucial for the achievable performance of the carburetor is the most uniform flow through the bed. This is characterized by a stepwise expression of the reaction zones in the bed of the fixed bed in the fixed bed gasifier. From bottom to top, ideally, the reaction zones are the oxidation (fire zone), the gasification (gasification zone), the pyrolysis (pyrolysis zone) and the preheating and drying (drying zone). If there is an uneven flow through the bed with preferential flow near the wall or in channels, the reaction zones are discarded. The fire zone can migrate locally far up to the area of the actual drying zone, the CO ₂ content of the raw gas increases and dust is increasingly discharged with the raw gas. In extreme cases, even hot spots can lead to slagging in the fixed-bed gasifier. To avoid these negative consequences, the performance of the fixed-bed gasifier has to be reduced. In addition, an increase in the vapor to oxygen ratio of the gasifying agent (steam to oxygen ratio in kg / Nm ³ ) may be required to lower the maximum temperatures of the gasification. These measures are economically disadvantageous.

Another major disadvantage of an uneven flow through the bed is that the lower grain size of the coal used raised, d. H. that fine grain must be endured from the feed coal. In the coalification of hard coal, the lower end of the graining belt is therefore limited to about 5 mm. In the gasification of lignite briquettes, during which a decomposition takes place up to the Brikettierkörnung of about 0-4 mm during gasification, about half as high specific carburetor performance as in the gasification of lumpy hard coal can be achieved to avoid uneven flow. To solve the problem, therefore, great efforts are made to feed the bed of the fixed bed gasifier evenly across its cross section, d. H. the gasification agents, which are supplied with the rotary grate, should flow through the gasification substance uniformly over the cross section of the bed regardless of the operating conditions.

This is done according to DE 11 2005 002 983 proposed to make the Vergasungsmittelauslässe located on the surface of the rotary grate, which are vertically and radially spaced, according to the opening sizes so that the outermost Vergasungsmittelauslässe the highest proportion and the innermost Vergasungsmittelauslässe feed the lowest proportion of the gasification agent in the bed. Thus, at most the area proportions of the bed to be flowed through section is met. Unevenness resulting from the inhomogeneities of the bed can not be compensated.

In DD141246A3 It is proposed to improve the uniform distribution by means of a grate construction in which the pressure loss of the Vergasungsmittelauslässe is higher than the pressure loss of the bed.

suggestion DD260192A3 finally recommends a specific expression of flow channels. For this purpose, a rotary grate is described, in which the distances of the Vergasungsmittelauslässe are chosen so large that should form a flow channel at defined, stepped rotation of the grate in the holding period over each Vergasungsmittelauslass.

The previous proposals for improving the rotary grate and its operation are unsuitable to achieve a homogenization of the flow at high specific power of the fixed-bed gasifier, since a non-controllable and uncontrolled redistribution of the flow takes place only in the bed. It has not yet found a solution, as imbalances of the flow with the result of an elevated fire bed to hot spots in the center or near the wall of the fixed-bed gasifier can be actively resolved without strong power drops to decommissioning of the carburetor are required.

In order to influence the bed, the problem of fine grain formation and the flowability of the forming bed has been dealt with very intensively, in particular in connection with the use of briquettes from lignite, and a number of proposals for equalizing the flow and reducing the dust discharge have been worked out.

• • in DD38791 und DD136505 die Abführung einer Teilmenge des erzeugten Vergasungsgases über einen gesonderten Gasabgang,
• • in DD120043 und DD121796 die Erhöhung des Wassergehalts des Vergasungsstoffes,
• • in DD138221 und DD26392 das Einleiten von Gaswasser bzw. Staub-Dickteer-Produkt.

To reduce the thermal stress by lowering the temperature in the top of the carburetor is proposed:

• • in DD38791 and DD136505 the removal of a portion of the gasification gas generated via a separate gas outlet,
• • in DD120043 and DD121796 the increase of the water content of the gasification substance,
• • in DD138221 and DD26392 the introduction of gas water or dust Dickteer product.

To restrict or eliminate the formation of channels in the bed are in DD148641 and DD148642 proposed special coal distribution, which are provided with gas passage openings and thus prevent lifting of the bed after exceeding the stability limit.

In DD145403 and DD152805 the arrangement of loosening elements in the bed is proposed by which a uniform distribution of forming flow channels is to be achieved. In DD280776 . DD280777 . DD280778 and DD280779 special coal distributors are proposed which form an annular gas collection channel or distributed over the carburetor cross section a number of gas collection chambers to produce a uniform bulk movement and gas flow.

For the retention of dust is in DD150906 proposed a horizontally flow-through packed bed filter in the coal manifold. In DD218774 It is proposed to use the space of the coal distributor filled with gasification substance for the preheating, drying and partial degassing of the gasification substance by the thermals of the gas flows.

The dust discharge is also in the gasification of chunky coal, whose grain sizes about 5 to 50 mm, in some cases up to 100 mm amount, a hitherto unsolved problem. According to JR Bunt, coarse-grained particles with grain sizes up to 6 mm are also discharged with the raw gas (Bunt 2006). Coarse-grained particles of this particle size can only from gas strands, which emerge with flow rates of several meters per second (m / s) from the fixed bed in the form of flow channels, or by the formation of local fluidized beds on the surface of the fixed bed, the local flow rates of approx. 1 m / s, be entrained in the gas outlet. Locally increased exit velocities are also caused by imbalances and atypically high levels of the Feuerbet, as described by JR Bunt and FB Waanders and others ( Bunt, Waanders 2008; Glover et al. 1995 ).

