CN112321177A - An energy-saving vertical preheater system for active lime calcination - Google Patents
An energy-saving vertical preheater system for active lime calcination Download PDFInfo
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- CN112321177A CN112321177A CN202011369842.6A CN202011369842A CN112321177A CN 112321177 A CN112321177 A CN 112321177A CN 202011369842 A CN202011369842 A CN 202011369842A CN 112321177 A CN112321177 A CN 112321177A
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2/00—Lime, magnesia or dolomite
- C04B2/10—Preheating, burning calcining or cooling
- C04B2/12—Preheating, burning calcining or cooling in shaft or vertical furnaces
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Abstract
本发明公开了一种用于活性石灰煅烧的节能竖式预热器系统，所述系统由多个竖式预热器呈环形排布，在环形的中心位置设有回转窑；其中，每个预热器的热交换室为圆筒形结构，热交换室的顶部设有下料管和排气管道，下料管与物料仓连通，热交换室底部开口与设在其下方的楔形腔对应布置，楔形腔上开设有卸料口，每个卸料口均与回转窑连通，回转窑煅烧产生的烟气余热通过卸料口进入楔形腔和热交换室对堆积的物料预热，楔形腔上还安装推料装置，用于将预热后的物料推入到回转窑内。本发明通过布置合理的预热室容积与个数，精准控制给料，保持预热室物料的高径比在一个合理范围，从而使回转窑产生的烟气与物料热交换率最大化，以节省能源消耗。
The invention discloses an energy-saving vertical preheater system for calcining active lime. The system consists of a plurality of vertical preheaters arranged in a ring, and a rotary kiln is arranged at the center of the ring; The heat exchange chamber of the preheater is a cylindrical structure. The top of the heat exchange chamber is provided with a feeding pipe and an exhaust pipe. The feeding pipe is communicated with the material bin, and the bottom opening of the heat exchange chamber corresponds to the wedge-shaped cavity located below it. The wedge-shaped cavity is provided with a discharge port, each discharge port is connected to the rotary kiln, and the waste heat of flue gas generated by the calcination of the rotary kiln enters the wedge-shaped cavity and the heat exchange chamber through the discharge port to preheat the accumulated materials, and the wedge-shaped cavity A pushing device is also installed on the top to push the preheated material into the rotary kiln. By arranging a reasonable volume and number of preheating chambers, the invention precisely controls the feeding and keeps the height-diameter ratio of the material in the preheating chamber within a reasonable range, thereby maximizing the heat exchange rate between the flue gas and the material generated by the rotary kiln, and reducing the Save energy consumption.
Description
Technical Field
The invention belongs to the technical field of active lime production equipment, and particularly relates to an energy-saving vertical preheater system for active lime calcination.
Background
The active lime calcining process comprising three main machines, namely a vertical preheater, a rotary kiln and a vertical cooler, has a dominant position in the lime production industry in China, wherein the preheater is a main device in a rotary kiln limestone calcining process system, limestone is fully preheated in the preheater and has a temperature of about 960 ℃, partial limestone is decomposed and gradually enters the rotary kiln to be calcined to produce active lime, namely the heat exchange effect of the limestone in the preheater directly influences the yield of the active lime, and the method also relates to the full utilization of heat energy and the normal use of subsequent process equipment of the system. Therefore, people generally pay attention to the reasonability of the structure and parameter design of the preheater.
At present, a heat exchange chamber part in a vertical preheater in the prior art is of a square box-shaped structure, the volume of preheated materials is small, a feed bin is connected with a feeding pipe, the feeding is uneven and unsmooth, the heat energy absorption rate is low when the materials are exchanged with reverse hot air flow, equipment is easy to burn out, production is often stopped, and economic loss is caused; meanwhile, a large amount of flue gas waste heat generated when the active lime is produced by the rotary kiln is not recycled, so that a large amount of heat energy is wasted and the environment pollution of dust is caused. Under the national policy of energy conservation and emission reduction, the process and equipment which can reduce the fuel consumption of the rotary kiln and the production cost of the active lime and meet the national environmental protection policy and emission standard are urgently adopted.
