KR20130065696A - Solid fired hot gas generator with extended regulating range - Google Patents

Abstract

The present invention relates to a solid combustion hot gas generator comprising a plurality of solid burners for extending the control range, forming multiple solid burners having an extended control range. A solid supply and a combustion air supply are installed in each solid burner, and a separate dose amount solid supply is supplied to each solid burner with the aid of the dose amount means. The thermal power of multiple solid burners, in particular multiple impulse burners, is increased from the minimum thermal power of one solid burner to the maximum thermal power of all solid burners to cover all necessary amounts of control of the plant apparatus to be fed.

Description

Solid Fired Hot Gas Generator With Extended Regulating Range

The present invention relates to a pulverization-drying plant, such as a solid combustion hot gas generator with an extended control range that can preferably be used for pulverizing solid fuels.

Air swept mills, such as LOESCHE type vertical roller mills, suspended roller mills or ring roller mills, in which wet raw coal is introduced into a pulverization-drying process with the supply of hot gas and pulverized into coal dust; A separator, such as a filter, in which the coal dust-gas mixture is separated; And a hot gas generator for generating a hot gas in which a portion of the gas is recycled as a purifying gas, the coal crushing plant is a coal gasification, pig iron and steel manufacturing industry by the PCI (Pulverised Coal Injection) process. And in the cement industry (DE 40 35 730 C2, catalog of LOESCHE GmbH, Dusseldorf, "Loesche-Muhlen fur feste Brennstoffe" 01/2008).

Coal dust burning hot gas generators are additionally used in the nonmetallic mineral industry to dry raw powder, slag and granulated blast furnace slag and cement. Hot gas generators that are burned with lignite or light coal dust are known in the gypsum, sugar and potassium industries.

DE 197 06 077 A1 further includes burners which are burned with pneumatic conveying combustion dusts such as light coal or lignite dust, biomass dust or mixtures thereof with the supply of combustion air; A burner muffle installed on the outlet side of the burner; Hot gas with a mixing section which is formed after the supply section of the gas to be heated and the burner muffle and which is formed as a staggered cylinder portion and a protective jacket (LOMA) with a protective jacket to form an annular channel of the gas to be heated The generator is described.

The hot gas generator described in DE 42 08 951 A1 already comprises a metal perforated jacket for the introduction of gas to be heated and a burner muffle formed shorter in the axial direction than the perforated jacket and lined with a refractory material. . However, the burners described herein are multiple lance burners with lean gas-fired air nozzles surrounded by one another.

DE 197 25 613 A describes burners for generating hot waste gases by burning heated oil, heated gases or coal dust. Coal dust is conveyed by a gaseous carrier medium, preferably air, and is injected through an injection lance, which extends into the reaction chamber from the burner head to the point of the largest diameter of the conical burner chamber, This injection lance is provided at the outlet end with a deflection hood. Combustion air is supplied through the radial blade cascade at the head side end of the reaction chamber. The blade cascade and part of the reaction chamber are surrounded by an air collection housing that passes through the blade cascade into the reaction chamber after the combustion air has been retained. This burner produces a large amount of turbulent motion, in particular according to this flow pattern. Combustion dust is transported back to the air guiding blade after leaving the deflection hood and then heated to about 1000 ° C. by a screw-type swirling flame to ignite. Flame jets have strong impulses and recirculate gases very rapidly.

In the Internet publication "Impuls-Brenner, System Dr. Schoppe, fur Braunkohlenstaub, Heizol und gas von 100 kW bis 35 MW", the burner described above is described as an impulse burner.

DE 102 32 373 B4 describes further development of impulse burners with flame stability and flame jet velocity for increasing the hot gas temperature range from at least 200 ° C to 900 ° C.

The burners for solid fuels used in connection with the mixing chamber have a control range of up to 1: 5. Technically limiting the range of control makes it difficult or impossible to use a mixing chamber, such as a hot gas generator with a perforated jacket, in installations of process systems that require a greater range of control, such as 1:10 or less. Do not have. This control range can be varied by varying the moisture of the material to be dried and the throughput change of the aggregate to be fed.

The yield of vertical roller mills of the type LOESCHE amounts to 100% to 40%, for example. Therefore, this mill has a control ratio of 1: 2.5. If the minimum yield matches very low moisture and relatively high outside temperatures, only relatively low heat is needed. Maximum heat consumption is achieved by maximum yield, maximum moisture of the material to be ground and dried, and relatively low external temperatures.

The following detailed example shows that an adjustment ratio of about 1: 8 is necessary to achieve all “operating points”.