Imbalances with increased firebed and channel-like flow occur systematically preferably in the vicinity of or below the gas outlet. The reason for this lies in the preferred flow of the raw gas on the shortest path to the laterally arranged gas outlet (in extreme cases as a short-circuit flow). Such imbalances are still supported by a possible edge flow of the flow due to the larger void volume and / or the accumulation of large particles near the wall. Another reason for the skew formation is, especially in lightly baked hard coal, that the formation of melt bonds in bed is dependent on the heating rate. Slow heating favors such fusion dressings, while rapid heating suppresses them.

Remedy to equalize the gas flow according to DE2005002983 be created by a static coal distributor, with which the raw gas is sucked out of an annular zone, which is located at a distance from the wall. However, due to the formation of an annular zone remote from the wall, a geometrically unfavorable ratio of gas outlet area to bed cross-sectional area (bed area ratio) is determined from the outset. Thus, the mean gas outlet velocity increases, which - greatly simplified - results by multiplying the gas outlet velocity from the bed at theoretically complete availability of the bed surface with the reciprocal of the bed area ratio. The gas outlet velocity locally reaches very high values (up to approx. 1 m / s) which, for a grain size spectrum of the dust, can be from 0 to approx. 6 mm above the vortex point velocity.

The gas exit surface and the bed cross-sectional area are defined herein as cross-sectional areas perpendicular to the axis of the carburetor. The gas outlet surface, which forms below the gas collection chamber, is according to DE 11 2005 002 983 from the lower edge of the static coal distributor or, in the case of a simple hanger, according to DE 10 2012 009 265 B4 bounded by the lower edge of the shaft, and the inner wall of the carburetor.

The bulk of the raw gas flows either via a relatively small gas outlet surface at the surface of the bed in the gas collection chamber or preferably in the vicinity of the wall and in the preferred direction to the gas outlet. These one-sided flows cause local concentrations of the reaction zones. In the area of high flow velocities, the processes of drying and degassing proceed at an increased speed, so that these zones have a lower thickness here than in the remaining area of the predominantly carburettor cross section. The accelerated process requires a higher thermal load of the gasification substance and thus a stronger decay and an increased formation of secondary fine grain. This fine grain, which at the high flow velocity over the Gas outlet from the bed and the carburetor is discharged as dust, limiting the performance of the carburetor.

No solution has yet been found for correcting imbalances with elevated fire beds to hot spots in the center of the carburetor or near the carburetor wall. The result is performance limitations to avoid excessive dust emissions and / or the formation of large smelting dressings or even slagging. Further, additional performance limitations exist with increased levels of primary fines in the feed coal or reduced tolerance to the lower grain size of the feed coal, thus limiting feed coal grades and synthesis gas performance at operating parameters that are within commercially acceptable limits.

The aim of the invention is to increase the specific power for fixed bed gasifier. The invention has for its object to develop a method and the associated devices, which allows a uniform flow through the bed of the bed.

According to the invention this is achieved for fixed bed gasifier with a circular cross section of the bed of the bed (bed cross section), a continuously or non-continuously rotated rotary grate, which is both non-reversible and reversible operable, and a static coal distribution in the form of a Einhängeschachtes,
that the rotary grate and the manhole are two elements of a functional unit, which consists in that the flow of the rotary grate circular sectors of the bed of the bed (rust-bed sectors) and the circular sectors of the bed close to the bed of the bed (shaft-bed sectors) of both elements coordinated and sektorgenau forced and reduced,
whereby the flow through the sectors of the bed of the entire bed (bed sectors) is dynamically uniformed overall,
the dynamic grate (and reduction) of the flow through the grate filling sectors and through the suspension shaft the static forcing (and reduction) of the throughflow of the shaft filling sectors is effected by the rotary grate,
that the circular sectors of the rotary grate (rotary grate sectors) form the grate filling sectors in the lower part of the bed,
wherein the rotary grate sectors are provided with different sector loads such that the gasification agent is reduced and forcedly fed into the grate bed sectors, the sector loading of the forced sectors of the rotary grate (forced rotary grate sectors) being 20 to 100% above the sector load of the reduced ones Sectors of the rotary grate (reduced rotary grate sectors),
the hanger shaft, by its design and arrangement, forms the manhole bulk sectors in the upper part of the bed,
wherein the cylinder sectors of the carburetor interior bounded by the carburettor inner wall (sectors) with defined ratios of the gas outlet surface at the upper limit of the bed to gas collection space to the surface of the associated, close to the hangar circular sector of the bed of the bed (shaft-bed sector), called sector area ratios, equipped and that the sector area ratios are different from each other in at least two sectors so that different raw gas quantities are subtracted from the manhole fields according to the sector area ratios, the ratio of maximum to minimum sector area ratio> 1.1 and the bed area ratio as Ratio of the total gas exit area to the bed cross-sectional area is greater than 0.33,
and that the rotary grate sectors and the hang-in shaft sectors have the same or a specifically different sectoring.

The first part of the invention relates to the rotary grate. The rotary grate is functionalized according to the invention so that during the regular operation of the fixed-bed gasifier a targeted, dynamic forcing of the raw gas flow in the grate-bed sectors is carried out in the lower part of the bed. The defined sector loads of the rotary grate sectors assign a defined proportion of supplied gasification agent to each grate filling sector, which is temporarily variable as a result of the rotation of the rotary grate. This allows a) permanent, systematic imbalances of the gas flow, such as the preferred flow to the gas outlet, selectively interrupting and compensating in the lower part of the bed and / or b) furthermore to force a dynamic uniform distribution of the flow over the bed cross-section.

According to the invention, for the first time, a temporarily uneven, dynamized flow of the rust bed sectors of the bed is made in order to dynamically compensate for the recurring irregularities in the flowability of the bed in the individual bed sectors.

