RU2044246C1 - Contact heat exchanger - Google Patents

Abstract

FIELD: power engineering, recovery of heat of waste gases. SUBSTANCE: installed in the upper and lower parts of chamber 1 along its axis are shells forming heating medium passages. Heating medium is fed to chamber 1 through tangential branch pipes 2 and 3, in branch pipe 3 the medium is sprinkled by liquid. From branch pipe 2 the medium is fed to a contracting passage formed by shell 7. The latter is made as a truncated cone with an opening angle determined from inequality indicated in the description. A slotted cut-out is made in the cone through which liquid sprayer through the nozzles in chamber 1 gets into the flow of medium supplied through lower branch pipe 2. EFFECT: improved design. 2 dwg

Description

 The invention relates to contact heat exchangers and is intended for use in industry, since it provides high efficiency of heat recovery of flue gases from heat-using equipment.

 A contact heat exchanger is known that contains a working chamber with tangential nozzles for supplying a heating medium located in its upper and lower parts, mounted along the axis of the housing, respectively, of the cylindrical nozzles in its upper part and two coaxial cylinders in the lower. The latter form guide channels for the passage of the heating medium. The liquid distributor is located along the axis of the chamber between the nozzles for supplying a heating medium.

 Due to the presence of two counter-swirling flows to the location of the water distributor along the chamber axis, intense contact heat transfer occurs over the entire chamber volume between the gaseous heated medium and the liquid.

 However, not all possibilities are realized in this design, which ensure full surface contact of the heated medium and the irrigated liquid.

 Known for one of the upgrades of the specified contact heat exchanger, which further comprises nozzles located in the nozzles for supplying the heating medium, in the upper part of the chamber, in the gap between the walls of the last and cylindrical fit and in the guide channel.

 Additional nozzles located in the tangential nozzles provide additional contact heat transfer between the heated gaseous medium and the liquid at the inlet to the heat exchanger; additional nozzles located inside the device body, providing secondary irrigation inside the device body, allow the most complete utilization of the heat of the exhaust gases of the process equipment.

 However, this design requires a large flow of water for irrigation, while the temperature potential of the water after contact with gaseous heat flows is small (due to the large flow of water).

> α > 2 arctg

где d₀ диаметр большего основания усеченного конуса;
d₂ диаметр верхней обечайки;
h₁ высота усеченного конуса;
h₂ расстояние между меньшим основанием конуса и нижнем торцом верхней обечайки.The aim of the invention is to increase the complete utilization of heat by increasing the potential of process water, after irrigation while reducing its flow rate and maintaining a high intensity of heat exchange between the gaseous medium and the irrigated water. The essence of the invention lies in the fact that in a contact heat exchanger containing a chamber with upper and lower tangential nozzles for supplying heating medium, mounted along the axis of the chamber in the upper and lower parts of the shell, forming channels for the passage of the heating medium, and liquid distributors located along the axis of the chamber between the indicated pipes and in the upper of the latter, the lower shell is made in the form of a truncated cone with a slotted cutout, and the cone with a large base is fixed in the chamber above the lower pipe and facing the slotted cut With a move toward the latter, and with a smaller base to the upper shell, the truncated cone is made with an opening angle that is a value determined from the following inequality:
2 arctg

>α> 2 arctg

where d _{0 is the} diameter of the larger base of the truncated cone;
d ₂ diameter of the upper shell;
h _{1 the} height of the truncated cone;
h _{2 the} distance between the smaller base of the cone and the lower end of the upper shell.

 In the proposed design, water from the slotted gap formed by the lower nozzle and the casing, having a higher temperature potential than the irrigated water at the inlet, enters the lower nozzle for irrigation, which allows increasing the temperature potential of the process water at the outlet while reducing its flow rate.

 In FIG. 1 shows the proposed heat exchanger, General view; in FIG. 2 cross section of a heat exchanger.

 The heat exchanger contains a vertical chamber 1, tangential nozzles 2 and 3 for supplying a gaseous medium. In this case, the pipe 2 is located in the lower part of the chamber 1, and the pipe 3 in the upper part. The pipe 4 serves to drain the gaseous medium, and the pipe 5, combined with the conical base of the working chamber, to drain the heated process water. The nozzles 6 and 7 are installed along the chamber axis in the upper and lower parts. The cylindrical nozzles 6 are connected to the outlet pipe 4 and form a guide channel for the exhaust gas stream, and the nozzles 7 form a tapering guide channel for the gaseous mixture entering through the lower tangential pipe. In this case, the lower nozzle 7 is made in the form of a truncated cone, is rigidly connected to the working chamber 1 with a large base and forms a gap 8 with its inner surface located above the lower tangential branch pipe 2. The water distributor 9 is located along the axis of the chamber 1 and has sections of perforated holes or nozzle . The nozzle 10 is designed for additional irrigation of the heat flux entering through the upper tangential branch pipe.