Example: Light Coal

Max case yield = 80 t / h

Moisture = 15%

Temperature = 5 ° C

Calories = 49.66 x 10 ⁶ kJ / h (13.8 MW)

Minimum yield = 32 t / h

Moisture = 5%

Temperature = 35 ℃

Calories = 6.1x10 ⁶ kJ / h (1.695 MW)

Therefore, the adjustment ratio is 49.66: 6.1 = 1: 8.14.

The above adjustment ratio 1: 8.14 was difficult to achieve without a hot gas generator with a solid burner. Therefore, in the grinding-drying facility for crushing coal, a hot gas generator with a gas or oil burner is mainly used as long as waste heat cannot be used from the process itself. In the case of coal vaporization plants, syngas is generally supplied to the hot gas generator as fuel and as a combustion PCI plant blast furnace gas. Coal crushers in the coal vaporization, PCI plant and cement industries require a control ratio of at least 1: 8. In general, a control ratio of at least 1:10 of oil and gas-fired hot gas generators is already known.

It is an object of the present invention to make it possible to replace solid combustion hot gas generators, in particular heating oils and gases, with cost-saving fuels such as lignite dust, light coal dust and the like and to produce hot gases in the hot gas generator, In order to exclude economically inefficient use of blast furnace gas and the like, there is provided a coal dust-fired hot gas generator having an extended control range.

The object of the invention is achieved through the construction of claims 1 and 2. Useful and advantageous embodiments are included in the description of the dependent claims and the figures.

The key technical idea is to install multiple burners in the hot gas generator to increase the control range.

In accordance with the present invention, the solid combustion hot gas generator comprises multiple solid burners to form a multiple solid burner to increase or extend the control range.

Independent solid supply and combustion air supply are installed in each solid burner, and each solid burner can be combusted independently of other solid fuel burners. The fire power of multiple solid burners is increased from the minimum fire power of one solid burner to the maximum fire power of all solid burners provided. Therefore, the control ratio is increased and all parts of the aggregate supplied with the hot gas generated in the hot gas generator can be covered.

1 is a longitudinal sectional view of a hot gas generator with multiple solid burners in accordance with the present invention.
FIG. 2 is a plan view taken along the line II-II of FIG. 1.

In a preferred embodiment, the hot gas generator is provided with a burner muffle and a start burner installed on the burner plate of the burner muffle, a supply means of gas to be heated and a mixing section in which the resulting combustion gas is mixed with the gas to be heated and installed after the burner muffle. And a plurality of solid burners installed coaxially with the start burner and fixed to the burner plate of the burner muffle.

The number of burners can be advantageously determined as necessary. For example, 2, 3 or 4, if possible a larger number of solid burners may be flanged to the burner plate of the burner muffle. Burners of the same size or different sizes, ie burners with the same large or different fire power, may also be used.

It is useful for the hot gas generator of the present invention to be designed in a vertical structure, and since the multiple solid burners are installed in the burner plate of the burner muffle, a solid burner having a coal dust supply part and its reaction chamber extends into the burner muffle.

It is advantageous for the three solid burners to be installed coaxially with the start burner which is installed at the same distance to each other and is guided through the burner plate on the longitudinal shaft of the burner muffle. The burner may be installed at a certain angle such that flue gas leaving the burner is directed to the center of the outlet of the burner muffle. If a solid burner for ash-containing fuel is provided, a vertical or downwardly inclined arrangement is recommended in the burner plate or burner muffle of the hot gas generator.

It is also advantageous to be able to use burner muffles which should simply match their size to the provided number of solid burners in the burner plate. The burner muffle can be lined with a refractory material.

It is also useful that the burner muffle is surrounded by supply means for the gas to be heated, and that the gas to be heated can be supplied to its subsequent mixture for mixing with the produced combustion gas.

The perforated jacket portion is formed as a steel combustion chamber and includes a plurality of cylindrical and coaxial perforated jackets forming an annular gap in the direct transition portion for introducing gas to be heated and forming an annular channel surrounded by an outer, It may be advantageous to be provided as a mixing portion including the mixing portion in the axial direction. Such sheet steel chambers are known as perforated jacket combustion chambers (LOMA-combustion chambers).

The impulse burners of "Carbotechnik Energiesysteme GmbH, Geretsried" can be used advantageously as solid burners, for example. These are described as described above in connection with DE 197 25 613 A1 and DE 102 32 373 B4 and the company's Internet publication. However, other solid burners can also be used.

The impulse burner has a thermal power of 0.5 to 100 MW and is suitably installed on the burner plate upper end face of the burner muffle of the hot gas generator according to the invention to form multiple impulse burners.

In order to control and regulate the solid burners separately, the coal dust can be fed independently of the operation of the burners adjacent to each solid burner and provide a dosing means that can be changed to each desired control point.

