SU924478A1

SU924478A1 - Cyclone shaft furnace

Info

Publication number: SU924478A1
Application number: SU802990518A
Authority: SU
Inventors: Эдуард Николаевич Сабуров; Юрий Леонидович Леухин; Сергей Иванович Осташев
Original assignee: Архангельский Ордена Трудового Красного Знамени Лесотехнический Институт Им.В.В.Куйбышева
Priority date: 1980-10-08
Filing date: 1980-10-08
Publication date: 1982-04-30

Description

Изобретение относится к устройствам для термообработки сыпучих материалов и может быть использовано на предприятиях химической и других отраслей промышленности, а также в производстве строительных материалов.The invention relates to a device for heat treatment of bulk materials and can be used in enterprises of chemical and other industries, as well as in the production of building materials.

Известна установка, состоящая из двуХступен- ⁵чато расположенных вращающихся печей с самостоятельной подачей топлива и подогретого воздуха, содержащая также теплообменники барабанного, колосникового и циклонного типов и циклонный пылеуловитель [1].A well-known installation consisting of two-stage- ⁵ chatrooms located rotary kilns with independent supply of fuel and heated air, containing also drum, grate and cyclone heat exchangers and a cyclone dust collector [1].

Недостатками установки являются высокий удельный расход топлива и пылеунос материала, что вызывает необходимость установки громоздких обеспыливающих систем с циклонами отделителями.The disadvantages of the installation are the high specific fuel consumption and dust extraction of the material, which necessitates the installation of bulky dedusting systems with cyclones separators.

Известна циклонная камера для термообработки полидисперсного материала, содержащая цилиндрический корпус с газогорелочными устройствами, центральной загрузкой обрабатываемого материала и нижним выводом из циклонной камеры дымовых газов и обрабатываемого материала. В этой печи с целью интенсификации теплообмена, на внутренней поверх^f 2 ности камеры выполнены выступы, располб-~ женные в несколько рядов по высоте корпуса под углом к образующей последнего в направлении крутки газового потока [2).Known cyclone chamber for heat treatment of polydisperse material, containing a cylindrical body with gas burner devices, a Central loading of the processed material and the lower output from the cyclone chamber of flue gases and the processed material. In this furnace, in order to intensify heat transfer, protrusions are made on the inner surface of ^f 2 of the chamber, arranged in several rows along the height of the body at an angle to the generatrix of the latter in the direction of the gas flow twist [2).

Недостатком такой печи является то, что она требует установки дополнительно сепарационного оборудования, вследствие того, что дымовые газы имеют непосредственный контакт с сыпучим материалом.The disadvantage of such a furnace is that it requires the installation of additional separation equipment, due to the fact that flue gases have direct contact with bulk material.

Наиболее близкой по технической сущности и достигаемому эффекту к предлагаемой является шахтная печь, содержащая расширяющуюся книзу рабочую камеру с центральным расширяющимся кверху дымоходом, соединенным с топочной камерой, окружающей рабочую камеру. В этой печи с целью интенсификации теплообмена и снижения пылеуноса верхняя часть топочной камеры соединена с нижней частью дымохода каналом, оборудованным топливосжигающим устройством, а стенки камеры выполнены сплошными [3].The closest in technical essence and the achieved effect to the proposed one is a shaft furnace containing a working chamber expanding downward with a central chimney expanding upward, connected to a combustion chamber surrounding the working chamber. In this furnace, in order to intensify heat transfer and reduce dust extraction, the upper part of the combustion chamber is connected to the lower part of the chimney by a channel equipped with a fuel-burning device, and the chamber walls are solid [3].

Недостатком известной печи является низкая теплоотдача вследствие того, что не используются возможности интенсификации jpa бочего процесса за счет повышения уровня конвективного теплообмена, который открывает применение закрученных выхревых потоков.A disadvantage of the known furnace is the low heat transfer due to the fact that the possibilities of intensifying the jpa of the process by not increasing the level of convective heat transfer, which opens up the use of swirling exhaust flows, are not used.

Цель изобретения - интенсификация теплообмена. jThe purpose of the invention is the intensification of heat transfer. j

Указанная цель достигается тем, что в шахтной печи, содержащей расширяющуюся книзу рабочую камеру с центральным расширяющимся кверху дымоходом, соединенным с топочной камерой, окружающей рабочую камеру, рабо- щ чая камера выполнена в виде усеченной правильной четырехугольной пирамиды.This goal is achieved by the fact that in a shaft furnace containing a downwardly expanding working chamber with a central upwardly extending chimney connected to the combustion chamber surrounding the working chamber, the working chamber is made in the form of a truncated regular quadrangular pyramid.

