DE2736493A1 - Powdered coal burning arrangement - uses pyrolyser bed with spout followed by fluidised char burner and cyclone separators connected to gas burner - Google Patents

Abstract

The coal burning arrangement comprises, in combination a spouted bed pyrolyzer, a fluidized bed combustor, a first cyclone, a second cyclone, and an afterburner. The pyrolyzer is connected to accept pulverized coal and to discharge char to the combustor and gaseous materials with entrained particulate material to the first cyclone. The first cyclone is connected to deliver gases to the afterburner. The combustor is connected to accept also a combustion supporting gas and to deliver to the second cyclone gaseous materials with entrained particulate material. The second cyclone is connected to deliver gaseous material to the afterburner.

Description

Method and device for burning coal

The invention relates to a method for burning coal and a device for performing this method. It is about especially coal dust.

The benefits of coal as an energy source need to be historical Time not to be specified. But coal also has its disadvantages had: initial handling, handling of combustion residues, corrosion on the facilities and air pollution.

In recent years, fluidized bed incinerators have become developed which solve most of these problems.

Cyclones can be used in fluidized beds because of the Coarse ash agglomeration, as in U.S. Patents 3,431,892 and 3 171 269 shown. The emission of harmful trace elements (e.g. beryllium, Cadmium and mercury) are in fluidized beds due to their much lower working temperature lowered to a minimum.

However, the low outlet temperatures of conventional fluidized bed outlet gases cannot be used to generate heat for high temperature furnaces. Such low temperatures also cause excessive flue gas losses if conventional Fluid bed incinerators on existing boilers and space heating furnaces be connected. The present invention overcomes these disadvantages Creation of a system with high outlet temperatures, which nevertheless allows that the animal charcoal incinerator operated at low temperatures can be. A known device, which also generates outlet temperatures, which are noticeably higher than the animal charcoal burner temperature is in the US patent 3 358 624. This device uses a pyrolysis device for Separate the charcoal into animal charcoal and volatiles, a burner for that Animal charcoal, cooled by excess air, but only around the ashes in the melted State so that it is more likely to deposit on the walls than slag than to be vaporized, as well as a second burner for the volatiles and the combustion products and the excess air of the first burner, whereby a high outlet temperature results.

Numerous pyrolysis devices have long been designed to be volatile Separate constituents from the coal. There is a need for a pyrolysis device which can handle caked coals without fouling. The through the U.S. Bureau of Mines (Bureau of Mines Report of Investigation 7843, 1973) perfected construction is for the needs of the present invention particularly suitable.

This design has been modified to incorporate solid particles into one Pulling out the standpipe, rather than by gas entrainment from the top, reducing the particle abrasion is decreased. This modification is in the "Spouted Beds" reference by US Pat Kishan B. Mathur, Norman Epstein, Academic Press, New York, 1974.

The present invention is based on the object of a simple and to provide effective method and apparatus for burning coal, which do not have the disadvantages of the known devices.

According to the invention, this object is achieved in each case by the characteristic features of claims 1, 2, 9 and 16 solved. Further features of the invention result from the other claims.

A method according to the invention is thus characterized by thermal Decomposition of coal dust into animal charcoal and volatile components, separation of animal charcoal of the volatile constituents, burning the animal charcoal in heat transfer relationship with a stoichiometric excess of air, thereby forming ash and a mixture of gases, the excess air being chosen such that a temperature in the ash is generated, which is below the melting temperature of this, separating the mixture of gases from the ashes and subsequent burning of the volatile components in the mixture of gases.

An apparatus according to the invention is characterized by the following Combined features: a whirlpool fluidized bed pyrolysis device, a fluidized bed incinerator, a first cyclone, a second cyclone and an afterburner, wherein the pyrolysis device is connected in such a way that it receives coal dust and animal coal to the incinerator and releases gaseous substances with entrained solid particles to the first cyclone, the first cyclone is connected in such a way that it emits gases to the afterburner, the incinerator is connected in such a way that it also has gases to support it the combustion takes up and gaseous substances with entrained at the second cyclone Releases solid particles, and the second cyclone is connected in such a way that it releases gaseous substances to the afterburner.

In accordance with preferred embodiments, the invention is further characterized by bringing the stoichiometric excess air into contact with the animal charcoal during thermal decomposition, provision of specific characteristics in the pyrolysis device, Performing the solid-gas separation processes in cyclones, burning the animal charcoal in a high-speed fluidized bed incinerator recirculating solid particles, Providing specific characteristics in the combustion device, generating of heat in the pyrolysis device by burning part of the combustible In this, vary the melting temperature by adding one to the temperature changing material, adding a diluent gas to the volatile components before burning it, adding water to the pyrolysis device, adding an absorbent in the pyrolysis device and adding oil in the afterburner.

