Device for improving combustion efficiency of decomposing furnace

Abstract

The utility model provides a device for improving the combustion efficiency of a decomposing furnace. The device comprises a gas storage tank for generating oxygen-enriched air, a pure oxygen gas pipeline, a gas dilution unit and an oxygen-enriched air pipeline, two independent conveying cavities are jointly formed by the main pipe and the sleeve fixedly arranged outside the main pipe in a sleeving mode, one conveying cavity is a main pipe inner cavity and serves as a pulverized coal conveying cavity, the other conveying cavity is an oxygen-enriched conveying cavity, and a pipe opening in the side, facing the outside of the furnace, of the sleeve is independent of a coal air inlet and serves as an oxygen-enriched inlet; an annular interlayer cavity coaxially distributed on the periphery of the pulverized coal conveying cavity is formed between the main pipes from the outlet end of the coal injection pipe in the axial direction, the tail end of the inner side of the furnace is packaged through a sealing plate with a plurality of through holes, the through holes jointly serve as an oxygen-enriched outlet, and the interior of the sleeve is communicated from the oxygen-enriched inlet to the oxygen-enriched outlet. According to the utility model, the current situation that the end part of the outlet side of the coal injection duct is easy to damage and deform in a high-temperature environment can be improved, sufficient combustion of pulverized coal is facilitated, and crust caused by insufficient combustion is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to cement production technical field more specifically, it is a device that improves the device of decomposition furnace combustion efficiency. BACKGROUND

[0002] The decomposition furnace is the key equipment in the clinker production process, the limestone, carbide slag, slag or fly ash, sandstone in the raw material produce relative motion in the flow field in the decomposition furnace, can reach the effect of high dispersion, uniform mixing and distribution, rapid heat exchange, the carbonate component and Ca(OH)2 in the raw material rapidly absorb heat, decompose in the decomposition furnace, so that the decomposition rate of the material into the kiln reaches 90%~95%, the oxide after decomposition enters the kiln from the kiln tail (the high end of the cylinder) of the rotary kiln. Because the carbonate decomposition needs to absorb a large amount of heat, a certain fuel needs to be fed in the decomposition furnace to supply, at present, the kiln tail of the cement plant adopts coal injection combustion, and the conventional air is used as the source of oxygen required when burning. Generally speaking, the fuel in the decomposition furnace accounts for about 60% of the fuel consumption in the entire cement clinker calcination process, if the coal powder combustion is insufficient, it will inevitably cause the problems of large coal powder consumption and high production cost; on the other hand, if the coal powder combustion is insufficient, the temperature in the decomposition furnace will be unstable, and the decomposition rate of the raw material will fluctuate, thereby affecting the yield and quality of the clinker, therefore, whether the coal powder in the decomposition furnace can be fully burned becomes the focus of the enterprise, because the conveying coal powder air volume fluctuates little under the process technology requirement, whether the oxygen content in the decomposition furnace can meet the full combustion of the coal powder becomes the focus. CONTENT

[0003] In order to solve the above technical problems, the utility model provides a device that improves the device of decomposition furnace combustion efficiency, is applied to cement production process, mixes the oxygen-rich air after obtaining the oxygen-rich air of pure oxygen gas and environment air and sends into the oxygen-rich delivery cavity of the modified coal injection pipe, utilizes the oxygen-rich air to improve the coal powder combustion efficiency in the decomposition furnace, improves the present situation that the outlet side end part of the coal injection pipe is easy to be damaged and deformed under high temperature environment, reduces the skin caused by insufficient combustion.

[0004] In order to achieve the above object, the utility model adopts the following technical scheme:

[0005] A device that improves the device of decomposition furnace combustion efficiency, comprising:

[0006] Gas storage tank for receiving, storing and outputting pure oxygen gas to the gas dilution unit, the oxygen concentration of the pure oxygen gas is 50%-90%;

[0007] Pure oxygen gas pipeline for inputting pure oxygen gas to the gas storage tank and for conveying pure oxygen gas in the gas storage tank to the gas dilution unit;

[0008] The gas dilution unit is provided with a dilution cavity which receives ambient air through an ambient air inlet and receives pure oxygen gas through a pure oxygen inlet, and oxygen-enriched air formed by mixing the received ambient air and pure oxygen gas in the cavity is output through an oxygen-enriched air outlet.

