CN111167621A - Multistage combined weak vortex low-resistance cyclone preheating system - Google Patents

Multistage combined weak vortex low-resistance cyclone preheating system Download PDF

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Publication number
CN111167621A
CN111167621A CN202010091442.7A CN202010091442A CN111167621A CN 111167621 A CN111167621 A CN 111167621A CN 202010091442 A CN202010091442 A CN 202010091442A CN 111167621 A CN111167621 A CN 111167621A
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China
Prior art keywords
cyclone
cylinder
inlet
volute
airflow
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马娇媚
李波
武晓萍
赵亮
高为民
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Tianjin Cement Industry Design and Research Institute Co Ltd
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Tianjin Cement Industry Design and Research Institute Co Ltd
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Priority to CN202010091442.7A priority Critical patent/CN111167621A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
    • B04C5/00—Apparatus in which the axial direction of the vortex is reversed
    • B04C5/24—Multiple arrangement thereof
    • B04C5/26—Multiple arrangement thereof for series flow
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
    • B04C5/00—Apparatus in which the axial direction of the vortex is reversed
    • B04C5/02—Construction of inlets by which the vortex flow is generated, e.g. tangential admission, the fluid flow being forced to follow a downward path by spirally wound bulkheads, or with slightly downwardly-directed tangential admission
    • B04C5/06—Axial inlets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
    • B04C5/00—Apparatus in which the axial direction of the vortex is reversed
    • B04C5/08—Vortex chamber constructions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
    • B04C5/00—Apparatus in which the axial direction of the vortex is reversed
    • B04C5/08—Vortex chamber constructions
    • B04C5/081—Shapes or dimensions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D13/00—Apparatus for preheating charges; Arrangements for preheating charges

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Geometry (AREA)
  • Fluid Mechanics (AREA)
  • Furnace Details (AREA)
  • Cyclones (AREA)

Abstract

The invention belongs to the technical field of cement industrial production, and particularly discloses a multistage combined weak vortex low-resistance cyclone preheating system which comprises an N-stage low-resistance weak vortex cyclone, an air pipe, a feeding pipe and a self-denitrification decomposing furnace which are sequentially connected in series; n is a positive integer of 3 or more; all the cyclones comprise inlet air pipes, volute bodies, inner cylinders, upper cones and lower cones; the inlet air pipe is arranged at the inlet of the volute body; the inlet air pipe is provided with an airflow inlet; the inner cylinder is a cylindrical cylinder body, and the inner cylinder and the airflow outlet are welded into a whole and are sleeved and welded in the volute body; the volute body is a three-center equal-height variable-angle volute structure formed by welding three arcs with different radiuses; the top of the volute body is provided with a top cover; and an airflow outlet is formed in the center of the top cover. The resistance of the preheater can be greatly reduced on the premise of ensuring the separation efficiency, so that the energy conservation and the consumption reduction are realized, compared with a common preheater, the preheater has lower resistance loss, and the power consumption of a system is greatly reduced by more than 10 percent.

Description

Multistage combined weak vortex low-resistance cyclone preheating system
Technical Field
The invention belongs to the technical field of cement industrial production, and particularly discloses a multistage combined weak vortex low-resistance cyclone cylinder cyclone preheating system.
Background
The preheating and predecomposition technology in the novel dry cement production line is one of the cores, wherein the preheater has the important function of preheating raw materials and recovering the waste gas enthalpy of the rotary kiln, the preheater generally comprises a plurality of stages of serially connected cyclones, and the lower system resistance is an important index for judging the cyclone preheater. The low-resistance cyclone preheater in the prior art can reduce the operation load of a high-temperature fan at the tail of a kiln, effectively reduce the power consumption of the low-resistance cyclone preheater, is beneficial to system ventilation, contributes to capacity excavation and adaptability of the system to poor-quality raw fuel, and is a research hotspot of cement engineering technical practitioners.