The invention enables coal to be burned at a high Efficiency and with very much reduced corrosion and air pollution. Problems in the handling of the products are reduced to a minimum, the inventive Procedure is simple and can be automated. The invention is adaptable to the widest range of installation sizes. Either wet or dry broken Coal with or without additives can be burned. The burn is calm and evenly and takes place at a tightly controllable combustion temperature.

Flemish temperatures close to the stoichiometric are with a low Excess air achieved. Even fine fly ash becomes large along with sulfur Effectiveness removed, and it yields get a minimal education of trace elements and NO compounds. Corrosion of the facilities is on reduced to a minimum. It can be connected to existing facilities. Overall, the invention promises to be the cheapest method of using coal in an environmentally friendly way with connected high temperature furnaces and boilers to be compared to other fuels.

The invention is illustrated schematically below with reference to one in the drawing illustrated embodiment explained in more detail.

1 shows a schematic flow diagram for illustration a preferred embodiment of the invention, Fig. 2 is a table to show the temperatures and flow rates at different points in this embodiment, Fig. 3 shows in vertical section a preferred embodiment of one used therein Pyrolysis device, FIG. 4 shows a vertical section of a preferred embodiment a fluidized bed incinerator for use therein, Fig. 5 is a partial section 5-5 of Fig. 4, Fig. 6 is a vertical section of the preferred afterburner for use therein, Figure 7 is a vertical section of the preferred preheaters for use therein and FIG. 8 is a schematic perspective illustration of the preferred embodiment the invention.

Referring to Fig. 1, there is a schematic flow diagram for illustrative purposes a combination of elements for burning coal according to the present invention Invention shown.

In this preferred embodiment, bituminous Illinois coal is used Grade B with a high proportion of volatile components, 3.0 sulfur content, 10.5% ash content and a calorific value of 6278.9896 kcal / kg burned. The coal is dried and crushed to pass through an 8 mesh screen in the mine.

Dry calcium carbonate crushed to 8 mesh is made with the coal just above the coal-calcium carbonate feed line 10 (Fig. 1) mixed (not shown) by dropping the two components of their separate screw conveyors into a venturi device for transport air (not shown), with the two venturis in a common zone empty. From this downstream, but just upstream of the feed line 10, bleed air is introduced. (The compressor for the transport air has a capacity of 2.81229 kp / cm2 and carries the transport air for each of the following purposes to. The blower for the air to be tapped has a capacity of 0.140614 kp / cm2.) Coal, Calcium carbonate, transport air and bleed air enter the pyrolysis device 12 through line 10.

The gaseous products move through a refractory material lined line 13 in an animal charcoal cyclone 16, which swept away Solid particles removed. The purified gases are then passed through a refractory Material lined conduit 18 introduced into an afterburner 20.

Most of the animal charcoal produced in the pyrolysis device 12 enters an inlet conduit 24 through standpipe 22.

The animal charcoal emerging from the cyclone 16 through a line 26 also enters line 24. (One venturi device in each of the lines 22 and 26, which interact with the transport air from the transport air compressor, are merged in a Y, the only outlet of which is the pipe 24 is. The venturi devices and compressors are not shown in the drawing.) Line 24 empties into a rapid fluidized bed incinerator 28, which serves as a preferred animal charcoal burner. Combustion air passing through a pipe 30 is blown by a compressor 32, this also exits into the rapid fluidized bed incinerator 28 (transfer line reactor with solids recirculation).

All combustion products, nitrogen and the remaining oxygen flow into a pipe 34 provided with a refractory lining Ash cyclone 36, in which most of the ash (with used calcium carbonate) is removed by a line 42. Most of the residue (ash and spent limestone) leaving the fluidized bed incinerator 28, exits through a standpipe 40. The residue emerging through the standpipe 40 is with the residue, which leaves the ash cyclone 36 through line 42, mixed with each of lines 40 and 42 being a venturi (not shown) have, which interact with transport air, and wherein the mixed residue emerges from a line 44. Hot gases leave the ash cyclone 36 through a line 46 insulated with refractory lining and mix and burn with gases from line 18 in afterburner 20. The hot products of combustion exit afterburner 20 and enter a furnace (not shown).