[0009] The oxygen-enriched air pipeline is used for conveying the oxygen-enriched air formed by the gas dilution unit to the oxygen-enriched inlet of the coal injection pipe through the Roots blower.

[0010] The coal injection pipe is arranged at the conical part of the decomposing furnace, has an outlet extending into the furnace and blowing horizontally along the radial direction of the furnace, and has an inlet located outside the furnace; the coal injection pipe forms two independent conveying cavities through a main pipe and a sleeve pipe fixedly sleeved outside the main pipe; one of the two conveying cavities is a through main pipe cavity with two open pipe mouths and serves as a pulverized coal conveying cavity, the outside pipe mouth of the main pipe cavity serves as a coal wind inlet, the inside pipe mouth of the main pipe cavity serves as a coal wind outlet, and the other conveying cavity is an oxygen-enriched conveying cavity, the sleeve pipe is bent towards the outside of the furnace and is separated from the main pipe, the pipe mouth of the sleeve pipe is independent of the coal wind inlet and serves as an oxygen-enriched inlet, and a circular annular interlayer cavity is formed between the sleeve pipe and the main pipe along the axial direction from the outlet end of the coal injection pipe and is distributed around the pulverized coal conveying cavity, the inside end of the circular annular interlayer cavity is sealed by a sealing plate provided with a plurality of through holes which are equidistantly distributed along the circumferential direction and jointly serve as an oxygen-enriched outlet, and the sleeve pipe is through from the oxygen-enriched inlet to the oxygen-enriched outlet and serves as the oxygen-enriched conveying cavity.

[0011] The structure of the utility model also has the following characteristics:

[0012] The circular annular interlayer cavity covers at least half of the length of the main pipe along the axial direction, and the through holes of the oxygen-enriched outlet are circular through holes.

[0013] The utility model also comprises four oxygen concentration on-line analyzers, one of which is arranged on the pure oxygen gas pipeline near the pure oxygen inlet of the dilution cavity, one of which is arranged on the dilution cavity and used for detecting the oxygen concentration of the gas in the cavity, one of which is arranged on the oxygen-enriched air pipeline near the oxygen-enriched air outlet of the dilution cavity, and one of which is arranged on the oxygen-enriched air pipeline between the air outlet of the Roots blower and the oxygen-enriched inlet of the coal injection pipe.

[0014] The pure oxygen gas pipeline inputs pure oxygen gas into the gas storage tank through a pure oxygen input pipeline, and is connected between the tank body gas outlet of the gas storage tank and the pure oxygen inlet of the gas dilution unit through a pure oxygen output pipeline which is sequentially provided with an oxygen flow meter, a first adjusting valve, a first filter, a first check valve, a cut-off valve and a first oxygen concentration on-line analyzer along the gas flow direction.

[0015] The dilution cavity is provided with a second oxygen concentration on-line analyzer; the ambient air inlet of the dilution cavity is connected with an ambient air conveying pipeline, and the ambient air conveying pipeline is sequentially provided with a second filter and a second adjusting valve along the gas flow direction.

[0016] The oxygen-enriched air pipeline is communicated between the oxygen-enriched air outlet of the dilution chamber and the air inlet of the Roots blower through an oxygen-enriched input pipeline, which is communicated between the oxygen-enriched air outlet of the dilution chamber and the air inlet of the Roots blower and is provided with a third oxygen concentration on-line analyzer and a second check valve in sequence along the airflow direction.

[0017] The pure oxygen gas received by the gas storage tank is pure oxygen separated by a nitrogen production system air separation device.

[0018] The oxygen concentration of the oxygen-enriched air sent into the coal injection pipe is 25%-30%.

[0019] The gas storage tank is provided with a pressure relief valve, and the preset pressure threshold of the pressure relief valve is 30 Kpa, and the pressure relief output flow is 50 Nm 3 / h.

[0020] The volume of the gas storage tank is 20 m 3 , and the pressure is 20-30 Kpa.