The resistance of the preheater mainly comes from a cyclone, and the cyclone is a gas-solid separation device which separates the particle dust from the airflow by utilizing the centrifugal force generated by the rotating dust-containing gas, and the device is most widely applied in industry and has the characteristics of simple structure, convenient operation, high dust collection efficiency and low price, and is suitable for purifying non-viscous non-fibrous dry dust with the particle dust size of more than 5-10 mu m. The fineness of raw materials fed into a preheater in the cement industry is generally less than or equal to 25 percent of screen residue with the particle size of 80 mu m, less than or equal to 3 percent of screen residue with the particle size of 200 mu m, the resistance of a single-stage cyclone cylinder is generally 800-1500 Pa, the resistance of a production line with large specific overproduction amplitude exceeds 2000Pa, the resistance of the whole preheater exceeds 5000Pa by taking a five-stage preheater as an example, exceeds 6000Pa by taking a six-stage preheater as an example, even exceeds 9000Pa, and the power consumption of a high-temperature fan exceeds 10 kWh/t.cl. In order to reduce resistance, related technology research and development mechanisms provide a cone expanding structure cyclone, an expansion bin, a guide plate, a volute form change and the like, and some preheaters even directly increase one to two scales of the selection of the preheater, but the negative effects include that the structure is complex, structural parts are easy to damage, the separation efficiency is obviously sacrificed, and dust at the outlet of the preheaterOver 100g/Nm3Up to 200g/Nm3The separation efficiency is reduced to below 90%, the ash return of the sintering system is large, the heat content is more, and the heat consumption of the whole sintering system is greatly improved.
High performance cyclones need to have both significant features of high separation efficiency and low drag loss. The cyclone has high separation efficiency, low dust content in the outlet cyclone and low system heat loss; the resistance loss of the cyclone cylinder is small, the load of the high-temperature fan is low, and the power consumption is low. In the design and development process of the cyclone, high separation efficiency and low pressure loss are a pair of indexes for mutual balance control, in the existing practical application, in order to keep the cyclone at higher separation efficiency, a part of pressure indexes need to be sacrificed, otherwise, the resistance of the cyclone is greatly reduced, which often influences the separation efficiency, thereby influencing the normal working performance of the cyclone. Therefore, on the premise of ensuring the separation efficiency, the research on the cyclone with smaller resistance loss has an important influence on the improvement of the overall performance of the preheating and pre-decomposition system in the cement industry.
In summary, the problems of the prior art are as follows:
(1) the resistance of the preheating system is large, the resistance of the single-stage cyclone reaches 800-2000Pa, the power consumption of the high-temperature fan is high, and the power consumption of unit clinker exceeds 10 kWh/t.cl.
(2) The separation efficiency of the preheating system is low, a large amount of hot raw materials are taken away, the ash return of the preheater is large, and the heat consumption is large;
(3) the ubiquitous low resistance pre-heaters are complex in result and parts are prone to wear.
The difficulty and significance for solving the technical problems are as follows:
the preheater with simple structure and good effect is found, and has important significance for reducing the power consumption and the heat consumption of a cement burning system. Energy conservation, emission reduction and environmental protection become the trend of industrial high-quality development, and the high-efficiency low-resistance preheater has a very wide application prospect.
Disclosure of Invention
The invention provides a multistage combined weak vortex low-resistance cyclone preheating system for solving the technical problems in the prior art, which can still greatly reduce the resistance on the premise of ensuring the separation efficiency so as to realize energy conservation and consumption reduction, has lower resistance loss compared with a common preheater, and greatly reduces the power consumption of the system by more than 10 percent.
In order to achieve the purpose, the invention adopts the following technical scheme:
a multistage combined weak vortex low-resistance cyclone preheating system comprises an N-stage low-resistance weak vortex cyclone cylinder, an air pipe, a feeding pipe and a self-denitrification decomposing furnace which are sequentially connected in series; n is a positive integer of 3 or more; the last stage cyclone is named as N stage.
The cyclone cylinders are divided into top-level cyclone cylinders and non-top-level cyclone cylinders according to the positions arranged on the preheater; the top-level cyclone cylinder is arranged at the top of the preheating system, and the non-top-level cyclone cylinder is arranged below the top-level cyclone cylinder; all the cyclones comprise inlet air pipes, volute bodies, inner cylinders, upper cones and lower cones;
the inlet air pipe is a part of the end part of the air pipe connected with the cyclone cylinder and is arranged at the inlet of the volute body; the inlet air pipe is provided with an airflow inlet;
the inner cylinder is a cylindrical cylinder body, and the inner cylinder and the airflow outlet are welded into a whole and are sleeved and welded in the volute body;
the volute body is a three-center equal-height angle-variable volute structure formed by welding three arcs with different radiuses; the top of the volute body is provided with a top cover; an airflow outlet is formed in the center of the top cover;
the cylinder is a cylindrical hollow shell, and the upper vertebral body and the lower vertebral body are sequentially connected below the cylinder; the lower vertebral body outlet is a feed opening.