The design of the rotary grate sectors is carried out according to the specific application, in particular with regard to the flowability of the bed and the ash content of the gasification materials, corresponding to the sectoring of the Einhängeschachtes. For fixed bed gasifiers, where a preferred flow to the gas outlet, thus to the gas outlet associated grate filling sector is to be prevented, the sectoring of the rotary grate is made such that the preferred flow to the gas outlet in the bed sector of the positions 11-1 o'clock (position of the gas outlet 12 o'clock) is reduced during the majority of the rotary grate. Accordingly, the rotary grate sectors are set in the position 1-11 o'clock as a reduced rotary grate sector and in the position 11-1 o'clock as a forced rotary grate sector. It is included that other sectoring such. B. 10 o'clock 30 min-1 o'clock 30 minutes, to be selected.

In the case of a predominantly well-flowable fixed bed, but a slight skew flow to the gas outlet, it is sufficient if the sector load of the forced rotary grate sector is 20% above that of the reduced rotary grate sector. With stronger skew currents, a forcing of 40-50%, or even 100%, is appropriate. The forcing is achieved in the usual case that an even distribution of the gasification agent over the circumference of the rotary grate takes place, that in the forced rotary grate sector, the area of the Vergasungsmittelauslässe, more precisely, the quotient of the cross-sectional area of the Vergasungsmittelauslässe to cross-sectional area of the rotary grate sector ( specific outlet area), larger than in the reduced rotary grate sector. The cross-sectional area of the rotary grate sector is the projection surface in the axial direction. For an increase of 20%, the specific discharge area of the forced rotary grate sector is 20% higher than that of the reduced rotary grate sector. This is considered constructively in new rotary grates without additional equipment overhead by the outlet surfaces are made correspondingly larger. At a low forcing of 20% existing grate constructions can be changed by very simple adjustments, such. For example, closing every fifth gasification agent outlet in the reduced rotary grate sector or expanding the gasification agent outlets in the forced rotary grate sector by 20%. The stepped promotion and reduction of one rotary grate sector described here is referred to as stepped one-sector forcing. Mixed and non-graded, continuous or sliding expansions and reductions in the areas of the gasification agent outlets are also easily possible.

A development of one-sector forcing represents the non-stepped and sliding, symmetrical forcing in a rotary grate sector and the non-stepped and sliding, symmetrical reduction in the other rotary grate sector, z. For example, by increasing 0 to 20% forcing along the 0-3 o'clock angular positions and decreasing 20 to 0% forcing along the 3-6 o'clock angular positions and increasing 0 to 20 percent reduction along the 6-9 o'clock and 20-0 descending angular positions % Reduction along the angle positions 9-12 o'clock.

In the case of the above-described stepped one-sector forcing in the position 11-1 o'clock, the grate filling sector associated with the gas outlet is subjected to the forced quantity of gasification agent in position 11-1 o'clock on average only in 1/6 of the operating time On the other hand, the rust discharge sector, which is not assigned to the gas outlet, is subject to a locally increased sector load of gasification agent at 1-11 o'clock. This very simplified estimation presupposes the commonly used continuous, constant-speed rotation of the rotary grate.

The dynamic rotary grate forcing, in combination with the incremental (intermittent) and variable speed rotation of the rotary grate (step mode and step mode), adds another time dimension to the dynamic forcing of the grate bed sectors so that for the first time there is a controlled, dynamic flow uniformity across the grate Cross section of the lower portion of the bed is possible. If the in o. G. For example, the rotary grate with one-sector forcing (11-1 o'clock forcing) described above is stepwisely rotated (stepping) so as to be stopped every 1/3 revolution, the grate-filling sectors become 1-3 o'clock, 5-7 o'clock and 9-11 clock forced in the downtime of the rotary grate applied, d. H. the forced flow is allocated step by step and at sectoral intervals to the grate bed sectors. By a rotation angle accurate, stepped Drehrostfahrweise almost all desired Forcierungsmuster can be adjusted, such. For example, the forced-by-hold periods of forcing the landfill sectors of the positions 1-3 o'clock, 3-5 o'clock, 5-7 o'clock, 7-9 o'clock, 9-11 o'clock and the rotation-related reduction in the rust-bed sector of the position 11-1 Clock.

Instead of turning and stoppage (stepping), a sectoral slower and faster rotation of the rotary grate (step mode), as well as a combination of both modes, can be done. With a speed range of 0 (interruption) or 3-12 revolutions per hour (0 h ^-1 , 3-12 h ^-1 ) there are wide variations.

Prerequisite for a rotation angle accurate positioning of the rotary grate sectors is the knowledge of the angular position of the rotary grate. This is mathematically possible without much effort by position and number of revolutions of the outer drive shaft of the rotary grate permanently detected, converted into angular positions and integrated into the control algorithms of the carburetor.

For even better dynamic equalization of the flow through the fixed bed and in the case of beds that tend to strong, flow-related faults over the entire bed cross section of the fixed bed, the rotary grate forcing of several grate-bed sectors is indicated, for example by a 50% three-sector Promotion with the accelerated sectors in the positions 1-3 o'clock, 5-7 o'clock and 9-11 o'clock and the reduced sectors in the positions 3-5 o'clock, 7-9 o'clock and 11-1 o'clock. So that rust-bed sectors can also be driven overlapping and alternately accelerated or reduced. Instead of the symmetrical sectoring of the rotary grate, a non-symmetrical, ie asymmetric, sectoring may also be advantageous in order to produce alternating forcing patterns with the same rotary grate positions.

