DK150704B - PROCEDURES FOR THE SEPARATION OF GASFUL, DAMAGING SUBSTANCES, SAASO HYDROGEN CHLORIDE, HYDROGEN FLUORIDE AND SULFUR OXYDE, OF EXHAUST GAS, NAMELY FROM WASTE COMBUSTION PLANT AND SEPARATE SEPARATING PLANT - Google Patents

Description

The invention relates to a plant for the separation of harmful substances in gaseous form, such as hydrogen chloride, hydrogen fluoride and sulfur oxide, from combustion gases and as stated in the preamble of claim 1.

10 Installations for the separation of harmful substances in gaseous form from combustion gases of this kind are known from DE Publication No. 2,615,828. In this plant, the additives are administered substantially in horizontal sections of the pipe cascades in the flue gas stream, whereby each of these horizontal sections is connected in series with a substantially vertically arranged separator.

The additives collected in the separator are then returned - in the direction of the gas flow - into the subsequent pipe cascade. In all cases, the administration of the additives is effected in the substantially horizontal section of the pipe cascade from below, and namely by means of transport apparatus and associated intermediate containers arranged between the individual separators and the pipe cascades provided. The administration of the additives in the individual horizontal cascades of the individual pipe cascades is thereby each time - seen in the direction of the gas flow - from a venturi stretch, in order to achieve an intense swirling movement between the additives and the gas flow, thus effecting a faster reaction between the harmful substances and the additives.

However, this known plant for the separation of harmful substances in gaseous form from combustion gases has various disadvantages. On the one hand, it only works with an indirect countercurrent effect between the gases and the additives, the latter being practically administered in the horizontal sections of the pipe cascades in the direction of the gas flow. Therefore, it is necessary to equip each tube cascade of substantially horizontal sections with a venturi stretch to ensure the necessary intensive mixing between the gas stream and the additives.

10 Aside from the fact that the construction costs for the individual pipe cascades are increased due to the necessary venturi stretches, it is a disadvantage that undesirable deposits of additives in the horizontal flow sections, namely behind the venturi stretches 15 of the venturi stretches, cannot be avoided with certainty.

It is an object of the invention to provide a plant for the separation of harmful substances in gaseous form from combustion gases of the specified kind, which can be built up with 20 less construction costs, and which additionally safely prevents deposits of additives in the pipe cascades and which finally ensures easy insertion -the addition of the additives in the flue gas stream according to the true countercurrent principle.

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This is achieved according to the invention by designing the plant as set forth in the characterizing part of claim 1. The incorporation of the additives into the vertical sections of the pipe cascades according to the true countercurrent principle, on the one hand, has the advantage that the additive is mixed intensively with the gas flow, even without the presence of venturi stretches, thereby ensuring a rapid and intense reaction.

On the other hand, it is also ensured that the additives not teared by the gas stream are immediately directed downward to the pre-engaged cyclone, from which they then safely reach into the vertical section provided by the cyclone dosing tube for the further upstream countercurrent. rørkaskade.

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By designing the system according to the invention as set forth in the characterizing part of claim 2, it is achieved that the whole system only needs a single transport system for the return transport of the additives, while all the apparatus parts 10 which serve the dosing of the additives can be designed relatively simply.

If the system according to the invention is designed as claimed in the characterizing part of claim 3, it is possible to optionally add fresh additives, already enriched additives or a mixture of fresh and enriched additives, to the vertical section of the last pipe cascade.

If the system according to the invention is designed as further specified in the characterizing part of claim 4, it is possible to remove used additives from the duty cycle as desired and need.

According to an embodiment as claimed in the characterizing part of claim 5, the metering locks can be designed as 25 cell wheel locks or double pendulum valves.

The construction of the separation plant according to the invention is further simplified if it is designed as indicated in the characterizing part of claim 6.

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The invention is then explained in more detail with reference to the drawing, which shows in schematic representation the principle structure of a plant for the separation of gaseous, harmful substances from flue gases.

The separator system has several, at least three pipe cascades 1, 2 ... 3 which are in flow communication with each other by means of interposed cyclone separators 4 ... 5 forming cyclones, while an upper pipe cascade, in the exemplary embodiment with the cascade 3, culminates in a clean separation cyclone.