The preferred embodiment described above produces a Energy of 39666790 kcal / h. The incoming flow rates are 421.93393 kg / h Coal transport air, 626.09551 kg / h bleed air and 4087.7685 kg / h combustion air (130% of the stoichiometric amount). The lines are designed as follows: management No. Standard pipe size / I.D. Non-standard (mm) 10 50.8 (standard) 14 254.0 (I.D. Non-standard) 18 152.4 (I.D. non-standard) 22 50.8 (I.D. non-standard) 24 25.4 (I.D. non-standard) 26 50.8 (I.D. non-standard) 30 203.2 (I.D. non-standard) 34 558.8 (I.D. non-standard) 40 50.8 (I.D. non-standard) 42 50.8 (I.D. non-standard) 44 19.05 (I.D. non-standard) 46 304.8 (I.D. non-standard) Only enough air is in the pyrolysis device 12 is provided to bring its temperature to 871.110C, ie below of the melting point of the ashes of the special charcoal used.

The temperature in the upper zone of the fluidized bed incinerator 28 is held at 848.89 ° C (in the pyrolysis device 12 as well as in the rapid fluidized bed incinerator 28 the temperature is maintained by a sensor, which with a device to regulate the air flow to the relevant system unit). if the temperature in the pyrolysis device 12 drops excessively, become less volatile Constituents created, resulting in more intense combustion in the fluidized bed incinerator 28 means with the consequent increased necessary excess air in this and thus a lower overall temperature at the afterburner 20. Furthermore, a excessively lower temperature in the pyrolysis device results in less precipitation of fuel-nitrogen compounds, from which it can be seen what on the other hand one of the advantages of the present invention is that it burns coal with little generation of NOx compounds. On the other hand, surrendered excessively high temperatures in the pyrolysis device and the fluidized bed incinerator one unwanted slagging and structural problems. An excessively high temperature in the fluidized bed incinerator also causes excessive limestone consumption. Excessively low temperatures in the fluidized bed combustor causes excessive Limestone consumption and also a larger excess air requirement and thus undesirable lower afterburner temperature. Flow rate values and transport air quantities are specified in detail in the table according to FIG.

When starting up, when a thermostat moves to call for heat, turn on the pneumatic air transport compressor and the air blower. Of the Compressor cleans the lines during preheating, while the fan cleans air blows through the preheater. Three preheaters (not shown), one each for the pyrolysis device 12, the animal coal cyclone 16 and the fluidized bed combustor 28, are then switched on (if not a thermal sensor worn by each of them in one or more of them to sense that the element in question is still from a previous run is hot. Each preheater switches off when it does heated area the specified temperature (minimum operating temperature) of 648.89 ° C achieved. The outlet temperatures from the preheaters are 704.44 ° C in the pyrolysis device and the fluidized bed incinerator into and 982.22 ° C into the animal charcoal cyclone into it. When the individual elements are at the desired temperature, the supply of coal and limestone begins.

Fan air is then sent from the preheaters to the pyrolysis device and returned to the fluidized bed incinerator.

Forced air at room temperature is also used (not shown) in FIG the line 18 inserted, just downstream of the animal carbon cyclone 16, and with volatile constituents (not shown) at the inlet of the line 18 in order to remove them to heat. (This prevents unwanted condensation as well as unwanted one Soot buildup in the line 18.) If the downstream end of the line 18 reaches its minimum operating temperature of 537.780C as indicated by a thermocouple is displayed, the air supply to line 18 is switched off.

The lines 24 and 44 are water-cooled.

When the system is switched off, the compressor runs for a short time Time to make sure the lines are empty.

Many modifications within the scope of the invention can be made by those skilled in the art be made. Thus, for example, the animal charcoal burner can be a slow fluidized bed incinerator or a gas turbine (dilute phase) incinerator. If coal low sulfur content may be used, for example, an incinerator with a single zone at ash agglomeration temperatures (from 1037.78 0C to 1204,440C), causing agglomeration and effective removal of fly ash by means of a cyclone. A fine particle separator can be added to the plant downstream of the ash cyclone and upstream of the afterburner (a sand bed filter) or downstream of the furnace or boiler (various Low temperature filter). A desulfurization chamber can also be added as a separate piece of equipment, downstream of the agglomerating incinerator, upstream of the charcoal cyclone.

Pyrolysis can be achieved by recirculating some hot products rather than directly from a portion of the coal as in the preferred one Embodiment. Any charcoal of grade hvAb or lower can be used. On the other hand, cooling air or cooling water can be used through a heat exchanger at the incinerator rather than adding combustion air. That Absorbents for trapping sulfur compounds can be lime, semi-burnt Limestone or dolomite rather than limestone. Flux can be used with the feed material to the pyrolysis device or to the animal charcoal burner, around the ash melting point to humiliate.