Basically, one- and two-sector Forcierungen preferably be applied when a fixed grate operation is provided for fixed-bed gasifier, in which the rotary grate with several revolutions per hour, z. B. greater than 5 h ^-1 , rotates. This is the case when coals with increased ash contents of z. B.> 10 wt .-% gasified. Then the rust-bed sectors are forced in sufficiently short intervals. For fixed-bed gasifiers with slow-moving rotary grates, which are also temporarily stopped, are recommended for the reasons mentioned above multiple forcing, z. B. three, four or five sector forcing. In the fixed bed pressure gasification step grates are used due to the large diameter of the fixed bed gasifier. Usual are three-stage rotary grates. In this case, the gasification agent enters three levels, the altitude of which changes from stage to stage by about 0.3 m, into the ash bed.

The realization of the previously described cases of different loading of the rust-bed sectors with gasification requires in step grates that the rotary grate sectoring in the individual stages takes place in the same way. However, the sectoring of the rotary grate can also be carried out differently in the individual stages.

In a three-stage rotary grate, the inner, middle and outer sections are each supplied with gasifying agent through the upper, middle and lower stages, respectively. In this way it can be achieved that the bedding sectors are acted upon in different ways with gasification agent. For example, the rotary grate sectoring can be carried out in such a way that the supply of gasification agent in these regions of the filling sectors is forced or reduced in alternation.

The different rotary grate sectoring in the individual stages thus achieves a further increase in the possibilities for improving the flow in the bed of the bed.

Due to the pressure loss caused by the flow of the gasification agent through the ash bed, the back pressure at the outlet openings of the gasification agent at the rotary grate decreases from stage to stage in the direction of the upper stage. At the same internal pressure of the rotary grate thus increases the pressure drop at the outlet openings of the gasifying agent from the lowest to the highest level. Thus, the exit velocity from the outlet openings also increases from the lowest to the highest level. This exit velocity has an influence on the formation of preferably flow-through areas of the bed.

To limit the differences between the exit velocities occurring at the individual stages of the rotary grate, the pressure loss at the outlet openings of the lowest-stage gasification means should be at least equal to twice the pressure loss of the ash bed between the lowest and upper stages.

At the outlet openings of the gasification agent is usually followed by a solids-free annular space, via which an adjustment of the entry speeds takes place in the bed. This must be stopped. Therefore, according to the invention, the annular space is interrupted at intervals, the length of the interruptions being at least 30 mm and the intervals from interruption to interruption being less than 1 m, and wherein the interruptions are arranged such that between forced and reduced rotary grate sectors no adjustment of the entry speeds can be done in the bed.

The solution according to the invention can bring its advantages to even greater advantage when the sectored rotary grate is combined with a customized, sectored coal distributor.

The second part of the invention relates to the coal distributor in the form of a Einhängeschachtes. According to the invention, the cylinder sectors of the carburetor interior (sectors) bounded by the carburettor inner wall are defined by the design and arrangement of the attachment shaft with defined ratios of the gas outlet surface at the upper limit of the bed to the gas collection chamber to the surface of the associated circular sector of the bed of the bed (shaft bed sector) Area ratios, with sector area ratios differing for at least two sectors, so in accordance with sector area ratios, different amounts of raw gas are withdrawn from the manhole land sectors, the ratio of maximum to minimum sector area ratio> 1.1, and the bed area ratio as the ratio of the total gas exit area to the bed area is greater than 0.33.

The sectors look like high cake pieces. In the sectors with a higher sector-area ratio, the discharge of the raw gas to the gas collection room is favored. Thus, the reduced raw gas removal due to fine grain deposits or melt bonds in baking coals can be compensated for by an increased sector area ratio. This is called sectoral forcing of the raw gas flow.

By a proper determination of the sector-area ratios and the arrangement of the sectors and taking into account the thermal stability of the gasification material can thus be achieved that the raw gas from the bed below and within the Einhängeschachtes in normal operation sectorally forced and thus distributed evenly over the circumference of the gas collection chamber discharged into the gas collection chamber and thus a one-sided flow and formation of the reaction zones is avoided. The sector-area ratio of the accelerated sectors can be up to 100%, in special cases up to 500%, above that of the reduced sectors.

The regular operation is characterized with respect to the coal feed by the fact that at any time a sufficiently high coal bed in the fixed bed gasifier is present, which extends beyond the lower edge of the Einhängeschachtes in height. Among other things, the coal stock in the infeed shaft ensures the constant bedding height of the coal bed during operation, which is relevant for the flow. Furthermore, the hanger has either a positive, more or less gas-tight, connection to the upper carburetor inner wall, as in accordance with DE 10 2012 009 265 B4 the welded construction of a cooled shaft, or the hanger is fastened with releasable connections to the carburetor inner wall, that the width of the annular gap between the Einhängeschacht and the upper carburetor inner wall is as small as possible, preferably less than 1 cm. This ensures that the sectoral forcing of the raw gas flow, even with a small overlap of the lower edge of the Einhängeschachtes fully occurs.

In order to avoid local fluidized bed formation, a sufficiently large bed area ratio of greater than 0.33 is required, which guarantees that the empty tube velocities at entry into the gas collection chamber at less than 1 m / s below the fluidized point of the fine grain introduced with the gasification materials remain from the bed discharged secondary fine grain, which is deposited on the bed surface remain.

Fine grain deposits and smelting dressings are to be expected especially in the areas of the annular gas collecting space, which are opposite to the gas outlet. There, therefore, the higher sector-area ratios are to be realized.

According to the invention, the discharge of the raw gas into the annular gas collecting space can be further equalized by the fact that the height position of the bed to the gas collection chamber is different with respect to the direction of the gas outlet.