[0021] Compared with the prior art, the coal injection pipe is modified, and the coal injection pipe is supplied with oxygen-enriched air formed by mixing pure oxygen gas and ambient air, so that the coal injection pipe can simultaneously and independently convey the pulverized coal and the oxygen-enriched air, the annular interlayer cavity in the oxygen-enriched conveying cavity surrounds the periphery of the pulverized coal conveying cavity, and the oxygen-enriched outlet is uniformly distributed around the coal outlet, and the beneficial effects are as follows:

[0022] 1. The outlet side end portion of the coal injection pipe extending into the furnace is cooled by the oxygen-enriched air, and the damage and deformation of the outlet side end portion in the high-temperature environment are improved.

[0023] 2. An oxygen-enriched environment is formed in the coal injection pipe area of the decomposition furnace, which is beneficial to the full combustion of the pulverized coal and reduces the consumption of the pulverized coal.

[0024] 3. After the pulverized coal is fully combusted, the temperature distribution in the decomposition furnace is uniform, the decomposition rate of the raw materials is improved, the consumption of the pulverized coal is reduced, and the production and quality of the clinker are stable.

[0025] 4. The decomposition furnace and the preheater can reduce the skin caused by insufficient combustion of the pulverized coal. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1 is a structural schematic view of the utility model;

[0027] Fig. 2 is a front view structural schematic view of the coal injection pipe;

[0028] Fig. 3 is a side view structural schematic view of the outlet side of the coal injection pipe.

[0029] Fig.:

[0030] 1 gas storage tank; 11 pressure relief valve;

[0031] 21 pure oxygen input pipeline; 22 pure oxygen output pipeline; 23 oxygen flow meter; 24 first regulating valve; 25 first filter; 26 first check valve; 27 shut-off valve; 28 first oxygen concentration on-line analyzer;

[0032] 3 gas dilution unit; 31 dilution chamber; 32 pure oxygen inlet; 33 ambient air inlet; 34 ambient air conveying pipeline; 35 second filter; 36 second regulating valve; 37 second oxygen concentration on-line analyzer; 38 oxygen-enriched air outlet;

[0033] 41 oxygen-enriched input pipeline; 42 third oxygen concentration on-line analyzer; 43 second check valve; 44 Roots blower; 45 oxygen-enriched output pipeline; 46 third regulating valve; 47 flame arrester; 48 fourth oxygen concentration on-line analyzer;

[0034] 5 coal injection pipe; 51 main pipe; 511 pulverized coal conveying chamber; 512 coal air inlet; 513 coal air outlet; 52 sleeve pipe; 521 oxygen-enriched conveying chamber; 5211 annular interlayer chamber; 522 oxygen-enriched inlet; 523 oxygen-enriched outlet; 524 sealing plate;

[0035] 6 decomposition furnace. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0037] Please refer to Figs. 1 to 3 The device for improving the combustion efficiency of the decomposition furnace in the embodiments comprises:

[0038] The gas storage tank 1 is used for receiving, storing and outputting pure oxygen gas to the gas dilution unit 3, and the oxygen concentration of the pure oxygen gas is 50%-90%;

[0039] The pure oxygen gas pipeline is used for inputting pure oxygen gas to the gas storage tank 1 and conveying the pure oxygen gas in the gas storage tank 1 to the gas dilution unit 3;

[0040] The gas dilution unit 3 is provided with a dilution cavity 31, which receives ambient air through an ambient air inlet 33 and receives pure oxygen gas through a pure oxygen inlet 31. The received ambient air and pure oxygen gas are mixed in the cavity to form oxygen-enriched air, which is output through an oxygen-enriched air outlet 38.

[0041] An oxygen-enriched air pipeline is used to transport the oxygen-enriched air formed by the gas dilution unit 3 to the oxygen-enriched inlet of the coal injection pipe 5 through the Roots blower.