Anhydrous soda (pa204 borax (B203) or potash (K20) can be added be used to lower the melting temperature, thus reducing the tendency to agglomerate and is increased to improve the collection efficiency. In contrast, will the melting point is increased by adding silica, if this is the case he wishes is to prevent slagging. If desired, diluent gases, such as steam or recirculated combustion products, to line 14 be added to the hydrocarbon concentration in line 14 and the downstream elements / decrease, causing cracking of saturated Hydrocarbons and pollution is prevented. Water can go to the pyrolysis system be added to gasify some of the animal charcoal, in principle through the steam-carbon reaction (H20 + C- CO + H2).

This reduces the supply of animal charcoal to the animal charcoal burner and the supply of volatiles to the afterburner 20 is increased. This diminishes the required combustion air (through line 30) and makes an addition of Preheated air to the afterburner 20 is possible. This reduces the consumption of fuel for the system and increases the flame temperature and the furnace outlet, enables the Use of coals with lower volatile content without reduction the outlet flame temperature and allows the use of coal pulp as Feed material (which simplifies the handling, storage and transport of the coal) and eliminates the need for coal drying and ultimately reduces the size and costs of the plant (since the added combustion air blows the reactors and Bypasses cyclones).

If the coal during mining contains pyrite in an amount which is a Results in a sulfur content of over 3%, any excess in the mine is removed.

The individual parts of the system according to Fig. 1 described in detail. In Fig. 3, the pyrolysis device 12 is shown which an inlet 50, a tank 52, a deflector 54, a standpipe outlet 56, and has an upper outlet 58. The pyrolysis device 12 is 3835.41 mm high, is provided with a refractory lining (Tmax = 982.22 ° C for tank 52) and has an outer wall made of carbon steel.

During operation, the pyrolysis device 12 is initially with filled with powdery material. In a new facility, the material can be any non-melting substance such as sand; after running in instead used the animal charcoal and limestone from the previous run.

The contents and the walls of the pyrolysis device 12 are during of the start-up heated by combustion products, which in the supply line 10 enter as described above.

When the temperature in the pyrolysis device 12 rises to 648.890C Preheating is brought about as described above, coal, limestone, transport air occur and bleed air into inlet 50 from line 10. The conical deflector 54 prevents the feed items from being flushed through the tank during start-up 52 and out through outlet 58. The feed goods collect inside the tank on due to the whirlpool fluid bed, which is created by an interaction between the incoming transport air flow, the coal, the limestone and the bleed air Animal charcoal and limestone is produced.

The feed material thus bubbles upwards in the center of the tank 52. The animal charcoal produced by the thermal decomposition circulates along with the limestone by flowing down the annulus, is then carried along at the bottom of tank 52 the incoming current before they fall back into the annulus.

The pyrolysis of the coal takes place when the coal particles enter be heated by the recirculating animal charcoal and the limestone. Every particle the incoming coal is immediately replaced by several particles of inert, non-sticky, Surrounded by animal charcoal and limestone. (This is important when the incoming coal is from is of an adhesive type; without the effect of dilution, the coal entering would stick together in a large lump. The slenderness of the cone of only 200 helps with to the rapid mixing of the recirculating solid particles with the incoming Coal to advance.) The combustion of the incoming air with the coal, the Animal charcoal and the volatile components heat the solids in the pyrolysis device by incineration, being merely sufficient Air to generate of 871.11 ° C is supplied. Ralk (whose reaction products are here always with "consumed Limestone "are designated), which is produced from the limestone thus burnt reacts with the liberated sulfur compounds in the volatile components (primarily H2S), whereby the gas stream is scrubbed while consumed Absorbent (primarily CaS (calcium sulfide)) is formed.

The animal charcoal and the used limestone pass through the standpipe 56 to conduit 24 and thereafter to incinerator 28 as described above. The gaseous products and entrained animal charcoal and fine particles of limestone exit through upper outlet 58 and through line 14 to the charcoal cyclone 16.

The animal charcoal cyclone 16 is completely a standard cyclone separator, which for a removal of the entrained particles from the pyrolysis device 12 leaving gases is designed with high efficiency. The gases with a Velocity of 15.24 m / sec step tangentially into the side of the cyclone close its further head end, the solid particles are thrown outwards and gyrate downward until it passes through a bottom outlet connected to line 26 fall through. The transport air (from a compressor, not shown) holds the movement of particulate matter out of cyclone 16 and through conduits 26 and 22 upright by ejector action. The purified gases occur at the head of the Cyclones through an outlet which is connected to line 18. The cyclone 16 is 4267.21 mm high and is lined with a 19.05 mm thick with refractory Material-filled hexagonal steel honeycomb (Umax = 982.22 ° C) anchored with pins, which of a 76.2 mm thick thermal insulating liner and an outer Housing made of carbon steel is surrounded.