The removal of fine grain to the gas outlet is favored when the height of the bed decreases in the direction of gas outlet. For coals with high primary or secondary fines, it is therefore advantageous if the height of the bed to the gas outlet decreases.

For baking coal, in which the imbalances of the flow mainly caused by caking bed compaction caused by caking, conversely, just the increase in height in the direction of gas outlet provide, since the heating rate decreases with increasing altitude of the bed.

A simple embodiment according to the invention of the attachment shaft consists in the fact that the cylindrical attachment shaft is displaced towards the gas outlet along the extended symmetry axis of the gas outlet (asymmetrical suspension slot). There are according to the invention, other cross-sectional shapes of the Einhängeschachtes, such. As the oval, applicable.

To effectively prevent imbalances to the gas outlet, the

Sector area ratio of the sector opposite to the gas outlet, compared to the sector associated with the gas outlet, increased by about 10-30%, the ratio of maximum to minimum sector area ratio should always be> 1.1.

By this measure, the flow is shifted to the gas outlet opposite side of the bed. However, a near-wall preferential flow on the inner wall of the carburetor with respect to the gas outlet is excluded, since such experience does not occur on this side of the carburetor.

With this very simple measure, a substantial improvement in the uniformity of the flow in the upper region of the bed is achieved. The specific power of the carburetor can be increased, the dust discharge is simultaneously reduced and the tolerance of the carburetor operation against increased fine grain contents in the feed coal increases. In cases in which no strong particle decay occurs in the bed, the bottom grain size of the feed coal of about 5 mm can be reduced to about 3 mm, since neither a channel-like flow of the bed occurs, nor a fluidized bed is formed on the bed surface. With heavy disintegration of the gasification substance, which is determined by the type of gasification substance and the amount of specific gasifier performance, an increased amount of fine grain can counteract the homogenization of the flow conditions. For an asymmetrically horizontally offset suspension shaft with horizontally formed lower edge, the fine grain at the lowest point of the bed, ie opposite the gas outlet, collect and cover the enlarged surface of the bed against the gas outlet successively, so that the flow is no longer moved to this side and the Inventive arrangement of the Einhängeschachtes shows no effect to improve the uniformity of the flow.

According to the lower edge of the horizontally offset Einhängeschachtes in this case is tapered perform such that it drops in the direction of the gas outlet. The angle of inclination of the lower edge against the horizontal should be smaller than the slope angle of the gasification substance.

The reduction in the height of the bulk material surface in the direction of the gas outlet, which has been produced in this way, favors, as already stated, the transport of fine grain in this direction and the flow through the region lying diametrically opposite the gas outlet. For baking, less prone to disintegration hard coal according to the invention, the lower edge of the horizontally offset Einhängeschachtes bevelled perform such that it rises in the direction of gas outlet.

The formation of sectors with an increased sector-area ratio can also be achieved according to the invention by means of a hook-in shaft with a circular cross-section in that the sectors of the hook-in shaft (hang-box sectors) are conically tapered in the lower region. Thus, the interchangeable arrangement of sectors with high and low sector area ratios can be realized by a Einhängeschacht, the lower region is tapered sector by sector alternately tapered cylindrical or conical.

In the simplest geometric case, the sectors are alternately equipped with a low and a high sector area ratio. But it is also a multiple grading between high and low value possible. In order to achieve the targeted, sectoral promotion of flow areas, the high value is at least 50% to 100% above the low value. Advantageously, three, four or five forces and correspondingly three, four or five reductions are applied, wherein the sector associated with the gas outlet is preferably to be reduced. But there are also more than five forcing possible. The forced and the reduced sectors are preferably equal in terms of sector angles. An exception may be the sector associated with the gas outlet, whose sector angle may be larger and up to twice as large as that of the other sectors.

In addition to the sector-wise tapering of the suspension shaft described so far, other geometrical configurations of the suspension shaft can lead to the generation of different sector-area ratios. One of these embodiments provides for the sector-by-sector enlargement of the diameter of the suspension shaft or a different sector-wise widening of the cross section of the suspension shaft. This enlargement or widening can be provided either over the entire or a shortened height of the Einhängeschachtes, which in the case of the shortened height, this is at least so high that the surface of the bed located in the Einhängeschacht leaned from the inside at least to the lower edge of the Einhängeschachtes. Another embodiment uses the sector-wise reduction of the diameter of the Einhängeschachtes or another type of sectoral narrowing of the cross section of the Einhängeschachtes. This reduction or constriction is preferably carried out over the entire height of the Einhängeschachtes, thereby ensuring that the coal infiltrated no impact surfaces.

Finally, the promotion can be temporarily or permanently lifted by the dumping height of the coal bed is temporarily or permanently lowered below the lower edge of the Einhängeschachtes.

With the above-described embodiments of the Einhängeschachtes ensures that the flow imbalances are prevented to the gas outlet. The designs are selected and optimized according to the grain size and the decay properties of the gasification materials used. The result is a significant increase in specific carburetor performance and an extension of the grain size spectrum the gasification materials to small particle sizes achieved.

The two invention parts give the invention only in their combination the actual value. The combination consists in the coordinated, sectoral forcing and reduction of the grate filling sectors and the shaft filling sectors as well as a coordinated rotary grate method.

The simple rule is: the maximum dynamic equalization through reinforcement and reduction of the bed sectors is achieved when a symmetrical equal distribution of Forchungen and reductions of the Einhängeschacht sectors and the rotary grate sectors is made and if they are in the angular positions for the Einhängeschacht Sectors and rotating grate sectors are the same (example: a 3-Sided two-sided forcing with the positions 0-3 o'clock, 3-6 o'clock, etc.). For example, if a wider in relation to the other Einhängeschacht sectors hangman sector selected at the gas outlet, this sectoring can also be made in the same way advantageous on the rotary grate. The possible imbalance of the raw gas flow is statically suppressed, while the gas outlet remote bed sectors are maximally dynamically uniformed. The amount of forcing depends on the requirements of the dynamic homogenization according to the specific application, in particular with regard to the flowability of the bed and the ash content of the gasification materials from.