Furthermore, in all the adjacent cyclones, the airflow inlet of the upper stage of cyclone is connected with the airflow outlet of the lower stage of cyclone through an air pipe; all the feed openings are connected with feed pipes; the discharge pipe on any cyclone cylinder of the front N-3 level is communicated with the air pipe between the two stages of cyclone cylinders behind the cyclone cylinder;
the decomposing furnace is arranged below all the cyclones; the feeding pipe of the N-1 level cyclone cylinder is communicated with the decomposing furnace;
a smoke chamber communicated with the rotary kiln is also arranged below the decomposing furnace, and a discharging pipe of the N-stage cyclone cylinder is communicated with the smoke chamber; a raw material feeding pipe is communicated with the air pipe between the top stage cyclone cylinder and the secondary cyclone cylinder;
the high-temperature fan is arranged on the ground; and the high-temperature fan is connected with an air outlet at the top of the top-level cyclone cylinder through a pipeline.
Furthermore, the volute body is composed of an R2 arc section with O2 as a center, one end of the R2 arc section is welded with an R1 arc section with O1 as a center, and the other end of the R2 arc section is welded with an R3 arc section with O3 as a center; the sum of the angles of the three arc sections with different radiuses is 270 degrees, and the three arc sections are connected with the column body in an equal-height angle-changing mode.
Further, for the non-top-level weak vortex cyclone, the width-to-height ratio b/a of the airflow inlet is 0.3-0.6; and/or the ratio Fi/F of the vertical sectional area Fi of the airflow inlet to the sectional area F of the cylinder is 0.2-0.5; and/or the distance between the position of the inlet air pipe close to the inner cylinder and the inner cylinder is more than 150 mm.
Furthermore, the ratio of the inner diameter d of the inner cylinder to the inner diameter Di of the cylinder is d/Di 0.4-0.6; and/or the spiral lines of the volute are sequentially tangent, and the ratio of the eccentricity e1 of the R2 arc segment to the inner diameter Di of the cylinder is e1/Di which is 0.06-0.09; the ratio of the eccentricity e2 of the R3 arc segment to the internal diameter Di of the cylinder is e2/Di equal to 0-0.4.
Further, for the top-level weak vortex cyclone C1, the width-to-height ratio b/a of the airflow inlet is 0.3-0.6; and/or the ratio Fi/F of the vertical sectional area Fi of the airflow inlet to the sectional area F of the cylinder is 0.15-0.25; and/or the distance between the position of the inlet air pipe close to the inner cylinder and the inner cylinder is more than 500 mm.
Furthermore, the ratio of the inner diameter d of the inner cylinder to the inner diameter Di of the cylinder is d/Di 0.3-0.5; and/or the ratio of the eccentricity e1 of the R2 arc segment to the internal diameter Di of the cylinder is e1/Di equal to 0.1-0.2; the eccentricity e2/Di of the R3 arc segment is 0.
Further, the ratio of the height H of the cyclone cylinder to the inner diameter Di of the cylinder is 1.1-3.1.
Further, the airflow inlet wind speed V of the cyclone cylinderInto12-18 m/s; air flow velocity V of air flow outletGo out＝13-19m/s。
Furthermore, the wind speed of the cylinder is 2-8 m/s; and/or the section wind speed of the wind pipe is 16-24 m/s.
The invention has the advantages and positive effects that:
according to the preheating device, the weak vortex low-resistance cyclone cylinder airflow is stably introduced into the cyclone cylinder, and materials reach the cylinder wall under the action of inertia force and centrifugal force, so that the improvement of material separation efficiency and the reduction of resistance of the cyclone cylinder are facilitated; the eddy resistance in the inlet area is reduced, the resistance loss is lower, the speed of the inlet airflow and the rotating speed of the airflow in the inner cylinder can be effectively controlled, the collision of the inlet airflow and the backflow is reduced or avoided, and the separation efficiency is improved; the top-level cyclone ensures high overall separation efficiency of the preheater; the last cyclone is provided with a flat-nozzle air cannon, so that the skinning blockage caused by reduction atmosphere or high-temperature material stickiness is reduced.
The resistance of the multi-stage preheating system obtained by adopting the technology of the invention is 500-2000 Pa lower than that of a common kiln tail preheater, the power consumption of a high-temperature fan can be controlled below 4kWh/t.cl, the electricity is saved by more than 10%, the six-stage preheater can reach the resistance of the traditional five-stage preheater, namely, the first-stage heat exchange is increased on the premise of not increasing the power consumption, and the energy consumption is reduced by 3-5 kgce/t.cl; the technology is also suitable for the reconstruction and the upgrade of the existing production line, and does not influence the civil structure of the original kiln tail preheater.