In view of the above, the present inventors have devised an energy-saving vertical preheater system for calcining active lime to solve the above technical problems.
Disclosure of Invention
In order to solve the problems in the prior art, the invention aims to provide an energy-saving vertical preheater system for calcining active lime, which effectively utilizes a large amount of flue gas waste heat generated by a rotary kiln by optimizing the height-diameter ratio of the preheater, so that the capacity of a rotary kiln production line is improved, the ton heat consumption of the active lime is reduced, the consumption of raw materials and fuels is reduced, and the CO is reduced2The discharge amount achieves the purposes of energy conservation, emission reduction and cost saving.
The technical problem to be solved by the invention is realized by the following technical scheme: an energy-saving vertical preheater system for calcining active lime is characterized in that a plurality of vertical preheaters are arranged in an annular shape, and a rotary kiln is arranged at the central position of the annular shape;
each vertical preheater comprises a cylindrical heat exchange chamber, a blanking pipe and an exhaust pipeline are arranged at the top of the cylindrical heat exchange chamber, the blanking pipe is communicated with a material bin arranged at the top of the vertical preheater, an opening at the bottom of the cylindrical heat exchange chamber is arranged corresponding to a wedge-shaped cavity arranged below the cylindrical heat exchange chamber, a discharge opening is formed in the wedge-shaped cavity and faces the annular center, each discharge opening is communicated with an inlet of the rotary kiln, and flue gas waste heat generated by calcination of the rotary kiln enters the wedge-shaped cavity and the cylindrical heat exchange chamber through the discharge openings to preheat stacked materials;
and the wedge-shaped cavity is also provided with a material pushing device for pushing the preheated material into the rotary kiln from the discharge opening, and is formed by building refractory material bricks.
Further, a gas distributor is arranged at the joint of the discharge opening and the rotary kiln, and the gas distributor is used for uniformly distributing the flue gas waste heat generated by the calcination of the rotary kiln to each wedge-shaped cavity and each cylindrical heat exchange chamber.
Furthermore, the included angle alpha between the bottom surface of the wedge-shaped cavity and the horizontal plane ranges from 10 degrees to 12 degrees.
Furthermore, the pushing device comprises a push rod, a push head and a hydraulic driving device, the push head is arranged on the bottom surface of the wedge-shaped cavity, the push rod is inserted into a guide hole formed in the wedge-shaped cavity, the inner side end of the push head is connected with the push head, the hydraulic driving device is arranged on the outer side of the wedge-shaped cavity, the output end of the hydraulic driving device is connected with the outer side end of the push rod, and the hydraulic driving device drives the push head to do reciprocating linear motion on the bottom surface of the wedge-shaped cavity through driving the push rod so as to continuously push the preheated materials into the rotary kiln.
Furthermore, the hydraulic driving device comprises a rectangular frame and a hydraulic cylinder, the upper end of the rectangular frame is hinged to the outer wall of the cylindrical heat exchange chamber, the lower end of the rectangular frame is hinged to a piston rod of the hydraulic cylinder, the outer side end of the push rod is hinged to the rectangular frame, the hydraulic cylinder drives the rectangular frame to move, and the rectangular frame pushes the push rod to do linear motion.
Furthermore, the material of the push head is heat-resistant alloy cast steel.
Further, the ratio (H/phi) of the height to the diameter of the effective space inside the cylindrical heat exchange chamber of each vertical preheater ranges from 1.1 to 1.4;
wherein, the height (H) refers to the effective stacking height of the material layer in the cylindrical heat exchange chamber; the diameter (phi) means that the effective cross-sectional area of the cylindrical heat exchange chamber is converted into the area of a corresponding circle, and then the corresponding diameter is obtained.
Furthermore, the system is mainly formed by uniformly distributing 12 vertical preheaters in a 360-degree annular mode.