An advantageous, simple embodiment relates to the combination of non-stepped and sliding, symmetrical one-sector forcing the rotary grate and the asymmetric Einhängeschachtes.

The combination of single forcing of the rotary grate and multiple forcing the Einhängeschachtes or vice versa are advantageous. In choosing the sectoring and the amount of forcing, again, the evaluation of the flow behavior of the bed in the grate bed sectors and the manhole bed sectors is crucial.

Embodiment 1, shown in FIG 1 , Describes an advantageous solution for uniform distribution of the flow in the bed cross-section of the entire coal bed of fixed bed gasifier by means of a targeted local Forcierung the flow through both the execution of the Einhängeschachtes and the special functionalization of the rotary grate. Here, the non-stepped and sliding, symmetrical three-sector forcing of the rotary grate and the symmetrical three-sector forcing of the hanging bay are combined.

The fixed bed carburetor 1 with the pressure-bearing outer jacket 2 and an inner diameter of 3.9 m is used for the gasification of slightly baking, lumpy hard coal 3 used with a grain size of about 3 to 50 mm. The longitudinal section of the upper part of the fixed bed gasifier 1 is in 1a shown.

The coal 3 is in 1a from the above the fixed bed gasifier 1 arranged coal lock (not shown) via the feed shaft 4 in the carburetor interior 5 of the fixed bed gasifier 1 introduced. Below the feed shaft 4 is the 2 m long hanging bay 6 arranged. The top edge 7 of the hang-in 6 is with detachable connections 8th , with very small gap of a few mm (<1 cm), inconclusive with the carburetor inner wall 9 connected. The hanging bay 6 serves as a storeroom for the coal 3 so the upper limit 10 the coal bed 11 between two chattering processes not below the lower edge 12 of the hang-in 6 decreases and thus during operation a constant bed height of the bed of coal bedding 11 is guaranteed. The cylindrical hanging bay 6 (Outer diameter 3.1 m) is in the lower half 13 Sector-shaped conical tapered (to the diameter of 2.5 m) and the lower edge 12 is horizontally flat. At the height of the upper half of the Einhängeschachtes 6 is the side gas outlet 14 , The hanging bay 6 lies in the axis of symmetry 16 of the fixed bed gasifier 1 ,

1a thus shows, as well 1b and 1c , the static forcing of the flow in the top of the coal bed 11 due to the special configuration of the hanging bay 6 ,

In 1b , Section AA, the six sectors are 11-1 o'clock (11 ⁰⁰ -1 ⁰⁰ ) 1-3 o'clock (1 ⁰⁰ -3 ⁰⁰ ) 3-5 o'clock (3 ⁰⁰ -5 ⁰⁰ ), 5-7 o'clock (5 ⁰⁰ o'clock). 7 ⁰⁰ ), 7-9 o'clock (7 ⁰⁰ -9 ⁰⁰ ) and 9-11 o'clock (9 ⁰⁰ -11 ⁰⁰ ). The sectors 1-3 o'clock, 5-7 o'clock and 9-11 o'clock are by the rejuvenation of the Einhängeschachtes 6 in these areas flow-forced and the sectors 11-1 clock, 3-5 clock and 7-9 clock are flow-reduced. According to the invention are located at the gas outlet 14 at 12 o'clock position with the sector 11-1 o'clock a flow-reduced sector (hatched sector 19 ) and diametrically opposite the gas outlet 14 a flow-enforced sector (hatched sector 20 ). The sector area ratio of the flow -forced sectors is 60% higher than the sector area ratio of the flow-reduced sectors. The bed area ratio is 0.48.

The hanging bay 6 with sectoral, conical taper is in 1c illustrated in non-scale spatial representation.

As a second part of the invention is in 1d the energized forcing of the flow in the lower part of the bed in the fixed-bed gasifier 1 by means of a specially functionalized rotary grate 15 shown, with Forcierungen and reductions of the flow in the lower part of the bed with Forcierungen and reductions in the flow in the upper part of the bed through the configuration of the Einhängeschachtes 6 are coordinated. In 1d is in highly simplified form the top view of the lower part of the fixed bed gasifier 1 with the outer jacket 2 and the rotary grate 15 shown. The rotary grate 15 is through the outer edge 21 located. The six grate filling sectors 11-1 o'clock, 1-3 o'clock, 3-5 o'clock, 5-7 o'clock, 7-9 o'clock and 9-11 o'clock are drawn. The gas outlet 14 (not shown) is in the 12 o'clock position.

The rotary grate 15 is equipped with a 30% three sector forcing, with in 1d the flow-reinforced grate filling sectors are at 1-3 o'clock, 5-7 o'clock and 9-11 o'clock and the flow-reduced grate filling sectors are assigned to the positions 11-1 o'clock, 3-5 o'clock and 7-9 o'clock. According to the invention is in the position of the gas outlet 14 at 12 o'clock with the sector 11-1 o'clock a flow-reduced rust-dumping sector 22 (hatched) and diametrically to a flow-reinforced rust-filling sector, by the rotary grate sector 23 (hatched) is acted upon with gasification agent.