The animal coal and limestone from line 24 enter the fluidized bed incinerator 28 (Fig. 4) a, where the burning of the animal charcoal takes place. The incinerator 28 has concentric tubes 100 and 102, which form the main body of the incinerator and an annular combustion zone 104 between the tubes 100, 102 and an inner chamber 106 within the tube 102 set. The bottom 108 of the incinerator, which is fastened to pressure rods 102 has a hollow conical portion 109 which extends upward into chamber 106 protrudes, creating a tapered annulus 106a between the tube 102 and the conical area 109 is formed. Annulus 104 is in a lower, rapid fluidized bed ash agglomeration combustion zone at 1093.33 ° C and an upper rapid fluidized bed desulfurization zone at 848.89 ° C divided by an air inlet manifold 113 and circumferentially arranged Through holes 115 in the annular zone 104. Deflection rings 119a and 119b prevent backflow of solids and aid in the formation of the two Zones. The tube 102 is arranged at a distance above the floor 108 in order to be in the floor area of the combustion device 28 to form a zone 107 which the zone 104 with the annular space 106a and the chamber 106 connects. The circular animal charcoal inlet manifold 110 connects the line 24 with the combustion zone 104 by 18 tubes 111, which through Bores fitted in the walls of the tube 100 and spaced around its circumference are arranged distributed. An air inlet 112 connects line 30 to one circular manifold 114, which in turn by 24 at a distance on the circumference distributed ejector tubes 116 is connected to the zone 107, the ejector tubes 116 are fitted through bores in the conical section 109. Furthermore is through the conical portion 109 an ash outlet pipe 117 fitted therethrough, which the annular zone 106a near the head of the conical section 109 with the standpipe 40 connects. A smoke tube 118 connects the chamber 106 with the conduit 34. The Combustion zone 104 and chamber 106 at the top of the incinerator 28 are interconnected by a blade separator 120 which 12 has blades 121 located at the same distance from one another (750) (Fig.

5). A ceiling 122 of the incinerator 28 rests on top the Separating device 120 and the pipe 102 and is on top with the separating device 120 connected.

The incinerator 28 is 5384.3 mm high. The pipe 100 has an outer steel case (6.35mm thick) containing a 76.2mm thick castable refractory The lining is surrounded by a 19.5 mm thick refractory material hexagonal steel honeycomb surrounds. The tube 102 consists of an outer wall of a 19.05 mm thick hexagonal steel honeycomb filled with refractory material and one inner wall made of the same 19.05 mm thick refractory lining. Between inner and outer honeycomb runs a 4.7625 mm thick steel tube over the entire Length of the tube 102 and is welded to the honeycomb with a center-to-center distance of 152.4 mm. The through holes 115 are 4.7625 mm thick.

During operation, the incinerator is preheated 28 is performed by passing preheated air through the air inlet as described above 112 enters to bring the combustor 28 to 648.89 ° C. Combustion air from Fan 32 then passes directly to combustor 28 through the air inlet 112 a. Animal charcoal and limestone from the pyrolysis device 12 and the animal charcoal cyclone 16, which are carried by transport air, pass from the line 24 into the Manifold 110 and are through the tubes 111 in the bottom area of the combustion zone 104 distributed into it. Incoming from air inlet 112 into manifold 114 Air is distributed through the ejector nozzles 116 into the zone 107 and sweeps from there Animal charcoal and limestone up through burn zone 104. Combustion begins in zone 104 after ignition by the heat of the recirculated particulate matter. The combustion continues upward through zone 104 in the form of a Rapid fluid bed, which consists of animal charcoal, limestone and combustion air.

The products of combustion move upward at a surface velocity of 5.4864 m / sec. The products of combustion, excess oxygen and unburned Animal charcoal rise up to the separator 120, which is connected to the Chamber 106 working like a conventional cyclone separator causes that the oncoming mass of solids and gases is swirled around. the whirled around solids, including ash, spent limestone and some unburned Animal charcoal enters chamber 106 and falls along the inner walls of the tube 102 down into the beveled annular space 106a. The twirling poses sure that only very small particles of ash and coal still burning from the Burner can escape.

The ejection process, which is made by the air flow in a suitable Wisely sized ejector tubes 116 are brought about, pulling some of the first falling solid particles out through the zone 107 and leads them again back up through zone 104 to burn any unburned animal charcoal. In spite of the ejection process, solid particles thus collect in the annular space 106a in the form of a slow fluidized bed. When the bed is the height of the ash outlet pipe 117 reached, the pipe 117 acts as a weir to remove the excess solid particles, which consist of ashes and used limestone, peel off and bring them down to the Standpipe 40 to carry. From there, the solid particles migrate to line 44 and are finally transported by air to an ash container (not shown) washed out.