На фиг. 1 представлена камера, общий вид; на фиг. 2 - разрез А-А на фиг. 1; на фиг. 3 зависимость теплоотдачи для различных форм , ₅рабочей камеры от нагрузки устройства по Газу (линия 1 в виде усеченного конуса, линия 2 — в виде усеченной правильной четырехугольной пирамиды).In FIG. 1 shows a camera, a General view; in FIG. 2 is a section AA in FIG. 1; in FIG. 3 the dependence of heat transfer for various forms, _{5 of the} working chamber on the gas load of the device (line 1 in the form of a truncated cone, line 2 - in the form of a truncated regular quadrangular pyramid).

Печь содержит расширяющуюся книзу рабо- ₂₀чую камеру 1 с центральным расширяющимся кверху дымоходом 2. Рабочая камера 1 расположена в центре топочной камеры 3 и выполнена в виде правильной усеченной пирамиды. Топочная камера оборудована двумя горел- ₂₅ками 4, расположенными тангенциально к внут ренней поверхности камеры, и соединена каналом 5 с дымоходом 2. Канал 5 снабжен .топливосжигающим устройством 6. Печь оборудована разгрузочным приспособлением 7. Поверхности 8 и 9 образуют рабочую камеру и изолируют обрабатываемый материал от греющего агента (дымовых газов).The furnace includes a flared downwardly rabo- ₂₀ smell chamber 1 with a central expanding upward chimney 2. The process chamber 1 is located in the center of the combustion chamber 3 and formed as a truncated right pyramid. The heating chamber ₂₅ is equipped with two gorel- kami 4 arranged tangentially to vnut renney chamber surface, and channel 5 is connected with a chimney 2. The channel 5 is provided .toplivoszhigayuschim device 6. The furnace is equipped with an unloading device 7. The surfaces 8 and 9 form the working chamber is isolated and treated material from a heating agent (flue gas).

Печь работает следующим образом.The furnace operates as follows.

Сыпучий материал поступает в рабочую камеру 1 через зазор между поверхностями 8 ³⁵ и 9. Под действием собственного веса материал опускается вниз со скоростью, определяемой разгрузочным приспособлением 7. При работе печи топливо и воздух подают в необходимых количествах в горелки 4. Образую- ⁴⁰щиеся дымовые газы обогревают обрабатываемый материал снаружи через поверхность 8 и, перетекая по каналу 5, обогревают материал изнутри через поверхность 9.Bulk material enters the processing chamber 1 through the gap ³⁵ between the surfaces 8 and 9. Under the effect of its own weight of the material falls down at a rate determined by a discharge device 7. In operation, the furnace fuel and air are supplied in the required quantities in the burner 4. The smoke thus formed ⁴⁰ schiesya gases heat the processed material from the outside through the surface 8 and, flowing along the channel 5, heat the material from the inside through the surface 9.

Выполнение рабочей камеры в виде правиль- 45 ной усеченной четырехугольной пирамиды вмес то усеченного круглого конуса позволяет значительно интенсифицировать процесс теплоотдачи на ее внешней поверхности. Связано это с тем, что у поверхности грани пирамиды дви жение потока носит отрывной - вихревой характер, а у поверхности конуса - безотрывный. Сопоставления проведены для рабочих камер с одинаковой площадью поперечного сечения и прочих равных условиях. N« = - число kjfj· с?The design of the working chamber in the form of a correct truncated quadrangular pyramid instead of a truncated round cone allows one to significantly intensify the heat transfer process on its outer surface. This is due to the fact that, at the surface of the pyramid’s face, the flow motion is detached - vortex, and at the cone surface it is continuous. Comparisons were made for working chambers with the same cross-sectional area and other equal conditions. N «= is the number kjfj · s?

Нуссельта; R_e--— число Рейнольда, где а - коэффициент теплоотдачи, d - средний диаметр рабочей камеры, - скорость газов на выходе из горелок, и \1 - соответственно коэффициенты теплопроводности и кинематической вязкости газов при их температуре на выходе из горелок. Как видно из сопоставления (фиг. 3) теплоотдача конвекцией от дымовых газов и рабочей камеры, выполненной в виде четырехугольной пирамиды. в 2,15 раза интенсивнее, чем рабочей камеры выполненной в виде усеченного конуса. Значительное повышение конвективного» тепло обмена позволяет интенсифицировать рабочий процесс и увеличить производительность печи.Nusselt R _{e is} the Reynold number, where a is the heat transfer coefficient, d is the average diameter of the working chamber, is the gas velocity at the outlet of the burner, and \ 1 are the coefficients of thermal conductivity and kinematic viscosity of the gases at their temperature at the outlet of the burner. As can be seen from the comparison (Fig. 3), heat transfer by convection from flue gases and the working chamber, made in the form of a quadrangular pyramid. 2.15 times more intense than a working chamber made in the form of a truncated cone. A significant increase in convective heat exchange allows you to intensify the workflow and increase the productivity of the furnace.