The lower pipe cascade 1 communicates with a flue gas line 7, while a suction pull 8 is connected 10 to a diving pipe 9 in the separator cyclone 6.

Each of the pipe cascades 1, 2 ... 3 has a substantially vertical flow section 1 ', 2', 3 ', to which joins a pipe curvature 1 ", 2", 3 ", which again leads to a raw gas inlet 4. ', 5', 6 'in the cyclone separator 4, 5, 6.

While the lower end of the upright flow section 1 'of the pipe cascade 1 is connected 20 immediately to the flue gas line 7, the flow sections 2' and 3 'of the other pipe cascades 2 ... 3 are each connected to the diving pipe 10 and 11 respectively. the front cyclone separator 4 ... 5.

Conveniently, the separator system is constructed such that the upwardly flowing through sections 1 ', 3 · of odd cascades 1 and 3 are associated with the cyclone separators 5 arranged after the pipe cascades 2 having an odd number, while the upwardly extending throughflows 2' the even-numbered pipe cascades 2 belong to the separators 4 and 6 disposed after the odd-numbered cascades 1 and 3 in a vertical axis flight position.

The outlet 4 "from the cyclone separator 4 communicates at its lower end with a lock 12, for example a cell wheel lock or a double pendulum flap, after which a compressed air conveyor 13 is arranged.

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The outlet 5 "from the cyclone separator 5 is connected at its lower end to a lock 14, which may also be formed by a cell wheel lock or a double pendulum flap. To this lock 14 is joined below a dosing tube 15 which is vertically inserted into the tube cascade 1 and is disposed coaxially with its upward flow passage 1 ', the lower end of the metering tube 15 having a certain distance from the lower end of the upward flow passage 15'.

Also the outlet 6 "from the cyclone separator 6 is connected at its lower end to a lock 16, which may again be a cell wheel lock or a double pendulum flap 20 and cooperates with a metering tube 17 which is inserted vertically into the tube cascade 2. The metering tube 17 also extends coaxially with the upward flow passage 2 'in the pipe cascade and projecting down to a location some distance from the lower end of the diving tube 10.

Coaxially with the upward flow passage 3 'in the tube cascade 3, a metering tube 18 is provided, the lower end of which is a certain distance from the lower end of the diving tube 11 in the cyclone separator 5.

From above, there is joined to the dosing tube 18 a fork tube 19, whose branch pieces 19 'are connected to a dosing sluice 20 and whose branch piece 19 "is connected to a dosing sluice 21. These two dosing locks 20 and 21 may also be designed. such as cell wheel locks or double pendulum valves.

The metering lock 20 communicates with an outlet funnel from a storage container 22, in which e.g. is filled with freshly burnt lime (CaO) or calcium carbonate (CaCO3).

The cell wheel lock 21, on the other hand, is connected to an outlet funnel 23 from a storage container 24 having an additional outlet funnel 25. Both outlet funnels 23 and 25 thus belong to the storage container 24 so that each can only be supplied with goods from a partial cross-section 15 in the storage container 24. A discharge pipe 26 is connected to the outlet hopper 25 which can be opened and closed by means of a slider 27 of choice. Instead of the slider 27, a free outlet or one can also be found. dosage sluice.

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The storage container 24 is connected via a pipeline 25 to the compressed air conveyor 13.

By means of the suction draft 8, the flue gas flowing into the flue gas pipe is forced at a certain flow rate, which the flue gas maintains on its way through the pipe boilers 1, 2 ... 3 and the cyclone separators 4, 5 ... 6.

30 Countercurrent with the direction of movement of the flue gas, through each of the dosing tubes 15, 17, 18, burnt lime or calcium carbonate is introduced into the pipe cascades by means of the individual dosing locks 20 and / or 21 so that the imported goods distribute 7 as evenly as possible in the flue gas stream. Thereby the flue gas reacts with the additives in the way that e.g. the chlorine contained therein settles on the additives and becomes bound by these.

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The dosing locks 20 and / or 21 are adjusted so that the additives in the flue gas reach a concentration of between 100 and 500 g / m 2 and thus exist in a stoichiometric ratio of 40 to 200.

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The reaction of the flue gases with the additives takes place partly in the individual pipe cascades 1, 2 ... 3 and partly also in the post-deposited cyclone separators 4 and 5, i.e. the cyclone separators 4 and 5 form so-called working cyclones or reactors.