 The heat exchanger operates as follows.

 The heated gaseous medium is simultaneously fed towards the upper 3 and lower 2 tangential nozzles, so that it acquires a helical motion.

 Thanks to the nozzle 10, the gaseous mixture supplied through the pipe 3 is irrigated, which provides the first contact heat exchange between the gaseous medium and the liquid. Next, the flows move along closed paths towards each other and are irrigated from the water distributor 9. The dimensions of the upper stream are limited by the inner diameter of the working chamber and the cylindrical nozzle 6, and the sizes of the lower stream are limited by the conical nozzle 7.

> α > 2 arctg

Под действием центробежных сил сконденсированная в центральном потоке вода и орошаемая вода переходит в верхний поток воздуха, которым вместе со сконденсированной влагой верхнего потока переносится в нижнюю часть камеры, а также на стенки аппарата, по которым также стекает в зазор между коническим насадком 7 и камерой 1 верхней части аппарата. Воздух верхнего потока подсасывается нижним потоком по всей высоте аппарата (от верхнего торца конуса до нижнего торца верхнего цилиндрического насадка) за счет разрежения, создаваемого нижним потоком. Нижний поток воздуха с перешедшим в него воздухом периферийного потока попадает в верхний отводящий патрубок благодаря указанному условию, т. е. благодаря обхватыванию верхним цилиндрическим насадком образующих усеченного конуса в случае их продолжения. Это условие может быть выражено математически как
2 arctg

> α > 2 arctg

Вода, подаваемая на орошение под действием центробежных сил, скапливается в верхней части рабочей камеры и через щелевидный зазор, образованный между камерой 1 и коническим насадком 7, орошает тепловой поток, поступающий через тангенциальный патрубок 2. Температурный потенциал воды, поступившей на орошение в патрубок 2, выше, чем потенциал воды, поступившей через другие форсунки, следовательно, повышается полнота утилизации тепла за счет увеличения потенциала выходной технологической воды и уменьшения ее расхода. При этом сохраняется высокая интенсивность теплообмена в объеме рабочей камеры между газообразной средой и орошаемой водой.In this case, the truncated cone 7 is made with an opening angle constituting a value determined from the following inequality:
2 arctg

>α> 2 arctg

Under the action of centrifugal forces, the water condensed in the central stream and irrigated water passes into the upper air stream, which, together with the condensed moisture of the upper stream, is transferred to the lower part of the chamber, as well as to the walls of the apparatus, through which it also flows into the gap between the conical nozzle 7 and chamber 1 top of the apparatus. The air of the upper stream is sucked in by the lower stream over the entire height of the apparatus (from the upper end of the cone to the lower end of the upper cylindrical nozzle) due to the rarefaction created by the lower stream. The lower air stream with the peripheral stream air transferred into it enters the upper outlet pipe due to the indicated condition, i.e., due to the clipping of the truncated cone by the upper cylindrical nozzle if they continue. This condition can be expressed mathematically as
2 arctg

>α> 2 arctg

Water supplied to the irrigation under the action of centrifugal forces accumulates in the upper part of the working chamber and through the slit-like gap formed between the chamber 1 and the conical nozzle 7, irrigates the heat flow entering through the tangential branch pipe 2. The temperature potential of the water supplied to the branch pipe 2 for irrigation is higher than the potential of water entering through other nozzles, therefore, the completeness of heat recovery is increased due to an increase in the potential of the outlet process water and a decrease in its consumption. At the same time, a high intensity of heat transfer is maintained in the volume of the working chamber between the gaseous medium and the irrigated water.

Claims (1)

A CONTACT HEAT EXCHANGER containing a chamber with upper and lower tangential nozzles for supplying heating medium, mounted along the axis of the chamber in the upper and lower parts of the shell, forming channels for the passage of the heating medium, and liquid distributors located along the axis of the chamber between the said nozzles and in the upper of the latter, characterized in that the lower shell is made in the form of a truncated cone with a slotted cutout, and the cone with a large base fixed in the chamber above the lower pipe and facing the slotted cut towards the last o, a smaller base to the upper shell, wherein the truncated cone is configured with an angle of opening α, integral value determined from the following inequality:

where d _{0 is the} diameter of the larger base of the truncated cone;
d ₂ diameter of the upper shell;
h _{1 the} height of the truncated cone;
h _{2 the} distance between the smaller base of the cone and the lower end of the upper shell.

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