In order to further realize the purposes of energy conservation and consumption reduction and solve the problem of two contradictory performances of the resistance and the separation efficiency of the preheater, in the technical scheme, a high-efficiency low-resistance preheating technology is preferably combined with a gradient combustion self-denitration decomposition furnace to form a preheating pre-decomposition technology with high efficiency, low resistance, low energy consumption and low NOx emission, and simultaneously, the functions of energy conservation and environmental protection are achieved.
In addition, the volute body adopts an equal-height variable-angle three-center 270-degree large volute spiral structure, three arcs with different radiuses are connected smoothly, airflow can be led into the cyclone cylinder stably, materials reach the cylinder wall under the action of inertia force and centrifugal force, and the improvement of material separation efficiency and the reduction of resistance of the cyclone cylinder are facilitated;
the spiral line of the volute adopts an equal-height variable-angle structure, and the included angle between the outer side wall of the volute connected with the cylinder and the horizontal direction is gamma; the included angle gamma is 50 degrees at the air inlet and gradually increases to 90 degrees along the spiral line of the volute, so that the occurrence of slope material accumulation can be effectively prevented, and the interference of collapsed materials on the air flow in the cyclone barrel is reduced;
the volute body adopts a large volute spiral structure, so that the inlet area is larger, the wind speed is lower, the eddy resistance in an inlet area is reduced, and the resistance loss is lower;
the size design of the inlet air pipe is more reasonable, the width-height ratio of the inlet is 0.3-0.6, and the ratio of the vertical sectional area F of the airflow inlet to the sectional area Fi of the cylinder is 0.2-0.4; the speed of the inlet airflow and the rotating speed of the airflow in the inner cylinder can be effectively controlled, the collision of the inlet airflow and the backflow is reduced or avoided, and the separation efficiency is improved;
the inlet air pipe is opposite to the airflow inlet, and the airflow is guided into the volute body by adopting a smooth and stable inclined wall, the angle of the inclined wall is gradually increased from top to bottom, so that the airflow guiding effect is realized, the eddy resistance at the inlet of the volute body can be reduced, the resistance loss is lower, the speed of the inlet airflow and the rotation speed of the airflow at the inner barrel can be effectively controlled, the collision of the inlet airflow and the backflow is reduced or avoided, and the separation efficiency is improved; the stability of airflow at the inlet of the cyclone is ensured, the vortex is reduced, and the resistance is reduced.
Description of the drawings:
FIG. 1 is a schematic diagram of the preheating system of the present invention;
FIG. 2 is a front view of the cyclone cartridge;
FIG. 3 is a top view of FIG. 2;
FIG. 4 is a left side view of the inlet ductwork of the present invention;
FIG. 5 is a schematic view of the flow direction of the air in the cyclone according to the present invention; wherein the solid lines are inlet flows and the dashed lines are outlet flows.
Wherein:
1. a cyclone; 11. an inlet air duct; 11a, an airflow inlet; 11b, an outer side wall; 11c, an inclined wall; 12. a volute housing; 12a, a top cover; 12b, an airflow outlet; 13. an inner barrel; 14. a cylinder; 15. an upper cone; 16. a lower cone; 16a and a feed opening; 2. an air duct; 3. a discharging pipe; 4. a decomposing furnace; 5. a smoking chamber; 6. a raw material feeding pipe; 7. a high temperature fan.
Detailed Description
The drawings in the embodiments of the invention will be combined; the technical scheme in the embodiment of the invention is clearly and completely described; obviously; the described embodiments are only some of the embodiments of the invention; rather than all embodiments. Based on the embodiments of the invention; all other embodiments obtained by a person skilled in the art without making any inventive step; all fall within the scope of protection of the present invention.
As shown in figure 1, the invention provides a multistage combined weak vortex low-resistance cyclone preheating system, which comprises an N-stage low-resistance weak vortex cyclone cylinder 1, an air pipe 2, a discharging pipe 3 and a self-denitrification decomposing furnace 4 which are sequentially connected in series; n is a positive integer of 3 or more; the cyclone cylinders are divided into top-level cyclone cylinders and non-top-level cyclone cylinders according to the positions arranged on the preheater; the top-level cyclone cylinder is arranged at the top of the preheating system, and the non-top-level cyclone cylinder is arranged below the top-level cyclone cylinder;
specifically, all the cyclones comprise inlet air pipes 11, volute bodies 12, inner cylinders 13, cylinders 14, upper cones 15 and lower cones 16; the last cyclone cylinder at the lowest part is provided with a flat nozzle air cannon, so that the skinning blockage caused by reduction atmosphere or high-temperature material stickiness is reduced.