CT dose devices for fluidization, dosing and pneumatic conveying of "Carbotechnik Energiesysteme GmbH, Geretsried" are particularly suitable.

Such dose devices are described in the company's Internet publications and in EP 0 054 018 B1 and EP 0 210 162 B2.

The extended or increased control range of the hot gas generator according to the invention with multiple solid burners or multiple impulse burners is described in more detail with reference to the embodiments described above.

In this example, a maximum heat of 13.8 MW is required. The three solid burner numbers are chosen as the optimal arrangement with respect to the process reasons and the burner installation in the burner muffle. Each solid burner should provide 4.6 MW of heat. When the control ratio of each solid burner is 1: 4, the minimum heat amount is 1.15 MW. One burner lacks the required heat of 1.695 MW, and the control range 1: 4 of each solid burner extends the control range of the multiple burners according to the invention with three solid burners to 1:12.

Depending on the calories required, only one solid burner of the multiple burners, or both or two or three fuel burners can be operated. The total control ratio of the hot gas generator with three solid burners is 1:12.

This value is also achieved only in exceptional cases in the case of gas burners.

The arrangement of the multiple solid burners according to the invention in the burner muffle of the hot gas generator facilitates the production of hot gases in grinding-drying plants and other heating plants in a particularly effective way. Particularly advantageous is the addition of suitable amounts of solid fuels, such as lignite dust, which are much more economical compared to heating oils and combustion gases. Particularly when coal blast furnace gas or syngas is used to produce hot gases for the drying process in coal mills, it can be used as coal dust.

The invention is explained in more detail with reference to the drawings. The drawings are schematically illustrated in the majority.

1 and 2 show as an example a hot gas generator with multiple solid burners 10 consisting of three solid burners 3, 4, 5.

In the two solid burners 3 and 4 shown in FIG. 1, a solid supply part 6 and a combustion air supply part 7 are provided in each solid burner 3, 4 and 5, and the solid burner 3, 4. 4 and 5 are provided in the burner plate 12 of the burner muffle 2. The burner muffle 2 and the subsequent mixing section 9 are vertically oriented like the solid burners 3, 4, 5 and the start burner 8.

An impulse burner for coal dust, such as lignite dust, has a conical elongated reaction chamber 16 with a tapered flame acceleration nozzle 17 and a deflection hood 19 for injecting fluidized coal dust. One injection lance 18 and a radial blade cascade 25 on the burner head to allow combustion air to pass into the reaction chamber 16, whereby combustion air flows through the side inlet 7. It is used as solid burners 3, 4 and 5, which enters into the housing 28 and passes from there to the radial blade cascade 25 and the reaction chamber 16.

The impulse burner combusted with the solid fuel has a high speed flame jet, and the flame 30 extends into the mixing section 9 through the burner muffle 2, as shown in FIG.

If no solid fuel is available, the impulse burner can then be converted for gas to keep the plant running. In FIG. 1, the gas supply 27 next to the solid supply 6 is connected to the solid or impulse burners 3, 4 shown.

The combustion gas produced in the multiple solid burners 10 with the process gas 13 to be heated supplied via the supply means 11 is heated and mixed in the mixing section 9.

The supply means 11 with radial housing surround a burner muffle 2 in which solid burners 3, 4, 5 extend together with the reaction chamber 16 and the flame acceleration nozzle 17.

In this embodiment, the burner muffle 2 is lined with a refractory material 15. Fire resistant linings can also be omitted. The perforated jacket portion 20 is connected to the burner muffle 2 on the outlet side and is thus connected as a mixing section 9 on the opposite side of the multiple solid burners 10 of the burner plate 12. This perforated jacket portion 20 consists of a plurality of cylindrical and coaxial perforated jackets 21 which are part of the steel combustion chamber and have an enlarged diameter. An annular gap 22 for introducing gas 13 to be heated is formed between each of the perforated jackets 21, and an annular channel 24 is formed for each of the perforated jackets 21 and the outer hermetically sealed steel sheet 23. And a gas 13 to be heated to the interior of the annular channel 24, through the holes of the annular gap 22 and the perforated jacket 21 from the supply means 11, inside the mixing chamber 26. Is supplied. The formed hot gas 14 is removed through the outlet 29.

2 shows a plan view of the hot gas generator on top of the burner plate 12 of the burner muffle 2 with the helical housing of the supply means 11 of the gas to be heated, which is installed on the outer periphery of the burner muffle 2. The start burner 8 operated by gas or oil is installed in the center of the burner plate 12, and the three solid burners 3, 4 and 5 are perpendicular to the start burner 8 at the same distance from each other. It is downward and extends coaxially.