Compared with the prior art, the invention has the beneficial effects that:
1. the energy-saving vertical preheater system for active lime calcination maintains the height-diameter ratio of the preheating chambers by designing reasonable volumes and numbers of the preheating chambers and accurately controlling feeding through the control system, so that the heat exchange efficiency is maximized. Specifically this system is 360 annular arrangements by 12 vertical preheater, lime stone in the lime stone feed bin at vertical preheater top gets into the cylinder heat exchange chamber that the preheater corresponds through 12 unloading pipes, every cylinder heat exchange chamber lower part is equipped with a set of hydraulic pressure blevile of push that is opened by control system is automatic, the lime stone carries out the heat exchange with the flue gas in the preheater, the heat temperature that the lime stone absorbed hot waste gas rises, the lime stone that preheats, promote through every pushing head, get into the rotary kiln through the discharge opening and calcine, simultaneously the rotary kiln calcine the flue gas waste heat that produces after with the lime stone heat exchange in the preheating chamber, exhaust into the atmosphere through dust collector purification after the temperature reduces, realize energy-concerving and environment-protective purpose. Compared with a square box-shaped heat exchange chamber, the cylindrical heat exchange chamber has the advantages of large volume, high heat exchange rate, good material fluidity, uniform material accumulation, high heat energy absorption rate when the material exchanges with reverse hot air flow, simplicity and convenience in building refractory materials and easiness in maintenance.
2. The invention relates to an energy-saving vertical preheater system for active lime calcination, wherein a gas distributor is arranged at the joint of a discharge opening and a rotary kiln, and the gas distributor can ensure that residual heat energy of flue gas generated by the rotary kiln calcination uniformly enters each wedge-shaped cavity and each cylindrical heat exchange chamber, thereby realizing the efficient preheating and partial decomposition of blocky limestone in a stacking state.
3. According to the energy-saving vertical preheater system for calcining the active lime, the limestone material bin is connected with the vertical preheater through the long material pipe, so that the material sealing effect on the negative-pressure preheating chamber is realized, the cold air is prevented from entering, and the heat efficiency of the system is improved.
Drawings
FIG. 1 is a schematic diagram of the overall structure of an energy-saving vertical preheater system according to the present invention;
FIG. 2 is a front view of the energy saving vertical preheater system of the present invention;
fig. 3 is a sectional view a-a in fig. 2.
In the figure: 1. a vertical preheater; 2. a rotary kiln; 3. a gas distributor; 4. a material pushing device; 11. a cylindrical heat exchange chamber; 12. a discharging pipe; 13. an exhaust duct; 14. a wedge-shaped cavity; 15. a discharge opening; 41. a push rod; 42. pushing the head; 43. a hydraulic drive device; 431. a rectangular frame; 432. and a hydraulic cylinder.
Detailed Description
In order that the objects, aspects and advantages of the invention will become more apparent, the invention will be described by way of example only, and in connection with the accompanying drawings. It is to be understood that such description is merely illustrative and not restrictive of the scope of the invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the equipment or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.
Example (b): referring to fig. 1 to 3, an energy-saving vertical preheater system for calcining active lime is provided, wherein a plurality of vertical preheaters 1 are arranged in an annular shape, and a rotary kiln 2 is arranged at the central position of the annular shape. Each vertical preheater 1 comprises a cylindrical heat exchange chamber 11, a discharging pipe 12 and an exhaust pipeline 13 are arranged at the top of the cylindrical heat exchange chamber 11, a tail gas purification device can be installed on the exhaust pipeline 13, the discharging pipe 12 is communicated with a material bin arranged at the top of the vertical preheater 1, preferably, the discharging pipe 12 is connected with a limestone material bin through a long material pipe, so that the material sealing effect on the negative-pressure preheating chamber is realized, the cold air is prevented from entering, and the heat efficiency of the system is improved.