The inlet air pipe 11 is a part of the end part of the air pipe connected with the cyclone cylinder and is arranged at the inlet of the volute body 12; the inlet air pipe 11 is provided with an airflow inlet 11 a;
the inner cylinder 13 is a cylindrical cylinder, and the inner cylinder 13 and the airflow outlet 12b are welded into a whole and sleeved in the volute body 12;
the volute body 12 is a three-center equal-height angle-variable big volute structure formed by welding three arcs with different radiuses; the top of the volute body 12 is provided with a top cover 12 a; the center of the top cover 12a is provided with an airflow outlet 12 b; specifically, the volute body 12 is formed by welding an R1 arc segment with O1 as a center at one end of an R2 arc segment with O2 as a center, and welding an R3 arc segment with O3 as a center at the other end; the sum of the angles of the three arc sections with different radiuses is 270 degrees, and the three arc sections are connected with the lower column body 14 in an equal-height angle-changing mode; the three arcs with different radiuses are connected more smoothly, so that airflow can be stably led into the cyclone, and materials reach the wall of the cyclone under the action of inertia force and centrifugal force, thereby being beneficial to improving the material separation efficiency and reducing the resistance of the cyclone; the spiral line of the volute adopts an equal-height variable-angle structure, and the included angle between the outer side wall 11b of the volute 12 connected with the cylinder 14 and the horizontal direction is gamma; the included angle gamma is 50 degrees at the air inlet and gradually increases to 90 degrees along the spiral line of the volute. Therefore, the slope material accumulation can be effectively prevented, and the interference of collapsed materials on the airflow in the cyclone barrel is reduced; the volute inlet adopts the large volute spiral structure, so that most of the inlet area and the volute are enlarged, the inlet area is larger, the wind speed is lower, the eddy resistance in the inlet area is reduced, and the resistance loss is lower;
the column body 14 is a cylindrical hollow shell, and the upper vertebral body 15 and the lower vertebral body 16 are sequentially connected below the column body 14; the outlet of the lower vertebral body is a feed opening 16 a. The upper cone body is a straight cone body with the diameter reduced from top to bottom, and the lower cone body is a tilted cone body with the diameter reduced from top to bottom; the minimum included angle between the axis of the askew cone and the horizontal plane is 60 degrees, so that the air flow is convenient to return while the blanking is not hindered.
preferably, the air inlet duct 11 is provided with a smooth and stable inclined wall 11c facing the airflow inlet 11a to guide the airflow into the volute 12, specifically, the inclined wall 11c is composed of two sections, an included angle α between the upper inclined wall 11c and the horizontal direction is 15-20 degrees, an included angle β between the lower inclined wall 11c and the horizontal direction is 60-70 degrees, and the structure that the angle of the inclined wall 11c gradually increases from top to bottom not only plays a role of airflow guiding, but also can ensure stable airflow at the cyclone inlet, reduce vortex and reduce resistance.
Preferably, for a non-top-level weak vortex cyclone: the width-to-height ratio b/a of the airflow inlet 11a is 0.3-0.6, the ratio Fi/F of the vertical sectional area Fi of the airflow inlet 11a to the sectional area F of the column 14 is 0.2-0.5, and the distance between the position, close to the inner cylinder, of the inlet air duct 11 and the inner cylinder is more than 150 mm; the speed of the inlet airflow and the rotating speed of the airflow in the inner cylinder 13 can be effectively controlled, the collision of the inlet airflow and the backflow is reduced or avoided, and the separation efficiency is improved; preferably, if the inner diameter of the inner cylinder is d and the effective inner diameter of the cylinder is Di, the ratio of the inner diameter d of the inner cylinder to the inner diameter Di of the cylinder is d/Di of 0.4-0.6; the spiral lines of the volute body are sequentially tangent, the eccentricity e1/Di of the R2 arc section is 0.06-0.09, the eccentricity e2/Di of the R3 arc section is 0-0.4, and when e2 is 0, the center point of the R3 arc section and the center point of the R1 arc section are superposed and fall at the center of a cylinder; in addition, the ratio of the height H of the cyclone to the inner diameter Di of the cylinder is 2.2-4.5.