The presence of a stoichiometric excess of air in the Incinerator 28 maintains its temperature at 848.89 ° C, which is the temperature is, in which a desulphurization by limestone takes place at the lowest Use of the absorbent. However, it is desirable to have a portion of the annulus 104 at a higher temperature, namely 1093.330C, to operate in order to agglomerate of fine fly ash particles to a maximum. It is therefore desirable to operate the combustion device 28 with two temperature zones, namely the lower one Zone at the higher temperature.

The two zones are created by arranging a fluid dynamic Check valve, which is located in the middle of the annular space 104. Those forming the check valve opposite rings inhibit slip of solids by mechanical means Blocking their flow. The effect of the check valve is further improved by introducing the flow of air through the through holes 115, whichever to cool the gases from the optimum ash agglomeration temperature (1093.33 ° C) the optimal desulfurization temperature (848.89 ° C) is used. The relative amount the air entering through the air inlet 112 and the through holes 115 becomes regulated by two temperature sensors, one in each ring-shaped rapid fluidized bed zone. A sensor in the lower zone regulates the air through the air inlet 110 to the Keep the temperature of the lower zone at 1093.330C, and a sensor in the upper Zone regulates the air through the through holes 115 to the appropriate temperature maintain in the upper zone.

Similar to the animal coal cyclone 16 is the ash cyclone 36 of which two used in parallel in the preferred embodiment of the invention will. The ash cyclone 36 is entirely a standard cyclone separator, which is designed for removing particulate matter with high efficiency and which of generally the same materials for the refractory lining and the casing 16 as the cyclone 16 consists.

The cyclone 36 is 4826.01 mm high and has a tangential inlet at his side near his head. The formation of the upper and lower outlet is essentially the same as cyclone 16. Pedaling during operation hot gases from incinerator 28 at an inlet velocity of 22.8601 m / sec through the tangential inlet. Ash and spent limestone are whirled around by centrifugal force, fall down and finally kick through the bottom outlet, which is connected to the line 42 and then the line 44 is. Clean combustion gases (848.89 ° C) exit through the top outlet and flow through line 46 to afterburner 20.

The afterburner 20 (Fig. 6) receives clean combustible gases from the Animal charcoal cyclone 16 through line 18 and clean combustion gases as well Nitrogen and residual oxygen from the ash cyclones 36 through the line 46. The gases from line 46 enter cylindrical afterburner 20 axially through inlet 30. The gases from line 18 enter tangentially under pressure through inlet 132 into an annular chamber 134, from which it is uniform radially into the gas flow from inlet 130 for even mixing thereof are introduced through a manifold 136, like a ring with a number of circumferential openings 136a made within afterburner 20 downstream of the inlet 130 and is fitted concentrically within the annular chamber 134. While During operation, the gases from inlets 130 and 132 are hot enough to cause combustion in combustion chamber 138 between the combustible gases from inlet 132 and to introduce the unconsumed oxygen from inlet 130.

The afterburner 20 empties directly into an oven (not shown) through an opening with a diameter of 609.6 mm. The afterburner 20 is in an opening built into the furnace wall by attaching a flange 142 to the furnace housing. In In the illustrated embodiment, the combustion chamber 138 has a length of 1219.2 mm. Alternatively, a flange 142a may be on the afterburner as shown be arranged and attached to the furnace. In the latter case, the afterburner housing is used located downstream of the flange 142a. In this construction, the combustion chamber has 138 a length of 350.52 mm. When training with flange 142, the combustion essentially completed within the afterburner. When training with the Flange 142a stops combustion inside the furnace.

The first mentioned training can increase the completeness of the combustion especially with boilers or other furnaces whose walls are relatively cold. The latter training is more compact and cheaper to build.

A system element used when starting up as described above is the preheater 150 (Fig. 7), two of which are the same size are used for the pyrolysis device 12 and the animal carbon cyclone 16 and a larger one is used for the incinerator 28. For each start-up, which requires preheating, the fan 32 blows air (1 5.560C) in each preheater 150 through an inlet 152. The air enters one bladed chamber 154 where it splits, with a portion being axial passes through a central passage 156 and another portion through blades 155 (approximately 450) is whirled outward into the annular space, which surrounds chamber 154 and then flows into combustion chamber 158. natural gas is fed through an inlet 160 into a manifold 162 and flows therefrom in / the annulus surrounding chamber 154, it being with the swirled air mixes and after initial ignition by means of a (not shown) in the Chamber 158 arranged spark plug burns. The one passing through passage 156 Air is swirled around by vortex generator 164 and mixes as it exits of the passage 156 with the gases passing through the combustion chamber 158, which Are combustion products.