The bottom opening of the cylindrical heat exchange chamber 11 is arranged corresponding to a wedge-shaped cavity 14 arranged below the cylindrical heat exchange chamber 11, discharge openings 15 are formed in the wedge-shaped cavity 14 and face the annular center, each discharge opening 15 is communicated with an inlet of the rotary kiln 2 through a discharge chute, and flue gas waste heat generated by calcination of the rotary kiln 2 enters the wedge-shaped cavity 14 and the cylindrical heat exchange chamber 11 through the discharge openings 15 to preheat accumulated materials.
Preferably, a gas distributor 3 is installed at the junction of the discharge opening 15 and the rotary kiln 2, and the gas distributor 3 is used to uniformly distribute the preheated exhaust gas generated by the calcination of the rotary kiln 2 to each of the wedge-shaped cavities 14 and the cylindrical heat exchange chamber 11 so as to accelerate the decomposition of limestone by high temperature, based on the principle that CaCO3 (limestone) is decomposed to generate CaO (activated lime) + CO (carbon monoxide) under high temperature environment2×) @. On one hand, the preheating temperature in the vertical preheater is increased, so that the massive limestone is efficiently preheated and partially and quickly decomposed in an accumulation state; on the other hand, after the preheated waste gas generated by the calcination of the rotary kiln is exchanged with limestone in a heat exchange way, the temperature is reduced, the waste gas is conveniently purified by a purifying device on an exhaust pipeline and then is exhausted into the atmosphere, the ton heat consumption of the active lime is reduced, and the original energy is savedConsumption of fuel and fuel.
The wedge-shaped cavity 14 is also provided with a material pushing device 4 for pushing the preheated material into the rotary kiln 2 from the discharge opening 15, the preferred included angle alpha between the bottom surface of the wedge-shaped cavity 14 and the horizontal plane is 10-12 degrees so as to discharge the material by utilizing the labor-saving characteristic of the inclined plane, and the wedge-shaped cavity 14 is formed by bricking refractory materials.
Specifically, as shown in fig. 2 and 3, the pushing device 4 includes a pushing rod 41, a pushing head 42 and a hydraulic driving device 43, wherein the pushing head 42 is disposed on the bottom surface of the wedge-shaped cavity 14, preferably, the pushing head 42 is made of heat-resistant alloy cast steel material to ensure normal operation under a high temperature condition of about 1000 ℃, the pushing rod 41 is inserted into a guide hole formed in the wedge-shaped cavity 14, and the inner end of the pushing rod is connected to the pushing head 42, the hydraulic driving device 43 is mounted on the outer side of the wedge-shaped cavity 14, and the output end of the hydraulic driving device is connected to the outer end of the pushing rod 41, and the hydraulic driving device 43 drives the pushing head 42 to perform reciprocating linear motion on the bottom inclined surface of the wedge-shaped cavity 14 by driving the pushing rod 41, so as to continuously push the preheated.
The hydraulic driving device 43 comprises a rectangular frame 431 and a hydraulic cylinder 432, the upper end of the rectangular frame 431 is hinged with the outer wall of the cylindrical heat exchange chamber 11, the lower end of the rectangular frame 431 is hinged with the end part of a piston rod of the hydraulic cylinder 432, the outer side end of the push rod 41 is hinged with the middle part of the rectangular frame 431, the hydraulic cylinder 432 drives the rectangular frame 431 to move, and the rectangular frame 431 pushes the push rod 41 to move linearly.
Through inventor's experiment, the lime stone is after fully preheating in the preheater, and the temperature can reach about 950 ℃, and partial lime stone decomposes, and in the research and development process of equipment, research and development personnel carry out the heat transfer principle of heat exchange to the hot flue gas about 1150 ℃ and the indoor material of cylinder heat exchange, adjusts the height to radius ratio of traditional preheater, specifically is: when the ratio (H/phi) of the height of an effective space inside a cylindrical heat exchange chamber 11 of the vertical preheater to the diameter is controlled to be 1.1-1.4, the heat convection efficiency is highest, wherein the height (H) refers to the effective accumulation height of a material layer inside the cylindrical heat exchange chamber 11; the diameter (phi) means that the effective cross-sectional area of the cylindrical heat exchange chamber 11 is converted into the area of the corresponding circle, and then the corresponding diameter is obtained.