The last cyclone separator 6 located in the direction of flow of the flue gases has the main task of separating the additives contained in the flue gases so that as soon as the flue gases leave the last pipe cascade 3.

From the considerations above, it will be apparent that the additives (burnt lime and / or calcium carbonate) are technically introduced at several cascade successive locations, namely in the pipe cascades 1, 2 ... 3 in the substantially upwardly directed section 1 ', 2 ^ .. 31 in the flue gas stream. Subsequently, these additives are then behind the substantially horizontal flow paths 1 ", 2" ... 3 "at vortex formation in the cyclone separators 4, 5 ... 6 again separated by the flue gas stream. The separated additives are thereby removed through the outlets 4 ", 5" ... 6 ". While the additives removed from the flue gas by the cyclone separator 150704 δ 1 4 after the first pipe cascade 1, over the lock 12 and the compressed air conveyor 13 reach the storage container 24, the additives removed after the pipe cascade 2 by the cyclone separator 5, over the lock 14 and the dosing tube 15 are again fed into the leading pipe cascade 1.

In the last tube cascade 3, fresh additives of the storage container 22 are introduced over the dosing sluice 20 and the dosing tube 18, and at the same time additives, which have already been enriched in a certain subset, can also enter the tube cascade 3 through the dosing sluice 24 and the dosing tube 18.

The rear cascade 3 in the cyclone separator 6 for flue gas separated additives is once again introduced into the leading pipe cascade over the dosing sluice 16 and the dosing tube 17 in the illustrated embodiment of the pipe cascade 2.

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To a certain extent, in countercurrent to the flue gas movement, the dosing of the additives takes place in stationary operation of the separator system, that the additives have the highest enrichment rate, where also the 25 flue gases have the highest content of harmful substances, while the enrichment rate of the additives, seen in the direction of flow of the flue gas. , are correspondingly lower and their reactivity is therefore inversely proportional to the content of harmful substances in the flue gases.

By the multiple insertion of the additives at a greater number of locations in the flue gas stream, the reaction and bonding ability of the additives is optimally utilized in a simple manner until it is practically depleted, after which the additives can be removed from the storage container 24 through the exhaust pipe 26.

5 The cascade-like structure of the separator system makes it easy to adapt this system to different needs in practice, simply by varying the number of pipe cascades and cyclone separators inserted in the flow direction for the flue gases one after the other. .

Finally, it is still to be noted that the design of the locks as cell wheel locks or double pendulum flaps is also advantageous in that they can prevent false flow paths for the flue gases.

Claims (2)

150704 1. Plants for the separation of harmful substances in gaseous form, such as hydrogen chloride, hydrogen fluoride and sulfur oxide, from combustion gases, in particular from waste incineration plants, by reaction with dust additives such as burnt lime (CaO) or calcium carbonate (CaCC> 3) and bonding thereto, consisting of several in the flow direction of the flue gases one after the other, series connected flow lines with pipe cascades (1, 2 ... 3) connected by means of interposed cyclone separators (4 ... 5), and by dosing tubes (15, 17 ... 18) for additives arranged in the flow cascades of the pipe cascades, whereby the dosing pipe 15 (18) projecting into the last pipe cascade is provided with a supply line (19) for fresh additives, while the other dosing tubes each connected to the subsequent cyclone separator of the subsequent pipe cascade, viewed in the direction of the gas flow, characterized in that the metering pipe (15, 17 ... 18) is arranged in the vertical sections of the pipe cascades (1, 2 ... 3) it (1 *, 2'- ... 3 ') and is connected to the outlet (5 ", 6") of the cyclone separator (5, ... 6) which is coupled to the second highest pipe cascade (2, .. .3) and that the pipe cascades (1, 3) of odd numbers in the vertical shaft escape position are arranged for the cyclone separators (5) of the pipe cascades (2) of equal number and that the pipe cascades (2) of equal number in the vertical shaft flight position are provided to the cyclone separators (4, 6) of the pipe cascades (1, 3) 30 of odd numbers. 1 PATENT REQUIREMENT Discharge system according to claim 1, characterized in that the outlet (4 ") of the cyclone separator (4) which is coupled to the first pipe cascade (1),