The rotary grate 15 is rotated evenly at 10 revolutions per hour, ie 1 revolution per 6 minutes. Due to the flow forcing a preferred flow is enforced in the respectively forced grate-bed sectors. In combination with the coordinated three-fold forcing of the hanging bay 6 , In the present example, a symmetrical uniform distribution of Forcierungen and reductions of the Einhängeschachtes 6 as well as the rotary grate 15 and in this case the angular positions for the shaft filling sectors and for the grate filling sectors coincide, a maximum dynamic homogenization of the flow is achieved by the reinforcement and reduction of the flow in the individual bed sectors. As a result, a uniform flow through the entire bed of fixed bed gasifier 1 reached.

Embodiment 2 shown in FIG 2 describes a simple advantageous solution for preventing imbalances of the gas flow to the gas outlet 14 in fixed bed gasifier 1 by means of a targeted local Forcierung the flow through both the execution of the Einhängeschachtes 6 as well as the special functionalization of the rotary grate 15 , This is the non-stepped and sliding, symmetrical one-sector forcing the rotary grate 15 and asymmetric one-sector forcing of the hang-in 6 combined.

The fixed bed carburetor 1 in 2a with the pressure-bearing outer jacket 2 and an inner diameter of 3.9 m is used for the gasification of lumpy hard coal 3 used with a grain size of about 3 to 50 mm. The longitudinal section of the upper part of the fixed bed gasifier 1 is in 2a shown and shows, as well 2 B , the static forcing of the flow in the upper part of the bed due to the special configuration of the hanging bay 6 ,

The coal 3 is in 2a from the above the fixed bed gasifier 1 arranged coal lock (not shown) via the feed shaft 4 in the carburetor interior 5 of the fixed bed gasifier 1 introduced. Below the feed shaft 4 is a 2 m long hanging bay 6 arranged. The top edge 7 of the hang-in 6 is with detachable connections 8th not form-fitting with the carburetor inner wall 9 connected. Which is between the hanging bay 6 and the upper carburetor inner wall 9 forming gap is less than 1 cm. The hanging bay 6 serves as a storeroom for the coal 3 so the upper limit 10 the coal bed 11 between two chattering processes not below the lower edge 12 of the hang-in 6 decreases and thus during operation a constant bed height of the bed of coal bedding 11 is guaranteed. The cylindrical hanging bay 6 (Outer diameter 3.1 m) is in the lower half 13 uniform conical tapered (to the diameter of 2.5 m) and the lower edge 12 horizontally flat. At the height of the upper half of the Einhängeschachtes 6 is the side gas outlet 14 ,

According to the invention is the Einhängeschacht 6 from the symmetry axis 16 of the fixed bed gasifier 1 to the gas outlet 14 along the extended axis of symmetry 17 the gas outlet 14 shifted by 0.2 m so that the axis of symmetry 18 of the hang-in 6 by 0.2 m from the axis of symmetry 16 of the fixed bed gasifier 1 differs.

In 2 B , Section AA, is the simple sectoring of the hanging bay 6 shown. The flow-reduced sector 19 (hatched) in the position 10: 30-1: 30 clock is according to the invention at the gas outlet 14 (12 o'clock position) and the flow-forced sector 20 in the position 1: 30-10: 30 clock opposite the gas outlet 14 ,

The sector area ratio of the flow-forced sector is 1: 30-10: 30 o'clock 95% higher than the sector area ratio of the flow-reduced sector at 10: 30-1: 30 o'clock. The bed area ratio is 0.53.

As a second part of the invention is in 2c the energized forcing of the flow in the lower part of the bed in the fixed-bed gasifier 1 by means of a specially functionalized rotary grate 15 shown, with Forcierungen and reductions of the flow in the lower part of the bed with Forcierungen and reductions in the flow in the upper part of the bed through the configuration of the Einhängeschachtes 6 are coordinated. In 2c is in highly simplified form the top view of the lower part of the fixed bed gasifier 1 with the outer jacket 2 and the rotary grate 15 shown. The rotary grate 15 is through the outer edge 21 located.

The rotary grate 15 is equipped with a 40% one-sector forcing in the position 5-7 o'clock, whereby in 2c the gas outlet 14 Nearly reduced area of the rust-dumping sector 22 (hatched) according to the invention straight in position 11-1 clock and the forced rotary grate sector 23 (hatched) is currently in position 1-11 o'clock. The gas outlet 14 (not shown) is in the 12 o'clock position.

The rotary grate 15 is rotated evenly at 10 revolutions per hour, ie 1 revolution per 6 minutes. Due to the flow forcing a preferential flow is enforced in the respective forced grate filling sector, which is the preferential flow occurring in the absence of forcing gas outlet 14 stopped for 5/6 of the time.

In combination with the coordinated single forcing of the hanging bay 6 For example, maximum dynamic equalization of the flow through the reinforcement and reduction of the flow in the individual bed sectors is achieved. The possible imbalance of the raw gas flow is statically suppressed, while the gas outlet remote bed sectors are maximally dynamically uniformed. As a result, a uniform flow through the bed of fixed bed gasifier 1 reached.