The system is mainly formed by uniformly distributing 12 vertical preheaters 1 in a 360-degree annular manner. The pushing action period and the pushing amount of the push rod are accurately controlled by a computer (or a PLC), and the height-diameter ratio range of the cylindrical preheating chamber is kept between 1.1 and 1.4, so that the heat exchange efficiency is maximized, and the purposes of energy conservation and emission reduction are achieved.
Through the arrangement, the periodical operation of static preheating of the branch chamber under the premise of the maximum decomposition rate of the limestone is realized.
After the improvement of the existing system, the utilization rate of the waste heat of the rotary kiln is obviously improved, the yield and the quality of the active lime are improved, the capacity is improved, and the heat consumption per ton of the active lime is reduced. The following economic benefits are obtained:
(1) the yield of the vertical preheater before improvement is 600t/d per day and 20 ten thousand tons per year.
(2) After the vertical preheater is improved, the yield is 800t/d per day, 26.7 ten thousand tons per year and 6.7 ten thousand tons per year.
(3) According to the heat consumption reduction of 20%, the coal consumption per ton of lime is reduced by about 44Kg, the lime cost is reduced by about 22 yuan, and the annual energy is saved by about 587.4 ten thousand yuan.
(4) According to the sale price of 380 yuan per ton of lime, the cost of 230 yuan per ton of lime, the pure profit of 125 yuan and the new profit of 837.5 ten thousand yuan per year.
(5) The annual benefit is integrated with 1424.9 ten thousand yuan.
Therefore, the improved energy-saving vertical preheater system obviously improves the economic benefit of enterprises and is beneficial to other enterprises to popularize the technology.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.
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| CN202011369842.6A CN112321177A (en) | 2020-11-30 | 2020-11-30 | An energy-saving vertical preheater system for active lime calcination |
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| CN202011369842.6A CN112321177A (en) | 2020-11-30 | 2020-11-30 | An energy-saving vertical preheater system for active lime calcination |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115355723A (en) * | 2022-10-21 | 2022-11-18 | 中航超能(苏州)科技有限公司 | Lime stone rotary kiln preheating device |
| CN116199434A (en) * | 2023-04-27 | 2023-06-02 | 淄博志华环保科技有限公司 | Preheating tower for calcium oxide production |
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| CN201892430U (en) * | 2010-12-10 | 2011-07-06 | 苏根华 | Novel energy-saving and environmentally-friendly vertical preheater with twelve push heads |
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| CN213739210U (en) * | 2020-11-30 | 2021-07-20 | 陕西省建筑材料工业设计研究院 | Energy-saving vertical preheater system for active lime calcination |
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2020
- 2020-11-30 CN CN202011369842.6A patent/CN112321177A/en active Pending
Patent Citations (4)
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| US20050069832A1 (en) * | 2003-09-30 | 2005-03-31 | Townsend John P. | Method and apparatus for preheating particulate material |
| CN201892430U (en) * | 2010-12-10 | 2011-07-06 | 苏根华 | Novel energy-saving and environmentally-friendly vertical preheater with twelve push heads |
| CN205580223U (en) * | 2016-05-04 | 2016-09-14 | 吉安鑫泰科技股份有限公司 | Roasting kiln flue gas cooling heat exchange device |
| CN213739210U (en) * | 2020-11-30 | 2021-07-20 | 陕西省建筑材料工业设计研究院 | Energy-saving vertical preheater system for active lime calcination |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115355723A (en) * | 2022-10-21 | 2022-11-18 | 中航超能(苏州)科技有限公司 | Lime stone rotary kiln preheating device |
| CN116199434A (en) * | 2023-04-27 | 2023-06-02 | 淄博志华环保科技有限公司 | Preheating tower for calcium oxide production |
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