For the top-level weak vortex cyclone C1: the width-to-height ratio b/a of the airflow inlet 11a is 0.3-0.6, the ratio Fi/F of the vertical sectional area Fi of the airflow inlet 11a to the sectional area F of the column 14 is 0.15-0.25, and the distance between the position, close to the inner cylinder, of the inlet air duct 11 and the inner cylinder is more than 500 mm; preferably, the ratio of the inner diameter d of the inner cylinder to the inner diameter Di of the cylinder is d/Di of 0.3-0.5, the spiral lines of the volute bodies are sequentially tangent, the eccentricity e1/Di of the R2 arc section is 0.1-0.2, the eccentricity e2/Di of the R3 arc section is 0, and the eccentricity e2 is 0, wherein the center point of the R3 arc section is coincident with the center point of the R1 arc section and falls at the center of the cylinder. In addition, the ratio of the height H of the cyclone to the inner diameter Di of the cylinder is 1.1-3.1. Preferably, the top stage cyclone is of a double-cyclone-cylinder structure which is symmetrically arranged, and inlet air pipes of the two cyclones are arranged adjacently.
The entrained air flow enters the cyclone cylinder from the air flow inlet 11a of the inlet air pipe 11 in a relatively stable mode, rotates to flow downwards along the wall surface of the volute body 12, and the raw material enters the feed opening 61 along the wall surfaces of the cylinder 14, the upper cone 15 and the lower cone 16 in sequence, so that the raw material is discharged out of the cyclone cylinder; the gas is folded back under the action of the upper cone 15 and the lower cone 16 and is discharged out of the cyclone cylinder from the airflow outlet 12b through the inner cylinder 13; the gas-solid separation of the dusty gas flow is realized.
In all the adjacent cyclones, the airflow inlet of the upper stage of cyclone is connected with the airflow outlet of the lower stage of cyclone through an air pipe; all the feed openings are connected with feed pipes; the discharge pipe on any cyclone cylinder of the front N-3 level is communicated with the air pipe between the two stages of cyclone cylinders behind the cyclone cylinder;
the decomposing furnace is arranged below all the cyclones; the feeding pipe of the N-1 level cyclone cylinder is communicated with the decomposing furnace;
a smoke chamber 5 communicated with the rotary kiln is also arranged below the decomposing furnace, and a discharging pipe of the N-stage cyclone cylinder is communicated with the smoke chamber; the wind pipe between the top stage cyclone cylinder and the second stage cyclone cylinder is communicated with a raw material feeding pipe 6.
Also comprises a high temperature fan 7 arranged on the ground; the high-temperature fan is connected with an air outlet at the top of the top-level cyclone cylinder C1 through a pipeline, and the high-temperature fan provides air for the whole system.
As shown in fig. 1, taking a six-stage cyclone preheater as an example, when in operation, raw meal enters the C2-C1 wind pipe through the raw meal feeding pipe, because hot air flow pulled by a high-temperature fan flows through all the wind pipes, the raw meal heated by the hot ascending air flow enters the C1 cyclone 1 along with the air flow to be subjected to gas-solid separation, the separated raw meal enters the C3-C2 wind pipe from the C1 blanking pipe, the raw meal heated in the same way enters the C2 cyclone to be subjected to gas-solid separation, the separated raw meal enters the C4-C3 wind pipe from the C2 blanking pipe, the separated raw meal enters the C3 cyclone to be subjected to gas-solid separation after being heated, the separated raw meal enters the C5-C4 wind pipe from the C3 blanking pipe, the heated raw meal enters the C4 cyclone to be subjected to gas-solid separation, the separated raw meal enters the C6-C5 wind pipe from the C4 blanking pipe, the heated raw meal enters the C5 cyclone for gas-solid separation, and the separated raw meal enters the C5, the raw material is decomposed in the decomposing furnace and carried into the C6 cyclone cylinder by hot air flow for gas-solid separation, and the separated raw material enters the smoke chamber from the C6 blanking pipe and finally enters the rotary kiln for calcination.
Because the decomposing furnace is provided with two different feed inlets corresponding to decomposing areas with different temperatures, the C5 cyclone cylinder is provided with two C5 blanking pipes communicated with the feed inlets, and a material distributing valve is arranged below the airlock valve of the C5 cyclone cylinder so as to distribute materials for the two C5 blanking pipes.