[0042] The coal injection pipe 5 is arranged at the conical part of the decomposition furnace 6, with one side being an outlet extending into the decomposition furnace 6 and horizontally blowing into the furnace along the radial direction, and the other side being an inlet located outside the decomposition furnace 6. The coal injection pipe 5 forms two independent conveying cavities through the main pipe 51 and the sleeve pipe 52 fixedly sleeved outside the main pipe 51. Among the two conveying cavities, one is a through main pipe 51 cavity with two open pipe mouths, serving as a pulverized coal conveying cavity 511, with the outside pipe mouth serving as a coal wind inlet 512 and the inside pipe mouth serving as a coal wind outlet 513, and the other is an oxygen-enriched conveying cavity 521, with the sleeve pipe 52 bent towards the outside of the furnace and diverged from the main pipe 51, and the pipe mouth being independent of the coal wind inlet 512 and serving as an oxygen-enriched inlet 522. A circular annular interlayer cavity 5211 is formed between the sleeve pipe 52 and the main pipe 51 along the axial direction from the outlet end of the coal injection pipe 5 and distributed around the pulverized coal conveying cavity 511. The inside end of the circular annular interlayer cavity 5211 is sealed by a sealing plate 524 with a plurality of through holes equally spaced along the circumferential direction, and the through holes collectively serve as an oxygen-enriched outlet 523. The sleeve pipe 52 is through from the oxygen-enriched inlet 522 to the oxygen-enriched outlet 523, serving as the oxygen-enriched conveying cavity 521.

[0043] In specific implementations, the corresponding structural arrangement of the device also includes:

[0044] The circular annular interlayer cavity 5211 covers at least half the length of the main pipe 51 along the axial direction, and the through holes of the oxygen-enriched outlet 523 are circular through holes.

[0045] The existing coal injection pipe 5 has a high equipment damage rate due to the pipe end deeply extending into the decomposition furnace 6 and being exposed to a high-temperature environment, which easily causes damage and deformation of the end of the coal injection pipe 5. After the pipe end is damaged and deformed, the pulverized coal is easily dispersed when injected at the end, which leads to uneven temperature distribution in the decomposition furnace 6 and often causes fluctuations in the outlet temperature of the decomposition furnace 6 due to insufficient combustion of the pulverized coal. In addition, due to the insufficient combustion of the pulverized coal, part of the pulverized coal falls into the raw material and burns in the raw material, which leads to the early appearance of liquid phase in the raw material and the easy occurrence of skinning in the decomposition furnace 6 and the preheater.

[0046] The device adds an oxygen-enriched conveying cavity independent of the pulverized coal conveying cavity to the coal injection pipe 5 by modifying the structure of the coal injection pipe 5, and sends oxygen-enriched air formed by mixing pure oxygen gas and ambient air into the oxygen-enriched conveying cavity. When put into use:

[0047] During the process of conveying oxygen-enriched air, the oxygen-enriched conveying chamber can cool the outlet end of the pulverized coal injection pipe 5, effectively protecting the end of the pulverized coal injection pipe 5 and preventing damage and deformation of the end of the pulverized coal injection pipe 5 in a high-temperature environment.

[0048] After adding oxygen-enriched air, the oxygen content in the decomposition furnace 6 increases, forming an oxygen-enriched environment in the area of ​​the pulverized coal injection pipe 5 in the decomposition furnace 6, which is conducive to the complete combustion of pulverized coal.

[0049] After the pulverized coal is fully combusted, the temperature distribution inside the decomposition furnace 6 is uniform, the decomposition rate of raw materials is increased, and the consumption of pulverized coal can be reduced.

[0050] After the technology is applied, the crusting caused by incomplete combustion of pulverized coal in the decomposition furnace 6 and preheater can be reduced. The comparison before and after use shows that the crusting in the decomposition furnace 6 and preheater is significantly reduced, especially in the three-stage conical section, where no crusting is caused by pulverized coal.

[0051] It also includes four online oxygen concentration analyzers: one installed on the pure oxygen gas pipeline near the pure oxygen inlet of the dilution chamber; one installed on the dilution chamber to detect the oxygen concentration of the gas inside the chamber; one installed on the oxygen-enriched air pipeline near the oxygen-enriched air outlet of the dilution chamber; and one installed on the oxygen-enriched air pipeline between the air outlet of the Roots blower and the oxygen-enriched inlet of the pulverized coal injection pipe 5.