Solid burners 3, 4 and 5 used as impulse burners are also suitable for burning gases. If the coal dust is not available and the operation is interrupted, the impulse burners can be switched to natural gas, syngas or blast furnace gas without problems, such as subsequent generation of coal-fired power plants, blast furnaces in PCI plants, etc. The operation of the equipment can be maintained.

The main advantage of the multiple fuel burners according to the invention is the interchangeable use of the hot gas generators with solid burners.

Hot gas generators with multiple fuel burners, in particular multiple impulse burners, can be used in coal gasification plants, PCI plants in the steel industry, non-ferrous metallurgical processes and in general heating systems. Syngas produced in the coal vaporization process can be used progressively advantageously in the energy production industry and in the plastics industry. On the other hand, when the syngas is branched off as an energy carrier for the grinding-drying process, it is usually about 11,000 kJ / m _N ³ as the calorific value of the syngas for heat generation of 10 to 30 MW. It requires both 3300 m ³ _N / h to about 10,000 m ³ _N / h of synthesis gas. This represents a great loss in purpose use. At the same time blast furnace gas from the steelmaking industry has also been increasingly used for power generation in special power plants. The use of coal dust for hot gas generation avoids the use of the above-mentioned gases and other fuels such as light oil, heavy oil, natural gas in the hot gas generator, and is very advantageous with regard to energy and investment.

2: burner muffle 3,4,5: solid burner
6: solid supply part 7: combustion air supply part
8: Start burner 9: Mixing unit
10: muffle solid burner 11: supply means
12: burner plate 13: gas
14: hot gas 16: reaction chamber
17: nozzle 18: injection lance
20: perforated jacket part 21: perforated jacket
22: annular gap 26: mixing chamber
30: flame

Claims (11)

Multiple solid burners 3, 4, 5 are installed, multiple solid burners 10 are formed, and an independent solid supply 6 and combustion air supply 7 are each solid burner 3, 4, 5 ), The thermal power of the multiple solid burners 10 can be adjusted from the minimum thermal power of the solid burners to the maximum thermal power of all solid burners 3, 4 and 5, and to cover all the necessary amounts of subsequent equipment. A solid combustion hot gas generator having an extended control range. The burner muffle (2) and the start burner (8) provided in the burner plate (12) of the burner muffle (2), the supply means (11) of the gas (13) to be heated, and the burner muffle ( 2) In the hot gas generator having a mixing section 9 provided next, in which the generated combustion gas is mixed with the gas 13 to be heated, a plurality of solid burners 3, 4, 5 are used for the start burner 8 And coaxially with and fixed to the burner plate (12) of the burner muffle (2). 3. The hot gas generator as claimed in claim 1, wherein solid burners (3, 4, 5) of the same or different size form multiple solid burners (10). 4. The process according to claim 2 or 3, wherein the three solid burners 3, 4, 5 are provided at a constant angle with respect to each other and at the same radial distance from the start burner 8 of the burner plate 12. Hot gas generator, characterized in that. The hot gas generator according to any one of claims 1 to 4, wherein the solid burners (3, 4, 5) are provided at a specific angle with respect to the longitudinal axis of the burner muffle (2). 6. The hot gas generator as claimed in claim 1, wherein a dose amount means is provided for the separate dose amount solids supply to each solid burner. 3. 7. The hot gas generator as claimed in claim 1, wherein dusty fuels, in particular coal dusts or biomass dusts, can be supplied in solid form to the solid burners. 3. The impulse burner according to any one of the preceding claims, in particular hard coal dust, lignite dust, petroleum coke dust, biomass dust and dust mixtures, each having a tapered flame acceleration nozzle 17. A conical extending reaction chamber 16, an injection lance 18 having a deflection hood 19 for injecting fluidized dust-like fuel and a radial blade cascade 25 for supplying combustion air. A hot gas generator, characterized in that it is installed as a solid burner (3, 4, 5). 9. The hot gas generator according to claim 8, characterized in that the impulse burners used as solid burners (3, 4, 5) can be converted to gas burners, for example operating with natural gas, syngas or blast furnace gas. 10. The method according to any one of the preceding claims, wherein a plurality of cylindrical and coaxial perforated jackets, annular gaps between the perforated jackets 21 and perforated jackets 21 and externally sealed sheet steel jackets 23. A hot gas generator, characterized in that a perforated jacket section (LOMA) with annular channels (24) between) is provided as mixing section (9). The hot gas generator according to any one of claims 1 to 10, which is used for installations in coal gasification plants, PCI plants in steel industry and non-metallurgical metallurgical processes, cement industry and general heating systems.

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