Experimental research and engineering practice show that the air speed V at the airflow inlet of the cyclone cylinderIntoThe influence on the resistance and the efficiency is large, and V is desirable from the viewpoint of resistance reductionIntoLower level; from the viewpoint of improving the air volume and efficiency, VIntoHigher, better; when V isIntoBeyond a certain limit, the resistance increases dramatically, and the efficiency increases only slightly. The optimum inlet wind speed is different according to the structure of the cyclone preheater and the temperature of the treated gas, and V is taken in the inventionInto12-18 m/s; air flow velocity V of air flow outletGo out13-19 m/s; the air speed of the column body is 2-8m/s, and the air speed of the section of the air pipe is 16-24 m/s.
In this embodiment, same from denitration dore furnace corresponds two preheating device, also can be a list preheater or three rows preheater in the actual design process.
TABLE 1 Multi-stage preheater technical parameters of the present invention
Four-stage preheater Five-stage preheater Six-stage preheater Seven-stage preheater
General resistance/Pa 4600 5200 6000 6700
resistance/Pa of the invention ≤3300 ≤3900 ≤4500 ≤5100
Temperature/. degree.C ≤380 ≤320 ≤260 ≤230
Standard coal consumption/kgce/t.cl ≤107 ≤100 ≤94 ≤90
The power consumption of the resistance high-temperature fan of the multi-stage preheating system obtained by the technology can be controlled below 4kWh/t.cl, electricity is saved by more than 10%, the six-stage preheater can reach the resistance of the traditional five-stage preheater, the first-stage heat exchange is added on the premise of not increasing the power consumption, and the energy consumption is reduced by 3-5 kgce/t.cl; the technology is also suitable for the reconstruction and the upgrade of the existing production line, and does not influence the civil structure of the original kiln tail preheater. The following are the main performance assurance parameters of the present invention under normal raw fuel conditions:
furthermore, in the 5500t/d production line six-stage high-efficiency low-resistance weak vortex cyclone preheater technology in the table 1, on the premise that the kiln tail is not increased in the model selection specification, the yield of the device after production is stabilized at 6000-6200t/d, the temperature at the outlet of the preheater is 260 ℃, the pressure at the outlet of the preheater is 4200-4500Pa, the resistance of a top-stage cyclone cylinder C1 is below 800Pa, and the resistance of a non-top-stage cyclone cylinder is below 500 Pa; the separation efficiency of the non-top-level cyclone of the preheater reaches about 90 percent, and the separation efficiency of the top-level cyclone reaches 97 percent. The dust concentration at the outlet of the preheater is less than or equal to 60g/Nm3, the separation efficiency reaches more than 95%, the power consumption of a high-temperature fan is 3.6-4.0kWh/t.cl, the comprehensive power consumption of clinker is less than 40kWh/t.cl, and the standard coal consumption is less than or equal to 94kgce/t.cl, so that good energy-saving and emission-reducing effects are achieved.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention, and should not be taken as limiting the invention, for example, single or double or triple row preheaters, such as two, three, four, five, six, seven, eight, etc. stages of cyclones may be used, and any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (10)

1. The utility model provides a weak vortex low resistance whirlwind preheating system of multistage combination which characterized in that: the device comprises an N-level low-resistance weak vortex cyclone cylinder, an air pipe, a feeding pipe and a self-denitrification decomposing furnace which are sequentially connected in series; n is a positive integer more than 3, and the top is set as level 1;
the cyclone cylinders are divided into top-level cyclone cylinders and non-top-level cyclone cylinders according to the positions arranged on the preheater; the top-level cyclone cylinder is arranged at the top of the preheating system, and the non-top-level cyclone cylinder is arranged below the top-level cyclone cylinder; all the cyclones comprise inlet air pipes, volute bodies, inner cylinders, upper cones and lower cones;
the inlet air pipe is a part of the end part of the air pipe connected with the cyclone cylinder and is arranged at the inlet of the volute body; the inlet air pipe is provided with an airflow inlet;
the inner cylinder is a cylindrical cylinder body, and the inner cylinder and the airflow outlet are welded into a whole and are sleeved and welded in the volute body;
the volute body is a three-center equal-height angle-variable volute structure formed by welding three arcs with different radiuses; the top of the volute body is provided with a top cover; an airflow outlet is formed in the center of the top cover;
the cylinder is a cylindrical hollow shell, and the upper vertebral body and the lower vertebral body are sequentially connected below the cylinder; the lower vertebral body outlet is a feed opening.