[0052] The pure oxygen gas pipeline inputs pure oxygen gas into the gas storage tank 1 through the pure oxygen input pipeline 21, and connects the pure oxygen output pipeline 22, which is equipped with an oxygen flow meter 23, a first regulating valve 24, a first filter 25, a first check valve 26, a shut-off valve 27, and a first online oxygen concentration analyzer 28 in sequence along the airflow direction, between the gas outlet of the gas storage tank 1 and the pure oxygen inlet of the gas dilution unit 3.

[0053] The dilution chamber 31 is equipped with a second online oxygen concentration analyzer 37; the ambient air inlet of the dilution chamber is connected to the ambient air delivery pipe 31, and the ambient air delivery pipe 34 is equipped with a second filter 35 and a second regulating valve 36 in sequence along the airflow direction. The ambient air is filtered by the second filter 35 to remove dust and other impurities.

[0054] The oxygen-enriched air pipeline connects the oxygen-enriched air outlet 38 of the dilution chamber 31 to the air inlet of the Roots blower 44 via an oxygen-enriched air input pipeline 41, which is sequentially equipped with a third online oxygen concentration analyzer 42 and a second check valve 43 along the airflow direction. An oxygen-enriched air output pipeline 45, sequentially equipped with a third regulating valve 46, a flame arrester 47, and a fourth online oxygen concentration analyzer 48 along the airflow direction, connects the oxygen-enriched air outlet 523 of the Roots blower 44 to the oxygen-enriched air inlet 523 of the pulverized coal injection pipe 5. The third regulating valve 46 and the flame arrester 47 prevent backfire when the ambient pressure exceeds the oxygen-enriched air flow pressure due to abnormal reasons. The oxygen-enriched air output pipeline can have multiple branches to supply oxygen-enriched air to multiple pulverized coal injection pipes 5 on the decomposition furnace 6.

[0055] The pure oxygen gas received by gas storage tank 1 is pure oxygen separated by the air separation unit of the nitrogen generation system, and is introduced into gas storage tank 1 through the pure oxygen input pipeline.

[0056] The oxygen concentration of the oxygen-enriched air supplied to pulverized coal injection pipe 5 is 25%-30%. Real-time monitoring is achieved using four online oxygen concentration analyzers. If the oxygen concentration of the oxygen-enriched air deviates from the set range, adjustments are made using various valves and a Roots blower.

[0057] The gas storage tank 1 is equipped with a pressure relief valve 11, which has a preset pressure threshold of 30 kPa and a pressure relief output flow rate of 50 Nm³. 3 / h. The pressure relief valve 11 is used to relieve pressure when the pressure exceeds a preset threshold during maintenance shutdown of the cement production system or when the air separation unit of the nitrogen production system is separating pure oxygen.

[0058] The volume of gas storage tank 1 is 20m³. 3 The pressure is 20-30 kPa.

[0059] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A device for improving the combustion efficiency of a decomposition furnace, characterized in that: include: A gas storage tank is used for receiving, storing, and discharging pure oxygen gas into a gas dilution unit, wherein the oxygen concentration of the pure oxygen gas is 50%-90%. Pure oxygen gas pipeline, used to input pure oxygen gas into the gas storage tank, and for conveying pure oxygen gas from the gas storage tank to the gas dilution unit; The gas dilution unit is provided with a dilution chamber. The dilution chamber receives ambient air through an ambient air inlet and pure oxygen gas through a pure oxygen inlet. The oxygen-enriched air formed by the mixing of the received ambient air and pure oxygen gas in the chamber is output through an oxygen-enriched air outlet. Oxygen-enriched air pipeline, used for conveying oxygen-enriched air generated by the gas dilution unit to the oxygen-enriched inlet of the pulverized coal injection pipe via a Roots blower; A pulverized coal injection pipe is installed at the conical part of the decomposition furnace. One side is the outlet, extending into the decomposition furnace and horizontally injecting coal into the furnace along the radial direction. The other side is the inlet, located outside the decomposition furnace. The pulverized coal injection pipe forms two independent conveying chambers through the main pipe and the sleeve fixedly fitted outside the main pipe. One of the two conveying chambers is the inner cavity of the main pipe with two open and continuous openings, serving as the pulverized coal conveying chamber. The pipe opening on the outside of the furnace serves as the coal air inlet, and the pipe opening on the inside of the furnace serves as the coal air outlet. The other is the oxygen-enriched conveying chamber. The sleeve bends towards the outside of the furnace and forks from the main pipe. The pipe opening is independent of the coal air inlet and serves as the oxygen-enriched inlet. A circular annular interlayer cavity is formed axially from the outlet end of the pulverized coal injection pipe between the sleeve and the main pipe, distributed around the pulverized coal conveying chamber. The inner end of the circular annular interlayer cavity is sealed by a sealing plate with several through holes evenly spaced along the circumference. All through holes serve as the oxygen-enriched outlet. The sleeve runs from the oxygen-enriched inlet to the oxygen-enriched outlet, serving as the oxygen-enriched conveying chamber.