The air passing through the blades 156 is primary air and has approximately the amount required for complete combustion of the gas is. The air passing through passage 156 is and will be secondary air to cool the combustion products to the temperature required for preheating used. Without this cooling air, the products of combustion exiting preheater 150 would be too hot, which could damage lines 10, 14 and 30. The flow of air through tube 156 also cools the tube and prevents destruction this, on the other hand, due to the heating by the hot gases in the Combustion chamber 158 would occur. The passage 156 and the combustion chamber 158 are made of stainless steel. The smaller version of the preheater 150 has a length of 431.8 mm. The flow rate of the natural gas into the inlet 160 is 5.6 Nm3 / h, the flow rate into the inlet 152 is 203.88 Nm3 / h for the pyrolysis device 12th and 135.92 Nm5 / h for the animal charcoal cyclone 16. The larger version of the preheater 150 for incinerator 28 is 1066.8 mm long. The flow rate of the Natural gas into the inlet 160 is 28.3167 Nm3 / h and the flow rate of the air into inlet 152 is 1019.4012 Nm3 / h. The heated air passes through outlets 166 from and into the pyrolysis device 12, the animal coal cyclone 16 and the fluidized bed incinerator 28 through their usual air inlets.

Finally, in Fig. 8 a combustion station is shown, such as it would be usable, for example, in a factory or power supply system. The preheaters 150 are not shown in this drawing. A compressor 31 is shown adjacent to fan 32. Different elements of the plant are mounted on foundations 6 and 8 (with the support struts and other supports are not shown). A system of valves (not shown) can be used to coordinate the supply of coal, limestone, air and water to the station, an operator at a central control desk (not shown) effectively controls burner according to the invention. Containers for storing coal dust, Ash and limestone are not shown.

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Claims (22)