LIST OF REFERENCE NUMBERS

1

Fixed bed gasifier

2

Outer jacket of the fixed bed gasifier 1

3

hard coal

4

insertion slot

5

Carburetor interior

6

Einhängeschacht

7

Top edge of the hanging bay 6

8th

Detachable connections

9

Gasifier inner wall

10

Upper limit of coal bedload 11

11

coal charge

12

Lower edge of the hanging bay 6

13

Lower half of the hang-in 6

14

gas outlet

15

rotary grate

16

Symmetry axis of the fixed bed gasifier 1

17

Symmetry axis of the gas outlet 14

18

Symmetry axis of the hanging bay 6

19

Sector near the gas outlet 14

20

Sector opposite the gas outlet 14

21

Outer edge of the rotary grate 15

22

Rust-dumping sector near the gas outlet 14

23

Rotary grate sector opposite the gas outlet 14

Quoted non-patent literature

• Bunt, J. R .; Sasol-Lurgi MK IV fixed-bed gasifier. 2006: A new dissection methodology and investigation into coal property transformation. PhD Thesis. North West University, Potchefstroom
• Bunt, J. R .; Waanders, F. B .; 2008: Trace element behavior in the Sasol-Lurgi MK IV FBDB gasifier. Part 1 - The volatile elements: Hg, As, Se, Cd and Pb. In: Fuel 87 (12), pp. 2374-2387
• Glover, G .; van der Walt, T.J .; Glasser, D .; Prinsloo, N.M .; Hildebrandt, D .; 1995: DRIFT spectroscopy and optical reflectance of heat-treated coal from a quenched gasifier. Fuel 78 (8), pp. 1216-1219

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 112005002983 [0004, 0016]
• DD 141246 [0005]
• DD 260192 [0006]
• DD 38791 [0009]
• DD 136505 [0009]
• DD 120043 [0009]
• DD 121796 [0009]
• DD 138221 [0009]
• DD 26392 [0009]
• DD 148641 [0010]
• DD 148642 [0010]
• DD 145403 [0011]
• DD 152805 [0011]
• DD 280776 [0011]
• DD 280777 [0011]
• DD 280778 [0011]
• DD 280779 [0011]
• DD 150906 [0012]
• DD 218774 [0012]
• DE 2005002983 [0015]
• DE 102012009265 B4 [0016, 0042]

Cited non-patent literature

• Bunt, Waanders 2008; Glover et al. 1995 [0013]

Claims (11)

Method for fixed-bed pressure gasification for static and dynamic equalization of the flow and increase of the specific carburetor performance when using a continuously or non-continuously rotating rotary grate ( 15 ), which is both non-reversible or reversible operable, and a static coal distribution in the form of a Einhängeschachtes ( 6 ), characterized in that the gasification agent of different circular sectors of the rotary grate ( 15 ) (Rotary grate sectors) with different sector loads (forced or reduced) are fed into the rotary grate-close circular sectors of bed bed (grate bed sectors) or areas of these sectors, the sector load of forced grate sectors being 20 to 100% higher than the sector load of the reduced rotary grate sectors, and that the residence time of the rotary grate sectors in the area of the grate filling sectors is kept the same or varied, that the cylinder sectors of the through the carburetor inner wall ( 9 ) limited carburetor interior ( 5 ) (Sectors) by the design and arrangement of the Einhängeschachtes ( 6 ) with defined ratios of the gas outlet area at the upper limit of the bed to the gas collecting space to the surface of the associated, the Einhängeschacht ( 6 ), and that the sector area ratios differ from one another in at least two sectors, the ratio of maximum to minimum sector area ratio> 1.1 and the Bed area ratio as the ratio of the total gas outlet area to the bed cross-sectional area is greater than 0.33, and that by the rotary grate ( 15 ) produced dynamic forcing or reducing the loading of rust-bed sectors with gasification agent with the through the hanger ( 6 ) is tuned by the formation of different sector-area ratios, static forcing or reducing the flow in the shaft-bed sectors. A method according to claim 1, characterized in that in turn rotary grate sectors are arranged with high and low sector loads, wherein the sector loads are executed at the high or low level uniform or stepped. A method according to claim 1, characterized in that the sector area ratio in the direction of the sector below the gas outlet ( 14 ) decreases. A method according to claim 1, characterized in that sectors with high and low sector area ratios with respect to the gas outlet ( 14 ) are each alternately arranged so that below the gas outlet ( 14 ) is a sector of low sector area ratio and diametrically a sector of high sector area ratio. A method according to claim 1, characterized in that the height position of the bulk material surface to the gas collecting space in the individual sectors is different. Device for carrying out the method according to claims 1 and 2, characterized in that the rotary grate sectors of the rotary grate ( 15 ) are separated from one another by the fact that the solids-free annular space adjoining the gasification agent outlet openings is interrupted at intervals, the length of the interruptions being at least 30 mm and the intervals from interruption to interruption being less than 1 m, and the interruptions are arranged in this way are that between forced and reduced rotary grate sectors can not be made equalization of entry speeds in the bed. Apparatus according to claim 6, characterized in that a forcing or reducing the sector load of the rotary grate sectors is achieved by the quotient of the cross-sectional area of the Vergasungsmittelaustrittsöffnungen the rotary grate ( 15 ) to the cross-sectional area of the rotary grate sector (specific outlet area) is increased or decreased. Device for carrying out the method according to claims 1 and 3, characterized in that the hanging shaft ( 6 ) is designed with a circular cross-section and that this Einhängeschacht ( 6 ) along the extended axis of symmetry ( 16 ) of the gas outlet ( 14 ) horizontally in the direction of the gas outlet ( 14 ) is shifted. Device for carrying out the method according to claims 1 and 4, characterized in that the hanging shaft ( 6 ) is designed with a circular cross-section in the lower region sectorally alternating cylindrical or conically tapered, wherein below the gas outlet ( 14 ) a sector without rejuvenation and diametrically a sector with rejuvenation. Device for carrying out the method according to claims 1 and 4, characterized in that the hanging shaft ( 6 ) with a circular cross section sector by sector different diameters is carried out, wherein below the gas outlet ( 14 ) is a sector of comparatively larger diameter. Device for carrying out the method according to claims 1 and 5, characterized in that the lower edge ( 12 ) of the hanging bay ( 6 ) with respect to the direction of the gas outlet ( 14 ) is inclined to the horizontal.

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