Claims

The invention relates to devices for the heat treatment of bulk materials and can be used in chemical and other industries, as well as in the production of building materials. The known installation consists of two stages of rotary kilns with independent fuel supply and air preheating, which also contains drum, grate and cyclone type heat exchangers with a dust collector 1. The unit has the high specific consumption of fuel and dust from the material, which is necessary installation of cumbersome dust systems with cyclone separators. A known cyclone chamber for heat treatment of a polydisperse material comprising a cylindrical body with gas-burning devices, a central loading of the material being processed and a bottom outlet from the cyclone chamber of the flue gases and the material being processed. In this furnace for the purpose of intensification and heat transfer, protrusions are arranged on the inner surface of the chamber, arranged in several rows along the height of the body at an angle to the generator of the latter in the direction of the gas flow 2. The disadvantage of such a furnace is that it requires additional installation. separation equipment, due to the fact that the flue gases have direct contact with the bulk material. The closest in technical essence and achievable effect to the present invention is a shaft furnace containing a downwardly expanding working chamber with a central upwardly expanding chimney connected to the combustion chamber surrounding the working chamber. In this furnace, in order to intensify heat exchange and reduce pulverization, the upper part of the furnace chamber is connected to the lower part of the chimney with a channel equipped with a fuel-burning device, and the chamber walls are made with spline 3. A disadvantage of the known furnace is low heat transfer due to the fact that the intensification of the jpa39 process is not used by increasing the level of convective heat transfer, which opens up the use of swirling outflow streams. The purpose of the invention is to intensify heat transfer. This goal is achieved by the fact that a shaft furnace containing a downwardly expanding working chamber with a central chimney extending upwards, connected to a fire chamber surrounding the working chamber, the working chamber is made in the form of a truncated regular quadrangular pyramid. FIG. 1 shows a camera; a general view of FIG. 2 shows section A-A in FIG. one; on fng. 3 dependence of heat transfer for various forms of the working chamber on the load of the device along the taay (line 1 in the form of a truncated cone, line 2 in the form of a truncated regular four coal pyramid |). The furnace contains an expanding downward working chamber 1 with a central expanding chimney 2 upwards. Working chamber 1 is located in the center of the combustion chamber 3 and is made in the form of a regular truncated pyramid. The furnace chamber is equipped with two burners 4, located tangentially to the inner surface of the chamber, and connected by channel 5 to chimney 2. Channel 5 is equipped with a heating and burning device 6. The furnace is equipped with a discharge device 7. Surfaces 8 and 9 form a working chamber and isolate the material being processed heating agent (flue gas). The furnace works as follows. The dry material enters the working chamber 1 through the gap between surfaces 8 and 9. Under its own weight, the material is lowered down at a speed determined by the discharge device 7. During operation of the furnace, the fuel and air are supplied in the required quantities to the burners 4. The resulting flue gases heat the material being processed is externally through the surface 8 and, flowing through channel 5, heats the material from the inside through the surface 9. The working chamber is made in the form of a regular truncated quadrilateral pyramid 8 months of that truncated round cone allows to significantly intensify the process of heat transfer on its outer surface. This is due to the fact that at the surface of the face of the pyramid the movement of the flow is tear-off - a vortex character, and at the surface of the cone it is continuous. Comparisons are made for working camps with the same cross-sectional area and other conditions being equal. N4 4 is the Nusselt number; Re - is the Reynold number, where a is the heat transfer coefficient, d is the average diameter of the working chamber, the velocity of the gases at the burner exit, and) are the heat conductivity and kinematic viscosity of the gases at their exit temperature from the burners, respectively. As can be seen from the comparison (Fig. 3), the heat transfer by convection from the flue gases and the working chamber, made in the form of a quadrangular pyramid, is 2 times more intense than the working chamber made in the form of a truncated cone. A significant increase in convective heat exchange allows to intensify the working process and increase the productivity of the furnace. Claims of the invention: A cyclone shaft furnace containing a downwardly expanding working chamber with a central upward-expanding chimney connected to a combustion chamber surrounding the working chamber, characterized in that, in order to enhance heat exchange during heat treatment of bulk materials quadrangular pyramid. Sources of information taken into account in the examination 1. Tsibin I. P., et al. Start-up, adjustment, thermal tests of furnaces and drying of the refractory industry. M., Metallurgists, 1978, p. 256.

2. USSR author's certificate number 346563, cl. F 27 B 15/00, 1970.

3. USSR author's certificate number 381854, cl. F 27 В 1/08, 1971 (prototype).

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