2. The apparatus for improving the combustion efficiency of a decomposition furnace according to claim 1, characterized in that: The annular interlayer cavity covers at least half the length of the main pipe along the axial direction; each through hole of the oxygen-enriched outlet is a circular through hole.

3. The apparatus for improving the combustion efficiency of a decomposition furnace according to claim 1, characterized in that: It also includes four online oxygen concentration analyzers: one installed on the pure oxygen gas pipeline near the pure oxygen inlet of the dilution chamber; one installed on the dilution chamber to detect the oxygen concentration of the gas inside the chamber; one installed on the oxygen-enriched air pipeline near the oxygen-enriched air outlet of the dilution chamber; and one installed on the oxygen-enriched air pipeline between the air outlet of the Roots blower and the oxygen-enriched inlet of the pulverized coal injection pipe.

4. The apparatus for improving the combustion efficiency of a decomposition furnace according to claim 3, characterized in that: The pure oxygen gas pipeline inputs pure oxygen gas into the gas storage tank through a pure oxygen input pipeline, and connects the gas storage tank outlet to the gas dilution unit through a pure oxygen output pipeline that is sequentially equipped with an oxygen flow meter, a first regulating valve, a first filter, a first check valve, a shut-off valve, and a first online oxygen concentration analyzer in the direction of airflow.

5. The apparatus for improving the combustion efficiency of a decomposition furnace according to claim 3, characterized in that: The dilution chamber is equipped with a second online oxygen concentration analyzer; the ambient air inlet of the dilution chamber is connected to an ambient air delivery pipe, and a second filter and a second regulating valve are sequentially installed on the ambient air delivery pipe in the direction of airflow.

6. The apparatus for improving the combustion efficiency of a decomposition furnace according to claim 3, characterized in that: The oxygen-enriched air pipeline is connected between the oxygen-enriched air outlet of the dilution chamber and the air inlet of the Roots blower via an oxygen-enriched input pipeline that is sequentially equipped with a third online oxygen concentration analyzer and a second check valve along the airflow direction. The oxygen-enriched output pipeline is connected between the air outlet of the Roots blower and the oxygen-enriched inlet of the pulverized coal injection pipe via an oxygen-enriched output pipeline that is sequentially equipped with a third regulating valve, a flame arrester, and a fourth online oxygen concentration analyzer along the airflow direction.

7. The apparatus for improving the combustion efficiency of a decomposition furnace according to claim 1, characterized in that: The pure oxygen gas received by the gas storage tank is pure oxygen separated from the air separation unit of the nitrogen generation system.

8. The apparatus for improving the combustion efficiency of a decomposition furnace according to claim 1, characterized in that: The oxygen concentration of the oxygen-enriched air supplied to the pulverized coal injection pipe is 25%-30%.

9. The apparatus for improving the combustion efficiency of a decomposition furnace according to claim 1, characterized in that: The gas storage tank is equipped with a pressure relief valve, which has a preset pressure threshold of 30 kPa and a pressure relief output flow rate of 50 Nm³. 3 / h.

10. The apparatus for improving the combustion efficiency of a decomposition furnace according to claim 1, characterized in that: The gas storage tank has a volume of 20m³. 3 The pressure is 20-30 kPa.

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