2. The multi-stage combined weak vortex low resistance cyclone preheating system of claim 1, wherein: in all the adjacent cyclones, the airflow inlet of the upper stage of cyclone is connected with the airflow outlet of the lower stage of cyclone through an air pipe; all the feed openings are connected with feed pipes; the discharge pipe on any cyclone cylinder of the front N-3 level is communicated with the air pipe between the two stages of cyclone cylinders behind the cyclone cylinder;
the decomposing furnace is arranged below all the cyclones; the feeding pipe of the N-1 level cyclone cylinder is communicated with the decomposing furnace;
a smoke chamber communicated with the rotary kiln is also arranged below the decomposing furnace, and a discharging pipe of the N-stage cyclone cylinder is communicated with the smoke chamber; a raw material feeding pipe is communicated with the air pipe between the top stage cyclone cylinder and the secondary cyclone cylinder;
the high-temperature fan is arranged on the ground; and the high-temperature fan is connected with an air outlet at the top of the top-level cyclone cylinder through a pipeline.
3. The multi-stage combined weak vortex low resistance cyclone preheating system of claim 2, wherein: the volute body is composed of an R2 circular arc section with O2 as a center, one end of the R2 circular arc section is welded with an R1 circular arc section with O1 as a center, and the other end of the R2 circular arc section is welded with an R3 circular arc section with O3 as a center; the sum of the angles of the three arc sections with different radiuses is 270 degrees, and the three arc sections are connected with the column body in an equal-height angle-changing mode.
4. The multi-stage combined weak vortex low resistance cyclone preheating system of claim 3, wherein: for the non-top-level weak vortex cyclone, the width-to-height ratio b/a of the airflow inlet is 0.3-0.6;
and/or the ratio Fi/F of the vertical sectional area Fi of the airflow inlet to the sectional area F of the cylinder is 0.2-0.5;
and/or the distance between the position of the inlet air pipe close to the inner cylinder and the inner cylinder is more than 150 mm.
5. The multi-stage combined weak vortex low resistance cyclone preheating system of claim 4, wherein: the ratio of the inner diameter d of the inner cylinder to the inner diameter Di of the cylinder is d/Di 0.4-0.6;
and/or the spiral lines of the volute are sequentially tangent, and the ratio of the eccentricity e1 of the R2 arc segment to the inner diameter Di of the cylinder is e1/Di which is 0.06-0.09; the ratio of the eccentricity e2 of the R3 arc segment to the internal diameter Di of the cylinder is e2/Di equal to 0-0.4.
6. The multi-stage combined weak vortex low resistance cyclone preheating system of claim 3, wherein: for the top-level weak vortex cyclone C1, the width-to-height ratio b/a of the airflow inlet is 0.3-0.6;
and/or the ratio Fi/F of the vertical sectional area Fi of the airflow inlet to the sectional area F of the cylinder is 0.15-0.25;
and/or the distance between the position of the inlet air pipe close to the inner cylinder and the inner cylinder is more than 500 mm.
7. The multi-stage combined weak vortex low resistance cyclone preheating system of claim 6, wherein: the ratio of the inner diameter d of the inner cylinder to the inner diameter Di of the cylinder is d/Di 0.3-0.5;
and/or the ratio of the eccentricity e1 of the R2 arc segment to the internal diameter Di of the cylinder is e1/Di equal to 0.1-0.2; the eccentricity e2/Di of the R3 arc segment is 0.
8. The multi-stage combined weak vortex low resistance cyclone preheating system of claim 6, wherein: the ratio of the height H of the cyclone to the inner diameter Di of the cylinder is 1.1-3.1.
9. The multi-stage combined weak vortex low resistance cyclone preheating system of claim 2, wherein: airflow inlet wind speed V of cyclone cylinderInto12-18 m/s; air flow velocity V of air flow outletGo out＝13-19m/s。
10. The multi-stage combined weak vortex low resistance cyclone preheating system of claim 2, wherein: the wind speed of the cylinder is 2-8 m/s; and/or the wind speed of the wind pipe is 16-24 m/s.
CN202010091442.7A 2020-02-13 2020-02-13 Multistage combined weak vortex low-resistance cyclone preheating system Pending CN111167621A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114522476A (en) * 2022-03-07 2022-05-24 广东石油化工学院 Reducing spiral dust removal channel based on cyclone separation principle

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114522476A (en) * 2022-03-07 2022-05-24 广东石油化工学院 Reducing spiral dust removal channel based on cyclone separation principle
CN114522476B (en) * 2022-03-07 2023-08-25 广东石油化工学院 Diameter-reduced spiral dust removal channel based on cyclone separation principle

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