Claims 1. A method for burning coal, characterized by thermal decomposition of coal dust to form animal charcoal and volatile components, Separation of the animal charcoal from the volatile components, burning of the animal charcoal in heat exchange relationship with a stoichiometric excess of air, creating ash and forming a mixture of gases and choosing the excess air to generate a temperature in the ash below its melting temperature, Separating the mixture of gases from the ashes and then burning the volatile ones Components in the mixture of gases. 2. Device for burning coal, characterized by the the following features in combination: A whirlpool fluidized bed pyrolysis device (12), a fluidized bed incinerator (28), a first cyclone (16), a second Cyclone (36) and an afterburner (20), the pyrolysis device (12) being switched on is for receiving coal dust and delivering animal coal to the incinerator (28) and gaseous substances with entrained solid particles to the first cyclone (16), the first cyclone (16) is connected to deliver gases to the afterburner (20), the combustion device (28) is further connected to receive a the combustion supporting gas and for the release of gaseous substances with entrained particulate matter to the second cyclone (36) and the second cyclone (36) is connected to deliver a gaseous substance to the afterburner (20). 3. Device for burning coal according to claim 2, characterized in that that the pyrolysis device (12) has a lower inlet (50), whose direction changes continuously from the horizontal to the vertical, one cylindrical chamber section, which by a around the longitudinal axis of the pyrolysis device (12) rotated line is formed, a conical transition section between the Inlet (50) and the cylindrical chamber portion, one above the cylindrical Chamber portion located outlet (58) of smaller diameter than the cylindrical Chamber section, a deflector (54) which is located in the cylindrical chamber section is arranged to block the flow directly along a line parallel to the longitudinal axis from the lower part of the cylindrical chamber section into the outlet (58) and a Standpipe (56) extending from the cylindrical chamber portion upstream of the deflector (54) exits. 4. Device for burning coal according to claim 2 or 3, characterized characterized in that the fluidized bed incinerator (28) is made of faster, solids is of a recirculating type and has a central recirculation chamber (106), which by a first cylindrical about the longitudinal axis of the combustion device (28) extending part (102) and a generally conical part (109) is formed, a annular rapid fluidized bed chamber (104) around the central recirculation chamber (106) is arranged, the central recirculation chamber (106) and the rapid fluidized bed chamber (104) below the first part (102) are in communication with one another, which with the generally conical part (109) a central recirculation ring chamber (106a) forms the generally conical portion (109) with a plurality of penetrating therethrough Nozzles (116) is provided and the rapid fluidized bed chamber (104) with a plurality of charcoal inlets (111) which are provided around a lower peripheral surface the chamber (104) open into this. 5. Apparatus according to claim 4, characterized in that the central recirculation chamber (106) and the rapid fluidized bed chamber (104) at their opposite ends around the other end of the first part (102) by a A plurality of blades (121) are in communication with each other, which are engaged are for causing movement of the fabrics from the fluidized bed chamber (104) to the central recirculation chamber (106) with a centrifugal motion for throwing the particulate matter against the inner wall of the first part (102), and generally conical part (109) has a pull-off standpipe (107). 6. Apparatus according to claim 4 or 5, characterized in that the air nozzles (116) are designed to assist the circulation from the central Recirculation chamber (106) into the rapid fluidized bed chamber (104). 7. Device according to one of claims 4 to 6, characterized in that that the rapid fluidized bed rammer (104) in a lower agglomeration chamber and a upper desulfurization chamber is divided. 8. Apparatus according to claim 7, characterized in that the agglomeration chamber and the desulfurization chamber from each other through a fluidic shut-off valve are separated. 9. A method for burning coal, characterized by introducing of pulverized coal and an absorbent in a fluidized bed pyrolysis device, Carrying out a reaction in the pyrolysis device to produce animal charcoal, desulphurized volatile components and sulfur-bearing absorbents, which contains the sulfur removed from the volatiles, separating the animal charcoal and the absorbent from the desulphurized volatile components, Introducing the animal charcoal and the sulfur-laden absorbent into a fluidized bed incinerator, Introducing a stoichiometric excess of air into the combustion device, where the excess air is chosen is used to generate an ash temperature below the melting temperature of the ashes, burning the animal charcoal in contact with the sulfur-laden absorbent and in heat transfer relationship with the stoichiometric excess air, thereby forming ash, a desulphurized A mixture of gases and sulfur carrying absorbent substances in increased quantities, Separating the gas mixture from the ashes and burning the desulphurized volatile ones Components in the desulphurized mixture of gases. 10. The method according to claim 9, characterized in that the stoichiometric Excess air is brought into physical contact with the animal charcoal. 11. The method according to claim 9 or 10, characterized in that the pyrolysis device by burning a part of combustibles introduced therein Fabrics are heated. 12. The method according to any one of claims 9 to 11, characterized in, that a diluent gas is added to the volatiles before the volatiles Components in the mixture of gases are burned. 13. The method according to any one of claims 9 to 12, characterized in that that H20 is added to the pyrolysis device. 14. The method according to claim 13, characterized in that preheated Air is added as the volatiles burn. 15. The method according to any one of claims 9 to 14, characterized in that that the coal is bituminous Illinois grade B coal with a high volatile content Constituents and the ash temperature is 871.11 0C. 16. Device for burning coal, characterized by the the following features in combination: a whirlpool fluidized bed -Pyrolysis device (12), a fluidized bed incinerator (28), a first cyclone (16), a second cyclone (36), an afterburner (20), means (10) for introducing Coal dust and an absorbent in the pyrolysis device (12), facilities (22) for conveying animal charcoal and the absorbent from the pyrolysis device (12) to the combustion device (28), devices (14) for conveying gaseous Substances with entrained solid particles in the pyrolysis device (12) the first cyclone (16), Einriditungen (18) for conveying gaseous substances from the first cyclone (16) to the afterburner (20), means for introducing one combustion assisting gas in the incinerator (28) in a sufficient amount to maintain a temperature of the combustion products below the melting temperature of the ashes from the animal charcoal, facilities (34) for conveying gaseous substances with entrained solid particles out of the Combustion device (28) for the second cyclone (36) and devices (46) for Conveying gaseous substances from the second cyclone (36) into the afterburner (20). 17. The device according to claim 16, characterized in that the Fluidized bed incinerator (28) of faster solids recirculating Kind is. 18. Apparatus according to claim 16 or 17, characterized in that that the pyrolysis device (12) is a solids recirculating device. 19. Device according to one of claims 16 to 18, characterized in that that the combustion device (28) has a collector in itself. 20. Device according to one of claims 16 to 19, characterized marked, that in the combustion device (28) ejector devices (116) for support the recirculation are arranged. 21. Device according to one of claims 16 to 20, characterized in that that the pyrolysis device (12) has a standpipe (22) for removing animal charcoal has through this. 22. Device according to one of claims 16 to 21, characterized in that that hot particles which are in an area of the incinerator (28) close an outlet (118) these are recirculated, are passed over blades (121), which are disposed around the outlet (118) for providing swirling motion and lowering a required level height to prevent an escape from too hot particles.